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11942969 | DETAILED DESCRIPTION The present principles are directed to methods and apparatus for unified significance map coding. The present description illustrates the present principles. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the present principles and are included within its spirit and scope. All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the present principles and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the present principles, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. Thus, for example, it will be appreciated by those skilled in the art that the block diagrams presented herein represent conceptual views of illustrative circuitry embodying the present principles. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudocode, and the like represent various processes which may be substantially represented in computer readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown. The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term “processor” or “controller” should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (“DSP”) hardware, read-only memory (“ROM”) for storing software, random access memory (“RAM”), and non-volatile storage. Other hardware, conventional and/or custom, may also be included. Similarly, any switches shown in the figures are conceptual only. Their function may be carried out through the operation of program logic, through dedicated logic, through the interaction of program control and dedicated logic, or even manually, the particular technique being selectable by the implementer as more specifically understood from the context. In the claims hereof, any element expressed as a means for performing a specified function is intended to encompass any way of performing that function including, for example, a) a combination of circuit elements that performs that function or b) software in any form, including, therefore, firmware, microcode or the like, combined with appropriate circuitry for executing that software to perform the function. The present principles as defined by such claims reside in the fact that the functionalities provided by the various recited means are combined and brought together in the manner which the claims call for. It is thus regarded that any means that can provide those functionalities are equivalent to those shown herein. Reference in the specification to “one embodiment” or “an embodiment” of the present principles, as well as other variations thereof, means that a particular feature, structure, characteristic, and so forth described in connection with the embodiment is included in at least one embodiment of the present principles. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment”, as well any other variations, appearing in various places throughout the specification are not necessarily all referring to the same embodiment. It is to be appreciated that the use of any of the following “/”, “and/or”, and “at least one of”, for example, in the cases of “A/B”, “A and/or B” and “at least one of A and B”, is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of both options (A and B). As a further example, in the cases of “A, B, and/or C” and “at least one of A, B, and C”, such phrasing is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of the third listed option (C) only, or the selection of the first and the second listed options (A and B) only, or the selection of the first and third listed options (A and C) only, or the selection of the second and third listed options (B and C) only, or the selection of all three options (A and B and C). This may be extended, as readily apparent by one of ordinary skill in this and related arts, for as many items listed. Also, as used herein, the words “picture” and “image” are used interchangeably and refer to a still image or a picture from a video sequence. As is known, a picture may be a frame or a field. Additionally, as used herein, the phrases “significant coefficients” and “significant transform coefficients” refer to transform coefficients having a nonzero value. Moreover, as used herein, the phrase “level information” refers to the value of a transform coefficient. For purposes of illustration and description, examples are described herein in the context of improvements over the video coding experts group (VCEG) key technical area (KTA) software, using the KTA software as the baseline for our description and explaining the improvements and extensions beyond the KTA software. However, it is to be appreciated that the present principles are not limited solely to the KTA software and/or extensions thereof. Given the teachings of the present principles provided herein, one of ordinary skill in this and related arts would readily understand that the present principles are equally applicable and would provide at least similar benefits when applied to extensions of other standards, or when applied and/or incorporated within standards not yet developed. It is to be further appreciated that the present principles also apply to video encoders and video decoders that do not conform to standards, but rather confirm to proprietary definitions. Turning toFIG.4, an exemplary video encoder to which the present principles may be applied is indicated generally by the reference numeral400. The video encoder400includes a frame ordering buffer410having an output in signal communication with a non-inverting input of a combiner485. An output of the combiner485is connected in signal communication with a first input of a transformer and quantizer425. An output of the transformer and quantizer425is connected in signal communication with a first input of an entropy coder445and a first input of an inverse transformer and inverse quantizer450. An output of the entropy coder445is connected in signal communication with a first non-inverting input of a combiner490. An output of the combiner490is connected in signal communication with a first input of an output buffer435. A first output of an encoder controller405is connected in signal communication with a second input of the frame ordering buffer410, a second input of the inverse transformer and inverse quantizer450, an input of a picture-type decision module415, a first input of a macroblock-type (MB-type) decision module420, a second input of an intra prediction module460, a second input of a deblocking filter465, a first input of a motion compensator470, a first input of a motion estimator475, and a second input of a reference picture buffer480. A second output of the encoder controller405is connected in signal communication with a first input of a Supplemental Enhancement Information (SEI) inserter430, a second input of the transformer and quantizer425, a second input of the entropy coder445, a second input of the output buffer435, and an input of the Sequence Parameter Set (SPS) and Picture Parameter Set (PPS) inserter440. An output of the SEI inserter430is connected in signal communication with a second non-inverting input of the combiner490. A first output of the picture-type decision module415is connected in signal communication with a third input of the frame ordering buffer410. A second output of the picture-type decision module415is connected in signal communication with a second input of a macroblock-type decision module420. An output of the Sequence Parameter Set (SPS) and Picture Parameter Set (PPS) inserter440is connected in signal communication with a third non-inverting input of the combiner490. An output of the inverse quantizer and inverse transformer450is connected in signal communication with a first non-inverting input of a combiner419. An output of the combiner419is connected in signal communication with a first input of the intra prediction module460and a first input of the deblocking filter465. An output of the deblocking filter465is connected in signal communication with a first input of a reference picture buffer480. An output of the reference picture buffer480is connected in signal communication with a second input of the motion estimator475and a third input of the motion compensator470. A first output of the motion estimator475is connected in signal communication with a second input of the motion compensator470. A second output of the motion estimator475is connected in signal communication with a third input of the entropy coder445. An output of the motion compensator470is connected in signal communication with a first input of a switch497. An output of the intra prediction module160is connected in signal communication with a second input of the switch197. An output of the macroblock-type decision module420is connected in signal communication with a third input of the switch497. The third input of the switch497determines whether or not the “data” input of the switch (as compared to the control input, i.e., the third input) is to be provided by the motion compensator470or the intra prediction module460. The output of the switch497is connected in signal communication with a second non-inverting input of the combiner419and an inverting input of the combiner485. A first input of the frame ordering buffer410and an input of the encoder controller405are available as inputs of the encoder400, for receiving an input picture. Moreover, a second input of the Supplemental Enhancement Information (SEI) inserter430is available as an input of the encoder400, for receiving metadata. An output of the output buffer435is available as an output of the encoder400, for outputting a bitstream. Turning toFIG.5, an exemplary video decoder to which the present principles may be applied is indicated generally by the reference numeral500. The video decoder500includes an input buffer510having an output connected in signal communication with a first input of an entropy decoder545. A first output of the entropy decoder545is connected in signal communication with a first input of an inverse transformer and inverse quantizer550. An output of the inverse transformer and inverse quantizer550is connected in signal communication with a second non-inverting input of a combiner525. An output of the combiner525is connected in signal communication with a second input of a deblocking filter565and a first input of an intra prediction module560. A second output of the deblocking filter565is connected in signal communication with a first input of a reference picture buffer580. An output of the reference picture buffer580is connected in signal communication with a second input of a motion compensator570. A second output of the entropy decoder545is connected in signal communication with a third input of the motion compensator570, a first input of the deblocking filter565, and a third input of the intra predictor560. A third output of the entropy decoder545is connected in signal communication with an input of a decoder controller505. A first output of the decoder controller505is connected in signal communication with a second input of the entropy decoder545. A second output of the decoder controller505is connected in signal communication with a second input of the inverse transformer and inverse quantizer550. A third output of the decoder controller505is connected in signal communication with a third input of the deblocking filter565. A fourth output of the decoder controller505is connected in signal communication with a second input of the intra prediction module560, a first input of the motion compensator570, and a second input of the reference picture buffer580. An output of the motion compensator570is connected in signal communication with a first input of a switch597. An output of the intra prediction module560is connected in signal communication with a second input of the switch597. An output of the switch597is connected in signal communication with a first non-inverting input of the combiner525. An input of the input buffer510is available as an input of the decoder500, for receiving an input bitstream. A first output of the deblocking filter565is available as an output of the decoder500, for outputting an output picture. As noted above, the present principles are directed to methods and apparatus for unified significance map coding. To consider the coefficient distributions from different transform sizes, we adapt context sharing patterns to the transform size, while keeping a unified structure for all transform sizes for simplicity. In order to reduce the number of contexts in coding the residual data, a few transform coefficient positions may share one context model. In the MPEG-4 AVC Standard, the context sharing is designed for each transform. In accordance with an embodiment of the present principles, we propose a unified rule-based approach to design for all transforms on how to share the contexts, where the rule is adaptive to the encoder setup. In accordance with an embodiment of the present principles, we propose to unify the context sharing for multiple transforms. While still keeping the number of context models at a small number, different transforms use the same approach to design context sharing among multiple coefficient positions. This unifies the context sharing, preparing the next-generation of standards to accommodate more transforms. The present principles propose new methods to code the significance map. Different from the prior art where a separate context sharing method is pre-defined for each transform, we provide a method to unify the context sharing among different transforms. This simplifies the design of an encoder and/or decoder, particularly when there are multiple transforms. Typical Significance Map Coding Turning toFIG.6, a conventional method for encoding a significance map is indicated generally by the reference numeral600. The method600includes a start block610that passes control to a function block620. The function block620reads the pre-defined context sharing maps for the transform, and passes control to a function block630. The function block630encodes the significance map, and passes control to an end block699. The context sharing maps are pre-defined for various transforms, and the sharing patterns may differ for significant_coeff_flag or last_significant_coeff_flag. Turning toFIG.7, a conventional method for decoding a significance map is indicated generally by the reference numeral700. The method700includes a start block710that passes control to a function block720. The function block720reads the pre-defined context sharing maps for the transform, and passes control to a function block730. The function block730decodes the significance map, and passes control to an end block799. The decoder uses the corresponding context sharing map to decode the significance map. Proposed Method—Unify the Context Sharing Map Generation In the KTA software, macroblock sizes of 32×32 and 64×64 are supported. For 32×32 blocks, in addition to the existing MPEG-4 AVC Standard motion partition sizes (16×16, 16×8, 8×16, 8×8, 8×4, 4×8, and 4×4), inter coding using 32×32, 32×16 and 16×32 partitions is also enabled. Bigger transforms can better capture the smoother content in high-definition video. For inter pictures, 16×16, 16×8, and 8×16 transforms are used in addition to 4×4 and 8×8 transforms for the luma components. Specifically, for each motion partition of sizes 16×16, 16×8, and 8×16, transforms of sizes 16×16, 16×8, and 8×16 may be used in addition to the 4×4 and 8×8 transforms. For motion partitions bigger than 16×16, a 16×16 transform is used in addition to 4×4 and 8×8 transforms. To encode the significance map of transform coefficients from newly introduced transforms (16×8, 8×16, and 16×16), separate context sharing maps are designed for each transform. For example, the pattern for context sharing of a 16×16 transform is approximately an upsampled version of that of 8×8. Since transforms usually compact energies into the first coefficients in the scanning order, such a context sharing may not suit the transform coefficient distribution. Further, such a context sharing requires storing the map for each transform. We propose to unify the generation of the context sharing maps to simplify the encoder and/or decoder design. In one embodiment, we convert the 2-D transform coefficient block into a 1-D transform coefficient array according to a scanning order (for example, a zig-zag scanning order). Depending on the transform coefficient position x, we assign a context according to a rule F(x). This rule is consistent for all transforms. For example, F(x)={x,0≤x<NN,otherwise, where N is the number of contexts. For example, when N=15, there are 15 contexts. When we apply this rule to generate the context sharing maps, there is no need to design separate maps for each transform, and it can be easily extended to multiple transforms. The same rule is known and used at both the encoder and decoder. Turning toFIG.8, an exemplary method for encoding a significance map is indicated generally by the reference numeral800. The method800includes a start block810that passes control to a function block820. The function block820generates the context sharing maps for the transform based on the rule, and passes control to a function block830. The function block830encodes the significance map, and passes control to an end block899. Regarding function block820, the rule for generating the context sharing maps for the transform may involve, for example, assigning a separate context to the first N coefficient positions in a pre-defined scanning order (for example, a zig-zag scanning order), and having all other coefficient positions share one context. Turning toFIG.9, an exemplary method for decoding a significance map is indicated generally by the reference numeral900. The method900includes a start block910that passes control to a function block920. The function block920generates the context sharing maps for the transform based on the rule, and passes control to a function block930. The function block930decodes the significance map, and passes control to an end block999. Regarding function block920, the rule for generating the context sharing maps for the transform is the same as what is used at the encoder. It may involve, for example, assigning a separate context to the first N coefficient positions in a pre-defined scanning order (for example, a zig-zag scanning order), and having all other coefficient positions share one context. Variation In an embodiment of the present principles, the rule for generating the context sharing maps might vary for different sequences, picture resolutions, quantization parameters, and so forth. For example, we can have a variation of F(x) as follows: F(x)={x,0≤x<Nx-N2+N,x<Mx+N2,otherwise. We propose to indicate which rule to use in the syntax. In one embodiment, the rules are known at both the encoder and the decoder. In such a case, the encoder indicates which rule to use through an index in the bitstream. This approach provides more flexibility. Turning toFIG.10, another method for encoding a significance map is indicated generally by the reference numeral1000. The method1000includes a start block1010that passes control to a function block1020. The function block1020decides the rule to generate the context sharing map, indicates the rule in a bitstream, and passes control to a function block1030. The function block1030generates the context sharing maps for the transform based on the rule, and passes control to a function block1040. Regarding function block1020, the rule may be selected based on video sequences to which the coefficients correspond, picture resolutions, quantization parameters, and so forth. Regarding function block1030, the rule for generating the context sharing maps for the transform may involve, for example, assigning a separate context for the first N coefficient positions in a pre-defined scanning order, and having all other coefficient positions share one context. Turning toFIG.11, another exemplary method for decoding a significance map is indicated generally by the reference numeral1100. The method1100includes a start block1110that passes control to a function block1120. The function block1120decodes the rule to generate the context sharing map, and passes control to a function block1130. The function block1130generates the context sharing maps for the transform based on the rule, and passes control to a function block1140. The function block1140decodes the significance map, and passes control to an end block1199. Regarding function block1130, the rule for generating the context sharing maps for the transform may involve, for example, assigning a separate context for the first N coefficient positions in a predefined scanning order, and having all other coefficient positions share one context. Syntax Our proposed method provides the flexibility to select the rule for generating the context sharing maps through, for example, the sequence parameter set (SPS) or picture parameter set (PPS). TABLE 1 shows exemplary syntax for use in a picture parameter set, in accordance with an embodiment of the present principles. Similar syntax can be applied on other syntax levels, including but not limited to the sequence parameter set. TABLE 1CDescriptorpic_parameter_set_rbsp( ) {. . .significance_map_context_rule11 ae(v). . .} The semantics of the syntax element shown in TABLE 1 is as follows: significance_map_context_rule specifies the particular rule to be applied to generate the context sharing maps for coding the significance map. A description will now be given of some of the many attendant advantages/features of the present invention, some of which have been mentioned above. For example, one advantage/feature is an apparatus having a video encoder for encoding transform coefficients for at least a portion of a picture. The transform coefficients are obtained using a plurality of transforms. One or more context sharing maps are generated for the transform coefficients based on a unified rule. The one or more context sharing maps are for providing at least one context that is shared among at least some of the transform coefficients obtained from at least two different ones of the plurality of transforms. Another advantage/feature is the apparatus having the video encoder as described above, wherein the transform coefficients are two-dimensional transform coefficients, and the unified rule specifies mapping the two-dimensional transform coefficients into a one-dimensional array according to a scanning order, and assigning first N coefficients from among the transform coefficients to separate contexts. Yet another advantage/feature is the apparatus having the video encoder wherein the transform coefficients are two-dimensional transform coefficients, and the unified rule specifies mapping the two-dimensional transform coefficients into a one-dimensional array according to a scanning order, and assigning first N coefficients from among the transform coefficients to separate contexts as described above, wherein remaining coefficients from among the transform coefficients are assigned to a single context. Moreover, another advantage/feature is the apparatus having the video encoder wherein the transform coefficients are two-dimensional transform coefficients, and the unified rule specifies mapping the two-dimensional transform coefficients into a one-dimensional array according to a scanning order, and assigning first N coefficients from among the transform coefficients to separate contexts as described above, wherein the scanning order is a zig-zag scanning order. Further, another advantage/feature is the apparatus having the video encoder as described above, wherein the transform coefficients are encoded into a resultant bitstream, multiple rules are used as candidates for the unified rule, and the unified rule is indicated in the resultant bitstream. Also, another advantage/feature is the apparatus having the video encoder as described above, wherein the unified rule includes at least two unified rules that vary based on video sequences to which the transform coefficients correspond, picture resolutions, and quantization parameters. These and other features and advantages of the present principles may be readily ascertained by one of ordinary skill in the pertinent art based on the teachings herein. It is to be understood that the teachings of the present principles may be implemented in various forms of hardware, software, firmware, special purpose processors, or combinations thereof. Most preferably, the teachings of the present principles are implemented as a combination of hardware and software. Moreover, the software may be implemented as an application program tangibly embodied on a program storage unit. The application program may be uploaded to, and executed by, a machine comprising any suitable architecture. Preferably, the machine is implemented on a computer platform having hardware such as one or more central processing units (“CPU”), a random access memory (“RAM”), and input/output (“I/O”) interfaces. The computer platform may also include an operating system and microinstruction code. The various processes and functions described herein may be either part of the microinstruction code or part of the application program, or any combination thereof, which may be executed by a CPU. In addition, various other peripheral units may be connected to the computer platform such as an additional data storage unit and a printing unit. It is to be further understood that, because some of the constituent system components and methods depicted in the accompanying drawings are preferably implemented in software, the actual connections between the system components or the process function blocks may differ depending upon the manner in which the present principles are programmed. Given the teachings herein, one of ordinary skill in the pertinent art will be able to contemplate these and similar implementations or configurations of the present principles. Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present principles is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present principles. All such changes and modifications are intended to be included within the scope of the present principles as set forth in the appended claims. | 28,116 |
11942970 | DETAILED DESCRIPTION Described herein are techniques for compressing data using bit masks. In the following description, for purposes of explanation, numerous examples and specific details are set forth in order to provide a thorough understanding of some embodiments. Various embodiments as defined by the claims may include some or all of the features in these examples alone or in combination with other features described below and may further include modifications and equivalents of the features and concepts described herein. Features and advantages of the present disclosure include techniques for compressing data using a tree based encoded bit mask. For example, an input vector may comprise a plurality of values, which may be represented by a plurality of digital bits using a variety of different formats (e.g., 4 bit float, 8 bit integer, 8 bit float, etc. . . . ). A set of bits may be used specify the location of particular values within the input vector (e.g., non-zero values). Sets of bits that specify the location of values of interest in the input vector are referred to herein as a bit mask. The input vector may be received on inputs of switch circuits, and a set of bits specifying the location of a particular value of interest may be used to select multiple values from all the values of the input vector. The multiple values include the particular value of interest. A logic circuit may be used to detect the particular value of interest from the multiple values at the output of each switch circuit and control selection of the particular values of interest using second switch circuits. The set of bits used to select values from the input vector may advantageously use a tree encoding, thus reducing the number of bits in the bit mask needed to specify the location of values of interest in an input vector. In one embodiment, multiplexers are used as switch circuits. FIG.1Aillustrates a circuit for compressing data according to an embodiment. It may be desirable to compress an input vector101comprising a plurality of values (e.g., represented as digital bits) such that only particular values of interest remain (e.g., P1-Pn). Here, the values of input vector101are coupled to inputs of first switch circuits102a-102n. Switch circuits102a-102nmay further include control inputs coupled to sets of bits from a bit mask190. As used herein, switch circuits are electronic circuits comprising a plurality of transistors configured to selectively couple values on one or more inputs to one or more outputs. A variety of transistor circuit configurations may be used for switch circuits. One common switch circuit is a multiplexer, for example. Features and advantages of the present disclosure include the use of sets of bits (aka bit mask sets)190a-190nthat specify locations of particular values in the input vector101. A bit mask set may specify the location of a particular value using a tree encoding, for example. For example, each bit in a bit mask set may indicate a portion of the input vector where the value of interest is located (e.g., upper half bits of the vector, then lower half, and then upper half, etc. . . . ) similar to a binary search. The bits of the bit mask selectively couple multiple values from the input vector on a switch circuit input to a corresponding output of the switch circuit. For instance, multiple values from the input vector may be coupled to each input (e.g., input150) of switch circuits102a-102n. One set of bit mask bits (e.g., bits190a) may be used to select one of the inputs of switch circuit102aand couple the selected input to the output of switch circuit102a. As illustrated further below, the set of bits coupled to each switch circuit102a-102nmay select inputs using a tree encoding. The outputs of the switch circuits102a-102nproduce the multiple values150a-150non the selected input. Second switch circuits103a-103nhave inputs coupled to the multiple values150a-150non the outputs of the first switch circuits102a-102n. A logic circuit104includes inputs coupled to the outputs of the first switch circuits102a-102n. Outputs of logic circuit104are coupled to select inputs of second switch circuits103a-103n. The multiple values on the outputs of the switch circuits102a-102nmay be coupled to different inputs of the switch circuits103a-103n. Logic circuit104may detect particular values (e.g., zero and non-zero values) of the multiple values on outputs of the first switch circuits102a-102nand configure the second switch circuits103a-103nto output one of the particular values. For example, logic circuit104may detect a non-zero value in one of the multiple values150aon the output of switch circuit102aand configure switch circuit103ato select the corresponding input and couple the non-zero value to the output, P1. FIG.1Billustrates bit mask encoding according to an embodiment. As illustrated here, locations in the input vector101may be specified using a set of bits. For example, an MSB may be used to determine if the value is located above or below a midpoint. Here, a value in an N value vector may be above (1) or below (0) the N/2 point, above (1) or below (0) the N/4 point, above (1) or below (0) the N/8 point, etc. . . . . In various embodiments, locations of different sets of multiple values may be specified for N values in an input vector using the encoded inFIG.1B. Example values of interest are illustrated in vector101a. In this example, input vector has N=16 values and there are 4 particular values of interest180a-dthat are to be retained in the compressed output. In this example, a set of 3 bits is used for each value. The location of value180ais specified as one of a pair of values by bits 000. The location of value180ais specified as one of a pair of values by bits [000]. The location of value180bis specified as one of a pair of values by bits [010]. The location of value180cis specified as one of a pair of values by bits. Finally, the location of value180dis specified as one of a pair of values by bits [110]. The sets of bits may be combined into a bit mask specifying locations of values180a-din vector101a, and the input vector may be associated with the bit mask and/or compressed values when processing the data. The final values from the specified multiple values (here, pairs of values) are selected by the second switch circuits and logic circuit described above, thus reducing the number of bits required in a bit mask and reducing the data overhead associated with processing the data. From the above description it can be seen that in some cases particular values of interest may be in the same group multiple values specified by two different sets of bit masks. For example, both of the values at [110] may be values of interest to be produced as a compressed output. In these cases, logic circuit104may compare bits coupled to the control inputs of the first switch circuits102a-102nto determine if the same bit mask set is used to specify two different values in the input vector. Logic circuit104may configure one switch circuit of the second switch circuits103a-103n(e.g., switch circuit103a) to output a first particular value (e.g., v1) from a first set of multiple values (e.g.,150a) and configure a second switch circuit (e.g., switch circuit103b) of the second switch circuits to output a second particular value (e.g., v2) from the first set of multiple values (e.g., 150b), where the multiple values from switch circuits102aand102bmay hold the same values because the bit mask sets are the same, for example. FIG.2illustrates a method of compressing data according to an embodiment. At201, an input vector comprising a plurality of values is received on a plurality of inputs of a first plurality of switch circuits. The plurality of values may include zero values and non-zero values. In other embodiments, the values (e.g., an absolute value) may be selected based on being above or below a threshold, for example. The switching circuits may be multiplexers (MUXs), for example. At202, multiple values of the values on the inputs of the first switch circuits are selectively coupled, based on a plurality of sets of bits, to corresponding outputs of the first switch circuits. For example, for values having a length of 4 bits, 2 values (total of 8 bits) may be coupled to each input of a MUX, and multiple MUXs may receive the input vector and a set of mask bits to select multiple values (8bits) including each of the particular values of interest. At203, the multiple values from the outputs of the first switch circuits are received on a plurality of inputs of second switch circuits. At204, a portion of the multiple values (e.g., the particular value of interest and another adjacent value) are selectively coupled to outputs of the second switch circuits. Selectively coupling is based on particular values of the multiple values. For example, the output values from each of the first stage of MUXs may be coupled to a logic circuit which detects the particular values of interest and outputs select signals to second stage MUXs. FIG.3illustrates an example circuit for compressing data using a tree based encoding of bit masks according to an embodiment. In various embodiments, the input vector may comprise two (2) to a power of N values (2N) and the bit mask may comprise a plurality of (N-1) length sets of bits, where N is an integer. The present example illustrates compressing a N=4, 16 value sparse vector301with4non-zero (NZ) values301a-dand the other values all zeros (e.g., 75% compression by removal of all zero values). In this example, the values are 4 bits each (e.g., 4 bit floating point with separate exponent and sign bits). Vector301is applied to the inputs of 4 MUXs302a-d. Each MUX302a-dreceives all 16 values. The inputs (e.g., input350) of each MUX are 8-bit inputs, and MUXs302a-dare 8:1 MUXs. Thus, each input receives 2 values of the input vector301. Each MUX302a-dreceives a set of bits for specifying the location (or position) of the group of values (multiple values) that include a particular value of interest in the input vector301. In this example, each MUX receives a set of 3-bits. Accordingly, bit mask set390aspecifies the location of a pair of values including value301a, bit mask set390bspecifies the location of another pair of values including value301b, bit mask set390cspecifies the location of yet another pair of values including value301c, and bit mask set390dspecifies the location of a pair of values including value301d. Accordingly, the output of MUXs302a-dare pairs of values350a-deach including one or more of the particular values of interest301a-d. The outputs of MUXs302a-dare coupled to logic circuit304. Logic circuit304detects the values in the pairs of values350a-dand generates a select control signal for second stage2:1MUXs303a-d. The pair of values at the output of each MUX302a-dmay be separately coupled to inputs of 2:1 MUXs303a-d, and select inputs to each MUX couple a particular value of interest, such as301a-d, to produce a compressed output P1, P2, P3, P4. In some instances, the values of interest may be spread out across an input vector, and each of the outputs of MUXs302a-dincludes only 1 value of interest. However, in some cases multiple values of interest may be located next to each other in the input vector. Accordingly, in some cases, two values of interest may have the same bit mask sets (e.g., 2 values of interest are in the 1stand 2ndpositions or 3rdpositions and 4thpositions). In this case, the outputs of multiple MUXs may be the same, with both pairs of values350a,350b,350c, or350dbeing values of interest (e.g.,301a-bor301b-c, etc. . . . ). Therefore, the logic circuit may further include logic gates to detect this condition and selectively couple the proper value to the output. The following is example logic that may be implemented in logic circuit304to select a value of interest, include cases where two sets of bit masks are the same: MUX303a:if(m)thenP0=m,elseP0=n; MUX303b:if(xORp&˜y)thenP1=p,elseP1=o; MUX303c:if(yORr&˜z)thenP2=r,elseP2=q; MUX303d:if(zORt)thenP3=t,elseP3=s, Where m and n are outputs of MUX302a, oandpare outputs of MUX302b, qandrare outputs of MUX302c, sandtare outputs of MUX302d, xis true when bit mask set390ais the same is bit mask set390b, yis true when bit mask set390bis the same is bit mask set390c, and z is true when bit mask set390cis the same is bit mask set390d. FIG.4illustrates a simplified block diagram of an example computer system used to execute hardware description language (HDL) code according to various embodiments. In some embodiments, computer system400executes hardware description code to generate logic circuits and/or other portions of an integrated circuit to perform the techniques described herein. A hardware description language (HDL) is a specialized computer language used to describe the structure and behavior of electronic circuits, and most commonly, digital logic circuits. HDL code may be executed on a computer system to generate digital logic circuits, including circuits described herein.FIG.4illustrates a simplified block diagram of an example computer system400, which can be used to implement the techniques described in the foregoing disclosure. In some embodiments, computer system400may be used to generate logic circuits, switches, and other digital circuits described above, for example. As shown inFIG.4, computer system400includes one or more processors402that communicate with a number of peripheral devices via a bus subsystem404. These peripheral devices may include a storage subsystem406(e.g., comprising a memory subsystem408and a file storage subsystem410) and a network interface subsystem416. Some computer systems may further include user interface input devices412and/or user interface output devices414. Bus subsystem404can provide a mechanism for letting the various components and subsystems of computer system400communicate with each other as intended. Although bus subsystem404is shown schematically as a single bus, alternative embodiments of the bus subsystem can utilize multiple busses. Network interface subsystem416can serve as an interface for communicating data between computer system400and other computer systems or networks. Embodiments of network interface subsystem416can include, e.g., Ethernet, a Wi-Fi and/or cellular adapter, a modem (telephone, satellite, cable, ISDN, etc.), digital subscriber line (DSL) units, and/or the like. Storage subsystem406includes a memory subsystem408and a file/disk storage subsystem410. Subsystems408and410as well as other memories described herein are examples of non-transitory computer-readable storage media that can store executable program code and/or data that produce circuits having the functionality of embodiments of the present disclosure. Memory subsystem408includes a number of memories including a main random access memory (RAM)418for storage of instructions and data during program execution and a read-only memory (ROM)420in which fixed instructions are stored. File storage subsystem410can provide persistent (e.g., non-volatile) storage for program and data files, and can include a magnetic or solid-state hard disk drive, an optical drive along with associated removable media (e.g., CD-ROM, DVD, Blu-Ray, etc.), a removable flash memory-based drive or card, and/or other types of storage media known in the art. It should be appreciated that computer system400is illustrative and many other configurations having more or fewer components than system400are possible. Further Examples Each of the following non-limiting features in the following examples may stand on its own or may be combined in various permutations or combinations with one or more of the other features in the examples below. In one embodiment, the present disclosure includes a circuit to compress data comprising: a first plurality of switch circuits having inputs coupled to a plurality of values of an input vector, the first plurality of switch circuits further having control inputs coupled to bits of a bit mask to selectively couple multiple values of the plurality of values on one input of each of the first plurality of switch circuits to corresponding outputs of the first plurality of switch circuits; a second plurality of switch circuits having inputs coupled to the multiple values on the outputs of the first plurality of switch circuits; and a logic circuit having inputs coupled to the outputs of the first plurality of switch circuits and having outputs coupled to select inputs of the second plurality of switch circuits, the logic circuit detecting particular values on the outputs of the first plurality of switch circuits and configuring the second plurality of switch circuits to each output one of the particular values. In another embodiment, the present disclosure includes a method of compressing data comprising: receiving an input vector comprising a plurality of values on a plurality of inputs of a first plurality of switch circuits; selectively coupling, based on a plurality of sets of bits, multiple values of the plurality of values on the inputs of the first plurality of switch circuits to corresponding outputs of the first plurality of switch circuits; receiving the multiple values from the outputs of the first plurality of switch circuits on a plurality of inputs of a second plurality of switch circuits; and selectively coupling a portion of the multiple values to outputs of the second plurality of switch circuits, wherein the selectively coupling is based on particular values of the multiple values. In another embodiment, the present disclosure includes a non-transitory machine-readable medium storing a hardware definition language (HDL) program executable by a computer, the program comprising sets of instructions for: receiving an input vector comprising a plurality of values on a plurality of inputs of a first plurality of switch circuits; selectively coupling, based on a plurality of sets of bits, multiple values of the plurality of values on the inputs of the first plurality of switch circuits to corresponding outputs of the first plurality of switch circuits; receiving the multiple values from the outputs of the first plurality of switch circuits on a plurality of inputs of a second plurality of switch circuits; and selectively coupling a portion of the multiple values to outputs of the second plurality of switch circuits, wherein the selectively coupling is based on particular values of the multiple values. In one embodiment, the plurality of values comprises zero values and non-zero values, and wherein in the particular values are zero values. In one embodiment, the bit mask comprises a plurality of subsets of bits, each subset of bits selecting one of the particular values of the plurality of values, wherein each subset of bits is coupled to a different one of the first plurality of switch circuits. In one embodiment, the inputs of the first plurality of switch circuits are coupled to two or more values of the input vector. In one embodiment, each input of the first plurality of switch circuits is coupled to two values of the input vector. In one embodiment, the bits of the bit mask couple a particular plurality of values to the output of each switch circuits based on a binary tree selection. In one embodiment, the inputs of each switch circuit of the first plurality of switch circuits are coupled to the plurality of values of the input vector, and wherein the select inputs of each switch circuit are coupled to a different portion of a total number of bits of a bit mask to couple a unique subset of plurality of values to an output of each of the first plurality of switch circuits. In one embodiment, the first plurality of switch circuits and the second plurality of switch circuits are multiplexers. In one embodiment, the input vector comprises two (2) to a power of N bits, wherein the bit mask comprises a plurality of N minus 1 length sets of bits. In one embodiment, the logic circuit compares bits coupled to the control inputs of at least two switch circuits of the first plurality of switch circuits and configures a first switch circuit of the second plurality of switch circuits to output a first particular value from a first set of multiple values and configures a second switch circuit of the second plurality of switch circuits to output a second particular value from the first set of multiple values. In one embodiment, the first plurality of switch circuits comprise a plurality of stages. In one embodiment, the second plurality of switch circuits comprise a plurality of stages. The above description illustrates various embodiments along with examples of how aspects of some embodiments may be implemented. The above examples and embodiments should not be deemed to be the only embodiments, and are presented to illustrate the flexibility and advantages of some embodiments as defined by the following claims. Based on the above disclosure and the following claims, other arrangements, embodiments, implementations and equivalents may be employed without departing from the scope hereof as defined by the claims. | 21,275 |
11942971 | DETAILED DESCRIPTION The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary implementations and is not intended to represent the only implementations in which the invention may be practiced. The term “exemplary” used herein means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other exemplary implementations. The detailed description includes specific details for the purpose of providing a thorough understanding of the exemplary implementations. In some instances, some devices are shown in block diagram form. Drawing elements that are common among the following figures may be identified using the same reference numerals. The progression of wireless communication infrastructure, particularly for Third Generation Partnership Project (3GPP) fifth generation (5G) millimeter wavelength (mmW) systems, involves the use of antenna arrays with tens, hundreds, or thousands of elements. 5G systems have performance criteria where improved link budget within devices and improved wireless coverage performance are important design considerations. The signal delivery routings for antenna arrays with smaller numbers of antenna elements oftentimes use one-to-many splitters, such as 1:2 or 1:4 splitters. Such splitters may introduce large splitter losses into the signal path, increase module area and cost, and may introduce additional challenges associated with the use of merged control, clock, and data signals. For example, in some implementations, to accommodate 1:2 or 1:4 splitters, an IF transceiver needs higher control/data or clock/data swing, which limits the total number of antenna array sizes with a given number of ports from intermediate frequency (IF) and mmW transceivers. Additionally, some systems use DC-chained supplies and implement configurations to address voltage drop concern when massive phase arrays operate simultaneously. Some aspects described herein are only limited to four low frequency routings, or other low numbers of low frequency routings (e.g., 2, 4, etc.) Such aspects may reduce or eliminate direct current chained supply issues used to accommodate drop concerns when massive phase arrays in a single mmW device operate simultaneously. According to aspects described, devices are described that include transceivers (e.g., intermediate frequency (IF) and mmW transceivers) which use chained signal paths instead of one-to-many (e.g., 1:2, 1:4, etc.) splitters to route data, control, and clock signals. Apparatuses and devices according to such aspects can, in some implementations, provide flexibility in signal routing and lower loss in the paths for such routing. Such characteristics improve the performance of devices in the context of large arrays of antenna elements for beamforming systems and other such systems in communication devices. Such performance can be used to improve 5G user equipment or terminals (UE), customer premises equipment (CPE), 5G radio area network small cells (FSM), and 5G radio area network base stations (CSM). Further details regarding aspects of the disclosure will be described with respect to the figures. FIG.1is a diagram showing a wireless device110communicating with a wireless communication system120. In accordance with aspects described herein, the wireless device can include transceivers configured for chained signal routing in accordance with aspects described herein. The wireless communication system120may be a Long Term Evolution (LTE) system, a Code Division Multiple Access (CDMA) system, a Global System for Mobile Communications (GSM) system, a wireless local area network (WLAN) system, a 5G NR (new radio) system, or some other wireless system. A CDMA system may implement Wideband CDMA (WCDMA), CDMA 1×, Evolution-Data Optimized (EVDO), Time Division Synchronous CDMA (TD-SCDMA), or some other version of CDMA. Communication elements of the wireless device110for implementing mmW and non-mmW communications in accordance with any such communication standards can be supported by various designs of transceivers using a chained signal routing. For simplicity,FIG.1shows wireless communication system120including two base stations130and132and one system controller140. In general, a wireless communication system may include any number of base stations and any set of network entities. The wireless device110may also be referred to as a user equipment (UE), a mobile station, a terminal, an access terminal, a subscriber unit, a station, etc. Wireless device110may be a cellular phone, a smartphone, a tablet, or other such mobile device (e.g., a device integrated with a display screen). Other examples of the wireless device110include a wireless modem, a personal digital assistant (PDA), a handheld device, a laptop computer, a smartbook, a netbook, a tablet, a cordless phone, a medical device, a device configured to connect to one or more other devices (for example through the internet of things), a wireless local loop (WLL) station, a Bluetooth device, etc. Wireless device110may communicate with wireless communication system120. Wireless device110may also receive signals from broadcast stations (e.g., a broadcast station134) and/or signals from satellites (e.g., a satellite150in one or more global navigation satellite systems (GNSS), etc.). Wireless device110may support one or more radio technologies for wireless communication such as LTE, WCDMA, CDMA 1×, EVDO, TD-SCDMA, GSM, 802.11, 5G, etc. The wireless communication system120may also include a wireless device160. In an exemplary embodiment, the wireless device160may be a wireless access point, or another wireless communication device that comprises, or comprises part of a wireless local area network (WLAN). In an exemplary embodiment, the wireless device110may be configured as a customer premises equipment (CPE), which may be in communication with a base station130and another wireless device110, or other devices in the wireless communication system120. In some embodiments, the CPE may be configured to communicate with the wireless device160using WAN signaling and to interface with the base station130based on such communication instead of the wireless device160directly communicating with the base station130. In exemplary embodiments where the wireless device160is configured to communicate using WLAN signaling, a WLAN signal may include WiFi, or other communication signals. FIG.2Ais a block diagram showing a wireless device200in which aspects of the present disclosure may be implemented. The wireless device200may, for example, be an embodiment of the devices (e.g., the base station130or132, the wireless device110or160, etc.) illustrated inFIG.1. The circuitry described may be circuitry supporting mmW communications or other such communications using large arrays of antenna elements structured to receive signals via a chained routing (e.g., rather than a splitter-based routing). In some examples, the wireless device200(or any of the devices described and/or illustrated hereinafter) may be an example of any of the devices illustrated inFIG.1. FIG.2Ashows an example of a transceiver220having a transmitter230and a receiver250. In general, the conditioning of the signals in the transmitter230and the receiver250may be performed by one or more stages of amplifier, filter, upconverter, downconverter, etc. These circuit blocks may be arranged differently from the configuration shown inFIG.2A. Furthermore, other circuit blocks not shown inFIG.2Amay also be used to condition the signals in the transmitter230and receiver250. Unless otherwise noted, any signal inFIG.2A, or any other figure in the drawings, may be either single-ended or differential. Some circuit blocks inFIG.2Amay also be omitted. In the example shown inFIG.2A, wireless device200generally comprises the transceiver220and a data processor210. The data processor210may include a processor296operatively coupled to a memory298. The memory298may be configured to store data and program codes, and may generally comprise analog and/or digital processing components. The transceiver220includes a transmitter230and a receiver250that support bi-directional communication. In general, wireless device200may include any number of transmitters and/or receivers for any number of communication systems and frequency bands. All or a portion of the transceiver220may be implemented on one or more analog integrated circuits (ICs), RF ICs (RFICs), mixed-signal ICs, etc. A transmitter or a receiver may be implemented with a super-heterodyne architecture or a direct-conversion architecture. In the super-heterodyne architecture, a signal is frequency-converted between radio frequency (RF) and baseband in multiple stages, e.g., from RF to an intermediate frequency (IF) in one stage, and then from IF to baseband in another stage for a receiver. In the direct-conversion architecture, a signal is frequency converted between RF and baseband in one stage. The super-heterodyne and direct-conversion architectures may use different circuit blocks and/or have different requirements. In the example shown inFIG.2A, transmitter230and receiver250are implemented with the direct-conversion architecture. In the transmit path, the data processor210processes data to be transmitted and provides in-phase (I) and quadrature (Q) analog output signals to the transmitter230. In an exemplary embodiment, the data processor210includes digital-to-analog-converters (DAC's)214aand214bfor converting digital signals generated by the data processor210into the I and Q analog output signals, e.g., I and Q output currents, for further processing. In other embodiments, the DACs214aand214bare included in the transceiver220and the data processor210provides data (e.g., for I and Q) to the transceiver220digitally. Within the transmitter230, baseband (e.g., lowpass) filters232aand232bfilter the I and Q analog transmit signals, respectively, to remove undesired images caused by the prior digital-to-analog conversion. Amplifiers (Amp)234aand234bamplify the signals from the baseband filters232aand232b, respectively, and provide I and Q baseband signals. An upconverter240having upconversion mixers241aand241bupconverts the I and Q baseband signals with I and Q transmit (TX) local oscillator (LO) signals from a TX LO signal generator290and provides an unconverted signal. A filter242filters the upconverted signal to remove undesired images caused by the frequency upconversion as well as noise in a receive frequency band. A power amplifier244amplifies the signal from filter242to obtain the desired output power level and provides a transmit RF signal. The transmit RF signal is routed through a duplexer or switch246and transmitted via an antennas248. While examples discussed herein utilize I and Q signals, those of skill in the art will understand that components of the transceiver may be configured to utilize polar modulation. In the receive path, the antennas248receives communication signals and provides a received RF signal, which is routed through duplexer or switch246and provided to a low noise amplifier (LNA)252. The switch246is designed to operate with a specific RX-to-TX duplexer frequency separation, such that RX signals are isolated from TX signals. The received RF signal is amplified by LNA252and filtered by a filter254to obtain a desired RF input signal. Downconversion mixers261aand261bin a downconverter260mix the output of filter254with I and Q receive (RX) LO signals (i.e., LO_I and LO_Q) from an RX LO signal generator280to generate I and Q baseband signals. The I and Q baseband signals are amplified by amplifiers262aand262band further filtered by baseband (e.g., lowpass) filters264aand264bto obtain I and Q analog input signals, which are provided to data processor210. In the exemplary embodiment shown, the data processor210includes analog-to-digital-converters (ADC's)216aand216bfor converting the analog input signals into digital signals to be further processed by the data processor210. In some embodiments, the ADCs216aand216bare included in the transceiver220and provide data to the data processor210digitally. InFIG.2A, TX LO signal generator290generates the I and Q TX LO signals used for frequency upconversion, while RX LO signal generator280generates the I and Q RX LO signals used for frequency downconversion. Each LO signal is a periodic signal with a particular fundamental frequency. A phase locked loop (PLL)292receives timing information from data processor210and generates a control signal used to adjust the frequency and/or phase of the TX LO signals from LO signal generator290. Similarly, a PLL282receives timing information from data processor210and generates a control signal used to adjust the frequency and/or phase of the RX LO signals from LO signal generator280. In an exemplary embodiment, the RX PLL282, the TX PLL292, the RX LO signal generator280, and the TX LO signal generator290may alternatively be combined into a single LO generator circuit295, which may include common or shared LO signal generator circuitry to provide the TX LO signals and the RX LO signals. Alternatively, separate LO generator circuits may be used to generate the TX LO signals and the RX LO signals. Certain components of the transceiver220are functionally illustrated inFIG.2A, and the configuration illustrated therein may or may not be representative of a physical device configuration in certain implementations. For example, as described above, transceiver220may be implemented in various integrated circuits (ICs), RF ICs (RFICs), mixed-signal ICs, etc. In some embodiments, the transceiver220is implemented on a substrate or board such as a printed circuit board (PCB) having various modules, chips, and/or components. For example, the power amplifier244, the filter242, and the switch246may be implemented in separate modules or as discrete components, while the remaining components illustrated in the transceiver220may be implemented in a single transceiver chip. The power amplifier244may comprise one or more stages comprising, for example, driver stages, power amplifier stages, or other components, that can be configured to amplify a communication signal on one or more frequencies, in one or more frequency bands, and at one or more power levels. Depending on various factors, the power amplifier244can be configured to operate using one or more driver stages, one or more power amplifier stages, one or more impedance matching networks, and can be configured to provide good linearity, efficiency, or a combination of good linearity and efficiency. In an exemplary embodiment in a super-heterodyne architecture, the power amplifier244, and the LNA252(and filter242and/or254in some examples) may be implemented separately from other components in the transmitter230and receiver250, and may be implemented on a millimeter wave integrated circuit. An example super-heterodyne architecture is illustrated inFIG.2B. FIG.2Bis a block diagram showing a wireless device in which aspects of the present disclosure may be implemented. Certain components, for example which may be indicated by identical reference numerals, of the wireless device200ainFIG.2Bmay be configured similarly to those in the wireless device200shown inFIG.2Aand the description of identically numbered items inFIG.2Bwill not be repeated. The wireless device200ais an example of a heterodyne (or superheterodyne) architecture in which the upconverter240and the downconverter260are configured to process a communication signal between baseband and an intermediate frequency (IF). For example, the upconverter240may be configured to provide an IF signal to an upconverter275. In an exemplary embodiment, the upconverter275may comprise summing function278and upconversion mixer276. The summing function278combines the I and the Q outputs of the upconverter240and provides a non-quadrature signal to the mixer276. The non-quadrature signal may be single ended or differential. The mixer276is configured to receive the IF signal from the upconverter240and TX RF LO signals from a TX RF LO signal generator277, and provide an upconverted mmW signal to phase shift circuitry281. While PLL292is illustrated inFIG.2Bas being shared by the signal generators290,277, a respective PLL for each signal generator may be implemented. In an exemplary embodiment, components in the phase shift circuitry281may comprise one or more adjustable or variable phased array elements, and may receive one or more control signals from the data processor210over connection289and operate the adjustable or variable phased array elements based on the received control signals. In an exemplary embodiment, the phase shift circuitry281comprises phase shifters283and phased array elements287. Although three phase shifters283and three phased array elements287are shown for ease of illustration, the phase shift circuitry281may comprise more or fewer phase shifters283and phased array elements287. Each phase shifter283may be configured to receive the mmW transmit signal from the upconverter275, alter the phase by an amount, and provide the mmW signal to a respective phased array element287. Each phased array element287may comprise transmit and/or receive circuitry including one or more filters, amplifiers, driver amplifiers, and power amplifiers. In some embodiments, the phase shifters283may be incorporated within respective phased array elements287. The output of the phase shift circuitry281is provided to an antennas248. In an exemplary embodiment, the antennas248comprises a number of antennas that typically correspond to the number of phase shifters283and phased array elements287, for example such that each antenna element is coupled to a respective phased array element287. In an exemplary embodiment, the phase shift circuitry281and the antennas248may be referred to as a phased array. In a receive direction, an output of the phase shift circuitry281is provided to a downconverter285. In an exemplary embodiment, the downconverter285may comprise an I/Q generation function291and a downconversion mixer286. In an exemplary embodiment, the mixer286down converts the receive mmW signal provided by the phase shift circuitry281to an IF signal according to RX mmW LO signals provided by an RX mmW LO signal generator279. The I/Q generation function291receives the IF signal from the mixer286and generates I and Q signals for the downconverter260, which down converts the IF signals to baseband, as described above. While PLL282is illustrated inFIG.2Bas being shared by the signal generators280,279, a respective PLL for each signal generator may be implemented. In some embodiments, the upconverter275, downconverter285, and the phase shift circuitry281are implemented on a common IC. In some embodiments, the summing function278and the I/Q generation function291are implemented separate from the mixers276and286such that the mixers276,286and the phase shift circuitry281are implemented on the common IC, but the summing function278and I/Q generation function291are not (e.g., the summing function278and I/Q generation function291are implemented in another IC coupled to the IC having the mixers276,286). In some embodiments, the LO signal generators277,279are included in the common IC. In some embodiments in which phase shift circuitry is implemented on a common IC with276,286,277,278,279, and/or291, the common IC and the antennas248are included in a module, which may be coupled to other components of the transceiver220via a connector. In some embodiments, the phase shift circuitry281, for example, a chip on which the phase shift circuitry281is implemented, is coupled to the antennas248by an interconnect. For example, components of the antennas248may be implemented on a substrate and coupled to an integrated circuit implementing the phase shift circuitry281via a flexible printed circuit board or other such substrate. In some embodiments, both the architecture illustrated inFIG.2Aand the architecture illustrated inFIG.2Bare implemented in the same device. For example, a wireless device110or200may be configured to communicate with signals having a frequency below about 20 GHz using the architecture illustrated inFIG.2Aand to communicate with signals having a frequency above about 20 GHz using the architecture illustrated inFIG.2B. In devices in which both architectures are implemented, one or more components ofFIGS.2A and2Bthat are identically numbered may be shared between the two architectures. For example, both signals that have been downconverted directly to baseband from mmW and signals that have been downconverted from mmW to baseband via an IF stage may be filtered by the same baseband filter264a,264b. In other embodiments, a first version of the filter264a,264bis included in the portion of the device which implements the architecture ofFIG.2Aand a second version of the filter264a,264bis included in the portion of the device which implements the architecture ofFIG.2B. As described above, example wireless devices can be configured with or without the use of an intermediate frequency (IF). Aspects described below are discussed in the context of systems that merge IF signals with control and clock signals. In some other implementations, chained signals can be used in accordance with the descriptions herein for systems without IF signals, or where control and clock signals are not merged with data signals. FIG.2Cis a block diagram illustrating aspects of a wireless device in which aspects of the present disclosure may be implemented. The wireless device illustrated byFIG.2Ccan structure the circuitry inFIGS.2A-Babove in an IF transceiver201(e.g., an IF integrated circuit (IFIC)) and mmW transceivers301(e.g.,301-1,301-M,301-N, etc.). In some examples, IF transceiver201is implemented in a separate chip from mmW transceiver(s)301, and the signal paths204and207can be implemented using cables. In some such examples, the IFIC is coupled to an IC including the mmW transceiver301-1, which may or may not be included in a package or module. In other implementations, the transceivers can be implemented on a shared PCB, in a shared package, or in a single IC where other routing paths can be used. Additional circuitry can be present in such elements, and is not shown for simplicity or is described below. In some examples, the mmW transceivers includes the mixers276and286and the phase shift circuitry281, and the IF transceiver201contains the remaining elements of the transceiver220. The IF transceiver201includes two data sources, shown as data source202and data source205. Each of the data source202and the data source205may provide information to be sent over a channel in a mmW communication system. Similarly, circuitry for receiving information may also or alternatively be included in place of the data sources202and/or205. In one illustrative example, the data source202or the data source205is representative of DAC214aand/or DAC214bintegrated into IF transceiver201to provide converted I and/or Q analog data from the digital signals generated by the data processor210(e.g., I and Q output currents). The IF transceiver can include data sources for a large number of different signal paths for different signal routings for a large array of antenna elements. Each routing can provide a signal path for multiple mmW transceivers301, and multiple signal paths with a chained routing can be present in a device to support the antenna elements in the large array. Each signal path, as described above, includes analog components (e.g., H and V, different channels or frequencies, etc.). Components for a given signal path are combined, as illustrated inFIG.2C, with a control signal203or a clock signal206using diplexers299(e.g., or a splitter/combiner), as illustrated. The merger of the data signal from data source202with control signal203creates a merged control/data signal that is communicated to the first mmW transceiver301-1in the daisy chain via merged control/signal path204. The merger of the clock signal206with the data signal from data source205creates a merged clock/data signal that is communicated to the first mmW transceiver301in the daisy chain using merged clock/signal path207. For example, the data on path204may be for one polarization of an antenna or array of antennas, and the data on path207may be for another polarization of the antenna or array of antennas. Data sent on different polarizations may be the same (e.g., for diversity purposes) or different (e.g., for MIMO). In another example, the data on path204may be for a first antenna or array of antennas, and the data on path207may be for a second antenna or array of antennas. The first and second antennas or arrays may be spaced apart, pointed in different directions, configured to communicate using different frequencies, configured as different types of antennas (e.g., one as a patch and another as a dipole), etc. In some examples, additional paths including additional data (e.g., for other or additional antennas) may be coupled between the IF transceiver201and the mmW transceiver301-1(and between mmW transceivers in the chain). In some such examples, the additional path includes data from multiple sources, which may be separated using a diplexer or other splitter as described below with respect to the paths204and207. Circuitry of the mmW transceiver301-1can use the signals from signal paths204and207to transmit data on the antennas248of the mmW transceiver301-1. Similarly, data received on the antennas248of the mmW transceiver301-1can be communicated to the IF transceiver201using the paths204and207. The chained path209can be used to communicate data between the IF transceiver201and the mmW transceiver301N via the chained path209and the mmW transceiver301-1. In such an implementation, mmW transceiver301-1can be considered a primary, master, or initial mmW transceiver in a first signal routing for the device ofFIG.2C. The mmW transceiver301N can be considered a secondary, slave, or subsequent mmW transceiver in the first signal routing. Additional chained paths can be used to connect mmW transceiver301N to additional mmW transceivers301(e.g.,301-o,301-p,301-z, etc.) in the first signal routing. The control signal203can be used to manage the routing of signals to and from antennas248of various mmW transceivers in the first signal routing. The mmW transceiver301N may thus, in some aspects, receive signals from one mmW transceiver that are simply passed to another mmW transceiver, without the signals interacting with the antenna elements of a large phased array that are integrated with the mmW transceiver301N based on the control signal203. Further, the control signal203may facilitate operation within a mmW transceiver, for example controlling a signal beam (e.g., to select a codebook for beam formation), a gain of one or more amplifiers, etc. During operation, the processor296(which may be an example of the data processor210, and is not illustrated inFIG.2C) can manage transmission of data from memory298(not illustrated inFIG.2C) or receipt of data for storage in the memory298. During transmission, control circuitry (e.g., processor296or other such control circuitry) can generate control data that identifies one or more target mmW transceivers301to be used in transmitting or receiving data. When the transmit data is merged with clock and control data using the diplexer299(e.g., splitter/combiners), the control data in the merged control and data signal may include information regarding the target mmW transceiver(s)301indicated to transmit the data. The transmit data is then communicated through the daisy chain routing to the target mmW transceiver (e.g., mmW transceiver301N, or any other mmW transceiver in a daisy chain routing). The switching circuitry of the daisy chain routing then passes the transmit data through the routing to the appropriate mmW transceiver, where the transmit data is then processed and sent to the antennas248of the target mmW transceiver. Examples of how signals are routed or used within a particular transceiver of a daisy chain routing are described below inFIGS.3A-B,4,5, and6A-C. FIG.2Dis a block diagram illustrating aspects of a wireless device in which aspects of the present disclosure may be implemented. The wireless device ofFIG.2Dillustrates how multiple IF transceivers201and associated daisy chains of multiple mmW transceivers201can be combined to provide signal routing to any number of antenna elements to support a massive phase array in accordance with aspects described herein. As illustrated, a processor296(e.g., or any control circuitry) can be combined with any number of transceivers201(e.g., as described above forFIG.2C). The example ofFIG.2Dshows IF transceivers201-1,201-2, and201-M. Each of the IF transceivers201has an associated set of mmW transceivers. IF transceiver201-1is associated with mmW transceivers301-1-1and301-1-N. IF transceiver201-2is associated with mmW transceivers301-2-1and301-2-N. IF transceiver201-M is associated with mmW transceivers301-M-1and301-M-N. If each mmW transceiver includes P antenna elements, then the illustrated wireless device supports M×N×P antenna elements. Such a routing structure can support hundreds, thousands, or any number of antenna elements in a massive antenna array. Such a structure improves the design of a device by reducing routing complexity when compared with a multi-stage 1:N splitter tree. The reduced complexity can improve the link budget performance of a design, and support coverage to meet 5G performance criteria for 5G customer terminal equipment, 5G radio area networks for small cells, and 5G radio area networks for base stations. While each chain is illustrated inFIG.2Das having the same number of mmW transceivers301, the number of mmW transceivers in each chain may vary. FIG.3Ais a diagram illustrating aspects of an apparatus300including a chained signal routing for a large phase array in accordance with some aspects.FIG.3Bis a diagram illustrating aspects of a mmW transceiver301for use with apparatus300ofFIG.3Athat includes a chained signal routing for a large phase array in accordance with some aspects. FIG.3A, similar toFIGS.2C and2D, includes an IF transceiver. The illustrated IF transceiver310has two paths (but may have more paths, as described above) connected to the chained routing for mmW transceivers301A,301B, and301C, or more in similar methods. The two paths are merged control path381, which is similar to merged control/signal path204ofFIG.2C, and merged clock path371, which is similar to merged clock/signal path207ofFIG.2C. As described above, the two paths204,207may be used for separate data, carriers, streams, channels, etc. to be communicated using the antenna(s) supported by IF transceiver201and mmW transceivers301in the chained routing illustrated byFIG.3A. The two paths371and381connect IF transceiver310to an initial (e.g., master or first) chain-connected mmW transceiver301A. The initial chain-connected mmW transceiver301A includes circuitry to support both transmission and reception of signals that use paths371and381, as well as circuitry to support relay of such signals between IF transceiver310and mmW transceivers301further down the daisy chain away from IF transceiver310(e.g., the mmW transceiver301B and the mmW transceiver301C, which may be considered secondary or slave mmW transceivers to the primary or master mmW transceiver301A). While apparatus300is illustrated with three mmW transceivers301A,301B, and301C, additional numbers of mmW transceivers can be used in other configurations. Additionally, as described above, IF transceiver310can have other connections similar to paths371and381to connect to additional chains of mmW transceivers. In the example ofFIG.3A, the routing path of the chain connected mmW transceivers301connects from the path381through the mmW transceiver301A to separate signal path383and control path382. In the example ofFIG.3A, the merged signal from merged control path381that includes both a data signal and a control signal is split inside of the mmW transceiver301A, and separate paths are used for the signal and control data communicated between the mmW transceiver301A and the mmW transceiver301B. The signal path carries data signals between the mmW transceiver301B and the mmW transceiver301A, and the control path382carries a control signal between the mmW transceiver301B and the mmW transceiver301A. Similarly, data from the merged clock path371is separated inside of the chain-connected mmW transceiver301A. The data can be communicated to the chain-connected mmW transceiver301B using signal path373and clock path372. The two separate data signals, the clock signal, and the control signal can be conveyed down the daisy chain routing separately in any number of subsequent chain-connected transceivers after the initial chain connected mmW transceiver301(e.g., using signal paths385,375, control path384, clock path374, and similar paths for any subsequent mmW transceivers away from IF transceiver310in the daisy chain routing). In addition to the daisy chain connection to the IF transceiver310, each mmW transceiver301of the chain of mmW transceivers may be associated with a separate power management integrated circuit (PMIC)320. The PMICs320provide reference voltages and current to support amplifiers and power both for transmission and reception of signals using antennas for each individual mmW transceiver301, as well as to compensate for losses in the data, control, and clock signals as the signals pass along the daisy chain of the chain-connected mmW transceivers301. While apparatus300is illustrated with each mmW transceiver pairing with a PMIC chip, it is possible to pair one PMIC with more than one mmW transceivers to save cost especially for massive phase array system. For example, one or more reference voltages may be communicated though the chain of mmW transceivers, and power management circuitry within each transceiver may convert the reference voltages to voltages required in the transceiver. FIG.3Bis a diagram illustrating aspects of a mmW transceiver301for use with apparatus300ofFIG.3Athat includes a chained signal routing (e.g., including the chain-connected mmW transceivers301A,301B,301C) for a large phase array in accordance with some aspects.FIG.3Billustrates the chain-connected mmW transceiver301B ofFIG.3A. The illustrated transceivers301A,301B,301C are shown as duplicates, so that even if some elements are not used due to the particular configuration, the below description of the chain-connected mmW transceiver301B can be extrapolated to any transceiver in a daisy chain, including the first mmW transceiver in the chain (e.g., the mmW transceiver301A). As shown inFIG.3Band alsoFIG.3A, the chain connected mmW transceiver301B has connections to a previous and a subsequent mmW transceiver in the daisy chain. The connections to the previous mmW transceiver (e.g., mmW transceiver301A) include signal path383, control path382, signal path373, and clock path372. The connections to the subsequent mmW transceiver in the chain (e.g., mmW transceiver301C) include the signal path385, the control path384, the signal path375, and the clock path374. As a secondary (e.g., slave, subsequent, etc.) mmW transceiver, signal path383will be used only for data signals, and control signals are received via the control path382. If transceiver301B was the primary (e.g., first, master, etc.) transceiver, the signal path383would include a combined data and control signal that would be split by control/signal diplexer389. Because the control and data signals for such a combination are different frequencies, the diplexer389can be a simple passive diplexer that splits the signals of different frequencies along separate paths. The upper illustrated path is connected to Tx and Rx paths for antennas connected to the mmW transceiver301B. The lower path is attached to control circuitry380. When the control signal is received via control path382or control path384, the signal is coupled directly to the control circuitry380as shown. In alternate embodiments, for receive path signals, the control/signal diplexer389can similarly be used to combine data and control signals into a combined control/data signal for communication to an IF transceiver if the mmW transceiver301B is the primary transceiver in a chain. The data signal communicated via signal path383can either be connected to signal path385, if the signal is to or from a subsequent mmW transceiver301further along the chain (e.g., the mmW transceiver301C), or to Rx path311or Tx path312for signals transmitted or received using the antenna elements directly coupled to the chain connected mmW transceiver301B. The signal path373and the clock path372are similarly connected to a clock/signal diplexer379and clock circuitry370. The clock circuitry370can be used for managing signals transmitted and received using the antennas coupled directly to the transceiver301B (e.g., for mixers such as mixers276,286), and can be used to refresh or otherwise manage and distribute the clock signal up and down the daisy chain routing. Both data paths through chain connected transceiver have three connections: a signal path connection for conveying signals up and down the daisy chain routing (e.g. via signal path385or signal path375); a receive path for signals received at antenna elements connected to the mmW transceiver301B (e.g., Rx path311and Rx path321); and a transmit path for signals transmitted using antenna elements directly connected to the mmW transceiver301B (e.g., Tx path312and Tx path322), which may be selectively coupled together via one or more switches or other means.FIG.4below illustrates an example implementation of Tx paths312,322.FIG.5below illustrates an example implementation of Rx paths311,321. The Tx path312and Rx path311may be coupled to the same antenna or array of antennas. Similarly, the Tx path322and Rx path321may be coupled to another antenna or array of antennas. A mixer, amplifier, phase shifter, filer, splitter and/or combiner, transformer, and/or other components may be coupled between each of the Tx and Rx paths and its respective antenna or array.FIGS.6B and6Cillustrate certain of these components, but other configurations may be used. FIG.4is a diagram illustrating aspects of a transmit (Tx) path (e.g., Tx path312or Tx path322) in a mmW transceiver for use with a chained signal routing for a large phase array in accordance with some aspects. As shown, the circuitry ofFIG.4illustrates routing for signals from the signal path383ofFIGS.3A and3Bto the Tx path312and the signal path385. Additional switching or isolation circuitry may be present to manage signals along such paths, but are not shown for simplicity. As illustrated inFIGS.3A and3B, duplicate circuitry or other circuitry similar to the illustrated circuitry ofFIG.4can be used for both data paths in any mmW transceiver301. As shown, the circuitry is connected to the signal path383and the control/signal diplexer389described above (a path for control data to or from the diplexer389is not shown inFIGS.4and5for ease of illustration). The data output of the control/signal diplexer389can be coupled to the Rx path311, circuitry for the Tx path312, and circuitry for the signal path385. For transmit data to be transmitted using the antenna elements coupled to the circuitry illustrated inFIG.4, the transmit data will be received at the control/signal diplexer389, and the switching for the Rx path311(not illustrated inFIG.4, but shown inFIG.5to ensure clarity) and the signal path385will be in an open/isolated position. The transmit data will be amplified by the Tx variable gain amplifier (VGA)410, and then passed along the Tx path312. For transmit data indicated to be passed further along the daisy chain routing, Rx path switching409(e.g., switching for the Rx path311, seeFIG.4) and Tx path switching509for the Tx VGA410(seeFIG.5) will be open/isolated, and the Tx buffer VGA412will be connected to the output of the control/signal diplexer389. The Tx buffer VGA412is used to compensate for losses along the daisy chain routing, and then passes the signal through switching to the signal path385. The transmit data can be passed through multiple chains of such Tx buffers in the daisy chain routing to a mmW transceiver301associated with the transmit data by the control data. The switching between the Tx buffer VGA412and the signal path385includes switching to connect signal path385to both the Tx Buffer VGA412, as well as to an Rx buffer VGA512for receive signals sent up the daisy chain routing as described inFIG.5. FIG.5is a diagram illustrating aspects of a receive (Rx) path311in the mmW transceiver301B for use with a chained signal routing for a large phase array in accordance with some aspects. As described above, both the Rx Buffer VGA514and the Tx buffer VGA412can be connected to the signal path385via switching circuitry. The switching circuitry allows the signal path385to connect to Tx buffer VGA412when signals are being transmitted down the daisy chain routing to mmW transceivers further down the chain, and to connect to Rx buffer VGA514via matching circuitry502when received signals are being transmitted up the daisy chain toward an IF transceiver. In the illustrated circuitry ofFIG.5, such a receive signal being transmitted up the daisy chain is input to signal path385from another mmW transceiver (e.g., the mmW transceiver301C). The matching circuitry502then provides the signal to Rx buffer VGA514, which can compensate for signal losses from signal path385or other parts of the daisy chain routing. The receive signal is then provided to the control/signal diplexer389and passed further up the chain via the signal path383. Just as described above inFIGS.4and5, the Tx path312is connected to the Rx path, and switching circuitry (e.g., the Rx path switching409and the Tx path switching509) can be used to isolate these paths depending on the path that is in use, or to isolate these local antenna element Tx/Rx paths from the daisy chain routing when signals are passed up and down the daisy chain. When a signal is received at antennas of the transceiver containing the circuitry ofFIG.5(e.g., the mmW transceiver301B), the signal is processed via circuitry (e.g., such as the transmitter230or receiver250circuitry described inFIG.2B), and then passed to the Rx VGA512via the Rx path311. The received signal is then passed to the control/signal diplexer389and passed toward the IF transceiver via the path383. Just as for the transmit path, a mmW transceiver such as the chained mmW transceiver301B can include two copies of the circuitry ofFIG.4, with one copy using the control/signal diplexer389, and the other copy using a clock diplexer (e.g., the clock diplexer379) and an associated separate path. In other examples, different circuitry can be used to manage the different data signals, clock signal(s), and control signal(s) to compensate for routing losses, signal integrity, and to provide signals up and down the daisy chain with adequate signal quality to be processed in the communication system. FIG.6Ais a diagram illustrating aspects of an apparatus including a chained signal routing for a phase array (e.g., a large phase array) in accordance with some aspects. In the implementations illustrated inFIGS.3A-B,4, and5, the merged clock/data signals and merged control/data signals are split at the primary mmW transceiver, and the clock, control, and two data signals are then passed up or down the daisy chain separately.FIG.6Aillustrates an implementation where, rather than passing these signals up or down the chain separately, the signals are passed together. Other aspects of the apparatus can operate as described above, with merged signals provided to and from an IF transceiver in a merged format via merged clock/signal path602and merged control/signal path604. Signals can then be passed up (e.g., Rx signals) or down (e.g., Tx signals) the chain connecting multiple mmW transceivers601A-601N via chain path622, chain path624, second chain path623, and second chain path625. Signals received at antennas695of one or more mmW transceivers601A-601N are passed up the chain to the IF transceiver610, and signals to be transmitted using the antennas695of one or more mmW transceivers are passed down the daisy chain to the assigned mmW transceiver from mmW transceivers601A-601N (e.g., mmW transceiver601N) for transmission using the corresponding antennas695for the designated transceiver(s). FIG.6Bis a diagram illustrating aspects of a mmW transceiver for use with a chained signal routing for a (large) phase array in accordance with some aspects.FIG.6Billustrates an example implementation of a transceiver601A different than the implementation(s) described inFIGS.3B,4, and5. In the example ofFIG.6B, the mmW transceiver601A is configured to receive combined transmit data signals at merged clock/signal path602and merged control/signal path604. The corresponding merged transmit signals from each path are split at diplexers630and631. In contrast to the examples above, when the signals are designated to be passed down the daisy chain rather than transmitted via the antennas695for the mmW transceiver601A (e.g., via phase shifters650and Tx/Rx amplifiers690), the signals are recombined at diplexers640and641. The signals that are remerged within the mmW transceiver601A using diplexers640and641are then communicated down the daisy chain routing via the chain clock/signal path622and the chain control/signal path624. Receive signals follow the opposite path, with the combined signals received via the chain control/signal path624and the chain clock/signal path622. The receive signals follow the reverse of the transmit signals, and the signals are similarly split and recombined within the mmW transceiver601A before passing up the daisy chain routing to an IF transceiver such as the IF transceiver610. At the mmW transceiver where signals are transmitted, switching circuitry coupled to diplexers630and631route the signals along signal paths. This includes a route from a data terminal of diplexer630and a route from a data terminal of diplexer631to antennas695using phase shifters650and amplifiers690. While signal path phase shifting is illustrated herein, those of skill in the art will understand that phase shifting may be accomplished by instead shifting an LO and/or mixer signal (in this figure and in other figures, such asFIGS.3A,3B,6C). The clock signal from the merged clock/signal path602is coupled to a clock signal terminal and output from a clock terminal of diplexer631to be provided to circuitry to manage timing of the data signals and/or conversion of data signals between IF and RF (e.g., provided to mixers in the mmW transceiver601A or to circuitry configured to generate an LO input(s) for the mixers based on the clock signal). The control signal from merged control signal path604is provided to a control signal terminal of diplexer631and output from a control terminal of diplexer631to control/wireline interface689to manage transmission of the data signals. For example, the interface689may be configured to adjust the phase shifters650, set one or more switches in the mmW transceiver601A, set the gain of one or more amplifiers (e.g., any of the amplifiers690) in the transceiver601A, etc. For received signals, the antennas695receive the signals which are amplified by amplifiers690. Additional circuitry then manages the data, clock, and control signals for conveyance up the daisy chain via signal paths632and633. FIG.6Cis a diagram illustrating aspects of a mmW transceiver for use with a chained signal routing for a (large) phase array in accordance with some aspects. Similar to the device ofFIG.6B, the device ofFIG.6Ccommunicates merged signals at merged signal paths602and604when the device is an initial mmW transceiver. Diplexers630and631split any merged signals received from up the daisy chain (e.g., toward an IF transceiver) and merge any split signals to be sent directly to an IF transceiver. Signals communicated using antennas695are routed to phase shifters650and TX or RX amplifiers690, e.g., based on control data from control/wireline interface689with timing managed by the clock signal on clock path685. Devices not connected to the IF transceiver (e.g., in a middle of a daisy chain) communicate data, control, and clock signals separately using paths602,604,622A,622B,624A, and624B. In contrast to the device ofFIG.6B, the device ofFIG.6Cdoes not remerge data and control or clock signals prior to communicating the signals up or down the daisy chain, unless the signals are being passed to the IF transceiver. Merged signals split at diplexers630and631when the device ofFIG.6Cis the first mmW transceiver in a chain are thus communicated down the daisy chain (e.g., away from the IF transceiver) separately using signal paths622B,624B, and separate clock path622A and control path624A. For example, if the device is a 2ndor additional mmW transceiver in a daisy chain, the control signal is received as a stand-alone signal via chain control path624A. For the first mmW transceiver in such a daisy chain, a data signal to be passed to the second mmW transceiver (e.g., away from the IF transceiver610) is output from the signal paths622B and624B of the first mmW transceiver and then input to the corresponding signal paths622B and624B of the second mmW transceiver. Daisy chain routing architectures described herein may improve devices using such an architecture by avoiding the loss associated with splitters, and by reducing the number of independent IF transceiver ICs, e.g., by a factor associated with the number of mmW transceivers in a daisy chain. For example, if two mmW transceivers are used in a daisy chain, the number of IF transceiver ICs may be cut in half. For a 32×32 antenna array, the number of IF transceiver ICs may be cut from 16 to 8, reducing space usage of the device and providing a corresponding improvement to the device associated with the reduced number of IF transceiver ICs. Additionally, as described above, using multiplexing and demultiplexing diplexers on the mmW transceiver reduces path loss (e.g., by ˜4 dB from a 1:2 splitter, etc.) and allows for corresponding improvements in signal to noise ratios. Such an approach can further reduce the number of elements for a common RFIC design for UE and CPE, which otherwise come with an area and current consumption penalty (e.g., due to the 1:3 splitter used at IF connection ports). Further, such aspects allow increased device design flexibility using a daisy chain when compared with the 1:2 or 1:4 splitter configuration, e.g., in an environment where routing mm-wave signals more than a few millimeters results in large losses. FIGS.7A and7Bare block diagrams collectively illustrating some aspects of a millimeter wave (mmW) module in accordance with some aspects of the disclosure. The circuitry above illustrates mmW elements that can be disposed in a mmW module (e.g., on a mmW PCB and/or in a mmW IC). The elements of the mmW module can include mmW transceivers as described inFIGS.2D,3A-B,4,5, and6A-C, as well as antenna elements used in large antenna arrays as described throughout the specification. Such mmW elements can also include chained signal path routings in accordance with the descriptions herein. FIG.7Ashows a side view of a millimeter wave (mmW) module700. The mmW module700may be an example of the mmW modules used for mmW transceivers, PMICs, and other such mmW elements described herein. In some aspects, the mmW module700may comprise a massive phased array fabricated on a substrate703. Such a massive phase array module can include any number of antenna elements (e.g., 64 elements, 128 elements, 1024 elements, etc.). In some aspects, the mmW module700may comprise a mmWIC710, a PMIC715, a connector717and a plurality of antennas in an array. The side view ofFIG.7Ashows columns of antennas721,722,723,724,725,726,727and728fabricated on a substrate703, a mmWIC710, a PMIC715, and a connector717.FIG.7Bis a top view of the mmW module700showing a plurality of antennas721-1through721-N,722-1through722-N,723-1through723-N,724-1through724-N,725-1through725-N,726-1through726-N,727-1through727-N and728-1through728-N on the substrate703. In other aspects, a mmW module700can have other numbers of antennas in other organizations besides the 8×8 grid illustrated inFIG.7B(e.g., 1×8, 16×16, 4×6, 8×16, etc.). Other aspects include devices where the mmW module may comprise a plurality of antennas of an array on separate PCBs mounted to a main mmW PCB. In some examples, the antennas illustrated inFIG.7Bmay be supported by a plurality of mmW transceivers. For example, each column of antennas may be supported by an IF transceiver and a plurality of chained mmW transceivers, each of which drives or receives from a subset of antennas in the column. In another example, one IF transceiver supports all of the antennas illustrated inFIG.7B, and is coupled to a daisy-chained plurality of mmW transceivers, each of which drivers or receives from the antennas in a respective column. FIG.8is a flow diagram describing an example of the operation of a method800for operation of a device including a chained signal routing for a large phase array in accordance with some aspects. The blocks in the method800can be performed in or out of the order shown, and in some embodiments, can be performed at least in part in parallel. Method800includes block802, which involves generating a first analog data signal and a second analog data signal. The analog data signals can be generated by a digital to analog converter (e.g., the DAC214aand214b) from first and second digital data signals received from a processor (e.g., the processor296) or memory (e.g., the memory298) of a device. Method800includes block804, which involves generating control data and clock data for the first analog data signal and the second analog data signal. The clock data can be generated by clock circuitry in the IF transceiver, and the control data can be generated by control circuitry for the wireless communication system (e.g., the processor296). Method800includes block806, which involves merging, by an IF transceiver (e.g., the diplexers299of IF transceiver201), the control data and the first analog data signal to generate a merged control and data signal. Method800includes block808, which involves merging, by the IF transceiver (e.g., the diplexers299of IF transceiver201), the clock data and the second analog data signal to generate a merged clock and data signal. Method800includes block810, which involves communicating the first analog data signal and the second analog data signal between the IF transceiver and a target mmW transceiver via a daisy chain routing, wherein the daisy chain routing comprises at least a first mmW transceiver in the daisy chain routing between the IF transceiver and the target mmW transceiver. In some aspects, operations of block810can involve splitting the merged control and data signal using a first diplexer of a first mmW transceiver between the IF transceiver and the target mmW transceiver; splitting the merged clock and data signal using a second diplexer of a first mmW transceiver between the IF transceiver and the target mmW transceiver; and routing, by the first mmW transceiver, the clock signal, the control signal, the first analog data signal, and the second analog data signal to the target mmW transceiver. Method800describes transmit operations in a device including a daisy chain routing for mmW communications. Corresponding blocks will be apparent for receive operations performable by the same device. In some aspects, a method for such receive operations can involve receiving a third analog data signal, a fourth analog data signal, a second control signal, and a second clock signal at one or more antennas of the target mmW transceiver; and downconverting the third analog data signal and the fourth analog data signal from mmW frequencies to IF frequencies using frequency conversion circuitry of the target mmW transceiver. Some such aspects further involve communicating the third analog data signal, the fourth analog data signal, the second control signal, and the second clock signal to the first mmW transceiver from the target mmW transceiver; merging, by a first diplexer of the first mmW transceiver, the second control signal and the third analog data signal to generate a second merged control and data signal; and merging, by a second diplexer of the first mmW transceiver, the clock data and the fourth analog data signal to generate a second merged clock and data signal. Some such aspects further involve communicating the second merged control and data signal and the second merged clock and data signal from the first mmW transceiver to the IF transceiver; converting the third and fourth analog data signals to third and fourth digital data signals using an analog to digital converter coupled to the IF transceiver; and processing the third and fourth digital data signals using a processor coupled to the analog to digital converter. FIG.9is a functional block diagram of an apparatus including a chained signal routing for a large phase array in accordance with some aspects. The apparatus900comprises means902for transmitting and/or receiving mmW signals. The apparatus900further comprises means904for communicating data signals used to generate mmW signals to or from a daisy chained mmW transceiver. The daisy chained mmW transceiver can be connected directly to the means904(e.g., via routing to communication ports of the means904and the daisy chained mmW transceiver), or can be connected via additional instances of means904or similar devices including both means for transmitting or receiving mmW signals and means for routing data signals used to generate mmW signals along a daisy chain signal path. The apparatus900can additionally include means for selecting between the means902and the means904(e.g., using circuitry ofFIG.4orFIG.5). In some aspects, the apparatus900can further include means for duplexing signals, and means for converting IF data signals or portions of IF data signals between IF frequencies and mmW frequencies (e.g., to convert between IF frequency data signals and mmW signals transmitted or received via antennas of the apparatus900). In various aspects, apparatus900can additionally include elements in accordance with any description provided herein. In some aspects, apparatus900can further include means for serial connection of merged chain clock and data signals as well as merged chain control and data signals to a mmW transceiver in a daisy chain as described herein. Various devices described herein are illustrated with an IF frequency used to provide a signal to mmW transceivers. In various examples, any structure can be used for converting digital signals into mmW signals. In some aspects, IF frequencies are provided to separate mmW transceivers using the described daisy chain structures, with IF to mmW conversion occurring within mmW transceivers. In other aspects, mmW signals are generated at a transceiver, and mmW signals are communicated up and down the daisy chain, with down conversion from mmW frequencies occurring outside of the daisy chain structure. Thus, in some aspects, the data paths described in aspects above can be configured as routing paths structured to propagate mmW frequency signals. In some such aspects, a baseband signal is converted to a mmW frequency using direct conversion in a transceiver connected to a processor. Similarly, received mmW signals may be converted to baseband via direct conversion or using a low or zero IF configuration in the transceiver connected to the processor. In other aspects, a super-heterodyne architecture is used (e.g., and is contained entirely within a single transceiver connected to the processor), but mmW signals are propagated between the mmW transceivers. Devices, networks, systems, and certain means for transmitting or receiving signals described herein may be configured to communicate via one or more portions of the electromagnetic spectrum. The electromagnetic spectrum is often subdivided, based on frequency or wavelength, into various classes, bands, channels, etc. In 5G NR two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles, and will be referred to herein as “sub-7 GHz”. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” (mmW) band in documents and articles, despite including frequencies outside of the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “mmWave” or mmW band. With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-7 GHz” or the like if used herein may broadly represent frequencies that may be less than 7 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “mmWave”, mmW, or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, or may be within the EHF band. The circuit architecture described herein described herein may be implemented on one or more ICs, analog ICs, mmWICs, mixed-signal ICs, ASICs, printed circuit boards (PCBs), electronic devices, etc. The circuit architecture described herein may also be fabricated with various IC process technologies such as complementary metal oxide semiconductor (CMOS), N-channel MOS (NMOS), P-channel MOS (PMOS), bipolar junction transistor (BJT), bipolar-CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), heterojunction bipolar transistors (HBTs), high electron mobility transistors (HEMTs), silicon-on-insulator (SOI), etc. An apparatus implementing the circuit described herein may be a stand-alone device or may be part of a larger device. A device may be (i) a stand-alone IC, (ii) a set of one or more ICs that may include memory ICs for storing data and/or instructions, (iii) an RFIC such as an RF receiver (RFR) or an RF transmitter/receiver (RTR) or corresponding mmW elements, (iv) an ASIC such as a mobile station modem (MSM), (v) a module that may be embedded within other devices, (vi) a receiver, cellular phone, wireless device, handset, or mobile unit, (vii) etc. Although selected aspects have been illustrated and described in detail, it will be understood that various substitutions and alterations may be made therein without departing from the spirit and scope of the present invention, as defined by the following claims. Illustrative aspects of the present disclosure include, but are not limited to:Aspect 1. A wireless communication apparatus, comprising: a first millimeter wave (mmW) transceiver, the first mmW transceiver comprising: a first port for communicating a merged control and data signal; a second port for communicating a merged clock and data signal associated with the merged control and data signal; one or more antenna elements; a plurality of chain mmW transceiver ports; and switching circuitry controllable by control data to route portions of the merged clock and data signal and the merged control and data signal between: a first route between the one or more antenna elements and the first port and a second route between the one or more antenna elements and the second port; and a third route between the first port and the plurality of chain mmW transceiver ports and a fourth route between the second port and the plurality of chain mmW transceiver ports.Aspect 2. The wireless communication apparatus of aspect 1, further comprising: a second mmW transceiver, the second mmW transceiver comprising: a first port coupled to a first data port of the plurality of chain mmW transceiver ports; and a second port coupled to a second data port of the plurality of chain mmW transceiver ports.Aspect 3. The wireless communication apparatus of aspect 2, wherein the first data port is a chained control and data port coupled to a first multiplexing diplexer of the first mmW transceiver; wherein the second data port is a chained clock and data port coupled to a second multiplexing diplexer of the first mmW transceiver.Aspect 4. The wireless communication apparatus of aspect 2, wherein the second mmW transceiver further comprises a second clock port coupled to a first clock port of the plurality of chain mmW transceiver ports as part of a chain clock path.Aspect 5. The wireless communication apparatus of aspect 4, wherein the second mmW transceiver further comprises a second control port coupled to a first control port of the plurality of chain mmW transceiver ports as part of a chain control path.Aspect 6. The wireless communication apparatus of any of aspects 2 through 5, wherein the first mmW transceiver comprises a first demultiplexing diplexer that couples the first port of the first mmW transceiver to the first data port and the first clock port to demultiplex the merged clock and data signal into separate clock and data signals.Aspect 7. The wireless communication apparatus of aspect 6, wherein the first mmW transceiver comprises a second demultiplexing diplexer that couples the second port of the first mmW transceiver to the second data port and the first control port to demultiplex the merged control and data signal into separate control and data signals.Aspect 8. The wireless communication apparatus of any of aspects 2 through 7, wherein the first mmW transceiver further comprises: first frequency conversion circuitry in the first route configured to convert a first data signal associated with the merged control and data signal between IF frequencies and mmW frequencies; and second frequency conversion circuitry in the second route configured to convert a second data signal associated with the merged clock and data signal between the IF frequencies and the mmW frequencies.Aspect 9. The wireless communication apparatus of any of aspects 2 through 7, wherein the first mmW transceiver further comprises frequency conversion circuitry in the first route configured to convert a data signal associated with the merged control and data signal between baseband frequencies and mmW frequencies.Aspect 10. The wireless communication apparatus of any of aspects 2 through 9, wherein the second mmW transceiver further comprises: second one or more antenna elements; and second switching circuitry controllable by the control data to select between: a fifth route coupling the first port to the one or more antenna elements and a sixth route coupling the second port to the one or more antenna elements; and a seventh route coupling the first port to a first chained data port of the second mmW transceiver and an eighth route coupling the second port to a second chained data port of the second mmW transceiver.Aspect 11. The wireless communication apparatus of aspect 10, wherein the second mmW transceiver further comprises: first frequency conversion circuitry in the fifth route configured to convert a first data signal associated with the merged control and data signal between IF frequencies and mmW frequencies; and second frequency conversion circuitry in the sixth route configured to convert a second data signal associated with the merged clock and data signal between the IF frequencies and the mmW frequencies.Aspect 12. The wireless communication apparatus of aspect 11, further comprising a third mmW transceiver, the third mmW transceiver comprising: third one or more antenna elements; a first port coupled to the first chained data port, the first port configured to communicate a first data signal associated with the merged control and data signal with the second mmW transceiver; a second port coupled to the second chained data port, the second port configured to communicate a second data signal associated with the merged clock and data signal with the second mmW transceiver; a third port coupled to a chained control port of the second mmW transceiver, the second port configured to communicate a control signal associated with the merged control and data signal; and a fourth port coupled to a chained clock port of the second mmW transceiver, the fourth port configured to communicate a clock signal associated with the merged clock and data signal.Aspect 13. The wireless communication apparatus of aspect 12 further comprising: a processor; and an intermediate frequency (IF) transceiver coupled to the processor, the IF transceiver comprising: an IF merged clock and data port coupled to the first port of the first mmW transceiver as part of a merged clock and data path for the merged clock and data signal; and an IF merged control and data port coupled to the second port of the first mmW transceiver as part of a merged control and data path for the merged control and data signal.Aspect 14. The wireless communication apparatus of aspect 13, wherein the wireless communication apparatus is configured to transmit the first data signal and the second data signal via the third one or more antenna elements using the first data signal, the second data signal, the clock signal, and the control signal received from the IF transceiver via the first mmW transceiver and the second mmW transceiver.Aspect 15. The wireless communication apparatus of aspect 13, wherein the wireless communication apparatus is configured to: receive the first data signal, the second data signal, the clock signal, and the control signal at the third one or more antennas; communicate the first data signal and the control signal to the IF merged control and data port of the IF transceiver via the second mmW transceiver and the first mmW transceiver; communicate the second data signal and the clock signal to the IF merged clock and data port of the IF transceiver via the second mmW transceiver and the first mmW transceiver; and process the data signal using the processor.Aspect 16. The wireless communication apparatus of aspect 15, wherein the first mmW transceiver is configured to merge the first data signal and the control signal into the merged control and data signal using a first diplexer; wherein the first mmW transceiver is configured to merge the second data signal and the control signal into the merged clock and data signal using a second diplexer.Aspect 17. The wireless communication apparatus of any of aspects 1 through 16, further comprising: a display screen; and control circuitry coupled to the display screen and the first mmW transceiver and configured to transmit and receive data using a daisy chain routing including the first mmW transceiver.Aspect 18. The wireless communication apparatus of any of aspects 1 through 17, wherein the first route comprises a first transmit path variable gain amplifier (VGA), a first receive path VGA coupled between the first port and the one or more antenna elements, and switching circuitry to select between the first transmit path VGA and the first receive path VGA; wherein the second route comprises a second transmit path VGA, a second receive path VGA coupled between the second port and the one or more antenna elements, and switching circuitry to select between the second transmit path VGA and the second receive path VGA.Aspect 19. The wireless communication apparatus of any of aspects 1 through 18, wherein the third route comprises a first receive signal path VGA buffer, a first transmit signal path VGA buffer, and switching circuitry to select between the first receive signal path VGA buffer and the first transmit signal path VGA buffer; wherein the fourth route comprises a second receive signal path VGA buffer, a second transmit signal path VGA buffer, and switching circuitry configured to select between the second receive signal path VGA buffer and the second transmit signal path VGA buffer.Aspect 20. The wireless communication apparatus of any of aspects 1 through 7 or 17 through 19, wherein the wireless communication apparatus is configured to convert baseband signals to mmW signals without the use of an intermediate frequency (IF) signal.Aspect 21: The wireless communication apparatus of claim1, wherein the first route, the second route, the third route, and the fourth route are configured for mmW signals.Aspect 22. The wireless communication apparatus of claim1, further comprising: a first diplexer having a merged control signal terminal coupled to the first port, a control terminal, and a first data terminal; a second diplexer having a merged clock signal terminal coupled to the second port, a clock terminal, and a second data terminal; a third diplexer having a chain clock signal terminal coupled to a first port of the plurality of chain mmW transceiver ports, a third data terminal coupled to the first data terminal, and a second control terminal coupled to the control terminal; and a fourth diplexer having a chain control signal terminal coupled to a second port of the plurality of chain mmW transceiver ports, a fourth data terminal coupled to the second data terminal, and a second clock terminal coupled to the clock terminal; wherein the first route includes a signal path between the one or more antenna elements and the first data terminal, the second route includes a signal path between the one or more antenna elements and the second data terminal, the third route includes a signal path between the first data terminal and the third data terminal, and the fourth route includes a signal path between the second data terminal and the fourth data terminal.Aspect 23. The wireless communication apparatus of claim1, further comprising: a first diplexer having a merged control signal terminal coupled to the first port, a control terminal, and a first data terminal; a first chain signal port coupled to the first data terminal; a chain control port coupled to the control terminal; a second diplexer having a merged clock signal terminal coupled to the second port, a clock terminal, and a second data terminal; a second chain signal port coupled to the second data terminal; and a clock port coupled to the clock terminal.Aspect 24. A method comprising: generating a first analog data signal and a second analog data signal; generating control data and clock data for the first analog data signal and the second analog data signal; merging, by an intermediate frequency (IF) transceiver, the control data and the first analog data signal to generate a merged control and data signal; merging, by the IF transceiver, the clock data and the second analog data signal to generate a merged clock and data signal; and communicating the first analog data signal and the second analog data signal between the IF transceiver and a target mmW transceiver via a daisy chain routing, wherein the daisy chain routing comprises at least a first mmW transceiver in the daisy chain routing between the IF transceiver and the target mmW transceiver.Aspect 25. The method of aspect 24, further comprising: splitting the merged control and data signal using a first diplexer of a first mmW transceiver between the IF transceiver and the target mmW transceiver; splitting the merged clock and data signal using a second diplexer of a first mmW transceiver between the IF transceiver and the target mmW transceiver; and routing, by the first mmW transceiver, the clock signal, the control signal, the first analog data signal, and the second analog data signal to the target mmW transceiver.Aspect 26. The method of any of aspects 24 through 25, further comprising: receiving a third analog data signal, a fourth analog data signal, a second control signal, and a second clock signal at one or more antennas of the target mmW transceiver; and downconverting the third analog data signal and the fourth analog data signal from mmW frequencies to IF frequencies using frequency conversion circuitry of the target mmW transceiver.Aspect 27. The method of aspect 26, further comprising: communicating the third analog data signal, a fourth analog data signal, the second control signal, and the second clock signal to the first mmW transceiver from the target mmW transceiver; merging, by a first diplexer of the first mmW transceiver, the second control signal and the third analog data signal to generate a second merged control and data signal; and merging, by a second diplexer of the first mmW transceiver, the clock data and the second analog data signal to generate a second merged clock and data signal.Aspect 28. The method of aspect 27, further comprising: communicating the second merged control and data signal and the second merged clock and data signal from the first mmW transceiver to the IF transceiver; generating, by the IF transceiver, the second analog data signal using the second merged control and data signal and the second merged clock and data signal; converting the second analog data signal to a second digital data signal using an analog to digital converter coupled to the IF transceiver; and processing the second digital data signal using a processor coupled to the analog to digital converter.Aspect 29. A wireless communication apparatus, comprising: a first millimeter wave (mmW) transceiver; and a second mmW transceiver coupled to the first mmW transceiver via a daisy chain routing path; the first mmW transceiver comprising: a plurality of intermediate frequency (IF) transceiver connection ports; one or more antenna elements; and switching circuitry configured to select between connecting the plurality of IF transceiver connection ports to the one or more antenna elements and connecting the plurality of IF transceiver connection ports to the second mmW transceiver via the daisy chain routing path.Aspect 30. The wireless communication apparatus of aspect 29, wherein the first mmW transceiver further comprises: a first diplexer coupled to a first port of the plurality of IF transceiver connection ports, a first data port of the second mmW transceiver, and a control port of the second mmW transceiver; wherein the first diplexer is configured for two-way operation to convert between a merged control and data signal communicated with an IF transceiver via the first port and separate control and first data signals communicated with the second mmW transceiver via the control port and the first data port; wherein the daisy chain routing path comprises the control port and the first data port.Aspect 31. The wireless communication apparatus any of aspects 29 through 30, wherein the first mmW transceiver further comprises: a second diplexer coupled to a second port of the plurality of IF transceiver connection ports, a second data port of the second mmW transceiver, and a clock port of the second mmW transceiver; wherein the second diplexer is configured for two-way operation to convert between a merged clock and data signal communicated with the IF transceiver via the second port and separate clock and second data signals communicated with the second mmW transceiver via the control port and the second data port; wherein the daisy chain routing path comprises the clock port and the second data port.Aspect 32: A wireless communication apparatus comprising means for transmitting or receiving mmW signals; and means for communicating an IF signal used to generated mmW signals to or from a mmW transceiver via a daisy chain routing.Aspect 33: A wireless communication apparatus comprising means for selecting between the means for transmitting or receiving mmW signals the means for communicating the IF signal used to generated the mmW signals to or from the mmW transceiver via the daisy chain routing.Aspect 34: An apparatus comprising means for performing operations according to any of aspects 1 through 31 above.Aspect 35: A non-transitory computer-readable storage medium comprising instructions stored thereon which, when executed by one or more processors, cause the one or more processors to implement operations according to any of aspects 1 through 31 above. | 80,913 |
11942972 | DETAILED DESCRIPTION OF EMBODIMENTS The following detailed description of certain embodiments presents various descriptions of specific embodiments. However, the innovations described herein can be embodied in a multitude of different ways, for example, as defined and covered by the claims. In this description, reference is made to the drawings where like reference numerals can indicate identical or functionally similar elements. It will be understood that elements illustrated in the figures are not necessarily drawn to scale. Moreover, it will be understood that certain embodiments can include more elements than illustrated in a drawing and/or a subset of the elements illustrated in a drawing. Further, some embodiments can incorporate any suitable combination of features from two or more drawings. The International Telecommunication Union (ITU) is a specialized agency of the United Nations (UN) responsible for global issues concerning information and communication technologies, including the shared global use of radio spectrum. The 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications standard bodies across the world, such as the Association of Radio Industries and Businesses (ARIB), the Telecommunications Technology Committee (TTC), the China Communications Standards Association (CCSA), the Alliance for Telecommunications Industry Solutions (ATIS), the Telecommunications Technology Association (TTA), the European Telecommunications Standards Institute (ETSI), and the Telecommunications Standards Development Society, India (TSDSI). Working within the scope of the ITU, 3GPP develops and maintains technical specifications for a variety of mobile communication technologies, including, for example, second generation (2G) technology (for instance, Global System for Mobile Communications (GSM) and Enhanced Data Rates for GSM Evolution (EDGE)), third generation (3G) technology (for instance, Universal Mobile Telecommunications System (UMTS) and High Speed Packet Access (HSPA)), and fourth generation (4G) technology (for instance, Long Term Evolution (LTE) and LTE-Advanced). The technical specifications controlled by 3GPP can be expanded and revised by specification releases, which can span multiple years and specify a breadth of new features and evolutions. In one example, 3GPP introduced carrier aggregation (CA) for LTE in Release 10. Although initially introduced with two downlink carriers, 3GPP expanded carrier aggregation in Release 14 to include up to five downlink carriers and up to three uplink carriers. Other examples of new features and evolutions provided by 3GPP releases include, but are not limited to, License Assisted Access (LAA), enhanced LAA (eLAA), Narrowband Internet of things (NB-IOT), Vehicle-to-Everything (V2X), and High Power User Equipment (HPUE). 3GPP introduced Phase 1 of fifth generation (5G) technology in Release 15, and introduced Phase 2 of 5G technology in Release 16. Subsequent 3GPP releases will further evolve and expand 5G technology. 5G technology is also referred to herein as 5G New Radio (NR). 5G NR supports or plans to support a variety of features, such as communications over millimeter wave spectrum, beamforming capability, high spectral efficiency waveforms, low latency communications, multiple radio numerology, and/or non-orthogonal multiple access (NOMA). Although such RF functionalities offer flexibility to networks and enhance user data rates, supporting such features can pose a number of technical challenges. The teachings herein are applicable to a wide variety of communication systems, including, but not limited to, communication systems using advanced cellular technologies, such as LTE-Advanced, LTE-Advanced Pro, and/or 5G NR. FIG.1is a schematic diagram of one example of a communication network10. The communication network10includes a macro cell base station1, a small cell base station3, and various examples of user equipment (UE), including a first mobile device2a, a wireless-connected car2b, a laptop2c, a stationary wireless device2d, a wireless-connected train2e, a second mobile device2f, and a third mobile device2g. Although specific examples of base stations and user equipment are illustrated inFIG.1, a communication network can include base stations and user equipment of a wide variety of types and/or numbers. For instance, in the example shown, the communication network10includes the macro cell base station1and the small cell base station3. The small cell base station3can operate with relatively lower power, shorter range, and/or with fewer concurrent users relative to the macro cell base station1. The small cell base station3can also be referred to as a femtocell, a picocell, or a microcell. Although the communication network10is illustrated as including two base stations, the communication network10can be implemented to include more or fewer base stations and/or base stations of other types. Although various examples of user equipment are shown, the teachings herein are applicable to a wide variety of user equipment, including, but not limited to, mobile phones, tablets, laptops, IoT devices, wearable electronics, customer premises equipment (CPE), wireless-connected vehicles, wireless relays, and/or a wide variety of other communication devices. Furthermore, user equipment includes not only currently available communication devices that operate in a cellular network, but also subsequently developed communication devices that will be readily implementable with the inventive systems, processes, methods, and devices as described and claimed herein. The illustrated communication network10ofFIG.1supports communications using a variety of cellular technologies, including, for example, 4G LTE and 5G NR. In certain implementations, the communication network10is further adapted to provide a wireless local area network (WLAN), such as WiFi. Although various examples of communication technologies have been provided, the communication network10can be adapted to support a wide variety of communication technologies. Various communication links of the communication network10have been depicted inFIG.1. The communication links can be duplexed in a wide variety of ways, including, for example, using frequency-division duplexing (FDD) and/or time-division duplexing (TDD). FDD is a type of radio frequency communications that uses different frequencies for transmitting and receiving signals. FDD can provide a number of advantages, such as high data rates and low latency. In contrast, TDD is a type of radio frequency communications that uses about the same frequency for transmitting and receiving signals, and in which transmit and receive communications are switched in time. TDD can provide a number of advantages, such as efficient use of spectrum and variable allocation of throughput between transmit and receive directions. In certain implementations, user equipment can communicate with a base station using one or more of 4G LTE, 5G NR, and WiFi technologies. In certain implementations, enhanced license assisted access (eLAA) is used to aggregate one or more licensed frequency carriers (for instance, licensed 4G LTE and/or 5G NR frequencies), with one or more unlicensed carriers (for instance, unlicensed WiFi frequencies). As shown inFIG.1, the communication links include not only communication links between UE and base stations, but also UE to UE communications and base station to base station communications. For example, the communication network10can be implemented to support self-fronthaul and/or self-backhaul. The communication links can operate over a wide variety of frequencies. In certain implementations, communications are supported using 5G NR technology over one or more frequency bands that are less than 6 Gigahertz (GHz) and/or over one or more frequency bands that are greater than 6 GHz. For example, the communication links can serve Frequency Range 1 (FR1), Frequency Range 2 (FR2), or a combination thereof. For example, 5G NR can operate with different specifications across frequency bands for 5G, including with flexible numerology compared with fixed numerology for 4G. FR1 (400 MHz to 7125 MHz) bands operate with numerology subcarrier spacing of 15 kHz, 30 kHz and 60 kHz. Additionally, FR2 includes FR2-1 (24 GHz to 52 GHz) and FR2-2 (52 GHz to 71 GHz) and operates with numerology subcarrier spacing of 60 kHz, 120 kHz and 240 kHz to be able to handle higher phase noise and Doppler effects (for instance, for train applications up to 500 km/h). In certain implementations, a base station and/or user equipment communicates using beamforming. For example, beamforming can be used to focus signal strength to overcome path losses, such as high loss associated with communicating over high signal frequencies. In certain embodiments, user equipment, such as one or more mobile phones, communicate using beamforming on millimeter wave frequency bands in the range of 30 GHz to 300 GHz and/or upper centimeter wave frequencies in the range of 6 GHz to 30 GHz, or more particularly, 24 GHz to 30 GHz. In one embodiment, one or more of the mobile devices support a HPUE power class specification. Different users of the communication network10can share available network resources, such as available frequency spectrum, in a wide variety of ways. In one example, frequency division multiple access (FDMA) is used to divide a frequency band into multiple frequency carriers. Additionally, one or more carriers are allocated to a particular user. Examples of FDMA include, but are not limited to, single carrier FDMA (SC-FDMA) and orthogonal FDMA (OFDMA). OFDMA is a multicarrier technology that subdivides the available bandwidth into multiple mutually orthogonal narrowband subcarriers, which can be separately assigned to different users. Other examples of shared access include, but are not limited to, time division multiple access (TDMA) in which a user is allocated particular time slots for using a frequency resource, code division multiple access (CDMA) in which a frequency resource is shared amongst different users by assigning each user a unique code, space-divisional multiple access (SDMA) in which beamforming is used to provide shared access by spatial division, and non-orthogonal multiple access (NOMA) in which the power domain is used for multiple access. For example, NOMA can be used to serve multiple users at the same frequency, time, and/or code, but with different power levels. Enhanced mobile broadband (eMBB) refers to technology for growing system capacity of LTE networks. For example, eMBB can refer to communications with a peak data rate of at least 10 Gbps and a minimum of 100 Mbps for each user. Ultra-reliable low latency communications (uRLLC) refers to technology for communication with very low latency, for instance, less than 2 milliseconds. uRLLC can be used for mission-critical communications such as for autonomous driving and/or remote surgery applications. Massive machine-type communications (mMTC) refers to low cost and low data rate communications associated with wireless connections to everyday objects, such as those associated with Internet of Things (IoT) applications. The communication network10ofFIG.1can be used to support a wide variety of advanced communication features, including, but not limited to, eMBB, uRLLC, and/or mMTC. FIG.2Ais a schematic diagram of one example of a communication link using carrier aggregation. Carrier aggregation can be used to widen bandwidth of the communication link by supporting communications over multiple frequency carriers, thereby increasing user data rates and enhancing network capacity by utilizing fragmented spectrum allocations. In the illustrated example, the communication link is provided between a base station21and a mobile device22. As shown inFIG.2A, the communications link includes a downlink channel used for RF communications from the base station21to the mobile device22, and an uplink channel used for RF communications from the mobile device22to the base station21. AlthoughFIG.2Aillustrates carrier aggregation in the context of FDD communications, carrier aggregation can also be used for TDD communications. In certain implementations, a communication link can provide asymmetrical data rates for a downlink channel and an uplink channel. For example, a communication link can be used to support a relatively high downlink data rate to enable high speed streaming of multimedia content to a mobile device, while providing a relatively slower data rate for uploading data from the mobile device to the cloud. In the illustrated example, the base station21and the mobile device22communicate via carrier aggregation, which can be used to selectively increase bandwidth of the communication link. Carrier aggregation includes contiguous aggregation, in which contiguous carriers within the same operating frequency band are aggregated. Carrier aggregation can also be non-contiguous, and can include carriers separated in frequency within a common band or in different bands. In the example shown inFIG.2A, the uplink channel includes three aggregated component carriers fUL1, fUL2, and fUL3. Additionally, the downlink channel includes five aggregated component carriers fDL1, fDL2, fDL3, fDL4, and fDL5. Although one example of component carrier aggregation is shown, more or fewer carriers can be aggregated for uplink and/or downlink. Moreover, a number of aggregated carriers can be varied over time to achieve desired uplink and downlink data rates. For example, a number of aggregated carriers for uplink and/or downlink communications with respect to a particular mobile device can change over time. For example, the number of aggregated carriers can change as the device moves through the communication network and/or as network usage changes over time. FIG.2Billustrates various examples of uplink carrier aggregation for the communication link ofFIG.2A.FIG.2Bincludes a first carrier aggregation scenario31, a second carrier aggregation scenario32, and a third carrier aggregation scenario33, which schematically depict three types of carrier aggregation. The carrier aggregation scenarios31-33illustrate different spectrum allocations for a first component carrier fUL1, a second component carrier fUL2, and a third component carrier fUL3. AlthoughFIG.2Bis illustrated in the context of aggregating three component carriers, carrier aggregation can be used to aggregate more or fewer carriers. Moreover, although illustrated in the context of uplink, the aggregation scenarios are also applicable to downlink. The first carrier aggregation scenario31illustrates intra-band contiguous carrier aggregation, in which component carriers that are adjacent in frequency and in a common frequency band are aggregated. For example, the first carrier aggregation scenario31depicts aggregation of component carriers fUL1, fUL2, and fUL3that are contiguous and located within a first frequency band BAND1. With continuing reference toFIG.2B, the second carrier aggregation scenario32illustrates intra-band non-continuous carrier aggregation, in which two or more components carriers that are non-adjacent in frequency and within a common frequency band are aggregated. For example, the second carrier aggregation scenario32depicts aggregation of component carriers fUL1, fUL2, and fUL3that are non-contiguous, but located within a first frequency band BAND1. The third carrier aggregation scenario33illustrates inter-band non-contiguous carrier aggregation, in which component carriers that are non-adjacent in frequency and in multiple frequency bands are aggregated. For example, the third carrier aggregation scenario33depicts aggregation of component carriers fUL1and fUL2of a first frequency band BAND1 with component carrier fUL3of a second frequency band BAND2. FIG.2Cillustrates various examples of downlink carrier aggregation for the communication link ofFIG.2A. The examples depict various carrier aggregation scenarios34-38for different spectrum allocations of a first component carrier fDL1, a second component carrier fDL2, a third component carrier fDL3, a fourth component carrier fDL4, and a fifth component carrier fDL5. AlthoughFIG.2Cis illustrated in the context of aggregating five component carriers, carrier aggregation can be used to aggregate more or fewer carriers. Moreover, although illustrated in the context of downlink, the aggregation scenarios are also applicable to uplink. The first carrier aggregation scenario34depicts aggregation of component carriers that are contiguous and located within the same frequency band. Additionally, the second carrier aggregation scenario35and the third carrier aggregation scenario36illustrates two examples of aggregation that are non-contiguous, but located within the same frequency band. Furthermore, the fourth carrier aggregation scenario37and the fifth carrier aggregation scenario38illustrates two examples of aggregation in which component carriers that are non-adjacent in frequency and in multiple frequency bands are aggregated. As a number of aggregated component carriers increases, a complexity of possible carrier aggregation scenarios also increases. With reference toFIGS.2A-2C, the individual component carriers used in carrier aggregation can be of a variety of frequencies, including, for example, frequency carriers in the same band or in multiple bands. Additionally, carrier aggregation is applicable to implementations in which the individual component carriers are of about the same bandwidth as well as to implementations in which the individual component carriers have different bandwidths. Certain communication networks allocate a particular user device with a primary component carrier (PCC) or anchor carrier for uplink and a PCC for downlink. Additionally, when the mobile device communicates using a single frequency carrier for uplink or downlink, the user device communicates using the PCC. To enhance bandwidth for uplink communications, the uplink PCC can be aggregated with one or more uplink secondary component carriers (SCCs). Additionally, to enhance bandwidth for downlink communications, the downlink PCC can be aggregated with one or more downlink SCCs. In certain implementations, a communication network provides a network cell for each component carrier. Additionally, a primary cell can operate using a PCC, while a secondary cell can operate using a SCC. The primary and second cells may have different coverage areas, for instance, due to differences in frequencies of carriers and/or network environment. License assisted access (LAA) refers to downlink carrier aggregation in which a licensed frequency carrier associated with a mobile operator is aggregated with a frequency carrier in unlicensed spectrum, such as WiFi. LAA employs a downlink PCC in the licensed spectrum that carries control and signaling information associated with the communication link, while unlicensed spectrum is aggregated for wider downlink bandwidth when available. LAA can operate with dynamic adjustment of secondary carriers to avoid WiFi users and/or to coexist with WiFi users. Enhanced license assisted access (eLAA) refers to an evolution of LAA that aggregates licensed and unlicensed spectrum for both downlink and uplink. Furthermore, NR-U can operate on top of LAA/eLAA over a 5 GHz band (5150 to 5925 MHz) and/or a 6 GHz band (5925 MHz to 7125 MHz). FIG.3Ais a schematic diagram of one example of a downlink channel using multi-input and multi-output (MIMO) communications.FIG.3Bis schematic diagram of one example of an uplink channel using MIMO communications. MIMO communications use multiple antennas for simultaneously communicating multiple data streams over common frequency spectrum. In certain implementations, the data streams operate with different reference signals to enhance data reception at the receiver. MIMO communications benefit from higher SNR, improved coding, and/or reduced signal interference due to spatial multiplexing differences of the radio environment. MIMO order refers to a number of separate data streams sent or received. For instance, MIMO order for downlink communications can be described by a number of transmit antennas of a base station and a number of receive antennas for UE, such as a mobile device. For example, two-by-two (2×2) DL MIMO refers to MIMO downlink communications using two base station antennas and two UE antennas. Additionally, four-by-four (4×4) DL MIMO refers to MIMO downlink communications using four base station antennas and four UE antennas. In the example shown inFIG.3A, downlink MIMO communications are provided by transmitting using M antennas43a,43b,43c, . . .43mof the base station41and receiving using N antennas44a,44b,44c, . . .44nof the mobile device42. Accordingly,FIG.3Aillustrates an example of m×n DL MIMO. Likewise, MIMO order for uplink communications can be described by a number of transmit antennas of UE, such as a mobile device, and a number of receive antennas of a base station. For example, 2×2 UL MIMO refers to MIMO uplink communications using two UE antennas and two base station antennas. Additionally, 4×4 UL MIMO refers to MIMO uplink communications using four UE antennas and four base station antennas. In the example shown inFIG.3B, uplink MIMO communications are provided by transmitting using N antennas44a,44b,44c, . . .44nof the mobile device42and receiving using M antennas43a,43b,43c, . . .43mof the base station41. Accordingly,FIG.3Billustrates an example of n×m UL MIMO. By increasing the level or order of MIMO, data bandwidth of an uplink channel and/or a downlink channel can be increased. MIMO communications are applicable to communication links of a variety of types, such as FDD communication links and TDD communication links. FIG.3Cis schematic diagram of another example of an uplink channel using MIMO communications. In the example shown inFIG.3C, uplink MIMO communications are provided by transmitting using N antennas44a,44b,44c, . . .44nof the mobile device42. Additional a first portion of the uplink transmissions are received using M antennas43a1,43b1,43c1, . . .43m1of a first base station41a, while a second portion of the uplink transmissions are received using M antennas43a2,43b2,43c2, . . .43m2of a second base station41b. Additionally, the first base station41aand the second base station41bcommunication with one another over wired, optical, and/or wireless links. The MIMO scenario ofFIG.3Cillustrates an example in which multiple base stations cooperate to facilitate MIMO communications. FIG.4is a schematic block diagram of one embodiment of a power amplifier system140. The illustrated power amplifier system140includes an RF switching circuit127that includes a series switch transistor125and a shunt switch transistor126. The illustrated power amplifier system140further includes charge pumps122, a level shifter123, a directional coupler124, a power amplifier bias circuit130, a power amplifier132, and a transmitter133. The illustrated transmitter133includes a baseband processor134, an I/Q modulator137, a mixer138, and an analog-to-digital converter (ADC)139. Although not illustrated inFIG.4for clarity, the transmitter133can include circuitry associated with receiving signals over one or more receive paths such that transceiver functionality is achieved. The baseband signal processor134can be used to generate an in-phase (I) signal and a quadrature-phase (Q) signal, which can be used to represent a sinusoidal wave or signal of a desired amplitude, frequency, and phase. For example, the I signal can be used to represent an in-phase component of the sinusoidal wave and the Q signal can be used to represent a quadrature component of the sinusoidal wave, which can be an equivalent representation of the sinusoidal wave. In certain implementations, the I and Q signals can be provided to the I/Q modulator137in a digital format. The baseband processor134can be any suitable processor configured to process a baseband signal. For instance, the baseband processor134can include a digital signal processor, a microprocessor, a programmable core, or any combination thereof. Moreover, in some implementations, two or more baseband processors134can be included in the power amplifier system140. The I/Q modulator137can be configured to receive the I and Q signals from the baseband processor134and to process the I and Q signals to generate an RF signal. For example, the I/Q modulator137can include DACs configured to convert the I and Q signals into an analog format, mixers for upconverting the I and Q signals to radio frequency, and a signal combiner for combining the upconverted I and Q signals into an RF signal suitable for amplification by the power amplifier132. In certain implementations, the I/Q modulator137can include one or more filters configured to filter frequency content of signals processed therein. The power amplifier bias circuit130can receive one or more control signals from the baseband processor134, which can be used to generate one or more bias signals for the power amplifier132. The control signals can include, for example, bias settings or levels and/or enable functionality. The power amplifier132can receive the RF signal from the I/Q modulator137of the transmitter133. The level shifter123can turn on and off the series switch transistor125and the shunt switch transistor126in a complementary manner. For example, the level shifter123can be used to turn on the series switch transistor125and turn off the shunt switch transistor126such that the power amplifier132provides an amplified RF signal to the antenna114through the series switch transistor125. Additionally, the level shifter123can be used to turn off the series switch transistor125and turn on the shunt switch transistor126to provide a high impedance path between the output of the power amplifier132and the antenna114while providing termination to the power amplifier's output. To control a state of the RF switching circuit127, the level shifter123can receive a switch enable signal (not illustrated inFIG.4) from any suitable circuitry, such as the transmitter133. The directional coupler124can be positioned between the output of the power amplifier132and the source of the series switch transistor125, thereby allowing an output power measurement of the power amplifier132that does not include insertion loss of the series switch transistor125. The sensed output signal from the directional coupler124can be provided to the mixer138, which can multiply the sensed output signal by a reference signal of a controlled frequency so as to downshift the frequency content of the sensed output signal to generate a downshifted signal. The downshifted signal can be provided to the ADC139, which can convert the downshifted signal to a digital format suitable for processing by the baseband processor134. By including a feedback path between the output of the power amplifier132and the baseband processor134, the baseband processor134can be configured to dynamically adjust the I and Q signals to optimize the operation of the power amplifier system140. For example, configuring the power amplifier system140in this manner can aid in controlling the power added efficiency (PAE) and/or linearity of the power amplifier132. In the illustrated configuration, the charge pumps122provide a positive charge pump voltage and a negative charge pump voltage to the level shifter123. In certain configurations (for instance, when the switches are implemented using n-type transistors), the positive charge pump voltage is used to bias the gate voltage of the series switch transistor125and/or the shunt switch transistor126when turned on, while the negative charge pump voltage is used to bias the gate voltage of the series switch transistor125and/or the shunt switch transistor126when turned off. Although the series switch transistor125and the shunt switch transistor126are each depicted as a single transistor, typically a stack of transistors is used to implement each of the series switch transistor125and the shunt switch transistor126. For example, stacking transistors aids in meeting a desired power handling capability. Furthermore, certain biasing details of the series switch transistor125and the shunt switch transistor126, such as gate resistors and other biasing, are not depicted inFIG.4for clarity of the drawing. FIG.5Ais a circuit diagram of one embodiment of a level shifter210. The level shifter210includes a first n-type metal oxide semiconductor (NMOS) level-shifting transistor171, a second NMOS level-shifting transistor172, a third NMOS level-shifting transistor173, a fourth NMOS level-shifting transistor174, a first NMOS cascode transistor181, a second NMOS cascode transistor182, a first p-type metal oxide semiconductor (PMOS) level-shifting transistor191, a second PMOS level-shifting transistor192, a first PMOS cascode transistor193, a second PMOS cascode transistor194, a third PMOS cascode transistor195, a fourth PMOS cascode transistor196, a first enable level shifter207, and a second enable level shifter208. In the illustrated embodiment, the level shifter210receives a switch enable signal SWEN, an inverted switch enable signal SWENB, a regulated voltage VREG(from a voltage regulator, such as a low dropout regulator), a negative charge pump voltage VNEG(from a negative charge pump), and a positive charge pump voltage VPOS(from a positive charge pump). The level shifter210includes a non-inverted switch control output SWCTLand an inverted switch control output SWCTLBfor generating switch controls signals of complementary polarity for controlling an RF switching circuit (for instance, one for controlling a series switch and another for controlling a shunt switch as in the configuration ofFIG.4). Although both outputs are used in certain applications, in other implementations only one of the level shifter's outputs is used. The first enable level shifter207level shifts the switch enable signal SWENto generate a level-shifted switch enable signal in a voltage domain of the positive charge pump (the first enable level shifter207and the second enable level shifter208are powered by VPOSand ground). Additionally, the second enable level shifter208level shifts the inverted switch enable signal SWENBto generate a level-shifted inverted switch enable signal in the voltage domain of the positive charge pump. Although shown as receiving a pair of switch enable signals of complementary polarity, in another embodiment the level shifter210receives a single switch enable signal, which can be inverted (for instance, using an inverter) to generate the pair of switch enable signals. As shown inFIG.5A, the first NMOS level-shifting transistor171and the first NMOS cascode transistor181are in series (from source to drain) between the negative chare pump voltage VNEGand the inverted switch control output SWCTLB, while the first PMOS level-shifting transistor191and the first PMOS cascode transistor193are in series (from source to drain) between the positive charge pump voltage VPOSand the inverted switch control output SWCTLB. Furthermore, the fourth NMOS level-shifting transistor174and the second NMOS cascode transistor182are in series (from source to drain) between the negative charge pump voltage VNEGand the non-inverted switch control output SWCTL, while the second PMOS level-shifting transistor192and the fourth PMOS cascode transistor196are in series (from source to drain) between the positive charge pump voltage VPOSand the non-inverted switch control output SWCTL. In the illustrated embodiment, the gate of first NMOS level-shifting transistor171and the gate of the third NMOS level-shifting transistor173are connected to a drain of the second NMOS level-shifting transistor172. Additionally, the gate of second NMOS level-shifting transistor172and the gate of the fourth NMOS level-shifting transistor174are connected to a drain of the third NMOS level-shifting transistor173. The gates and drains of the second NMOS level-shifting transistor172and the third NMOS level-shifting transistor173are cross-coupled. The gate of the first NMOS cascode transistor181and the gate of the second NMOS cascode transistor182are connected to the regulated voltage VREG. Additionally, the gate of the second PMOS cascode transistor194is controlled by the switch enable signal SWEN, while the gate of the third PMOS cascode transistor195is controlled by the inverted switch enable signal SWENB. The gate of first PMOS cascode transistor193and the fourth PMOS cascode transistor196are grounded. Additionally, the gate of first PMOS level-shifting transistor191receives the level-shifted inverted switch enable signal, while the gate of the second PMOS level-shifting transistor192receives the level-shifted switch enable signal. The level shifter210provides a number of advantages, including low current draw from the charge pump voltages VPOSand VNEG, low voltage headroom, and robust latching (of cross-coupled transistors172and173) during low voltage operation. Moreover, the regulated voltage VREGis low impedance to maintain robust operation, and also is active quickly after start-up. Thus, the level shifter210is associated with fast start-up time, and can perform level-shifting even when the charge pump voltages VPOSand/or VNEGare not at a steady-state value, such as shortly after power supply sequencing and/or start-up. FIG.5Bis a graph of one example of waveforms for the level shifter210ofFIG.5A. The graph includes waveforms of the positive charge pump voltage VPOS, the negative charge pump voltage VNEG, the switch control output SWCTL, and the inverted switch control output SWCTLBfor an example in which the positive and negative charge pumps drive many level shifters and suffer from large current draws at certain time instances (at about 12 microseconds (μs) and 27 μs in this simulation) associated with changing the state of the switches, for instance, at end of the transmit or receive time slot in a time-division duplexing (TDD) application. As shown inFIG.5B, even in the presence of large current draws on the charge pump supplies, the level shifter210continues to properly operate. FIG.6is a schematic diagram of one embodiment of a charge pump220. The charge pump220includes a first group of clock inverters211a/212a/213a, a second group of clock inverters211b/212b/213b, a first flying capacitor Cfly1, a second flying capacitor Cfly2, a first NMOS transistor215, a second NMOS transistor216, a first PMOS transistor217, and a second PMOS transistor218. With continuing reference toFIG.6, the charge pump220includes a first clock input CLK for receiving a non-inverted clock signal for driving the first group of clock inverters211a/212a/213a, and a second clock input CLK_B for receiving an inverted clock signal for driving the second group of clock inverters211b/212b/213b. The first group of clock inverters211a/212a/213aare sized to buffer the non-inverted clock signal to provide a drive strength sufficient for driving a first end of the first flying capacitor Cfly1. Similarly, the second group of clock inverters211b/212b/213bare sized to buffer the inverted clock signal to provide a drive strength sufficient for driving a first end of the second flying capacitor Cfly2. The clock inverter groups can include any suitable number of inverters, and can be scaled (1×, 4×, and 12×, in this example) in any suitable manner. Thus, although an example with three inverts with a 4× scaling is shown, more or fewer inverters and/or a different scaling can be used. In certain implementations, the buffered clock signals used to drive the flying capacitors correspond to a pair of non-overlapping clock signals. As shown inFIG.6, the charge pump220includes a first terminal VP and a second terminal VN. Based on the connectivity of the first terminal VP and the second terminal VN, the charge pump220can serve as either a positive charge pump (generating VPOSat the first terminal VP with a boosted voltage relative to the second terminal VN, for instance, connected to a normal supply voltage provided to a pin of the die) or a negative charge pump (generating VNEGat the second terminal VN with a reduced or buck voltage relative to the first terminal VP, for instance, connected to ground). FIG.7Ais a schematic diagram of one embodiment of a charge pump clock generator230. The charge pump clock generator230includes a multi-phase oscillator (corresponding to a seven phase ring oscillator221, in this example). The charge pump clock generator230further includes a clock phase logic circuit222(implemented as AND gates222a,222b,222c,222d,222e,222f, and222g, in this example) and a clock phase combining circuit223. In the illustrated embodiment, the ring oscillator221generates clock signals clk<1>, clk<2>, clk<3>, clk<4>, clk<5>, clk<6>, and clk<7>, which are of common frequency but of different (for instance, evenly separated) phases. Additionally, the AND gates222a,222b,222c,222d,222e,222f, and222gperform logical operations on adjacent clock signal phases to generate clock phase signals ph1, ph2, ph3, ph4, ph5, ph6, and ph7, which are processed by the phase combining circuit223to generate a clock signal CLK of multiplied frequency relative to the oscillation frequency of the ring oscillator221. In this example, the AND gates each operate with a respective enable signal EN1, EN2, EN3, EN4, EN5, EN6, and EN7 to selectively enable one or more of the clock phase signals ph1, ph2, ph3, ph4, ph5, ph6, and ph7, respectively. The charge pump clock generator230advantageously synthesizes a clock signal of higher frequency than the oscillator221. This in turn reduces frequency spurs and/or undesired clock noise in a charge pump output voltage (for instance, VPOSor VNEG) that is generated by a charge pump that uses the clock signal to control pumping. FIG.7Bis a schematic diagram of one embodiment of frequency multiplying logic240for a charge pump clock generator. The frequency multiplying logic240includes a clock phase logic circuit232(implemented as AND gates232a,232b,232c,232d,232e,232f,232g,232h, and232i, in this example) and a clock phase combining circuit233(implemented as OR gates233a,233b,234, and235, in this example). In the illustrated embodiment, the clock phase logic circuit processes nine clock signals (CLK<1>, CLK <2>, CLK <3>, CLK <4>, CLK <5>, CLK <6>, CLK <7>, CLK <8>, and CLK <9>) from a multi-phase oscillator (for instance, a ring oscillator) to generate clock signal phases CLK_a<1>, CLK_a<2>, CLK_a<3>, CLK_a<4>, CLK_a<5>, CLK_a<6>, CLK_a<7>, CLK_a<8>, and CLK_a<9>. The phase combining circuit233performs a logical OR of the clock signal phases to generate a boosted clock signal FCLK_BOOST of higher frequency than that of the received clock signals from the multi-phase oscillator. FIG.7Cis a graph of one example of waveforms for positive and negative charge pumps operating at different clock frequencies. As shown by the waveforms, faster clock speed is advantageous for providing a charge pump with higher output drive capability and/or initial ramp-up time. Although fast clock speed is desirable, frequency spurs and/or undesired clock noise is introduced when using a fast oscillator. By synthesizing a faster clock signal for a charge pump using a slower running oscillator in accordance with the teachings herein, the benefits of fast pumping, small frequency spurs, and/or low clock noise are achieved. FIG.8Ais a schematic diagram of another embodiment of a charge pump clock generator250. The charge pump clock generator250includes a multi-phase oscillator (corresponding to a seven phase ring oscillator241, in this example). The charge pump clock generator230further includes a clock phase logic and combining circuit242(implemented as exclusive OR gates242a,242b, and242c, in this example). The clock phase logic and combining circuit242processes the oscillator clock signals from the multi-phase oscillator to generate a first multiplied clock signal (CLK_DBL<1> or pvg) for driving a positive charge pump (for example, CLK_DBL<1> can be inverted to generate a pair of input clock signals CLK and CLKB to the charge pump220ofFIG.6) and a second multiplied clock signal (CLK_DBL<3> or nvg) for driving a negative charge pump. Advantageously, the first multiplied clock signal and the second multiplied clock signal are of common frequency, but offset in phase to spread out the time instances of current draw of the positive charge pump and the negative charge pump. Thus, enhanced performance is achieved relative to a configuration in which the clock signals to the positive charge pump and the negative charge pump are of the same phase (phase-aligned). FIG.8Bis a schematic diagram of another embodiment of frequency multiplying logic260for a charge pump clock generator. In this example, XOR gates251and252are used to process clock signal phases (CLK<1>, CLK<3>, CLK<5>, and CLK<8>) to synthesize clock signals CLK_DBL1 and CLK_DBL2, respectively, of double frequency (doubling). Additionally, OR gate253is used to process the clock signals CLK_DBL1 and CLK_DBL2 to generate a clock signal CLK_4× of four times the frequency (frequency quadrupling) relative to the original clock signal phases (CLK<1>, CLK<3>, CLK<5>, and CLK<8>). FIG.8Cis a graph of one example of waveforms for a charge pump clock generator. The waveforms correspond to a charge pump clock generator that including the frequency multiplying logic260ofFIG.8B. As shown inFIG.8C, frequency quadrupling is achieved. FIG.9is a schematic block diagram of an RF switch system290according to one embodiment. The RF switch system290includes RF switches291a,291b, . . .291n, a switch controller292, a positive charge pump293that generates a positive charge pump voltage VPOS, a negative charge pump294that generates a negative charge pump voltage VNEG, and a charge pump clock generator295. As shown inFIG.9, the switch controller292includes a voltage regulator (corresponding to a low dropout regulator297, in this example) that generates a regulated voltage VREG, and level shifters298a,298b, . . .298n. The level shifters298a,298b, . . .298noperate to level shift the switch enable signals SWENa, SWENb, . . . SWENnto generate the switch control signals SWCTLa, SWCTLb, . . . SWCTLnfor the RF switches291a,291b, . . .291n, respectively. As shown inFIG.9, the level shifters298a,298b, . . .298neach receive the regulated voltage VREG, the positive charge pump voltage VPOS, and the negative charge pump voltage VNEG. Additionally, the charge pump clock generator295generates clock signals for the positive charge pump293and the negative charge pump294. The level shifters298a,298b, . . .298nand/or the charge pump clock generator295can be implemented in accordance with any of the embodiments herein. Although the illustrated RF switch system290includes three level shifters and three switches, any number of level shifters and switches can be included. FIG.10Ais a schematic diagram of one embodiment of a packaged module300.FIG.10Bis a schematic diagram of a cross-section of the packaged module300ofFIG.10Ataken along the lines10B-10B. The packaged module300includes an IC or die301, surface mount components303, wirebonds308, a package substrate320, and encapsulation structure340. The package substrate320includes pads306formed from conductors disposed therein. Additionally, the die301includes pads304, and the wirebonds308have been used to electrically connect the pads304of the die301to the pads306of the package substrate301. As illustrated inFIGS.10A and10B, the die301includes charge pumps122, level shifter123, and switches127, which can be as described earlier. The packaging substrate320can be configured to receive a plurality of components such as the die301and the surface mount components303, which can include, for example, surface mount capacitors and/or inductors. As shown inFIG.10B, the packaged module300is shown to include a plurality of contact pads332disposed on the side of the packaged module300opposite the side used to mount the die301. Configuring the packaged module300in this manner can aid in connecting the packaged module300to a circuit board such as a phone board of a wireless device. The example contact pads332can be configured to provide RF signals, bias signals, power low voltage(s) and/or power high voltage(s) to the die301and/or the surface mount components303. As shown inFIG.10B, the electrically connections between the contact pads332and the die301can be facilitated by connections333through the package substrate320. The connections333can represent electrical paths formed through the package substrate320, such as connections associated with vias and conductors of a multilayer laminated package substrate. In some embodiments, the packaged module300can also include one or more packaging structures to, for example, provide protection and/or facilitate handling of the packaged module300. Such a packaging structure can include overmold or encapsulation structure340formed over the packaging substrate320and the components and die(s) disposed thereon. It will be understood that although the packaged module300is described in the context of electrical connections based on wirebonds, one or more features of the present disclosure can also be implemented in other packaging configurations, including, for example, flip-chip configurations. FIG.11is a schematic diagram of an RF switch network420according to another embodiment. The RF switch network420includes a first series transistor switch361, a second series transistor switch365, a first input shunt transistor switch381, a second input shunt transistor switch385, a first output shunt transistor switch401, and a second output shunt transistor switch405. The RF switch network420ofFIG.11illustrates another embodiment of an RF switch network suitable for use in an RF switch system, such as the RF switch system120ofFIG.4. However other implementations are possible, including, but not limited, RF switch networks including more or fewer series transistor switches and/or more or fewer shunt transistor switches. In the illustrated embodiment, the first series transistor switch361is electrically connected between a first RF input terminal RF_IN1 and an RF output terminal RF_OUT, and the second series transistor switch365is electrically connected between a second RF input terminal RF_IN2 and the RF output terminal RF_OUT. Additionally, the first input shunt transistor switch381is electrically connected between the first RF input terminal RF_IN1 and ground, and the second input shunt transistor385is electrically between the second RF input terminal RF_IN2 and ground. Furthermore, the first output shunt transistor switch401is electrically connected between the RF output terminal RF_OUT and ground, and the second output shunt transistor switch405is electrically connected between the RF output terminal RF_OUT and ground. As shown inFIG.11, a first switch control voltage VCTL1controls the first series transistor switch361, and a first inverted switch control voltage VCTL1Bcontrols the first input shunt transistor switch381and the first output shunt transistor switch401. Furthermore, a second switch control voltage VCTL2controls the second series transistor switch365, and a second inverted switch control voltage VCTL2Bcontrols the second input shunt transistor switch385and the second output shunt transistor switch405. In certain implementations, a first level shifter generates the first switch control voltage VCTL1and the first inverted switch control voltage VCTL1B, while a second level shifter generates the second switch control voltage VCTL2and the second inverted switch control voltage VCTL2B. The depicted transistor switches each include a number of transistors in series to achieve a desired power handling capability, with the transistors biased used corresponding gate resistors and channel resistors. For example, the first series transistor switch361includes NFETs371a,371b, . . .371n, gate resistors372a,372b, . . .372n, and channel resistors373a,373b, . . .373n. Additionally, the second series transistor switch365includes NFETs375a,375b, . . .375n, gate resistors376a,376b, . . .376n, and channel resistors377a,377b, . . .377n. Furthermore, the first input shunt transistor switch381includes NFETs391a,391b, gate resistors392a,392b, and channel resistors393a,393b. Additionally, the second input shunt transistor switch385includes NFETs395a,395b, gate resistors396a,396b, and channel resistors397a,397b. Furthermore, the first output shunt transistor switch401includes NFETs411a,411b, gate resistors412a,412b, and channel resistors413a,413b. Additionally, the second output shunt transistor switch405includes NFETs415a,415b, gate resistors416a,416b, and channel resistors417a,417b. FIG.12is a schematic diagram of one embodiment of a mobile device800. The mobile device800includes a baseband system801, a transceiver802, a front end system803, antennas804, a power management system805, a memory806, a user interface807, and a battery808. The mobile device800can be used communicate using a wide variety of communications technologies, including, but not limited to, 2G, 3G, 4G (including LTE, LTE-Advanced, and LTE-Advanced Pro), 5G NR, WLAN (for instance, WiFi), WPAN (for instance, Bluetooth and ZigBee), WMAN (for instance, WiMax), and/or GPS technologies. The transceiver802generates RF signals for transmission and processes incoming RF signals received from the antennas804. It will be understood that various functionalities associated with the transmission and receiving of RF signals can be achieved by one or more components that are collectively represented inFIG.12as the transceiver802. In one example, separate components (for instance, separate circuits or dies) can be provided for handling certain types of RF signals. The front end system803aids is conditioning signals transmitted to and/or received from the antennas804. In the illustrated embodiment, the front end system803includes level shifters810, power amplifiers (PAs)811, low noise amplifiers (LNAs)812, filters813, switches814, and signal splitting/combining circuitry815. However, other implementations are possible. For example, the front end system803can provide a number of functionalities, including, but not limited to, amplifying signals for transmission, amplifying received signals, filtering signals, switching between different bands, switching between different power modes, switching between transmission and receiving modes, duplexing of signals, multiplexing of signals (for instance, diplexing or triplexing), or some combination thereof. In certain implementations, the mobile device800supports carrier aggregation, thereby providing flexibility to increase peak data rates. Carrier aggregation can be used for both Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD), and may be used to aggregate a plurality of carriers or channels. Carrier aggregation includes contiguous aggregation, in which contiguous carriers within the same operating frequency band are aggregated. Carrier aggregation can also be non-contiguous, and can include carriers separated in frequency within a common band or in different bands. The antennas804can include antennas used for a wide variety of types of communications. For example, the antennas804can include antennas for transmitting and/or receiving signals associated with a wide variety of frequencies and communications standards. In certain implementations, the antennas804support MIMO communications and/or switched diversity communications. For example, MIMO communications use multiple antennas for communicating multiple data streams over a single radio frequency channel. MIMO communications benefit from higher signal to noise ratio, improved coding, and/or reduced signal interference due to spatial multiplexing differences of the radio environment. Switched diversity refers to communications in which a particular antenna is selected for operation at a particular time. For example, a switch can be used to select a particular antenna from a group of antennas based on a variety of factors, such as an observed bit error rate and/or a signal strength indicator. The mobile device800can operate with beamforming in certain implementations. For example, the front end system803can include amplifiers having controllable gain and phase shifters having controllable phase to provide beam formation and directivity for transmission and/or reception of signals using the antennas804. For example, in the context of signal transmission, the amplitude and phases of the transmit signals provided to the antennas804are controlled such that radiated signals from the antennas804combine using constructive and destructive interference to generate an aggregate transmit signal exhibiting beam-like qualities with more signal strength propagating in a given direction. In the context of signal reception, the amplitude and phases are controlled such that more signal energy is received when the signal is arriving to the antennas804from a particular direction. In certain implementations, the antennas804include one or more arrays of antenna elements to enhance beamforming. The baseband system801is coupled to the user interface807to facilitate processing of various user input and output (I/O), such as voice and data. The baseband system801provides the transceiver802with digital representations of transmit signals, which the transceiver802processes to generate RF signals for transmission. The baseband system801also processes digital representations of received signals provided by the transceiver802. As shown inFIG.12, the baseband system801is coupled to the memory806of facilitate operation of the mobile device800. The memory806can be used for a wide variety of purposes, such as storing data and/or instructions to facilitate the operation of the mobile device800and/or to provide storage of user information. The power management system805provides a number of power management functions of the mobile device800. In certain implementations, the power management system805includes a PA supply control circuit that controls the supply voltages of the power amplifiers811. For example, the power management system805can be configured to change the supply voltage(s) provided to one or more of the power amplifiers811to improve efficiency, such as power added efficiency (PAE). As shown inFIG.12, the power management system805receives a battery voltage from the battery808. The battery808can be any suitable battery for use in the mobile device800, including, for example, a lithium-ion battery. The mobile device800can include any combination of features of the present disclosure. For example, in certain embodiments, the power management system805includes a positive charge pump that generates a positive charge pump voltage, a negative charge pump that generates a negative charge pump voltage, and a voltage regulator that generates a regulated voltage. Additionally, the front end system803includes an RF switch (of switches814) controlled by a level shifter (of level shifters810) with the level shifter receiving the positive charge pump voltage, the negative charge pump voltage, and the regulated voltage. CONCLUSION Some of the embodiments described above have provided examples in connection with mobile devices. However, the principles and advantages of the embodiments can be used for any other systems or apparatus that have needs for RF switching. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” The word “coupled”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Likewise, the word “connected”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. Moreover, conditional language used herein, such as, among others, “may,” “could,” “might,” “can,” “e.g.,” “for example,” “such as” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment. The above detailed description of embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while processes or blocks are presented in a given order, alternative embodiments may perform routines having steps, or employ systems having blocks, in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and/or modified. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel, or may be performed at different times. The teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure. | 59,794 |
11942973 | DESCRIPTION OF EMBODIMENTS Embodiments of the disclosure will be described in detail below. The embodiments to be described below represent comprehensive or concrete examples. The numerical values, shapes, materials, constituent elements, the arrangement and connection state of the constituent elements to be described in the following embodiments are merely illustrative examples, and are not intended to be limiting. Among the constituent elements included in the following embodiments and the following modifications, those not recited in the independent claims are described as optional constituent elements. The sizes or the ratio of sizes of the constituent elements illustrated in the drawings are not necessarily precise. Throughout the drawings, the same numeral is given to substantially the same element, and redundant description may be omitted or simplified. In the following, a term that indicates a relation between elements such as “parallel” or “perpendicular”, a term that indicates the shape of an element such as “rectangular”, and a numerical range do not necessarily have only strict meanings, and also cover substantially equivalent ranges that include a difference of about several percent, for example. In the following, regarding A, B, and C mounted on a substrate, “C is disposed between A and B in plan view of the substrate (or a principal surface of the substrate)” means a straight line connecting any point in A and any point in B passes through a region of C in the plan view of the substrate. Plan view of a substrate means that the substrate and a circuit element mounted on the substrate are viewed, being orthogonally projected onto a plane parallel to the substrate. Embodiment 1. Circuit Configuration of Radio Frequency Module1and Communication Device5 [1.1 Circuit Configuration of Communication Device5] FIG.1is a diagram illustrating the circuit configuration of a radio frequency module1according to a first embodiment and a communication device5according to the first embodiment. As illustrated inFIG.1, the communication device5includes the radio frequency module1, an antenna2, a radio frequency integrated circuit (RFIC)3, and a baseband integrated circuit (BBIC)4. The radio frequency module1conveys a radio frequency (RF) signal between the antenna2and the RFIC3. The circuit configuration of the radio frequency module1will be described in detail below. The antenna2is connected to antenna connection terminals101,102, and103of the radio frequency module1, transmits a transmission signal output from the radio frequency module1, and outputs an externally received reception signal to the radio frequency module1. The RFIC3is an example of a signal processing circuit (transceiver circuitry) that processes a radio frequency signal that is to be transmitted or has been received by the antenna2. Specifically, the RFIC3performs signal processing such as downconversion upon a radio frequency reception signal input through a reception signal path in the radio frequency module1and outputs a reception signal generated as a result of the signal processing to the BBIC4. The RFIC3performs signal processing such as upconversion upon a transmission signal input from the BBIC4and outputs a radio frequency transmission signal generate as a result of the signal processing to a transmission signal path in the radio frequency module1. The BBIC4is a baseband signal processing circuit that performs signal processing using an intermediate frequency band lower than the frequency band of a radio frequency signal passing through the radio frequency module1. A signal processed by the BBIC4is used as, for example, an image signal for image display or an audio signal for conversation through a speaker. The RFIC3also functions as a control unit (also referred to a controller or control circuitry) that controls the connections of switching circuits30,40, and70in the radio frequency module1on the basis of a communication band used. Specifically, the control unit transmits control signals for the connection switching of the switching circuits30,40, and70in the radio frequency module1to a control circuit90in the radio frequency module1. The control unit transmits control signals for, for example, the adjustment of gains of power amplifiers (PAs)11,12, and13and low-noise amplifiers21,22, and23in the radio frequency module1to the control circuit90and a PA control circuit34. The PA control circuit34is an example of a controller that controls a first transmission amplifier, a second transmission amplifier, and a third transmission amplifier and, in this example, is a power amplifier controller that controls the power amplifiers11,12, and13. The PA control circuit34outputs control signals to the power amplifiers11,12, and13upon receiving a control signal from the control unit. The control circuit90outputs control signals to the switching circuits30,40, and70and the low-noise amplifiers21,22, and23upon receiving a control signal from the control unit. The control circuit90may include the PA control circuit34. The control unit may be provided outside of the RFIC3and, for example, may be provided in the BBIC4. In the communication device5according to this embodiment, the antenna2and the BBIC4are optional features. [1.2 Circuit Configuration of Radio Frequency Module1] Next, the configuration of the radio frequency module1will be described in detail below. As illustrated inFIG.1, the radio frequency module1includes the antenna connection terminals101,102, and103, a first band circuit1A, a second band circuit1B, a third band circuit1C, the PA control circuit34, the control circuit90, transmission input terminals111,112, and113, and reception output terminals121,122, and123. The antenna connection terminals101,102, and103are connected to the antenna2. The first band circuit1A transmits respective radio frequency signals (first transmission signals and first reception signals) in a plurality of first communication bands in a first communication band group. The second band circuit1B transmits respective radio frequency signals (second transmission signals and second reception signals) in a plurality of second communication bands in a second communication band group. The third band circuit1C transmits respective radio frequency signals (third transmission signals and third reception signals) in a plurality of third communication bands in a third communication band group. Each of the first to third communication band groups is, for example, one of a low-band group, a middle-band group, and a high-band group. The first communication band group and the third communication band group may be the same communication band group. In this case, the second communication band group may be different from the first communication band group and the third communication band group. Alternatively, the first communication band group and the third communication band group may be different from each other. In this case, the second communication band group may be the same as one of the first communication band group and the third communication band group. The low-band group is a frequency band group that includes, for example, the frequency range of 0.4 GHz to 1.0 GHz and includes a plurality of communication bands for 4G and 5G. The low-band group includes, as LTE (long term evolution) bands and NR (new radio) bands, for example, B5 and n5 (transmission band: 824 MHz to 849 MHz, reception band: 869 MHz to 894 MHz), B8 and n8 (transmission band: 880 MHz to 915 MHz, reception band: 925 MHz to 960 MHz), B28 and n28 (transmission band: 703 MHz to 748 MHz, reception band: 753 MHz to 803 MHz), and B71 and n71 (transmission band: 663 MHz to 698 MHz, reception band: 617 MHz to 652 MHz). The middle-band group is a frequency band group including a plurality of communication bands for 4G and 5G. The middle-band group is located on the higher-frequency side of the low-band group and has, for example, the frequency range of 1.5 GHz to 2.2 GHz. The middle-band group includes, as LTE bands and NR bands, for example, B1 and n1 (transmission band: 1920 MHz to 1980 MHz, reception band: 2110 MHz to 2170 MHz), B3 and n3 (transmission band: 1710 MHz to 1785 MHz, reception band: 1805 MHz to 1880 MHz), B39 and n39 (transmission and reception bands: 1880 MHz to 1920 MHz), and B66 and n66 (transmission band: 1710 MHz to 1780 MHz, reception band: 2110 MHz to 2200 MHz). The high-band group is a frequency band group including a plurality of communication bands for 4G and 5G. The high-band group is located on the higher-frequency side of the middle-band group and has, for example, the frequency range of 2.3 GHz to 2.8 GHz. The high-band group includes, as LTE bands and NR bands, for example, B7 and n7 (transmission band: 2500 MHz to 2570 MHz, reception band: 2620 MHz to 2690 MHz), B40 and n40 (transmission and reception bands: 2300 MHz to 2400 MHz), and B41 and n41 (transmission and reception bands: 2496 MHz to 2690 MHz). In this example, simultaneous transmission and simultaneous reception can be performed in the combination of the first communication band and the third communication band. That is, the combination of the first communication band and the third communication band enables simultaneous transmission and simultaneous reception. At that time, it is not precluded that each of the first communication band and the third communication band is used alone. Simultaneous transmission and simultaneous reception cannot be performed in the combination of the first communication band and the second communication band and the combination of the second communication band and the third communication band. That is, each of the combination of the first communication band and the second communication band and the combination of the second communication band and the third communication band forbids simultaneous transmission and simultaneous reception. The availability of simultaneous transmission and simultaneous reception in these multiple communication bands is defined in advance by a standardizing organization such as 3GPP (3rd generation partnership project). As the combination of the first communication band and the third communication band, for example, the combination of LTE bands can be used. Specifically, as the combination of the first communication band and the third communication band, for example, the combination of B1 and B3, the combination of B3 and B7, or the combination of B40 and B41 can be used. As the combination of the first communication band and the third communication band, the combination of an LTE band and an NR band can also be used. Specifically, as the combination of the first communication band and the third communication band, for example, the combination of B3 and n3, the combination of B41 and n41, the combination of B71 and n71, or the combination of B1 and n41 can be used. The above combinations of the first communication band and the third communication band are examples, and are optionally included in this exemplary embodiment. As the combination of the first communication band and the third communication band, the combination of NR bands may be used. [1.2.1 Circuit Configuration of First Band Circuit1A] The circuit configuration of the first band circuit1A will be described. The first band circuit1A includes the power amplifier11, the low-noise amplifier21, duplexers61and62, and switches31,41, and71. The power amplifier11is an example of the first transmission amplifier and is a transmission power amplifier that amplifies a transmission signal in the first communication band group. The low-noise amplifier21is an example of a first reception amplifier and is a reception low-noise amplifier that amplifies a reception signal in the first communication band group with low noise. The duplexer61passes a radio frequency signal in one (hereinafter referred to as “communication band A”) of the multiple first communication bands included in the first communication band group. The duplexer61includes a transmission filter61T and a reception filter61R. The transmission filter61T is disposed on a transmission path that connects the power amplifier11and the antenna connection terminal101. The transmission filter61T passes a transmission signal in the transmission band of the communication band A among transmission signals amplified by the power amplifier11. The reception filter61R is disposed on a reception path that connects the low-noise amplifier21and the antenna connection terminal101. The reception filter61R passes a reception signal in the reception band of the communication band A among reception signals input from the antenna connection terminal101. The duplexer62passes a radio frequency signal in another one (hereinafter referred to as “communication band B”) of the multiple first communication bands included in the first communication band group. The duplexer62includes a transmission filter62T and a reception filter62R. The transmission filter62T is disposed on a transmission path that connects the power amplifier11and the antenna connection terminal101. The transmission filter62T passes a transmission signal in the transmission band of the communication band B among transmission signals amplified by the power amplifier11. The reception filter62R is disposed on a reception path that connects the low-noise amplifier21and the antenna connection terminal101. The reception filter62R passes a reception signal in the reception band of the communication band B among reception signals input from the antenna connection terminal101. The switch31is disposed on a transmission path that connects the power amplifier11and each of the transmission filters61T and62T and switches between the connection between the power amplifier11and the transmission filter61T and the connection between the power amplifier11and the transmission filter62T. The switch31is, for example, an SPDT (single-pole double-throw) switching circuit having a common terminal connected to the power amplifier11, one of selection terminals connected to the transmission filter61T, and the other selection terminal connected to the transmission filter62T. The switch41is disposed on a reception path that connects the low-noise amplifier21and each of the reception filters61R and62R and switches between the connection between the low-noise amplifier21and the reception filter61R and the connection between the low-noise amplifier21and the reception filter62R. The switch41includes, for example, an SPDT switching circuit having a common terminal connected to the low-noise amplifier21, one of selection terminals connected to the reception filter61R, and the other selection terminal connected to the reception filter62R. The switch71switches between the connection between the antenna2and the duplexer61and the connection between the antenna2and the duplexer62. The switch71includes, for example, an SPDT switching circuit having a common terminal connected to the antenna connection terminal101, one of selection terminals connected to the duplexer61, and the other selection terminal connected to the duplexer62. The switch71can disable the transmission of a radio frequency signal to the first band circuit1A under a condition the common terminal thereof is connected to none of the selection terminals thereof. That is, the switch71may function as an antenna switch that switches between the connection and disconnection between the first band circuit1A and the antenna2. In the first band circuit1A, the number of supportable communication bands is not limited two, and may be one or three or more. The number of duplexers and the necessity or unnecessity of each switch are determined in accordance with the number of communication bands. [1.2.2 Circuit Configuration of Second Band Circuit1B] Next, the circuit configuration of the second band circuit1B will be described. The second band circuit1B includes the power amplifier12, the low-noise amplifier22, duplexers63and64, and switches32,42, and72. The power amplifier12is an example of a second transmission amplifier and is a transmission power amplifier that amplifies a transmission signal in the second communication band group. The low-noise amplifier22is an example of a second reception amplifier and is a reception low-noise amplifier that amplifies a reception signal in the second communication band group with low noise. The duplexer63passes a radio frequency signal in one (hereinafter referred to as “communication band C”) of the multiple second communication bands included in the second communication band group. The duplexer63includes a transmission filter63T and a reception filter63R. The transmission filter63T is disposed on a transmission path that connects the power amplifier12and the antenna connection terminal102and passes a transmission signal in the transmission band of the communication band C among transmission signals amplified by the power amplifier12. The reception filter63R is disposed on a reception path that connects the low-noise amplifier22and the antenna connection terminal102and passes a reception signal in the reception band of the communication band C among reception signals input from the antenna connection terminal102. The duplexer64passes a radio frequency signal in one (hereinafter referred to as “communication band D”) of the multiple second communication bands included in the second communication band group. The duplexer64includes a transmission filter64T and a reception filter64R. The transmission filter64T is disposed on a transmission path that connects the power amplifier12and the antenna connection terminal102. The transmission filter64T passes a transmission signal in the transmission band of the communication band D among transmission signals amplified by the power amplifier12. The reception filter64R is disposed on a reception path that connects the low-noise amplifier22and the antenna connection terminal102. The reception filter64R passes a reception signal in the reception band of the communication band D among reception signals input from the antenna connection terminal102. The switch32is disposed on a transmission path that connects the power amplifier12and each of the transmission filters63T and64T and switches between the connection between the power amplifier12and the transmission filter63T and the connection between the power amplifier12and the transmission filter64T. The switch32includes, for example, an SPDT switching circuit having a common terminal connected to the power amplifier12, one of selection terminals connected to the transmission filter63T, and the other selection terminal connected to the transmission filter64T. The switch42is disposed on a reception path that connects the low-noise amplifier22and each of the reception filters63R and64R and switches between the connection between the low-noise amplifier22and the reception filter63R and the connection between the low-noise amplifier22and the reception filter64R. The switch42includes, for example, an SPDT switching circuit having a common terminal connected to the low-noise amplifier22, one of selection terminals connected to the reception filter63R, and the other selection terminal connected to the reception filter64R. The switch72switches between the connection between the antenna2and the duplexer63and the connection between the antenna2and the duplexer64. The switch72includes, for example, an SPDT switching circuit having a common terminal connected to the antenna connection terminal102, one of selection terminals connected to the duplexer63, and the other selection terminal connected to the duplexer64. The switch72can disable the transmission of a radio frequency signal to the second band circuit1B under a condition the common terminal thereof is connected to none of the selection terminals thereof. That is, the switch72may function as an antenna switch that switches between the connection and disconnection between the second band circuit1B and the antenna2. In the second band circuit1B, the number of supportable communication bands is not limited two, and may be one or three or more. The number of duplexers and the necessity or unnecessity of each switch are determined in accordance with the number of communication bands. [1.2.3 Circuit Configuration of Third Band Circuit1C] Next, the circuit configuration of the third band circuit1C will be described. The third band circuit1C includes the power amplifier13, the low-noise amplifier23, duplexers65and66, switches33,43, and73. The power amplifier13is an example of a third transmission amplifier and is a transmission power amplifier that amplifies a transmission signal in the third communication band group. The low-noise amplifier23is an example of a third reception amplifier and is a reception low-noise amplifier that amplifies a reception signal in the third communication band group with low noise. The duplexer65passes a radio frequency signal in one (hereinafter referred to as “communication band E”) of the multiple third communication bands included in the third communication band group. The duplexer65includes a transmission filter65T and a reception filter65R. The transmission filter65T is disposed on a transmission path that connects the power amplifier13and the antenna connection terminal103and passes a transmission signal in the transmission band of the communication band E among transmission signals amplified by the power amplifier13. The reception filter65R is disposed on a reception path that connects the low-noise amplifier23and the antenna connection terminal103and passes a reception signal in the reception band of the communication band E among reception signals input from the antenna connection terminal103. The duplexer66passes a radio frequency signal in one (hereinafter referred to as “communication band F”) of the multiple third communication bands included in the third communication band group. The duplexer66includes a transmission filter66T and a reception filter66R. The transmission filter66T is disposed on a transmission path that connects the power amplifier13and the antenna connection terminal103. The transmission filter66T passes a transmission signal in the transmission band of the communication band F among transmission signals amplified by the power amplifier13. The reception filter66R is disposed on a reception path that connects the low-noise amplifier23and the antenna connection terminal103. The reception filter66R passes a reception signal in the reception band of the communication band F among reception signals input from the antenna connection terminal103. The switch33is disposed on a transmission path that connects the power amplifier13and each of the transmission filters65T and66T and switches between the connection between the power amplifier13and the transmission filter65T and the connection between the power amplifier13and the transmission filter66T. The switch33includes, for example, an SPDT switching circuit having a common terminal connected to the power amplifier13, one of selection terminals connected to the transmission filter65T, and the other selection terminal connected to the transmission filter66T. The switch43is disposed on a reception path that connects the low-noise amplifier23and each of the reception filters65R and66R and switches between the connection between the low-noise amplifier23and the reception filter65R and the connection between the low-noise amplifier23and the reception filter66R. The switch43includes, for example, an SPDT switching circuit having a common terminal connected to the low-noise amplifier23, one of selection terminals connected to the reception filter65R, and the other selection terminal connected to the reception filter66R. The switch73switches between the connection between the antenna2and the duplexer65and the connection between the antenna2and the duplexer66. The switch73includes, for example, an SPDT switching circuit having a common terminal connected to the antenna connection terminal103, one of selection terminals connected to the duplexer65, and the other selection terminal connected to the duplexer66. The switch73can disable the transmission of a radio frequency signal to the third band circuit1C under a condition the common terminal thereof is connected to none of the selection terminals thereof. That is, the switch73may function as an antenna switch that switches between the connection and disconnection between the third band circuit1C and the antenna2. In the third band circuit1C, the number of supportable communication bands is not limited two, and may be one or three or more. The number of duplexers and the necessity or unnecessity of each switch are determined in accordance with the number of communication bands. In the above switches31to33in the radio frequency module1, the state is allowed in which the power amplifier11is connected to the transmission filter61T or62T and the power amplifier13is connected to the transmission filter65T or66T. That is, the switches31and33enable the simultaneous connection of the power amplifiers11and13to different transmission filters. On the other hand, in the switches31to33, the state is prohibited in which the power amplifier11and/or the power amplifier13is/are connected to respective transmission filters and the power amplifier12is connected to the transmission filter63T or64T. In the switches41to43, the state is allowed in which the low-noise amplifier21is connected to the reception filter61R or62R and the low-noise amplifier23is connected to the reception filter65R or66R. That is, the switches41to43enable the simultaneous connection of the low-noise amplifiers21and23to different reception filters. On the other hand, for the switches41to43, the state is prohibited in which the low-noise amplifier21and/or the low-noise amplifier23is/are connected to respective reception filters and the low-noise amplifier22is simultaneously connected to the reception filter63R or64R. In the switches71to73, the state is allowed in which the first band circuit1A and the third band circuit1C are connected to the antenna2. That is, the switches71and73enable the simultaneous connection of the first band circuit1A and the third band circuit1C to the antenna2. On the other hand, in the switches71to73, the state is prohibited in which the first band circuit1A and/or the third band circuit1C is/are connected to the antenna2and the second band circuit1B is connected to the antenna2. In the radio frequency module1, the switches31to33may be formed as the single switching circuit30. In this case, the switching circuit30becomes a multiple-connection switching circuit capable of simultaneously establishing the connection of the power amplifier11to the transmission filter61T or62T and the connection of the power amplifier13to the transmission filter65T or66T. The switches41to43may be formed as the single switching circuit40. In this case, the switching circuit40becomes a multiple-connection switching circuit capable of simultaneously establishing the connection of the low-noise amplifier21to the reception filter61R or62R and the connection of the low-noise amplifier23to the reception filter65R or66R. The switches71to73may be formed as the single switching circuit70. In this case, the switching circuit70becomes a multiple-connection switching circuit capable of simultaneously establishing the connection of the first band circuit1A to the antenna2and the connection of the third band circuit1C to the antenna2. Examples of the transmission filters61T to66T and the reception filters61R to66R include a surface acoustic wave (SAW) filter, an acoustic wave filter using bulk acoustic waves (BAWs), an LC resonator filter, and a dielectric filter. The number of antennas connected to the radio frequency module1may be two or more. In this case, corresponding antennas may be connected to the antenna connection terminals101to103. Each of the power amplifiers11to13and the low-noise amplifiers21to23may include, for example, a field-effect transistor (FET) or a heterojunction bipolar transistor (HBT) which includes, for example, Si-based complementary metal oxide semiconductor (CMOS) or GaAs as a material. Each of the duplexers61to66may be a time-division duplexer including a transmission/reception filter and a transmission/reception changeover switch. Also in this case, transmission and reception in different bands included in the same band group can be simultaneously performed. For example, the case is assumed where a transmission signal in the communication band A in the first communication band group and a reception signal in the communication band B in the first communication band group are simultaneously transmitted. In the radio frequency module1, the switches31to33,41to43, and71to73, the PA control circuit34, and the control circuit90are optionally included in a radio frequency module according to the disclosure. The radio frequency module1includes both a transmission circuit and a reception circuit, but may include one of them. In this case, the radio frequency module1optionally includes the power amplifiers11to13or the low-noise amplifiers21to23as part(s) of the radio frequency module1. 2. Arrangement of Circuit Elements in Radio Frequency Module1 Next, the arrangement of circuit elements in the radio frequency module1having the above configuration will be described in detail with reference toFIGS.2A and2B. FIGS.2A and2Bare plan views of the radio frequency module1according to an embodiment. Specifically,FIG.2Ais a plan view of circuit elements on a principal surface91aof a substrate91in the radio frequency module1as viewed from the location of the principal surface91a.FIG.2Bis a perspective view of circuit elements on a principal surface91bof the substrate91in the radio frequency module1as viewed from the location of the principal surface91aof the substrate91. As illustrated inFIGS.2A and2B, the radio frequency module1further includes the substrate91and a plurality of external connection terminals150in addition to the circuit configuration illustrated inFIG.1. The substrate91is a mounting board on which the circuit elements of the radio frequency module1are mounted and has the principal surfaces91aand91bon opposite sides of the mounting board. Examples of the substrate91include a low-temperature co-fired ceramic (LTCC) substrate including the laminate of a plurality of dielectric layers and a printed circuit board. The principal surfaces91aand91bof the substrate91are covered with a resin member (not illustrated). The resin member ensures reliability such as the mechanical strength and moisture resistance of the circuit elements on the principal surfaces91aand91b. The substrate91is optionally covered with a resin member. That is, the resin member is an optional feature of a radio frequency module according to the disclosure. As illustrated inFIGS.2A and2B, the power amplifiers11to13, the PA control circuit34, and the duplexers61to66are surface-mounted on the principal surface91aof the substrate91. The low-noise amplifiers21to23, the switching circuits30,40,70, and90are surface-mounted on the principal surface91bof the substrate91. InFIGS.2A and2B, blocks with no reference numeral are optional circuit elements. The multiple external connection terminals150are disposed on the principal surface91bof the substrate91. The multiple external connection terminals150are connected to an external substrate disposed near the principal surface91bof the radio frequency module1. The radio frequency module1exchanges signals with the external substrate via some of the multiple external connection terminals150. Some of the multiple external connection terminal150are set as the ground potential of the external substrate. The power amplifiers11to13are disposed on the principal surface91aand the low-noise amplifiers21to23, the switching circuits30,40, and70, and the control circuit90are disposed on the principal surface91b, so that the radio frequency module1can be entirely reduced in profile. The multiple external connection terminals150used as ground electrodes are disposed around the low-noise amplifiers21to23having large influences upon the reception sensitivity of a reception circuit, so that the degradation in the reception sensitivity of the reception circuit can be suppressed. Each of the multiple external connection terminals150may be a columnar electrode that penetrates a resin member covering the principal surface91bor a bump electrode disposed on an electrode formed on the principal surface91b. Under the condition that the external connection terminal150is a bump electrode, the principal surface91bis optionally covered with a resin member. The arrangement of circuit elements illustrated inFIGS.2A and2Bis a non-limiting example. For example, the switching circuit30may be disposed on the principal surface91a. For example, the low-noise amplifiers21to23, the switching circuits30,40, and70, and the control circuit90may be formed in a single semiconductor IC (integrated circuit). A semiconductor IC is formed of, for example, CMOS. Specifically, a semiconductor IC is formed by an SOI (silicon on insulator) process, so that the cost of manufacturing the semiconductor IC can be reduced. A semiconductor IC may include GaAs, SiGe, or GaN or any combination thereof, so that a radio frequency signal having high-quality amplification performance and noise performance can be output. [2.1 Arrangement of Power Amplifiers11to13and PA Control Circuit34] The planar arrangement of the power amplifiers11to13and the PA control circuit34on the principal surface91aof the substrate91will be described in detail with reference toFIG.3A.FIG.3Ais a diagram illustrating the arrangement of power amplifiers in a radio frequency module according to an embodiment. Specifically,FIG.3Ais an enlarged view of region iii-A inFIG.2A. In this embodiment, the power amplifiers11to13and the PA control circuit34are mounted on respective chips and have an equal-sized rectangular outer shape in plan view. The power amplifiers11to13and the PA control circuit34are arranged in a row at a distance from each other on the principal surface91aof the substrate91. The power amplifier12and the PA control circuit34are located between the power amplifiers11and13. That is, in orthogonal projection onto a plane parallel to the substrate91, a straight line connecting any point in the power amplifier11and any point in the power amplifier13passes through the power amplifier12and the PA control circuit34. For example, in orthogonal projection onto a plane parallel to the substrate91, a straight line connecting an output terminal11aof the power amplifier11and an output terminal13aof the power amplifier13passes through the power amplifier12and the PA control circuit34. At that time, in plan view of the substrate91, a distance Dp13between the output terminal11aof the power amplifier11and the output terminal13aof the power amplifier13is longer than a distance Dp12between the output terminal11aof the power amplifier11and an output terminal12aof the power amplifier12and a distance Dp23between the output terminal12aof the power amplifier12and the output terminal13aof the power amplifier13. As a distance between output terminals, a distance between any points (e.g., center points) in the output terminals may be used. The power amplifiers11to13and the PA control circuit34are equal in shape and size inFIG.3A, but need not be equal in shape and size. Furthermore, the respective shapes of the power amplifiers11to13and the PA control circuit34are not limited to rectangles. [2.2 Arrangement of Low-Noise Amplifiers21to23] Next, the planar arrangement of the low-noise amplifiers21to23on the principal surface91bof the substrate91will be described with reference toFIG.3B.FIG.3Bis a diagram illustrating the arrangement of low-noise amplifiers in a radio frequency module according to an embodiment. Specifically,FIG.3Bis an enlarged view of region iii-B inFIG.2B. In this embodiment, the low-noise amplifiers21to23are mounted on respective chips and have an equal-sized rectangular outer shape in plan view. The low-noise amplifiers21to23are arranged in a row at a distance from each other on the principal surface91bof the substrate91. The low-noise amplifier22is located between the low-noise amplifiers21and23. That is, in orthogonal projection onto a plane parallel to the substrate91, a straight line connecting any point in the low-noise amplifier21and any point in the low-noise amplifier23passes through the low-noise amplifier22. For example, in orthogonal projection onto a plane parallel to the substrate91, a straight line connecting an output terminal21aof the low-noise amplifier21and an output terminal23aof the low-noise amplifier23passes through the low-noise amplifier22. At that time, in plan view of the substrate91, a distance Dr13between the output terminal21aof the low-noise amplifier21and the output terminal23aof the low-noise amplifier23is longer than a distance Dr12between the output terminal21aof the low-noise amplifier21and an output terminal22aof the low-noise amplifier22and a distance Dr23between the output terminal22aof the low-noise amplifier22and the output terminal23aof the low-noise amplifier23. The low-noise amplifiers21to23are equal in shape and size inFIG.3B, but need not be equal in shape and size. Furthermore, the respective shapes of the low-noise amplifiers21to23are not limited to rectangles. 3. Effects, Etc. As described above, the radio frequency module1according to this embodiment includes the substrate91, the power amplifier11that is mounted on the substrate91and that amplifies a transmission signal in a first communication band, the power amplifier12that is mounted on the substrate91and that amplifies a transmission signal in a second communication band, and the power amplifier13that is mounted on the substrate91and that amplifies a transmission signal in a third communication band. Simultaneous transmission can be performed in a combination of the first communication band and the third communication band. Simultaneous transmission cannot be performed in a combination of the first communication band and the second communication band and a combination of the second communication band and the third communication band. In plan view of the substrate91, the distance Dp13between the output terminal11aof the power amplifier11and the output terminal13aof the power amplifier13is longer than the distance Dp12between the output terminal11aof the power amplifier11and the output terminal12aof the power amplifier12and the distance Dp23between the output terminal12aof the power amplifier12and the output terminal13aof the power amplifier13. With this configuration, the distance between the output terminal11aof the power amplifier11and the output terminal13aof the power amplifier13can be increased. Accordingly, under a condition a transmission signal in the first communication band and a transmission signal in the third communication band are simultaneously transmitted, the mutual interference between the transmission signal of high power in the first communication band amplified by the power amplifier11and the transmission signal of high power in the third communication band amplified by the power amplifier13can be suppressed. That is, the degree of isolation between the transmission circuit for the first communication band and the transmission circuit for the third communication band can be increased. Simultaneous transmission cannot be performed in the combination of the first communication band and the second communication band and the combination of the second communication band and the third communication band. Accordingly, even if a transmission signal in the first communication band and a transmission signal in the third communication band flow into the transmission circuit for the second communication band because of the smallness of the distance Dp12between the output terminal11aof the power amplifier11and the output terminal12aof the power amplifier12and the smallness of the distance Dp23between the output terminal12aof the power amplifier12and the output terminal13aof the power amplifier13, the transmission of a transmission signal in the second communication band is not affected. That is, in the radio frequency module1, the degree of isolation between the transmission circuit for the first communication band and the transmission circuit for the third communication band can be increased while the reduction in quality of a transmission signal in the second communication band is prevented. In the radio frequency module1according to this embodiment, the power amplifier12may be disposed between the power amplifiers11and13in the plan view of the substrate91. With this configuration in which the power amplifier12is interposed between the power amplifiers11and13, the signal interference between the power amplifiers11and13can be suppressed. Furthermore, the power amplifiers11to13can be effectively disposed while the conditions of distances among the output terminals of the power amplifiers11to13are satisfied. This can also contribute to the miniaturization of the radio frequency module1. The radio frequency module1according to this embodiment may further include the PA control circuit34that is mounted on the substrate91and that controls the power amplifiers11to13. In this case, the PA control circuit34may be disposed between the power amplifiers11and13in plan view of the substrate91. With this configuration in which the PA control circuit34is interposed between the power amplifiers11and13, the signal interference between the power amplifiers11and13can be suppressed. Furthermore, the PA control circuit34can be effectively disposed while the distance between the output terminal11aof the power amplifier11and the output terminal13aof the power amplifier13is ensured. This can also contribute to the miniaturization of the radio frequency module1. The radio frequency module1according to this embodiment includes the substrate91, the low-noise amplifier21that is mounted on the substrate91and that amplifies a reception signal in a first communication band, the low-noise amplifier22that is mounted on the substrate91and that amplifies a reception signal in a second communication band, and the low-noise amplifier23that is mounted on the substrate91and that amplifies a reception signal in a third communication band. Simultaneous reception can be performed in a combination of the first communication band and the third communication band. Simultaneous reception cannot be performed in a combination of the first communication band and the second communication band and a combination of the second communication band and the third communication band. In plan view of the substrate91, the distance Dr13between the output terminal21aof the low-noise amplifier21and the output terminal23aof the low-noise amplifier23is longer than the distance Dr12between the output terminal21aof the low-noise amplifier21and the output terminal22aof the low-noise amplifier22and the distance Dr23between the output terminal22aof the low-noise amplifier22and the output terminal23aof the low-noise amplifier23. With this configuration, the distance between the output terminal21aof the low-noise amplifier21and the output terminal23aof the low-noise amplifier23can be increased. Accordingly, under a condition a reception signal in the first communication band and a reception signal in the third communication band are simultaneously received, the mutual interference between the reception signal in the first communication band amplified by the low-noise amplifier21and the reception signal in the third communication band amplified by the low-noise amplifier23can be suppressed. That is, the degree of isolation between the reception circuit for the first communication band and the reception circuit for the third communication band can be increased. Simultaneous reception cannot be performed in the combination of the first communication band and the second communication band and the combination of the second communication band and the third communication band. Accordingly, even if a reception signal in the first communication band and a reception signal in the third communication band flow into the reception circuit for the second communication band because of the smallness of the distance Dr12between the output terminal21aof the low-noise amplifier21and the output terminal22aof the low-noise amplifier22and the smallness of the distance Dr23between the output terminal22aof the low-noise amplifier22and the output terminal23aof the low-noise amplifier23, the transmission of a reception signal in the second communication band is not affected. That is, in the radio frequency module1, the degree of isolation between the reception circuit for the first communication band and the reception circuit for the third communication band can be increased while the reduction in quality of a reception signal in the second communication band is prevented. (Modifications) Next, a modification will be described. This modification differs from the above embodiment in that the power amplifiers12and13are formed on a single chip. The radio frequency module1according to this modification will be described focusing on differences from the above embodiment. FIG.4is a diagram illustrating the arrangement of power amplifiers in the radio frequency module1according to a modification. In this modification, the power amplifiers12and13are formed on a single chip. The power amplifiers11and13are formed on different chips. The formation of a plurality of circuit elements on a single chip means that the multiple circuit elements are integrated on a single semiconductor substrate. In contrast, the formation of a plurality of circuit elements on different chips means that the multiple circuit elements are mounted on separate semiconductor substrates. Also, in the case illustrated inFIG.4where the power amplifiers12and13are formed on a single chip, the distance Dp13between the output terminal11aof the power amplifier11and the output terminal13aof the power amplifier13is longer than the distance Dp12between the output terminal11aof the power amplifier11and the output terminal12aof the power amplifier12in plan view of the substrate91like in the above embodiment. As described above, in the radio frequency module1according to this modification, the power amplifiers12and13are formed on a single chip. With this configuration, the footprints of the power amplifiers12and13can be reduced while the conditions of distances among the output terminals of the power amplifiers11to13are satisfied. This can contribute to the miniaturization of the radio frequency module1. In the radio frequency module1according to this modification, the power amplifiers11and13are formed on different chips. With this configuration in which the power amplifiers11and13are not formed on a single chip, the reduction in the degree of isolation between the transmission circuit for the first communication band and the transmission circuit for the third communication band can be prevented. Although the power amplifiers11to13have been described in this modification, the low-noise amplifiers21to23can also be similarly configured. That is, the low-noise amplifiers22and23can be formed on a single chip. At that time, the low-noise amplifiers21and23may be formed on different chips. Other Embodiments A radio frequency module according to an aspect of the disclosure and a communication device according to an aspect of the disclosure have been described above through the exemplification of the embodiment and the modifications, but are not limited to the above embodiment and the above modifications. The disclosure also includes other embodiments achieved by combining optional constituent elements of the above embodiment and the above modifications, modifications obtained by making various changes, which are conceived by those skilled in the art, to the above embodiment and the above modifications without departing from the spirit and scope of the disclosure, and various apparatuses including the above radio frequency module and the above communication device. For example, in the radio frequency module1and the communication device5according to the above embodiment and the above modifications, other circuit elements and other wiring lines may be inserted between the illustrated circuit elements and between the illustrated paths each connecting signal paths. For example, an impedance matching circuit may be inserted between a duplexer and a power amplifier and/or between a duplexer and a low-noise amplifier. The power amplifier12is disposed between the power amplifiers11and13in the above embodiment and the above modifications, but need not be disposed between them. For example, the power amplifiers11to13may be disposed as illustrated inFIG.5. Referring toFIG.5, the power amplifiers11and13are disposed to face each other and the output terminals11aand13aare located on the two respective sides opposite the two facing sides of the power amplifiers11and13. The power amplifier12is not disposed between the power amplifiers11and13but next to the power amplifiers11and13. Even in the case where the power amplifiers11to13are disposed as above, the distance Dp13between the output terminal11aof the power amplifier11and the output terminal13aof the power amplifier13can be larger than the distance Dp12between the output terminal11aof the power amplifier11and the output terminal12aof the power amplifier12in plan view of the substrate91like in the above embodiment. The power amplifiers11to13are disposed on the same principal surface of the substrate91in the above embodiment and the above modifications, but need not be disposed on the same principal surface of the substrate91. On condition that the positional relationship among the power amplifiers11to13in plan view is maintained, one of the power amplifiers11to13may be disposed on a principal surface different from a principal surface on which the other two of them are disposed. For example, the power amplifier11may be disposed on a principal surface different from a principal surface on which the power amplifiers12and13are disposed. A part of or the whole of each of the power amplifiers11to13may be disposed in the substrate91. A similar thing can be applied to the low-noise amplifiers21to23. INDUSTRIAL APPLICABILITY The disclosure can be used as a radio frequency module disposed in a multiband front-end portion and is widely applicable to communication devices such as mobile phones each including the radio frequency module. REFERENCE SIGNS LIST 1radio frequency module1A first band circuit1B second band circuit1C third band circuit2antenna3RFIC4BBIC5communication device11,12, and13power amplifier11a,12a,13a,21a,22a, and23aoutput terminal21,22, and23low-noise amplifier30,40,70switching circuit31,32,33,41,42,43,71,72, and73switch61,62,63,64,65, and66duplexer61R,62R,63R,64R,65R, and66R reception filter61T,62T,63T,64T,65T, and66T transmission filter91substrate91aand91bprincipal surface101,102, and103antenna connection terminal111,112, and113transmission input terminal121,122, and123reception output terminal150external connection terminal | 51,629 |
11942974 | DETAILED DESCRIPTION OF THE INVENTION FIG.1provides a schematic block diagram example of a radio transmit/receive (TRX) (transceiver) front end10adapted to share an antenna or antenna array between the transmission (TX) and receive (RX) paths of a transceiver. In the example, a power amplifier (PA)122and a low-noise amplifier (LNA)112are coupled share a common balanced to unbalanced (balun) transformer118. In an example, the LNA112is based on a common gate design to provide high impedance when in an off state. In another example, the PA122and LNA112are adapted to have similar on-impedance, such that a common balun118can be used for matching. In yet another example, a DC supply switch116is coupled to an additional winding in the balun. In an example, the system ofFIG.1can be described as a substantially switchless transmit/receive (TRX) front end, since the system does not incorporate a lossy element in the transmission (TX) and receive (RX) paths of the radio front end. FIG.2is a logic diagram of an example of a method for utilizing a DC supply source to implement a test loop back for a radio front end. In practice, using the method ofFIG.2, defective parts of a radio system can be identified prior to delivery to customers. For example, millimeter wave (mmwave) loop back testing can be executed at the wafer or packaged die scale to screen for bad devices prior to assembly on application and/or product printed circuit boards (PCBs) or even on an application or product board and/or in an original equipment manufactured (OEM) product. Advantages of loop back testing include simplification of test equipment setup (leading to lower test-cost per unit of time), potentially resulting in lower production costs at the device level, which in turn provides for higher margins and/or lower average selling price (ASP) to direct customers. The method begins at step100, with a DC supply being used to bias the third winding of a balanced to unbalanced (balun) transformer coupling the power amplifier (PA) and a low-noise amplifier (LNA) in a radio transmit/receive (TRX) front end, such as the TRX front end illustrated inFIG.1. In an example, the primary winding forms the input to the balun and a secondary winding forms the output of the balun. In a specific example, the third winding of the balun can be an additional point of a two winding balun or a true tap in the middle winding of the balun. For example, the voltage from the neutral to the center point will equal the voltage from the center point to end of the coil for a center tap balun. In an alternative example, the third winding can be a winding separate from the primary and secondary windings. The method continues at step102, where the resultant power output signal of the PA is provided to the input of the LNA. At step104, the parameters of the signal path, such as power output at a particular frequency are measured. At step106the measured parameters are compared to desired performance of the signal path elements. In an example, the loop back testing method ofFIG.2can be used to validate the entire front end signal path (with the possible exception of the power amplifier (PA)) without a degradation of radio frequency (RF) performance that can be common with other test methods. In an example, the third winding can comprise a weakly-coupled winding below the balun to couple the input signal in receive (RX) mode to the low noise amplifier (LNA) gates to boost its gain, thereby providing a lower total RX noise figure for the front end. In a specific example, the third winding can be implemented to provide half of the DC supply voltage to the LNA. In another specific example, the third winding can be implemented to provide almost any predetermined fractional voltage for the loop back test. In practice, a loop back test using a fractional voltage will have the disadvantage of testing the LNA in different operating conditions than the PA testing, however this disadvantage can be mitigated somewhat by using a comparative mechanism, such as a look up table, or by extrapolating the measured LNA measurements to a nonfractional operating voltage. In a specific example of implementation and operation, a method for testing a radio front-end comprises biasing a balun at a third winding, where a transmit power amplifier and a low noise amplifier are coupled to a secondary winding of the balun and the biasing causes the transmit power amplifier in a transmit path to partially activate to produce a power amplifier output. The method continues, by providing the power amplifier output to the low noise amplifier and measuring one or more signal path parameters of the radio front-end to produce one or more test results. The method continuers, by correlating the one or more test results to one or more predetermined test values; and in response to the correlating, determining whether the test results are favorable. In a specific example, the method includes activating a transmit/receive switch to bias the balun, where the transmit/receive switch is integrated on the radio front-end. In an example, a power amplifier, low-noise amplifier, transmit/receive switch and balun are integrated on a common integrated circuit. In another specific example of implementation and operation, method for testing a radio front-end comprises biasing a balun at a third winding, where a transmit power amplifier and a low noise amplifier are coupled to a secondary winding of the balun and where the biasing causes the transmit power amplifier in the TX path to partially activate to produce a power amplifier output. The method continues by providing the power amplifier output to the low noise amplifier, and measuring one or more signal path parameters of the radio front-end to produce one or more test results. The method then continues by correlating the one or more test results to one or more predetermined test values to produce correlated test values and based on the correlated test values, determining whether the test results are favorable. In a specific related example, the method includes activating a transmit/receive switch to bias the balun, where the transmit/receive switch is integrated on the radio front-end. In another specific related example, the power amplifier, the low-noise amplifier, the transmit/receive switch and the balun are integrated on a common integrated circuit. FIG.3provides a schematic block diagram an example transmission (TX) and receive (RX) paths of a transceiver10. In an example, a switchless transmit/receive (TRX) front end can be useful for switching between TX/RX modes, an LNA can comprise one or more input transistors that will degrade and/or be permanently damaged when the TRX front end is in transmit mode, due to the relatively high power from the PA. In an example, the degradation can increase when the circuit results in positive feedback to the input transistor gate(s). In an example, provisioning the TRX front end10with an LNA switch126(between LNA112a& LNA112b) adapted to short the LNA gate(s)112aor112bto ground when the TRX front end10is in TX mode can reduce or eliminate degradation to an LNA input transistor and the subsequent reliability thereof. In an example, local oscillator feed-through (LOFT) and image rejection signals can be found in the transmit (TX) signal for a radio. The LOFT and/or image rejection signals can be removed and/or attenuated using an ADC, to convert the TX signal to digital for processing in the digital domain (using, for example, a fast Fourier transform function (FFT)), however, the ADC and processing consume power and can introduce latency to the TX signal. For example, an ADC can be implemented as a successive-approximation-register (SAR). In a related example, the SAR ADC mentioned is configured for low frequency conversion and can be used as a house-keeping ADC (HKADC) (sometimes referred to as an auxiliary ADC). In a specific example, a signal path ADC can be differentiated from a traditional SAR, due to, for example, due to its relatively high sample rate requirement(s). FIG.4provides a schematic block diagram of a mechanism for calibrating LOFT and image rejection signals in a millimeter wave (mmwave) radio implementation. In the example, an envelope detector222is used with a low pass filter (LPF)224followed by a Log amplifier (log Amp)226circuit to isolate and attenuate low frequency feedthrough (LOFT), allowing an associated intermodulation (IM) signal to be measured using a low frequency, low power ADC such as a successive-approximation-register (SAR) ADC or a dual-slope ADC and calibrated out of the TX signal. FIG.5provides schematic block diagram of a system for calibrating of LOFT and image rejection signals in a millimeter wave (mm wave) radio implementation. FIG.6illustrates a method for calibrating local oscillator feed-through (LOFT) and image rejection signal calibration. The method begins at step600by transmitting a pure tone at a fixed offset from the carrier, where both the pure tone and the fixed offset are predetermined. At step602, the method continues with the generation of local oscillator (LO) and IM signals due to any impairments in the mixer. At step604the ( )2functions as a mixer to migrate the signal to DC, then, at step606, the LO is moved to the predetermined offset from DC and the IM is moved to 2× of the known offset from DC. At step608the LO is separated from the IM with one or more low-pass filters and at step610the amplitude of the LO is measured using the log Det. Finally, at step612, the IM can be measured. In an alternate example referring toFIG.4, a pass through path from the Envelope Detect to LogAmp can be replaced by a high pass filter (HPF) to further improve the LO-feedthrough and image suppression capability of the calibration system illustrated. In a quadrature-based RF transceiver, a local oscillator (LO) can leak to the output of the receiver, producing LO feedthrough. In an example, DC offset is multiplied with the local oscillator (LO) signal and can be a dominant contributor to LO Feedthrough “leakage”. Whereas leakage can be the result of capacitive coupling to the output, etc., in an example, DC offset can derive from a baseband signal being multiplied by LO coupling to the output. Additionally, quadrature-based RF transceiver with in-phase and quadrature (I/Q) components are known to exhibit imbalance (I/Q imbalance) between the two 90-degree quadrature signals, caused by, for example, non-ideal mixers, amplifier offsets and frequency error between transmit and receive channels, etc. An amount of I/Q imbalance can be represented as I/Q Offset (also called I/Q origin offset), where the I/Q offset indicates the magnitude of a carrier feedthrough signal. Additionally, uncalibrated I/Q gain/offset can result in undesired sideband emissions in an associated transmitter. In most cases the response for a given transceiver can be calibrated so that I/Q components will have substantially the same gain/offset. In an example, calibration can be accomplished in the digital domain using an analog to digital converter (ADC). In another example, calibration can be done using readily available measuring equipment, such as an oscilloscope. In a specific example of implementation and operation, an envelope detector can be configured to measure the power output of a transceiver. In an example, the envelope detector can be used initially to measure a signal envelope at each of a plurality of power levels. FIG.7Aprovides schematic block diagram of a system for calibrating of LOFT rejection signals in a millimeter wave (mm wave) radio implementation. FIG.7Billustrates a method for inserting a low frequency tone for calibrating LO feedthrough in a transceiver. At step400a 50 MHz tone is inserted with an LO operating at 60 GHz. At step402, the 50 MHz tone is upconverted and at step404the 60.05 GHz tone presents at the output of the power amplifier and the insertion of the 50 MHz tone will likewise result in an LO feedthrough tone at 60 GHz. In an example, in the time-domain the output of an example transceiver will be modulated with a 50 MHz sine wave, enabling an envelope detector at step406to extract the LO feedthrough tone. At step408, if only one tone is measured at the input of the envelope detector the output will be representative of DC offset. At step410DC offset is determined based on the single tone. FIG.8Aprovides a schematic block diagram of a system for calibrating of I/Q balance image rejection signals in a millimeter wave (mm wave) radio implementation. FIG.8Billustrates a method for inserting a low frequency tone for calibrating IQ imbalance in a transceiver. In an example, calibration can require determining what side (negative or positive) to imbalance and by how much (i.e. amplitude). In an example, the DC offset can be modified based on the power level of the representative tone measured by the envelope detector to produce an imbalance offset. In a related example, a resultant attenuation or amplification will be an indicator of the correct (or incorrect) imbalance offset, enabling the imbalance to be corrected by adjusting the gain of the I or the Q as appropriate. At step412a 50 MHz tone is inserted with an LO operating at 60 GHz. At step414, the 50 MHz tone is upconverted. At step416, a 100 MHz “ripple” presents at the PA output. At step418the 100 MHz ripple is translated to a 100 MHz I/Q imbalance “image” at the envelope detector and at step420a preset to I/Q is determined based on the image. FIG.9Aprovides a schematic block diagram of a system for calibrating of I/Q balance image rejection signals in a millimeter wave (mm wave) radio implementation. FIG.9Billustrates a method for detecting LO feedthrough and determining I/Q imbalance. In a specific example of implementation and operation, a given transceiver can exhibit both LO feedthrough and I/Q imbalance simultaneously. At step422, a 50 MHz tone is injected at the transmit (TX) input and upconverted at step424, resulting, at step426, in 3 tones at the TX output: 1) a desired signal; 2) LO feedthrough; and 3) the image representative of I/Q imbalance. In an example, the TX output will result in a 50 MHz ripple and a 100 MHz ripple in the time domain. In a further example, translating the TX output can enable the 50 MHz ripple and a 100 MHz ripple to be determined in either of the time domain, for example using an oscilloscope, or in the frequency domain, for example after performing a Fast-Fourier transform (FFT) in the digital domain. At step428a FFT is used to provide an indication of which of the 50 MHz ripple and a 100 MHz ripple is the LO feedthrough tone and which is the nonideal image of the I/Q imbalance at step430. In an alternative example, when an FFT is not implemented, the I/Q imbalance can be filtered out, leaving only the LO feedthrough tone for detection and/or rejection/reduction. At step432the method continues by calibrating the LO feedback and finally, at step434, by calibrating for the I/Q imbalance. In another specific example of implementation and operation, the Log Amplifier can be configured to provide an average DC out voltage for the LO feed through tone and the I/Q imbalance image as a function of sweeping the low frequency injection tone across a range of frequencies. In an example, the average DC out voltage from the Log Amplifier can be dependent on the filter response “shape”. In an example, the average DC out voltage from the Log Amplifier sweeping the low frequency injection tone across a range of frequencies will produce a peak that correlates to the peak of the low pass filter response. In a related example, the low pass filter response can exhibit a different peak position (at a lower or higher peak based on sweep frequency), however the relationship (correlation) of the low pass filter response peak will be substantially maintained once the LO feedthrough and I/Q imbalance are characterized in a given system. In another specific example of implementation and operation, referring, for example, toFIG.9A, an LO feed through chain can be characterized and/or calibrated during a test procedure of a transceiver device and/or in a procedure adapted for implementation by a user in the “field”, such as anytime the transceiver device is used, or on an otherwise incremental basis. FIG.10illustrates the effect of low pass filter frequency on filter response. In the example, rejection/reduction of I/Q increases, depending on the particular frequency used for a low frequency injection tone. In an example of implementation, a calibration function can be configured to determine the low frequency injection tone based on a desired filter response. In a related example, when the response of the filter is not known, low frequency injection tone can sweep across a range of frequencies (for example, between minimum setting522and maximum setting526), such that a measured filter response can be used to select an optimum/desired frequency for a low frequency injection tone (for example, nominal setting524). In a specific example of implementation, by measuring the output from the log amplifier across a range of low frequency injection tone frequencies, a peak average filter response can be determined (i.e. the average filter response from the log amplifier will increase to a peak average and then decrease). Accordingly, in some examples, by sweeping a low frequency injection tone across a range of frequencies, a frequency dependent optimum calibration tone can be determined, thereby eliminating the need for a complex calibrated filter circuit requiring undesirable additional hardware. FIG.11provides a representation of results from using a log amplifier for LO feedthrough amplitude resolution. In an example, as an LO feedthrough tone is progressively attenuated using a calibration function, resolution of an analog to digital converter (ADC) used for the calibration function becomes progressively more difficult. Accordingly, in a further related example, a logarithmic amplifier (log amplifier) can be used to increase the resolution as the LO feedthrough tone approaches zero amplitude. In an example, the log amplifier can be used to convert a DC out voltage to increasingly higher negative value as the LO feedthrough tone approaches zero amplitude, thereby enabling higher ADC resolution for rejection/reduction of the LO feedthrough tone. In the example ofFIG.10, as LO feedthrough tone308decreases, log amplifier DC output306increases, enabling the calibration function to further attenuate LO feedthrough tone308. In some examples of implementation, the quality of rejection of an LO feedthrough tone used in a calibration process can depend on the quality of one or more filters used in the calibration mechanism. For example, if a filter used in the implementation is insufficiently precise, a resultant LO feedthrough tone rejection/reduction will be affected adversely. In an example, if cut-off for a particular filter is at a frequency higher than an associated calibration tone (LOFT), a respective level of IQ tone rejection can be diminished. In another example, if a given filter is at a frequency lower than an associated calibration tone (LOFT), the residue level of a desired LO feedthrough tone selected for detection is reduced and, the resultant calibration result will be at respectively lower precision. Accordingly, in an example, when the frequency response of a select filter can be predetermined, the associated low frequency tone for calibrating LO feedthrough can be better adjusted to increase the efficiency of the associated filter response. FIG.12provides a schematic block diagram of a radio transceiver with a calibration structure. In the example ofFIG.12, transceiver10includes transmit (TX) mixer518with signals from TX mixer518amplified at power amplifier (PA)502. The output of PA502is coupled to the input of envelope detector516, with the output of envelope detector516coupled to the input of envelope amplifier514. The input of low pass filter504is coupled to the output of envelope amplifier514and the output of low pass filter504is coupled to the input of log amplifier (amp)512. Log amplifier (AMP)512is then coupled at its output to ADC508, which is configured with a filter/buffer506. FIG.13is a schematic representation of a calibration architecture incorporating a by-pass circuit. In specific example of implementation and operation, a calibration structure, such as the calibration structure ofFIG.12, can be configured with a bypass circuit530to enable a bypass mode for removing the low pass filter from the signal chain to a log amplifier. In an example of implementation and operation, when LO feedthrough can be substantially eliminated, by using one of the mechanisms provided herein, an I/Q imbalance image can present as a single tone, thereby eliminating the need for either a low pass filter and/or an instrumentation gain response structure. In an example, a bypass circuit, such as bypass circuit530, includes a uses a software switch or a hardware switch to engage or disengage a by-pass mode. In a related example, when an I/Q imbalance image presents as a single tone, a Log Amplifier, such as log AMP226referring toFIG.4, can provide an accurate measurement of the I/Q imbalance and enable calibration to balance I/Q. In an example, I/Q imbalance can be corrected by adjusting the gain of the I or the Q as appropriate to attenuate and/or eliminate the I/Q imbalance image. In a related example, an envelope detector can be adapted to operate more efficiently when the amplitude of a low frequency injection tone increases. In an example, as a low frequency injection tone increases, the amplitude of any higher order harmonics will also increase. Accordingly, if a low frequency injection tone amplitude is sufficiently high, the I/Q imbalance image in bypass mode can include a second harmonic of the low frequency injection tone. In an example of implementation, a low frequency injection tone can be configured for programmability, so that when the calibration procedure is adapted for bypass mode the low frequency injection tone can be selected at frequency high enough that second (and higher) harmonics of the low frequency injection tone will not be problematic. In an alternative example of implementation and operation, when the calibration procedure is adapted for bypass mode the low frequency injection tone frequency can be divided in half, so that any harmonics are filtered out in the LO feed through process. It is noted that terminologies as may be used herein such as bit stream, stream, signal sequence, etc. (or their equivalents) have been used interchangeably to describe digital information whose content corresponds to any of a number of desired types (e.g., data, video, speech, text, graphics, audio, etc. any of which may generally be referred to as ‘data’). As may be used herein, the terms “substantially” and “approximately” provide industry-accepted tolerance for its corresponding term and/or relativity between items. For some industries, an industry-accepted tolerance is less than one percent and, for other industries, the industry-accepted tolerance is 10 percent or more. Other examples of industry-accepted tolerance range from less than one percent to fifty percent. Industry-accepted tolerances correspond to, but are not limited to, component values, integrated circuit process variations, temperature variations, rise and fall times, thermal noise, dimensions, signaling errors, dropped packets, temperatures, pressures, material compositions, and/or performance metrics. Within an industry, tolerance variances of accepted tolerances may be more or less than a percentage level (e.g., dimension tolerance of less than +/−1%). Some relativity between items may range from a difference of less than a percentage level to a few percent. Other relativity between items may range from a difference of a few percent to magnitude of differences. As may also be used herein, the term(s) “configured to”, “operably coupled to”, “coupled to”, and/or “coupling” includes direct coupling between items and/or indirect coupling between items via an intervening item (e.g., an item includes, but is not limited to, a component, an element, a circuit, and/or a module) where, for an example of indirect coupling, the intervening item does not modify the information of a signal but may adjust its current level, voltage level, and/or power level. As may further be used herein, inferred coupling (i.e., where one element is coupled to another element by inference) includes direct and indirect coupling between two items in the same manner as “coupled to”. As may even further be used herein, the term “configured to”, “operable to”, “coupled to”, or “operably coupled to” indicates that an item includes one or more of power connections, input(s), output(s), etc., to perform, when activated, one or more its corresponding functions and may further include inferred coupling to one or more other items. As may still further be used herein, the term “associated with”, includes direct and/or indirect coupling of separate items and/or one item being embedded within another item. As may be used herein, the term “compares favorably”, indicates that a comparison between two or more items, signals, etc., provides a desired relationship. For example, when the desired relationship is that signal1has a greater magnitude than signal2, a favorable comparison may be achieved when the magnitude of signal1is greater than that of signal2or when the magnitude of signal2is less than that of signal1. As may be used herein, the term “compares unfavorably”, indicates that a comparison between two or more items, signals, etc., fails to provide the desired relationship. As may be used herein, one or more claims may include, in a specific form of this generic form, the phrase “at least one of a, b, and c” or of this generic form “at least one of a, b, or c”, with more or less elements than “a”, “b”, and “c”. In either phrasing, the phrases are to be interpreted identically. In particular, “at least one of a, b, and c” is equivalent to “at least one of a, b, or c” and shall mean a, b, and/or c. As an example, it means: “a” only, “b” only, “c” only, “a” and “b”, “a” and “c”, “b” and “c”, and/or “a”, “b”, and “c”. As may also be used herein, the terms “processing module”, “processing circuit”, “processor”, “processing circuitry”, and/or “processing unit” may be a single processing device or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on hard coding of the circuitry and/or operational instructions. The processing module, module, processing circuit, processing circuitry, and/or processing unit may be, or further include, memory and/or an integrated memory element, which may be a single memory device, a plurality of memory devices, and/or embedded circuitry of another processing module, module, processing circuit, processing circuitry, and/or processing unit. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. Note that if the processing module, module, processing circuit, processing circuitry, and/or processing unit includes more than one processing device, the processing devices may be centrally located (e.g., directly coupled together via a wired and/or wireless bus structure) or may be distributedly located (e.g., cloud computing via indirect coupling via a local area network and/or a wide area network). Further note that if the processing module, module, processing circuit, processing circuitry and/or processing unit implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory and/or memory element storing the corresponding operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. Still further note that, the memory element may store, and the processing module, module, processing circuit, processing circuitry and/or processing unit executes, hard coded and/or operational instructions corresponding to at least some of the steps and/or functions illustrated in one or more of the Figures. Such a memory device or memory element can be included in an article of manufacture. One or more examples have been described above with the aid of method steps illustrating the performance of specified functions and relationships thereof. The boundaries and sequence of these functional building blocks and method steps have been arbitrarily defined herein for convenience of description. Alternate boundaries and sequences can be defined so long as the specified functions and relationships are appropriately performed. Any such alternate boundaries or sequences are thus within the scope and spirit of the claims. Further, the boundaries of these functional building blocks have been arbitrarily defined for convenience of description. Alternate boundaries could be defined as long as the certain significant functions are appropriately performed. Similarly, flow diagram blocks may also have been arbitrarily defined herein to illustrate certain significant functionality. To the extent used, the flow diagram block boundaries and sequence could have been defined otherwise and still perform the certain significant functionality. Such alternate definitions of both functional building blocks and flow diagram blocks and sequences are thus within the scope and spirit of the claims. One of average skill in the art will also recognize that the functional building blocks, and other illustrative blocks, modules and components herein, can be implemented as illustrated or by discrete components, application specific integrated circuits, processors executing appropriate software and the like or any combination thereof. In addition, a flow diagram may include a “start” and/or “continue” indication. The “start” and “continue” indications reflect that the steps presented can optionally be incorporated in or otherwise used in conjunction with one or more other routines. In addition, a flow diagram may include an “end” and/or “continue” indication. The “end” and/or “continue” indications reflect that the steps presented can end as described and shown or optionally be incorporated in or otherwise used in conjunction with one or more other routines. In this context, “start” indicates the beginning of the first step presented and may be preceded by other activities not specifically shown. Further, the “continue” indication reflects that the steps presented may be performed multiple times and/or may be succeeded by other activities not specifically shown. Further, while a flow diagram indicates a particular ordering of steps, other orderings are likewise possible provided that the principles of causality are maintained. The one or more examples are used herein to illustrate one or more aspects, one or more features, one or more concepts, and/or one or more examples. A physical example of an apparatus, an article of manufacture, a machine, and/or of a process may include one or more of the aspects, features, concepts, examples, etc. described with reference to one or more of the examples discussed herein. Further, from figure to figure, the examples may incorporate the same or similarly named functions, steps, modules, etc. that may use the same or different reference numbers and, as such, the functions, steps, modules, etc. may be the same or similar functions, steps, modules, etc. or different ones. Unless specifically stated to the contra, signals to, from, and/or between elements in a figure of any of the figures presented herein may be analog or digital, continuous time or discrete time, and single-ended or differential. For instance, if a signal path is shown as a single-ended path, it also represents a differential signal path. Similarly, if a signal path is shown as a differential path, it also represents a single-ended signal path. While one or more particular architectures are described herein, other architectures can likewise be implemented that use one or more data buses not expressly shown, direct connectivity between elements, and/or indirect coupling between other elements as recognized by one of average skill in the art. The term “module” is used in the description of one or more of the examples. A module implements one or more functions via a device such as a processor or other processing device or other hardware that may include or operate in association with a memory that stores operational instructions. A module may operate independently and/or in conjunction with software and/or firmware. As also used herein, a module may contain one or more sub-modules, each of which may be one or more modules. As may further be used herein, a computer readable memory includes one or more memory elements. A memory element may be a separate memory device, multiple memory devices, or a set of memory locations within a memory device. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. The memory device may be in a form a solid-state memory, a hard drive memory, cloud memory, thumb drive, server memory, computing device memory, and/or other physical medium for storing digital information. While particular combinations of various functions and features of the one or more examples have been expressly described herein, other combinations of these features and functions are likewise possible. The present disclosure is not limited by the particular examples disclosed herein and expressly incorporates these other combinations. | 34,430 |
11942975 | DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS In the following description, embodiments are discussed in detail, however, it should be appreciated that the embodiments provide many applicable concepts that can be embodied in a wide variety of correcting an input signal. The specific embodiments discussed are merely illustrative of specific ways to implement and use the present concept, and do not limit the scope of the embodiments. In the following description of embodiments, the same or similar elements that have the same functionality are provided with the same reference sign or are identified with the same name, and a repeated description of elements provided with the same reference number or being identified with the same name is typically omitted. Hence, descriptions provided for elements having the same or similar reference numbers or being identified with the same names are mutually exchangeable or may be applied to one another in the different embodiments. In the following description, a plurality of details is set forth to provide a more thorough explanation of embodiments of the disclosure. However, it will be apparent to one skilled it the art that other embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form rather than in detail in order to avoid obscuring examples described herein. In addition, features of the different embodiments described herein may be combined with each other, unless specifically noted otherwise. FIG.1shows a schematic representation of an apparatus10for correcting an input signal11according to an embodiment. The apparatus10is configured for receiving the input signal11, the received input signal11comprising a series of input values12. The apparatus10comprises means, such as a matching unit15, for matching a series of template values13to the series of input values12by warping the series of template values13and the series of input values12relative to each other so as to assign one or more template values of the series of template values13to one or more input values of the series of input values12. The series of template values13represents an approximation of a noise signal that is expected to be part of the input signal11. For example, the noise signal may superpose or corrupt a signal of interest that may be comprised in the input signal11. The apparatus10is configured for obtaining a series of corrected input values17based on a mismatch between the input values12and their respective assigned template values13. The apparatus10is further configured for providing a corrected signal19based on the series of corrected input values17. Thus, in embodiments of the present disclosure, the series of template values13, also referred to as template13in the following, may be used to correct the input signal11for an expected noise signal. To account for deviations between the template13and the noise signal, the series of template values13may be matched to the series of input values12by warping. For example, the series of template values13may be generated during a calibration process of a device or may rely on a general knowledge about a specific type of device or noise signal. For example, a value of a series of values, e.g. a template value or an input value, may be attributed an index describing a position of the value within the series of values. The index of the value may be attributed an index value within an index value interval. For example, warping a series of values may comprise shifting or changing the index value of a value of the series, for example within the index value interval. For example, a series may be warped linearly or non-linearly by stretching or shrinking a spacing of the index values of neighboring values of the series, although the index of the values may remain unaltered. For example the series of input values12and the series of template values13may have same or overlapping index value intervals. Thus, warping one or both series may comprise assigning a template value with a first index value to an input value with a second index value which is different from the first index value. Assigning the template values to the input values based on the matching of the series of template values13and the series of input values12may adapt the series of template values13to the noise signal that may be comprised in the series of input values12, even if the series of template values13is distorted with respect to the noise signal. For example, a mismatch between an input value and its assigned template value may be determined based on a distance, an absolute distance, or a difference between the values. Thus, the corrected values of the series of corrected input values17may be based on the determined mismatch of a template value and an input value. Thus, corrected signal19may be based on the series of corrected values17may within an index value interval of the series of input values. For example, the corrected signal19may comprise the series of corrected input values17. For example, the corrected signal19may be obtained from the input signal n by replacing the series of input values12by the series of corrected input values17, for example by a patching or a stitching operation. That is, the input signal n may be patched with the series of corrected input values12. Alternatively, the series of corrected input values17and a part of the input signal n that is not part of the series of input values12may be stitched or joined. By obtaining the series of corrected input values17by considering a mismatch of associated template values and input values, the association between the template values and the input values being based on the matching of the series of template values13to the series of input values12, artefacts, which may arise from considering unmatched values, may be avoided or reduced. Thus, a correction of the input signal n with the template13, for example, comprising a template subtraction, may be effectively performed despite of variances of the noise signal with respect to the template13. Such variances may occur, for example, due to manufacturing differences among measurement devices, due to a change of a measurement conditions or setup, or due to a change of the measurement device, for example due to aging, or degradation of single components. Thus, the apparatus10may also compensate input signals n provided by different devices by using a generalized template13, and despite of modifications that might appear overtime. As the series of template values13is matched to the input signal comprising the noise signal, a single template13may be sufficient for correcting many or all possible variations of the input signal or the noise signal, for example without the need of a template library. Therefore, the apparatus10may have low memory requirements. Also, the apparatus10may correct the input signal11with low computational effort. For these reasons, the apparatus10may be advantageously implemented in mobile applications. Further, matching the series of template values13to the series of input values by warping may show high performance even if a width and a shape of the template13have large variances. According to an embodiment, matching the series of template values13to the series of input values12comprises assigning one or more template values to one or more input values so as to decrease or minimize a sum of absolute distances between the input values and their respective assigned template values. For example, the absolute distances may be calculated using Euclidean or Manhattan metrics. For example, the matching may comprise choosing an input value that is to be assigned to a template value, or vice versa, so that the sum of absolute distances may be decreased. This way of assigning template values and input values to each other may be a particularly efficient way to match the two series, so that a computational effort for correcting the input signal may be small. According to an embodiment, the series of input values12and the series of template values13may be represented by a series X having a number of M input values and a series Y having a number of N template values, respectively. X=x1,x2, . . . x|M| Y=y1,y2, . . . y|N| Matching the series of input values12and the series of template values13may comprise decreasing a distance of a warping path W=w1, w2, . . . w|K|, wherein the kthelement of the warping path is wk=(i, j), with i being an index from time series X, and j being an index from time series Y. Thus, the warping path may define the assignment between the input values and the template values. The distance of the warping path Dist(W), which may be referred to as figure of merit, may for example be calculated as: Dist(W)=∑k=1k=KDist(wki,wkj) For example, wkiand wkjmay refer to xiand yj, the indices i and j being defined by wk. According to an embodiment, matching the series of input values12and the series of template values13comprises assigning the first input value of the series of input values12to the first template value of the series of template values13and the last template value of the series of template values13to the last input value of the series of input values12. Further, the series may be matched so that a first input value assigned to a first template value has a lower or equal index than a second input value assigned to a second template value if the index of the first template value is lower than or equal to the index of the second template value. Thus, the warping of the series may preserve the order of the values of the series and the boundaries of the series. As the boundaries may be preserved, discontinuities may be avoided, for example a discontinuity of the series of input values to a neighboring part of the input signal. According to an embodiment, matching the series of template values13to the series of input values12comprises using dynamic time warping algorithm for assigning the template values to the input values. Using the DTW algorithm may be very efficient for obtaining a warping path, e.g. the warping path W, and may result in a very accurate matching of multiple series. For example, allowed transformations in DTW may be only time and amplitude warping. Using the DTW algorithm may provide a fast matching of the series of template values13to the series of input values12with low computational effort. In other words, the DTW algorithm may find a good or an optimal alignment between two series, if one series may be warped non-linearly by stretching or shrinking it along its domain, for example if one time series may be warped non-linearly by stretching or shrinking it along its time axis. This warping may then be used to find corresponding regions between the two series, for example, time series, and to determine the similarity between the two. According to an embodiment, the series of input values12and the series of template values13have equal lengths. Equal lengths of the two series may enhance an efficiency of the matching of the two series and/or may enhance an efficiency of determining a mismatch or a difference between values of the series, or may be beneficial for providing the corrected signal19. For example, the series of input values12and the series of template values13have equal lengths, and a spacing between the input values and a spacing between the template values may be constant throughout the series. Thus, an matching the series, and obtaining the series of corrected input values may rely on indices of the template values and the input values and the corrected input values, e.g. without considering index values attributed to the indices. Thus, the processing of the series may rely on few steps, saving computational effort. According to an embodiment, the series of corrected input values17has the same length as the series of input values12. For example, the series of corrected input values17may be reshaped or resampled to have the same number of data points as the series of input values12, for example in order to avoid artefactual discontinuities arising from a patching operation, or from a stitching operation. For better understanding, the functionality and some features of the apparatus10may be described in the context of time series and in the context of an input signal provided by an ultrasonic transceiver. Thus, an index value attributed to an input value or a template value may represent a time value within a time interval spanned by the series of input values or the series of template values. However, time is only exemplary for a physical domain, to which the input values and the template values may refer, so that the series may also refer to another measureable size. In general, the concept may be applicable to any series, without the need of an index value being attributed to an element of the series. Similarly, ultrasonic signals are only an exemplary application of the presented concept. Nevertheless, the concept may also be applied to other signals, in particular to signals that are subject to noise signals the form of which is approximately known or expected. FIG.2shows a diagram comprising a series of template values23and a series of input values22, which may correspond to the series of template values13and the series of input values12, respectively. The series22and23are time series of an output signal of a microphone, e.g. a CMUT, as it may be used in the context described in the introduction. The series22,23shown inFIG.2span an exemplary interval from 0 to 0.3 ms. For example, the series of input values22comprises a noise signal, but a contribution of a signal of interest, e.g. an ultrasonic signal such as an echo, to the series of input values22may be negligible or not present. Nevertheless, as shown inFIG.2, there may be a mismatch between the series of template values23and the series of input values22. Accordingly, the input signal11may represent a time series of a measured value, and the series of template values13may comprises a time series of a noise signal. Further, the series of input values12and the series of template values13may cover an equal timespan. FIG.3shows a diagram comprising a series of corrected values37as it may result from a conventional solution, namely as it may result from a blind subtraction of series of template values23from the series of input values22. Blind subtraction may refer to a subtraction without matching the series of template values23to the series of input values22, for example by subtracting a template value from an input value having the same time value, i.e. the same index value, as the template value. As indicated in region38, strong artefact peaks may arise from the blind subtraction, which may lead to a false-positive echo detection in the case of ultrasonic signal detection. In other words,FIG.3may show an example of a template subtraction with mismatches, e.g. amplitude and phase mismatches. For example, artifact peaks that may arise from the procedure, may lead to a false-positive echo detection, e.g. in an ultrasonic signal. FIG.4illustrates the procedure of matching of the series of template values23to the series of input values22according to an embodiment.FIG.4shows a cost matrix44, in which the abscissa may indicate an index of the series of template values23and the ordinate may indicate an index of the series of input values22. For example, a brightness value of a point with the coordinates (i, j) may indicate a cost, e.g. a contribution to a distance of a warping path, of assigning a template value with index i to an input value with index j. A warping path48assigns a template value to an input value by assigning an index of the series of template values23to an index of the series of input values22. The warping path48may represent a warping path W with a low or minimal distance Dist(W). For example, the warping path48may be obtained by means of a DTW algorithm. FIG.5shows a diagram comprising the series of input values22and the series of template values23. Lines58between input values and template values indicate the assignment between the template values and the input values. As indicated, an input value may be assigned to a template value that is shifted along the time axis with respect to the input value.FIG.6shows a diagram comprising a series of corrected input values67, which may correspond to the series of corrected input values17. For example, the series of corrected input values67may have been obtained by subtracting a template value of the series of template values23from its assigned input value of the series of input values22. The series of corrected input values67may correspond to a template subtraction with mismatches, after application of DTW as matching mechanism. Compared to the blind subtraction37shown inFIG.3, the artificial peak does not appear in the series of corrected input values67. In other words, an effectiveness of the ad-hoc transformation is illustrated byFIGS.3,6, where spurious peaks within a blanking zone are suppressed when applying the warping beforehand, for example by comparing a subtraction without warping shown inFIG.3to a subtraction with warping shown inFIG.6. FIG.7shows a schematic representation of a further embodiment of the apparatus10, according to which the apparatus10comprises means, e.g. the matching unit15, for obtaining a corrected template76and a series of warped input values78based on the matching of the series of template values13to the series of input values12. Further, the apparatus10may be configured for obtaining the series of corrected input values17based on a difference between the series of warped input values78and the corrected template76. For example, the corrected template76comprises a series of corrected template values which may be obtained by assigning a template value to a corrected template value, the assigned template value having an index or an index value that equals an index or an index value of an input value assigned to a template value having an equal index or index value as the corrected template value. According to an embodiment, the apparatus10is configured for splitting the input signal11into a plurality of intervals, e.g. by means of a splitting unit74. The plurality of intervals comprises an interval of interest, within which the noise signal is expected to occur. The interval of interest comprises the series of input values12, which is to be matched with the series of template values13. By splitting the input signal11into a plurality of intervals, correcting the input signal11with the series of template values13may be applied selectively to the interval of interest. Thus, the correction is not necessarily applied to an interval of the input signal11that is not expected to be corrupted by the noise signal. Thus, the series of template values13and the series of input values12may be chosen to be shorter, so that computational effort may be saved. Further, avoiding correcting an interval which is not expected to be corrupted by the noise signal, may limit artefacts of the correction, which may possibly occur, to the interval of interest. Such, the quality of the corrected signal may be enhanced. For example, the selective transformation, for example, the splitting of the input signal into an interval of interest and one or more further intervals, may be made possible due to the presence of dedicated boundary conditions in the algorithm definition for example in the definition of the algorithm for matching the series of input values12to the series of template values13. For example, given two time series X=x1, x2, . . . x|m|and Y=y1, y2, . . . y|N|, the boundary conditions may enforce that the first elements of X and Yare aligned to each other, and that the last elements of X and Y are aligned to each other. Thus, the alignment may be selectively applied to the interval where the noise signal, for example, the membrane reverberation is expected to be. Thus, no discontinuities may arise from the processing steps, for example the splitting of the input signal. It is pointed out, that the feature of the splitting unit74and the feature of obtaining a corrected template76shown inFIG.7are independent from each other. For example, the splitting unit74may provide a part of the input signal that is not part of the series of input values as a passthrough input signal14. For example, a sum of a length of the series of input values12and a length of the passthrough input signal14may equal a length of the input signal. The apparatus10may stitch or join the series of corrected input values17and the passthrough input signal14so as to obtain the corrected signal19. According to an alternative embodiment, the passthrough input signal14may represent the input signal11, and the apparatus10may patch the passthrough input signal14, i.e. the input signal11, with the series of corrected input values17so as to obtain the corrected signal19. Accordingly, the apparatus10may be configured for patching the interval of interest of the input signal11using the series of corrected input values17, so as to obtain the corrected signal19. For example, patching the interval of interest may be performed by replacing the series of input values12in the input signal11by the series of corrected input values17. According to an embodiment, the corrected template76and the series of input values12have an equal length, so that artefactual discontinuities in the patching may be avoided, for example in a patching operation or a stitching operation for obtaining the corrected signal19from the series of corrected input values17and the passthrough input signal14, e.g. an unprocessed ultrasonic signal. According to an embodiment, the corrected template76and the series of warped input values78are resampled in order to have the equal length as the series of input values12. Hence, the subtraction may be performed efficiently by pairwise subtraction and the resulting series of corrected input values17can be patched to the passthrough input signal14without additional discontinuities. FIG.8shows a diagram comprising a series of template values83and a series of input values82, which may correspond to the series of template values13and the series of input values12, respectively. No signal of interest or echo may be present in the series of input values82.FIG.9shows a diagram comprising the series of template values83and the series of input values82, and illustrating the assignment of template values to input values. The assignment of the input values to the template values may be based on the warping path118as shown inFIG.11, which illustrates the matching of the series of the series of template values83and the series of input values82according to an embodiment, similar to the illustration shown inFIG.4.FIG.10shows a comparison between a series of corrected input values108and a series of corrected input values107. The series of corrected input values108may be a result of a conventional correction of the series of input values82using a blind subtraction. The series of corrected input values107may correspond to the series of corrected input values17and may be a result of using a DTW algorithm. As visible fromFIG.10, the series of corrected input values107may have a lower amplitude and a different frequency compared to the series of corrected input values108. According to an embodiment, the apparatus10is configured for identifying a part of the series of corrected input values17as a signal of interest, if the corrected input values of the part of the series of corrected input values17exceed a threshold value. Further, the apparatus10may be configured for identifying a part of the series of corrected input values17as a residual noise signal, if the corrected input value of the part of the series of corrected input vales17do not exceed the threshold value. For example, the series of corrected input values17may comprise a signal, e.g. deviate from 0, even if the input signal does not comprise a signal of interest, as it may be the case for the series of input values22and82. In contrast, as may be seen inFIG.6and in the lower panel ofFIG.10, the series of corrected input values17,67,107, may comprise a residual noise signal. For example, a further use of the corrected signal19may depend on the indication of the apparatus10, whether the corrected signal19comprises a signal of interest or not. Thus, processing effort may be saved in the case that no signal of interest is detected. In other words, a DTW algorithm may be tuned to reconstruct a time warped signal. When the figure of merit shows low or minimum realizations i.e. a high degree of similarity between two time series, the warped subtraction may lead to the highest suppression and spurious peaks are suppressed. When the figure of merit shows high realizations i.e. low degree of similarity between the two time series, the warped subtraction may give origin to residual errors, which may corresponds to a searched echo and may then furtherly be processed. In short, echoes appearing in the blanking region may only be partially affected by the selective DTW transformation, guaranteeing improved object detection capabilities in the very-close proximity range. According to an embodiment, the apparatus10is configured for applying a frequency filter to the series of corrected input values17. For example, applying the frequency filter may facilitate differentiating a signal of interest from an artificial signal originating from the correction of the input signal19or from a residual noise signal. For example, a residual noise signal or a signal originating from the correction of the input signal19, may have a different frequency than a signal of interest that is expected to occur in the input signal19. For example, the signal of interest is expected to have a specific frequency. Thus, the frequency filter may be a band pass filter configured for transmitting a frequency of the signal of interest while attenuating frequencies that deviate by more than 50% or 20% or 5% from the frequency of the signal of interest. Thus, the frequency filter may further enhance a signal to noise ratio of the corrected signal19. FIG.12shows a schematic representation of an apparatus1200for obtaining information1290about a TOF of an ultrasonic signal1220according to an embodiment. The apparatus1200comprises a transceiver1210, configured for transmitting the ultrasonic signal1220during a first time span, and configured for receiving an ultrasonic signal1230during a second time span. The transceiver1210is configured for providing an input signal11representing the received ultrasonic signal1230in a time series. The apparatus1200further comprises the apparatus10for correcting an input signal, configured for receiving the input signal11and configured for providing the corrected signal19. Further, the apparatus1200comprises means, e.g. a signal processor1240, for obtaining the information1290about the TOF of the ultrasonic signal by evaluating the corrected signal19. For example, the received ultrasonic signal1230may originate from a reflection of the ultrasonic signal1220at a surface region of an object facing the apparatus1200. Thus, the apparatus1200may obtain the information1200about the TOF of the ultrasonic signal by determining a time difference between transmitting the ultrasonic signal1220and receiving the ultrasonic signal1230. For this purpose, the apparatus1200may determine an instant of time of receiving the ultrasonic signal1230by evaluating the input signal11, which may comprise a time series comprising the series of input values. FIG.13shows a diagram comprising an input signal1301which may correspond to the input signal11. The input signal1301is a time series of input values which may be provided by the transceiver1210, e.g. as a voltage. The inset ofFIG.13illustrates an exemplary arrangement of an example of the apparatus1200and an object138, which is an origin of a reflection1230of an ultrasonic signal1220transmitted by the apparatus1200. For example, the reflected ultrasonic signal1230may be referred to as an echo of the ultrasonic signal1220. For example, the information about the TOF of an ultrasonic signal may be a time between transmitting the ultrasonic signal and receiving the echo of the ultrasonic signal. A distance between the transceiver1210and the object1380may be inferred from the information1290about the TOF of the ultrasonic signal. The input signal1301comprises a ringing1370which may correspond to the noise signal. For example, the ringing1370may arise from a reverberation of the transmitter1210after transmitting the ultrasonic signal1220. The time frame within which the ringing1370occurs may be referred to as blanking zone and may be selected as the interval of interest1308for the correction of the input signal1301. Thus, the input values of the input signal1301within the blanking zone1308may represent a series of input values1302which may correspond to the series of input values12. As the ringing1370may be characteristic for the transmitter1210, the ringing1370may be described by an example of the series of template values13. However, the ringing1370may change over time. The input signal1301further comprises an echo1360which may correspond to the signal of interest. An amplitude of the echo1360may be lower than an amplitude of the ringing1370. Therefore, the echo1360may be difficult to detect if a distance between the transmitter1210and the object causing the echo1360is low, so that the echo1360occurs within the blanking zone. As the ringing may be characteristic for the used transceiver1210, it may be corrected by using a template13. However, degradation or variations between different transceivers may modify the ringing, so that degradation over time could bring to false-positive echo detection as in case of blind subtraction. Matching the template to the input signal may prevent such a false-echo detection. The upper panel ofFIG.14shows a diagram comprising a series of input values1402, which may correspond to the series of input values12and a series of template values1403, which may correspond to the template13. The series of input values1402comprises a signal representing a ringing of an ultrasonic transceiver and an echo1460of an ultrasonic signal. The second panel comprises a difference between the series of input values1402and the series of template values1403determined without using the warping. The difference signal1408comprises a high amplitude peak1480which represents an artefact of the template subtraction. The lower panel ofFIG.14shows a series of corrected input values1407as an example of the series of correct input values17. The series of corrected input values1407comprises a residual noise signal1450and further comprises a signal representing an echo1460. For example, the residual noise signal1450may have a different, e.g. a higher frequency than the signal of interest1460. In other words,FIG.14may illustrate an example of a DTW algorithm applied in presence of an echo. Spurious peaks in the blanking zone may be suppressed while the echo signal1460may remain unchanged, or may remain detectable in the corrected signal. According to an embodiment, the apparatus10is configured for applying a frequency filter to the corrected signal. The frequency filter is configured for transmitting a signal with a frequency within a range of ±50%, preferably ±20%, more preferably ±5% of a frequency of the transmitted ultrasonic signal1220and configured for attenuating a signal with a frequency outside the range. For example, by applying the frequency filter, a residual noise signal, for example the residual noise signal1450, may be attenuated, while a signal of interest, for example the echo1460, may be transmitted. Thus, the frequency filter may prevent a false detection of echo signal in case of a residual noise signal. According to an embodiment, the series of input values12and the series of template values13cover a timespan of a ringing of the transceiver1210after transmitting the ultrasonic signal1220. For example, the timespan may be 0 to 1 ms after transmitting the ultrasonic signal1220. By covering the timespan of the ringing of the transceiver, a noise signal originating from a reverberation of the transceiver may be efficiently corrected. FIG.15shows a flow chart of a method1500for correcting an input signal11according to an embodiment. The method1500comprises a step1510of receiving the input signal11, the received input signal11comprising a series of input values12. The step1520comprises matching a series of template values13to the series of input values12by warping the series of template values13and the series of input values12relative to each other so as to assign one or more template values to one or more input values. The series of template values13represents an approximation of a noise signal that is expected to be comprised in the input signal11. The method1500further comprises a step1530of obtaining a series of corrected input values17based on a mismatch between the input values and their respective assigned template values. Further, the step1540comprises providing a corrected signal19based on the series of corrected input values17. The method1500provides the features, functionalities and advantages described with respect to the apparatus10for correcting an input signal11. FIG.16shows a flow chart of a method1600for obtaining an information about a TOF of an ultrasonic signal according to an embodiment. For example, the method1600may be implemented by the apparatus1200. The method1600comprises a step1699of correcting the input signal11. The step1699may be an implementation of the method1500. The input signal11may represent a detected ultrasonic signal. The step1699may comprise splitting the detected ultrasonic signal11into intervals so as to obtain a series of input values12which may represent an interval of the detected ultrasonic signal11within which a ringing is to be expected. In other words, an a-priori knowledge about the localization and duration of a membrane reverberation may be exploited to segment the time series11into intervals. The splitting may also be referred to as signal windowing. The selective transformation may bring considerable advantages in the blanking zone, while maintaining unaltered the echo signal-to-noise ratio after or without the blanking zone, since not suppressed by adaptive mechanisms. Further, the step1699comprises a step1625, in which the series of input values12is matched to a series of template values13. Hence, the warping may be selectively applied only to the first interval of the time series, leaving the remaining epochs of the recorded time series11untouched. The template13may represent an approximation of the ringing. For example, the step1625may rely on a DTW algorithm. For example, the step1625implements the steps1520,1530of the method1500. The step1625may provide a series of corrected input values17. A patching operation may use the series of corrected input values17for patching the detected ultrasonic signal11, so as to obtain the corrected or patched signal19. In a step1650, a band pass filter1651, for example a frequency filter is applied to the patched signal19so as to obtain a filtered signal1652. In a further step1660a cross-correlation between the filtered signal1652, e.g. a warped difference, and an echo template1662is determined, so as to obtain a correlated signal1661. For example, the echo template1662comprises information about a transmitted ultrasonic signal being a basis or an origin of an echo which may be comprised in the detected ultrasonic signal11. For example, the echo template1662is based on a form of the transmitted ultrasonic signal and/or may comprise information about a transfer function or response function of the transceiver or other hardware in the signal chain. In a further step1670a maximum of the correlated signal1661is determined based on a time gain compensation1671. For example, a detected maximum may represent a received echo, so that the information1290about a TOF of the ultrasonic signal may be estimated based on a position of the detected maximum on the time axis. The upper panel ofFIG.17shows a diagram comprising a series of template values1703and a series of input values1702, which may correspond to the series of template values13and the series of input values12, respectively. The series of input values1702may represent a case of no echo in the blanking zone. The second panel ofFIG.17shows a diagram comprising a cross correlated signal1798. The cross-correlated signal1798may have been derived by a method similar to the method1600, wherein the step1625is replaced by a simple blind subtraction. The cross-correlation1798of the blind difference may lead to a false echo detection. The lower panel ofFIG.17shows an example of the cross-correlated signal1661which may have been derived as described with respect toFIG.16. A maximum or a local maximum of the cross-correlated signal1661occur in a region where no echo may be expected, for example due to actuation. Thus, no object may be detected based on the cross-correlated signal1798. The upper panel ofFIG.18shows a diagram comprising a series of template values1803and a series of input values1802, which may correspond to the series of template values13and the series of input values12, respectively. The series of input values1802may represent a case of an overlapping echo in the blanking zone, for example the series of input values1802may comprise a signal representing an echo1860. The second panel ofFIG.18shows a cross-correlated signal1898which may have been derived based on a blind subtraction, similar to the cross-correlated signal1798ofFIG.17. A maximum1897of the cross-correlated signal1898appears at a time value which is different from a time value of the echo1860in the upper panel. The lower panel ofFIG.18shows a diagram comprising an example of the correlated signal1661which may have been derived as described with respect toFIG.16. A maximum1862of the cross-correlated signal1661is close to a position of the echo1860of the upper panel. Thus, the cross-correlation1661of the warped difference, for example a series of corrected input values derived from the series of input values1802and the series of template values1803, may lead to a more accurate detection of the echo1860compared to the cross-correlated signal1898, although a signal to noise ratio of the cross correlated signal1661may be lower. FIG.19shows a method1900for obtaining an information1290about a TOF of an ultrasonic signal according to an embodiment. The method1900is based on the method1600comprising the indicated features of the method1600. In the method1900, the step1625is replaced by a step1925. Step1925comprises matching the series of input values12and the series of template values13and comprises obtaining the corrected template76. The method1900comprises a subtraction1947of the corrected template76from the input signal11. For example, the corrected template may be zero-padded for subtracting it from the input signal11. In other words, the warped template76may be zero-padded in order to reach the length of the received time series11, which may constitute the corrected template76. The subtraction1947results in a processed signal which may be similar to the patched signal19. In other words, the described method1900may reach from signal windowing, for membrane ringing epoch identification, to TOF estimation for echo detection. Specifically, a block1991may be referred to as Interval Selective DTW and may be responsible for signal windowing, cost function calculation and template warping. A following block1992may represent a proper Ringing subtraction. The subtraction may lead to a ‘similarity fingerprint’, which may be zero-padded to return the Corrected Template76. The disclosed apparatuses10,1200and methods1500,1600,1900may fulfill low-power requirements, for example of mobile applications. Ultrasonic usage in mobile devices is attractive for disparate applications such as range finding, presence detection, wind/temperature measurement, gesture classification. When considering single CMUT, the ringing subtraction problem may have to be taken into account. Thus, the disclosed apparatuses10,1200and methods1500,1600,1900provide a low-cost methodology for effective ringing suppression for precise short-range measurements with ultrasonic transceivers. The concept may embed a DTW-based non-linear transformation for epochs-selective warping of a membrane reverberation artifact. The selectivity may be guaranteed by the a-priority knowledge of the localization and duration of the artifacts, as well as by the selection of appropriate boundary conditions. The concept may return a warped difference as similarity fingerprint, which may be used for ringing suppression in the real-time recorded signal. When the similarity is high, the subtraction may return its minimum realization, i.e. zeroing the warped difference. When the similarity is low, the subtraction may contain residuals which are assumed to be constituents of the echo and thus used for subsequent processing. The concept may implement a low-complexity always-on mechanism for template matching which may guarantee enhanced adaptability to diverse MEMS devices, e.g. revealing manufacturing tolerances, as well as adaptability for the same devices, which proved to be variable overtime e.g. due to temperature changes. The concept may enable a reduced calibration routine since the same template can be stored in each sensor, allowing mass-applications. Thus, the base template is adjusted automatically for each device. According to an alternative aspect, the matching of the template13to the series of input values12is based on a template-matching algorithm based on a Kalman filter. The implementation of the Kalman filter based matching may determine matching points, for example best matching points, between the reference ringing template, e.g. the template13, and the real-time recorded data, e.g. the series of input values. The implementation of the Kalman filter based matching may comprise a prediction step which may be based on inference from a prior knowledge state, and may comprise an update step which may be based on a comparison between a prediction and a measurement, e.g. the input values. For example, the prediction step is unbounded and the filter or the matching may be applied to the entire ultrasonic recording, e.g. the series of input values12may represent the entire range of the input signal11. Additional embodiments and aspects are described which may be used alone or in combination with the features and functionalities described herein. According to an embodiment, an apparatus10for correcting an input signal11is configured for: receiving the input signal11, the received input signal11comprising a series of input values12; matching a series of template values13to the series of input values12by warping the series of template values13and the series of input values12relatively to each other so as to assign one or more template values to one or more input values, wherein the series of template values13represents an approximation of a noise signal that is expected to be comprised in the input signal11; obtaining a series of corrected input values17based on a mismatch between the input values and their respective assigned template values; providing a corrected signal19based on the series of corrected input values17. According to another embodiment, matching the series of template values13to the series of input values12comprises assigning one or more template values to one or more input values so as to decrease a sum of absolute distances between the input values and their respective assigned template values. According to another embodiment, matching the series of template values13to the series of input values12comprises using a dynamic time warping algorithm for assigning the template values to the input values. According to another embodiment, the apparatus10is configured for obtaining a corrected template76and a series of warped input values78based on the matching of the series of template values13to the series of input values12; and the apparatus10is configured for obtaining the series of corrected input values17based on a difference between the series of warped input values78and the corrected template76. According to another embodiment, the apparatus10is configured for splitting the input signal11into a plurality of intervals comprising an interval of interest1308, within which the noise signal is expected to occur, wherein the interval of interest1308comprises the series of input values12, which is to be matched with the series of template values13. According to another embodiment, the apparatus10is configured for patching the interval of interest1308of the input signal11using the series of corrected input values17, so as to obtain the corrected signal19. According to another embodiment, the input signal1301represents a time series of a measured value; the series of template values13comprises a time series of a noise signal; and wherein the series of input values12and the series of template values13cover an equal time span. According to another embodiment, the apparatus10is configured for identifying a part of the series of corrected input values17as a signal of interest, if the corrected input values of the part of the series of corrected input values17exceed a threshold value; and the apparatus10is configured for identifying a part of the series of corrected input values17as a residual noise signal, if the corrected input values of the part of the series of corrected input values17do not exceed the threshold value. According to another embodiment, the apparatus10is configured for applying a frequency filter to the series of corrected input values17. According to another embodiment, the series of input values12and the series of template values13have equal lengths. According to another embodiment, an apparatus1200for obtaining an information1290about a time of flight of an ultrasonic signal comprises: a transceiver1210, configured for transmitting the ultrasonic signal1220during a first time span, and configured for receiving an ultrasonic signal1230during a second time span, wherein the transceiver1210is configured for providing an input signal11comprising the received ultrasonic signal1230in a time series; the apparatus10for correcting an input signal according to any of the preceding embodiments, configured for receiving the input signal11and configured for providing the corrected signal19; means1240for obtaining the information1290about the time of flight of the ultrasonic signal by evaluating the corrected signal19. According to another embodiment, the apparatus1200is configured for applying a frequency filter to the corrected signal19, wherein the frequency filter is configured for transmitting a signal with a frequency within a range of ±50%, preferably ±20%, more preferably ±5% of a frequency of the transmitted ultrasonic signal1220and configured for attenuating a signal with a frequency outside of the range. According to another embodiment, the series of input values12and the series of template values13cover a time span of a ringing of the transceiver1210after transmitting the ultrasonic signal1220. According to another embodiment, a method1500for correcting an input signal11, comprises: receiving1510the input signal11, the received input signal11comprising a series of input values12; matching1520a series of template values13to the series of input values12by warping the series of template values13and the series of input values12relatively to each other so as to assign one or more template values to one or more input values, wherein the series of template values13represents an approximation of a noise signal that is expected to be comprised in the input signal11; obtaining1530a series of corrected input values17based on a mismatch between the input values and their respective assigned template values; providing1540a corrected signal19based on the series of corrected input values17. According to another embodiment, a computer program implements the method of the preceding embodiment when being executed on a computer or signal processor. Although some aspects have been described as features in the context of an apparatus it is clear that such a description may also be regarded as a description of corresponding features of a method. Although some aspects have been described as features in the context of a method, it is clear that such a description may also be regarded as a description of corresponding features concerning the functionality of an apparatus. Some or all of the method steps may be executed by (or using) a hardware apparatus, like for example, a microprocessor, a programmable computer or an electronic circuit. In some embodiments, one or more of the most important method steps may be executed by such an apparatus. Depending on certain implementation requirements, embodiments of the invention can be implemented in hardware or in software or at least partially in hardware or at least partially in software. The implementation can be performed using a digital storage medium, for example a floppy disk, a DVD, a Blu-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed. Therefore, the digital storage medium may be computer readable. Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed. Generally, embodiments of the present invention can be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer. The program code may for example be stored on a machine readable carrier. Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier. In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer. A further embodiment of the inventive methods is, therefore, a data carrier (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein. The data carrier, the digital storage medium or the recorded medium are typically tangible and/or non-transitory. A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the Internet. A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein. A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein. A further embodiment according to the invention comprises an apparatus or a system configured to transfer (for example, electronically or optically) a computer program for performing one of the methods described herein to a receiver. The receiver may, for example, be a computer, a mobile device, a memory device or the like. The apparatus or system may, for example, comprise a file server for transferring the computer program to the receiver. In some embodiments, a programmable logic device (for example a field programmable gate array) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods are preferably performed by any hardware apparatus. The apparatus described herein may be implemented using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer. The methods described herein may be performed using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer. In the foregoing Detailed Description, it can be seen that various features are grouped together in examples for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed examples require more features than are expressly recited in each claim. Rather, as the following claims reflect, subject matter may lie in less than all features of a single disclosed example. Thus the following claims are hereby incorporated into the Detailed Description, where each claim may stand on its own as a separate example. While each claim may stand on its own as a separate example, it is to be noted that, although a dependent claim may refer in the claims to a specific combination with one or more other claims, other examples may also include a combination of the dependent claim with the subject matter of each other dependent claim or a combination of each feature with other dependent or independent claims. Such combinations are proposed herein unless it is stated that a specific combination is not intended. Furthermore, it is intended to include also features of a claim to any other independent claim even if this claim is not directly made dependent to the independent claim. The above described embodiments are merely illustrative for the principles of the present disclosure. It is understood that modifications and variations of the arrangements and the details described herein will be apparent to others skilled in the art. It is the intent, therefore, to be limited only by the scope of the pending patent claims and not by the specific details presented by way of description and explanation of the embodiments herein. | 54,769 |
11942976 | DETAILED DESCRIPTION Some embodiments of the present disclosure provide a communication anti-interference detection method, in which a radio-frequency signal is demodulated and then subjected to interference detection, after the demodulated signal is subjected to inverse Fourier transform and convolution, the signal enters a logic control switch, an interfering signal is filtered out by an anti-interference circuit, and a useful signal is modulated to a radio-frequency signal. If there is no interfering signal, the radio-frequency signal is processed by the radio-frequency circuit. The embodiments of the present disclosure provide a novel wireless communication anti-interference detection module. When two adjacent frequency bands, especially current 5G and 4G or future 5G and 6G, work at the same time, an intermediate protection bandwidth between the two adjacent frequency bands is narrow and an interfering signal is strong. The embodiments of the present disclosure detect and filter out an interfering signal, so that a good radio-frequency performance can be achieved, thereby alleviating the disadvantages of the related art. Furthermore, the solution of the embodiments of the present disclosure has the advantages of low cost, strong operability, easiness in implementation, good effect and high performance-price ratio. According to some embodiments of the present disclosure, a communication anti-interference detection method is provided.FIG.2is a schematic diagram of an anti-interference detection method according to some embodiments of the present disclosure. As shown inFIG.2, the method includes the following operations. In A100, an input radio-frequency signal is demodulated to acquire a demodulated signal. In B100, a first signal and a second signal are convolved to acquire a detection signal, so as to detect whether there is an interfering signal in the input radio-frequency signal, wherein the first signal is a signal acquired by performing inverse Fourier transform on the demodulated signal, and the second signal is a signal acquired by performing phase inversion on a preset baseband signal. In some embodiments, the input radio-frequency signal includes a first input radio-frequency signal and/or a second input radio-frequency signal, and the first input radio-frequency signal and the second input radio-frequency signal are based on different systems. In some embodiments, the operation that the input radio-frequency signal is demodulated includes: attenuation processing is performed on the input radio-frequency signal, and then the attenuated radio-frequency signal is demodulated to acquire the demodulated signal. In some embodiments, the operation of detecting whether there is an interfering signal in the input radio-frequency signal includes: the inverse Fourier transform is performed on the demodulated signal to acquire the first signal, wherein a manner for performing the inverse Fourier transform on the demodulated signal includes performing the inverse Fourier transform on the demodulated signal to generate a superposition of sine waves having different frequencies; the phase inversion is performed on the preset baseband signal to acquire the second signal; the first signal and the second signal are convolved to remove a useful sine wave signal, so as to acquire the detection signal; and whether the detection signal is interfering is determined. In C110, in cases where the detection signal is interfering, anti-interference processing is performed on the interfering detection signal. In D101, in cases where the detection signal is not interfering, the input radio-frequency signal enters, via a non-interfering channel, the radio-frequency circuit for processing. Some embodiments of the present disclosure provide a signal anti-interference method, which includes the operations of the foregoing signal interference detection method. The signal anti-interference method further includes: in cases where there is the interfering signal in the radio-frequency signal, the interfering detection signal and the first signal are processed to acquire a third signal; and the third signal is modulated to acquire an output radio-frequency signal. In some embodiments, the operation that the third signal is acquired further includes: after the interfering detection signal is deconvolved, subtraction or inverse superposition is performed on the interfering detection signal and the first signal, and the interfering signal is filtered out to acquire the third signal. According to some embodiments of the present disclosure, a communication anti-interference detection device is provided.FIG.3is a schematic structural diagram of an anti-interference detection device according to some embodiments of the present disclosure. As shown inFIG.3, the device includes: a demodulation module A100, an interference detection module B100, an anti-interference module C100, and a radio-frequency circuit processing module D100. After being demodulated by the demodulation module, an input radio-frequency signal enters the interference detection module to acquire a detection signal; and in cases where the detection signal is interfering, the input radio-frequency signal enters the anti-interference module to acquire a third signal, and the third signal is modulated to acquire an output radio-frequency signal, and is processed by the radio-frequency circuit processing module. In some embodiments, as shown inFIG.4which is a schematic structural diagram of a demodulation module and an interference detection module according to some embodiments of the present disclosure, the demodulation module includes: a first antenna A101and/or a second antenna A101, an attenuator A103, and a demodulator A104. The first antenna and/or the second antenna are/is configured to receive the input radio-frequency signal. The attenuator is configured to perform attenuation processing on the input radio-frequency signal. The demodulator is configured to demodulate the signal. The attenuator and demodulator through which the input radio-frequency signal received by the first antenna passes, and the attenuator and demodulator through which the input radio-frequency signal received by the second antenna passes are the same set of attenuator and demodulator, or are two or more sets of attenuators and demodulators. Any antenna, attenuator, and demodulator having the functions and capable of meeting the requirements are applicable to the embodiments of the present disclosure, which is not specifically limited in the present disclosure. In some embodiments, as shown inFIG.4which is a schematic structural diagram of a demodulation module and an interference detection module according to some embodiments of the present disclosure, the interference detection module includes an interference detection circuit which includes an inverse Fourier transformer B101, a memory B201, a phase inverter B202and a convolutor B102. The demodulated signal is subjected to inverse Fourier transform to generate a superposition of sine waves having different frequencies, so as to acquire a first signal. The phase of a preset baseband signal in the memory is inverted by the phase inverter to acquire a second signal. The first signal and the second signal are convolved by the convolutor to remove a useful sine wave signal, so as to acquire a convolved detection signal. It is determined whether the detection signal is interfering. In cases where the detection signal is interfering, the interfering detection signal enters an anti-interference circuit via a logic control switch B300for anti-interference processing. In cases where the detection signal is not interfering, the input radio-frequency signal enters, via a non-interfering channel, the radio-frequency circuit processing module for processing. The same set of inverse Fourier transformer, memory, phase inverter, convolutor and logical control switch is shared by signals of different systems, or two or more sets of inverse Fourier transformers, memories, phase inverters, convolutors and logical control switches are respectively used for signals of different systems. Any module having the function and capable of performing the required inverse Fourier transform-like function is suitable for the embodiments of the present disclosure. Any memory, ant inverter and any convolutor having the functions and capable of meeting the requirements are suitable for the embodiment of the present disclosure, which is not specifically limited in the present disclosure. In some embodiments, as shown inFIG.5which is a schematic structural diagram of an anti-interference module according to some embodiments of the present disclosure, the anti-interference module includes: an anti-interference circuit, a Fourier transformer and a demodulator. The anti-interference circuit includes a deconvolutor C111and a subtracter C112. The deconvolutor is configured to process the interfering detection signal. After passing through the deconvolutor, the interfering detection signal is subtracted from or reversely superimposed with the signal subjected to Fourier transform, and an interfering signal is filtered out to acquire the third signal. The third signal is processed by Fourier transformer C120and then modulated by a modulator C130to acquire the output radio-frequency signal. The same set of convolutor, subtracter and Fourier transformer is shared by signals of different systems, or two or more sets of convolutors, subtracters and Fourier transformers are respectively used for signals of different systems. Any module having the function and capable of performing the required Fourier transform-like function is suitable for the embodiments of the present disclosure. Any deconvolutor, any subtracter, and any demodulator having the functions and capable of meeting the requirements are suitable for the embodiments of the present disclosure, which is not specifically limited in the present disclosure. According to some embodiments of the present disclosure,FIG.6is a schematic diagram of an overall flow framework of wireless communication anti-interference detection according to some embodiments of the present disclosure. As shown inFIG.6, the radio-frequency circuit processing module includes: a radio-frequency circuit D101and a radio-frequency chip D102. The output radio-frequency signal is processed by the radio-frequency circuit. In cases where the detection signal is not interfering, the input radio-frequency signal enters, via a non-interfering channel, the radio-frequency circuit for processing. Any radio-frequency circuit and any radio-frequency chip having the functions and capable of meeting the requirements are applicable to the embodiments of the present disclosure, which is not specifically limited in the present disclosure. A storage medium is also provided, wherein the storage medium is configured to store a computer program, and the computer program is configured to execute the foregoing method during running. Any storage medium having the functions and capable of meeting the requirements is suitable for the embodiments of the present disclosure, and the present disclosure is not specifically limited. An electronic device is also provided, including a memory and a processor, wherein the memory is configured to store a computer program, and the processor is configured to run the computer program to execute the foregoing method. Any memory and any processor having the functions and capable of meeting the requirements are suitable for the embodiments of the present disclosure, and the present disclosure is not specifically limited. In addition, some embodiments of the present disclosure provide a computer program product. The computer program product includes a computer program stored in a non-transitory computer-readable storage medium. The computer program product includes a program instruction, and when the program instruction is executed by a computer, the computer is caused to execute the method of the foregoing method embodiments. The present disclosure will be described below in details with reference to the accompanying drawings. It should be understood that the exemplary embodiments described herein are only intended to explain the present disclosure, but not to limit the present disclosure. The embodiments and the features of embodiments of the present disclosure can be combined in case that no conflict is caused. The embodiments provide a communication anti-interference detection method.FIG.6is a schematic block diagram of an overall flow of wireless communication anti-interference detection according to some embodiments of the present disclosure. As shown inFIG.6, the method includes the following operations. A radio-frequency signal received by a first antenna A101and/or a second antenna A101passes through a coupler A102, and is processed by an anti-interference detection module B100. The determination result on whether the value of the signal is zero or whether the signal is interfering controls a logic control switch B300, such as a switch SP2T. If the value is zero or the signal is not interfering, the coupler A102is controlled to send the received radio-frequency signal directly to a radio-frequency circuit D101for processing. If the value is not zero or the signal is interfering, an interfering signal is filtered out by an anti-interference module C100, and finally a useful signal is modulated to the radio-frequency signal and processed by the radio-frequency circuit D101. In some embodiments,FIG.7is a schematic diagram of a detailed framework of a wireless communication anti-interference detection system according to some embodiments of the present disclosure. As shown inFIG.7, the method includes the following operations. A radio-frequency signal received by a first antenna A101and/or second antenna A101passes through a coupler A102, an attenuator A103and a demodulator A104, and the acquired signal is subjected to inverse Fourier transform B101to form into a superposition of sine waves having different frequencies. The superposition of sine waves and a specific baseband signal stored in a memory B201and subjected to phase inversion of a phase inverter B202are convolved by a convolutor B102. It is determined whether the value of the convolved signal is zero or whether the convolved signal is interfering, and the determination result controls a logic control switch B300, such as a switch SP2T. If the value is zero or the signal is not interfering, the coupler A102is controlled to send the received radio-frequency signal directly to a radio-frequency circuit D101for processing. If the value of the convolved signal is not zero or the signal is interfering, an interfering signal is filtered out by an anti-interference module C100, and finally, by a Fourier transform C120and a modulator C130, a useful signal is modulated to the radio-frequency signal and the radio-frequency signal is processed by the radio-frequency circuit D101. Some embodiments provide a communication anti-interference detection method. An exemplary embodiment describing an application scenario example of the method of the embodiments of the present disclosure is provided as follows, and this exemplary embodiment is used for further illustrating the embodiments of the present disclosure, and does not limit the method of the embodiments of the present disclosure. For example, a full-band bandwidth of the Band 41 is 196 MHz, and is divided according to the current requirements of an operator (Sub6G 100 MHz, LTE 60 MHz). In the example, the intermediate protection bandwidth between Sub6G N41 and LTE Band 41 is only 36 MHz. During the transmission based on the Sub6G, the sideband noise of the Sub6G transmission may fall into the receiving band of the LTE. Likewise, during the transmission based on the LTE, the sideband noise of the LTE transmission may also fall into the receiving band of the Sub6G. As shown inFIGS.6and7, 4G and 5G communications work at the same time. When N41 works on a first antenna A101, and B41works on a second antenna, after two signals enter a switch, the two signals respectively pass through an attenuator A103and a demodulator A104. A signal acquired by demodulating the radio-frequency signal is subjected to inverse Fourier transform to form a superposition of sine waves having different frequencies. The superposition of sine waves is convolved with a specific signal stored in a memory and subjected to phase inversion, so as to acquire a convolved interfering signal. A comparator determines whether the convolved interfering signal is zero or whether the convolved interfering signal is interfering. If the value is not zero or the convolved interfering signal is interfering (there is radio-frequency interference), a switch SP2T is controlled to send the signal to an additional anti-interference circuit C110, the received signal of N41 and the interfering signal acquired by the deconvolutor are inversely superposed and then filtered out, and a useful signal is modulated to the radio-frequency signal. When communications of multiple systems work at the same time, interference may exist between the two frequency bands. When one of the systems works on a first antenna and the other works on a second antenna, after two signals enter a coupler, the two signals respectively pass through an attenuator and a demodulator, a signal acquired by demodulating the radio-frequency signal is subjected to inverse Fourier transform to form a superposition of sine waves having different frequencies, and then the superposition of sine waves is convolved with a specific signal stored in a memory and subjected to phase inversion to remove a useful sine wave signal, so as to acquire a convolved interfering signal. It is determined whether the convolved interfering signal is interfering. The Fourier transform formula is as follows: f^(u)=12π∫-∞∞f(t)e-iutdt This formula is referred to as the Fourier transform of ƒ, and is denoted as convolution (u). In some books, the factor preceding the integral is replaced. Assuming that the function ƒ∈(−∞,∞), the integral in the formula above can be calculated. If the convolved interfering signal is interfering, the switch SP2T is controlled to turn on an anti-interference circuit, the convolved interfering signal passes through a deconvolutor and then is subtracted from a signal subjected to Fourier transform, so as to filter out the interfering signal, and finally a useful signal is modulated to a radio-frequency signal. If the convolved interfering signal is not interfering, the switch SP2T is controlled to send the radio-frequency signal directly to the radio-frequency circuit. In some embodiments, the interference detection module includes an attenuator, a demodulator, an inverse Fourier transform module, a convolutor, and a memory. In some embodiments, the inverse Fourier transform module needs to transform the demodulated radio-frequency signal into a superposition of sine waves having different frequencies. In some embodiments, the type of the antenna circuit includes 2G antenna, 3G antenna, 4G antenna, 5G antenna, and/or 6G antenna. In some embodiments, the anti-interference circuit includes a deconvolutor and a subtracter. Some embodiments provide a communication anti-interference detection method. An exemplary embodiment describing an application scenario example of the method of the embodiments of the present disclosure is provided as follows, and this exemplary embodiment is used for further illustrating the embodiments of the present disclosure, and does not limit the method of the embodiments of the present disclosure. For example, the transmission frequency band of Band 7 is 2500 MHz-2570 MHz, while the frequency band of WIFI 2.4G is 2400 MHz-2483 MHz. When the two frequency bands work at the same time, the protection bandwidth between the two frequency bands is 17 MHz. During the transmission based on Band 7, the sideband noise of the Band 7 transmission may fall into the receiving band of the WIFI 2.4G. Likewise, during the transmission based on WiFi 2.4G, the sideband noise of the WIFI 2.4G transmission may also fall into the receiving band of the Band 7. As shown inFIGS.6and7, LTE and WIFI communications work at the same time. When the LTE works on a first antenna, and the WIFI works on a second antenna, after two signals enter a switch, the two signals respectively pass through an attenuator and a demodulator. A signal acquired by demodulating the radio-frequency signal is subjected to inverse Fourier transform to form a superposition of sine waves having different frequencies. Herein, C is the direct-current component mentioned above, and an and bn are amplitudes of sinusoids of different frequencies. The sine waves are convolved with a specific signal stored in a memory and subjected to phase inversion, so as to acquire a convolved interfering signal. A comparator determines whether the convolved interfering signal is zero. If the value is not zero, the convolved interfering signal is interfering (i.e., there is radio-frequency interference), a switch SP2T is controlled to send the signal to an additional anti-interference circuit. The received signal of LTE Band 7 and the interfering signal acquired by the deconvolutor are inversely superposed and then filtered out, and a useful signal is modulated to the radio-frequency signal. The foregoing descriptions are merely embodiments of the present disclosure applied to a wireless terminal access product such as a 5G mobile phone. All those modifications, equivalents and improvements falling within the principle of the present disclosure and made by combinations of frequency bands of different systems and transformation of a connection manner are intended to be encompassed in the scope of protection of the present disclosure. The exemplary embodiments of the present disclosure described above are intended to illustrate but not limit the present invention. Any modification, equivalent replacement and improvement made within the principle of the present disclosure shall be encompassed in the scope defined by claims of the present application. | 22,343 |
11942977 | Similar reference numerals may have been used in different figures to denote similar components. DESCRIPTION OF EXAMPLE EMBODIMENTS The present disclosure is made with reference to the accompanying drawings, in which embodiments are shown. However, many different embodiments may be used, and thus the description should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. Like numbers refer to like elements throughout. Separate boxes or illustrated separation of functional elements or modules of illustrated systems and devices does not necessarily require physical separation of such functions or modules, as communication between such elements can occur by way of messaging, function calls, shared memory space, and so on, without any such physical separation. As such, functions or modules need not be implemented in physically or logically separated platforms, although they are illustrated separately for ease of explanation herein. Different devices can have different designs, such that while some devices implement some functions in fixed function hardware, other devices can implement such functions in a programmable processor with code obtained from a machine readable medium. In examples disclosed herein, methods and systems are described for calibration of offset voltage drift in a receiver sampler. To assist in understanding the present disclosure,FIG.1is first described. FIG.1illustrates a simplified block diagram of conventional receiver sampler during calibration. As shown, signals are transmitted to a receiver10over a differential pair wireline communication channel12. The receiver10may be a SerDes receiver. Conventionally, in order to perform the sampler calibration, sampler16is disconnected from the front end portion14of receiver10by opening connection switches18A and18B. Once the sampler is disconnected from the front end portion14, the two input terminals20A and20B of the sampler16, which are configured to receive differential signals, are tied together by closing connection switch22. Typically when one of the input terminals, for example20A, has a higher voltage than that of20B, the sampler may detect a signal “1”, and vice versa when the voltage at input terminal20B is higher than that of terminal20A, the sampler detects a signal “0”. With the two input terminals20tied together, two input terminals20A and20B should have no voltage difference in between them. Then statistically, the sampler should have equal probabilities of detecting “1” and detecting a “0” as shown inFIG.2A. However, with a sampler offset, the probability of detecting either a “1” or a “0” is skewed in favor of one detection as shown inFIG.2B. Thus, during calibration, an offset voltage is applied to the sampler until the skewed detection probability as shown inFIG.2Bis adjusted to that of a balanced detection probability as shown inFIG.2A. Once the calibrated offset voltage has been determined, the sampler is reconnected to the front end portion14to commence receiver operation in mission mode. Since the conventional sampler calibration requires the sampler to be disconnected from the rest of the circuit, it can only be performed during startup of the system when error rate or failed communications are inconsequential. However, once the sampler enters into mission mode, calibration is no longer feasible as it would cause transmission failure. FIG.3illustrates a plot300showing impact of temperature drift on system performance. As shown in theFIG.3, the sampler has a starting temperature of −25° C., which is also the temperature at which the initial calibrated offset was determined as described above with respect toFIG.1. As time, in terms of iteration numbers, progresses, the operating temperature of the sampler, as indicated by plot302, fluctuates between 105° C. and −25° C. The fluctuation in system performance, as measured by BER illustrated by plot304, appears to correlate with that of temperature variation. As the operating temperature increases, the system performance degrades with higher BER. The cause of the system performance degradation can be traced to drift of the sampler offset as the result of varying operating temperature. This phenomenon is commonly referred to in the art as temperature drift. FIG.4illustrates a simplified block diagram of an example data communication system400utilizing a SerDes transmitter410to transmit a signal over a communication channel420to a SerDes receiver430in accordance with exemplary embodiments of the present disclosure. The data communication system400may be a telecommunications system, such as a base station, a relay station, a scheduler, a controller, a gateway, a router, an applications server, or any other device in the data communications system. In other embodiments, the system400is in a user-side device, such as a mobile station, a user equipment (UE), a personal computer (PC), a tablet, a wearable communications device (e.g., a smartwatch, etc.), or any other device adapted to communicate data. The SerDes transmitter410is configured to transmit parallel data streams412(1)-412(n) (generically referred to as data streams412), through the communication channel420, to one or more SerDes receivers430. Each data stream412may include signals that are defined by a sequence of regular units in time domain. The unit may be a frame, a symbol, a sub-frame or multiple frames of the signal, for example. In the illustrated embodiment, the SerDes transmitter410includes a Parallel In Serial Out (PISO) converter414configured to convert parallel data streams412into a single data stream for transmission. The PISO converter414may be a parallel-in serial-out shift register or any other suitable circuit implementation. When the clock frequencies used within system400are slower than the transmission rate on over channel420, multiple parallel data streams412may be serially shifted out of the PISO converter414to create a high speed serial data stream. The illustrated SerDes transmitter410further includes an optional correction module416to counteract signal impairments, such as inter-symbol interference (ISI) and channel noise from channel420. The correction module416may include one or more finite impulse response (FIR) filters or any other suitable implementation. The SerDes410may further include an optional amplifier418to amplify the serialized data stream after equalization. The communication channel420may be a wireline channel, including but not limited to cables, bond wires, PCB traces, package pins along with any other suitable wireline channels. Alternatively, the communication channel may be a wireless channel, including but not limited to 4G LTE, 3G and 2G wireless services, wireless local area network (WLAN) channels, short-range wireless channels, such as Bluetooth®, and any other suitable wireless channels. The communication channel420may introduce various signal impairments to the transmitted signal. In the illustrated embodiment, the SerDes receiver430includes two samplers432A and432B (collectively referred to as samplers432) configured to sample the received signal. Samplers432A and432B include respective voltage offsets436A and436B, which may be used to apply an offset compensation voltage to samplers432A and432B, respectively. The transmitted signal may first be received by a front portion434of the receiver prior to sampling. The front portion434may include one or more equalizers (not shown) for removing ISI and/or channel noise impairments. By way of non-limiting example, the equalizers in the front portion434may be implemented as a high-pass function in the form of a FFE (Feed-Forward Equalizer). The front portion434may also include variable gain amplifiers (VGA's) or a continuous-time linear equalizer (CTLE) (not shown) among other circuit elements. The samplers432are configured to convert the received signal in analog form back into a digital serial stream of 1's and0's. In some embodiments, the sampler432A may be a data recovery sampler used for recovering the transmitted data, and sampler432B may be an eye monitor sampler configured for determining data eye statistics of sampler432A. Conventionally, an eye monitor sampler is configured to monitor data eye characteristics of the signal in a data stream. The eye monitor sampler generates data eye statistics by varying a voltage offset to the eye monitor sampler and comparing the sampler output to that of the data recovering sampler such as432A. The eye statistics of a sampler may be composed into an eye pattern or eye diagram. Eye diagrams include multiple signals comprised of data bits that are triggered by a clock. Signals are superimposed on top of one another which show an envelope of amplitude and timing fluctuations. In other words, an eye diagram provides indications of a range of amplitude and timing deviations associated with data bits.FIG.5Ashows an eye diagram500that may be generated from samplers432A and432B. As shown, the received analog waveforms are superimposed on top of one another based on a common time interval (i.e. the period of the waveform). As may be observed, the overlapping waveforms form an eye shaped opening502. The eye opening502is defined by a vertical eye opening504and a horizontal eye opening506. Generally, a wider eye opening502, as defined by eye openings504and506, is indicative of a channel with decreased channel noise. As the amount of signal interference from channel noise, among other sources, increases, the eye opening502becomes smaller. Samplers, such samplers432A and432B, have a sampling threshold that is ideally located at the middle of the eye opening502, as indicated by middle line508. Any signal sampled above the sampling threshold is taken to be a signal “1” while anything sampled below the sampling threshold is taken to be a “0”, thus, converting the received analog waveform into a digital data stream. By sampling the received signal at middle line508, system margin510, as defined by the voltage amplitude between the middle line508and the upper or lower bound of the vertical eye opening504, may be maximized. A maximized system margin510allows the most amount of voltage variation (or noise) in the received signal and yet still make the correct sampling prediction. As the operating temperature increases during receiver operation, the sampling threshold of the sampler drifts above or below the middle line508, which can cause incorrect signal prediction. For example, when the sampling threshold shifts up into the upper half of the eye opening502, a signal having a voltage amplitude above the middle line508and below the sampling threshold may be interpreted as a “0”, when it should have been interpreted as a “1”. FIG.5Billustrates a plot550of a bit error rate tester (BERT) scan, also referred to as a bathtub curve, of the sampler that generated the eye diagram inFIG.5A. Typically, a bathtub curve of a sampler may be generated by sweeping the voltage offset of an eye monitor sampler such as sampler432B, and its output is compared against that of a data sampler, such as sampler432A, to generate BER values plotted as shown inFIG.5Bhaving portions552A and552B. It is understood that although it appear that portions552A and552B are disjointed, they are connected for voltage amplitude range that result in a BER of0. In a bathtub curve plot, such as shown inFIG.5B, the least vertical distance between portions552A and552B (referred to as base width554) is indicative of the size of the vertical opening504of the eye opening502. Thus, a channel with increased channel noise results in a narrower base width554, and vice versa, a channel with less channel noise provides a wider base width554. Ideally, the sampling threshold, as denoted by556, is located in the middle of the base width554as this would provide maximum voltage margin in both directions. Ideally, the start-up phase calibration would place the sampling level at the middle of the base width554. As temperature drift occurs during receiver operation, the sampling level556will drift up or down, and follow either the portion552A or552B of plot550as system BER increases. Referring back toFIG.4, the outputs438A and438B of respective samplers432A and432B are provided to a receiver logic block440configured to process and operate on sampled data. In the illustrated embodiment, the receiver logic440includes a comparator442, calibration module444, Serial-In Parallel-Out (SIPO) converter446, and a forward error correction (FEC) module448. It should be understood that the comparator442, calibration module444, SIPO converter446, and FEC module448are not necessarily separate units of the receiver430, and that the illustration of these inFIG.4as separate blocks within the receiver430may only be a conceptual representation of the overall operation of the receiver430. For example, comparator442may be implemented as part of calibration module444. Further, although SIPO converter446and FEC module448are shown to be part of the receiver logic block440, they may be partially or fully located in components outside of receiver430in some embodiments. As used here, a “module” can refer to a combination of a hardware processing circuit and machine-readable instructions (software and/or firmware) executable on the hardware processing circuit. A hardware processing circuit can include any or some combination of a microprocessor, a core of a multi-core microprocessor, a microcontroller, a programmable integrated circuit, a programmable gate array, a digital signal processor, an application specific integrated circuit (ASIC), field programmable gate array (FPGA), or a system on a chip (SoC) or another hardware processing circuit. The comparator442configured to compare the outputs432A and432B is described in more detail below. As shown, the comparator442is implemented in the form of an exclusive OR (XOR) gate, which is able to detect when outputs432A and432B differ from one another as described in more detail below. It is understood that other suitable implementations of the comparator442may be possible. The SIPO converter446is configured to convert the high-speed sampled data stream of 1's and 0's back to a multiple parallel data streams. The FEC module448configured to apply error correction on the parallel data streams. The FEC module448may implement any suitable FEC scheme, including but not limited to any one of Reed Solomon FEC (RSFEC), Enhanced FEC (EFEC), Bose-Chaudhuri-Hocquenghem (BCH), and/or Ultra FEC (UFEC) schemes. FEC typically requires insertion of additional redundant data bits into the transmitted data stream. Hence, stronger FEC tend to require more redundancy and thereby reducing the effective data rate of the transmission, and vice versa, less redundancy coding may result in higher bit rate at the cost of higher BER. Accordingly, FEC module448is associated with a FEC threshold (or FEC limit), which is defined as the pre-FEC BER required to achieve a certain post-FEC BER. The calibration module444is configured to determine a sampler offset of the data recovery sampler432A and adjust the voltage offset436A to calibrate sampler432A. In some embodiments, the calibration module444configures the sampler432B (i.e. the eye monitor sampler) to mirror the operating conditions, including sampling threshold, of voltage output438A of sampler432A at the start of the calibration process. The sampler432A may be subject to temperature drift during receiver operation, and may not be operating with the ideal sampling level as described above despite the voltage offset by436A. By adjusting the voltage offset436B, the sampling threshold of sampler432B is made to match the sampling threshold of the data recovery sampler432A. The calibration module444is further configured to sweep the voltage value of the voltage offset436A of the data recovery sampler432A by continually increasing or decreasing the voltage offset436A.FIG.6shows a hypothetical bathtub curve of a sampler432A to illustrate the voltage offset calibration operations of the calibration module444. As shown, the initial calibrated voltage offset602, indicative of the sampling level of a sampler432A after the initial calibration, is shifted from its ideal position at the middle of the bathtub curve base due at least in part to temperature drift. Although calibrated voltage offset602is shown as drifted towards right portion604B of the plot, it is understood that the offset602can be drifted in the other direction towards the left portion604A of the plot as well. As the voltage offset436A is varied from the initial calibrated voltage offset602, the sampling level of the sampler432A is also varied in response, resulting in increased discrepancy between the output438A of sampler432A and output438B of sampler432B. The difference between the two samplers produces increased BER that follows the bathtub curve600. For example, gradual increase in voltage offset may cause the BER to increase along the right portion604B of bathtub curve600, and vice versa, continued voltage offset decrease may cause the BER to follow the left portion604A of the bathtub curve600. The voltage offset602is continually varied in one direction (i.e. by continually increasing or decreasing the voltage offset value) until the corresponding BER meets a BER threshold value606. The voltage offset values608A and608B denote the voltage offset value that results in a BER that meets the BER threshold606on the left portion604A and right portion604B of the plot, respectively. Intuitively, the BER threshold value606may be met by both increasing and decreasing the sampling level by increasing and decreasing the voltage offset436A from the initial value of the calibrated voltage offset602. The BER threshold606may be determined based on system requirement or design specification or any other suitable criteria. In some embodiments, the BER threshold value606is set as a BER value that is less than a FEC limit610of the FEC module448. The variation in sampling level of the data recovery sampler432A from voltage offset sweep introduces additional errors into the sampler output as reflected by the increased BER. Thus, by keeping the BER threshold value606below the FEC limit610, the impact of the error introduced by the sampler calibration may be minimized by the error correction performed by FEC module448. In some embodiments, the calibration module444is configured to first vary the voltage offset436A from its initial value of602in one direction of the bathtub curve600, such as direction612A along left portion604A of the curve600. Upon the BER meeting the BER threshold606on the left portion604A, the calibration module444records the corresponding voltage offset value608A, such as by storing the value in memory, and varies the voltage offset436A in the opposite direction as shown by dashed line612B towards, and along, the right portion604B of the bathtub curve600. The voltage offset436A is continually varied in the opposite direction until the BER meets the BER threshold606again, and the corresponding voltage offset value608B is recorded. AlthoughFIG.6shows voltage offset variation towards left portion604A first then back towards right portion604B, it is understood that the direction of voltage offset variation may be reversed. Once both threshold voltage values608A and608B, also referred to as boundary voltage offset values, are obtained, the calibration module444is configured to adjust the voltage offset436A to a value in between the two boundary voltage offset values608A and608B. In some embodiments, the calibration module444is configured to determine a middle value between the two boundary voltage offset values608A,608B, and adjusts the voltage offset436A to the middle value as the calibrated voltage offset value to provide maximum error margin. Advantageously, the data sampler432A is functional during the calibration process, which allows the calibration to occur during operation of the receiver. There exists a direct tradeoff between the threshold BER606and the run time of the calibration process. For example, in embodiments where the BER threshold606is relatively high (i.e. closer to the FEC limit610), the temporary BER degradation may be more pronounced. However, the increased BER allows the BER threshold606to be determined relatively quickly. In turn, the corresponding boundary voltage offset values608A and608B may be determined within shorter run time, allowing the calibration process to complete more quickly. For embodiments where the BER threshold606is relatively low (i.e. further away from the FEC limit610), the BER degradation may be less, but given less errors are generated, it may take longer run time to reach BER threshold606and determine the corresponding boundary voltage offset values608A,608B, leading to a lengthier calibration process. During the calibration process described herein, more consistent system performance with respect to sampler calibration may be achieved at the cost of an increase in average BER. In some embodiments, the average BER of the system may be higher because of the sampling threshold variations. However, errors introduced by the calibration process may be correctable through FEC.FIGS.7A and7Billustrate the performance impact of the calibration processed described herein.FIG.7Aillustrates system performance (as measured by BER) in response to temperature drift without use of the calibration process described herein. The operating temperature of the receiver over time is shown in plot702. The design specification dictates a receiver BER limit704of 1×10−06as denoted by the dashed line. The performance (as measured by BER) of a first channel, Lane1characterized with a loss of 17.93 decibel (dB) is shown in plot706. Notably, Lane1has less margin with respect to the BER limit704, and as temperature exceeds 60, the channel communication starts to fail at708with BER exceeding the system limit704. In contrast, the second channel Lane2, characterized with a loss of 10.8 dB, has considerably more margin and does not fail for any operating temperature as shown by plot710.FIG.7Billustrates the system performance (as measured by BER) of the same receiver chip that generatedFIG.7Ain response to temperature drift having applied the calibration process described herein. As may be observed fromFIG.7B, both channels now exhibit similar BER performance as shown by plots716and720for a similar operating temperature plot712. The BER plot716of channel Lane1is now more consistent in value compared to that of706inFIG.7A. More importantly, there are no failed communication packets as the BER of channel Lane1is below the required BER limit704. For channel Lane2, its BER, as shown by plot720, is now elevated compared to710ofFIG.7Aand is now similar to that of channel Lane1. Thus, rather than one channel failing some of the time as shown inFIG.7A, the sampler calibration process described herein was able to correct for the sampler voltage offset drift during operation of the receiver and allow both channels Lane1and Lane2to meet the BER requirement. In some embodiments, the calibration process described herein may be performed continuously during operation of the receiver. In some other embodiments, the calibration process described herein may be performed intermittently between fixed or variable time intervals. In some further embodiments, the calibration may be performed based on changes in operating temperature. For example, the calibration process may be initiated for every 10-degree change in operating temperature. Other methods for invoking the calibration process described herein may be adopted. For example, the calibration process described herein may be performed as the initial calibration during start up phase of the receiver. FIG.8is a flowchart illustrating an example method800of sampler voltage offset calibration performed by the calibration module444in accordance with an example embodiment. At802, the calibration module444is configured to match the operating condition of a first sampler (i.e. a data recovery sampler) with that of another sampler (i.e. an eye monitor sampler). The matching includes adjusting the voltage offset of the second sampler until the sampling threshold of the second sampler is identical to the sampling threshold of the first sampler. At804, the calibration module444adjusts the voltage offset of the first sampler in a first voltage direction until an error rate, for example the BER, between the outputs of the first and second samplers meets a first threshold error rate value at a first threshold voltage offset value. The adjustment may include continually increasing or continually decreasing the voltage value of the voltage offset. At806, the calibration module444adjusts the voltage offset of the first sampler, for example in the opposite voltage direction of the first voltage direction applied to reach the first threshold voltage offset value. For example, if the first voltage direction was increasing the voltage, then the second direction is to decrease the voltage of the voltage offset and vice versa. The voltage offset adjustment is continued until the error rate between the outputs of the first and second samplers meet a second error rate threshold value at a second threshold voltage offset value. At808, the calibration module444sets the first voltage offset to a value between the first voltage offset value and the second voltage offset value. In some embodiments, the value is a middle value, in other words the average, of the first and second threshold voltage offset values to provide maximum error margin. FIG.9is a block diagram illustrating an example apparatus900in which the receiver10may be implemented. For example, the apparatus900may be an electronic device, such as a server, a computing system, an access point (AP), a terminal device, etc. The apparatus900is capable of wireline communications, and may optionally also have capabilities for wireless communications. Other communication devices suitable for implementing examples described in the present disclosure may be used, which may include components different from those discussed below. AlthoughFIG.9shows a single instance of each component, there may be multiple instances of each component in the apparatus900and the apparatus900could be implemented using parallel and/or distributed architecture. In this example, the apparatus900includes one or more processing devices902, such as a processor, a microprocessor, an ASIC, a field-programmable gate array (FPGA), a dedicated logic circuitry, or combinations thereof. The apparatus900may also include one or more optional input/output (I/O) interfaces904, which may enable interfacing with one or more optional input devices912and/or output devices914. The apparatus900includes one or more network interfaces906, including the receiver10for receiving an electronic signal. The network interface(s)906may additionally include a transmitter (not shown) for transmitting an electronic signal. The receiver10and transmitter may be implemented using any suitable wireline transceiver. Optionally, if the apparatus900has capabilities for both wireline and wireless communications, the apparatus900may include one or more antennas916to enable wireless communication. In this example, one antenna916is shown, which may serve for both transmitter and receiver. However, in other examples there may be multiple antennas for transmitting and receiving. In examples where the apparatus900does not have capability for wireless communications, the antenna(s)916may be omitted. The apparatus900includes one or more storage units908, which may include a mass storage unit such as a solid state drive, a hard disk drive, a magnetic disk drive and/or an optical disk drive. The apparatus900also includes one or more memories910, which may include a volatile or non-volatile memory (e.g., a flash memory, a random access memory (RAM), and/or a read-only memory (ROM)). The non-transitory memory(ies)910(as well as storage908) may store instructions for execution by the processing device(s)902. The memory(ies)910may include software instructions, such as for implementing the calibration module444. In some examples, instructions may also be provided by an external memory (e.g., an external drive in wired or wireless communication with the apparatus900) or may be provided by a transitory or non-transitory computer-readable medium. Examples of non-transitory computer readable media include a RAM, a ROM, an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, a CD-ROM, or other portable memory storage. Optional input device(s)912(e.g., a keyboard, a mouse, a microphone, a touchscreen, and/or a keypad) and optional output device(s)914(e.g., a display, a speaker and/or a printer) are shown as external to the apparatus900, and connected to optional I/O interface904. In other examples, one or more of the input device(s)912and/or the output device(s)914may be included as a component of the apparatus900. Although the present disclosure describes methods and processes with steps in a certain order, one or more steps of the methods and processes may be omitted or altered as appropriate. One or more steps may take place in an order other than that in which they are described, as appropriate. Although the present disclosure is described, at least in part, in terms of methods, a person of ordinary skill in the art will understand that the present disclosure is also directed to the various components for performing at least some of the aspects and features of the described methods, be it by way of hardware components, software or any combination of the two. Accordingly, the technical solution of the present disclosure may be embodied in the form of a software product. A suitable software product may be stored in a pre-recorded storage device or other similar non-volatile or non-transitory computer readable medium, including DVDs, CD-ROMs, USB flash disk, a removable hard disk, or other storage media, for example. The software product includes instructions tangibly stored thereon that enable a processor device (e.g., a personal computer, a server, or a network device) to execute examples of the methods disclosed herein. The present disclosure may be embodied in other specific forms without departing from the subject matter of the claims. The described example embodiments are to be considered in all respects as being only illustrative and not restrictive. Selected features from one or more of the above-described embodiments may be combined to create alternative embodiments not explicitly described, features suitable for such combinations being understood within the scope of this disclosure. All values and sub-ranges within disclosed ranges are also disclosed. Also, although the systems, devices and processes disclosed and shown herein may comprise a specific number of elements/components, the systems, devices and assemblies could be modified to include additional or fewer of such elements/components. For example, although any of the elements/components disclosed may be referenced as being singular, the embodiments disclosed herein could be modified to include a plurality of such elements/components. The subject matter described herein intends to cover and embrace all suitable changes in technology. | 31,626 |
11942978 | DETAILED DESCRIPTION OF THE INVENTION The ‘Phone Flash Strap’ was invented to enable active cell phone users to inconspicuously carry and utilize their cell phone and camera “lens” features. The motivation for the ‘Phone Flash Strap’ includes the following. First and foremost, to enable civilians to capture photos and video in light of recent excessive use of force by police and for the benefit of the many perspectives and real-time witness evidence. By keeping all essential items in a cross-body strap, users will not have to hold small personal items (ID, credit card, cell phone, etc.) in their pockets and therefore not have to reach for them. The additional motivation is to provide a foundation and support utility for using the phone's voice activated hands-free controls. We will never advance with phone voice-activated controls (the future) if we do not have a convenient and supportive “holder”. The first person and third-person point of view hands-free functionality allows users to be present to their environment and capture photos and videos without interrupting the moment. Phone video calls and third-person video/pictures are increasing and a hands-free phone support is needed. Industry professionals such as security guards, package delivery personnel, or other active professionals where the phone is, or could be part of their job, will find efficiencies in their workday without needing to get their phone in and out (e.g. an Amazon delivery driver may hold a package in front of them and scan packages while the phone is in the ‘Phone Flash Strap’). The technology in the present invention includes a concealed design, utilization of a phone's features while ‘put away’, and a concealed hands-free “selfie arm”. Handicapped or lesser abled individuals can use this product as a ‘third eye’ and/or ‘third hand’ to support everyday interactions. Those blind or with low visibility may use the lens feature to receive guidance regarding items in front of them. Those with physical handicaps may benefit from a support structure to hold their phone in the perpendicular ‘dashboard’ position or third-person position via the selfie arm. Users desire to have phone and features more conveniently available. Having one's phone readily available to use is a necessity, not having the phone “handy” presents a problem with increasing phone use. Phone and phone camera users are too frequently ‘putting-away’ and ‘getting-out’ their devices from pockets, purses, or other holders. While phones are ‘put-away’, users do not have functional use or utility of their phone, although the technology exists. The phone is used in a common place/vicinity, but not kept readily available and accessible. There is a growing desire and need to be ready to capture video and photos in an instance/on a moment's notice, as well as be able to do so hands-free, thereby still being fully available and present in one's environment. There is a need for hands-free and voice automated mobile device use, eliminating having to reach for one's phone. Hands-free technology interaction is underutilized despite increasing towards the tipping point. Technology is underutilized because there lacks adequate “hands-free” holders which enable or encourage voice-commands/interaction. General consumers are increasingly adopting “talk-to-text” or voice controlled technology interaction (Google home, Siri, talk to text, talk to car, voice notes). Third-person (self-view) recording and camera use is on the rise and no convenient products exist. The technology to do so is not at an average-consumer level of convenience. People are recording video, pictures, and using live recording technology. As we become ‘increasingly social’ and ‘individual sharing’ increases, there will be a demand for third-person capabilities. Existing wearable technology isn't fashionable. Existing camera straps and/or chest mounts for first or third person view are not stylish and can't be worn regularly. Current self-view camera mounts are not fashionable. Current mobile device or camera mounts, tripods or other extendible products are not designed to conceal or limit visibility of the product features/elements. There is also a focus on the wrong features of use over human wear/design. Current fashion doesn't provide modern functions or features that are wanted and available to consumers. Functional use of a cell phone holder, a purse, or a fanny pack is limited. In the present invention, the phone5will be concealed by the external design of the strap/pack10, as shown inFIGS.1-6. InFIGS.10-11andFIGS.15-22, additional embodiments of the strap/pack10are shown. The strap/pack10is designed to keep the mobile device vertical, with its “lens” facing forward in position for optimal filming and other lens functions, as shown inFIG.1andFIG.27. Designs include standard vertical placement as well an adaptable feature that allows for a diagonal, in-line with the cross-shoulder strap12, carry feature that adjusts to vertical when using the phone's camera feature. Commercial products utilized in practicing the invention include: Common phone Android and Apple Operating systems and voice activation features; Flexible and sturdy wire gooseneck arms; extendable telescoping support arms; adjustable cell phone holder mount; camera phone lens covers; magnetic squeeze clasps—coin purse; locking and quick-release/adjustable2-endstrap clasp. The present invention is designed to conceal the presence of a phone and its camera lens6. It is designed to purposefully hold a mobile device (within any holder or accessory) vertically or otherwise stable or purposefully/functionally placed within any accessory/apparel/bag apparatus with the purpose of concealing the mobile device, making it visually indistinguishable from the strap, with the mobile device's camera lens6exposed (full visibility with functionality intact) facing outwards, away from the user's body, through the aperture14on the main body20of the strap10, as shown inFIG.27. It is designed to enable the function of capturing video and image as well as other device lens features and functions while the mobile device remains within the strap10. It is further designed to enable and utilize a mobile device's innate voice activated controls. The phone is preferably placed on the chest/sternum or central part of the body in order to take photos and video directly in front of the user. If placed otherwise, it may aim upwards, towards the sky. The phone is preferably inserted in a pouch between the front and back cloth, not on the front. One embodiment also includes a sport side strap15for lateral tension and stability.FIG.7is a detailed illustration of the sport strap15.FIG.8is an illustration of the sliding keeper16on which the sport strap15connects to.FIG.9andFIG.22show the sport strap15connected to the loop behind the gusset on the main body of the strap/pack10.FIG.13shows the sport strap15in the vicinity of the gusset, about to be looped. The additional/optional strap15provides side support over the user's side-body on the opposite side of where the strap sash angle hangs. It is an elastic or otherwise adjustable VELCRO strap that connects the back of the main strap12to the main body20for lateral stability. The additional sport strap15is housed in-line with the back strap12, as shown inFIGS.1,6,11,15,20and21, in alternative embodiments. The sport strap15can be repositioned as needed to reach around and connect to the backside of the main body20. The lens aperture14in the fabric or design body of the strap/pack10is concealed through variable means of a tinted plastic, or two-way mirror style plastic, screen, or other technology allowing the camera lens to see through the carrying strap/pack10but not to be obviously seen from the outside. An adjustable lens cover11feature is created to show or hide the camera depending on the user's desire at the time of use. The lens may be framed to keep the surrounding structure of the lens. The lens cover11can be a see-through concealed cover, such as a two-way mirror, one-way glass, tinted, screen, or other material, used for any fashionable accessory/apparel/bag or specific mobile device holders. It can be adjustable or adaptable to reveal the mobile device's camera lens or completely conceal it from the outside while retaining full camera lens functionality. It fits all lenses and model types through a built-in specific design. In one embodiment, the lens concealer is a flap or cover. In another embodiment, the lens concealer is a tint or film. In another embodiment, the lens concealer is a plastic external circle or square that covers the outside of the phone and the material of the front of the pack is similar to a wetsuit material that conforms around the specific shape. In another embodiment, the lens concealer is a screen material or the like. In another embodiment, the lens concealer is a camera lens cover that can be closed and opened (similar to a traditional camera shutter lens cover). The selfie-arm25and all components are concealed by the design and is indistinguishable from the cross-body strap/pack10. The structural support components are revealed and put together to create an extended arm/tripod/support mount to properly position the phone at a distance in front of the user. A transparent and operable back-end (close to chest) strap13with clear plastic allows for full mobile device function without putting the mobile device away and taking it out: camera in a bag—use your device while it's put away. A quick-adjust/release clasp17, as shown inFIG.21is a preferably inconspicuous clasp that allows for quick adjustment of the strap12. This enables tightening of the strap12for active use and loosening to remove (without unbuckling) and to enable better use of the phone without taking the phone out of the phone strap10. An alternative embodiment has a clear back end. There may also be a structure similar to a collapsible diagonal camera holder. One embodiment is a phone strap10for concealing a mobile phone. The phone strap10comprises a main body20and a cover11. The main body20defines an internal compartment21in an upper front section. The main body20also has a lens aperture14therethrough to the internal compartment. The lens cover11is positioned over the lens aperture14. The internal compartment21is configured to hold a mobile phone5with a camera of the mobile phone5positioned at the lens aperture14. The lens cover11is designed to conceal the lens aperture while permitting lens' functionality through the lens cover11. A front panel of the main body20preferably encompasses the lens cover11and is preferably interchangeable and/or modular. The main body20is also preferably interchangeable and/or modular. Each strap12is also preferably interchangeable and/or modular. Strap covers for the strap12are also preferably interchangeable and/or modular. Accessories for the phone strap10are also preferably interchangeable and/or modular. Another embodiment is a garment for concealing a mobile phone. The garment comprises a main body defining an internal compartment in an upper front section, the main body also having a lens aperture therethrough to the internal compartment. The internal compartment is configured to hold a mobile phone with a camera and all lens features of the mobile phone positioned at the lens aperture. The lens aperture is concealed while permitting lens' functionality. Another embodiment is a phone strap10with an extendable arm25, as shown inFIG.26. The phone strap10comprises a main body20and an extendable arm25. The main body20has an upper section18and lower section19. The extendable arm25is attached at the upper section18and the lower section19of the main body20, the extendable arm25comprises an extension arm26with a phone holder27, a structural support member28and an under structural support member29. The extendable arm25is designed to rest on the main body in a resting state, and extending forward from a body of user in an extended state.FIG.26Ais a detailed illustration of the extendable arm25in a resting state. In one embodiment, the extendable arm25is a folding arm with a support. In another embodiment, the extendable arm25is telescoping. The arm may have a support arm to maintain lateral stability similar to a hinge of a folding table hinge that goes within the telescoping arm. The selfie stick will work on the waist as well as over the shoulder. The internal compartment21is preferably configured to hold a mobile phone in an upright position. The internal compartment is alternatively configured to hold a mobile phone in a diagonal position. The cover11is preferably a two-way mirror or composed of a tinted plastic or a screen. The main body preferably comprises a magnet receptor and the cover comprises a magnet to permit the cover to be positioned in an open state exposing the lens aperture. The cover preferably comprises a sign holder on an interior surface. The main body preferably comprises a lower section composed of a flexible material. The phone strap10further comprises an extendable arm25designed to hold a mobile phone5at an extended end. The extendable arm preferably comprises a structural support member and an under structural support member. The extendable arm is preferably telescoping or folding. The extendable arm is preferably composed of a rigid wire, a folding plastic or a sturdy flexible material. The phone strap according further comprises a locking and quick release adjustable two end strap tensioner buckle. The main body20is preferably designed to enable voice activation of all mobile phone voice controls. An internal surface of the main body preferably defines an interior wall of the internal compartment, which is transparent and configured to allow operation of a mobile phone by a user. The main body is preferably configured to be worn over a shoulder of a user. The main body is preferably composed of a fabric material. The main body preferably has a length ranging from two feet to four feet, and a width ranging from two inches to five inches. The internal compartment is preferably designed to be positioned on a chest of a user. The lens aperture preferably has a diameter of 0.25 inch to 1.0 inch. A length of the main body is preferably adjustable. The utility of the phone strap10includes the following: hands-free filming by a user with the front dash cover (face of the strap) up; use or view a phone screen with the front dash cover perpendicular to the wearer's body; the device fits all types and sizes of phones; interchangeable components for different types of front covers (e.g. phone pouch stays the same and the front covers are replaceable for different designs); the phone strap can be worn with the pouch diagonal (crossbody), vertical in center of torso, vertical offset, or around a user's waist to film in all ways of use; filming with a phone using a Bluetooth lens cover slide to initiate a phone shutter button; and filming third-person POV with the selfie arm component. The components of a preferred embodiment of the phone strap include a crossbody strap with a pouch. The crossbody strap includes the following: pivots; magnetic fasteners/closure; overlapping pockets in back of pouch; an external battery pack pocket—which allows for wired and wireless phone charging; a RFID/EMF blocking panel; an expandable/flexible material; and a waterproof pocket The components of a preferred embodiment of the phone strap also include a phone holder which includes: an exterior (face)—which conceals, secures, and protects the entire phone and lens, and a top lock connection design for quick release and quick closure; an interior—when up/closed/secure—holds a phone vertical between a front panel and a pouch face, and when down—holds a phone perpendicular to the strap and the wearer's body; a dash platform—which secures a phone to the top right with tension from the bottom left, and allows all phones sizes with and without cases to fit securely and with forward facing camera lens in position of the front dash; and a dashboard—which operates like a dashboard. The components of a preferred embodiment of the phone strap also include a lens cover slide, which includes: a normal lens cover—vertical, horizontal, or other means for a flap or cover to conceal the cell phone device camera lens(es); a Bluetooth shutter; and a manual shutter. The components of a preferred embodiment of the phone strap also include a selfie stick, which: extends a phone in front of a body and a phone pouch; provides lateral and vertical support to eliminate sway; acts as a self-balanced stabilizer hand to minimize video bounce; and provides options of telescoping or folding outward from the phone strap. The components of a preferred embodiment of the phone strap also include a ride-along stabilizer strap, which: stabilizes around the wearer's torso to connect to the other side of the pouch to maintain stable vertical position; pivots to position in-line with the strap and rotates to wear around the torso; and provides a single fixture quick detachment and attachment. The components of a preferred embodiment of the phone strap also include a leash clip dog waste bag holder. A leash clip may have carabiners on both ends of a short nylon strap and there may be a dog waste bag dispenser fixed in between. The components of a preferred embodiment of the phone strap also include a strap sleeve covers, shown inFIG.27, which includes: a solar panel covered strap cover24works for this phone strap but also other types of bags; a flexible solar material attached to other fabric to cover the length of the straps, which attaches with VELCRO or zippers; a cable attached from the solar panel to run down the strap into the battery pack in the front of the pack to store the charge from the solar panel strap sleeve cover; and means to plug directly into the phone if the battery is not available. Extension components include the option of front dash, and the phone rotates on pivot arm/hinge base, as shown inFIG.24, with a design that includes: a phone within the front dash that rotates/pivots (not the bag); and a phone and front dash (and support arm mechanism) that can flip/reverse so that the phone screen and “interior” of the phone dash face and lock forward (facing out). The phone locks the same, but the front dash cover is not connected to the pivot point at the bottom of the bag. The rotation mechanism (tiltawhirl axis type that also serves as the bottom front dash hinge) is connected to the bottom of the bag and the middle of the front dash cover. A rotation hinge folds up and down from the bottom just like the others. A Locking thumb screw allows it to lock at different angles rather than just parallel to the ground. A pivoting center axis allows the front dash and the phone to rotate and pivot and lock into place. A bottom hinge/arm can flip at the bottom and rotate and lock. Additional back strap cover designs include a sport (yoga mat holder), and a water bottle/pouch holder (camel back). A sensor and a tracker can also be installed (similar to a TILE brand product tracker). The phone strap can also include programmable phone controls (live video, photo, emergency button, flashlight). External add-on components such as a speaker, a rear camera, VR components and drone components can also be included. A preferred embodiment of the selfie stick design includes is a telescoping function that lays stowed next to the phone on the dashboard. When in the down position, the vertical hinge (similar to a folding table) locks to keep the down position perpendicular to the body. Once extended, with the phone out/extended away from the dash, a lateral kickstand similar to the folding table hinge locks horizontally to prevent lateral sway. A phone holder, when stowed, is a rubber material, and the phone holder is preferably connected to the selfie stick so it is always ready to extend or collapse and fold up. Requirements of a preferred embodiment of the selfie stick include: compact and hidden (collapsible and extendable); lightweight and slim; stabilized vertical and lateral sway; strong enough to hold phone at length; record stable video; hold all phones with and without cases; easily and secure phone attachment; and Bluetooth remote within reach. A preferred embodiment of the Bluetooth lens cover design includes: lens cover11has an on/off switch within the recessed section; a battery is within the mechanism or within the front panel; an option for non-battery powered shutter that runs a small chord to the bottom of the front cover to the bottom inside of the front dash to plug into the bottom of the phone; other functions operate just like current BLUETOOTH selfie stick shutter buttons with regards to how it connects/pairs to a phone. The operations/requirements include; it keeps a camera app running in the background: a Bluetooth shutter will start and stop camera, but requires a predecessor of having the camera app open/running; a shutter feature—which starts a camera and stops a camera (photo or video); Android, iOS and Waway compatible; On and off switch for while in use; charge via wireless, USB-C/iPhone charger, or replaceable (rechargable) battery; non-obvious aesthetics when not in use; and no half-position available, e.g. user confidence in on/off, no accidental recording or no thinking it's recording when it isn't. The phone strap10also includes a “camera available” indicator, which is a transparent package and “flap” indicator of use of a camera. Used if a user “must express if you are currently filming in public.” A preferred embodiment of the solar charge strap cover includes: wraps around current straps with VELCRO or unique straps/buttons/zipper; has a chord that reaches down into the strap into the phone charger in the pouch; has connecters to connect and create a flowing look with all bags; and has flexible solar panel material on the outside back wraps around similar to a SAMSUNG s9 screen. The requirements include: a sock-style sleeve that covers the back strap; flexible material solar panels; sturdy enough not to twist to keep solar panels facing out (neoprene); stores charge to battery pack or direct to phone; attaches to a bag and stays in place; removable; and creates a maximum charge. A preferred embodiment of the dog leash clip w/waste bag holder design includes: a bag dispenser; leash clip attaches to the phone strap and dog leash; leash clip attaches to pants waistline without sliding forward or ripping pants; and leash held at a shorter distance. The main body preferably defines an internal compartment in an upper front section, the main body also having a lens aperture therethrough to the internal compartment, and a cover positioned over the lens aperture. The internal compartment is preferably configured to hold a mobile phone with a camera of the mobile phone positioned at the lens aperture. The lens cover11is designed to conceal the lens aperture while permitting filming through the lens cover11. The internal compartment is preferably designed to hold multiple sized phones with a spring-loaded or other support device that holds the phone to the top of the phone compartment, thereby enabling different sized phones to have their “lens” components to align with the aperture in the phone strap. The phone strap or garment preferably allows for lifting off of a chest of a user quickly and easily to operate the phone. The phone strap or garment preferably further comprises a sport side strap for lateral tension and stability. The sport side strap provides side support over a user's lats on the opposite side of where the phone strap angle hangs; an elastic or otherwise adjustable Velcro strap that connects the back of the main strap to the front pack for lateral stability; and the additional elastic strap is housed in-line with the back strap and can repositioned as needed to reach around and connect to the back side of the front pack. The lens' functionality preferably comprises filming, viewing, scanning or projecting. The selfie “arm” also preferably contains a selfie “hand” and “wrist” that holds the phone in front of a user and allows adjustment; and the positioning of the selfie arm overall ensures that the phone is at eye/chest level or the appropriate height for 3rdperson view recording. The tensioner buckle preferably allows the excess male end of the strap to be concealed within the body of the overall pack. The internal compartment is preferably configured for the rotation of the phone from diagonal into a vertical position or horizontal position and configured to lock the phone in place. The extendable arm preferably has a concealed support structure behind, under or within an overall pack. The extendable arm is preferably removable. The phone strap10or garment is preferably configured to be worn around a waist of a user as a secondary position or use of a pack overall. The main body is also preferably configured to be a holder of daily essential items. The phone strap preferably also includes a dashboard design to hold and maintain the mobile phone within a front panel substantially perpendicular to the main body and a wearer's torso wherein the bottom is fixed and the top releaseable/folds down. The phone strap preferably also includes a front panel quick locking and release mechanism to attach the main body, and/or locking mechanisms to secure the phone to allow full/direct phone screen access. The strap, attached to the main body has an associated ‘ride-along’ smaller overlapping stabilizer strap that attaches and pivots at the center of the strap and attaches to the opposite side of the main body to further secure the strap and main body to the wearer/user. A seflie arm of the phone strap allows for third person filming. A dashboard front panel rests perpendicular to the body of the main body and a wearer's torso (with a quick release and locking mechanism at the top of the front panel to connect to the main body. A lens cover slide has three lens cover modes and a Bluetooth slide cover to initiate mobile device camera shutter interaction. A main body front center pocket holds an external battery charger. A front panel utility and function is applied to outer garments such as jackets, vests, and other types of wear. The apparatus/phone strap has an interchangeable and modular design such that there are different main bodies (fixed or rotatable) and different front panels (different front panel types e.g. Bluetooth shutter, selfie arm, and different types and sizes of phones. The strap covers for device solar charging, water bottles, yoga mat holders and other types of strap covers. The strap allows for attachment of other wearable accessories (e.g. the dog waste clip). The main body may be positioned in different pre-fixed positions around the strap (locks into place via magnets or clips). It also can be worn diagonal, vertical on the torso, or around the waist). For the phone to lock into place the tensioner mechanisms hold the bottom of the phone and pull it up and to the right against the top of phone holding mechanism thereby positioning any size or type of phone to have the lens in the correct placement of the lens aperture. The main body alternatively comprises a magnet receptor and the lens cover comprises a magnet to permit the cover to be positioned in an open state exposing the lens aperture. The main body alternatively comprises a lens cover slides to cover the lens aperture to permit the cover to be positioned in an open state exposing the lens aperture. The main body alternatively comprises a lens cover flap to cover the lens aperture to permit the cover to be positioned in an open state exposing the lens aperture. Preferably, at least one of a plurality of strap components (strap, main body/bag, front panel and accessories) is modular/interchangeable for a plurality of utilities and designs. Alternatively, all of a plurality of strap components (strap, main body/bag, front panel and accessories) are modular/interchangeable for a plurality of utilities and designs. From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes modification and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claim. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims. | 29,021 |
11942979 | Description of reference numerals:1. Radio frequency transceiver,2. First radio frequency module,3. Second radio frequency module,21. First DPDT switch,22. First transmitting module,23. First receiving module,31. First switch unit,32. Second transmitting module,33. Second receiving module,34. First transmitting submodule,35. Second transmitting submodule,36. First MIMO module,37. Second MIMO module,311. Second DPDT switch,312. DP4T switch,313. First SPDT switch, and314. Second SPDT switch. DETAILED DESCRIPTION OF THE EMBODIMENTS Exemplary embodiments of the present application will be described below reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application may be implemented in various forms without being limited to the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to convey the scope of the present application to those skilled in the art. In a 5G radio frequency structure, a switch module is complex and includes multiple three pole three throw (3P3T) switches or double pole four throw (DP4T) switches. Therefore, insertion losses and costs are high, and there are a large number of antennas. As a result, design is complex, performance is poor, and a layout area is large. As shown inFIG.1, an embodiment of the present application provides a network radio frequency structure, applied to an electronic device and including:a radio frequency transceiver1; a first radio frequency module2connected to the radio frequency transceiver1, where the first radio frequency module2is connected to a first antenna and a second antenna through a first double pole double throw (DPDT) switch21; anda second radio frequency module3connected to the radio frequency transceiver1, where the second radio frequency module3is connected to a third antenna and a fourth antenna through a first switch unit31;where the first radio frequency module2includes: a first transmitting module22and a first receiving module23, the first transmitting module22is connected to a first interface of the first DPDT switch21; and the first receiving module23is connected to a second interface of the first DPDT switch21. In this embodiment, the first radio frequency module2may be a long term evolution (LTE) radio frequency module. It should be noted that the first transmitting module22is a transmitting module that satisfies the transmitting functions of the LTE signal frequency band and the 5G signal frequency band (such as the N41 frequency band). The first receiving module23is a receiving module that satisfies receiving functions of the LTE signal frequency band and the 5G signal frequency band. As shown inFIG.2, for example, the first transmitting module22is an LTE transmitting module and the first receiving module23is an LTE receiving module. The LTE transmitting module is connected to a first interface K1of the first DPDT switch21, and the LTE receiving module is connected to a second interface K2of the first DPDT switch21. A first contact a1of the first DPDT switch21is connected to the first antenna ANT1, and a second contact a2of the first DPDT switch21is connected to the second antenna ANT2. A signal sent by the radio frequency transceiver1can pass through the LTE transmitting module and the first DPDT switch21and is sent though ANT1and ANT2. The second radio frequency module3may be an NR radio frequency module. The signal sent by the radio frequency transceiver1can pass through the second radio frequency module3(that is, the NR radio frequency module) and the first switch unit31, and is sent to the base station through the third antenna ANT3and the fourth antenna ANT4. It should be noted that during signal transmission, for example, a signal sent by the radio frequency transceiver1is a sounding reference signal (SRS). Standalone and non-standalone NR bands need to support a technology of 2T4R (2 channels of transmissions and 4 channels of reception) or 1T4R (1 channel of transmission and 4 channels of reception) that transmits SRSs by turns through antennas. 2T4R of SRS signals includes two channels of SRS signals. Because 2T4R of SRS signals includes two channels of SRS signals, optionally, a first channel of SRS signal passes through the first radio frequency module2(that is, the LTE radio frequency module) and the first DPDT switch21, and is sent through ANT1and ANT2. A second channel of SRS signal passes through the second radio frequency module3(that is, the NR radio frequency module) and the first switch unit31, and is sent through ANT3and ANT4. In this way, the network radio frequency structure implements 2T4R of SRS signals. Optionally, for 2T4R of SRS signals, the two channels of SRS signals can also be sent through the second radio frequency module3(that is, the NR radio frequency module), that is, the second radio frequency module3sends the two channels of SRS signals through different antennas respectively by using the first switch unit31. 1T4R of an SRS signal only needs to send one channel of SRS signal. Therefore, the SRS signal can pass through the second radio frequency module3and the first switch unit31, and is sent through ANT3and ANT4and the other two antennas. Alternatively, the SRS signal passes through the first radio frequency module2and the first DPDT switch21, and is sent through the ANT1and ANT2. In addition, the SRS signal passes through the second radio frequency module3and the first switch unit31and is sent through the ANT3and ANT4. It should be noted that the SRS signal needs to be transmitted through the first radio frequency module2and the second radio frequency module3at a preset time sequence. In this way, the network radio frequency structure implements 1T4R of an SRS signal. Certainly, the first radio frequency module and the second radio frequency module in this embodiment may also be radio frequency modules in bands other than 4G LTE and 5G NR bands, which is not limited in this embodiment. The embodiments of the present application simplify the network radio frequency structure, use a DPDT switch and a switch unit to replace a 3P3T switch or a DP4T switch, reduce switch insertion losses, and therefore improve the sensitivity of the radio frequency structure. In addition, switch logic is simple and the layout is flexible. At the same time, the SRS function and the antenna switching function of the network radio frequency structure can be performed. Structural forms of the second radio frequency module3and the first switch unit31are described below with embodiments. In form1, as shown inFIG.3, optionally, the first switch unit31includes: a second DPDT switch311. The second radio frequency module3includes: a second transmitting module32and a second receiving module33, the second transmitting module32is connected to a first interface of the second DPDT switch311; and the second receiving module33is connected to a second interface of the second DPDT switch311. For example, the second radio frequency module3is an NR radio frequency module, the second transmitting module32may be an NR transmitting module, and the second receiving module33may be an NR receiving module. As shown inFIG.4, the NR transmitting module is connected to the first interface L1of the second DPDT switch311, the first contact b1of the second DPDT switch311is connected to the third antenna ANT3, the NR receiving module is connected to the second interface L2of the second DPDT switch311, and the second contact b2of the second DPDT switch311is connected to the fourth antenna ANT4. A signal sent by the radio frequency transceiver1passes through the NR transmitting module and the second DPDT switch311and is sent though ANT3and ANT4. As shown inFIG.4, 2T4R of SRS signals includes two channels of SRS signals, a first channel of SRS signal passes through the first transmitting module22and the first DPDT switch21, and is sent through ANT1and ANT2. A second channel of SRS signal passes through the NR transmitting module and the second DPDT switch311, and is sent through ANT3and ANT4. In this way, the network radio frequency structure implements 2T4R of SRS signals. It should be noted that the first transmitting module22and the NR radio frequency module need to work simultaneously for the first channel of SRS signal and the second channel of SRS signal, that is, while the first transmitting module22transmits the first channel of SRS signal, the NR radio frequency module transmits the second channel of SRS signal. For 1T4R of an SRS signal, the SRS signals need to be sent at a preset time sequence. Optionally, as shown inFIG.4, through the NR transmitting module and the switching of the second DPDT switch311, the SRS signal is transmitted to ANT3and ANT4and is sent through ANT3and ANT4; transmission of an SRS signal by the NR radio frequency module is stopped; and through the first transmitting module22and the switching of the first DPDT switch21, the SRS signal is transmitted to ANT1and ANT2and sent through ANT1and ANT2. In this way, the network radio frequency structure implements the 1T4R function of an SRS signal in general. In this embodiment, the first switch unit is set as a DPDT switch, and an externally connected 5G transmitting module and two DPDT switches may be configured to perform 2T4R and 1T4R functions of SRS signals, which effectively reduces the number of radio frequency amplifier components, channel switches, and antennas, thereby reducing costs. Compared with the 3P3T switch or the DP4T switch, switch insertion losses are reduced, thereby improving sensitivity of the radio frequency structure. This can greatly improve the overall performance of the network radio frequency structure. In form2, as shown inFIG.5, optionally, the first switch unit31includes:a DP4T switch312; a first single pole double throw (SPDT) switch313connected to a first contact of the DP4T switch312, where the first SPDT switch313is connected to the third antenna; and a second SPDT switch314connected to a fourth contact of the DP4T switch312, where the second SPDT switch314is connected to a sixth antenna; where a second contact of the DP4T switch312is connected to the fourth antenna, and a third contact of the DP4T switch312is connected to the fifth antenna. Optionally, the second radio frequency module3includes: a first transmitting submodule34, connected to the first interface of the DP4T switch312; a second transmitting submodule35, connected to a second interface of the DP4T switch312; a first multiple-input multiple-output (MIMO) module36, connected to the first SPDT switch313; and a second MIMO module37, connected to the second SPDT switch314. As shown inFIG.5, the first transmitting submodule34is connected to the first interface M1of the DP4T switch312, and the second transmitting submodule35is connected to the second interface M2of the DP4T switch312. The first contact c1of the DP4T switch312is connected to the first contact d1of the first SPDT switch313, and the interface of the first SPDT switch313is connected to ANT3. The second contact c2of the DP4T switch312is connected to ANT4, and the third contact c3of the DP4T switch312is connected to ANT5. The fourth contact c4of the DP4T switch312is connected to the first contact e1of the second SPDT switch314, and the interface of the second SPDT switch314is connected to ANT6. The first MIMO module36is connected to the second contact d2of the first SPDT switch313, and the second MIMO module37is connected to the second contact e2of the second SPDT switch314. The second radio frequency module3may be an NR radio frequency module, the first transmitting submodule34may be a first NR transmitting module, the second transmitting submodule35may be a second NR transmitting module, the first MIMO module36may be a first NR MIMO module, and the second MIMO module37may be a second NR MIMO module. As shown inFIG.5, for 2T4R of SRS signals, the first channel of SRS signal passes through the first transmitting submodule34and the DP4T switch312, is transmitted to ANT3through the first SPDT switch313, is transmitted to ANT4through the second contact of the DP4T switch312, and is sent by ANT3and ANT4. The second channel of SRS signal passes through the second transmitting submodule35and the DP4T switch312, is transmitted to ANT6through the second SPDT switch314, is transmitted to ANT5through the third contact of the DP4T switch312, and is sent by ANT5and ANT6. In this way, the network radio frequency structure implements the 2T4R function of SRS signals. As shown inFIG.6, for 1T4R of SRS signals, through the second transmitting submodule35and the switching of the DP4T switch312, the SRS signal passes through the first SPDT switch313and the second SPDT switch314, and is transmitted to ANT3, ANT4, ANT5, and ANT6. In this way, the network radio frequency structure implements the 1T4R function of an SRS signal. In this embodiment, the first switch unit is set as a structure of a DP4T switch and two SPDT switches to replace a 3P3T switch or a DP4T switch, to reduce switch insertion losses, and therefore improve the sensitivity of the radio frequency structure. In addition, switch logic is simple and the layout is flexible. At the same time, the SRS function and the antenna switching function of the network radio frequency structure can be performed. An embodiment of the present application further provides an electronic device, including the foregoing network radio frequency structure. A person skilled in the art may understand that, the electronic device may be a mobile phone, and may also be applied to another electronic device that has a display screen, such as a tablet computer, an e-book reader, a moving picture experts group audio layer III (MP3) player, a moving picture experts group audio layer IV (MP4) player, a laptop computer, a vehicle-mounted computer, a desktop computer, a set top box, a smart television, and a wearable device that all fall within the protection scope of the embodiments of the present application. As shown inFIG.7, an embodiment of the present application further provides a radio frequency control method, applied to an electronic device. The electronic device includes a first radio frequency module and a second radio frequency module, and the method includes the following steps. Step701: Control the first radio frequency module and the second radio frequency module to transmit a first signal and a second signal respectively; where the first radio frequency module transmits the first signal through a first antenna and a second antenna, and the second radio frequency module transmits the second signal through a third antenna and a fourth antenna; or control the second radio frequency module to transmit the first signal and the second signal. The first signal and the second signal may be a same signal or different signals. The first radio frequency module may be an LTE radio frequency module, and the second radio frequency module may be an NR radio frequency module. During signal transmission of the electronic device, standalone and non-standalone NR bands need to support a technology of 2T4R (2 channels of transmissions and 4 channels of reception) or 1T4R (1 channel of transmission and 4 channels of reception) that transmits SRSs by turns through antennas. Since 2T4R of SRS signals includes two channels of SRS signals, a first signal and a second signal are signals of a same type with different transmission channels. Optionally, the first channel of SRS signal (that is, the first signal) is transmitted by the first radio frequency module through the first antenna and the second antenna, and the second channel of SRS signal (that is, the second signal) is transmitted by the second radio frequency module through the third antenna and the fourth antenna; or the two channels of SRS signals are both transmitted by the second radio frequency module, so that 2T4R of SRS signals is implemented. For 1T4R of SRS signals, since only one channel of SRS signal needs to be sent, when the second radio frequency module is controlled to transmit the first signal and the second signal, the first signal and the second signal are a same signal. The SRS signal may be sent by the second radio frequency module through multiple antennas; or the SRS signal may be sent by the first radio frequency module through the first antenna and the second antenna, and the SRS signal is sent by the second radio frequency module through the third antenna and the fourth antenna. It should be noted that the transmission of the SRS signal by the first radio frequency module and the second radio frequency module needs to be performed in a preset time sequence. In this way, 1T4R of an SRS signal is implemented. In the embodiments of the present application, signals are transmitted in multiple modes, and network radio frequency sensitivity of the electronic device is improved. Besides, in the method, the electronic device can perform 2T4R and 1T4R functions of SRS signals. Optionally, the controlling the first radio frequency module and the second radio frequency module to transmit the first signal and the second signal respectively includes: controlling the first radio frequency module and the second radio frequency module to transmit the first signal and the second signal respectively at a first moment; or controlling the first radio frequency module and the second radio frequency module to transmit, according to a preset time sequence, the first signal and the second signal respectively. That the first radio frequency module and the second radio frequency module transmit the first signal and the second signal respectively at the first moment means: while the first radio frequency module transmits the first signal, the second radio frequency module transmits the second signal. For 2T4R of SRS signals, for example, the first signal is the first channel of SRS signal and the second signal is the second channel of SRS signal. As shown inFIG.4, the first radio frequency module sends the first channel of SRS signal to the first antenna and the second antenna, and the first channel of SRS signal is sent by the first antenna and the second antenna; and the second radio frequency module sends the second channel of SRS signal to the third antenna and the fourth antenna, and the second channel of SRS signal is sent by the third antenna and the fourth antenna. In addition, the first radio frequency module and the second radio frequency module send the first channel of SRS signal and the second channel of SRS signal at the same moment, so that 2T4R of the SRS signals is implemented. For 1T4R of an SRS signal, SRS signals need to be sent at a preset time sequence. Optionally, the controlling the first radio frequency module and the second radio frequency module to transmit, according to a preset time sequence, the first signal and the second signal respectively includes: controlling the second radio frequency module to transmit the second signal; and after the second radio frequency module transmits the second signal, controlling the first radio frequency module to transmit the first signal. For 1T4R of an SRS signal, for example, the first signal is the first channel of SRS signal and the second signal is the second channel of SRS signal. As shown inFIG.4, although two transmitting modules are configured to perform the 1T4R function of a signal, in this solution, one transmitting module (that is, the second radio frequency module) is configured to transmit the second signal to the third antenna and the fourth antenna, and then this channel of transmission needs to be stopped, and the other transmitting module (that is, the first radio frequency module) is configured to transmit the first signal to the first antenna and the second antenna, thereby implementing the 1T4R function of the SRS signal in general. Optionally, the second radio frequency module includes the first transmitting submodule and the second transmitting submodule, and the controlling the second radio frequency module to transmit the first signal and the second signal includes:controlling the first transmitting submodule and the second transmitting submodule to transmit a first signal and a second signal respectively; where the first transmitting submodule transmits the first signal through a third antenna and a fourth antenna, and the second transmitting submodule transmits the second signal through a fifth antenna and a sixth antenna. For example, the first signal is the first channel of SRS signal and the second signal is the second channel of SRS signal. As shown inFIG.5, the first transmitting submodule sends the first channel of SRS signal to the third antenna and the fourth antenna, and the first channel of SRS signal is sent by the third antenna and the fourth antenna; and the second transmitting submodule sends the second channel of SRS signal to the fifth antenna and the sixth antenna, and the second channel of SRS signal is sent by the fifth antenna and the sixth antenna. In this way, the two channels of SRS signals are both transmitted by the second radio frequency module, to implement the 2T4R function of SRS signals. Optionally, the second radio frequency module includes the first transmitting submodule and the second transmitting submodule, and the controlling the second radio frequency module to transmit the first signal and the second signal includes:controlling the second transmitting submodule to transmit the first signal and the second signal; where the second transmitting submodule transmits the first signal through the third antenna and the fourth antenna, and transmits the second signal through the fifth antenna and the sixth antenna. In this embodiment, the first signal and the second signal are a same signal. For example, the signal is an SRS signal. This solution is applicable to 1T4R of an SRS signal, that is, only one transmitting module is required to transmit the SRS signal. As shown inFIG.6, the second transmitting submodule sends the SRS signal to the third antenna, the fourth antenna, the fifth antenna, and the sixth antenna, where a signal sent by the third antenna and the fourth antenna is considered to be the first signal, and a signal sent by the fifth antenna and the sixth antenna is considered to be the second signal. It should be noted that for 1T4R of the SRS signal, the first signal and the second signal are a same signal. In the embodiments of the present application, signals are transmitted in multiple modes, and network radio frequency sensitivity of the electronic device is improved. An externally connected 5G transmitting module can be configured to perform the 2T4R and 1T4R functions of the SRS signals, effectively reducing the costs. As shown inFIG.8, an embodiment of the present application further provides an electronic device800, including a first radio frequency module and a second radio frequency module, and further including:a control module801, configured to control the first radio frequency module and the second radio frequency module to transmit a first signal and a second signal respectively; where the first radio frequency module transmits the first signal through a first antenna and a second antenna, and the second radio frequency module transmits the second signal through a third antenna and a fourth antenna; orcontrol the second radio frequency module to transmit the first signal and the second signal. Optionally, the control module801includes:a first control unit, configured to control the first radio frequency module and the second radio frequency module to transmit the first signal and the second signal respectively at a first moment; orcontrol the first radio frequency module and the second radio frequency module to transmit, according to a preset time sequence, the first signal and the second signal respectively. Optionally, the first control unit is configured to:control the second radio frequency module to transmit the second signal; andafter the second radio frequency module transmits the second signal, control the first radio frequency module to transmit the first signal. Optionally, the second radio frequency module includes a first transmitting submodule and a second transmitting submodule; and the control module801includes:a second control unit, configured to control the first transmitting submodule and the second transmitting submodule to transmit the first signal and the second signal respectively;where the first transmitting submodule transmits the first signal through the third antenna and the fourth antenna; and the second transmitting submodule transmits the second signal through the fifth antenna and the sixth antenna. Optionally, the second radio frequency module includes a first transmitting submodule and a second transmitting submodule; and the control module801includes:a third control unit, configured to control the second transmitting submodule to transmit the first signal and the second signal;where the second transmitting submodule transmits the first signal through the third antenna and the fourth antenna, and transmits the second signal through the fifth antenna and the sixth antenna. The electronic device provided in this embodiment of the present application can implement the processes that are implemented by the electronic device in the foregoing method embodiments. To avoid repetition, details are not described herein again. In the embodiments of the present application, signals are transmitted in multiple modes, and network radio frequency sensitivity of the electronic device is improved. An externally connected 5G transmitting module can be configured to perform the 2T4R and 1T4R functions of the SRS signals, effectively reducing the costs. FIG.9is a schematic diagram of a hardware structure of an electronic device according to embodiments of the present application. The electronic device900includes but is not limited to components such as a radio frequency unit901, a network module902, an audio output unit903, an input unit904, a sensor905, a display unit906, a user input unit907, an interface unit908, a memory909, a processor910, and a power supply911. A person skilled in the art may understand that the structure of the electronic device shown inFIG.9constitutes no limitation on the electronic device. The electronic device may include more or fewer components than those shown in the figure, or a combination of some components, or an arrangement of different components. In this embodiment of the present disclosure, the electronic device includes, but is not limited to, a mobile phone, a tablet computer, a notebook computer, a palmtop computer, a vehicle-mounted terminal, a wearable device, a pedometer, or the like. The processor910is configured to control the first radio frequency module and the second radio frequency module to transmit a first signal and a second signal respectively; where the first radio frequency module transmits the first signal through a first antenna and a second antenna, and the second radio frequency module transmits the second signal through a third antenna and a fourth antenna; or control the second radio frequency module to transmit the first signal and the second signal. In the embodiments, signals are transmitted in multiple modes, and network radio frequency sensitivity of the electronic device is improved. An externally connected 5G transmitting module can be configured to perform the 2T4R and 1T4R functions of the SRS signals, effectively reducing the costs. It should be understood that, in this embodiment of the present application, the radio frequency unit901may be configured to receive and send information or receive and send a signal in a call process. For example, after downlink data from a base station is received, the processor910processes the downlink data. In addition, uplink data is sent to the base station. Generally, the radio frequency unit901includes, but not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like. In addition, the radio frequency unit901may further communicate with another device by using a wireless communications system and network. The electronic device provides users with wireless broadband Internet access through the network module902, for example, helps users receive and send e-mails, browse web pages, and access streaming media. The audio output unit903can convert audio data received by the radio frequency unit901or the network module902or stored in the memory909into an audio signal, and output the audio signal into sound. Moreover, the audio output unit903can further provide audio output related to a specific function performed the electronic device900(for example, call signal receiving sound and message receiving sound). The audio output unit903includes a loudspeaker, a buzzer, a receiver, and the like. The input unit904is configured to receive audio or video signals. The input unit904may include a graphics processing unit (GPU)9041and a microphone9042. The graphics processing unit9041is configured to process image data of a static picture or a video obtained by an image capturing device (for example, a camera) in a video capturing mode or an image capturing mode. A processed image frame may be displayed on the display unit906. The image frame processed by the graphics processing unit9041may be stored in the memory909(or another storage medium) or sent by using the radio frequency unit901or the network module902. The microphone9042may receive sound and can process such sound into audio data. The audio data obtained through processing may be converted, in a telephone call mode, into a format that may be sent to a mobile communication base station via the radio frequency unit901for output. The electronic device900further includes at least one sensor905, for example, a light sensor, a motor sensor, and another sensor. For example, the light sensor includes an ambient light sensor and a proximity sensor. The ambient light sensor can adjust brightness of a display panel9061according to ambient light brightness. The proximity sensor can switch off the display panel9061and/or backlight when the electronic device900moves close to an ear. As a motion sensor, an accelerometer sensor can detect magnitude of acceleration in various directions (usually three axes), can detect magnitude and the direction of gravity when stationary, can be configured to identify electronic device postures (such as switching between a landscape mode and a portrait mode, related games, and magnetometer posture calibration), can perform functions related to vibration identification (such as a pedometer and a knock), and the like. The sensor905may further include a fingerprint sensor, a pressure sensor, an iris sensor, a molecular sensor, a gyroscope, a barometer, a hygrometer, a thermometer, an infrared sensor, or the like. Details are not described herein. The display unit906is configured to display information entered by a user or information provided for a user. The display unit906may include the display panel9061, and the display panel9061may be configured in a form of a liquid crystal display (LCD), an organic light-emitting diode (OLED), or the like. The user input unit907can be configured to receive entered number or character information, and generate key signal input related to user settings and function control of the electronic device. For example, the user input unit907includes a touch panel9071and another input device9072. The touch panel9071, also referred to as a touch screen, may collect a touch operation of a user on or near the touch panel (for example, the user uses any suitable object or accessory such as a finger or a stylus to operate on the touch panel9071or near the touch panel9071). The touch panel9071can include two parts: a touch detection apparatus and a touch controller. The touch detection apparatus detects a touch position of a user, detects a signal brought by a touch operation, and transmits the signal to the touch controller. The touch controller receives touch information from the touch detection apparatus, converts the touch information into touch point coordinates, sends the touch point coordinates to the processor910, and receives and executes a command sent by the processor910. In addition, the touch panel9071may be implemented by various types, such as a resistive type, a capacitive type, an infrared type, a surface acoustic wave type, or the like. The user input unit907may further include another input device9072in addition to the touch panel9071. For example, the another input device9072may include, but is not limited to, a physical keyboard, function keys (such as a volume control key and a switch key), a trackball, a mouse, and a joystick. Details are not described herein. Optionally, the touch panel9071can cover the display panel9061. When detecting a touch operation on or near the touch panel, the touch panel9071transmits the touch operation to the processor910to determine a type of a touch event. Then the processor910provides corresponding visual output on the display panel9061based on the type of the touch event. Although inFIG.9, the touch panel9071and the display panel9061are configured as two independent components to implement input and output functions of the electronic device, in some embodiments, the touch panel9071and the display panel9061can be integrated to implement the input and output functions of the electronic device. Details are not limited herein. The interface unit908is an interface for connecting an external apparatus and the electronic device900. For example, the external apparatus may include a wired or wireless headset port, an external power supply (or a battery charger) port, a wired or wireless data port, a memory card port, a port for connecting an apparatus having an identification module, an audio input/output (I/O) port, a video I/O port, a headset port, and the like. The interface unit908can be configured to receive input from an external apparatus (for example, data information and power) and transmit the received input to one or more elements in the electronic device900, or can be configured to transmit data between the electronic device900and the external apparatus. The memory909may be used to store software programs and various data. The memory909may mainly include a program storage area and a data storage area. The program storage area may store an operating system, an application required by at least one function (for example, a sound play function or an image display function), and the like. The data storage area may store data (for example, audio data or an address book) or the like created based on use of the mobile phone. In addition, the memory909may include a high-speed random access memory, and may further include a non-volatile memory, for example, at least one magnetic disk storage device, a flash memory device, or another volatile solid-state storage device. The processor910is a control center of the electronic device and connects all parts of the electronic device using various interfaces and circuits. By running or executing software programs and/or modules stored in the memory909and by calling data stored in the memory909, the processor910implements various functions of the electronic device and processes data, thus performing overall monitoring on the electronic device. The processor910may include one or more processing units. Optionally, the processor910may integrate an application processor and a modem processor. The application processor mainly deals with an operating system, a user interface, an application, and the like. The modem processor mainly deals with wireless communication. It can be understood that, alternatively, the modem processor may not be integrated into the processor910. The electronic device900may further include the power supply911(such as a battery) supplying power to each component. For example, the power supply911may be logically connected to the processor910by using a power management system, so as to implement functions such as charging management, discharging management and power consumption management by using the power management system. In addition, the electronic device900includes some functional modules not shown. Details are not described herein. For example, an embodiment of the present application further provides an electronic device, including a processor, a memory, and a computer program stored in the memory and executable on the processor. When the computer program is executed by the processor, each process of the foregoing embodiments of the radio frequency control method is implemented, and a same technical effect can be achieved. To avoid repetition, details are not described herein. An embodiment of the present application further provides a non-transitory computer readable storage medium. The non-transitory computer readable storage medium stores a computer program, and when the computer program is executed by a processor, the processes of the foregoing embodiments of the radio frequency control method are implemented, and same technical effects can be achieved. To avoid repetition, details are not described herein again. The non-transitory computer readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a magnetic disk, a compact disc, or the like. It should be noted that in this specification, the term “include”, “including”, or any other variant is intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus that includes a series of elements includes not only those elements but also other elements that are not explicitly listed, or includes elements inherent to such a process, method, article, or apparatus. In the absence of more restrictions, an element defined by the statement “including a . . . ” does not exclude another same element in a process, method, article, or apparatus that includes the element. According to the foregoing descriptions of the implementations, a person skilled in the art may clearly understand that the foregoing method embodiments may be implemented by using software and a required universal hardware platform, or certainly may be implemented by using hardware. However, in many cases, the former is a better implementation. Based on such an understanding, the technical solutions of the present application essentially or the part contributing to the prior art may be implemented in a form of a software product. The computer software product is stored in a nonvolatile storage medium (such as a ROM/RAM, a magnetic disk, or an optical disc), and includes several instructions for instructing a terminal (which may be a mobile phone, a computer, a server, an air conditioner, a network device, or the like) to perform the methods described in the embodiments of the present application. It may be understood that some embodiments of the present application may be implemented by hardware, software, firmware, middleware, microcode, or a combination thereof. For implementation with hardware, the module, unit, submodule, subunit, and the like may be implemented in one or more application specific integrated circuits (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field-programmable gate array (FPGA), general processors, controllers, micro-controllers, micro-processors, and other electronic units for implementing the functions of the present application, or their combinations. For software implementation, the technology described in the embodiments of the present application may be implemented by using a module (for example, a process or a function) that performs the function in the embodiments of the present application. Software code may be stored in a memory and executed by a processor. The memory may be implemented inside or outside the processor. Therefore, the objectives of the present application may also be achieved by running a program or a set of programs on any computing apparatus. The computing apparatus may be a well-known general-purpose apparatus. Therefore, the objective of the present application may also be achieved only by providing a program product including program code for implementing the method or the apparatus. In other words, such a program product also constitutes the present application, and a nonvolatile storage medium storing such a program product also constitutes the present application. Obviously, the nonvolatile storage medium may be any well-known nonvolatile storage medium or any nonvolatile storage medium to be developed in the future. It should also be noted that in the apparatus and method of the present disclosure, apparently, the components or steps may be divided and/or recombined. These division and/or recombination should be considered as equivalent solutions of the present application. Moreover, the steps for performing the foregoing series of processing may be performed naturally in a chronological order according to a described sequence, but do not necessarily need to be performed in the chronological order, and some steps may be performed in parallel or independently. The embodiments of the present application are described above with reference to the accompanying drawings, but the present application is not limited to the foregoing implementations. The foregoing implementations are merely exemplary instead of restrictive. Under enlightenment of the present application, a person of ordinary skill in the art may make many forms without departing from the aims of the present application and the protection scope of claims, all of which fall within the protection of the present application. | 42,156 |
11942980 | DETAILED DESCRIPTION Certain example embodiments are described in detail with reference to the accompanying drawings, wherein the features of the embodiments can be freely combined with each other unless otherwise described. However, it is to be expressly understood that the description of certain embodiments is given by way of example only, and that it is by no way intended to be understood as limiting to the disclosed details. Moreover, it is to be understood that the apparatus is configured to perform the corresponding method, although in some cases only the apparatus or only the method are described. The operations of the method may be embodied in a computer program product on, for example, a non-transitory medium. Certain abbreviations will be used herein, which are set out below for ease of reference. Abbreviations 2G/3G/4G/5G 2nd/3rd/4th/5thGeneration3GPP 3rdGeneration Partnership ProjectCD Compact DiscDCS Digital Cellular SystemDPD Digital PredistortionDVD Digital Versatile DiskeNB, NB evolved NodeBFDD Frequency Division DuplexIEC International Electrotechnical CommissionIMP/IM Intermodulation ProductIMP3/IMP5/ . . . IMP of 3rdorder/5thorder/ . . .LMS Least Mean SquareNR New RadioOCNS Orthogonal Channel Noise SimulatorPIM Passive InterModulationPIMC Passive InterModulation CancellationRF Radio FrequencyRX ReceiveTX TransmitUE User Equipment Cellular base stations may de-sense their own uplink owing to PIM products, for example introduced by passive components such as duplexers, cables, connector interfaces, antennas etc. If PIM is not mitigated, e.g. reduced or cancelled, it may not be possible to decode received signals. Operators may use PIM cancellation algorithms to improve uplink signal quality. Passive InterModulation (PIM) is a physical process where transmit signals generate intermodulation products in passive devices. PIM products may be generated at very low power levels, for example due to the aging of antennas, corroded or loose connectors and duplex filters that are passive. Imperfections of cables, combiners and attenuators may also generate PIM. PIM generation with transmit signals is generally harmless due to its low level. However, when PIM products line up with receive signals, issues can arise. Although the level of PIM in a typical radio can range from −110 dBc to −150 dBc (w.r.t to the transmit signal) it can cause the receiver to desensitize. As an example, a transmit signal that is 49 dBm of power causes PIM levels that are −81 dBm to −101 dBm corresponding to −130 dBc to −150 dBc PIM source range. Hence, on some occasions, PIM signals can be higher than the receive signals. When PIM is higher than the receive signal, the receiver decoding process will fail due to negative signal to noise ratio. This may cause a significant throughput loss in the uplink direction (mobile to base station). Some radios or associated equipment are designed to mitigate, i.e. reduce or avoid, such PIM effects with PIM cancellation (PIMC) systems or algorithms. In this respect, the term cancellation may also mean mitigate. A PIMC algorithm uses a model that attempts to cancel, or at least reduce, the PIM products on the receiver (Rx) bandwidth. FIG.1is a schematic diagram of an example transceiver system10that involves PIM cancellation according to example embodiments. The transceiver system10comprises a duplexer12connected to a common antenna14; the duplexer12comprises first and second duplexer filters, a first being a transmitter (Tx) duplexer filter having a passband providing a signal path between a transmitter (Tx)16and the antenna, and the second being a receiver (Rx) duplexer filter providing a signal path between the antenna and a receiver (Rx)18. No path between the transmitter16and the receiver18should exist. A PIMC module20may be provided between the input and output paths of the transmitter16and receiver18respectively. The PIMC module20may be implemented in hardware, software or a combination thereof. The PIMC module20operates using an algorithm which is similar to known PIMC algorithms and which uses a PIM model22to determine how to cancel the PIM. IEC-62037 describes a way to measure PIM using a so-called two-tone test. Example embodiments may also involve PIMC algorithms that may be enabled (turned ON) and disabled (turned OFF), which may be applied when the transceiver system10operates in a Frequency Division Duplex (FDD) mode. Example embodiments may be applied in any related or future telecoms technology, including for example, 3G, 4G, 5G etc. PIM effects may differ depending on factors such as, but not limited to, where the base station is positioned geographically, the environment it is in, the specific components used and their interconnections. PIMC techniques may allow the network operator to turn ON the PIMC algorithm when the radio equipment ages. For example, ageing connectors and bolts of the radio equipment may create intermodulation products that land on receive frequencies causing the receiver SNR to degrade. Thus, this may result in significant uplink throughput losses. Although PIMC algorithms may mitigate the problem by cancelling out interfering PIM products, the time to turn ON the algorithm is a separate, but equally important consideration. The PIMC turn ON decision may be based on the amount of PIM that is above the noise floor. For example, when PIM is detected tens of dB above the noise floor, the accuracy of the extracted PIM model is found to be high. Hence, the PIMC algorithm will substantially eliminate the interfering PIM, enabling the user to recover the loss in throughput. However, when the PIM is only a few dBs above the noise floor, the extracted PIM model may not be that accurate. Thus, the cancellation may, on some occasions, cause more degradation than the interfering PIM signal itself. Therefore, on such occasions, it may be better to leave the PIM products in the uncorrected state to cause no further damage. Besides the level of the PIM signal, the other concern for model extraction is the lack of static and stable downlink traffic during actual operation. Note that real traffic is non-contiguous. Hence, during the model extraction process, the PIMC algorithm may experience little traffic, thus exacerbating the problem of what the input noise would do to the model. To determine when to turn PIMC ON or OFF, the level of PIM signal in decibels relative to the carrier (dBc) may be used to compare how close it is to the noise floor. A decision threshold may be set a certain number of dBs above the noise floor. If the estimated level of the PIM signal is closer to the noise floor, i.e. at or below the decision threshold, PIMC can be turned OFF. If above, PIMC can be turned ON. However, the level of the PIM signal can only be accurately determined or estimated when the “slope” of the PIM source presented to the system is obtained either empirically or theoretically, as explained later. Referring toFIG.2, a PIM slope29refers to the relationship between an input power (in dBm) and PIM signal power (also in dBm) that result from the input signal power. In theFIG.2example, the PIM signal power is based on the IM3 component only, and different slopes29for each of three different PIM sources are shown. The PIM slope for a given component forms the basis of the model22used in PIMC algorithms and systems, e.g. in the PIMC module20. If the PIM slope29of a PIM source is unknown, even if the model22is accurate (e.g. PIMC is ON because PIM signal is determined to be considerably higher than the noise floor) estimation and subsequent reporting of PIM level in dBc, per the IEC-62037 standard, requires “assuming” a “typical” slope of the PIM source based on typical PIM components characterized in a laboratory. Often, the PIM slope29of a PIM source in the field is totally different from a typical PIM slope. This may lead to inaccurate estimation and reporting of PIM levels due to mismatch error between the “actual” PIM slope of the PIM source in the field and the “typical” PIM slope of PIM sources characterized in the lab. Hence, example embodiments relate to characterizing the PIM slope, for example without disrupting the normal operation of the transmitter, for example using live traffic, of the presented PIM source in the field. An error equation, in dB, representing the mismatch between “unknown, actual” PIM in the field versus “assumed, typical” PIM, based on lab components, can be written as: errordB=(XrefdB−XdB)·{massumed−mactual(t)} (1) whereXrefdB→the “reference power” at which a system is calibrated or, equivalently, the “normalized power” with respect to which the estimated PIM level in dBc is reported; With the IEC-62037 standard, XrefdB=43 dBm per carrier (2×43 dBm per carrier);xdB→the transmitted power from the radio;massumed→the “typical” slope of a PIM source component characterized in the lab. This is a constant, typically an averaged, static slope from different PIM source components; andmactual(t)→the “actual” unknown slope of a PIM source in the field, which is a time-varying quantity. The derivation of equation (1) is presented in the Appendix. Example embodiments herein provide a way of estimating the real-time slope29of a PIM source in the field, which may be presented to a system in the presence of real-time, live traffic. Further, example embodiments may use the estimated PIM slope29to determine whether or not to turn PIMC ON or OFF. Further, the estimated PIM slope29may be used to report the PIM level in dBc, as per the IEC-62047 standard, more accurately and in real-time or near real-time. In overview, example embodiments to be described below are based on third order PIM products, i.e. IM3. This is because most in-field configurations are exposed to IM3 PIM products and the PIM level is higher on such products. However, for the avoidance of doubt, example embodiments are not limited to IM3 PIM products, and can be extended to fifth order (IM5) and seventh order (IM7) PIM products etc. if they are relatively higher than the receiver noise floor. Using mathematical derivations, it can be shown that the power of the third order PIM product IM3 is dependent on the power of transmit signals. Mathematics can also show that, for every 1 dB drop of transmit power, the power of the third order PIM will drop by 3 dB. Hence, with a 2 dB of transmit power, the drop of the third order PIM power is expected to be 6 dB. This is simply annotated by the theoretical 3 dB per 1 dB PIM slope. However, passive devices in nature do not follow the theoretical 3 dB per 1 dB slope. Instead, the typical PIM slopes for practical devices range between 2.2-2.8 dB per every one dB drop. A PIM slope is intimately related to PIMC ON/OFF decisions. Since an ON/OFF decision occurs when PIM level is closer to the noise floor, the PIMC algorithm cannot rely on the extracted PIM model alone to make a correct decision. PIM slope number will take a higher weight on the decision to turn ON/OFF the PIMC algorithm. The PIM slope also helps characterize the PIM level in dBc at a higher accuracy, which subsequently helps in ON/OFF decisions as well as reporting the “real-time” dBc value of the PIM source per IEC-62037. Experimental Approach Where radio equipment utilizes an Orthogonal Channel Noise Simulator (OCNS) for accurate delay search computation, for the PIMC algorithm, the OCNS fills-in unused resource blocks of LTE carriers. Hence, the power of the LTE carrier will be at a maximum during the OCNS transmission. Third order PIM products IM3 will be at their highest power during this time as well. A receiver, e.g. an eNB/gNB/base station noise floor (N dBm per MHz) can be known by prior measurements. Peak PIM power location (frequency) is known from a transmit signal configuration. With an FFT based filter, the peak PIM power per MHz (P dBm per MHz) can also be computed. Now (P-N) dBc will be the level of PIM at the highest point above the noise floor. Although the calculations are shown using a dBm/MHz basis, software may measure the power across F MHz before normalizing the result on a per MHz basis. The PIM peak will be contained within the F MHz window. To detect the PIM slope experimentally, the power towards the PIM load needs to be lowered by a known amount. For the purpose of this disclosure, the power reduction is denoted as P_diff. Regarding when to turn the PIMC algorithm ON or OFF, a first example embodiment will be described. As mentioned above, the OCNS fills-in all available LTE resource blocks. By removing a certain number of resources blocks, the power of the transmit signal can be reduced by P_diff. Assuming the PIM peak is still well above the noise floor, the peak PIM power per MHz Preducedcan be computed as described later on. Knowing P_diff and (P−Preduced), the PIM slope can be computed as follows: PIM slope=(P−Preduced)/Pdiff(2) A second example embodiment method will now be described. While the first method may require a specific alternation for OCNS, a statistical method may also yield the same answer. The statistical method can be applied with real traffic and so not requiring an OCNS for PIM power measurement. With the statistical method, it is proposed to monitor the transmit power using power meters. Power meters are available on a per-carrier basis. RF software may be used to measure the statistical power of the transmit signals within a time period from t1to t2. Baseband transmit signal power measured during this time period is compared with when OCNS is ON. The difference will be equivalent to P_diffnew as in the first method. During the same time (i.e. t1to t2), the RF software will make a statistical measurement of the PIM at its peak (Preduced_new). With these measurements the PIM slope can be computed with the equation shown below: PIM slope=(P−Preduced_new)/Pdiffnew(3) Note that with a statistical method, the frequency location of the PIM peak may move slightly within the F MHz measurement window. However, the window will be sufficiently wide, and will capture the power of the PIM during the allotted time. For the final calculation, the PIM power can be normalized to a per MHz basis. With knowledge of the PIM slope, as well as the baseband signal power via power meters, the level of the PIM signal can be predicted with equation [3]. In addition, RF software can corroborate the predicted answer by performing a statistical measure of Peak PIM power per MHz via FFT filtering, at the same time as when the transmit power was measured. With knowledge of above steps, we are now able to make an accurate decision as to whether to turn ON/OFF the PIMC algorithm within the radio equipment. If PIM is deemed closer to the noise floor, the algorithm can be turned OFF. If it is reasonably above the noise floor, the algorithm can be turned ON. Other example embodiments may involve reporting the PIM level per the IEC-62037 standard with an accurate model. In an example embodiment, as before, the OCNS fills-in all available LTE resource blocks. By removing a certain number of resource blocks, the power of the transmit signal can be reduced by P_diff. Next, the “model” to cancel PIM at full power (i.e., all available resource blocks) can be estimated and at reduced power (i.e. using reduced resource blocks.) The dBc level of PIM signal from the model estimate at full power (denote it as PdBc) and reduced power (denote it as Preduced_dBc) can be found. Knowing P_diff and (PdBc−Preduced_dBc), the PIM slope can be computed as follows: PIM slope=(PdBc−Preduced_dBc)/Pdiff(4) A second example embodiment method will now be described. While the first method may require a specific alternation for OCNS, a statistical method may also yield the same answer. The statistical method can be applied with real traffic and thus does not requiring OCNS for PIM power measurement. With the statistical method, the transmit power may be monitored using power meters. Power meters are available on a per carrier basis. RF software may measure the statistical power of the transmit signals within a time period from t1to t2. Baseband transmit signal power measured during this time period is compared with when OCNS is ON. The difference will be equivalent to P_diffnew_dBc. During the same time (i.e. t1to t2), the RF software will make a statistical measurement of the PIM level in dBc (Preduced_new_dBc). With these measurements, the PIM slope can be computed with the equation shown below: PIM slope=(PdBc−Preduced_new_dBc)/Pdiffnew_dBc(5) Note that with a statistical method, the frequency location of the PIM peak may move slightly within the F MHz measurement window. However, the window is sufficiently wide, and may capture the power of the PIM during the allotted time. For the final calculation, the PIM power can be normalized to a per MHz basis. With knowledge of the PIM slope, as well as the baseband signal power via power meters, it is possible to predict the level of the PIM signal with the help of equation [5]. It is also possible to report the PIM signal level in dBc in real-time per the IEC-62037 standard, without interruption to the transmitted signal. Theoretical Approach While the experimental approach will provide the actual status or the prediction of the level of the PIM signal, a theoretical approach can be considered as an enhancement. The theoretical approach requires some initial measurements:a) the level of the PIM with OCNS turned on. As discussed in the prior section, the PIM power can be computed on a specified bandwidth using an FFT based filter. This level will be recorded as P dbm, for the specified bandwidth;b) with OCNS turned OFF, either of the statistical methods described above can be used to determine the PIM power Preduced_newdBm within the same specified bandwidth as in a). As described above, P_diffnew (difference in transmit power from measurement a) to b)) can be recorded; andc) knowing the PIM powers of P dbm and Preduced_newdBm of a) and b), as well as the transmit power difference P_diffnew, the standard PIM model can be modified so that it is able to predict the PIM power variation that adheres to a practical PIM slope. Practical PIM slopes typically range from 2.2-2.8 dB per each dB drop. Note that the theorical PIM predictive models hitherto have not addressed PIM power level differences. The proposed PIM model here addresses that and can predict the PIM level at another power (i.e. usually at a lower transmit power.) A notable advantage of this technique is the accuracy of the PIM power when PIM is closer to the noise floor. So long as step b), the second input to the model, is measured at a relatively higher power (PIM signal well above the noise floor), the derived model is usually unimpacted by the receiver noise floor. Mathematical Description of the Theoretical Model: Since the third order (IM3) PIM model is applicable for the vast majority of the PIM configurations, the following mathematical model is derived considering IM3 PIM power in mind. For simplicity, it is assumed that only IM3 is deemed to follow the PIM slope. Typical PIM model with IM3: With OCNS turned ON (i.e. with full traffic occupancy of the LTE carriers) the following expression will provide the PIM power within a specified bandwidth. As shown later, the fifth order terms are used primarily to provide extra degrees of freedom to augment the IM3 PIM. Pim_OCNS=filt(c1*x(n)*|x(n)|2+c2*x(n−1)*|x(n−1)|2+c3*x(n+1)*|x(n+1)|2+c4*x(n)*|x(n)|4+c5*x(n−1)*|x(n−1)|4+c6*x(n+1)*|x(n+1)|4) (6) Where the Pim_OCNS signal consist of three memory taps (more can be used if needed.) Coefficients C1, C2, C3, . . . C6 are extracted using the standard least squares method, using conventional techniques. The function filt filters the PIM signal to a known bandwidth (i.e. F MHz). The function filt can either be a time domain mechanism or a frequency domain (i.e. FFT based) mechanism. The term x(n) is the transmit signal. Bandwidth of filt is selected to capture only IM3 PIM components of the PIM signal. The power of the transmit signal can be computed or measured using power meters. The computed transmit power is given as: P_OCNS_trmt=∑i=0i=Nx(n)*conj(x(n))(7) The computed transmit power at reduced transmit power is given as: P_xr_trmt=∑i=0i=Nxr(n)*conj(xr(n))(8) where xr(n) is the equivalent base band signal associated with: Pim_xr=filt(c1*xr(n)*|xr(n)|2+c2*xr(n−1)*|xr(n−1)|2+c3*xr(n+1)*|xr(n+1)|2+c4*xr(n)*|xr(n)|4+c5*xr(n−1)*|xr(n−1)|4+c6*xr(n+1)*|xr(n+1)|4) (9) Note that power of Pim_OCNS and Pim_xr will not follow the expected PIM slope as per the measurements in steps a) and b). Note that the power differences of PIM_OCNS and PIM_xr ought to satisfy: Pim_OCNSpower−Pim_Xrpower=PimΔpower(10) Equation [9], unaltered, will not follow the PIM slope inherent with the two measurements described in a) and b). Some modifications will be required to make it compliant with equation [10]. Note that the concerned PIM power difference (PimΔpower) is primarily based on IM3 PIM products only. The extra fifth order terms, shown in equation [9], can then be used to rectify the non-compliant problem with the PIM slope. As the reader may be aware, the fifth order terms also contribute energy towards the IM3 PIM products. Hence by manipulating the fifth order terms, it is possible to match any PIM slope that appears in nature. The technique that makes use of the fifth order terms to predict the IM3 PIM slope is illustrated with equations (11) and (12): Pimxrmatched=filt(c1*xr(n)*|xr(n)|2+c2*xr(n−1)*|xr(n−1)|2+c3*xr(n+1)*|xr(n+1)|2+c4*r*xr(n)*|xr(n)|4+c5*r*xr(n−1)*|xr(n−1)|4+c6*r*xr(n+1)*|xr(n+1)|4) (11) PimOCNSmatched=filt(c1*x(n)*|x(n)|2+c2*x(n−1)*|x(n−1)|2+c3*x(n+1)*|x(n+1)|2+c4*r*x(n)*|x(n)|4+c5*r*x(n−1)*|x(n−1)|4+c6*r*x(n+1)*|x(n+1)|4) (12) Note that equations [11] and [12] consist of an extra rotation coefficient r that multiplies 5thorder coefficients c4, c5, and c6. By rotating the 5thorder, its contribution towards IM3 can be used appropriately to match the PIM slope. In this way, r can be used to match any natural PIM slope in the range of 2.2-2.8 dB per dB power change. Note that the magnitude of r is equal to a. It consists of a complex rotation as shown below: r=α*exp(jθ) (11) where θ indicates the appropriate rotation and α the appropriate magnitude that are needed to match the PIM slope. The values of θ and α can be determined iteratively through software. Once the angle of rotation and magnitude are determined, any future PIM power delta PimΔpowerdue to a reduction of transmit power can be computed using equations [11] and [12] as follows: Pim_OCNS_matchedpower−Pim_xr_matchedpower=(P−Preducednew)=PimΔ_matchedpower(12) To summarise, equations [11] and [12] are altered to match only the power differences of Pim_OCNS_matched and Pim_xr_matched to (P−Preducednew). In other words, Pim_OCNS_matchedpowerand Pim_xr_matchedpowerdo not have to be equal to P or Preduced_new. Since P is known, the difference in power is sufficient to predict the PIM power that is compliant with the PIM slope. FIG.3is a flow diagram illustrating operations according to an example embodiment that may be performed by an RF system, for example a control system in, or associated with, a base station. A first operation S31may comprise determining a PIM slope using any above method. A second operation S32may comprise deriving a PIM value based on the PIM slope. A third operation S33may comprise reporting the PIM value, for example as per the IEC-62037 standard. FIG.4is a flow diagram illustrating operations according to another example embodiment that may be performed by an RF system, for example a control system in, or associated with, a base station. A first operation S41may comprise determining a PIM slope using any above method. A second operation S42may comprise deriving a PIM value based on the PIM slope. A third operation S43may comprise controlling PIMC accordingly. FIG.5is a flow diagram illustrating operations according to another example embodiment that may be performed by an RF system, for example a control system in, or associated with, a base station. A first operation S51may comprise determining a noise floor for the RF system. A second operation S52may comprise determining a PIM value of a source component of the RF system. A third operation S53may comprise determining to turn on a PIM cancellation system if the PIM value is above a predetermined threshold from the noise floor. Note that the predetermined threshold may be a configurable parameter. A fourth operation S54may comprise determining to turn off a PIM cancellation system if the PIM value is at or below the predetermined threshold from the noise floor. As the arrows indicate, one of the two operations S33, S34may be entered from the second operation S32, depending on the current state. Thus, the term “turn” may be replaced with “maintain” with no change to the intended scope of the term if the current on/off state is to remain the same. FIGS.6and7are flow diagrams illustrating operations according to other example embodiments that may be performed by an RF system, for example a control system in, or associated with, a base station. More specifically,FIGS.6and7relate to calculating the PIM slope using the experimental approach outlined above using noise, for example using OCNS. Referring toFIG.6, a first operation S61may comprise applying noise to blocks of a carrier signal. A second operation S62may comprise determining peak PIM power. A third operation S63may comprise removing noise from some of the blocks. A fourth operation S64may comprise determining reduced noise peak PIM power. A fifth operation S65may comprise calculating the PIM slope. Referring toFIG.7, a first operation S71in this case may comprise measuring the power in normal use. A second operation S72may comprise determining peak PIM power, without noise. A third operation S73may comprise applying noise. A fourth operation S74may comprise determining peak PIM power, with the applied noise. A fifth operation S75may comprise calculating the PIM slipe. FIG.8is a flow diagram illustrating operations according to another example embodiment that may be performed by an RF system, for example a control system in, or associated with, a base station. More specifically, the flow diagram relates to the above-mentioned theoretical approach. A first operation S81may comprise measuring transmit power with full noise, e.g. OCNS, on, and determining the value to be P_OCNS. The first operation S82, or another operation, may also comprise measuring the transmit power with partial noise, and determining the value to be P_reduced. The first operation S82, or another operation, may also comprise measuring the PIM level with full noise and partial noise and determining the values to be PIM_OCNS_measured and PIM_Reduced_measured respectively. A second operation S82may comprise estimating the PIM with noise on for all blacks (with full noise on) with 3rdand 5thorder terms. This value may be determined as PIM_OCNS. A third operation S83may comprise estimating the PIM with noise on for some blocks (partial noise on) with 3rdand 5thorder terms. This value may be determined as PIM_Reduced. A fourth operation S84may comprise rotating the 5thorder terms used in PIM_OCNS with a complex rotation ‘r.’ This value may be determined as PIM_OCNS_matched. A fifth operation S85may comprise rotating the 5thorder terms used in PIM_Reduced with a complex rotation ‘r.’ A sixth operation S86may comprise determining the PIM_slope_measured to be: (PIM_OCNS_measured−PIM_Reduced_measured)/P_OCNS−P_Reduced. A seventh operation S87may comprise determining the PIM_slope_actual to be: (PIM_OCNS_matched-PIM_Reduced_measured)P_OCNS-P_Reduced. An eighth operation S88may comprise finding the rotation ‘r’ until PIM_slope_actual matches PIM_slope_measured. Additional operations may be provided in some embodiments. The operations above, and referred in relation toFIGS.3-8, may be implemented in hardware, software or a combination thereof. FIG.9shows an apparatus according to an embodiment. The apparatus may be configured to perform the operations described herein, for example operations described with reference to any one or more ofFIGS.3-8. The apparatus comprises at least one processor420and at least one memory410directly or closely connected to the processor. The memory410includes at least one random access memory (RAM)410band at least one read-only memory (ROM)410a. Computer program code (software)415is stored in the ROM410a. The apparatus may be connected to a TX path and a RX path of a base station in order to obtain respective signals. However, in some embodiments, the TX signals and RX signals are input as data streams into the apparatus. The apparatus may be connected with a user interface UI for instructing the apparatus and/or for outputting results. However, instead of by a UI, the instructions may be input e.g. from a batch file, and the output may be stored in a non-volatile memory. The at least one processor420, with the at least one memory410and the computer program code415are arranged to cause the apparatus to at least perform at least the method according toFIG.3. FIG.10shows a non-transitory media430according to some embodiments. The non-transitory media430is a computer readable storage medium. It may be e.g. a CD, a DVD, a USB stick, a blue ray disk, etc. The non-transitory media430stores computer program code causing an apparatus to perform the method ofFIG.3. Names of network elements, protocols, and methods are based on current standards. In other versions or other technologies, the names of these network elements and/or protocols and/or methods may be different, as long as they provide a corresponding functionality. For example, embodiments may be deployed in 2G/3G/4G/5G networks and further generations of 3GPP but also in non-3GPP radio networks such as WiFi. Accordingly, a base station may be a BTS, a NodeB, an eNodeB, a WiFi access point etc. A memory may be volatile or non-volatile. It may be e.g. a RAM, an SRAM, a flash memory, an FPGA block ram, a DCD, a CD, a USB stick, and a blue ray disk. If not otherwise stated or otherwise made clear from the context, the statement that two entities are different means that they perform different functions. It does not necessarily mean that they are based on different hardware. That is, each of the entities described in the present description may be based on a different hardware, or some or all of the entities may be based on the same hardware. It does not necessarily mean that they are based on different software. That is, each of the entities described in the present description may be based on different software, or some or all of the entities may be based on the same software. Each of the entities described in the present description may be embodied in the cloud. According to the above description, it should thus be apparent that example embodiments provide, for example, a PIM slope estimator, a PIMC algorithm module or controller therefore, or a component thereof, an apparatus embodying the same, a method for controlling and/or operating the same, and computer program(s) controlling and/or operating the same as well as mediums carrying such computer program(s) and forming computer program product(s). Implementations of any of the above described blocks, apparatuses, systems, techniques or methods include, as non-limiting examples, implementations as hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. Some embodiments may be implemented in the cloud. It is to be understood that what is described above is what is presently considered the preferred embodiments. However, it should be noted that the description of the preferred embodiments is given by way of example only and that various modifications may be made without departing from the scope as defined by the appended claims. APPENDIX Derivation of Equation (1) PIM coefficients obtained from the least-squares method can be expressed as: coeff=Model⊗RxModel⊗Model(A15) where ⊗ represents correlation operator. At the aligned phase, after doing a delay search (i.e., at the cross correlation peak point), ⊗ simply turns to the multiplication operator, and “coeff” is just “gain” of the output/input transfer function, as used in systems theory. The below equation is valid for single a coeff, in the case of multi-tap coefficients, and we can substitute the “power” term with the FFT amplitude: coeffgain=α·Model×RxModel×Model(A16) where α is a scalar (α=1 implies unity gain) Simplifying it yields: coeff_gain=α·RxModel(A13) Model is our basis function X.|X|2i.e., denoted as X3for convenience, and Rx is Xm, where m<3and where X is the Tx power. Since third order (IM3) PIM is most useful, we have used X.|X|2as our basis function for illustration, and ‘m’ is the actual PIM slope of the PIM source in the field that is presented to the system. Substituting this in the above equation, we get: coeffgain=α·XmX3(A18) which can be written as: coeffgain=α·XmXm+(3-m)(A14) which can be written as: coeffgain=α·XmXm×X(3-m)=α·1X(3-m).(A20) Now, the theoretical coeffs should be: coeffgain_theoretical=α·XmXm=α.(A21) Substituting this, we get: coeffgain=coeffgain_theoretical·1X(3-m)(A22) or, equivalently: coeffgain_theoretical=coeffgain·X(3-m). (A23) Our objective is to get coeffgain_theoreticalso we “de-embed” the actual measured coeffgainby the factor X(3-m). Now, we have to calibrate (normalize) with a two tone 43 dBm/carrier power, as per IEC-62037, so that the reference power i.e., Xref=43 dBm/carrier. At m=3, coeffgain_theoretical=coeffgain⇒Rx=Model and X=Xrefduring the calibration/normalization process. Since IEC-62037 requires estimation and reporting of dBc normalized to Xref=43 dBm/carrier, the linear equation [A23] needs to be normalized to Xref. To do normalization, we modify [A23] as follows: coeffgaintheoreticalcoeffgain=X(3-m)(A23.1) Now, we divide the right hand side of equation [A] by Xrefto normalize it with respect to Xref. Consequently, we divide the left hand side of equation [A23.1] by 1 because at X=Xref,coeffgain_theoretical=coeffgain⇒coeffgain_theoreticalcoeffgain=1. Doing these operations gives us equation [A23.2]: coeffgaintheoreticalcoeffgain=X(3-m)Xref(3-m)(A23.2) In dB terms, we can write [A23] as: coeffgain_theorettcal_dB=coeffgain_dB+(3−m)·XdB. (A24) In dB terms, we can write equation [A23.2] as: coeffgain_theoretical_dB=coeffgain_dB+(3−m)·{XdB−XrefdB} (A25) Or equivalently: coeffgain_theoretical_dB=coeffgain_dB−(3−m)·{XrefdB−XdB} (A26) Now, let us denote the actual slope to be mactual(t) and the assumed slope to be massumed. Therefore, “error” in coeffglain_theoretical_dBdue to two different slopes now becomes: errordB=(XrerdB−XdB)·{(3−mactual(t))−(3−massumed)} (A27) i.e.: errordB=(XrefdB−XdB)·{massumed−mactual(t)} (A28). | 35,239 |
11942981 | DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a receiver, a communication system, a control circuit, and a storage medium according to embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments. First Embodiment FIG.1is a diagram illustrating an example of a configuration of a communication system3according to a first embodiment. The communication system3includes a transmitter1and a receiver2. First, the configuration and operation of the transmitter1will be described. As illustrated inFIG.1, the transmitter1includes a modulation unit11, a chirp spread unit12, a preamble generation unit13, a frame generation unit14, a transmission filter15, and a transmission antenna16.FIG.2is a flowchart illustrating the operation of the transmitter1according to the first embodiment. The modulation unit11modulates information bits including zeros and ones (step S101). The modulation unit11can use, for example, phase shift keying (PSK), frequency shift keying (FSK), or the like as the modulation system. The modulation unit11outputs a modulated signal to the chirp spread unit12. The chirp spread unit12performs spread spectrum on the modulated signal acquired from the modulation unit11by a chirp signal (step S102). The chirp spread unit12can use, for example, a Zadoff-Chu sequence as a sequence used in the spread spectrum. When a length of sequence Ncis an even number, a t-th element C (t) of a Zadoff-Chu sequence C is expressed as in the following expression (1). C(t)=expj(Mπt2/Nc)(1) In expression (1), “M” is a sequence parameter and is relatively prime to “Nc”. Also, “M” represents the number of increases from a minimum frequency fmin to a maximum frequency fmax in the length of sequence Nc. When M=1, the frequency increases from the minimum frequency fmin to the maximum frequency fmax once in the length of sequence Nc. When M=2, in the length of sequence Nc, the frequency increases from the minimum frequency fmin to the maximum frequency fmax, and then increases again from the minimum frequency fmin to the maximum frequency fmax. That is, when M=2, the frequency increases from the minimum frequency fmin to the maximum frequency fmax twice in the length of sequence Nc. On the other hand, when M=−1, the frequency decreases from the maximum frequency fmax to the minimum frequency fmin once in the length of sequence Nc. When M=−2, in the length of sequence Nc, the frequency decreases from the maximum frequency fmax to the minimum frequency fmin, and then decreases again from the maximum frequency fmax to the minimum frequency fmin. That is, when M=−2, the frequency decreases from the maximum frequency fmax to the minimum frequency fmin twice in the length of sequence Nc. The chirp spread unit12outputs data generated by performing the spread spectrum on the modulated signal to the frame generation unit14. In the following description, the data generated by the chirp spread unit12may be referred to as a data block. The preamble generation unit13generates a preamble by performing spread spectrum on a known signal (step S103). Specifically, the preamble generation unit13performs the spread spectrum on the known signal using up chirp and down chirp. In the present embodiment, the up chirp is a signal generated using the generation expression of the Zadoff-Chu sequence in which M=1 in expression (1), and is a phase rotation signal in which the frequency linearly increases with time. Also, in the present embodiment, the down chirp is a signal generated using the generation expression of the Zadoff-Chu sequence in which M=−1 in expression (1), and is a phase rotation signal in which the frequency linearly decreases with time.FIG.3is a diagram illustrating an example of the preamble generated by the preamble generation unit13of the transmitter1of the first embodiment. As illustrated inFIG.3, the preamble generation unit13generates the preamble by performing, on the known signal, up chirp spreading using the up chirp for a signal in a block corresponding to a first half of the preamble, and down chirp spreading using the down chirp for a signal in a block corresponding to a second half of the preamble. The preamble generation unit13outputs the preamble generated by performing the spread spectrum to the frame generation unit14. In the following description, the preamble generated by the preamble generation unit13may be referred to as a preamble block. Note that the preamble generation unit13may generate the preamble by performing, on the known signal, down chirp spreading using the down chirp for the signal in the block corresponding to the first half of the preamble, and up chirp spreading using the up chirp for the signal in the block corresponding to the second half of the preamble. That is, the preamble generation unit13may spread the first half of the preamble block with one of the up chirp or the down chirp, and spread the second half of the preamble block with the other one of the up chirp or the down chirp. The frame generation unit14frames, as illustrated inFIG.3, the data block generated by performing the spread spectrum in the chirp spread unit12and the preamble block generated by performing the spread spectrum in the preamble generation unit13(step S104).FIG.3illustrates an example of the preamble generated by the preamble generation unit13as described above, and also illustrates an example of a signal framed by the frame generation unit14. The frame generation unit14outputs the framed signal to the transmission filter15. The transmission filter15performs band limitation on the signal framed by the frame generation unit14(step S105). The transmission filter15outputs a spread signal that has been subjected to band limitation to the transmission antenna16. The transmission antenna16transmits the signal that has been subjected to band limitation acquired from the transmission filter15(step S106). Next, the configuration and operation of the receiver2will be described. As illustrated inFIG.1, the receiver2includes a reception antenna21, a reception filter22, an initial synchronization unit23, a frequency offset fine synchronization unit24, a spread code generation unit25, a despreading unit26, a frequency offset correction unit27, and a demodulation unit28.FIG.4is a flowchart illustrating the operation of the receiver2according to the first embodiment. The reception antenna21receives a signal transmitted from the transmitter1(step S201). The signal received by the reception antenna21, that is, a received signal, is the signal transmitted from the transmitter1and is the signal including the preamble spread with the up chirp that is a spread code whose frequency increases with time and the down chirp that is a spread code whose frequency decreases with time. The reception antenna21outputs the received signal to the reception filter22. The reception filter22performs filtering on the received signal acquired from the reception antenna21(step S202). The reception filter22outputs the signal that has been subjected to the reception filtering to the initial synchronization unit23and the despreading unit26. In the following description, the signal that has been subjected to the reception filtering may be referred to as a reception filter passed signal. The initial synchronization unit23performs initial synchronization on the basis of the reception filter passed signal acquired from the reception filter22(step S203). In the present embodiment, as the initial synchronization, the initial synchronization unit23first performs synchronization of the timing of multiplication by the spread code in the transmitter1, that is, initial acquisition. As the initial synchronization, the initial synchronization unit23further performs coarse frequency offset estimation on the basis of the spread code timing estimated by the initial acquisition. The coarse frequency offset estimation refers to frequency offset estimation performed with coarse accuracy as compared to the accuracy of estimating a frequency offset by the frequency offset fine synchronization unit24described later. The initial synchronization unit23outputs the spread code timing estimated by the initial acquisition to the spread code generation unit25as an estimated spread code timing, and outputs a result of the coarse frequency offset estimation to the frequency offset fine synchronization unit24. Note that detailed configuration and operation of the initial synchronization unit23will be described later. The frequency offset fine synchronization unit24performs fine synchronization of the frequency offset on the basis of the result of the coarse frequency offset estimation acquired from the initial synchronization unit23(step S204). The fine synchronization of the frequency offset is to correct the amount of frequency offset in a case where an error remains in the result of the coarse frequency offset estimation acquired from the initial synchronization unit23. The frequency offset fine synchronization unit24outputs a corrected amount of frequency offset to the frequency offset correction unit27. The spread code generation unit25generates a spread code for despreading on the basis of the estimated spread code timing acquired from the initial synchronization unit23(step S205). The spread code generation unit25outputs the generated spread code to the despreading unit26. The despreading unit26multiplies the reception filter passed signal acquired from the reception filter22by a complex conjugate of the spread code acquired from the spread code generation unit25, thereby despreading the reception filter passed signal (step S206). The despreading unit26outputs the signal that has been despread to the frequency offset correction unit27. In a case where the frequency offset remains in the despread signal acquired from the despreading unit26, the frequency offset correction unit27corrects the frequency offset with the corrected amount of frequency offset acquired from the frequency offset fine synchronization unit24(step S207). The frequency offset correction unit27outputs the signal that has been subjected to the frequency offset correction to the demodulation unit28. The demodulation unit28demodulates the signal that has been subjected to the frequency offset correction acquired from the frequency offset correction unit27(step S208). Next, the configuration and operation of the initial synchronization unit23included in the receiver2will be described in detail.FIG.5is a diagram illustrating an example of the configuration of the initial synchronization unit23included in the receiver2according to the first embodiment. As illustrated inFIG.5, the initial synchronization unit23includes an up chirp correlation value calculation unit231, a down chirp correlation value calculation unit232, a first power value calculation unit233, a second power value calculation unit234, a first averaging processing unit235, a second averaging processing unit236, a first correlation power memory237, a second correlation power memory238, a first threshold determination unit239, a second threshold determination unit240, and an estimation unit241. Note that the up chirp correlation value calculation unit231and the down chirp correlation value calculation unit232form a correlation value calculation unit251. The first power value calculation unit233and the second power value calculation unit234form a power value calculation unit252. The first averaging processing unit235and the second averaging processing unit236form an averaging processing unit253. The first correlation power memory237and the second correlation power memory238form a correlation power memory254. The first threshold determination unit239and the second threshold determination unit240form a threshold determination unit255.FIG.6is a flowchart illustrating the operation of the initial synchronization unit23included in the receiver2according to the first embodiment. The flowchart illustrated inFIG.6illustrates details of the operation in step S203of the flowchart illustrated inFIG.4. The up chirp correlation value calculation unit231uses a matched filter (hereinafter referred to as an MF) to calculate a cross-correlation function between the reception filter passed signal acquired from the reception filter22and the up chirp used for the spread spectrum by the preamble generation unit13of the transmitter1(step S301). The cross-correlation function calculated by the up chirp correlation value calculation unit231is set as a first cross-correlation function. The up chirp correlation value calculation unit231outputs the first cross-correlation function obtained by the calculation to the first power value calculation unit233. The down chirp correlation value calculation unit232uses the MF to calculate a cross-correlation function between the reception filter passed signal acquired from the reception filter22and the down chirp used for the spread spectrum by the preamble generation unit13of the transmitter1(step S302). The cross-correlation function calculated by the down chirp correlation value calculation unit232is set as a second cross-correlation function. The down chirp correlation value calculation unit232outputs the second cross-correlation function obtained by the calculation to the second power value calculation unit234. Note that the initial synchronization unit23performs the operation of the down chirp correlation value calculation unit232in parallel with the operation of the up chirp correlation value calculation unit231. The first power value calculation unit233calculates a power value by squaring an absolute value of the first cross-correlation function acquired from the up chirp correlation value calculation unit231(step S303). The power value calculated by the first power value calculation unit233is set as a first power value. The first power value calculation unit233outputs the first power value obtained by the calculation to the first averaging processing unit235. Likewise, the second power value calculation unit234calculates a power value by squaring an absolute value of the second cross-correlation function acquired from the down chirp correlation value calculation unit232(step S304). The power value calculated by the second power value calculation unit234is set as a second power value. The second power value calculation unit234outputs the second power value obtained by the calculation to the second averaging processing unit236. Note that the initial synchronization unit23performs the operation of the second power value calculation unit234in parallel with the operation of the first power value calculation unit233. The first averaging processing unit235averages the first power values acquired from the first power value calculation unit233at each sample timing. Specifically, the first averaging processing unit235performs averaging by using the first power value acquired from the first power value calculation unit233, and the first power value previously acquired from the first power value calculation unit233at the same sample timing in the previous block (step S305). In the present embodiment, one block corresponds to the length of spread code Nc×the number of oversamples Novs, and the sample timing is one element of k=1 to Nc×Novs. The first averaging processing unit235stores the first power value averaged at each sample timing in the first correlation power memory237. Similarly, the second averaging processing unit236averages the second power values acquired from the second power value calculation unit234at each sample timing. Specifically, the second averaging processing unit236performs averaging by using the second power value acquired from the second power value calculation unit234, and the second power value previously acquired from the second power value calculation unit234at the same sample timing in the previous block (step S306). The second averaging processing unit236stores the second power value averaged at each sample timing in the second correlation power memory238. Note that the initial synchronization unit23performs the operation of the second averaging processing unit236in parallel with the operation of the first averaging processing unit235. The first correlation power memory237and the second correlation power memory238are configured to be able to store the power values at the sample timings for one period of the spread code, that is, the power values corresponding in number to the length of spread code Nc×the number of oversamples Novs. The first correlation power memory237stores the averaged power values acquired from the first averaging processing unit235for the length of spread code Nc×the number of oversamples Novs, that is, for the period of one block (step S307). Similarly, the second correlation power memory238stores the averaged power values acquired from the second averaging processing unit236for the length of spread code Nc×the number of oversamples Novs, that is, for the period of one block (step S308). Here, in the initial synchronization unit23, the processing up to the first averaging processing unit235and the second averaging processing unit236is the operation performed in sample time units, but the processing of the first correlation power memory237and the second correlation power memory238and the processing subsequent thereto are changed to the operation performed in block time units. The first threshold determination unit239determines an estimated up chirp timing n1, which is a first estimated timing for the up chirp, from the first power values for one period of the spread code. Specifically, the first threshold determination unit239detects a first maximum power value having the maximum power value from the averaged power values for the period of one block stored in the first correlation power memory237, and compares the detected first maximum power value with a first threshold. If the first maximum power value exceeds the first threshold, the first threshold determination unit239determines that the sample timing corresponding to the first maximum power value is the estimated up chirp timing n1(step S309). The first threshold determination unit239outputs the estimated up chirp timing n1to the estimation unit241. The second threshold determination unit240determines an estimated down chirp timing n2, which is a second estimated timing for the down chirp, from the second power values for one period of the spread code. Specifically, the second threshold determination unit240detects a second maximum power value having the maximum power value from the averaged power values for the period of one block stored in the second correlation power memory238, and compares the detected second maximum power value with a second threshold. If the second maximum power value exceeds the second threshold, the second threshold determination unit240determines that the sample timing corresponding to the second maximum power value is the estimated down chirp timing n2(step S310). The second threshold determination unit240outputs the estimated down chirp timing n2to the estimation unit241. Note that the initial synchronization unit23performs the operation of the second threshold determination unit240in parallel with the operation of the first threshold determination unit239. Although the estimated up chirp timing n1from the first threshold determination unit239and the estimated down chirp timing n2from the second threshold determination unit240may be output at the same time, it should be noted that the output of one of them is delayed by a plurality of blocks. The following method is an example of the method of threshold determination by the first threshold determination unit239and the second threshold determination unit240. The first threshold determination unit239calculates an average value of the power values for the period of one block read from the first correlation power memory237, and sets a value obtained by multiplying the average value by a constant α as a threshold. Similarly, the second threshold determination unit240calculates an average value of the power values for the period of one block read from the second correlation power memory238, and sets a value obtained by multiplying the average value by the constant α as a threshold. Note that 1≤α.FIG.7is a diagram illustrating an image of threshold setting by the first threshold determination unit239and the second threshold determination unit240according to the first embodiment. InFIG.7, the horizontal axis represents the sample timing, and the vertical axis represents the averaged power value. As illustrated inFIG.7, as the value of the constant α is set to be larger, the first threshold determination unit239and the second threshold determination unit240can reduce false alarms for establishing an erroneous synchronization point, but timing detection tends to take time. On the other hand, as the value of the constant α is set to be smaller, the first threshold determination unit239and the second threshold determination unit240can shorten the time for timing detection, but false alarms tend to increase. The estimation unit241detects an intermediate timing n0between the estimated up chirp timing n1and the estimated down chirp timing n2by using the estimated up chirp timing n1acquired from the first threshold determination unit239and the estimated down chirp timing n2acquired from the second threshold determination unit240. The estimation unit241rounds off the intermediate timing n0when the intermediate timing n0is a decimal. The estimation unit241estimates the intermediate timing n0as the spread code timing in the transmitter1(step S311). Furthermore, the estimation unit241performs coarse estimation of the frequency offset between the transmitter1and the receiver2from a difference between the estimated up chirp timing n1and the estimated down chirp timing n2as in expression (2) (step S312). (n2-n1)/2×(symbolrate)/Novs(2) The estimation unit241outputs the spread code timing estimated to the spread code generation unit25as an estimated spread code timing. The estimation unit241further outputs a result of the coarse frequency offset estimation, which is a result of performing the coarse estimation of the frequency offset, to the frequency offset fine synchronization unit24. Note that in the present embodiment, the initial synchronization unit23of the receiver2includes the first averaging processing unit235and the second averaging processing unit236, but the present disclosure is not limited to such a configuration. The initial synchronization unit23may be configured not to include the first averaging processing unit235and the second averaging processing unit236. In this case, the first power value calculation unit233stores the first power values obtained by the calculation in the first correlation power memory237, and the second power value calculation unit234stores the second power values obtained by the calculation in the second correlation power memory238. The first threshold determination unit239determines the estimated up chirp timing n1from the first power values for one period of the spread code stored in the first correlation power memory237. The second threshold determination unit240determines the estimated down chirp timing n2from the second power values for one period of the spread code stored in the second correlation power memory238. Next, a hardware configuration of the receiver2will be described. In the receiver2, the reception antenna21is implemented by an antenna device. The reception filter22is implemented by a filter circuit. The initial synchronization unit23, the frequency offset fine synchronization unit24, the spread code generation unit25, the despreading unit26, the frequency offset correction unit27, and the demodulation unit28are implemented by processing circuitry. The processing circuitry may include a memory and a processor executing a program stored in the memory, or may include dedicated hardware. The processing circuitry is also referred to as a control circuit. FIG.8is a diagram illustrating an example of a configuration of processing circuitry90in a case where the processing circuitry included in the receiver2according to the first embodiment is implemented by a processor and a memory. The processing circuitry90illustrated inFIG.8is the control circuit, and includes a processor91and a memory92. When the processing circuitry90incudes the processor91and the memory92, each function of the processing circuitry90is implemented by software, firmware, or a combination of software and firmware. The software or firmware is described as a program and stored in the memory92. The processing circuitry90implements each function by the processor91reading and executing the program stored in the memory92. That is, the processing circuitry90includes the memory92for storing the program that results in the execution of the processing of the receiver2. It can also be said that this program is a program for causing the receiver2to execute each function implemented by the processing circuitry90. This program may be provided by a storage medium in which the program is stored, or may be provided by another means such as a communication medium. The above program can also be said to be a program that causes the receiver2to execute: a first step in which the correlation value calculation unit251calculates a first cross-correlation function between a received signal and an up chirp and a second cross-correlation function between the received signal and a down chirp, the received signal being a signal transmitted from the transmitter1and having a preamble spread with the up chirp signal whose frequency increases with time and the down chirp signal whose frequency decreases with time; a second step in which the power value calculation unit252calculates a first power value of the first cross-correlation function, calculates a second power value of the second cross-correlation function, and stores the first power value and the second power value in the correlation power memory254; a third step in which the threshold determination unit255determines a first estimated timing for the up chirp from the first power values for one period of a spread code stored in the correlation power memory254, and determines a second estimated timing for the down chirp from the second power values for one period of the spread code stored in the correlation power memory254; and a fourth step in which the estimation unit241estimates a spread code timing of the transmitter1using the first estimated timing and the second estimated timing, and performs coarse estimation of a frequency offset with respect to the transmitter1. Here, the processor91is, for example, a central processing unit (CPU), a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a digital signal processor (DSP), or the like. The memory92corresponds to, for example, a non-volatile or volatile semiconductor memory such as a random access memory (RAM), a read only memory (ROM), a flash memory, an erasable programmable ROM (EPROM), or an electrically EPROM (EEPROM (registered trademark)), a magnetic disk, a flexible disk, an optical disk, a compact disc, a mini disc, a digital versatile disc (DVD), or the like. FIG.9is a diagram illustrating an example of processing circuitry93in a case where the processing circuitry included in the receiver2according to the first embodiment includes dedicated hardware. The processing circuitry93illustrated inFIG.9corresponds to, for example, a single circuit, a complex circuit, a programmed processor, a parallel-programmed processor, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a combination thereof. The processing circuitry may be implemented partly by dedicated hardware and partly by software or firmware. The processing circuitry can thus implement the aforementioned functions by the dedicated hardware, software, firmware, or a combination thereof. While the hardware configuration of the receiver2has been described, the transmitter1has a similar hardware configuration. In the transmitter1, the transmission antenna16is implemented by an antenna device. The transmission filter15is implemented by a filter circuit. The modulation unit11, the chirp spread unit12, the preamble generation unit13, and the frame generation unit14are implemented by processing circuitry. The processing circuitry may include a memory and a processor executing a program stored in the memory, or may include dedicated hardware. The above program can also be said to be a program that causes the transmitter1to execute: a first step in which the chirp spread unit12spreads a data signal with a chirp that is a spread code; a second step in which the preamble generation unit13spreads a known signal with an up chirp whose frequency increases with time and a down chirp whose frequency decreases with time; and a third step in which the frame generation unit14frames a data block that is spread and generated in the chirp spread unit12and a preamble block that is spread and generated in the preamble generation unit13. As described above, in the communication system3of the present embodiment, the preamble generation unit13of the transmitter1performs up chirp spreading in the block corresponding to the first half of the preamble, and performs down chirp spreading in the block corresponding to the second half of the preamble. The initial synchronization unit23of the receiver2detects the estimated up chirp timing n1and the estimated down chirp timing n2, estimates the intermediate timing n0between the two estimated timings as the spread code timing, and performs the coarse estimation of the frequency offset from the difference between the two estimated timings. This utilizes the occurrence of a timing shift in an opposite direction in up chirp spreading and down chirp spreading by the frequency offset, and the initial synchronization unit23can cancel the timing shift occurring in the opposite direction, that is, remove the timing shift, by obtaining the intermediate timing n0and can estimate the spread code timing and perform the coarse frequency offset estimation even in an environment where there is a large frequency offset. The accuracy of the coarse frequency offset estimation depends on the accuracy of estimation of the spread code timing. For example, in a case where the accuracy of estimation of the spread code timing is within one sample, the accuracy of the coarse frequency offset estimation corresponds to an amount of frequency offset that causes the timing shift off by one sample. After estimating the spread code timing and performing the coarse estimation of the frequency offset as the initial synchronization, the receiver2performs the frequency offset correction and corrects the frequency offset error remaining in the initial synchronization. The receiver2can thus estimate the spread code timing and the frequency offset even in an environment where there is a large frequency offset while preventing or reducing a processing delay and preventing or reducing an increase in the circuit scale. Note that the present embodiment has described, as an example, the case where the Zadoff-Chu sequence according to expression (1) is used by the chirp spread unit12and the preamble generation unit13of the transmitter1, but the present disclosure is not limited thereto. Even in a case where the chirp spread unit12and the preamble generation unit13of the transmitter1use, for the spread code, another phase rotation sequence such as a Zadoff-Chu sequence in which the center frequencies are matched between the up chirp and the down chirp, or a constant amplitude zero auto correlation (CAZAC) sequence, the spread code timing can be estimated. In addition, the chirp spread unit12and the preamble generation unit13of the transmitter1can use a Zadoff-Chu sequence in which the sequence parameter is not M=1, and can perform synchronization with reduced inter-user interference by using a sequence in which the sequence parameter is changed for each user. Moreover, in the present embodiment, the preamble generation unit13of the transmitter1divides the preamble into the first half being the block subjected to up chirp spreading and the second half being the block subjected to down chirp spreading, but the preamble configuration is not limited thereto. The preamble generation unit13of the transmitter1may be configured to alternately perform up chirp spreading and down chirp spreading for every one to several blocks, for example. That is, the preamble generation unit13may divide the preamble block into a plurality of blocks, and alternately arrange the block spread by the up chirp and the block spread by the down chirp. In this case, the receiver2can double the gap between the blocks subjected to up chirp spreading or down chirp spreading as compared to the case where up chirp spreading and down chirp spreading are performed in the first half and the second half, and can improve the accuracy of estimation of the frequency offset fine synchronization using multiple open loop automatic frequency control (AFC). Moreover, in the present embodiment, the initial synchronization unit23of the receiver2is configured to perform averaging with the power value at the same sample timing in the previous block, but the present disclosure is not limited thereto. The initial synchronization unit23may perform averaging at the same sample timing in all preamble blocks subjected to the same chirp spreading. For example, in a case where up chirp spreading is performed in first, third, and fifth blocks and down chirp spreading is performed in second, fourth, and sixth blocks, the first averaging processing unit235may perform averaging at the same sample timing in the first, third, and fifth blocks of the input signal, and the second averaging processing unit236may perform averaging at the same sample timing in the second, fourth, and sixth blocks of the input signal. As a result, the receiver2can prevent or reduce noise and improve synchronization accuracy. Second Embodiment In a second embodiment, a transmitter performs space time code (hereinafter referred to as space time block code (STBC) coding) as transmit diversity after modulating transmit data by the modulation unit11. A receiver successively performs timing synchronization of spread codes and combining of STBC transmit diversity in the initial synchronization, thereby improving estimation accuracy while preventing or reducing an increase in the circuit scale. Differences from the first embodiment will be described. FIG.10is a diagram illustrating an example of a configuration of a communication system3aaccording to the second embodiment. The communication system3aincludes a transmitter1aand a receiver2a. First, the configuration and operation of the transmitter1awill be described. As illustrated inFIG.10, the transmitter1aincludes the modulation unit11, an STBC coding unit31, chirp spread units12and12a, a preamble generation unit32, a frame generation unit33, transmission filters15and15a, and transmission antennas16and16a.FIG.11is a flowchart illustrating the operation of the transmitter1aaccording to the second embodiment. After step S101, the STBC coding unit31performs STBC coding on modulated signals acquired from the modulation unit11. Specifically, in a case where the STBC coding unit31successively acquires modulated signals s1and s2from the modulation unit11, the STBC coding unit performs STBC coding using the modulated signals s1and s2as expressed by expression (3) (step S111). [Expression1](s1-s2*s2s1*)(3) In expression (3), “( )” represents a complex conjugate. In the matrix expressed by expression (3), the row direction corresponds to the transmission antennas16and16aincluded in the transmitter1a, and the column direction corresponds to time. That is, the STBC coding unit31performs STBC coding such that, at time t1, the modulated signal s1is transmitted from the first transmission antenna and the modulated signal s2is transmitted from the second transmission antenna, and at time t2, a modulated signal −s2* is transmitted from the first transmission antenna and a modulated signal s1* is transmitted from the second transmission antenna. Here, the first transmission antenna corresponds to the transmission antenna16, and the second transmission antenna corresponds to the transmission antenna16a. The chirp spread units12and12aperform spread spectrum for each transmission antenna, that is, on the signals to be transmitted from the corresponding transmission antennas (step S112). Specifically, the chirp spread unit12employs a method similar to that of the first embodiment to perform the spread spectrum using a chirp signal on the signals subjected to STBC coding by the STBC coding unit31and corresponding to the first row of the matrix expressed by expression (3), that is, the signals to be transmitted from the transmission antenna16. The chirp spread unit12outputs data generated by performing the spread spectrum to the frame generation unit33. The chirp spread unit12aemploys a method similar to that of the chirp spread unit12to perform the spread spectrum using a chirp signal on the signals subjected to STBC coding by the STBC coding unit31and corresponding to the second row of the matrix expressed by expression (3), that is, the signals to be transmitted from the transmission antenna16a. The chirp spread unit12aoutputs data generated by performing the spread spectrum to the frame generation unit33. Note that the spread codes used for spreading by the chirp spread unit12and the chirp spread unit12aare assumed to be the same. The configuration of the chirp spread unit12ais assumed to be similar to the configuration of the chirp spread unit12. The preamble generation unit32employs a method similar to expression (3) to perform STBC coding on a known signal, and then performs spread spectrum thereon by up chirp and down chirp to generate a preamble (step S113). It is assumed that the preamble generation unit32uses a common code for the spread code of two transmission antennas at the same time. The two transmission antennas refer to the transmission antennas16and16ain the present embodiment. As with the first embodiment, the preamble generation unit32of the present embodiment may spread the signal in the block corresponding to the first half of the preamble by the up chirp, and spread the signal in the block corresponding to the second half of the preamble by the down chirp. Also, for every two blocks subjected to STBC coding, the preamble generation unit32may spread one of the blocks by the up chirp and spread the other block by the down chirp. The frame generation unit33frames a data block and a preamble block for each transmission antenna (step S114). Specifically, the frame generation unit33frames the preamble block generated by the preamble generation unit32to be transmitted from the transmission antenna16, and the data block generated by the chirp spread unit12. The frame generation unit33outputs the framed signal to the transmission filter15. Similarly, the frame generation unit33frames the preamble block generated by the preamble generation unit32to be transmitted from the transmission antenna16a, and the data block generated by the chirp spread unit12a. The frame generation unit33outputs the framed signal to the transmission filter15a. After that, the operation of the transmission filters15and15ais similar to the operation of the transmission filter15of the first embodiment (step S105), and the operation of the transmission antennas16and16ais similar to the operation of the transmission antenna16of the first embodiment (step S106). The configuration of the transmission filter15ais assumed to be similar to the configuration of the transmission filter15, and the configuration of the transmission antenna16ais assumed to be similar to the configuration of the transmission antenna16. Next, the configuration and operation of the receiver2awill be described. The receiver2aof the second embodiment illustrated inFIG.10is obtained by replacing, with an initial synchronization unit23a, the initial synchronization unit23in the receiver2of the first embodiment illustrated inFIG.1and further adding thereto an STBC decoding unit41. The STBC decoding unit41performs STBC decoding well known to those skilled in the art on a signal that has been subjected to frequency offset correction acquired from the frequency offset correction unit27. The STBC decoding unit41outputs the signal that has been subjected to STBC decoding to the demodulation unit28.FIG.12is a flowchart illustrating the operation of the receiver2aaccording to the second embodiment. The flow of the operation of the receiver2aincludes performing frequency offset correction (step S207), then performing STBC decoding (step S211), and performing demodulation (step S208). The rest of the operation of the receiver2ais similar to the operation of the receiver2of the first embodiment. The configuration and operation of the initial synchronization unit23aincluded in the receiver2awill be described in detail.FIG.13is a diagram illustrating an example of the configuration of the initial synchronization unit23aincluded in the receiver2aaccording to the second embodiment. The initial synchronization unit23aof the second embodiment illustrated inFIG.13is obtained by removing the first power value calculation unit233and the second power value calculation unit234from the initial synchronization unit23of the first embodiment illustrated inFIG.5, and adding thereto a first STBC decoding unit341, a second STBC decoding unit342, a first power value calculation unit343, a second power value calculation unit344, a third power value calculation unit345, a fourth power value calculation unit346, a first power value combining unit347, and a second power value combining unit348. Note that the first STBC decoding unit341and the second STBC decoding unit342form an STBC decoding unit351. The first power value calculation unit343, the second power value calculation unit344, the third power value calculation unit345, and the fourth power value calculation unit346form a power value calculation unit352. The first power value combining unit347and the second power value combining unit348form a power value combining unit353.FIG.14is a flowchart illustrating the operation of the initial synchronization unit23aincluded in the receiver2aaccording to the second embodiment. The flowchart illustrated inFIG.14illustrates details of the operation in step S203of the flowchart illustrated inFIG.12. In the second embodiment, the reception antenna21of the receiver2areceives a signal that has been subjected to STBC coding in the transmitter1aand transmitted from the plurality of transmission antennas16and16a. The reception filter22performs filtering on the received signal acquired from the reception antenna21. The up chirp correlation value calculation unit231calculates a first cross-correlation function between a reception filter passed signal acquired from the reception filter22and the up chirp used for the spread spectrum by the preamble generation unit32of the transmitter1a(step S301). The down chirp correlation value calculation unit232calculates a second cross-correlation function between the reception filter passed signal acquired from the reception filter22and the down chirp used for the spread spectrum by the preamble generation unit32of the transmitter1a(step S302). The first STBC decoding unit341performs STBC decoding on the first cross-correlation function calculated by the up chirp correlation value calculation unit231(step S321). Specifically, the first STBC decoding unit341multiplies the first cross-correlation function by a complex conjugate element of the matrix expressed by expression (3) at each timing corresponding to the length of spread code Nc×the number of oversamples Novs. The complex conjugate of the matrix expressed by expression (3) is expressed in expression (4). [Expression2](s1*-s2s2*s1)(4) For example, when the length of spread code used by the preamble generation unit32and the chirp spread units12and12ais Nc=4, the number of oversamples is onefold, and the first cross-correlation function for the up chirp of x1, x2, x3, x4, x5, x6, x7, x8, . . . is obtained, the output of the first STBC decoding unit341is a matrix as expressed by expression (5). [Expression3](x1s1*+x5s2*x2s1*+x6s2*x3s1*+x7s2*⋯x1(-s2)+x5s1x2(-s2)+x6s1x3(-s2)+x7s1⋯)(5) The first STBC decoding unit341outputs the first row of the sequence expressed in expression (5) to the first power value calculation unit343, and outputs the second row of the sequence expressed in expression (5) to the second power value calculation unit344. In the sequence expressed in expression (5), the column direction corresponds to the sample time. Similarly, the second STBC decoding unit342performs STBC decoding on the second cross-correlation function calculated by the down chirp correlation value calculation unit232(step S322). Specifically, the second STBC decoding unit342multiplies the second cross-correlation function by the complex conjugate element expressed in expression (4) at each timing corresponding to the length of spread code Nc×the number of oversamples Novs. Once obtaining a sequence similar in form to expression (5), the second STBC decoding unit342outputs the first row of the sequence to the third power value calculation unit345, and outputs the second row of the sequence to the fourth power value calculation unit346. The power value calculation unit352calculates power values of the signals corresponding to the plurality of transmission antennas obtained by decoding the first cross-correlation function and power values of the signals corresponding to the plurality of transmission antennas obtained by decoding the second cross-correlation function. Specifically, the first power value calculation unit343and the second power value calculation unit344calculate the power value by squaring an absolute value of the signal acquired from the first STBC decoding unit341(step S323). The first power value calculation unit343and the second power value calculation unit344output the power value obtained by the calculation to the first power value combining unit347. Similarly, the third power value calculation unit345and the fourth power value calculation unit346calculate the power value by squaring an absolute value of the signal acquired from the second STBC decoding unit342(step S324). The third power value calculation unit345and the fourth power value calculation unit346output the power value obtained by the calculation to the second power value combining unit348. The power value combining unit353combines the power values corresponding to the plurality of transmission antennas obtained by decoding the first cross-correlation function, and combines the power values corresponding to the plurality of transmission antennas obtained by decoding the second cross-correlation function. Specifically, when the power values acquired from the first power value calculation unit343and the second power value calculation unit344are |b1|2and |b2|2, respectively, the first power value combining unit347combines the power values as |b1|2+|b2|2(step S325). Similarly, when the power values acquired from the third power value calculation unit345and the fourth power value calculation unit346are |b3|2and |b4|2, respectively, the second power value combining unit348combines the power values as |b3|2+|b4|2(step S326). The operation of the first averaging processing unit235and the second averaging processing unit236and subsequent operations are similar to those of the first embodiment. Note that hardware configurations of the receiver2aand the transmitter1aare similar to the hardware configurations of the receiver2and the transmitter1of the first embodiment. Processing circuitry included in the receiver2aand the transmitter1amay include a memory and a processor executing a program stored in the memory, or may include dedicated hardware. As described above, in the communication system3aof the present embodiment, the STBC coding unit31and the preamble generation unit32of the transmitter1agenerate the signals for the two transmission antennas. The initial synchronization unit23aof the receiver2acalculates the cross-correlation function for each of the up chirp and the down chirp, and then the first STBC decoding unit341and the second STBC decoding unit342multiply the cross-correlation function by the complex conjugate of the STBC coding by the transmitter1a, so that transmission path response values from the transmission antennas can be separated, and the power values are combined. As a result, the receiver2acan improve the synchronization accuracy as compared to a case of using only one transmission antenna. In addition, the receiver2aperforms STBC decoding after performing correlation calculation on the spread sequence, and thus can perform the initial synchronization in which an increase in the circuit scale is prevented or reduced as the circuit scale does not depend on the number of blocks. The receiver according to the present disclosure can estimate the spread code timing and also perform the coarse estimation of the frequency offset even in the environment where there is a large frequency offset while preventing or reducing the processing delay and preventing or reducing the increase in the circuit scale. The configurations illustrated in the above embodiments merely illustrate an example so that another known technique can be combined, the embodiments can be combined together, or the configurations can be partially omitted and/or modified without departing from the scope. | 50,241 |
11942982 | DETAILED DESCRIPTION Embodiments illustrated herein implement an overlay spread spectrum device applied between a legacy transmitter (such as a 5G and/or Code Division Multiple Access (CDMA) transmitter) and a legacy receiver. This device takes the legacy Radio Frequency (RF) waveform as input, applies spreading techniques (such as direct sequence, frequency hop, chaotic, or other spreading), and then re-transmit the waveform as a spread signal. Note that legacy, as used herein simply refers to signals and waveforms transmitted from a different communications device that can be received and processed by spread spectrum devices and/or modules to produce a spread signal. Often, legacy signals and waveforms will have vulnerabilities with respect to detection, interception, jamming, geolocation, etc., that can be addressed by creating the spread signal. A corresponding mission module at the receiving end reverses the spreading (i.e., de-spreading the waveform) to re-create the legacy waveform. In some embodiments, a so-called Bolt-On Spread Spectrum (BOSS) module (whether at the transmitter or the receiver) can be a plug-in addition to legacy end-user equipment. The BOSS module does not require redesign of the legacy standard or legacy equipment and does not affect wireless link performance. The BOSS module can be combined with highly directional mid-band systems for Low Probability of Interception/Detection (LPI/LPD) and Anti-Jam (AJ). Once applied to legacy waveforms, the BOSS module spreads power across wider bandwidths below the noise floor making it more difficult to detect, jam or geo-locate transmitters. Examples of this are illustrated inFIG.1, which will be illustrated in more detail below. In particular,FIG.1illustrates a legacy transmitter102and a legacy receiver104. In this example, the legacy transmitter102is shown as a cellular telephone with 5G capabilities. The legacy receiver104is shown as a 5G cell tower. While a separate transmitter and receiver are shown in this example, it should be appreciated that most implementations will include nodes having both transmit and receive functionality. Thus, for example, the cellular telephone illustrated could be either a transmitter or receiver. Similarly, the cell tower illustrated could be a transmitter or receiver. FIG.1illustrates that the legacy transmitter transmits a legacy RF signal106. For example, the legacy RF signal106may be a signal transmitted in 5G. In some embodiments, as illustrated at108, the legacy RF signal106will often be transmitted with a power spectral density that causes the legacy RF signal106to be transmitted in a fashion whereby the legacy RF signal106exists above a noise floor. The noise floor is generally understood to be a level of background noise in an environment. Note that in some embodiments, the legacy transmitter102can transmit the legacy RF signal106to other nodes that are proximate the legacy transmitter102. Thus, for example, in some embodiments a smaller network of devices that are within some predetermined proximity to each other may be able to communicate using signals that have not been spread, such as the legacy RF signal106. FIG.1illustrates that a spread spectrum module110is deployed on a relay platform112. In this example, the relay platform112is illustrated as a drone which carries the spread spectrum module110. The spread spectrum module110intercepts the legacy RF signal106and performs spreading operations on the legacy signal106to produce a spread signal114. As illustrated inFIG.1at116, the spread signal116is spread such that it exhibits a power spectral density that causes the spread signal114to be below the noise floor. In this way, the legacy RF signal106can be spread in a fashion to produce the spread signal114where the spread signal114exhibits LPI/LPD/AJ characteristics. Note that this method of altering the original (or legacy) signal can be implemented in a fashion that does not need to know data or data format being transmitted. It can be implemented in a fashion that does not need to know error correction or modulation types of the original legacy communication signal. This process can be implemented in a fashion that is agnostic to communication or signal formats. As illustrated inFIG.1, the spread signal114is transmitted to a spread spectrum module118included on a relay platform120. Again, as illustrated in this example, the relay platform120is a drone that is able to receive communications from the relay platform112.FIG.1illustrates that the spread spectrum module118performs de-spreading operations to recover the legacy RF signal106which is then transmitted to the legacy receiver104. For example, de-spreading can be performed by applying multiply and accumulate operations to identify acquisition markers, such as a pilot sequence, and then sweep pseudo-random noise code on incoming signals as appropriate. FIG.1further illustrates at122that de-spreading performed by the spread spectrum module118causes the recovered legacy RF signal106to again be above the noise floor. Note that in some embodiments, the legacy receiver104may be located in an area where there is less concern about detection, interception, and/or jamming of the legacy RF signal106. Embodiments may support full duplex scenarios where individual devices are capable of functioning in both send and receive capacities. Thus, for example, while the spread spectrum module110is illustrated as a spreading module and the spread spectrum module118is illustrated as a de-spreading module, it should be appreciated that often the various spread spectrum modules will have functionality for both spreading and de-spreading. Some embodiments may include separate components for accomplishing this functionality. However, in other embodiments, various portions of hardware including pseudo-random noise (PN) generators and other components can be used for both spreading and de-spreading functionality. Thus,FIG.1illustrates a relay system. In particular, legacy transmissions over-the-air between the end-user and the relay drone are standard legacy transmissions, which is then spread generating a legacy-spread spectrum signal from the first drone to the second drone. The second drone re-creates and retransmits the standard legacy waveform to the end tower. The over-the-air section between the two drones has an obfuscated waveform with LPD, LPI, AJ, and Low Probability of Geo-location (LPG) features. This greatly reduces the ability for equipment observing the emissions to detect that the two drones are communicating and track their traffic patterns. Note the mission spread spectrum module inside the drone is not demodulating legacy communications and re-modulating data into another waveform. It is only processing the sampled legacy RF by spreading, spectrum re-allocation, acquisition marker handing (e.g., inserting pilot acquisition codes, coordinating time stamps, providing signals on alternate command channels, etc.), and/or other signal processing. That is, spreading is applied to samples of a legacy waveform after the legacy waveform has been modulated. Thus, in some embodiments, spreading is not applied to information bits or symbols in the legacy waveform, but rather samples of the modulated legacy waveform itself are spread. Similarly, receiver acquisition and tracking of pseudo-random noise codes using a pilot waveform or other acquisition marker combined with a legacy waveform can be used for de-spreading. Embodiments use an external channel for acquisition and pseudo-random noise alignment without using data information carried by the legacy waveform or relying on demodulation of the legacy waveform. That is, the spread waveform is de-spread to obtain the legacy waveform, which is then demodulated to obtain data in the legacy signal of interest. Demodulation occurs subsequent to de-spreading such that demodulated data is not required for de-spreading. FIGS.2A and2Billustrate alternate examples where a spread spectrum module210is coupled in a wired, wireless, or other tethered fashion to a transmitter/receiver202, which is illustrated as a handheld radio. In this example, the spread spectrum module210is coupled to signal processing circuitry230. The signal processing circuitry230includes various components such as modulators, filters, digital to analog converters, analog to digital converters, and the like configured to generate the legacy RF signal206. Ordinarily, the legacy RF signal206produced by the processing circuitry would be provided to the antenna232where it would be propagated as a wireless signal, such as is illustrated by the legacy transmitter102illustrated inFIG.1. However, in some embodiments illustrated herein, the legacy RF signal206is provided to the spread spectrum module210, where the legacy RF signal is spread to form the spread signal214. The spread signal214is then transmitted by a transceiver234in the spread spectrum module210. In an alternative embodiment as illustrated inFIG.2B, the spread signal214is provided to the antenna232(and potentially other related communication hardware) where it is propagated as a wireless signal. Thus, in this example, the legacy RF signal206is not subject to being used for interception, detection, geolocation, or subject to being jammed. Rather, only the spread signal214is transmitted over the air, and due to it being characteristically below the noise floor, the spread signal214can likely not be used for interception, detection, geolocation, and is likely not subject to being jammed. Embodiments may be implemented using a mission module that contains the forward (spreading) and inverse (de-spreading) processing applied to legacy RF signals at RF and not on the bits or symbols. The application of spread spectrum as an overlay can be reversed without altering the structure, format or performance of legacy RF waveforms so all the benefits that are embedded within legacy technology (including, e.g., 5G technology) are maintained. A given mission module (such as the spread spectrum module110or118) does not need to contain any information about legacy communications other than the frequency band(s). Attention is now directed toFIGS.3and4, which illustrate frequency and time domain graphs, respectively, showing legacy signal waveforms, spread signal waveforms, and a representation of the noise floor. For example,FIG.3illustrates a frequency domain representation where signals are graphed by power spectral density with respect to frequency. In particular,FIG.3illustrates a legacy waveform306, a spread signal waveform314and a noise floor334. In this example, the legacy waveform306has significant portions that exceed the noise floor334in spectral power density at certain frequencies. In contrast, the spread signal waveform314formed from the legacy waveform306exists below the noise floor334at all relevant frequencies. FIG.4illustrates a time domain plot.FIG.4illustrates a time domain representation of the legacy signal waveform406and a corresponding time domain representation of the spread signal waveform414. In this example, the legacy signal waveform406is further modulated using a pseudo-random noise waveform (as will be illustrated in more detail below) to create the spread signal waveform414. Note thatFIG.4illustrates the spread signal waveform414having a variable waveform envelope. Some embodiments may be implemented using outphasing to cause spread signal waveforms to have constant envelopes. In particular, embodiments may employ outphasing to mitigate the increase of peak-to-average-power ratio (PAPR) and to eliminate any time variations in the waveform envelope. Outphasing typically involves deconstructing a variable envelope signal into two constant envelope signals, that when recombined produce the original variable envelope signal. Some embodiments may combine outphased signals at the transmitter and/or over the air. As noted above, outphasing breaks a variable envelope waveform into two constant-envelope components, where those two components are then sent through two power amplifiers. After amplification, the two components are combined to recover the original (still spread, but now amplified) waveform. Thus, in some embodiments, outphasing is implemented on a single (2-channel) transmitter with two power amplifiers and antennas (each transmitting one component of the outphased waveform), these combine in the air, such that they are combined at the receiver. Alternatively, outphasing can be implemented using two independent but synchronous transceivers so that they add up coherently at the receiving antenna thus optimizing size, weight and power for radio equipment. Further, such embodiments can be used to further hinder detection operations being performed by adversarial entities. In yet another alternative example, outphasing recombination is implemented by combining the two constant-envelope components after they are passed through the two power amplifiers, (and not in air). Additional details are now illustrated with reference toFIGS.5A,5B, and6, whereFIGS.5A and5Billustrate block diagrams of a transmitter502and a receiver504and associated spread spectrum modules510and518respectively, whileFIG.6illustrates a legacy signal waveform606, sampling636of the legacy signal waveform606, and a pseudo-random noise code638used to spread the legacy signal waveform606. FIGS.5A and5Bshows a block diagram of the processing inside the spread spectrum module510for spreading functionality when coupled to the legacy transmitter502. When the spread spectrum module510is wireless (such as is illustrated inFIG.1), it would include antennas and Radio Frequency Equipment (RFEs) to receive legacy communications. Alternatively the legacy communications can be received over a wired signal path. FIG.6illustrates a legacy waveform606that is sampled as illustrated by the sampling638. Sampling can be performed by the analog to digital converter550illustrated inFIGS.5A and5Bsampling the legacy waveform. Further, as illustrated inFIGS.5A and5B, the spread spectrum module510uses a pseudo noise code generator552to spread the legacy signal waveform606. In some embodiments, spreading may make use of a pseudo-random noise sequence. Additionally, a pilot code generator554is used to add a pilot code, beacon, or other acquisition marker which can be used for alignment by the spread spectrum module518associated with the receiver504, as will be discussed in more detail below. Note that in some embodiments, acquisition markers do not necessarily need to be added as the spread spectrum modules510and518may include other functionality for acquisition such as through the use of various clocks or other timing circuitry, or other synchronization means. FIGS.5A and5Bfurther illustrates that a frequency shifter556can be used to move the spread signal to a different, non-overlapping carrier frequency, or otherwise reallocate spectrum, used for the spread signal.FIGS.5A and5Bfurther illustrates that the spread signal can be passed through a digital to analog converter558to create a signal that can be propagated by a transceiver559. Alternatively, the signal can be sent to the transmitter (if the transmitter includes functionality to receive the signal) as illustrated inFIG.5B. In either case, the transceiver559or the output of the transmitter502are used to send the spread signal. In some embodiments, this may include sending the spread signal to a transceiver569in a spread spectrum module518associated with the receiver504as illustrated inFIG.5A. Alternatively, as illustrated inFIG.5B, the spread signal is sent directly to the receiver504where it can be passed to the spread spectrum module518for processing. In some embodiments, a pilot code or other acquisition marker is used to determine timing within the pseudo-random noise sequence and time tracking/alignment at the receiver504. In some embodiments, the waveform spreading pseudo-random noise sequence is implemented as a featureless sequence that does not repeat, while the pilot code repeats often but is maintained at lower power so as not to jeopardize low probability of detection. Spectrum re-allocation (frequency shift) functionality implemented by the frequency shifter556is shown as a digital implementation (by virtue of being included prior to the digital to analog converter558), but this functionality can be split between digital and analog processing to extend the frequency agility range. Available bands for use by spread spectrum modules (e.g., leveraging military bands) can be made known dynamically using external sensing and Dynamic Spectrum Access (DSA) software or at pre-mission planning through existing spectrum allocation tools and procedures. FIGS.5A and5Bfurther shows a similar functional block diagram for the receive processing at the receiver504and its associated spread spectrum module518. In this example, the processing illustrated in the spread spectrum module518searches for a pilot symbol added by the pilot code generator554(or other acquisition marker) to determine a position in the waveform spreading code to align the code accordingly for de-spreading. Thus, in the example illustrated inFIGS.5A and5B, a received spread spectrum signal (received either directly at the spread spectrum module518as illustrated inFIG.5A, or received at the receiver504and provided to the spread spectrum module518as illustrated inFIG.5B) is filtered and then sampled by the analog to digital converter560, shifted back to the expected legacy band by the frequency shifter562, acquiring timing is acquired using a pilot code acquisition detector564to search for the pilot code, and de-spreading using the same pseudo-random noise code, e.g., by using a complex conjugate of the pseudo-random noise code, used at the transmitter spread spectrum module510, where the pseudo-random noise code is generated at the receiver spread spectrum module at the pseudo-random noise generator566. The de-spread waveform is converted to an analog signal by the digital to analog converter568, and coupled back into the receive path of the legacy radio receiver504. Acquisition and tracking using pilot code compensates for oscillator offsets and Doppler in highly mobile applications and can be made to exceed the requirements for legacy radios. In typical embodiments, neither the spreading nor the de-spreading uses any legacy waveform information. The hardware does not need to be designed for required center frequencies, bandwidths and power levels, as is the case for transmitting legacy signals over the air. In some embodiments, coupling into a legacy radio such as the transmitter502and/or the receiver504, is performed with an analog coupler before a power amplifier. In some embodiments, the analog coupler may include a connector form factor specifically for military use. For example, as illustrated inFIG.2B, a power amplifier may be associated with the antenna232, where the power amplifier is coupled to an analog connector to which the spread spectrum module210can be connected. Various features that can be implemented are now discussed. In some embodiments, a waveform spreading/de-spreading code may use a very long, non-repeating pseudo-random noise sequence that is difficult to detect. This sequence does not exhibit features or repeating patterns that would appear using correlation. As noted above, this is useful to minimize detection of the signal. In some embodiments, the pilot code design and acquisition are combined with the waveform spreading sequence and used to synchronize and track transmitters in the presence of Doppler and various offsets imposed by the communication systems and channel. As illustrated above, a frequency shifters556and562can be used for spectrum re-allocation. Spectrum re-allocation to military bands, for example, can occur dynamically using dynamic spectrum allocation, or during pre-mission planning following military spectrum allocation tools and procedures. Embodiments may be implemented where bolt-on spread spectrum can incorporate various notching and interference cancellation algorithms at the receiving end to eliminate strong jammers before de-spreading to produce legacy communications. Thus, for example, an adversarial entity may attempt to introduce a jammer between the transmitter502and the receiver504with a power spectral density consistent with a legacy waveform, such as the waveform306illustrated inFIG.3. This may be done, for example, based on the adversarial entity believing that that bandwidth is the bandwidth where signals of interest reside. However, by using the bolt-on spread spectrum techniques illustrated herein, and in some embodiments, in conjunction with notch filtering, the jammer can be rendered ineffective. In particular, the de-spreading process performed at the receiver504tends to concentrate the signal of interest in a desired power spectral density while actually spreading the jammer waveform below the noise flower. However, simply relying on the de-spreader to eliminate and/or reduce the effects of the jammer may nonetheless leave portions of the jammer in a state that allow for interference with the signal of interest when de-spread. Thus, some embodiments can notch out the jammer using a notch filter and/or other narrow frequency band filtering prior to de-spreading. This results in an even further improved elimination and/or reduction of the jammer waveform by both notching out portions of the jamming waveform and spreading any remaining portion as part of the de-spreading process. Various benefits can be obtained using various embodiments of the invention. For example, depending on the legacy mode of communication in use, spreading gain can increase power for a received signal. The benefit is dependent on the legacy mode in use and the bandwidth available for the spread spectrum waveform. For example, a 1-MHz legacy waveform frequency spread over 20 MHz of bandwidth confers a 13 dB benefit. In another example, for a 1-MHz legacy waveform spread over 100 MHz, a 20 dB benefit is conferred. Another benefit relates to the fact that acquisition and tracking using a pilot code provides tolerance to Doppler (i.e., vehicle and channel dynamics) beyond those provided by the legacy equipment. This allows the legacy system and bolt-on spread spectrum system to operate on board of vehicles moving in excess of 3000 knots. Another benefit relates to the fact that spreading and interference cancellation provides legacy radio front-end protection and increased dynamic range to continue operation in the presence of jammers. Interference cancellation provides, for example, up to 20 dB benefit for wideband interference and up to 30 dB for narrowband interference. The following discussion now refers to a number of methods and method acts that may be performed. Although the method acts may be discussed in a certain order or illustrated in a flow chart as occurring in a particular order, no particular ordering is required unless specifically stated, or required because an act is dependent on another act being completed prior to the act being performed. Referring now toFIG.7, a method700is illustrated. The method700includes acts for communicating using spread spectrum. The method700includes intercepting a legacy RF signal from a legacy radio (act702). For example, inFIG.1, a legacy RF signal106is intercepted by the spread spectrum module110. InFIGS.2A and2B, a legacy RF signal206is intercepted by the spread spectrum module210. InFIGS.5A and5B, a legacy RF signal is intercepted by the spread spectrum module510. The method700further includes performing spread spectrum processing on the legacy RF signal to create a spread signal (act704). For example,FIG.3illustrates a legacy waveform306spread to a spread signal waveform314. The method700further includes transmitting the spread signal to a receiver, whereafter the spread signal is de-spread to recover the legacy RF signal (act706).FIG.1illustrates the spread signal114is transmitted to the spread spectrum module118, which de-spreads the spread signal114to recover the legacy RF signal106, which is then further transmitted to the receiver104. Thus, in this example, the spread spectrum module118is one receiver that receives the spread signal114, while the receiver104is a second receiver that receives the legacy RF signal104. The method700may be practiced where intercepting the legacy RF signal comprises intercepting the legacy RF signal, in a wired fashion, at a device physically attached to the legacy radio. The method700may be practiced where intercepting the legacy RF signal comprises intercepting the legacy RF signal at a device distant the legacy radio by intercepting the legacy RF signal over the air. An example of this is illustrated inFIG.1and the description of that figure discussed above. The method700may be practiced where performing spread spectrum processing on the legacy RF signal is performed to cause the spread signal to be below a predetermined noise floor. An example of this is illustrated inFIG.3, where the spread signal waveform314is below the noise floor334. The method700may be practiced where performing spread spectrum processing on the legacy RF signal is performed to cause the spread signal to be suitable for use in a CDMA system. The method700may further include adding an acquisition marker to the spread signal. Thus, for example, a low power, pseudo-random noise code can be added to the spread waveform to facilitate acquisition, alignment, and tracking of the spread signal at a receiver to facilitate de-spreading. The method700may be practiced where the acts are performed such that communications in the legacy RF signal are sent in the spread signal with the spread signal originating at the legacy radio and persisting to the receiver. An example of this is illustrated inFIGS.5A and5B, where legacy RF signals and spread signals are both handled at the transmitter502and where the receiver504handles both legacy RF signals and spread signals, each with assistance of spread spectrum modules510and518respectively. The method700may be practiced where the acts are performed such that communications in the legacy RF signal are sent such that devices proximate the legacy radio receive the legacy RF signal, but where other devices receive the communications by receiving the spread signal. Examples of this are illustrated inFIG.1where communications proximate the transmitter102can be performed using only the legacy RF signal to other devices (not shown), but where communication from the transmitter102to other locations, such as the location of the receiver104, are accomplished using the spread signal114. Thus, embodiments may be such that communications intended for devices in a predetermined geographical area are performed using legacy RF communications, but communications intended to devices outside that predetermined geographical area are performed using spread signals formed using the legacy RF communications. The method700may further include performing outphasing on the spread signal. The method700may further include performing frequency shifting on the spread signal. For example, this may be done to move the spread signal to a different portion of a frequency band. Referring now toFIG.8, a method800is illustrated. The method800includes acts for communicating using spread spectrum. The method800includes receiving a spread signal, the spread signal having been formed by spreading a legacy RF signal (act802). For example,FIG.1illustrates a spread signal114is received by a spread spectrum module118. Similarly,FIGS.5A and5Billustrates a spread spectrum module518that can receive a spread signal. The method800further includes performing spread spectrum processing on the spread signal to recover the legacy RF signal (act804). For example, the spread spectrum modules118and/or518can process the spread signals (e.g., signal114) to recover the legacy RF signal (e.g., signal106). The legacy RF signal is later demodulated, potentially by legacy hardware, to obtain data in the legacy RF signal. The method800may be practiced where receiving the spread signal comprises receiving the spread signal at a relay platform. In some such embodiments, the method further includes the relay platform wirelessly sending the legacy RF signal to a receiver. An example of this is illustrated atFIG.1, where the relay platform120sends the legacy RF signal106to the receiver104. The method800may be practiced where receiving the spread signal comprises receiving the spread signal at a spread spectrum module coupled in a wired fashion to a receiver. The spread spectrum module performs the spread spectrum processing and the receiver demodulates the legacy RF signal. The method800may be practiced where performing spread spectrum processing on the spread signal comprises using an acquisition marker included in the spread signal to process the spread signal. The method800may be practiced where performing spread spectrum processing on the spread signal comprises performing frequency shifting on the spread signal. For example, this may be performed when the spread signal has been shifted by a transmitter as described previously herein. Further, the methods may be practiced by a computer system including one or more processors and computer-readable media such as computer memory. In particular, the computer memory may store computer-executable instructions that when executed by one or more processors cause various functions to be performed, such as the acts recited in the embodiments. Embodiments of the present invention may comprise or utilize a special purpose or general-purpose computer including computer hardware, as discussed in greater detail below. Embodiments within the scope of the present invention also include physical and other computer-readable media for carrying or storing computer-executable instructions and/or data structures. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer system. Computer-readable media that store computer-executable instructions are physical storage media. Computer-readable media that carry computer-executable instructions are transmission media. Thus, by way of example, and not limitation, embodiments of the invention can comprise at least two distinctly different kinds of computer-readable media: physical computer-readable storage media and transmission computer-readable media. Physical computer-readable storage media includes RAM, ROM, EEPROM, CD-ROM or other optical disk storage (such as CDs, DVDs, etc.), magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store desired program code means in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer. A “network” is defined as one or more data links that enable the transport of electronic data between computer systems and/or modules and/or other electronic devices. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a computer, the computer properly views the connection as a transmission medium. Transmission media can include a network and/or data links which can be used to carry desired program code means in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer. Combinations of the above are also included within the scope of computer-readable media. Further, upon reaching various computer system components, program code means in the form of computer-executable instructions or data structures can be transferred automatically from transmission computer-readable media to physical computer-readable storage media (or vice versa). For example, computer-executable instructions or data structures received over a network or data link can be buffered in RAM within a network interface module (e.g., a “NIC”), and then eventually transferred to computer system RAM and/or to less volatile computer-readable physical storage media at a computer system. Thus, computer-readable physical storage media can be included in computer system components that also (or even primarily) utilize transmission media. Computer-executable instructions comprise, for example, instructions and data which cause a general-purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. The computer-executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, or even source code. Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the described features or acts described above. Rather, the described features and acts are disclosed as example forms of implementing the claims. Those skilled in the art will appreciate that the invention may be practiced in network computing environments with many types of computer system configurations, including, personal computers, desktop computers, laptop computers, message processors, hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, mobile telephones, PDAs, pagers, routers, switches, and the like. The invention may also be practiced in distributed system environments where local and remote computer systems, which are linked (either by hardwired data links, wireless data links, or by a combination of hardwired and wireless data links) through a network, both perform tasks. In a distributed system environment, program modules may be located in both local and remote memory storage devices. Alternatively, or in addition, the functionality described herein can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (ASICs), Application-specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc. The present invention may be embodied in other specific forms without departing from its characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | 35,160 |
11942983 | Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION The following description is directed to certain implementations for the purposes of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some of the examples in this disclosure are based on wireless and wired local area network (LAN) communication according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standards, the IEEE 802.3 Ethernet standards, and the IEEE 1901 Powerline communication (PLC) standards. However, the described implementations may be implemented in any device, system or network that is capable of transmitting and receiving RF signals according to any of the wireless communication standards, including any of the IEEE 802.11 standards, the Bluetooth® standard, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), Global System for Mobile communications (GSM), GSM/General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution Data Optimized (EV-DO), 1×EV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), Evolved High Speed Packet Access (HSPA+), Long Term Evolution (LTE), AMPS, or other known signals that are used to communicate within a wireless, cellular or internet of things (IOT) network, such as a system utilizing 3G, 4G or 5G, or further implementations thereof, technology. A user equipment (UE) may utilize a subset of total cell bandwidth of a cell referred to as a Bandwidth Part (BWP). For example, in 5G NR releases 15 and 16, a maximum BWP size is 100 MHz. In higher frequency ranges (e.g., FR 2), the size of bandwidth parts may increase. Such large bandwidths may be designed to satisfy the demands of premium smartphones utilizing enhanced mobile broadband (eMBB) and other use cases such as ultra-reliable low latency communication (URLLC) and vehicle to anything (V2X). For some devices, referred to as reduced capability or RedCap devices, a narrower bandwidth part (NBWP) may be desirable for reduced complexity and power saving. That is, a first type of UE be capable of using a BWP of the maximum BWP size, whereas a RedCap UE may be a second type of UE that has lower maximum BWP size than the first type of UE for a frequency range. Example RedCap devices may include wearables, industrial wireless sensor networks (IWSN), surveillance cameras, and low-end smartphones. For instance, data rates for RedCap devices may be achieved with BWP sizes less than 100 MHz in FR2. In an example implementation, in FR1, a maximum device bandwidth for a non-RedCap device may be 100 MHz, while the maximum device bandwidth for a RedCap device may be 20 MHz. In FR2, the maximum device bandwidth for a non-RedCap device may be 200 MHz, while the maximum device bandwidth for a RedCap device may be 100 MHz. Other maximum device bandwidths may be applicable in other implementations. When a UE operates with a reduced BWP, it may be desirable to reduce narrowband interference effects and/or achieve frequency diversity gains. In an aspect, the present disclosure provides for a NBWP hopping pattern that allows a UE configured with a NBWP to hop frequency (for example, within a larger BWP or within the carrier system bandwidth). The UE may be configured with separate NBWPs and NBWP hopping patterns. Each NBWP may be associated with one or more NBWP hopping patterns. The network may activate one NBWP hopping pattern to be applied to the active NBWP. Accordingly, both the UE and the network may communicate on a bandwidth at a given time based on a current hop of the NBWP hopping pattern. Procedures such as hybrid automatic repeat request (HARQ), timers, grants, etc. may be transparent to the frequency hopping pattern at least for the UE. That is, the UE may adjust the frequency domain resources based on the NBWP hopping pattern without changing scheduling procedures. The network may consider NBWP frequency hopping patterns when scheduling and adjust the NBWP frequency hopping patterns for one or more UEs to meet scheduling demands. Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. RedCap devices may use a narrower bandwidth, which may save power. The NBWP frequency hopping pattern may mitigate narrowband interference effects by changing the frequency domain resources. Additionally, the NBWP frequency hopping pattern may hop over a larger bandwidth than the NBWP to provide frequency diversity gains. Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. The processor may include an interface or be coupled to an interface that can obtain or output signals. The processor may obtain signals via the interface and output signals via the interface. In some implementations, the interface may be a printed circuit board (PCB) transmission line. In some other implementations, the interface may include a wireless transmitter, a wireless transceiver, or a combination thereof. For example, the interface may include a radio frequency (RF) transceiver which can be implemented to receive or transmit signals, or both. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Accordingly, in one or more example implementations, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media, which may be referred to as non-transitory computer-readable media. Non-transitory computer-readable media may exclude transitory signals. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. FIG.1is a diagram illustrating an example of a wireless communications system and an access network100. The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations102, UEs104, an Evolved Packet Core (EPC)160, and another core network190(such as a 5G Core (5GC)). The base stations102may include macrocells (high power cellular base station) or small cells (low power cellular base station). The macrocells include base stations. The small cells include femtocells, picocells, and microcells. The small cells include femtocells, picocells, and microcells. The base stations102can be configured in a Disaggregated RAN (D-RAN) or Open RAN (O-RAN) architecture, where functionality is split between multiple units such as a central unit (CU), one or more distributed units (DUs), or a radio unit (RU). Such architectures may be configured to utilize a protocol stack that is logically split between one or more units (such as one or more CUs and one or more DUs). In some aspects, the CUs may be implemented within an edge RAN node, and in some aspects, one or more DUs may be co-located with a CU, or may be geographically distributed throughout one or multiple RAN nodes. The DUs may be implemented to communicate with one or more RUs. In some implementations, one or more of the UEs104may include a NBWP hopping component140that manages a NBWP to frequency hop over time according to a NBWP hopping pattern. The NBWP hopping component140may include a pattern configuration component142configured to receive a configuration of one or NBWP hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of the UE104. The NBWP hopping component140may include a pattern activation component144configured to determine an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs. The NBWP hopping component140may include communication component146configured to communicate on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP. In some implementations, the NBWP hopping component140may optionally include a pattern deactivation component148configured to disable NBWP hopping in response to a disable command. In some implementations, one or more of the base stations102may include a NBWP control component120configured to manage NBWP hopping pattern configurations for a UE and communicate with the UE over a NBWP according to the active NBWP hopping pattern. The NBWP control component120may include a configuration component122configured to configure one or more UEs with one or more NBWP hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of a respective UE. The NBWP control component120may include an activation component124configured to determine, for the respective UE, an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs. The NBWP control component120may include a communication component126configured to communicating with the respective UE on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP for the UE. The base stations102configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC160through first backhaul links132(such as S1 interface), which may be wired or wireless. The base stations102configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network190through second backhaul links184, which may be wired or wireless. In addition to other functions, the base stations102may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (such as handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations102may communicate directly or indirectly (such as through the EPC160or core network190) with each other over third backhaul links134(such as X2 interface). The third backhaul links134may be wired or wireless. The base stations102may wirelessly communicate with the UEs104. Each of the base stations102may provide communication coverage for a respective geographic coverage area110. There may be overlapping geographic coverage areas110. For example, the small cell102′ may have a coverage area110′ that overlaps the coverage area110of one or more macro base stations102. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network also may include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links112between the base stations102and the UEs104may include UL (also referred to as reverse link) transmissions from a UE104to a base station102or DL (also referred to as forward link) transmissions from a base station102to a UE104. The communication links112may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, or transmit diversity. The communication links may be through one or more carriers. The base stations102/UEs104may use spectrum up to Y MHz (such as 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (such as more or fewer carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). Certain UEs104may communicate with each other using device-to-device (D2D) communication link158. The D2D communication link158may use the DL/UL WWAN spectrum. The D2D communication link158may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR. The wireless communications system may further include a Wi-Fi access point (AP)150in communication with Wi-Fi stations (STAs)152via communication links154in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs152/AP150may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. The small cell102′ may operate in a licensed or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell102′ may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP150. The small cell102′, employing NR in an unlicensed frequency spectrum, may boost coverage to or increase capacity of the access network. A base station102, whether a small cell102′ or a large cell (such as macro base station), may include an eNB, gNodeB (gNB), or other type of base station. Some base stations, such as gNB180may operate in one or more frequency bands within the electromagnetic spectrum. The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” (mmW) band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, or may be within the EHF band. Communications using the mmW radio frequency band have extremely high path loss and a short range. The mmW base station180may utilize beamforming182with the UE104to compensate for the path loss and short range. The EPC160may include a Mobility Management Entity (MME)162, other MMES164, a Serving Gateway166, a Multimedia Broadcast Multicast Service (MBMS) Gateway168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway172. The MME162may be in communication with a Home Subscriber Server (HSS)174. The MME162is the control node that processes the signaling between the UEs104and the EPC160. Generally, the MME162provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway166, which itself is connected to the PDN Gateway172. The PDN Gateway172provides UE IP address allocation as well as other functions. The PDN Gateway172and the BM-SC170are connected to the IP Services176. The IP Services176may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, or other IP services. The BM-SC170may provide functions for MBMS user service provisioning and delivery. The BM-SC170may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway168may be used to distribute MBMS traffic to the base stations102belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. The core network190may include an Access and Mobility Management Function (AMF)192, other AMFs193, a Session Management Function (SMF)194, and a User Plane Function (UPF)195. The AMF192may be in communication with a Unified Data Management (UDM)196. The AMF192is the control node that processes the signaling between the UEs104and the core network190. Generally, the AMF192provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF195. The UPF195provides UE IP address allocation as well as other functions. The UPF195is connected to the IP Services197. The IP Services197may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, or other IP services. The base station may include or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. The base station102provides an access point to the EPC160or core network190for a UE104. Examples of UEs104include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (such as a MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs104may be referred to as IoT devices (such as a parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE104also may be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies including future 6G technologies. FIG.2Ais a diagram200illustrating an example of a first frame.FIG.2Bis a diagram230illustrating an example of DL channels within a subframe.FIG.2Cis a diagram250illustrating an example of a second frame.FIG.2Dis a diagram280illustrating an example of a subframe. The 5G NR frame structure may be FDD in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either DL or UL, or may be TDD in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both DL and UL. A subset of the total cell bandwidth of a cell is referred to as a Bandwidth Part (BWP) and bandwidth adaptation is achieved by configuring the UE with BWP(s) and telling the UE which of the configured BWPs is currently the active one. In an aspect, a narrow bandwidth part (NBWP) refers to a BWP having a bandwidth less than or equal to a maximum configurable bandwidth of a BWP for a UE. The bandwidth of the NBWP is less than the carrier system bandwidth. The NBWP may hop over the maximum configurable bandwidth of a BWP for the UE or over the carrier system bandwidth. The hopping may provide frequency diversity gains without increasing the BWP size over the size of a NBWP. In the examples provided byFIGS.2A,2C, the 5G NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL), where D is DL, U is UL, and X is flexible for use between DL/UL, and subframe 3 being configured with slot format 34 (with mostly UL). While subframes 3, 4 are shown with slot formats 34, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI), or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI). Note that the description infra applies also to a 5G NR frame structure that is TDD. Other wireless communication technologies may have a different frame structure or different channels. A frame (10 milliseconds (ms)) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. Subframes also may include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. The symbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission). The number of slots within a subframe is based on the slot configuration and the numerology. For slot configuration 0, different numerologies μ 0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology μ, there are 14 symbols/slot and 2μslots/subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2μ*15 kHz, where μ is the numerology 0 to 5. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=5 has a subcarrier spacing of 480 kHz. The symbol length/duration is inversely related to the subcarrier spacing.FIGS.2A-2Dprovide an example of slot configuration 0 with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 microseconds (μs). A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme. As illustrated inFIG.2A, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulation RS (DM-RS) (indicated as Rxfor one particular configuration, where 100× is the port number, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS also may include beam measurement RS (BRS), beam refinement RS (BRRS), and phase tracking RS (PT-RS). FIG.2Billustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE104to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DM-RS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block (SSB). The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages. As illustrated inFIG.2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS). The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL. FIG.2Dillustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), or UCI. FIG.3is a diagram of an example of a base station310and a UE350in an access network. In the DL, IP packets from the EPC160may be provided to a controller/processor375. The controller/processor375implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor375provides RRC layer functionality associated with broadcasting of system information (such as MIB, SIBs), RRC connection control (such as RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. The transmit (TX) processor316and the receive (RX) processor370implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor316handles mapping to signal constellations based on various modulation schemes (such as binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may be split into parallel streams. Each stream may be mapped to an OFDM subcarrier, multiplexed with a reference signal (such as a pilot) in the time or frequency domain, and combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator374may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal or channel condition feedback transmitted by the UE350. Each spatial stream may be provided to a different antenna320via a separate transmitter318TX. Each transmitter318TX may modulate an RF carrier with a respective spatial stream for transmission. At the UE350, each receiver354RX receives a signal through its respective antenna352. Each receiver354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor356. The TX processor368and the RX processor356implement layer 1 functionality associated with various signal processing functions. The RX processor356may perform spatial processing on the information to recover any spatial streams destined for the UE350. If multiple spatial streams are destined for the UE350, they may be combined by the RX processor356into a single OFDM symbol stream. The RX processor356converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station310. These soft decisions may be based on channel estimates computed by the channel estimator358. The soft decisions are decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station310on the physical channel. The data and control signals are provided to the controller/processor359, which implements layer 3 and layer 2 functionality. The controller/processor359can be associated with a memory360that stores program codes and data. The memory360may be referred to as a computer-readable medium. In the UL, the controller/processor359provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC160. The controller/processor359is also responsible for error detection using an ACK or NACK protocol to support HARQ operations. Similar to the functionality described in connection with the DL transmission by the base station310, the controller/processor359provides RRC layer functionality associated with system information (such as MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. Channel estimates derived by a channel estimator358from a reference signal or feedback transmitted by the base station310may be used by the TX processor368to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor368may be provided to different antenna352via separate transmitters354TX. Each transmitter354TX may modulate an RF carrier with a respective spatial stream for transmission. The UL transmission is processed at the base station310in a manner similar to that described in connection with the receiver function at the UE350. Each receiver318RX receives a signal through its respective antenna320. Each receiver318RX recovers information modulated onto an RF carrier and provides the information to a RX processor370. The controller/processor375can be associated with a memory376that stores program codes and data. The memory376may be referred to as a computer-readable medium. In the UL, the controller/processor375provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE350. IP packets from the controller/processor375may be provided to the EPC160. The controller/processor375is also responsible for error detection using an ACK or NACK protocol to support HARQ operations. At least one of the TX processor368, the RX processor356, and the controller/processor359may be configured to perform aspects in connection with the NBWP hopping component140ofFIG.1. For example, the memory360may include executable instructions defining the NBWP hopping component140. The TX processor368, the RX processor356, and/or the controller/processor359may be configured to execute the NBWP hopping component140. At least one of the TX processor316, the RX processor370, and the controller/processor375may be configured to perform aspects in connection with the NBWP control component120ofFIG.1. For example, the memory376may include executable instructions defining the NBWP control component120. The TX processor316, the RX processor370, and/or the controller/processor375may be configured to execute the NBWP control component120. FIG.4is a diagram400illustrating an example of NBWP hopping. A UE104may be configured with a nominal active BWP420within a carrier bandwidth410that hops over time412. The nominal active BWP420may be configured with a bandwidth up to a maximum BWP bandwidth422of a UE for a frequency range. For instance, for FR1, the maximum BWP bandwidth422may be 100 MHz. For a NBWP, the bandwidth of the nominal active BWP420may be less than or equal to the maximum BWP bandwidth422. The bandwidth of the nominal active BWP420may be less than a carrier bandwidth410. NBWP hopping allows the active BWP for a UE to hop over different frequencies within the carrier bandwidth410. For example, a UE104may be configured with one or more virtual NBWPs430(e.g., NBWP430a,430b, and430c). Each virtual NBWP430may be defined by a frequency reference point432and a hop duration434. The virtual NBWPs430may be separated by gaps436. Resources within a virtual NBWP may be defined relative to the frequency reference point432for the virtual NBWP430. Procedures such as hybrid automatic repeat request (HARQ), timers, grants, etc. may be transparent to frequency hopping. That is, the procedures may be signaled as if the nominal NBWP420is to be used, but transmissions may actually occur on the virtual NBWP430at the time of the transmission. In an aspect, the present disclosure provides for NBWP hopping patterns that can be associated with one or more configured NBWPs for a UE. NBWP hopping patterns may simplify signaling related to virtual NBWPs. In particular, configuration and activation of virtual NBWPs according to NBWP hopping patterns may allow determination of the virtual NBWP for a UE at a given time. The active NBWP hopping pattern may be dynamically changed among configured NBWP hopping patterns. In some implementations, the NBWP hopping pattern may be deactivated or a default NBWP hopping pattern (e.g., with a single hop and infinite duration) may be activated. FIG.5is a diagram illustrating an example configuration500of NBWPs510and NBWP hopping patterns520. The NBWPs510(e.g., NBWP510aand510b) may be configured for each serving cell. The NBWPs510may be configured via RRC configuration messages. Generally, a UE has one active BWP for each serving cell. The active BWP may be dynamically selected based on PDCCH signaling (e.g., downlink control information (DCI)), timers, or UE status. The active BWP may correspond to the nominal NBWP420. The NBWP hopping patterns520(e.g., NBWP hopping patterns520a,520b, and520c) may be similarly configured via RRC signaling. The RRC signaling may be specific to the UE104or the cell. Each NBWP510may be configured or associated with one or more NBWP hopping patterns520. For example, the NBWP510amay be associated with the NBWP hopping patterns520aand520band the NBWP510bmay be associated with the NBWP hopping patterns520a,520b, and520c. The configuration530for each hopping pattern520may include a number of hops532. In some implementations, the number of hops may be represented as (n) and an index of a hop may be represented as (i). For each hop, the configuration530may include a duration534(e.g., duration534a,534b, or534c) and a frequency offset536(e.g., frequency offset536a,536b, or536c) for the respective hop. In some implementations, the configuration530may include a gap538(e.g., gap538a,538b, or538c) for each hop. The hop duration534(Thop, i) may be duration for which a virtual NBWP is active on certain frequency resources. The hop duration534may be the same or different for each hop within a hopping pattern520. The hop frequency offset536(FOhop,i) may be a frequency offset of the respective hop from a reference frequency. The hop frequency offset536may indicate the beginning of virtual NBWP resources on the frequency grid. In some implementations, the hop frequency offset536may be defined based on the carrier center frequency, the lowest resource element (RE) or physical resource block (PRB) index of the nominal NBWP510. In some implementations, the hop frequency offset may be described as an integer or fractional multiple of the NBWP bandwidth. For instance, frequency offset536amay be −1 times the nominal NBWP bandwidth, frequency offset536bmay be 0 times the nominal NBWP bandwidth, and frequency offset536cmay be 1 times the nominal NBWP bandwidth. FIG.6is a diagram600of the NBWP hopping pattern520aofFIG.5applied to the nominal NBWP420. The NBWP hopping pattern520amay include 3 hops610(e.g., hop610a,610b, and610c). Each hop610may be defined by a respective duration534, frequency offset536, and gap538. In the illustrated example, the duration534and the gap538may be the same for each hop610, but the duration534and gap538may be different for each hop610. After the hop610c, the NBWP hopping pattern520amay repeat. FIG.7is a message diagram700illustrating example messages between a base station102and a UE104for managing a NBWP hopping pattern. The base station102may broadcast system information710. The system information710may define an initial BWP that may be used by one or more UEs104. The system information710may transmit a BWP configuration720to the UE104. The BWP configuration720may be, for example, an RRC message that configures the NBWPs510. The base station102may transmit a NBWP hopping pattern configuration message730to the UE104. The NBWP hopping pattern configuration message730may be, for example, an RRC message that configures the NBWP hopping patterns520. The NBWP hopping pattern configuration message730may be UE specific, UE type specific, or cell specific. A non-RedCap UE or baseline device may refer to a first type of UE capable of using a BWP of a maximum BWP size, whereas a RedCap UE may refer a second type of UE that has lower maximum BWP size than the first type of UE for a frequency range. Descriptions here of a non-RedCap UE and a RedCap UE may be equally applicable the first type of UE and the second type of UE. In an aspect, a RedCap UE may signal a maximum configurable bandwidth (e.g., via an RRC capability message). The NBWP hopping pattern configuration message730may be specific for a first type of UE (e.g., non-RedCap UEs) or a second type of UE (e.g., RedCap UEs). The NBWP hopping pattern configuration message730may also associate each NBWP hopping pattern520with one or more of the configured NBWPs510of the UE104. The base station102may indicate an active NBWP hopping pattern. In some implementations, if no NBWP hopping pattern520is currently active (e.g., NBWP hopping is currently disabled), base station102may transmit an enable command735. The enable command735may indicate the active hopping pattern for the UE104. The base station102may also change the active NBWP hopping pattern. For example, the base station102may transmit an active NBWP hopping pattern indication740that indicates a target hopping pattern for the UE104. For example, the network may switch the active NBWP hopping pattern520for a cell or a UE based on channel conditions, network load, or other factors. In some implementations, the active NBWP hopping pattern indication740may be used to enable NBWP hopping. The active NBWP hopping pattern indication740may apply to one or more UEs and may be transmitted as a MAC-CE, DCI, or an RRC message. In some implementations, the NBWP hopping pattern configuration message730may specify a timer for changing the active NBWP hopping pattern520. The UE104may transmit a response742in response to the active NBWP hopping pattern indication740. The response742may explicitly or implicitly indicate that the active NBWP hopping pattern indication740was received. For example, the response742may be a HARQ-ACK for a PDSCH carrying the active NBWP hopping pattern indication740as an RRC message or MAC-CE. As another example, the response742may be a PUSCH message scheduled by a DCI including the active NBWP hopping pattern indication740. The UE104may switch to the active NBWP hopping pattern520indicated by the NBWP hopping pattern indication740during a switching delay744. The switching delay744may be a minimum time between receiving the indication of the target NBWP hopping pattern and communicating according to the target NBWP hopping pattern. That is, the UE may be able to transmit or receive on the time and frequency resource configured according to the active NBWP hopping pattern520after the switching delay744, which may be referred to as TNBWP-HP-SwitchDelay. The switching delay744may depend on the relation between the source hopping pattern520and the target hopping pattern520, e.g., frequency span of the hopping patterns520, a frequency separation between the last active hop in the source hopping pattern520and the first hop in the target hopping pattern520, etc. The switching delay744may depend on the signaling used to initiate the NBWP hopping pattern switch (e.g., the active NBWP hopping pattern indication740). The switching delay744may depend on the SCS of the active NBWP510. The switching delay744may depend on a combination of the preceding factors. The UE104may switch to the new active NBWP hopping pattern according to one or more rules. According to a first example rule, the UE104may switch to a hop of the new active NBWP hopping pattern immediately after the switching delay744. For example, the UE104may switch to a first hop in the new active NBWP hopping pattern. As another example, the UE104may switch to a closest hop in frequency to the current hop, which may reduce the switching delay744. According to a second example rule, the UE104may complete a current cycle of the old NBWP hopping pattern before switching. Once again, the UE104may switch to the first hop of the new pattern or the closest hop in frequency. According to a third example rule, the UE104may continue to hop according to the current NBWP hopping pattern until there is an overlapping hop with the new active NBWP hopping pattern, then switch to the new pattern starting at the overlapping hop. In another aspect, the active NBWP hopping pattern indication740may be implicitly indicated by a DCI scheduling a downlink or uplink transmission on a new hopping pattern. For example, the DCI may indicate a frequency domain resource allocation outside of the current hopping pattern. In this example, the UE104may switch immediately to the hop containing the scheduled transmission and continue with the new active NBWP hopping pattern after the scheduled transmission. The base station102and the UE104may exchange communication750according to the active NBWP hopping pattern. The communication750may refer to any transmission scheduled on the active NBWP510. For example, if the active NBWP510is a downlink BWP, the communication750may be a PDCCH or PDSCH. If the active NBWP510is an uplink BWP, the communication750may be a PUCCH or PUSCH. In an aspect, the base station102may transmit a disable command760to disable a NBWP hopping pattern. For example, the disable command760may be a MAC-CE, DCI, or RRC message. In some implementations, the NBWP hopping pattern configuration message730may specify a timer for disabling active NBWP hopping pattern520. When the active NBWP hopping pattern520is disabled the UE104may stay on a current hop610and discontinue hopping. In this case, no switching delay744is associated with disabling NBWP the hopping pattern. Alternatively, the UE104may switch to a default hop in response to the disable command760. The default hop may be preconfigured per NBWP510or per NBWP hopping pattern520. The UE104may switch to the default hop after a switching delay744. In another aspect, one of the configured NBWP hopping patterns520may correspond to disabled NBWP hopping. For example, a disabled NBWP hopping pattern520may include a single hop with a frequency offset536of 0 and infinite duration534. The base station102may disable NBWP hopping by transmitting the active NBWP hopping pattern indication740indicating the disabled NBWP hopping pattern520. The UE104may immediately switch to the disabled NBWP hopping pattern520. FIG.8is a conceptual data flow diagram800illustrating the data flow between different means/components in an example base station802, which may be an example of the base station102including the NBWP control component120. The NBWP control component120may be implemented by the memory376and the TX processor316, the RX processor370, and/or the controller/processor375ofFIG.3. For example, the memory376may store executable instructions defining the NBWP control component120and the TX processor316, the RX processor370, and/or the controller/processor375may execute the instructions. The base station102may include a receiver component850, which may include, for example, a radio frequency (RF) receiver for receiving the signals described herein. The base station102may include a transmitter component852, which may include, for example, an RF transmitter for transmitting the signals described herein. In an aspect, the receiver component850and the transmitter component852may co-located in a transceiver such as illustrated by the TX/RX318inFIG.3. As discussed with respect toFIG.1, the NBWP control component120may include the pattern configuration component142, the pattern activation component144, and the communication component146. The receiver component850may receive UL signals from the UE104including UL communications. In some implementations, the receiver component850may optionally receive a random access message from the UE104seeking to connect to the base station802. The receiver component850may provide an identification of the UE104to the configuration component122. The configuration component122may receive an identification of a UE104from the receiver component850. The configuration component122may transmit one or more configuration messages to the UE104via the transmitter component852. For example, the configuration messages may be RRC configuration message. In particular, the configuration component122may transmit the NBWP hopping pattern configuration message730. The NBWP hopping pattern configuration message730may include one or more NBWP hopping pattern configuration530. The configuration component122may provide the configure NBWP hopping patterns to the activation component124. The activation component124may receive the configured NBWP hopping patterns for a UE from the configuration component122. The activation component124may determine whether to activate any of the configured NBWP hopping patterns. For example, the activation component124may select a configured NBWP hopping pattern base on UE channel feedback, base station channel measurements, or network load. The activation component124may transmit an active NBWP hopping pattern indication740via the transmitter component852. In some implementations, if no NBWP hopping pattern is currently active, the activation component124may transmit an enable command735indicating the new active NBWP hopping pattern. In some implementations, if the activation component124determines to disable NBWP hopping, the activation component124may transmit a disable command760. In any case, the activation component124may provide the active NBWP hopping pattern (if any) to the communication component126. The communication component126may receive the active NBWP hopping pattern from the activation component124. The communication component126may determine a current hop based on the active NBWP hopping pattern. The communication component126may tune the receiver component850and/or the transmitter component852to the correct bandwidth based on the current hop. The communication component126may receive uplink communications (e.g., PUSCH and/or PUCCH) from the receiver component850. The communication component126may transmit downlink communications (e.g., PDCCH and/or PDSCH) via the transmitter component852. FIG.9is a conceptual data flow diagram900illustrating the data flow between different means/components in an example UE904, which may be an example of the UE104and include the NBWP hopping component140. The NBWP hopping component140may be implemented by the memory360and the TX processor368, the RX processor356, and/or the controller/processor359. For example, the memory360may store executable instructions defining the NBWP hopping component140and the TX processor368, the RX processor356, and/or the controller/processor359may execute the instructions. The UE104may include a receiver component970, which may include, for example, a RF receiver for receiving the signals described herein. The UE104may include a transmitter component972, which may include, for example, an RF transmitter for transmitting the signals described herein. In an aspect, the receiver component970and the transmitter component972may co-located in a transceiver such as the TX/RX352inFIG.3. As discussed with respect toFIG.1, the NBWP hopping component140may include the pattern configuration component142, the pattern activation component144, and the communication component146. The NBWP hopping component140may optionally include the pattern deactivation component148. The receiver component970may receive DL signals described herein such as the system information710, BWP configuration720, NBWP hopping pattern configuration message730, enable command735, active NBWP hopping pattern indication740, disable command760, and downlink communications. The receiver component970may provide the system information710, BWP configuration720, and NBWP hopping pattern configuration message730to the pattern configuration component142. The receiver component970may provide the enable command735and/or active NBWP hopping pattern indication740to the activation component144. The receiver component970provide a disable command to the deactivation component148. The receiver component970may provide downlink communications to the communication component146. The pattern configuration component142may receive configuration messages from the receiver component970. In particular, the pattern configuration component142may receive the NBWP hopping pattern configuration message730including one or more configurations530. The pattern configuration component142may extract the parameters (e.g., number of hops532, duration534, frequency offset536, and gap538) from the configurations530and store the hopping patterns520. The pattern configuration component142may provide the configured NBWP hopping patterns520to the pattern activation component144. The pattern activation component144may receive the configured NBWP hopping patterns from the pattern configuration component142. The pattern activation component144may receive an indication of one of the configured NBWPs as a target NBWP hopping pattern. For example, the pattern activation component144may receive the enable command735or the active NBWP hopping pattern indication740via the receiver component970. The pattern activation component144may identify one of the configured NBWP hopping patterns520indicated by the indication. The pattern activation component144may provide the active NBWP hopping pattern to the communication component146. In some implementations, the indication may identify a default NBWP hopping pattern that includes a single hop. By selecting the default NBWP hopping pattern, the pattern activation component144may disable NBWP hopping. In some implementations, where the NBWP hopping component140includes the pattern deactivation component148, the pattern activation component144may indicate to the communication component146that no BWP hopping pattern is active. The communication component146may receive the active NBWP hopping pattern from the pattern activation component144. The communication component146may determine a current hop based on the active NBWP hopping pattern. The communication component146may tune the receiver component970and/or the transmitter component972based on the current hop. The communication may transmit uplink communications (e.g., PUSCH and/or PUCCH) via the transmitter component972. The communication component126may receive downlink communications (e.g., PDCCH and/or PDSCH) via the receiver component970. FIG.10is a flowchart of an example method1000for a UE to perform NBWP hopping according to a configured and activated hopping pattern. The method1000may be performed by a UE (such as the UE104, which may include the memory360and which may be the entire UE104or a component of the UE104such as the NBWP hopping component140, TX processor368, the RX processor356, or the controller/processor359). The method1000may be performed by the NBWP hopping component140in communication with the NBWP control component120of the base station102. Optional blocks are shown with dashed lines. At block1010, the method1000may include receiving a configuration of one or more NBWP hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of a bandwidth part. In some implementations, for example, the UE104, the RX processor356or the controller/processor359may execute the NBWP hopping component140or the pattern configuration component142to receive the NBWP hopping pattern configuration message730. For example, at sub-block1012, the block1010may include receiving RRC signaling that is specific for the UE104, a type of the UE104, or a cell. The NBWP hopping pattern configuration message730may include one or more NBWP hopping pattern configurations530for a respective NBWP hopping pattern520. The configuration530of one or more NBWP hopping patterns may include a number of hops532for each hopping pattern, and a hop duration534and a hop frequency offset536for each of the number of hops. The configuration530may optionally include a duration of the gap538for each hop610. In some implementations, the hop frequency offset is measured from one of: a carrier center frequency, a lowest resource element of the active NBWP, or a lowest physical resource block index of the active NBWP. In some implementations, the hop frequency offset is a multiple of a bandwidth of the active NBWP. The NBWP hopping pattern configuration message730may associate each NBWP hopping pattern520with one or more configured NBWPs510. Each NBWP510has a bandwidth less than or equal to the maximum BWP bandwidth422for the UE. The bandwidth of the NBWPs510is less than a carrier bandwidth410. Accordingly, the UE104, the RX processor356, or the controller/processor359executing the NBWP hopping component140or the pattern configuration component142may provide means for receiving a configuration of one or more NBWP hopping patterns for one or more configured NBWPs. At block1020, the method1000may include determining an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs. In some implementations, for example, the UE104, the RX processor356or the controller/processor359may execute the NBWP hopping component140or the pattern activation component144to determine the active NBWP hopping pattern (e.g., NBWP hopping pattern520a) for an active NBWP (e.g., NBWP510a) of the one or more configured NBWPs510. In some implementations, at sub-block1022, the block1020may include receiving an indication of one of the configured NBWP hopping patterns520as a target NBWP hopping pattern. For instance, the pattern activation component144may receive the enable command735or the active NBWP hopping pattern indication740specifying the target NBWP hopping pattern. In some implementations, the UE104may not change NBWP hopping pattern until after a switching delay744. The switching delay744may indicate a minimum time between receiving the indication of the target NBWP hopping pattern and communicating according to the target NBWP hopping pattern. The switching delay744may be based on: a relation between a source NBWP hopping pattern and the target NBWP hopping pattern, a type of the indication of the target NBWP hopping pattern, or a subcarrier spacing of the active NBWP, or a combination thereof. In some implementations, the indication of the target NBWP hopping pattern is a DCI indicating a communication outside of the active NBWP hopping pattern520, in which case the pattern activation component144may switch to the target NBWP hopping pattern for the communication. In some implementations, the target NBWP hopping pattern is a default hopping pattern including a single hop. The default hopping pattern may be used to effectively disable NBWP hopping. In some implementations, at sub-block1024, the block1020may further include transmitting an uplink transmission according to the active NBWP hopping pattern. The uplink transmission may explicitly or implicitly acknowledge receipt of the indication in sub-block1022. At sub-block1026, the block1020may optionally further include switching the active NBWP hopping pattern520to the target NBWP hopping pattern520aat an agreed event after the uplink transmission. For example, the agreed event may be an expiration of the switching delay744, an expiration of a current hop, a completion of a NBWP hopping pattern, or an occurrence of an overlapping hop between the current active NBWP hopping pattern and the target NBWP hopping pattern. Accordingly, the UE104, the RX processor356, or the controller/processor359executing the NBWP hopping component140or the pattern activation component144may provide means for determining an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs. At block1030, the method1000may include communicating on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP. In some implementations, for example, the UE104, the RX processor356, the TX processor368, or the controller/processor359may execute the NBWP hopping component140or the communication component146to communicate on frequency domain resources for a frequency domain hop (e.g., hop610a) indicated by the active NBWP hopping pattern520applied to the active NBWP510. Accordingly, the UE104, the RX processor356, the TX processor368, or the controller/processor359executing the NBWP hopping component140or the communication component146may provide means for communicating on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP. At block1040, the method1000may optionally include receiving a signal to disable the active NBWP hopping pattern. In some implementations, for example, the UE104, the RX processor356, or the controller/processor359may execute the NBWP hopping component140or the deactivation component148to receive the disable command760to disable the active NBWP hopping pattern520. In some implementations, at block1050, the method1000may include setting the active NBWP510to a bandwidth of the frequency domain hop610indicated by the active NBWP hopping pattern520in response to the signal disabling the active NBWP hopping pattern. That is, the deactivation component148may stop any further hopping in response to the disable command760. As another example, at block1060, the method1000may optionally include setting the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. That is, the deactivation component148may immediately hop to the default bandwidth and stop following the NBWP hopping pattern. In view of the foregoing, the UE104, the RX processor356, or the controller/processor359executing the NBWP hopping component140or the deactivation component148may provide means for receiving a signal to disable the active NBWP hopping pattern. FIG.11is a flowchart of an example method1100for a base station to control NBWP hopping for a UE104according to a NBWP hopping pattern. The method1000may be performed by a base station (such as the base station102, which may include the memory376and which may be the entire base station102or a component of the base station102such as the NBWP control component120, the TX processor316, the RX processor370, or the controller/processor375). The method1000may be performed by the NBWP control component120in communication with the NBWP hopping component140of the UE104. At block1010, the method1000may include configuring one or more UEs with one or more NBWP hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of a respective UE. In some implementations, for example, the base station102, the TX processor316, or the controller/processor375may execute the NBWP control component120or the configuration component122to configure one or more UEs104with one or more NBWP hopping patterns520for one or more configured NBWPs510. In some implementations, at sub-block1112, the block1110may include transmitting a configuration530of one or more NBWP hopping patterns520that includes a number of hops532for each hopping pattern520, and a hop duration534and a hop frequency offset536for each of the number of hops. The configuration530may optionally include a duration of the gap538for each of the number of hops. In some implementations, at sub-block1114, the block1110may include transmitting RRC signaling that is specific for the one or more UEs104, specific for a type of UE, or specific for a cell of the base station102. Accordingly, the base station102, the TX processor316, or the controller/processor375executing the NBWP control component120or the configuration component122may provide means for configuring one or more UEs with one or more NBWP hopping patterns for one or more configured NBWPs. At block1120, the method1000may include determining, for the respective UE, an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs. In some implementations, for example, base station102, the TX processor316, or the controller/processor375may execute the NBWP control component120or the activation component124to determine, for the UE104, an active NBWP hopping pattern (e.g., NBWP hopping pattern520a) for an active NBWP (e.g., NBWP510a) of the one or more configured NBWPs510. In some implementations, at sub-block1122, the block1120may include transmitting an indication (e.g., enable command735or active NBWP hopping pattern indication740) of one of the configured NBWP hopping patterns520as a target NBWP hopping pattern. In some implementations, at sub-block1124, the block1120may include receiving an uplink transmission according to the active NBWP hopping pattern after transmitting the indication of the target NBWP hopping pattern. The uplink transmission may be an explicit or implicit acknowledgment of the indication. In some implementations, at sub-block1126, the block1120may include switching the active NBWP hopping pattern to the target NBWP hopping pattern at an agreed event after the uplink transmission. For example, the agreed event may be an expiration of the switching delay744, an expiration of a current hop, a completion of a NBWP hopping pattern, or an occurrence of an overlapping hop between the current active NBWP hopping pattern and the target NBWP hopping pattern. Accordingly, the base station102, the TX processor316, or the controller/processor375executing the NBWP control component120or the activation component124may provide means for determining, for a UE, an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs. At block1130, the method1100may include communicating with the UE on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP for the UE. In some implementations, for example, the base station102, the RX processor370, or the controller/processor375may execute the NBWP control component120or the communication component126to communicate with the UE104on frequency domain resources for a frequency domain hop (e.g., hop610a) indicated by the active NBWP hopping pattern520applied to the active NBWP510. Accordingly, the base station102, the RX processor370, or the controller/processor375executing the NBWP control component120or the communication component126may provide means for communicating with the UE on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP for the UE At block1140, the method1100may optionally include transmitting a signal to disable the active NBWP hopping pattern. In some implementations, for example, base station102, the TX processor316, or the controller/processor375may execute the NBWP control component120or the activation component124to transmit the disable command760to disable the active NBWP hopping pattern520. In some implementations, at block1150, the method1100may include setting the active NBWP510to a bandwidth of the frequency domain hop610indicated by the active NBWP hopping pattern520in response to the signal disabling the active NBWP hopping pattern. That is, the activation component126may stop any further hopping in response to the disable command760. As another example, at block1160, the method1100may optionally include setting the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. That is, the activation component126may immediately hop to the default bandwidth and stop following the NBWP hopping pattern. Accordingly, the base station102, the TX processor316, or the controller/processor375executing the NBWP control component120or the activation component126may provide means for transmitting a signal to disable the active NBWP hopping pattern. SOME FURTHER EXAMPLE CLAUSES Implementation examples are described in the following numbered clauses: 1. A method of wireless communication, comprising, at a user equipment (UE):receiving a configuration of one or more narrow bandwidth part (NBWP) hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of the UE;determining an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs; andcommunicating on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP. 2. The method of clause 1, wherein the configuration of one or more NBWP hopping patterns includes a number of hops for each hopping pattern, and a hop duration and a hop frequency offset for each of the number of hops. 3. The method of clause 2, wherein the hop frequency offset is measured from one of: a carrier center frequency, a lowest resource element of the active NBWP, or a lowest physical resource block index of the active NBWP. 4. The method of clause 2 or 3, wherein the hop frequency offset is a multiple of a bandwidth of the active NBWP. 5. The method of any of clauses 1-4, wherein receiving the configuration of the one or more NBWP hopping patterns comprises receiving radio resource control (RRC) signaling that is specific for the UE, a type of UE, or a cell. 6. The method of any of clauses 1-5, wherein determining the active NBWP hopping pattern comprises receiving an indication of one of the configured NBWP hopping patterns as a target NBWP hopping pattern. 7. The method of clause 6, wherein the one or more NBWP hopping patterns is associated with a NBWP hopping pattern switching delay indicating a minimum time between receiving the indication of the target NBWP hopping pattern and communicating according to the target NBWP hopping pattern. 8. The method of clause 7, wherein the NBWP hopping pattern switching delay is based on: a relation between a source NBWP hopping pattern and the target NBWP hopping pattern, a type of the indication of the target NBWP hopping pattern, or a subcarrier spacing of the active NBWP, or a combination thereof. 9. The method of any of clauses 6-8, further comprising:transmitting an uplink transmission according to the active NBWP hopping pattern; andswitching the active NBWP hopping pattern to the target NBWP hopping pattern at an agreed event after the uplink transmission. 10. The method of any of clauses 6-9, wherein the indication of the target NBWP hopping pattern is a downlink control information (DCI) indicating a communication outside of the active NBWP hopping pattern, further comprising switching to the target NBWP hopping pattern for the communication. 11. The method of any of clauses 6-10, wherein the target NBWP hopping pattern is a default hopping pattern including a single hop. 12. The method of any of clauses 1-5, further comprising receiving a signal to enable or disable the active NBWP hopping pattern. 13. The method of clause 12, further comprising setting the active NBWP to a bandwidth of the frequency domain hop indicated by the active NBWP hopping pattern in response to the signal disabling the active NBWP hopping pattern. 14. The method of clause 12, further comprising setting the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. 15. A method of wireless communication, comprising, at a base station:configuring one or more user equipment (UEs) with one or more narrow bandwidth part (NBWP) hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of a respective UE;determining, for the respective UE, an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs; andcommunicating with the respective UE on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP for the respective UE. 16. The method of clause 15, wherein configuring the one or more UEs comprises transmitting a configuration of one or more NBWP hopping patterns that includes a number of hops for each hopping pattern, and a hop duration and a hop frequency offset for each of the number of hops. 17. The method of clause 15 or 16, wherein configuring the one or more UEs with one or more narrow NBWP hopping patterns for the one or more configured NBWPs comprises transmitting radio resource control (RRC) signaling that is specific for the one or more UEs, specific for a type of UE, or specific for a cell of the base station. 18. The method of any of clauses 15-17, wherein determining the active NBWP hopping pattern for the active NBWP of the one or more configured NBWPs comprises transmitting an indication of one of the configured NBWP hopping patterns as a target NBWP hopping pattern. 19. The method of clause 18, wherein the one or more NBWP hopping patterns is associated with a NBWP hopping pattern switching delay indicating a minimum time between receiving the indication of the target NBWP hopping pattern at the respective UE and communicating according to the target NBWP hopping pattern. 20. The method of clause 19, wherein the NBWP hopping pattern switching delay is based on one of: a relation between a source NBWP hopping pattern and the target NBWP hopping pattern, a type of the indication of the target NBWP hopping pattern, or a subcarrier spacing of the active NBWP. 21. The method of any of clauses 18-20, wherein determining the active NBWP hopping pattern for the active NBWP of the one or more configured NBWPs comprises:receiving an uplink transmission according to the active NBWP hopping pattern after transmitting the indication of the target NBWP hopping pattern; andswitching the active NBWP hopping pattern to the target NBWP hopping pattern at an agreed event after the uplink transmission. 22. The method of any of clauses 18-21, wherein the indication of the target NBWP hopping pattern is a downlink control information indicating a communication outside of the active NBWP hopping pattern, further comprising switching to the target NBWP hopping pattern for the communication. 23. The method of any of clauses 18-222, wherein the target NBWP hopping pattern is a default hopping pattern including a single hop. 24. The method of any of clauses 15-17, further comprising transmitting a signal to enable or disable the active NBWP hopping pattern. 25. The method of clause 24, further comprising setting the active NBWP to a bandwidth of the frequency domain hop indicated by the active NBWP hopping pattern in response to the signal disabling the active NBWP hopping pattern. 26. The method of clause 24, further comprising setting the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. 27. An apparatus for wireless communication by a user equipment (UE), comprising:a memory storing computer-executable instructions; andat least one processor coupled to the memory and configured to execute the computer-executable instructions to:receive a configuration of one or more narrow bandwidth part (NBWP) hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of the UE;determine an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs; andcommunicate on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP. 28. The apparatus of clause 27, wherein the configuration of one or more NBWP hopping patterns includes a number of hops for each hopping pattern, and a hop duration and a hop frequency offset for each of the number of hops. 29. The apparatus of clause 28, wherein the hop frequency offset is measured from one of: a carrier center frequency, a lowest resource element of the active NBWP, or a lowest physical resource block index of the active NBWP. 30. The apparatus of clause 28 or 29, wherein the hop frequency offset is a multiple of a bandwidth of the active NBWP. 31. The apparatus of any of clauses 27-30, wherein to receive the configuration of the one or more NBWP hopping patterns, the at least one processor is configured to receive radio resource control (RRC) signaling that is specific for the UE, a type of UE, or a cell. 32. The apparatus of any of clauses 27-31, wherein to determine the active NBWP hopping pattern, the at least one processor is configured to receive an indication of one of the configured NBWP hopping patterns as a target NBWP hopping pattern. 33. The apparatus of clause 32, wherein the one or more NBWP hopping patterns is associated with a NBWP hopping pattern switching delay indicating a minimum time between receiving the indication of the target NBWP hopping pattern and communicating according to the target NBWP hopping pattern. 34. The apparatus of clause 33, wherein the NBWP hopping pattern switching delay is based on: a relation between a source NBWP hopping pattern and the target NBWP hopping pattern, a type of the indication of the target NBWP hopping pattern, or a subcarrier spacing of the active NBWP, or a combination thereof. 35. The apparatus of any of clauses 32-34, wherein the at least one processor is configured to:transmit an uplink transmission according to the active NBWP hopping pattern; andswitch the active NBWP hopping pattern to the target NBWP hopping pattern at an agreed event after the uplink transmission. 36. The apparatus of any of clauses 32-35, wherein the indication of the target NBWP hopping pattern is a downlink control information (DCI) indicating a communication outside of the active NBWP hopping pattern, wherein the at least one processor is configured to switch to the target NBWP hopping pattern for the communication. 37. The apparatus of any of clauses 32-36, wherein the target NBWP hopping pattern is a default hopping pattern including a single hop. 38. The apparatus of any of clause 27-31, wherein the at least one processor is configured to receive a signal to enable or disable the active NBWP hopping pattern. 39. The apparatus of clause 38, wherein the at least one processor is configured to set the active NBWP to a bandwidth of the frequency domain hop indicated by the active NBWP hopping pattern in response to the signal disabling the active NBWP hopping pattern. 40. The apparatus of clause 38, wherein the at least one processor is configured to set the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. 41. An apparatus for wireless communication by a base station, comprising:a memory storing computer-executable instructions; andat least one processor coupled to the memory and configured to execute the computer-executable instructions to:configure one or more user equipment (UEs) with one or more narrow bandwidth part (NBWP) hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of a respective UE;determine, for the respective UE, an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs; andcommunicate with the respective UE on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP for the respective UE. 42. The apparatus of clause 41, wherein the at least one processor is configured to transmit a configuration of one or more NBWP hopping patterns that includes a number of hops for each hopping pattern, and a hop duration and a hop frequency offset for each of the number of hops. 43. The apparatus of clause 41 or 42, wherein to configuring the one or more UEs with one or more narrow NBWP hopping patterns for the one or more configured NBWPs, the at least one processor is configured to transmit radio resource control (RRC) signaling that is specific for the one or more UEs, specific for a type of UE, or specific for a cell of the base station. 44. The apparatus of any of clauses 41-43, wherein the at least one processor is configured to transmit an indication of one of the configured NBWP hopping patterns as a target NBWP hopping pattern. 45. The apparatus of clause 44, wherein the one or more NBWP hopping patterns is associated with a NBWP hopping pattern switching delay indicating a minimum time between receiving the indication of the target NBWP hopping pattern at the respective UE and communicating according to the target NBWP hopping pattern. 46. The apparatus of clause 45, wherein the NBWP hopping pattern switching delay is based on one of: a relation between a source NBWP hopping pattern and the target NBWP hopping pattern, a type of the indication of the target NBWP hopping pattern, or a subcarrier spacing of the active NBWP. 47. The apparatus of any of clauses 44-46, wherein the at least one processor is configured to:receive an uplink transmission according to the active NBWP hopping pattern after transmitting the indication of the target NBWP hopping pattern; andswitch the active NBWP hopping pattern to the target NBWP hopping pattern at an agreed event after the uplink transmission. 48. The apparatus of any of clauses 44-47, wherein the indication of the target NBWP hopping pattern is a downlink control information indicating a communication outside of the active NBWP hopping pattern, wherein the at least one processor is configured to switch to the target NBWP hopping pattern for the communication. 49. The apparatus of any of clauses 44-48, wherein the target NBWP hopping pattern is a default hopping pattern including a single hop. 50. The apparatus of any of clauses 41-43, wherein the at least one processor is configured to transmit a signal to enable or disable the active NBWP hopping pattern. 51. The apparatus of clause 50, wherein the at least one processor is configured to set the active NBWP to a bandwidth of the frequency domain hop indicated by the active NBWP hopping pattern in response to the signal disabling the active NBWP hopping pattern. 52. The apparatus of clause 50, wherein the at least one processor is configured to set the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. 53. An apparatus for wireless communication at a user equipment (UE), comprising:means for receiving a configuration of one or more narrow bandwidth part (NBWP) hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of the UE;means for determining an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs; andmeans for communicating on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP. 54. The apparatus of clause 53, wherein the configuration of one or more NBWP hopping patterns includes a number of hops for each hopping pattern, and a hop duration and a hop frequency offset for each of the number of hops. 55. The apparatus of clause 54, wherein the hop frequency offset is measured from one of: a carrier center frequency, a lowest resource element of the active NBWP, or a lowest physical resource block index of the active NBWP. 56. The apparatus of clause 54 or 55, wherein the hop frequency offset is a multiple of a bandwidth of the active NBWP. 57. The apparatus of any of clauses 53-56, wherein the means for receiving the configuration of the one or more NBWP hopping patterns is configured to receive radio resource control (RRC) signaling that is specific for the UE, a type of UE, or a cell. 58. The apparatus of any of clauses 53-57, wherein the means for determining the active NBWP hopping pattern is configured to receive an indication of one of the configured NBWP hopping patterns as a target NBWP hopping pattern. 59. The apparatus of clause 58, wherein the one or more NBWP hopping patterns is associated with a NBWP hopping pattern switching delay indicating a minimum time between receiving the indication of the target NBWP hopping pattern and communicating according to the target NBWP hopping pattern. 60. The apparatus of clause 59, wherein the NBWP hopping pattern switching delay is based on: a relation between a source NBWP hopping pattern and the target NBWP hopping pattern, a type of the indication of the target NBWP hopping pattern, or a subcarrier spacing of the active NBWP, or a combination thereof. 61. The apparatus of any of clauses 58-60, wherein the means for communicating is configured to:transmit an uplink transmission according to the active NBWP hopping pattern; andswitch the active NBWP hopping pattern to the target NBWP hopping pattern at an agreed event after the uplink transmission. 62. The apparatus of any of clauses 58-61, wherein the indication of the target NBWP hopping pattern is a downlink control information (DCI) indicating a communication outside of the active NBWP hopping pattern, wherein the means for communicating is configured to switch to the target NBWP hopping pattern for the communication. 63. The apparatus of any of clauses 58-61, wherein the target NBWP hopping pattern is a default hopping pattern including a single hop. 64. The apparatus of any of clauses 53-57, further comprising means for disabling the active NBWP hopping pattern. 65. The apparatus of clause 64, wherein the means for disabling the active NBWP hopping pattern is configured to set the active NBWP to a bandwidth of the frequency domain hop indicated by the active NBWP hopping pattern in response to the signal disabling the active NBWP hopping pattern. 66. The apparatus of clause 64, wherein the means for disabling the active NBWP hopping pattern is configured to set the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. 67. An apparatus for wireless communication at a base station, comprising:means for configuring one or more user equipment (UEs) with one or more narrow bandwidth part (NBWP) hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of a respective UE;means for determining, for the respective UE, an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs; andmeans for communicating with the respective UE on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP for the respective UE. 68. The apparatus of clause 67, wherein the means for configuring the one or more UEs is configured to transmit a configuration of one or more NBWP hopping patterns that includes a number of hops for each hopping pattern, and a hop duration and a hop frequency offset for each of the number of hops. 69. The apparatus of clause 67 or 68, wherein the means for configuring the one or more UEs with one or more narrow NBWP hopping patterns for the one or more configured NBWPs is configured to transmit radio resource control (RRC) signaling that is specific for the one or more UEs, specific for a type of UE, or specific for a cell of the base station. 70. The apparatus of any of clauses 67-69, wherein the means for determining the active NBWP hopping pattern for the active NBWP of the one or more configured NBWPs is configured to transmit an indication of one of the configured NBWP hopping patterns as a target NBWP hopping pattern. 71. The apparatus of clause 70, wherein the one or more NBWP hopping patterns is associated with a NBWP hopping pattern switching delay indicating a minimum time between receiving the indication of the target NBWP hopping pattern at the respective UE and communicating according to the target NBWP hopping pattern. 72. The apparatus of clause 71, wherein the NBWP hopping pattern switching delay is based on one of: a relation between a source NBWP hopping pattern and the target NBWP hopping pattern, a type of the indication of the target NBWP hopping pattern, or a subcarrier spacing of the active NBWP. 73. The apparatus of any of clauses 70-72, wherein the means for determining the active NBWP hopping pattern for the active NBWP of the one or more configured NBWPs is configured to:receive an uplink transmission according to the active NBWP hopping pattern after transmitting the indication of the target NBWP hopping pattern; andswitch the active NBWP hopping pattern to the target NBWP hopping pattern at an agreed event after the uplink transmission. 74. The apparatus of any of clauses 70-73, wherein the indication of the target NBWP hopping pattern is a downlink control information indicating a communication outside of the active NBWP hopping pattern, wherein the means for communication is configured to switch to the target NBWP hopping pattern for the communication. 75. The apparatus of any of clauses 70-74, wherein the target NBWP hopping pattern is a default hopping pattern including a single hop. 76. The apparatus of any of clauses 67-69, further comprising means for transmitting a signal to disable the active NBWP hopping pattern. 77. The apparatus of clause 76, wherein the means for transmitting a signal to disable the active NBWP hopping pattern is configured to set the active NBWP to a bandwidth of the frequency domain hop indicated by the active NBWP hopping pattern in response to the signal disabling the active NBWP hopping pattern. 78. The apparatus of clause 76, wherein the means for transmitting a signal to disable the active NBWP hopping pattern is configured to set the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. 79. A non-transitory computer-readable medium storing computer-executable instructions that when executed by a processor of a user equipment (UE), cause the processor to:receive a configuration of one or more narrow bandwidth part (NBWP) hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of the UE;determine an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs; andcommunicate on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP. 80. The non-transitory computer-readable medium of clause 79, wherein the configuration of one or more NBWP hopping patterns includes a number of hops for each hopping pattern, and a hop duration and a hop frequency offset for each of the number of hops. 81. The non-transitory computer-readable medium of clause 80, wherein the hop frequency offset is measured from one of: a carrier center frequency, a lowest resource element of the active NBWP, or a lowest physical resource block index of the active NBWP. 82. The non-transitory computer-readable medium of clause 80 or 81, wherein the hop frequency offset is a multiple of a bandwidth of the active NBWP. 83. The non-transitory computer-readable medium of any of clauses 79-82, wherein the code to receive the configuration of the one or more NBWP hopping patterns comprises code to receive radio resource control (RRC) signaling that is specific for the UE, a type of UE, or a cell. 84. The non-transitory computer-readable medium of any of clauses 79-83, wherein the code to determine the active NBWP hopping pattern comprises code to receive an indication of one of the configured NBWP hopping patterns as a target NBWP hopping pattern. 85. The non-transitory computer-readable medium of clause 84, wherein the one or more NBWP hopping patterns is associated with a NBWP hopping pattern switching delay indicating a minimum time between receiving the indication of the target NBWP hopping pattern and communicating according to the target NBWP hopping pattern. 86. The non-transitory computer-readable medium of clause 85, wherein the NBWP hopping pattern switching delay is based on: a relation between a source NBWP hopping pattern and the target NBWP hopping pattern, a type of the indication of the target NBWP hopping pattern, or a subcarrier spacing of the active NBWP, or a combination thereof. 87. The non-transitory computer-readable medium of any of clauses 84-86, further comprising code to:transmit an uplink transmission according to the active NBWP hopping pattern; andswitch the active NBWP hopping pattern to the target NBWP hopping pattern at an agreed event after the uplink transmission. 88. The non-transitory computer-readable medium of any of clauses 84-87, wherein the indication of the target NBWP hopping pattern is a downlink control information (DCI) indicating a communication outside of the active NBWP hopping pattern, further comprising code to switch to the target NBWP hopping pattern for the communication. 89. The non-transitory computer-readable medium of any of clauses 84-88, wherein the target NBWP hopping pattern is a default hopping pattern including a single hop. 90. The non-transitory computer-readable medium of any of clauses 79-83, further comprising code to receive a signal to enable or disable the active NBWP hopping pattern. 91. The non-transitory computer-readable medium of clause 90, further comprising code to set the active NBWP to a bandwidth of the frequency domain hop indicated by the active NBWP hopping pattern in response to the signal disabling the active NBWP hopping pattern. 92. The non-transitory computer-readable medium of clause 90, further comprising code to set the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. 93. A non-transitory computer-readable medium storing computer-executable instructions that when executed by a processor of a base station, cause the processor to:configure one or more user equipment (UEs) with one or more narrow bandwidth part (NBWP) hopping patterns for one or more configured NBWPs, each configured NBWP having a bandwidth less than or equal to a maximum configurable bandwidth of a respective UE;determine, for the respective UE, an active NBWP hopping pattern for an active NBWP of the one or more configured NBWPs; andcommunicate with the respective UE on frequency domain resources for a frequency domain hop indicated by the active NBWP hopping pattern applied to the active NBWP for the respective UE. 94. The non-transitory computer-readable medium of clause 93, wherein the code to configure the one or more UEs comprises code to transmit a configuration of one or more NBWP hopping patterns that includes a number of hops for each hopping pattern, and a hop duration and a hop frequency offset for each of the number of hops. 95. The non-transitory computer-readable medium of clause 93 or 94, wherein the code to configure the one or more UEs with one or more narrow NBWP hopping patterns for the one or more configured NBWPs comprises code to transmit radio resource control (RRC) signaling that is specific for the one or more UEs, specific for a type of UE, or specific for a cell of the base station. 96. The non-transitory computer-readable medium of any of clauses 93-95, wherein the code to determine the active NBWP hopping pattern for the active NBWP of the one or more configured NBWPs comprises code to transmit an indication of one of the configured NBWP hopping patterns as a target NBWP hopping pattern. 97. The non-transitory computer-readable medium of clause 96, wherein the one or more NBWP hopping patterns is associated with a NBWP hopping pattern switching delay indicating a minimum time between receiving the indication of the target NBWP hopping pattern at the respective UE and communicating according to the target NBWP hopping pattern. 98. The non-transitory computer-readable medium of clause 97, wherein the NBWP hopping pattern switching delay is based on one of: a relation between a source NBWP hopping pattern and the target NBWP hopping pattern, a type of the indication of the target NBWP hopping pattern, or a subcarrier spacing of the active NBWP. 99. The non-transitory computer-readable medium of any of clauses 96-98, wherein the code to determine the active NBWP hopping pattern for the active NBWP of the one or more configured NBWPs comprises code to:receive an uplink transmission according to the active NBWP hopping pattern after transmitting the indication of the target NBWP hopping pattern; andswitch the active NBWP hopping pattern to the target NBWP hopping pattern at an agreed event after the uplink transmission. 100. The non-transitory computer-readable medium of any of clauses 96-99, wherein the indication of the target NBWP hopping pattern is a downlink control information indicating a communication outside of the active NBWP hopping pattern, further comprising code to switch to the target NBWP hopping pattern for the communication. 101. The non-transitory computer-readable medium of any of clauses 96-100, wherein the target NBWP hopping pattern is a default hopping pattern including a single hop. 102. The non-transitory computer-readable medium of any of clauses 93-95, further comprising code to transmit a signal to enable or disable the active NBWP hopping pattern. 103. The non-transitory computer-readable medium of clause 102, further comprising code to set the active NBWP to a bandwidth of the frequency domain hop indicated by the active NBWP hopping pattern in response to the signal disabling the active NBWP hopping pattern. 104. The non-transitory computer-readable medium of clause 102, further comprising code to set the active NBWP to a default bandwidth in response to the signal disabling the active NBWP hopping pattern. As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c. The various illustrative logics, logical blocks, modules, circuits and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. The interchangeability of hardware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware or software depends upon the particular application and design constraints imposed on the overall system. The hardware and data processing apparatus used to implement the various illustrative logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes and methods may be performed by circuitry that is specific to a given function. In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and their structural equivalents thereof, or in any combination thereof. Implementations of the subject matter described in this specification also can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on a computer storage media for execution by, or to control the operation of, data processing apparatus. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. The processes of a method or algorithm disclosed herein may be implemented in a processor-executable software module which may reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program from one place to another. A storage media may be any available media that may be accessed by a computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store desired program code in the form of instructions or data structures and that may be accessed by a computer. Also, any connection can be properly termed a computer-readable medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and instructions on a machine readable medium and computer-readable medium, which may be incorporated into a computer program product. Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein. Additionally, a person having ordinary skill in the art will readily appreciate, the terms “upper” and “lower” are sometimes used for ease of describing the figures, and indicate relative positions corresponding to the orientation of the figure on a properly oriented page, and may not reflect the proper orientation of any device as implemented. Certain features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one more example processes in the form of a flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. | 108,773 |
11942984 | DESCRIPTION OF EMBODIMENTS As mentioned above, ultra-wideband (UWB) is a technology that uses a high signal bandwidth, in particular for transmitting digital data over a wide spectrum of frequency bands with very low power. For example, UWB technology may use the frequency spectrum of 3.1 to 10.6 GHz and may feature a high-frequency bandwidth of more than 500 MHz and very short pulse signals, potentially capable of supporting high data rates. The UWB technology enables a high data throughput for communication devices and a high precision for the localization of devices. In particular, UWB technology may be used for so-called ranging operations, i.e. for determining the distance between communicating devices. UWB technology—also referred to as impulse-radio ultra-wideband (IR-UWB)—is a RF communication technology that uses pulses having a short duration for data communication. An important feature of IR-UWB technology is that it can be used for secure and accurate distance measurements between two or more devices. Typical distance measurement methods are the so-called single-sided two-way ranging (SS-TWR) method and the double-sided two-way ranging (DS-TWR) method. Because UWB technology has an accurate distance measurement capability, it may be used to advantage in access systems in which the position of devices should be determined to enable access to an object. For instance, a vehicle access system may comprise a user's smart device (e.g., key fob) and another smart device (e.g., an anchor embedded in the vehicle). To enable access to the vehicle, the user's smart device must have a predefined range, velocity, and/or angle relative to the other smart device. In order to measure these parameters, UWB transceivers may operate in different modes of operation, such as a ranging mode, an angle-of-arrival (AoA) mode and a radar mode. In the ranging mode of operation, frames will typically be exchanged between two devices via at least one antenna on each device, and at least a SS-TWR operation will be carried out (which may also be referred to as a ping-pong operation). In particular, channel impulse responses (CIRs) are estimated on both devices, timestamps will be generated based on the CIRs on both devices, and those timestamps are exchanged. Then, a time of flight (ToF) is calculated based on the timestamps and a range (i.e., a distance) is calculated based on the ToF. Alternatively, a DS-TWR operation may be carried out (which may also be referred to as a ping-pong-ping operation). The AoA mode of operation is similar to the ranging mode, but it involves at least two antennas on one device. In particular, in the AoA mode of operation, two phase values associated with at least two CIRs are calculated on one device. Then, a phase difference of arrival (PDoA) is calculated based on the two phase values, and an AoA is calculated based on the PDoA. In the radar mode of operation, frames are transmitted by at least one device and those frames are received by the same device and/or by one or more other devices. Then, the CIRs are estimated on the device or devices receiving the frames, and the range and/or velocity and/or AoA are calculated based on the estimated CIRs. The skilled person will appreciate that these are non-limiting examples of how the different modes of operation can be implemented. In other words, the modes may be implemented differently, depending on the requirements imposed by the application, for example. Each of these technologies have their own advantages in terms of how accurately the range, velocity, and/or angle of a user's smart device (e.g. key fob) relative to another smart device (e.g., a car anchor) can be determined. For instance, compared to the AoA mode and the radar mode, the ranging mode offers a high accuracy of the measured distance (i.e., of the range). In particular, the AoA mode would only enable a distance resolution if many anchors are used, unless range information is taken into account as well. However, compared to the radar mode, the ranging mode offers only a low accuracy of the velocity measurement, and the AoA mode does not enable a velocity measurement at all. Furthermore, compared to the ranging mode and the radar mode, the AoA mode offers a high accuracy of the angle measurement. In particular, for achieving an angular resolution in the radar mode, many antennas would have to be used. Furthermore, the ranging mode would only enable an angle measurement if multiple anchors are used. Accordingly, since a UWB transceiver typically operates in one of these modes, a sufficiently accurate measurement of all the parameters (i.e., range, velocity and angle) may not be possible. Now a communication device and a corresponding method of operating a communication device will be discussed, which facilitate achieving a sufficiently accurate measurement of the range, velocity and angle of said device relative to an external communication device. FIG.1shows an illustrative embodiment of a communication device100. The communication device100comprises an UWB transceiver102and a processing unit104. The UWB transceiver102is configured to communicate with an external communication device (not shown), which is also UWB-enabled. Furthermore, the processing unit104is configured to switch the UWB transceiver102between different transceiver modes of operation while the UWB transceiver102receives or transmits a data frame. In particular, the different transceiver modes of operation include a ranging mode, an AoA mode and/or a radar mode. By switching the UWB transceiver102between these modes while it receives or transmits a data frame, a sufficiently accurate measurement of the range, velocity and angle of the communication device100relative to the external communication device can be achieved, because the advantages of each of these modes can be exploited. More specifically, ranging, AoA and/or radar operations may be carried out using the same UWB frame exchanged between smart devices, thereby achieving a high accuracy of the measured distance, velocity and angle using a minimal energy or power consumption as well as minimizing the channel occupancy. It is noted that, although the UWB transceiver102and the processing unit104are shown as functionally separate units, they may be combined in single physical component of the communication device100. In one or more embodiments, the data frame includes one or more data sequences which are specifically suited for use in operations performed when the UWB transceiver operates in one of said plurality of different transceiver modes. In this way, the operation of the UWB transceiver in the specific mode for which the data sequence is suited may be facilitated. In particular, data sequences may be specifically suited for use in a particular transceiver mode in the sense that their contents can be processed by the transceiver or operated on by the transceiver when the transceiver operates in said particular mode. In one or more embodiments, the data frame further includes time gaps between said data sequences. In this way, the UWB transceiver may be given enough time to switch to the desired mode of operation. This, in turn, increase the reliability of the transceiver's operation. Furthermore, in one or more embodiments, the data sequences have different lengths. In this way, the performance of the communication device may be increased. For instance, longer data sequences may be used for an improved radar signal-to-noise ratio (SNR). In one or more embodiments, the processing unit is further configured to assign the data sequences to specific antennas within a set of antennas included in the communication device. In this way, specific antennas may be used for the particular modes. For instance, when the UWB transceiver operates a radar mode, a different antenna may be used than when the UWB transceiver operates in the ranging mode or the AoA mode. Furthermore, in one or more embodiments, the processing unit is further configured to assign the data sequences to specific transmission or receiving functions of the communication device. In this way, specific functions may be used for the particular modes. For instance, a radar mode operation may be performed on one receiver followed by a ranging operation on a second receiver, with the first receiver operating in a first receiver mode and the second receiver in a second receiver mode. In one or more embodiments, the processing unit is further configured to change a power level for one or more of said data sequences. In this way, the power consumption of the communication device may be reduced. For instance, the power for radar mode operations may be reduced when a user is close to a vehicle. In a practical implementation, the power level that is changed may be the transmit power. In one or more embodiments, the processing unit is further configured to cause a change of pulse shape of a signal carrying the data frame while said data frame is being received or transmitted. In this way, the pulse shape may be optimized, for instance, to increase the sensitivity of the UWB transceiver when it operates in the ranging mode, such that the time of arrival of messages can be estimated with increased accuracy. Alternatively, the pulse shape may be optimized to increase the radar SNR when the UWB transceiver operates in the radar mode. In one or more embodiments, the processing unit is further configured to perform a correlation operation on the data frame before a binning operation on said data frame when the UWB transceiver operates in the ranging mode or the AoA mode. In this way, the likelihood of a correct operation in the ranging mode or the AoA mode may be increased. In one or more embodiments, the processing unit is further configured to perform a binning operation on the data frame before a correlation operation on said data frame when the UWB transceiver operates in the radar mode. In this way, the complexity of the required hardware may be reduced. In the ranging mode, the received signal originates from the transmitter of another device. Since it is not known when the other device starts transmitting, the correlation should be performed first to determine that the received signal is a valid signal (i.e., that it has a high correlation peak). However, in the radar mode the binning can be performed first, because the received signal originates from the transmitter on the same device and therefore it is known when it has been transmitted. Thus, the binning can be performed straight away with the full analog-to-digital convertor (ADC) resolution, thereby improving the SNR. It is noted that a data frame, in particular the SYNC part, consists of a repetition of multiple symbols (for example, 512 symbols). Each symbol consists of a sequence of pulses (for example, 127 pulses), where a positive pulse represents the bit +1 and a negative pulse the bit −1. A sequence may be obtained from a specific known code (for example, +1, +1, −1, +1, −1, . . . etc.). Binning means that the symbols are averaged (binned), in the sense that the first pulses of each symbol are averaged (i.e., put into the same bin), and the second pulses are averaged as well. Thus, the 512 symbols may be averaged down to 1 “average symbol”, thereby reducing noise. Correlation means that the resulting average symbol, which consists of the series of pulses, is correlated against a predefined pulse sequence, for example against the known code (say +1, +1, −1, +1, −1, . . . etc.) in the example given above. If the sequence of pulses in a received data frame was generated based on the known code, then the correlation will contain a maximum or peak (high correlation); similarly, the correlation will contain no peak (low correlation) if the data frame was generated based on a different code. Since correlation and binning are linear operations, they can easily be interchanged, in the sense that each one of them can precede the other one. In one or more embodiments, the processing unit is further configured to include synchronization information in said data frame when the UWB transceiver operates in the radar mode. In this way, multiple radar devices may be synchronized more easily. Said multiple radar devices may be anchors that can operate in a radar mode, in addition to the ranging mode and the AoA mode. For example, in a child presence detection application, multiple synchronized anchors inside a vehicle (e.g., in the front and back) may be used to detect a breathing child. In one or more embodiments, the processing unit is further configured to initialize the UWB transceiver for use in the radar mode, such that the latter may operate in said radar mode. In a practical implementation, the processing unit is configured to initialize the UWB transceiver using previously obtained configuration data. In this way, the initialization of the UWB transceiver is facilitated. In one or more embodiments, a bi-static radar system comprises a communication device of the kind set forth. In those embodiments, the communication device is configured to act as an initiator, and the system further comprises a plurality of responders, wherein each of said responders comprises a transceiver configured to operate in a predefined sequence of modes of operation. In this way, a UWB-based bi-static radar system can easily be implemented. Furthermore, the predefined sequence of modes of operation in which the transceivers of the responder can operate may be configured by the communication device acting as an initiator. In this way, said predefined sequence can easily be configured, which in turn facilitates properly tuning the bi-static radar system. In a practical implementation of the system, the responders are configured to toggle between a ranging mode and a radar mode in a time-multiplexed manner. FIG.2shows an illustrative embodiment of a method200of operating a communication device. The method200comprises the following steps. At202, a UWB transceiver comprised in a communication device communicates with an external communication device. Furthermore, at204, a processing unit comprised in the communication device switches the UWB transceiver between different transceiver modes of operation while the UWB transceiver receives or transmits a data frame. In particular, the different transceiver modes of operation include a ranging mode, an AoA mode and/or a radar mode. The method200facilitates achieving a sufficiently accurate measurement of the range, velocity and angle of the communication device relative to an external communication device. UWB-enabled communication devices may act as an initiator in a communication session, or as a responder. More specifically, an initiator is configured to initiate the communication with another communication device, and if the latter device responds to the initiator, then it is acting as a responder. Thus, the presently disclosed communication device may either be an initiator or a responder in a communication session. Accordingly, the mode of operation of a UWB transceiver of an initiator or a responder (or both) may be changed between a ranging mode, an AoA mode and/or a radar mode during any part of the frame which is exchanged between the initiator and the responder. The addition of the radar mode to the ranging mode and the AoA mode may effectively be supported by making the hardware reconfigurable, in particular by interchanging the binning and correlation operation within a data frame. The different modes of operation of the UWB transceiver may have the following properties. In the ranging mode, either the transmitter (TX) or the receiver (RX) of the UWB transceiver is active. Furthermore, a correlation operation is performed before a binning operation. Also, in the ranging mode, a single fixed antenna may be used for the communication. In the AoA mode, either the TX or RX is active. Furthermore, the correlation operation is performed before the binning operation. Also, in the AoA mode, the antenna used for the communication may be switched. In the radar mode, both the TX and RX are simultaneously active. Furthermore, a self-interference cancellation (SIC) function of the TX may be active. Furthermore, the binning operation is performed before the correlation operation, in order to achieve a higher signal-to-noise ratio. Also, in the radar mode, the antenna used for the communication may be switched. By using such a reconfigurable hardware a cost-effective solution may be realized. FIG.3shows an illustrative embodiment of a data frame300. In particular, to facilitate switching the UWB transceiver between the different modes of operation, the data frame300may have a predefined structure as shown inFIG.3. The data frame300includes a synchronization (SYNC) pattern302, start-of-frame (SFD) delimiter304, a plurality of data sequences306,308,310and a physical layer (PHY) service data unit (PSDU)312. It is noted that the IEEE 802.15.4 standard already defines the SYNC pattern302, the SFD304and the PSDU312. The plurality of data sequences SEQ1, . . . N,306,308,310are inserted to facilitate switching the UWB transceiver between the different modes of operation. Each of said data sequences SEQ1, . . . N,306,308,310is specifically suited for use in operations performed when the UWB transceiver operates in one of said modes. For instance, these sequences may include a pseudo-random scrambled timestamp sequence (STS) as currently defined in the standard IEEE 802.15.4, periodic radar SYNC sequences which are specific to the radar mode, to improve system performance parameters such as the SNR and the velocity resolution. In the latter case, an IEEE SYNC frame with 1024 symbols would be a suitable implementation. The skilled person will appreciate that different techniques may be applied for triggering the processing unit to switch the UWB transceiver to another mode. For instance, a data word may be added at the end of each SEQ, based on which the particular mode for the next SEQ is selected. Alternatively, the device may be configured with a sequence of modes, including the duration of each SEQ, before the UWB session is started. It is noted that time gaps may be provided between the sequences, such that the UWB transceiver can be reconfigured to the desired mode. Alternatively, some sequences may be skipped during a frame exchange, such that the UWB transceiver has enough time to switch to another mode. Furthermore, the sequences may have varying lengths, so that system performance can be optimized. For instance, longer sequences may be used in order to improve the radar SNR. Furthermore, arbitrary sequences may be assigned to specific antennas. For example, a designated antenna may be used for the radar mode, which is different from the antenna used for the ranging mode and the AoA mode. In addition, the pulse shape may be changed during operation. For instance, the pulse shape may be changed in such a way that the time of arrival of messages can be estimated with increased accuracy in the ranging mode. Alternatively, as mentioned above, the pulse shape may be optimized to increase the radar SNR when the UWB transceiver operates in the radar mode. Now some examples will be described, which are based on the single-sided two-way ranging (SS-TWR) method. It is noted that the ranging mode is not limited to single-sided two-way ranging. The skilled person will appreciate that the ranging mode may also use the doubled-sided two-way ranging (DS-TWR) method, for example. The examples show details of the data frame content as well as the reconfiguration of the respective transmitters and receiver. FIG.4shows an illustrative embodiment of a transceiver reconfiguration400. In this embodiment, both an initiator402and a responder404contain a transceiver chip which can be configured or reconfigured to operate in predefined transceiver modes of operation. In particular, it is shown how the ranging mode, AoA mode and radar mode can be used during a UWB frame exchange between the initiator402and the responder404. The initiator402may be a smart key fob and the responder404may be a car anchor, for example. First, the initiator402transmits a POLL frame. When doing so, the transceiver chip of the initiator402is configured to operate in the ranging mode. In this example, the operation in the ranging mode means that the transmission function of the chip is ON in order to transmit the POLL frame, and that its receiver function is OFF. Subsequently, the responder404receives the POLL frame transmitted by the initiator402. When doing so, its transceiver chip is configured to operate in the ranging mode and/or the AoA mode. In this example, this means that the transmission function of the chip is OFF, and that its receiver function is configured to operate in a first receiver mode (the details of which are described below). It is noted that the receiver function may compute the AoA. Next, the responder404transmits a response (RESP) frame. When doing so, its transceiver chip is configured to operate in the radar mode. In this example, this means that the transmission function (TX) of the chip is ON in order to transmit the RESP frame, and that its receiver function is ON to receive the reflection of the data sequences SEQ1, . . . , N. Furthermore, it means that the receiver function is configured to operate in a second receiver mode (the details of which are described below), and that the SIC function may be ON to cancel its own TX during reception. Finally, the initiator402receives the RESP frame transmitted by responder404. When doing so, its transceiver chip is still configured to operate in the ranging mode. During reception of a frame, the operation in the ranging mode means that the transmission function of the chip is OFF and that its receiver function is ON in order to receive the frame, wherein the data sequences SEQ1, . . . , N are ignored. It is noted that the PSDU shown inFIG.3is not shown inFIG.4for the sake of simplicity, but it would be transmitted in the RESP frame as the PSDU contains the timestamps needed for the range determination. Thus, the RX within initiator402would only ignore SEQ1, . . . N but not the PSDU. Furthermore, it is noted that in case of secure ranging, SEQ1is an STS which is processed by the initiator402. FIG.5shows illustrative embodiments of receiver modes of operation500. As mentioned above, the receiver function of a transceiver may be configured to operate in a first receiver mode502and in a second receiver mode504. In the first receiver mode502, a correlation operation is performed on the output of an analog front-end (AFE) before a binning operation, to allow frame acquisition. For example, only a few bits output by an analog-to-digital converter included in said AFE may be used for the correlation, in order to save power. In the second receiver mode504, a binning operation is performed before a correlation operation. This typically consumes more power, but the signal-to-noise ratio can be increased. Furthermore, the correlation can be performed by a digital signal processor (DSP) to reduce the hardware complexity. It is noted that a full-bit correlator would be area-consuming. FIG.6shows an illustrative embodiment of a bi-static radar operation600with multiple responders. In a bi-static radar operation, the transmitter and receiver are physically separated by a sufficient distance. For instance, vehicle anchors may operate in a bi-static mode, with one anchor operating in a TX mode and the other operating in a RX mode. In particular, in this embodiment, an initiator602communicates with a plurality of responders604,606,608. The transceivers of the respective responders604,606,608operate in a predefined sequence of modes of operation610which may be configured by the initiator602. In particular, it is shown how a bi-static radar operation with multiple responders can work using only one SS-TWR frame exchange. The initial transmission of a POLL frame and its reception by a single responder has been explained with reference toFIG.4. In this example, the POLL frame is received by multiple responders604,606,608. The responders604,606,608would normally respond in a time-multiplexed manner, which would be configured in advance by the initiator602. More specifically, in the embodiment shown inFIG.6, the responders604,606,608toggle between a ranging mode and a radar mode in a time-multiplexed manner, and the SYNC part of the frame is used for radar. Initially, RESPONDER1604operates in the ranging mode with its TX sending back a frame (SYNC, SFD, STS etc.) to the initiator602, and its RX is OFF. Furthermore, RESPONDER2, . . . , N606,608operate in the radar mode, and the corresponding receivers RX2, . . . , N receive the SYNC part of RESPONDER1604which is reflected by a target object, while the corresponding transmitters TX2, . . . , N are OFF. Next, RESPONDER2606operates in the ranging mode while RESPONDER1,3, . . . , N604,608operate in the radar mode, with the former sending back its frame to the initiator602and the latter receiving the SYNC part as reflected by the target object. This process is repeated for each of the N responders. It is noted that the order of responding in the ranging mode may be different from the above-described order. For example, RESPONDER2606may be the first responder that operates in the ranging mode. Furthermore, not all responders need to be switched into the radar mode at any particular time. For example, the RX of RESPONDERN608may only listen to TX of RESPONDER1604, but not of the other responders. Furthermore, it is noted that the initiator602may ignore the sequence SEQ and merely sequentially receive the frames RESP1-N. Furthermore, it is noted that this scheme may be extended to cover any combination of responders transmitting and receiving the radar SEQ (for example, also to a multi-static radar operation). It is noted that the PSDU shown inFIG.3is not shown inFIG.6for the sake of simplicity, but it would be transmitted in the RESP1, RESP2, RESPN frames as the PSDU contains the timestamps needed for the range determination. As mentioned above, the processing unit may be configured to include synchronization information in the data frame when the UWB transceiver operates in the radar mode. In this way, multiple radar devices may be synchronized more easily. For example, the XO oscillators (i.e., clocks) and carrier frequency offset of multiple radar devices may be synchronized using a current radar frame or a preceding ranging or radar frame. Furthermore, the processing unit may be configured to initialize the UWB transceiver for use in the radar mode, in particular by using previously obtained configuration data. In this way, the initialization of the UWB transceiver is facilitated. For example, when a radar operation is executed within a frame exchange, the radar configuration (e.g., the number of symbols) may be shared beforehand via a controller area network (CAN bus) or via the initiator, which would then act as a master. The systems and methods described herein may at least partially be embodied by a computer program or a plurality of computer programs, which may exist in a variety of forms both active and inactive in a single computer system or across multiple computer systems. For example, they may exist as software program(s) comprised of program instructions in source code, object code, executable code or other formats for performing some of the steps. Any of the above may be embodied on a computer-readable medium, which may include storage devices and signals, in compressed or uncompressed form. As used herein, the term “computer” refers to any electronic device comprising a processor, such as a general-purpose central processing unit (CPU), a specific-purpose processor or a microcontroller. A computer is capable of receiving data (an input), of performing a sequence of predetermined operations thereupon, and of producing thereby a result in the form of information or signals (an output). Depending on the context, the term “computer” will mean either a processor in particular or more generally a processor in association with an assemblage of interrelated elements contained within a single case or housing. The term “processor” or “processing unit” refers to a data processing circuit that may be a microprocessor, a co-processor, a microcontroller, a microcomputer, a central processing unit, a field programmable gate array (FPGA), a programmable logic circuit, and/or any circuit that manipulates signals (analog or digital) based on operational instructions that are stored in a memory. The term “memory” refers to a storage circuit or multiple storage circuits such as read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, Flash memory, cache memory, and/or any circuit that stores digital information. As used herein, a “computer-readable medium” or “storage medium” may be any means that can contain, store, communicate, propagate, or transport a computer program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (non-exhaustive list) of the computer-readable medium may include the following: an electrical connection having one or more wires, a portable computer diskette, a random-access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CDROM), a digital versatile disc (DVD), a Blu-ray disc (BD), and a memory card. It is noted that the embodiments above have been described with reference to different subject-matters. In particular, some embodiments may have been described with reference to method-type claims whereas other embodiments may have been described with reference to apparatus-type claims. However, a person skilled in the art will gather from the above that, unless otherwise indicated, in addition to any combination of features belonging to one type of subject-matter also any combination of features relating to different subject-matters, in particular a combination of features of the method-type claims and features of the apparatus-type claims, is considered to be disclosed with this document. Furthermore, it is noted that the drawings are schematic. In different drawings, similar or identical elements are provided with the same reference signs. Furthermore, it is noted that in an effort to provide a concise description of the illustrative embodiments, implementation details which fall into the customary practice of the skilled person may not have been described. It should be appreciated that in the development of any such implementation, as in any engineering or design project, numerous implementation-specific decisions must be made in order to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill. Finally, it is noted that the skilled person will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference sign placed between parentheses shall not be construed as limiting the claim. The word “comprise(s)” or “comprising” does not exclude the presence of elements or steps other than those listed in a claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. Measures recited in the claims may be implemented by means of hardware comprising several distinct elements and/or by means of a suitably programmed processor. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. LIST OF REFERENCE SIGNS 100communication device102UWB transceiver104processing unit200method of operating a communication device202communicating, by a UWB transceiver comprised in a communication device, with an external communication device204causing, by a processing unit comprised in the communication device, the UWB transceiver to switch between different transceiver modes of operation while the UWB transceiver receives or transmits a data frame, wherein the different transceiver modes of operation include a ranging mode, an angle of arrival mode and/or a radar mode300data frame302synchronization (SYNC) pattern304start-of-frame delimiter (SFD)306sequence1308sequence2310sequence N312PHY service data unit (PSDU)400transceiver reconfiguration402initiator404responder500receiver modes of operation502receiver mode1504receiver mode2600bi-static radar operation with multiple responders602initiator604responder1606responder2608responder N610transceiver mode of operation | 33,526 |
11942985 | DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Clearly, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts or inventive steps fall within the protection scope of the present invention. According to the present invention, a 10G rate OLT terminal transceiver integrated chip based on XGSPON and DFB laser is provided. The fast recovery circuit in the receiver (RX) within the chip frame, the amplitude detection of the electrical signal transmitted from the TIA, the switchable start-stop clock data recovery (CDR) module in the transmitter (TX), the laser driver which is capable of driving of the DFB laser, and the modular and configurable digital part (Digital) are the keys to the realization of the present invention. The clock data recovery module CDR in the continuous mode transmitter TX can be activated or stopped according to the quality of actual transmission eye diagram, and the DFB laser, which is much cheaper than the EML laser, is used to emit and transmit data. In the burst mode receiver RX, the amplitude detection of the electrical signal transmitted by the upper-level TIA can be performed, and the output driver (CML Buffer) can be turned on after meeting the requirements to transmit data. In order to meet the strict timing sequence requirements of the XGSPON protocol, a fast recovery circuit is added to the periphery or inside of the chip to discharge the charges in the AC coupling capacitor to achieve multi-packet transmission without interfering with each other. The digital control unit Digital, communicates with the host through two signal lines SCL and SDA to optimize data transmission quality of RX and TX inside the OLT transceiver integrated chip. It should be noted that as long as there is no conflict, the different embodiments or the different features in different embodiments can be combined with each other. The present invention is further described in conjunction with accompanying drawings and specific embodiment as follows, which is not intended to be limiting. Embodiment 1: This embodiment is described below with reference toFIGS.1-4. According to this embodiment, a 10G rate OLT terminal transceiver integrated chip based on XGSPON and DFB laser comprises: a burst mode receiver RX, a continuous mode transmitter TX and a digital control unit DIGIITAL. A burst transimpedance amplifier TIA processes an optical signal from each ONU client into an electrical signal, the burst mode receiver RX amplifies the electrical signal and processes amplitude detection of the electrical signal, judges if an amplitude of the electrical signal meets the threshold requirements, and outputs a judgment result of the electrical signal to a host, and comprises a fast recovery module to discharge charges in an AC coupling capacitor to achieve multi-packet transmission without mutual interference, thereby meeting the timing sequence requirement of the XGSPON protocol. The continuous mode transmitter TX receives the electrical signal attenuated by the PCB board, and according to the degree of attenuation, selects the bypass BYPASS path for transmission or outputs the signal after the signal quality is improved through the clock data recovery CDR path. The digital control unit DIGIITAL communicates with the host, and is arranged to provide control signals for the burst mode receiver RX and the continuous mode transmitter TX. This embodiment is equipped with a DFB laser and its peripheral circuit comprises resistors R1-R6, capacitors C1-C7, inductors L1-L7and monitoring diode MPD, wherein a monitoring current is led to the chip MPD pin through the monitoring diode MPD, which is shown inFIG.1of the drawings. The burst mode receiver RX comprises a pre-amplifier Pre_Amplifier, a level detector Level Detector, a 10G burst-mode limiting amplifier BurstLA_10G, a current mode logic output buffer CML Buffer, a signal detection output buffer Buffer and a fast recovery module; a non-inverting input and an inverting input of the pre-amplifier Pre_Amplifier are arranged to receive a burst data packet from the burst transimpedance amplifier TIA; the fast recovery module is arranged to provide a fast recovery circuit to ensure the timing sequence is correct, so that physical collision of two burst data packets before and after is avoided; an output terminal of the pre-amplifier Pre_Amplifier is simultaneously connected to an input terminal of the 10G burst-mode limiting amplifier BurstLA_10G and an input terminal of the level detector LEVEL DETECTOR; an output terminal of the 10G burst-mode limiting amplifier BurstLA_10G is connected to an input terminal of the current mode logic output buffer CML Buffer; an output terminal of the level detector Level Detector is simultaneously connected to an input terminal of the signal detection output buffer Buffer and an on/off control terminal of the current mode logic output buffer CML Buffer; two output terminals of the current mode logic output buffer CML Buffer are connected to output pins RX_OUTP and RX_OUTN of the burst mode receiver RX respectively; an output of the signal detection output buffer Buffer is connected to a chip pin RX_SD, and the burst mode receiver RX sends a detection result to the host through the chip pin RX_SD. When a reset signal is received by a chip pin LA_RESET from the host, the chip sends a feedback signal to the host through the pin RX_SD. The fast recovery module is built-in or external to the burst mode receiver RX. Referring toFIG.1andFIG.2of the drawings, the fast recovery module is external to the burst mode receiver RX. The fast recovery module comprises resistors R7, R8, R9, R10, and switches S1, S2; a non-inverting output terminal of the burst transimpedance amplifier TIA is connected to one end of the resistor R10of the fast recovery module, one end of the resistor R8of the fast recovery module and a non-inverting input pin RX_INP of the chip through an AC coupling capacitor C9; an inverting output terminal of the burst transimpedance amplifier TIA is connected to one end of the resistor R9and one end of the resistor R7of the fast recovery module, and an inverting input pin RX_INN of the chip through the AC coupling capacitor C8; a non-inverting input pin RX_INP of the chip and an inverting input pin RX_INN of the chip are connected to a non-inverting input terminal and an inverting input terminal of the pre-amplifier Pre_Amplifier respectively; another end of the resistor R10is connected to one end of the switch S1; another end of the resistor R9is connected to one end of the switch S2; control ends of the switches S1and S2are connected to a reset signal line LA_RESET simultaneously; and a reference voltage pin Vref of the burst mode receiver RX is simultaneously connected to another end of the resistor R7, another end of the R8, another end of the switch S1and another end of the switch S2. Referring toFIG.3andFIG.4of the drawings, the fast recovery module is built in the burst mode receiver RX. The fast recovery module comprises resistors R7, R8, R9, R10, and switches S1, S2; a non-inverting output terminal and an inverting output terminal of the burst transimpedance amplifier TIA are connected to a non-inverting input pin RX_INP and an inverting input pin RX_INN of the chip through an AC coupling capacitor C9and C8; inside the chip, the non-inverting input pin RX_INP of the chip is connected to one end of the resistor R10, one end of the resistor R8and the non-inverting input terminal of the pre-amplifier Pre_Amplifier; the inverting input pin RX_INN of the chip is connected to one end of the resistor R9, one end of the resistor R7and the inverting input of the pre-amplifier Pre_Amplifier; another end of the resistor R10is connected to one end of the switch S1; another end of the resistor R9is connected to one end of the switch S2; control ends of the switches S1and S2are connected to a reset signal line LA_RESET of the chip simultaneously; a reference voltage Vref of the burst mode receiver RX is simultaneously connected to another end of the resistor R7, another end of the R8, another end of the switch S1and another end of the switch S2. When the built-in configuration is used, the fast recovery module is built into the transceiver integrated chip, which has the advantage of reducing the footprint of the peripheral circuit and saving costs. The working principles of the burst mode receiver RX: The OLT transceiver integrated chip located in the central office corresponds to multiple ONUs at the user end, therefore the receiving terminal RX of the OLT transceiver integrated chip needs to receive bursts of electrical signals of different amplitudes from the ONU terminal (burst TIA has converted optical signals of different amplitudes into electrical signals and then sent them to the limiting amplifier LA of RX). The pre-amplifier Pre-Amplifier enhances (pre-emphasizes) the attenuated electrical signal output by the upper TIA, and then divides the electrical signal into two paths. One of the path is passing to the LA_10G limiting amplifier to amplify the signal to the limited state. In order to achieve the 10G rate, the 10G limiting amplifier requires a variety of methods to increase the rate bandwidth: such as inductive peaking, capacitor degeneracy, or using bipolar transistors with high cut-off frequencies at key signal path nodes. The other path is passing to the signal detection module (level detector Level Detector). The module detects the amplitude of the signal (in order to meet the XGSPON protocol, the chip is simplified and rate detection, which is difficult to design, is not processed). Only when the amplitude meets the threshold requirement, the signal detection module outputs a command to turn on the output driver stage CML Buffer, and at the same time transmits the judgment result to the host which is external to the chip (through the RX_SD pin). In order to meet the strict timing sequence requirement protocol of XGSPON, a fast recovery circuit must be added in the RX part, so that after the burst LA completes the reception of a data packet, it can immediately return to the normal state, and then continue to receive the next burst data packet such that the physical collision of two adjacent data packets can be avoided. The chip pin Vref provides a DC operating point for the two input terminals of LA, and also discharges the charge of the capacitors C8and C9which are connected to the two input terminals of LA. When the reset signal LA_RESET is 0, the switches S1and S2are turned off, and the charges on the capacitor is slowly discharged to the ground through the resistor R7=R8(large resistance value). When the reset signal LA_RESET is 1, the switches S1and S2are turned on, and the charges on the capacitor is quickly discharged to the ground through the resistor R9=R10(small resistance value) so as to achieve the quickly rebuilding of the DC operating point. By adjusting the resistance of resistors R7, R8, R9, R10, the performance requirements and timing sequence requirements of RX are met. The voltage value of Vref can be artificially set through the two communication signal lines of the digital part. The reset signal LA_RESET is given by the host. The continuous mode transmitter TX comprises an input buffer Input Buffer, a bypass ByPass, a clock data recovery CDR, a DFB laser driver, a bias current control unit and a modulation current control unit, one of the bypass ByPass or the clock data recovery CDR path is selected to activate; an attenuated signal formed by an original high-speed electrical signal passing through a metal trace on a PCB is connected to the input buffer Input Buffer through the chip pins TX_INP and TX_INN, then the input buffer Input Buffer transmits the attenuated signal to the input terminal of the DFB laser driver along the activated path; a bias current output terminal of the bias current control unit is connected to the chip pin BIAS, and provides a bias current for the DFB laser; a modulation current output terminal of the modulation current control unit is connected to a modulation current input terminal of the DFB laser driver; an output terminal of the DFB laser driver is connected to the chip pins TX_OUTP and TX_OUTN, and the DFB laser driver provides modulation current for the DFB laser; the host sends commands to the chip to turn off the bias current and the modulation current through the chip pin TXDIS to turn off the continuous mode transmitter TX. The activation of one of the bypass ByPass or the clock data recovery CDR path is controlled by digital control unit Digital according to an external command. The activation of one of the bypass ByPass or the clock data recovery CDR path is controlled through the host automatically switching the channel by itself, when the rate is below 8G, the signal attenuation is not serious, and the bypass ByPass is activated; when the rate is 8G-14G, the signal attenuation is serious, and the clock data recovery CDR path is activated under the control of the host. The working principles of continuous mode transmitter TX: The TX part of the main channel is capable of receiving and processing continuous electrical signal data streams with a rate of 1-14 Gbps. The original high-speed electrical signal is attenuated after passing through the metal traces on the PCB, resulting in signal errors. In order to solve the problem of high-speed signal attenuation, CDR (clock data recovery) is added inside the TX to improve the quality of high-speed signal. If the attenuation of the high-speed signal is not serious, it can also be transmitted directly from the ByPass path. DFB type lasers support long-distance (>10 km) data transmission, so TX needs to provide a driver with high output current 10G DFB DRIVER. The bias current Bias and modulation current Modulation of the laser need to adjust the current in real time according to the ambient temperature, the luminous efficiency of the laser, and the aging of the laser. Therefore, the Current Control module cooperates with the APC optical power control module to feed back the laser luminous power information collected by the monitoring photodiode MPD, and configure a reasonable current value through the data writing of the digital part. The activation of one of the bypass ByPass or the clock data recovery CDR path includes the following two configurations: Type 1: Pre-judgment, and then write the external command into the digital control unit Digital through the SAD pin according to the judgment result, and the digital control unit Digital sends the selection command to the TX. Pre-judgment refers to the selection of the bypass ByPass path or the clock data recovery CDR path, which is judged based on the attenuation of the signal measured by the chip. Before using the chip, first detect the attenuated signal generated after passing through the metal wiring on the PCB board, and check whether the quality of the TX output eye diagram meets the protocol standard. If it meets the standard, it will be transmitted from bypass ByPass, and if it does not meet the standard, CDR will be turned on to optimize the signal quality. Type 2: The host switches channels by itself. When the rate is below 8G, the signal attenuation is not serious, and ByPass is activated; when the rate is 8G-14G, the signal attenuation is serious, and the host controls the clock data recovery CDR path to optimize signal quality. The digital control unit Digital comprises a register digital core, an analog-to-digital converter ADC, a I2C slave and temperature sensor Temp Sensor; an output terminal of the temperature sensor Temp Sensor is connected to a temperature signal input terminal of the register digital core through the analog-to-digital converter ADC; an input terminal of I2C slave is connected to a pin SCL of a clock chip; an input and output ports of I2C slave are connected to a pin SDA of an external command chip; an output terminal of I2C slave is connected to an external command input terminal of the register digital core, and the register digital core controls a path selection of the continuous mode transmitter TX; the register digital core also realizes a configuration of the burst mode receiver RX and the continuous mode transmitter TX through a control port. The control port of the burst mode receiver RX in the digital control unit Digital comprises an eye cross point adjustment control port CPA, an output swing control port SW CTRL, an output polarity inversion control port POL CTRL, and a signal loss control port LOS CTRL. The control port of the continuous mode transmitter TX in the digital control unit Digital comprises an optical power control port APC, an eye cross point adjustment control port CPA, a jitter optimization control port EQ, an eye diagram optimization control port EO and an output polarity inversion control port POL CTRL; an input terminal of the optical power control port APC is connected to a chip pin MPD for monitoring current. The working principle of the digital control unit Digital: The digital control unit Digital can complete the internal configuration of the burst mode receiver RX and the continuous mode transmitter TX. The functions configurable in the burst mode receiver RX are: eye diagram cross point adjustment CPA, output swing control SW_CTRL, output polarity inversion POL_CTRL, signal loss threshold setting and mode selection LOS_CTRL, etc. The configurable functions in the continuous mode transmitter TX are: laser optical power control APC, eye diagram intersection optimization CPA, jitter optimization EQ, eye diagram optimization EO, output polarity inversion POL_CTRL, etc. The built-in high-precision multi-bit ADC converts the ambient temperature collected by the temperature sensor Temp Sensor into a digital value and then reads it to the outside through the I2C slave data signal line SDA. ADC can also read other quantifiable data to the outside through I2C slave, such as monitoring current value, bias current value, modulation current value, etc. Users can also write digital quantities to the register digital core inside the chip through the master I2C outside the chip to optimize the transmission performance of the integrated transceiver chip. The digital control unit also adds a digital diagnostics monitoring (DDM) function to monitor light level, chip temperature, power supply voltage and other data in real time. According to the present invention, the 10G rate OLT terminal transceiver integrated chip based on XGSPON and DFB laser uses amplitude detection at the 10G burst receiving terminal RX to simultaneously judge whether the input signal meets the requirements of the transmission protocol, and can have a built-in or external fast recovery circuit, which can allow the AC coupling capacitor to quickly discharge the charge and establish a stable working point for the next data packet reception. A high-speed clock data recovery unit CDR is built in the 10G continuous transmitting terminal TX to ensure the integrity of the electrical signal to be transmitted, which is conducive to the laser emitting high-quality light. In order to drive long-distance high-speed DFB lasers, the built-in high-speed laser driver cooperates with the bias current and modulation current modules to output large current. In the digital control unit, there are built-in multi-bit registers, high-precision ADC and I2C slave. All kinds of key data are transmitted to the outside through the SDA signal line, and the digital quantities of related modules with optimized performance can also be written through this line to ensure the high quality of the receiving signal and sending model of the transceiver integrated chip. The DDM module reads the key working information in the chip in real time, and when the threshold is exceeded, the integrated transceiver chip can be turned off to avoid damage to the chip and laser. Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It shall be understood that different dependent claims and features described herein may be combined in a different way than that described in the original claims. It should also be appreciated that features described in connection with individual embodiments can be used in other described embodiments. | 21,208 |
11942986 | DETAILED DESCRIPTION For simplicity and illustrative purposes, the present disclosure is described by referring mainly to examples thereof. In the following description, details are set forth in order to provide an understanding of the present disclosure. It will be readily apparent however, that the present disclosure may be practiced without limitation to these details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure. Throughout the present disclosure, the terms “a” and “an” are intended to denote at least one of a particular element. As used herein, the term “includes” means includes but not limited to, the term “including” means including but not limited to. The term “based on” means based at least in part on. According to examples of the present disclosure, an optical time-domain reflectometer (OTDR) including a channel checker (hereinafter also referred to as “channel checker OTDR”) may utilize a tunable narrow linewidth laser. In this regard, the channel checker OTDR may include combined channel checker and OTDR functionality for dense wavelength division multiplexing (DWDM) network testing. The DWDM OTDR may utilize narrow linewidth lasers that may also be utilized for coherent detection of live traffic on a test port. The channel checker OTDR may mix a small portion of the signal from a device under test (e.g., an optical fiber) with a portion of a tunable laser acting as a local oscillator, and detect the beat terms with a high speed photodiode. A depolarizer at an output of the laser may reduce polarization dependent noises on OTDR traces, and serve as a means to reduce the strong polarization dependency of coherent detection. In this regard, the coherent detection may provide additional sensitivity and selectivity against direct detection. In some examples, a complete polarization diversity reception may either be used for reflectometric purposes, for a channel checker, or even for a fully featured High Resolution Optical Spectrum Analyzer (HROSA). A channel checker may display a power reading present at predefined wavelength ranges, corresponding to channels on the WDM grid, whereas the HROSA may display the spectrum with fine details. With respect to OTDRs generally, in some applications, both an OTDR and a spectrum analyzer/channel checker may be utilized, with both devices operating in the same wavelength bands. In one example, a tunable filter may be utilized to provide for OTDR testing by cleaning out the spectrum of a laser. In another example, for OTDR testing, alien signals present on a fiber may be filtered, directing only the OTDR laser wavelength toward the receiver. In a further example, with respect to Optical Spectrum Analyzer (OSA) channel checker functionality, any wavelength coming from the CUT may be selectively filtered, which, combined with an OTDR Avalanche Photodiode (APD) or an additional p-i-n (PIN) photodiode, provides the basis for a spectral analysis. The losses of the tunable filter (˜3-4 dBs) may directly affect the OTDR dynamic range, and in this regard, it is technically challenging to implement a channel checker with low loss, and to implement a 50 GHz grid capability for the OSA in a compact solution. The channel checker OTDR disclosed herein may overcome at least the aforementioned technical challenges by including a channel checker without impacting the performance and cost of the channel checker OTDR, as well as achieving a 50 GHz grid capability. According to examples disclosed herein, for the channel checker OTDR, only a relatively small percentage of signals may be extracted from a test port to thus limit losses associated with the OTDR. According to examples disclosed herein, for the channel checker OTDR, a coherent detection may provide high sensitivity. According to examples disclosed herein, for the channel checker OTDR, the coherent detection may provide high spectral resolution, for example, at 50 GHZ. In some examples, the channel checker OTDR may scan two laser beams over a wavelength range with a maintained frequency shift between the two laser beams. For example, the two laser beams may be set with an offset frequency shift. According to an example, the range of the offset frequency shift for the Rayleigh trace determination may include frequencies between approximately 100.0 KHz to approximately 1 GHz. For example, the offset frequency shift may be set at approximately 240 MHz. According to an example, the wavelength range may include a range of 10's of GHz (e.g., 15 GHz) to several THz (e.g., 50 THz). A first laser beam may be modulated with an external modulator. The modulated laser beam may be injected into the DUT. For example, the DUT may include an optical fiber. A backscattered signal from the DUT may be acquired by the coherent receiver. The backscattered signal may be mixed with the second laser beam that is used as a local oscillator. A sensor controller may perform various functions as disclosed herein with respect to Rayleigh trace determination. For example, the sensor controller may perform averaging of repeated acquisitions while scanning the two laser beams in order to reduce coherent fading noises. The coherent detection at the predetermined offset frequency shift yields the Rayleigh trace. The Rayleigh trace may be used to identify anomalies in transmission of a signal along the DUT. FIG.1illustrates an architecture of an OTDR including a channel checker (hereinafter referred to as “channel checker OTDR100”), according to an example of the present disclosure. Referring toFIG.1, the channel checker OTDR100may include laser102. As shown inFIG.1(and similarly inFIGS.2and3), the modulator may be optional in case of a direct pulsing of the laser diode, or be an Acousto-Optic-Modulator, a Semiconductor Optical Amplifier (SOA), an Electro-Optic-Modulator, or an Electro-Absorption-Modulator, with a pulsed drive. In some examples, the laser102may include a CW laser with a pulsed SOA. The laser102may inject a laser beam into Polarization Maintaining (PM) fiber104, which may be input to a coupler106. The coupler106may be a 90/10 coupler. The coupler106may be optically connected to a coupler108, which may be a 50/50 coupler. The coupler108may receive input from a photodiode110, which may receive input from a radio frequency (RF) detector112. The photodiode110may be a 10-25 GHz photodiode. Outputs of the coupler108may be fed to coupler106, and to a coupler114, which may be a 99/1 coupler. The coupler114may receive input from a circulator116, which may be optically connected to an avalanche photodiode (APD)118. Output of the coupler114may be connected to a connector120, which may be connected to a device under test (DUT) such as an optical fiber (not shown). In the OTDR mode, the light pulse generated by the laser102may be launched with polarization state at 45° with respect to the PM fiber104Eigen axis. As the laser102wavelength is scanned, the polarization state at the output of the PM fiber104will rotate, and the polarization dependent loss related errors may be reduced. The largest portion of the light pulse may then be directed towards the fiber under test plugged at connector120(e.g., path through the coupler106, circulator116and coupler114). The backscattered light from fiber under test may then be directed to the APD118by means of the circulator116. In the channel checker mode, the smaller portion of the light from the laser102directed by the coupler106toward the photodiode110may be utilized as a local oscillator. Live signals present in the fiber under test plugged at connector120may also be directed to the photodiode110, through the coupler114, and are mixed with local oscillator at coupler108. Beat terms signals from the high speed photodiode may be passed to the RF detector112, and the output may be sampled with a converter. The sampled signal may be proportional to the power of the beat terms, which may be themselves proportional to the power of the live signals around the frequency of the local oscillator (e.g., optical bandwidth is equal to twice the electrical bandwidth of the photodiode). Alternatively, based on sampling and processing speeds, the beat signals may be sampled directly and processed numerically. The channel checker OTDR100may send continuous-wave (CW) light into the network during operation as a channel checker. The same light may cause backscattering, and be detected by coherent detection (where scan/time delay=frequency shift=beat term). FIG.2illustrates another architecture of an OTDR including a channel checker (hereinafter referred to as “channel checker OTDR200”), according to an example of the present disclosure. Referring toFIG.2, the channel checker OTDR200may include laser202. The laser202may inject a laser beam into PM fiber204, which may be input to a coupler206. The coupler206may be a 90/10 coupler. The coupler206may be optically connected to a coupler208, which may be a 50/50 coupler. The coupler208may be optically connected to a photodiode210, which may be optically connected to a high pass filter222and a RF detector212. The photodiode210may be a 10-25 GHz photodiode. The coupler208may be optically connected to the coupler206, and to a coupler214, which may be a 99/1 coupler. The coupler214may be optically connected to a circulator216, which may be optically connected to an avalanche photodiode (APD)218. The coupler214may be optically connected to a launch fiber224, which may be optically connected to a connector220. The connector220may be connected to a DUT such as an optical fiber (not shown). In the OTDR mode, the light pulse generated by the laser202may be launched with the polarization state at 45° with respect to the PM fiber204Eigen axis. As the laser202wavelength is scanned, the polarization state at the output of the PM fiber204rotates, and the polarization dependent loss related errors may be reduced. The largest portion of the light pulse may then be directed towards the fiber under test by the coupler206, the circulator216, the coupler214and the launch fiber220. The backscattered light from fiber under test may be directed to the APD218by means of the circulator216. In the channel checker mode, the smaller portion of laser202light directed by the coupler206toward the210photodiode may be utilized as a local oscillator. Live signals present in the fiber under test may be directed to photodiode210, go through launch fiber224, the coupler214and are mixed with local oscillator at coupler208. Beat terms signals from the high speed photodiode may be passed to the RF detector212, and the output may be sampled with a converter. The sampled signal may be proportional to the power of the beat terms, which are proportional to the power of the live signals around the frequency of the local oscillator (e.g., optical bandwidth is equal to twice the electrical bandwidth of the photodiode). Alternatively, based on sampling and processing speeds, the beat signals may be sampled directly and processed numerically. For the channel checker OTDR200, the source laser may be pulsed, and the RF detection may be synchronized to this pulse in such a way that measurement is not perturbed by the light sent into the network through circulator216. A launch fiber220added before the output connector may provide for storage of the pulse into the fiber and avoid detection of the reflectance of this pulse at the instrument output connector added to live signals from fiber under test. With the objective of reducing parasitic signals, which would appear continuously in the case of a limited extinction-ratio on the pulses, a high-pass filter222inserted before the RF detector may filter out the low frequency beat-terms of the backscattered or reflected probe laser signals with itself onto the photodiode. Pulses of 50-200 ns may be utilized depending on the RF detector rise-time. FIG.3illustrates another architecture of an OTDR including a channel checker (hereinafter referred to as “channel checker OTDR300”), according to an example of the present disclosure. Referring toFIG.3, the channel checker OTDR300may include laser302, which may include a CW tunable laser as shown. In one example, the CW tunable laser may be combined with a pulsed SOA. The laser302may inject a laser beam into Polarization-maintaining (PM) optical fiber304, which may be input to an optical switch306. The PM optical fiber304may be specified to include length that is sufficient to measure a beat to such as a few tens of meter long. The optical switch306may be optically connected to a circulator308. The circulator308may be optically connected to a coupler310, which may be a 99/1 coupler. The coupler310may be optically connected to an avalanche photodiode (APD)312. The coupler310may be optically connected to a coupler314, which may be a 50/50 coupler. The coupler314may be optically connected to a photodiode316, which may be a 10-25 GHz photodiode. The coupler314may be optically connected to a connector318. Output of the connector318may be connected to a DUT such as an optical fiber (not shown). In the OTDR mode, the optical switch306may direct pulses to its “upper” output port320. The light pulse generated by the laser302may be launched with polarization state at 45° with respect to a PM optical fiber304Eigen axis. As the laser202wavelength is scanned, the polarization state at the output of the PM optical fiber304is rotating, and the polarization dependent loss related errors may be reduced. The light pulse may then be directed towards the fiber under test through the circulator308. The backscattered light from the fiber under test that is redirected by the circulator308, and the largest portion thereof may go to the APD312through the coupler310. In the channel checker mode, the optical switch306may direct the continuous wave light of the laser302to its “lower” output port322, coupler314and photodiode316, where it serves as a local oscillator. A small portion of the live signals present in the fiber under test are directed to photodiode316, followed by the circulator308, the coupler310, and are mixed with the local oscillator at the coupler314. FIG.4illustrates a radio frequency detector output versus wavelength of the lasers102,202or302to illustrate operation of the channel checker OTDRs ofFIGS.1-3, assuming a live channel is present in the center of the scan, according to an example of the present disclosure. Referring toFIG.4, the fiber beat frequency for PMF may be specified at400. InFIG.4, three traces are presented, the top curve402materializes the bandwidth of the photodiode/RF detector, the two oscillating curves404and406illustrate the expected RF detector output while scanning the wavelength of the local oscillator. The curve406may correspond to a particular case where the polarization state of the local oscillator coincides with one of the channels, when at its wavelength. The curve404corresponds to another situation where the polarization of the local oscillator is orthogonal to one of the channels, when at its wavelength. Mile the delay in the PMF may be precisely controlled by controlling the temperature of this fiber, in some examples such as a field application and a channel checker function, the delay may be allowed to drift with the internal temperature of the instrument, so that the phase of the oscillating pattern is considered as a random and unknown parameter. In other examples, the delay of the PMF may be set so that typically one period of the beat pattern is of the same order of magnitude as the detector bandwidth, and therefore, several peaks for each channel may be detected. In this manner, based on an assessment of the situation (e.g., resonant, anti-resonant or intermediate), a correction may be applied to the peak power estimate, based on the knowledge of the photodiode response profile and where the peak was detected on this profile. The detection bandwidth may be smaller than the channel spacing of the live channels so that recorded signals from adjacent channels are not mixed. The precise value of the bandwidth and the PMF delay may be tuned to allow the analysis of a specific DWDM grid and channel modulation format. FIG.5illustrates another example of a channel checker OTDR500, according to an example of the present disclosure. Referring toFIG.5, the channel checker OTDR500may include a first laser source that emits a first laser beam at502and a second laser source that emits a second laser beam at504. The first laser beam and the second laser beam may be respectively designated as Laser Beam-1and Laser Beam-2. Each of the laser sources may be a distributed feedback (DFB) laser source. A DFB laser source may be described as an optical fiber laser source where the active region of the laser source is periodically structured as a diffraction grating. In some examples, the layout ofFIG.5may be designated as a fully featured high dynamic range C-OTDR and high-resolution spectrum analyzer. A modulator driver506may drive a modulator508. The modulator508may modulate the Laser Beam-1. The modulator508may be an external modulator. Examples of the modulator508include an AOM (Acousto-Optic Modulator), EOM (Electro-Optic Modulator), or SOA (Semiconductor Optical Amplifier). The modulator508may modulate the Laser Beam-1, for example, between a range of 1 ns to 20 μs. The modulator508may be intermediately disposed between the Laser Beam-1and an optical fiber510. The modulator508may provide for amplification of the optical signal from a coupler512. That is, the modulator508may provide high optical gain with respect to the optical signal from the coupler512over a wide wavelength range. A photodiode514may be connectively disposed between the Laser Beam-1and the Laser Beam-2. The photodiode514may measure the frequency of the beat between the Laser Beam-1and the Laser Beam-2. The frequency of the beat between the Laser Beam-1and the Laser Beam-2may be used to set a predetermined offset frequency shift between the Laser Beam-1and the Laser Beam-2. With respect to the predetermined offset frequency shift, the photodiode514may provide a signal proportional to the intensity of an optical field. The optical field may be composed of two monochromatic optical signals in the same linearly polarized state, with a frequency difference between the Laser Beam-1and the Laser Beam-2within the response bandwidth of the photodiode514. The two field interferences may produce a beat frequency at this frequency, which is observable in the output signal of the photodiode514. Couplers512,516, and518may be connected to the Laser Beam-1, photodiode514, and the Laser Beam-2. The couplers512,516, and518may include 1×2 couplers as shown inFIG.5. For example, the coupler512provides fiber optic coupling for the transmission to the modulator508and the coupler516The coupler512may be designated as a 90/10 coupler, where 90% of the laser beam is directed to the modulator508, and 10% of the laser beam is directed to the photodiode514. Coupler516may be designated as a 50/50 coupler, and coupler518may be designated as a 90/10 coupler. A circulator520may be intermediately disposed between the modulator508and the optical fiber510. The circulator520may receive the amplified laser beam from the modulator508, and direct the amplified laser beam to the optical fiber510. Further, the circulator520may receive the backscattered signal from the optical fiber510. A polarization beam splitter (PBS)522may be used to receive the backscattered signal from the optical fiber518via the circulator520. The PBS522may separate the backscatter signal into two different polarization beams. That is, because the backscattered light from the optical fiber510is at an unknown polarization state, the PBS522may divide the backscattered light into two polarization states. The polarization states may represent projections over two polar states. The two polar sates may represent S-polarized light and P-polarized light. The S-polarization refers to light that is polarized perpendicularly to the plane of incidence. The P-polarization refers to light that is polarized parallel to the plane of incidence. A PBS524may be used to receive the Laser Beam-2. The PBS524may separate the Laser Beam-2into two different polarization beams. Output from the PBS522may be separated between splitters526and528. At splitter526, S-polarized light may be mixed with the S-polarized Laser Beam-2. At spotter528, P-polarized light may be mixed with the P-polarized Laser Beam-2. The outputs from the splitters526and528may be directed to photodiodes. The splitters526and528may include 2×2 splitters. The splitters526and528may be 50/50 splitters where 50% of the backscattered signal and 50% of the laser beam at the correct polarization is directed to the corresponding photodiodes. A sensor controller530may operate in conjunction with a coherent receiver532to determine the Brillouin trace and the Rayleigh trace as disclosed herein. The coherent receiver532may include the PBS522, the PBS524, the splitters526and528, and the photodiodes. When operated for spectral analysis, the second laser source may be used as a local oscillator and beat with the live signals from the optical fiber510, and the first laser source will be off. With this polarization diversity scheme, the sum of the beat terms on the two polarizations is proportional to the optical power present at the local oscillator wavelength. Low bandwidth photodiodes (<GHz) may be used in this scheme, which will result in a high resolution spectral analysis. The channel checker OTDR500may be considered as an optical spectrum analyzer, where spectral traces can be presented (as opposed to the channel checker OTDRs100,200, and300) where the spectra recorded are distorted by the polarization rotation technique and may retrieve a channel power within a comparatively coarse frequency range. The Rayleigh trace or the Brillouin trace may represent the temporal evolution of optical power at the corresponding optical frequency or range of frequencies, acquired synchronously after each pulse. The electrical signals generated by the photodiodes of the coherent receiver532may reflect beat frequencies of the backscattered fields with the local oscillator. The bandwidth of the photodiodes of the coherent receiver532, electrical amplification, and analogue to digital conversion may set some frequency limits to the optical signals that may be acquired. The accessible optical frequency range is then comprised between the frequency of the optical oscillation plus or minus a global electrical bandwidth. The electrical signals generated by the photodiodes of the coherent receiver532may be processed to further reduce the range of accessible frequencies, for example, by analogue or digital filters, which may be low-pass and band-pass filters. The electrical signals generated by the photodiodes of the coherent receiver532are proportional to the field of the optical backscattered signal, and may be processed by analogue or digital techniques in order to determine a power. For example, a digital squaring and averaging procedure may yield the effective power. With respect to the Brillouin trace, the Laser Beam-1and the Laser Beam-2may be set to an offset frequency shift within a range of approximately 10.0 GHz-13.0 GHz. For example, the Laser Beam-1and the Laser Beam-2may be set to approximately 10.8 GHz offset frequency shift. With such a value of the frequency shift, a coherent detection at low frequencies (e.g., around zero frequency) may yield the Brillouin trace. In this regard, a low-pass filter may be used with respect to the Brillouin trace determination. With respect to the Rayleigh trace, the Laser Beam-1and the Laser Beam-2may be set with an offset frequency shift. The coherent detection at this same frequency yields the Rayleigh trace. For example, with respect to the Rayleigh trace, the Laser Beam-1and the Laser Beam-2may be set to an offset frequency shift within a range of approximately 100.0 KHz to approximately 1.0 GHz. According to an example, with respect to the Rayleigh trace, the Laser Beam-1and the Laser Beam-2may be set to an offset frequency shift of approximately 240 MHz. In this regard, a band-pass filter may be used with respect to the Rayleigh trace determination. Operation of the channel checker OTDR500for Brillouin trace determination is described with reference toFIG.5. With respect to Brillouin trace determination, the channel checker OTDR500may maintain a predetermined offset frequency shift between the Laser Beam-1and the Laser Beam-2. For example, the Laser Beam-1and the Laser Beam-2may be set to approximately 10.8 GHz offset frequency shift. For example, the Laser Beam-1may be set to a predetermined frequency of 193 THz and an offset frequency shift of 10.8 GHz, and the Laser Beam-2may be set to the predetermined frequency of approximately 193 THz. When the Laser Beam-1and the Laser Beam-2are shifted at a high frequency of approximately 10.8 GHz, the backscattered light returning from the optical fiber510is approximately at a frequency of the Laser Beam-2, which provides for Brillouin detection. The Laser Beam-1may be modulated with the modulator508. The modulated Laser Beam-1may be injected into the DUT. For the example ofFIG.5, the DUT may include the optical fiber510. The backscattered signal from the optical fiber510may be acquired with the coherent receiver532. At the coherent receiver532, the Laser Beam-2may be used as a local oscillator. The acquisitions of the backscattered signal may be repeated for various frequency shifts between the two laser beams in order to sample the distributed Brillouin spectra. For example, assuming that a Brillouin trace is determined at approximately 10.8 GHz, the acquisitions may be acquired for various frequency shifts in the range of approximately 10.7 GHz to 10.9 GHz in increments of 1.0-10.0 MHz. A coherent detection at low frequencies (e.g., around zero frequency), with laser beam frequency shift set at 10.8 GHz yields the Brillouin trace. The resonant Brillouin frequency shift along the optical fiber510may be determined from the distributed Brillouin spectra. The resonant Brillouin frequency shift along the optical fiber510may be determined by fitting the distributed Brillouin spectra. Further, the integrated Brillouin power may be determined from the distributed Brillouin spectra. For example, the integrated Brillouin power may be determined from the distributed Brillouin spectra by applying an integration operation to the distributed Brillouin spectra. The resonant Brillouin frequency shift along the optical fiber510and the integrated Brillouin power may be used to determine the mechanical strain and temperature along the optical fiber510. The combined information of Brillouin power, Rayleigh power and Brillouin frequency shift allows for the discrimination of temperature and strain. In reflectometric applications, the Brillouin power trace may be advantageous against the Rayleigh trace, as the Brillouin trace is exempt of the large Fresnel reflections and the associated dead zones. Operation of the channel checker OTDR500for Rayleigh trace determination is described with reference toFIG.5. With respect to the Rayleigh trace determination, for the channel checker OTDR500, the Laser Beam-1and the Laser Beam-2may be scanned over a wavelength range with a maintained frequency shift between the two laser beams. With respect to the Rayleigh trace determination, the offset frequency shift may include frequencies within a range of approximately 100.0 KHz to approximately 1 GHz. For example, the Laser Beam-1and the Laser Beam-2may be set to a predetermined frequency of approximately 193 THz, with a 240 MHz offset frequency shift specified for the Laser Beam-1. Thus, at low frequency shifts, the Rayleigh trace may be determined. The scanning of the Laser Beam-1and the Laser Beam-2over a wavelength range with a maintained frequency shift between the two laser beams may be used to continuously tune the laser sources for the Laser Beam-1and the Laser Beam-2. The Laser Beam-1may be modulated with the modulator508. The modulated Laser Beam-1may be injected into the DUT. For the example ofFIG.5, the DUT may include the optical fiber510. The backscattered signal from the optical fiber510may be acquired with the coherent receiver532. At the coherent receiver532, the Laser Beam-2may be used as a local oscillator. The acquisitions of the backscattered signal may be repeated at the same predetermined offset frequency shift. For the Rayleigh traces the repeated acquisitions may be averaged while scanning the two laser beams in order to reduce coherent fading noises. Thus the coherent detection at the offset frequency shift yields the Rayleigh trace, where the range of possible frequencies includes approximately 100.0 KHz to approximately 1 GHz. The Rayleigh trace may represent the Rayleigh power as function of time or distance along the optical fiber510. The channel checker OTDR500may provide for polarization diversity, and balanced detection (e.g., for a better sensitivity/rejection). The channel checker OTDR500may provide a tunable Coherent-OTDR. In this regard, the channel checker OTDR500may provide for improved dynamic range (e.g., 50 dB equivalent). The channel checker OTDR500may be natively resilient to live signals over a DUT, and natively resilient to its own laser amplified spontaneous emission (ASE) (e.g., problems encountered with direct detection, injection on a common port, and strong reflectances from all demultiplexer ports). The channel checker OTDR500may diminish the contrast on all OTDR signals such as reflectance, losses of splitter, losses of fiber (dBs divided by two). The channel checker OTDR500may include HROSA functionalities. For the channel checker OTDR500, the first laser source that emits a first laser beam at502may serve as a fixed absolute referential if lockable at specific wavelength of the telecom grid (for example, lasers following the Integrable Tunable Laser Assembly Multi Source Agreement may be used), then the photodiode514, with selected RF filters providing relative trigger signals, while the second laser source that emits a second laser beam at504is being scanned for spectral analysis. FIG.6shows a computer system600that may be used with the examples described herein. The computer system may represent a generic platform that includes components that may be in a server or another computer system. The computer system600may be used as part of a platform for a controller of the channel checker OTDR (e.g., OTDR controller as shown inFIG.6). The computer system600may execute, by a processor (e.g., a single or multiple processors) or other hardware processing circuit, the methods, functions and other processes described herein. These methods, functions and other processes may be embodied as machine readable instructions stored on a computer readable medium, which may be non-transitory, such as hardware storage devices (e.g., RAM (random access memory), ROM (read only memory), EPROM (erasable, programmable ROM), EEPROM (electrically erasable, programmable ROM), hard drives, and flash memory). The computer system600may include a processor602that may implement or execute machine readable instructions performing some or all of the methods, functions and other processes described herein. Commands and data from the processor602may be communicated over a communication bus604. The computer system may also include a main memory606, such as a random access memory (RAM), where the machine readable instructions and data for the processor602may reside during runtime, and a secondary data storage608, which may be non-volatile and stores machine readable instructions and data. The memory and data storage are examples of computer readable mediums. The memory606may include the OTDR controller including machine readable instructions residing in the memory606during runtime and executed by the processor602. The computer system600may include an I/O device610, such as a keyboard, a mouse, a display, etc. The computer system may include a network interface612for connecting to a network. Other known electronic components may be added or substituted in the computer system. The processor602may be designated as a hardware processor. The processor602may execute operations associated with various components of the OTDR including a channel checker100. For example, the processor602may execute operations associated with the OTDR controller, etc. What has been described and illustrated herein is an example along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the spirit and scope of the subject matter, which is intended to be defined by the following claims—and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. | 33,255 |
11942987 | DETAILED EMBODIMENTS The present disclosure is described in detail below in connection with specific embodiments. The following embodiments are intended to assist those skilled in the art in further understanding the present disclosure, rather than limiting the present disclosure in any way. It should be noted for those skilled in the art that several variations and improvements can be made to the present application without departing from the conception of the present disclosure, all of which fall within the scope of protection of the present disclosure. As shown inFIG.1, the present disclosure provides a method for measuring an optoelectronic device and/or a channel. The method comprises the following steps:Step S1: configuring a periodic excitation source to transmit a periodic excitation signal A;Step S2: sampling an output signal A+NAat an output point of the periodic excitation signal A with a sampling device AA, and averaging the output signal A+NAover one or more periods to filter noise;Step S3: inputting the sampled output signal A+NAas in input to a device or a channel H to be measured;Step S4: sampling an output signal B+NBat an output point of the device or the channel H to be measured with a sampling device BB, and averaging the output signal B+NBover one or more periods to filter noise; andStep S5: transmitting sampling results from the sampling device AA and the sampling device BB to an analysis software C to calculate a transfer function of the device or the channel H to be measured. In specific, the optoelectronic device or the channel H is a device or a transmission channel to be measured. The periodic excitation source G is controlled by the device/channel correlation analysis software C to generate the periodic excitation signal A. The period of the periodic excitation signal A per baud is T, the length of a code pattern of the periodic excitation signal A is M, and the periodic excitation signal A is repeated in a periodicity of baud length of M. NAis the noise of the excitation source, and A+NAis converted into signal B+noise NBafter going through the optoelectronic device or the channel H. Noise NH is the noise generated by the device or the channel H to be measured. The signals A and B may be electrical signals or optical signals. The sampling device AA and the sampling device BB sample the input signal and the output signal. The sampled signals are averaged several times in the periodicity of the baud length of M. The noise signals are filtered by averaging the signals over the baud length of M. The samples of the signals A and B are input to the software. The transfer function of the device or channel H to be measured is obtained through correlation calculation, wherein the transfer function may be an impulse response, a pulse response, a frequency response, which reflects characteristics such as bandwidth, gain, reflection, impedance matching etc., of the device or the channel to be measured. The transfer function is a transfer function in the usual sense, that is, an impulse response of a system. The pulse transfer function described below is a pulse response of a system. The difference between the above two cases lies in that: an input to the system is an impulse in the first case, while an input to the system is a pulse in the second case. The pulse refers to a signal transmitting a signal ‘1’ at a specified baud rate. For example, if a period of data is 100 ps at a rate of 10 Gb/s, then a pulse at 10 Gb/s is a waveform which is ‘1’ for 100 ps and ‘0’ for rest of the time. When coming to a pulse, there will be a related rate of the pulse, thus a pulse response is also related to the rate. In theory, a pulse response is a convolution of a pulse signal at a certain rate and an impulse response of the system. The periodic excitation signal A can be generated by a code pattern generator, an arbitrary waveform generator, a chip or an apparatus capable of such function. The measurement of the device or the channel to be measured is based on the following two principles: 1. Randomness and Correlation of the Periodic Excitation Source A signal that satisfies these characteristics may be a pseudo-random code (PRBS 27-1,210-1,215-1,223-1 . . . ), the length and code pattern of the pseudo-random code may be changed by adjusting a polynomial that generates the code pattern. For example, for PRBS code 27-1 (X7+X6+1), which has a period length of the code pattern of 127, and its sequence D(i) is: 1,−1,−1,1,1,−1,1,1,−1,1,−1,1,1,−1 . . . . This sequence is repeated every 127 bits, and an absolute value of a self-correlation function of this signal has the following characteristics: When i=j, ABS (Correlation(D(i),D(j)))=M,When1≠j, ABS (Correlation(D(i),D(j)))=1 or 0, wherein M is the period length of the code pattern of the sequence, and for PRBS code 27-1, M=127. As M increases, the average (1/M) of its self-correlation function (i≠j) for the period length of the code pattern of the sequence approaches 0. When a pulse waveform and an impulse sequence of code patterns in time domain are convolved in time domain, the signal A inFIG.1is obtained: A=CONVOLVE(PULSE, Dt(i)), wherein PULSE is the pulse waveform, and Dt(i) is the impulse sequence in time domain of code patterns sequence. 2. Filtering of Noise by Averaging Sampled Signals As noise in the sampled signals is unavoidable, noise signal is filtered by calculating an average of one or more sets of signals from the sampled code patterns: Average(A+NA)=average(A)+average(NA) Due to non-correlation of the noise signals, noise may be filtered by averaging the sampled signals such that calculation on the transfer function of the device or the channel to be measured is more accurate. Usually, 16 or more sets of sampled code patterns are averaged. After filtering noise during sampling, the signal A generated by the excitation source is converted into the signal B after going through the device or the channel (H) to be measured, which may be expressed as: B(t)=H(t)*Dt(i), wherein Dt(i) and B(t) are the impulse sequence of code patterns in time domain and the output sampled signals of the device or the channel to be measured, respectively. H(t) is a convolution matrix of the transfer function of the pulse response of the device or the channel to be measured. Both sides of the expression are simultaneously multiplied by the impulse sequence in time domain Dt(i) of a sequence of code patterns of the excitation source D(i). B(t)*Dt(i)=H(t)*Dt(i)*Dt(i), According to the aforementioned correlation characteristics of D(j):Dt(i)*Dt(i)=kM, wherein k is a constant and is related to a number of sampled points per baud, and thus H(t)=B(t)*Dt(i)/kM. The pulse transfer function of the device or the channel to be measured is a normalization result of a product of the output signal and impulse sequences in time domain of the input signal. kM is a constant, wherein k is determined by a number of sampled points per baud and M is the length of code patterns of the input signal. The impulse transfer function can be derived from the pulse transfer function, and a frequency response function in frequency domain may be derived by conducting an FFT operation. When the periodic excitation signal A is not an ideal pulse output, the pure transfer function of the device or the channel to be measured may be obtained in a similar way of deriving a pulse response transfer function of A according to a product of A and an impulse sequence in time domain of the input signal, and then eliminating a pulse response effect of A from a pulse response transfer function obtained at point B via deconvolution. An ideal device or channel is the one that has an output pulse which is exactly the same as the input pulse, i.e., the device has no other limitations such as bandwidth or amplitude. However, no actual device can have an output pulse which is exactly the same as the input pulse. Through the above method, the transfer function of different optoelectronic devices or channels may be obtained easily in a transmission path as follows: (1) from an electrical signal to an electrical signal: for example,a. an electric chip drives a laser, wherein an optical signal passes through an optical fiber, and then is converted into an electrical signal through a PD/APD or TIA;b. an electric chip drives a cable or PCB line to an input of the other end of the electric chip.c. the internal circuit of the electrical chip drives a package to the pins of the chip. (2) from an electrical signal to an optical signal: for example,a. an electric chip drives a laser to generate an optical signal;b. an electric chip drives a laser to generate an optical signal, and the optical signal passes through an optical fiber to generate an optical signal. (3) from an optical signal to an electrical signala. an optical signal is converted into an electrical signal after going through a PD/APD;b. an optical signal is converted into an electrical signal after going through a PD/APD and then converted into an electrical signal after going through a TIA or other electric chip. (4) from an optical signal to an optical signala. an optical signal goes through an optical distribution or an optical fiber to generate an optical signal. The present disclosure also provides a system for measuring an optoelectronic device and/or a channel. The system comprises: Module M1: to configure a periodic excitation source to transmit a periodic excitation signal A; Module M2: to sample an output signal A+NAat an output point of the periodic excitation signal A with a sampling device, and averaging the output signal A+NAover one or more periods to filter noise; Module M3: inputting the sampled output signal A+NAas an input to a device or a channel H to be measured; Module M4: sampling an output signal B+NBat an output point of the device or the channel H to be measured with a sampling device, and averaging the output signal B+NBover one or more periods to filter out noise; and Module M5: to transmit sampling results from the sampling device AA and the sampling device BB to an analysis software C to calculate a transfer function of the device or the channel H to be measured, and to obtain performance indexes such as loss, reflection and bandwidth of the device or the channel H to be measured. Those skilled in the art are aware of that, in addition to implementing the system and its various means, modules, and units provided in the present disclosure in a form of a purely computer readable program code, it is entirely possible to enable the system and its various means, modules, and units provided in the present disclosure to implement the same functions in a form of logic gates, switches, Application Specific Integrated Circuits, programmable logic controllers, and embedded microcontrollers, etc., by logically programming the steps of the method. Thus, the system and its various means, modules, and units provided in the present disclosure can be considered as a hardware component. Also, the means, modules, and units for implementing various functions included therein can also be considered as structures within the hardware component. Alternatively, the means, modules, and units for implementing various functions included therein can be considered as software modules for implementing the method or structures within the hardware component. Specific embodiments of the present disclosure are described above. It shall be understood that the present disclosure is not limited to the specific embodiments as described above. Those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substance of the present disclosure. The embodiments and features in the embodiments of the present application may be combined with each other arbitrarily, provided that there is no conflict between them. | 11,962 |
11942988 | DETAILED DESCRIPTION While aspects of the subject matter of the present disclosure may be embodied in a variety of forms, the following description and accompanying drawings are merely intended to disclose some of these forms as specific examples of the subject matter. Accordingly, the subject matter of this disclosure is not intended to be limited to the forms or embodiments so described and illustrated. FIG.1illustrates an example of an optical communications platform100configured to use an USPL source as an optical source for transport. As shown inFIG.1, a USPL source102may be directly modulated by an external source element104. Optical power from the USPL source102can be coupled across free space110to a transmitting element106, optionally by an optical telescope. The transmitting element106can optionally include optical components formed by hyperbolic mirror fabrication techniques, conventional Newtonian designs, or the like. A reciprocal receiving telescope at a receiver system can provide for optical reception. Consistent with implementations of the current subject matter, each optical transport platform can be designed to operate as a bi-directional unit. In other words, the transmitting element106of the optical communications platform100can also function as a receiving element. In general, unless otherwise explicitly stated, a transmitting element106as described can be considered to also be functional as a receiving element and vice versa. An optical element that performs both transmission and receiving functions can be referred to herein as an optical transceiver. FIG.2illustrates an example of an optical communications system200that includes the optical communications platform100ofFIG.1. Also shown inFIG.2is a second complementary receiving element204, which can be a receiving telescope located at a remote distance from the transmitting element106. As noted above, both the transmitting element106and the receiving element204can be bi-directional, and each can function as both a transmitting element106and a receiving element204depending on the instantaneous direction of data transmission in the optical communications system200. This feature applies throughout this disclosure for transmitting and receiving elements unless otherwise explicitly stated. Either or both of the transmitting element106and the receiving element204can be optical telescopes or other devices for transmitting and receiving optical information. FIG.3illustrates an example of an optical communications platform300for using an USPL source102fiber coupled to an external modulator302through a fiber medium304and connected to a transmitting element106through an additional transmission medium306, which can optionally be a fiber medium, a free space connection, etc. The USPL source102can be externally modulated by the external modulator302such that optical power from the USPL source102is fiber coupled to the transmitting element106or handled via an equivalent optical telescope. FIG.4illustrates an example of an optical communications system400that includes the optical communications platform300ofFIG.3. Also shown inFIG.4is a second complementary receiving telescope204, which, as noted above in relation toFIG.2, can be a receiving telescope located at a remote distance from the transmitting element106. FIG.5illustrates an example of an optical communications architecture500. The architecture500ofFIG.5may include the elements ofFIG.4and may further include a first communication network502connected to a first optical communications platform300. The receiving element204is part of a second optical communications platform504, which can optionally include components analogous to those of the first optical communications platform300. A second communications network506can be connected to the second optical communications platform504such that the data transmitted optically between the transmitting element106and the receiving element204or are passed between the first and second communications networks502,506, which can each include one or more of optical and electrical networking features. FIG.6illustrates an example of an optical communications system600. As part of an optical communications platform602, an USPL source102is fiber coupled to an external modulator302, for example through an optical fiber202or other transmission medium. The light from the USPL source102is propagated via a transmitting element106in a similar manner as discussed above. An optical amplifier element604, which can optionally be an optical fiber amplifier element, can be used to increase optical transmit launch power, and can optionally be disposed between the external modulator302and the transmitting element106and connected to one or both via an additional transmission medium306, which can optionally be a fiber medium, a free space connection, etc. Also shown inFIG.6is a second complementary receiving element204located at a remote distance from the optical communications platform602. It will be readily understood that a second optical communications platform504that includes the receiving element204can also include an optical amplifier element604. First and second communications networks502,506can be connected respectively to the two optical communications platforms602,504. FIG.7illustrates an example of an optical communications system700. The optical communications platform602shown inFIG.6can be in communication with a second optical communications platform702, which can in this implementation include a receiving element204and an optical preamplifier704. Other components similar to those shown in the optical communications platform602can also be included in the second optical communications platform702, although they are not shown inFIG.7. It will be understood that a bi-directional optical communications platform can include both of an optical preamplifier704for amplifying a received optical signal and an optical amplifier element604for boosting a transmitted optical signal. Consistent with the implementation depicted inFIG.7and other implementations of the current subject matter, optical amplification (e.g. for either or both of an optical amplifier element604or an optical preamplifier704) be included for enhancing the optical budget for the data-link between the transmitting element106and the receiving element204(and vice versa), for example using one or more of an erbium-doped fiber amplifier (EDFA), a high power erbium-ytterbium doped fiber amplifier (Er/Yb-DFA), or equivalents, which can include but are not limited to semiconductor-optical-amplifiers (SOA). FIG.8illustrates an example of an optical communications system800. The optical communications platform602shown inFIG.6can be in communication with a second optical communications platform802, which can in this implementation include a receiving element204and an optical preamplifier704similar to those shown inFIG.7. As shown inFIG.8, the second optical communications platform802can further include optical receiver circuitry804, which can receive amplified and electrically recovered data received at the receiving element204and amplified by the optical preamplifier. A plurality of clock sources806can interface to multiple remote multi-point network connections with a plurality of communications networks810as required. In a similar manner, a complementary set of clock sources and multiple communication networks can be operated in conjunction with the optical communications platform602(e.g. in place of the single depicted communication network502inFIG.8). FIG.9illustrates an example of an optical communications system900. An optical communications platform902, which can feature similar elements to those in the optical communications platform602first discussed herein in reference toFIG.6, can also include an additional USPL source904acting as a tracking and alignment (pointing) beacon source. A second optical communications platform906can also include an additional USPL source910acting as a tracking and alignment (pointing) beacon source. The tracking and alignment (pointing) beacon sources904,910can optionally originate from available communications sources used in data transport transmission, or can be provided by separate, dedicated USPL sources. In addition, each USPL beacon source904,910can include an in-band or out-of-band source, thereby allowing the advantage of available optical amplification sources, or from dedicated optical amplification resources. FIG.10illustrates an example of a FSO communication system1000that includes a dual polarization USPL-FSO optical data-link platform1001in which USPL sources are polarization multiplexed onto a transmitted optical signal to thereby provide polarization multiplexed USP-FSO (PM-USP-FSO) functionality. Two USPL sources102and1002are fiber coupled to either directly modulated or externally modulated modulation components1004,1006respectively. Each respective modulated signal is optically amplified by an optical amplifier component1010,1012followed by adjustment of optical polarization states using polarization components1014,1016. The polarization state signals are fiber coupled to a polarization dependent multiplexer (PDM) component1020for interfacing to an optical launch platform component1022, which can be similar to the transmit element106discussed above. The PDM1020multiplexes the light of differing polarization states into a single pulse train for transmission via the optical launch platform component1022. An USPL optical beacon904can be included to provide capabilities similar to those discussed above in reference toFIG.9, for example to operate along or in conjunction with a second USPL optical beacon906at a receiving platform1024, which can include a receiving element204similar to those described above. As previously noted, the receiving element204as well as other features and components of the receiving platform1024can generally be capable of supporting transmission functions such that a bi-directional link is established. A received signal recovered by the receiving element204can provide an optical signal that is interfaced to an appropriate polarization dependent de-multiplexer1026capable of providing two signals for further optical amplification using amplification elements1030,1032. Each optical amplified signal as provided by the amplification elements1030,1032can be interfaced to an appropriate optical network1034,1036for network usage. FIG.11Ashows an example of a system1100in which USPL-FSO transceivers can be utilized for use in line-of-sight optical communication (e.g. “lasercom”) applications, andFIG.11Bshows an example of a system1150in which USPL-FSO transceivers can be utilized for use in non-line-of-sight lasercom applications. An advantage to some implementations of the current subject matter can be realized due to scattering of the optical signal sent from a transmit element as the transmitted light passes through the atmosphere. This scattering can permit the use of non-line-of-sight communication. In addition, radios used in such communication systems can operate in the solar-blind portion of the UV-C band, where light emits at a wavelength of 200 to 280 nm. In this band, when solar radiation propagates through the environment, it is strongly attenuated by the Earth's atmosphere. This means that, as it gets closer to the ground, the amount of background noise radiation drops dramatically, and low-power communications link operation is possible. On the other hand, environmental elements such as oxygen, ozone and water can weaken or interrupt the communications broadcast, limiting usage to short-range applications. When UV waves spread throughout the atmosphere, they are typically strongly scattered into a variety of signal paths. Signal scattering is essential to UV systems operating in non-line-of-sight conditions, and the communications performance can highly dependent on the transmission beam pointing and the receiver's field of view. A line-of-sight arrangement1100as shown inFIG.11Acan differ in bandwidth size from a non-line-of-sight arrangement1150as shown inFIG.11B. Ultraviolet communication can more strongly rely on a transmitter's beam position and a receiver's field of view. As a result, refining of the pointing apex angle, for example by experimenting with supplementary equipment to enhance the UV-C signal, can be advantageous. FIG.12illustrates an example of a remote sensing system1200in which an USPL source102is fiber coupled by an optical fiber component202to an optical launch element1202capable of transmitting and receiving optical signals. Some of the light propagated forward including the light from data signal through the optical launch element1202is backscattered by interaction with air-borne particulates that are the subject of investigation. The optical backscattered signal is detected through the optical launch element1202or a similar receive aperture and passed along for detection and spectrographic analysis through detection circuitry1204or the like inFIG.12. The signature of particulates within a target atmospheric region1206within which an investigation is made can be calibrated through known approaches, for example using predetermined spectrographic calibration measurements based on one or more of ultraviolet spectroscopy, infrared spectroscopy, Raman spectroscopy, etc. Consistent with this implementation, an optical system can be operated as a LIDAR instrument providing enhanced resolution and detection sensitivity performance, using USPL laser sources operating over a spectral range of interest. Adjustability of spectral range can aid in evaluating and analyzing chemical constituents in the atmosphere. USPL-FSO transceivers can be utilized for remote sensing and detection for signatures of airborne elements using ionization or non-ionization detection techniques, utilizing optical transport terminals manufactured through either the Hyperbolic Mirror Fabrication Techniques or conventional Newtonian designs that focus a received signal at one ideal point. Also certain adaptations can be related to ionization probing of remote regions include controllable ionization, which has been shown to occur at these frequencies and an ionization process, which can be focused at distance to adjust depth of atmospheric penetration especially in weather and clouds. FIG.13illustrates an example of use of USPL sources as well as optical reception techniques to improve detection sensitivity. Researchers at the National Institute of Standards and Technology (NIST), US, have built a laser ranging system that can pinpoint multiple objects with nanometer precision over distances up to 100 km. The LIDAR (light detection and ranging) system could have applications from precision manufacturing on Earth to maintaining networks of satellites in perfect formation (Nature Photonics DOI: 10.1038/NPHOTON.2009.94). The NIST device uses two coherent broadband fiber-laser frequency combs. Frequency combs output a series of stable short pulses that also contain a highly coherent carrier that extends across the pulse train. This means a frequency comb can be employed to simultaneously make an interferometric measurement as well as a time-of-flight measurement, thereby enhancing analytical capabilities for application specific situations. In the arrangement shown inFIG.13, two phase-locked frequency combs1301and1302are used in a coherent linear optical sampling configuration, also known as a multi-heterodyne, meaning that one frequency comb measures both distance paths, while the other frequency comb provides distance information encoded in the light of the first comb. Pulses from one frequency comb1301can be launched out of the fiber and directed towards two glass plates, a reference1303and a target1304. The plates1303and1304can reflect a certain fraction (e.g. approximately 4%) of the pulse back down the fiber, effectively creating two new pulses. The time separation between the two pulses1301can give the distance between the moveable target plate and reference plates. A second frequency comb1302is tightly phase-locked with the first, but has a slightly different repetition rate. Due to the different delay between consecutive pulses when the sources interfere, the second frequency comb can sample a slightly different part of the light from the electric field of the first comb. Using the technique described is reference toFIG.13, it is possible to replace the two coherent broadband fiber-laser sources with two appropriate USPL sources used within the scope of the configuration outlined having each USPL source fiber coupled to dedicated free-space optical telescope designs. By doing so, the overall efficiency, optical ranging and accuracy can be improved substantially. In some embodiments, a native pulse repetition rate of a USPL laser source and may be 50 MHz or less, which may be undesirably low for optical data transmission, limiting the system to low data rate applications of 50 Mbps or less. Accordingly, systems to increase USPL operational rates are needed for providing solutions for data transport in excess of 50 Mbps. FIG.14illustrates an example of a remote sensing system1400in which an USPL source102is fiber coupled by an optical fiber component202to an optical launch element1202capable of transmitting and receiving optical signals. Light propagated forward by the optical launch element1202including light from the data signal is backscattered by interaction with targets known and unknown that are the subject of investigation within an atmospheric region1206. The optical backscattered signal including light from the data signal is detected through the optical launch element1202or a similar receive aperture and passed along for detection analysis through a detection circuitry and spectrographic analysis component1402inFIG.14. The signature of particulates within the region1206under investigation can be calibrated, for example where range-finding analysis can be performed. A system1400as inFIG.14can include a USPL-FSO transceiver utilized and operated across the infrared wavelength range as a range-finder and spotting apparatus for the purposes of target identification and interrogation applications. As used herein, the term “optical” includes at least visible, infrared, and near-infrared wavelengths. FIG.15illustrates an optical pulse multiplier module1500that can increase the repetition rate of the output from a USPL source102. An exemplary USPL may have a pulse width of 10-100 femto-seconds and a repetition rate of, for example, 50 MHz. The output from the USPL102can be fed as an input1502into a USPL photonic chip pulse multiplier module1504. In this example, the photonic chip can contain a 20,000:1 splitter element1506that splits the input into discrete light elements. Each light element on the opposite side of the splitter element1506contains the 50 MHz pulse train. Each light element then passes through a delay controller (either a fiber loop or lens array)1510, which delays the pulse train for that element in time, for example by a number of picoseconds. Successive light elements are thereby delayed by incremental picoseconds. All of these pulse trains with their unique time delays are combined into a single pulse train in a fashion similar to time division multiplexing utilizing a 20,000:1 optical combiner element1512. The required ratios of splitters and combiners can be controlled to provide necessary optical designs for the application required. The final output1514is a pulse train of 10-100 femto-second pulses with a repletion rate of 1 THz. This THz pulse train can then be modulated by a 10 or 100 GigE signal, such as shown inFIG.28, resulting in 100 femto-second pulses per bit for the 10 GigE system, and 10 femto-second pulses per bit for 100 GigE systems. The application cited is not limited to specific data rates of 10 and 100 Gbps, but can operate as required by the application under considerations. These numbers are just for illustration purposes. Implementations of the current subject matter can use any multiplier factor to increase the repetition rate of the USPL via the photonic chip pulse multiplier module1504to any arbitrary repetition rate. Other examples used in generation of enhanced USPL repetition rates are illustrated within this submission. FIG.16depicts a system1600for generation, transmission, and receiving of high pulse rate USPL optical streams. An optical chip multiplexing module1610, which can for example be similar to that discussed in reference toFIG.15, can be used in this application. In this approach to achieve USPL pulse multiplication, a series of 10 GigE router connections (10 GigE is not intended to be a limiting feature) described by signals1601,1602,1603,1604(four signals are shown inFIG.16, but it will be understood that any number is within the scope of the current subject matter) are interfaced to the optical chip multiplexing module1610. In operation, the optical chip multiplexing module1610can support full duplex (Tx and Rx) to connect with the 10 GigE routers1601,1602,1603,1604. The optical chip multiplexing module1610can provide efficient modulation by a USPL signal1685output from a USPL source1690for ingress optical signals1601,1602,1603,1604. The optical chip multiplexing module1610can provide capabilities to modulate and multiplex these ingress optical signals. At a remote receive site where a receiving device is positioned, all signals sent via a transmitting element1660at the transmitting device can be recovered using an appropriate receiver element1665. A complementary set of optical chip multiplexing module1675can provide necessary capabilities for demultiplexing the received data stream as shown by elements for delivery to a series of routers1601′,1602′,1603′,1604′ (again, the depiction of four such routers is not intended to be limiting). End-to-end network connectivity can be demonstrated through network end-point elements. FIG.17depicts an example system1700in which an optical chip is interconnected to a wavelength division multiplexing (WDM) system. WDM systems have the advantage of not requiring timing or synchronization as needed with a 10 GigE (or other speed) router1701, since each 10 GigE signal runs independent of other such signals on its own wavelength. Timing or synchronization of the TDM optical chip with 10 GigE routers can be important in a TDM optical chip. A GbE switch1701can provide the necessary electrical RF signal1705, from the switch1701to modulate a USPL source1702, either directly or by use of USPL a pulse multiplier module previously detailed within this document. A typical RZ output1710can be coupled into an external modulator1720, which can be modulated using a NRZ clock source for the switch1701, thereby resulting in a RZ modulated spectrum1730. The conversion process using readily available equipment can provide capabilities for introducing USPL sources and their benefits into the terrestrial backhaul network spectrum. For the optical chip system to successfully bridge between two remote 10 GigE switches, the chip may act like a simple piece of fiber. The timing of the TDM chip can therefore be driven by the 10 GigE switch1701. Both actively mode-locked USPLs (i.e. 40 GHz, 1 picosecond pulse width) and passively mode-locked USPLs (i.e. 50 MHz, 100 femtosecond pulse width) can be driven by a RF timing signal. FIG.18illustrates a device1800that can support another approach to progression to a high pulse repetition data rate operation, such as for extremely high data rate operation in which optical chip design can be performed using either fiber or free-space optics. A 50 MHz USPL source1801may be interfaced to a series of optical delay controller elements1802, which can be designed using either fiber loops or offset lenses, to result in producing exactly a 10.313 Gbps RZ output stream, which is the 10 GigE line rate (greater than 10 Gbps because of 64B/66B encoding). A splitter element1803provides splitting functionality of the incoming optical signal train1801into (in this example)206paths, along with variable optical delay lines1804. After sufficient delay is introduced through design all signals are multiplexed together through a combiner element1805. In so doing a series of optical signals each identical, and equally spaced between adjacent pulses form a continuum of pulses for modulation. Prior to entering an E-O modulator element1806, all optical ingress signals can be conditioned by pre-emphasis techniques, for example using typical optical amplification techniques, to result in a uniform power spectrum for each egress signal from the combiner element1805. The conditioned egress signals may then be coupled into the E-O modulator element1806and modulated with an available NRZ signal from the 10 GigE signal source element1807. The 10 GigE modulated output1809can interface to an EDFA and then into the TX of a FSO system (or a fiber optic system). The Rx side (after the detector) can be fed directly into a 10 GigE switch as a modulated and amplified output1810. FIG.19illustrates another example of a device1900that can be used for USPL pulse multiplication consistent with implementations of the current subject matter. Consistent with this approach, a 10×TDM system is configured to give a 100 Gbps output. A TDM demux chip can be on the receive side of a communication link to break up the individual 10 GigE signals, and can include a reciprocal approach to the design shown inFIG.19. As inFIG.18, a 50 MHz USPL source1801may be interfaced to a series of optical delay controller elements1802, which can be designed using either fiber loops or offset lenses, to result in producing exactly a 10.313 Gbps RZ output stream, which is the 10 GigE line rate (greater than 10 Gbps because of 64B/66B encoding). A splitter element1803provides splitting functionality of the incoming optical signal train1801into (in this example)206paths, along with variable optical delay lines1804. After sufficient delay is introduced through design all signals are multiplexed together through a combiner element1805. Instead of a single modulator element1806as shown inFIG.18, however, the 10.313 GHz RZ output1901from the combiner element1805may be fed into a second splitter element1910, which in this case can be a 10× splitter, which splits the optical signal into ten parallel paths. Other implementations of this design can support various split ratios as required by design. Optical paths out from second splitter element1910are individually connected to specified optical delay lines1920. Each individual delayed path is connected to a dedicated optical modulator of a set of optical modulators1930modulated with an available NRZ signal from the 10×10 GigE signal source element1931, resulting in a series of modulated optical signals1935. An optical combiner identified1940provides a single optical pulse train1950. The series of optical pulses in the single optical pulse train1950can be interfaced to an appropriate optical amplifier for desired optical conditioning for network use. FIG.20illustrates another example of a device2000that can be used for USPL pulse multiplication consistent with implementations of the current subject matter. A device2000as depicted can provide the ability to achieve high USPL pulse repetition data rates for network applications by modulation of the low repetition rate intra-channel pulses. By applying direct modulation of each channel on the delay controller, creation of a modulation scheme, which is not constrained by the current speed limitations from the electronics technology, can be beneficially accomplished. Implementations of the current subject matter can provide a mechanism to enhance the data transmission capacity of a system, by separately modulating individual channels at the current standard electronic modulation speed (in the example ofFIG.20at the rate of 100×10 GigE signal input2001) and time-multiplexing the channels into a single frequency high rep rate pulse stream. In this approach, the current standard, which is limited by the speed of electro-optic modulators (40 Gbps), can be enhanced by approximately N orders of magnitude, where N is the number of channels of the time-multiplexer. For example, a 100 channel TDM with each channel amplitude modulated at the current standard data rate can be able to offer data rates at speeds of up to 4 Tbs. N can be limited by the width of the optical pulse itself. In the limit that information is carried 1 bit/pulse, the time slot occupied by 1 bit is the width of the pulse itself (in that sense, RZ system would converge to a NRZ). For example, in the scheme, a 40 fs pulse width laser with a 40 GHz rep rate is able to carry information at a maximum rate of 25 Tbps. This approach can be used in a 40 Gbps-channel modulation scheme (i.e., 1 bit every 25 ps) and can correspond to a capacity of N˜625 channels in a single transmission, which can be the number of 40 fs time intervals fitting in a 25 ps time interval. A significant advantage of this approach is the ability to “optically enhance” an otherwise limited data capacity modulation scheme, while still interfacing with the existing data rate limited modulators. For example, an amplitude modulator based on a Mach-Zehnder interferometer can be easily integrated in a TDM IC package, in that required is the ability to branch out the channel into two separate paths, add a tiny phase modulator (nonlinear crystal) in one of the paths, and combine the paths for interference. FIG.20includes a USPL source2010coupled to a multi-port optical splitter element2020. The number of optical ports identified need not be limited to those described or shown herein. A series of optical delay lines2030provide required optical delays between each parallel path from the multi-port optical splitter element2020, and can be tailored for specific applications. The optical delay paths from the optical delay lines2030are summed together using an optical combiner element2035. The resulting combined optical data stream appearing through element2040represents a multiplicative enhancement in the pulse repetition rate of the original USPL source identified by element2010. Further enhancement in pulse repetition rate is accomplished though the usage of element2041, described by an optical splitter where the incoming signal2040is split into a series of paths not limited to those identified by element2041. By way of a second delay controller2045, optical delays may be introduced to each path within the device as identified by the second set of optical delay paths2042. Each parallel path2042in turn is modulated by a modulating element2044with an available RF signal source element identified by the signal input2001. An optical combiner element2050integrates all incoming signals onto a single data stream2060. Optical pre-emphasis and de-emphasis techniques can be introduced within each segment of elements described to custom tailor the optical spectrum for a uniform or asymmetric optical power distribution. Pre- & de-emphasis can be accomplished using commonly used optical amplifiers such as Er-Doped Optical amplifiers (EDFA). FIG.21depicts an example of a system2100that includes a mode-locked USPL source2101, which can be used to generate appropriately required clock and data streams for the application. Mode-locked lasers can represent a choice of high performance, high finesse source for clocks in digital communication systems. In this respect, mode-locked fiber lasers—in either linear or ring configuration—can make an attractive candidate of choice, as they can achieve pulse widths on the USPL source region and repetition rate as high as GHz. In addition to that, fibers offer compactness, low cost, low sensitivity to thermal noise, low jitter, no problems associated with diffraction or air dust pollution, just to name a few. In a communications scenario, the pulse width can determine the available bandwidth of the system, and the repetition rate limits the data rate. The pulse width can be determined by the intrinsic characteristics of the laser cavity—i.e. balancing of the overall group-velocity dispersion (GVD), and the choice of the saturable absorber (in the case of a passive system)—or the bandwidth of an active element (in the case of an active mode-locked system). The repetition rate of the pulse train is constrained by the length of the fiber. For example, in a linear laser, the fundamental mode vos, of the laser can be expressed as: vosc=c2ngL where c is the speed of light in vacuum, n g is the average group index, and L is the length of the cavity. Therefore, a 10 cm long fiber laser cavity element2110with an average group index of 1.47 would have a repetition rate of 1 GHz. In strictly passive systems, mode-locking can be achieved through the use of a saturable absorber. In an active laser, an amplitude modulator element2150can be inserted in the cavity to increase the repetition rate of the laser (harmonic mode locking). In order to achieve high repetition rate clocks using mode-locked USPL source, it is possible to use one or more of (i) an intra-cavity amplitude Mach-Zehnder modulator (MZM)2150as shown inFIG.21and (ii) a low threshold saturable absorber. These techniques, known as “harmonic mode-locking”, can be utilized within a fiber based plant distribution system or within a FSO system, for terrestrial, submarine or FSO system either in air, space or submarine applications. Detailed withinFIG.21is 980 nm pump element2102coupled to an optical WDM device2105. An erbium doped optical amplifier2110or equivalent can be used to create a non-linear environment to obtain a mode-locked pulse train emission within a closed cavity established between two Faraday reflectors2101and2160on either end of the optical USPL cavity. Operation of the device is capable of establishing a self-contained series of optical pulse in excess of 100 Gbps, and highly synchronized in nature at the output port2170of the module. In order to achieve a high gain non-linear medium the EDFA2110can be specially designed. A phase lock loop2130can provide advantageous stability in operation by maintaining a synchronized clock source through modulation of the signal through components2120,2130,2150of the self-contained high-repetition rate pulse generator. To achieve high rep rates in a laser that is limited by its dimensions (length in the case of a linear laser and perimeter in the case of a ring laser), it can be necessary to stimulate intra-cavity generation of the multiples of the fundamental mode. In the active case, an amplitude modulator inserted in the cavity modulates the loss of the system operating as a “threshold gating” device. For this approach to be successful, it can be necessary that the controlling signal to the modulator be referenced to the oscillation of the laser itself to avoid the driving signal “forcing” an external frequency of oscillation on the laser. This can be realized by the introduction of a phase-lock-loop element2130, or a synchronous oscillator circuit to track-and-lock onto the repetition rate of the laser, and regenerate the signal. In the case of a PLL, the RF output can be set to a multiple of the input signal (much as this device is used in cell phone technology), and the rep rate of the laser increased. The signal can then be used for triggering of a pulse generator, or in conjunction with a low-pass filter. A MZ amplitude modulator2150outside the laser cavity can be used to create On-Off Keying (OOK) modulation on the pulse train coming out of the mode-locked laser. FIG.22shows a graphical depiction2200illustrating effects of a loss modulation introduced to the input pulse train2201due to the presence of the amplitude modulator2205with a controlling signal NRZ signal2210made of a bit sequence as illustrated. The resulting signal at the output of the device2220represents an NRZ to RZ converter device for use in telecommunications and scientific applications where the application may benefit from RZ data streams. A clock signal2201(optical input) at a given pulse repetition rate will pass through the modulator2205. At the same time, a controlling signal consisting of a sequence of 1's and 0's can be applied to the RF port of the modulator element2215. When the modulator element2215is biased at minimum transmission, in the absence of a controlling signal the loss experienced by the optical signal can be at its maximum. In the presence of the RF signal (1's), the loss will drop to a minimum (OPEN GATE), thus working as an On-Off Keying modulation device. The pulse width of the output optical signal is typically much less than the time slot occupied by a single bit of information (even less than a half clock period of a NRZ scheme) making this system genuinely RZ as identified by element2220. FIG.23illustrates an example system2300for generation of high optical harmonic USPL pulse streams having high pulse repetition rate using a saturable absorber (SA) device2330. The SA device2330can in some examples include carbon nanotubes. Passive mode-locked fiber lasers using carbon nanotubes SA (CNT-SA) make another attractive option for high rep rate sources due to their ability to generate high harmonics of the fundamental rep rate. In the approach described, a closed, self-contained optical cavity is established, in which two Faraday reflectors2301and2350form the optical cavity. Although a high-power erbium doped fiber amplifier (EDFA)2310is shown inFIG.23, any inverting medium producing a non-linear optical cavity can be used. A seed laser2315, such as for example a 980 nm pump laser as shown inFIG.23can be used in generating a high-repetition rate optical train. In particular, any suitable pump laser may be considered in terms of optical wavelength and pulse repetition rate required. The SA element2330can be placed within the cavity to establish required optical pulse characteristics2350as required through design requirements. FIG.23shows the schematics of an example of a laser that can be used in one or more implementations of the current subject matter. Unlike the active laser shown inFIG.22, here the MZ modulator can be replaced by the SA element2330. A technique similar to those described herein can be utilized within a fiber based plant distribution system or within a FSO system, for terrestrial, submarine or FSO system either in air, space or submarine applications. FIG.24illustrates an approach to providing time-domain multiplexing (TDM) where the TDM multiplexes a pulse train using parallel time delay channels. In some instances, it can become important to manipulate the delay channels such that they are “consistent” relative to each another. The frequency of the output multiplexed pulse train can ideally as much as possible be insensitive to environmental changes. For that, a proposed feedback loop control system is design to correct the delay units for any fluctuations which compromises the stability of the output rep rate. FIG.24shows a diagram of an example of a delay control system2400. The control loop can be implemented in one of several ways consistent with the current subject matter.FIG.24describes one possibility for illustration purposes. The input pulse train enters the TDM and multiplexes into N paths, each with its own delay line. If the paths are made of low “bending-loss” fiber waveguides, then each path can be coiled around a cylindrical piezoelectric actuator (PZ) of radius R. The actuators generally expand in a radial direction as a result of a controlling voltage (Vc). This expansion ΔR, which is linearly proportional to Vc, causes a change in length of the fiber ΔL=2πNAR, where N is the number of fiber turns around the PZ. For Terahertz multiplexing, the delay between the pulses (and thus of PZ1) must be 1 picosecond. This can require a change in length equals to 200 microns, which, for a one turn PZ actuator corresponds to a ΔR=32.5 microns. Most commercially available piezoelectric actuators are highly linear and operate well within this range. The control mechanism can, therefore, be based on several PZ actuators, each with a number of turns corresponding to multiples of the first delay, i.e. (32, 64, 96 microns, etc.), and controlled by a single voltage Vc. The controlling voltage is determined by the feedback system, which compares the frequency of the output signal using a 1/N divider, with the frequency of the input signal, using a phase comparator (PC). The frequency of the “slow” input optical signal (represented by the waveform withTRT inFIG.24is converted to an RF signal using photo-detector PDin. In order to reduce the effects of electronic jitter, a “differentiator” (or high pass filter) can be applied to the RF signal as to steepen the leading edges of the pulses. A phase-locked loop is used to track-and-lock the signal, and to regenerate it into a 50% duty-cycle waveform. Likewise, in the output side, the optical signal is picked-up by photo-detector PDout, high-pass filtered, and regenerated using the clock output port of a clock-and-data recovery system. The clock of the output signal, which has a frequency N times the frequency of the input signal, is send to an N times frequency divider before going to the phase comparator. From the phase comparator, a DC voltage level representing the mismatch between the input and output signals (much as what is used in the architecture of PLL circuits) indicates the direction of correction for the actuators. A low-pass filter adds a time constant to the system to enhance its insensitivity to spurious noise. A CDR can advantageously be used in the output, as opposed to a PLL such that the output signal may, or may not, be modulated. This system can be designed to work in both un-modulated, and “intra-TDM modulated” (i.e. one modulator at each delay path) schemes. However, this is a completely deterministic approach to compensating for variations on the length of the delay lines. Ideally, and within a practical standpoint, the delay paths should all be referenced to the same “thermal level” i.e. be sensitive to the same thermal changes simultaneously. In the event that each line senses different variation, this system would not be able to correct for that in real time. In the alternative, a completely statistical approach can include summing of op amp circuits (S1 . . . SN) to deliver the controlling voltage to the actuators. Using such an approach, input voltages (V1 to VN) can be used to compensate for discrepancies in length between the lines, in a completely static sense, otherwise they can be used for initial fine adjustments to the system. The approach typically must also compensate or at least take into account any bending loss requirements of the fibers used. Some new fibers just coming out in the market may have a critical radius of only a few millimeters. In the event that each path delay line senses different variation in temperature or experiences uncorrelated length changes due to spurious localized noise, the previously described approach, as is, may suffer from difficulties in performing a real time correction. A more robust approach operating in a completely statistical sense can be used consistent with some implementations of the current subject matter. In such an approach, summing op amp circuits (S1 . . . SN) can be used to deliver the controlling voltages to the actuators. In this case, the input voltages (V1 to VN) can be used to compensate for discrepancies in length between the delay lines in a completely statistical sense, otherwise they can only be useful for initial fine adjustments to the system (calibration). Referring again toFIG.24, an incoming USPL source identified as element2401is coupled to an optical coupler element2403, such that one leg of the coupler connects to an optical photodiode selected for operation at the operational data rate of2401. Using standard electronic filtering techniques described by elements2404,2405, and2406an electrical square wave representation of the incoming USPL signal is extracted and identified by element2407. The second optical leg of coupler2403is interfaced into an appropriate optical splitter element identified by2410, where the incoming signal into2410is split into206parallel optical paths. Also illustrated are variable rate optical delay lines established in parallel for each of the parallel branches of the splitter element2410. The parallel piezoelectric elements are identified by elements242N and are controlled electronically through feedback circuitry within the diagram. A control voltage identified by Vc is generated through a photodiode2485along with electronic circuitry elements2480and2475. The clock-and-data Recovery (CDR) element2475produces a clock source that is used in controlling each of the PZ elements. Optical paths identified as244N are combined after a proper delay is introduced into each leg of element2410. The pulse multiplied USPL signal2490is thereby generated. FIG.25Ashows a schematic of a fiber PZ actuator2500, andFIG.25Bshows a graph2590of radius vs. voltage for such an actuator. Together, these drawings illustrate operation of a PZ actuator for increasing the pulse repetition rate of an incoming USPL pulse train through induced optical delay. Although shown for use as an element for enhancing pulse repetition rate generation for USPL signals, the same technique can be used for other optical devices requiring or benefiting from optical delay. The basic structure for the device is a fiber based PZ actuator2501. When a voltage2550is applied to electrodes2520a voltage induced stress results within the fiber, causing a time delay of the optical signal traveling through the fiber. By varying applied voltage a performance curve of optical delay vs. applied voltage is obtained as shown in the graph2590ofFIG.25B. FIG.26shows a diagram illustrating features of an example statistical corrector2600. The coarse correction controller2640shown inFIG.26corresponds to the system described in the previous section, which can correct for length variations simultaneously picked up by all delay lines. As mentioned, these variations are expected to occur in a time scale much slower than the “infra delay line” spurious variations. This latter effect can manifest itself as a period-to-period jitter introduced on the system. This type of jitter can be monitored using an RF Spectrum Analyzer (RFA), causing the rep rate line of the system to display “side lines” (or side bands), which are the result of the analyzer beating together noisy frequencies resulting from uneven time intervals between consecutive pulses. One such pattern can be processed using an analog-to-digital converter (ADC) and saved as an array of values, which can then be fed to a neural network (NN) machine. Neural network machines are known to possess excellent adaptability characteristics that allow them to essentially learn patterns from outside events by adapting to new set of input and outputs. A set of inputs in this case can be generated from a set of “imperfect observations”, i.e. “noisy” outputs of the TDM system as detected by the RFA and converted to digital arrays by the ADC ({f1, f2, . . . , fN}, where fi is a frequency component picked up by the RFA). A set of outputs can be generated from the corrections ({V1, V2, . . . , VN}, where Vt is a compensating input voltage to the summing op amp) required to rid the output frequency set from the undesired excess frequency noise, which is due to the outside perturbations to the system. With a sufficiently large number of {f,V} pairs, where f, V are frequency, voltage arrays, one can build an statistical set to train the NN machine to learn the underlying pattern associated with the presence of the intra-channel noise. These machines can be found commercially in an IC format from several manufacturers, or implemented as software and used in conjunction with a computer feedback control mechanism. A single layer Perceptron type neural network, or ADALINE (Adaptive Linear Neuron or later Adaptive Linear Element), should be sufficient to accomplish the task. Similar to the description provided above in relation toFIG.24, a statistical corrector element2670can include electronic circuitry that is similar to or that provides similar functionality as the electrical circuitry elements2480and2475and the photodiode2485ofFIG.24. For the approach illustrated inFIG.26, a RF spectra analyzer2695along with a Neural Network2670and a Coarse Correction Controller element2640are used to perform the requirement of optical delay introduced into a parallel series of PZ elements262N. FIG.27illustrates concepts and capabilities of approaches consistent with implementations of the current subject matter in which performance, accuracy, and resolution can be improved through replacement of piezoelectric disk (PZ) modules identified by elements2795and272N, where compact micro fiber based collimators (MFC)2795encircled by ceramic disks are used to obtain optical delay lines. Although illustrating a technique for increasing the native pulse repetition rate for a USPL pulse train, the design illustrated is not limited to such applications but can be applied or extended to other needs within the optical sector wherever optical delay is required. In so doing, a more controlled amount of temporal delay can be introduced within each MFC element of the circuit. The improvement through the use of utilizing MFC elements can improve response, resolution, and the achievement of reproducing in a rapid fashion required voltage responses in a mass production means. The concept identified withinFIG.27can be incorporated into precisely produced elements that can serve as complementary paired units for use in reducing USPL pulse-to-pulse jitter as well as for the purposes of data encryption needs. With further reference toFIG.27, a USPL source2701having a certain pulse repetition rate is split into a preselected number of optical paths271N (which can number other than 206) as identified by splitter element2705. An appropriately controlled delay273N is introduced into each parallel leg of the split optical paths271N using elements described by2795and272N. The resulting delayed paths274N are added together through an optical combiner element2760. The pulse multiplied USPL signal2780results. One potential disadvantage of some previously available TDM designs, in which fibers are “wrapped-around” the piezo actuators, is that the mechanism must comply with the bending loss requirements of the fibers used. Some new fibers just coming out in the market have critical radius of only a few millimeters. To correct for this issue, implementations of the current subject matter can use of micro-machined air-gap U-brackets in lieu of the fiber-wrapped cylindrical piezo elements.FIG.27illustrates this principle. In this approach, the piezoelectric actuators (PZ1, . . . PZN) can be replaced by air gap U-bracket structures constructed using micro-fiber collimators (MFCs), and micro-rings made of a piezoelectric material. In this case, however, the piezoelectric actuator expands longitudinally, increasing (or decreasing) the air gap distance between the collimators, in response to the controlling voltages (V1, V2, . . . VN). As in the case of the cylindrical piezoelectric, a single voltage Vc can be use to drive all the piezoelectric devices, provided that the gains of each channel (G1, G2, . . . GN) are adjusted accordingly to provide the correct expansion for each line. Ideally, except for inherent biases to the system (i.e. intrinsic differences between op amps), the gain adjustments should be as G1, 2G1, 3G1, and so forth, in order to provide expansions, which are multiples of the TRT/N. Another way of implementing such an approach can be the use of multiple piezoelectric rings at the channels. In that manner, one can have channels with 1, 2, 3, N piezoelectric rings driven by the same voltage with all amplifiers at the same gain. FIG.28provides a conceptual presentation of an optical chip system2800to successfully bridge between two remote 10 GigE switches. Ideally, such a connection can perform similarly to a simple piece of fiber. The timing of the TDM chip can be driven by the 10 GigE switch. In reference toFIG.28, a USPL source2805having a predetermined native pulse repetition rate identified by2806connects to an optical Pulse multiplier chip2807. Element2807is designed to convert the incoming pulse repetition rate signal2806into an appropriate level for operation with high-speed network Ethernet switches as identified by2801. Switch2801provides a reference signal2802used to modulate signal2809by way of a standard electro-optic modulator2820at the data rate of interest. A resulting RZ optical signal is generated as shown in element2840. An alternative to having the timing run from the 10 GigE switch is to buildup the USPL to a Terabit/second (or faster) with a multiplier photonic chip, and then modulate this Terabit/second signal directly from the 10 GigE switch. Each bit will have 100 or so pulses. An advantage of this approach can be the elimination of a need for separate timing signals to be run from the switch to the USPL. The USPL via multiplier chip just has to pump out the Terabit/second pulses. Another advantage is that the output of the Multiplier Chip does not have to be exactly 10.313 or 103.12 Gbps. It just has to at a rate at about 1 Terabit/second. Where each 10 GigE bit has 100 or 101 or 99 pulses, this limitation is a non-issue. Another advantage is each bit will have many 10 USPL, so the 10 GigE signal will have the atmospheric propagation (fog and scintillation) advantage. Another advantage can be realized at the receiver end. It should be easier for a detector to detect a bit if that bit has 100 or so USPL pulses within that single bit. This could result in improved receiver sensitivity, and thus allow improved range for the FSO system. An additional advantage can be realized in that upgrading to 100 GigE can be as simple as replacing the 10 GigE switch with a 100 GigE switch. Each bit will have around 10 pulses in this case. From a purely signal processing perspective this approach demonstrates an efficient way to send data and clock combined in a single transmission stream. Much like a “sampling” of the bits using an optical pulse stream, this approach has the advantage that the bit “size” is determined by the maximum number of pulses the it carries, therefore establishing a basis for counting bits as they arrive at the receiving end. In other words, if the bit unit has a time slot which can fit N pulses, the clock of the system can be established as “one new bit of information” after every 5th. A technique similar to those described herein can be utilized within a fiber based plant distribution system or within a FSO system, for terrestrial, submarine or FSO system either in air, space or submarine applications, and illustrates for the first time how the interconnection from USPL sources to optical network elements is achieved for networking applications. FIG.29shows a system2900that illustrates a conceptual network extension for the design concept reflected withinFIG.28. As multiple USPL sources2901,2902,2903(it should be noted that while three are shown, any number is within the scope of the current subject matter), each modulated through dedicated optical switches and USPL laser Multiplier Chips circuits are configured in a WDM arrangement. As described in reference toFIG.28, electrical signals from each Ethernet switch can be used to modulate dedicated optical modulators2911,2922,2928for each optical path. Optical power for each segment of the system can be provided by optical amplification elements2931,2932,2933for amplification purposes. Each amplified USPL path can then be interfaced to an appropriate optical combiner2940for transport to a network2950, and can be either free space or fiber based as required. The output from the WDM module can then be configured to a transmitting element102for FSO transport or into fiber plant equipment. The technique described herein can be utilized within a fiber based plant distribution system or within a FSO system, for terrestrial, submarine or FSO system either in; air, space or submarine applications, and illustrates for the first time how the interconnection from USPL sources to optical network elements is achieved for networking applications. FIG.30shows the schematics of an experimental setup for implementations of the current subject matter to include construction of a computer assisted system to control the pulse width of an all-fiber mode-locked laser using recursive linear polarization adjustments with simultaneous stabilization of the cavity's repetition rate using a synchronous self-regenerative mechanism. The design can also offer tune-ability of the repetition rate, and pulse width. The fiber ring laser is represented by the inner blue loop, where all intra-cavity fiber branches are coded in blue, except for the positive high dispersion fiber outside the loop, which is part of the fiber grating compressor (coded in dark brown). The outside loops represent the feedback active systems. FIG.30shows a diagram of a system3000illustrating features of an USPL module providing control of pulse width and pulse repetition rate control through mirrors (M1, M2), gratings (G1,G2), lengths (L1,L2), second-harmonic generator (SHG), photomultiplier tube (PMT), lock-in amplifier (LIA), data acquisition system (DAC), detector (DET), clock-extraction mechanism (CLK), frequency-to-voltage controller (FVC), high-voltage driver (HVD), reference signal (REF), pulse-generator (PGEN), amplitude modulator (AM), isolator (ISO), piezoelectric actuator (PZT), optical coupler (OC), polarizer (POL), and polarization controller (PC) all serve to provide control of pulse repetition rate and pulse width control. The passive mode-locking mechanism can be based on nonlinear polarization rotation (NPR), which can be used in mode-locked fiber lasers. In this mechanism, weakly birefringent single mode fibers (SMF) can be used to create elliptically polarized light in a propagating pulse. As the pulse travels along the fiber, it experiences a nonlinear effect, where an intensity dependent polarization rotation occurs. By the time the pulse reaches the polarization controller (PC)3001the polarization state of the high intensity portion of the pulse experiences more rotation than the lower intensity one. The controller can perform the function of rotating the high intensity polarization component of the pulse, bringing its orientation as nearly aligned to the axis of the polarizer (POL) as possible. Consequently, as the pulse passes through the polarizer, its lower intensity components experience more attenuation than the high intensity components. The pulse coming out of the polarizer is, therefore, narrowed, and the entire process works as a Fast-Saturable Absorber (FSA). This nonlinear effect works in conjunction with the Group-Velocity Dispersion (GVD) of the loop, and, after a number of round trips, a situation of stability occurs, and passive mode-locking is achieved. The overall GVD of the optical loop can be tailored to produce, within a margin of error, an specific desired pulse width, by using different types of fibers (such as single mode, dispersion shifted, polarization maintaining, etc. . . . ), and adding up their contributions to the average GVD of the laser. An active control of the linear polarization rotation from the PC can greatly improve the performance of the laser. This can be achieved using a feedback system that tracks down the evolution of the pulse width. This system, represented by the outer loop inFIG.1, can be used to maximize compression, and consequently, the average power of the pulse. A pulse coming out of the fiber ring laser through an OC is expected to have a width on the order of a few picoseconds. An external pulse compression scheme, which uses a fiber grating compressor, is used to narrow the pulse to a sub 100 fsec range. This technique has been extensively used in many reported experiments, leading to high energy, high power, USPL pulses. Here, the narrowed pulse is focused on a Second-Harmonic Generator (SHG) crystal and detected using a Photo-Multiplying Tube (PMT). The lock-in-amplifier (LIA) provides an output DC signal to a Data Acquisition Card (DAC). This signal follows variations of the pulse width by tracking increases, or decreases, in the pulses' peak power. A similar technique has been successfully used in the past, except that, in that case, a Spatial Light Modulator (SLM) was used instead. Here, a programmable servo-mechanism directly controls the linear polarization rotation using actuators on the PC. With the DC signal data provided by the DAC, a decision-making software (such as, but not limited to, LABVIEW or MATLAB SIMULINK) can be developed to control the servo-mechanism, which in turn adjusts the angle of rotation of the input pulse relative to the polarizer's axis. These adjustments, performed by the actuators, are achieved using stress induced birefringence. For instance, if the pulse width decreases, the mechanism will prompt the actuator to follow a certain direction of the linear angular rotation to compensate for that, and if the pulse width increases, it will act in the opposite direction, both aimed at maximizing the average output power. A self-regenerative feedback system synchronized to the repetition rate of the optical oscillation, and used as a driving signal to an amplitude modulator (AM), can regulate the round trip time of the laser. In the active system, the amplitude modulator acts as a threshold gating device by modulating the loss, synchronously with the round trip time. This technique has can successfully stabilize mode-locked lasers in recent reports. A signal picked up from an optical coupler (OC) by a photo-detector (DET) can be electronically locked and regenerated by a clock extraction mechanism (CLK) such as a Phase-Locked Loop or a Synchronous Oscillator. The regenerated signal triggers a Pulse Generator (PGen), which is then used to drive the modulator. In a perfectly synchronized scenario, the AM will “open” every time the pulse passes through it, at each round trip time (TRT). Because the CLK follows variations on TRT, the driving signal of the AM will vary accordingly. An outside reference signal (REF) can be used to tune the repetition rate of the cavity. It can be compared to the recovered signal from the CLK using a mixer, and the output used to drive a Piezoelectric (PZT) system, which can regulate the length of the cavity. Such use of a PZT system to regulate the cavity's length is a well-known concept, and similar designs have already been successfully demonstrated experimentally. Here a linear Frequency-to-Voltage Converter (FVC) may be calibrated to provide an input signal to the PZT's High Voltage Driver (HVD). The PZT will adjust the length of the cavity to match the repetition rate of the REF signal. If, for instance the REF signal increases its frequency, the output of the FVC will decrease, and so will the HV drive level to the piezoelectric-cylinder, forcing it to contract and, consequently increasing the repetition rate of the laser. The opposite occurs when the rep. rate of the reference decreases. It is possible to have the width of the pulse tuned to a “transformed-limited” value using a pair of negative dispersion gratings. This chirped pulse compression technique is well established, and there has been reports of pulse compressions as narrow as 6 fs. The idea is to have the grating pair pulse compressor mounted on a moving stage that translates along a line which sets the separation between the gratings. As the distance changes, so does the compression factor. In an example of a data modulation scheme consistent with implementations of the current subject matter, a passively mode locked laser can be used as the source of ultrafast pulses, which limits our flexibility to change the data modulation rate. In order to scale up the data rate of our system, we need to increase the base repetition rate of our pulse source. Traditionally, the repetition rate of a passively mode locked laser has been increased by either shortening the laser cavity length or by harmonic mode-locking of the laser. Both techniques cause the intra-cavity pulse peak power to decrease, resulting in longer pulse-widths and more unstable mode-locking. One approach to solving this problem involves use of a modified pulse interleaving scheme, by a technique which we call pulse multiplication.FIG.31illustrates this concept. The lower repetition rate pulse train of a well-characterized, well-mode locked laser3101is coupled into an integrated-optical directional coupler3180, where a well-determined fraction of the pulse is tapped off and “re-circulated” in an optical loop with an optical delay3150equal to the desired inter-pulse spacing in the output pulse train, and re-coupled to the output of the directional coupler. For instance, to generate a 1 GHz pulse train from a 10 MHz pulse train, an optical delay of Ins is required, and to enable the 100th pulse in the train to coincide with the input pulse from the 10 MHz source, the optical delay might have to be precisely controlled. The optical delay loop includes optical gain3120to compensate for signal attenuation, dispersion compensation3160to restore pulse-width and active optical delay control3150. Once the pulse multiplication has occurred, the output pulse train is OOK-modulated 3175 with a data stream3182to generated RZ signal3190, and amplified in an erbium-doped fiber amplifier3185to bring the pulse energy up to the same level as that of the input pulse train (or up to the desired output pulse energy level). One or more of the features described herein, whether taken alone or in combination, can be included in various aspects or implementations of the current subject matter. For example, in some aspects, an optical wireless communication system can include at least one USPL laser source, which can optionally include one or more of pico-second, nano-second, femto-second and atto-second type laser sources. An optical wireless communication system can include USPL sources that can be fiber-coupled or free-space coupled to an optical transport system, can be modulated using one or more modulation techniques for point-to-multi-point communications system architectures, and/or can utilize optical transport terminals or telescopes manufactured through one or more of hyperbolic mirror fabrication techniques, conventional Newtonian mirror fabrication techniques, or other techniques that are functionally equivalent or similar. Aspheric optical designs can also or alternatively be used to minimize, reduce, etc. obscuration of a received optical signal. Free-space optical transport systems consistent with implementations of the current subject matter can utilize USPL laser designs that focus a received signal at one ideal point. In some implementations one telescope or other optical element for focusing and delivering light can be considered as a transmitting element and a second telescope or other optical element for focusing and receiving light positioned remotely from the first telescope or other optical element can function as a receiving element to create an optical data-link. Both optical communication platforms can optionally include components necessary to provide both transmit and receive functions, and can be referred to as USPL optical transceivers. Either or both of the telescopes or other optical elements for focusing and delivering light can be coupled to a transmitting USPL source through either via optical fiber or by a free-space coupling to the transmitting element. Either or both of the telescopes or other optical elements for focusing and receiving light can be coupled to a receive endpoint through either optical fiber or a free-space coupling to the optical receiver. A free-space optical (FSO) wireless communication system including one or more USPL sources can be used: within the framework of an optical communications network, in conjunction with the fiber-optic backhaul network (and can be used transparently within optical communications networks within an optical communications network (and can be modulated using On-Off keying (OOK) Non-Return-to-Zero (NRZ), and Return-to-Zero (RZ) modulation techniques, within the 1550 nm optical communications band), within an optical communications network (and can be modulated using Differential-Phase-Shift Keying (DPSK) modulation techniques), within an optical communications network (and can be modulated using commonly used modulation techniques for point-to-point communications system architectures using commonly used free-space optical transceiver terminals), within an optical communications network utilizing D-TEK detection techniques, within a communications network for use in conjunction with Erbium-Doped Fiber Amplifiers (EDFA) as well as high power Erbium-Ytterbium Doped Fiber Amplifiers (Er/Yb-DFA), within an optical communications network (and can be modulated using commonly used modulation techniques for point-to-multi-point communications system architectures), etc. USPL technology can, in some aspects, be utilized as a beacon source to providing optical tracking and beam steering for use in auto-tracking capabilities and for maintaining terminal co-alignment during operation. The recovered clock and data extracted at the receive terminal can be used for multi-hop spans for use in extending network reach. The optical network can be provided with similar benefits in WDM configurations, thereby increasing the magnitude of effective optical bandwidth of the carrier data link. USP laser sources can also or alternatively be polarization multiplexed onto the transmitted optical signal to provide polarization multiplex USP-FSO (PM-USP-FSO) functionality. The recovered clock and data extracted at the receive terminal can be used for multi-hop spans for use in extending network reach, and can include a generic, large bandwidth range of operation for providing data-rate invariant operation. An optical pre-amplifier or semi-conductor optical amplifier (SOA) can be used prior to the optical receiver element and, alternatively or in combination with the recovered clock and data extracted at the receive terminal, can be used for multi-hop spans for use in extending network reach, having a generic, large bandwidth range of operation for providing data-rate invariant operation. Terminal co-alignment can be maintained during operation, such that significant improvement in performance and terminal co-alignment can be realized through the use of USPL technology, through the use of USPL data source as well as providing a improved approach to maintaining transceiver alignment through the use of USPL laser beacons. USPL-FSO transceivers can be utilized in some aspects for performing remote-sensing and detection for signatures of airborne elements using ionization or non-ionization detection techniques, utilizing optical transport terminals manufactured through either the Hyperbolic Mirror Fabrication Techniques or conventional Newtonian designs that focus a received signal at one ideal point. USPL-FSO transceivers consistent with implementations of the current subject matter can be utilized in non-line of sight lasercom applications. USPL-FSO transceivers consistent with implementations of the current subject matter can allow adjustment of the distance at which the scattering effect (enabling NLOS technique) takes place, reception techniques to improve detection sensitivity using DTech detection schemes, and improved bandwidth via broadband detectors including frequency combs. USPL-FSO transceivers consistent with implementations of the current subject matter can be utilized in conjunction with Adaptive Optic (AO) Techniques for performing incoming optical wave-front correction (AO-USPL-FSO). USPL-FSO transceivers consistent with implementations of the current subject matter can be utilized and operate across the infrared wavelength range. USPL-FSO transceivers consistent with implementations of the current subject matter can be utilized in conjunction with optical add-drop and optical multiplexing techniques, in both single-mode as well as multi-mode fiber configurations. A USPL-FSO transceiver consistent with implementations of the current subject matter can be utilized and operated across the infrared wavelength range as a range-finder and spotting apparatus for the purposes of target identification and interrogation applications. In other aspects of the current subject matter, a series of switched network connections, such as for example 10 GigE, 100 GigE, or the like connections can be connected from one point to another, either over fiber or free-space optics, for example via Time Division Multiplexing (TDM). A mode-locked USPL source consistent with implementations of the current subject matter can be used to generate both clock and data streams. Mode-locked lasers can represent a choice of a high performance, high finesse source for clocks in digital communication systems. In this respect, mode-locked fiber lasers—in either linear or ring configuration—can make an attractive candidate of choice, as they can achieve pulse widths of the USPL sources region and repetition rate as high as GHz. High harmonic generation can be achieved using carbon nano-tubes saturable absorbers. Passive mode-locked fiber lasers using carbon nano-tubes saturable absorbers (CNT-SA) make an option for high rep rate sources due to their ability to readily generate high harmonics of the fundamental rep rate. FSO can be used in terrestrial, space and undersea applications. Conditional path lengths control from splitter to aperture can be an important parameter. TDM multiplexes can be employed consistent with implementations of the current subject matter to control the relative temporal time delay between aperture-to-source paths. Each pulse train can be controlled using parallel time delay channels. This technique can be used to control conventional multiple-transmit FSO aperture systems employing WDM as well as TDM systems. USPL laser pulse-to-pulse spacing can be maintained and controlled to precise temporal requirements for both TDM and WDM systems. The techniques described can be used in TDM and WDM fiber based system. The use of TDM multiplexers as described herein can be used implement unique encryption means onto the transmitted optical signal. A complementary TDM multiplexer can be utilized to invert the incoming received signal, and thereby recover the unique signature of the pulse signals. A TDM multiplexer described herein can be utilized to control WDM pulse character for the purpose of WDM encryption. A TDM multiplexer can be used in conventional FSO systems wherein multiple apertures connected to a common source signal are capable of having the temporal delay between pulses controlled to maintain constant path lengths. A TDM multiplexer can be used for TDM fiber based and FSO based systems. A TDM multiplexer can be an enabling technology to control optical pulse train relationship for USPL sources. A TDM multiplexer can be used as an atmospheric link characterization utility across an optical link through measurement of neural correction factor to get same pulse relational ship. Any combination of PZ discs can be used in a transmitter and can have an infinite number of encryption combinations for USPL based systems, both fiber and FSO based. The timing can run from 10 GigE switches or the equivalent and to build up the USPL to a Terabit/second (or faster) rate with a Multiplier Photonic chip, and this Terabit/second signal can be modulated directly from the 10 GigE switch. While operating in a WDM configuration, an interface either to a fiber based system or to a FSO network element can be included. A system can accept an ultrafast optical pulse train and can generate a train of optical pulses with pulse-width, spectral content, chirp characteristics identical to that of the input optical pulse, and with a pulse repetition rate being an integral multiple of that of the input pulse. This can be accomplished by tapping a fraction of the input pulse power in a 2×2 optical coupler with an actively controllable optical coupling coefficient, re-circulating this tapped pulse over one round trip in an optical delay line provided with optical amplification, optical isolation, optical delay (path length) control, optical phase and amplitude modulation, and compensation of temporal and spectral evolution experienced by the optical pulse in the optical delay line for the purpose of minimizing temporal pulse width at the output of the device, and recombining this power with the 2×2 optical coupler. Passive or active optical delay control can be used, as can optical gain utilizing rare-earth-doped optical fiber and/or rare-earth-doped integrated optical device and/or electrically- or optically-pumped semiconductor optical amplification. Dispersion compensation can be provided using fiber-Bragg gratings and/or volume Bragg gratings. Wavelength division multiplexing data modulation of the pulse traversing the delay line can be sued as can pulse code data modulation of the pulse traversing the delay line. The tailoring of conventional USPL sources through synthesis of USPL square wave pulses can be accomplished utilizing micro-lithographic amplitude and phase mask technologies, for FSO applications. The ability to adjust pulse widths using technology and similar approaches to control and actively control pulse with this technology can improve propagation efficiency through FSO transmission links, thereby improving system availability and received optical power levels. Active programmable pulse shapers can be used to actively control USPL pulse-width can include matching real-time atmospheric conditions to maximize propagation through changing environments. One or more of the following techniques can be used in FSO applications to adapt the optical temporal spectrum using techniques: Fourier Transform Pulse shaping, Liquid Crystal Modular (LCM) Arrays, Liquid Crystal on Silicon (LCOS) Technology, Programmable Pulse Shaping using Acousto-optic modulators (AOM), Acousto-optic Programmable Dispersive Filter (AOPDF), and Polarization Pulse Shaping. FIG.32shows a process flow chart3200illustrating features of a method, one or more of which can appear in implementations of the current subject matter. At3202, a beam of light pulses each having a duration of approximately 1 nanosecond or shorter is generated. At3204, a modulation signal is applied to the beam to generate a modulated optical signal. The modulation signal carrying data for transmission to a remote receiving apparatus. The modulated optical signal is received at an optical transceiver within an optical communication platform at3206, and at3210the modulated optical signal is transmitted using the optical transceiver for receipt by the second optical communication apparatus FIG.33shows another process flow chart3300illustrating features of a method, one or more of which can appear in implementations of the current subject matter. At3302, a beam of light pulses each having a duration of approximately 1 nanosecond or shorter is generated, for example using a USPL source. The beam of light pulses is transmitted at3304toward a target atmospheric region via an optical transceiver. At3306, optical information received at the optical transceiver as a result of optical backscattering of the beam of light pulses from one or more objects in the target atmospheric region is analyzed. FIG.34shows another process flow chart3400illustrating features of a method, one or more of which can appear in implementations of the current subject matter. At3402, first and second beams comprising light pulses are generated, for example by a USPL source. At3404, a first modulation signal is applied to the first beam to generate a first modulated optical signal and a second modulation signal is applied to the second beam to generate a second modulated optical signal. A first polarization state of the first modulated optical signal is adjusted at3406. Optionally, a second polarization states of the second modulated optical signal can also be adjusted. At3410, the first modulated optical signal having the adjusted first polarization state is multiplexed with the second modulated signal. At3412, the multiplexed first modulated optical signal having the adjusted first polarization state with the second modulated signal is transmitted by an optical transceiver for receipt by a second optical communication apparatus. FIGS.35A and35Bshow exemplary nodes that can be used for transmitting and/or receiving information. Transmit node3510and receiving node3530may be communications platforms as described above, including with reference toFIGS.1-9. Additionally, while transmit node3510is shown with components for generating and transmitting a data-bearing optical signal, and while receiving node3530is shown with components for receiving and extracting data from an optical signal, these components may be combined in a single node configured to both transmit and receive optical signals. In some embodiments, for example, a telescope3522may act as both an aperture for transmitting and receiving optical signals. FIG.35Ashows an exemplary transmit node3510. In some embodiments, transmit node3510may include a source3512. In some embodiments, the source3512may be an USPL source, superluminescent diode, or other source. In other embodiments, the source3512may be a continuous wave source. Preferably, the source3512may be configured to generate a beam of light pulses, in which each pulse has a coherence length of less than 400 microns. The coherence length of the source is determined as: L=Cλ2Δλ, where C is a shaping constant equal to ½, λ is the central wavelength of the pulse, and AA is the full width at half maximum (FWHM) spectral width of the pulse. In some embodiments, the coherence length may be less than 1 mm, less than 600 microns, less than 400 microns, less than 200 microns, less than 100 microns, less than 50 microns, or less than 1 micron. In embodiments where a continuous wave source is used, these values may refer to the coherence length of the continuous wave beam, rather than that of the pulses. In some embodiments, the source3512may have a central wavelength in the infrared range. For example, the central wavelength of the source3512may be between 1400 nm and 1700 nm. In some embodiments, the source3512may be configured to output pulses at a repetition rate of at least 50 MHz, 100 MHz, 200 MHz, 500 MHz, 800 MHz, 1 GHz, 1.25 GHz, 1.5 GHz, 2 GHz, 5 GHz, or 10 GHz. The source3512may include (internally or externally) a pulse multiplier, as generally described above, including with reference toFIGS.15and18-20. In some embodiments, the pulse width may be less than 10 ns, less than 1 ns, less than 500 ps, less than 300 ps, less than 100 ps, less than 50 ps, less than 10 ps, less than 1 ps, less than 700 fs, less than 500 fs, less than 300 fs, less than 200 fs, or less than 100 fs. Transmit node3510may optionally include a splitter3514. Splitter3514may be configured to split pulses from source3512into a plurality of separated pulses having different wavelength bands. For example, a pulse having an original spectral width of 1500-1600 nm could be split into twenty-five pulses, each having a respective spectral width of 4 nm from 1500 nm to 1600 nm (e.g., 1500-1504 nm, 1504-1508 nm, 1508-1512 nm, and so on). Splitter3514may use any known beam-splitting mechanism. Each of the plurality of separated pulses may have coherence lengths of less than 1 mm, less than 600 microns, less than 400 microns, less than 200 microns, less than 100 microns, less than 50 microns, or less than 1 micron. Transmit node3510may include one or more modulators3516. In some embodiments, each of the modulators3516may be a Mach-Zehnder Modulator (MZM). The modulators3516may receive a data signal indicating data to be transmitted in an optical beam, and based on that data signal, may encode the data into the pulses of the beam using on-off keying or other modulation techniques. In some embodiments, the modulators3516may allow pulses to pass to indicate a ‘1’ and may block or reduce the amplitude of a pulse to indicate a ‘0’ in a bit stream. In embodiments where the beam is split, each of a plurality of separated pulses may be directed to a respective modulator3516of a plurality of modulators. In other embodiments, each of the plurality of separated pulses may be modulated by a single modulator3516. For example, the separated pulses may be delayed and staggered in time relative to one another, and the modulator3516may encode data into each pulse at a higher repetition rate than the pulse-generating repetition rate of the source. In a case where the source3512generates pulses at a rate of at least 1 GHz, for example, the splitter may split each pulse into twenty-five or more separated pulses, which can be modulated by one or more modulators3516to encode data at a rate of at least 25 Gbps. In some embodiments, the source may generate pulses at a rate of at least 1 GHz, and the splitter may split each pulse into at least ten, at least twenty, at thirty, at least forty, or at least fifty separated pulses, to produce data rates of at least 10 Gbps, at least 20 Gbps, at least 30 Gpbs, at least 40 Gpbs, or at least 50 Gbps. In some embodiments, the FWHM bandwidth of the source may be at least 100 nm, at least 150 nm, or at least 200 nm, which may allow pulses to be split into more separated pulses without reducing the coherence length of those pulses below the values described below with respect toFIGS.40and41. After being modulated, the pulses (optionally, the separated pulses in the case where a splitter is used) may be passed to an optional thresholding filter3518. In some embodiments, the thresholding filter may be a saturable absorber (or a different nonlinear device) that attenuates weak pulses and transmits strong pulses. The thresholding filter3518may be configured to eliminate or substantially diminish pulses below a defined threshold, while allowing pulses above that threshold to pass. In some embodiments, modulator3516may significantly diminish pulses where a “0” is intended to be transmitted, but it may be imperfect and some amount of optical energy may pass through, which, when amplified by amplifier3520, could produce signals strong enough to generate bit errors. By using a thresholding filter3518, pulses that are intended to be eliminated may be more fully eliminated, thereby improving the system's data transmission accuracy. The modulated pulses may be passed to an amplifier3520, which may increase the magnitude of the pulses for transmission by telescope3522(which may be, for example, an aperture and/or lens). In cases where a splitter is used, the separated pulses may be recombined using a recombiner (not shown) before or after being passed to amplifier3520. FIG.35Bshows an exemplary embodiment of a receiving node3530, which may be configured to receive and extract data from an optical beam transmitted by, e.g., a transmit node3510. Receiving node3530may include an aperture3532, an optional splitter3534, and one or more photoreceivers3536, which may have specific characteristics in relation to the source, as described in detail below. The photoreceivers3536may include a photodiode and processing circuitry. In some embodiments, the photoreceivers3536may be, for example, an avalanche photodiode. In some embodiments, the processing circuitry of a photoreceiver may determine whether received light in a detection window exceeds a detection threshold and output bit data (e.g., a ‘0’ or ‘1’) for that window based on the result of that determination. Receiving node3530may be an optical communications platform as described above. In some embodiments, the components of transmit node3510and receiving node3530may be included in a single transceiver node. Aperture3532may be configured to receive an optical signal, such as an optical beam transmitted by a transmit node3510as described inFIG.35A. In some embodiments, the light received at aperture3532may pass through a filter that screens wavelengths of light that are not near the center wavelength of the source. For example, the source in the transmit node may have a center wavelength between 1500 nm and 1700 nm, and the filter at the receiving node3530may block or reduce light outside of the source band. For example, the filter may reduce a magnitude of light below 1500 nm. Optionally, the filter may additionally block longer wavelengths of light, or the threshold may be set at lower wavelengths, such as at 1480 nm or 1460 nm. Optionally, receive node3530may include a splitter3534, which may split pulses in a received beam into a plurality of separated pulses of different wavelength bands. In a case where the pulses are split and separately modulated at the transmit node3510, the pulses may be split into the same wavelength bands by the splitter3534in the receive node. The pulses (combined pulses or separated pulses, in the case where a splitter is used) may then be processed by one or more photoreceivers3536. In embodiments where a pulse is split into a plurality of separated pulses, each pulse may be directed to a respective photoreceiver, which may be configured to determine whether an “on” or “off” signal was transmitted in a given detection window. In some embodiments, encoding modalities other than on-off keying may be used, such as frequency modulation. Additional detail regarding photoreceivers3536is provided below with respect to FIG. FIG.36shows an exemplary arrangement in which data is transmitted from a first communications network3542to a second communications network3544over an optical communication distance D using a transmit node3510and a receiving node3530, such as those described above with respect toFIGS.35A-35B. Data may be received from optical communications network3542encoded into an optical beam and transmitted across optical communications distance D using transmit node3510. Receiving node3530may receive the optical beam, extract the transmitted data, and pass the data to communications network3544. In some embodiments, data from communications3544may also be transmitted from node3530back to node3510, which may pass that data to communications network3542to enable two-way communication. In some embodiments, optical communication distance may be at least 0.5 miles, at least 1 mile, at least 2 miles, at least 3 miles, at least 5 miles, at least 7 miles, at least 10 miles, or at least 20 miles. FIG.37shows an exemplary beam traveling over an optical communication distance D, such as 1 mile, through a perfectly uniform refractive index medium. Even in a medium of perfectly constant index of refraction, the beam will spread naturally due to diffraction, however the beam remains the same shape and simply expands by an amount that is proportional to the propagation distance, and there are no beam scintillation effects in a uniform index of refraction medium. FIG.38provides a diagrammatic representation of photons in a beam traveling through a variably refractive medium. The atmosphere has fluctuations in temperature, density, pressure, humidity, aerosols, wind, convection, and other parameters, which causes a refractive index of the atmosphere to vary. As an optical beam travels through the atmosphere or other variably refractive medium such as water, photons within the beam may be refracted slightly differently than other photons. As shown inFIG.38, different ray paths within the beam may be refracted differently due to variations in the refractive index in the variably refractive medium. As a result, in a system such as that shown inFIG.35where a free space optical beam is transmitted over a sufficiently large optical communication distance D and received at a receiving node, different photons within a single pulse may take paths of different lengths to reach the receiving node and may arrive at different times. These differences in path length, and the time required for a photon to travel these distances, can produce coherent interference and diminish signal quality in a free space optical communications system if the time delays are less than the coherence length of the source. Solutions for this problem are described herein, including with reference toFIGS.40and41and as applied within a system such as those shown inFIGS.35A,35B, and36. In addition to variance in path length, photons in a pulse may travel at variable speeds to due to variations in atmospheric conditions, including humidity, temperature, and density. Because different photons in a pulse travel though slightly different atmospheric conditions, the photons may travel at different speeds and arrive at different times. Additionally, different wavelengths of light within a pulse may travel at different speeds, which can further broaden a pulse as it travels through a variably refractive medium. FIG.39shows a diagrammatic representation of a pulse as launched by a transmitter and as received by a photoreceiver. As shown inFIG.39, the pulse may have a 90 femtosecond pulse width when it is transmitted by a transmit node. The pulse may then travel over an optical transmission distance where it may be received by a photoreceptor having a detection window4020of a defined duration, such as 500 picoseconds. When the pulse is received by the photoreceiver, its received pulsewidth may be broadened by passing through the variably refractive medium, as described above with respect toFIGS.37-38. Due to variance in path lengths traveled by the beams and variance in atmospheric conditions through which the beams travel, different photons may arrive at the detector at different times according to a distribution curve, which may have a temporal duration that is longer than the pulse duration at launch. The amount of broadening can vary depending on the length of the optical communication distance and atmospheric conditions, including humidity, temperature, density, and the presence of aerosols such as fog. This broadening can be the order of picoseconds or more in some conditions. The pulse may have a temporal distribution curve as shown. While a normal temporal distribution curve is shown, other pulse shapes are possible. By making the width of the curve4010longer (e.g., 3× longer) than the coherence length of pulses that are launched, coherent beam interference and coherent beam scintillation may be reduced. FIG.40shows an exemplary temporal distribution curve of a short-duration (e.g., approximately 100 femtosecond) pulse4010that traveled a substantial distance (e.g., one mile) through a variably refractive medium and been temporally broadened. The pulse, as it arrives at the photoreceiver, may have a FWHM duration4030and a coherence time4040, which may be equal to a coherence length of the pulse divided by the speed of light through the variably refractive medium. In some embodiments, the FWHM duration4030may be greater than the coherence time4040of the pulse. Preferably, the FWHM duration4030may be at least 2×, at least 3×, at least 4×, at least 5×, at least 6×, at least 8×, at least 10×, or at least 12× the coherence time4040of the pulse. By ensuring that the FWHM duration4030of the pulse as received at the photoreceiver is relatively large as compared to the coherence time4040of the pulse4010, interference between the different ray paths of the pulse as they arrive at the photoreceivers at different times may be reduced, and a signal with reduced noise and higher quality may arrive at the photoreceiver. The photoreceiver may have a detection window4020of a specified duration. A shorter detection window generally allows higher data throughput. For example, in a system that uses on-off keying for data modulation, a photoreceiver having a detection window of 1 nanosecond can extract up to 1 Gbps while a photoreceiver having a detection window of 100 picoseconds can extract up to 10 Gbps. The photoreceiver may have repeating detection windows of less than 100 ns, less than 10 ns, less than 1 ns, less than 100 ps, or less than 10 ps. Pulse length and temporal broadening can, however, cause photons from a pulse intended to be received in one detection window to fall into an adjacent detection window. In the case where the adjacent detection window should not receive transmitted photons (e.g., because a ‘0’ is transmitted in that bit position), this phenomenon can produce bit errors. Accordingly, to maximize data transmission accuracy, it is important that the FWHM duration4030of the pulse as received at the photoreceiver be greater (and preferably at least three times as large) than the coherence length4040of the pulse, while at the same time, the FWHM duration4030of the pulse as received at the photoreceiver should also be substantially less than the detection window4020of the photoreceiver. For example, the detection window4020may be at least 2×, at least 5×, at least 6×, at least 7×, at least 8×, at least 10×, or at least 20× as large as the FWHM duration4030of the pulse as received at the photoreceiver. Preferably, at least 95%, at least 99%, or at least 99.99% of the photons in a pulse that arrive at the photoreceiver may arrive at a respective arrival time that is spaced from a center4040of the temporal distribution curve of the pulse by a respective time difference that is less than half of the detection window duration of the photoreceiver. Note that although the center4040of the temporal distribution curve of the pulse is shown at the center of the detection window4020, this need not be the case, and pulses may arrive earlier or later than the midpoint of a detection window. It may be preferable that the center4040of the temporal distribution curve be at or near the center of the detection window4020to reduce the potential for photons in a pulse to spill over into an adjacent detection window. In some embodiments, the center4040of the temporal distribution curve may be less than 100 picoseconds, 50 picoseconds, 20 picoseconds, 10 picoseconds, 5 picoseconds, 1 picosecond, 800 femtoseconds, or 500 femtoseconds from the center of the detection window4020. By specifying relationships between the coherence time4040of the pulse, the FWHM duration4030of the pulse as it arrives at the photoreceiver, and the detection window4020of the photoreceiver in the manner described herein, data transmission accuracy and effective transmission range can be greatly improved (see below discussion with respect toFIG.42for test results). The FWHM duration4030of the pulse as it arrives at the photoreceiver may vary depending on the pulse length as transmitted from the source, the medium through which the pulse travels (e.g., atmospheric pressure, temperature, sunlight intensity, aerosols), and the distance over which the pulse travels to reach the photoreceiver. Accordingly, the coherence time4040of the pulse may need to be decreased and/or the detection window4020of one or more photoreceivers may need to be increased depending on conditions for the optical communication system. Decreasing coherence time4040and increasing detection window4020may thus improve data transmission quality while negatively impacting data throughput. In some embodiments, the system may be configured to determine a data transmission quality of the system (e.g., a bit error rate or a measurement of signal values above or below a detection threshold), and in response to the determined data transmission quality, modify either or both of the coherence time4040of the pulse or the detection window duration4020of the photoreceiver. Similarly, when using a source that can continuously emit light, such as a continuous wave source or a superluminescent diode, the emitted light can be gated into pulses (or otherwise converted into pulses using data modulation or other known techniques) that occupy only a relatively small fraction of the duration of the detection window, and those pulses may be timed to arrive at or near the centers of the detection windows of the photoreceiver. Gating and timing the pulses in this manner can reduce the risk that photons in an “on” window (where light is intended to be transmitted) may spill over into an “off” window (where light is not intended to be transmitted) and produce bit errors. The pulse durations and positions relative to the detection windows described above may thus also apply to pulses generated using sources that can continuously emit light. In such cases, although the sources can continuously emit light, the effective output may be “off” for a majority of the time even during “on” transmission windows where light is intended to be transmitted, so that sufficient space may be left between the center of the pulse and the ends of the detection window to avoid spillover. For example, during an “on” bit window where light is intended to be transmitted, the effective output from the continuous emission source may be “on” less than 50%, less than 30%, less than 20%, or less than 10% of the respective transmission bit window. FIG.41shows a diagrammatic representation of light pulses arriving in detection windows4020a,4020b,4020cof a photoreceiver. The light pulses may be of any shape and generally may be broadened to some extent by traveling over an optical communication distance through a variably refractive medium. In a first detection window4020a, a light pulse may arrive at or near the center of the window and may cause the total received light in that window to exceed a detection threshold Vth, which may be processed by circuitry of the photoreceiver to indicate that a pulse was received in that window. In some embodiments, this may cause the photoreceiver to output a ‘1’ for this detection window. At the end of detection window4020aand before detection window4020b, the photoreceiver circuit may be reset and return to zero. In detection window4020b, no pulse is transmitted (e.g., because a ‘0’ is intended to be transmitted and a modulator at the transmit node blocked the pulse), and the total light received in window4020bmay be below the detection threshold Vth. This may cause the photoreceiver to output a ‘0’ for this detection window. The photoreceiver circuit may again be reset and return to zero, and the cycle may repeat with a third window4020c, and so on. The detection threshold Vth may be configured so that it is sufficiently high that environmental light will not trigger a false positive but sufficiently low that true pulses will reliably exceed the detection threshold Vth. It is important that pulses sufficiently exceed a noise floor so that there is sufficient signal difference between “on” and “off” bit windows so that the detection threshold Vth may be both high enough to ignore environmental noise but low enough to capture every transmitted pulse. This is particularly challenging over longer distances (e.g., a mile or more) and in suboptimal environmental conditions (e.g., partly sunny, significant aerosols). The relationships between pulse length at the photoreceiver, coherence time, and detection window described herein with respect toFIGS.39-41greatly improve signal quality transmission and allow effective detection thresholds Vth even for free space optical systems transmitting data over optical transmission distances in excess of 1 mile, 2 miles, 3 miles, 5 miles, or 7 miles. In a case with a beam splitter and multiple photoreceivers, each of the multiple photoreceivers may generate a bit stream based on the separated pulses that are directed to that photoreceiver, and the bit streams from the respective photoreceivers may be interleaved to produce a combined bit stream having a higher data rate. The combined bit stream may be outputted to a communication network as described above, including with respect toFIG.36. FIG.42shows an example of test data received over a one-mile optical communication distance. The test data compares optical signals generated using a transmit node as described above with respect toFIG.35Aagainst optical signals generated using a continuous wave source having the same average power as the USPL source. Specifically, to generate the data shown in the top row of the chart shown inFIG.42, a USPL source incorporated in a transmit node as described above with respect toFIG.35Awas used to transmit data over an optical communication distance of one mile. The received signal was directed at a piece of white paper, and an infrared camera was placed behind the paper to record the light that passed through the paper. To generate the data shown in the bottom row of the chart shown inFIG.42, the same experimental setup was used with a continuous wave source having the same average power and same optical communication distance as the USPL source. The light from both the USPL source and the CW source was directed at the same sheet of white paper, and the two signal spots were captured in the same frame using the infrared camera. The spot sizes were approximately 12 inches in diameter. Background environmental light was subtracted from each pixel, and a each pixel was subjected to a thresholding logic such that pixels in which the received optical signal was above the threshold were set to “white” and pixels in which the received optical signal was below the threshold were set to “black.” The four images shown for each source were taken from the same frames in the video feed, and those frames were equally spaced at intervals of 10 seconds. Frame A shows the received signals from the USPL and CW sources at 10 seconds, Frame B shows the shows the received signals from the USPL and CW sources at 20 seconds, Frame C shows the shows the received signals from the USPL and CW sources at 30 seconds, and Frame D shows the shows the received signals from the USPL and CW sources at 40 seconds. This data shows that the transmit node as described herein produces ultrashort pulses that are substantially more clustered and, within the detection field, much more reliably exceed the detection threshold. As applied to a communication system using a photoreceiver having the characteristics described above, including with reference toFIGS.35B to41, this produces vastly improved data transmission accuracy. Applicant's testing of systems in accordance with this description has demonstrated free space optical communication distances in excess of 1 mile, 2 miles, 3 miles, 5 miles, and up to as much as 7.4 miles with zero bit error rate as measured over time intervals of at least 10 seconds, at least 30 seconds, at least 60 seconds, at least 10 minutes, at least 30 minutes, and at least 1 hour. In some embodiments, systems described herein may transmit data over an optical communication distance of at least one mile and have a measured bit error rate of less than one in one million, less than one in one billion, less than one in one trillion, or less than one in one quadrillion over a measurement period of at least sixty seconds. To Applicant's knowledge, no other free space optical system has achieved similarly low over optical communication distances of even one half of one mile. Thus, the systems described herein allow for substantially improved data transmission accuracy, communication link distance, and they also allow free space optical communication to be used in inclement environmental conditions (e.g., rain, fog, atmospheric scintillation) that, in prior systems, rendered free space optical communication ineffective. In some embodiments, the improved data transmission quality and range may also allow for free space optical communication to be applied to systems that would have previously been impossible to use effectively. For example, a transmit node and/or receiving node in accordance with the present disclosure may be provided in an Earth-orbiting satellite to provide for ground-to-space and/or space-to-ground free space optical communication. Due to the amount of atmosphere that a beam must travel between Earth's ground level and space, effective optical data transmission has not been demonstrated using technologies prior to the present disclosure, but the technology described herein can achieve effective optical communication over this distance. FIG.43shows an exemplary ranging node4400that can be used to detect objects or surfaces and determine positions of those objects relative to the node. The ranging node4400may generally include the components of the transmit and receiving nodes3510,3530described above with respect toFIGS.35A and35B. For example, the ranging node4400may include a source3512, a splitter, one or more modulators, an amplifier, and a telescope. These elements may collectively be configured to emit optical pulses that travel through a variably refractive medium toward a surface S. In the case of a laser ranging node, data modulation is optional but may be included to encode information relating to the pulses, nodes, or other information. Photons from the optical pulses may be reflected by surface S and return to the node4400. The total travel distance of the optical pulses from transmission by the ranging node to receipt of the reflected pulse may be twice the distance of the node to the surface S. Upon return to the node, the pulses may be received by an aperture3532, optionally split by a splitter3534, and analyzed using one or more photoreceivers3536. Each of these components may have the same properties and parameters as the corresponding components described above with respect toFIGS.35A to41. Ranging node4400may additionally include a time-of-flight (TOF) circuit4410, which may be configured to determine the time of flight of a pulse to reach surface S and return to node4400, and thereby determine a distance of that surface S from the ranging node4400. One or more aspects or features of the subject matter described herein can be realized in digital electronic circuitry, integrated circuitry, specially designed application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) computer hardware, firmware, software, and/or combinations thereof. These various aspects or features can include implementation in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device. These computer programs, which can also be referred to as programs, software, software applications, applications, components, or code, include machine instructions for a programmable processor, and can be implemented in a high-level procedural and/or object-oriented programming language, and/or in assembly/machine language. As used herein, the term “machine-readable medium” refers to any computer program product, apparatus and/or device, such as for example magnetic discs, optical disks, memory, and Programmable Logic Devices (PLDs), used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term “machine-readable signal” refers to any signal used to provide machine instructions and/or data to a programmable processor. The machine-readable medium can store such machine instructions non-transitorily, such as for example as would a non-transient solid-state memory or a magnetic hard drive or any equivalent storage medium. The machine-readable medium can alternatively or additionally store such machine instructions in a transient manner, such as for example as would a processor cache or other random access memory associated with one or more physical processor cores. To provide for interaction with a user, one or more aspects or features of the subject matter described herein can be implemented on a computer having a display device, such as for example a cathode ray tube (CRT) or a liquid crystal display (LCD) or a light emitting diode (LED) monitor for displaying information to the user and a keyboard and a pointing device, such as for example a mouse or a trackball, by which the user may provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, such as for example visual feedback, auditory feedback, or tactile feedback; and input from the user may be received in any form, including, but not limited to, acoustic, speech, or tactile input. Other possible input devices include, but are not limited to, touch screens or other touch-sensitive devices such as single or multi-point resistive or capacitive trackpads, voice recognition hardware and software, optical scanners, optical pointers, digital image capture devices and associated interpretation software, and the like. A computer remote from an analyzer can be linked to the analyzer over a wired or wireless network to enable data exchange between the analyzer and the remote computer (e.g. receiving data at the remote computer from the analyzer and transmitting information such as calibration data, operating parameters, software upgrades or updates, and the like) as well as remote control, diagnostics, etc. of the analyzer. While the subject matter of this disclosure has been described and shown in considerable detail with reference to certain illustrative embodiments, including various combinations and sub-combinations of features, those skilled in the art will readily appreciate other embodiments and variations and modifications thereof as encompassed within the scope of the present disclosure. Moreover, the descriptions of such embodiments, combinations, and sub-combinations are not intended to convey that the claimed subject matter requires features or combinations of features other than those expressly recited in the claims. Accordingly, the scope of this disclosure is intended to include all modifications and variations encompassed within the spirit and scope of the following appended claims. | 115,195 |
11942989 | DETAILED DESCRIPTION In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed implementations. However, one skilled in the relevant art will recognize that implementations may be practiced without one or more of these specific details, or with other methods, components, materials, and the like. In other instances, well-known structures associated with light sources have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the implementations. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its broadest sense, that is as meaning “and/or” unless the content clearly dictates otherwise. The headings and Abstract of the Disclosure provided herein are for convenience only and do not interpret the scope or meaning of the implementations. Throughout this specification and the appended claims, the term “carries” and variants such as “carried by” are generally used to refer to a physical coupling between two objects. The physical coupling may be direct physical coupling (i.e. with direct physical contact between the two objects) or indirect physical coupling that may be mediated by one or more additional objects. Thus, the term carries and variants such as “carried by” are meant to generally encompass all manner of direct and indirect physical coupling, including without limitation: carried on, carried within, physically coupled to, secured to, and/or supported by, with or without any number of intermediary physical objects therebetween. A wearable heads-up display (WHUD) may be used to communicate with a communicant device. In some examples, such a communicant device may include another WHUD, or another device capable of sending or receiving messages. Examples of such other devices may include base stations, and the like.FIG.1shows a flowchart of an example method100for communicating between a WHUD and a communicant device. At box105, an incoming identifier (ID) may be received at a first WHUD. The incoming ID may be associated with a communicant device. Example WHUDs are described in greater detail in relation toFIGS.2and3. In some examples, the incoming ID may include a serial number, MAC address, or other identifier, associated with the communicant device. In some examples, the communicant device may include another WHUD, a base station, and the like. Examples of communication between a WHUD and another WHUD and between a WHUD and a base station are described in greater detail in relation toFIGS.4and5respectively. In examples where the communicant device includes another WHUD, the incoming ID may include a WHUD ID associated with the other WHUD. Similarly, in examples where the communicant device includes a base station, the incoming ID may include an ID associated with the base station. Such an ID may also be referred to as a base station ID. Moreover, in some examples, the incoming ID may be received via a wireless electromagnetic signal, such as an optical transmission, a Bluetooth™ transmission, and the like. Moving onto box110, match data may be sent from the first WHUD to a match engine. The match data may include a first WHUD ID and the incoming ID. The first WHUD ID may be associated with the first WHUD. In some examples, the match data may be sent directly from the first WHUD to the match engine. Moreover, in some examples, this transmission may include a data transmission over a wireless network. Furthermore, it is contemplated that in some examples the match data may be sent indirectly from the first WHUD to the match engine. For example, the match data may be sent from the first WHUD to a mobile device, which mobile device may then send the match data to the match engine. In addition, in some examples, the match engine may include a computing engine including one or more processors in communication with one or more non-transitory processor-readable storage media. In some examples, the match engine may be implemented using cloud computing, distributed computing, virtualized computing, and the like. Furthermore, in some examples, the match engine may include one or more servers. At box115, a match indicator may be received at the first WHUD from the match engine. The match indicator may indicate a match event between the first WHUD and the communicant device based on the match data. In some examples, the match indicator may be generated by the match engine. Moreover, in some examples, the determination regarding matching may be made based on one or more of the first WHUD ID and the incoming ID, a timestamp associated with the receipt of the incoming ID at the first WHUD, location data associated with the locations of one or more of the first WHUD and the communicant device, and the like. At box120, communication may be effected between the first WHUD and the communicant device. This communication may include at least one of sending a message from the first WHUD to the communicant device, and receiving at the first WHUD a corresponding message from the communicant device. In this manner, the match engine may be used to authorize or enable communication between the first WHUD and the communicant device based on the match data. Such authorization may be reflected in the match indicator. Further details and examples of the matching process are described in relation toFIGS.4-6. Once the match indicator is received by the first WHUD, then communication may take place between the first WHUD and the communicant device. In some examples, if no match is made at the match engine between the first WHUD and the communicant device, the match engine may generate a no-match indicator. Moreover, in some examples, such a no-match indicator may be sent by the match engine and received by the first WHUD. Furthermore, in some examples, if no match is made at the match engine between the first WHUD and the communicant device, the match engine may not generate any indicator associated with match event. In such examples, in the absence of such an indicator no communication may be effected between the first WHUD and the communicant device. As discussed above, in some examples the communicant device may include a second WHUD, and the incoming ID may include a second WHUD ID associated with the second WHUD. In such examples, receiving the incoming ID at the first WHUD may include receiving the second WHUD ID at the first WHUD. In such examples, method100may be used to authorize or enable communication between the first WHUD and the second WHUD. Moreover, in some examples, receiving the incoming ID may include receiving an optical transmission from the communicant device. The optical transmission may include the incoming ID. In some examples the optical transmission may include an infrared (IR) transmission, and receiving the incoming ID may include receiving the IR transmission from the communicant device. As optical transmissions may be line-of-sight transmissions, the use of optical transmissions may allow for spatial aiming or targeting of the transmissions or communications between the first WHUD and the communicant device. The use of IR transmissions may allow such optical transmissions to remain invisible to human eyes. The use of optical transmissions is described in greater detail in relation toFIGS.4-5. Furthermore, in some examples, the optical transmission may include pulsed bursts. In some examples, the optical transmission may be binary-coded. Moreover, in some examples, the optical transmission may comprise pulsed binary-coded bursts. In such examples, receiving the incoming ID may include receiving the pulsed binary-coded bursts from the communicant device. In some examples, the use of pulsed bursts may provide some power savings compared to continuous optical transmissions. Moreover, the use of binary coding may provide a relatively simple way of encoding and transmitting transmissions or messages. The simplicity of binary encoding may provide corresponding savings in power and computational resources. In addition, in some examples, method100may further include sending the first WHUD ID from the first WHUD to the communicant device. In some examples, this may allow the second WHUD to obtain its own authorization to communicate with the first WHUD. Moreover, in some examples, sending the first WHUD ID to the communicant device may allow the communicant device to accept or reject communication with the first WHUD. In some examples, sending the first WHUD ID to the communicant device may include sending an optical transmission from the first WHUD to the communicant device. This optical transmission may include the first WHUD ID. Moreover, in some examples, the optical transmission may include an IR transmission, and sending the first WHUD ID to the communicant device may include sending the IR transmission from the first WHUD to the communicant device. Furthermore, in some examples, the optical transmission may include pulsed binary-coded bursts. In such examples, sending the first WHUD ID to the communicant device may include sending the pulsed binary coded bursts from the first WHUD to the communicant device. In some examples, the match data may further comprise a timestamp to indicate the time of receipt of the incoming ID by the first WHUD. It is also contemplated that in some examples the timestamp may, instead or in addition, indicate the time of transmission of the incoming ID from the communicant device. In some examples, sending the match data from the first WHUD to the match engine may include sending the timestamp from the first WHUD to the match engine. As discussed above, in such examples, the timestamp may be taken into account when the match engine determines whether to authorize or enable communication between the first WHUD and the communicant device. For example, the match engine may use the timestamp to authorize communication between the first WHUD and the communicant device during certain events or during certain times of the day. In addition, in some examples, match data may further include location data of at least one of the communicant device and the first WHUD. In such examples, sending the match data from the first WHUD to the match engine may include sending the location data from the first WHUD to the match engine. In such examples, the match engine may take the location data into account in determining whether to authorize or enable communication between the first WHUD and the communicant device. For example, the match engine may use the location data to authorize communication within a predetermined place, when the first WHUD and the communicant device are located within a given distance of one another, and the like. Furthermore, in some examples, the communicant device may include a base station, and the incoming ID may include a base station ID associated with the base station. In such examples, receiving the incoming ID at the first WHUD includes receiving the base station ID at the first WHUD. In some examples where the communicant device includes a base station, receiving the base station ID at the first WHUD includes receiving, at the first WHUD, at least one of an optical transmission including the base station ID and a Bluetooth™ transmission including the base station ID. An example where the communicant device includes a base station is described in greater detail in relation toFIG.5. In some examples, sending the match data from the first WHUD to the match engine may include sending the match data wirelessly to at least one of the match engine, and a mobile device. Such a mobile device, in turn, may send the match data to the match engine. In some examples, sending the match data wirelessly may include sending the match data using a wireless data network. Moreover, such a wireless data network may include a cellular network, a Wi-Fi network, a LAN, an LTE network, and the like. Moreover, as discussed above, in some examples the match event may include providing authorization for communication between first WHUD and the communicant device based on the match data. In some examples, method100may further include receiving a communication request from the communicant device at the first WHUD, and sending the communication request from the first WHUD to the match engine. In such examples, receiving the match indicator at the first WHUD from the match engine may include receiving the match indicator at the first WHUD from the match engine to indicate the match event between the first WHUD and the communicant device based on the match data and the communication request. Moreover, the effecting the communication between the first WHUD and the communicant device may include receiving at the first WHUD the corresponding message from the communicant device. The corresponding message may be associated with the communication request. Furthermore, in some examples, receiving the incoming ID at the first WHUD may include receiving outgoing communications from the communicant device at the first WHUD for a minimum time duration. The outgoing communications may include the incoming ID. In some examples, this minimum time duration may be less than or equal to about 10 seconds. Moreover, in some examples, this minimum time duration may be less than or equal to about 5 seconds. Furthermore, in some examples, this minimum time duration may be less than or equal to about one second. Other minimum time durations may also be used. Such a minimum time duration may reduce the likelihood of accidental or unintended connections or communications between the first WHUD and the communicant device. In addition, in some examples, method100may further include, prior to sending the match data to the match engine, receiving at the first WHUD a user input to send the match data to the match engine. The user input may be from a user of the first WHUD. In such examples, the user may be able to control the sending of the match data to the match engine in order to control if or when communication between the first WHUD and the communicant device is authorized. In some examples, the user input may include the user initiating the sending of the match data to the match engine, approving or declining sending the match data to the match engine, and the like. Moreover, in some examples, method100may further include, prior to effecting communication between the first WHUD and the communicant device, receiving at the first WHUD a user input to effect communication between the first WHUD and the communicant device. The user input may be from a user of the first WHUD. In such examples, the user may initiate or tailor the communication between the first WHUD and the communicant device. In some examples where user input is received in the process of authorizing or effecting communication between the first WHUD and the communicant device, the user input may be received via an input terminal. In some examples the input terminal may be part of the first WHUD, for example, the input terminal may include a microphone to detect a voice or sound input from the user, a camera to detect a visual input from the user, an inertial measurement unit to detect a haptic or touch input from the user, and the like. Moreover, in some examples, the input terminal may include a device or component separate from the first WHUD and in communication with the first WHUD. In some examples, the input terminal may be implemented as part of a mobile device in communication with the first WHUD. In some examples, such a mobile device may include a smart phone, a smart watch, a tablet, and the like. Moreover, in some examples, the input terminal may be implemented as a dedicated device that receives input from the user and cooperates with the first WHUD to communicate the input to the first WHUD. In some examples, such a dedicated device may include a ring worn around a finger of the user. Such a ring may receive touch input from the user, and communicate that input wirelessly to the first WHUD. In some examples, such a dedicated device may receive the touch input via a button or another touch sensor. In some examples, the WHUDs described herein may include a light source, a spatial modulator, a display optic, a communication module, and a controller. Example displays and WHUDs are described in greater detail in relation toFIGS.2and3. Turning now toFIG.2, a schematic representation of an example system200is shown. System200may be used to form or project an image viewable by an eye205of a viewer. System200may also be referred to or described as an image projection device, a display device, a display system, or a display. System200may include a light source210to generate an output light215. In some examples, system200may be used to implement method100and the other methods described herein. Light source210may include a laser, a light emitting diode, and the like. System200may also comprise a spatial modulator220to receive output light215from light source210. In some examples, spatial modulator220may include a movable reflector, a micro-electro-mechanical system (MEMS), a digital micromirror device (DMD), and the like. In some examples, light source210and spatial modulator220may together form a light engine221. Moreover, while inFIG.2light engine221is shown as including a light source and a spatial modulator, it is contemplated that in some examples the light engine may include different components such as a micro-display, and the like. It is contemplated that in some examples, system200may include a light engine that has components different than those of light engine221shown inFIG.2. Furthermore, system200may include a display optic225to receive output light215from spatial modulator220and direct the output light towards eye205of a viewer. The viewer may also be referred to as the user of system200. In some examples, display optic225may include an optical combiner such as a holographic optical element (HOE), and the like. Moreover, in some examples, display optic225may include an optical incoupler, a waveguide, and an optical outcoupler. Moreover, in some examples system200may be a part of or incorporated into a wearable heads-up display (WHUD). Such a heads-up display may have different designs or form factors, such as the form factor of eyeglasses, as is described in greater detail in relation toFIG.3. In examples where system200is in the form factor of glasses, display optic225may be on or in a lens of the glasses. System200may also include a communication module227. In some examples, communication module227may include a receiver228and a transmitter229. In some examples, receiver228may receive wireless signals. Moreover, in some examples, these wireless signals may include optical signals, Bluetooth™ signals, and the like. Similarly, in some examples, transmitter229may transmit wireless signals. Furthermore, in some examples, these wireless signals may include optical signals, Bluetooth™ signals, and the like. In addition, system200includes a controller230in communication with light source210, spatial modulator220, and communication module227. Controller230may control light source210and spatial modulator220to project an image. In some examples, the image to be projected may be a still image, a moving image or video, an interactive image, a graphical user interface, and the like. In some examples, the controllers described herein such as controller230may include a processor in communication with a non-transitory processor-readable medium. The processor-readable medium may include instructions to cause the processors to control the light source and the spatial modulator as described in relation to the methods and systems described herein. Moreover, in some examples the controllers may be free-standing components, while in other examples the controllers may include functional modules incorporated into other components of their respective systems. Furthermore, in some examples the controllers or their functionality may be implemented in other ways, including: via Application Specific Integrated Circuits (ASICs), in standard integrated circuits, as one or more computer programs executed by one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs executed by on one or more controllers (e.g., microcontrollers), as one or more programs executed by one or more processors (e.g., microprocessors, central processing units, graphical processing units), as firmware, and the like, or as a combination thereof. Turning now toFIG.3, a perspective view of an example wearable heads-up display (WHUD)300is shown. WHUD300includes a support structure305that in use is worn on the head of a user and has the general form factor and appearance of an eyeglasses (e.g. sunglasses) frame. Eyeglasses or sunglasses may also be generically referred to as “glasses”. Support structure305may carry components of a system to display an image, such as system200. For example, the light source module may be received in a space310in a side arm of support structure305. In other examples, one or more of the image projection and output light adjustment system components or systems described herein may be received in or carried by support structure305. The spatial modulator of the systems described herein may be received in or be part of support structure305. The spatial modulator in turn may direct the output light onto a display optic320carried by a lens325of support structure305. In some examples, display optic320may be similar in structure or function to display optic225. Moreover, in some examples display optic320may include an optical incoupler, a waveguide, and an optical outcoupler. WHUD300may also include a communication module similar to communication module227of system200. This communication module may include one or more receivers and or transmitters similar respectively to receiver228and transmitter229of system200. These receivers or transmitters may be located at different positions on support structure305. In some examples, these receivers or transmitters may be carried by a front frame307of support structure305. Moreover, in some examples, these receivers or transmitters may be carried by front frame307on or near a side of front frame307that faces away from a face of the user when WHUD300is worn by the user. Arrows330,335, and340show some example positions of such receivers and transmitters relative to front frame307. It is contemplated that in some examples, a receiver or transmitter need not be carried at each of the positions indicated by arrows330,335,340, and that a receiver or transmitter may be present at one or more of those positions. It is also contemplated that in some examples, the receivers or transmitters may be carried by support structure305or front frame307. As shown inFIGS.2and3, in some examples the functions and methods described herein may be performed by a display system or WHUD, such as by system200or WHUD300, which display system or WHUD may include a controller such as controller230. The functions of the WHUD, and its controller, are described herein in relation to system200and its components. It is contemplated that similar functions may be performed by WHUD300, and the other WHUDs described herein. Controller230may receive an incoming ID associated with the communicant device. In some examples, the incoming ID may include a serial number, MAC address, or other identifier associated with the communicant device. The incoming ID may be received from the communicant device at communication module227. Moreover, controller230may control communication module227to send match data to a match engine. The match data may include a WHUD ID and incoming ID. The WHUD ID may be associated with the WHUD, such as system200or WHUD300. In some examples, the IDs described herein in relation to WHUDs or communicant devices may be IDs that are unique to their respective WHUDs or communicant devices. Moreover, in some examples, the IDs described herein may be selected from a sufficiently large set of possible IDs to make each ID nearly or practically unique to its respective WHUD or communicant device. Furthermore, in some examples, the IDs described herein may be unique to a user associated with a WHUD or a communicant device. Moreover, whileFIG.2shows receiver228and transmitter229as being located side by side in communication module227, it is contemplated that in some examples the receiver and transmitter of the communication module may be spaced from one another, or may be carried components or at different positions relative to the display system or WHUD. Controller230may also receive a match indicator from the match engine. The match indicator may indicate a match event between the WHUD and the communicant device based on the match data. As discussed above, the WHUD may include system200, WHUD300, or another one of the WHUDs described herein. Furthermore, controller230may effect communication between the WHUD and the communicant device. To effect the communication controller230may perform at least one of the following: controller230may control communication module227to send a message to the communicant device, and controller230may receive a corresponding message from the communicant device. In some examples, controller230may further control light source210and spatial modulator220to display to the user at least one of the message and the corresponding message. Furthermore, in some examples, the communicant device may include a second WHUD. In such examples, the incoming ID may include a second WHUD ID associated with the second WHUD. Moreover, in some examples, receiver228of communication module227may include an optical receiver. Such an optical receiver may receive an optical transmission from the communicant device. The optical transmission may include the incoming ID. In some examples, the optical transmission may include an IR transmission. Moreover, in some examples, the optical transmission may include pulsed binary-coded bursts. In addition, in some examples, the optical receiver may include an avalanche photodiode and a transimpedance amplifier. In some examples, such an optical receiver may further include a bandpass filter. It is also contemplated that in some examples the optical receiver may include a PIN diode and a transimpedance amplifier. In addition, it is contemplated that in some examples the optical receiver may include a camera. In some examples, an avalanche photodiode may receive a photon of an optical transmission and in response generate one or more electrons or an electric current. The transimpedance amplifier may amplify this electric current, and may convert it to a voltage signal. In some examples, the bandpass filter may be used to further filter the voltage signal. Moreover, in some examples, this filtering may serve to enhance the signal-to-noise ratio in the voltage signal. Furthermore, in some examples, a PIN diode may be less susceptible to thermal changes and may be able to operate at lower voltages compared to an avalanche photodiode. As such, in some examples, the avalanche photodiode may be replaced with a PIN diode. In some examples, controller230may further control communication module227to send the WHUD ID to the communicant device. In some examples, transmitter229of communication module227may include an optical transmitter. To send the WHUD ID to the communicant device controller230may control the optical transmitter to send an optical transmission to the communicant device. The optical transmission may include the WHUD ID. In some examples, the optical transmission sent to the communicant device may include an IR transmission. Moreover, in some examples, this optical transmission may include pulsed binary-coded bursts. Furthermore, in some examples, the optical transmitter may include a vertical cavity surface emitting laser (VCSEL). In some examples, the match data may further include a timestamp to indicate a time of receipt of the incoming ID by the WHUD. Moreover, in some examples, the match data may further include location data of at least one of the communicant device and the WHUD. Furthermore, in some examples, the communicant device may include a base station to transmit the incoming ID. The incoming ID may include a base station ID associated with the base station. In some examples, receiver228of communication module227may include one or more of an optical receiver and a Bluetooth™ receiver. To receive the base station ID from the base station controller230may receive from the base station at least one of an optical transmission including the base station ID and a Bluetooth™ transmission including the base station ID. In addition, in some examples, to send the match data from the WHUD to the match engine controller230may control communication module227to send the match data wirelessly to at least one of the match engine and a mobile device. The mobile device, in turn, may send the match data to the match engine. In some examples, to send the match data wirelessly controller230may control communication module227to send the match data using a wireless data network. Moreover, in some examples, the wireless data network may include at least one of a cellular network, a Wi-Fi network, a LAN, an LTE network, and the like. In some examples, the match event may include providing an authorization for communication between the WHUD and the communicant device based on the match data. Moreover, in some examples, controller230may further receive a communication request from the communicant device. Controller230may also control the communication module227to send the communication request to the match engine. In such examples, to receive the match indicator at the WHUD from the match engine, controller230may receive the match indicator at the WHUD from the match engine to indicate the match event between the WHUD and the communicant device based on the match data and the communication request. Moreover, to effect the communication between the WHUD and the communicant device controller230may receive the corresponding message from the communicant device. The corresponding message may be associated with the communication request. In addition, in some examples, to receive the incoming ID controller230may receive outgoing communications from the communicant device for a minimum time duration. The outgoing communications may include the incoming ID. Furthermore, in some examples, prior to controlling communication module227to send the match data to the match engine, controller230may further receive a user input to send the match data to the match engine. The user input may be from the user of the WHUD. Moreover, in some examples, prior to effecting the communication between the WHUD and the communicant device, controller230may further receive a user input to effect the communication between the WHUD and the communicant device. The user input may be from the user of the WHUD. Turning now toFIG.4, a schematic representation is shown of a WHUD405communicating with a second WHUD410. WHUDs405and410may be similar to system200and WHUD300described in relation toFIGS.2and3respectively. WHUD405may be worn by a respective user415, and WHUD410may be worn by a respective user420. WHUD405may receive an incoming ID425from WHUD410. Incoming ID425may include a WHUD ID associated with WHUD410. In some examples, incoming ID425may be transmitted from WHUD410to WHUD405using a wireless transmission. Moreover, in some examples, this wireless transmission may include an optical transmission. Optical transmissions are line-of-sight and may have relatively small divergence or cones of propagation. This, in turn, may allow for targeted or directional communication between WHUD405and WHUD410. In some examples, the optical transmission may be transmitted as pulsed binary-coded bursts. In addition, in some examples, error correcting codes may be incorporated into the transmissions to reduce the likelihood or rate of errors in the communications between the WHUD and the communicant device. In the example shown inFIG.4, the communicant device includes WHUD410. Examples of such error correcting codes may include Reed-Solomon error correcting codes, and the like. Moreover, in some examples, a wavelength of light outside of the visible spectrum may be used for the optical transmissions between a WHUD and a communicant device, as the communications between WHUD410and WHUD405. For example, IR transmission may be used. In some examples, the IR transmission may have a wavelength in the range of about 700 nm to about 1 mm. Moreover, in some examples, the IR transmission may have a wavelength in the near infrared. Furthermore, in some examples, near infrared may include a wavelength range from about 700 nm to about 1400 nm. In some examples, the IR transmissions may use a wavelength of about 940 nm. Using a wavelength outside of the visible spectrum may reduce interference or artifacts visible to users, such as users415and420, caused by the optical transmissions by or between WHUD410and WHUD405. In addition, in some examples, divergence or the cone of propagation of such optical transmissions may be tailored to tailor the directionality of the optical transmissions. In some examples, the divergence of the optical transmissions may be tailored to cover an area about the size of the face of a human user, such as user415or420, at a distance of about 2 m. Other divergences or cones of propagation are also contemplated. It is also contemplated that in some examples, transmissions other than optical transmissions may also be used between WHUD405and a communicant device such as WHUD410. Examples of such other transmissions may include stereo Bluetooth™, and the like. Similar to optical transmissions, stereo Bluetooth™ may also exhibit controlled or directional propagation similar to line-of-sight propagation. While optical and other types of transmissions are described in relation to transmission of incoming ID425, it is contemplated that in some examples, other communications between WHUD405and the communicant device, such as WHUD410, may also include similar optical or other types of transmissions. In some examples, WHUD410may send to WHUD405additional information in addition to incoming ID425. Such additional information may include a timestamp associated with the transmission of incoming ID425, location data associated with WHUD410, and the like. Upon receipt of incoming ID425, WHUD405may send match data430to a match engine435. In some examples, the match data may be communicated wirelessly to match engine435. WhileFIG.4shows WHUD405sending match data430directly to match engine435, it is contemplated that in some examples, the communication between WHUD405and match engine435may be effected via a data communication network. In some examples, such a data communication network may include a cellular network, a Wi-Fi network, a LAN, an LTE network, and the like through any number of intervening communicative devices. In addition, whileFIG.4shows WHUD405sending match data430directly to match engine435, it is contemplated that in some examples, WHUD405may send the match data to a mobile device460of user415, and mobile device460may then send the match data to match engine435. The match data sent to match engine435may include incoming ID425and a WHUD ID associated with WHUD405. The WHUD ID may include a serial number or other identifier of WHUD405. Based on match data430, match engine435may authorize or otherwise enable communication between WHUD405and WHUD410. To authorize or enable such communication, match engine435may send a match indicator440to WHUD405. In some examples, the determination of whether to enable or authorize communication may be based on whether the ID of WHUD410is on a black list or white list. If the ID is on the white list, the communication will be authorized or enabled; whereas, if the ID is on the blacklist, communication may not be authorized or enabled. Moreover, in some examples, the determination of whether to enable or authorize communication may be based on whether WHUD405is in a public mode or private mode. The information regarding which mode WHUD405is in may be communicated to match engine435as part of match data430. If WHUD405is in public mode, match engine435may authorize or enable communication with WHUD410. If, on the other hand, WHUD405is in public mode, match engine435may determine not to authorize or enable communication with WHUD410. As discussed above, the determination of match engine435to enable or authorize communication may be reflected in match indicator440. This match indicator440may then be received by WHUD405. Match indicator440may indicate a match event between WHUD405and the communicant device based on match data430. In the example ofFIG.4, the communicant device is WHUD410. Based on match indicator440, WHUD405may then effect communication445between WHUD405and WHUD410. Communication445may include WHUD405sending a message to WHUD410or WHUD405receiving a message from WHUD410. As shown inFIG.4, in some examples communication445may be effected via directional transmissions between WHUDs405and410. Examples of such directional transmissions may include optical transmissions, stereo Bluetooth™ transmissions, and the like. It is also contemplated that in some examples, communication445may be effected via nondirectional transmissions such as Bluetooth™ transmissions, cellular transmissions, and the like. Moreover, whileFIG.4shows communication445being effected directly between WHUDs405and410, it is contemplated that in some examples, communication445may be affected indirectly between WHUDs405and410. For example, to effect communication445, WHUD405may communicate with mobile device460. Mobile device460, in turn, may communicate directly or indirectly with a mobile device465of user420. Mobile device465may then communicate with WHUD410. FIG.4shows example greetings450and455that may be displayed to users415and420by their respective WHUDs405and410as part of effecting communication445. In some examples, the content of such greetings may be generated by match engine435and communicated to WHUD405as part of match indicator440. While not shown inFIG.4, it is contemplated that in some examples match engine435may also communicate with WHUD410. In some examples, the contents of such communications may include the content of the greeting to be displayed by WHUD410to user420as part of effecting communication445. In some examples, the content of such greetings may be selectable or dynamically generated. In some examples, the content of the greetings may be selectable or dynamically generated via an app executable on WHUD405, or on mobile device460in communication with WHUD405. Moreover, in some examples, the content of the greetings may be tailored based on the context of the interaction between user415wearing WHUD405and user420wearing WHUD410. For example, the content of the greetings may be selected based on the location of one or more of user415wearing WHUD405and user420wearing WHUD410. The content of the greetings may also be selected based on an event being attended by one or both of the users, or by other factors such as applications running on the WHUDs or their corresponding mobile devices, the time of day, a user status or message defined by the user, other predetermined or user-selectable settings, and the like. In some examples, such greetings may be muted based on the context of the interaction between user415wearing WHUD405and user420wearing WHUD410. It is also contemplated that in some examples user input may be received as part of the communication process between WHUD405and the communicant device such as WHUD410. For example, input from user415may be received and used to determine whether match data430is sent to match engine435. Such an arrangement may be used to give user415control over whether or not communications are authorize or enabled between WHUD405and WHUD410of user420. Furthermore, in some examples, user input may be received after match indicator440is received by WHUD405and before communication is effected between WHUDs405and410. Such an arrangement, in turn, may be used to give user415control over whether communication445is effected in response to receiving match indicator440. It is also contemplated that input from user420may also be received in relation to the transmissions made by WHUD410, or communications sent or received by WHUD410. For example, input may be received from user420to give the user control over whether WHUD410transmits incoming ID425to WHUD405to initiate the communication between WHUDs405and410. Moreover, in some examples, input may be received from user420to control whether communication445is sent or received by WHUD410. In some examples receiving such user input may include receiving the input directly via the WHUD of the user. Examples of receiving the input directly via the WHUD may include receiving sound inputs at the WHUD from the user, receiving visual inputs at the WHUD from the user, receiving touch inputs at the WHUD from the user, and the like. Furthermore, in some examples, the user input may be received at the mobile device of the user, which mobile device may be in communication with the WHUD of the user. Moreover, in some examples, the user may use a dedicated input terminal for providing input to the WHUD. For example, the user may use a ring capable of receiving input from a finger or hand of the user. Such a ring may be in communication with the WHUD of the user. In this manner, the user may be able to use the ring to provide touch input to the WHUD via the ring. It is also contemplated that in some examples, user input may be used to determine the content of the greetings or other communications effected between WHUD405and WHUD410. For example, user input may be received to select between different types of greetings or messages to be included in the communications between WHUD405and WHUD410. Moreover, it is contemplated that in some examples match engine435may use a predetermined or dynamically generated list of permissions to determine whether to authorize or enable communications between WHUD405and WHUD410. In some examples, the list of permissions may be dynamically generated or modified based on the contexts of WHUDs405and410and their respective users415and420. In some examples, match engine435may use different types of match data to determine whether to authorize or enable communications between WHUD405and the communicant device. For example, match engine435may use the incoming ID of the communicant device and the WHUD ID of WHUD405to determine whether to authorize communications. Moreover, in some examples, match engine435may also take into account location data or timestamps when determining whether to authorize communications. For example, location data may be used to determine whether user415wearing WHUD405and user420wearing WHUD410are located sufficiently near each other to justify authorizing communications. In some examples, being sufficiently near may include being located in the same building, the same geographical area, within a certain radius of one another, and the like. Moreover, in some examples, match engine435may also take into account timestamps to determine whether to authorize communications. Such timestamps may be associated with the time of transmission or receipt of the directional communications between WHUDs405and410. Such timestamps may be used by match engine435to determine whether directional communications between WHUD405and410have been sufficiently close in time to justify authorizing the communication between WHUDs405and410. Furthermore, in some examples, such timestamps may be used to determine whether to authorize communications based on considerations such as the time of day, whether the timestamps coincide with a particular event or activity, and the like. Turning now toFIG.5, a schematic representation is shown of communications between a WHUD405and a communicant device.FIG.5shows a shop505having a shop window510. Displayed in the shop window is a boat515for sale. Boat515is positioned on a base station520. In the example shown inFIG.5, the base station520acts as the communicant device. In some examples, base station520may transmit its base station ID to form incoming ID525. Moreover, in some examples base station520may operate in an always-on mode, whereby base station520transmits its base station ID regardless of whether base station520receives a transmission from WHUD405to trigger the transmission of the base station ID. In such examples, base station520may transmit its base station ID on a schedule which may be continuous, intermittent, periodic, random or pseudorandom, and the like. Moreover, in some examples, base station520may transmit its base station ID using directional transmissions such as optical transmissions and the like. In this manner, base station520may aim or target its transmissions at the users, such as user415, who may be in the vicinity of or looking at shop window510. It is also contemplated that in some examples base station520may transmit its base station ID using nondirectional transmission such as Bluetooth™ transmissions, and the like. In these examples the transmission may be detectable by WHUDs within a predetermined distance from base station520based on the range or strength of the transmissions from base station520. In addition, in some examples, base station520may transmit its base station ID in a sometimes-on mode. In this mode, the transmission of the base station ID by base station520is triggered by base station520receiving a transmission from WHUD405. Such a transmission from WHUD405may include a directional transmission from WHUD405such as an optical transmission. It is also contemplated that in some examples the transmission from WHUD405may be a proximity-based transmission, the receipt of which by base station520may indicate to the base station520that WHUD405is within a given distance of base station520. As discussed above, incoming ID525, such as the base station ID, may be received by WHUD405. WHUD405may then send match data530to a match engine535. Match engine535may be similar in structure or function to match engine435. In some examples, match data530may include incoming ID525and a WHUD ID of WHUD405. Based on match data530, match engine535may then send a match indicator540, which match indicator540may be received by WHUD405. Based on match indicator540WHUD405may effect communication545between WHUD405and base station520. In some examples, effecting communication545may include WHUD405displaying a message550to user415. Moreover, in some examples, the content of message550may be provided to WHUD405as part of sending incoming ID525to WHUD405. Furthermore, in some examples, the content of message550may be provided to WHUD405by match engine535. In such examples, match engine535may determine the content of message550based on the base station ID sent to match engine535as part of match data530. Match engine535may then communicate the content of message550to WHUD405as part of sending matching indication540to WHUD405. It is also contemplated that in some examples, the content of message550may be tailorable or dynamic. For example, the content of message550may be tailored based on the WHUD ID of WHUD405sent to match engine535as part of match data530, and/or based on data attributable to a user of WHUD405and accessible by match engine535. Moreover, in some examples, the content of message550may be tailored based on the nature of the interaction between WHUD405worn by user415and base station520. For example, the content of message550may be tailored based on the distance between WHUD405worn by user415and base station520. Furthermore, in some examples, the content of message550may be tailored based on how intensely or attentively user415looks at or otherwise interacts with boat515or base station520. The level of intensity or attentiveness of user415in relation to boat515of base station520may be determined based on the continuousness or duration of interaction between WHUD405and base station520via directional transmissions such as optical transmissions and the like. In other words, if user415, wearing WHUD405, looks at boat515or its base station520continuously or for a long time, a determination may be made that user415has a high level or intensity of interest or attentiveness towards boat515. This level or intensity of interest or attentiveness may, in turn, be used to tailor the content of message550. In the example ofFIG.5, base station520need not interact with match engine535. As such, in some examples, base station520need not have network or wireless communication connectivity. This in turn, may allow base station520to have a simpler or less expensive construction. In addition, it is contemplated that in some examples, input from user415may be received in order to control or tailor communications between WHUD405and base station520. For example, the user input may be received to control whether match data530is sent to match engine535. Moreover, in some examples, user input may be received to control whether message550is displayed by WHUD405to user415. Furthermore, in some examples, user input may be received to determine further interaction between WHUD405and base station520. For example, upon receipt of the initial message550, user input may be received to request or obtain further information, or to activate or cash-in a promotion. Moreover, in some examples, user input may be received to electronically purchase the item associated with base station520. In some examples, to accomplish such a purchase, the user may not need to enter shop505or to otherwise physically interact with boat515or shop505. WhileFIGS.4and5each show a one-to-one communication scheme where one WHUD is in communication with one communicant device, it is contemplated that in some examples the communication scheme may be one-to-many, many-to-one, or many-to-many. Methods and devices similar to those described herein may be used for such one-to-many, many-to-one, and many-to-many communication schemes. Turning now toFIG.6, a flowchart is shown of an example method600. Method600may be performed by a match engine to authorize or otherwise enable communication between a WHUD and a communicant device. At box605, match data may be received at a match engine. The match data may include a wearable heads-up display (WHUD) ID associated with a WHUD and an incoming ID associated with a communicant device. At box610, a match indicator may be generated to indicate a match event between the WHUD and the communicant device based on the match data. In some examples, a no-match indicator may be generated if no match can be made between the WHUD and the communicant device based on the match data. Moreover, in some examples, no indicator may be generated if no match can be made between the WHUD and the communicant device. At box615, in turn, the match indicator may be sent to the WHUD. In some examples, method600may further include sending the match indicator to the communicant device. Moreover, in some examples, method600may further include routing a message between the WHUD and the communicant device. In such examples, the match engine may rout between the WHUD and the communicant device messages that are sent via data networks. In some examples, such messages that are sent via data networks may be different than communications that are affected directly between the WHUD and the communicant device using optical transmissions, Bluetooth™ transmissions, and the like. In some examples, the match data may include location data of one or more of the communicant device and the WHUD. Receiving the match data at the match engine may include receiving the location data at the match engine. Moreover, generating the match indicator may include generating the match indicator based on locations of the WHUD and the communicant device relative to one another. For example, the match indicator may be generated if the locations of the WHUD and the communicant device are such that the WHUD is within a predetermined distance from the communicant device. Furthermore, in some examples, match data may include at least one timestamp associated with at least one of the WHUD ID and the incoming ID. Moreover receiving the match data at the match engine may include receiving the at least one timestamp at the match engine. In addition, in some examples, match data may include a first timestamp associated with the WHUD ID and a second timestamp associated with the incoming ID. In such examples, generating the match indicator may include generating the match indicator based on the first timestamp and the second timestamp relative to one another. For example, the match indicator may be generated if the first and second timestamps are within a given time window relative to one another. In some examples, method600and the related methods described herein may be performed by match engines435and535. Moreover, whileFIGS.4and5show match engines435and535as being separate from WHUDs405and410, it is contemplated that in some examples, the match engine or its functionality may be incorporated into, or performed by, one or more of WHUDs405and410, or by one or more of mobile devices460and465. In such examples where the match engine is part of a WHUD, the communications that are described as taking place between WHUD405and match engine435or535inFIGS.4and5, may include communications between various components internal to a given WHUD. In addition, in such examples where the matching engine as part of a mobile device associated with a WHUD, the communications that are described as taking place between WHUD405and match engine435or535inFIGS.4and5, may include communications between the WHUD and its associated mobile device. Turning now toFIG.7, a schematic representation is shown of an example match engine700. Match engine700may include a processor705in communication with a memory710. In some examples, match engine700may also include a communication terminal715in communication with processor705. Memory710may include a non-transitory machine-readable storage medium that may be any electronic, magnetic, optical, or other physical storage device that stores executable instructions. The machine-readable storage medium may include, for example, random access memory (RAM), read-only memory (ROM), electrically-erasable programmable read-only memory (EEPROM), flash memory, a storage drive, an optical disc, and the like. The machine-readable storage medium may be encoded with executable instructions. Processor705may include a central processing unit (CPU), a graphics processing unit (GPU), a microcontroller, a microprocessor, a processing core, a field-programmable gate array (FPGA), or similar device capable of executing instructions. Processor705may cooperate with the memory710to execute instructions. Moreover, communication terminal715may include a wired or wireless communication terminal to send or receive data from a WHUD. It is contemplated that in some examples, match engine700may be implemented using one or more servers, cloud computing, distributed computing, as a virtual or virtualized machine, and the like. In some examples, match engine700may have the features or perform the functions of match engines435,535, and the other match engines described herein. Moreover, in some examples, match engine700may perform method600, or the other associated methods described herein. For example, match engine700may receive match data720from a WHUD. In some examples, match engine700may receive match data720via communication terminal715. Match data720may include a WHUD ID725and an incoming ID730of a communicant device. WHUD ID725and incoming ID730may be similar to the corresponding WHUD IDs and incoming IDs described herein in relation toFIGS.1-6. Match data720may be stored in memory710of match engine700. Processor705may generate a match indicator735to indicate a match event between the WHUD and the communicant device based on match data720. The determination of whether there is a match event between the WHUD and the communicant device may be made by processor705in a manner similar to the corresponding determinations of match events described herein in relation toFIGS.1-6. Moreover, match indicator735may be similar to the corresponding match indicators described herein in relation toFIGS.1-6. Processor705may then send match indicator730to the WHUD. In some examples, processor705may control communication terminal715to send match indicator735to the WHUD. InFIG.7, communication terminal715is shown in dashed lines to indicate that in some examples match engine700need not include communication terminal715. In such examples where match engine700does not include a communication terminal, match engine700or processor705may be in communication with a communication terminal external to match engine700, and may use this external communication terminal to send match indicator735to the WHUD. It is also contemplated that in some examples, match engine700need not be a component separate from the WHUD or its associated mobile device. As such, in some examples, match engine700may be incorporated into or implemented as a part of the WHUD. For example, match engine700may be incorporated into or implemented by controller230of system200shown inFIG.2. Moreover, in some examples, match engine700may be incorporated into or implemented as a part of the mobile device associated with the WHUD. As discussed above, method100and the other methods described herein may be performed by the display systems and WHUDs described herein such as system200and WHUDs300,405, and410. Moreover, method100and the other methods described herein may also be performed by systems other than those described herein. Furthermore, system200, WHUD300, and the other systems and WHUDs described herein may have the features and perform the functions described herein in relation to method100and the other methods described herein. It is also contemplated that system200, WHUD300, and the other systems and WHUDs described herein may perform methods other than methods described herein. According to an implementation of the present specification there is provided a method including: receiving an incoming ID at a first wearable heads-up display (WHUD), the incoming ID associated with a communicant device; sending match data from the first WHUD to a match engine, the match data including a first WHUD ID and the incoming ID, wherein the first WHUD ID is associated with the first WHUD; receiving a match indicator at the first WHUD from the match engine, the match indicator to indicate a match event between the first WHUD and the communicant device based on the match data; and effecting communication between the first WHUD and the communicant device including at least one of sending a message from the first WHUD to the communicant device and receiving at the first WHUD a corresponding message from the communicant device. The communicant device may include a second WHUD and the incoming ID may include a second WHUD ID associated with the second WHUD; and the receiving the incoming ID at the first WHUD may include receiving the second WHUD ID at the first WHUD. The receiving the incoming ID may include receiving an optical transmission from the communicant device, the optical transmission including the incoming ID. The optical transmission may include an infrared (IR) transmission; and the receiving the incoming ID may include receiving the IR transmission from the communicant device. The optical transmission may include pulsed binary-coded bursts; and the receiving the incoming ID may include receiving the pulsed binary-coded bursts from the communicant device. The method may further include: sending the first WHUD ID from the first WHUD to the communicant device. The sending the first WHUD ID to the communicant device may include sending an optical transmission from the first WHUD to the communicant device, the optical transmission including the first WHUD ID. The optical transmission may include an IR transmission; and the sending the first WHUD ID to the communicant device may include sending the IR transmission from the first WHUD to the communicant device. The optical transmission may include pulsed binary-coded bursts; and the sending the first WHUD ID to the communicant device may include sending the pulsed binary-coded bursts from the first WHUD to the communicant device. The match data may further include a timestamp to indicate a time of receipt of the incoming ID by the first WHUD; and the sending the match data from the first WHUD to the match engine may include sending the timestamp from the first WHUD to the match engine. The match data may further include location data of at least one of the communicant device and the first WHUD; and the sending the match data from the first WHUD to the match engine may include sending the location data from the first WHUD to the match engine. The communicant device may include a base station and the incoming ID may include a base station ID associated with the base station; and the receiving the incoming ID at the first WHUD may include receiving the base station ID at the first WHUD. The receiving the base station ID at the first WHUD may include receiving, at the first WHUD, at least one of an optical transmission including the base station ID and a Bluetooth™ transmission including the base station ID. The sending the match data from the first WHUD to the match engine may include sending the match data wirelessly to at least one of: the match engine; and a mobile device, the mobile device to send the match data to the match engine. The sending the match data wirelessly may include sending the match data using a wireless data network. The sending the match data wirelessly using the wireless data network may include sending the match data using at least one of: a cellular network, a WiFi network, a LAN, and an LTE network. The match event may include providing an authorization for communication between the first WHUD and the communicant device based on the match data. The method may further include: receiving a communication request from the communicant device at the first WHUD; sending the communication request from the first WHUD to the match engine; wherein: the receiving the match indicator at the first WHUD from the match engine may include receiving the match indicator at the first WHUD from the match engine to indicate the match event between the first WHUD and the communicant device based on the match data and the communication request; and the effecting the communication between the first WHUD and the communicant device may include receiving at the first WHUD the corresponding message from the communicant device, the corresponding message associated with the communication request. The receiving the incoming ID at the first WHUD may include receiving outgoing communications from the communicant device at the first WHUD for a minimum time duration, the outgoing communications including the incoming ID. The method may further include: prior to the sending the match data to the match engine, receiving at the first WHUD a user input to send the match data to the match engine, the user input from a user of the first WHUD. The method may further include: prior to the effecting the communication between the first WHUD and the communicant device, receiving at the first WHUD a user input to effect the communication between the first WHUD and the communicant device, the user input from a user of the first WHUD. According to another implementation of the present specification there is provided a wearable heads-up display (WHUD) including: a light source to generate an output light; a spatial modulator to receive the output light from the light source and spatially modulate the output light; a display optic to receive the output light from the spatial modulator and direct the output light towards an eye of a user of the WHUD; a communication module; and a controller in communication with the light source, the spatial modulator, and the communication module, the controller to: receive an incoming ID associated with a communicant device, the incoming ID received from the communicant device at the communication module; control the communication module to send match data to a match engine, the match data including a WHUD ID and the incoming ID, the WHUD ID associated with the WHUD; receive a match indicator from the match engine, the match indicator to indicate a match event between the WHUD and the communicant device based on the match data; and effect communication between the WHUD and the communicant device, to effect the communication the controller to at least one of: control the communication module to send a message to the communicant device and receive a corresponding message from the communicant device. The controller may be further to control the light source and the spatial modulator to display to the user at least one of the message and the corresponding message. The communicant device may include a second WHUD, and the incoming ID may include a second WHUD ID associated with the second WHUD. The communication module may include an optical receiver; and the optical receiver may be to receive an optical transmission from the communicant device, the optical transmission including the incoming ID. The optical transmission may include an infrared (IR) transmission. The optical transmission may include pulsed binary-coded bursts. The optical receiver may include an avalanche photodiode and a transimpedance amplifier. The optical receiver may further include a bandpass filter. The optical receiver may include a PIN diode and a transimpedance amplifier. The optical receiver may include a camera. The controller may be further to: control the communication module to send the WHUD ID to the communicant device. The communication module may include an optical transmitter; and to send the WHUD ID to the communicant device the controller may be to control the optical transmitter to send an optical transmission to the communicant device, the optical transmission including the WHUD ID. The optical transmission may include an infrared (IR) transmission. The optical transmission may include pulsed binary-coded bursts. The optical transmitter may include a vertical cavity surface emitting laser (VCSEL). The match data may further include a timestamp to indicate a time of receipt of the incoming ID by the WHUD. The match data may further include location data of at least one of the communicant device and the WHUD. The communicant device may include a base station to transmit the incoming ID; and the incoming ID may include a base station ID associated with the base station. The communication module may include one or more of an optical receiver and a Bluetooth™ receiver; and to receive the base station ID from the base station the controller may be to receive from the base station at least one of an optical transmission including the base station ID and a Bluetooth™ transmission including the base station ID. To send the match data from the WHUD to the match engine the controller may be to control the communication module to send the match data wirelessly to at least one of: the match engine; and a mobile device, the mobile device to send the match data to the match engine. To send the match data wirelessly the controller may be to control the communication module to send the match data using a wireless data network. The wireless data network may include at least one of: a cellular network, a WiFi network, a LAN, and an LTE network. The match event may include providing an authorization for communication between the WHUD and the communicant device based on the match data. The controller may be further to: receive a communication request from the communicant device; control the communication module to send the communication request to the match engine; wherein: to receive the match indicator at the WHUD from the match engine the controller may be to receive the match indicator at the WHUD from the match engine to indicate the match event between the WHUD and the communicant device based on the match data and the communication request; and to effect the communication between the WHUD and the communicant device the controller may be to receive the corresponding message from the communicant device, the corresponding message associated with the communication request. To receive the incoming ID the controller may be to receive outgoing communications from the communicant device for a minimum time duration, the outgoing communications including the incoming ID. The controller may be further to: prior to controlling the communication module to send the match data to the match engine, receive a user input to send the match data to the match engine, the user input from the user of the WHUD. The controller may be further to: prior to effecting the communication between the first WHUD and the communicant device, receive a user input to effect the communication between the WHUD and the communicant device, the user input from the user of the first WHUD. According to yet another implementation of the present specification there is provided a method including: receiving match data at a match engine, the match data including a wearable heads-up display (WHUD) ID associated with a WHUD and an incoming ID associated with a communicant device; generating a match indicator to indicate a match event between the WHUD and the communicant device based on the match data; and sending the match indicator to the WHUD. The method may further include: sending the match indicator to the communicant device. The method may further include: routing a message between the WHUD and the communicant device. The match data may include location data of one or more of the communicant device and the WHUD; the receiving the match data at the match engine may include receiving the location data at the match engine; and the generating the match indicator may include generating the match indicator based on locations of the WHUD and the communicant device relative to one another. The match data may include at least one timestamp associated with at least one of the WHUD ID and the incoming ID; and the receiving the match data at the match engine may include receiving the at least one timestamp at the match engine. The match data may include a first timestamp associated with the WHUD ID and a second timestamp associated with the incoming ID; and the generating the match indicator may include generating the match indicator based on the first timestamp and the second timestamp relative to one another. Throughout this specification and the appended claims, infinitive verb forms are often used. Examples include, without limitation: “to send,” “to receive,” “to effect,” “to transmit,” and the like. Unless the specific context requires otherwise, such infinitive verb forms are used in an open, inclusive sense, that is as “to, at least, send,” to, at least, receive,” “to, at least, effect,” and so on. The above description of illustrated example implementations, including what is described in the Abstract, is not intended to be exhaustive or to limit the implementations to the precise forms disclosed. Although specific implementations of and examples are described herein for illustrative purposes, various equivalent modifications can be made without departing from the spirit and scope of the disclosure, as will be recognized by those skilled in the relevant art. Moreover, the various example implementations described herein may be combined to provide further implementations. In general, in the following claims, the terms used should not be construed to limit the claims to the specific implementations disclosed in the specification and the claims, but should be construed to include all possible implementations along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure. | 72,803 |
11942990 | As illustrated in the figures, the sizes of layers and regions are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of embodiments of the present invention. Like reference numerals refer to like elements throughout. DETAILED DESCRIPTION The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person. Referring initially toFIG.1, a schematic drawing of the principle of the invention is shown. A laser1is emitting a scanning beam2, which is reflected of a first optical element3. The laser1may be fixed wavelength laser or tunable wavelength laser. The first optical element3may be a diffraction grating, a mirror or a deformable grating. The cooperation between the laser1and the first optical element3allows for the scanning beam2to be swept in a scanning direction S2. Not shown onFIG.1is a second optical element configured to broaden the scanning beam2. The second optical element is configured to broaden the scanning beam2reflected off the first optical element3. In particular, the second optical element is configured to broaden the scanning beam2along a broadening direction S1. Sweeping of the broadened scanning beam2in the scanning direction S2, then allows for the scanning beam2to scan a scanning area extending along the broadening direction S1and the scanning direction S2. In particular, the second optical element is configured for broadening the scanning beam to a width larger than the width of the scanning area along the broadening direction S1. In another embodiment the sweeping and broadening of the scanning beam2may be achieved by the same optical element. This can for instance be done by providing a deformable grating that can tilt and/or vary shape, e.g. from flat to cylindrically, concave or convex. The tilting and/or the deforming of the grating may then be used for broadening or narrowing of the scanning beam2, and the sweeping of the broadened scanning beam may be done by tuning the wavelength of the scanning beam2. The first optical element3and the second optical element4may then be collected into a single optical component. Referring toFIG.2, which depicts a schematic cross-sectional view of a first embodiment of the invention, the optical components have been integrated with a casing6. The laser1, the first optical element3, and the second optical element4have all been integrated with the casing6. Furthermore, a third optical element5has also been integrated with the casing6. The third optical element5is in the shown embodiment a collimator. The third optical element5is arranged in-between the laser1and the first optical element3. The laser1is emitting the scanning beam2which passes through the third optical element5, thereby parallelly aligning the scanning beam2before being reflected off the first optical element3. The first optical element3is an echelle grating. After being reflected off the first optical element3the scanning beam2passes through the light exit window7of the casing6. The light exit window7is preferably made from an optically transparent material, to limit the losses of the scanning beam2passing through the light exit window7. In the shown embodiment a part of the light exit window has been formed to define the second optical element4. The second optical element4is a broadening lens with a planoconvex geometry. The scanning beam2passing through the second optical element4is broadened. The laser1in the shown embodiment is a wavelength tunable laser. By changing the wavelength of the laser1, the scanning beam reflected of the second optical element3is reflected in different directions. Thereby a scanning mechanism is obtained by the cooperation between the laser1and the first optical element3. Although the scanning beam2is shown to be reflected off an echelle grating, in other embodiments other types of refraction or diffraction gratings may be used for refracting or reflecting the scanning beam2by the grating. Referring toFIG.3, which shows a schematic perspective view of a second embodiment of the invention, the optical components3and4have been integrated with a casing6. In contrast to the first embodiment of the invention, cf.FIG.2, the scanning mechanism is not obtained by a wavelength tunable laser cooperating with a diffraction grating. Instead the laser1is a fixed wavelength laser and the first optical element3is a rotatable mirror. By reflecting the scanning beam2emitted from the laser1off the first optical element3, while rotating the first optical element3a scanning mechanism is obtained, thereby allowing the scanning beam2to be scanned along the scanning direction S2. The first optical element3is capable of rotating around an axis of rotation parallel to the broadening direction S1. The second optical element4is a lens configured to broaden the scanning beam2along the broadening direction S1. The lens is formed as part of the light exit window7of the casing6. The lens extends longitudinally in parallel with the scanning direction S2, and perpendicular to the direction in which the laser1emits the scanning beam2. Furthermore, the curvature of the lens in the scanning direction S2is substantially zero. The substantially zero curvature ensures the scanning beam2is not broaden in the scanning direction S2, assuring resolution is not lost along the scanning direction S2. Referring toFIG.4, which shows a schematic perspective view of a third embodiment of the invention, the first optical elements3and the second optical element4have been integrated with a casing6. The third embodiment is similar to the second embodiment, with the change that the second optical element4which is a broadening lens has been rotated 90 degrees. The rotation of the broadening lens4results in the broadening lens extending longitudinally in parallel with the scanning direction S2, and in parallel with the direction in which the laser1emits the scanning beam2. The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, even though only a lens has been mentioned as the second optical component, reflectors or other optical components may also be used for widening the scanning beam in the broadening direction. The invention is also not limited to the optical components mentioned herein, but several other optical components may be incorporated, such as beam splitters or phase modulators. These other optical components may be placed in-between the laser and the first optical component, in-between the first optical component and the second optical component, and/or after the second optical component. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. | 7,707 |
11942991 | DESCRIPTION OF EMBODIMENTS Example embodiments will be described with reference to the drawings hereinbelow. Note that, in the example embodiments, the same signs are assigned to the same or equivalent elements and overlapping description thereof will sometimes be omitted. Although the drawings to be described hereinbelow include drawings in which unidirectional arrows are drawn, each of the arrows simply illustrates a direction of a flow of a signal (data) and does not rule out bidirectionality. First Example Embodiment An optical submarine branching apparatus according to a first example embodiment and an optical submarine cable system including the optical submarine branching apparatus will be described referring toFIGS.1and2.FIG.1is a block diagram illustrating a configuration example of the optical submarine branching apparatus according to the first example embodiment, andFIG.2is a schematic diagram illustrating a configuration example of the optical submarine cable system including the optical submarine branching apparatus. As illustrated inFIG.1, an optical submarine branching apparatus1according to the present example embodiment includes a control unit1aand a switching unit1band can be used to branch optical communication between terminal stations to another terminal station (branch terminal station) side, that is, to distribute light to the branch terminal station side. The control unit1aand the switching unit1bwill be described later. As illustrated inFIG.2, the optical submarine branching apparatus1according to the present example embodiment can be connected to a first terminal station21via a plurality of optical fiber transmission lines (hereinafter, referred to as first optical fiber transmission lines) and connected to a second terminal station22via a plurality of optical fiber transmission lines (hereinafter, referred to as second optical fiber transmission lines). Further, the optical submarine branching apparatus1can be connected to a third terminal station23via an optical fiber transmission line (hereinafter, referred to as a third optical fiber transmission line). The optical submarine branching apparatus1, the first terminal station21, the second terminal station22, the third terminal station23, and the optical fiber transmission lines connecting the apparatus and the terminal stations constitute the optical submarine cable system (hereinafter, referred to as the system) in the present example embodiment. Note that each terminal station can be installed on land and optical fiber transmission lines between each terminal station and the optical submarine branching apparatus1can be contained in a single optical cable and laid on the sea floor. For example, the first optical fiber transmission lines between the first terminal station21and the optical submarine branching apparatus1can be contained in a single optical cable and laid on the sea floor. The same applied to the second optical fiber transmission lines connected to the second terminal station22and the third optical fiber transmission lines connected to the third terminal station23. Note, however, that the plurality of first optical fiber transmission lines can be divided into sets and contained in a plurality of optical cables, and the plurality of second optical fiber transmission lines can also be divided into sets and contained in a plurality of optical cables. This system is an optical network system performing optical communication between terminal stations, and a wavelength division multiplexing (WDM) transmission method is employed for the optical communication. In other words, the system is a wavelength multiplexing optical transmission system in which a WDM transmission network performing single-fiber bidirectional communication is included. For example, installing an optical transmission apparatus including a multiplexer/demultiplexer or the like at each terminal station enables wavelength multiplexing communication between terminal stations via an optical fiber transmission line to be performed. Respective constituent elements of the optical submarine branching apparatus1will be described. The control unit1acontrols switching of a transmission route by the switching unit1b. The control unit1acan be configured as a part that performs control of the entire optical submarine branching apparatus1including switching control for the switching unit1b. The control unit1ais capable of performing the switching control in accordance with, for example, a control signal acquired from an optical fiber transmission line. Extracting an optical signal of a specific wavelength among wavelength-multiplexed signals from an optical fiber transmission line and converting the optical signal to an electrical signal enables such a control signal to be acquired. The control unit1acan be achieved by, for example, a central processing unit (CPU), a working memory, and a non-transitory storage device storing a program for controlling the entire optical submarine branching apparatus1. In other words, the control unit1acan include a control computer in which the program is incorporated in an executable manner. The control unit1acan also be achieved using, for example, an integrated circuit. The switching unit1bconnects to the plurality of first optical fiber transmission lines connecting to the first terminal station21, the plurality of second optical fiber transmission lines connecting to the second terminal station22, and the third optical fiber transmission line connecting to the third terminal station23and switches a transmission route of a wavelength-multiplexed optical signal. As described above, the switching unit1bis configured to be able to switch a connection state in a transmission route in accordance with control from the control unit1a In particular, the switching unit1bincludes a function of connecting each of the plurality of first optical fiber transmission lines to one of the plurality of second optical fiber transmission lines. This function is basically a function of connecting each of the plurality of first optical fiber transmission lines to preset one of the plurality of second optical fiber transmission lines. In other words, a correspondence relation between a first optical fiber transmission line and a second optical fiber transmission line to be connected to the first optical fiber transmission line can be determined in advance, and the first terminal station21and the second terminal station22can be connected with respect to each set of a first optical fiber transmission line and a second optical fiber transmission line corresponding to each other. The above-described set can be used as, for example, a single trunk line, and, in the system, the first terminal station21and the second terminal station22can be connected to each other, using a plurality of trunk lines. Note that it is possible to use each of the above-described sets for a different type of system, that is, an apparatus including a different function can be connected via a terminal station with respect to each set. Further, the third optical fiber transmission line can also be used for a system of a different type from systems usable through the above-described sets. As one of the principal features of the present example embodiment, the switching unit1bfurther includes a function of switching any one of the plurality of first optical fiber transmission lines to connect to the third optical fiber transmission line. The any one of the plurality of first optical fiber transmission lines can be indirectly specified by the control unit1acontrolling the switching of a transmission route by the switching unit1b. Note that, in the following description including the other example embodiments, such indirect specification will sometimes also be described as a specification by a control unit. In other words, the switching unit1bincludes a configuration capable of connecting any one of the plurality of first optical fiber transmission lines to the third optical fiber transmission line. The switching unit1bis configured such that whether or not branching one of the above-described sets to the third optical fiber transmission line is controllable by the control unit1aand, in the case of branching one of the above-described sets to the third optical fiber transmission line, to which one of the first optical fiber transmission lines the third optical fiber transmission line is to be connected is controllable by a specification from the control unit1a. Note, however, that all of the plurality of first optical fiber transmission lines do not include to be included in the alternative optical fiber transmission lines to be branched and it is only required to be able to specify an optical fiber transmission line to be branched out of two or more first optical fiber transmission lines. Note that the third optical fiber transmission line can be used as, for example, a branch line to which the above-described trunk line is branched. It is needless to say that the switching unit1bcan also include a function of, after such switching to the third terminal station23has been performed, restoring the connection to an original connection state, controlled by the control unit1a. In other words, the switching unit1bcan include a function of switching each of the plurality of first optical fiber transmission lines to connect to one of the plurality of second optical fiber transmission lines. According to the present example embodiment, in an optical submarine cable system in which terminal stations are connected by a plurality of optical fiber transmission lines, it is possible to branch a specified optical fiber transmission line to the third optical fiber transmission line for branching (to branch a specified optical fiber transmission line to a branch station). Therefore, in the system, it is also possible to branch an optical fiber transmission line to a third terminal station when optical communication is interrupted due to damage to an optical fiber in an optical submarine cable or a malfunction of a submarine apparatus, such as a repeater, that is installed in the middle of an optical submarine cable. Further, according to the present example embodiment, such branching enables the number of constituent elements (such as a transmission line other than the third optical fiber transmission line) between the optical submarine branching apparatus1and a branch station to be prevented from increasing, to the extent possible. In other words, in the system, configuring the optical submarine branching apparatus1as described above enables the plurality of first optical fiber transmission lines to share the third optical fiber transmission line for a branch line. For example, according to the system, the system enables two or more trunk lines to share a single branch line. Thus, in the system, it is possible to reduce the number of the optical fiber transmission lines for branching (the number of optical fibers in the optical cable between the optical submarine branching apparatus1and the third terminal station23). In addition, in the system, such capability of reducing the number of optical fiber transmission lines enables the number of submarine apparatuses, such as a repeater, that are installed for the purpose of amplifying optical signals to be reduced. The switching method in the optical submarine branching apparatus1will be complemented below. The optical submarine branching apparatus1is capable of performing a switching method including the following control steps, as described in the switching processing thereof. The above-described control steps control the switching unit1bin the optical submarine branching apparatus, which is connected to the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line, to switch a transmission route of a wavelength-multiplexed optical signal. The above-described control steps include a step of connecting each of the plurality of first optical fiber transmission lines to one of the plurality of second optical fiber transmission lines. The above-described control steps further include a step of switching any one of the plurality of first optical fiber transmission lines to connect to the third optical fiber transmission line. In this configuration, the above-described control steps can include a step of accepting a specification specifying the any one of the plurality of first optical fiber transmission lines through extraction from an optical signal or the like. The other examples are as described above, and examples that will be described in example embodiments to be described later can also be applied. A program that can be incorporated in the optical submarine branching apparatus1will be complemented below. A program incorporated in the above-described control unit1aserves as a program causing a control computer included in the optical submarine branching apparatus1to perform the above-described control steps. The other examples are as described above, and examples that will be described in example embodiments to be described later can also be applied. Second Example Embodiment Although a second example embodiment will be described with additional reference toFIGS.3to10, focusing on differences from the first example embodiment, various examples described in the first example embodiment are applicable.FIG.3is a diagram illustrating a configuration example of a switching unit included in an optical submarine branching apparatus according to the second example embodiment. The optical submarine branching apparatus according to the present example embodiment is an optical submarine branching apparatus in which the switching unit1bin the optical submarine branching apparatus1inFIG.1is configured into a switching unit40illustrated inFIG.3, and, in the present example embodiment, the other parts will also be described referring toFIGS.1and2. As illustrated inFIG.3, the switching unit40of an optical submarine branching apparatus1according to the present example embodiment can include a configuration in which a first optical switch41and second optical switches42,43, and so on are connected in multi-stages. A first optical switch, a second optical switch, and a third optical switch, which will be described later, are optical switches that include a difference from one another in at least either the number of inputs (the number of input paths) or the number of outputs (the number of output paths). Note that, without being limited to an example described in the present example embodiment, the switching unit can be configured by a combination of a plurality of optical switches. The first optical switch41is an optical switch including an input path and two output paths. The second optical switch42is an optical switch including two input paths and two output paths. The second optical switch43includes the same configuration as that of the second optical switch42, and the same applies to another second optical switch that is arranged at the succeeding stage (on the third terminal station23side). In the above description, the input and the output are only distinguished from each other for the purpose that the description is made assuming, for convenience, the first terminal station21side as the origin of information transmission, and the following description will also appropriately be made based on the origin of information transmission. As described more specifically, the first optical switch41uses the first one of the first optical fiber transmission lines as input and uses the first one of the second optical fiber transmission lines and the second optical switch42as output, and is configured to be capable of switching the output to either of the output destinations. The second optical switch42uses the second one of the first optical fiber transmission lines and an output of the first optical switch41as input and uses the second one of the second optical fiber transmission lines and the second optical switch43as output, and is configured to be capable of switching the input to either of the input sources and switching the output to either of the output destinations. The second optical switch43uses the third one of the first optical fiber transmission lines and an output of the second optical switch42as input and uses the third one of the second optical fiber transmission lines and the another second optical switch at the succeeding stage as output, and is configured to be capable of switching the input to either of the input sources and switching the output to either of the output destinations. Although description is omitted, the another second optical switch at the succeeding stage to the second optical switch43(on the third terminal station23side) includes the same connection configuration as that of the second optical switch43, and each of the input and the output is selectable from two paths. In such a configuration in which optical switches are arranged and connected in multi-stages, the number of first optical switches can be set at one as exemplified by the first optical switch41. The number of second optical switches can be set at a number obtained by subtracting1from the number of the first optical fiber transmission lines that are provided in the system (when fiber pairs, which will be described later, are employed, a number twice the number of the fiber pairs). In other words, the second optical switch43and second optical switches at succeeding stages are disposed according to the number of the above-described sets, and, when the number of sets is, for example, two, such second optical switches do not include to be disposed. Note that the description is made targeting, as the above-described sets, a number of first optical fiber transmission lines that are included in the system and the description is also made under the assumption that all of the first optical fiber transmission lines belonging to the sets are transmission lines to be branched. With reference toFIGS.4and5, examples of the first optical switch and the second optical switch will be described below.FIG.4is a diagram illustrating an example of the first optical switch in the switching unit40, andFIG.5is a diagram illustrating an example of the second optical switch in the switching unit40. InFIGS.4and5, a path that is in a connected state (a state in which light is transmitted) and a path that is in a non-connected state (a disconnected state) are illustrated by a solid line and a dashed line, respectively. Both states can be achieved by the control unit1acontrolling each optical switch to switch a transmission route. The first optical switch41can internally include a terminal a, a terminal b, and a terminal c, as illustrated inFIG.4and use the terminal a as an input terminal and the terminal b and the terminal c as output terminals. The terminal a, the terminal b, and the terminal c can be connected to the first one of the first optical fiber transmission lines, the first one of the second optical fiber transmission lines, and an input terminal of the second optical switch42, respectively. In a switching state in the first optical switch41, connection of the terminal a and the terminal b as illustrated by a state on the left-hand side inFIG.4enables the first one of the first optical fiber transmission lines and the first one of the second optical fiber transmission lines to be connected and the first terminal station21and the second terminal station22to be thereby connected. In the other switching state in the first optical switch41, connection of the terminal a and the terminal c as illustrated by a state on the right-hand side inFIG.4causes the first one of the first optical fiber transmission lines and an input terminal (the terminal c inFIG.5) of the second optical switch42to be connected. Because of this connection, putting the switching state of the second optical switch42and the second optical switch at the succeeding stage thereto in a state in which the second optical switch42and the other second optical switch can be connected to the third terminal station23enables the first terminal station21and the third terminal station23to be connected by a route including the first one of the first optical fiber transmission lines and the third optical fiber transmission line. The second optical switch42can internally include terminals a to d, as illustrated inFIG.5and use the terminal a and the terminal c as input terminals and the terminal b and the terminal d as output terminals. In the second optical switch42, the terminal a, the terminal b, the terminal c, and the terminal d can be connected to the second one of the first optical fiber transmission lines, the second one of the second optical fiber transmission lines, the terminal c of the first optical switch41, and an input terminal of the second optical switch43, respectively. In a switching state in the second optical switch42, connection of the terminal a and the terminal b as illustrated by a state on the left-hand side inFIG.5enables the second one of the first optical fiber transmission lines and the second one of the second optical fiber transmission lines to be connected and the first terminal station21and the second terminal station22to be thereby connected. In the switching state, connection of the terminal c and the terminal d causes the terminal c of the first optical switch41and an input terminal of the second optical switch43to be connected. On this occasion, putting the terminal a and the terminal c of the first optical switch41in the non-connected state, that is, connecting the first terminal station21and the second terminal station22, using the first set, enables the terminal c of the second optical switch42to be put in a state in which there is no input thereto. Alternatively, connecting the terminal a and the terminal c of the first optical switch41enables the first one of the first optical fiber transmission lines and an input terminal of the second optical switch43, which connects to the third terminal station23side, to be put in the connected state. Putting the switching state of the second optical switch43and the second optical switch at the succeeding stage thereto in a state in which connection to the third terminal station23is allowed enables the first terminal station21and the third terminal station23to be connected by a transmission route including the first one of the first optical fiber transmission lines and the third optical fiber transmission line. In the other switching state in the second optical switch42, connection of the terminal a and the terminal d as illustrated by a state on the right-hand side inFIG.5causes the second one of the first optical fiber transmission lines and an input terminal of the second optical switch43to be connected. Because of this connection, putting the switching state of the second optical switch43and the second optical switch at the succeeding stage thereto in a state in which connection to the third terminal station23is allowed enables the first terminal station21and the third terminal station23to be connected by a route including the second one of the first optical fiber transmission lines and the third optical fiber transmission line. As described above, when the first optical switch41is connected to the second optical switch42, the second optical switch42switches an internal connection in such a way as to output the input from the first optical switch41to the third optical fiber transmission line for branching. At this time, the second one of the second optical fiber transmission lines is configured not to be connected to the third optical fiber transmission line for branching. On the other hand, when the first optical switch41is not connected to the second optical switch42, the second optical switch42can perform control not only to connect, but also not to connect the second optical fiber transmission lines to the third optical fiber transmission line for branching. Next, a detailed configuration example of the system will be described with additional reference toFIGS.6to9.FIGS.6to8are diagrams illustrating a configuration example of the system and illustrate connection states that are different from one another. InFIGS.6to8, the first terminal station21, the second terminal station22, the third terminal station23, and the optical submarine branching apparatus1are exemplified by a terminal station A (21), a terminal station B (22), a terminal station C (23), and a branching apparatus10, respectively. For example, in the system, the terminal stations A, B, and C, which perform optical communication, are installed on land, and it is configured such that, with the terminal station A (21) and the terminal station B (22) assigned to the trunk line side and the terminal station C (23) assigned to the branch line side, a transmission route can be switched by the branching apparatus10. In the system, as exemplified inFIG.6, one or a plurality of repeaters A (24) can be interposed between the terminal station A (21) and the branching apparatus10. Likewise, one or a plurality of repeaters B (25) can be interposed between the terminal station B (22) and the branching apparatus10, and one or a plurality of repeaters C (26) can be interposed between the terminal station C (23) and the branching apparatus10. Each repeater (repeating apparatus) is an example of an apparatus for submarine installation (submarine apparatus) and can include an optical amplifier that amplifies an input optical signal. Each repeater can also be a submarine reconfigurable optical add/drop multiplexer (ROADM) apparatus or include a ROADM function of a submarine ROADM apparatus. In particular, it can be said that an effect of being able to share an optical fiber transmission line for branching as in the present example embodiment is beneficial because, when a submarine apparatus is connected between the branching apparatus10and the third terminal station on the third optical fiber transmission line, it is possible to reduce the number of submarine apparatuses. Note that examples of an environment requiring a submarine apparatus include a case where distance between terminal stations is so long that it is necessary to install a repeater, and the number and type of required submarine apparatuses sometimes vary depending on an environment. This system can be configured in such a way that respective optical fiber transmission lines in the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line are paired into fiber pairs. Each of the fiber pairs can be composed of a pair of an optical fiber for upstream transmission and an optical fiber for downstream transmission. The following description will be made assuming that information is uploaded from the terminal station A (21) side to the terminal station B (22) side or uploaded to the terminal station B (22) via the terminal station C (23) and defining the uploading direction as an upstream direction, for convenience. Although, inFIG.6, an example in which two fiber pairs are used to connect the terminal station A (21) and the terminal station B (22) is illustrated, this example is equivalent to the above-described example in which the number of sets is two. The following description will be made assuming that one of the fiber pairs is composed of an optical fiber for a first upstream signal FP1U and an optical fiber for a first downstream signal FP1D and includes the first one of the first optical fiber transmission lines and the first one of the second optical fiber transmission lines. It is also assumed that the other of the fiber pairs is composed of an optical fiber for a second upstream signal FP2U and an optical fiber for a second downstream signal FP2D and includes the second one of the first optical fiber transmission lines and the second one of the second optical fiber transmission lines. Fiber pairs serving as the third optical fiber transmission line are used as shared fiber pairs. In other words, the fiber pairs can be used as optical fibers for the first upstream signal FP1U and optical fibers for the first downstream signal FP1D, as illustrated inFIG.6. The fiber pairs can also be used as optical fibers for the second upstream signal FP2U and optical fibers for the second downstream signal FP2D, as illustrated inFIG.7. For which one of the purposes the fiber pairs are used can be changed by switching in the switching unit exemplified by the switching unit40. Note that, in the present example embodiment, the description is made assuming both optical fibers included in a fiber pair to be a single optical fiber transmission line lest optical communication for upstream transmission and optical communication for downstream transmission be performed through different routes (for example, communications by way of different terminal stations). However, the respective optical fibers in a fiber pair can also be considered as separate optical fiber transmission lines. The branching apparatus10, which is incorporated into the system as described above, will be described. The branching apparatus10can include a not-illustrated control unit, and, since the control unit is equivalent to the control unit1ainFIGS.1and2, the control unit will be described as a control unit1ain the following description. The branching apparatus10can include optical switches11-1and11-6that operate on one input and two outputs, optical switches11-2and11-5that operate on two inputs and one output, and optical switches11-3,11-4,11-7, and11-8that operate on two inputs and two outputs. The optical switches11-1and11-6are equivalent to the first optical switch41inFIG.4, and the optical switches11-3,11-4,11-7, and11-8are equivalent to the second optical switch42inFIG.5. The optical switches11-2and11-5are equivalent to an optical switch obtained by replacing the input and the outputs of the first optical switch41with each other and are examples of the third optical switch including two input paths and an output path. Note that changes in switching states of the first to third optical switches are as described afore with reference toFIGS.4and5. Hereinafter, the switching unit including the respective optical switches will be described as a switching unit40. Note that switching control of the switching unit40by the control unit1awill be described later. InFIG.6, the first fiber pair serving as a medium for the signals FP1U and FP1D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station C (23) and bidirectional communication between the terminal station C (23) and the terminal station B (22) are performed therethrough. Hereinafter, the description will be made with the former and the latter referred to as first bidirectional communication and second bidirectional communication, respectively. InFIG.6, the second fiber pair serving as a medium for the signals FP2U and FP2D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Hereinafter, the description will be made with the bidirectional communication referred to as third bidirectional communication. The first bidirectional communication can be achieved by switching the optical switches11-1,11-3,11-5, and11-7to a switching state as illustrated inFIG.6. The optical switches11-1and11-3are switched in such a way as to drop (transmit) a signal FP1U output (sent) from the terminal station A (21) to the terminal station C (23) side. This switching causes light including the signal FP1U sent from the terminal station A (21) to enter the branching apparatus10through the repeater A (24) and to be transmitted to the repeater C (26) and to the terminal station C (23) through a connection between the terminals a and c of the optical switch11-1and a connection between the terminals c and d of the optical switch11-3. With respect to the opposite direction, the optical switches11-5and11-7are switched in such a way as to transmit a signal FP1D sent from the terminal station C (23) to the terminal station A (21) side. This switching causes light including the signal FP1D sent from the terminal station C (23) to be transmitted to the repeater A (24) and to the terminal station A (21) through the repeater C (26) and a connection between the terminals d and c of the optical switch11-7and a connection between the terminals c and a of the optical switch11-5in the branching apparatus10. The second bidirectional communication can be achieved by switching the optical switches11-2,11-4,11-6, and11-8to a switching state as illustrated inFIG.6. The optical switches11-2and11-4are switched in such a way as to transmit the signal FP1U sent from the terminal station C (23) to the terminal station B (22) side. This switching causes light including the signal FP1U sent from the terminal station C (23) to be transmitted to the repeater B (25) and to the terminal station B (22) through the repeater C (26) and a connection between the terminals d and c of the optical switch11-4and a connection between the terminals c and a of the optical switch11-2in the branching apparatus10. With respect to the opposite direction, the optical switches11-6and11-8are switched in such a way as to drop (transmit) the signal FP1D sent from the terminal station B (22) to the terminal station C (23) side. This switching causes light including the signal FP1D sent from the terminal station B (22) to enter the branching apparatus10through the repeater B (25) and to be transmitted to the repeater C (26) and to the terminal station C (23) through a connection between the terminals a and c of the optical switch11-6and a connection between the terminals c and d of the optical switch11-8. The third bidirectional communication can be achieved by switching the optical switches11-3,11-4,11-7, and11-8to a switching state as illustrated inFIG.6. The optical switches11-3and11-4are switched in such a way as to transmit a signal FP2U sent from the terminal station A (21) to the terminal station B (22) side. This switching causes light including the signal FP2U sent from the terminal station A (21) to enter the branching apparatus10through the repeater A (24), to be directly transmitted through a connection between the terminals a and b of the optical switch11-3and a connection between the terminals b and a of the optical switch11-4, and to be directed to the repeater B (25) and to the terminal station B (22). With respect to the opposite direction, the optical switches11-7and11-8are switched in such a way as to transmit a signal FP2D sent from the terminal station B (22) to the terminal station A (21) side. This switching causes light including the signal FP2D sent from the terminal station B (22) to enter the branching apparatus10through the repeater B (25), to be directly transmitted through a connection between the terminals a and b of the optical switch11-8and a connection between the terminals b and a of the optical switch11-7, and to be directed to the repeater A (24) and to the terminal station A (21). The branching apparatus10is capable of switching the connection state illustrated inFIG.6to a connection state illustrated inFIG.7and restoring the connection state to the original state. In the connection state illustrated inFIG.7, a fiber pair used for connection to the terminal station C (23), differing from the one in the connection state illustrated inFIG.6, is the second fiber pair. In other words, the connection state illustrated inFIG.7is a connection state obtained from the connection state illustrated inFIG.6by, with respect to a fiber pair used for connection to the terminal station C (23), replacing the first one with the second one of the fiber pairs. InFIG.7, the second fiber pair serving as a medium for signals FP2U and FP2D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station C (23) and bidirectional communication between the terminal station C (23) and the terminal station B (22) are performed therethrough. Hereinafter, the description will be made with the former and the latter referred to as fourth bidirectional communication and fifth bidirectional communication, respectively. InFIG.7, the first fiber pair serving as a medium for signals FP1U and FP1D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Hereinafter, the description will be made with the bidirectional communication referred to as sixth bidirectional communication. The fourth bidirectional communication can be achieved by switching the optical switches11-3and11-7to a switching state as illustrated inFIG.7. The optical switch11-3is switched in such a way as to drop (transmit) a signal FP2U sent from the terminal station A (21) to the terminal station C (23) side. This switching causes light including the signal FP2U sent from the terminal station A (21) to enter the branching apparatus10through the repeater A (24) and to be transmitted to the repeater C (26) and to the terminal station C (23) through a connection between the terminals a and d of the optical switch11-3. With respect to the opposite direction, the optical switch11-7is switched in such a way as to transmit a signal FP2D sent from the terminal station C (23) to the terminal station A (21) side. This switching causes light including the signal FP2D sent from the terminal station C (23) to be transmitted to the repeater A (24) and to the terminal station A (21) through the repeater C (26) and a connection between the terminals d and a of the optical switch11-7in the branching apparatus10. The fifth bidirectional communication can be achieved by switching the optical switches11-4and11-8to a switching state as illustrated inFIG.7. The optical switch11-4is switched in such a way as to transmit the signal FP2U sent from the terminal station C (23) to the terminal station B (22) side. This switching causes light including the signal FP2U sent from the terminal station C (23) to be transmitted to the repeater B (25) and to the terminal station B (22) through the repeater C (26) and a connection between the terminals d and a of the optical switch11-4in the branching apparatus10. With respect to the opposite direction, the optical switch11-8is switched in such a way as to drop (transmit) the signal FP2D sent from the terminal station B (22) to the terminal station C (23) side. This switching causes light including the signal FP2D sent from the terminal station B (22) to enter the branching apparatus10through the repeater B (25) and to be transmitted to the repeater C (26) and to the terminal station C (23) through a connection between the terminals a and d of the optical switch11-8. The sixth bidirectional communication can be achieved by switching the optical switches11-1,11-2,11-5, and11-6to a switching state as illustrated inFIG.7. The optical switches11-1and11-2are switched in such a way as to transmit a signal FP1U sent from the terminal station A (21) to the terminal station B (22) side. This switching causes light including the signal FP1U sent from the terminal station A (21) to enter the branching apparatus10through the repeater A (24), to be directly transmitted through a connection between the terminals a and b of the optical switch11-1and a connection between the terminals b and a of the optical switch11-2, and to be directed to the repeater B (25) and to the terminal station B (22). With respect to the opposite direction, the optical switches11-5and11-6are switched in such a way as to transmit a signal FP1D sent from the terminal station B (22) to the terminal station A (21) side. This switching causes light including the signal FP1D sent from the terminal station B (22) to enter the branching apparatus10through the repeater B (25), to be directly transmitted through a connection between the terminals a and b of the optical switch11-6and a connection between the terminals b and a of the optical switch11-5, and to be directed to the repeater A (24) and to the terminal station A (21). Although the details are not described, the system can also be put in a connection state in which, for example, the terminal station C (23) and the terminal station B (22) are not connected in the connection state inFIG.6or the connection state inFIG.7. The branching apparatus10is capable of switching the connection state illustrated inFIG.6or the connection state illustrated inFIG.7to a connection state illustrated inFIG.8and restoring the connection state to the original state. The connection state illustrated inFIG.8can be said to be a basic connection state and is a connection state in which connection to the terminal station C (23) using any fiber pair is not established. InFIG.8, the first fiber pair serving as a medium for signals FP1U and FP1D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Hereinafter, the description will be made with the bidirectional communication referred to as seventh bidirectional communication. InFIG.8, the second fiber pair serving as a medium for signals FP2U and FP2D transmitted and received by the terminal station A (21) is also connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Hereinafter, the description will be made with the bidirectional communication referred to as eighth bidirectional communication. The seventh bidirectional communication can be achieved by switching the optical switches11-1,11-2,11-5, and11-6to a switching state as illustrated inFIG.8. The seventh bidirectional communication can be described in the same manner as the sixth bidirectional communication, and description thereof will be omitted. The eighth bidirectional communication can be achieved by switching the optical switches11-3,11-4,11-7, and11-8to a switching state as illustrated inFIG.8. The eighth bidirectional communication can be described in the same manner as the third bidirectional communication, and description thereof will be omitted. As described with respect to the bidirectional communication (second bidirectional communication or fifth bidirectional communication) from the terminal station C (23) to the terminal station B (22), the switching unit40is capable of controlling connection in such a way as to connect one of the second optical fiber transmission lines to the third optical fiber transmission line. In other words, the switching unit40can include a function of switching any one of the plurality of second optical fiber transmission lines to connect to the third optical fiber transmission line. As described in the examples of bidirectional communication in the present example embodiment, the switching unit40can include a configuration in which the second optical switch and the third optical switch are connected in multi-stages, and, in that case, the switching unit40is capable of switching a transmission route by controlling the second optical switch and the third optical switch. As illustrated by the examples inFIGS.6to8, the switching unit40can include a function of switching any one of the plurality of first optical fiber transmission lines and the plurality of second optical fiber transmission lines to connect to the third optical fiber transmission line. As illustrated by the examples inFIGS.6to8, the switching unit40can include a configuration in which the first to third optical switches are connected in multi-stages, and, in that case, the switching unit40is capable of switching a transmission route by controlling the optical switches. As described above, the connection state inFIG.6is a state in which one of the two fiber pairs connecting the terminal station A (21) and terminal station B (22) is connected to the terminal station C (23), and the connection state inFIG.7is a state in which the other fiber pair is connected to the terminal station C (23). The connection state inFIG.8is a state in which both of the two fiber pairs connect the terminal station A (21) and the terminal station B (22). As described above, each of the fiber pairs connecting the terminal station A (21) and the terminal station B (22) can be used as a trunk line, and the fiber pairs connecting the branching apparatus10and the terminal station C (23) can be used as a branch line. In other words, the system illustrated inFIGS.6to8can include two trunk lines and a single branch line. Note that, although a distinction between a trunk line and a branch line is generally made based on a power supply system and line length, distinction criteria are not limited thereto. The following description will be made based on the distinction between the trunk line and the branch line that are arrange as described above. The connection state inFIG.6indicates a state in which the terminal station A (21) is connected to the terminal station B (22), using the second trunk line and the terminal station C (23) is connected to the terminal station A (21) and the terminal station B (22) by connecting the first trunk line to the branch line. The connection state inFIG.7indicates a state in which the terminal station A (21) is connected to the terminal station B (22), using the first trunk line and the terminal station C (23) is connected to the terminal station A (21) and the terminal station B (22) by connecting the second trunk line to the branch line. The connection state inFIG.8indicates, as a basic connection state, a state in which the terminal station A (21) and the terminal station B (22) are connected using both the first trunk line and the second trunk line. The switching unit40is also capable of performing switching bringing a connection state to the above-described basic connection state. As described above, in the system, two optical fiber transmission lines connecting terminal stations (for example, trunk stations) to each other share a transmission line (branch line) to another terminal station (for example, a branch station). In the system, this sharing enables either transmission line of the two optical fiber transmission lines to be selectively connected to the branch line, and it is needless to say that the connection state can be brought to a state in which neither transmission line is connected to the branch line. Next, an example of switching control of the switching unit40and a configuration example of the terminal station A (21), the terminal station B (22), and the terminal station C (23) will be described with additional reference toFIG.9.FIG.9is a block diagram illustrating a configuration example of a portion of the system exemplified inFIGS.6to8. As illustrated inFIG.9, in the system, each terminal station can include an optical transmission apparatus30. The optical transmission apparatus30is connected to the branching apparatus10via an optical fiber transmission line. The optical transmission apparatus30can include optical transmitters31each of which is configured to send an optical signal of a wavelength, a multiplexing unit32configured to input and multiplex optical signals of respective wavelengths from the optical transmitters31, and a control signal generation unit33. Additionally, although not illustrated, the optical transmission apparatus30can include a demultiplexing unit and an optical receiver for each wavelength. Note that the demultiplexing unit can be integrated with the multiplexing unit and thereby configured as a multiplexing/demultiplexing unit. The terminal station C (23) can, for example, include an optical transmission apparatus30for communication with the terminal station A (21) and an optical transmission apparatus30for communication with the terminal station B (22). The terminal station A (21) and the terminal station B (22) can include an optical transmission apparatus30with respect to each fiber pair. The control signal generation unit33generates a control signal for controlling the optical switches11-1to11-8, and the multiplexing unit32also multiplexes the control signal. The control signal may be an optical signal of a wavelength different from a main signal on which data to be sent are superimposed (a wavelength different from output wavelengths of the optical transmitters31) or a signal obtained by modulating a main signal with a low frequency component by full-wave modulation. Such a configuration enables the optical transmission apparatus30to output the control signal as an optical signal. Note that the configuration in which a control signal is output does not include to be employed by all the terminal stations. Note, however, that, in order to provide redundancy in consideration of a malfunction, such as disconnection, it is desirable to employ a configuration in which a plurality of terminal stations output control signals, that is, a configuration in which the branching apparatus10is able to extract control signals from a plurality of routes. The branching apparatus10can include an optical switch group11, an extraction unit12configured to extract a control signal from an optical signal received from the optical transmission apparatus30via an optical fiber transmission line, and a control unit1aconfigured to control the optical switch group11in accordance with an extracted control signal. Note that the optical switch group11is composed of the optical switches11-1to11-8illustrated inFIGS.6and7. The extraction unit12may be installed with respect to each optical fiber and may also be installed on the input side from a branch station. When a plurality of extraction units12are installed, a plurality of control units1amay be installed in correspondence to the respective extraction units12. The extraction unit12extracts a control signal from an optical signal (including a main signal and a control signal) that is input via the optical fiber transmission line. The extraction unit12may be constituted by, for example, a combination of an optical coupler (branching coupler) and an optical filter extracting a control signal. When the control signal uses a wavelength different from that of the main signal, the optical filter can be a filter selectively transmitting the wavelength, and, when the control signal is a signal generated by superimposing a low frequency component on a main signal, the optical filter can be a low-pass filter. The control unit1acontrols the optical switch group11in response to reception of a control signal from a terminal station as described above. In other words, the switching control by the control unit1acan be performed based on the following control signal. That is, the above-described control signal is a signal that is extractable from a wavelength-multiplexed optical signal having been optically transmitted through each optical fiber transmission line in the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line. In particular, as described above, it can be said that the above-described control signal is preferably a signal extractable from wavelength-multiplexed optical signals optically transmitted through at least two or more optical fiber transmission lines out of such optical fiber transmission lines, in terms of providing the control signal with redundancy. Note, however, that the control unit1acan be configured to control the optical switch group11, based on a control signal received from another route (a route different from the data communication route) as an electrical signal or an optical signal. Alternatively, the control unit1acan also be configured to control the optical switch group11according to change in external power supply to the branching apparatus10. In this case, the branching apparatus10is configured to include a detection unit configured to detect whether or not external power is supplied from each terminal station. When, for example, it is detected that external power supply between trunk stations is interrupted, the control unit1acan control the switch group11to drop a trunk line to a branch line. In the system described referring toFIGS.6to8, the branching apparatus10can also be configured to include, out of the optical switches11-1to11-8, only the optical switches11-1to11-4that are required for the upstream transmission or to include only the optical switches11-5to11-8that are required for the downstream transmission. Next, an optical submarine cable system according to a comparative example (hereinafter, referred to as a comparative system) will be described with reference toFIG.10.FIG.10is a diagram illustrating a configuration of the comparative system. In the comparative system, a switching function of switching a trunk line to connect to a branch line is provided with respect to all trunk lines. Specifically, the respective constituent elements in the comparative system, although description thereof will be omitted, correspond to the respective constituent elements of the system exemplified inFIG.6and the like, and are denoted by reference signs obtained by adding100to the reference signs of the corresponding constituent elements of the system. For example, the comparative system includes a branching apparatus110for branching. Note, however, that the comparative system is a system in which, as illustrated inFIG.10, first optical switches and third optical switches are employed as optical switches111-3and111-7and optical switches111-4and111-8, respectively. Thus, the comparative system can only be configured in such a way that all the fiber pairs are dropped to the terminal station C (126) side as illustrated inFIG.10or any of the fiber pairs is not dropped to the terminal station C (126) side by directly connecting the trunk stations to each other through the fiber pairs. In other words, in the comparative system, selection of a fiber pair connecting to the terminal station C (126) side as in the system is not allowed. In addition, in the comparative system including such a configuration, fiber pairs connecting the optical switches111-3,111-4,111-7, and111-8to the terminal station C (126) via a repeater C (125) are additionally required for branching, compared with the system. It is needless to say that the additional fiber pairs causes the repeater C (125) interposed in the fiber pairs or optical amplifiers inside the repeater C (125) to be additionally required, compared with the system. As described above, in the comparative system, a number of branch lines equal to, for example, the number of trunk lines are required and submarine instruments on the branch lines corresponding to the respective branch lines are further required, which causes cost to be increased. As described above, according to the present example embodiment, in an optical submarine cable system in which terminal stations are connected by a plurality of optical fiber transmission lines, it is possible to connect a specified optical fiber transmission line to a third optical fiber transmission line for branching, in a similar manner to the first example embodiment. In the system, this capability enables the number of fiber pairs on the branching side to be reduced, which enables the number of apparatuses, such as repeaters, on the branched side to be reduced and cost to be thereby reduced. For example, even when a network of multiple fiber pairs including a lot of the branching apparatuses10according to the present example embodiment is constructed, it becomes possible to flexibly configure add/drop of signals among the multiple fiber pairs according to change in traffic demand in the network without worrying about additional cost. In the system, it becomes possible to reduce the number of apparatuses, such as a repeater, on the terminal station C (26) side at the time of construction of a network. In particular, using optical switches including two inputs and two outputs as some optical switches inside the branching apparatus10enables a fiber pair dropped to the terminal station C (26) side to be selected without increasing the number of optical switches, and it is possible to reduce cost in terms of this perspective. Third Example Embodiment A third example embodiment will be described with additional reference toFIGS.11and12, focusing on differences from the second example embodiment. Note, however, that, to the third example embodiment, various examples described in the first and second example embodiments can be appropriately applied.FIGS.11and12are diagrams illustrating a configuration example of an optical submarine cable system according to the third example embodiment. The optical submarine cable system illustrated inFIG.11(hereinafter, referred to as the system) is a system configured by, in a system illustrated inFIG.6, interposing a multiplexing/demultiplexing apparatus27between a branching apparatus10and a repeater C (26), that is, on the branched side (for example, the branch line side). The multiplexing/demultiplexing apparatus27can include wavelength selective switches (WSSes)28-1and28-2and can, although not illustrated, also include optical filters. The WSSes28-1and28-2(and the optical filters) are examples of a selection unit configured to perform wavelength selection. As exemplified in the example embodiment, submarine apparatuses connecting to a third optical fiber transmission line connecting to a third terminal station can be the multiplexing/demultiplexing apparatus27including a function of selecting a wavelength to be output to the succeeding stage and a repeater (repeating apparatus) C (26) on the terminal station C (23) side. Note that the repeater C (26) is sometimes not required depending on length of optical cables. In particular, although switching of a connection destination requires selection of a wavelength to be output to the succeeding stage, including the multiplexing/demultiplexing apparatus27enables the requirement to be coped with and light to be multiplexed and demultiplexed based on wavelength, using a specific fiber pair. The WSS28-1can be connected between a terminal d of an optical switch11-7and the repeater C (26), for a downstream signal in a connection between a terminal station A (21) and a terminal station C (23). The WSS28-1can also be connected between a terminal d of an optical switch11-8and the repeater C (26), for a downstream signal in a connection between the terminal station C (23) and a terminal station B (22). The WSS28-2can be connected between a terminal d of an optical switch11-3and the repeater C (26), for an upstream signal in the connection between the terminal station A (21) and the terminal station C (23). The WSS28-2can also be connected between a terminal d of an optical switch11-4and the repeater C (26), for an upstream signal in the connection between the terminal station C (23) and the terminal station B (22). Such a configuration enables the system to be brought to a connection state as described inFIG.6, as illustrated inFIG.11. The system can also be brought to a connection state as described inFIG.7, as illustrated inFIG.12. Although not illustrated, the system can also be put in a basic connection state as described inFIG.8. Switching control of the optical switches is as described afore with reference toFIGS.6to8. Specifically, the only difference is that the connection from the branching apparatus10to the repeater C (26) described in the connection states inFIGS.6to8is replaced with a connection from the branching apparatus10to the WSS28-1or the WSS28-2. The multiplexing/demultiplexing apparatus27is, as with a control unit1aof the branching apparatus10, capable of acquiring a control signal from an optical signal or the like and performing control of wavelength selection and the like, based on the control signal. This control is only required to be performed in such a way as to appropriately transmit an optical signal of a required wavelength to a transmission destination according to switching control of the optical switches. In a connection state inFIG.11, connections can be controlled in the following manner with respect to a first fiber pair. That is, the control is performed in such a way that the WSS28-1can transmit a wavelength output from the terminal station B (22) to the terminal station C (23) side and, in conjunction therewith, the control is performed in such a way that the WSS28-1can transmit a wavelength output from the terminal station C (23) to the terminal station A (21) side. In addition, the control is performed in such a way that the WSS28-2can transmit a wavelength output from the terminal station A (21) to the terminal station C (23) side and, in conjunction therewith, the control is performed in such a way that the WSS28-2can transmit a wavelength output from the terminal station C (23) to the terminal station B (22) side. In a connection state inFIG.12, connections can be controlled in the following manner with respect to a second fiber pair. That is, the control is performed in such a way that the WSS28-1can transmit a wavelength output from the terminal station B (22) to the terminal station C (23) side and, in conjunction therewith, the control is performed in such a way that the WSS28-1can transmit a wavelength output from the terminal station C (23) to the terminal station A (21) side. In addition, the control is performed in such a way that the WSS28-2can transmit a wavelength output from the terminal station A (21) to the terminal station C (23) side and, in conjunction therewith, the control is performed in such a way that the WSS28-2can transmit a wavelength output from the terminal station C (23) to the terminal station B (22) side. In the system described inFIGS.11and12, the branching apparatus10can also be configured to include, out of the optical switches11-1to11-8, only the optical switches11-1to11-4that are required for the upstream transmission or to include only the optical switches11-5to11-8that are required for the downstream transmission. Consequently, according to the present example embodiment, it is possible to appropriately transmit an optical signal of a required wavelength to a transmission destination when a transmission line is branched or a transmission line having branched is restored to an original state, in addition to the advantageous effects of the second example embodiment. Fourth Example Embodiment A fourth example embodiment will be described with additional reference toFIG.13, focusing on differences from the first example embodiment. Note, however, that, to the fourth example embodiment, various examples described in the first to third example embodiments can be appropriately applied.FIG.13is a schematic diagram illustrating a configuration example of an optical submarine cable system including an optical submarine branching apparatus according to the fourth example embodiment. As illustrated inFIG.13, the optical submarine cable system according to the present example embodiment (hereinafter, referred to as the system) can include a first terminal station21, a second terminal station22, and a third terminal station23and, in conjunction therewith, include an optical submarine branching apparatus3configured to branch connections thereamong. The optical submarine branching apparatus3can include a control unit3acorresponding to the control unit1ainFIG.2and, in conjunction therewith, include a switching unit3bcorresponding to the switching unit1binFIG.2. The switching unit3bcan be connected to one or a plurality of fourth optical fiber transmission lines connected to the third terminal station23, in addition to the function of the switching unit1b. In this case, the switching unit3bcan include a function of switching any one of the plurality of first optical fiber transmission lines to connect to the fourth optical fiber transmission lines. The control unit3ais configured to be capable of also performing control of such switching, compared with the control unit1a. In other words, in the system, third optical fiber transmission line described afore can be installed in plurality, and description is made considering the third optical fiber transmission lines as the fourth optical fiber transmission lines. Thus, a submarine apparatus or the like as described in the second example embodiment can be interposed in the fourth optical fiber transmission lines, as with the third optical fiber transmission lines. Further, in the present example embodiment, the switching unit3bcan include a function of switching any one of the plurality of second optical fiber transmission lines to connect to the fourth optical fiber transmission lines, as with the function of connection to the third optical fiber transmission line. Note that it can be said that considering the fourth optical fiber transmission lines connecting to the third terminal station23is equivalent to a case where each optical fiber in a fiber pair is considered as an individual optical fiber transmission line in the second example embodiment. Thus, in consideration of this point, it can be said that description about a specific configuration in the second example embodiment can also be applied to the present example embodiment. Consequently, according to the present example embodiment, it is possible to branch a plurality of transmission lines to the third terminal station and this capability enables the number of interposed submarine apparatuses to be further reduced, in addition to the advantageous effects in any of the first to third example embodiments. Fifth Example Embodiment A fifth example embodiment will be described with additional reference toFIG.14, focusing on differences from the first example embodiment. Note, however, that, to the fifth example embodiment, various examples described in the first to fourth example embodiments can be appropriately applied.FIG.14is a schematic diagram illustrating a configuration example of an optical submarine cable system including an optical submarine branching apparatus according to the fifth example embodiment. As illustrated inFIG.14, the optical submarine cable system according to the present example embodiment (hereinafter, referred to as the system) can include, as an optical submarine branching apparatus1inFIG.2, a main body unit1-1, an optical switch unit1-2bon the first terminal station21side, and an optical switch unit1-3bon the second terminal station22side as separate housings. InFIG.14, an example in which a control unit1-2aconfigured to control the optical switch unit1-2bis included in an apparatus1-2that includes a housing including the optical switch unit1-2band a control unit1-3aconfigured to control the optical switch unit1-3bis included in an apparatus1-3that includes a housing including the optical switch unit1-3bis illustrated. As described above, the switching unit1binFIG.2can include a first switching apparatus provided on the first terminal station21side as a separate housing from the main body and a second switching apparatus provided on the second terminal station22side as a separate housing from the main body and the first switching apparatus. The first switching apparatus is an apparatus exemplified by the apparatus1-2including the optical switch unit1-2b, and the second switching apparatus is an apparatus exemplified by the apparatus1-3including the optical switch unit1-3b. The main body unit1-1can include a control unit1aand a branching path1-1band, in conjunction therewith, include, for example, a circuit or the like for power supply, and can include no selective switching function relating to optical signals. For example, the optical switch unit1-2bcan include an optical switch performing switching of first optical fiber transmission lines, and the optical switch unit1-3bcan include an optical switch performing switching of second optical fiber transmission lines. Note that allocation of switches inside the optical switch unit1-2band the optical switch unit1-3bmay be a combination other than the above-described combination and it is only required that necessary optical switches be included anywhere in the combination of the optical switch unit1-2band the optical switch unit1-3b. In addition, the allocation of switches inside the optical switch unit1-2band the optical switch unit1-3bcan be concentrated on either thereof, and a configuration in which, for example, either the apparatus1-2or the apparatus1-3is omitted can be employed. The optical switch unit1-2b(and the control unit1-2a) can also be included in another submarine instrument, such as a repeating apparatus, that is interposed between the first terminal station21and the main body unit1-1. Likewise, the optical switch unit1-3b(and the control unit1-3a) can also be included in another submarine instrument, such as a repeating apparatus, that is interposed between the main body unit1-1and the second terminal station22. On the third terminal station23side, an optical switch or an optical switch and a control unit can be installed as a separate housing. Consequently, according to the present example embodiment, it is possible to miniaturize the housing of each unit, such as the main body unit, that constitutes the optical submarine branching apparatus and, in particular, facilitate winding work of optical cables at the time of laying and retrieval of the optical cables, in addition to the advantageous effects of any of the first to fourth example embodiments. Sixth Example Embodiment A sixth example embodiment will be described with additional reference toFIGS.15to18, focusing on differences from the second example embodiment. Note, however, that, to the sixth example embodiment, various examples described in the first to fifth example embodiments can be appropriately applied.FIGS.15to18are schematic diagrams illustrating a configuration example of an optical submarine cable system including an optical submarine branching apparatus according to the sixth example embodiment. As illustrated inFIG.15, the optical submarine cable system according to the present example embodiment (hereinafter, referred to as the system) is configured such that a terminal station A (21) and a terminal station B (22) are connected by three first optical fiber transmission lines and three second optical fiber transmission lines and the optical fiber transmission lines are allowed to branch to a terminal station C (23). As illustrated inFIG.15, a branching apparatus10ain the system is a branching apparatus configured by adding optical switches11-9to11-12to the branching apparatus10inFIG.6. The branching apparatus10a, with respect to the upstream direction, connects the optical switch11-9between a terminal d of an optical switch11-3and a repeater C (26) and connects the optical switch11-10between a terminal d of an optical switch11-4and the repeater C (26). The branching apparatus10a, with respect to the downstream direction, connects the optical switch11-12between a terminal d of an optical switch11-8and the repeater C (26) and connects the optical switch11-11between a terminal d of an optical switch11-7and the repeater C (26). In the system, although control of the added optical switches needs to be added, the description that was made referring toFIGS.6to8can basically be applied with respect to switching control of the optical switches, and the switching control will be schematically described with detailed description thereof omitted. InFIG.15, the first fiber pair serving as a medium for signals FP1U and FP1D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station C (23) and bidirectional communication between the terminal station C (23) and the terminal station B (22) are performed therethrough. In addition, inFIG.15, the second fiber pair serving as a medium for signals FP2U and FP2D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Moreover, inFIG.15, the third fiber pair serving as a medium for signals FP3U and FP3D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. The branching apparatus10ais capable of selectively switching the connection state illustrated inFIG.15to any of connection states illustrated inFIGS.16to18and restoring the connection state to the original state. In the system, including such switching, any one of the above-described connection states can be selectively switched to another of the connection states. In the connection state illustrated inFIG.16, a fiber pair used for connection to the terminal station C (23), differing from the one in the connection state illustrated inFIG.15, is the second fiber pair. In other words, the connection state illustrated inFIG.16is a connection state obtained from the connection state illustrated inFIG.15by, with respect to a fiber pair used for connection to the terminal station C (23), replacing the first one with the second one of the fiber pairs. InFIG.16, the second fiber pair serving as a medium for the signals FP2U and FP2D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station C (23) and bidirectional communication between the terminal station C (23) and the terminal station B (22) are performed therethrough. In addition, inFIG.16, the first fiber pair serving as a medium for the signals FP1U and FP1D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Moreover, inFIG.16, the third fiber pair serving as a medium for the signals FP3U and FP3D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. In the connection state illustrated inFIG.17, a fiber pair used for connection to the terminal station C (23), differing from the one in the connection state illustrated inFIG.15, is the third fiber pair. In other words, the connection state illustrated inFIG.17is a connection state obtained from the connection state illustrated inFIG.15by, with respect to a fiber pair used for connection to the terminal station C (23), replacing the first one with the third one of the fiber pairs. InFIG.17, the third fiber pair serving as a medium for the signals FP3U and FP3D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station C (23) and bidirectional communication between the terminal station C (23) and the terminal station B (22) are performed therethrough. In addition, inFIG.17, the first fiber pair serving as a medium for the signals FP1U and FP1D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Moreover, inFIG.17, the second fiber pair serving as a medium for signals FP2U and FP2D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Although the details are not described, the system can also be put in a connection state in which, for example, the terminal station C (23) and the terminal station B (22) are not connected in the connection states inFIGS.15to17. The branching apparatus10ais capable of switching the connection states illustrated inFIGS.15to17and the like to a connection state illustrated inFIG.18and restoring the connection state to the original state. The connection state illustrated inFIG.18can be said to be a basic connection state and is a connection state in which connection to the terminal station C (23) using any fiber pair is not established. InFIG.18, the first fiber pair serving as a medium for the signals FP1U and FP1D transmitted and received by the terminal station A (21) is connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. In addition, inFIG.18, the second fiber pair serving as a medium for the signals FP2U and FP2D transmitted and received by the terminal station A (21) is also connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Moreover, inFIG.18, the third fiber pair serving as a medium for the signals FP3U and FP3D transmitted and received by the terminal station A (21) is also connected in such a way that bidirectional communication between the terminal station A (21) and the terminal station B (22) is performed therethrough. Consequently, according to the present example embodiment, it is possible to expand the optical submarine cable system in such a way as to include more transmission lines, in addition to the advantageous effects of any of the first to fifth example embodiments. Although, in the present example embodiment, an example in which three first optical fiber transmission lines and three second optical fiber transmission lines are included was described, it is possible to include four or more first optical fiber transmission lines and the same number of second optical fiber transmission lines as the first optical fiber transmission lines. For example, although the second example embodiment was exemplified by two fiber pairs and the present example embodiment was exemplified by three fiber pairs inFIGS.15to18, the system may include more fiber pairs than these examples. Seventh Example Embodiment A seventh example embodiment will be described with additional reference toFIG.19, focusing on differences from the first, second, and fourth example embodiments. Note, however, that, to the seventh example embodiment, various examples described in the first to sixth example embodiments can be appropriately applied.FIG.19is a schematic diagram illustrating a configuration example of an optical submarine cable system including an optical submarine branching apparatus according to the seventh example embodiment. As illustrated inFIG.19, the optical submarine cable system according to the present example embodiment (hereinafter, referred to as the system) allows a mode in which a branch line is shared as described in the first example embodiment and a mode in which no branch line is shared to coexist. Hereinbelow, description will be made on individual cases categorized by whether or not the sharing is performed. As illustrated inFIG.19, an optical submarine branching apparatus4can include a switching unit40athat includes the same configuration as the switching unit1bin the optical submarine branching apparatus1inFIG.2and a switching unit40bthat includes the same configuration as the switching unit40in the optical submarine branching apparatus3inFIG.14, for providing the sharing mode. The numbers of the switching units40aand the switching units40bcan be any numbers. The switching unit40a, for example, allows arbitrary two trunk lines among the trunk lines connected to the optical submarine branching apparatus4to share a branch line among the branch lines connected to the optical submarine branching apparatus4. The switching unit40b, for example, allows arbitrary two trunk lines among the trunk lines connected to the optical submarine branching apparatus4to share two branch lines among the branch lines connected to the optical submarine branching apparatus4. Note that the number of trunk lines that are allowed to share a branch line(s) by each of the switching units40aand40bis not limited to two. As illustrated inFIG.19, the optical submarine branching apparatus4can include a switching unit (switching unit of a comparative example)111athat includes the same configuration as the switch group in the branching apparatus110ofFIG.10according to the comparative example, for providing the non-sharing mode. The number of the switching units111acan be any number. The switching unit111a, for example, allows arbitrary two trunk lines among the trunk lines connected to the optical submarine branching apparatus4to be connected to two branch lines among the branch lines connected to the optical submarine branching apparatus4without sharing. In other words, the switching unit111aallows branching in such a way that, with respect to each trunk line, a branch line corresponding to the trunk line exists. Note that some functions or all the functions of control units can be configured to be the same as one another among the switching units40a,40b, and111a. Consequently, according to the present example embodiment, it is possible to construct an optical submarine cable system while appropriately selecting required apparatuses according to cost, installation timing, and the like, in addition to the advantageous effects of any of the first to sixth example embodiments. Other Example Embodiments Although, in the above-described example embodiments, the functions of the respective units in the optical submarine branching apparatus and the optical submarine cable system were described, such functions are only required to be achieved as an optical submarine branching apparatus or an optical submarine cable system. Although, in the above-described example embodiments, configurations of the optical submarine cable system were exemplified, the configurations are not limited to the exemplifications. Various examples described in the example embodiments can be appropriately combined. The optical submarine branching apparatuses according to the example embodiments can include the following hardware configuration.FIG.20is a diagram illustrating an example of a hardware configuration of a portion of each of the optical submarine branching apparatuses according to the example embodiments. An optical submarine branching apparatus100illustrated inFIG.20includes a processor101, a memory102, and an interface103. The interface103can be configured as an interface to a not-illustrated switching unit, such as an optical switch. The functions of the respective units described in the example embodiments can be achieved by the processor101reading a program stored in the memory102and executing the program in collaboration with the interface103. The program can serve as the programs described in the example embodiments. In the above-described example, the program can be stored using various types of non-transitory computer readable media and provided to the computer. The non-transitory computer readable media include various types of tangible storage media. Examples of the non-transitory computer readable medium include a magnetic recording medium (such as a flexible disk, a magnetic tape, and a hard disk drive) and an optical magnetic recording medium (such as a magneto-optical disk). The examples further include a CD-read only memory (ROM), a CD-R, and a CD-R/W. The examples still further include a semiconductor memory (such as a mask ROM, a programmable ROM (PROM), an erasable PROM (EPROM), a flash ROM, and a random access memory (RAM)). The above-described program may be supplied to the computer by means of various types of transitory computer readable media. Examples of the transitory computer readable medium include an electrical signal, an optical signal, and an electromagnetic wave. The transitory computer readable medium can supply the program to the computer via a wired communication line, such as an electric wire and an optical fiber, or a wireless communication line. Note that the present disclosure is not limited to the above-described various example embodiments and can be changed appropriately without departing from the spirit and scope of the present invention. The present disclosure may also be carried out by arbitrarily combining respective example embodiments. All or part of the example embodiments described above may be described as in the following supplementary notes, but the present invention is not limited thereto. Supplementary Notes (Supplementary Note 1) An optical submarine branching apparatus comprising: switching unit configured to connect to a plurality of first optical fiber transmission lines connecting to a first terminal station, a plurality of second optical fiber transmission lines connecting to a second terminal station, and a third optical fiber transmission line connecting to a third terminal station and to switch a transmission route of a wavelength-multiplexed optical signal; and control unit configured to control switching of the transmission route by the switching unit, wherein the switching unit includes a function of connecting each of the plurality of first optical fiber transmission lines to one of the plurality of second optical fiber transmission lines and a function of switching any one of the plurality of first optical fiber transmission lines to connect to the third optical fiber transmission line. (Supplementary Note 2) The optical submarine branching apparatus according to Supplementary Note 1, wherein the switching unit includes a configuration in which a first optical switch including an input path and two output paths and a second optical switch including two input paths and two output paths are connected in multi-stages. (Supplementary Note 3) The optical submarine branching apparatus according to Supplementary Note 1, wherein the switching unit includes a function of switching any one of the plurality of second optical fiber transmission lines to connect to the third optical fiber transmission line. (Supplementary Note 4) The optical submarine branching apparatus according to Supplementary Note 3, wherein the switching unit includes a configuration in which a second optical switch including two input paths and two output paths and a third optical switch including two input paths and an output path are connected in multi-stages. (Supplementary Note 5) The optical submarine branching apparatus according to Supplementary Note 3, wherein the switching unit includes a configuration in which a first optical switch including an input path and two output paths, a second optical switch including two input paths and two output paths, and a third optical switch including two input paths and an output path are connected in multi-stages. (Supplementary Note 6) The optical submarine branching apparatus according to any one of Supplementary Notes 1 to 5, wherein each optical fiber transmission line in the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line includes a fiber pair composed of an optical fiber for optically transmitting information from the first terminal station side and an optical fiber for optically transmitting information to the first terminal station side. (Supplementary Note 7) The optical submarine branching apparatus according to any one of Supplementary Notes 1 to 6, wherein control of the switching unit by the control unit is performed based on a control signal extractable from a wavelength-multiplexed optical signal having been optically transmitted through at least two or more optical fiber transmission lines out of respective optical fiber transmission lines of the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line. (Supplementary Note 8) The optical submarine branching apparatus according to any one of Supplementary Notes 1 to 7, wherein, in the third optical fiber transmission line, a submarine apparatus is connected between the optical submarine branching apparatus and the third terminal station, the submarine apparatus being an apparatus for submarine installation. (Supplementary Note 9) The optical submarine branching apparatus according to Supplementary Note 8, wherein the submarine apparatus is a multiplexing/demultiplexing apparatus including a function of selecting a wavelength to be output to a succeeding stage. (Supplementary Note 10) The optical submarine branching apparatus according to Supplementary Note 8, wherein, to the third optical fiber transmission line, a multiplexing/demultiplexing apparatus including a function of selecting a wavelength to be output to a succeeding stage and a repeating apparatus arranged on the third terminal station side of the multiplexing/demultiplexing apparatus are connected as the submarine apparatuses. (Supplementary Note 11) The optical submarine branching apparatus according to any one of Supplementary Notes 1 to 10, wherein the switching unit is further connected to a fourth optical fiber transmission line connected to the third terminal station and includes a function of switching any one of the plurality of first optical fiber transmission lines to connect to the fourth optical fiber transmission line. (Supplementary Note 12) The optical submarine branching apparatus according to any one of Supplementary Notes 1 to 11, wherein the switching unit includes a first switching apparatus, the first switching apparatus being provided on the first terminal station side as a separate housing from a main body of the optical submarine branching apparatus, and a second switching apparatus, the second switching apparatus being provided on the second terminal station side as a separate housing from the main body of the optical submarine branching apparatus and the first switching apparatus. (Supplementary Note 13) An optical submarine cable system comprising:a first terminal station;a second terminal station;a third terminal station;an optical submarine branching apparatus;a plurality of first optical fiber transmission lines configured to connect the optical submarine branching apparatus to the first terminal station;a plurality of second optical fiber transmission lines configured to connect the optical submarine branching apparatus to the second terminal station; anda third optical fiber transmission line configured to connect the optical submarine branching apparatus to the third terminal station, whereinthe optical submarine branching apparatus includes:switching unit configured to connect to the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line and to switch a transmission route of a wavelength-multiplexed optical signal; andcontrol unit configured to control switching of the transmission route by the switching unit, andthe switching unit includes a function of connecting each of the plurality of first optical fiber transmission lines to one of the plurality of second optical fiber transmission lines and a function of switching any one of the plurality of first optical fiber transmission lines to connect to the third optical fiber transmission line. (Supplementary Note 14) The optical submarine cable system according to Supplementary Note 13, wherein the switching unit includes a configuration in which a first optical switch including an input path and two output paths and a second optical switch including two input paths and two output paths are connected in multi-stages. (Supplementary Note 15) The optical submarine cable system according to Supplementary Note 13, wherein the switching unit includes a function of switching any one of the plurality of second optical fiber transmission lines to connect to the third optical fiber transmission line. (Supplementary Note 16) The optical submarine cable system according to Supplementary Note 15, wherein the switching unit includes a configuration in which a second optical switch including two input paths and two output paths and a third optical switch including two input paths and an output path are connected in multi-stages. (Supplementary Note 17) The optical submarine cable system according to Supplementary Note 15, wherein the switching unit includes a configuration in which a first optical switch including an input path and two output paths, a second optical switch including two input paths and two output paths, and a third optical switch including two input paths and an output path are connected in multi-stages. (Supplementary Note 18) The optical submarine cable system according to any one of Supplementary Notes 13 to 17, wherein each optical fiber transmission line in the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line includes a fiber pair composed of an optical fiber for optically transmitting information from the first terminal station side and an optical fiber for optically transmitting information to the first terminal station side. (Supplementary Note 19) The optical submarine cable system according to any one of Supplementary Notes 13 to 18, wherein control of the switching unit by the control unit is performed based on a control signal extractable from a wavelength-multiplexed optical signal having been optically transmitted through at least two or more optical fiber transmission lines out of respective optical fiber transmission lines of the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line. (Supplementary Note 20) The optical submarine cable system according to any one of Supplementary Notes 13 to 19 comprising a submarine apparatus, the submarine apparatus being an apparatus for submarine installation and being connected between the optical submarine branching apparatus and the third terminal station in the third optical fiber transmission line. (Supplementary Note 21) The optical submarine cable system according to Supplementary Note 20, wherein the submarine apparatus is a multiplexing/demultiplexing apparatus including a function of selecting a wavelength to be output to a succeeding stage. (Supplementary Note 22) The optical submarine cable system according to Supplementary Note 20 comprising a multiplexing/demultiplexing apparatus including a function of selecting a wavelength to be output to a succeeding stage and a repeating apparatus connected on the third terminal station side of the multiplexing/demultiplexing apparatus, as the submarine apparatuses connected to the third optical fiber transmission line. (Supplementary Note 23) The optical submarine cable system according to any one of Supplementary Notes 13 to 22, wherein the switching unit is further connected to a fourth optical fiber transmission line connected to the third terminal station and includes a function of switching any one of the plurality of first optical fiber transmission lines to connect to the fourth optical fiber transmission line. (Supplementary Note 24) The optical submarine cable system according to any one of Supplementary Notes 13 to 23, wherein the switching unit includes a first switching apparatus, the first switching apparatus being provided on the first terminal station side as a separate housing from a main body of the optical submarine branching apparatus, and a second switching apparatus, the second switching apparatus being provided on the second terminal station side as a separate housing from the main body of the optical submarine branching apparatus and the first switching apparatus. (Supplementary Note 25) A switching method comprising a control step of controlling switching unit in an optical submarine branching apparatus, the switching unit being connected to a plurality of first optical fiber transmission lines connecting the optical submarine branching apparatus to a first terminal station, a plurality of second optical fiber transmission lines connecting the optical submarine branching apparatus to a second terminal station, and a third optical fiber transmission line connecting the optical submarine branching apparatus to a third terminal station, to switch a transmission route of a wavelength-multiplexed optical signal, wherein the control step includes a step of connecting each of the plurality of first optical fiber transmission lines to one of the plurality of second optical fiber transmission lines and a step of switching any one of the plurality of first optical fiber transmission lines to connect to the third optical fiber transmission line. (Supplementary Note 26) The switching method according to Supplementary Note 25, wherein the switching unit includes a configuration in which a first optical switch including an input path and two output paths and a second optical switch including two input paths and two output paths are connected in multi-stages, and the control step switches the transmission route by controlling the first optical switch and the second optical switch. (Supplementary Note 27) The switching method according to Supplementary Note 25, wherein the control step includes a step of switching any one of the plurality of second optical fiber transmission lines to connect to the third optical fiber transmission line. (Supplementary Note 28) The switching method according to Supplementary Note 27, wherein the switching unit includes a configuration in which a second optical switch including two input paths and two output paths and a third optical switch including two input paths and an output path are connected in multi-stages, and the control step switches the transmission route by controlling the second optical switch and the third optical switch. (Supplementary Note 29) The switching method according to Supplementary Note 27, wherein the switching unit includes a configuration in which a first optical switch including an input path and two output paths, a second optical switch including two input paths and two output paths, and a third optical switch including two input paths and an output path are connected in multi-stages, and the control step switches the transmission route by controlling the first optical switch, the second optical switch, and the third optical switch. (Supplementary Note 30) The switching method according to any one of Supplementary Notes 25 to 29, wherein each optical fiber transmission line in the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line includes a fiber pair composed of an optical fiber for optically transmitting information from the first terminal station side and an optical fiber for optically transmitting information to the first terminal station side. (Supplementary Note 31) The switching method according to any one of Supplementary Notes 25 to 30, wherein the control step is performed based on a control signal extractable from a wavelength-multiplexed optical signal having been optically transmitted through at least two or more optical fiber transmission lines out of respective optical fiber transmission lines of the plurality of first optical fiber transmission lines, the plurality of second optical fiber transmission lines, and the third optical fiber transmission line. (Supplementary Note 32) The switching method according to any one of Supplementary Notes 25 to 31, wherein, in the third optical fiber transmission line, a submarine apparatus is connected between the optical submarine branching apparatus and the third terminal station, the submarine apparatus being an apparatus for submarine installation. (Supplementary Note 33) The switching method according to Supplementary Note 32, wherein the submarine apparatus is a multiplexing/demultiplexing apparatus including a function of selecting a wavelength to be output to a succeeding stage. (Supplementary Note 34) The switching method according to Supplementary Note 32, wherein, to the third optical fiber transmission line, a multiplexing/demultiplexing apparatus including a function of selecting a wavelength to be output to a succeeding stage and a repeating apparatus arranged on the third terminal station side of the multiplexing/demultiplexing apparatus are connected as the submarine apparatuses. (Supplementary Note 35) The switching method according to any one of Supplementary Notes 25 to 34, wherein the switching unit is further connected to a fourth optical fiber transmission line connected to the third terminal station, and the control step includes a step of switching any one of the plurality of first optical fiber transmission lines to connect to the fourth optical fiber transmission line. (Supplementary Note 36) The switching method according to any one of Supplementary Notes 25 to 35, wherein the switching unit includes a first switching apparatus, the first switching apparatus being provided on the first terminal station side as a separate housing from a main body of the optical submarine branching apparatus, and a second switching apparatus, the second switching apparatus being provided on the second terminal station side as a separate housing from the main body of the optical submarine branching apparatus and the first switching apparatus. (Supplementary Note 37) A program to be executed by a control computer included in an optical submarine branching apparatus, the program being a program causing a control step of controlling switching unit in an optical submarine branching apparatus, the switching unit being connected to a plurality of first optical fiber transmission lines connecting the optical submarine branching apparatus to a first terminal station, a plurality of second optical fiber transmission lines connecting the optical submarine branching apparatus to a second terminal station, and a third optical fiber transmission line connecting the optical submarine branching apparatus to a third terminal station, to switch a transmission route of a wavelength-multiplexed optical signal to be executed, wherein the control step includes a step of connecting each of the plurality of first optical fiber transmission lines to one of the plurality of second optical fiber transmission lines and a step of switching any one of the plurality of first optical fiber transmission lines to connect to the third optical fiber transmission line. The claimed invention was described above with reference to example embodiments thereof, but the claimed invention is not limited to the above example embodiments. Various modifications that could be understood by a person skilled in the art may be applied to the configurations and details of the claimed invention within the scope of the present invention. This application is based upon and claims the benefit of priority from Japanese patent application No. 2019-061901, filed on Mar. 27, 2019, the disclosure of which is incorporated herein in its entirety by reference. REFERENCE SIGNS LIST 1,3,4,100Optical submarine branching apparatus1-1Main body unit1-2,1-3Apparatus1-2b,1-3bOptical switch unit1-1bBranching path1a,1-2a,1-3a,3aControl unit1b,3b,40,40a,40bSwitching unit10,10aBranching apparatus11Switch group11-1to11-12,41,42,43Optical switch11Optical switch group12Extraction unit21First terminal station (terminal station A)22Second terminal station (terminal station B)23Third terminal station (terminal station C)27Multiplexing/demultiplexing apparatus28-1,28-2WSS30Optical transmission apparatus31Optical transmitter32Multiplexing unit33Control signal generation unit101Processor102Memory103Interface111aSwitching unit of a comparative example | 105,199 |
11942992 | DETAILED DESCRIPTION OF THE EMBODIMENTS The following description is written by referring to terms of this technical field. If any term is defined in this specification, such term should be interpreted accordingly. In addition, the connection between objects or events in the below-described embodiments can be direct or indirect provided that these embodiments are practicable under such connection. Said “indirect” means that an intermediate object or a physical space exists between the objects, or an intermediate event or a time interval exists between the events. The disclosure herein includes an operation method of a network device and a control chip of the network device. On account of that some or all elements of the control chip of the network device could be known, the detail of such elements is omitted provided that such detail has little to do with the features of this disclosure, and that this omission nowhere dissatisfies the specification and enablement requirements. Some or all of the processes of the operation method of a network device may be implemented by software and/or firmware, and can be performed by the control chip of the network device or its equivalent. A person having ordinary skill in the art can choose components or steps equivalent to those described in this specification to carry out the present invention, which means that the scope of this invention is not limited to the embodiments in the specification. FIG.1is a schematic diagram of the control chip of the network device according to an embodiment of the present invention. The network device can be a router, a switch, or a terminal device (such as a server, a computer, or other devices that has the network function). The control chip100implements the OSI model. However,FIG.1only shows the MAC layer110, the reconciliation sublayer (RS)120, and a part of the physical layer130, and other layers that are less relevant to the technologies of this disclosure are omitted. The control chip100further includes a media selection unit140, a control circuit150, and an analog front-end (AFE) circuit160. The control chip100transmits the output signal Vout and receives the input signal Vin through the optical module210and the fiber medium200. One of the functions of the optical module210is to perform conversion between optical signals and electrical signals. Therefore, the optical module210may also be referred to as a photoelectric conversion element. The AFE circuit160receives the input signal Vin through the optical module210and the fiber medium200and detects the amplitude or energy of the input signal Vin to generate a detection signal SD, which represents the amplitude or energy of the input signal Vin. The technique of detecting the amplitude or energy of a signal is well known to people having ordinary skill in the art, and the details are thus omitted for brevity. When the amplitude or energy of the input signal Vin is greater than a threshold (e.g., the detection signal SD corresponding to a first level), the input signal Vin can be determined to be a meaningful signal; on the contrary, when the amplitude or energy of the input signal Vin is not greater than the threshold (e.g., the detection signal SD corresponding to a second level), the input signal Vin can be determined to be a meaningless signal, which may indicate a link-failure of the receiving path of the local device. The control circuit150generates a speed setting signal SS according to the preset speed SK and the detection signal SD. The media selection unit140selects, according to the speed setting signal SS, one of the physical layer transmit data of multiple speeds (the physical layer transmit data SPD-A PHY of speed SPD-A, the physical layer transmit data SPD-B PHY of speed SPD-B, . . . , the physical layer transmit data SPD-X PHY of speed SPD-X) as the target transmit data TD of the control chip100. The speed of the target transmit data TD is the target speed ST of the control chip100. In some embodiments, the media selection unit140may be a multiplexer. In other embodiments, the detection signal SD can be replaced with the detection signal SD′. The detection signal SD′ is generated by measuring loss of signal (LOS) by the optical module210in the fiber medium200and can also be used to represent the amplitude or energy of the input signal Vin (the larger the loss of signal, the smaller the amplitude or energy of the input signal Vin). Reference is made toFIG.2, which is a flowchart of the operation method of the network device according to an embodiment of the present invention. The steps ofFIG.2are performed by the control circuit150. First, after the system of the network device is started or restarted (step S210in which the control circuit150performs some initialization procedures), the control circuit150controls, through the speed setting signal SS, the media selection unit140to set the speed of the network device to the first speed (for example, when the first speed is the preset speed SK which is SPD-A, the media selection unit140selects the physical layer transmit data SPD-A PHY) (step S220), and then the control circuit150controls, through the speed setting signal SS, the AFE circuit160to transmit and/or receive data at the first speed (step S230). Next, the control circuit150determines whether the detection signal SD is at the first level (step S240). The detection signal SD being at the first level (e.g., the high level) indicates that the amplitude or energy of the input signal Vin is greater than the threshold; the detection signal SD being not at the first level (e.g., the detection signal SD being at the low level) indicates that the amplitude or energy of the input signal Vin is not greater than the threshold. In other words, step S240is equivalent to monitoring whether the detection signal SD changes its level and is also equivalent to determining whether the amplitude or energy of the input signal Vin is greater than the threshold. When the detection signal SD is at the first level (the result of step S240is YES, that is, the amplitude or energy of the input signal Vin is greater than the threshold), the control circuit150maintains the speed of the network device the first speed (step S220) and proceeds to transmit and/or receive data (step S230). When the detection signal SD is not at the first level (the result of step S240is NO, that is, when the detection signal SD changes from the first level to the second level), the control circuit150controls, through the speed setting signal SS, the media selection unit140to set the speed of the network device to the second speed (step S250). The second speed is different from the first speed. For example, if the first speed is 2500BASE-FX (i.e., 2500 M bps), the second speed can be, for example but not limited to, 1000BASE-X (i.e., 1000 M bps) or 100BASE-FX (i.e., 100 M bps). The options of the combinations of the first speed and the second speed include 5000BASE-X (i.e., 5000 M bps), 2500BASE-FX (i.e., 2500 M bps), 1000BASE-X (i.e., 1000 M bps) or 100BASE-FX (i.e., 100 M bps) or the like. The speeds 1000BASE-X and 100BASE-FX are defined and described in detail in IEEE 802.3, and the definitions of 5000BASE-X and 2500BASE-X can be obtained by the designer or manufacturer by adjustment or extension according to practical requirements and the definition of 1000BASE-X. Step S250includes sub-step S255: the control circuit150transmits the preset data to the link partner. The preset data, for example, can be an Idle code group which is a 4 b/5 b code group defined under the 100BASE-X protocol or an IDLE ordered sets which is an 8 b/10 b code group defined under the 1000BASE-X protocol. One of the functions of the Idle code group or the IDLE ordered sets is to notify the link partner that the local device is idling (i.e., no data packet is being sent) but the link-up remains. Because the local device has changed its speed in step S250, the link partner afterwards cannot correctly decode the preset data received; as a result, the link partner will switch to the unlinked state. After switching from the link-up state to the unlinked state, the link partner stops transmitting packets, so as to avoid packet loss and prevent causing problems to the upper layer(s) of the OSI model. After step S250finishes, the control circuit150proceeds to determine whether the detection signal SD is at the first level (step S240). When the receiving path of the local device is back to normal (the result of step S240is YES, that is, the local device can receive the signal from the link partner again), the control circuit150sets the speed of the local device to the first speed (step S220). In this way, the link partner can establish the link-up with the local device again, and both can resume normal packet transmission and/or reception. In some embodiments, the second speed in step S250is less than the first speed. For example, if the first speed is 2500BASE-X, the second speed can be 1000BASE-X or 100BASE-FX. When the network quality is poor, the network device implements the down speed function, utilizing a lower data rate to improve the signal transmission quality in an attempt to establish a link-up, thereby increasing the probability of establishing a link-up between two network devices. For example, if a local device and a link partner that both support 1000BASE-X or 100BASE-FX cannot establish a link-up at the speed of 1000BASE-X, both devices will down speed to 100BASE-FX and reconnect. Based on the aforementioned down speed function, the present invention also provides an operation method of a network device, andFIG.3shows the flowchart. The flow ofFIG.3is also performed by the control circuit150. Steps S210-S240inFIG.3are the same as those inFIG.2, so the details are thus omitted for brevity. In this embodiment, the second speed is 100BASE-FX, and step S250includes sub-step S257: the control circuit150transmits a Far-End Fault (FEF) indication, which is only defined in the 100BASE-FX protocol. Because after step S250the link partner that implements the down speed function reduces its own speed to 100BASE-FX (as a result, the link partner and the local device are operating at the same speed), the control circuit150of the local device can thus send the FEF indication to the link partner at the speed of 100BASE-FX to notify the link partner that the local device is faulty. In comparison withFIG.2, in the embodiment ofFIG.3, the link partner can quickly learn that the local device is faulty and/or the cause of the fault at the local device; therefore, the link partner can respond quickly. Reference is made toFIG.4, which is a functional block diagram of the control circuit150according to an embodiment. The control circuit150includes a processing unit152and a memory154. The processing unit152may be a circuit or electronic component with program execution capability, such as a central processing unit, a microprocessor, or a micro-processing unit, which executes program instructions or program codes stored in the memory154to perform the flow ofFIG.2orFIG.3. In other embodiments, people having ordinary skill in the art can design the control circuit150based on the above discussions, that is, the control circuit150can be an application specific integrated circuit (ASIC) or embodied by circuits or hardware such as a programmable logic device (PLD) or finite state machine (FSM). According to the present invention, the control chip of the network device and the operation method of the network device can prevent the one-sided link-up state, and therefore can effectively avoid packet loss or prevent causing problems to the upper layer(s) of the OSI model. Since a person having ordinary skill in the art can appreciate the implementation detail and the modification thereto of the present method invention through the disclosure of the device invention, repeated and redundant description is thus omitted. Furthermore, the shape, size, and ratio of any element in the disclosed figures are exemplary for understanding, not for limiting the scope of this invention. Moreover, there is no step sequence limitation for the method inventions as long as the execution of each step is applicable. In some instances, the steps can be performed simultaneously or partially simultaneously. The aforementioned descriptions represent merely the preferred embodiments of the present invention, without any intention to limit the scope of the present invention thereto. Various equivalent changes, alterations, or modifications based on the claims of the present invention are all consequently viewed as being embraced by the scope of the present invention. | 12,749 |
11942993 | DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before the present disclosure is described in detail, it should be noted that like elements are denoted by the same reference numerals in the following description. Referring toFIG.1, an embodiment of an optical transmission device1of the present disclosure is adapted to an optical communication system10. The optical communication system10includes an optical fiber3and an optical receiving device4which includes an optical receiver41and a multi-level pulse amplitude demodulator (PAM-N Demodulator)42. The optical transmission device1is used to modulate an optical signal Ls, which is emitted by a laser2inside the optical transmission device1and has a continuous wave, to generate an optical modulate signal Lm having a chirp, and transmit the optical modulate signal Lm to the optical receiver41via the optical fiber3. The optical receiver41converts the received optical modulate signal Lm to an electrical signal Es and outputs the electrical signal Es to the multi-level pulse amplitude demodulator42. The multi-level pulse amplitude demodulator42demodulates the received electrical signal Es to generate a data output Do. The optical transmission device1of the present embodiment further includes a control module11, a multi-level pulse amplitude modulator (PAM-N Modulator)12, an amplifier13and an asymmetrical optical modulator14. The control module11is used to receive an input signal Is indicating a dispersion amount, and generate a control signal output Co including a slope adjust signal Sa and a bias voltage offset adjust signal Ba according to the input signal Is, an electrical level adjust signal La changing as the bias voltage offset adjust signal Ba changes, and a polarity adjust signal Pr changing as the slope adjust signal Sa changes. The slope adjust signal Sa and the bias voltage offset adjust signal Ba respectively change as a polarity and a magnitude (that is, an absolute value of the dispersion amount) of the dispersion amount change. In the present embodiment, the polarity and the magnitude of the dispersion amount are associated with a wavelength of the optical modulate signal Lm and a length of the optical fiber3. The control module11includes a slope controller111, a bias voltage offset controller112, an optical modulator bias voltage controller113and an electrical level adjustor114. The slope controller111receives the input signal Is, and generates the slope adjust signal Sa according to the polarity of the dispersion amount of the input signal Is, and generates and outputs the polarity adjust signal Pr according to the slope adjust signal Sa. The bias voltage offset controller112receives the input signal Is, and generates the bias voltage offset adjust signal Ba according to the magnitude of the dispersion amount of the input signal Is. The optical modulator bias voltage controller113connects the slope controller111and the bias voltage offset controller112to respectively receive the slope adjust signal Sa and the bias voltage offset adjust signal Ba, and generate and output the control signal output Co according to the received slope adjust signal Sa and the received bias voltage offset adjust signal Ba. The electrical level adjustor114connects the bias voltage offset controller112, and generates and outputs the electrical level adjust signal La according to the bias voltage offset adjust signal Ba. The multi-level pulse amplitude modulator12is used to receive a data input Di (which is a binary data), and connect the slope controller111and the electrical level adjustor114to respectively receive the polarity adjust signal Pr and the electrical level adjust signal La and perform multi-level pulse amplitude modulation (PAM-N) on the data input Di according to the polarity adjust signal Pr and the electrical level adjust signal La, so as to generate a multi-level pulse amplitude modulation signal Pam. In the present embodiment, the multi-level pulse amplitude modulation signal Pam is a four-level pulse amplitude modulation (PAM-4) signal, and the four-level pulse amplitude modulation signal has a zeroth electrical level, a first electrical level, a second electrical level and a third electrical level. The amplifier13is connected between the multi-level pulse amplitude modulator12and the asymmetrical optical modulator14, and amplifies the multi-level pulse amplitude modulation signal Pam from the multi-level pulse amplitude modulator12and outputs to the asymmetrical optical modulator14. The asymmetrical optical modulator14connects the laser2to receive the optical signal Ls, and connects the amplifier13and the optical modulator bias voltage controller113to respectively receive the multi-level pulse amplitude modulation signal Pam and the control signal output Co. The asymmetrical optical modulator14is controlled by the slope adjust signal Sa of the control signal output Co to be operated at one of a positive slope and a negative slope of a transfer function of the asymmetrical optical modulator14itself, and is controlled by the bias voltage offset adjust signal Ba of the control signal output Co to offset a bias voltage point of the asymmetrical optical modulator14itself from a quadrature point of the transfer function, and modulates the multi-level pulse amplitude modulation signal Pam to the optical signal Ls to generate the optical modulate signal Lm having the chirp. A polarity and a magnitude (that is, an absolute value) of the chirp respectively change as the slope adjust signal Sa and the bias voltage offset adjust signal Ba change. It is noted that, in the present embodiment, when the polarity of the dispersion amount of the input signal Is is positive polarity, the chirp of the optical modulate signal Lm is negative polarity, when the polarity of the dispersion amount of the input signal Is is negative polarity, the chirp of the optical modulate signal Lm is positive polarity. The asymmetrical optical modulator14is a Mach-Zehnder modulator (MZM), the Mach-Zehnder modulator is made of one of a LiNbO3-based, a silicon and an Inp. Moreover, the asymmetrical optical modulator14receives the multi-level pulse amplitude modulation signal Pam which is amplified by the amplifier13, but the present disclosure is not limited thereto. The present embodiment also may omit the amplifier13, as such, the asymmetrical optical modulator14directly connects the multi-level pulse amplitude modulator12to receive the multi-level pulse amplitude modulation signal Pam. In addition, the asymmetrical optical modulator14may be realized by one of following unbalanced design manners, for example: (1) making the asymmetrical optical modulator14have an unbalanced optical splitting ratio; (2) making lengths or shapes of two electrodes (not shown) included by the asymmetrical optical modulator14unbalanced; (3) making the two electrodes receive driving signals having different amplitudes; or (4) making PN junction bias voltages of the two electrodes unbalanced, and so on, but the present disclosure is not limited thereto. Referring toFIG.2andFIG.3,FIG.2andFIG.3illustrates a relationship among the dispersion amount of the input signal Is (as shown in the horizontal axis of the figures), a chirp parameter had by the asymmetrical optical modulator14(a parameter a as the chirp parameter in the figures) and the Dispersion-induced Optical Power Penalty (that is, as shown in the vertical axis in the figures) of the optical modulate signal Lm received by the optical receiver41when the optical modulate signal Lm is a 53.125 GBd four-level pulse amplitude modulation (PAM4) optical signal. As may be seen fromFIG.2, when the dispersion amount is negative polarity, that the chirp parameter of the asymmetrical optical modulator14is positive polarity indeed may make the Dispersion-induced Optical Power Penalty of the optical modulate signal Lm become small. As may be seen fromFIG.3, when the dispersion amount is positive polarity, that the chirp parameter of the asymmetrical optical modulator14is negative polarity indeed may make the Dispersion-induced Optical Power Penalty of the optical modulate signal Lm become small. Therefore, the optical transmission device1of the present disclosure makes the optical modulate signal Lm have the optimized chirp, to lower effect of dispersion caused by the optical fiber3on transmission of the optical communication system10, in turn promote the optical transmission distance of the optical communication system10. Hereinafter an operation of the optical transmission device1of the present embodiment is described by way of example, and an order performed with respect to the slope controller111and the bias voltage offset controller112is not limited thereto. Specifically, the polarity of the chirp parameter of the asymmetrical optical modulator14is associated with that the asymmetrical optical modulator14is operated at the positive slope or the negative slope of the transfer function of the asymmetrical optical modulator14itself, and the magnitude of the chirp parameter of the asymmetrical optical modulator14is associated with an offset between the bias voltage point of the asymmetrical optical modulator14and the quadrature point of the transfer function. For example, as shown inFIG.4,FIG.4illustrates a relationship between the chirp parameter of the asymmetrical optical modulator14(as shown in the vertical axis of the figure) and the offset of the bias voltage point of the asymmetrical optical modulator14and the quadrature point of the transfer function (as shown in the horizontal axis of the figure) when the asymmetrical optical modulator14is operated at the positive slope of the transfer function. Moreover, when that the asymmetrical optical modulator14is operated at the positive slope of the transfer function is changed to that the asymmetrical optical modulator14is operated at the negative slope of the transfer function according to the change of the slope adjust signal Sa, a relationship between the chirp parameter of the asymmetrical optical modulator14and the offset of the bias voltage point of the asymmetrical optical modulator14and the quadrature point of the transfer function is shown as inFIG.5. As may be seen fromFIGS.4and5, larger the offset between the bias voltage point and the quadrature point is, larger the magnitude of the absolute value of the chirp parameter is. In addition, the polarity of the chirp parameter may be adjusted by the positive slope or the negative slope of the transfer function. As such, in operation, the slope controller111generates the slope adjust signal Sa according to the polarity of the dispersion amount of the input signal Is, and outputs the slope adjust signal Sa to the asymmetrical optical modulator14via the optical modulator bias voltage controller113, to adjust that the asymmetrical optical modulator14is operated at the positive slope or the negative slope of the transfer function of the asymmetrical optical modulator14itself, making the polarity of the chirp parameter of the asymmetrical optical modulator14and the polarity of the dispersion amount opposite. At the same time, when the slope adjust signal Sa generated by the slope controller111is to make that the asymmetrical optical modulator14is operated at the negative slope of the transfer function, the slope controller111generates and outputs the polarity adjust signal Pr to the multi-level pulse amplitude modulator12, to cause the polarity of the multi-level pulse amplitude modulation signal Pam generated by the multi-level pulse amplitude modulator12to be reversed, making the polarity of the multi-level pulse amplitude modulation signal Pam and the polarity of the optical modulate signal Lm different. On the contrary, when the slope adjust signal Sa generated by the slope controller111is to make that the asymmetrical optical modulator14is operated at the positive slope of the transfer function, because at this time the polarity of the multi-level pulse amplitude modulation signal Pam and the polarity of the optical modulate signal Lm are identical, according to practical circuit application requirement, the slope controller111may be designed not to output the polarity adjust signal Pr, or the slope controller111may be designed to still output the polarity adjust signal Pr to inform the multi-level pulse amplitude modulator12to maintain the polarity of the multi-level pulse amplitude modulation signal Pam generated by the multi-level pulse amplitude modulator12to be unchanged. Next, the bias voltage offset controller112generates the bias voltage offset adjust signal Ba according to the magnitude of the dispersion amount of the input signal Is, and outputs the bias voltage offset adjust signal Ba to the asymmetrical optical modulator14via the optical modulator bias voltage controller113, to adjust the offset between the bias voltage point of the asymmetrical optical modulator14and the quadrature point of the transfer function (for example, control a bias voltage of the asymmetrical optical modulator14via an electrode in the asymmetrical optical modulator14to adjust the bias voltage point), making the magnitude of the chirp parameter of the asymmetrical optical modulator14changed. It is additionally noted that, further referring toFIG.6,FIG.6illustrates changes of the eye of the optical modulate signal Lm when the asymmetrical optical modulator14is operated at the positive slope of the transfer function and the bias voltage point of the asymmetrical optical modulator14is located at different positions of the transfer function of the sine electrical-optical (E/O) conversion of the asymmetrical optical modulator14. The optical modulate signal Lm is a PAM-4 optical signal, the eye thereof has an electrical level0, an electrical level1, an electrical level2and an electrical level3, and has three eye openings, the electrical level0to the electrical level1is a first eye opening, the electrical level1to the electrical level2is a second eye opening, the electrical level2to the electrical level3is a third eye opening. A first eye Lm1of the optical modulate signal Lm is the case that the bias voltage point is at the quadrature point of the positive slope of the transfer function (that is, at a parameter B1ofFIG.6), because of sine symmetrical characteristics with respect to the quadrature point, a vertical height VH01from the electrical level0to the electrical level1, a vertical height VH12from the electrical level1to the electrical level2and a vertical height VH23from the electrical level2to the electrical level3are identical (that is, VH01=VH12=VH23, the optical communication system10may obtain the maximum signal-to-noise ratio (SNR)). However, because of nonlinearity of the transfer function, when the bias voltage point is above the quadrature point (that is, at a parameter B2ofFIG.6), in a second eye Lm2of the optical modulate signal Lm, the vertical height VH23becomes small, but the vertical height VH01becomes large, when the bias voltage point is below the quadrature point (that is, at a parameter B3ofFIG.6), in a third eye Lm3of the optical modulate signal Lm, the vertical height VH23becomes large, but the vertical height VH01becomes small, causing maximum signal-to-noise ratio which may be obtained by the optical communication system10to be lower, causing transmission performance of the communication system10to be degraded. Therefore, before the multi-level pulse amplitude modulation signal Pam is transmitted to the asymmetrical optical modulator14, it needs to adjust the first and second electrical levels of the multi-level pulse amplitude modulation signal Pam (that is, parameters L1, L2ofFIG.6respectively are the first and second electrical levels), to make the vertical heights VH01, VH12, VH23still have the identical vertical height when the bias voltage point of the asymmetrical optical modulator14is made to offset from the quadrature point of the transfer function to adjust the magnitude of the chirp parameter of the asymmetrical optical modulator14. That is, finally, the electrical level adjustor114generates and outputs the electrical level adjust signal La according to the bias voltage offset adjust signal Ba to the multi-level pulse amplitude modulator12, to cause the multi-level pulse amplitude modulator12to adjust the first electrical level L1and the second electrical level L2of the multi-level pulse amplitude modulation signal Pam according to the electrical level adjust signal La. In the present embodiment, when the asymmetrical optical modulator14is operated at the positive slope of the transfer function and the asymmetrical optical modulator14is controlled by the bias voltage offset adjust signal Ba so that the bias voltage point of the asymmetrical optical modulator14itself offsets to above the quadrature point of the positive slope of the transfer function, the multi-level pulse amplitude modulator12modulates the data input Di according to the electrical level adjust signal La, to cause the first electrical level L1and the second electrical level L2of the multi-level pulse amplitude modulation signal Pam generated by the multi-level pulse amplitude modulator12to offset toward the zeroth electrical level (that is, a parameter L0is the zeroth electrical level inFIG.6), but when the asymmetrical optical modulator14is controlled by the bias voltage offset adjust signal Ba so that the bias voltage point of the asymmetrical optical modulator14itself offsets to below the quadrature point of the positive slope of the transfer function, the multi-level pulse amplitude modulator12modulates the data input Di according to the electrical level adjust signal La, to cause the first electrical level L1and the second electrical level L2of the multi-level pulse amplitude modulation signal Pam generated by the multi-level pulse amplitude modulator12to offset toward the third electrical level (that is, the parameter L3is the third electrical level inFIG.6), thus when the bias voltage point offsets from the quadrature point, the vertical heights VH01, VH12, VH23of the eyes of the optical modulate signal Lm still have the identical height, in turn promote transmission performance of the optical communication system10. Similarly, when the asymmetrical optical modulator14is operated at the negative slope of the transfer function, if the asymmetrical optical modulator14is controlled by the bias voltage offset adjust signal Ba so that the bias voltage point of the asymmetrical optical modulator14itself offsets to above the quadrature point of the negative slope of the transfer function, the multi-level pulse amplitude modulator12modulates the data input Di according to the electrical level adjust signal La, to cause the first electrical level L1and the second electrical level L2of the multi-level pulse amplitude modulation signal Pam generated by the multi-level pulse amplitude modulator12to offset toward the third electrical level L3; but if the asymmetrical optical modulator14is controlled by the bias voltage offset adjust signal Ba so that the bias voltage point of the asymmetrical optical modulator14itself offsets to below the quadrature point of the negative slope of the transfer function, the multi-level pulse amplitude modulator12modulates the data input Di according to the electrical level adjust signal La, to cause the first electrical level L1and the second electrical level L2of the multi-level pulse amplitude modulation signal Pam generated by the multi-level pulse amplitude modulator12to offset toward the zeroth electrical level L0, thus when the bias voltage point offsets from the quadrature point, each vertical height of the eyes of the optical modulate signal Lm is identical, to promote transmission performance of the optical communication system10. Referring toFIG.7, in the second embodiment, the optical transmission device1is adapted to another optical communication system100, the second embodiment is similar to the first embodiment, a difference therebetween lies in that, the optical communication system100is used to long distance transmission (for example, 40 km), and further includes an optical amplifier5and a detector6; the optical receiver41connects the optical amplifier5; the control module11further connects the detector6. The optical amplifier5connects the asymmetrical optical modulator14via the optical fiber3to receive the optical modulate signal Lm, and amplifies the optical modulate signal Lm to generate an optical amplified signal Lma. The optical receiver41receives the optical amplified signal Lma from the optical amplifier5, and converts the optical amplified signal Lma to another electrical signal Es and outputs the another electrical signal Es to the multi-level pulse amplitude demodulator42. The multi-level pulse amplitude demodulator42demodulates the another electrical signal Es to generate the data output Do. In the present embodiment, the optical receiver41is an optical receiver based on one of Avalanche Photodiode (APD) and PIN Photodiode. The detector6connects the multi-level pulse amplitude demodulator42and the control module11, and generates a measuring signal Ms according to the data output Do and outputs the measuring signal Ms to the control module11. The measuring signal Ms indicates one of a Bit Error Rate (BER), a Forward Error Coding (FEC) and a signal-to-noise ratio of the data output Do. In the control module11, the slope controller111further connects the detector6to receive the measuring signal Ms, and generates the slope adjust signal Sa according to the polarity of the dispersion amount of the input signal Is and the measuring signal Ms. The bias voltage offset controller112further connects the detector6to receive the measuring signal Ms, and generates the bias voltage offset adjust signal Ba according to the magnitude of the dispersion amount of the input signal Is and the measuring signal Ms. The electrical level adjustor114further connects the detector6to receive the measuring signal Ms, and generates and outputs the electrical level adjust signal La according to the measuring signal Ms and the bias voltage offset adjust signal Ba. Specifically, an operation of the optical transmission device1of the second embodiment is similar to the operation of the optical transmission device1of the first embodiment, so similar contents are not repeated herein. In the second embodiment, in order to be used to long distance transmission, by that the optical amplifier5promotes the optical power to the optical receiver41or by that the optical receiver41uses APD, sensitivity of the optical receiver41is improved. However, a signal-dependent noise caused with the laser2, the optical amplifier5or APD will lower linkage performance of the optical communication system100. In order to reduce the signal-dependent noise, it needs to adjust the electrical levels in the multi-level pulse amplitude modulation signal Pam and offset the bias voltage point of the asymmetrical optical modulator14to below the quadrature point, to cause the vertical height VH23of the optical modulate signal Lm to be maximum to improve the signal-dependent noise problem. Therefore, in the second embodiment, considering compromise between Inter symbol interference (ISI) due to optical fiber dispersion and the signal-dependent noise, the bias voltage offset controller112generates the bias voltage offset adjust signal Ba further according to the measuring signal Ms, the electrical level adjustor114generates the electrical level adjust signal La further according to the measuring signal Ms, to optimize linkage performance of the optical communication system100. Moreover, the slope controller111generates the slope adjust signal Sa further according to the measuring signal Ms, to assure the slope adjust signal Sa generated by the slope controller111to conform with the requirement of the optical communication system100. For example, when the slope adjust signal Sa initially generated by the slope controller111makes that the asymmetrical optical modulator14is operated at the positive slope of the transfer function, if at this time according to the measuring signal Ms the slope controller111knows that, the Bit Error Rate indicated by the measuring signal Ms is too large or the signal-to-noise ratio indicated by the measuring signal Ms is too small, it is shown that the slope adjust signal Sa initially generated does not conform with the requirement of the optical communication system100, in turn the slope controller111adjusts the slope adjust signal Sa to make that the asymmetrical optical modulator14is operated at the negative slope of the transfer function, but the present disclosure is not limited thereto. In conclusion, in the present disclosure, adjusting that the asymmetrical optical modulator14is operated at the positive slope or the negative slope of the transfer function of the asymmetrical optical modulator14itself is used to change the polarity of the chirp parameter of the asymmetrical optical modulator14, and that the bias voltage point of the asymmetrical optical modulator14offsets from the quadrature point of the transfer function is used to change the magnitude of the chirp parameter of the asymmetrical optical modulator14, so the chirp of the optical modulate signal Lm is not constant. As such, the optical modulate signal Lm transmitted out by the optical transmission device1of the present disclosure has the optimized chirp, may lower effect of dispersion caused by the optical fiber3on the transmission of the optical communication systems10,100, make the Dispersion-induced Optical Power Penalty received by the optical receiver41decreased, in turn promote transmission performance of the optical communication systems10,100and increase optical transmission distance. At the same time, because the multi-level pulse amplitude modulation signal Pam has a plurality of electrical levels, in the optical communication system10without the signal-dependent noise, the electrical level adjustor114performs adjustment to make the vertical height of each eye opening of the optical modulate signal Lm identical, in turn promote the signal-to-noise ratio of the optical communication system10to promote transmission performance, and increase optical transmission distance. In addition, in the optical communication system100with the signal-dependent noise, the electrical level adjustor114performs adjustment to make the vertical height of each eye opening of the optical modulate signal Lm different, in turn promote the signal-to-noise ratio of the optical communication system100to promote transmission performance, and increase optical transmission distance. However, the above description is only for the embodiments of the present disclosure, and it is not intended to limit the implementing scope of the present disclosure, and the simple equivalent changes and modifications made according to the claims and the contents of the specification are still included in the scope of the present disclosure. | 27,164 |
11942994 | DETAILED DESCRIPTION OF THE INVENTION FIG.1aillustrates an apparatus for determining an interference in a transmission medium during a transmission of a data input signal according to an embodiment. The apparatus comprises a transform module110configured to transform the data input signal from a time domain to a frequency domain comprising a plurality of frequency channels to obtain a frequency-domain data signal comprising a plurality of spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ1], Aλ[μ2], Aλ[μ3], . . . ), wherein each spectral coefficient of the plurality of spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ2], Aλ[μ3], . . . ), is assigned to one of the plurality of frequency channels. Moreover, the apparatus comprises an analysis module120configured to determine the interference by determining one or more spectral interference coefficients (e.g., ΔAλSCI[μ]), wherein each of the one or more spectral interference coefficients (e.g., ΔA2SCI[μ]) is assigned to one of the plurality of frequency channels. The analysis module120configured to determine each of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]) depending on the plurality of spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ2], Aλ[μ3], . . . ), and depending on a transfer function (Hρ[μ1, μ2, μ3]; Hv(ω1, ω2, ω3)) wherein the transfer function (Hρ[μ1, μ2, μ3]: (ω1, ω2, ω3)) is configured to receive two or more argument values (μ1, μ2, μ3; ω1, ω2, ω3), wherein each of the two or more argument values (μ1, μ2, μ3; ω1, ω2, ω3) indicates one of the plurality of frequency channels, and wherein the transfer function is configured to return a return value depending on the two or more argument values (μ1, μ2, μ3; ω1, ω2, ω3). In an embodiment, the transmission medium may, e.g., be a fiber-optical channel. FIG.1billustrates another embodiment, wherein the apparatus further comprises a signal modification module130being configured to modify the frequency-domain data signal using the one or more spectral interference coefficients to obtain a modified data signal. The apparatus ofFIG.1bfurther comprises an inverse transform module135configured to transform the modified data signal from the frequency domain to the time domain to obtain a corrected time-domain data signal. According to an embodiment, the signal modification module130ofFIG.1bmay, e.g., be configured to combine each one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]), or a value derived from said one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]), and one of the plurality of spectral coefficients (Aλ[μ], Aλ[1], Aλ[μ2], Aλ[μ3], . . . ) to obtain the modified data signal. In a particular embodiment, the signal modification module130ofFIG.1bmay, e.g., be configured to combine each one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]), or a value derived from said one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]), and one of the plurality of spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ2], Aλ[μ3], . . . ) to obtain the modified data signal by subtractingeach one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]), or a value derived from said one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]),from one of the plurality of spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ2], Aλ[μ3]), . . . ); or, in another embodiment, to obtain the modified receive signal/sequence by subtractingeach one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]), or a value derived from said one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]),from one of the plurality of the spectral coefficients of the distorted receive sequence Yλ[μ]; or, in a further embodiment, to inverse Discrete Fourier Transform the spectral interference coefficients ΔAλ[k] to obtain time domain interference coefficients Δaλ[k], and to subtract the time domain interference coefficients Δaλ[k] from the (time-domain) receive sequence yλ[k]; or, in a yet further embodiment, to obtain the modified data or receive signal by subtractingeach one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]), or a value derived from said one of the one or more spectral interference coefficients(e.g., ΔAλSCI[μ]), and by multiplying each one of the one or more spectral phase and polarization coefficients (exp(−jϕλI−j{right arrow over (S)}λ))from one of the plurality of spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ2], Aλ[μ3], . . . ) or from one of the plurality of the spectral coefficients of the distorted receive sequence Yλ[μ]. In an embodiment, the transform module110ofFIG.1bmay, e.g., be configured to transform the data input signal from the time domain to the frequency domain by transforming a plurality of overlapping blocks of the data input signal from the time domain to the frequency domain to obtain a plurality of blocks of the frequency-domain data signal. The inverse transform module135may, e.g., be configured to transform the modified data signal from the frequency domain to the time domain by transforming a plurality of blocks from the frequency domain to the time domain and by overlapping said plurality of blocks being represented in the time domain to obtain the corrected time-domain data signal. FIG.1cillustrates a further embodiment, wherein the apparatus further comprises an inverse transform module135configured to transform the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]) from the frequency domain to the time domain. The apparatus ofFIG.1cfurther comprises a signal modification module130being configured to modify the data input signal being represented in the time domain using the one or more spectral interference coefficients being represented in the time domain to obtain a corrected time-domain data signal. According to an embodiment, the signal modification module130ofFIG.1cmay, e.g., be configured to combine each one of the one or more spectral interference coefficients being represented in the time domain, or a value derived from said one of the one or more spectral interference coefficients, and a time domain sample of a plurality of time domain samples of the data input signal being represented in the time domain to obtain the corrected time-domain data signal. In a particular embodiment, the signal modification module130ofFIG.1cmay, e.g., be configured to combine each one of the one or more spectral interference coefficients being represented in the time domain, or a value derived from said one of the one or more spectral interference coefficients, and a time domain sample of a plurality of time domain samples of the data input signal being represented in the time domain to obtain the corrected time-domain data signal by subtractingeach one of the one or more spectral interference coefficients being represented in the time domain, or a value derived from said one of the one or more spectral interference coefficients,from a time domain sample of a plurality of time domain samples of the data input signal being represented in the time domain. In an embodiment, the transform module110ofFIG.1cmay, e.g., be configured to transform the data input signal from the time domain to the frequency domain by transforming a plurality of overlapping blocks of the data input signal from the time domain to the frequency domain to obtain a plurality of blocks of the frequency-domain data signal. The inverse transform module135may, e.g., be configured to transform a plurality of interference coefficients blocks from the frequency domain to the time domain, said plurality of blocks comprising the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]). The signal modification module130may, e.g., be configured to modify the overlapping blocks of the data input signal, being represented in the time domain, using the plurality of interference coefficients blocks to obtain a plurality of corrected blocks, wherein the signal modification module130is configured to overlap the plurality of corrected blocks to obtain the corrected time-domain data signal. FIG.1dillustrates another embodiment, wherein the apparatus further comprises a transmitter module140configured to transmit the corrected time-domain data signal over the transmission medium. FIG.1eillustrates a further embodiment, wherein the apparatus further comprises a receiver module105configured to receive the data input signal being transmitted over the transmission medium. In an embodiment, the analysis module120may, e.g., be configured to determine an estimation of a perturbated signal depending on the data input signal using the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]). According to an embodiment, the analysis module120may, e.g., be configured to determine the estimation of the perturbated signal by adding each one of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]) with one of the plurality of spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ2], Aλ[3], . . . ). In an embodiment each of the two or more argument values may, e.g., be a channel index (μ1, μ2, μ3) being an index which indicates one of the plurality of frequency channels. Or, in another embodiment, each of the two or more argument values is a frequency (ω1, ω2, ω3) which indicates one of the plurality of frequency channels, wherein said one of the plurality of frequency channels comprises said frequency. In an embodiment, the analysis module120may, e.g., be configured to determine each spectral interference coefficient (e.g. ΔAλSCI[μ]) of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]) by determining a plurality of addends. The analysis module120may, e.g., be configured to determine each of the plurality of addends as a product of three or more of the spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ2], Aλ[μ3], . . . ) and of the return value of the transfer function, the transfer function having three or more channel indices or three or more frequencies as the two or more argument values of the transfer function, which indicate three or more of the plurality of frequency channels to which said three or more of the spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ2], Aλ[μ3], . . . ) are assigned. In an embodiment, the analysis module120may, e.g., be configured to determine each spectral interference coefficient (e.g., ΔAλSCI[μ]) of the one or more spectral interference coefficients (e.g., ΔAλSCI[μ]) by determining a plurality of addends, wherein the analysis module120may, e.g., be configured to determine each of the plurality of addends as a product of three or more of the spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ2], Aλ[μ3], . . . ) and of the return value of the transfer function, the transfer function having three or more channel indices or three or more frequencies as the two or more argument values of the transfer function, which indicate three or more of the plurality of frequency channels to which said three or more of the spectral coefficients (Aλ[μ], Aλ[μ1], Aλ[μ1], Aλ[μ2], Aλ[μ3], . . . ) are assigned. According to an embodiment, the analysis module120may, e.g., be configured to determine each spectral interference coefficient (e.g., ΔAλSCI[μ]) according to: ΔAλSCI[μ]=-jϕNL,ρNDFT2×∑μ1,μ2Aλ[μ1]AλH[μ2]Aλ[μ3]Hρ[μ1,μ2,μ3] wherein ΔAλSCI[μ] is said spectral interference coefficient, wherein Aλ[μ1] is a first one of the three or more spectral coefficients, wherein Aλ[μ2] is a second one of the three or more spectral coefficients, wherein, Aλ[μ3] is a third one of the three or more spectral coefficients, wherein μ1is a first index which indicates a first one of the plurality of frequency channels, wherein μ2is a second index which indicates a second one of the plurality of frequency channels, wherein μ3is a third index which indicates a third one of the plurality of frequency channels, wherein Hρ[μ1,μ2μ3] indicates the transfer function, wherein NDFT2indicates a square of a number of the plurality of frequency channels of the frequency domain, wherein ϕNL,ρ is a number. In an embodiment, the transfer function may, e.g., be normalized and nonlinear. According to an embodiment, the analysis module120is configured to determine the interference by applying a regular perturbation approach (e.g., Algorithm 1). In an embodiment, the analysis module120is configured to determine the interference by applying a regular logarithmic perturbation approach (e.g., Algorithm 2). In an embodiment, the frequency domain may, e.g., be a regular-logarithmic frequency domain. According to an embodiment, the transfer function may, e.g., depend on Hν(ejωT)=1T3∑m∈ℤ3Hν(ω-2πmT). In the following, embodiments of the present invention are described in more detail. At first, the notation and the overall system model is introduced. The notation and basic definitions are now described. Sets are denoted with calligraphic letters, e.g.,is the set of data symbols, i.e., the symbol alphabet or signal constellation. A set of numbers or finite fields are typeset in blackboard bold typeface, e.g., the set of real numbers is. Bold letters, such as x, indicate vectors. If not stated otherwise, a vector x=[x1, x2, . . . , xn]Tof dimension n is a column vector, and the set of indices to the elements of the vector is ℐ=def{1,…,n}. Non-bold italic letters, like x, are scalar variables, whereas non-bold Roman letters refer to constants, e.g., the imaginary number is j with j2=−1. (⋅)Tdenotes transposition and (⋅)His the Hermitian transposition. A real (bandpass) signal is typically described using the equivalent complex baseband (ECB) representation, i.e., we consider the complex envelope x(t)∈with inphase (real) and quadrature (imaginary) component. The n-dimensional Fourier transform of a continuous-time signal x(t)=x(t1, t2, . . . , tn) depending on the n-dimensional time vector t=[t1, t2, . . . , tn]T∈n(in seconds) is denoted by X(ω)={x(t)}, and defined as [14, Ch. 4] X(ω)={x(t)}=def∫ℝnx(t)e-jω·tdnt(1)x(t)=-1{X(ω)}=1(2π)n∫ℝnX(ω)ejω·tdnω.(2) Here, X(ω) is a continuous function of angular frequencies ω=[ω1, ω2, . . . , ωn]T∈nwith ω=2πf and frequency f∈(in Hertz). In the exponential we made use of the dot product of vectors inngiven by ω·t=ω1t1+ω2t2+ . . . +ntn. The integral is an n-fold multiple integral overnand with integration boundaries at −∞ and ∞ in each dimension. We use the expression dnt as shorthand for dt1dt2. . . dtn. For the one-dimensional case with n=1 the variable subscript is dropped. We may also write the correspondence as x(t)X(ω) for short. The n-dimensional discrete-time Fourier transform (DTFT) of a discrete-time sequence <x[k]> with k=[k1, k2, . . . , kn]T∈nwith spacing T between symbols is periodic with 1/T in frequency domain and denoted as X(ejωT)={circumflex over (F)}{x|k|}, and defined as X(ejωT)=^{x[k]}=def∑k∈ℤnx[k]e-jω·kT(3)x[k)=^-1{X(ejωT)}=(T2π)n∫𝕋nX(ejωT)ejω·kTdnω.(4) The set of frequencies in the Nyquist interval is 𝕋=def{ω∈ℝ|-ωNyq≤ω<ωNyq} with the Nyquist (angular) frequency ωNyq=def2π/(2T). If a whole (finite-length) sequence is treated, this is indicated by the square bracket notation, i.e., <x[k]> The notation Σk∈nis short for Σk1=−∞∞Σk2=−∞∞. . . Σkn=−∞∞. Embodiments employ the so-called engineering notation of the Fourier transform with a negative sign in the complex exponential (in the forward, i.e., time-to-frequency, direction) is used. This has immediate consequences for the solution of the electro-magnetic wave equation (cf. Helmholtz equation), and therefore also for the NLSE. In the optical community, there exists no fixed convention with respect to the sign notation, e.g., some of the texts are written with the physicists' (e.g., [15, Eq. (2.2.8)] or [10]) and others with the engineering (e.g., [16], [17, Eq. (A.4)]) notation in mind. Consequently, the derivations shown here may differ marginally from some of the original sources. Continuous-time signals are associated with meaningful physical units, e.g., the electrical field has typically units of volts per meter (V/m). The NLSE and the Manakov equation derived thereof are carried out in Jones space over a quantity u(t)=[ux(t), uy(t)]T∈2called the optical field envelope. The optical field envelope has the same orientation as the associated electrical field but is renormalized s.t. uHu equals the instantaneous power given in watts (W). Here, signals are instead generally treated as dimensionless entities as this considerably simplifies the notation when we move between the various signal domains (see, e.g., discussion in [18, P. 11] or [19, P. 230]). To this end, the nonlinearity coefficient γ commonly given in W−1m−1is also renormalized to have units of m−1, cf. II-B2. To distinguish a two-dimensional complex vector u=[ux, uy]T∈2in Jones space from its associated three-dimensional real-valued vector in Stokes space, we use decorated bold letters {right arrow over (u)}=[u1, u2, u3]T∈3. The (permuted) set of Pauli matrices is given by [20] σ1=def[100-1]σ2=def[0110]σ3=def[0-jj0],(5) and the Pauli vector is σ→"\[Rule]"=def[σ1,σ2,σ3]T where each vector component is a 2×2 Pauli matrix. The relation between Jones and Stokes space can then be established by the concise (symbolic) expression {right arrow over (u)}=uH{right arrow over (σ)}u to denote the elementwise operation ui=uHσiu for all Stokes vector components i=1, 2, 3. The Stokes vector {right arrow over (u)} can also be expanded using the dot product with the Pauli vector to obtain the complex-valued 2×2 matrix with u→"\[Rule]"·σ→"\[Rule]"=u1σ1+u2σ2+u3σ3=[uxux*-uyuy*2uxuy*2ux*uyuyuy*-uxux*](6) which will later be used to describe the instantaneous polarization rotation around the Stokes vector {right arrow over (u)} using the Jones formalism. We may also use the equality [20, Eq. (3.9)] uuH½(uHuI+{right arrow over (u)}·{right arrow over (σ)}) (7) with the identity matrix I and ∥u∥2=uHu=uxux*+uyuy*. In the following, a system model according to embodiments is considered. Some embodiments provide a point-to-point coherent optical transmission over two planes of polarization in a single-mode fiber. This results in a complex-valued 2×2 multiple-input/multiple-output (MIMO) transmission which is typically used for multiplexing. One of the major constraints of today's fiber-optical transmission systems is the bandwidth of electronic devices which is orders of magnitude smaller than the available bandwidth of optical fibers. It is hence routine to use wavelength-division multiplexing (WDM), where a number of so-called wavelength channels are transmitted simultaneously through the same fiber. Each wavelength signal is modulated on an individual laser operated at different wavelengths such that the spectral support of neighboring signals is not overlapping. FIG.2illustrates a generic fiber-optical transmission system model. In particular,FIG.2shows the block diagram of a coherent optical transmission system exemplifying the digital, analog, and optical domains of a single wavelength channel. Within the bandwidth of a wavelength channel, we can consider the optical end-to-end 2×2 MIMO channel as frequency-flat if we neglect the effects of bandlimiting devices (e.g., switching elements in a routed network). The nonlinear property of the fiber-optical transmission medium is the source of interference within and between different wavelength channels. In the following, we will call the channel under consideration the probe channel, while a co-propagating wavelength channel is called interferer. This allows us to discriminate between self-channel interference (SCI) and cross-channel interference (XCI). InFIG.2the probe channel in the optical domain is denoted by a subscript ρ, whereas interferers are labeled by the channel index v with v∈{1, . . . , Nch|v≠ρ}. The various domains and its entities are discussed in the following. FIG.3aillustrates a transmitter frontend of a generic fiber-optical transmission system model. FIG.3billustrates an optical channel of the generic fiber-optical transmission system model. FIG.3cillustrates an receiver frontend of the generic fiber-optical transmission system model and variables associated with the regular perturbation model. In the following the transmitter frontend ofFIG.3ais described. The transmission system is fed with equiprobable source bits of the probe (and interferer) channel. The binary source generates uniform i.i.d. information bits q[K]∈2at each discrete-time index K∈.2denotes the Galois field of size two andis the set of integers. The binary sequence <q[K]> is partitioned into binary tuples of length Rm, s.t. q[k]=[q1[k], . . . qRm[k]]∈{0, 1}Rm, where k∈is the discrete-time index of the data symbols. Here, Rmis called the rate of the modulation and will be equivalent to the number of bits per transmitted data symbol, if we assume that the size of the symbol set is a power of two. Each Rm-tuple is associated with one of the possible data symbols a=[ax,ay]T∈⊂2, i.e., with one of the constellation points. We say that the binary Rm-tuples are mapped to the data symbols a∈A by a bijective mapping rule:qa. The size of the data symbol set is M=||=2Rmand we can write the alphabet as 𝒜=def{a1,…,aM}⊂ℂ2 The symbol set has zero mean if not stated otherwise, that is E{a}=0 and we deliberately normalize the variance of the symbol set to σa2=defE{a2}=1 (the expectation is denoted by E{⋅} and the Euclidean vector norm is ∥⋅∥). For reasons of readability we denote the data symbols of the interfering channels by bv[k]. The discrete-time data symbols a[k] are converted to the continuous-time transmit signal s(t) by means of pulse-shaping constituting the digital-to-analog (D/A) transition, cf.FIG.3a. We can express the transmit signal s(t)=[s1(t), s2(t)]T∈2as a function of the data symbols with s(t)=T·∑k∈ℤa[k]hT(t-kT),(8) where s(t) is a superposition of a time-shifted (with symbol period T) basic pulses hT(t) weighted by the data symbols. The pre-factor T is used to preserve a dimensionless signal in the continuous-time domain (cf. [18, P. 11]). We assume that the transmit pulse has √{square root over (Nyquist)} property, i.e., |HT(ω)|2has Nyquist property with the Fourier pair hT(t)HT(ω). To keep the following derivations tractable, all wavelength channels transmit at the same symbol rate Rs=def1/T as the probe channel. the pulse energy ETof the probe channel is given by [18, Eq. (2.2.22)] ET=∫-∞∞❘"\[LeftBracketingBar]"T·hT(t)❘"\[RightBracketingBar]"2dt=12π∫-∞∞❘"\[LeftBracketingBar]"T·HT(ω)❘"\[RightBracketingBar]"2dω.(9) The pulse energy EThas the unit seconds due to the normalization of the signals. Using the symbol energy Es=defσa2ET, the average signal power P calculates to [18, Eq. (4.1.1)] P=def1T∫0TE{s(t)2}dt=σa2TET=EsT(10) Since, see above, the variance of the data symbols σa2is fixed to 1, the transmit power P is directly adjusted via the pulse energy ET. The corresponding quantities related to one of the interferers are indicated by the subscript v. In the following, an optical channel according toFIG.3bis described. The electrical-to-optical (E/O) conversion is performed by an ideal dual-polarization (DP) inphase-quadrature (IQ) converter. The two elements of the transmit signal sv(t) correspond to the modulated optical signals in the x- and y-polarization. The optical field envelope uv(z, t) of each wavelength channel uv(0,t)=sv(t)exp(jΔωvt), (11) is modulated at its angular carrier frequency ωv=ω0+Δωvat the input of the optical transmission line z=0. Here, ω0=2πf0is the center frequency of the signaling regime of interest. For the probe channel, the carrier frequency ωpis to coincide with ω0such that Δωp=0 and uρ(0, t)=sρ(t). The transmitter frontend of the probe channel is shown inFIG.3a. The Nchwavelength signals uv(0, t) at z=0 are combined by an ideal optical multiplexer to a single WDM signal, cf.FIG.3b. The optical field envelope before transmission is then u(0,t)=∑v=1Nchuv(0,t)=∑v=1Nchsv(t)exp(jΔωvt)(12)U(0,ω)=∑v=1NchUv(0,ω)=∑v=ANchSv(ω-Δωv),(13) with the Fourier pairs sv(t)Sv(ω) and u(0, t)U(0, ω). Any initial phase and laser phase noise (PN) are neglected to focus only on deterministic distortions. The optical field envelope is the ECB representation of the optical field uo(z, t) in the passband notation uo(z,t)=defu(z,t)·exp(jω0t-jβ0(z)z),(14) which is known as the slowly varying amplitude approximation [15, Eq. (2.4.5)]. For consistency of notation we treat the optical field envelope as a dimensionless entity (in accordance with the electrical signals). The optical field propagates in z-direction (the dimension z has units of meter) with the local propagation constant β0(z)=β(z, ω0), and β(z, ω) is the space and frequency-dependent propagation constant. A Taylor expansion of β(z, ω) is performed around ω0with the derivatives of β(z, ω) represented by the coefficients [15, Eq. (2.4.4)] βn(z)=def∂nβ(z,ω)∂ωn|ω=ω0,n∈ℕ.(15) Here, we only consider coefficients up to second order, i.e., n∈{0, 1, 2}. We also introduce the path-average4 dispersion length LD=def12π❘"\[LeftBracketingBar]"β2❘"\[RightBracketingBar]"Rs2,(16) which denotes the distance after which two spectral components spaced B=RsHertz apart, experience a differential group delay of T=1/Rsdue to chromatic dispersion (CD). We can equivalently define the walk-off length of the probe and one interfering wavelength channel as Lwo,v=def1❘"\[LeftBracketingBar]"Δωvβ2❘"\[RightBracketingBar]"Rs,(17) which quantifies the fiber length that must be propagated in order for the vthwavelength channel to walk off by one symbol from the probe channel. 4We discriminate between local (i.e., α(z), β(z), γ(z)) and path-average (i.e. α, β, ≢) properties of the transmission link. The latter are implicitly indicated if the z-argument of the local property is omitted, e.g., β2=Δ1L∫0Lβ2(ζ)dζ. Now, signal propagation is considered. In the absence of noise, the two dominating effects governing the propagation of the optical signal in the fiber are dispersion-expressed by the z-profile of the fiber dispersion coefficient β2(z)—and nonlinear signal-signal interactions. Generation of the so-termed local NLI depends jointly on the local fiber nonlinearity coefficient γ(z) and the z-profile of the optical signal power. For ease of the derivation, we assume that all z-dependent variation in γ(z) can be equivalently expressed in a variation of either a local gain g(z) or the local fiber attenuation α(z). We also neglect the time- (and frequency-) dependency of the attenuation, gain, and nonlinearity coefficient. The interplay between the optical signal, dispersion, and nonlinear interaction is all combined in the noiseless Manakov equation. It is a coupled set of partial differential equations in time-domain for the optical field envelope u(z, t) in the ECB, and the derivative is taken w.r.t. propagation distance z∈and to the retarded time t∈. The retarded time is defined as t=deft′-z/vg, where t′ is the physical time and vgis the (path-average) group velocity vg=1/β1of the probe channel [15, Eq. (2.4.8)]. It can be understood as a time frame that moves at the same average velocity as the probe to cancel out any group delay at the reference frequency ωp=ω0. All other frequencies experience a residual group delay relative to the reference frequency due to CD. The propagation of u(z, t) in the signaling regime of interest is governed by [17, Eq. (6.26)] ∂∂zu=jβ2(z)2∂2∂z2u+g(z)-α(z)2u-jγ(z)89u2u.(18) The space- and time-dependency of u(z, t) is omitted here for compact notation. By allowing the local gain coefficient g(z) to contain Dirac δ-functions one can capture the z-dependence of an amplification scheme, i.e., based on lumped erbium-doped fiber amplifier (EDFA) or Raman amplification. Polarization-dependent effects such as birefringence and polarization mode dispersion (PMD) are neglected limiting the following derivations to the practically relevant case of low-PMD fibers. We also assume that all wavelength channels are co-polarized, i.e., modulated on polarization axes parallel to the ones of the probe channel. Now, the dispersion profile is considered. The accumulated dispersion is a function that satisfies [21, Eq. (8)] dℬ(z)dz=β2(z).(19) Here, B(z) can be used to express a z-dependency in the dispersion profile, i.e., lumped dispersion compensation by inline dispersion compensation or simply a transmission link with distinct fiber properties across multiple spans. We obtain (z)=∫0zβ2(ζ)dζ+0, (20) where ℬ0=defℬ(0) is the amount of pre-dispersion (in units of squared seconds, typically given in ps2) at the beginning of the transmission line. Now, the power profile is considered. To describe the power evolution of u(z, t), we introduce the normalized power profile P(z) as a function that satisfies the equation [21, Eq. (7)] d(z)dz=(g(z)-α(z))(z),(21) with boundary condition P(0)=P(L)=1, i.e., the last optical amplifier resets the signal power to the transmit power. The z-dependence on α(z) allows for varying attenuation coefficients over different spans. In writing (21) we assumed that both the local gain coefficient and attenuation coefficient are frequency-independent. We may also define the logarithmic gain/loss profile as (z)=defln((z))=∫0z(g(ζ)-α(ζ))dζ.(22) The last expression in (22) is obtained by solving (21) for(z)=e(z). The boundary conditions on P(z) immediately give the boundary condition(0)=(L)=0. We can now define the impulse response and transfer function of the linear channel—that is, when the fiber nonlinearity coefficient is zero, i.e., γ=0 in (18). To that end, we define the optical field envelope uLIN(z, t)ULIN(z, ω) that propagates solely according to linear effects with the boundary condition uLIN(0, t)=u(0, t) at the input of the transmission link. The linear channel transfer function and impulse response is then given by HC(z,ω)=defexp((z)-jω2(z)2)(23)hC(z,t)=12π1j(z)exp((z)+jt2/(z)2),(24) which represents the joint effect of chromatic dispersion and the gain/loss variation along the link. We finally have the linear channel relation in time-domain hC(z, t)*uLIN(0, t) and frequency-domain ULIN(z, ω)=HC(z, ω)ULIN(0, ω), which will be used in the following to derive the first-order perturbation method. In the following, a receiver frontend according toFIG.3cis described. Again, we assume ideal optical-to-electrical (O/E) and analog-to-digital (A/D) conversion. The received continuous-time, optical signal u(L, t), is first matched filtered w.r.t. the linear channel response and transmit pulse and then sampled at the symbol period T, cf.FIG.3(c). The receiver frontend hence also compensates for any residual link loss and performs perfect CD compensation. Note, that the analog frontend is usually realized using an oversampled digital representation. E.g., CD compensation is typically performed in the (oversampled) digital domain. Here, we favour to conceptually incorporate it in the analog domain since it significantly simplifies notation in the derivation of the end-to-end channel model. The transfer function of the entire cascade of the receiver frontend is given by HR(ω)=TETHC*(L,ω)HT*(ω).(25) The factor T/ET re-normalizes the received signal to the variance of the constellation σa2. Since we only consider T-spaced sampling any fractional sampling phase-offset or timing synchronization is already incorporated as suited delay in the receive filter hR(t), s.t. the transmitted and received sequence of the probe are perfectly aligned in time. Note, that the time delay L/vgat ω0and any initial phase β0has already been canceled from the propagation equation. In the following, first-order perturbation is considered. A concept of fiber-optical channel models based on the perturbation method is to assume that nonlinear distortions are weak compared to its source, i.e., the linearly propagating signal. Starting from this premise the regular perturbation (RP) approach for the optical end-to-end channel is written as u(L,t)=uLIN(L,t)+Δu(L,t), (26) where uLIN(z, t)∈2is the signal propagating according to the linear effects, i.e., according to (23), (24). In this context, the nonlinear distortion Δu(z, t)∈2is termed perturbation, which is generated locally according to nonlinear signal-signal interaction and is then propagated linearly and independently of the signal uLIN(z, t) to the end of the optical channel at z=L. We assume that the optical perturbation at z=0 is zero, i.e., Δu(0, t)=0. The received signal is then given as the sum of the solution for the linearly propagating signal and the accumulated perturbation representing the accumulated nonlinear effects. An objective here is to develop the input/output relation of the equivalent discrete-time end-to-end channel in the form of y[k]=a[k]+Δa[k],(27) where the total NLI is absorbed into a single discrete-time perturbative term Δa[k], cf.FIG.3(c). To that end, we start with a known RP solution of the optical end-to-end relation and successively incorporate the used components according toFIG.2andFIG.3. Now, the optical end-to-end channel is considered. The solution to the optical perturbation after transmission at z=L is given in frequency-domain by [4, Eq. (12)], [22, Eq. (2)], [23, Eq. (4)], [24, Eq. (24)-(27)], ΔU(L,ω)=-jγ89Leff(2π)2HC(L,ω)×∫2U¯(ω,v1,v2)HNL(v1,v2)d2v,(28) with the normalized nonlinear transfer function HNL(v1, v2) and U_(ω,v1,v2)=defU(0,ω+v2)UH(0,ω+v1+v2)U(0,ω+v1), i.e., a term that depends on the optical field envelope at the input of the transmission system. Note, that we made use of the common variable substitution ω1=defω+v1(29)ω2=defω+v1+v2(30)ω3=defω-ω1+ω2=ω+v2,(31) to express the field U in terms of difference frequencies v1and v2relative to ω.FIG.4aandFIG.4bsummarizes definitions of the time- and frequency variables that are used throughout this text. The integral over2in (28) can also be performed w.r.t. ω1and ω2. FIG.4aillustrates definitions of variables in the time-domain.FIG.4billustrates definitions of variables in the frequency-domain. Both1,2and v1, v2can take positive and negative values in. Equation (28) shows that the first-order RP method can be understood as a FWM process with un-depleted pumps where three wavelengths affect a fourth. Equivalently, one can think of the joint annihilation and creation of two two-photon pairs (i.e., with four frequencies involved) preserving both energy (frequency matching) and momentum (phase matching) during the interaction [25, FIG. 7.2.5]. The conjugate field corresponds to the inverse process where photon creation and annihilation is interchanged. FIG.5illustrates a magnitude in logarithmic scale of a single-span nonlinear transfer function for β2=−21 ps2/km,0=0 ps2, 10 log10eα=0.2 dB/km and Lsp=100 km over the difference frequencies v1and v2normalized to Rs=64 GBd. The red line denotes HNL(ξ) which only depends on the scalar ξ=v1v2. (Part for v1>v2not shown). The normalized nonlinear transfer function is a measure of the phase matching condition and defined as HNL(v1,v2)=def1Leff∫0Lexp((ζ)+jv1v2ℬ(ζ))dζ=1Leff∫0LHC*(ζ,v1v2)2dζ.(34) The pre-factor is the effective length of the whole transmission link defined as Leff=def∫0L(ζ)dζ=∫0Lexp((ζ))dζ,(35) and acts as a normalization constant s.t. HNL(0, 0)=1. The phase mismatch Δβ, i.e., the difference in the (path-average) propagation constant due to dispersion, is defined as [15, Eq. (6.3.19)] Δβ=defβ(ω)-β(ω1)+β(ω2)-β(ω3)=β22(ω2-ω12+ω22-(ω-ω1+ω2)2)=β2(ω1-ω)(ω2-ω1)=β2v1v2,(36) where the propagation constants at the four frequencies are developed in a second-order Taylor series according to (15). E.g., for transmission systems without inline dispersion compensation and zero pre-dispersion B0=0, we have B(z)=β2z and the phase mismatch Δβ can be found in the argument of the exponential in (34) with v1v2(z)=Δβz. In the context of the equivalent approach following the regular VSTF [3], [4], [24], the nonlinear transfer function HNL(v1, v2) is also referred to as 3rd-order Volterra kernel. Closed form analytical solutions to (34) can be obtained for single-span or homogeneous multi-span systems [24], [26]. It is noteworthy, that HNL(v1, v2) contains all information about the transmission link characterized by the dispersion profile (including CD pre-compensation0, cf. (20)) and the gain/loss profile. FIG.5shows the magnitude of HNL(v1, v2) exemplifying a single-span standard single-mode fiber (SSMF) link. Note, that HNL(v1, v2) depends in fact on the product ξ=defv1v2 and is hence a hyperbolic function in two dimensions [27, Sec. VIII] (cf. the contour inFIG.5). The bold red line drawn into the diagonal cross section inFIG.5is the corresponding nonlinear transfer function HNL(ξ) which only depends on the scalar variable ξ=defv1v2. FIG.6illustrates a magnitude in logarithmic scale of a single-span nonlinear transfer function for β2=−21 ps2/km,0ps2, 10 log10eα=0.2 and Lsp=100 km over ξ=v1v2. The normalization by (2πRs)2relates HNL(ξ) to the probe's spectral width. The width of |HNL(ξ/Rs2)|2is then proportional to 1/T ,ρ=LD/Leff∝Rs−2i.e., doubling Rsreduces the spectral width by a factor of 4. FIG.6shows the HNL(ξ) over the normalized variable ξ/(2πRs)2to relate the nonlinear transfer function to the spectral width of the probe channel. The spectral width of |HNL(ξ/(2πRs)2)|2is proportional to the inverse dimensionless map strength 1/T,ρ=defLD/Leff closely related to the nonlinear diffusion bandwidth defined in [22]. Conversely, the map strengthT,ρquantifies the number of nonlinearly interacting pulses in time over the effective length Leffwithin the probe channel [28]. It is therefore a direct measure of intra-channel (i.e., SCI) nonlinear effects [29]. The relevant quantity for inter-channel (i.e., XCI) effects is given by 𝒮T,v=defLeff/Lwo,v (with ν≠φ where the temporal walk-off between wavelength channels is the relevant length scale. In [23] it was shown that hNL(ξ) is related to the power-weighted dispersion distribution (PWDD) by a (one-dimensional) Fourier transformation (w.r.t. the scalar variable ξ) and has a time-domain counterpart which is discussed in the next paragraph. In the following, the electrical end-to-end channel is considered. To derive the discrete-time end-to-end channel model the filter cascade of the linear receiver frontend is subsequently applied to ΔU(L, ω). The perturbation ΔS(ω) (i.e., the perturbation in the electrical domain following our terminology, cf.FIG.3c) is obtained by ΔS(ω)=HC*(L,ω)ΔU(L,ω), (39) which cancels out the leading term HC(L, ω) in (28) since |HC(L, ω)|=1. The result is shown in (32) at the bottom of this page. Remarkably, there exists an equivalent time-domain representation ΔS(t)ΔS(ω) shown in (33) where the Fourier relation is derived in Appendix A. The time-domain perturbation ΔS(t) has the same form as its frequency-domain counterpart, i.e., the integrand is constituted by the respective time-domain representation of the optical signal and the double integral is performed over the time variables1and2(cf.FIG.4(a)and [23], [30]). The frequency matching with t3=deft-t1+t2 is translated to a temporal matching8 ω3=defω-ω1+ω2 (cf. [31]), i.e., the selection rules of FWM apply both in time and frequency. The temporal matching is not to be confused with the phase matching condition in (34), (36). Remarkably, the time-domain kernel hNL(1,2) is related to HNL(v1, v2) by an inverse two-dimensional (2D) Fourier transform (cf. [30, Appx.] and [28, Eq. (6)]) which can be written as hNL(τ1,τ2)=hNL(τ)=F-1{HNL(v)}=1Leff∫0L12π❘"\[LeftBracketingBar]"ℬ(ζ)❘"\[RightBracketingBar]"exp(G(ζ)-jτ1τ2B(ζ))dζ=B(z)≤0jLeff∫0LhC*(ζ,τ1τ2)2dζ,(40) with the tuples τ=[τ1, τ2] and v=[v1, v2]T. The time-domain kernel maintains its hyperbolic form as it is a function of the product τ1τ2. Also note the duality to (34), where in both representations the nonlinear transfer function can be understood as the path-average (cf. [32]) over an expression related to the linear channel response hc(z, t)Hc(z, w). Note, that in (40) the condition on B(z)≤0 (which is typically fulfilled in the anomalous dispersion regime with β2<0) is used to obtain the simple result without cumbersome differentiation of the term |B(z)|. The next step is to resolve the perturbation Δs(t). ΔS(w) into contributions originating from SCI, XCI or multichannel interference (MCI). We notice fromFIG.6that, given Rsis sufficiently large, |HNL(ξ)|2vanishes if ξ>>(2πRs)2i.e., if the phase matching condition is not properly met. Conversely, if the spectral width of |HNL(ξ/Rs2)|2(or equivalently the inverse map strength 1/ST,ρ) is small enough, the integrand in (32), (33) can be factored into a SCI and XCI term, i.e., mixing terms that originate either from within the probe channel (both v1<2πRsand v2<2πRs) or from within the probe channel and a single interfering wavelength channel (either v1<2πRsor v2<2πRs). Mixing terms originating from MCI are only relevant for small Rs. We hence neglect any FWM terms involving more than two wavelength channels. The optical field envelope u(0, t)U(0, w) in (32), (33) is now expanded according to (12), (13). By definition we have Δωρ=0 and we can expand the triple product of U(0, w) in (32) as UUHU=UρUρHUρ︸SCI+∑v≠ρ(UvUvHUρ+UρUvHUv)︸XCI(41) where the frequency-dependency of U(0, w) is omitted for short notation. The XCI term has two contributions—the first results from an interaction where w3and w2are from the vthinterfering wavelength channel and w and w1are within the probe's support (v2→ΔωvinFIG.4(b)). The second involves an interaction where w2and w1are from the interfering wavelength channel and w and w3are from the probe channel (v1→Δωv). We can exploit the symmetry of the nonlinear transfer function HNL(v1, v2)=HNL(v2, v1) to simplify the XCI expression in (41). Since UvHUvis a scalar, we have UρUvHUv=UvHUvUρ. The 2×2 identity matrix I is used to factor the XCI expression in a v- and ρ-dependent term. We obtain with the definition of the electrical signal of each wavelength channel (cf. (12), (13)) after rearranging some terms U(0,ω3)UH(0,ω2)U(0,ω1)HNL(ω2-ω3,ω2-ω1)=Sρ(ω1)SρH(ω2)Sρ(ω3)HNL(ω2-ω1,ω2-ω3)+∑v≠ρ(Sv(ω1)SvH(ω2)+SvH(ω2)Sv(ω1)I)Sρ(ω3)×HNL(ω2-ω1︸v2,ω2-ω3︸v1-Δwv),(42) which now corresponds to the case that w3always lays in the support of the probe 10. The signals of the interfering wavelength channels are now represented in their respective ECB and the relative frequency offset Δωvis accounted for in the modified nonlinear transfer function HNL. At this point, considering (32) and (42), we formulated the relation between the perturbation at the probe ΔS(w) after chromatic dispersion compensation and the transmit spectra Sv(w) of the probe and the interferers in their respective baseband. The remaining operation in the receiver cascade is to perform matched filtering w.r.t. the transmit pulse and then to perform T-spaced sampling. An alternative formulation with ω1 in the support of the probe is obtained by exchanging the subscripts of ω1 and ω3 in frequency-domain and t1 and t3 in time-domain. Now, the discrete-time end-to-end channel is considered. We recap that the periodic spectrum X(ejωT) of the sampled signal x[k]=defx(kT) is related to the aliased spectrum of the continuous-time signal x(t) over the Nyquist intervalby X(ejωT)=defALIAS{X(ω)}=1T∑m∈ℤX(ω-2πmT).(43) The matched filter HT*(ω) and the aliasing operator are used to translate (32), (33) to the equivalent discrete-time form in (37), (38) exemplarily for the SCI contribution ΔaSCI. The total perturbation inflicted on the probe channel is Δa[k]=ΔaSCI[k]+ΔaXCI[k]. In (37), (38) we use the 1/T-periodic spectrum A(ejωT) which is related to the discrete-time sequence <a[k]> by a DTFT A(ejωT)={a[k]}. The channel-dependent nonlinear length is LNL,ν=def1/(γPν) and Pvis the optical launch power of the vthwavelength channel. The normalized nonlinear end-to-end transfer function Hv(ω)=Hv(ω1, ω2, ω3) characterizes the nonlinear cross-talk from the vthwavelength channel to the probe channel. In particular, Hv(ω) describes SCI and Hv(ω) with ν≠ρ describes XCI. It is defined as Hv(ω)=defT·HT,v(ω1)T·HT,v*(ω2)/Pv×T·HT,ρ(ω3)T·HT,ρ*(ω1-ω2+ω3)/ET×HNL(ω2-ω1,ω2-ω3-Δωv),(44) and its periodic continuation, i.e., the aliased discrete-time equivalent is given by Hv(ejωT)=1T3∑m∈ℤ3Hν(ω-2πmT),(45) where the three-fold aliasing is done along each frequency dimension with ω=[ω1, ω2, ω3]Tand m=[m1, m2, m3]TThe normalization in (44) is done s.t. Hv(ej0T)=1 and dimensionless. Note, that by definition the optical launch power Pvof the vthwavelength channel is related to the pulse energy of H,v(ω) in (9), (10). The nonlinear end-to-end transfer function in (44) depends on the characteristics of the transmission link, comprised by HNL(⋅, ⋅), the characteristics of the pulse-shapes of the probe and interfering wavelength channel (assuming matched filtering w.r.t. the channel and the probe's transmit pulse) and the frequency offset Δω1, between probe and interferer. It is remarkable that the integration in (37) is over the twofold tuple [ω1, ω2]T∈2while the time-domain summation in (38) is over three independent variables κ=[κ1, κ2, κ3]T∈3This is a consequence of the time-frequency relation between convolution and element-wise multiplication. The temporal matching used for the optical field in (33) is now canceled in (38) due to the convolution with the matched filter hT*(−t) i.e., Θ3does not depend on κ1and κ2unlike t3=deft-t1+t2. Note, that the frequency variable w3in (37) still complies with the frequency matching ω3=ω−ω1+ω2but may be outside the Nyquist interval. Due to the 1/T-periodicity of the spectrum A(ejωT) any frequency component outsideis effectively folded back into the Nyquist interval by addition of integer multiples of ωNyq(denoted by the FOLD{⋅} operation in (37)). The XCI complement to (37) reads ΔAXCI(ejωT)=-j∑ν≠p89LeffLNL,νT2(2π)2∫𝕋2×(Bν(ejω1T)BνH(ejω2T)+BνH(ejω2T)Bν(ejω1T)I)×A(ejω3T)Hν(ejωT)d2ω.(46) The time-domain description of the T-spaced channel model in (38) is equivalent to the pulse-collision picture (cf. [13, Eq. (3-4)] and [33, Eq. (3-4)]) and the XCI result is repeated here for completeness ΔaXCI[k]=-j∑v≠ρ89LeffLNL,ν∑κ∈ℤ3(bν[k+κ1]bνH[k+κ2]+bνH[k+κ2]bν[k+κ1]I)a[h+κ3]hν[κ].(47) The time-domain and aliased frequency-domain kernel are related by a three-dimensional (3D) DTFT according to hv[κ]=−1{Hv(ejωT)}. (48) The kernel hv[κ]=hv[κ1, κ2, κ3] is equivalent to the kernel derived via an integration overtime and space in [10, Eq. (61), (62)] and used in [13]. Now, the relation to the GN-model and to system design rules is explained. Parseval's theorem applied to (48) yields Eh,ν=def∑κ∈ℤ3❘"\[LeftBracketingBar]"hν[κ]❘"\[RightBracketingBar]"2=(T2π)3∫𝕋3❘"\[LeftBracketingBar]"Hν(ejωT)❘"\[RightBracketingBar]"2d3ω,(49) where the right-hand side can be interpreted as an alternative formulation of the (frequency-domain) Gaussian noise (GN)-model [27] in 1/T-periodic continuous-frequency domain. In (49) the common pre-factor (89LeffLNL,ν)2 is omitted here and the energy in time- and frequency domain is calculated over the whole support of the probe and interfering wavelength channel, whereas [27, Eq. (1)] is evaluated only at a single frequency ω. Beyond that, to include all SCI and XCI contributions one needs to sum over all v—the GN-model in its standard form also includes MCI. This is the dual representation to the original work where the optical signal is constructed as a continuous-time signal with period T0and discrete frequency components (c.f. the Karhunen-Loève formula in [26], [34]). In other words, the discretization in one domain and the periodicity in the other is exchanged in (49) compared to the GN-model. In this view, the result obtained by the GN-model corresponds to the kernel energy Eh,vof the corresponding end-to-end channel. At the same time, the (system relevant) variance of the perturbation σΔa2=defE{Δa2} depends as well on the properties of the modulation format A which in turn is a problem addressed by the extended Gaussian noise (EGN)-model [34], cf. also the discussion in [5, Sec. F and Appx.]. Note, that the derivation of (49) does not require any assumptions on the signal (albeit its pulse-shape)—in particular no Gaussian assumption. We can identify three relevant system parameters that characterize the nonlinear response: the map strengthT,v=Leff/LD, (or equivalently the v-dependentT,v=Leff/Lwo,v) which is a measure of the temporal extent, i.e., the memory of the nonlinear interaction. Secondly, the (v-dependent) nonlinear phase shift ϕNL,v=def89LeffLN_L,ν that depends via LNL,vlinearly on the launch power Pvand essentially acts as a scaling factor to the nonlinear distortion Δa[k]. And at last, the total kernel energy Eh,vwhich characterizes the strength of the nonlinear interaction-independent of the launch power. Now, applications to fiber nonlinearity compensation according to embodiments is described. The derived channel models also finds applications for fiber nonlinearity compensation, where implementation complexity is of particular interest. An experimental demonstration of intra-channel fiber nonlinearity compensation based on the time-domain model in (38) has been presented in [35]. In terms of computational efficiency a frequency-domain implementation can be superior to the time-domain implementation, in particular, for cases where the number of nonlinear interacting pulses is large. This is typically the case for large map strengthsT,p, large relative frequency offsets Δωvi.e., largeT,vand pulse shapes hT(t) that extend over multiple symbol durations, e.g., a root-raised cosine (RRC) shape with small roll-off factor ρ. Then, the number of coefficients of the time-domain kernel hv[κ] exceeding a relevant energy level grows very rapidly leading to a large number of multiplications and summations. The frequency-domain picture comprises only a double integral instead of a triple sum and can be efficiently implemented using standard signal processing techniques. Algorithm 1: REG-PERT-FD for the SCI contribution1aλ[k] = overlapSaveSplit(a[k], NDFT, K)2k, μ, μ1, μ2∈ {0, 1, . . . , NDFT− 1}3Hρ[μ1,μ2,μ3]=Hρ[μ]=Hρ(ej2πNDFTμ)4forall λ do5Aλ[μ] = DFT{aλ[k]}6forall μ do7μ3= modNDFT(μ − μ1+ μ2)8ΔAλSCI[μ]=-jϕNL,ρNDFT2×∑μ1,μ2Aλ[μ1]AλH[μ2]Aλ[μ3]Hρ[μ1,μ2,μ3]9YλPERT[μ] = Aλ[μ] + ΔAλSCI[μ]10end11yλPERT[k] = DFT−1{YλPERT[μ]}12end13yPERT[k]= overlapSaveAppend(yλPERT[k], NDFT, K) Exemplarily for the SCI contribution, Algorithm 1 realizes the regular perturbation (REG-PERT) procedure in 1/T-periodic discrete frequency-domain (FD) corresponding to the continuous-frequency relation in (38). Here, the overlap-save algorithm is used to split the sequence <a[5]> into overlapping blocks aλ[k]Aλ[μ] of size NDFTenumerated by the subindex λ∈N [36]. The block size is equal to the size of the discrete Fourier transform (DFT) and the overlap between successive blocks is K. The one-dimensional DFT is performed on each vector component of aλ[k] and the correspondence always relates the whole blocks of length NDFT. The aliased frequency-domain kernel is discretized to obtain the coefficients Hρ[μ1,μ2,μ3]=Hρ[μ]=defHρ(ej2πNDFTμ)(50) where NDFTis the number of discrete-frequency samples. The discrete-frequency indices μ1and μ2are elements of the set {0, 1, . . . . NDFT−1} whereas μ3must be (modulo) reduced to the same number set due to the 1/T-periodicity of ω3in (37). The number of coefficients can be decreased by pruning, similar to techniques already applied to VSTF models [37]. However, note that in contrast to VSTF models the proposed algorithm operates on the 1/T-periodic spectrum of blocks of transmit symbols aλ[k] and the filter coefficients are taken from the aliased frequency-domain kernel. Line 8 of the algorithm effectively realizes equation (37) where the (double) sum is performed over all μ1and μ2After frequency-domain processing the blocks of perturbed receive symbols YλPERT[μ]yλPERT[k] are transformed back to time-domain where the NDFT−K desired output symbols of each block are appended to obtain the perturbed sequence <yPERT[k]>. Algorithm 1 can be generalized to XCI analogously to (46). According to an embodiment, Algorithm 1 for XCI reads as follows: Algorithm 1: REG-PERT-FD for the XCI contribution ofthe vthwavelength channel1aλ[k] = overlapSaveSplit(a[k], NDFT, K)2bλ[k] = overlapSaveSplit(bv[k], NDFT, K)3k, μ, μ1, μ2∈ {0, 1, . . . , NDFT− 1}4Hv[μ1,μ2,μ3]=Hv[μ]=Hv(ej2πNDFTμ)5forall λ do6Aλ[μ] = DFT{aλ[k]}7Bλ[μ] = DFT{bλ[k]}8forall μ do9μ3= modNDFT(μ − μ1+ μ2)10ΔAλXCI[μ]=-jϕNL,vNDFT2×∑μ1,μ2(Bλ[μ1]BλH[μ2]+BλH[μ2]Bλ[μ1]I)×Aλ[μ3]Hv[μ1,μ2,μ3]11YλPERT[μ] = Aλ[μ] + ΔAλXCI[μ]12end13yλPERT[k] = DFT−1{YλPERT[μ]}14end15yPERT[k]= overlapSaveAppend(yλPERT[k], NDFT, K) The time- and frequency-domain picture of the regular perturbation approach are equivalent due to the DTFT in (37), (38) which interrelates both representations. Algorithm 1 represents a practical realization in discrete-frequency which produces the same (numerical) results as the discrete-time model as long as NDFTand K are chosen sufficiently large for a given system scenario. To that end, below, the regular discrete-time and -frequency model and the reference channel model implemented via the SSFM are compared. Then, the regular model is extended to a combined regular-logarithmic model where a subset of the perturbations are considered as multiplicative, i.e., perturbations that cause a rotation in phase or in the state of polarization (SOP). Now, a regular-logarithmic model in the discrete-time domain is provided. It was already noted in [38] that the regular VSTF approach (or the equivalent RP method) in (26) reveals an energy-divergence problem if the optical launch power P is too high—or more precisely if the nonlinear phase shift ϕNLis too large.. Using a first-order RP approach, a pure phase rotation is approximated by exp(jϕ)≈1+jϕ. While multiplication with exp(jϕ) is an energy conserving transformation (i.e., the norm is invariant under phase rotation), the RP approximation is obviously not energy conserving. In the context of optical transmission, already a trivial (time-constant) average phase rotation due nonlinear interaction is not well modeled by the RP method. This inconsistency was first addressed in the early 2000s [4], [39] and years later revived in the context of intra-channel fiber nonlinearity mitigation. E.g. in [40], [41] it turned out that a certain subset of symbol combinations in the time-domain RP model deterministically creates a perturbation oriented into the −j-direction from the transmit symbol a[k]. Similarly, in the pulse-collision picture [11]-[13] a subset of degenerate cross-channel pulse collisions were properly associated to distortions exhibiting a multiplicative nature. In the same series of contributions, these subsets of degenerate, in the sense that not all four interacting pulses are distinct, distortions were first termed two- and three-pulse collisions, i.e., symbol combinations κ∈3in (47) with κ3=0 in our terminology. While the pulse collision picture covers only cross-channel effects, we will extent the analysis also to intra-channel effects. In this context, we review some properties of the kernel coefficients relevant for inter-channel (ν≠ρ) two- and three-pulse collisions [13] hν[κ1,κ2,0]∈, if κ1=κ2(51) hν[κ1,κ2,0]=hν*[κ2,κ1,0]∈if κ1≠κ2, (52) where two-pulse collisions with κ1=κ2in (51) are doubly degenerate and the kernel is real-valued. The transmit pulse-shape hT(t) is assumed to be a real-valued (root) raised-cosine. In case of three-pulse collisions, the kernel is generally complex-valued but due to its symmetry property in (52) and the double sum over all (nonzero) pairs of [κ1, κ2]Tin (47) the overall effect is still multiplicative. Additionally, for intra-channel contributions (ν=ρ) we find the following symmetry properties of the kernel hρ[κ1,κ2,κ3]=hρ[κ3,κ2,κ1] (53) hρ[κ1,κ2,κ3]=hρ[−κ1,−κ2,−κ3], (54) and we identify a second degenerate case with κ1=0 as source for multiplicative distortions, cf. the symmetric form of (38) w.r.t. κ1and κ3. In the following, the original RP solution is modified such that perturbations originating from certain degenerate mixing products are associated with a multiplicative perturbation. Similar to [13], [41], [42], we extend the previous RP model to a combined regular-logarithmic model. It takes the general form of y[k]=exp(jΦ[k]+j{right arrow over (s)}[k]·{right arrow over (σ)})(a[k]+Δa[k]). (55) In addition to the regular, additive perturbation Δa[k] we now also consider a phase rotation by exp(jΦ[k]) and a rotation in the state of polarization by exp(j{right arrow over (s)}[k]·{right arrow over (σ)}). Here, exp(⋅) denotes the matrix exponential. All perturbative terms combine both SCI and XCI effects, i.e., the additive perturbation Δa[k]∈2is the sum of SCI and XCI contributions. The time-dependent phase rotation is given by exp(jΦ[k]) with the diagonal matrix Φ[k]∈2×2defined as Φ[k]=defϕSCI[k]I+ϕXCI[k]I,(56) i.e., we find a common phase term for both polarizations originating from intra- and inter-channel effects. The combined effect of intra- and inter-channel cross-polarization modulation (XPolM) is expressed by the Pauli matrix expansion {right arrow over (s)}[k]·{right arrow over (σ)}∈2×2using (6), with the notation adopted from [20] and [43]. The expansion defines a unitary rotation in Jones space of the perturbed vector a[k]+Δa[k] around the time-dependent Stokes vector {right arrow over (s)}[k] and is explained in more detail in the following. 1) SCI Contribution: TAT o discuss the SCI contribution we first introduce the following symbol sets SCI={[k1,k2,k3]T∈ℤ3hp[k]/hρ[0]❘"\[RightBracketingBar]"2<ΓSCI}(57)ϕ⊕=def{SCI❘"\[LeftBracketingBar]"k1=0⋀k2≠0⋀k3≠0}(58)ϕ⊖=def{SCI❘"\[LeftBracketingBar]"k3=0⋀k2≠0∧k1≠0}(59)ϕSCI=defϕ⊕⋂ϕ⊖⋂{k=0}(60)ΔSCI=defSCI\ϕSCI,(61) where (57) defines the base set including all possible symbol combinations that exceed a certain energy level ΓSCInormalized to the energy of the center tap at κ=0. In (58), (59) the joint set of degenerate two- and three-pulse collisions for SCI are defined which follow directly from the kernel properties in (51),(52) for κ3=0, and (53),(54) for κ1=0. The set of indices for multiplicative distortionsϕSCIin (60) also includes the singular case κ=0. Then, the additive set is simply the complementary set ofϕSCI) w.r.t. the base setSCI. We start with the additive perturbation defined above in (38) which now reads ΔaSCI[k]=-jϕNL,ρ∑ΔSCIa[k+κ1]aH[k+κ2]a[k+κ3]hρ[κ],(62) where the triple sum is now restricted to the set KΔSCIexcluding all combinations which result in a multiplicative distortion, cf. (61). To calculate the common phase ϕSCI[k] and the intra-channel Stokes rotation vector {right arrow over (s)}SCI[k] we first analyse the expression a[k+κ1]aH[k+κ2]a[k+κ3] from the original equation in (38). For the set with Kϕawith κ1=0 the triple product factors into the respective transmit symbol a[k] and a scalar value aH[k+κ2]a[k+κ3]. After multiplication with hρ[0, κ2, κ3] and summation of all κ∈Kϕathe perturbation is strictly imaginary-valued (cf. symmetry properties in (53),(54)). On the other hand, for Kϕawith κ3=0 we have to rearrange the triple product using the matrix expansion from (7) to factor the expression accordingly as 16 aaHa=½(aHaI+(aH{right arrow over (σ)}a)·{right arrow over (σ)})a.(63) (multiplication with hρ[κ] and summation over κ∈KϕSCIare implied) The first term aHaI also contributes to a common phase term, whereas the second term (aH{right arrow over (σ)}a)·{right arrow over (σ)}∈2×2is a traceless and Hermitian matrix exp(j(aH{right arrow over (σ)}a)·{right arrow over (σ)}) is a unitary polarization rotation. Since the Pauli expansion {right arrow over (u)}·{right arrow over (σ)} in (6) is Hermitian, the expression exp(j{right arrow over (u)}·{right arrow over (σ)}) is unitary. The multiplicative perturbation exp(jϕSCI[k]) with ϕSCI[k]∈is then given by ϕSCI[k]=-ϕNL,ρ∑𝒦ϕ⊕aH[k+2]a[k+3]hρ[]-12ϕNL,ρ∑𝒦ϕ⊖aH[k+2]a[k+1]hρ[]-ϕNL,ρa[k]2hρ[0](64)=-32ϕNL,ρ∑𝒦ϕ⊖aH[k+2]a[k+1]hρ[]-ϕNL,ρa[k]2hρ[0].(65) Given a wide-sense stationary transmit sequence <a[k]>, the induced nonlinear phase shift has a time-average valueϕSCIaround which the instantaneous phase ϕSCI[k] may fluctuate (cf. also [44]). The instantaneous rotation of the SOP due to the expression exp(j{right arrow over (s)}SCI[k]·{right arrow over (σ)})∈2×2causes intra-channel XPolM [45]. It is given by s→SCI[k]·σ→=-12(ϕNL,ρ)∑ϕ⊖(2a[k+κ1]aH[k+κ2]-aH[k+κ2]a[k+κ1]I)hρ[κ],(66) where we made use of the relation in (6). The rotation matrix exp(j{right arrow over (s)}SCI[k]·{right arrow over (σ)}) is unitary and {right arrow over (s)}SCI[k]·{right arrow over (σ)} is Hermitian and traceless. The physical meaning of the transformation described in (66) is as follows: The perturbed transmit vector (a[k]+[k]) in (55) is transformed into the polarization eigenstate {right arrow over (s)}SCI[k] (i.e., into the basis defined by the eigenvectors of {right arrow over (s)}SCI[k]·{right arrow over (σ)}. There, both vector components receive equal but opposite phase shifts and the result is transformed back to the x/y-basis of the transmit vector. In Stokes space, the operation can be understood as a precession of (a[k]+Δa[k]) around the Stokes vector {right arrow over (s)}SCI[k] by an angle equal to its length ∥{right arrow over (s)}SCI[k]∥. The intra-channel Stokes vector {right arrow over (s)}SCI[k] depends via the nonlinear kernel hρ[κ] on the transmit symbols within the memory of the nonlinear interactionT,ρaround a[k]. Similar to the nonlinear phase shift—for a wide-sense stationary input sequence—the Stokes vector {right arrow over (s)}SCI[k] has a time-constant average value around which it fluctuates over time. 2) XCI Contribution: The same methodology is now applied to cross-channel effects. The symbol set definitions for XCI follow from the considerations described above. vXCI={[k1,k2,k3]T∈ℤ3❘"\[LeftBracketingBar]"❘"\[LeftBracketingBar]"hv[k]/hv[0]❘"\[RightBracketingBar]"2>ΓvXCI}ϕ,vXCI=def{vXCI❘"\[LeftBracketingBar]"k3=0⋀k2≠0⋀k1≠0}(67)⋂{k=0}(68)Δ,vXCI=defvXCI\ϕ,vXCI,(69) where the subscript v indicates the channel number of the respective interfering channel. For Kϕ,vXCI, only the degenerate case κ3=0 has to be considered due to the kernel properties of hv[κ1, κ2, 0] in (51),(52). Similar to (63), the expression bbH+bHbI from (47) is rearranged to obtain 32-[bxbx*+byby*00byby*+bxbx*]︸bHbI+12[bxbx*+byby*2bxby*2bybx*byby*+bxbx*]︸2bbH-bHbI=(bhσ→b)·σ→,(70) where the argument and subscript v is omitted for concise notation. The multiplicative cross-channel contribution is again split into a common phase shift in both polarizations and an equal but opposite phase shift in the basis given by the instantaneous Stokes vector of the vthinterferer. We define the total, common phase shift due to cross-channel interference as ϕXCI[k]=-∑ν≠ρ32ϕNL,ν∑ϕ,νXCIbνH[k+κ1]bν[k+κ2]hν[κ](71) which depends on the instantaneous sum over all interfering channels and the sum of bvHbvby over [k1, k2]T. The effective, instantaneous cross-channel Stokes vector ŝXCI[k] is given by s→XCI[k]·σ→=-∑ν≠p12ϕNL,ν∑ϕ,νXCI(2bν[k+κ1]bνH[k+κ2]-bνH[k+κ2]bν[k+κ1]I)hν[κ].(72) Note, that the expressions in (71), (72) include both contributions from two- and three pulse collisions (cf. [13, Eq. (10)-(13)]). 3) Energy of Coefficients in Discrete-Time Domain: The energy of the kernel coefficients is defined according to Parseval's theorem in (49) for the subsets given in (57-61). We find for the different symbol sets EhSCI=def∑ϕSCI❘"\[LeftBracketingBar]"hρ[κ]❘"\[RightBracketingBar]"2(73)Eh,ΔSCI=def∑ΔSCI❘"\[LeftBracketingBar]"hρ[κ]❘"\[RightBracketingBar]"2(74)Eh,ϕSCI=def∑ϕSCI❘"\[LeftBracketingBar]"hρ[κ]❘"\[RightBracketingBar]"2,(75) with the clipping factor ΓSCIin (57) equal to zero. The energy for cross-channel effects is defined accordingly with the sets from (67-69). Since the subsets for additive and multiplicative effects are always disjoint we have Eh=Eh,Δ+Eh,ϕ. Now, a regular-logarithmic model in frequency domain is provided. Similar to the above, we first review some kernel properties of the aliased frequency-domain kernel coefficients Hv(ejωT)∈ℝ,ifω2=ω1⇔ω3=ω⇔v2=0,(76)Hρ(ejωT)∈ℝ,ifω2=ω1⇔ω3=ω⇔v2=0⋁ω2=ω3⇔ω1=ω⇔v1=0,(77) where the two (doubly) degenerate cases ω1=ω2and ω3=ω2correspond to classical inter- and intra-channel cross-phase modulation (XPM). Accordingly, the frequency domain model is now modified such that these contribution will be associated with multiplicative distortions. However, due to the multiplicative nature, only average values can be incorporated into the frequency-domain model as they are both constant over time and frequency and can be treated as a common pre-factor in both pictures. We will see in the following that this already leads to significantly improved results compared to the regular model. Note that, in contrast to the regular models, the regular-logarithmic model in time and frequency are no longer equivalent. The general form of the combined regular-logarithmic model in frequency is given by Y(ejωT)=exp (jΦ+j{right arrow over (S)}·{right arrow over (σ)})×(A(ejωT)+ΔA(ejωT)), (78) where the phase- and polarization-term take on a frequency-constant value, i.e., independent of ejωTand vice-versa independent of k in the time-domain picture). Following the same terminology as before, we introduce the average multiplicative perturbation of the common phase term Φ_=defϕ_SCII+ϕ_XCII,(79) as the sum of the intra-channel contributionϕSCI∈and the inter-channel contributionϕXCI∈. Similarly, for the average polarization rotation we have S→·σ→=defS→SCI·σ→+S→XCI·σ→,(80) where {right arrow over (S)}·{right arrow over (σ)} is again Hermitian and traceless, which in turn makes the matrix exponential exp(j{right arrow over (S)}·{right arrow over (σ)}) unitary. 1) SCI Contribution: The two degenerate frequency conditions in (77) are used in the expression (37) to obtain the average, intra-channel phase distortion. To that end, the triple product AAHA in (37) is rearranged similar to (63). First, the general frequency-dependent expression ϕSCI(ejωT) is given by ϕSCI=-ϕNL,ρT(2π)2∫𝕋A(ejω2T)2Hp(ej[ω,ω2,ω2]TT)dω2-12ϕNL,ρT(2π)2∫𝕋A(djω1T)2Hp(ej[ω1,ω1,ω]TT)dω1,(81a) where the first term on the right-hand side in (81) corresponds to the degeneracy ω2=ω3⇔ω1=ω and the second term corresponds to ω2=ω1⇔ω3=ω. We simplify the expression using the RRC ρ=0 approximation to obtain the average, intra-channel phase distortion ϕ_SCI=32ϕNL,ρT(2π)2∫𝕋A(ejωT)2dω,(81b) which does no longer depend on the power or dispersion profile of the transmission link (given a fixed Leff). Similarly, the average intra-channel XPolM contribution can be simplified to S→SCI·σ→=12ϕNL,ρT(2π)2∫𝕋(2A(ejωT)AH(ejωT)-AH(ejωT)A(ejωT)I)dω.(88) In Algorithm 2 the used modifications to the regular perturbation model (REG-PERT) are highlighted to arrive at the regular-logarithmic perturbation model (REGLOG-PERT)-again exemplarily for the SCI contribution. Lines 6,7 of Algorithm 2 translate Eq. (81a), (81b), (82) to the discrete-frequency domain where the integral over all ω∈becomes a sum over all μ of the λthprocessing block. The average values, here, are always associated to the average values of the λthblock. In Lines 10,11, the double sum to obtain ΔAλSCI[μ] is restricted to all combinations u of the discrete frequency pair [μ1, μ2]Texcluding the degenerate cases corresponding to Eq. (76), (77). The perturbed receive vector YλPERTis then calculated according to (78) before it is transformed back to the discrete-time domain. 2) XCI Contribution: The cross-channel contributions follow from the considerations above and we obtain for the degenerate case in (76) the total, average XCI phase shift ϕ¯XCI=-∑ν≠ρ32ϕNL,νT(2π)2∫𝕋Bν(djωT)2dω(83) and analogously for the total, average XCI Stokes vector we find S→XCI·σ→=-∑ν≠ρ12ϕNL,νT(2π)2∫𝕋(2Bν(ejωT)BνH(ejωT)-BνH(ejωT)Bν(ejωT)I)dω.(84) 3) Energy of Coefficients in Discrete-Frequency Domain: With the notation of the discrete-frequency kernel Hν[μ1,μ2,μ3]=Hv[μ]=Hν(ej2πNDFTμ) we have the following definitions EHSCI=def1NDFT3∑𝒰SCI❘"\[LeftBracketingBar]"Hρ[μ]❘"\[RightBracketingBar]"2(85)EH,ΔSCI=def1NDFT3∑𝒰ΔSCI❘"\[LeftBracketingBar]"Hρ[μ]❘"\[RightBracketingBar]"2(86)EH,ϕSCI=def1NDFT3∑𝒰ϕSCI❘"\[LeftBracketingBar]"Hρ[μ]❘"\[RightBracketingBar]"2,(87) Following the regular-logarithmic approach, some of the degenerate distortion should be associated to multiplicative distortions. In the context of fiber nonlinearity compensation, these terms correspond to a nonlinear-induced phase distortion or a nonlinear-induced distortion of the state of polarization. These distortions can be compensated for by applying the inverse operation on the transmit or receive-side, e.g., mathematically speaking by changing the sign in the exponential in (55). The (frequency-domain) intra-channel phase distortion term can be calculated according to (81a) and (81b) while the polarization distortion term is calculated according to (82). The inter-channel terms are given in (83) and (84). In the following, Algorithm 2 (REGLOG-PERT-FD) for the SCI contribution is provided: Algorithm 2: REGLOG-PERT-FD for the SCI contribution1aλ[k] = overlapSaveSplit(a[k], NDFT, K)2k, μ, μ1, μ2∈ {0, 1, . . . , NDFT− 1}3Hρ[μ1,μ2,μ3]=Hρ[μ]=Hρ(ej2πNDFTμ)4forall λ do5Aλ[μ] = DFT{aλ[k]}6ϕ_λSCI=-32ϕNL,ρNDFT2∑μAλ[μ]27S→λSCI·σ→=-12ϕNL,ρNDFT2∑μ2Aλ[μ]AλH[μ]-Aλ[μ]2I8forall μ do9μ3= modNDFT(μ − μ1+ μ2)10U = {[μ1, μ2]T| μ2≠ μ1∧ μ2≠ μ3}11ΔAλSCI[μ]=-jϕNL,ρNDFT2×∑uAλ[μ1]AλH[μ2]Aλ[μ3]Hρ[μ1,μ2,μ3]12YλPERT[μ] = exp(jϕλSCII + j{right arrow over (S)}λSCI· {right arrow over (σ)}) ×(Aλ[μ] + ΔAλSCI[μ])13end14yλPERT[k] = DFT−1{YλPERT[μ]}15end16yPERT[k]= overlapSaveAppend(yλPERT[k], NDFT, K) with the sets according to (77) uSCI={μ=[μ1,μ2,μ3]T∈{0,1, . . . ,NDFT−1}3} (88) uΔSCI={uSCI|μ2≠μ1∧μ2≠μ3} (89) uϕSCI={uSCI|μ2=μ1∨μ2=μ3}. (90) Note, that we have again EHSCI=EH,ΔSCI+EH,ϕSCIand due to Parseval's theorem EhSCI=EHSCIfor NDPT→∞. The cardinalities of the sets are |uSCI|=NDFT3, |uϕSCI|=2NDFT2and |uΔSCI|=|uSCI|−|uϕSCI|. The cross-channel sets are defined according to (76) with only a single degeneracy.In an embodiment, algorithm 2 for XCI reads as follows: Algorithm 2: REGLOG-PERT-FD for the XCI contributionof the vthwavelength channel1aλ[k] = overlapSaveSplit(a[k], NDFT, K)2bλ[k] = overlapSaveSplit(bv[k], NDFT, K)3k, μ, μ1, μ2∈ {0, 1, . . . , NDFT− 1}4Hv[μ1,μ2,μ3]=Hv[μ]=Hv(ej2πNDFTμ)5forall λ do6Aλ[μ] = DFT{aλ[k]}7Bλ[μ] = DFT{bλ[k]}8ϕ_λXCI=-32ϕNL,vNDFT2∑μBλ[μ]29S→λXCI·σ→=-12ϕNL,vNDFT2∑μ2Bλ[μ]BλH[μ]-Bλ[μ]2I10forall μ do11μ3= modNDFT(μ − μ1+ μ2)12U = {[μ1, μ2]T| μ2≠ μ1}13ΔAλXCI[μ]=-jϕNL,vNDFT2×∑u(Bλ[μ1]BλH[μ2]+BλH[μ2]Bλ[μ1]I)×Aλ[μ3]Hv[μ1,μ2,μ3]14YλPERT[μ] = exp(jϕλXCII + j{right arrow over (S)}λXCI· {right arrow over (σ)}) ×(Aλ[μ] + ΔAλXCI[μ])15end16yλPERT[k] = DFT−1{YλPERT[μ]}17end18yPERT[k]= overlapSaveAppend(yλPERT[k], NDFT, K) In the following, numerical results are provided. The following complements the general considerations of the above by numerical simulations. To this end, we compare the simulated received symbol sequence <y[k]> obtained by the perturbation-based (PERT) end-to-end channel models to the sequence obtained by numerical evaluation via the SSFM (in the following indicated by the superscript SSFM). The evaluated metric is the normalized MSE between the two output sequences for a given input sequence <a[k]>, i.e., we have σe2=defE{ySSFM-yPERT2},(91) where the expectation takes the form of a statistical average over the time of the received sequence. The MSE is already normalized due to the fixed variance σn2=1 of the symbol alphabet and the receiver-side re-normalization in (25), s.t. the received sequence has (approximately 19) the same fixed variance as the transmit sequence. 19In the numerical simulation via SSFM signal depletion takes place due to an energy transfer from signal to NLI. For simplicity, this additional signal energy loss is not accounted for by additional receiver-side re-normalization. The simulation parameters are summarized in Table I. A total number of NSYM=216transmit symbols <a[k]> are randomly drawn from a polarization-division multiplex (PDM) 64-ary quadrature amplitude modulation (QAM) symbol alphabetwith (4D) cardinality M=||=4096, i.e., 64-QAM per polarization. The transmit pulse shape hT(t) is a RRC with roll-off factor ρ and energy ETto vary the optical launch power P. Above, signals have been treated as dimensionless entities, but by convention we will still associate the optical launch power P with units of [W] and the nonlinearity coefficient γ with [1/(Wm)]. Two different optical amplification schemes are considered: ideal distributed Raman amplification (i.e., lossless transmission) and transparent end-of-span lumped amplification (i.e., lumped amplification where the effect of signal-gain depletion [5, Sec. II B.] is neglected in the derivation of the perturbation model). For lumped amplification we consider homogeneous spans of SSMF with fiber attenuation 10 log10eα=0.2 dB/km and a span length of Lsp=100 km. In case of lossless transmission we have 10 log10eα=0 dB/km and span length Lsp=21.71 km corresponding to the asymptotic effective length Leff,a=def1/α of a fictitious fiber with infinite length and attenuation 10 log10eα=0.2 dB/km. The dispersion profile(z)=β2z conforms with modern dispersion uncompensated (DU) links, i.e., without optical inline dispersion compensation and bulk compensation at the receiver-side (typically performed in the digital domain). Dispersion pre-compensation at the transmit-side can be easily incorporated via0. The dispersion coefficient β2=−21 ps2/km and the nonlinearity coefficient is γ=1.1 W−1km−1, both constant over z and ω. Additive noise due to amplified spontaneous emission (ASE) and laser PN are neglected since we only focus on deterministic signal-signal NLI. The numerical reference simulation is a full-vectorial field simulation implemented via the symmetric split-step Fourier method [46] with adaptive step size and a maximum nonlinear phase-rotation per step of ϕNLmax=3.5×10−4rad. The simulation bandwidth is BSIM=8Rsfor single-channel and 16Rsfor dual-channel transmission. All filter operations (i.e., pulse-shaping, linear step in the SSFM, linear channel matched filter) are performed at the full simulation bandwidth via fast convolution and regarding periodic boundary conditions. The known fiber nonlinearity compensation schemes operating in the frequency-domain are typically some sort of Volterra-based compensators (cf. [37,38,39]). All results following the Volterra approach operate at a fractional sampling rate (usually at two samples-per-symbol) and are typically performed on the receive side (before linear equalization) jointly with (or instead of) chromatic dispersion compensation. Those approaches hence do not incorporate the channel matched filter and do not establish and end-to-end relation between transmit and receive symbol sequences. Those approaches also suffer from a higher implementation complexity due to the higher sampling, i.e., processing rate and must run on the receive samples at a potentially high fixed point resolution. Run-time adaptation of the equalizer coefficients is also hard to implement since the used control loop for the adaption of the coefficients has a long feedback cycle. Derived from the frequency-domain description, a novel class of algorithms is provided which effectively compute the end-to-end relation between transmit and receive sequences over discrete frequencies from the (periodic) Nyquist interval. Remarkably, the frequency-matching in (31) which is imposed along with the general four wave mixing (FWM) process in the optical domain is still maintained in the periodic frequency-domain. For application in fiber nonlinearity compensation this scheme can be well applied at the transmit-side during pulse-shaping (usually on the transmit-side, pulse-shaping can be well combined with linear pre-compensation of transmitter components—typically done in the frequency-domain anyway) or on the receive side after matched filtering. Moreover, while the time-domain implementation (cf. pulse collision picture) uses a triple summation per time-instance, the frequency-domain implementation involves only a double summation per frequency index. Similar as for linear systems, this characteristic allows for very efficient implementations using the fast Fourier transform when the time-domain kernel comprises many coefficients. Since the proposed algorithm only uses frequencies from within the Nyquist interval, it can be implemented at the same rate as the symbol rate. In [35] it was shown, that symbol pre-decisions (cf. decision-directed adaptation) can be used to calculate the perturbative terms using the time-domain implementation of the model. Symbol pre-decisions are also desirable since they use only a low fixed-point resolution. Similarly, symbol pre-decisions can be used for the frequency-domain implementation (cf. symbol pre-decisions instead of the known symbols in Algorithm 1 and 2). In the following, a discussion of the results is provided. FIG.7aandFIG.7billustrate contour plots of the normalized mean-square error σe2=R{∥ySSPM−yPERT∥2} in dB between the perturbation-based (PERT) end-to-end model and the split-step Fourier method (SSFM). In particular,FIG.7aillustrates a contour plot for a single-channel, single-span, lossless fiber scenario in the regular (REG) time-domain (TD) model (REG-PERT-TD) which is carried out as in (38). FIG.7billustrates a contour plot for a single-channel, single-span, lossless fiber scenario in the regular-logarithmic (REGLOG) model (REGLOG-PERT-TD) which is carried out as in (55). The results are shown w.r.t. the symbol rate Rsand the optical launch power of the probe Pρin dBm. Parameters as in Table I with roll-off factor ρ=0.2, Nsp=1, 10 log10eα=0 dB/km and Lsp=21.71 km. InFIG.7a, we start our evaluation with the most simple scenario, i.e., single-channel, single-span, and lossless fiber. The MSE is shown in logarithmic scale 10 log10σe2in dB over the symbol rate Rsand the launch power of the probe 10 log10(Pρ/mW) in dBm. The results are obtained from the regular (REG) perturbation-based (PERT) end-to-end channel model in discrete time-domain (TD), corresponding to (38). For the given effective length Leffand dispersion parameter β2, the range of the symbol rate between 1 GBd and 100 GBd corresponds to a map strengthT,ρbetween 0.003 and 28.7. This amounts to virtually no memory of the intra-channel nonlinear interaction for small symbol rates (hence only very few coefficients hρ[κ] exceeding the minimum energy level of 10 log10ΓSCI=−60 dB) to a very broad intra-channel nonlinear memory for high symbol rates (with coefficients hρ[κ] covering a large number of symbols). Likewise, the launch power of the probe Pρspans a nonlinear phase shift ϕNL,ρfrom 0.02 to 0.34 rad. We can observe a gradual increase in σe2of about 5 dB per 1.5 dBm launch power in the nonlinear transmission regime. We deliberately consider a MSE 10 log10σe2>−30 dB as a poor match between the perturbation-based model and the full-field simulation, i.e., here for Pρlarger than 9dBm(=Δ0.168rad≈10°) independent of Rs TABLE ISIMULATION PARAMETERSa, b ∈ APDM 64-QAMM4096(=Δ64-QAMperpolarization)hT(t)hRRC(t) with roll-off factor ργ1.1 W−1km−1β2−21 ps2/kmB00 ps2B(z)β2z10 log10eα0 dB/km0.2 dB/kmLsp21.71 km100 km(z)0−αz + αLsp Σi=1Nspδ(z − iLsp)NSYM216NDFTmax(+1, 64)10 log10Γ−60 dB InFIG.7bthe same system scenario is considered but instead of the regular model, now, the regular-logarithmic (REGLOG) model is employed according to (55). The gradual increase in σe2with increasing Pρis now considerably relaxed to about 5 dB per 2.5 dBm launch power. The region of poor model match with 10 log10σe2>−30 dB is now only approached for launch powers larger than 12 dBm. We can also observe that σe2improves with increasing symbol rate Rs, in particular for rates Rs>40 GBd. This is explained by the fact that the kernel energy EhSCIin (73) depends on the symbol rate Rs, s.t. σe2is reduced for higher symbol rates. FIG.8aillustrates an energy of the kernel coefficients in a time-domain Ehover the symbol rate Rs(PERT-TD, single-channel, single-span). FIG.8billustrates an energy of the kernel coefficients in a frequency-domain EHover the symbol rate Rs(PERT-FD, single-channel, single-span). The results are obtained from the regular-logarithmic (REGLOG) model for a single-channel (ρ=0.2) over a standard single-mode fiber (10 log10eα=0.2 dB/km and Lsp=100 km) or a lossless fiber (10 log10eα=0 dB/km and Lsp=21.71 km). The subscript Δ denotes the subset of all coefficients associated with additive and the subscript Ø denotes the subset of all coefficients with multiplicative perturbations. In particular,FIG.8ashows the energy of the (time-domain) kernel coefficients EhSCIover Rsfor a single-span SSMF with Lsp=100 km and for a lossless fiber with Lsp=21.71 km. Generally, we see that EhSCIis constant for small Rsand then curves into a transition region towards smaller energies before it starts to saturate for large Rs. For transmission over SSMF this transition region is shifted to smaller Rs, e.g., EhSCIdrops from 0.7 to 0.6 around 33 GHz for lossless transmission and at around 20 GHz for transmission over SSMF. We also present the kernel energies Eh,ØSCI, associated with additive perturbations, and Eh,ØSCIassociated with multiplicative perturbations. Most of the energy is concentrated in Eh,ØSCI, i.e., corresponding to the degenerate symbol combinations with κ1=0 or κ3=0 defined in (58)-(60). Interestingly, while the total energy EhSCIdecreases monotonically with Rs, the additive contribution EhSCIincreases in the transition region and then decreases again for large Rs. This behaviour is also visible in the results presented inFIGS.7(a) and (b). FIG.8bshows the energy of the kernel coefficients EHSCIin frequency-domain for the same system scenario as in (a). The total energies are the same (cf. Parseval's theorem), however, the majority of the energy is now contained in the regular, i.e., additive, subset of coefficients. Only, the amount of 1/NDFTindependent of Rsis contained in the degenerate, i.e., multiplicative, subset of coefficients. FIG.9aillustrates a contour plot in the regular model in the frequency domain of the normalized mean-square error σe2in dB for a single-channel, single-span, lossless fiber (REG-PERT-FD) according to an embodiment. FIG.9billustrates a contour plot in the regular-logarithmic model in the frequency domain of the normalized mean-square error σe2in dB for a single-channel, single-span, lossless fiber (REGLOG-PERT-FD) according to an embodiment. The results are shown w.r.t. the symbol rate Rsand the optical launch power of the probe Pρin dBm. Parameters as in Table I with roll-off factor ρ=0.2, Nsp=1, 10 log eα=0 dB/km and Lsp=21.71 km. In (a) the regular (REG) frequency-domain (FD) model is carried out as in Algorithm 1 and in (b) the regular-logarithmic (REGLOG) model is carried out as in Algorithm 2. InFIG.9aandFIG.9bthe respective results on σe2using the discrete frequency-domain (FD) model according to Algorithm 1 and 2 are shown. We can confirm our previous statement that the regular perturbation model in time and frequency are equivalent considering that the results shown inFIG.7aandFIG.9bare (virtually) the same. We also conclude that the REGLOG-FD performs very similar to the corresponding TD model despite the fact that only average terms can truly be considered as multiplicative distortions. This may motivate the application of the FD over the TD model for fiber nonlinearity mitigation when an implementation in frequency-domain is computationally more efficient. FIG.10aandFIG.10billustrate contour plots of the normalized mean-square error σe2in dB, wherein the results are obtained from the regular-logarithmic (REGLOG) time-domain (TD) model over a standard single-mode fiber with end-of-span lumped amplification (10 log10eα=0.2 dB/km and Lsp=100 km). InFIG.10a, the symbol rate Rsand the optical launch power Pρare varied for single-span (Nsp=1) transmission and fixed roll-off factor (ρ=0.2). (REGLOG-PERT-TD, single-channel, single-span, standard fiber). InFIG.10b, the roll-off factor ρ and number of spans Nspare varied with fixed symbol rate (Rs=64 GBd) and fixed launch power (10 log10(Pρ/mW)=3 dBm). (REGLOG-PERT-TD, single-channel, multi-span, standard fiber). The black cross inFIG.10aandFIG.10bindicates the point with a common set of parameters. We can see a dependency on the roll-off factor ρ which is due to a dependency of EhSCIon ρ (not shown here). With increasing ρ the kernel energy EhSCIdecreases and hence does ae too. FIG.10aandFIG.10bshow σe2for a single-channel over standard singlemode fiber (Lsp=100 km and 10 log10eα=0.2 dB/km) and lumped end-of-span amplification. In the full-field simulation, the lumped amplifier is operated in constant-gain mode compensating for the exact span-loss of 20 dB. The results over a single-span inFIG.10aare slightly better compared to the lossless case inFIG.7band the dependency on the symbol rate is even more pronounced. InFIG.10b, σe2is shown over the roll-off factor ρ and the number of spans Nspfor a fixed symbol rate of Rs=64 GBd and fixed launch power of 10 log10(Pρ/mW)=3 dBm. The black cross inFIGS.10(a) and (b)marks the point with common set of parameters. For dual-channel transmission the transmit symbols of the interferer (b[k]) are drawn from the same symbol set A. For both wavelength channels, the symbol rate is fixed to Rs=64 GBd and the roll-off factor of the RRC shape is ρ=0.2. The transmit power of the probe is set to 10 log10(Pρ/mW)=0 dBm while the transmit power of the interferer P1is varied together with the relative frequency offset Δω/(2π) ranging from 76.8 GHz (i.e., no guard interval with 1.2×64 GHz) to 200 GHz. InFIG.11a, an energy of the kernel coefficients (black lines, bullet markers, left y-axis) in time-domain Ehover Nspspans of standard single-mode fiber (10 log10eα=0.2 dB/km and Lsp=100 km, ρ=0.2) is illustrated (PERT-TD, single-channel, multi-span, standard fiber). Additionally, the kernel energies are shown scaled with Nsp2∝ØNL,ρ2(gray lines, cross markers, right y-axis) to indicate the general growth of nonlinear distortions with increasing Nsp(similar to the GN-model). InFIG.11b, kernel energies Ehfor cross-channel interference (XCI) imposed by a single wavelength channel spaced at Δω1/(2π) GHz over a single span of lossless fiber. Both probe and interferer have Rs=64 GBd and ρ=0.2 are illustrated (PERT-TD, dual-channel, single-span, lossless fiber). The scaling laws of σe2with Nspare complemented inFIG.11aby the energy of the kernel coefficients EhSCIfor the same system scenario as inFIG.10b(with ρ=0.2). It is interesting to see that (for this particular system scenario) Eh,ΔSCIand Eh,ØSCIintersect at Nsp=2. We can conclude that after the second span more energy is comprised within the additive subset of coefficients than in the multiplicative one. With increasing Nspthe relative contribution of Eh,ΔSCIto the total energy EhSCIis increasing. Note, while EhSCIis actually monotonically decreasing with Nsp, the common prefactor ØNL,ρhas to be factored in as it effectively scales the nonlinear distortion. Since for heterogeneous spans we have ØNL,ρ∝Leff∝Nsp, the same traces are shown scaled by Nsp2to illustrate how the energy of the total distortion accumulates with increasing transmission length. In this respect, similar results can be obtained from the presented channel model as from the GN-model (given proper scaling with ØNL,ρ2instead of just Nsp2, and similarly taking all other wavelength channels into account). Additionally, qualitative statements can be derived, e.g., whether the nonlinear distortion is predominantly additive or multiplicative or on which time scale nonlinear distortions are still correlated. FIG.12aandFIG.12billustrate contour plots of the normalized mean-square error σe2in dB. In particular,FIG.12aillustrates a contour plot in a time domain, for dual-channel, single-span, lossless fiber, (REGLOG-PERT-TD). FIG.12billustrates a contour plot in a frequency domain, for dual-channel, single-span, lossless fiber, (REGLOG-PERT-FD). InFIG.12aandFIG.12b, the results are obtained from two co-propagating wavelength channels with PDM 64-QAM and a symbol rate of 64 GBd and roll-off factor ρ=0.2. The launch power of the probe is fixed at 10 log10(Pρ/mW)=0 dBm while the power of the interferer P1and the relative frequency offset Δω1are varied. In (a) the regular-logarithmic (REGLOG) time-domain (TD) model for both SCI and XCI is carried out as in (55) and in (b) the REGLOG frequency-domain (FD) model is carried out as in Algorithm 2 and (78) for both SCI and XCI. FIG.12aandFIG.12bshow the σe2for dual-channel transmission using the REGLOG time-domain inFIG.12aand the frequency-domain model inFIG.12b. The transmit symbols of the interferer <b[k]> are drawn from the same symbol set A, e.g., 64-QAM per polarization. For both wavelength channels, the symbol rate is fixed to Rs=64 GBd and the roll-off factor of the RRC shape is ρ=0.2. The transmit power of the probe is set to 10 log10(Pρ/mW)=0 dBm while the transmit power of the interferer Pvwith channel number v=1 is varied together with the relative frequency offset Δω1/(2π) ranging from 76.8 GHz (i.e., no guard interval with (1+φ×64 GHz) to 200 GHz. In case of the end-to-end channel model both contributions from intra- and inter-channel distortions are combined into a single perturbative term (cf. (55) and (78)). The baseline error σe2is therefore approximately −55 dB considering the respective case with Rs=64 GBd and Pρ=0 dBm inFIG.7b. It is seen that the time- and frequency-domain model perform very similar. The dependency on the channel spacing Δω1is explained consideringFIG.11b. Here, the energy of the cross-channel coefficients h1[κ] is shown over Δω1. Generally, with increasing Δω1, EhSCIdecreases and additionally the relative contribution of the degeneracy at κ3=0, i.e., Eh,ØSCIis growing. Ultimately, the main distortion caused by an interferer spaced far away from the probe channel is a distortion in phase and state of polarization. Summarizing the above, a comprehensive analysis of end-to-end channel models for fiber-optic transmission based on a perturbation approach is provided. The existing view on nonlinear interference following the pulse collision picture is described in a unified framework with a novel frequency-domain perspective that incorporates the time-discretization via an aliased frequency-domain kernel. The relation between the time- and frequency-domain representation is elucidated and we show that the kernel coefficients in both views are related by a 3D discrete-time Fourier transform. The energy of the kernel coefficients can be directly related to the GN-model. While the pulse collision picture is a theory developed particularly for inter-channel nonlinear interactions, a generalization to intra-channel nonlinear interactions is presented. An intra-channel phase distortion term and an intra-channel XPolM term are introduced and both correspond to a subset of degenerate intra-channel pulse collisions. In analogy to the time-domain model, the frequency-domain model is modified to treat certain degenerate mixing products as multiplicative distortions. As a result, we have established a complete formulation of strictly regular (i.e., additive) models, and regular-logarithmic (i.e., mixed additive and multiplicative) models, both in time- and in frequency-domain, both for intra- and inter-channel nonlinear interference. Provided from the frequency-domain description, a novel class of algorithms is implemented which effectively computes the end-to-end relation between transmit and receive sequences over discrete frequencies from the Nyquist interval. In fiber nonlinearity compensation this scheme can be well applied at the transmit-side during pulse-shaping or on the receive side after matched filtering. Moreover, while the time-domain implementation uses a triple summation per time-instance, the frequency-domain implementation involves only a double summation per frequency index. Similar as for linear systems, this characteristic allows for very efficient implementations using the fast Fourier transform when the time-domain kernel comprises many coefficients. The provided algorithms were compared to the (oversampled and inherently sequential) split-step Fourier method using the mean-squared error between both output sequences. We show that, in particular, the regular-logarithmic models have good agreement with the split-step Fourier method over a wide range of system parameters. The presented results are further supported by a qualitative analysis involving the kernel energies to quantify the relative contributions of either additive or multiplicative distortions. In the following, a proof of the relation in (32), (33) is provided. The Fourier transform of Δs(t) in (33) similarly computed as in [30, Appx.]. We start our derivation by expressing the optical field envelope u(0, t) by its inverse Fourier transform of U(0, ω) to obtain Δs(t)=-jγ89Leff∫ℝ2hNL(τ1,τ2)×u(0,t+τ1)uH(0,t+τ1+τ2)u(t+τ2)d2τ=-jγ89Leff1(2π)3∫∫-∞+∞dτ1dτ2hNL(τ1,τ2)×∫-∞∞dω3U(0,ω3)exp(jω3τ1)×∫-∞∞dω2UH(0,ω2)exp(-jω2(τ1+τ2))×∫-∞∞dω1U(0,ω1)exp(jω1τ2)×exp(j(ω3-ω2+ω1)t).(92) The Fourier transform of the former expression yields ΔS(ω)=-jγ89Leff1(2π)3∫∫∫-∞+∞dtdτ1dτ2hNL(τ1,τ2)×∫-∞∞dω3U(0,ω3)exp(jω3τ1)×∫-∞∞dω2UH(0,ω2)exp(-jω2(τ1+τ2))×∫-∞∞dω1U(0,ω1)exp(jω1τ2)×exp(j(ω3-ω2+ω1-ω)t).(93) We now use the identity ∫−∞∞exp(j(ω3−ω2+ω1)t)dt=2πδ(ω3−ω2+ω1−ω) to obtain ΔS(ω)=-jγ89Leff1(2π)2∫∫-∞+∞dτ1dτ2hNL(τ1·τ2)×U(0,ω-ω1+ω2)exp(j(ω-ω1+ω2)τ1)×∫-∞∞dω2UH(0,ω2)exp(-jω2(τ1+τ2))×∫-∞∞dω1U(0,ω1)exp(jω1τ2).(94) After re-arranging the order of integration, we have ΔS(ω)=-jγ89Leff1(2π)2∫∫-∞+∞dω1dω2×U(0,ω-ω1+ω2)UH(0,ω2)U(0,ω1)×∫∫-∞∞dτ1dτ2hNL(τ1,τ2)exp(jω1τ2)×exp(-jω2(τ1+τ2))exp(j(ω-ω1+ω2)τ1).(95) And finally a change of variables with v1=ω1−ω and v2=ω2−ω1yields ΔS(ω)=-jγ89Leff1(2π)2∫∫-∞+∞dv1dv2×U(0,ω+v2)UH(0,ω+v1+v2)U(0,ω+v1)×∫∫-∞+∞dτ1dτ2(τ1,τ2)exp(-jv1τ1-jv2τ2),︸HNL(v1,v2)=ℱ{hNL(τ1,τ2)}(96) which is equivalent to the expression in (32). Although some aspects have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus. Some or all of the method steps may be executed by (or using) a hardware apparatus, like for example, a microprocessor, a programmable computer or an electronic circuit. In some embodiments, one or more of the most important method steps may be executed by such an apparatus. Depending on certain implementation requirements, embodiments of the invention can be implemented in hardware or in software or at least partially in hardware or at least partially in software. The implementation can be performed using a digital storage medium, for example a floppy disk, a DVD, a Blu-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed. Therefore, the digital storage medium may be computer readable. Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed. Generally, embodiments of the present invention can be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer. The program code may for example be stored on a machine readable carrier. Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier. In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer. A further embodiment of the inventive methods is, therefore, a data carrier (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein. The data carrier, the digital storage medium or the recorded medium are typically tangible and/or non-transitory. A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the Internet. A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein. A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein. A further embodiment according to the invention comprises an apparatus or a system configured to transfer (for example, electronically or optically) a computer program for performing one of the methods described herein to a receiver. The receiver may, for example, be a computer, a mobile device, a memory device or the like. The apparatus or system may, for example, comprise a file server for transferring the computer program to the receiver. In some embodiments, a programmable logic device (for example a field programmable gate array) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods may be performed by any hardware apparatus. The apparatus described herein may be implemented using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer. The methods described herein may be performed using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer. While this invention has been described in terms of several embodiments, there are alterations, permutations, and equivalents which will be apparent to others skilled in the art and which fall within the scope of this invention. 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11942995 | DETAILED DESCRIPTION OF THE INVENTION AND EXEMPLARY EMBODIMENT The photonic frequency converter (PFC) for values above and below the input radio frequency (RF) signal integrated to the optoelectronic oscillator (OEO) and process thereof, as disclosed herein, comprises a compact photonic frequency converter (PFC) for radio frequency (RF) signals consisting of an optoelectronic oscillator (OEO) and a radio frequency (RF) signal injection circuit (IC). The optoelectronic oscillator (OEO) is the local oscillator (LO) of the frequency conversion operation and uses only a single Mach-Zehnder (MZ) electro-optical modulator3and a single photodetector4, which allows for simultaneous performance of frequency conversion for values above and below (down/up converter) of the input radio frequency (RF) signal. As shown inFIG.1, the central dashed block1illustrates the optoelectronic oscillator (OEO)1of the frequency converter circuit. The optoelectronic oscillator (OEO)1is composed of a continuous light laser source2, a MZ electro-optical modulator3, a single photodetector4, a power splitter5, a band-pass radio frequency (RF) filter6, amplifier7and a power combiner8which is responsible for feeding back the radio frequency (RF) input of the MZ electro-optical modulator3. It is essential to note that the power splitter5cannot be connected to any point of the optoelectronic oscillator (OEO)1. The optoelectronic oscillator (OEO)1comprises an optical link and a feedback loop in the radio frequency (RF) domain. The optical link consists of the continuous light laser source2, the MZ electro-optical modulator3and the single photodetector4. The feedback loop in the radio frequency (RF) domain, in turn, consists of the power splitter5, the band-pass radio frequency (RF) filter6with centered frequency response band on f0, the amplifier7and the power combiner8. The power splitter5must be mandatorily connected after the single photodetector4and connected before the band-pass radio frequency (RF) filter6, so that the intermodulation signal is available for its processing. This is due to the fact that only in this arrangement/configuration the band-pass radio frequency (RF) filter6is able to only allow the passage of signals comprised in its frequency response band, that is, it will inhibit the other various frequency components generated by intermodulation inside the MZ electro-optical modulator3, thus preventing the operation of the optoelectronic oscillator (OEO)1, as a local oscillator, from being disturbed. The radio frequency (RF) signal source that will have its frequency shifted up or down is indicated by an input signal block9, and the injection circuit (IC)9consists of a block representing the radio frequency (RF) signal source with frequency f19A and a block representing the radio frequency (RF) signal source with frequency f29B. Note that in the injection circuit (IC)9the possibility of more than one signal applied simultaneously for frequency conversion is considered. Each radio frequency (RF) signal source,9A and9B, will inject a signal with a certain frequency. The outputs of these two signal sources will be combined in a power combiner10and then injected into the optoelectronic oscillator (OEO)1. For the purpose of understanding the operation of the photonic frequency converter (PFC) proposed herein, it should be considered that the optoelectronic oscillator (OEO)1generates a signal of frequency f0. The two applied radio frequency (RF) signals have frequencies f1and f2, respectively. In the optoelectronic oscillator (OEO)1block where the reference signal f0is generated, whose value is defined by the frequency response band of the bandpass radio frequency (RF) filter6, the applied radio frequency (RF) signals of frequencies f1and f2coming from the radio frequency (RF) signal blocks of frequency9A and9B, will undergo intermodulation with the signal of frequency f0generated in the optoelectronic oscillator (OEO). The intermodulation signal, with frequencies above and below the frequencies of the injected external signals (f0−f1, f0−f2, f0+f1, f1−f2, etc.) is selected by filters12A and13A after the power splitter5and amplifier11which are connected after the single photodetector4of the optoelectronic oscillator (OEO). After the power splitter5there are filters12A and13A for selecting frequencies above and below the f1and f2frequencies of the external signals applied. The signals after the filters that follow the power splitter5represent the output signals of the photonic frequency converter (PFC). After amplifier11, the signals with frequencies above and below the frequencies of the applied external signals can be used in transmission (T)12and reception (R) 13 steps. To illustrate with numerical values, we consider f0=2 GHz, f1=1.3 GHz and f2=1.5 GHz. For these values as an example, we can consider the reception and transmission output spectrum with frequencies from 200 MHz (f2−f1) up to 3.5 GHz (f0+f2), with difference (f0−f1)=700 MHz and f0−f2=500 MHz; and the sum f0+f1=3.3 GHz and f0+f2=3.5 GHz. Signals with the frequency value down converted, 500 MHz (f0−f2) and/or 700 MHz (f0−f1), can be directed to signal processing steps, thus completing the reception of the signal injected into the converter. Signals with the frequency value up converted, 3.3 GHz (f0+f1) and/or 3.5 GHz (f0+f2), can be directed to signal processing steps, thus completing the transmission of the signal injected into the converter. It is worth mentioning that applying only one signal at the input of the photonic frequency converter (PFC), the power spectrum at the output, whether receiving (R) or transmitting (T), will have a smaller number of spectral components without changing its operating principle as only operations with f0and f of the single applied signal will be counted in the definition of frequencies present at the outputs. | 5,905 |
11942996 | DETAILED DESCRIPTION Technical solutions in embodiments of the present disclosure will be clearly and completely described in conjunction with drawings in embodiments of the present disclosure. Embodiment I An embodiment of the present disclosure provides an optical signal outputting device1. As shown inFIG.2, the optical signal outputting device1comprises: a target optical fiber grating13having a preset angle optical fiber grating and/or a preset period optical fiber grating; a first optical fiber grating12connected to the target optical fiber grating; and a pump laser11connected to the first optical fiber grating; wherein the pump laser is configured to transmit a first optical signal to the first optical fiber grating when a target band optical signal emitting command is received, wherein a central wavelength of the first optical signal is a target wavelength of a target band optical signal; and to convert a second band optical signal into the target band optical signal by using resonance and output the target band optical signal when an optical signal adjusting command is received; the first optical fiber grating is configured to screen a first band optical signal from the first optical signal and transmit the first band optical signal to the target optical fiber grating, wherein a central wavelength of the first band optical signal is a target wavelength of the target band optical signal and a band scope of the first band optical signal is smaller than a band scope of the first optical signal; and the target optical fiber grating is configured to screen the second band optical signal and the target band optical signal from the first band optical signal to transmit the optical signal adjusting command to the pump laser by using the second band optical signal or the target band optical signal. The optical signal outputting device provided by the embodiment of the present application is suitable for the scenario of obtaining the target band optical signal by converting non-target band optical signals generated by the pump laser. In an embodiment of the present application, the optical signal outputting device comprises a target optical fiber grating, a first optical fiber grating connected to the target optical fiber grating, and a pump laser connected to the first optical fiber grating, wherein the target optical fiber grating comprises a preset angle optical fiber grating and a preset period optical fiber grating, the intersection angle between a grating plane of the preset angle optical fiber grating and an optical fiber shaft is a preset angle, and a period length of the preset period length optical fiber grating meets a preset period length. Exemplarily, the preset period length optical fiber grating can be an optical fiber grating having a period length greater than 1 um, such as a long period optical fiber grating. The specific preset period length can be identified according to the actual situations, which will not be limited by the present application. In an embodiment of the present application, the pump laser is provided with a target central wavelength. When the pump laser is activated, the pump laser receives the target band optical signal emitting command and begins to generate optical signals of the target central wavelength while generating optical signals of non-target central wavelengths. The pump laser transmits all the optical signals generated by the pump laser to the first optical fiber grating, that is, the pump laser transmits the first optical signal to the first optical fiber grating. It should be noted that the first optical signal is an optical signal generated by the pump laser. Exemplarily, the target central wavelength of the pump laser is 974 nm. When the pump laser is activated, the pump laser receives the target band optical signal emitting command and generates an optical signal with a wavelength of 974 nm while generating part of optical signals in a band scope of 960-973 nm and part of optical signals in a band scope of 975-980 nm. That is, the first optical signal is an optical signal having a wavelength in the band scope of 960-980 nm, and the pump laser emits the optical signal in the band scope of 960-980 nm. In an embodiment of the present application, a resonant cavity is provided in the pump laser. When the pump laser receives the optical signal adjusting command, the resonant cavity of the pump laser begins to resonate. As the optical signal adjusting command is an optical signal in the target band and received by the pump laser, the pump laser can convert the second band optical signal into the target band optical signal with the resonance, as such, the optical signal outputting device obtains the target band optical signal and outputs the target band optical signal. It should be noted that the target optical signal can be an optical signal in the target band and outputted by the optical signal outputting device. For example, if the target band configured for the optical signal outputting device is 974-975 nm, then the optical signal having a wavelength of 974-975 nm and outputted by the optical signal outputting device are the target band optical signal. It should be noted that the second band optical signal is an optical signal, other than the target band optical signal, screened out by the target optical fiber grating from the first band optical signal. Exemplarily, the wavelength scope of the target band optical signal is 974-975 nm and the wavelength scope of the second band optical signal is 976-978 nm. When the pump laser receives the adjusting command for optical signals in a wavelength scope of 974-975 nm, the pump laser generates a resonance to convert optical signals in the wavelength scope of 976-978 nm into optical signals in the wavelength scope of 974-975 nm, and at the same time, the optical signal outputting device obtains the target band optical signal in the wavelength scope of 974-975 nm and outputs the target band optical signal. In an embodiment of the present application, the first optical fiber grating is specified with a grating reflectivity. When the first optical fiber grating receives the first optical signal emitted by the pump laser, the first optical fiber grating screens the first band optical signal from the first optical signal and returns the optical signal consistent with the grating reflectivity in the first band optical signal back to the pump laser so as to trigger the resonant cavity of the pump laser to generate resonance, whereby converting the optical signal other than the first band optical signal in the first optical signal into the first band optical signal. As the central wavelength of the first band optical signal is the same as the target wavelength of the target band optical signal, the first band optical signal is screened out and transmitted to the target optical fiber grating. It should be noted that the first band optical signal is the optical signal screened out from the first optical signal by the first optical fiber grating, the central wavelength of the first band optical signal is the target wavelength of the target band optical signal and the band scope of the first band optical signal is smaller than the band scope of the first optical signal. In an embodiment of the present application, the first optical fiber grating may be an ordinary one and it can be specifically identified according to the actual situations, which will not be limited by embodiments of the present application. In an embodiment of the present application, the target optical fiber grating comprises a preset angle optical fiber grating and a preset period optical fiber grating. When the target optical fiber grating is specifically a preset angle optical fiber grating and the preset angle optical fiber grating receives the first band optical signal, the preset angle optical fiber grating screens out the second band optical signal and the target band optical signal from the first band optical signal and transmits the optical signal adjusting command to the pump laser by means of the second band optical signal; when the target optical fiber grating is specifically the preset period optical fiber grating and the preset period optical fiber grating receives the first band optical signal, the preset period optical fiber grating screens out the second band optical signal and the target band optical signal from the first band optical signal and transmits the optical signal adjusting command to the pump laser by means of the target band optical signal. In an embodiment of the present application, when the target optical fiber grating is a preset period optical fiber grating, the connection manner between the pump laser, the first optical fiber grating and the preset period optical fiber grating is shown inFIG.3. An output end of the pump laser is connected to an input end of the first optical fiber grating, and an output end of the first optical fiber grating is connected to an input end of the preset period optical fiber grating. The target central wavelength of the pump laser can be 974 nm, and the central wavelength scope of the first optical fiber grating and that of the preset period optical fiber grating can be 974-975 nm. When the pump laser receives the target band optical signal emitting command, the pump laser generates the first optical signal including the optical signal with a wavelength of 974 nm and the optical signal with a wavelength other than 974 nm, and transmits the same to the first optical fiber grating. The first optical fiber grating screens out optical signals in the wavelength scope of 974-975 nm from the first optical signal, and screens out an optical signal consistent with the grating reflectivity from the optical signals which are in the wavelength scope of 974-975 nm, and then returned the optical signal consistent with the grating reflectivity back to the pump laser so as to trigger the pump laser to generate resonance, converting the optical signal in a wavelength scope other than 974-975 nm in the first optical signal into an optical signal in the wavelength scope of 974-975 nm. The low filtering precision of the first optical fiber grating fails to convert all the optical signals in the wavelength scope other than 974-975 nm in the first optical signal, which means the first band optical signal outputted by the first optical fiber grating includes the target band optical signal in the wavelength scope of 974-975 nm and the second band optical signal in a wavelength scope of 976-978 nm. When receiving the first band optical signal, the preset period optical fiber grating returns the optical signal consistent with the preset period reflectivity in the target band optical signal back to the pump laser so as to trigger resonance of the pump laser, then converts the second band optical signal into the target band optical signal and outputs the obtained target band optical signal. Optionally, the preset angle optical fiber grating is an optical fiber grating whose preset angle is an intersection angle between a grating plane and an optical fiber shaft; the preset period optical fiber grating is an optical fiber grating whose period length meets a preset period length. In an embodiment of the present application, the preset angle optical fiber grating can be an inclined optical fiber grating and the preset period optical fiber grating can be a long period optical fiber grating, whose specific examples can be identified according to the actual situation and will not be limited by embodiments of the present application. Optionally, the preset angle optical fiber grating is further configured to identify a first preset band optical signal from the second band optical signal; to process the first preset band optical signal by means of the preset angle to obtain the target band optical signal; and to return the target band optical signal back to the pump laser so as to trigger the resonance of the pump laser; and the first preset band optical signal is a part of the second band optical signal. In an embodiment of the present application, the preset angle optical fiber grating is specified with a preset reflectivity and a preset angle. When the preset angle optical fiber grating screens out the second band optical signal and the target band optical signal from the first band optical signal, it outputs the target band optical signal, identifies the first preset band optical signal from the second band optical signal according to the preset reflectivity, converts the first preset band optical signal into the target band optical signal by means of the preset angle and returns the target band optical signal back to the pump laser so as to trigger the generation of resonance by the pump laser. It should be noted that the first preset band optical signal is a part of the second band optical signals. Optionally, the preset period optical fiber grating is further configured to identify the second preset band optical signal from the target band optical signal; and to return the second preset band optical signal back to the pump laser so as to trigger the generation of resonance by the pump laser; and the second preset band optical signal is a part of the target band optical signal. In an embodiment of the present application, the preset period optical fiber grating is specified with a preset period reflectivity. When the preset period optical fiber grating screens out the second band optical signal and the target band optical signal from the first band optical signal, it screens out the second preset band optical signal from the target optical signal according to the preset period reflectivity, outputs an optical signal in the target optical signal which is other than that in the second preset band from the target band optical signal, and returns the second preset band optical signal back to the pump laser so as to trigger the generation of resonance by the pump laser. It should be noted that the second preset band optical signal is a part of the target band optical signal. Optionally, the preset angle optical fiber grating is further configured to screen out a third optical signal that does not belong to a preset band scope corresponding to the preset angle optical fiber grating from a second optical signal and transmits the third optical signal to the output end of the first optical fiber grating when an output end of the preset angle optical fiber grating receives the second optical signal; and the first optical fiber grating is further configured to screen out the target optical signal that belongs to a preset band scope corresponding to the first optical fiber grating from the third optical signal. In an embodiment of the present application, the second optical signal is an optical signal received by the output end of the preset angle optical fiber grating; the third optical signal is an optical signal in the second optical signal and other than ones that belong to the preset band scope corresponding to the preset angle optical fiber grating. In an embodiment of the present application, when the output end of the first optical fiber grating receives the third optical signal, the target optical signal that belongs to the preset band scope corresponding to the first optical fiber grating is screened out from the third optical signal and is reversely transmitted to the pump laser. Optionally, the preset angle optical fiber grating comprises at least one of a first preset angle optical fiber grating and a second preset angle optical fiber grating; a central wavelength of the first preset angle optical fiber grating is smaller than the target central wavelength; and a central wavelength of the second preset angle optical fiber grating is larger than the target central wavelength. When the target optical fiber grating comprises a first preset angle optical fiber grating, the connection manner between the pump laser, the first optical fiber grating and the first preset angle optical fiber grating is shown inFIG.4. The output end of the pump laser is connected to the input end of the first optical fiber grating and the output end of the first optical fiber grating is connected to the input end of the first preset angle optical fiber grating. The target central wavelength of the pump laser can be 974 nm, and the central wavelength scope of the first optical fiber grating and that of the preset period optical fiber grating can be in 974-975 nm. When the pump laser receives the target band optical signal emitting command, the pump laser generates the first optical signal including an optical signal with a wavelength of 974 nm and an optical signal with a wavelength other than 974 nm. The pump laser transmits the first optical signal to the first optical fiber grating. The first optical fiber grating screens out the optical signal in the wavelength scope of 974-975 nm from the first optical signal, screens out the optical signal that meets the grating reflectivity from the optical signal in the wavelength scope of 974-975 nm and returns the screened optical signal back that meets the grating reflectivity to the pump laser so as to trigger the generation of resonance by the pump laser, thereby converting the optical signal in a wavelength scope other than 974-975 nm in the first optical signal into the optical signal in the wavelength scope of 974-975 nm. The low filtering precision of the first optical fiber grating fails to convert all optical signals in a wavelength scope other than 974-975 nm in the first optical signal, which means the first band optical signal outputted by the first optical fiber grating includes the target band optical signal in the wavelength scope of 974-975 nm and the second band optical signal in a wavelength scope of 976-978 nm. When the first preset angle optical fiber grating receives the first band optical signal, it outputs the target band optical signal, converts the optical signal that meets the preset reflectivity in the second band optical signal into the target band optical signal by means of the preset angle, and returns the target band optical signal back to the pump laser, thereby triggering the generation of resonance by the pump laser, converting the second band optical signal into the target band optical signal and outputting the obtained target band optical signal. In an embodiment of the present application, when the target optical fiber grating comprises a first preset angle optical fiber grating and a second preset angle optical fiber grating, the connection method of the optical signal outputting device is shown inFIG.5. The output end of the pump laser is connected to the input end of the first optical fiber grating, the output end of the first optical fiber grating is connected to the input end of the first preset angle optical fiber grating and the input end of the first preset angle optical fiber grating is connected to the output end of the second preset angle optical fiber grating. It should be noted that the target optical fiber grating can be a collection of a plurality of target optical fiber gratings, and the first optical fiber grating can also be a collection of a plurality of the first optical fiber gratings. As shown inFIG.6, the input end of the first target optical fiber grating among the four mutually connected target optical fiber gratings (the first preset angle optical fiber grating and the second preset angle optical fiber grating) is connected to the output end of the last first optical fiber grating of two mutually connected first optical fiber gratings, and the input end of the first of two mutually connected first optical fiber gratings is connected to the output end of the pump laser. The amount of the target optical fiber gratings and the amount of the first optical fiber gratings in embodiments of the present application are merely exemplary, and specific amount of the first optical fiber grating and that of the target optical fiber grating in the optical signal outputting device can be identified according to the actual situations, which will not be limited by embodiments of the present application. Optionally, the preset period optical fiber grating is an optical fiber grating featured by unidirectional optical signal transmission. In an embodiment of the present application, the preset period optical fiber grating is a coupled optical fiber grating where the fiber core fundamental mode and the cladding mode co-propagate, which means the optical signal transmission direction in the preset period optical fiber grating is from the input end to the output end of the preset period optical fiber grating. It will be appreciated that by providing the preset angle optical fiber grating or the preset period optical fiber grating behind the first optical fiber grating, the preset angle optical fiber grating or the preset period optical fiber grating screens out the target band optical signal while the second band optical signal is also converted into the target band optical signal by means of the resonance operation of the pump laser, thereby obtaining high quality target band optical signal and improving the quality of light having the target central wavelength outputted by the pump laser. Embodiment 2 An embodiment of the present application provides an optical signal outputting method applied to an optical signal outputting device which comprises a target optical fiber grating. As shown inFIG.7, the method includes: S101, emitting a first optical signal when a target band optical signal emitting command is received, wherein a central wavelength of the first optical signal is a target wavelength of a target band optical signal. In an embodiment of the present application, the optical signal outputting device comprises a target optical fiber grating, a first optical fiber grating connected to the target optical fiber grating, and a pump laser connected to the first optical fiber grating. The target optical fiber grating comprises a preset angle optical fiber grating and a preset period optical fiber grating. The intersection angle between a grating plane and an optical fiber shaft of the preset angle optical fiber grating is a preset angle, and a period length of the preset period length optical fiber grating meets a preset period length. The optical signal outputting device provided in an embodiment of the present application is suitable for the scenario of obtaining the target band optical signal by processing the generated optical signals. In an embodiment of the present application, the pump laser is specified with a target central wavelength. When the pump laser is activated, the pump laser receives the target band optical signal emitting command and begins to generate the optical signal with a wavelength being the target central wavelength while generating part of optical signals with a wavelength other than target central wavelength. The optical signal generated by the pump laser is the first optical signal, which will then be emitted by the pump laser. It should be noted that the first optical signal is an optical signal generated by the pump laser and the central wavelength of the first optical signal is the target wavelength of the target band optical signal. Exemplarily, the target central wavelength of the pump laser is 974 nm. When the pump laser is activated, the pump laser receives the target band optical signal emitting command and generates the optical signal with a wavelength of 974 nm while generating part of optical signals in a band scope of 960-973 nm and part of optical signals in a band scope of 975-980 nm. That is, the first optical signal is an optical signal in a band scope of 960-980 nm, and the pump laser emits the optical signal in the band scope of 960-980 nm. S102, screening the second band optical signal and the target band optical signal from the first optical signal by using the target optical fiber grating. In an embodiment of the present application, the optical signal outputting device further includes a first optical fiber grating. When the pump laser emits the first optical signal, the first optical fiber grating receives the first optical signal, screens the first band optical signal from the first optical signal, and transmits the first band optical signal to the target optical fiber grating. The optical signal outputting device screens the second band optical signal and the target band optical signal from the first band optical signal by using the target optical fiber grating. It should be noted that the first band optical signal is the optical signal screened out from the first optical signal, the central wavelength of the first band optical signal is the target wavelength of the target band optical signal and the band scope of the first band optical signal is smaller than the band scope of the first optical signal. It should be noted that the target optical signal can be an optical signal in the target band and outputted by the optical signal outputting device. For example, if the target band set by the optical signal outputting device is 974-975 nm, then the optical signal with a wavelength of 974-975 nm outputted by the optical signal outputting device is the target band optical signal. It should be noted that the second band optical signal is an optical signal screened out from the first band optical signal and other than the target band optical signal. S103, triggering a resonance operation by means of the second band optical signal or the target band optical signal, thereby converting the second band optical signal into the target band optical signal by means of the resonance operation, and outputting the target band optical signal. In an embodiment of the present application, the target optical fiber grating comprises a preset angle optical fiber grating provided with a preset angle, and the step of triggering the resonance operation by means of the second band optical signal or the target band optical signal specifically is: In an embodiment of the present application, the optical signal outputting device identifies a first preset band optical signal from the second band optical signal by using the preset angle optical fiber grating. In an embodiment of the present application, the preset angle optical fiber grating is specified with a preset reflectivity. When the preset angle optical fiber grating screens out the second band optical signal and the target band optical signal from the first band optical signal, the preset angle optical fiber grating outputs the target band optical signal and identifies the first preset band optical signal from the second band optical signal according to the preset reflectivity. In an embodiment of the present application, the optical signal outputting device obtains the target band optical signal by processing the first preset band optical signal by means of the preset angle. In an embodiment of the present application, the optical signal outputting device triggers the resonance operation by means of the target band optical signal to convert the second band optical signal into the target band optical signal with the resonance operation, and the first preset band optical signal is a part of the second band optical signals. In an embodiment of the present application, the preset angle optical fiber grating returns the target band optical signal obtained after the conversion back to the pump laser and the pump laser receives an optical signal adjusting command, after which the pump laser starts to resonate and convert the second band optical signal into the target band optical signal with the resonance operation. In an embodiment of the present application, the target optical fiber grating comprises a preset period optical fiber grating, and the step of triggering the resonance operation by means of the second band optical signal or the target band optical signal specifically is: In an embodiment of the present application, the second preset band optical signal is identified from the target band optical signal by using the preset period optical fiber grating. In an embodiment of the present application, the preset period optical fiber grating is specified with a preset period reflectivity. When the preset period optical fiber grating screens out the second band optical signal and the target band optical signal from the first band optical signal, the preset period optical fiber grating identifies the second preset band optical signal from the target optical signal according to the preset period reflectivity. It should be noted that the second preset band optical signal is a part of the target band optical signal. In an embodiment of the present application, the resonance operation is triggered with the second preset band optical signal to convert the second band optical signal into the target band optical signal with the resonance operation, and the second preset band optical signal is a part of the target band optical signal. In an embodiment of the present application, the preset period optical fiber grating returns the second preset band optical signal back to the pump laser, and the pump laser receives an optical signal adjusting command, after which the pump laser starts to resonate and convert the second band optical signal into the target band optical signal with the resonance operation. In an embodiment of the present application, when an output end of the preset angle optical fiber grating receives the second optical signal, the preset angle optical fiber grating screens out a third optical signal that does not belong to a preset band scope corresponding to the preset angle optical fiber grating from the second optical signal and transmits the third optical signal to an output end of the first optical fiber grating. In an embodiment of the present application, the second optical signal is an optical signal received by the output end of the preset angle optical fiber grating. In an embodiment of the present application, the target optical signal that belongs to a preset band scope corresponding to the first optical fiber grating is screened out from the third optical signal. In an embodiment of the present application, when the output end of the first optical fiber grating receives the third optical signal, the first optical fiber grating screens out the target optical signal that belongs to the preset band scope corresponding to the first optical fiber grating from the third optical signal and reversely transmits the target optical signal to the pump laser. It should be noted that the third optical signal is an optical signal in the second optical signal that is other than the optical signal belonging to the preset band scope corresponding to the preset angle optical fiber grating. It will be appreciated that the preset angle optical fiber grating or the preset period optical fiber grating screens out the target band optical signal by providing the preset angle optical fiber grating or the preset period optical fiber grating behind the first optical fiber grating while the second band optical signal is also converted into the target band optical signal with the resonance operation of the pump laser, thereby obtaining the high quality target band optical signal and improving the quality of light having the target central wavelength outputted by the pump laser. An embodiment of present application provide a storage medium stored with a computer program. The computer readable storage medium is stored with one or more programs that can be executed by one or more processors and that can be applied to the optical signal outputting device. The computer program achieves the output method for optical signals as described in Embodiment 2. Those skilled in the art will appreciate that embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can be achieved by embodiments such as a hardware, a software or the combination of a software and a hardware. Moreover, the present application can be achieved by a computer program product which is implemented on the computer available storage medium (including but not limited to a disk memory and an optical memory etc.) containing computer available program codes. The present application is described with reference to the flowcharts of the method and/or block diagrams of the device (system) and the computer program product in accordance with embodiments of the present application. It should be understood that each flow and/or block in the flowcharts and/or block diagrams as well as the combination of flows and/or blocks in the flowcharts and/or block diagrams can be achieved by computer program instructions. These computer program instructions can be provided to generic computers, dedicated computers, embedded processors or other programmable data processing equipments to generate a machine, enabling instructions executed by the computer or the processor of other programmable data processing equipment to generate a device that is used to achieve functions designed by one or more flows in the flowchart and/or one or more blocks in the block diagram. These computer program instructions can also be stored in a computer readable memory capable of booting a computer or other programmable data processing equipment to operate in a particular manner to allow the generation of manufactures including an instruction device by instructions stored in this computer readable memory, wherein the instruction device achieves the functions designed by one or more flows in the flowchart and/or one or more blocks in the block diagram. These computer program instructions can also be loaded on a computer or other programmable data processing equipment such that a series of steps can be executed on a computer or other programmable equipment to achieve the processing results like the computer, enabling instructions executed on a computer or other programmable equipment to provide steps capable of achieving functions designed by one or more flows in the flowchart and/or one or more blocks in the block diagram. The above mentioned embodiments are merely preferred embodiments of the present disclosure and do not mean to define the protection scope of the present disclosure. INDUSTRIAL APPLICABILITY By providing the preset angle optical fiber grating or the preset period optical fiber grating behind the first optical fiber grating, the preset angle optical fiber grating or the preset period optical fiber grating screens out the target band optical signal, and at the same time, the second band optical signal is also converted into the target band optical signal by means of the resonance operation of the pump laser, thereby obtaining the high quality target band optical signal and improving the quality of light having the target central wavelength outputted by the pump laser. | 35,156 |
11942997 | DESCRIPTION OF THE EMBODIMENTS Consistent with the present disclosure, a local oscillator is provided in a receiver. The local oscillator laser includes first and second mirrors and a phase section, and heaters are provided adjacent each portion of the laser, such that the temperature and thus the frequency of light output from the local oscillator laser may be tuned. Applying electrical power, such as a current or voltage to the phase section may result in rapid frequency tuning of light output from the local oscillator laser but over a limited frequency range. Temperature changes to the mirror sections, however, may afford frequency tuning over a wider range, but frequency tuning the mirror sections requires more time than that required to tune the phase section. Consistent with the present disclosure, a tuning method and apparatus is provided that optimizes laser tuning by selectively tuning the phase and mirror sections for rapid tuning across the C band (1530 nm-1565 nm), for example. Reference will now be made in detail to the present embodiment(s) (exemplary embodiments) of the present disclosure, an example(s) of which is (are) illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Before describing frequency tuning consistent with the present disclosure, an example optical network and node structure in which such frequency tuning may be employed will next be described with reference toFIGS.1-7. FIG.1illustrates an example of an aggregation network100consistent with the present disclosure in which primary node110may communicate with multiple secondary nodes112-jto112-m, which sometimes may be referred to individually or collectively as secondary node(s)112. Secondary nodes112, in one example, are remote from primary node110. Primary node110may transmit optical subcarriers, described in greater detail below, in a downstream direction onto an optical communication path111, which, like each of optical communication paths113-jto113-m, may include one or more segments of optical fiber, as well as one or more optical amplifiers, reconfigurable add-drop multiplexers (ROADMs) or other optical fiber communication equipment. Splitter114may be coupled to an end of optical communication path111to receive the optical subcarriers and provide a power split portion of each subcarrier to a corresponding one of secondary nodes112-jto112-mvia a respective one of optical communication paths113-jto113-m. As further shown inFIG.1, primary node110has a data capacity to receive n Gbit/s of data (e.g., a data stream) for transmission to secondary node112. Each secondary node112may receive and output to a user or customer a portion of the data input to primary node110. In this example, secondary nodes112-j,112-k,112-l, and112-moutput j Gbit/s, k Gbit/s, I Gbit/s, and m Gbit/s of data (data streams), respectively, whereby the sum of the j, k, l, and m may equal n (where j, k, l, m, and n are positive numbers). FIG.2illustrates primary node110in greater detail. Primary node110may include a transmitter202that supplies a downstream modulated optical signal including subcarriers, and a receiver that204that may receive upstream subcarriers carrying data originating from the secondary nodes, such as nodes112-jto112-m. FIG.2further shows a block diagram of one of secondary nodes112, which may include a receiver circuit302that receives one or more downstream transmitted subcarriers, and a transmitter circuit304that transmits one or more subcarriers in the upstream direction. The receiver circuits204and302may include local oscillator lasers that may be tuned as described in greater detail below. FIG.3illustrates an example a power spectral density plot300consistent with an aspect of the present disclose. Power spectral density plot300shows, in this example, 16 optical subcarriers (SC0-SC15), which may be included in a modulated optical signal output from primary node110. Each of subcarriers SC0to SC15has a corresponding one of frequencies f0to f15. Subcarriers SC0to SC15, in one example, are Nyquist subcarriers, which are a group of optical signals, each carrying data, wherein (i) the spectrum of each such optical signal within the group is sufficiently non-overlapping such that the optical signals remain distinguishable from each other in the frequency domain, and (ii) such group of optical signals is generated by modulation of light from a single laser. In general, each subcarrier may have an optical spectral bandwidth that is at least equal to the Nyquist frequency, as determined by the baud rate of such subcarrier. In another example, an individual subcarrier may be generated by modulating an optical signal supplied from a laser, and multiple subcarriers generated in this manner, in a respective leaf node, for example, may be combined and provided to a hub or primary node. In one example, the bandwidth is a range of frequencies for which data carried by optical signals having frequencies within such range may be detected by the secondary nodes112. As further shown inFIG.3, each of secondary nodes112-jto112-mmay have a respective one of bandwidths BWj to BWm, such that each secondary node has a data processing capacity or is capable of processing and outputting data carried by up to four subcarriers, in this example. Namely, in the example shown inFIG.3, bandwidth BWj associated with secondary node112-jextends over or encompasses a range including frequencies f0to f3of subcarriers SC0to SC3, respectively; bandwidth BWk associated with secondary node112-kextends over or encompasses a range including frequencies f4to f7of subcarriers SC4to SC7, respectively; bandwidth BWI associated with secondary node112-lextends over or encompasses a range including frequencies f8to f11of subcarriers SC8to SC11, respectively; and bandwidth BWm associated with secondary node112-mextends over or encompasses a range including frequencies f12to f15of subcarriers SC12to SC15, respectively. On the other hand, the bandwidth of primary node110, may encompasses the entire range of frequencies f0-f15of subcarriers SC0to SC15. Thus, as further shown inFIG.3, optical subcarriers SC0to SC3are associated with and carry data intended for secondary node112-j. Moreover, bandwidth BW is sufficient to encompass SC0to SC3, such that local oscillator light fLOj having a frequency in the middle of or within bandwidth BWj (as shown inFIG.4a) is sufficient for a receiver in secondary node112-jto detect data carried by optical subcarriers SC0to SC3. Similarly, optical subcarriers SC4to SC7are associated with and carry data intended for secondary node112-k. Also, bandwidth BWk is sufficient to encompass SC4to SC7, such that local oscillator light fLOk having a frequency in the middle of or within bandwidth BWk (as shown inFIG.4a) is sufficient for a receiver in secondary node112-kto detect data carried by optical subcarriers SC4to SC7. In addition, optical subcarriers SC8to SC11are associated with and carry data intended for secondary node112-l. Further, bandwidth BWI is sufficient to encompass SC8to SC11, such that local oscillator light fLOl having a frequency in the middle of or within bandwidth BWI (as shown inFIG.4a) is sufficient for a receiver in secondary node112-lto detect data carried by optical subcarriers SC8to SC11. Moreover, optical subcarriers SC12to SC15are associated with and carry data intended for secondary node112-m. Also, bandwidth BWm is sufficient to encompass SC12to SC15, such that local oscillator light fLOm having a frequency in the middle of or within bandwidth BWm (as shown inFIG.4a) is sufficient for a receiver in secondary node112-mto detect data carried by optical subcarriers SC12to SC15. When a secondary node112is newly added to a network, however, the secondary node local oscillator laser frequency should be set to an appropriate value, as noted above. Thus, a separate signal, referred to herein as a beacon optical signal is output from the primary node110. The beacon signal may be amplitude (AM) modulated to carry information that is provided to the newly added secondary node112, such that, based on such information, the secondary node may adjust its local oscillator laser for detecting data carried by particular optical subcarriers associated with that secondary node. However, the newly added secondary node112should detect the beacon signal at the outset and thus the local oscillator laser in the newly added secondary node should be tuned to quickly detect the beacon signal. Such tuning is described in greater detail below. In the example shown inFIG.3, the beacon signal is shows as SCB having a frequency f16. FIG.4aillustrates transmitter202of primary node110in greater detail. Transmitter202includes a transmitter DSP (TX DSP)902and a D/A and optics block901. DSP902receives, in this example data inputs D-0to D-15, and based on such inputs, DSP902supplies a plurality of digital outputs to D/A and optics block901including digital-to-analog conversion (DAC) circuits904-1to904-4, which convert digital signal received from DSP902into corresponding analog signals. D/A and optics block901also includes driver circuits906-1to906-2that receive the analog signals from DACs904-1to904-4and adjust the voltages or other characteristics thereof to provide drive signals to a corresponding one of modulators910-1to910-4. D/A and optics block901further includes modulators910-1to910-4, each of which may be, for example, a Mach-Zehnder modulator (MZM) that modulates the phase and/or amplitude of the light output from laser908. As further shown inFIG.4a, light output from laser908, also included in block901, is split such that a first portion of the light is supplied to a first MZM pairing, including MZMs910-1and910-2, and a second portion of the light is supplied to a second MZM pairing, including MZMs910-3and910-4. The first portion of the light is split further into third and fourth portions, such that the third portion is modulated by MZM910-1to provide an in-phase (I) component of an X (or TE) polarization component of a modulated optical signal, and the fourth portion is modulated by MZM910-2and fed to phase shifter912-1to shift the phase of such light by 90 degrees in order to provide a quadrature (Q) component of the X polarization component of the modulated optical signal. Similarly, the second portion of the light is further split into fifth and sixth portions, such that the fifth portion is modulated by MZM910-3to provide an I component of a Y (or TM) polarization component of the modulated optical signal, and the sixth portion is modulated by MZM910-4and fed to phase shifter912-2to shift the phase of such light by 90 degrees to provide a Q component of the Y polarization component of the modulated optical signal. The optical outputs of MZMs910-1and910-2are combined to provide an X polarized optical signal including I and Q components and are fed to a polarization beam combiner (PBC)914provided in block901. In addition, the outputs of MZMs910-3and910-4are combined to provide an optical signal that is fed to polarization rotator913, further provided in block901, that rotates the polarization of such optical signal to provide a modulated optical signal having a Y (or TM) polarization. The Y polarized modulated optical signal also is provided to PBC914, which combines the X and Y polarized modulated optical signals to provide a polarization multiplexed (“dual-pol”) modulated optical signal onto optical fiber916, for example, which may be included as a segment of optical fiber in optical communication path111. The polarization multiplexed optical signal output from D/A and optics block401includes subcarriers SC0-SC15and beacon signal SCB noted above, such that each subcarrier has X and Y polarization components and I and Q components. Moreover, each subcarrier SC0to SC15may be associated with or corresponds to a respective one of input D-0to D-15. WhileFIG.4ashows the primary node transmitter as including a particular number and arrangement of components, in some implementations, the primary node transmitter may include additional components, fewer components, different components, or differently arranged components. As noted above, optical subcarriers SC0to SC15may be provided to secondary nodes112inFIG.1. An example of receiver circuit302in one of secondary nodes112will be described next with reference toFIG.5. It is understood that each of the second node receivers may have a structure similar to that described in connection withFIG.5and may operate in a similar manner as the receiver shown inFIG.5. As shown inFIG.5, optical receiver302may include an Rx optics and ND block1100, which, in conjunction with DSP1150, may carry out coherent detection. Block1100may include a polarization splitter (PBS)1105with first (1105-1) and second (1105-2) outputs), a local oscillator (LO) laser1110, 90 degree optical hybrids or mixers1120-1and1120-2(referred to generally as hybrid mixers1120and individually as hybrid mixer1120), detectors1130-1and1130-2(referred to generally as detectors1130and individually as detector1130, each including either a single photodiode or balanced photodiode), AC coupling capacitors1132-1and1132-2, transimpedance amplifiers/automatic gain control circuits TIA/AGC1134-1and1134-2, ADCs1140-1and1140-2(referred to generally as ADCs1140and individually as ADC1140). In one example, the local oscillator laser1110include a distributed feedback laser (DFB). Polarization beam splitter (PBS)1105may include a polarization splitter that receives an input polarization multiplexed optical signal including optical subcarriers SC0to SC19supplied by optical fiber link1101, which may be, for example, an optical fiber segment as part of one of optical communication paths113-kto113-mnoted above. PBS1105may split the incoming optical signal into the two X and Y orthogonal polarization components. The Y component may be supplied to a polarization rotator1106that rotates the polarization of the Y component to have the X polarization. Hybrid mixers1120may combine the X and rotated Y polarization components with light from local oscillator laser1110, which, in one example, is a tunable laser. For example, hybrid mixer1120-1may combine a first polarization signal (e.g., the component of the incoming optical signal having a first or X (TE) polarization output from a first PBS port with light from local oscillator1110, and hybrid mixer1120-2may combine the rotated polarization signal (e.g., the component of the incoming optical signal having a second or Y (TM) polarization output from a second PBS port) with the light from local oscillator1110. In one example, polarization rotator1190may be provided at the PBS output to rotate Y component polarization to have the X polarization. Detectors1130may detect mixing products output from the optical hybrids, to form corresponding voltage signals, which are subject to AC coupling by capacitors1132-1and1132-1, as well as amplification and gain control by TIA/AGCs1134-1and1134-2. The outputs of TIA/AGCs1134-1and1134-2and ADCs1140may convert the voltage signals to digital samples. For example, two detectors (e.g., photodiodes)1130-1may detect the X polarization signals to form the corresponding voltage signals, and a corresponding two ADCs1140-1may convert the voltage signals to digital samples for the first polarization signals after amplification, gain control and AC coupling. Similarly, two detectors1130-2may detect the rotated Y polarization signals to form the corresponding voltage signals, and a corresponding two ADCs1140-2may convert the voltage signals to digital samples for the second polarization signals after amplification, gain control and AC coupling. RX DSP1150may process the digital samples associated with the X and Y polarization components to output data associated with one or more subcarriers within a group of subcarriers SC0to SC15encompassed by the bandwidth (one of bandwidths BW, BWk, BWI, and BWm) associated with the secondary node housing the particular DSP1150. The beacon signal SCB, as noted above, carries information for tuning local oscillator laser1110to detect data intended for a particular secondary node112and carried by a group of optical subcarriers associated with that secondary node. As further noted above, local oscillator laser1110may be rapidly tuned upon installation in order for the secondary node receive to quickly detect beacon signal SCB. WhileFIG.5shows optical receiver302as including a particular number and arrangement of components, in some implementations, optical receiver302may include additional components, fewer components, different components, or differently arranged components. The number of detectors1130and/or ADCs1140may be selected to implement an optical receiver302that is capable of receiving a polarization multiplexed signal. In some instances, one of the components illustrated inFIG.5may carry out a function described herein as being carry out by another one of the components illustrated inFIG.5. FIG.6shows local oscillator laser1110in greater detail. Local oscillator laser1110may include a waveguide WG, which further includes mirrors or mirror sections M1and M2, each of which including gratings G1and G2, respectively. Heaters H1and H2are provided adjacent gratings G1and G2, respectively, and heater H3is provided adjacent phase section P. Heaters H1, H2, and H3, in one example, may each include a respective thin film heater including platinum or other suitable material. Control circuit610is operable to provide electrical power, by way of, for example, a voltage or current supplied to each of heaters H1to H3, such that the temperature of the heaters may be adjusted based on the electrical power supplied thereto. Accordingly, control circuit610is thus further operable to control the temperature of the gratings G1and G2, as well as phase section P. By changing the temperature of gratings G1and G2, the spacing between such gratings may change, such that the wavelength or frequency of light output from laser1110also changes. Moreover, the refractive index of phase section P may also change as a function of temperature such that wavelength or frequency of light output from laser1110may be further controlled or adjusted by power supplied to heater H3. As further shown inFIG.6, light output from laser1110may be provided to splitter1105-3shown inFIG.5. As noted above and consistent with the present disclosure, power is selectively applied to heaters H1, H2, and H3in an optimal manner to facilitate rapid tuning of the local oscillator light. Such rapid tuning will next be described with reference toFIGS.7-9. FIG.7illustrates a plot700of heater power H1and corresponding heater powers H2. As shown inFIG.7, for a given heater power H1-1applied to heater H1, for example, heater powers H2-1to H2-4may be applied to heater H2. An “island” may be assigned for each combination of H1and H2heater powers. Thus, for example, heater power combination H1-1and H2-1is associated with island4I-4, heater power combination H1-1and H2-2is associated with island4I-3, heater power combination H1-1and H2-3is associated with island2I-4, and heater power combination H1-1and H2-4is associated with island1I-4. Each of remaining islands1I-1to1I-3,2I-1to2I-3,3I-1to3I-3, and4I-1to4I-3is similar associated with a heater a unique heater power combination. As further shown inFIG.7, incremental linear increases in powers applied to heaters H1and H2from one island to the next result in combinations of islands that constitute a “lane.” Thus, for example, islands1I-1to1I-4constitute lane L1, islands2I-1to2I-4constitute lane L2, islands3I-1to3I-4constitute lane L3, and islands4I-1to4I-4constitute lane L4. Tuning between lanes, tuning between islands within a given lane, and tuning within an island by applying power to phase section P may required different amounts of time or may be associated with different local oscillator frequency slew rates. For example, any change from the end of one lane to the beginning of another by way of applying power to heaters H1and H2may require 400 ms to 500 ms for the resulting local oscillator frequency to be stable within ±5 GHz. Thus, changing from a first lane to a third lane would require 500 ms, which is large amount of time. Changing from one island to another within a lane or to an adjacent island the next lane over by way of applying power to heaters H1and H2may require 40 ms per island transition for frequency stabilization. Thus, transitioning from island2I-1to2I-3by applying power to heaters H1and H2may require 3×40 ms or 120 ms for the local oscillator frequency to stabilize. However, tuning within an island by way of not changing the power to heaters H1and H2but applying power to phase section P may require 2 ms for the local oscillator laser to stabilize. Shorter stabilization times are desirable in order for the local oscillator laser to be used to detect the beacon signal and recover the data associated therewith. Thus, tuning by way of applying power to heater H3associated with phase section P, has the advantage of having such reduced stabilization times. However, tuning with the phase section heater is typically limited to narrow tuning ranges. FIG.4billustrates a further example of a beacon signal consistent with the present disclosure. Here, subcarriers SC0to SC15are collectively amplitude modulated (AM) with a low frequency signal carrying information for controlling the receiver and/or transmitter in the leaf node and thus corresponds to the beacon in this example. The AM modulation is represented double-head arrows487-2. The AM modulation may be, for example, at a frequency of 1-3 MHz, while the user data carried by each optical subcarrier SC0to SC15may be at a rate of 50 GHz or higher rate, such as 80 GHz or 100 GHz. In one example, such information includes information for controlling the local oscillator in the leaf node to tune to a frequency for detecting data associated with one or more optical subcarriers carrying data designated for that leaf node. As noted above, the leaf node has a local oscillator laser that supplies light having a frequency of fLO (here fLOj associated with leaf node112-j). Receiver circuitry in node112-jis operable to detect, by way of coherent detection, optical signals and/or subcarriers having frequencies within bandwidth BWj. As fLOj is tuned, as indicated by arrow487, bandwidth or capture frequency range BWj also shifts in frequency. After tuning fLOj so that one of optical subcarriers SC0to SC15, e.g., subcarrier SC0, falls within capture frequency range BW, the AM modulation may be detected by way of coherent detection in the leaf node receiver, and the information carried by the AM modulation may be used to further tune fLOj for detecting data carried by subcarrier associated with, in this example, secondary node or leaf node112-j. Accordingly, consistent with the present disclosure, when tuning local oscillator laser transitions between islands and within islands, (whereby the power levels applied to heaters H1and H2in addition to adjusting the phase section P) are maximized, while transitions between lanes are minimized. FIG.8shows an alternate representations of the lanes and islands shown inFIG.7. Here, lane I1is associated with a range of frequencies defined by a lowest frequency, f1, and a highest or maximum frequency, f4, and includes frequency sub-ranges S1-1to S1-4associated with islands1I-1to1I-4, respectively. As further shown inFIG.8, lane L2is associated with a range of frequencies extending from frequency f2to f5′ and includes frequency sub-ranges S2-1to S2-4corresponding to islands2I-1to2I-4, respectively. In addition, lane L3is associated with a range of frequencies extending from frequency f5to f7and includes frequency sub-ranges S3-1to S3-4corresponding to islands3I-1to3I-4, respectively. A frequency tuning method consistent with the present disclosure will next be described with further reference toFIG.8and flow chart900shown inFIG.9. It is noted that the powers supplied to heaters H1to H3for implementing the disclosed method may be supplied by control circuit610shown inFIG.6. In step920, a first range of frequencies is selected (e.g., lane L1) by control circuit610, and in step922a first subrange (e.g., island1I-1, subrange S1-1) of frequencies is selected by control circuit610in the first range of frequencies (lane L1). Next, in step924, a first power supplied to the third heater (heater H3) to thereby adjust a frequency of the local oscillator laser from a first frequency (f1) to a second frequency (f2) in a first plurality of successive frequency increments (such as 50 GHz increments, arrows A1and A2), the first (f1) and second (f2) frequencies being within the first subrange of frequencies (S1-1). Step924is typically repeated as many times as possible to detect the beacon signal until the wavelength limit of the current island is reached. As noted above, transitions or turning within an island require less time than transitions between island or between lanes. Accordingly, consistent with the present disclosure, faster tuning is achieved by maximizing tuning with islands while minimizing tuning between islands and lanes. In step926, a second power supplied to the first heater and a third power supplied to the second heater are changed (switch to island1I-4in the first lane] to thereby adjust the frequency of the local oscillator laser1110from the second frequency (f2) to a third frequency (f3) (arrows A3). In addition, the phase section heater H3may be reset to a lower level when tuning to a new island. Next, in step928, the first power is changed to thereby adjust the frequency (tuning within island1I-4in lane L1) of the local oscillator laser1110from the third frequency (f3) to a fourth frequency (f4) in a second plurality of successive frequency increments (arrows A4and A5), the third and fourth frequencies being within a second subrange (S1-4) of frequencies that is in the first range of frequencies (lane L1). In step930, a second range of frequencies (lane L3) is selected by control circuit610, and, in step932, the second power and the third power are changed to thereby adjust the frequency of the local oscillator laser from the fourth frequency (f4) to a fifth (f5) frequency (arrow A6). Further, in step934, the first power (heater H3) is changed to thereby adjust the frequency of the local oscillator laser from the fifth frequency (f5) to a sixth frequency (f6) in a third plurality of successive frequency increments (of 50 GHz, for example, see arrows A7and A8), the fifth (f5) and sixth (f6) frequencies being within a third subrange (S3-1) of frequencies that is within the second range of frequencies (lane L2), wherein the coherent receiver is operable to detect data carried by a received optical signal when the local oscillator laser1110has the sixth frequency (f6being the frequency of the beacon signal). It is noted that, in each transition to a new frequency, e.g., from f1to f2, a determination is made as to whether the beacon signal SCB has been detected. If it has, no further tuning to search for the beacon signal is performed. In the above example, the beacon signal frequency is f6, such that local oscillator frequency is set to the frequency of the beacon signal. It is also noted that a similar determination as to whether the beacon signal is detected is made after each frequency increment, e.g., after changing the frequency by an increment of 50 GHz from frequency f1to frequency f1′ (see arrow A1). Arrow A2represents a similar frequency increment, which may also be 50 GHz. It is noted that, in the above example, the transition from frequency f4to frequency f5skips lane L2(having a lowest frequency f3and a highest frequency f5′) and sub-ranges S2-1to S2-4, thereby reducing the tuning time by not tuning in those subranges. Moreover, most transitions occur within islands or subranges, e.g., S1-1, S1-4, and S3-1, thereby minimizing transitions between lanes, e.g., only one such transition, i.e., between lane L1and L3occurs in the above example. Consistent with a first aspect of the present disclosure, rather than sweep each lane in the same direction, alternating lane direction may be carried out whereby when a frequency sweep reaches the end of a lane, a transition is made to the closes island on the next lane, and the next lane is frequency swept in the opposite direction. Such alternate sweeping minimizes sweep time by avoiding large thermal transients when switching to a new lane. FIG.10aillustrates an example of such alternate sweeping. Here, a first tuning range (e.g., lane L1) is selected by control circuit610. L1, in this example, is defined by a lowest frequency associated with island1I-1and a highest frequency associated with island1I-4. Next, the frequency of the light output from output from local oscillator laser1110is increased (Sweep1) from a first frequency within the first tuning range (lane L1) to a second frequency within the first tuning range by changing, under control by control circuit610, a first power supplied to the first heater (H1) and changing a second power supplied to the second heater (H2). Next, a second tuning range, such as lane L2is selected by control circuit610. The second tuning range, lane L2, has a lowest second frequency associated with island2L-1and a highest second frequency associated with island2I-4. Next, based on outputs of control circuit610, the frequency of the light output from the local oscillator laser1110is decreased (Sweep2) from a third frequency within the second tuning range to a fourth frequency within the second tuning range by changing the first power and the second power supplied to heaters H1and H2, respectively. Next, the frequency of the light output from the local oscillator laser1110is adjusted from the fourth frequency to a fifth frequency by changing a third power supplied to the third heater (by using the phase section heater H3to rapidly fine tune the LO frequency). If the beacon signal is not detected during Sweep1or Sweep2, further frequency sweeps Sweep3and Sweep4may be carried out until to detect the beacon. FIG.10bis a plot of heater H1(Pa), heater H2(Pb), and heater H3(Pp) powers and associated leaf local oscillator frequencies (Freq). Here, the Transitions shown in the plot correspond to a transition from the top of a lane to the bottom of an adjacent lane or vis a versa (seeFIG.10a). Such transitions may result in significant changes in power between adjacent LO frequencies during the scan or tuning over the C band. Such power changes are minimized or reduced if the tuning is carried per the example shown inFIG.10a. FIG.10cis similar to the plot shown inFIG.10b, but tuning is carried out by alternating between lanes such that the local oscillator laser is tuned in one direction to the bottom of a first lane and then tuned in the opposite direction to the top of an adjacent lane as discussed above in connection withFIG.10a. Such tuning or sweeping avoids large thermal changes of the local oscillator laser so delays are minimized. Other embodiments will be apparent to those skilled in the art from consideration of the specification. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. | 31,650 |
11942998 | DESCRIPTION OF EMBODIMENTS Problems to be Solved by the Present Disclosure When a negative offset voltage provided to a reference voltage is large, outputs in a positive phase and a negative phase of an integrator may be inverted, thereby causing increase in potential difference. In such a case, transient response to a burst may be delayed, resulting in a failure of normal reception of the optical signal. In consideration of this problem, an object of the present disclosure is to suppress inversion of an output of an integrator in an optical reception device that receives an optical signal in a burst state. Effects of the Present Disclosure According to the present disclosure, inversion of an output of an integrator in an optical reception device that receives an optical signal in a burst state can be suppressed. Description of Embodiment of the Present Disclosure An embodiment of the present disclosure includes at least the following as a gist. (1) Disclosed as an optical reception device is an optical reception device configured to receive an optical signal in a burst state. The optical reception device includes: a light receiving element configured to receive the optical signal; an amplifier configured to receive and amplify a current based on an input current from the light receiving element; a direct-current adjustment circuit connected to an input electric path extending from the light receiving element to the amplifier, the direct-current adjustment circuit being configured to remove an offset current included in the input current; an alternating-current adjustment circuit connected to the input electric path and configured to cause a part of the input current to flow therein; and a controller configured to control the direct-current adjustment circuit and the alternating-current adjustment circuit on the basis of an output of the amplifier and a reference voltage. The controller includes: an integrator configured to integrate the output of the amplifier and output a resultant output to two electric paths of a positive phase and a negative phase; and an inversion suppression circuit configured to operate so as to inject a current to the positive phase and extract a current from the negative phase when a negative phase potential of the output of the integrator is higher than a positive phase potential thereof. In this optical reception device, when the output of the integrator is inverted and a state where the negative phase potential is higher than the positive phase potential is established, the inversion suppression circuit can operate so as to inject a current to the positive phase and extract a current from the negative phase. Accordingly, inversion of the output of the integrator is suppressed. Therefore, even when a sufficient negative offset voltage is provided, the potential difference in the output of the integrator can be suppressed from being inverted and increased. Thus, inversion of the output of the integrator in an optical reception device that receives an optical signal in a burst state can be suppressed. (2) Preferably, in the optical reception device of (1) above, the current injected by the inversion suppression circuit and the current extracted by the inversion suppression circuit are equivalent to each other. In this case, since the current that is injected and the current that is extracted are equivalent to each other, the common potential of the output of the integrator is not varied. (3) In the optical reception device of (1) or (2) above, the inversion suppression circuit may include: an operational transconductance amplifier configured to convert, into a current, a voltage outputted by the integrator and based on a potential difference between the positive phase and the negative phase, the operational transconductance amplifier being configured to output the current; and a current mirror circuit configured to generate a current to be injected to the positive phase and a current to be extracted from the negative phase, on the basis of an output of the operational transconductance amplifier. In this case, when the positive phase potential of the output of the integrator is higher than the negative phase potential thereof, the inversion suppression circuit neither applies a current nor extracts a current. Upon occurrence of a state where the negative phase potential of the output of the integrator is higher than the positive phase potential thereof, i.e., upon occurrence of inversion of the potentials, currents that suppress the inversion can be immediately generated by the current mirror circuit. (4) In the optical reception device of any one of (1) to (3) above, a negative offset voltage is added to the reference voltage, for example. In a case where there is a difference in the strength of an optical signal in a burst state, and, for example, the strength is relatively weak, if a negative offset voltage is not provided to the reference voltage, increase of noise may be caused by the direct-current adjustment circuit extracting a current in a condition where a positive offset voltage increases even in a small degree. Therefore, reducing the negative offset voltage is not a good measure, and a sufficient negative offset voltage is preferably provided. (5) In the optical reception device of any one of (1) to (4) above, when, for example, the positive phase potential is higher than the negative phase potential, the inversion suppression circuit does not perform an operation of injecting a current to the positive phase and extracting a current from the negative phase. When the positive phase potential is higher than the negative phase potential, the inversion suppression circuit does not perform wasteful operations. (6) As an optical line terminal, an optical line terminal connected to a plurality of optical network units via an optical transmission line formed by an optical fiber is provided. The optical line terminal includes: a light receiving element configured to receive an optical signal in a burst state from each optical network unit; an amplifier configured to receive and amplify a current based on an input current from the light receiving element; a direct-current adjustment circuit connected to an input electric path extending from the light receiving element to the amplifier, the direct-current adjustment circuit being configured to remove an offset current included in the input current; an alternating-current adjustment circuit connected to the input electric path and configured to cause a part of the input current to flow therein; and a controller configured to control the direct-current adjustment circuit and the alternating-current adjustment circuit on the basis of an output of the amplifier and a reference voltage. The controller includes: an integrator configured to integrate the output of the amplifier and output a resultant output to two electric paths of a positive phase and a negative phase; and an inversion suppression circuit configured to operate so as to inject a current to the positive phase and extract a current from the negative phase when a negative phase potential of the output of the integrator is higher than a positive phase potential thereof. In this optical line terminal, when the output of the integrator is inverted and a state where the negative phase potential is higher than the positive phase potential is established, the inversion suppression circuit can operate so as to inject a current to the positive phase and extract a current from the negative phase. Accordingly, inversion of the output of the integrator is suppressed. Therefore, even when a sufficient negative offset voltage is provided, the potential difference in the output of the integrator can be suppressed from being inverted and increased. Thus, inversion of the output of the integrator in an optical line terminal that receives an optical signal in a burst state can be suppressed. (7) As a PON system, provided is a PON system including: a plurality of optical network units; an optical transmission line formed by an optical fiber; and an optical line terminal configured to communicate with the plurality of optical network units via the optical transmission line. An optical reception device installed at least to the optical line terminal among the optical network units and the optical line terminal includes: a light receiving element configured to receive an optical signal in a burst state from each optical network unit; an amplifier configured to receive and amplify a current based on an input current from the light receiving element; a direct-current adjustment circuit connected to an input electric path extending from the light receiving element to the amplifier, the direct-current adjustment circuit being configured to remove an offset current included in the input current; an alternating-current adjustment circuit connected to the input electric path and configured to cause a part of the input current to flow therein; and a controller configured to control the direct-current adjustment circuit and the alternating-current adjustment circuit on the basis of an output of the amplifier and a reference voltage. The controller includes: an integrator configured to integrate the output of the amplifier and output a resultant output to two electric paths of a positive phase and a negative phase; and an inversion suppression circuit configured to operate so as to inject a current to the positive phase and extract a current from the negative phase when a negative phase potential of the output of the integrator is higher than a positive phase potential thereof. In this PON system, in an optical reception device in an optical line terminal, when the output of the integrator is inverted and a state where the negative phase potential is higher than the positive phase potential is established, the inversion suppression circuit can operate so as to inject a current to the positive phase and extract a current from the negative phase. Accordingly, inversion of the output of the integrator is suppressed. Therefore, even when a sufficient negative offset voltage is provided, the potential difference in the output of the integrator can be suppressed from being inverted and increased. Thus, inversion of the output of the integrator in an optical reception device that receives an optical signal in a burst state can be suppressed. (8) As a preamplifier, provided is a preamplifier including: an amplifier configured to receive and amplify a current based on an input current from a light receiving element configured to receive an optical signal in a burst state; a direct-current adjustment circuit connected to an input electric path extending from the light receiving element to the amplifier, the direct-current adjustment circuit being configured to remove an offset current included in the input current; an alternating-current adjustment circuit connected to the input electric path and configured to cause a part of the input current to flow therein; and a controller configured to control the direct-current adjustment circuit and the alternating-current adjustment circuit on the basis of an output of the amplifier and a reference voltage. The controller includes: an integrator configured to integrate the output of the amplifier and output a resultant output to two electric paths of a positive phase and a negative phase; and an inversion suppression circuit configured to operate so as to inject a current to the positive phase and extract a current from the negative phase when a negative phase potential of the output of the integrator is higher than a positive phase potential thereof. In this preamplifier, when the output of the integrator is inverted and a state where the negative phase potential is higher than the positive phase potential is established, the inversion suppression circuit can operate so as to inject a current to the positive phase and extract a current from the negative phase. Accordingly, inversion of the output of the integrator is suppressed. Therefore, even when a sufficient negative offset voltage is provided, the potential difference in the output of the integrator can be suppressed from being inverted and increased. Thus, inversion of the output of the integrator when an optical signal in a burst state is received can be suppressed. (9) As an optical reception method, an optical reception method for receiving an optical signal in a burst state is provided. The optical reception method includes, in a stage of preamplification: receiving and amplifying, by an amplifier, a current based on an input current from a light receiving element configured to receive the optical signal; removing an offset current included in the input current and releasing a part of the input current, on the basis of an output of the amplifier and a reference voltage; and integrating, by an integrator, the output of the amplifier and outputting a resultant output to two electric paths of a positive phase and a negative phase, and when a negative phase potential of the output to the two electric paths is higher than a positive phase potential thereof, injecting a current to the positive phase and extracting a current from the negative phase. According to this optical reception method, when the output of the integrator is inverted and a state where the negative phase potential is higher than the positive phase potential is established, it is possible to inject a current to the positive phase and extract a current from the negative phase. Accordingly, inversion of the output of the integrator is suppressed. Therefore, even when a sufficient negative offset voltage is provided, the potential difference in the output of the integrator can be suppressed from being inverted and increased. Thus, inversion of the output of the integrator when an optical signal in a burst state is received can be suppressed. (10) As a method for suppressing inversion of an output of an integrator, a method for suppressing inversion of an output of an integrator in a preamplifier for optical reception is provided. The method includes: receiving and amplifying a current based on an input current from a light receiving element configured to receive an optical signal in a burst state; removing an offset current included in the input current and releasing a part of the input current, on the basis of an output obtained through amplification and a reference voltage; and integrating, by the integrator, the output and outputting a resultant output to two electric paths of a positive phase and a negative phase, and when a negative phase potential of the output to the two electric paths is higher than a positive phase potential thereof, injecting a current to the positive phase and extracting a current from the negative phase. According to this method for suppressing inversion of the output, when the output of the integrator is inverted and a state where the negative phase potential is higher than the positive phase potential is established, it is possible to inject a current to the positive phase and extract a current from the negative phase. Accordingly, inversion of the output of the integrator is suppressed. Therefore, even when a sufficient negative offset voltage is provided, the potential difference in the output of the integrator can be suppressed from being inverted and increased. Thus, inversion of the output of the integrator when an optical signal in a burst state is received can be suppressed. Details of Embodiment of the Present Disclosure Hereinafter, a specific example of the present disclosure will be described with reference to the drawings. PON System FIG.1is a connection diagram of a PON system100according to an embodiment. InFIG.1, an optical line terminal (OLT)1is installed as an aggregation station for a plurality of optical network units (ONU)2,3,4connected in a P2MP (Point to Multipoint) relationship. The optical network units2,3,4are each installed in a house of a subscriber of the PON system100. In this system, an optical fiber network in which a single optical fiber (trunk line)5connected to the optical line terminal1is branched via an optical coupler6into a plurality of optical fibers (branch lines)7,8,9is formed. The number of optical network units is merely an example for facilitating drawing, and is much greater in actuality. Between the optical line terminal1and each optical network unit2,3,4, uplink communication from the optical network unit2,3,4to the optical line terminal1, and downlink communication from the optical line terminal1to each optical network unit2,3,4are possible. The distances from the optical coupler6to the respective optical network units2,3,4are not uniform, and there are differences in the distance. Therefore, there are differences in the strengths of optical signals that reach the optical line terminal1from the optical network units2,3,4. A line card1aincluding an optical reception device is installed in the optical line terminal1. Optical Reception Device FIG.2shows an example of a circuit configuration of an optical reception device10, and is a diagram particularly focused on the part of a preamplifier11. The optical reception device10is a device that receives an optical signal in a burst state (hereinafter, simply referred to as a “burst”) sent from the optical network unit2,3,4. The optical reception device10includes: an avalanche photodiode12as a light receiving element; an amplifier13; a direct-current adjustment circuit14; an alternating-current adjustment circuit15; a controller16; a differential circuit17; a detection circuit18; and a reference potential generation circuit19. The output (Vout, Voutb) of the preamplifier11is sent, via an AC coupling by a capacitor20, to a subsequent stage circuit21. The avalanche photodiode12having a voltage VPD applied to a cathode thereof converts an optical signal into a current. The amplifier13receives and amplifies the current based on an input current from the avalanche photodiode12, and outputs a voltage Va. The direct-current adjustment circuit14connected to an input electric path L extending from the avalanche photodiode12to the amplifier13includes current mirror circuits of MOSFETs (Metal-Oxide-Semiconductor-Field-Effect-Transistor, hereinafter, referred to as “MOS transistor”) M0, M1. The direct-current adjustment circuit14removes an offset current Iaoc from an input current Iin from the avalanche photodiode12. Similarly, the alternating-current adjustment circuit15connected to the input electric path L includes a MOS transistor M3. The alternating-current adjustment circuit15has a function of causing a part (current Iagc) of the current Iin from the avalanche photodiode12to flow (to be released) so as not to be sent to the amplifier13. In this manner, the current Iin is divided into the current Iaoc, the current Iagc, and an input current to the amplifier13. The controller16includes an integrator161, an inversion suppression circuit162, an operational transconductance amplifier (hereinafter, referred to as OTA)163, a current controller164, and a MOS transistor M2. The integrator161, the differential circuit17, and the MOS transistors M2, M3are provided with a reference voltage including a negative offset voltage from the reference potential generation circuit19. Due to the negative offset voltage, the alternating-current adjustment circuit15and the direct-current adjustment circuit14can be caused to operate with respect to a strong input burst, and the alternating-current adjustment circuit15and the direct-current adjustment circuit14can be caused not to operate with respect to a weak input burst. The integrator161integrates the output of the amplifier13, and outputs the resultant output to two electric paths of a positive phase P and a negative phase N. The output of the integrator161is provided via the OTA163to the current controller164. The OTA163includes a circuit that varies the amplification factor in accordance with an input. The current controller164sets an input current range for amplification ratio adjustment. The detection circuit18has a function of detecting an output from the differential circuit17and switching a time constant of the integrator161so as to cope with a strong input burst. The current controller164controls the current mirror circuit of the MOS transistors M2, M3, and the current mirror circuit of the MOS transistors M0, M1. FIG.3shows an internal circuit of the inversion suppression circuit162shown inFIG.2. InFIG.3, the inversion suppression circuit162includes: an OTA162A; PNP-type MOS transistors M11, M12, M13forming a current mirror circuit162B; and NPN-type MOS transistors M14, M15forming another current mirror circuit162C. A control power supply voltage Vcc is supplied to the source side of the MOS transistors M14, M15. The source side of the MOS transistors M11, M12, M13is connected to GND. The OTA162A operates on the basis of a positive phase potential Vp and a negative phase potential Vn inputted from the integrator161. Specifically, when Vp≥Vn, the OTA162A does not operate. When an inversion state in which the negative phase potential Vn is higher than the positive phase potential Vp is established, and the inverted potential difference exceeds a predetermined reference value, the OTA162A operates. The operation means to generate a positive output current that is proportional to a potential difference obtained by subtracting the reference value from the inverted potential difference. On the basis of the generated current, a current Ip is injected to the positive phase P and a current In is extracted from the negative phase N, by the current mirror circuit162B composed of the MOS transistors M11, M12, M13, and the current mirror circuit162C composed of the MOS transistors M14, M15. The optical reception device10having such an inversion suppression circuit162operates such that, when the output of the integrator161is inverted and a state where the negative phase potential Vn is higher than the positive phase potential Vp (strictly speaking, a state where the negative phase potential Vn has a high value exceeding a reference value) is established, the inversion suppression circuit162applies a current to the positive phase P and extracts a current from the negative phase N. Accordingly, inversion of the output of the integrator161is suppressed. Therefore, even when a sufficient negative offset voltage is provided to a reference voltage generated by the reference potential generation circuit19, the potential difference in the output of the integrator161can be suppressed from being inverted and increased. Due to the operation of the current mirror circuit162B composed of the MOS transistors M11, M12, M13, the same current In flows in the MOS transistors M11, M12, M13. As a result, a current Ip equivalent to the current In flows also in the MOS transistor M14, and due to the operation of the current mirror circuit162C composed of the MOS transistors M14, M15, the current Ip flows in the MOS transistor M15. That is, the current Ip injected to the positive phase P and the current In extracted from the negative phase N by the inversion suppression circuit162are equivalent to each other. Since the current that is injected and the current that is extracted are equivalent to each other, the common potential of the output of the integrator161is not varied. The OTA162A of the inversion suppression circuit162converts, into a current, the voltage outputted by the integrator161and based on the potential difference between the positive phase and the negative phase, and outputs the current. On the basis of the output of the OTA162A, the current mirror circuits162B,162C generate a current to be injected to the positive phase and a current to be extracted from the negative phase. In this case, when the positive phase potential Vp of the output of the integrator161is higher than the negative phase potential Vn, the inversion suppression circuit162neither applies nor extracts a current. In other words, the inversion suppression circuit162does not perform wasteful operations. Upon occurrence of a state where the negative phase potential Vn of the output of the integrator161is higher than the positive phase potential Vp, i.e., upon occurrence of inversion of the potentials, currents that suppress the inversion can be immediately generated by the current mirror circuits162B,162C. In the following, effects of the inversion suppression circuit162are described with reference to graphs. First, for comparison, a case where the inversion suppression circuit162is not provided is described. Case Where Inversion Suppression Circuit is not Provided Integrator Output Inversion in Open Loop Operation FIG.4shows graphs showing an example of integrator output inversion in open loop operation, as a result of DC analysis (static characteristic analysis). (a) shows the voltage (broken line) outputted by the amplifier13and a reference voltage (solid line) to which a negative offset voltage (40 mV) is added. (b) shows the positive phase potential (solid line) and the negative phase potential (broken line) of the output of the integrator161. (c) shows the gate potential (broken line) of the MOS transistor M3of the alternating-current adjustment circuit15and the gate potential (solid line) of the MOS transistor M0, M1of the direct-current adjustment circuit14. (d) shows the DC offset current to be removed. The horizontal axis represents a logarithmic scale for the input current (Iin) used in common for (a) to (d). In a current range (from 10−5[A] up to the one-dot chain line in the vertical direction inFIG.4) where the input current is low, the direct-current adjustment circuit14and the alternating-current adjustment circuit15do not function due to the effect of the negative offset voltage, and extracting (hereinafter, extracting a current will be referred to as “current extracting”) of AC and DC currents from the input current is not performed. With respect to the input current not less than the one-dot chain line, the direct-current adjustment circuit14and the alternating-current adjustment circuit15perform the current extracting. Here, as is apparent from the graph (b), it is a problem that, when the input current is less than the one-dot chain line, the positive phase potential and the negative phase potential of the output of the integrator161are inverted to a great extent. Next,FIG.5shows graphs showing an example of delay of transient response due to integrator output inversion, as a result of transience analysis. InFIG.5, (a) shows the input current (Iin) from the avalanche photodiode12at the time when an optical signal in which a strong input burst is followed by a weak input burst has been received. (b) shows an inverted amplification output (waveform in a burst state) of the amplifier13with respect to the input voltage, and −40 mV (linear portion) as a reference voltage. (c) shows the positive phase potential (solid line) and the negative phase potential (broken line) of the output of the integrator161. In (d), the upper line represents the source voltage of the MOS transistor M3for AC current extracting, and two lower lines overlapping each other represent the gate voltage of the MOS transistor M3for AC current extracting, and the gate voltage of the MOS transistor M0, M1for DC current extracting. The lower lines are at the level of GND. (e) shows two lines substantially overlapping each other for the entire time. The line having a slight up-down vibration represents the DC extracted current, and the linear line represents the AC extracted current. (f) shows the input voltage to the subsequent stage circuit21. The horizontal axis represents time that is common for (a) to (f). When (c) inFIG.5is focused on, an inversion state is established for the entire time, and as indicated by the elliptic dotted line, the burst ends while the inversion state with respect to the strong input burst is not eliminated. Therefore, the optical reception device10is in a state where the loop is open all the time. When (d) is focused on, the lower lines are at the GND level and current extracting is not performed. Also, when (e) is focused on, current extracting is not substantially performed.FIG.5reveals that, when the output of the integrator161is inverted, the inversion cannot be eliminated, whereby delay in transient response may be caused. In a case where a negative offset voltage is not provided to the reference voltage, and in a case of a PVT (Process-Voltage-Temperature) condition where a positive offset voltage increases even in a small degree, even a weak input burst may cause a closed loop, thereby causing current extracting, resulting in increase in noise. Therefore, reducing the negative offset voltage is not a good measure, and a sufficient negative offset voltage is preferably provided. In addition, a function that prevents, even when a sufficient negative offset voltage is provided, increase in the inverted potential difference between the positive phase potential and the negative phase potential of the output of the integrator161is necessary. The inversion suppression circuit162is a solution to this necessity. Case Where Inversion Suppression Circuit is Provided FIG.6shows graphs showing an example of integrator output inversion in open loop operation, as a result of DC analysis (static characteristic analysis). (a) shows the voltage (broken line) outputted by the amplifier13and a reference voltage (solid line) to which a negative offset voltage (40 mV) is added. (b) shows the positive phase potential (solid line) and the negative phase potential (broken line) of the output of the integrator161. (c) shows the gate potential (broken line) of the MOS transistor M3of the alternating-current adjustment circuit15and the gate potential (solid line) of the MOS transistor M0, M1of the direct-current adjustment circuit14. (d) shows the DC offset current to be removed. (e) shows the current (solid line) to be injected to the positive phase, and the current (broken line which is merged with the solid line at a point) to be extracted from the negative phase, for suppression of inversion of the output of the integrator161. The horizontal axis represents a logarithmic scale for the input current (Iin) used in common for (a) to (e). The vertical one-dot chain line inFIG.6shows the position of the input current at about 90 μA. As shown in (e) ofFIG.6, in a weak input range from an input current of 10 μA (10−5A) to 90 μA, a current is injected to the positive phase and a current equivalent thereto is extracted from the negative phase. As a result, as is apparent from the waveform of (b), even when a negative offset voltage is provided, large inversion of the output of the integrator161in the weak input range is suppressed. FIG.7shows graphs showing an example of a result of transience analysis. InFIG.7, (a) shows the input current (Iin) from the avalanche photodiode12at the time when an optical signal in which a strong input burst is followed by a weak input burst has been received. (b) shows an inverted amplification output (waveform in a burst state) of the amplifier13with respect to the input voltage, and −40 mV (linear portion) as a reference voltage. (c) shows the positive phase potential (solid line) and the negative phase potential (broken line) of the output of the integrator161. In (d), the upper line represents the source voltage of the MOS transistor M3for AC current extracting, the middle line represents the gate voltage of the MOS transistor M0, M1for DC current extracting, and the lower line represents the gate voltage of the MOS transistor M3for AC current extracting. In (e), the upper line having a large variation represents the DC extracted current, and the lower linear line represents the AC extracted current. (f) shows the input voltage to the subsequent stage circuit21. The horizontal axis represents time that is common for (a) to (f). When (c) inFIG.7is focused on, the inversion state is eliminated within about 0.2 μseconds (=200 n seconds), in a circular mark indicated by a dotted line, from the head of the first burst. When compared withFIG.5in which the inversion state cannot be eliminated before the end of the burst, it is clear that delay in transient response is dramatically improved and reduced. Thereafter, although an inversion state of the output of the integrator occurs with respect to the weak input burst, the gate voltage of the MOS transistor M0, M1of the direct-current adjustment circuit14is maintained, and the closed loop is maintained. In (e), the DC extracted current is reduced with respect to the weak input burst and is converged to several μA, but the closed loop is maintained. FIG.8is an example of a graph showing what frequency characteristics the amplification factor of the amplifier13exhibits with respect to input currents having various magnitudes, after the inversion suppression circuit162has been added. The lower graph is an enlarged view of the portion surrounded by the two-dot chain line in the upper graph. The portion surrounded by the elliptic dotted line in the lower graph shows that feedback is performed (a closed loop is established) even in the case of a weak input burst of less than 50 μA. Further, as for noise characteristics, with respect to an input current (Iin) of 24 μA as an integrated value for a 25 GHz band, the effective value of noise was 1.71 μA rms when a completely closed loop operation was performed without addition of a negative offset voltage. When a negative offset voltage is added without provision of the inversion suppression circuit162, 1.52 μA rms is realized, and noise is reduced. In contrast, when the inversion suppression circuit162was provided, the effective value of noise with respect to a similar input current was 1.54 μA. Therefore, even when the inversion suppression circuit162is provided, the increase is only 0.02 μA rms, and noise is sufficiently reduced relative to the case where the completely closed loop operation was performed. This is considered to be due to an influence of the fact that, when the inversion suppression circuit162is used and a closed loop is realized, the DC extracted current is as small as several μA. As described above, through provision of the inversion suppression circuit162, delay in transient response can be reduced, and in addition, under a condition that a reference voltage to which a negative offset voltage is added is lower than the output voltage of the amplifier13, a closed loop can be maintained without increase of noise. Others The optical reception device10of the disclosure above is provided to the optical line terminal1, but may be provided to the optical network units2,3,4. Supplementary Note The above embodiment is merely illustrative in all aspects and should not be recognized as being restrictive. The scope of the present disclosure is defined by the scope of the claims, and is intended to include meaning equivalent to the scope of the claims and all modifications within the scope. REFERENCE SIGNS LIST 1optical line terminal1aline card2,3,4optical network unit5optical fiber6optical coupler7,8,9optical fiber10optical reception device11preamplifier12avalanche photodiode13amplifier14direct-current adjustment circuit15alternating-current adjustment circuit16controller17differential circuit18detection circuit19reference potential generation circuit20capacitor21subsequent stage circuit100PON system161integrator162inversion suppression circuit162A operational transconductance amplifier (OTA)162B,162C current mirror circuit163operational transconductance amplifier (OTA)164current controllerL input electric pathM0, M1, M2, M3MOS transistorM11, M12, M13, M14, M15MOS transistorN negative phaseP positive phase | 36,036 |
11942999 | DETAILED DESCRIPTION Overview The present disclosure relates generally to devices and methods for interfacing a terrestrial optical network and a submarine optical network without specialized SLTE. Specifically, an OCI including a filter is positioned along a first optical communication path of the OCI from a terrestrial cable to a submarine cable. The filter is capable of passing communication signals within a first frequency band that is within the allowed frequency range for the submarine cable, while filtering out other signals, such as supervisory signals, that are outside of the allowed frequency range for the submarine cable. In some examples, the OCI may include a second filter positioned along a second optical communication path of the OCI from the submarine cable to the terrestrial cable. The first and second filter may be capable of looping the filtered-out other signals back towards the terrestrial cable network. At the terrestrial cable network, the looped back signals may be detected by standard terminal equipment, and their detection may be interpreted as indicating the presence of an interface between a terrestrial cable and a submarine cable. Because the presence of the interface is detectable using the looped back signals, standard terminal equipment within the terrestrial system can control a power level of the communication signals within the first frequency band based on the detection. Thus, both frequency control and power control using standard terrestrial terminal equipment are made possible by the inclusion of the first and second filters and a loopback path within the OCI. In some further examples, the OCI may also include at least one variable optical attenuator (VOA) positioned along the first optical communication path between the first filter and the submarine cable. The VOA may be responsible for adjusting the power level of the communication signals passed by the first filter before they are received at the submarine cable. Using a VOA positioned on the “submarine side” of the first filter, as opposed to attenuating elements positioned within the terrestrial network or on the “terrestrial side” of the first filter within the OCI, is beneficial for avoiding attenuation of the other signals that are looped back to the terrestrial network, especially considering that positioning attenuating elements on the “terrestrial side” of the filters would doubly attenuate the signals (once along each path) and would potentially make detection of the looped back signals more difficult. Inclusion of the OCI of the present disclosure at an interface between a terrestrial optical network and a submarine optical network avoids the need for specialized SLTE on the terrestrial side of the interface. This achieves a reduction in cost due to the relative low cost of standard terrestrial optical cables, as compared to SLTE. Furthermore, no hardware changes are needed to the terrestrial equipment. A software update can be provided to the standard terrestrial terminal equipment in order to detect locations of the terrestrial network that interface with submarine cables based on supervisory signals that loop back towards the standard terrestrial terminals. Additionally, when all terrestrial/submarine interfaces in the optical network are outfitted with the OCI of the present disclosure, a single SKU can be used for all terminal equipment of the entire network. Example Systems FIG.1is a schematic diagram of an optical network100including a first terrestrial optical network102and a second terrestrial optical network104connected to one another by a submarine optical network106. For instance, each of the terrestrial optical networks102,104may be situated at landmasses A and B that are separated by a body of water such as sea S, and the submarine network may be situated primarily in the sea S. The respective terrestrial networks of the landmasses A, B may be communicatively connected to one another via one or more submarine cables across the sea S. Each of the terrestrial optical networks102,104is shown to include at least one respective terminal including terminal equipment (TE)112,114for receiving and transmitting communication signals through the optical networks, and for monitoring operation of the optical networks. The terminal equipment112of the first terrestrial optical network102is connected to a first optical cable122, and the terminal equipment114of the second terrestrial optical network104is connected to a second optical cable124. The first and second optical cables are connected to each other by the submarine optical network106. Additional terminals and optical cables (not shown) may be included in each optical network. The submarine optical network106may include one or more submarine optical cables130that are connected at opposite ends to the first and second terrestrial optical networks102,104, respectively. In the example ofFIG.1, a first end of the one or more submarine optical cables130is connected to the first optical cable122through a first open cable interface (OCI)132, and an opposite second end of the one or more submarine optical cables130is connected to the second optical cable124through a second OCI134. Furthermore, each of terminal equipment112and114may be standard terrestrial terminal equipment, as compared to SLTE. As such, both ends of the one or more submarine optical cables130may be connected to standard terrestrial terminal equipment through respective optical cables. Each of the OCIs132,134may be adapted in order to support compatibility between the cables of the submarine optical network106and the terrestrial optical networks102,104.FIG.2Ais a schematic diagram of an example OCI230for interfacing a submarine optical network with a terrestrial optical network using standard terrestrial terminal equipment212. In the exampleFIG.2A, an optical cable214is shown as including two optical paths: a first optical path originating at point222from which the terminal equipment212is configured to transmit optical signals; and a second optical path ending at point224at which the terminal equipment212is configured to receive optical signals. Together, the first and second optical paths of the optical cable214facilitate bidirectional communication between the terminal equipment212and the OCI230. The optical signals transmitted and received by the terminal equipment212may include each of communication signals and secondary signals. The communication signals may include communication data, such as messages communicated between end terminals of the optical network. The communication signals may have a first wavelength λ1that is within a first frequency band supported by the submarine optical network. Thus, the communication signals may be transmitted between landmasses A, B, through the submarine optical network. The secondary signals may include telemetry signals for monitoring operation and performance of a terrestrial optical network, such as optical supervisory channel (OSC) signals, optical time-domain reflectivity (OTDR) signals, and the like. The secondary signals may not be supported by the submarine optical network. Therefore, in order to prevent the secondary signals from being transmitted to or relayed through the submarine optical network, the secondary signals may have a second wavelength λ2that is within a second frequency band that does not overlap with the first frequency band. In one example arrangement, the first frequency band may include wavelengths less than 1510 nm, and the second frequency band may include wavelengths between 1510-1610 nm. In a different example arrangement, the second frequency band may include a wavelength of 1625, such as to support terrestrial OTDR signals. The use of non-overlapping frequency bands for communication signals and secondary signals allows for the signals to be separated from one another using one or more filtering techniques, including but not limited to high-pass filtering, low-pass filtering, bandpass filtering, notch filtering, and so on. In the example ofFIG.2A, a filter232is positioned at the OCI230on the first optical path. Communication signals from a first terrestrial optical network λ1(A) and secondary signals from the first terrestrial optical network λ2(A) are transmitted from point222towards the OCI230. At the OCI, the filter232may be a wavelength division multiplexing (WDM) filter, and may be configured to pass the communication signals λ1(A) and to filter out the secondary signals λ2(A). Thus, only the communication signals λ1(A) that are supported by the submarine optical network are passed to point242and transmitted through the submarine optical network, while the secondary signals λ2(A) that are not supported are prevented from reaching the submarine optical network. In another example configuration, also shown inFIG.2A, a second filter234is positioned at the OCI230on the second optical path, and an optical loopback path236is provided between the first filter232and the second filter234. The first filter232may be configured to send the filtered-out secondary signals λ2(A) to the second filter234via the optical loopback path236, and the second filter may be configured to reflect the secondary signals λ2(A) received from the first filter232back to the terminal equipment212along the second optical path. The reflected-back or looped-back secondary signals λ2(A) may be transmitted from the OCI230along the second optical path. FIG.2Aalso shows communication signals from a second terrestrial network λ1(B) being received by the OCI230at point244of the second optical path. These communication signals may have the same wavelength as the communication signals from the first terrestrial optical network λ1(A), or may fall within the same first frequency band. Furthermore, the second filter234may be configured in the same or similar manner as the first filter232, and thus may be configured to pass the communication signals from the second terrestrial network λ1(B), resulting in the communication signals along with the looped back secondary signals λ2(A). In the example ofFIG.2A, power level control for communication signals from the first terrestrial optical network λ1(A) may be performed on the terrestrial side of the OCI230, such as at the terminal equipment212. Adjusting the signals' power level may involve adding a predetermined attenuation to the signals, and may be performed in order for the signals to meet power requirements of the submarine optical network. However, by performing the power level control on the terrestrial side of the OCI230, a power level of the secondary signals λ2(A) is also affected. Since the secondary signals λ2(A) are not directed through the submarine optical network, the power level of the secondary signals λ2(A) does not need to be adjusted in the same manner. FIG.2Bis a schematic diagram of another example OCI for selective power adjustment of communication signals without affecting secondary signals. Like the example OCI ofFIG.2A, the OCI ofFIG.2Binterfaces a submarine optical network with a terrestrial optical network using standard terrestrial terminal equipment. The features ofFIG.2Bare the same as forFIG.2A, except for the addition of one or more variable optical attenuators (VOA) along the first and second optical paths. Along the first optical path, a first VOA252is positioned between the first filter232and the submarine optical network. The first VOA252may be configured to adjust a power level of the communication signals from the first terrestrial optical network λ1(A), such as by lowering the power level in order to meet power requirements of the submarine optical network. By positioning the first VOA252on the first optical path after the filter232, the first VOA252is capable of controlling the power level of the communication signals λ1(A) without affecting the power level of the secondary signals λ2(A). In some examples, the attenuation introduced by the first VOA252may be a fixed value. For instance, the value may be set during installation of the OCI230, either manually or automatically. A manual approach to setting the attenuation value is for the value to be assigned by a remote operator through a network management software interface. An automatic approach to setting the attenuation value is for the value to be assigned according to an automated script or software controller. In either approach, the VOA252could include a sensor to monitor power at the VOA252by routing a small predetermined fraction of the transmitted signals to a photodetector. Measurements from the photodetector may then be provided to the remote operator or automated program, and in turn can be used to determine and set the fixed attenuation of the VOA252. In other examples, the attenuation introduced by the first VOA252may be a variable amount subject to continuous adjustments based on feedback from the VOA252. For instance, a local control loop may be provided within the OCI. The local control loop may include a photodetector to sense an amount of power being output through the VOA252, and a control mechanism such as a microcontroller to control the VOA252in a manner that reduces, and over time minimizes, a difference between a current power level of the VOA252and a preset target power level. In such an example, the preset target power level may be determined and programmed during the installation process. In some examples, a second VOA254may also be included in the OCI230. The second VOA254may be positioned along the second optical path, between the second filter234and the submarine optical network. The second VOA254may be configured to control the power level of the communication signals λ1(B). For example, the power level of the communication signals λ1(B) may be lowered by the second VOA254to within a preset level suitable for the terminal equipment212. Such power adjustment may be necessary if the terminal equipment212is positioned close to the OCI230, meaning that little to no attenuation occurs from the OCI230to the terminal equipment212. Both example arrangements ofFIGS.2A and2Ballow for passage of communication signals to the submarine optical network while blocking passage of the secondary signals. Both example arrangements also permit for control to power levels of the communication signals prior to their entry to submarine optical network. Both example arrangements also permit for the looping back of supervisory signals, which has the added benefit of communicating the presence of the OCI to the adjacent terminal equipment included in the terrestrial optical network, such as TE112of the first optical network102in the example ofFIG.1. For instance, if a given terrestrial terminal were to transmit supervisory signals to an adjacent node within the optical network and the supervisory signals were received back at the same given terrestrial terminal, it could be inferred that the supervisory signals were looped back towards the given terrestrial terminal by a filter and optical loopback path of an OCI, thus indicating the presence of the OCI, and by extension the presence of a submarine optical network interfaced to the terrestrial optical network by the OCI. Communicating the presence of the OCI may be beneficial for enabling the adjacent terminal equipment to adjust one or more settings for accommodating the nearby interface to the submarine optical network without requiring the specialized and dedicated hardware of SLTE. FIG.3is an example block diagram of standard terrestrial terminal equipment (TE). The standard terrestrial TE includes one or more computing devices300programmed with data and instructions sufficient for transmitting supervisory signals and detecting when the supervisory signals are rerouted or looped back towards their origin. The one or more computing devices300may include a processor310, memory320, and one or more communication devices350for receiving inputs and transmitting outputs. The processor310can be a well-known processor or other lesser-known type of processor. Alternatively, the processor can be a dedicated controller such as an ASIC. The memory320can store information accessible by the processor310including data that can be retrieved, manipulated or stored by the processor, instructions that can be executed by the processor, or a combination thereof. Memory may be a type of non-transitory computer readable medium capable of storing information accessible by a processor such as a hard-drive, solid state drive, tape drive, optical storage, memory card, ROM, RAM, DVD, CD-ROM, write-capable, and read-only memories. AlthoughFIG.3functionally illustrates each of the processor310and memory320as being a respective single block, the processor and memory may actually include multiple processors, multiple memories, or any combination thereof, that may or may not be stored in a common location or within the same physical housing. For example, some or all of the data and instructions can be stored on a removable CD-ROM and others within a read-only computer chip. For further example, some or all of the data and instructions can be stored in a location physically remote from, yet still accessible by, the processor. Similarly, the processor can actually include a collection of processors, which may or may not operate in parallel. The one or more communication devices may facilitate communication between the terminal and other remote terminals and components of the optical network that are in communication with the terminal. The remote terminals and components may include terrestrial nodes of the terrestrial optical network, as well as OCIs interfacing the terrestrial optical network to one or more submarine optical networks. The communication devices may be capable of transmitting data to and from other computers such as modems (e.g., dial-up, cable or fiber optic) and wireless interfaces. For example, each node may receive communications via the network connection130, such as through the Internet, World Wide Web, intranets, virtual private networks, wide area networks, local networks, private networks using communication protocols proprietary to one or more companies, Ethernet, WiFi (e.g., 702.71, 702.71b, g, n, or other such standards), and RPC, HTTP, and various combinations of the foregoing. The memory320may include instructions340, and may further include data330that can be retrieved, stored or modified by the processors310in accordance with the instructions340. For instance, although the computing devices300disclosed herein are not limited by a particular data structure, the data330can be stored in computer registers, in a data store as a structure having a plurality of different fields and records, or documents, or buffers. The data330can also be formatted in a computer-readable format such as, but not limited to, binary values, ASCII or Unicode. Moreover, the data330can include information sufficient to identify relevant information, such as numbers, descriptive text, proprietary codes, pointers, references to data stored in other memories, including other network locations, or information that is used by a function to calculate relevant data. The instructions340can be a set of instructions executed directly, such as machine code, or indirectly, such as scripts, by the processor310. In this regard, the terms “instructions,” “steps” and “programs” can be used interchangeably herein. The instructions340can be stored in object code format for direct processing by the processor310, or other types of computer language including scripts or collections of independent source code modules that are interpreted on demand or compiled in advance. In the example ofFIG.3, the data330stored in the memory320may include supervisory signal data332indicating information about the communication signals and the remote conditions of one or more optical terminals included in the network. The supervisory signal data332can be used to remotely determine whether nodes and terminals of the network are operating properly. For instance, the supervisory signal data332may be used to detect losses, delays, or disruptions within the network based on supervisory data, such as feedback from remote nodes, round trip times, and the like. Examples of supervisory signals include but are not limited to OSC signals and OTDR signals. The supervisory signal data332can further be used to facilitate remote management of the network based on detected issues within the network, such as by resending or rerouting optical signals. The data330may further include power level data334indicating prescribed power levels for optical signals transmitted to various terminals and nodes included in the network. For instance, the power level data may indicate a first power level at which communication signals to adjacent terrestrial terminals should be transmitted, and a second power level lower than the first power level at which communication signals to adjacent OCIs should be transmitted. The data330may further include a neighbor terminal status336indicating respective statuses for adjacent nodes of the network. For instance, with regard to adjacent terrestrial terminals, the neighbor terminal status of those nodes may indicate that they are terrestrial terminals. Alternatively, with regard to an OCI connected to the terminal equipment by an optical cable, the neighbor terminal status for such a node may indicate the presence of an OCI interfacing a neighboring submarine optical network. The instructions340stored in the memory may include a supervisory signal transmission routine342for transmitting supervisory signals and collecting supervisory signal data from remote nodes of the network. The instructions340may further include a terminal status check routine344for checking the status of a given terminal, such as an adjacent terminal within the network. For instance, the terminal status check routine344may involve transmitting an optical signal having a wavelength within a given range that corresponding to a waveband filtered by a filter of an OCI included in the network. Then, if the transmitted optical signal is received at the transmitting terminal, it may be determined that the signal was looped back towards the terminal by an OCI, thus indicating the presence of an interface with a neighboring submarine optical network. The instructions340may further include a submarine cable use case routine346for configuring a use case of the terminal in response to detection of an interface with a neighboring submarine optical network. The submarine cable use case routine346may involve changing one or more configurations of the terminal including the one or more computing devices300in order for the terminal to accommodate communications with an OCI interfacing the submarine optical network to the terminal. The configurations may include, but are not limited to, power level configurations, supervisory signal evaluation configurations, or any combination thereof. Some example submarine cable use cases are provided herein in connection withFIG.4. Example Methods Example routines400performed by the processor of one or more computing devices of terrestrial terminal equipment are described in greater detail in connection with the diagram ofFIG.4. The routines may include a terminal status check routine, a submarine cable use case routine, and so on. It should be understood that the routines described herein are merely examples, and in other examples, certain steps may be added, subtracted, replaced or reordered. At block410, a supervisory signal is transmitted from a first terminal of the terrestrial optical network. The supervisory signal may be transmitted through an optical cable to one or more adjacent nodes of the first terminal. The supervisory signal may be an OSC signal, an OTDR signal, or another signal through which the first terminal may be capable of monitoring performance of the optical network. At block420, the first terminal determines whether the supervisory signal is transmitted back to the first terminal. This may involve receiving signals at one or more input communication ports of the first terminal, processing the received signals, and identifying one or more of the received signals as being the same as a previously transmitted supervisory signal. In the absence of the supervisory signals being received at the first terminal, such as after passage of a predetermined duration of time, or after receiving an acknowledgment signal indicating that the transmitted supervisory signals were received at another node of the optical network, it may be determined that the supervisory signal was not transmitted back to the first terminal. If it is determined that the supervisory signal was not transmitted back to the first terminal, then operations continue at block430, at which the first terminal determines that the supervisory signal was transmitted to a second terminal, which may be another terminal of the terrestrial optical network connected to the first terminal. In this case, it may be determined that future optical signals transmitted to the same node may be configured as terrestrial optical signals. For instance, this may involve transmitting the optical signals at a predetermined power level or without adding attenuation to the optical signals before transmission. Alternatively, if it is determined that the supervisory signal was transmitted back to the first terminal, then operations continue at block440, at which the first terminal determines that the supervisory signal was rerouted or looped back to the first terminal by an OCI interfacing the terrestrial optical network to a submarine cable of a nearby submarine optical network. In response to the determination at block440, the first terminal, at block450, may initiate a submarine cable use case. Initiating the submarine cable use case may involve setting or changing one or more configurations of the first terminal in order to accommodate communication between the first terminal and the nearby submarine optical network through the OCI. In some examples, initiating the submarine cable use case may involve initiating a power reduction program452. The power reduction program may maintain power levels of transmissions to the OCI and submarine cable at or below a predetermined power level. The predetermined power level may be determined according to specifications and guidelines for submarine cables, such as safety guidelines. In the case of telecommunications, optical networks generally adhere to the safety guidelines for Class 1M lasers. In situations where a power level of the communication signal is above the predetermined power level, the power reduction program may cause a power level of the communication signal to be reduced. In some examples, initiating the submarine cable use case may involve updating a travel distance between the first terminal and the OCI454. Typically, supervisory signals transmitted between nodes of the terrestrial network travel between a transmitting node and a different receiving node, and the travel distance between the transmitting node and the receiving node can be derived from the elapsed time that the signal travels. However, in the case of a supervisory signal transmitted to an OCI and then looped back to the transmitting node, the travel distance of the signal is actually double the distance between the transmitting node and the OCI. Therefore, in order to correctly derive travel times between a transmitting node and an OCI, a distance between the transmitting node and OCI may be halved. Determining to halve the distance may be accomplished through a configuration at the first terminal, whereby when the configuration is active, a travel time of the supervisory signals transmitted from the first terminal to the OCI may be evaluated based on have the halved travel distance. In some examples, initiating the submarine cable use case may involve updating an actual loss or attenuation of the supervisory signal between the first terminal and the OCI456. Typically, for supervisory signals transmitted between nodes of the terrestrial network, an amount of signal loss experience between the transmitting node and the receiving node can be detected by determining a property the signal, such as the signal's power level, at each of the transmitting node and the receiving node. However, in the case of a supervisory signal transmitted to an OCI and then looped back to the transmitting node, since the signal travels double the distance, it is likely to experience double the losses during transmission. Therefore, in order to correctly derive actual losses experienced by the supervisory signals between a transmitting node and an OCI, the measured losses at the transmitting node may be halved. Determining to halve the measured losses may be accomplished through a configuration at the first terminal, whereby when the configuration is active, the measured losses are halved in order to derive an estimate of the actual losses experienced in a single trip from the first terminal to the OCI. The operations of the example routines400ofFIG.4may be conducted during an installation of the OCI. In other words, the first terminal may initially determine, at a time of installation of the OCI or of the first terminal, the presence of the OCI, and may initialize its settings to correctly and monitor the OCI, to transmit communication signals to the OCI in adherence with submarine cable guidelines, or a combination thereof. After this initialization, operations may continue based on the initialized configurations. In some instances, the first terminal may be capable of regularly or continuously monitoring the looping back of supervisory signals, meaning that if the signals are not looped back or if an acknowledgement is signal is received at a future time, the first terminal may determine to update its settings based on the detected presence of a second terrestrial terminal in place of the OCI. Since the configuration operations are carried out from a terrestrial terminal that is remote from the OCI, and are not carried out at the OCI itself, it should be recognized that the installation of the terrestrial terminal may be performed by an ordinary technician, even though the terminal is being installed adjacent to an OCI interfacing a submarine optical network. By comparison, when SLTE is required to be installed adjacent to an OCI to interface terrestrial and submarine optical networks, a technician specially trained for installing SLTE is required. As a result, terrestrial and submarine optical networks can be interfaced with one another with standard “terrestrial-grade” terrestrial terminal equipment and without requiring specialized or dedicated terminal equipment and furthermore the installation of the standard terrestrial terminal equipment can be performed by ordinary “terrestrial-grade” service technicians. This avoids the expensive costs typically associated with both specialized SLTE hardware and with installation by “white-glove” specialty technicians. Additionally, the use of standard terrestrial terminal equipment in place of SLTE means that all terminals included in the optical network have the same terminal equipment. This allows for a single SKU to be used to track all terminal equipment, which in turn saves considerable time and hassle, as well as expenses, for those responsible for tracking and maintaining the optical network hardware. Although the technology herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present technology. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present technology as defined by the appended claims. Most of the foregoing alternative examples are not mutually exclusive, but may be implemented in various combinations to achieve unique advantages. As these and other variations and combinations of the features discussed above can be utilized without departing from the subject matter defined by the claims, the foregoing description of the embodiments should be taken by way of illustration rather than by way of limitation of the subject matter defined by the claims. As an example, the preceding operations do not have to be performed in the precise order described above. Rather, various steps can be handled in a different order, such as reversed, or simultaneously. Steps can also be omitted unless otherwise stated. In addition, the provision of the examples described herein, as well as clauses phrased as “such as,” “including” and the like, should not be interpreted as limiting the subject matter of the claims to the specific examples; rather, the examples are intended to illustrate only one of many possible embodiments. Further, the same reference numbers in different drawings can identify the same or similar elements. | 33,254 |
11943000 | DETAILED DESCRIPTION Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention. Referring now toFIG.1a, wherein like reference numerals designate identical or corresponding parts throughout several views and embodiments; and wherein cascading boxes below a part designates a plurality of such parts, an exemplary embodiment of an electrical power architecture for a fiber optic wide area network is shown incorporating a subscriber-powered network element, according to the present invention. A FTTC or FTTN network using a PON (e.g., B-PON ITU-T G.983, G-PON ITU-T G.984, XG-PON ITU-T G.987, E-PON IEEE 802.3ah, 10G-EPON IEEE 802.3av, WDM-PON, TWDM-PON or RFoG SCTE IPS910) connects a central office (CO)100at the head-end of a passive optical distribution fabric (ODF)102to a subscriber premise104. The subscriber premise104may be a residential home, a multi-dwelling unit (MDU), a commercial building, or a cell tower. The passive ODF102is comprised of a plurality of passive optical splitters106and connectors (not shown). An Optical Line Terminal (OLT)108, which is generally located at the CO100but may be located in a remote or outside plant (OSP) cabinet, acts as a central transmission point and an overall controlling device for the network. The OLT108is in communication through the ODF102with a plurality of Optical Network Units (ONUs)110located in neighborhood terminals (also called pedestals) in FTTdp or FTTC networks112or in cabinets in FTTN networks114. The OLT108transmits and receives data to and from the ONUs110in the form of modulated optical light signals of known wavelength through the ODF102. The transmission mode of the data sent over the ODF102may be continuous, burst or both burst and continuous modes. The transmissions may be made in accordance with a time-division multiplexing (TDM) scheme or similar protocol. Frequently bi-directional wavelength-division multiplexing (WDM) is used and although the FTTC/FTTN network illustrated inFIG.1aincludes an OLT108in communication with a plurality of ONUs using a plurality of fibers, other implementations of such networks may only use ONTs or some combination of ONUs110and ONTs110. In some implementations, the ONUs and ONTs are generally similar. In other implementations, the ONUs and ONTs may differ in one or more aspects. As previously mentioned, the ONUs and ONTs are drop site network elements that generally, at a high level description, serve to convert information between the optical domain of a fiber and electrical domain of a twisted wire pair wire or possibly coaxial cable. An ONT is a single integrated electronics unit that terminates the PON and presents native service interfaces to the user or subscriber. An ONU is an electronics unit that terminates the PON and may present one or more converged interfaces, such as xDSL or Ethernet, toward the subscriber. An ONU typically requires a separate subscriber unit to provide native user services such as telephony, Ethernet data, or video. In practice, the difference between an ONT and ONU is frequently ignored, and either term is used generically to refer to both classes of equipment. Although in the hybrid fiber coaxial network case, ONUs/ONTs are called nodes, optical nodes or even taps depending on where the fiber network ends and the coaxial cable network begins. Referring again toFIG.1a, an exemplary embodiment of an ONU110is comprised of the following functional blocks: a PON transceiver116, a PON client Transmission Convergence Layer (TC-Layer) unit118; a CO modem aggregation and adaptation layer unit120; a plurality of Digital Subscriber Line (xDSL, i.e. ADSL, VDSL, or VDSL2) CO modems122; a plurality of Digital Access Arrangement (DAA) units124; a plurality of DC-to-DC power converters126, and a power supply128. The client PON transceiver116comprises the necessary components to convert optical-to-electrical (O/E) signal communications from the OLT108as well as convert electrical-to-optical (E/O) signal communications and communicate them to the OLT108. The PON transceiver116may be plugged into or comprise an optical port or socket, the optical port serving as a site for coupling to a fiber and for performing the O/E and E/O conversions. Some embodiments of network elements may be made without optical transceivers, however having an optical port for later installation of an optical transceiver. In embodiments of network elements made with an optical transceiver, the optical port and the optical transceiver are essentially the same. Some form factors for PON transceiver116include, but not limited to, SFF, SFP, SFP+, and XFP. The PON transceiver116communicates electrically with the TC-Layer118. The TC-Layer118comprises the functionality of: bundling or encapsulating and sending data into upstream subscriber data packets or frames; receiving and un-bundling or decapsulating data into downstream subscriber data packets or frames; managing the transmission of packets or frames on the network via medium access and bandwidth allocation protocols; providing necessary messaging and end point behavior, and checks, reports and may correct for detectable errors. The TC-Layer118communicates with both the PON transceiver116and optionally an 1:N aggregation and CO modem adaptation layer120. The 1:N aggregation and CO modem adaptation layer120has several functions. Modem communications over twisted wire pair transmission lines have lower bandwidth rates than communications over fiber. Thus to efficiently use the higher bandwidth rates of the fiber, the communications from multiple modems may be pooled or multiplexed/demultiplexed together (e.g., buffered using a first in first out manner). Modem communications from as many as one to some N number, for the purposes of this disclosure, may be aggregated or multiplexed/demultiplexed together. For example, some96modems can be aggregated together. The 1:N aggregation and CO modem adaptation layer120communications electrically to an N number of modems. Each modem serving to enable communications to/from a unique subscriber premise104over a unique twisted wire pair130. Additionally, in some embodiments, multiple modem communications may be binded or bonded together to/from a unique subscriber premise to achieve data rates beyond the capability of a single modem, these communications may also be aggregated by the 1:N aggregation and CO modem adaption layer120. Additionally, in some embodiments, the modem communications may comprise data that has priority over other data and the 1:N aggregation and CO modem adaptation layer120can aggregate or multiplex/demultiplex priority data before data that does not have priority. Communication devices such as xDSL capable modems122are chosen as the preferred modem types however it is envisioned that many types of modems can be used for communications over twisted pair wires or even coaxial cable transmission lines to a subscriber premise104. The xDSL capable modems of122are central office (CO) or head-end type modems. Each modem is in electrical communication with an electrical coupling device such as a DAA124and the DAA124is coupled to an electrical port or socket (e.g., RJ-11) which is then coupled to twisted wire pair130. A DAA is an interface that protects electronics connected to a telecommunication network from local-loop disturbances and vice versa. A DAA in general can mean many things because a DAA must perform varied and complex functions, including but not limited to line termination, isolation, hybrid functions, caller-ID and ring detection. A DAA must also provide a loop switch so that the DAA looks on- or off-hook to the loop; detect the state of the line and the incoming ringing signal, as well as include support of full-duplex operation. The International Telecommunication Union Telecommunication Standardization Sector (ITU-T) series G specification for transmission systems and media, digital systems and networks contains many documents, recommendations and specifications regarding DAA, as well as subscriber line interface circuits (SLIC)132, specifically ITU-T G.100-109 specifications that are hereby included by reference. For the purpose and needs of an embodiment of the present invention, the electrical coupling device DAA124is a device that: meets local regulatory requirements which differ by country or region; provides a measure of protection for both a network element, such as ONU110, and the local-loop such as twisted wire pair130transmission line; passes AC and/or DC based signal information to and from a modem, such as xDSL CO modem122, as well as decouples or passes DC power (DC current and DC voltage) (e.g. using a low pass filter) to a DC-to-DC power converter126from a twisted wire pair130transmission line. Additionally, the DAA124provides isolation protection to the modem from potentially damaging high voltage (e.g., from a lightning strike or malfunctioning equipment) on the twist pair130. The DAA124device may be of a design that is transformer-based, optically-based, capacitively coupled-based, silicon/integrated circuit-based, or some combination thereof which offer virtues in size, cost, and performance. As previously mentioned or indicated, the ONU110can provide broadband services to a plurality of subscriber premises104over twisted wire pair transmission lines. Located in each subscriber premise104is a customer premise equipment (CPE) or subscriber terminal (ST) device134which is connected to the twisted wire pair130. The twisted wire pair130passes through the demarcation point or network interface demarcation (NID)136to the CPE or ST134. The CPE/ST134device and uninterruptable power supply (UPS)150is powered by a subscriber's residential or commercial power outlet which are derived from subscriber mains power (not shown). The exemplary CPE/ST134is comprised of the functional blocks: a DC power source138; an xDSL client modem140; an electrical coupling device such as subscriber line interface circuit (SLIC)132; optionally one or more Internet Protocol Television (IPTV) codec and driver144; optionally one or more Voice Over IP (VoIP) codec and driver146(including FXS circuitry); optionally one or more IEEE 802.11x (WiFi) transceiver148; optionally a MoCA access network controller (i.e., MoCA MAC/PHY) (not shown); optionally a G.hn MAC/PHY; optionally a WiGig MAC/PHY, and one or more Ethernet LAN ports142with appropriate media access (MAC) and PHYs for operation with a subscriber's local area network (LAN) as well as with additional switching or routing functions to support the other services provided by the CPE/ST134(e.g., IPTV144, VoIP146, WiFi148). The DC Power source138may be derived from or be part of a DC-to-DC power supply or an AC-to-DC power supply. The DC Power source138provides DC power (DC current and DC voltage), which may be derived from subscriber mains power (e.g., AC power), in one or more power supply rails to the electrical coupling device SLIC132. Generally, SLICs provide the necessary signals, timing, and control functions for the plain old telephone system (POTS) line. SLICs and DAAs perform complementary functions with some overlap. The requisite functions of these devices, although similar at first look, differ enough that implementing the technologies requires different techniques. For example, SLICs act as line power drivers as they send ringing signals down the line and supply line power on to the twisted wire pair transmission line, generally from batteries, to the far end of the line. DAAs, on the other hand, act more like receivers and use the supplied line or loop power. For the purpose and needs of an embodiment of the present invention, the electrical coupling device SLIC132is a device that: meets local regulatory requirements which differ by country or region; provides a measure of protection for both a network element, such as ONU110, and the CPE/ST104; passes AC and/or DC based information signal to and from a modem, such as xDSL client modem140; accepts DC power (DC current and DC voltage) from a DC power source, such as138, and acts as a line power driver driving the accepted DC power and information signal as a combined electrical WAN signal through WAN port129and down a twisted wire pair, such as130. The SLIC132device may be of a design that is transformer-based, optically-based, capacitively coupled-based, silicon/integrated circuit-based, or some combination thereof which offer virtues in size, cost, and performance. The communication device such as xDSL client modem140is a complementary modem to the xDSL CO modem122and as previously indicated is in electrical signal communication with the SLIC132. With broadband communications established with the CO100and with the optional IPTV144, VoIP146, and WiFi148components the CPE/ST134is enabled to provide broadband internet access services, television subscription or pay-per-view services, VoIP services and wireless LAN services and capabilities. VoIP service can be used as the primary telephony line service to a subscriber. Primary line means the telephone service will be available all the time, and may even be available during a significant power failure event. In the case where a subscriber suffers a power outage, then the CPE/ST134will require a battery or uninterruptible power source150to meet lifeline service requirements, according to an embodiment of the invention. Referring toFIG.1b, an alternative embodiment ofFIG.1ais shown with CPE/ST135comprising SLIC133and DC Power source138. SLIC133operates similar to SLIC132, coupling DC power from DC power source138onto twisted cooper wire pair130with electrical signal communications from xDSL client modem140via twisted wire pair131onto subscriber-powered twisted wire pair130. SLIC133also decouples electrical signal communications from xDSL CO modem122on twisted wire pair130onto twisted wire pair131. CPE/ST135allows electrical modem signal communications to be exchanged between network element's CO modem122and CPE/ST137client modem140while coupling electrical power for use by network element ONU110on to twisted wire pair130. In the case where a subscriber suffers a power outage, then the CPE/ST137and CPE/ST135will require a battery or uninterruptible power source150to meet lifeline service requirements, according to an embodiment of the invention. Referring toFIG.2in view ofFIG.1a, a flow chart of a method of an embodiment of the present invention is illustrated. Powering a network element of a fiber optic wide area network, such as on ONU110inFIG.1a, from a subscriber terminal134at a subscriber premise104entails providing or supplying a DC power (e.g., from DC power source138) of sufficient threshold to electrically power the network element onto a twisted wire pair130as described at block200. At block202, electrical data communications from a communication device or modem, as in a client modem140or CO modem122, are coupled to the same twisted wire pair130along with the DC power. At block204, the DC power and electrical data communications are transmitted, driven or sent as a combined electrical WAN signal though WAN port129or DAA124across the twisted wire pair130from the subscriber terminal134to the network element, such as ONU110, or vice versa with respect to the electrical data communications. At block206, the driven DC power and electrical data communications as the combined electrical WAN signal are accepted or received at the network element over the same twisted wire pair130. At block208, the network element decouples (e.g., using a high pass filter) the electrical data communications from the DC power, or vice versa (e.g., using a low pass filter), with a DAA device124. At block210, the network element provides the DC power to a DC-to-DC power converter126for conversion and for use by the network element in the network element's power supply128. In the method described above, the power network and the information network become, and are, the same network. The DC power that is provided or supplied at the subscriber premise104for feeding the power needs of the network element is assumed to be of sufficient DC current and DC voltage required for delivery to the network element. In many embodiments of the invention, this required DC current and DC voltage will be of a high level (e.g., −48 volts, −24 volts) that necessitates the use of a DC converter by the network element to convert the delivered DC power to a usable level (e.g., 5 volts, 3.3 volts) for use by the network element's component subsystems as distributed by the power supply128(e.g., 3.3 volts, 1.8 volts, or 0.9 volts) which in some embodiments combines the DC power delivered by a plurality of DC-DC converters126. In alternate embodiments of the invention, such as those providing primary telephony line services without the use of a traditional POTS line, an uninterruptible power source or battery backup150device may be required to continue to meet lifeline telephony regulatory obligations. It will be appreciated that according to the method of an embodiment of the invention as described above, that with an increasing number of active subscribers the power needs of the network element, such as ONU110, increases and so does the amount of supplied DC power with each active subscriber. The method provides a solution to match increasing power demands with additional power supplied remotely from each active subscriber in a progressive manner wherein communications from the network element to each new active subscriber is established after the new active subscriber provides a sufficient threshold of electrical power to the network element. Referring toFIG.3in view ofFIG.1a, a FTTC or FTTN network is shown wherein the implementation of the network is a point-to-point (PtP) fiber optic wide area network. The ODF300lacks passive splitters and illustrates the one-to-one direct connection between terminals112and cabinets114and the CO100. Such PtP networks may be implemented by a point-to-point gigabit or 10 gigabit Ethernet network (e.g. active Ethernet IEEE 802.3 communication network) with complementary components such as optical transceiver302and data link layer304in accordance with whatever specific protocol is chosen for the network implementation (e.g., Ethernet). The optical transceiver302may be plugged into or comprise an optical port or socket, the optical port serving as a site for coupling to a fiber and for performing the O/E and E/O conversions. Some embodiments of network elements may be made without optical transceivers, however having an optical port for later installation of an optical transceiver. In embodiments of network elements made with an optical transceiver, the optical port and the optical transceiver are essentially the same. Some form factors for optical transceiver302include, but not limited to, SFF, SFP, SFP+, and XFP. Additionally some embodiments may use dual fibers for communications with the CO, head-end or OLT.FIG.3serves to show that the method of an embodiment of the invention as previously described, as inFIG.2, is a method apathetic and even naïve of the design choice or implementation of the fiber in the loop network. The method works equally well for both PtP networks and PONs. Referring toFIG.4in view ofFIG.1a, an alternative embodiment in accordance with the present invention is illustrated wherein the primary telephony line service400is served by legacy POTS from a CO or remote Digital Loop Carrier (DLC) network402. Traditionally, a CO or DLC402is the sole power source for legacy POTS lines; however in this embodiment the SLIC132provides the DC power to twisted wire pair130b,130c, and130dtransmission line. Twisted wire pair transmission line130ais connected to the CO or DLC402to a network element, such as ONU404. ONU404additionally comprises a splitter406that combines the POTS service with the electrical CO modem122communications together on the same twisted wire pair130bthrough an electrical port or socket (e.g., RJ-11). The splitter406places the POTS service at a lower and more narrow frequency (termed narrowband NB) than the xDSL modem communications which utilize higher frequencies to achieve greater bandwidth for data communications (termed broadband BB). In this embodiment a section of the twisted wire pair130btransmission line carries POTS (NB) signal, xDSL modem electrical communications (BB) and the DC power (both a DC current and a DC voltage). This section of twisted wire pair130blies between and connects the ONU404, through a second electrical port or socket (e.g., RJ-11) to the NID136of a subscriber premise104. At the NID136, another splitter408filters or separates the POTS NB signal and the xDSL modem electrical communications BB providing the NB signal to connect the subscriber's primary telephone line service400and providing the BB signal to the SLIC132. It will be appreciated that in this embodiment of the invention an uninterruptable power supply (UPS) or battery backup source is not required. If a subscriber suffers a power outage, the CPE/ST134will be without power and thus broadband communications will be down as well. This is tolerable since the outage will cause powered equipment such as TVs and the subscriber's LAN to be down as well. The CPE/ST134will not be able to provide DC power to the twisted wire pair. The CO or DLC402routinely monitors conditions on the twisted wire pair transmission line and sensing a loss of power on the line can provide the necessary DC power to continue providing POTS services such as primary telephony line service400. Referring toFIG.5in view ofFIG.1a, in which another alternative embodiment in accordance with the present invention is illustrated wherein the fiber in the loop network is a FTTP, FTTdp, FTTD or Fiber to the Home (FTTH) network and the subscriber-powered network element is an ONT500at or near the NID136. The ONT500does not support multiple subscriber premises thus aggregation methods are not necessary in the TC-Layer and CO modem adaptation device502and only a single DAA124, xDSL CO modem122and DC-to-DC converter126are required to perform a method of an embodiment of the invention. The FTTP or FTTH network illustrated inFIG.5is a passive optical network (PON). If primary telephone service line is to be provided by the FTTP or FTTH network then a UPS/battery backup source150for the CPE/ST134may be required for life-line regulatory obligations. Referring toFIG.6in view ofFIG.5, in which yet another alternative embodiment in accordance with the present invention is illustrated wherein the FTTP or FTTH does not provide a primary telephone service line. In this embodiment the POTS services provided by a CO or DLC402pass through the NID136with no splitting and on a separate twisted wire pair600from the twisted wire pair130which provides broadband services to the subscriber premise104and provides subscriber power to the ONT500as previously described and indicated. Referring toFIG.7ain view ofFIG.1a, an alternative embodiment in accordance with the present invention is illustrated wherein a FTTP, FTTdp, FTTD or FTTH network is shown with a subscriber-powered ONT700, which is powered by Power over Ethernet (PoE). The FTTP or FTTH network shown being a passive optical network (PON) implementation. PoE is defined by the IEEE 802.3af and IEEE 802.3at specifications (hereby included by reference) and defines a way to build Ethernet power-sourcing equipment and powered device terminals in local area networks (LANs). The specification involves delivering 48 volts of DC power over unshielded twisted-pair wiring in LANs. It works with existing LAN cable plant, including Category 3, 5, 5e or 6; horizontal and patch cables; patch-panels; outlets; and connecting hardware, without requiring modification. A CPE/ST702comprising a communication device such as an Ethernet MAC and PHY704device is in electrical communication with a first Power over Ethernet (PoE) capable device706. The PoE capable device706internally comprises an electrical coupling device such as a Power Sourcing Equipment (PSE) device in accordance with the 802.3af or 802.3at standard. The PSE electrical coupling device couples electrical Ethernet signals and DC power, which may be derived from subscriber mains power, provided by DC power source138. The first PoE capable device706passes electrical Ethernet signals as well as DC power through WAN port129as a combined electrical WAN signal over Ethernet cable708to an electrical port or socket (e.g., RJ-45) at a second PoE capable device710in the ONT700. The ONT700being at or near the NID136. The second PoE capable device710comprises an electrical coupling device such as a Powered Device (PD) in accordance with the 802.3af or 802.3at standard. The second PoE capable device710is capable of decoupling the electrical Ethernet signals from the combined electrical WAN signal, which are then provided to a communication device such as the Ethernet PHY712, and decouples DC power which is then provided to the ONT700power supply128. The second PoE capable device710may contain a DC-to-DC converter to supply (not shown) to a sufficient threshold the appropriate DC current and DC voltage needs of the ONT700. The communication device Ethernet PHY712is in electrical communication with a TC-Layer and Ethernet MAC adaptation device714to complete the broadband communication flow (e.g., bundling or encapsulating and sending data into upstream subscriber data packets or frames; receiving and un-bundling or decapsulating data into downstream subscriber data packets or frames; managing the transmission of packets or frames on the network via medium access and bandwidth allocation protocols; providing necessary messaging and end point behavior, and checks, reports and may correct for detectable errors) and to indicate the differences in ONT700over previous ONT500. It will be appreciate that in alternative embodiments wherein TC-Layer and Ethernet MAC adaptation device714is in electrical communication with a plurality of Ethernet PHY712devices the TC-layer and Ethernet MAC adaptation device714may also pool or multiplex/demultiplex together (e.g., buffered using a first in first out manner) the communications from the plurality of Ethernet PHY712devices. The CPE/ST702is provided power during subscriber power outages by a UPS/battery backup150for lifeline powering requirements. Referring toFIG.7b, an alternative embodiment ofFIG.7ais shown with a CPE/ST705comprising PoE capable device(s)706and DC power source138. The CPE/ST705passes electrical Ethernet signals between CPE/ST703aand ONT700via Ethernet cables707and708respectively as well as coupling DC power from the DC power source138onto708as a combined electrical WAN signal through WAN port129. CPE/ST705is provided power during subscriber power outages by the UPS/battery backup150for lifeline powering requirements. Referring toFIG.7c, an alternative embodiment ofFIG.7bis shown with a legacy CPE/ST703bthat is not PoE capable. PoE capable device706passes electrical Ethernet signals from Ethernet MAC and PHY704via Ethernet cable709as well as DC power provided by DC power source138over Ethernet cable708as a combined electrical WAN signal through WAN port129to the second PoE capable device710in ONT700. The CPE/ST703band CPE/ST705are provided power during subscriber power outages by the UPS/battery backup150for lifeline powering requirements. Referring toFIG.8in view ofFIG.7a, a flow chart of a method of an embodiment of the present invention utilizing PoE is illustrated. Powering a network element of a FTTP, FTTdp, FTTD, or FTTH network, such as ONT700inFIG.7a, from a subscriber terminal702or705at a subscriber premise104entails providing or supplying a DC power (e.g., from DC power source138to PSE706) of sufficient threshold to electrically power the network element onto a twisted wire pairs or Ethernet cable708from the subscriber terminal as indicated by block800. At block802, electrical Ethernet communications or signals from the Ethernet MAC and PHY device704or Ethernet PHY712are coupled to the same Ethernet cable708transmission line with the DC power. At block804, the DC power and electrical Ethernet signals are transmitted, driven or sent as a combined electrical WAN signal through WAN port129or PoE capable device710across the Ethernet cable708transmission lines from the subscriber terminal702or705to the network element, such as ONT700or vice versa. At block806, the driven DC power and electrical Ethernet signals as the combined electrical WAN signal are accepted or received at the network element over the same Ethernet cable708. At block808, the network element decouples (e.g. using a high pass filter) the electrical Ethernet signals from the DC power, or vice versa (e.g., using a low pass filter) with the second PoE capable device710. At block810, the network element performs DC-to-DC power conversion (e.g., by PoE capable device710and by power supply128which in some embodiments combines the DC power delivered by a plurality of PoE capable devices710) for use by the network element. Referring toFIG.9aandFIG.9bin view ofFIG.7a, a FTTP, FTTdp, FTTD or FTTH network is shown wherein the implementation of the network is a point-to-point (PtP) fiber optic wide area network. The ODF300lacks passive splitters and illustrates the one-to-one direct connection between terminals112, cabinets114, NIDs136and the CO100. Such PtP networks may be implemented by a point-to-point gigabit or 10 gigabit Ethernet network (e.g. active Ethernet communication network) with complementary components such as optical transceiver302and data link layer304in accordance with whatever specific protocol is chosen for the network implementation (e.g., active Ethernet). The optical transceiver302may be plugged into or comprise an optical port or socket, the optical port serving as a site for coupling to a fiber and for performing the O/E and E/O conversions. Some embodiments of network elements may be made without optical transceivers, however having an optical port for later installation of an optical transceiver. In embodiments of network elements made with an optical transceiver, the optical port and the optical transceiver are essentially the same. Some form factors for optical transceiver302include, but not limited to, SFF, SFP, SFP+, and XFP. Additionally some embodiments may use dual fibers for communications with the CO, head-end or OLT.FIG.9aandFIG.9bserve to show that the PoE exemplary embodiment of the invention as previously described, as inFIG.8, is a method apathetic and even naïve of the design choice or implementation of the fiber in the loop network. The method works equally well for both PtP networks and PONs. Referring now toFIG.10in view ofFIG.1a, an alternative embodiment in accordance with the present invention is illustrated wherein a FTTC, FTTdp, FTTD or FTTN network is shown with a subscriber-powered ONU1000, which is in communication with a subscriber's terminal or CPE1010over a coaxial cable1008transmission line using communication devices such as Multimedia over Coax Alliance (MoCA) devices1004/1012. The FTTC or FTTN network shown being a passive optical network (PON) implementation. MoCA is an industry driven specification for delivering networking, high-speed data, digital video, and entertainment services through existing or new coaxial cables in homes. A CPE/ST1010comprising a communication device such as MoCA network client1012device is in electrical communication with an electrical coupling device such as first bias T device1005. Bias T′s are coaxial components that are used whenever a source of DC power is connected to a coaxial cable. The bias T does not affect the AC or RF transmission through the cable. The first bias T device1005couples MoCA electrical communication signals from MoCA Network Client1012with DC power of sufficient threshold to electrically power ONU1000from DC power source138as a combined electrical WAN signal though WAN port129and transmitted over coaxial cable1008through an electrical port (e.g., F-type or N-type connector) to another electrical coupling device such as second bias T device1006in the network element ONU1000, the ONU1000being located away from the NID136(in this embodiment shown) and may serve a plurality of subscribers. The second bias T device1006is capable of decoupling (e.g., using a high pass filter) the MoCA electrical communication signals, which is provided to a second communication device such as the MoCA access network controller device1004, and decoupling (e.g. using a low pass filter) DC power to the ONU1000DC-to-DC converter126from the combined electrical WAN signal on coaxial cable1008. The DC-to-DC converter126supplying to a sufficient threshold the appropriate DC current and DC voltage regulation to the power supply128which in some embodiments combines the DC power delivered by a plurality of DC-DC converters126and distributes various voltage power-supply rails (e.g., 3.3 volts, 1.8 volts, or 0.9 volts) to ONU1000's subsystem devices. The MoCA access network controller device1004is in electrical communication with a 1:N Aggregation with MoCA adaptation layer device1002that aggregates or multiplexes/demultiplexes (e.g., buffered using a first in first out manner) the broadband communication and service flows between the CO and subscribers. Additionally, in some embodiments, the broadband communications may comprise data that has priority over other data and the 1:N aggregation with MoCA adaptation layer device1002can aggregate or multiplex/demultiplex priority data before data that does not have priority. The CPE/ST1010is provided power during subscriber power outages by a UPS/battery backup150for lifeline powering requirements. In this way, a bias T device serves to inject and extract DC power to supply the powering needs of the ONU1000while combining MoCA signals on a same subscriber-powered coaxial cable1008. Referring toFIG.11in view ofFIG.10, a flow chart of a method of an embodiment of the present invention utilizing power over coax is illustrated. Powering a network element of a FTTC, FTTdp, FTTD, or FTTN network, such as ONU1000inFIG.10, from a subscriber terminal1010at a subscriber premise104entails providing or supplying a DC power (e.g., from DC power source138) of sufficient threshold to electrically power ONU1000to bias T1005for coupling onto a coaxial cable1008from the subscriber terminal as indicated by block1100. At block1102, electrical MoCA communications or signals from the MoCA network client device1012or MoCA access network controller1004are coupled to the same coaxial cable1008with the DC power. At block1104, the DC power and electrical MoCA signals are transmitted, driven or sent as a combined electrical WAN signal though WAN port129or bias T1006across the coaxial cable1008from the subscriber terminal1010to the network element, such as ONU1000or vice versa with respect to the electrical MoCA communications or signals. At block1106, the driven DC power and electrical MoCA signals as the combined electrical WAN signal are accepted or received at the network element over the same coaxial cable1008. At block1108, the network element decouples (e.g. using a high pass filter) the electrical MoCA signals from the DC power, or vice versa (e.g., using a low pass filter) with the second bias T device1006. At block1110, the network element performs DC-to-DC power conversion on the supplied and decoupled DC power for use by the network element. Referring toFIG.12in view ofFIG.10, an alternative embodiment in accordance with the present invention is illustrated wherein a FTTP, FTTdp, FTTD, or FTTH network is shown wherein the implementation of the network is a point-to-point (PtP) fiber optic wide area network. The ODF300lacks passive splitters and illustrates the one-to-one direct connection between terminals112, cabinets114, NIDs136and the CO100. Such PtP networks may be implemented by a point-to-point gigabit or 10 gigabit Ethernet network (e.g. active Ethernet communication network) with complementary components such as optical transceiver302and data link layer304in accordance with whatever specific protocol is chosen for the network implementation. The optical transceiver302may be plugged into or comprise an optical port or socket, the optical port serving as a site for coupling to a fiber and for performing the O/E and E/O conversions. Some embodiments of network elements may be made without optical transceivers, however having an optical port for later installation of an optical transceiver. In embodiments of network elements made with an optical transceiver, the optical port and the optical transceiver are essentially the same. Some form factors for optical transceiver302include, but not limited to, SFF, SFP, SFP+, and XFP. Additionally some embodiments may use dual fibers for communications with the CO, head-end or OLT.FIG.12serves to show that the power over coax exemplary embodiment of the invention as previously described, as inFIG.10, is a method apathetic and even naïve of the design choice or implementation of the fiber in the loop network. The method works equally well for both PtP networks and PONs.FIG.12also serves to illustrate the power over coax method with an ONT1200as well as to show compatibility with other MoCA capable CPE devices1210that share network communications with the MoCA access network controller1004on the same coaxial cable1008, though such compatibility can be used with ONUs as well.FIG.12also serves to illustrate the use of an optical transceiver302and data link layer304, in accordance with whatever specific protocol is chosen for the network implementation that does not need to perform 1:N aggregation or multiplexing/demultiplexing of multiple MoCA connections. A DC block1207is used to isolate DC power while allowing data signals to pass through unaffected to allow use of other CPEs1210that do not provide DC power to the coaxial cable1008. The DC block1207may be internal to the CPE1210or external (not shown). The CPE/ST1010is provided power during subscriber power outages by a UPS/battery backup150for lifeline powering requirements. Referring toFIG.13ain view ofFIG.12, an alternative embodiment of the invention using a FTTP, FTTdp, FTTD, or FTTH network is shown wherein the implementation of the wide area network is a PON102. In this embodiment a CPE/ST1302comprising bias T1005and DC power source138is shown. The bias T1005of CPE/ST1302combines the MoCA or RF communications from coaxial cable1308onto coaxial cable1008transmission lines with DC power from the DC power source138as a combined electrical WAN signal though WAN port129. The bias T device1006is capable of decoupling the MoCA or RF communication signals, which are then provided to the MoCA or RF access network controller device1004, and decoupling DC power signal to the DC-to-DC converter126from coaxial cable1008. The DC-to-DC converter126supplying the appropriate DC current and DC voltage regulation to the power supply128to distribute power at different voltage rails (e.g., 3.3 volts, 1.8 volts, or 0.9 volts) throughout all the ONT1200subsystem devices. This allows simplification and use of legacy (i.e., non-subscriber powered) CPE/ST devices1300/1310while providing subscriber-power from CPE/ST1302to the network element ONT1200over same coaxial cable1008used for communications. Referring toFIG.13bin view ofFIG.13a, an alternative embodiment of the invention using a FTTP, FTTdp, FTTD or FTTH network is shown wherein the implementation of the wide area network is a PON102. In this embodiment a CPE/ST1304comprising bias T1305and DC power source138is shown and a UPS/battery backup source150for DC power source138is provided, which may be required for regulatory obligations. The bias T1305of CPE/ST1304combines the MoCA or RF communications from subscriber side coaxial cables1308and from network element side coaxial cable1008with DC power from the DC power source138and transmitted as a combined electrical signal on coaxial cables1008and1308. CPE/ST1301has a bias T1306that decouples MoCA or RF communications and DC power from coaxial cable1308. Bias T1306providing DC power to the CPE/ST1301's power supply1307for distributing the appropriate voltage supply rails to all of CPE/ST1301electrical subsystems. The embodiment enables a CPE/ST, such as CPE/ST1301, and a network element, such as ONT1200, to be powered by a second CPE/ST, such as CPE/ST1304, within the customer premise via the same coaxial cable transmission line used for network communications, such as coaxial cable1008and1308. Referring toFIG.14ain view ofFIG.10, an alternative embodiment of the invention using a FTTC, FTTdp, or FTTN network is shown wherein the implementation of the wide area network is a PON102. In this embodiment the bias T1005and DC power source138are external to the CPE/ST1300and are located at or near the NID136. The bias T1005combines MoCA or RF communications from subscriber side coaxial cable1308onto network element side coaxial cable1008with the DC power from the DC power source138of sufficient threshold to electrically power ONU1000as a combined electrical WAN signal. This allows simplification of CPE/ST devices1300/1310and simplification of subscriber installation. Generally, power is not available at the NID136; however power at the NID may be available in future Greenfield land (i.e., undeveloped land as opposed to Brownfield land) installations and this embodiment allows a network element, such as ONU1000, to be powered from the NID with power derived from subscriber mains power via the same coaxial cable transmission line used for network communications, such as coaxial cable1008and1308. Referring toFIG.14bin view ofFIG.14a, an alternative embodiment of the invention using a FTTC, FTTdp, or FTTN network is shown wherein the implementation of the wide area network is a PON102. In this embodiment the bias T1305, DC power source138and a UPS/battery backup source150are external to the CPE/ST1301and are located at or near the NID136. The bias T1305combines MoCA or RF communications from subscriber side coaxial cables1308and network element side coaxial cable1008with the DC power from the DC power source138as a combined electrical WAN signal. This allows simplification of subscriber installation as well as access for maintenance of the UPS/battery backup source150providing power during electrical power blackout enabling lifeline services. Additionally, this embodiment enables a CPE/ST, such as CPE/ST1301, and a network element, such as ONU1000, to be powered from the NID with power derived from subscriber mains power via the same coaxial cable transmission line used for network communications, such as coaxial cable1008and1308. In yet another alternative embodiment in accordance with the present invention, HomePNA is used as the communication method between an ONU/ONT and a plurality of subscriber terminal/CPEs. HomePNA is an industry standard for home networking solutions based on internationally recognized, open and interoperable standards that allow worldwide distribution of triple-play services, such as IPTV, voice and Internet data by leverage existing telephone wires (twisted wire pair) or coaxial cable transmission line. Thus, alternative embodiments ofFIGS.1-6are possible substituting xDSL devices with HomePNA capable devices for subscriber powering network elements over twisted wire pairs as well asFIGS.10-14bwith substitution of MoCA devices with HomePNA capable devices for subscriber powering network elements over coaxial cable. In yet another alternative embodiment in accordance with the present invention, ITU-T G.hn standard is used as the communication method between an ONU/ONT and a plurality of subscriber terminal/CPEs. G.hn is yet another industry standard for home networking solutions based on internationally recognized, open and interoperable standards that allow worldwide distribution of triple-play services, such as IPTV, voice and Internet data by leverage existing telephone wires (twisted wire pair) or coaxial cable transmission line. Thus, alternative embodiments ofFIGS.1-6are possible substituting xDSL devices with G.hn capable devices for subscriber powering network elements over twisted wire pair, and as well asFIGS.10-14bwith substitution of MoCA devices with G.hn capable devices for subscriber powering network elements over coaxial cable. A plurality of G.hn devices may be connected to the same subscriber-powered twisted wire pair130or subscriber-powered coaxial cable1008. While DC power is the preferred method of delivering power from a subscriber's premise to a network element, AC power is also possible. Alternate embodiments ofFIGS.1-6andFIGS.10-14bare possible with substitution of DC power with AC power. Alternate embodiments wherein elements such as: DC power source138,1307; DC-DC converter126; DC block1207; UPS backup150and electrical coupling devices such as: SLIC132; DAA124,125; and bias T1005,1006,1305,1306are appropriately substituted or designed with AC power in mind are also possible. While UPS/battery backup150in various embodiments of the present invention have been shown to be an external device. Alternate embodiments with the UPS/battery backup150internal to the CPE, communication and/or power-coupling device are possible (not shown). Alternate embodiments with the UPS/battery backup150may be combined with DC power source138. It will be appreciated by those skilled in the arts, that during lifeline powering events that network elements such as ONUs and ONTs and CPE/ST equipment may power down non-essential devices (e.g., modems, transceivers, power monitors) to extend the time that lifeline services can be provided. Such powering down events may also include reducing the line rates of communications. It will be appreciated that in the various embodiments of the present invention the network elements such as ONU or ONT may have circuitry to measure their power usage (not shown). Additionally, alternative embodiments of the ONUs and ONTs with power measurement, metering or monitoring circuitry may report their power usage back to the OLT or have their power meter or power measurement circuits reset, via the management or control channel with the OLT. Service Providers may use this information to reimburse subscribers for network element electricity usage and may reimburse government entities for related taxation regulations. In yet another alternative embodiment of the invention, an embodiment of a CPE or subscriber terminal may measure the amount of power supplied or injected over the transmission line between the subscriber terminal and the network element. The CPE or subscriber terminal may report (e.g., via the network element) the power supplied to the Service Provider or an affiliate via TR-069 or similar protocol. Additionally, the CPE or subscriber terminal may report the power supplied to a subscriber service entity (e.g., Smart Home Power Monitoring application). It will be appreciated that, while not shown, the subscriber terminal or CPE (e.g., CPE/ST shown inFIG.1a,1b,3-7c,9,10,13a-14b) may be a set-top box (e.g., IPTV, DVR, Media Hub) or may be incorporated into a television set (e.g., HDTV display). For example, a set-top box or a television incorporating an embodiment of the invention may power a service provider network element which provides services such as telephony, internet access, broadcast video, interactive video communications, and on-demand video. The set-top box, HDMI adaptor or high definition television (HDTV) may utilize G.hn communications and may be a slave G.hn device served by the service provider's network element serving as the master G.hn device controlling one or more slave G.hn based set-top box, HDMI adaptor or HDTV device. It will also be appreciated that embodiments of the invention have the advantage of reducing installation labor time and cost. A significant portion of the time taken to connect subscribers to the Service Provider's network is the time and labor involved in provisioning power to the network element (e.g., ONU, ONT) and obtaining government or regulatory permits when the location of the network element requires deployment of new power-main connections and power supplying equipment. Since embodiments of the invention use the communication medium used to provide services (e.g., internet access, voice over internet protocol, broadcast TV, video conferencing) to also provide electricity to the network element, additional time and labor to power the network element is saved. Furthermore, self-installation by subscribers is possible assuming a Service Provider has established service access to the premise (e.g., fiber connection or copper drop from a fiber). Self-installation by a subscriber may be made as simple as plugging a power cord into a wall outlet from the Service Provider provided or Subscriber purchased subscriber terminal (e.g., CPE, set top box, HDTV) and connecting the subscriber terminal to an electrical wire pair or cable from a wall phone jack or coaxial cable outlet. The reduction in installation labor time and cost may be significantly more than the cost of the network element (e.g., ONT) and the subscriber terminal. Additionally, Subscribers and Service Providers benefit from the ease of installation associated with embodiments of the invention due to the reuse of existing premise wiring which may preclude the deployment of new subscriber-premise overlay wiring that may compromise, during installation, the integrity of the subscriber premise thermal insulation, natural gas lines, sewer lines and mains power lines. FIG.15ais an example illustration of a circuit model of an electrical coupling device for coupling data communications and electrical power between a subscriber terminal and a network element. The circuit model uses hybrid transformers1510n,1510sto couple four-wires onto two-wire transmission lines for full duplex communications, wherein transmit and receive communication signals each comprise a pair of conductors (e.g., four wires total) as does the transmission line (i.e., two conductors)1512and communication signals pass through the transformers with minimal loss. The hybrid transformer15010n,1510sblocks or cancels out transmit signals from appearing at the receive port as well as blocks or cancels out receive signals from appearing at the transmit port thus enabling full duplex communications. A balancing network1514is a circuit comprising of capacitance and resistance and sometimes inductance, forming a complex impedance network as transmission lines are not purely resistive but rather a complex impedance causing both the amplitude and phase to vary as signal frequencies vary. The electrical power signal is also injected onto1516and recovered1518from the transmission line1512via center-tapped transformers and ZLis representative of the load of the network element. Equivalent circuits may be produced that, as previously mentioned, are transformer-based, optically-based, capacitively coupled-based, active silicon/integrated circuit-based (e.g., transistors, op-amps), or some combination thereof. Additional circuits or their equivalents for electrical protection and isolation (e.g., isolation transformer, low frequency blocking capacitors, common mode choke), AC-to-DC conversion (e.g., bridge rectifier, reservoir capacitor), transmit and receive signal filtering (e.g., capacitive, inductive and resistive elements) and device detection circuits to determine when a network element is attached or removed from the transmission line (e.g., methods utilizing a low level current) may also be included in embodiments of the invention. Additionally, modulators or mixers, low noise amplifiers and additional signal filters can be employed in embodiments to adjust the frequency of communication signals (e.g., xDSL, Ethernet, MoCA, G.hn, G.fast) as well as the voltage and current characteristics over the frequency of the electrical power signal. Referring now toFIG.15bin view ofFIG.15aandFIG.1a, an exemplary illustration of a circuit model of an electrical coupling device for coupling data communications and DC electrical power between the subscriber terminal104and the network element ONU110ofFIG.1ais shown. xDSL client modem140is coupled to SLIC132comprising of transmit signal filter1520, receive signal filter1522and transmission line hybrid coupling circuit1510s. A DC power source138is coupled to SLIC132and SLIC132also couples to twisted wire pair130. xDSL CO or Head-end modem122is coupled to DAA124comprising of transmit signal filter1524, receive filter1526and transmission line hybrid coupling circuit1510n. DAA124decouples electrical power signal carried on twisted wire pair130and provides the decoupled electricity to DC-DC converter126. Referring now toFIG.15c, an embodiment similar toFIG.15b, however, incorporating AC power is shown. AC power supply1550, which may derive power from subscriber mains power, is coupled to SLIC134and a bridge rectifier and reservoir capacitor1555to regulate and convert AC power signal to a DC power signal which is then provided to DC-DC converter126. Referring now toFIG.16a, an exemplary illustration of a circuit model of an electrical coupling device for coupling Ethernet communications and DC electrical power is shown. An Ethernet power source equipment device (PSE)1610and an Ethernet powered device (PD)1612utilize center-tapped transformers on two pairs of conductors1614(e.g., two twisted wire pairs) to evenly transfer electricity from the PSE1610to PD1612. An alternative embodiment may utilize the spare twisted wire pairs1616instead of twisted wire pairs1614. Referring now toFIG.16b, an exemplary illustration of a circuit model for coupling Ethernet communications and DC electrical power between a subscriber terminal702and a network element (e.g., ONU)700in view ofFIG.16aandFIG.7ais shown. Two pairs of conductors708are used to support fast Ethernet communications (i.e. 100 Mbit) and electrical power transfer between PSE706and PD710. Alternative embodiments may use four pairs of conductors to support gigabit Ethernet on CAT 5 cable or fast Ethernet over CAT 3 cable. It will be appreciated while embodiments of the invention employing Ethernet have been shown and referenced as using two or four pairs of conductors, as Ethernet is generally understood to be deployed and thus referenced as such to aid in teaching the invention, embodiments of the invention can use variants of Ethernet that use only a single twisted wire pair of conductors (i.e., one, two or four pairs or up to 4 twisted wire pairs can be used). However, xDSL (e.g., VDSL2, G.fast) and G.hn technologies are preferred in embodiments using single twisted wire pairs given the maturity and robustness of xDSL and G.hn technology over the medium of single twisted wire pairs. Referring now toFIG.17a, an exemplary illustration of a circuit model of an electrical coupling device for coupling data communications and DC electrical power is shown. An alternative method of combing data communications (e.g., DOCSIS, DOCSIS 2.0, DOCSIS 3.0, DOCSIS 3.1, MoCA, MoCA 2.0 or G.hn modem) and electrical power on the same transmission medium, preferably coaxial cable, utilizes a bias T. A bias T for a coaxial cable1708comprises a feed inductor1710, capable of blocking high frequency signals (e.g., communication signals), and a blocking capacitor1712, capable of blocking low frequency signals (e.g., DC electrical power, low frequency AC electrical power). Data communications signals are passed through IN1714and OUT1716ports with only the blocking capacitor in series. The inductor1710prevents communications signals from passing through the Power1718port and the capacitor1712prevents DC power from leaving through the IN1714port. The OUT1716port comprises both the communication signal from the IN1714port and the DC power from the Power1718port. Additional circuits or their equivalents may be incorporated to decrease signal losses (e.g., utilizing bias T designs from waveguides or microstrips, additional inductors and capacitors to form resonant frequency circuits, and shunt capacitors) and protect from application of reverse voltage (e.g., an internal blocking diode). Referring now toFIG.17b, an exemplary illustration of a circuit model of an electrical coupling device for coupling data communications and DC electrical power between a subscriber terminal1010and a network element (e.g., optical node, ONU)1000in view ofFIG.17aandFIG.10is shown. A coaxial cable1008is used to support data communication and electrical power transfer between bias T1005and bias T1006. Blocking capacitors allow data communications to flow between MoCA client1012and MoCA controller1004while blocking electrical power. And blocking inductors allow electrical power flow between DC power source138and DC-DC converter126while blocking data communications. Additional circuitry to translate four-wires onto two-wire transmission lines for full duplex communication is not shown but assumed (e.g., hybrid transformer as previously discussed) to be part of the communication devices or modem subsystems (e.g., MoCA client1012, MoCA controller1004). It will be appreciated that bias T1305ofFIG.13bandFIG.14bdoes not comprise a blocking capacitor, such as1712, to allow DC or AC power to flow onto coaxial cables1008and1308. As previously mentioned, device detection circuits to determine when a network element is attached or removed from the transmission line may also be included in embodiments of the invention. An exemplary detection circuit and process includes a resistive element or resistive load (e.g. 10Ω-35 kΩ resistor) at the network element placed between powered conductors of the transmission line. In alternative embodiments the resistive load may vary as a function of phase or frequency of a voltage or current. A subscriber terminal senses the resistance between powered conductors through an applied low level detection current (e.g., 20 mA dc) before applying additional voltage and current (e.g., 250 mA dc at 50 Vdc absolute). Additionally, a network element may vary the resistance seen by the subscriber terminal in a predetermined manner and thereby indicate to the subscriber terminal the power requirements of the network element. In other words, the subscriber terminal can have predetermined expectations for the resistance or load values applied by the network element that indicate to the subscriber terminal the power requirements of the sensed network element. Furthermore, a subscriber terminal may monitor the applied power at predetermined intervals (e.g., 50 ms) for power drops indicating that the network element has been disconnected or a problem with the transmission line. Power drops lasting longer than a second predetermined interval (e.g., 400 ms) will trigger the subscriber terminal to cease applying electrical power to the transmission line(s) until the subscriber terminal senses (e.g., again through a low level current) the predetermined resistive element of the network element once more. In an alternative embodiment wherein there are multiple subscriber terminals sharing the communication transmission line to the network element, after a first subscriber terminal has sensed the network element and provided electrical power to the network element subsequent subscriber terminals that couple to the communication transmission line can sense the presence of electrical power already on the transmission line and not provide additional power. In yet another alternative embodiment, a subscriber terminal (i.e., a second subscriber terminal) can be powered over a shared communication transmission line from another subscriber terminal (i.e., a first subscriber terminal). It will be appreciate that as previously discussed some embodiments of the invention may employ a low level detection current driven by a subscriber terminal to sense the network element. This low level detection current and associated detection voltage may be at levels below the threshold to sufficiently power the network element. A purpose of the low level detection current is to sense the presence of the network element and the load applied by the network element can be used to indicate the power requirements of the network element to the subscriber terminal, as previously discussed. Once the presence of the network element is sense by the subscriber terminal using a detection current, additional current or voltage can be applied by the subscriber terminal to a threshold to sufficiently power the network element, as previously discussed. This threshold may be determined by the power requirements of the network element as indicated by the load applied by the network element sensed by the subscriber terminal, again as previously discussed. It will be appreciated that embodiments of subscriber terminals or network elements may incorporate a large capacitor or small battery that can power the subscriber terminal or network element to support sending a Dying Gasp message. A Dying Gasp message or signal is sent by the subscriber terminal or network element to the head-end or CO letting the head-end or CO (e.g., an OLT) know that a subscriber terminal (Dying Gasp message relayed by the network element for the subscriber terminal) or network element has lost electrical power and is about to go offline. This saves a service provider time by alerting them to what has caused the connection failure. It will be appreciated that the large capacitor or small battery can be part of the power supply of the subscriber terminal or network element or the capacitors of the power supply (i.e., power supply reserves) can be used to support sending a Dying Gasp message. It will be appreciated that the large capacitor, small battery or power supply reserves in some embodiments can power the subscriber terminal or network element to send the Dying Gasp message for 50 ms or sending the Dying Gasp message multiple times. Additionally, parts or subcomponents of the subscriber terminal or network element (e.g., modems, transceivers) can be turned off when sensing power loss and the minimum number of subcomponents and network interfaces to support sending the Dying Gasp message maintained with power from the large capacitor, small battery or power supply reserves. Additionally the Dying Gasp message can be a bit indicator in the overhead section of a message frame used for network communications. Furthermore, the Dying Gasp message or signal can be sent between the subscriber terminal and the network element as well. It will be appreciated that embodiments of the subscriber terminal or network element can incorporate power status indicators (e.g., LED power status indicators that blink or change color). For example status indicators at the subscriber terminal can indicate whether the subscriber terminal is ready to supply electrical power to the network element or if the subscriber terminal is providing electrical power to network element or if the subscriber terminal has received a Dying Gasp message from the network element. The network element status indicators can indicate whether the network element is receiving electrical power from the subscriber terminal or if the network element is running on battery reserves or if the network element has received a Dying Gasp message from the subscriber terminal (network terminal is running on battery reserves). It will be appreciated there can also be communication status indicators at embodiments of the subscriber terminal or network element to indicate whether or not communication has been established or is taking place (e.g., blinking LED) between the subscriber terminal and the network element. It will be appreciated that the CO can monitor the power status (e.g., power ready, steady state, on battery reserves) of network elements and subscriber terminals through network administration or management messages or network system alarms. Referring now toFIG.18, an exemplary illustration of the frequency spectrum used by various communication protocols is shown. While not complete with all possible communication protocols nor drawn to scale,FIG.18serves to illustrate that communication protocols have defined frequency distributions and that the methods of embodiments of the invention for combining an electrical power signal or electricity and electrical data communication signals on the same communication medium as a combined electrical signal are methods that are apathetic and even naïve of the design choice or implementation of the data communication signals used between the network element and the subscriber. Communication devices compatible or compliant with communication protocols such as but not limited to: ADSL ANSI T1.413, ITU-T G.992.1 (G.DMT), ITU-T G.992.2 (G.lite); ADSL2 ITU-T G.992.3/4; ADLS2+ ITU-T G.992.5; VDSL ITU-T G.993.1; VDSL2 ITU-T G.993.2; DOCSIS 1.0, ITU-T J.112 (1998); DOCSIS 1.1, ITU-T J.112(2001); DOCSIS 2.0, ITU-T J.122; DOCSIS 3.0, DOCSIS 3.1, ITU-T J.222, ITU-T J.222.0, ITU-T J220.1, ITU-T J.222.2, ITU-T J.222.3; HomePNA (HPNA) 2.0, ITU-T G.9951, ITU-T G.9952, ITU-T G.9953; HomePNA (HPNA) 3.0, ITU-T G.9954 (02/05); HomePNA (HPNA) 3.1, ITU-T G.9954 (01/07); HomePlug 1.0, TIA-1113; HomePlug AV, HomePlug AV2, IEEE P1901; Multimedia over Coax Alliance (MoCA) 1.0, MoCA 1.1, MoCA 2.0; ITU-T G.hn, ITU-T G.9960, ITU-T G.9961, ITU-T G.hnta, ITU-T G.9970, ITU-T G.cx, ITU-T G.fast are congruent with methods and embodiments of the invention and these specifications are hereby included by reference. Preferred embodiments of the invention supply electrical power from the subscriber premise to the network element on the same communication medium on a frequency separate (preferably at a lower frequency) from the frequency of the network communication signals used between the network element and the subscriber premise. For example, using VDSL2 to communicate data between a network element (e.g. ONT/ONU) and a subscriber premise over a twisted wire pair transmission line while remotely powering the network element from the subscriber premise can be accomplished by transmitting DC power (i.e., essentially at zero frequency), AC power at 60 Hz or a DC power signal or AC power signal centered at some frequency other than that used by VDSL2 since VDSL2 occupies frequencies between 25.8 KHz and 30 MHz. In another example, using MoCA to communicate between a network element and a subscriber premise over a coaxial cable while remotely powering the network element can be accomplished by transmitting DC power, AC power at 60 Hz or a DC power signal or AC power signal centered at some frequency other than that used by MoCA since MoCA occupies frequencies between 860 MHz and 1.55 GHz. In yet another example, using ITU-T G.hn to communicate between a network element and a subscriber premise over either a twisted wire pair or coaxial cable transmission line while remotely powering the network element can be accomplished by transmitting a DC power, AC power at 60 Hz or a DC power signal or AC power signal centered at some frequency other than that used by ITU-T G.hn since ITU-T G.hn occupies frequencies between 25.8 KHz and 100 MHz-150 MHz range or bands (depending on speed mode of G.hn network). Alternatively, while not preferred, embodiments of the invention transmitting power remotely from the subscriber premise to the network element on a frequency occupied, at least in part, by the communication signals used to communicate between the network element and the subscriber premise are envisioned to be possible. The transmitted electrical power would raise the noise power in the communication protocol's frequency spectrum, however as long as the communication signals are transmitted at power levels greater than the raised noise power, communications between the network element and the subscriber premise are still be possible. For example, modern xDSL (e.g., adsl, adsl2, vdsl, vdsl2, G.fast) modems or G.hn modems measure the noise power spectrum encountered on their transmission lines dynamically or constantly. This information is used to determine the power level of their communication signal transmissions. Therefore, the rise in noise power from remotely transmitting electrical power from the subscriber premise to supply the network element at a frequency that overlaps with the communication frequencies may be compensated by the xDSL modems raising their communication signal transmission levels. However, modems with communication signal power levels beyond conventional signal power levels may be needed. Additionally, the subscriber premise xDSL or G.hn modem should observe the power spectral density or make a spectral density estimation of the twisted wire pair transmission line before any transmission, which can then be used to determine the power levels to supply power and data signals to the network element. It will be appreciated that while embodiments of the invention have been shown or referenced employing different methods of injecting electrical power to the network element at different locations, any method or combination of injection methods and locations can be employed and injecting electrical power to supply the network element from the subscriber electrical power mains can occur anywhere along the communication transmission line between the subscriber terminal and the network element. It will be appreciated that embodiments of subscriber terminals and network elements can employ power saving modes and that electrically powering the network element from subscriber mains power over the same medium used for communication as previously described in embodiments of the invention do not prohibit using power saving modes. These power saving modes can include, but not limited to, reducing line rates of communications as well as powering down non-essential devices such as modems or transceivers for communicating with a subscriber in which the subscriber is no longer active or is no longer supplying the network element with sufficient power (e.g., as measured by power monitoring circuitry), as previously discussed. It will be appreciated that while progressively powering a network element (e.g., an ONU) has previously been discussed, an embodiment of a network element can employ electrical power load balancing among subscriber terminals that are supplying the network element with electrical power. For example, referring now toFIG.1a, power supply128which is electrically coupled to a plurality of DC-DC converters126may balance the network element electrical power draw (e.g., varying a load) from associated subscriber terminals by balancing the electrical power drawn from DC-DC converters126. Electrical Power load balancing can include equal electrical power drawn from all subscriber terminals to electrical power drawn from only a single subscriber terminal. It will be appreciated that, in an alternative embodiment, network administration or management messages can be exchanged between subscriber terminals and network elements wherein subscriber terminals adjust the voltage or current of their electrical power signal supplying the network element responsive to a network message received from the network element or from the CO. Furthermore, in yet another alternative embodiment of the invention, network elements and subscriber terminals can utilize a communication channel modulated over the normal data commutations (i.e., out of band communication channel in a frequency band that does not interfere with normal data communications) to communicate messages only seen between a network element and a subscriber terminal. These messages can include requests from the network element to a subscriber terminal to adjust the voltage or current limits of the electrical power signal being supplied by the subscriber terminal to the network element. It will be further appreciated that network elements requesting subscriber terminals to adjust their voltage or current supplied to the network element for the purpose of load balancing can additionally be done for the purpose of improving line conditions. For example, a power supply at a subscriber terminal may have faulty switch circuitry inducing additional line noise interfering with communications or reducing the data rate of communications. A network element can use messages to subscriber terminals to determine which subscriber terminal is faulty and additionally determine if reduced electrical power signal voltage or current levels from the faulty subscriber terminal can eliminate the line noise. Alternatively, the network element can request the faulty terminal cease supplying an electrical power signal and request one or more other subscriber terminals to increase their electrical power signal voltage or currents to compensate for the loss of the faulty subscriber terminal. It will be appreciated that bundling or encapsulation and unbundling or decapsulation, as previously mentioned, includes the process of taking data from one communication protocol and translating or adapting it into another communication protocol so the data can continue across a network. As data is sent across a network (e.g., from either the service provider to a subscriber or vice versa) the data travels through communication protocol layers that can be represented by the Open Systems Interconnection (OSI) model. As the data flows down the OSI model the data is segmented into packets or frames (e.g., as data payload units) with additional control information appended to the packets or frames. The control information can include, but not limited to, source and destination addresses (e.g., as header information), packet or frame ordering to reassemble the data, as well as error detection means (e.g., as cycle redundancy check (CRC) in a trailer). This process of bundling control information with the segmented data is encapsulation and occurs before data is sent. A similar process occurs at a receiving end in which the control information is unbundled or removed from the segmented data as the data flows up the OSI model and is called decapsulation. Encapsulation and decapsulation can be performed in a combination of hardware and software. For example, referring now toFIG.5, xDSL client modem140encapsulates (e.g., at OSI model Layer 2) upstream (i.e., from the subscriber terminal to the service provider at CO or headend) subscriber data using an xDSL protocol (e.g., VDLS2, G.fast). The upstream subscriber data may be, for example, data that is already encapsulated (e.g., at OSI model Layer 2 or 3) by one or more protocols (e.g., VoIP146, Ethernet142, WiFi146or IPTV144) at the subscriber terminal. The xDSL encapsulated upstream subscriber data is then coupled with electrical power and transmitted to ONT500via twisted wire pair130and xDSL CO modem122then decapsulates (e.g., at OSI model Layer 2) the xDSL encapsulated upstream subscriber data according to the xDSL protocol and the upstream subscriber data is then provided to TC-Layer & CO Modem adaptation layer502. TC-Layer and CO modem adaptation device502then encapsulates (e.g., at OSI model Layer 2) the upstream subscriber data using a PON protocol (e.g., G-PON, 10G-PON, E-PON, 10G-EPON) which is then transmitted to OLT108using PON transceiver116. A similar process occurs in the downstream direction (i.e., from the service provider to the subscriber terminal) when TC-Layer and CO modem adaptation device502receives downstream subscriber data encapsulated using a PON protocol (e.g., G-PON, 10G-PON, E-PON, 10G-EPON) by OLT108and, assuming the downstream subscriber data is intended for an associated subscriber terminal, decapsulates (e.g., at OSI model Layer 2) the downstream subscriber data according to the PON protocol which is then provided to xDSL CO modem122. xDSL CO modem122then encapsulates (e.g., at OSI model Layer 2) the downstream subscriber data using an xDSL protocol (e.g., VDSL2, G.fast) which is then transmitted to xDSL client modem140via twisted wire pair130while ONT500is still being powered electrically over twisted wire pair130from subscriber terminal134. xDSL client modem140then decapsulates (e.g., at OSI model Layer 2) the downstream subscriber data according to the xDSL protocol and the data is then provided to the intended recipient device or port (e.g., VoIP146, IPTV144, Ethernet142, WiFi146). There can be circumstances wherein the conditions of wires inside a subscriber premise are not ideal to sustain desired high-speed communications. In such conditions it will be further appreciated that, in an embodiment of the invention, a first subscriber terminal can communicate and electrically power a network element over a first set of electrical wires or cables and the first subscriber terminal can be powered by a second subscriber terminal communicating and electrically powering the first subscriber terminal over a second set of electrical wires or cables. For example, a first subscriber terminal electrically powers and communicates using VDSL2 or G.fast over one or more twisted wire pairs out to a network element and the first subscriber terminal itself is electrically powered by and communicates using MoCA over a coax cable to a second subscriber terminal. The first subscriber terminal can be located at the NID (i.e., side of the subscriber premise) or in a pedestal nearby while the second subscriber terminal can be located within the subscriber premise. The first subscriber terminal including a VDSL2 or G.fast modem and a MoCA modem and functioning to converter data between the two protocols. Although the invention has been described in terms of particular implementations or embodiments, one of ordinary skill in the art, in light of this teaching, can generate additional implementations, embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof. | 79,867 |
11943001 | DETAILED DESCRIPTION Various embodiments of the disclosure provide a wireless communication system which is adapted to a network environment to support high efficiency and stability, and an electronic device having the same. According to various embodiments of the disclosure, it is possible to provide a wireless communication system which can monitor a network environment in real time and optimize its performance using parameters adapted to the network environment and an electronic device having the same. FIG.1is a block diagram illustrating an electronic device101in a network environment100according to various embodiments. Referring toFIG.1, the electronic device101in the network environment100may communicate with an electronic device102via a first network198(e.g., a short-range wireless communication network), or an electronic device104or a server108via a second network199(e.g., a long-range wireless communication network). According to an embodiment, the electronic device101may communicate with the electronic device104via the server108. According to an embodiment, the electronic device101may include a processor120, memory130, an input device150, a sound output device155, a display device160, an audio module170, a sensor module176, an interface177, a haptic module179, a camera module180, a power management module188, a battery189, a communication module190, a subscriber identification module (SIM)196, or an antenna module197. In some embodiments, at least one (e.g., the display device160or the camera module180) of the components may be omitted from the electronic device101, or one or more other components may be added in the electronic device101. In some embodiments, some of the components may be implemented as single integrated circuitry. For example, the sensor module176(e.g., a fingerprint sensor, an iris sensor, or an illuminance sensor) may be implemented as embedded in the display device160(e.g., a display). The processor120may execute, for example, software (e.g., a program140) to control at least one other component (e.g., a hardware or software component) of the electronic device101coupled with the processor120, and may perform various data processing or computation. According to one embodiment, as at least part of the data processing or computation, the processor120may load a command or data received from another component (e.g., the sensor module176or the communication module190) in volatile memory132, process the command or the data stored in the volatile memory132, and store resulting data in non-volatile memory134. According to an embodiment, the processor120may include a main processor121(e.g., a central processing unit (CPU) or an application processor (AP)), and an auxiliary processor123(e.g., a graphics processing unit (GPU), an image signal processor (ISP), a sensor hub processor, or a communication processor (CP)) that is operable independently from, or in conjunction with, the main processor121. Additionally or alternatively, the auxiliary processor123may be adapted to consume less power than the main processor121, or to be specific to a specified function. The auxiliary processor123may be implemented as separate from, or as part of the main processor121. The auxiliary processor123may control at least some of functions or states related to at least one component (e.g., the display device160, the sensor module176, or the communication module190) among the components of the electronic device101, instead of the main processor121while the main processor121is in an inactive (e.g., sleep) state, or together with the main processor121while the main processor121is in an active state (e.g., executing an application). According to an embodiment, the auxiliary processor123(e.g., an ISP or a CP) may be implemented as part of another component (e.g., the camera module180or the communication module190) functionally related to the auxiliary processor123. The memory130may store various data used by at least one component (e.g., the processor120or the sensor module176) of the electronic device101. The various data may include, for example, software (e.g., the program140) and input data or output data for a command related thereto. The memory130may include the volatile memory132or the non-volatile memory134. The program140may be stored in the memory130as software, and may include, for example, an operating system (OS)142, middleware144, or an application146. The input device150may receive a command or data to be used by other component (e.g., the processor120) of the electronic device101, from the outside (e.g., a user) of the electronic device101. The input device150may include, for example, a microphone, a mouse, a keyboard, or a digital pen (e.g., a stylus pen). The sound output device155may output sound signals to the outside of the electronic device101. The sound output device155may include, for example, a speaker or a receiver. The speaker may be used for general purposes, such as playing multimedia or playing record, and the receiver may be used for an incoming calls. According to an embodiment, the receiver may be implemented as separate from, or as part of the speaker. The display device160may visually provide information to the outside (e.g., a user) of the electronic device101. The display device160may include, for example, a display, a hologram device, or a projector and control circuitry to control a corresponding one of the display, hologram device, and projector. According to an embodiment, the display device160may include touch circuitry adapted to detect a touch, or sensor circuitry (e.g., a pressure sensor) adapted to measure the intensity of force incurred by the touch. The audio module170may convert a sound into an electrical signal and vice versa. According to an embodiment, the audio module170may obtain the sound via the input device150, or output the sound via the sound output device155or a headphone of an external electronic device (e.g., an electronic device102) directly (e.g., wiredly) or wirelessly coupled with the electronic device101. The sensor module176may detect an operational state (e.g., power or temperature) of the electronic device101or an environmental state (e.g., a state of a user) external to the electronic device101, and then generate an electrical signal or data value corresponding to the detected state. According to an embodiment, the sensor module176may include, for example, a gesture sensor, a gyro sensor, an atmospheric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor. The interface177may support one or more specified protocols to be used for the electronic device101to be coupled with the external electronic device (e.g., the electronic device102) directly (e.g., wiredly) or wirelessly. According to an embodiment, the interface177may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, a secure digital (SD) card interface, or an audio interface. A connecting terminal178may include a connector via which the electronic device101may be physically connected with the external electronic device (e.g., the electronic device102). According to an embodiment, the connecting terminal178may include, for example, a HDMI connector, a USB connector, a SD card connector, or an audio connector (e.g., a headphone connector). The haptic module179may convert an electrical signal into a mechanical stimulus (e.g., a vibration or a movement) or electrical stimulus which may be recognized by a user via his tactile sensation or kinesthetic sensation. According to an embodiment, the haptic module179may include, for example, a motor, a piezoelectric element, or an electric stimulator. The camera module180may capture a still image or moving images. According to an embodiment, the camera module180may include one or more lenses, image sensors, ISPs, or flashes. The power management module188may manage power supplied to the electronic device101. According to one embodiment, the power management module188may be implemented as at least part of, for example, a power management integrated circuit (PMIC). The battery189may supply power to at least one component of the electronic device101. According to an embodiment, the battery189may include, for example, a primary cell which is not rechargeable, a secondary cell which is rechargeable, or a fuel cell. The communication module190may support establishing a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device101and the external electronic device (e.g., the electronic device102, the electronic device104, or the server108) and performing communication via the established communication channel. The communication module190may include one or more CPs that are operable independently from the processor120(e.g., the AP) and supports a direct (e.g., wired) communication or a wireless communication. According to an embodiment, the communication module190may include a wireless communication module192(e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module194(e.g., a local area network (LAN) communication module or a power line communication (PLC) module). A corresponding one of these communication modules may communicate with the external electronic device via the first network198(e.g., a short-range communication network, such as Bluetooth™, wireless-fidelity (Wi-Fi) direct, or infrared data association (IrDA)) or the second network199(e.g., a long-range communication network, such as a cellular network, the Internet, or a computer network (e.g., LAN or wide area network (WAN)). These various types of communication modules may be implemented as a single component (e.g., a single chip), or may be implemented as multi components (e.g., multi chips) separate from each other. The wireless communication module192may identify and authenticate the electronic device101in a communication network, such as the first network198or the second network199, using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the subscriber identification module196. The antenna module197may transmit or receive a signal or power to or from the outside (e.g., the external electronic device) of the electronic device101. According to an embodiment, the antenna module197may include an antenna including a radiating element composed of a conductive material or a conductive pattern formed in or on a substrate (e.g., PCB). According to an embodiment, the antenna module197may include a plurality of antennas. In such a case, at least one antenna appropriate for a communication scheme used in the communication network, such as the first network198or the second network199, may be selected, for example, by the communication module190(e.g., the wireless communication module192) from the plurality of antennas. The signal or the power may then be transmitted or received between the communication module190and the external electronic device via the selected at least one antenna. According to an embodiment, another component (e.g., a radio frequency integrated circuit (RFIC)) other than the radiating element may be additionally formed as part of the antenna module197. At least some of the above-described components may be coupled mutually and communicate signals (e.g., commands or data) therebetween via an inter-peripheral communication scheme (e.g., a bus, general purpose input and output (OPIO), serial peripheral interface (SPI), or mobile industry processor interface (MIPI)). According to an embodiment, commands or data may be transmitted or received between the electronic device101and the external electronic device104via the server108coupled with the second network199. Each of the electronic devices102and104may be a device of a same type as, or a different type, from the electronic device101. According to an embodiment, all or some of operations to be executed at the electronic device101may be executed at one or more of the external electronic devices102,104, or108. For example, if the electronic device101should perform a function or a service automatically, or in response to a request from a user or another device, the electronic device101, instead of, or in addition to, executing the function or the service, may request the one or more external electronic devices to perform at least part of the function or the service. The one or more external electronic devices receiving the request may perform the at least part of the function or the service requested, or an additional function or an additional service related to the request, and transfer an outcome of the performing to the electronic device101. The electronic device101may provide the outcome, with or without further processing of the outcome, as at least part of a reply to the request. To that end, a cloud computing, distributed computing, or client-server computing technology may be used, for example. The electronic device according to various embodiments may be one of various types of electronic devices. The electronic devices may include, for example, a portable communication device (e.g., a smartphone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a home appliance. According to an embodiment of the disclosure, the electronic devices are not limited to those described above. It should be appreciated that various embodiments of the disclosure and the terms used therein are not intended to limit the technological features set forth herein to particular embodiments and include various changes, equivalents, or replacements for a corresponding embodiment. With regard to the description of the drawings, similar reference numerals may be used to refer to similar or related elements. It is to be understood that a singular form of a noun corresponding to an item may include one or more of the things, unless the relevant context clearly indicates otherwise. As used herein, each of such phrases as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B, or C,” “at least one of A, B, and C,” and “at least one of A, B, or C,” may include any one of, or all possible combinations of the items enumerated together in a corresponding one of the phrases. As used herein, such terms as “1st” and “2nd,” or “first” and “second” may be used to simply distinguish a corresponding component from another, and does not limit the components in other aspect (e.g., importance or order). It is to be understood that if an element (e.g., a first element) is referred to, with or without the term “operatively” or “communicatively”, as “coupled with,” “coupled to,” “connected with,” or “connected to” another element (e.g., a second element), it means that the element may be coupled with the other element directly (e.g., wiredly), wirelessly, or via a third element. As used herein, the term “module” may include a unit implemented in hardware, software, or firmware, and may interchangeably be used with other terms, for example, “logic,” “logic block,” “part,” or “circuitry”. A module may be a single integral component, or a minimum unit or part thereof, adapted to perform one or more functions. For example, according to an embodiment, the module may be implemented in a form of an application-specific integrated circuit (ASIC). Various embodiments as set forth herein may be implemented as software (e.g., the program140) including one or more instructions that are stored in a storage medium (e.g., internal memory136or external memory138) that is readable by a machine (e.g., the electronic device101). For example, a processor (e.g., the processor120) of the machine (e.g., the electronic device101) may invoke at least one of the one or more instructions stored in the storage medium, and execute it, with or without using one or more other components under the control of the processor. This allows the machine to be operated to perform at least one function according to the at least one instruction invoked. The one or more instructions may include a code generated by a complier or a code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Wherein, the term “non-transitory” simply means that the storage medium is a tangible device, and does not include a signal (e.g., an electromagnetic wave), but this term does not differentiate between where data is semi-permanently stored in the storage medium and where the data is temporarily stored in the storage medium. A method according to various embodiments of the disclosure may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or be distributed (e.g., downloaded or uploaded) online via an application store (e.g., PlayStore™), or between two user devices (e.g., smart phones) directly. If distributed online, at least part of the computer program product may be temporarily generated or at least temporarily stored in the machine-readable storage medium, such as memory of the manufacturer's server, a server of the application store, or a relay server. According to various embodiments, each component (e.g., a module or a program) of the above-described components may include a single entity or multiple entities. According to various embodiments, one or more of the above-described components may be omitted, or one or more other components may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into a single component. In such a case, according to various embodiments, the integrated component may still perform one or more functions of each of the plurality of components in the same or similar manner as they are performed by a corresponding one of the plurality of components before the integration. According to various embodiments, operations performed by the module, the program, or another component may be carried out sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations may be executed in a different order or omitted, or one or more other operations may be added. FIG.2is a block diagram illustrating a wireless communication system, according to an embodiment. The wireless communication system200may constitute at least a portion of a wireless communication module192of an electronic device101. Referring to PG,2, the wireless communication system200includes a modem220, a transceiver230, a Tx module240, and an ET modulator250. The illustrated components may only show some components that form a Tx path in the wireless communication system200, and various components not shown may be further included. The wireless communication system200may further include various components for processing an RF reception signal received from an antenna. The wireless communication system200ofFIG.2may perform ET, DPD, or CFR for an RF transmission signal, but may not include a network monitor360that monitors network environment information. The modem220may perform modulation and demodulation of signals in the wireless communication system200. The modem220may use various modulation and demodulation schemes such as a phase shift keying (PSK) method such as binary PSK (BPSK) or quadrature PSK (QPSK), and a quadrature amplitude modulation (QAM) method such as 64-QAM or 256-QAM. Various modulation and demodulation schemes are not limited to the above examples. The modem220may transmit and receive in phase and in quadrature (I/Q) signals of a digital baseband to and from the transceiver230using each channel. The transceiver230may perform digital/analog conversion based on the signals transmitted from the modem220, may up/down-convert a baseband signal into an RF signal, and may transmit and receive an RF signal to and from an RF front end module. Referring toFIG.2, the transceiver230includes a CFR block231, a digital to analog converter (DAC)/analog to digital converter (ADC) block232, a Tx operator233, an Rx operator234, an envelope tracking digital signal processor (ET DSP)235, a digital pre-distortion (DPD) block236, and an analyzer/calibration block237. The analyzer/calibration block237may check an output power of a Tx signal to adjust the Tx signal. The analyzer/calibration block237may acquire information related to the output power of the Tx signal in real time from the Tx module240through an FBRx path. The CPR block231may perform CFR on the input/output (I/O) signal of the digital baseband transmitted from the modem220for the purpose of controlling high power, high efficiency, and high linearity of a power amplifier (PA)241of the Tx module240. The CFR is a technique used to reduce a peak to average power ratio (PAPR) of the PA, and will be described later in more detail throughFIG.16. The DAC/ADC block232may convert a CFR processed signal into an analog signal and may convert a reception signal received from an external device through an antenna into a digital signal. InFIG.2, the DAC/ADC is shown as one block232, but the independent DAC block and ADC block may be arranged in a Tx path and an Rx path, respectively. The Tx operator233may process an analog transmission signal processed by the DAC/ADC block232to transmit the processed analog transmission signal to the Tx module240. The Rx operator234may process an analog reception signal received through an antenna to transmit the processed analog reception signal to the modem220through the DAC/ADC block232. The ET DSP235may generate and process an envelope signal input to the ET modulator250. For example, the ET DSP235may generate the envelope signal of the RF signal, may adjust the type of the envelope signal, and/or may adjust a delay. The DPD block may perform DPD to compensate for signal compression when an ET technology is applied. The DPD block236may perform pre-distortion before an I/Q signal is applied to the Tx module240by using a coefficient of a stored DPD lookup table (LUT). The I/Q signal input from the modem220to the transceiver230may be converted into a digital signal after CFR and DPD are applied. The DPD will be described later in more detail with reference toFIGS.13to15. InFIG.2and the above description, the DAC/ADC block232, the CFR block231, and the DPD block236are described as being included in the transceiver230, but according to various embodiments, some of the DAC/ADC block232, the CFR block231, or the DPD block236may be included in the modem220. In this case, the modem220may convert the I/Q signal into a digital signal after DPD and CFR processing is performed on the I/Q signal, and may transmit the obtained digital signal to the transceiver230. The ET modulator250may receive the envelope signal generated from the transmitted RF signal from the transceiver230, and may amplify the envelope signal to apply the amplified signal as the input power of the power amplifier of the Tx module240. The ET modulator250may include a linear regulator251and a switching converter252. The linear regulator251may linearly amplify the envelope signal through a sourcing/sinking process. The switching converter252may output a switching current which is a DC. The ET technology using the ET modulator250may reduce the current consumption of the wireless communication system200, and details of the ET technology and the configuration of the ET modulator250will be described in more detail with reference toFIGS.4to10. The Tx module240is a module for amplifying and transmitting an RF signal to an antenna. Referring toFIG.2, the Tx module240may include a PA241that amplifies a signal input from the transceiver230(or the Tx operator233), a duplexer242that filters a Tx signal and an Rx signal, respectively, an antenna switching module243that selects each band signal, a coupler244that couples a transmitted Tx signal to transmit the coupled Tx signal to the transceiver230through an FBRx path, a low noise amplifier (LNA)245that amplifies a reception signal applied to the antenna to transmit the amplified signal to the transceiver230, and at least one mobile industry processor interface (MIPI) controller246that adjusts respective sub blocks. The RF signal amplified by the Tx module240may be transmitted to an external device (e.g., a base station) through the antenna. FIG.3is a block diagram illustrating an electronic device, according to an embodiment. Referring toFIG.3, an electronic device300includes a wireless communication system310and an AP390. The electronic device300may be a portable electronic device having a wireless communication function such as a smart phone or a tablet personal computer (PC), and may include at least some of the components and/or functions of the electronic device101ofFIG.1. The AP390may be configured to control the respective components of the electronic device300and/or perform communication-related operations and data processing, and may include at least some of the components and/or functions of the processor120ofFIG.1. The AP390may be operatively, electrically, and/or functionally connected to the internal components of the electronic device300, such as the modem320, the transceiver330, or the network monitor360of the wireless communication system310. The AP390may execute instructions including control commands such as various arithmetic and logical operations, data movement, or input/output stored in a memory130. The operation and data processing functions that can be implemented in the electronic device300by the AP390are not limited, but in this application, a function for checking a network environment in real time and optimizing power consumption and data rate consumed by the wireless communication system310by adjusting various parameters used in the wireless communication system310based on the chocked network environment will be described. The wireless communication system310may include a modem320, a transceiver330, a Tx module340, an ET modulator350, and a network monitor360. The wireless communication system310may support at least one of various wireless communication protocols such as fourth generation (4G) communication (or long term evolution (LTE)) or 5G communication (or new radio (NR)). The network monitor360may check the network environment while the wireless communication system310performs wireless communication with an external device (e.g., a base station). In a case where the electronic device300is powered on, when a data transmission event occurs or according to a predetermined period, the AP390may allow the network monitor360to check the network environment and to provide the checked information to the AP390and/or other modules in the wireless communication system310(e.g., the CFR module, the sampling rate control block, the DPD block, and the ET control block). The network monitor360may check network environment information through an FBRx path and/or an Rx path (or Rx chain). The Rx path (or Rx chain) is a path for performing processing, such as demodulation or ADC, on an RF reception signal received from the external device at an antenna, and may check a variety of network environment information used for the RF signal received through the Rx path (or Rx chain). The network monitor360may be configured as an independent block, but may also be provided on the modem320or the AP390. The network environment information may include at least one of a bandwidth, a resource block, a sub-carrier spacing (SCS), or a modulation code and scheme. More specifically, the bandwidth is the bandwidth of the RF signal to be transmitted, and the wireless communication system310may communicate with a base station using some bandwidths determined in the base station and/or a CP among determined bandwidths (e.g., 20 megahertz (MHz) for long team evaluation (LTE) and 100 MHz for NR). The network monitor360may check the bandwidth currently used for wireless communication. The resource block is a unit of resources allocated based on frequency and time in orthogonal frequency-division multiplexing (OFDM), and the wireless communication system310may perform wireless communication using some resource blocks determined in the base station and/or the CP (e.g., the auxiliary processor123ofFIG.1) among the entire resource block (e.g., 12 subcarriers*7 symbols). The network monitor360may check the resource block currently used for wireless communication. The SCS is a bandwidth spacing of used sub-carriers, and may use a fixed SCS for each network (e.g., 15 kilohertz (KHz) for LTE) or a variable SCS (e.g., 15/30/60 KHz for NR). The network monitor360may check the SCS currently used for wireless communication. The modulation scheme is a scheme for modulating a signal such as QPSK, 160-QAM, 64-QAM, or 256-QAM, and the wireless communication system310may support various modulation schemes according to a wireless network situation. The network monitor360may check the modulation scheme currently used for wireless communication. Bach of the modem320, the transceiver330, the Tx module340, and the ET modulator350may include at least some components and/or functions of the modem220, the transceiver230, the Tx module240, and the ET modulator250, and may further include at least one component and/or function for controlling each function based on the network environment information obtained from the network monitor360in addition to the components and/or functions described inFIG.2. The wireless communication system310may control the ET modulator350, adjust a sampling rate, adjust a DPD order, apply a DPD coefficient in real time, or determine clipping of a CFR, based on the network environment information obtained from the network monitor360. The ET modulator350may adjust a drive stage in the linear regulator based on the network environment information (e.g., a modulation scheme, a bandwidth, a resource block, or an SCS) to determine a bias and a pass current Ishoot-through. This will be described later in more detail with reference toFIGS.4to10. The sampling rate control block may remove image/harmonic signals by adjusting a sampling frequency of a multiplier in the sampling rate control block and adjusting a cutoff frequency of a baseband (BB) low pass filter (LPF) based on the network environment information, thereby determining the sampling rate. This will be described later in more detail with reference to FIOS.11to12. The DPD block236may determine an appropriate coefficient in a DPD LUT based on the network environment information, and may perform DPD in real time using the determined coefficient. This will be described later in more detail with reference toFIGS.13to IS. The CFR control block231may adjust a clipping level during CFR by adjusting an Xmax variable and a weighting coefficient (p[n]) based on the network environment information. This will be described later in more detail with reference toFIG.16. The electronic device300may include only some components and/or functions among the above-described ET modulator350, sampling rate control block, DPD block236, or CFR control block231. FIG.4is a block diagram illustrating an ET system, according to an embodiment. FIG.4shows an ET system400and a power amplifier441for implementing ET in a wireless communication system200. In order to support a high data rate in a wireless network such as a 5G NR, the bandwidth of a corresponding signal is widened and the modulation method of the signal is complicated, so that a peak to average power ratio (PAPR) can be increased. Accordingly, a power amplifier441of a Tx module240that consumes a large amount of power in the wireless communication system is required to have high efficiency and high linearity. The ET technology can be applied to signals requiring broadband and high PAPR. Referring toFIG.4, a digital I/Q signal is input to a transceiver430through each channel from a modem220of the ET system400, and the I/Q signal may be input to an envelope generator438and an IQ modulator439. The I/Q signal modulated by the IQ modulator439may be mixed with a local oscillator (LO) signal and may be transmitted to the power amplifier441of the Tx module. The envelope generator438may generate an envelope signal from the I/Q signal. The envelope signal may include maximum values of a predetermined period of the I/Q signal. The ET DSP435may adjust the type of the generated envelope signal, may perform signal processing such as delay adjustment on the envelope signal, and then may output the obtained signal to the ET modulator450. The ET modulator450may apply the input envelope signal as an input power of the power amplifier441of the Tx module. Accordingly, the power amplifier441does not use fixed voltage input power but uses an envelope signal of an input signal (RFIN) applied to the power amplifier441as the input power, so that power consumed by the power amplifier441may be reduced. FIG.5is a block diagram illustrating an ET modulator and a power amplifier of a Tx module, according to an embodiment. Referring toFIG.5, the ET modulator550includes a linear regulator551and a switching converter552. The linear regulator551may linearly amplify an envelope signal through a sourcing/sinking process. The switching converter552may output a switching current that is a DC current according to a switching frequency. The linear regulator551may be a low drop-out (LDO) regulator that operates at a high speed but has a low efficiency, or may be a switching mode power supply (SMPS) DC-DC converter that operates at a low speed but has a high efficiency. The ET modulator550may have a hybrid structure that includes the linear regulator551and the switching converter552, and may track an envelope signal of a wide bandwidth while amplifying the envelope signal with high efficiency. FIG.6Ais a block diagram illustrating an ET modulator, according to an embodimentFIG.6Bis a diagram illustrating current waveforms in an ET modulator650, according to an embodiment. Referring toFIG.6A, the ET modulator650includes a hybrid, structure that includes a linear regulator651and a switching converter652. Referring toFIG.2, an input power Vcc of a power amplifier241of a Tx module240may be generated according to an output current Ioutof the ET modulator650, and an output current Ioutmay be output according to a source current Isourceand a sink current Isinkof the linear regulator651and a switch current Iswitchof the switching converter652. More specifically, the switching converter652may generate the switch current Iswitchthat is a direct current (DC) to output the generated switch current at a predetermined switching frequency through a coil, and the output current Ioutmay be generated through the sourcing/sinking process of the linear regulator651. InFIG.6A, the linear regulator651may use a fixed bias. The bias of the linear regulator651may be a bias voltage input to a buffer of the linear regulator651. In the sourcing/sinking process of the linear regulator651, crossover distortion noise may occur as two transistors operate alternately. Referring to the graph ofFIG.6B, the crossover distortion noise may occur in a crossing section between a source current and a sink current. A pass current Ishoot-throughmay be required to reduce this crossover distortion noise, and the magnitude of the pass current Ishoot-throughmay be determined by the bias condition of the linear regulator651. To reduce the crossover distortion noise, the bias may be increased (class-A direction) to increase the pass current, but in this case, power efficiency may be lowered. Conversely, when the bias current is reduced (class-B direction) in consideration of power efficiency to reduce the pass current, a problem of crossover distortion noise may occur. Therefore, in order to optimize the crossover distortion noise and power efficiency, a deep class-AB bias linear regulator may be used as the linear regulator651. In order to increase the operating speed of the linear regulator651, the current consumption of the drive stage in the linear regulator651may increase. In addition, since the crossover distortion noise of the linear regulator651that performs sourcing and sinking increases along with an increase in the bandwidth of the signal increases, the bias of the linear regulator651should be increased to solve this problem. At this time, when the bias of the linear regulator651increases, the magnitude of the pass current also increases, so that power efficiency of the ET modulator650may be lowered. Even in the case where the linear regulator651is configured with a fixed bias as described above, in a network environment having a low maximum bandwidth (e.g., 20 MHz for LTE), there is no significant problem in tracking the envelope signal by the ET modulator650. However, in a network environment having a high maximum bandwidth (e.g., 100 MHz for NR), the operating speed of the linear regulator651must be increased and for this, the consumption current and bias (or pass current Ishoot-through) of the drive stage of the linear regulator651are also required to be increased. In this case, when the current consumption is increased in consideration of the maximum bandwidth, in a low-band signal that is frequently used in a real network environment, or a partial resource block (RB) of 4G (or LTE) communication that uses only some of allocable RBs, or an inner RB of 5G (or NR) communication, the current may be unnecessarily consumed. In addition, inFIG.6A, the switching converter652may use a fixed switching frequency. The switching converter652may generate the switch current Iswitchwith high efficiency through a switching operation using a DC-DC converter. One important factor that determines the efficiency of the DC-DC converter is the switching frequency. When the switching frequency increases, a ripple decreases, but a switching loss increases, resulting in lower efficiency. Conversely, when the switching frequency decreases, the efficiency increases and the ripple increases. Therefore, it is necessary to maintain the switching frequency optimized according to an input envelope signal. Even when the switching converter652operates at a fixed switching frequency as described above, in the network environment having a low maximum bandwidth (e.g., 20 MHz for LTE), there may be no problem in the efficiency. However, in the network environment having a high maximum bandwidth (e.g., 100 MHz for NR), a dynamic range of an envelope signal bandwidth to be amplified increases, so that the operation of the switching converter652at the fixed switching frequency may have limitations in efficiency optimization. FIG.7is a block diagram illustrating an ET modulator that performs envelope tracking according to a network environment, according to an embodiment. FIG.8is a graph illustrating a bias and a pass current according to a signal bandwidth, according to an embodiment. The ET modulator650ofFIGS.6A and6Bincludes the linear regulator651of the fixed bias and the switching converter652of the fixed switching frequency, resulting in low efficiency. However, the ET modulator750ofFIG.7may control the operations of a linear regulator751and a switching converter752in consideration of a network environment, and thus higher efficiency may be obtained compared to when the linear regulator651of the fixed bias and switching converter652of the fixed switching frequency are used. Referring toFIG.7, the ET modulator750includes the linear regulator751, the switching converter752, and an ET control block755. The ET control block755may obtain network environment information including at least one of a bandwidth, an RB, an SCS, and a modulation scheme from a network monitor360. The ET control block755may determine the bias of the linear regulator751and/or the switching frequency of the switching converter752according to the input network environment information. Referring toFIG.8, when the bias of the linear regulator751is increased (class-A direction801) and the pass current Ishoot-throughis increased, the operating speed of the linear regulator751may be increased and accordingly envelope tacking may be implemented even in a network of a high bandwidth. Conversely, when the bias of the linear regulator751is reduced (class-B direction802) and the pass current Ishoot-throughis lowered, the operating speed of the linear regulator751may be reduced and power consumption may be reduced. The ET control block755may increase the bias of the linear regulator751when performing communication using a high bandwidth (or at least one of an RB, an SCS, or a modulation scheme) based on the network environment information, and may reduce the bias of the linear regulator751for the purpose of power efficiency when performing communication with a low bandwidth (or at least one of an RB, an SCS, or a modulation scheme). The ET modulator750may include a bias control circuit that can adjust the bias of the linear regulator751. The ET control block755may drive at least a portion of the bias control circuit based on the network environment information. The ET control block755may store a table obtained by mapping the magnitude of the bias of the linear regulator751to be used and/or a portion of the bias control circuit to be driven according to the network environment information (e.g., at least one of a bandwidth, an RB, an SCS, or a modulation scheme), and may perform control using the stored table. FIG.9is a diagram illustrating a structure of a linear regulator of an ET modulator, according to an embodiment. FIG.9illustrates a case using a fixed bias to a linear regulator950. Referring toFIG.9, the linear regulator950includes a class-AB bias circuit951, a buffer952, and an operational trans-conductance amplifier (OTA)953. The class-AB bias circuit951may adjust the bias of output source current Isourceand sink current Isinkto class-AB, so that the linear regulator950may operate with high efficiency through lower crossover distortion noise. A buffer952may be a final stage of the linear regulator950, and may output the source current Isourceand the sink current Isinkto form an output current Iouttogether with a switching current Iswitchoutput from a switching converter752. The OTA953is an amplifier that outputs an input voltage as an output current in proportion to trans-conductance, and may amplify an applied envelope signal and an output envelope signal in a differential manner. The linear regulator950ofFIG.9may use a fixed current to the class-AB bias circuit951through a fixed current mirror. Accordingly, in the class-AB bias circuit951, a common drain transistor may have the same gate to source voltage (VGS) regardless of the bandwidth of an RF transmission signal, so that the linear regulator950may output the source current Isourceand the sink current Isinkaccording to the fixed bias. FIG.10is a diagram illustrating a structure of a linear regulator of an ET modulator that performs ET according to a network environment, according to an embodiment. FIG.10shows a case using a variable bias to a linear regulator1050. Referring toFIG.10, the linear regulator1050includes a bias control circuit1055for variably controlling a bias. The bias control circuit1055may include a plurality of transistors connected in parallel to each other to be independently switchable. An ET control block755of an ET modulator750may obtain network environment information (e.g., at least one of a bandwidth, an RB, an SCS, or a modulation scheme) obtained from a network monitor360. The ET control block may switch the transistor of the bias control circuit1055or adjust the ratio of a current mirror based on the network environment information. Since a current received through a bandgap reference (BGR) circuit is constant, the current flowing in a class-AB bias circuit1051may be adjusted by adjusting the ratio of the current mirror differently. For example, when no current is output from the bias control circuit1055to the class-AB bias circuit1051, the class-AB bias circuit1051may generate a bias by a current input from the BGR circuit, and when at least a portion of the bias control circuit1055is switched and a current flows to the class-AB bias circuit1051, the class-AB bias circuit1051may generate a higher bias. The ET control block may control the ratio of the current mirror of the bias control circuit1055, may accordingly adjust a VGS value of a common drain transistor, and may adjust the bias of the buffer1052that generates the source current Isourceand the sink current Isink. Accordingly, the magnitude of the pass current Ishoot-throughmay be determined. For example, when the bias control circuit1055includes at least one switch (e.g., four switches), a thermal code including binary codes corresponding to on/off of each switch may be output. The ET control block may output “0000” as the thermal code when a bandwidth currently used for an RF transmission signal is 20 MHz, and thus the bias control circuit1055does not output a current to the class-AB bias circuit1051, and the bias may be determined by the output current of the BGR circuit. However, when the bandwidth used for the RF transmission signal increases to a higher value, such as 40 MHz, 60 MHz, 80 MHz, or 100 MHz, the BT control block may respectively output “0001”, “0011”, “0111”, or “1111” as the thermal code to the bias control circuit1055. The transistor of the bias control circuit1055may be switched and may be input to the class-AB as in the current of the BGR circuit, and accordingly, a higher bias may be generated in the linear regulator1050. A switching converter752that generates a DC current of the ET modulator with high efficiency may also adjust a switching frequency for determining the efficiency of a DC-DC converter based on the network environment information (e.g., the bandwidth of the RF transmission signal). The switching converter may include the same circuit as the bias control circuit1055of the linear regulator1050ofFIG.10, and the circuit may be controlled according to the control signal of the ET control block. Accordingly, a switching frequency of a drive stage of the switching converter (e.g., a drive stage752ainFIG.7) may be adjusted according to the control signal of the ET control block. FIG.11is a block diagram illustrating a modem and a transceiver for sampling rate control, according to an embodiment. Referring toFIG.11, a wireless communication system1100includes a modem1120and a transceiver1130. An AP390may process data to be transmitted to an external device as a digital signal, and an RF signal transmitted through an antenna is an analog signal. Accordingly, the wireless communication system1100may perform conversion between digital and analog signals through a DAC/ADC block1132. In order to convert the analog signal into the digital signal, sampling, quantization, and coding processes are required. In the sampling process, a sampling rate fsshould be at least twice the bandwidth of a transmission/reception baseband channel according to the Nyquist theory. Here, an interval Tdbetween sampling points is inversely proportional to the sampling rate fs. Therefore, as the sampling rate fsincreases, the interval Tdbetween sampling points decreases, thus the corresponding signal can be finely modulated and demodulated, and the signal can be adjusted in a shorter time unit. However, when a clock speed is increased to increase the sampling rate, an increase in current consumption causing heat generation and battery consumption may occur. A high-performance operation through the increase in the clock speed may have a more important effect in a broadband ET operation. For example, when a sampling rate used in a low-bandwidth wireless communication (e.g. LTE) is used for a broadband wireless communication (e.g. NR), there is a limitation in the delay adjustment between the RF signal and the envelope signal in the ET system, so that characteristics such as output power, efficiency, or linearity may deteriorate. On the other hand, the use of a high sampling rate for broadband wireless communication may cause a waste of current consumption when a low-bandwidth signal is transmitted. Accordingly, the electronic device may determine the sampling rate optimized for communication quality and current consumption based on the network environment information. Referring toFIG.11, the wireless communication system1100includes a sampling rate control block1138for determining a sampling rate according to the network environment information. The sampling rate control block1138may include a clock generator1138athat generates a clock signal of a specific frequency and a multiplier1138bthat determines a coefficient to be multiplied by the clock signal to determine the sampling rate. The network monitor1190may acquire network environment information including at least one of a bandwidth, an RB, or an SCS, and may provide the acquired information to the sampling rate control block1138. The sampling rate control block1138may use the network environment information received from the network monitor1190to select an optimized coefficient according to the current bandwidth, RB, or SCS through modeling and/or an algorithm of the multiplier1138b. Accordingly, the sampling rate of the DAC/ADC block1132may be adjusted by multiplying the clock signal generated by the clock generator1138aby the coefficient selected according to the bandwidth, the RB, or the SCS. When the sampling rate is changed, a BB LPF1133aof the Tx operator1133that rejects an image signal or a harmonic signal may also need to be changed. The sampling rate control block1138may adjust a cutoff frequency of the BB LPF1133ain response to the sampling rate adjusted according to the bandwidth, the RB, or the SCS. FIG.12Ais a diagram illustrating a method of determining a sampling rate, according to an embodiment.FIG.12Bis a diagram illustrating a method of determining a sampling rate, according to an embodiment.FIG.12Cis a diagram illustrating a method of determining a sampling rate, according to an embodiment. FIG.12Arelates to an embodiment of determining a sampling rate only based on a bandwidth. Referring toFIG.12A, a sampling rate of 30.72 megabits per second (Mbps) in a 10 MHz bandwidth, a sampling rate of 61.44 Mbps in a 20 MHz bandwidth, and a sampling rate of 307.2 Mbps in a 100 MHz bandwidth may be operated. In this case, since only the bandwidth is considered, the same sampling rate may be operated when only one RB is used in the bandwidth of 10 MHz and when a full RB is used in the same. This may be inefficient because the corresponding operation is performed at the same sampling rate even though the bandwidths required for actual communication are different according to the number of RBs despite the same bandwidth. FIG.12Brelates to an embodiment of determining a sampling rate based on the resource block. Referring toFIG.12B, as to the bandwidth of 100 MHz, when the RB is one RB, a sampling rate of 1.2288 Mbps may be operated, when the resource block is a half RB, a sampling rate of 153.6 Mbps may be operated, and when the resource block is a full RB, a sampling rate of 307.2 Mbps may be operated. Accordingly, even when communication is performed in a network having the same bandwidth, the corresponding operation is performed at a lower sampling rate depending on the number of used RBs, thereby reducing power consumption. FIG.12Crelates to an embodiment of determining a sampling rate based on an SCS, according to an embodiment. The wireless communication system may use a variable SCS (e.g., 15/30/60 KHz for NR), and accordingly, the bandwidth of one RB may also be variable. The sampling rate control block may determine the sampling rate according to the used SCS. Referring toFIG.12C, when the SCS used at the bandwidth of 100 MHz is 15 KHz, a sampling rate of 0.6144 Mbps may be operated, when the SCS is 30 KHz, a sampling rate of 1.2288 Mbps may be operated, and when the SCS is 60 KHz, a sampling rate of 2.4576 Mbps may be operated. FIG.13Ais a graph illustrating a gain of a power amplifier and an envelope trajectory of an ET system, according to an embodiment.FIG.13Bis a diagram illustrating a method of applying DPD, according to an embodiment. When an ET technology is applied, a power amplifier241may be operated at a saturation area to optimize the overall efficiency of a system (e.g., the wireless communication system200ofFIG.2). When the power amplifier1341follows an envelope signal of an RF signal in real time and operates in the saturation area, Vcc may be lowered due to the characteristic of the power amplifier and a gain may decrease, thereby obtaining a compression characteristic as shown inFIG.13A. The wireless communication system may use DPD to compensate for the gain compression characteristic. The DPD is a method of pre-distorting an RP input signal applied to the power amplifier by reflecting the gain characteristic of the power amplifier according to the voltage at the common collector (Vcc) based on an envelope trajectory that is actually used. For example, as shown inFIG.13B, since the power amplifier has a gain characteristic1391in the form of a logarithmic function as shown inFIG.13B, a DPD block1336may distort the RF signal in the form of an exponential function1392and may input the distorted RF signal to the power amplifier. Accordingly, a signal1393amplified by the power amplifier1341may have linearity. FIG.14Ais a diagram illustrating a method of applying DPD, according to an embodiment.FIG.14Bis a diagram illustrating a method of applying DPD, according to an embodiment. The wireless communication system may include a DPD block that pre-compensates for an input signal output from the modem according to the gain compression of the power amplifier. The DPD block may store a DPD LUT capable of compensating for the gain compression. The DPD LUT may be embedded in the DPD block at the time of manufacturing an electronic device (or a wireless communication system). FIG.14Ashows a case using the same DPD LUT for electronic devices A, B, and C. At this time, even if the electronic devices A, B, and C use the same structure and components, there may be variations in the characteristics of the Tx path between the components. Accordingly, gains for the input power of the power amplifier may be different. InFIG.14A, the same DPD LUT for electronic devices A, B, and C is used, and thus in some electronic devices, linearity of an output signal by DPD may not be completely compensated. FIG.14Bshows a case using different DPD LUTs according to the characteristics of the electronic devices A, B, and C. For example, at the time of manufacturing an electronic device, the DPD may be determined by modeling the gain characteristic of the power amplifier for each model. In this case, since the DPD LUT modeled for each of the electronic devices A, B, and C is used as shown inFIG.14B, the linearity of the output signal may be higher than the case ofFIG.14A. However, even in the case ofFIG.14B, the determining the DPD for each model of the electronic device may be performed once during calibration in the process and the determined DPD LUT may be embedded in the electronic device of the same model, so that applying an optimized DPD LUT for each various network scenario may be difficult. In addition, linearity may not be obtained by reflecting a change in the Tx characteristic according to the use of the electronic device, and it may be difficult to apply the DPD by determining the DPD LUT in real time by adapting to various RP signals transmitted in different network environments. FIG.15is a block diagram illustrating a wireless communication system that applies DPD according to a network environment, according to an embodiment. A wireless communication system1500may include a DPD block1536that processes a DPD for an RF signal to be transmitted based on network environment information obtained in real time from a network monitor1560. The DPD block1536may be provided on a transceiver1530and may perform DPD before a signal output from a modem1520is input to a power amplifier1541of a Tx module1540. For example, the DPD block1536may cause a signal which is pre-distorted with respect to a CFR-processed signal in a CFR block1531to be input to a DAC/ADC block1532. The DPD block1536may store a DPD LUT that maps a DPD coefficient to be used to correspond to each network environment (e.g., at least one of a bandwidth, an RB, an SCS, or a modulation scheme). The network monitor1560may check the network environment through operations such as transit antenna selection (TAS) and/or sounding reference signal (SRS) via a Tx operator1533and an Rx operator1534, and may provide network environment information1591related to an RP transmission signal to the DPD block1536. Also, the DPD block1536may further acquire characteristic information1592of the Tx path through an PBRx path. The DPD block1536may generate an optimized DPD coefficient based on the network environment information1591obtained through the network monitor1560and characteristic information1592of the Tx path obtained through the PBRx path, and may pre-distort the RF transmission signal in real time. The wireless communication system1500may adjust a DPD order according to the network environment, and may update the DPD coefficient in real time, thereby optimizing the performance of the wireless communication system1500such as Tx output power, efficiency, error vector magnitude (EVM), or linearity. A process of performing DPD using the network environment information by the DPD block1536may be based on Equations (1) to (3), below. an=f(Txchain) Equation (1) In Equation (1), anmay denote a DPD coefficient, and a Tx chain may denote gain compression from the transceiver1530to an antenna port of the Tx module1540. X(t)′=f(X(t))=a0+a1X(t)+a2X(t)2+a3X(t)3. . . +anX(t)nEquation (2) In Equation (2), X(t) may denote an input RF transmission signal, and X(t)′ may denote a pre-distorted RF transmission signal. an=f(Txchain,BW,RB,MCS,SCS) Equation (3) In Equation (3), BW may denote a bandwidth of an RF transmission signal being used, RB may denote a resource block allocated to the RF transmission signal, MCS may denote a modulation coding scheme, and SCS may denote a sub-carrier spacing. FIG.16is a diagram illustrating an example of signals clipped through CFR, according to an embodiment. A transceiver1530of a wireless communication system1500may use a CFR block1531to process CFR of a transmission signal. A CFR technology is a technology that is used to reduce a PAPR of a transmission signal so that a power amplifier1541of a Tx module1540that uses a large amount of power consumption in a wireless communication system of an electronic device can operate with a high efficiency. The CFR technology may be implemented through various algorithms, and a representative algorithm will be described below among the various algorithms, but the operation of a CFR block1531described in this application is not limited to the algorithm described below. The CFR may be applied through performing hard clipping and applying a LPF on an input signal. Referring toFIG.16, a portion exceeding a clipped point in the input signal may be fixed at a specific amplitude (Amax), and a portion lower than the clipped point may be kept in the same manner as in the original signal. This can be applied through Equations (4.1) and (4.2), below. Xclip[n]=c[n]*X[n]Equation (4.1) C[n]=Xmax/|X[n]|,|X[n]|>Xmax 1,|X[n]|>XmaxEquation (4.2) In Equations (4.1) and (4.2), X[n] may denote an input signal, Xclip[n] may denote a clipped signal, c[n] may denote a clipping coefficient, and Xmaxmay denote a clipped point. Referring toFIG.16, a sharp edge may be generated in a clipped signal C obtained by performing hard clipping on an input signal A through a clipped point B, which may be a high frequency component of the signal. High-frequency components may cause adjacent channel power (ACP). In order to reduce this unwanted ACP, the clipped signal C may be passed through an LPF to reduce the high-frequency signal corresponding to the sharp edge, and a windowed signal D may be generated. Here, a windowing method performs filtering with a weighting coefficient p[n] and a window function w[n] to remove the high-frequency component of the clipped signal. The windowing method may be expressed by Equation (5), below. c′[n]=1−p[n]*w[n]Equation (5) In Equation (5), p[n] may denote a weighting coefficient, and w[n] may denote a common window function such as a Gaussian function. As described above, main parameters to be considered in the CFR technology are a target PAPR, a maximum order of LPF, a pass frequency, a stoppage frequency, a pass ripple, and/or a stoppage ripple. The required specifications for QPSK/16-QAM/64-QAM/256-QAM in an LTE system have been established, but the usage frequency for 64-QAM and 256-QAM, which are actual high order modulation, may not be large. However, for more efficient data spectrum use and maximum data transmission speed, various signals can be actively used, including 64-QAM and 256-QAM which are high-order modulation. An error vector magnitude (EVM) specification according to a modulation scheme of a transmission signal is exemplified in Table 1, below. TABLE 1ModulationUnitAverage EVM LevelQPSK%17.516QAM%12.564QAM%8256QAM%3.5 A high-order modulation signal may require a high quality signal because demodulation is complex. Therefore, the Average EVM Level may vary from that which is shown in Table 1. In the case of using the CFR technology in a wireless communication system, the power amplifier may be operated with high power and/or high efficiency, but EVM characteristics may deteriorate because the original signal is modified. In the case of a signal using low-order modulation (e.g. QPSK or 16-QAM), CFR may be processed by hard clipping because some high-frequency components are allowed. However, when using high-order modulation such as 256-QAM as in a 5G NR network environment, it may be difficult to apply hard clipping because a strict EVM specification is required. In addition, when the wireless communication system uniformly applies soft clipping due to the EVM specification of the high-order modulation signal, the PAPR cannot be sufficiently low at the time of using the low-order modulation, so that the high output of the power amplifier that finally amplifies the RF transmission signal may cause a problem of low coverage in a real network environment. The CFR block of the wireless communication system may check a modulation scheme used for the RF transmission signal and may perform CFR with a corresponding clipping level. The CFR block may determine a clipping level applied to the CFR based on the network environment information. The CFR block may acquire information related to the modulation scheme currently being used for the RF transmission signal in real time or periodically from a network monitor1500. Accordingly, if CFR is performed using the same clipping coefficient regardless of the modulation scheme in a conventional CFR algorithm, the wireless communication system may determine the clipping level by the modulation scheme in real time. The CFR algorithm may be performed as shown in Equations (6) to (8), below. Xmax′[n]=f(MCS) Equation (6) In Equation (6), Xmax′[n] may be a clipped point determined in consideration of the modulation scheme, which can be calculated as a function of a modulation coding scheme (MCS). c′[n]=1−p[n]*w[n]Equation (7) In Equation (7), p[n] may denote a weighting coefficient, and w[n] may denote a common window function such as a Gaussian function. p[n]=f(MCS) Equation (8) In Equation (8), the weighting coefficient p[n] can be calculated as a function of MCS. FIG.17is a block diagram illustrating a wireless communication system1700that controls various parameters according to a network environment, according to an embodiment. FIG.17may include the components of the wireless communication system200ofFIG.2, and may acquire, when compared toFIG.2, network environment information using a network monitor1760and may perform at least one of, for example, controlling the ET modulator1750, adjusting a sampling rate, adjusting a DPD order and applying a DPD coefficient in real time, or determining clipping of CPR based on the acquired network environment information. Hereinafter, in order to avoid redundant descriptions, the technical features described with reference toFIGS.1to16will be omitted. Referring toFIG.17, the network monitor1760may check a network environment while a wireless communication system performs wireless communication with an external device (e.g., a base station). When the electronic device is turned on or according to a predetermined period, an AP may allow the network monitor1760to check the network environment and to provide the checked information to the AP and/or the wireless communication system (e.g., the CFR block1731, the DPD block1736, the sampling rate control block1739and the ET control block1759). The network monitor1760may check the network environment information through an FBRx path and/or an Rx chain. The network monitor1760may be configured as an independent block, but may be provided on the modem1720or the AP390. The network environment information may include at least one of a bandwidth, an RB, an SCS, or a modulation scheme. The ET control block1759may adjust a drive stage in the linear regulator1751of the ET modulator1750based on the network environment information to determine a bias and a pass current Ishoot-through. A method of controlling the drive stage of the linear regulator1751and/or the switching converter1752by the ET control block1759based on the network environment information and the circuit configuration therefor have been previously described with reference toFIGS.9to10. The sampling rate control block1739may determine a sampling rate according to the network environment information. The sampling rate control block1739may receive at least one piece of information related to the current bandwidth, RB, or SCS from the network monitor1760, and may determine the sampling rate to be used for sampling an RF transmission signal. The sampling rate control block1739may select a coefficient optimized according to the at least one of the current bandwidth, RB, or SCS through modeling and/or an algorithm of the multiplier. Accordingly, the sampling rate of the DAC/ADC may be adjusted by multiplying a clock signal generated by the clock generator by the coefficient selected according to the bandwidth, the RB, or the SCS. The method of controlling the sampling rate based on the network environment information by the sampling rate control block1739and the circuit configuration therefor have been previously described with reference toFIGS.11to12. The DPD block1736may process a DPD for an RP signal to be transmitted based on the network environment information acquired in real time. The DPD block1736may be provided on the transceiver1730, and may perform DPD before a signal output from the modem1720is input to the power amplifier1741of the Tx module1740. The DPD block1736may store a DPD LUT mapping a DPD coefficient to be used in correspondence with each network environment (e.g., at least one of the bandwidth, the RB, the SCS, or the modulation scheme). The method of performing DPD based on the network environment information by the DPD block1736and the circuit configuration therefor have been previously described with reference toFIGS.13to15. The CFR block1731may check the modulation scheme used for the RF transmission signal based on the network environment information received from the network monitor1760, and may perform CFR with a corresponding clipping level. A method of performing CFR based on the modulation scheme by the DPD block1736has been previously described with reference toFIG.16. Various embodiments of the application may include at least some of the components ofFIG.17. For example, the electronic device may include at least some of the CFR block1173, the DPD block1736, the sampling rate control block1739, and the ET control block1759, which perform determined processing by adapting to the network environment. Alternatively, some of the blocks may operate using fixed parameters without using the network environment information. According to an embodiment, an electronic device may include a network monitor configured to acquire network environment information related to an RF transmission signal; a transceiver configured to generate an envelope signal of the RF transmission signal; a Tx module including a power amplifier for receiving the RF transmission signal from the transceiver and amplifying the RF transmission signal; and an ET modulator configured to receive the envelope signal from the transceiver and to provide a bias of the power amplifier to correspond to the envelope signal, wherein the ET modulator may determine a magnitude of the bias of the power amplifier based on the network environment information acquired by the network monitor. The ET modulator may include a linear regulator configured to linearly amplify the envelope signal and the switching converter configured to output a switching current according to a switching frequency, and the ET modulator may output an output current to the Tx module, wherein the output current is obtained by mixing a pass current output from the linear regulator with the switching current. The ET modulator may further include an ET control block configured to determine a magnitude of the pass current output from the linear regulator based on the network environment information. The ET control block may control the magnitude of the pass current to be increased when the RF transmission signal is a high-bandwidth signal based on the network environment information. The liner regulator may include a bias control circuit configured to include a plurality of transistors that can be switched according to a control signal of the ET control block, and the ET control block may control a magnitude of a current that is input as a bias of the linear regulator from the bias control circuit based on the network environment information. The ET control block may determine the switching frequency of the switching converter based on the network environment information. The electronic device may further include a DAC configured to convert a digital signal into an analog signal and the sampling rate control block configured to determine a sampling rate of the DAC based on the network environment information. The sampling rate control block may determine the sampling rate by multiplying a clock signal generated by the clock generator with a coefficient selected according to the network environment information. The electronic device may further include the DPD block configured to output a linearized signal by pre-distorting the RF transmission signal according to a gain characteristic of the power amplifier, and the DPD block may distort the RF transmission signal using a DPD coefficient corresponding to the network environment information. The electronic device may further include the CFR block configured to reduce a PAPR of the RF transmission signal by clipping at least a portion of the RF transmission signal, and the CFR block may determine a clipping level for applying the CFR based on the network environment information. The network environment information may include at least one of a bandwidth, an RB, an SCS, or a modulation scheme. The network monitor may acquire the network environment information related to the RF transmission signal through at least one of an FBRx path and an Rx path. The network monitor may acquire the network environment information when the electronic device is powered on or for each predetermined period. The electronic device may further include the modem configured to transmit a digital baseband signal to the transceiver, and the network monitor1760may be included in the modem. The electronic device may output the RF transmission signal according to a 5G NR communication scheme. FIG.18is a flowchart illustrating a method of operating a wireless communication system, according to an embodiment. The illustrated method may be performed by the electronic device (or the wireless communication system) described with reference toFIGS.1to17above, and the description of the technical features described above will be omitted below. In step1811, an electronic device300is powered on. After the electronic device300is powered on in step1811, the electronic device monitors network environment information using a network monitor360in step1821. The network monitor360may monitor the network environment information in step1821by performing Tx chain calibration in step1823and/or by performing Rx chain calibration in step1822. The network environment information may include at least one of a bandwidth detected in step1831, an RB detected in step1832, an SCS detected in step1833, or a modulation scheme detected in step1834. In step1841, an ET control block755controls a drive stage of a linear regulator751and/or a switching converter752of the ET modulator750based on at least one of the detected bandwidth, RB, or SOS information. In step1842, a sampling rate control block1138determines a sampling rate based on the at least one of the detected bandwidth, RB, or SCS information. For example, the sampling rate control block1138may adjust a sampling frequency of a multiplier1138bin the sampling rate control block1138and a cutoff frequency of a BB LBF1133ato remove image/harmonic signals. In step1843, a DPD block1336receives the bandwidth, the RB, the SCS information and the modulation scheme information obtained from the network monitor and a characteristic of a transmitted Tx signal through the FBRx, and determines and updates a DPD LUT in real time. A DPD order may be embedded in a DPD LUT determination model to adjust a used order according to the type of signal. The DPD coefficient may characterize the Tx path based on the FBRx information detected in real time and may determine an optimized DPD coefficient by using the DPD order that matches the type of the signal. In step1844, a CFR block1173adjusts a clipping level by adjusting a clipping point and a weighting coefficient p[n] according to a modulation scheme of a transmitted signal. According to an embodiment, a control method of a wireless communication system of an electronic device may include acquiring network environment information related to an RF transmission signal; generating an envelope signal of the RP transmission signal; and providing a bias of a power amplifier for amplifying the RF transmission signal to correspond to the envelope signal, wherein providing the bias may include determining a magnitude of the bias of the power amplifier based on the network environment information. Determining the magnitude of the bias may include at least one of determining a magnitude of a pass current output from a linear regulator for linearly amplifying the envelope signal based on the network environment information and determining a switching frequency of the switching converter for outputting a switching current according to the switching frequency based on the network environment information. Determining the magnitude of the pass current may include increasing the magnitude of the pass current when the RF transmission signal is a high bandwidth-signal. The network environment information may include at least one of a bandwidth, an RB, an SCS, or a modulation scheme. Acquiring the network environment information may include acquiring the network environment information related to the RF transmission signal through at least one of an FBRx path and an Rx path. While the present disclosure has been particularly shown and described with reference to certain embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents. | 77,064 |
11943002 | DETAILED DESCRIPTION In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, interfaces, techniques, etc., in order to provide a thorough understanding of the examples. However, it will be apparent to those skilled in the art that the disclosed subject matter may be practiced in other illustrative examples that depart from these specific details. In some instances, detailed descriptions of well-known devices and/or methods are omitted so as not to obscure the description with unnecessary detail. The present subject matter may enable an accurate estimation of PIM correction signals. The present subject matter may enable a flexible choice of frequencies in a wireless system regardless of the presence of intermodulation frequencies. This may particularly be advantageous with the increasing requirements for bandwidth, output power and the coexistence of multiple radio standards such as2G,3G,4G and5G. According to an example, the method further comprises correcting a signal being received at the receiver by using the interference signal. The values of the first and second sets of machine learned parameters may be optimized values of first and second sets of parameters respectively. For example, a PIM signal or interference signal may be modeled as function of the composite signal, wherein the second set of parameters are parameters of the model. The modeling may be based on or may use the system configuration. The parallel operation of the receiver and the transmitters may cause interferences which may limit in particular the sensitivity on the receiver. For example, when considering e.g. a high power broadband multi-standard multicarrier FDD system, it is possible that the system performance and sensitivity is affected by transmitter induced intermodulation products falling into the receive band, e.g. at RX channels. This example may mitigate the distortion effect that affects received signals at the receiver. According to an example, the correcting of the signal includes a subtraction processing of the interference signal from the signal being received. According to an example, the method further comprises aligning the set of signals, in accordance with delays caused by the system configuration, before the weighting. Each individual signal of the set of signals may be correlated with the received signal to produce correlation data representing a correlation for each individual signal. The correlation data may be used to define delays to be used in the aligning step. The delays may be propagation delays inside the communication system. This example may further increase the estimation accuracy of the PIM correction signals and may reduce memory usage inside the estimation circuitry. According to an example, the aligning is performed so that the estimated interference signal is indicative of a particular order intermodulation (IM) product. For example, for each IM's frequency location, a PIM issue may be described by a model the PIM (PIM waveform) observed in a receiver chain. The model may include one or more order IM products. For example, a PIM can be modeled, for an IM3 location, taking into account only the IM3 product as follows: b3*ts(n).*(ts(n).*conj(ts(n))), where ts is the composite signal and conj(ts(n)) is the complex conjugate of ts(n) and b3 forms the second set of parameters. In another example, a PIM can be modeled, for an IM3 location, taking into account the IM3 and IM5 products as follows: b3*ts(n).*(ts(n).*conj(ts(n)))+b5*ts(n).*(ts(n).*conj(ts(n))){circumflex over ( )}2. Thus, each PIM issue may be associated with respective delays, first and second sets of machine learned parameters. According to an example, the method further comprises repeating the providing, weighting, combining and weighting steps, wherein the aligning is performed so that the estimated interference signal is indicative of another order IM product which is different from the order IM product. The nonlinear behavior that is taken into account by the present subject matter may be more complex, e.g. including higher order terms like the 5th or 7th order or involving a piecewise nonlinear input output mapping, since only a single block may need to be used and modelled in order to perform the present method. The single block may be a block used for weighting the (single) composite signal. This example may enable to double/triple generic PIM structures with different delay compensated input data to account for several concurrent PIM issues. According to an example, the first set of machine learned parameters are complex parameters, wherein the weighting of each of the received signals is performed using a respective single one of the complex parameters. The weighting may be performed to modify a characteristic of the signal. The characteristic may for example comprise at least one of the gain and the phase of the signal. For example, each individual signal of the set of signals may be modified in gain and phase via a single complex coefficient. According to an example, the weighting of each of the received signals is performed using a linear filter comprising taps of complex parameters, the complex parameters of the taps of the filters being the first set of machine learned parameters. Using linear tap filters may enable to use more complex parameters for weighing the signals. This may further increase the accuracy of the PIM correction signal estimation. These weighting examples may enable a flexible implementation of the weighting in accordance with the present subject matter. According to an example, the weighting of the received signals, the combining and the weighting of the composite signal defines an estimation method that estimates the interference signal for the received set of signals. The method further comprises optimizing an objective function in a multidimensional space defined by the first and second sets of parameters. The optimizing comprises: providing an initial set of values of the first second sets of parameters, iteratively modifying the values of the first and second sets of parameters until an optimal value of the objective function is obtained, wherein in each iteration the method comprises receiving a set of training transmit signals, performing the estimation method, and evaluating the objective function. The objective function relates a received training receive signal at the receiver with a corrected signal that is obtained by correcting the received training receive signal by the interference signal caused by the set of training transmit signals. The optimization results in the first and second sets of machine learned parameters. In one example, the same set of training transmit signals may be used in each iteration. This may save processing resources that would otherwise be required to use different set of training transmit signals. In another example, a different set of training transmit signals may be used for each iteration. This may improve the training as it may reduce potential bias that may be introduced when using the same input for multiple iterations. This example enables a training method for learning optimal values of the first and second sets of parameters that can be used in a real-time system to perform the estimation and cancelation of the PIM correction signal. For example, the training may be performed in the same or different apparatus where the estimation and cancelation of the PIM correction signal is executed. Performing the training in the same apparatus may enable an accurate determination of the first and second sets of the machine learned parameters since the same apparatus is used for the training and for the application stage. Performing the training in a different apparatus may enable to generate in a central manner and consistently the first and second sets of the machine learned parameters for different target apparatuses where the present method may be executed. In one example, the training method may be performed using a computer program that models the elements of the apparatus and that does the training method using the modeled apparatus. In one example, the values of the first and second set of machine learned parameters may be reused as new start values of the first and second set of parameters for repeating the training method e.g. at a later point of time. This may for example enable to adapt the first set and second set machine learned parameters to account for PIM changes during a run mode. This may reduce the required number of re-iterations in the optimization. According to an example, each set of signals of the sets of training transmit signals are uncorrelated signals, and each signal of the set of signals has all resource blocks being used for a maximum bandwidth usage and power. This may improve the training process and thus the resulting first and second sets of machine learned parameters may have optimal values that can be used to better estimate the PIM correction signal. According to an example, the objective function is 10 log(RMS(RXb)/RMS(RXa)), wherein the optimizing comprises maximizing the objective function, wherein Rxb is a signal received at the receiver and Rxa is a corrected signal that results from the subtraction of the interference signal from Rxb. The optimization of the cost function may for example be performed using the “Nelder Mead” method or a gradient based method. The gradient based method may have a better conversion speed. According to an example, the system configuration indicates at least one of frequencies of the transmitters and receiver and one or more sources of PIM. The system configuration is descriptive of the communication system. The communication system may comprise the apparatus. For example, the system configuration may define the number of transmitters, the placements of the transmitters, the receiver and the source(s) of PIMs etc. For example, the same system configuration of the communication system may be used to perform the training and to use the resulting first and second sets of machine leaned parameters to estimate the interference signal (e.g. in a real-time system). For example, the received set of signals may comprise signals s1, s2 . . . s10. The signals may be weighted using the first set of machine learned parameters. Following the example, the first set of parameters may comprise parameters a1, a2, a3 . . . a10. Each signal sj (j=1 . . . 10) of the received set of signals may be weighted by a respective parameter aj. Each parameter of the parameters may be a complex parameter aj=c1j+i*c2j. Each parameter aj of the parameters may be used to weight its respective signal sj so that the gain and phase of the signal sj may be changed accordingly. The weighted signals aj*sj may be combined e.g. summed to obtain a composite signal ts e.g. ts=a1*s1+a2*s2+ . . . a10*s10. A PIM issue may for example be modeled, for an IM3 location, taking into account the IM3 and IM5 products as follows: b3*ts(n).*(ts(n).*conj(ts(n)))+b5*ts(n).*(ts(n).*conj(ts(n))){circumflex over ( )}2, where n is time. In this case, b3 and b5 are the second set of parameters. In another example, PIM issue may be modeled for an IM3 location using the IM3 product only with different delays as follows: b3*ts(n).*(ts(n).*conj(ts(n)))+b13*ts(n).*(ts(n−1).*conj(ts(n−1)))+b23*ts(n).*(ts(n).)conj(ts(n)))+b33*ts(n+1).*(ts(n+1).*conj(ts(n+1))). In this case, b3 and b13, b23 and b33 are the second set of parameters. The first set and second set machine learned parameters are optimized values of first set (e.g. a1 . . . a10) and second set (b3 and b5) of parameters respectively. The values of the first and second sets of parameters are optimized so that they can be used to estimate the interference signal. The values a1 . . . a10 and b3-b5 may be estimated together in a multidimensional space defined by a1 . . . a10 and b3-b5 and using a common cost function. The values a1 . . . a10 and b3-b5 may be reused as new start values of the first and second set of parameters in another optimization. This may for example enable to adapt the first set and second set machine learned parameters to account for PIM changes during a run mode. This may reduce the required number of re-iterations in the optimization. According to an example, the apparatus further comprises a subtraction circuitry configured to correct a signal being received at the receiver by using the interference signal. According to an example, the subtraction circuitry is configured to correct the signal by a subtraction processing of the interference signal from the signal being received. According to an example, the estimation circuitry is further configured to align the set of signals, in accordance with delays caused by the system configuration, before the weighting. According to an example, the estimation circuitry is further configured to align the set of signals so that the estimated interference signal is indicative of a particular order intermodulation, IM, product. According to an example, the estimation circuitry is further configured to repeat the weighting, combining and weighting steps so that the estimated interference signal is indicative of another order IM product which is different from the order IM product. According to an example, the first set of parameters are complex parameters, wherein the estimation circuitry is configured to perform the weighting of each of the received signals using a respective one parameter of the complex parameters. According to an example, the estimation circuitry is configured to perform the weighting using a linear filter comprising taps of complex parameters, the complex parameters of the taps of the filters being the first set of machine learned parameters. According to an example, the estimation circuitry is configured to receive from an optimizer of the apparatus the set first set of machine learned parameters and the second set of machine learned parameters. The optimizer is configured to optimize an objective function in a multidimensional space defined by the first and second sets of parameters in order to obtain the set first set of machine learned parameters and the second set of machine learned parameters, the objective function relating a received training receive signal at the receiver with a corrected signal that is obtained by correcting the received training receive signal by the interference signal caused by a set of training transmit signals received at the estimation circuitry. According to an example, the apparatus comprises the transmitters and the receiver. FIG.1depicts a diagram of a communication system100. The communication system100comprises a transceiver system101. The transceiver system101may be a base station for a cellular communication network, but is not limited thereto. The transceiver system101may, for example, be a multi-carrier or multi-band system (e.g., a system that simultaneously operates in two different frequency bands or at least two carriers in the same frequency band). The transceiver system101is configured to send a set of signals via an antenna102. Although only a set of two signals Tx1and Tx2is illustrated for this particular example, it should be appreciated that the set of signals may comprise more than two signals. The set of signals Tx1and Tx2are transmitted at frequencies F1and F2respectively. However, intermodulation products may be generated when the set of signals Tx1and Tx2are transmitted along a signal path including a source of PIM. The source of PIM may be inside the transceiver system inducing a conducted PIM and/or outside the transceiver system triggering an air induced PIM. The air induced PIM may be caused by sources of PIM at predefined distances to the transceiver system101. For example, in case of a transceiver system of a MIMO installation with several transmit signals, the transmit signals on the same frequency may cause higher power spectrum densities and thus metallic objects in a 10 m distance or more from the transceiver system101are not negligible and can cause uplink (UL) desensitization and throughput losses. In the example shown inFIG.1, the set of signals Tx1and Tx2impinge upon a source of PIM106. The source of PIM106may, for example, be a metallic component comprising a ferromagnetic material. IM products107of the set of signals Tx1and Tx2are generated due to the non-linear response of the source of PIM106. The set of signals Tx1and Tx2may produce, for example, third order IM products at frequencies2F1-F2and2F2-F1, fifth order IM products at frequencies3F1-2F2and3F2-2F1and other products. This provides relationships between signal frequencies, e.g. F1-F2, and the frequencies of IM products produced from those frequencies.FIG.1shows that IM products107of the set of signals Tx1and Tx2are transmitted from the source of PIM106. The transmission of the IM products107may be performed at a respective frequency of the IM products107. The IM products107fall at least in part, within a received channel at frequency F3and appear as interference to a received signal Rx that is transmitted at radio frequency from, for example, a user equipment109in communication with the transceiver system101. FIG.2depicts a diagram of a transceiver system201in accordance with an example of the present subject matter. The transceiver system201may for example be configured to operate in a communication system such as communication system100ofFIG.1but it is not limited to. As illustrated, the transceiver system201includes multiple transmitters203A-N and a receiver210(also referred to herein as main receiver) coupled to an antenna215via a duplexer214. Each of the transmitters203A-N includes a digital-to-analog (D/A) converter204A-N and a PA205A-N connected as shown. Each of the transmitters203A-N operates to process a respective digital input signal Tx1-Txn, which may for example be a digital baseband signal, to output a radio frequency transmit signal. The radio frequency transmit signal of each of the transmitters203A-N passes through the duplexer214to the antenna215such that the radio frequency transmit signal is transmitted by the transceiver system201. After being output by the transmitter203A-N, the radio frequency transmit signal passes through a source of PIM indicated by an “X” inFIG.2. As indicated in connection with the antenna215, the location where the distortion (e.g. the PIM effect) is caused may be located there (indicated by an “X”), but it is to be noted that there may be more than one location where corresponding distortions (PIM effects) are caused e.g. as shown with reference toFIG.1. Due to the non-linearity of the source of PIM, PIM may be introduced into a radio frequency receive signal received at the antenna215. The PIM may comprise IM products of the radio frequency transmit signals. The IM products include 3rd order IM products, fifth order IM products, etc. The receiver210may, for example, include receiver components such as a LNA, filters, a down-conversion circuitry, an analog-to-digital converter, and the like. The receiver210operates to process (e.g., amplify, filter, down-convert, and analog-to-digital convert) a radio frequency receive signal received from the antenna215via the duplexer214to output a digital output signal220, which is referred to herein as a main receiver output signal220. The IM products of the radio frequency transmit signals produced by the source of PIM that fall within a passband of the receiver210result in a PIM distortion in the main receiver output signal that is output by the receiver210. An estimate of the PIM distortion, which is a digital signal referred to herein as a PIM correction signal or interference signal, is generated and provided to subtraction circuitry211. The subtraction circuitry211operates to subtract the PIM correction signal from the main receiver output signal220in the digital domain to provide a corrected output signal221which is referred to as a IM cleaned Rx main signal221. The PIM correction signal is generated such that the PIM distortion in the corrected output signal is minimized, or at least substantially reduced, as compared to the PIM distortion in the main receiver output signal220. The PIM correction signal is generated by an estimation circuitry212. The estimation circuitry212and the subtraction circuitry211may be referred to as a PIM correction system. The PIM correction system may enable a generic MIMO PIM cancellation, in accordance with the present subject matter, for FDD systems. The estimation circuitry212is configured to receive the digital input signals Tx1. . . Txn and to estimate the PIM correction signal in accordance with the present subject matter. In one example, the estimation circuitry212may be provided using an FPGA or ASIC implementation. As used in this application, the term “circuitry” may refer to one or more or all of the following:a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) andb) combinations of hardware circuits and software, such as (as applicable):I. a combination of analog and/or digital hardware circuit(s) with software/firmware andII. any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) andc) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device. FIG.3depicts a block diagram of an estimation circuitry312in accordance with an example of the present subject matter. The estimation circuitry312comprises a first weighting block320. The first weighting block320is configured to weight received set of signals Tx1. . . Txn (e.g. received from transmitters203A-N) by respective complex coefficients (A1. . . An) to generate a set of weighted signals. The complex coefficients A1, A2, . . . An are values of a first set of machine learned parameters (collectively referred to by reference numeral330). The weighted signals may be combined (e.g. summed) as shown at block322of the estimation circuitry312. The combination of the weighted signals results in a composite signal that is received at a second weighting block324(which may be named a non-linear (NL) block). The second weighting block324may use weights/values Bm of a PIM model of a particular order n IM product, where n=3, 5 or 7 etc. The composite signal may be weighted at the second weighting block324using values (Bm) of a second set of machine learned parameters (collectively referred to by reference numeral331). The values of An and Bm of the first and second sets of machine learned parameters may be learned together on the same set of data. The values of the first and second sets of machine learned parameters330and331may be obtained using a training method in accordance with the present subject matter. The weighted composite signal may be an estimated PIM correction signal that is caused by the received signals Tx1, . . . Txn. In one example, the received signals may, optionally, be pre-processed before being weighted by the first set of machine learned parameters330. The pre-processing comprises using a plurality of delays to generate delayed transmit signals by applying the delays to the set of signals Tx1. . . Txn. The delays may be obtained as follows. Each individual signal of the set of signals may be correlated with the received signal to produce correlation data representing a correlation for each individual signal. The correlation data may be used to define the delays. The correlation may be obtained by a cross-correlation function (xcorr) that has two arguments, wherein one of the arguments is the received signal Rx and the other argument can be a signal Tx or a particular order IM product. For example, the correlation may be obtained as a xcorr(abs(TX),abs(RX)) correlation or as a IM3 correlation xcorr(IM3(TX1,TX2),RX). The cross-correlation function determines the cross-correlation between a pair of signals (or a pair of discrete-time sequences) such as abs(TX) and abs(RX), where abs(X) returns the absolute value of each element in array X. FIG.4depicts a block diagram of an estimation circuitry412in accordance with an example of the present subject matter. The estimation circuitry412enables to account for several concurrent PIM issues. The estimation circuitry412comprises multiple estimation circuitries312A-M. Each of the multiple estimation circuitries312A-M is the estimation circuitry described with reference toFIG.3, wherein each of the estimation circuitries312A-M receives the same set of signals Tx1. . . Txn. However, each set of signals is pre-processed separately using different delay values. In addition, each of the multiple estimation circuitries312A-M comprises its own first and second sets of machine leaned parameters330A-M and331A-M that are obtained for the PIM issue for which the estimation circuitry is used. Since only a single NL block (i.e.324) may need to be modelled, the present subject matter may enable to treat more complex NL behaviors including higher order terms like the 5th and 7th order term using an estimation circuitry as described with reference toFIG.4. FIG.5is a flowchart of a method for estimating a PIM correction signal in accordance with an example of the present subject matter. For the purpose of explanation, the method may be implemented in the system illustrated in previousFIGS.1-4, but is not limited to this implementation. For example, the method may be performed using the estimation circuitry312. The PIM correction signal may, for example, be estimated for a specific PIM issue e.g. involving a 3rdorder IM product only. The PIM issue may be described by a model of PIM signals, wherein the second set of parameters are parameters of the model. This means that the estimation circuitry312may be configured accordingly e.g. the first and second sets of machine learned parameters330and331may have been obtained by a training for that specific PIM issue. A set of signals Tx1. . . Txn may be received from the transmitters203A-N in step501. The set of signals Tx1. . . Txn may be received at the estimation circuitry312. The estimation circuitry312may for example receive several signals, wherein the set of signals Tx1. . . Txn may be selected from the several signals. The estimation circuitry312may select the set of signals Tx1. . . Txn on the basis of a determination of which signal frequencies of the received several signals may produce IM products that may fall within a channel of the receiver210that carries the received signal. The determination may be performed using the relationships between signal frequencies and the frequencies of IM products produced from those frequencies. On the basis of this determination, the set of signals Tx1. . . Txn may be selected. The set of signals Tx1. . . Txn may be processed by an estimation method having steps503to507in order to estimate an interference signal caused by the set of signals. Each individual received signal of the set of signals Tx1. . . Txn may, for example, be weighted in step503. The weighting of the individual signal may for example be performed by modifying a characteristic of the signal. The characteristic of the signal may be at least one of a gain and phase of the signal. The modification may, for example, be performed via a single complex coefficient330. If, for example, the first set of machine learned parameters comprises a vector A of n complex coefficients, this step503may involve a multiplication of the vector with the received set of signals as follows: An*Txn. In another example, the weighting of the individual signal may be performed using a linear filter comprising taps of complex parameters, so that each individual signal of the set of signals Tx1. . . Txn may be filtered with an k tap filter. In this case, step503may involve a convolution operation as follows: conv(Ak*TXn), where Ak is a vector with n*k tap complex filter coefficients. Thus, the problem complexity may only linearly be dependent on the number of TX signals N, the number of filter coefficients k and a wanted complexity for the NL block. A simplest NL block may involve a third order IM product, IM3 with M=1 memory (e.g. one Bm value) and N=10, k=1, 11 complex coefficients may be for the first and second sets of machine learned parameters. The weighted signals that result from step503are combined in step505at the block322in order to generate a composite signal. The combination of the weighted signals may comprise the summation of the weighted signals. The obtained composite signal is fed through the second weighting block324with coefficients Bm. The composite signal is weighted in step507using the coefficients Bm. The weighted composite signal may be an estimation of an interference signal that is caused by the set of signals Tx1. . . Txn at the receiver210. The estimated interference signal may be a PIM correction signal which may, for example, be used for test purpose to accurately quantify the PIM issue and measure PIM impact in the communication system100. In another example, the PIM correction signal may be used to correct the main receiver output signal220. FIG.6is a flowchart of a method for estimating a PIM correction signal for different PIM issues in accordance with an example of the present subject matter. For the purpose of explanation, the different PIM issues may comprise two PIM issues, but is not limited to. For example, a first PIM issue may involve a 3rdorder IM product and a second PIM issue may involve the 3rdorder and 5thorder IM products. A set of signals Tx1. . . Txn may be received in step601from the transmitters203A-N at each estimation circuitry of two estimation circuitries312A and312M ofFIG.4. For example, estimation circuitry312A may be configured to estimate interference signals for the first PIM issue and the estimation circuitry312M may be configured to estimate interference signals for the second PIM issue. The set of signals received at each of the estimation circuitries312A and312M may be aligned in step603, in accordance with delays determined for the respective PIM issue. This results in multiple sets of aligned signals associated with receptive estimation circuitries312A and312M. The estimation method may be performed in step605for each set of the sets of aligned signals at respective estimation circuitry312A and312M. This may result in multiple estimated PIM correction signals. FIG.7is a flowchart of a method for learning optimal values of the first and second sets of parameters330-331. In step701, an initial set of values of the first and second sets of parameters330-331may be provided. The initial set of values are the current values of the first and second sets of parameters. For example, the estimation circuitry312may be configured to operate with those current values in step701. In step703, a set of training transmit signals may be received at the estimation circuitry312. The set of training transmit signals are uncorrelated signals, and each signal of the set of training transmit signals has all resource blocks being used for a maximum bandwidth usage and power. The estimation method may be performed in step705on the received set of training transmit signals to estimate a PIM correction signal using the current values of the first and second sets of parameters. An objective function may be evaluated in step707. The objective function relates a received training receive signal at the receiver210with a corrected signal that is obtained by correcting the received training receive signal by the interference signal caused by the set of training transmit signals. The objective function may for example be the following cost function, gain=10 log(RMS(RXb)/RMS(RXa)), where Rb is a signal received at the receiver, Rxa is a corrected signal that results from the subtraction of the interference signal from Rxb, and RMS refers to a root mean square power calculation. In another example, a receiver total wideband power (RTWP) method may be used in the cost function instead of RMS. In one example, Rxa may be defined as RXa=RXb−NL(ΣAn*TXn), where A is a vector with n complex coefficients. In this example, the n complex coefficients are the first set of learned machine parameters330. NL(ΣAn*TXn) may be the interference signal that is obtained by the estimation circuitry (NL). In another example, and in case the weighting of received signals is performed using linear filters, Rxa may be defined as follows, RXa=RXb−NL(Σ conv(Ak*TXn)), where Ak is vector with n*k tab complex filter coefficients. In this example, the n*k complex filter coefficients are the first machine learned set of parameters330. NL(Σ conv(Ak*TXn)) may be the interference signal that is obtained by the estimation circuitry (NL). It may be determined (inquiry step709) whether an optimal value of the objective function is obtained. If not, the current values of the first set and second set of parameters may be modified. The modified values become the current values of the first set and second sets of parameters for a next iteration of steps703-709. The optimal value of the objective function may be a maximum value of the cost function. If it is determined that an optimal value of the objective function is obtained, the current values of the first set and second set of parameters are values of the first and second sets of machine learned parameters. And the first and second sets of machine learned parameters may be provided in step711. Steps701,707,709and711may be performed by the optimizer and steps703-705may be performed by the estimation circuitry. The method ofFIG.7may optimize the objective function in a multidimensional space defined by the first and second sets of parameters using for example the “Nelder Mead” approach or a gradient based approach. A higher convergence speed may be obtained using a gradient-based approach while calculating a hessian matrix in accordance with a quasi-newton algorithm e.g. this may be performed using the function named “fminunc”. This leads to an optimization problem to adjust the complex coefficients An and Bm in such a manner that the cost function optimizes for a maximum PIM noise correction. The optimization process as described with reference toFIG.7is a machine-driven iteration and learning which leads to a numerical optimum. FIG.8shows the values of the objective function in different iteration steps of the learning (e.g. as described with reference toFIG.7) with real data using the gradient-based approach in accordance with a quasi-newton algorithm. FIG.9shows results of a PIM cancellation in accordance with the present subject matter.FIG.9shows the distribution of the main receiver output signal220and the IM cleaned Rx main signal221. The results ofFIG.8are obtained using “test” data to indicate the final cancellation gain obtained. FIG.10is a block diagram showing an example of an apparatus according to example of the present subject matter. InFIG.10, a block circuit diagram illustrating a configuration of an apparatus1070is shown, which is configured to implement at least part of the present subject matter. It is to be noted that the apparatus1070shown inFIG.10may comprise several further elements or functions besides those described herein below, which are omitted herein for the sake of simplicity as they are not essential for the understanding. Furthermore, the apparatus may be also another device having a similar function, such as a chipset, a chip, a module etc., which can also be part of an apparatus or attached as a separate element to the apparatus, or the like. The apparatus1070may comprise a processing function or processor1071, such as a CPU or the like, which executes instructions given by programs or the like related to a flow control mechanism. The processor1071may comprise one or more processing portions dedicated to specific processing as described below, or the processing may be run in a single processor. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors or processing portions, such as in one physical processor like a CPU or in several physical entities, for example. Reference sign1072denotes transceiver or input/output (I/O) units (interfaces) connected to the processor1071. The I/O units1072may be used for communicating with one or more other network elements, entities, terminals or the like. The I/O units1072may be a combined unit comprising communication equipment towards several network elements, or may comprise a distributed structure with a plurality of different interfaces for different network elements. Reference sign1073denotes a memory usable, for example, for storing data and programs to be executed by the processor1071and/or as a working storage of the processor1071. The processor1071is configured to execute processing related to the above described subject matter. In particular, the apparatus1070may be configured to perform at least part of the method as described in connection withFIG.7. The processor1071is configured to optimize an objective function in a multidimensional space defined by the first and second sets of parameters330-331using the estimation circuitry in accordance with the present subject matter. The optimization is performed in order to obtain the values of the first and second machine learned sets of parameters that can be used in real-time to estimate PIM correction signals using the estimation circuitry. | 38,702 |
11943003 | DETAILED DESCRIPTION The lack of reliable and suitable methods for wireless classification and/or authentication in cellular communication towers and indoor wireless networks might lead to a direct negative impact on individuals, communities, and nations. Impersonation attacks, identity theft, and illegal access to a spectrum are some of the problems that occur when it is not possible to reliably identify the real identity of a wireless device. Impersonation attacks occur when someone pretends to be someone else. Such attacks allow bad actors to commit crimes in someone else's name. Identity theft usually starts by stealing personal information and then using it to gain access to confidential and/or classified information or accounts which might lead to a huge damage for individuals, companies, communities, and governments. Illegitimate access to the spectrum may cause a loss of highly secure information, and a degradation on the quality of the service. Radio frequency spectrum is one of the most expensive commodities in the technology space. A radio frequency spectrum is divided into small chunks for a huge number of applications, from Amplitude Modulation (AM) and Frequency Modulation (FM) radio, television, and cellular networks to walkie-talkies, satellite communications, and military applications. Federal agencies such as the Federal Communication Commission (FCC) sell, regulate, and monitor the use of the spectrum. Illegal access to a licensed portion of the spectrum can cause a lot of damage to the service that is provided in that portion of the spectrum. Wireless network attacks and illegal spectrum access can be immensely overwhelming as it could lead to serious problems such as leaking sensitive and/or classified information, shutting down facilities, disrupting emergency and military services, degrading network performance for primary users, and other indirect financial and reputation impacts. Some security identification solutions use simple digital identifiers, such as Media Access Control (MAC) addresses, Internet Protocol (IP) addresses, and Services Set Identifier (SSID). However, most of the security identification solutions are not effective in detecting advanced and complicated attacks since those digital identifiers can be easily spoofed by existing software. Therefore, a more secure solution that does not only depend on simple digital identifiers is desired. One approach to identifying wireless devices is to use a similarity-based approach which involves comparing an observed signature of a given wireless device with provided signatures in a reference database. This approach uses techniques such as supervised Bayesian and Wavelet analysis to generate the fingerprint. However, the challenge with this approach is that it requires a priori knowledge of vendor specific features to be used as similarity measures. It also suffers from the scalability issue in that more specific features need to be added to the reference list every time a new type of device is to be recognized. Moreover, vendor-specific features are usually accessible or can be reverse-engineered, which make this approach very vulnerable to adversary attacks. Another approach to identifying wireless devices is a typical classification approach that relies on a set of hand-selected features of a given signal to perform the classification task. Some of the prevalent features are amplitude, phase, mean, variance, preamble, and spectral domain features. The extracted features are fed to classification methods such K-nearest neighbor (K-NN), Support Vector Machine (SVM), and simple Nearest Neighbor (NN). The challenge with this approach is that it requires expert knowledge and many trials and error iterations to find the optimal features. Different protocols do not share the same features, and hence, in many cases, we end up with protocol-specific or vendor-specific approaches that suffers from scalability and generalization issues. Another approach to identifying wireless devices is to use the power of deep learning (e.g., Convolution Neural Networks (CNN)s and Recurrent Neural Networks (RNNs)) to learn the appropriate features from the input using the hidden layers and use them to classify different signals. However, a shortcoming of this approach is that it suffers from poor performance when it comes to classifying high-end, bit-similar devices that are sending the same packets (the worst-case scenario). The variability among the hardware implementations in the high-end devices is extremely minimal, which makes the task of recognizing those variations in the presence of channel and environment impact is extremely challenging. Various embodiments describe a scheme for identifying wireless devices by capturing out-of-band information in addition to in-band information from wireless devices for enabling accurate classification of wireless devices. Both the in-band and out-of-band spectrum emissions of the received signal are used in establishing the hardware signatures. These hardware signatures are unique and discernible among devices, even when devices have the same hardware with significantly reduced distortions. In some embodiments, the out-of-band information can be extracted using radios with software defined capabilities. Some embodiments use a deep learning-based device classification technique that uses I/Q samples representing the RF signals to efficiently identify and classify high-performing transmitters that have the same, minimally distorted hardware components. There are many technical effects of various embodiments. The scheme of various embodiments achieves high accuracy of device identification. For example, the scheme achieves about 96% accuracy even when the transmitters of the wireless devices have similar features. The scheme of various embodiments is scalable in that it can distinguish among large numbers of minimally distorted devices with the same hardware, regardless of their protocol and/or software configurations. The scheme of various embodiments is robust against signature cloning and modification and uses little to no changes at the transmitters. The scheme of various embodiments incurs minimal extra processing at the receiver side that can be performed with existing hardware. Other technical effects will be evident from the various embodiments and figures. The embodiments of the disclosure will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the disclosure, which, however, should not be taken to limit the disclosure to the specific embodiments, but are for explanation and understanding only. In the following description, numerous details are discussed to provide a more thorough explanation of embodiments of the present disclosure. It will be apparent, however, to one skilled in the art, that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, to avoid obscuring embodiments of the present disclosure. Note that in the corresponding drawings of the embodiments, signals are represented with lines. Some lines may be thicker, to indicate more constituent signal paths, and/or have arrows at one or more ends, to indicate primary information flow direction. Such indications are not intended to be limiting. Rather, the lines are used in connection with one or more exemplary embodiments to facilitate easier understanding of a circuit or a logical unit. Any represented signal, as dictated by design needs or preferences, may actually comprise one or more signals that may travel in either direction, and may be implemented with any suitable type of signal scheme. It is pointed out that those elements of the figures having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner like that described but are not limited to such. Radio Frequency (RF) transmitters acquire benign hardware impairments during manufacturing and assembly stages. These device-specific impairments cause the transmitted RF signals to deviate from their ideal values, thereby establishing unique signatures for their corresponding devices. Despite the many great efforts aimed at designing hardware techniques that can eliminate or limit these hardware impairments so that they fall within tolerable ranges, these impairments cannot be eliminated completely. The scheme of various embodiments exploits such impairments to provide and enable efficient device classification. Described herein is a closer look at the sources, modeling, and impact of the most significant transmitter-specific impairments. These impairments become the basis of device identification and/or classification in accordance with various embodiments. FIG.1illustrates transceiver100with various RF impairments. The section starts with an analysis of quantization noise and clock source modulation. Transceiver100comprises source101which provides digital base-band data, digital-to-analog converters (DACs)102and103, anti-aliasing filter104and105, mixers106and107, local oscillator (LO)108, phase shifter109, adder or summer110, PA111, band-pass filter112, and antenna113coupled as shown. An interface between a digital processing unit (DSP) and an analog front-end (AFE) component in modern transmitters includes one or more DACs that convert digital baseband sequences (e.g., S1[n] for the in-phase (I) path component) to their equivalent time-continuous analog signals (e.g., S1(t)). Digital baseband sequences S1[n] and SQ[n] are generated by source101. Source101can be any suitable source. In some examples, the source is a digital signal processor. DACs102and103use different variations of zero order-hold circuits to generate staircase continuous waveforms as an approximation of the smooth waveforms. The high frequency components represented by the sharp edges of the staircase pattern are removed by Anti-Aliasing filters104and105. A limited number of DAC resolution bits, finite clipping levels, and nonlinearity nature of real DACs altogether result in the degradation of the signal-to-noise (SNR) values and the transmitter performance in general. The main three sources of a DAC's distortions include: horizontal quantization (HQ), vertical quantization (VQ), and clock source modulation (CM), and whose aggregated impact on the DAC functionality can be modelled as additive terms superimposed on the ideal analog output. For instance, considering the input S1[n], the output y(S1[n]) of DAC102in the I path can be modelled as: y(S1[n])=S1(t)+yS1HQ(t)+yS1VQ(t)+yS1CM(t) (1) where yS1HQ(t), yS1HQ(t), and yS1CM(t) represent HQ, VQ, and CM distortions, respectively. HQ distortion represents the built-in discrete nature of the DAC output since it produces staircase patterns by holding the sample value during the sampling period. Anti-Aliasing filters104and105are used to eliminate the superimposed frequency components due to this discrete nature. However, interfering spurious terms still appear closer to the bandwidth of the output signal when the generating frequency is not sufficiently greater than the Nyquist rate. This effect can be modelled as: yS1HQ(t)=∑n=-∞∞SI[n]g(t-nTgTg)-SI(t)(2) where g(θ) is a unitary pulse with 0≤θ≤1 and Tgis the generation time period. Here, the in-phase (I) path component is used as an example to illustrate and explain the presented concepts. Similar analysis and illustration can be done for the case of the quadrature (Q) path component. The time-domain instability of the clock source is what leads to periodic variation in the generating period, resulting in the CM impairment, which in turn generates unwanted spurious components in the signal spectrum and can be modeled as: yS1CM(t)=Σn=−∞∞S1[n]hn(t−nTg) (3) where the function hn(t) is defined as: hn(t)=-sign(Δn)g(t-nTgΔn)+sign(Δn+1)g(t-(n+1)TgΔn+1)(4) where sign(θ) is the sign function, and Δnis the deviation of the clock from its ideal value. The finite resolution of DACs102and103requires rounding the samples values to the nearest voltage level, referred to above as vertical quantization or VQ, giving rise to a quantization distortion proportional to the DAC resolution. Like the previous DAC impairments, VQ distortion increases the spurious content in the spectrum as well. It can be modelled as: yS1VQ(t)=∑n=-∞∞(S^I[n]+T[S^I[n]]-SI[n])(g(t-nTgΔn)+hn(t-nTg))(5) where T [Ŝ1[n]] is the Integral Nonlinearity (INL) term, which is a measure of the deviation of the output values from the ideal, and Ŝ1[n] is the approximated signal values. In ideal DAC, T [Ŝ1[n]]=0, making the VQ term go to zero. Each of these three DAC distortions (VQ, HQ, and CM) is hardware dependent, and hence, can be exploited as a feature or signature to distinguish one transmitter from another. This section describes the IQ imbalance. Zero Intermediate Frequency (IF) or direct transmitters, such as the one shown inFIG.1, leverage the quadrature mixer configuration to implement the up conversion of the baseband signal without the need for using any filtering methods. It does so by separately (in parallel) upconverting, at the carrier frequency ωc, the two in-phase (I) baseband modulated component, S1(t)=A(t)cos(Ø(t)), and quadrature (Q) baseband modulated component, SQ(t)=A(t)sin(Ø(t)), using two independent mixers106and107fed by local oscillator (LO)108tone shifted by 90° by phase shifter109from one another. Assuming perfectly matched I and Q paths, the two outputs are summed up, yielding the bandpass modulated signal (seeFIG.1): SRF(t)=A(t)cos(Ø(t))cos(ωct)−A(t)sin(Ø(t))sin(ωct) (6) Any amplitude mismatch Δα or phase deviation Δθ between the I and Q path components that can be caused by the DAC (e.g., DAC104and/or DAC106) and/or mixer (e.g., mixer106and/or mixer107) hardware impairments lead to imperfect image cancellation and result in residual energy at the mirror frequency −ωc, causing interference and signal-to-noise ratio (SNR) degradation. This amplitude mismatch and phase deviation, also known as IQ imbalance, can be quantified by measuring the power ratio between the image and the desired signal, which depends on Δα and Δθ. When using real mixers with amplitude and phase imbalances of Δα and Δθ, the upconverted (distorted) signal becomes: SRF(t)=1(1−Δα)S1(t)cos(ωct)−SQ(t)sin(ωct+Δθ) (7) Now when masking all other hardware impairments (e.g., assuming all other hardware components are ideal except DACs and mixers), the distorted complex baseband signal {tilde over (R)}(t)=SRF(t)e−jωctdown-converted at the receiver is: {tilde over (R)}(t)=[(1−Δα)S1(t)cos(ωct)−jSQ(t)sin(ωct+Δθ)]×[cos(ωct)−jsin(ωct)] (8) After some math manipulations and clearing the terms appearing at twice the carrier frequency (which are filtered out via low-pass filtering at the receiver), Eq. (8) yields: R~(t)=(1-Δα2)SI(t)+j(sin(Δθ)-jcos(Δθ)2)SQ(t).(9) Therefore, IQ imbalances manifest in in-band and out-of-band signal distortions that are exploited to increase device signature separability and classification accuracy, in accordance with some embodiments. The following section describes the DC offset. Ideal mixers output the product of the two signals coming from the input and the local oscillator (LO) ports, which comprises two terms, one appearing at the summation of the multiplied frequencies and one at their subtraction. However, due to hardware impairments, real mixers also produce some other unwanted emissions at different frequencies. Of a particular importance is a spike that appears at the center of the desired signal spectrum, known as DC offset, which cannot be easily filtered out because of its location in the middle of the message spectrum. DC offset impairments distort signal constellations and increase the error vector magnitude. There are two main sources of DC offsets: carrier leakage and second-order nonlinearity. Carrier leakage results from the LO leakage coming from the poor isolation between the three mixer ports limited by the different coupling effects. Thus, a strong LO signal can leak through unintended paths toward the mixer output port and appear at the middle of the desired signal spectrum, generating a static DC value at the receiver. For example, when mixing the in-phase component S1(t) while considering this LO leakage, the mixer output becomes: S1 RF=S1(t)cos(ωct)+ϑlocos(ωct) (10) where ϑlocos (ωct) is the unmodulated carrier term that leaks through the mixer output port and appears at the middle of the spectrum, and where ϑlois a hardware-specific feature that varies from a mixer to another. The second source of DC offset is second-order nonlinearity. When a single tone signal passes through a second-order nonlinearity system, the output signal exhibits frequency components at the integer multiple of the input frequency. To illustrate, consider feeding the in-phase baseband component to the mixer while considering only the nonlinearity up to the second order and ignoring the LO leakage effect. The output of the mixer in this case becomes: S1 RF=αS1(t)cos(ωct)+α2S12cos2(ωct) (11) where α1and α2are the parameters that model the mixer's first- and second-order nonlinearity terms. When replacing S1(t) by its expression A(t)cos(φ(t)), the second-order nonlinearity term—the one responsible for the DC component—can be written as: α2SI2cos2(ωct)=α2A2(t)4+α2A2(t)8[2cos(2ωct)+2cos(2φ(t))+cos(2(φ(t)-ωct))+cos(2(φ(t)+ωct))](12) Note that the first term in Eq. (12) represents the DC component, and it is affected by the nonlinearity distortion captured by the parameter α2. The characteristics of the DC component are determined by both the silicon-level circuitry of the LO and the second-order nonlinearity of the device. Therefore, DC offsets also contribute to the establishment of unique signatures and hardware features and are leveraged for uniquely identifying transmitters among one another, in accordance with some embodiments The following section describes the phase noise. Local oscillators (LOs) are fundamental blocks in RF transmitter architectures. They are responsible for producing periodic oscillating signals that can be used by the mixer to up-convert the baseband signal at the carrier frequency. The output of an ideal LO can be represented as a pure sinusoidal waveform cos(ωct) that would help to translate signals to the RF domain while preserving the original spectrum shape. FIGS.2A-Billustrate plots200and220showing the phase noise effect with an ideal local oscillator and a real local oscillator, respectively.FIG.2Aillustrates plot200showing the up-conversion of a baseband tone to 100 KHz using an ideal LO signal. Like the clock source issue in the DAC, the time domain instability of the generated signals by real LOs causes random phase fluctuations, known as phase noise, that expand the signal spectrum by introducing unwanted spectrum in both sides of the carrier frequency. This can be seen in plot220ofFIG.2Bwhich shows the same previous frequency translation (FIG.2A), but using a real LO signal, which can be represented as cos(ωct+θ(t)) with θ(t) being the phase noise term. The phase noise manifests in different noises within the LO circuit, such as thermal noise and flicker noise. It can be quantified by measuring the power of the 1-Hz bandwidth at a frequency offset with respect to the carrier frequency. It results in a random rotation in the receiver signal constellation, thereby increasing the symbol detection error as well as the out-of-band noise level. To show this impact, consider mixing the in-phase baseband signal, S1(t), with an LO signal, cos(ωct+θ(t)). After up-conversion, the mixer output can be expressed as: S1 RF(t)=S1(t)cos(ωct+θ(t))=S1(t)(ejωctejθ(t)) (13) where ejθ(t)is the phase noise term, and(x) refers to the real part of complex x. Given θ(t) is small and using the approximation ejθ(t)≈1+jθ(t), Eq. (13) can be rewritten as: S1 RF(t)≈S1(t)cos(ωct)−S1(t)θ(t)sin(ωct) (14) It is seen from Eq. (14) that the transmitted signal is composed of an undistorted component and an LO-dependent, phase-noise distorted component of the up-converted signal. This LO-dependent component implies that phase noise can also be considered as one of the hardware impairments that can contribute to transmitters' signatures, and hence can be leveraged to increase device distinguishability. The following section describes power amplifier nonlinearity distortion. The majority of circuit nonlinearity is attributed to power amplifiers (PAs) (e.g., PA111), which are the last elements in the transmitter chain as shown inFIG.1. They provide the modulated RF signals with the required radiation power to reach their destination. When a PA operates in the linear region, its I/O characteristics are deterministic, and an acceptable performance is ensured. However, operating in that region leads to more power consumption due to the associated low power efficiency characteristic. Since PAs are major power-hungry blocks, most of the transmitters drive their PAs to work near the saturation region to be more power efficient. Unfortunately, power efficiency and linearity of the PA conflict one another. Hence, the signal severely suffers from the nonlinearity of the PA when it works in the saturation region. The nonlinearity distortion results in amplitude compression, as well as in high adjacent channel power because of the bandwidth expansion, known as spectral regrowth. Although many linearization methods have been proposed to minimize the distortion and attenuate the spectral regrowth, PAs still exhibit some nonlinearity. PA nonlinearity distortion is typically captured through the instantaneous amplitude and phase responses to changes in the amplitude of the input signal, respectively known as Amplitude-to-Amplitude (AM-AM) and Amplitude-to-Phase (AM-PM) distortion curves. Using the complex power series to model the bandpass nonlinearity of the PA, the PA output SPA(t) that models the instantaneous AM-AM and AM-PM distortions can be expressed as: SPA(t)=∑n=0N-12α~2n+122n{(2n+1n+1)[A(t)2nS~(t)]1}ejωct(15) Where {tilde over (α)}iS are the complex coefficients of the model, N is the maximum order of nonlinearity, and {tilde over (S)}(t)=S1(t)+jSQ(t) is again the complex baseband envelope of the signal. It can be inferred from Eq. (15) that the odd terms can be determined from single-tone complex compression characteristics, but fortunately, the odd-order terms are the most important as they produce intermodulation distortion in-band and adjacent to the desired signal. Each nonlinear RF component enjoys a variation of I/O characteristics, leading to a unique distortion that is captured by a unique set of coefficients {tilde over (α)}iS, and can therefore help in composing the device's unique signature in accordance with some embodiments. The following section describes how out-of-band distortions are leveraged for robust device classification in accordance with various embodiments. Out-of-Band (OOB) emissions are the emissions in the frequencies immediately outside the message bandwidth that predominate the OOB domain. OOB domain (e.g., OOB spectra, band, or information) is defined as the frequency range separated from the assigned frequency of the emission by less than 250% of the message bandwidth. These emissions are mainly caused by the modulation and the nonlinear components of an RF transceiver front-end and result in in-band distortions as well as in an interference into adjacent channels. As a result, spectrum regulatory agencies, such as FCC and International Telecommunication Union (ITU), specify and regulate the permissible levels of the out-of-band (OOB) emissions of different emission classes using OOB spectral masks. Here, in-band domain (e.g., in-band spectra, band, or information) is defined as the frequency range within an allocated bandwidth for a particular protocol. For example, an in-band domain may reside between OOB emissions. In variable-envelope modulation schemes (like 16 QAM), the spectrum of a modulated signal expands into adjacent channels when it passes through nonlinear components, resulting in an increase in the OOB emissions due to the spectral regrowth. The characteristics of a spectral regrowth are directly related to the unique coefficients of the corresponding nonlinear components in the RF transceiver chain. The DAC impairments, also, can generate OOB emissions due to the quantization and clipping noise as explained in the previous section. The other major RF front-end component that contributes to the OOB emissions is the LO. Due to the phase noise that is impaired with the LOs, these OOB emissions cause both an in-band and out-of-band noise scaled by the signal power. The out-of-band spectrum of a Phase-Locked-Loop (PLL), which is a widely used block for frequency synthesis in application-specific IC designs, is a function of the Voltage-Controlled Oscillator (VCO) parameters. Despite efforts to reduce the OOB emissions, there is always some inevitable amount of the OOB emissions that can be tolerated by standards, but also can be exploited for providing unique device signatures in accordance with some embodiments. Various embodiments describe a device classification technique that exploits such OOB emissions to provide accurate and robust classification. Based on the discussion about the relationship between the out-of-band emissions and the hardware impairments of RF front-end components, and the observations from various simulation studies described herein, leveraging in-band message bandwidth alone for providing device signatures does not lead to a robust device signature. Various embodiments consider both the in-band and out-of-band spectra by oversampling the captured signals at a receiver with an appropriate factor. Without any further processing, the raw IQ values obtained from the oversampled captured signals are then fed into a deep neural network to provide device identification and classification. The scheme of various embodiments use a Convolutional Neural Network (CNN), which is designed and tuned to recognize RF devices signatures and identify wireless devices. Technology advancements of transceiver designs (e.g., software defined and cognitive radios) can easily allow for sampling the captured signals in the out-of-band region, and therefore, the scheme of some embodiments can be implemented without using new and/or sophisticated receiver designs. The following sections provides more depth and insights on out-of-band (OOB) spectrum distortions that arise from the transmitter hardware components that contribute significantly to these OOB distortions: power amplifier (PA), local oscillator (LO), mixers, and digital-to-analog converter (DAC). With reference to the PA, Eq. (15) expresses the output signal of nonlinear or real PA as a function of all odd nonlinear terms. For ease of illustration, the third-order nonlinearity term is reviewed, when feeding the output signal, SRF(t)=A(t)cos(ωct+θ(t)), of the in-phase branch mixer as an input to the PA. In this case, the PA output is SPA(t)={tilde over (α)}1SRF(t)+{tilde over (α)}3SRF3(t), with the third-order nonlinearity term, {tilde over (α)}3SRF3(t), being: α~3SRF3(t)=α~3A3(t)4[3cos(ωct+φ(t))+cos(3ωct+3φ(t))](16) where {tilde over (α)}1and {tilde over (α)}3are again the complex coefficients modeling the nonlinearity terms. Note that given that the out-of-band component at 3ωcis located sufficiently far away from the center frequency, ωc, and that the bandwidth of the original signal is much less than ωc, this out-of-band component can easily be filtered out without causing any bandwidth regrowth around the original signal spectrum. However, the first term at ωcmay lead to spectrum regrowth of the original message bandwidth, depending, for example, on the modulation technique being used. For instance, in the case of constant-envelope modulation schemes such as BPSK where the amplitude A(t) is constant, the spectrum of the modulated signal in the vicinity of ωcremains unchanged. FIGS.3A-Billustrate plots300and320showing the nonlinearly effect under Binary Frequency Shift Key (BFSK) modulation for linear power amplifier (PA) and non-linear PA, respectively. Plot320shows that the spectrum of a BFSK modulated signal has not changed after passing through a nonlinear PA. Note that the shape of the spectrum is the same under both linear and nonlinear PAs shown in plots300and320. However, for variable-envelope modulation schemes such as 16 QAM where the amplitude A(t) varies over time, because the {tilde over (α)}33A3(t)/4 term generally exhibits a broader spectrum than A(t) itself, nonlinearity causes spectral regrowth. For this case of modulation, the severity of the spectral growth also depends on the nonlinearity model parameter {tilde over (α)}3. FIGS.4A-Cillustrate plots400,420, and430showing the nonlinearity effect under 16 Quadrature Amplitude Modulation (QAM) for linear PA, non-linear PA1and non-linear PA2, respectively.FIGS.4A-Cillustrate the case of a 16 QAM modulated signal passing through a linear PA (FIG.4A) and two nonlinear PAs (FIG.4BandFIG.4C) each under slightly different nonlinearity parameters. Two observations are made from these results. First, the nonlinearity of the PA does lead to an out-of-band spectrum growth (or distortion). Second, even a slight difference in the nonlinearity impairments causes differences in the amplitude of the frequency components in the out-of-band domain, as observed from the indicated amplitudes of the spikes. That is, even a slight nonlinearity impairment difference causes quite different out-of-band spectrum distortions. The classification technique of various embodiments exploits this out-of-band distortion information to increase both the accuracy and scalability of device classification. In modern transceivers, LOs are usually made with Phase-Locked Loops (PLLs) that ensure high-frequency stability and minimum phase noise. FIG.5shows a simple schematic of PLL500. PLL500comprises phase frequency detector (PFD)501, loop filter502, voltage-controlled oscillator (VCO)503, and divider504coupled as shown. Here, frefis the reference frequency and foutis the output frequency. Looking into the transfer functions of a PLL's components, which comprise the closed-loop transfer function of PLL500, provides an insight into the noise contribution of each of them. The transfer function of PLL500from the reference frequency to VCO503, for example, has a low-pass characteristic and can be expressed as: Href(s)=R(2ϵωns+ωn2)s2+2ϵωns+ωn2(17) where R is the feedback divider and ωnand ∈ are the natural frequency and the damping coefficient, respectively. The transfer function of VCO503, on the other hand, has a high-pass characteristic and can be defined as: HVCO(s)=s2(s2+2ϵωns+ωn2)(18) Hence, in-band phase noise of PLL500is dominated by the three components described above that have low-pass characteristics, while the out-of-band noise is mainly a function of the impaired VCO. To illustrate the impact of phase noise on out-of-band distortion, consider the mixer output signal in the in-band path, S1RF(t)=S1(t)cos(ωct+θ(t)) as given as in Eq. (13), where θ(t) is again the LO phase noise. Applying the Fourier transform to both sides of this mixer output equation yields: F[S1 RF(t)]=½{S1(f−fc)*F[ejθ(t)]+S1(f−fc)*F[e−iθ(t)]} (19) where fc=2πωc, S1(f)=F[S1(t)], and F [·] and * are the Fourier transform and convolution operators. Eq. (19) shows that there is a bandwidth expansion around the carrier frequency fcbeyond the spectrum of the original signal, resulting from the convolution of the original signal spectrum and the spectrum of LO impairment term e−jθ(t). FIGS.6A-Cillustrate plots600,620, and630showing the phase noise effect for device 1 (ideal), device 2 (−80 dBC/Hz), and device 3 (−72 dBC/Hz) at a frequency offset of 1 MHz, respectively. Since the spectrum expansion (or regrowth) is a function of the LO phase noise term, eθ(t), different devices will exhibit different spectral regrowth; i.e., different out-of-band distortions. This is seen inFIGS.6A-C, where the power spectral density (PSD) of three simulated devices, each with different phase noise value, but at the same frequency offset, are displayed. Device 1 enjoys an ideal LO (i.e., zero phase noise value), while device 2 and device 3 suffer from a phase noise value of −80 and −72 dBc/Hz, respectively, at the same frequency offset, 1 MHz. Therefore, considering the out-of-band information makes the spectra of devices more discernible and thus enhances the performance of the classifier. The classification technique of various embodiments exploits out-of-band distortion information caused by LO phase noise to improve classification accuracy and device separability. This section describes the role of mixers in the out-of-band emissions. Beside the relatively large DC component at the center of the signal spectrum that real mixers introduce, the nonlinearity of the mixer also introduces other undesired harmonic spurs within the out-of-band domain. The amplitude of the DC component and its harmonics depend on both the silicon level circuitry of the mixer and the second-order nonlinearity distortion of the device. This can be clearly observed by comparing the amplitudes of the spikes shown in the PSD of the three simulated devices inFIGS.7A-C. FIGS.7A-Cillustrate plots700,720, and730showing DC offset effect for device 1 (ideal mixer with DC offset=0), device 2 (DC offset: 1=0.9 and Q=0.9), device 3 (DC offset 1=0.5 and Q=0.5), respectively. Device 1 mimics an ideal mixer (i.e., zero DC offset), while device 2 and device 3 mimic real mixers with in-phase DC offset values of 0.9 and 0.5 and quadrature offset values of 0.9 and 0.5, respectively. It can be observedFIGS.7A-Cthat ideal mixers do not yield any DC component nor its harmonics, whereas hardware-impaired, real mixers yield DC spurs at the center of the spectrum as well as in the out-of-band region. Also, it can be observed that the amplitudes of the DC spurs of device 2 and device 3 occurring in both the in-band and the out-of-band spectrum are different from one another, even though the differences between their DC offset values are insignificant. Therefore, a transmitter's DC component and its harmonic spurs caused by mixer impairments can potentially be leveraged for providing unique device signatures that can be used for device classification. The classification technique of various embodiments leverages the out-of-band information that captures the differences between the DC offset harmonic spurs of devices to increase device separability classification accuracy. The following section describes the role of Digital-to-Analog converters (DACs) in generating out-of-band emissions. DACs also suffer from nonlinearities and hardware impairments that can be exploited to provide unique features and signatures for devices. In addition to degrading the error vector magnitude (EVM) of a transmitter, DAC impairments are responsible for generating out-of-band (OOB) emissions as well. To quantify and illustrate these OOB distortions, refer to Eq. (1), which models the DAC output when considering the in-phase signal component, S1[n], as its input, while capturing the three main distortions, horizontal quantization (HQ), vertical quantization (VQ), and clock source modulation (CM), caused by the DAC. Although this section focuses on the in-phase (I) path component for illustration purposes, similar analysis and illustration can be done for the case of the quadrature (Q) path component. Even though each of the three DAC impairments, HQ, VQ, and CM, yields OOB emissions, HQ contributes the most when the DAC generation frequency is not sufficiently greater than the Nyquist rate, and hence, the following section focuses on HQ's impact in this illustration. Using Fourier series representations, the HQ term, yS1HQ(t), can be written as yS1HQ(t)=Σn=−∞ckHQej2πkfΩt, with the Fourier coefficients ckHQbeing. ckHQ=1TΩ∫0TΩ(∑n=-∞∞SI[n]g(t-nTgTg)-SI(t))e-j2πkfΩtdt(20) where TΩis the time period of the three distortion additive terms in Eq. (1), which is the least common period of the three periods: output signal period, T0, DAC generation period, Tg, and the clock modulation period, Tm. Leveraging the fact that g(θ) is a unitary pulse when 0≤θ<1 and TΩ=ZTgthe integral can be extended to (−∞, ∞), while restricting the index n in the first term from 0 to Z−1 and introducing a unitary window in the second term W[0,TΩ]. Then Eq. (20) is rewritten as: ckHQ=1TΩ∫-∞∞(∑n=0Z-1SI[n]g(t-nTgTg)-SI(t)W[0,TΩ])e-j2πkfΩtdt(21) By Fourier-analyzing the second term in the right-hand side of Eq. (21), it is observed that the spectral contribution of the second term would be samples of the spectrum of the distorted version of S1(t) at frequencies kfΩ, where k ranges from 0 to Z−1, which lie mostly outside the bandwidth of S1(t). Therefore, most effects of the yS1HQ(t)term lie outside the bandwidth of S1(t), resulting in the growth of the number of attenuated replicas in the out-of-band domain of the signal S1(t). The following section describes the performance evaluation and analysis. Here, MATLAB's Communications toolbox is used to design a simulation model of a full wireless communications processing chain for 5 different devices. Each device represents a transmitter that sends 16 QAM modulated signals over an Adaptive White Gaussian Noise (AWGN) channel. Different RF impairment blocks are used to introduce and set different values for IQ imbalance, DC offset, carrier frequency offset, phase noise, and PA nonlinearity distortion. Table I shows the different transceiver hardware impairment values used in an experiment. TABLE 1IQ-ampIQ-phaseI-DCQ-DCPhase noiseFrequencyRF(DB)(Deg)offsetoffsetAM-AMAM-PM(dBc/Hz)Offset (Hz)Device10.080.10.10.15[2.178, 1.12157][4.0893, 9.2040][−60, −80][20, 200]Device20.10.090.1090.1[2.197, 1.16157][4.13, 9.2540][−60, −80][20, 200]Device30.090.090.10.1[2.16, 1.10157][4.033, 9.2840][−59.9, −80][20, 200.9]Device40.1090.1080.10.1[2.17, 1.12157][4.113, 9.2040][−60, −80.1][20, 200]Device50.10.0990.0990.1[2.1587, 1.15157][4.133, 9.2040][−60, −80][20.1, 200] IQ imbalance values are shown in first and the second columns of the table, where the first one represents the amplitude mismatch, IQ-amp, and the second column represents the phase deviation, IQ-phase. The in-phase DC offset and the quadrature DC offset values are presented in the third and fourth columns. The PA nonlinearity distortion is represented in the fifth and sixth columns by the alpha and beta parameters of Saleh model functions of the Amplitude-to-Amplitude (AM-AM) and Amplitude-to-Phase (AM-PM) distortion curves. The last two columns of Table 1 show the LO phase noise introduced by a filtered Gaussian noise using a spectral mask specified by noise level and the frequency offset vectors. For each device, the raw IQ values are collected of two different bandwidths, 2.075-2.125 GHz, which represents the bandwidth of the message (in-band), and 1.9-2.3 GHz, which includes both in-band (message bandwidth) and out-of-band domain. Here, 200 k samples are generated for each device, which are divided into training, validation, and test sets. FIG.8illustrates Convolutional Neural Network (CNN) architecture800, in accordance with some embodiments. A CNN architecture is designed that uses raw time-series IQ samples generated by a Simulink model. A variation of the CNN architecture is used, which is depicted inFIG.8. Specifically, each IQ input sequence is represented as a two dimensional real-valued tensor801of size, for example, 2×1024. Thus, the in-phase (I) and quadrature (Q) components are processed independently and in the fully connected layer where the information of the two components are combined. The input is fed to the first convolutional layer (Conv1), which comprises 16 filters, each of size 1×4. In other embodiments, other filter size may be used. Each filter learns 4-sample variations in time over the I or Q dimension separately to generate 16 distinct feature maps over the complete input sample. Each ConvLayer is followed by a Batch normalization layer, a Rectified Linear Unit (ReLU) activation (e.g., together referred to by802), and a maximum pooling (MaxPool) layer803with filters of size, for example, 1×2, and stride to perform a pre-determined non-linear transformation on each element of the convolved output, except the last ConvLayer, which is followed by an Average Pooling (AP) layer804with a dimension, for example, 1×32. The dimensions and filter size here are examples and other values may be used in other embodiments. The output of the AP layer804is then provided as an input to the Fully Connected (FC) layer805, which has, for example, 5 neurons. In other embodiments, other number of neurons may be used. Then, the output of FC layer805is finally passed to a classifier layer806. To overcome overfitting, the dropout rate is set to, for example, 0.5 at the dense layers. In other embodiments, a different dropout rate may be used. In some embodiments, Softmax classifier806is used in the last layer to output the probabilities of each frame being fed to the CNN. In other embodiments, other classifiers may be used. Weights are trained using stochastic gradient descent with momentum optimizer with an initial learning rate of, for example, 1=0.02 and a learning rate drop factor of, for example, 0.1 with a learning rate drop period of, for example, 9. The prediction error is minimized through backpropagation, using categorical cross-entropy as a loss function computed on the classifier output. In one example, CNN architecture in MATLAB is implemented using the Deep Learning Toolbox running on a system with Intel Corei7 8th Gen CPU. FIG.9illustrates system900showing an environmental context, in accordance with some embodiments. Here, component1is a Software Defined Network (SDR)901. This component can be any network subsystem with software defined radio and data collection capabilities. Component2is a Computing System902. This component can be a computer, server, Jetson Nano, basically any computing system that can receive live-captured data and run deep learning algorithms. In various embodiments, Computing System902executes the classification scheme discussed with reference toFIG.8(e.g., CNN network800). In some embodiments, Computing System902includes machine-readable media that stores instructions for classifying the various wireless devices as discussed with reference to various embodiments. Computing System902can be a local computer, a private server, a cloud computing device, a distributed system, etc. Component3represents wireless devices (e.g., wireless devices903-1,903-2, and903-3). Any wireless device that can sense and transmit data can serve as component3. For example, a wireless device can be mobile phone, a laptop, a HAM radio, etc. Component4is Wireless channel904. This component truly affects the signals which directly affect the classification accuracy. The system diagram of system900is very similar to other wireless classification systems. However, one difference is in the data collection system configuration. The scheme of various embodiments configures the data collection system to capture both the in-band and the out-of-band information of a given signal. In some embodiments, the environmental context is a base station (e.g., eNode-B (eNB)) or an edge device. In some embodiments, the base station comprises a processor, a memory coupled to the processor, and receiver. In some embodiments, the memory stores weights associated with a machine-learning model that is used to classify a wireless device based on an in-band information and an out-of-band information from the wireless device. In some embodiments, the receiver receives a first in-band information and a first out-of-band information from a first wireless device. In some embodiments, the processor applies the weights to the machine-learning model to determine whether the first wireless device is a valid device or an invalid device. In some embodiments, the first wireless device (e.g.,903-1) is an eNB. In some embodiments, the machine-learning model is trained to generate the weights that are stored in the memory. In some embodiments, the receiver (e.g., radio901) is configured to collect data to capture the first in-band information and the first out-of-band information. In some embodiments, the base station is one of an access-point or a base-station for a cellular communication network. FIG.10illustrates flowchart1000of the scheme of various embodiments. While various blocks are illustrated in a particular order, the order can be modified. For example, some blocks can be performed before others while some blocks are performed in parallel. The blocks of flowchart1000can be performed by software and/or hardware. For example, flowchart1000may be executed by computing system902. At block1001, the data collecting device is configured with the appropriate configuration. This configuration captures both the in-band and out-of-band information. At block1002, the captured data is saved, labeled, and sent to a machine learning system to train the neural network. At block1003, after training the network, the weights are saved, and then used in the computing system for inference scenarios. At block1004, a wireless device starts to transmit and at block1005a receiver begins to collect the data. The collected data is then sent to a computing system (e.g., computing system902such as one described inFIG.13) which processes the collected data for classification using the trained neural network. At block1006, a determination is made regarding whether the computing system has processed the collected data for the wireless device. Based on the processed information, the computing system determines the identity of the wireless device (i.e., the wireless device is classified) as a valid device (as shown in block1007) or an invalid device (as shown in block1008). The process then continues with block1003where another wireless device is triggered and the process is repeated for any wireless device that needs to be identified. The flowchart ofFIG.10can be implemented in software, hardware, or a combination of both. In some embodiments, capturing out-of-band information for enabling accurate classification can be done using existing software-defined radios at the receiver side. Little to no change may be done at the transmitter side. The scheme of various embodiments outperforms existing approaches substantially. For example, the scheme achieves around 96% accuracy even when the transmitters have very similar features (worst-case scenario). The scheme is also simple in that capturing the out of band information can be done using radios with software defined capabilities. The scheme of various embodiments can be used for indoor localization. In this application, device finger printing is used to accurately determine the location of the corresponding device in an indoor environment. The scheme of various embodiments can be used in 5G network deployment. For 5G networks, fingerprinting can be used for network security purposes and during the beamforming process. In some embodiments, the scheme can be implemented as an additional security layer in IoT (Internet-of-Things) gateways and access points where it is integrated in the system. Hence, the scheme of various embodiments can be used in Radio, IoT technologies, and mobile cellular technologies, for example. In some embodiments, the scheme can be implemented in cellular base stations for both eNode-B and IoT devices and gNode-B for 5G cellular devices. One of the functionalities of the cell is to establish the connection for new devices and give them access to the resource. Hence, the scheme of various embodiments can be a very efficient tool to detect the spoofed device and increase the security of the cell. The scheme of various embodiments can be used in testing devices that could be used by regulatory agencies to scan and monitor the spectrum and determine illegal users. FIGS.11A-Billustrate plots1100and1120showing training and validation accuracy of the scheme ofFIG.10that uses in-band and out-of-band radiation, and existing technique, respectively. The following section evaluates and compares the performance of the technique of various embodiments, leveraging both in-band and out-of-band spectrum distortions, and the conventional classification technique, using in-band distortion information only. The impairments' values used in this experiment, which are shown in Table I, are set very similar to one another so that the devices resemble bit-similar radios to make the identification task even harder. The generated frames are divided into 80% training, 10% validation, and 10% testing. As seen fromFIGS.11A-B, the training accuracy (curves1101and1121) of the technique of various embodiments outperforms the traditional classifier that uses in-band information only. The experiments show that the out-of-band additional processing exploited in the technique of various embodiments does not incur an increase in the computation time of the method; the running times of the reported results are 97.38 and 96.35 minutes for the in-band only technique and the in-band and out-of-band technique, respectively. Also, from the validation accuracy (the black dotted lines1102and1122), it can be inferred that the model used here does not suffer from overfitting. FIGS.12A-Billustrate confusion matrices1200and1220for the scheme ofFIG.10that uses in-band and out-of-band radiation, and an existing technique, respectively. The confusion matrices1200and1220results depicted inFIGS.12A-Bshow that the technique of various embodiments achieves substantially higher classification accuracy than the in-band only technique. The testing accuracy obtained under the technique of various embodiments across the five tested devices is 96.2% whereas that obtained under the in-band only approach is merely 48.6%. Similar results are also obtained when considering the 8-PSK modulation scheme as opposed to the 16 QAM scheme. The technique of various embodiments achieves much higher accuracy because it leverages, in addition to the in-band distortion information already exploited by the prior methods, out-of-band distortion information caused by the different radio hardware components, which, as explained in the previous sections, provide unique device signatures that lead to substantial increase in device separability. Here the experiments indicate that this accuracy gap between the technique of various embodiments and the prior in-band only method is inversely proportional to the hardware impairments variability among devices. This means that both techniques enjoy high classification accuracy when the devices exhibit relatively high hardware impairments. However, as technology advancements continue to reduce such impairments, the variability among the hardware impairments across different devices continues to shrink, making the reliance on in-band only information for device classification inefficient and inaccurate. The technique of various embodiments leverages out-of-band distortion in addition to in-band information to provide high device separability performance. FIG.13illustrates a block diagram of an embodiment of a computing device to execute the scheme of various embodiments. In some embodiments, computing device1300represents an appropriate computing device, such as a computing tablet, a mobile phone or smart-phone, a laptop, a desktop, an IOT device, a server, a set-top box, a wireless-enabled e-reader, or the like. It will be understood that certain components are shown generally, and not all components of such a device are shown in computing device1300. In some embodiments, computing device1300includes processor1310, audio subsystem1320, display subsystem1330, I/O controller1340, power management1350, memory subsystem1360, connectivity1370, and peripheral connections1380. In one embodiment, processor1310can include one or more physical devices, such as microprocessors, graphics processor, accelerator, inference logic, computational processor, application processors, microcontrollers, programmable logic devices, or other processing means. The processing operations performed by processor1310include the execution of an operating platform or operating system on which applications and/or device functions are executed. The processing operations include operations related to I/O (input/output) with a human user or with other devices, operations related to power management, and/or operations related to connecting the computing device1300to another device. The processing operations may also include operations related to audio I/O and/or display I/O. In some embodiments, processor1310executes the scheme for identifying wireless devices by capturing out-of-band information in addition to in-band information from wireless devices for enabling accurate classification of wireless devices. Both the in-band and out-of-band spectrum emissions of the received signal are used to capture hardware signatures and features. In some embodiments, computing device1300includes audio subsystem1320, which represents hardware (e.g., audio hardware and audio circuits) and software (e.g., drivers, codecs) components associated with providing audio functions to the computing device. Devices for such functions can be integrated into computing device1300or connected to the computing device1300. Audio functions can include speaker and/or headphone output, as well as microphone input. In some embodiments, a user interacts with the computing device1300by providing audio commands that are received and processed by processor1310. Display subsystem1330represents hardware (e.g., display devices) and software (e.g., drivers) components that provide a visual and/or tactile display for a user to interact with the computing device1300. Display subsystem1330includes display interface1332, which includes the particular screen or hardware device used to provide a display to a user. In one embodiment, display interface1332includes logic separate from processor1310to perform at least some processing related to the display. In one embodiment, display subsystem1330includes a touch screen (or touch pad) device that provides both output and input to a user. I/O controller1340represents hardware devices and software components related to interaction with a user. I/O controller1340is operable to manage hardware that is part of audio subsystem1320and/or display subsystem1330. Additionally, I/O controller1340illustrates a connection point for additional devices that connect to computing device1300through which a user might interact with the system. For example, devices that can be attached to the computing device1300might include microphone devices, speaker or stereo systems, video systems or other display devices, keyboard or keypad devices, or other I/O devices for use with specific applications such as card readers or other devices. As mentioned above, I/O controller1340can interact with audio subsystem1320and/or display subsystem1330. For example, input through a microphone or other audio device can provide input or commands for one or more applications or functions of the computing device1300. Additionally, audio output can be provided instead of, or in addition to display output. In another example, if display subsystem1330includes a touch screen, the display device also acts as an input device, which can be at least partially managed by I/O controller1340. There can also be additional buttons or switches on the computing device1300to provide I/O functions managed by I/O controller1340. In one embodiment, I/O controller1340manages devices such as accelerometers, cameras, light sensors or other environmental sensors, or other hardware that can be included in the computing device1300. The input can be part of direct user interaction, as well as providing environmental input to the system to influence its operations (such as filtering for noise, adjusting displays for brightness detection, applying a flash for a camera, or other features). In one embodiment, computing device1300includes power management1350that manages battery power usage, charging of the battery, and features related to power saving operation. In some embodiments, a power management system1350controls the power consumption of processor1310. For example, power management system1350can clock gate, power gate, or apply any other power management techniques. In some embodiments, memory subsystem1360includes memory devices for storing information in computing device1300. Memory can include nonvolatile (state does not change if power to the memory device is interrupted) and/or volatile (state is indeterminate if power to the memory device is interrupted) memory devices. Examples of nonvolatile memory include flash memory, magnetic memory, resistive memory. Examples of volatile memory include static random-access memory, dynamic random-access memory, etc. Memory subsystem1360can store application data, user data, music, photos, documents, or other data, as well as system data (whether long-term or temporary) related to the execution of the applications and functions of the computing device1300. Elements of embodiments are also provided as a machine-readable medium (e.g., memory1360) for storing the computer-executable instructions (e.g., instructions to implement any other processes discussed herein). The machine-readable medium (e.g., memory1360) may include, but is not limited to, flash memory, optical disks, CD-ROMs, DVD ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, phase change memory (PCM), or other types of machine-readable media suitable for storing electronic or computer-executable instructions. For example, embodiments of the disclosure may be downloaded as a computer program (e.g., BIOS) which may be transferred from a remote computer (e.g., a server) to a requesting computer (e.g., a client) by way of data signals via a communication link (e.g., a modem or network connection). In some embodiments, machine-readable medium1360includes computer-executable instructions that when executed by processor1310cause processor1310to perform a method of identifying wireless devices by capturing out-of-band information in addition to in-band information from wireless devices for enabling accurate classification of wireless devices. In some embodiments, the method comprises applying a neural network trained using the first in-band information and the first out-of-band information. In some embodiments the method comprises receiving a first in-band information and a first out-of-band information from a first wireless device. In some embodiments, the method comprises identifying whether the first wireless device is a valid or invalid device based on applying the neural network which is trained to classify the wireless device. In some embodiments, the method comprises configuring a data collection device to capture the first in-band information and the first out-of-band information. In some embodiments, the method comprises training a machine-learning model to classify the wireless device based on the in-band information and the out-of-band information. In some embodiments, training the machine-learning model comprises determining weights for the machine-learning model and saving the weights in memory (e.g., memory1360). In some embodiments, applying the neural network trained to classify the wireless device based on the in-band information and the out-of-band information comprises multiplying the saved weights to an input for each layer to infer classification of the first wireless device. In some embodiments, the input comprises the first in-band information and the first out-of-band information. In some embodiments, in the training phase, the method comprises triggering the first wireless device to start transmission, wherein the transmission includes the first in-band information and the first out-of-band information. In some embodiments, in the training phase, the method comprises triggering a receiver to receive the first in-band information and the first out-of-band information from the first wireless device. In some embodiments, the method comprises notifying a user when the first wireless device is invalid. The various embodiments of the present disclosure may also comprise a network interface within1370such as a wireless interface so that a system embodiment may be incorporated into a wireless device, for example, cell phone or personal digital assistant. Connectivity1370includes hardware devices (e.g., wireless and/or wired connectors and communication hardware) and software components (e.g., drivers, protocol stacks) to enable the computing device1300to communicate with external devices. The computing device1300could be separate devices, such as other computing devices, wireless access points or base stations, as well as peripherals such as headsets, printers, or other devices. Connectivity1370can include multiple different types of connectivity. To generalize, the computing device1300is illustrated with cellular connectivity1372and wireless connectivity1374. Cellular connectivity1372refers generally to cellular network connectivity provided by wireless carriers, such as provided via GSM (global system for mobile communications) or variations or derivatives, CDMA (code division multiple access) or variations or derivatives, TDM (time division multiplexing) or variations or derivatives, or other cellular service standards. Wireless connectivity (or wireless interface)1374refers to wireless connectivity that is not cellular, and can include personal area networks (such as Bluetooth, Near Field, etc.), local area networks (such as Wi-Fi), and/or wide area networks (such as LTE), or other wireless communication. Peripheral connections1380include hardware interfaces and connectors, as well as software components (e.g., drivers, protocol stacks) to make peripheral connections. It is understood that the computing device1300could both be a peripheral device (“to”1382) to other computing devices, as well as have peripheral devices (“from”1384) connected to it. The computing device1300commonly has a “docking” connector to connect to other computing devices for purposes such as managing (e.g., downloading and/or uploading, changing, synchronizing) content on computing device1300. Additionally, a docking connector can allow computing device1300to connect to certain peripherals that allow the computing device1300to control content output, for example, to audiovisual or other systems. In addition to a proprietary docking connector or other proprietary connection hardware, the computing device1300can make peripheral connections1380via common or standards-based connectors. Common types can include a Universal Serial Bus (USB) connector (which can include any of a number of different hardware interfaces), DisplayPort including MiniDisplayPort (MDP), High-Definition Multimedia Interface (HDMI), Firewire, Thunderbolt, or other types. Throughout the specification, and in the claims, the term “connected” means a direct connection, such as electrical, mechanical, or magnetic connection between the things that are connected, without any intermediary devices. The term “coupled” means a direct or indirect connection, such as a direct electrical, mechanical, or magnetic connection between the things that are connected or an indirect connection, through one or more passive or active intermediary devices. The term “adjacent” here generally refers to a position of a thing being next to (e.g., immediately next to or close to with one or more things between them) or adjoining another thing (e.g., abutting it). The term “circuit” or “module” may refer to one or more passive and/or active components that are arranged to cooperate with one another to provide a desired function. The term “signal” may refer to at least one current signal, voltage signal, magnetic signal, or data/clock signal. The meaning of “a,” “an,” and “the” include plural references. The meaning of “in” includes “in” and “on.” The term “analog signal” refers to any continuous signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. The term “digital signal” refers to a physical signal that is a representation of a sequence of discrete values (a quantified discrete-time signal), for example of an arbitrary bit stream, or of a digitized (sampled and analog-to-digital converted) analog signal. The term “scaling” generally refers to converting a design (schematic and layout) from one process technology to another process technology and may be subsequently being reduced in layout area. In some cases, scaling also refers to upsizing a design from one process technology to another process technology and may be subsequently increasing layout area. The term “scaling” generally also refers to downsizing or upsizing layout and devices within the same technology node. The term “scaling” may also refer to adjusting (e.g., slowing down or speeding up—i.e. scaling down, or scaling up respectively) of a signal frequency relative to another parameter, for example, power supply level. The terms “substantially,” “close,” “approximately,” “near,” and “about,” generally refer to being within +/−10% of a target value. Unless otherwise specified the use of the ordinal adjectives “first,” “second,” and “third,” etc., to describe a common object, merely indicate that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking or in any other manner. For the purposes of the present disclosure, phrases “A and/or B” and “A or B” mean (A), (B), or (A and B). For the purposes of the present disclosure, the phrase “A, B, and/or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. For purposes of the embodiments, the transistors in various circuits and logic blocks described here are metal oxide semiconductor (MOS) transistors or their derivatives. The MOS transistors include drain, source, gate, and bulk terminals or regions. The transistors and/or the MOS transistor derivatives also include Transistors, Tunneling FET (TFET), Tri-Gate and FinFET transistors, ferroelectric FET (FeFETs), Gate All Around Cylindrical Square Wire, or Rectangular Ribbon Transistors, or other devices implementing transistor functionality like carbon nanotubes or spintronic devices. MOSFETs have symmetrical source and drain terminals, so source and drain terminals are considered identical terminals and are interchangeably used here. Compared to a MOSFET, A TFET device has asymmetric source and drain terminals. Those skilled in the art will appreciate that other transistors, for example, CMOS, Bi-polar junction transistors (BJT PNP/NPN), BiCMOS, etc., may be used without departing from the scope of the disclosure. Reference in the specification to “an embodiment,” “one embodiment,” “some embodiments,” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments. The various appearances of “an embodiment,” “one embodiment,” or “some embodiments” are not necessarily all referring to the same embodiments. If the specification states a component, feature, structure, or characteristic “may,” “might,” or “could” be included, that particular component, feature, structure, or characteristic is not required to be included. If the specification or claim refers to “a” or “an” element, that does not mean there is only one of the elements. If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional elements. Furthermore, the particular features, structures, functions, or characteristics may be combined in any suitable manner in one or more embodiments. For example, a first embodiment may be combined with a second embodiment anywhere the particular features, structures, functions, or characteristics associated with the two embodiments are not mutually exclusive. While the disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations of such embodiments will be apparent to those of ordinary skill in the art considering the foregoing description. The embodiments of the disclosure are intended to embrace all such alternatives, modifications, and variations as to fall within the broad scope of the appended claims. Where specific details are set forth to describe example embodiments of the disclosure, it should be apparent to one skilled in the art that the disclosure can be practiced without, or with variation of, these specific details. The description is thus to be regarded as illustrative instead of limiting. The following examples pertain to further embodiments. Specifics in the examples may be used anywhere in one or more embodiments. All optional features of the apparatus described herein may also be implemented with respect to a method or process. The examples can be combined in any suitable manner. Example 1: A machine-readable storage media having machine-readable instructions stored thereon, that when executed, cause one or more machines to perform a method comprising: applying a neural network trained to classify a wireless device based on in-band and out-of-band information; receiving a first in-band information and a first out-of-band information from a first wireless device; and identifying whether the first wireless device is a valid or invalid device based on applying the neural network and using the first in-band information and the first out-of-band information. Example 2: The machine-readable storage media of example 1 having machine-readable instructions stored thereon, that when executed, cause the one or more machines to perform the method comprising: configuring a data collection device to capture the first in-band information and the first out-of-band information. Example 3: The machine-readable storage media of example 2 having machine-readable instructions stored thereon, that when executed, cause the one or more machines to perform the method comprising: training a machine-learning model to classify the wireless device based on the in-band information and the out-of-band information. Example 4: The machine-readable storage media of example 3, wherein training the machine-learning model comprises: determining weights for the machine-learning model; and saving the weights in memory. Example 5: The machine-readable storage media of example 4, wherein applying the neural network trained to classify the wireless devices based on the in-band information and the out-of-band information comprises: multiplying the saved weights to an input to infer classification of the first wireless device, wherein the input comprises the first in-band information and the first out-of-band information. Example 6: The machine-readable storage media of example 1 having machine-readable instructions stored thereon, that when executed, cause the one or more machines to perform the method comprising: triggering the first wireless device to start transmission, wherein the transmission includes the first in-band information and the first out-of-band information. Example 7: The machine-readable storage media of example 6 having machine-readable instructions stored thereon, that when executed, cause the one or more machines to perform the method comprising: triggering a receiver to receive the first in-band information and the first out-of-band information from the first wireless device. Example 8: The machine-readable storage media of example 1 having machine-readable instructions stored thereon, that when executed, cause the one or more machines to perform the method comprising: notifying a user when the first wireless device invalid. Example 9: A base-station comprising: a processor circuitry; a memory coupled to the processor circuitry, wherein the memory is to store weights associated with a machine-learning model that is used to classify a wireless device based on an in-band information and an out-of-band information from the wireless device; and a receiver to receive a first in-band information and a first out-of-band information from a first wireless device, wherein the processor is to apply the weights to the machine-learning model and apply the first in-band information and the first out-of-band information to determine whether the first wireless device is a valid device or an invalid device. Example 10: The base-station of example 9, wherein the first wireless device is a phone. Example 11: The base-station of example 9, wherein the machine-learning model is trained to generate the weights that are stored in the memory. Example 12: The base-station of example 9, wherein the receiver is configured to collect data to capture the first in-band information and the first out-of-band information. Example 13: The base-station of example 9, wherein the base-station is one of an access-point or a base-station for a cellular communication network. Example 14: A method comprising: applying a neural network trained to classify a wireless device based on in-band and out-of-band information; receiving a first in-band information and a first out-of-band information from a first wireless device; and identifying whether the first wireless device is a valid device or an invalid device based on applying the neural network and using the first in-band information and the first out-of-band information. Example 15: The method of example 14 comprising: configuring a data collection device to capture the first in-band and the first out-of-band information. Example 16: The method of example 14 comprising: training a machine-learning model to classify the wireless device based on the in-band information and the out-of-band information. Example 17: The method of example 16, wherein training the machine-learning model comprises: determining weights for the machine-learning model; and saving the weights in memory. Example 18: The method of example 17, wherein applying the neural network trained to classify the wireless device based on the in-band information and the out-of-band information comprises: multiplying the saved weights to an input to infer classification of the wireless device, wherein the input comprises the in-band information and the out-of-band information. Example 19: The method of example 14 comprising: triggering the first wireless device to start transmission, wherein the transmission includes the first in-band information and the first out-of-band information; and triggering a receiver to receive the first in-band information and the first out-of-band information from the first wireless device. Example 20: The method of example 14 comprises notifying a user when the first wireless device is invalid. An abstract is provided that will allow the reader to ascertain the nature and gist of the technical disclosure. The abstract is submitted with the understanding that it will not be used to limit the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment. | 76,548 |
11943004 | DETAILED DESCRIPTION OF THE EMBODIMENTS Disclosed herein are systems and methods for extending a wireline communication network. The new systems and methods may be used, for example, to provide broadband and other information services to rural areas, or to overcome geographic obstacles to conventional wireline communication network extension. While the new systems and methods use wireless transmission, they may significantly leverage conventional hardware and data transmission protocols. For example, some embodiments allow use of a conventional modem or optical network terminal (ONT) at a customer's premises, thereby promoting low cost, ease of component procurement, ease of supply chain management, ease of system support, and ease of installation. As another example, certain embodiments support one or more conventional wireline communication protocols, such as a cable communication protocol, an optical communication protocol, or a digital subscriber line communication protocol, thereby promoting ease of integration into an existing wireline communication network. Furthermore, some embodiments are compatible with conventional wireline communication nodes, or require only minor modifications to existing wireline communication nodes, thereby further promoting low cost, ease of component procurement, ease of system support, and ease of deployment. Additionally, some embodiments can operate with a simple and low-cost wireline communication node. Moreover, some embodiments do not require modifications to a network core or other central element of the wireline communication network. Accordingly, the new systems and methods advantageously facilitate deployment of broadband communication services and/or other information services to underserved areas at a lower cost than conventional approaches. FIG.1is a block diagram of a system100for extending a wireline communication network, which is one embodiment of the new systems disclosed herein. System100extends reach of an existing wireline communication network101, which is depicted by a wireline cable102and a wireline communication node104, to a customer premises106, e.g. a residence or a business, that is remote from wireline communication node104. System100is configured, for example, to provide Internet service, video service, voice service, and/or other data services to customer premise106from wireline communication network101. Wireline cable102is, for example, an optical cable or an electrical cable (e.g., a coaxial electrical cable or a twisted pair electrical cable). Wireline cable102may be an existing cable in a wireline communication network, such as an existing cable connecting respective infrastructure at two different locations. Alternately, wireline cable102may be newly installed to support system100. In some embodiments, data is transmitted over wireline cable102according to a cable protocol (e.g., a Data Over Cable Service Interface Specification (DOCSIS) protocol), an optical protocol (e.g., an Ethernet passive optical network (EPON) protocol, a radio frequency over glass (RFOG) protocol, or a gigabit passive optical network (GPON) protocol), a digital subscriber line (DSL) protocol or another telecommunications protocol (e.g. a T-carrier or E-carrier protocol), an Internet protocol, or variations, extensions, or successors of any of the foregoing. While not required, wireline communication network101will typically include additional elements, such as a network core or other central element, that are not shown inFIG.1for illustrative clarity. System100further includes an access cable108, an antenna adapter110, an antenna cable112, a service provider antenna114, a customer antenna116, an antenna cable118, an antenna adapter120, an access cable122, and a wireline communication device124. Any of access cable108, antenna cable112, antenna cable118, and access cable122could be replaced with an alternative communication medium, such as an electrical or optical conductor on a printed circuit board (PCB) or an electrical or optical conductor within an integrated circuit. For example, communication node104and antenna adapter110could be disposed on a common PCB and communicatively coupled via one or more PCB conductors in place of access cable108. As another example, communication node104, antenna adapter110, and service provider antenna114could be mounted on a common PCB and communicatively coupled by PCB conductors in place of access cable108and antenna cable112. Communication node104is configured to interface wireline cable102with access cable108. Specifically, communication node104is configured to (a) convert downlink wireline signals on wireline cable102to downlink access signals on access cable108, and (b) convert uplink access signals on access cable108to uplink wireline signals on wireline cable102. In some embodiments, access cable108is either an electrical cable or an optical cable. Discussed below are several example configurations of communication node104. It is appreciated, however, that communication node104is not limited to these examples; instead, communication node104could have other configurations as long as it is capable of interfacing wireline cable102with access cable108. In some embodiments, communication node104is a cable system fiber node, wireline cable102is an optical cable, and access cable108is a coaxial electrical cable or an optical cable. In these embodiments, downlink and uplink access signals on access cable108comply with a cable communication protocol, such as a DOC SIS protocol. Downlink and uplink wireline signals on wireline cable102may also comply with the cable communication protocol, or the wireline signals may comply with an alternative communication protocol. In the later case, communication node104is configured to translate between the alternative communication protocol and the cable communication protocol. In some other embodiments, communication node104is an optical line terminal (OLT), wireline cable102is an electrical or optical cable, and access cable108is an optical cable. In certain of these embodiments, downlink and uplink access signals on access cable108comply with an EPON protocol, a RFOG protocol, a GPON protocol, or extensions, variations, or successors of any of these communication protocols. Uplink and downlink signals on wireline cable102comply, for example, with an Ethernet communication protocol. In some other embodiments, communication node104is a digital subscriber line access multiplexer (DSLAM), wireline cable102is an electrical or optical cable, and access cable108is a twisted pair electrical cable. In certain of these embodiments, downlink and uplink access signals on access cable108comply with a DSL protocol. Uplink and downlink signals on wireline cable102comply, for example, with a telecommunications protocol or an Ethernet communication protocol. Antenna adapter110enables service provider antenna114to operate with communication node104. Specifically, antenna adapter110is configured to interface access cable108and antenna cable112by converting between access signals on access cable108and RF electrical signals on antenna cable112. In particular, antenna adapter110is configured to (a) convert downlink access signals on access cable108to downlink RF electrical signals on antenna cable112, and (b) convert uplink RF electrical signals on antenna cable112to uplink access signals on access cable108. In some embodiments, antenna adapter110is not configured to perform communication protocol translation, such that access signals on access cable108comply with the same communication protocol as RF electrical signals on antenna cable112. For example, in certain embodiments, antenna adapter110is configured to perform amplification and impedance matching between communication node104and service provider antenna114without performing communication protocol translation, thereby promoting low cost of antenna adapter110and low data transmission latency in system100. While communication node104and antenna adapter110are depicted inFIG.1as being separate elements, these two elements could be combined such that access cable108is not required. For example, communication node104and antenna adapter110could be combined into a commonly assembly which converts between the wireline domain and the RF electrical domain, i.e. a common assembly configured to (a) convert downlink wireline signals on wireline cable102to downlink RF electrical signals on antenna cable112and (b) convert uplink RF electrical signals on antenna cable112to uplink wireline signals on wireline cable102. For example, in particular embodiments, communication node104and antenna adapter110are combined into a common assembly which is configured to operate as a remote physical layer (PHY) device or a remote media access control layer-physical layer (MAC-PHY) device. The common assembly could be configured to operate solely in the digital domain or solely the analog domain. For example, in some embodiments, the common assembly is configured to convert wireline signals in digital form to RF electrical signals in digital form, and vice versa. Alternately, the common assembly could be configured to convert between the digital domain and the analog domain. For example, in some embodiments, the common assembly is configured to convert wireline signals in digital form to RF electrical signals in analog form, and vice versa. Several example configurations of communication node104and antenna adapter110being combined into a common assembly are discussed below with respect toFIGS.5-7. In some embodiments where antenna adapter110and communication node104are separate elements, communication node104includes a connector138for physically connecting to access cable108. Connector138is, for example, a coaxial electrical cable connector, a telephone cable connector, an optical cable connector, or an Ethernet cable connector. Some embodiments of antenna adapter110include a connector140capable of physically connecting to connector138and/or to access cable108. Additionally, some embodiments of antenna adapter110include a connector142capable of connecting to antenna cable112. Connector140is, for example, a coaxial electrical cable connector, a telephone cable connector, an optical cable connector, or an Ethernet cable connector. Connector142is, for example, a coaxial electrical cable connector. In some embodiments including connectors138and140, the two connectors can by physically connected to together, such that access cable108is embodied by connectors138and140instead of an element separate from connectors138and140. Service provider antenna114is configured to wirelessly link wireline communication system101with one or more customer antennas116. Specifically, service provider antenna114is configured to (a) convert downlink RF electrical signals on antenna cable112to downlink wireless signals126, and (b) convert uplink wireless signals128from customer antenna116to uplink RF electrical signals on antenna cable112. Service provider antenna114could be implemented by respective uplink and downlink antennas (not shown inFIG.1) instead of a single antenna. Downlink wireless signals126and uplink wireless signals128could be in either analog form or digital form. In some embodiments, uplink and/or downlink wireless signals126and128are within one or more of the 3.5 GHz band, the ISM band, and the TVWS band. Furthermore, in certain embodiments, downlink and uplink wireless signals126and128have the same respective frequencies as downlink and uplink access signals on access cable108, such that antenna adapter110need not be capable of performing frequency shifting. In some other embodiments, though, antenna adapter110is configured to shift frequency of one or more of downlink and uplink signals when converting between access signals on access cable108and RF electrical signals on antenna cable112. Customer antenna116is configured to wirelessly link customer premises106with wireline communication system101. Specifically, customer antenna116is configured to (a) convert downlink wireless signals126to downlink RF electrical signals on antenna cable118, and (b) convert uplink RF electrical signals on antenna cable118to uplink wireless signals128. Customer antenna116is, for example, mounted on a tall structure adjacent customer premises106or on customer premises106itself. In particular embodiments, customer antenna116is capable operating in the 5 to 800 megahertz (MHz) range and has a gain of 6 decibels relative to isotrope (dBi). Customer antenna116could be implemented by respective uplink and downlink antennas (not shown inFIG.1) instead of a single antenna. Box130inFIG.1illustrates elements of system100within customer premises106. In theFIG.1embodiment, antenna adapter120, access cable122, and wireline communication device124are located in customer premises106, and antenna cable118communicatively couples customer antenna116and antenna adapter120. However, one or all of the elements illustrated inFIG.1as being within customer premises106could alternatively be located outside of customer premises106, such as on a structure supporting customer antenna116, in a ground-mounted enclosure or a pole-mounted enclosure, or on the exterior of customer premises106. Antenna adapter120enables wireline communication device124to operate with customer antenna116by interfacing antenna cable118with access cable122. In particular, antenna adapter120is configured to (a) convert downlink RF electrical signals on antenna cable118to downlink access signals on access cable122and (b) convert uplink access signals on access cable122to uplink RF electrical signals on antenna cable118. The downlink access signals have a format that is compatible with wireline communication device124, and the uplink RF electrical signals optionally have a format that is compatible with wireline communication network101. In some embodiments, antenna adapter120is not configured to perform communication protocol translation, such that access signals on access cable122comply with the same communication protocol as RF electrical signals on antenna cable118. For example, in certain embodiments, antenna adapter120is configured to perform amplification and impedance matching between wireline communication device124and customer antenna116without perform communication protocol translation, thereby promoting low cost of antenna adapter120and low data transmission latency in system100. Additionally, in some embodiments, frequency of access signals on access cable122is the same as frequency of wireless signals126and128, such that antenna adapter120need not be cable of performing frequency shifting. In some other embodiments, antenna adapter120is configured to shift frequency of uplink signals and/or downlink signals. In certain embodiments, antenna adapter120is combined with wireline communication device124, such that access cable122is not required. Several example configurations of antenna adapter120are discussed below with respect toFIGS.11-15. Wireline communication device124may be any device that is configured to physically connect to wireline communication network101. For example, wireline communication device124may be a modem, such as a cable modem operating according to a cable communication protocol (e.g. a DOCSIS communication protocol) or a DSL modem operating according to a DSL protocol. As another example, wireline communication device124may be an optical network terminal (ONT) or an optical network unit (ONU) operating according to an optical communication protocol (e.g., a GPON communication protocol, an EPON communication protocol, or a RFOG communication protocol. Additionally, wireline communication device124may be a set-top box (STB), a premises gateway, or a digital-to-analog (DTA) and embedded multimedia terminal adapter (EMTA). Additionally, wireline communication device124could be a wireless access base station, including but not limited to a long-term evolution (LTE) wireless base station, a fifth generation (5G) new radio (NR) wireless base station, a sixth generation (6G) wireless base station, an unlicensed radio spectrum wireless base station (e.g. a Wi-Fi or unlicensed NR), or extensions and/or variations thereof. Wireline communication device124could be another type of device without departing from the scope hereof. Some embodiments of wireline communication device124include a connector132for physically connecting to access cable122. Connector132is, for example, a coaxial electrical cable connector, a telephone cable connector, an optical cable connector, or an Ethernet cable connector. Some embodiments of antenna adapter120include a connector134capable of physically connecting to connector132and/or to access cable122. Additionally, some embodiments of antenna adapter120include a connector136capable of connecting to antenna cable118. Connector134is, for example, a coaxial electrical cable connector, a telephone cable connector, an optical cable connector, or an Ethernet cable connector. Connector136is, for example, a coaxial electrical cable connector. Antenna adapter120delivers downlink access signals to connector134for transporting to wireline communication device124, and adapter120receives uplink access signals from wireline communication device124via connector134. In some embodiments including connectors132and134, the two connectors can by physically connected to together, such that access cable122is embodied by connectors132and134instead of an element separate from connectors132and134. Frequency shifting by antenna adapters110and120may be required when downlink and/or uplink wireless signals126and128must be within a different frequency band than corresponding access signals. Additionally, frequency shifting can be used to increase data transmission capacity of system100. For example, in applications where system100serves multiple customer premises106, each customer premises106could be configured to operate in a different frequency band to help maximize system100's capacity. Frequency shifting by antenna adapters110and120may be required to enable the respective frequency bands associated with each customer premises106to be wirelessly transmitted between service provider antenna114and customer antenna116, such as due to wireless spectrum constraints in the geographic operating area of system100. For example, frequency shifting may be employed to map a shared frequency band of downlink wireless signals126to RF electrical signals in different respective frequency bands for each customer premises106. FIG.2is a dataflow diagram200illustrating one example of operation of system100. Diagram200includes vertical lines logically representing each of communication node104, antenna adapter110, service provider antenna114, customer antenna116, antenna adapter120, and wireline communication device124. In this example, communication node104receives a downlink wireline signal202from wireline cable102(not shown inFIG.2), where information carried by wireline signal202is destined for wireline communication device124. Communication node104converts downlink wireline signal202to downlink access signal204, and access cable108transports downlink access signal204from communication node104to antenna adapter110. Antenna adapter110converts downlink access signal204to downlink RF electrical signal206, and antenna cable112transports downlink RF electrical signal206from antenna adapter110to service provider antenna114. Service provider antenna114converts RF electrical signal206to downlink wireless signal126, and customer antenna116receives downlink wireless signal126. Customer antenna116converts downlink wireless signal126into downlink RF electrical signal208, and antenna cable118transports downlink RF electrical signal208from customer antenna116to antenna adapter120. Antenna adapter120converts downlink RF electrical signal208to downlink access signal210, and access cable122transports downlink access signal210from antenna adapter120to wireline communication device124. Downlink access signal210, which has a format that is compatible with wireline communication device124, includes the information carried by downlink wireline signal202that is destined for wireline communication device124. Diagram200also includes an example of uplink transmission. Specifically, wireline communication device124provides uplink access signal212to access cable122, where uplink access signal212carries information destined for wireline communication network101. Access cable122transports uplink access signal212to antenna adapter120, and antenna adapter120converts uplink access signal212into uplink RF electrical signal214. Antenna cable118transports uplink RF electrical signal214from antenna adapter120to customer antenna116, and customer antenna116converts uplink RF electrical signal214to uplink wireless signal128. Service provider antenna114receives uplink wireless signal128, and service provider antenna114converts uplink wireless signal128to uplink RF electrical signal216. Antenna cable112transports uplink RF electrical signal216from service provider antenna114to antenna adapter110, and antenna adapter110converts uplink RF electrical signal216to uplink access signal218. Access cable108transports uplink access signal218to communication node104, and communication node104converts uplink access signal218to uplink wireline signal220, for transporting by wireline cable102. Uplink wireline signal220, which has a format that is compatible with wireline communication network101, includes the information carried by uplink access signal212that is destined for wireline communication network101. In some embodiments, uplink wireline signal220and uplink RF electrical signal216comply with a common communication protocol, such that antenna adapter110does not need to perform communication protocol translation. AlthoughFIG.2illustrates downlink and uplink transmission occurring at different times, some embodiments of system100support simultaneous downlink and uplink transmission. Referring again toFIG.1, in some embodiments, access signals on access cable122comply with the same communication protocol as access signals on access cable108. In these embodiments, wireline communication device124may therefore be a standard communication device intended to operate on wireline network101, instead of communication device specifically designed to operate with system100. Such potential standardization of wireline communication device124promotes low cost of wireline communication device124, ease of procuring wireline communication device124, ease of installation of wireline communication device124, and ease of support of wireline communication device124. In conventional fixed wireless communication systems, in contrast, customer premises equipment is typically proprietary equipment, as discussed above. Additionally, in certain embodiments, antenna adapter110handles any required conversion of signals between communication node104and service provider antenna114, thereby enabling communication node104to be a standard communication node, i.e. a communication node that is not specially designed for use with system100. The ability of communication node104to be a standard device further promotes low cost, ease of procuring node104, ease of installation of node104, and ease of support of node104. Alternately, communication node104could be specially designed for use in system100, thereby potentially enabling communication node104to be simpler and cheaper than a conventional communication node. Additionally, in some embodiments, no changes are needed to a network core or other central element of wireline communication network101to support system100. Indeed, in particular embodiments, the network core/central element may not even be able to detect that wireline communication device124is connected to wireline communication network101via system100, instead of being directly physically connected to wireline communication network101. Conventional fixed wireless communication systems, in contrast, typically require dedicated central equipment, such as a cellular network core, to support wireless customers. WhileFIG.1depicts customer premises106as being a rural building, system100is not limited to use in rural areas. Additionally, customer premises106could be something other than a building, such as a wireless antenna site, a utility site, or another infrastructure site. For example,FIG.3is a block diagram of a system300for extending a wireline communication network, which is an alternate embodiment of system100ofFIG.1that is configured to extend wireline communication network101across a road334to reach a wireless antenna site336. Wireless antenna site336includes a cellular tower338and a wireline communication device324. In some embodiments, cellular tower338is configured to operate as one or more of a LTE wireless base station, a 5G NR wireless base station, a 6G wireless base station, an unlicensed radio spectrum wireless base station (e.g. a Wi-Fi or unlicensed NR), or extensions and/or variations thereof. Wireline communication device324, which is an embodiment of wireline communication device124ofFIG.1, interfaces cellular tower338with access cable122. In some embodiments, wireline communication device324is a modem, an ONT, or an ONU. Additionally, a given customer antenna, such as customer antenna116ofFIGS.1and3, could be configured to support multiple customer premises. For example,FIG.4is a block diagram of a system400for extending a wireline communication network, which is an alternate embodiment of system100ofFIG.1that is configured to extend wireline communication network101to two customer premises, i.e. to customer premises406and407, using a single customer antenna116. Antenna adapter120is located outside of customer premises406and407, and access cable122communicatively couples antenna adapter120to a respective wireline communication device124(not shown inFIG.4) in each of customer premises406and407. Discussed below with respect toFIGS.5-10are several example embodiments of communication node104and/or antenna adapter110. It is understood, though, that communication node104and antenna adapter110are not limited to these example embodiments. FIG.5is a schematic diagram of a portion500of a system for extending a wireline communication network including an assembly502which is a combination of a communication node and an antenna adapter. Assembly502is one embodiment of communication node104and antenna adapter110, where communication node104and antenna adapter110are combined in a common assembly. Assembly502includes an optical module504, amplifiers506,508,510, and512, couplers514and516, attenuators518and520, diplexers522and524, and connectors526and528. Assembly502optionally further includes frequency converters558and572. Frequency converters558and572are included, for example, if frequency of uplink wireless signal128is outside of a range that is compatible with communication node104. Amplifier506, coupler514, attenuator518, and amplifier510are communicatively coupled in series between receiver536and a H-port of diplexer522. Connector526is communicatively coupled to a S-port of diplexer522. Optional frequency converter558, coupler516, and amplifier508are communicatively coupled in series between a L-port of diplexer522and transmitter538. Amplifier506, coupler514, attenuator520, and amplifier512are communicatively coupled in series between receiver536and a H-port of diplexer524. Connector528is communicatively coupled to a S-port of diplexer524. Optional frequency converter572, coupler516, and amplifier508are communicatively coupled in series between a L-port of diplexer524and transmitter538. Assembly502is configured to support two wireless sectors, but assembly502could be modified to support only a single wireless sector or three or more wireless sectors by removing components or by replicating components as appropriate. Assembly502is generally discussed below in the context of a cable application, i.e. where assembly502is configured to operate as a cable node and comply with a cable communication protocol (e.g. a DOCSIS communication protocol). However, assembly502is not limited to cable applications and could instead be adapted for use with other wireline communication networks, such as by changing the characteristics of amplifiers of assembly502. Optical module504is configured to interface assembly502with a strand530of an optical cable532. Optical cable532is an embodiment of wireline cable102(FIG.1) including a dedicated strand, i.e. strand530, for assembly502. Optical module504includes a splitter534, a receiver536, and a transmitter538. Splitter534is configured to split optical signals on strand530into a downlink optical wireline signal540and an uplink optical wireline signal542. Splitter534delivers downlink optical wireline signal540to receiver536, and splitter534receives uplink optical wireline signal542from transmitter538. Receiver536is configured to perform optical to electrical conversion by converting downlink optical wireline signal540to a downlink intermediate electrical signal544. Amplifier506is configured to amplify downlink intermediate electrical signal544to generate downlink intermediate electrical signal546. Assembly502is optionally designed to support specific wireless transmission frequencies for system100, instead of a wide range of wireline transmission frequencies, which may advantageously limit required operating frequency range of assembly502, thereby promoting low cost and simplicity of assembly502. For example, an equalizer may not be required, and amplifiers may be narrowband amplifiers. Accordingly, in some embodiments, amplifier506is a narrowband amplifier, e.g. having a range from approximately 400 to 928 MHz Coupler514is configured to communicatively couple downlink intermediate electrical signal546to respective circuitry supporting each wireless sector. Specifically, coupler514communicatively couples signal546to circuitry supporting a first wireless sector as a downlink intermediate electrical signal548, and coupler514communicatively couples signal546to circuitry supporting a second wireless sector as a downlink intermediate electrical signal550. Attenuator518, amplifier510, diplexer522, connector526, and optional frequency converter558support the first wireless sector, and attenuator520, amplifier512, diplexer524, connector528, and optional frequency converter572support the second wireless sector. Coupler514could be replaced with a splitter that performs functions similar to coupler514. Attenuator518is configured to attenuate downlink intermediate electrical signal548to generate a downlink intermediate electrical signal552that is optimized for amplifier510. Amplifier510is configured to amplify downlink intermediate electrical signal552to generate a downlink RF electrical signal554, which is an embodiment of RF electrical signal206ofFIG.2. Diplexer522is configured to multiplex downlink RF electrical signal554at its H-port with an uplink RF electrical signal556(discussed below) at its S-port. In some embodiments, uplink and downlink frequencies handled by assembly502are far apart so that diplexer522need not have sharp roll-off characteristics. For example, in particular embodiments, downlink frequencies may be in the range of 400 to 928 MHz, and uplink frequencies may in the range of 40 to 200 MHz. Accordingly, in certain embodiments, diplexer522may be a simple and low-cost diplexer, which promotes low cost of assembly502. Connector526is configured to communicatively couple assembly502with a service provider antenna560, where antenna560is an embodiment of service provider antenna114ofFIG.1. Service provider antenna560is optionally a log-periodic Yagi antenna. Connector526is, for example, a 50 ohm or 75 ohm connector, and in particular embodiments, connector526is a SubMiniature version A (SMA) connector or a F-type connector. Service provider antenna560converts downlink RF electrical signal554to downlink wireless signal126ofFIGS.1and2. Assembly502processes an uplink signal from the first wireless sector as follows. Service provider antenna560converts uplink wireless signal128ofFIGS.1and2to uplink RF electrical signal556, which is an embodiment of uplink RF electrical signal216ofFIG.2. Diplexer522de-multiplexes uplink RF electrical signal556at its S-port to provide uplink RF electrical signal556at its L-port. Optional frequency converter558, if present, is configured to shift frequency of uplink RF electrical signal556, e.g. lower frequency of uplink RF electrical signal556, to generate an uplink RF electrical signal556′. Coupler516communicatively couples uplink RF electrical signal556(or uplink RF electrical signal556′) and an uplink RF electrical signal562(or an uplink RF electrical signal562) (discussed below) to generate an uplink RF electrical signal564. Coupler516could be replaced with a splitter performing similar functions to coupler516. Amplifier508is configured to amplify uplink RF electrical signal564to generate an uplink intermediate electrical signal566. In some embodiments, amplifier508is a narrowband amplifier, e.g. having a range from approximately 40 to 200 MHz. Amplifier508optionally has automatic gain control to help ensure that uplink intermediate electrical signal566has a magnitude that is compatible with transmitter538of optical module504. Transmitter538is configured to convert uplink intermediate electrical signal566to uplink optical wireline signals542, for receipt by splitter534and injection onto strand530of optical cable532. The circuitry supporting the second wireless sector, i.e. attenuator520, amplifier512, diplexer524, connector528, and optional frequency converter572operates in the same manner as the circuitry supporting the first wireless sector. Specifically, attenuator520is configured to attenuate downlink intermediate electrical signal550to generate downlink intermediate electrical signal568that is optimized for amplifier512. Amplifier512is configured to amplify downlink intermediate electrical signal568to generate downlink RF electrical signal570, which is an embodiment of downlink RF electrical signal206ofFIG.2. Diplexer524is configured to multiplex downlink RF electrical signal570at its H-port with an uplink RF electrical signal562at its S-port. In some embodiments, diplexer524is a simple and low-cost diplexer for the reasons discussed above with respect to diplexer522. Connector528is configured to communicatively couple assembly502with a service provider antenna574, which is an embodiment of service provider antenna114ofFIG.1and has the same configuration as service provider antenna560. Connector528also has the same configuration as connector526. Service provider antenna574converts downlink RF electrical signal570to downlink wireless signal126ofFIGS.1and2. Assembly502processes an uplink signal from the second wireless sector as follows. Service provider antenna574converts uplink wireless signal128ofFIGS.1and2to uplink RF electrical signal562, which is an embodiment of uplink RF electrical signal216ofFIG.2. Diplexer524de-multiplexes uplink RF electrical signal562at its S-port to provide uplink RF electrical signal562at its L-port. Optional frequency converter572, if present, shifts frequency of uplink RF electrical signal562, e.g. lowers frequency of uplink RF electrical signal562, to generate uplink RF electrical signal562′. Coupler516communicatively couples uplink RF electrical signals556and562(or uplink RF electrical signals556′ and562′) as discussed above. Uplink signals from the second wireless sector are handled by amplifier508, transmitter538, and splitter534in the manner discussed above with respect to uplink signals from the first wireless sector. Assembly502could be modified to include frequency converters analogous to frequency converters558and572in downlink signal paths, if frequency needs to be shifted before transmission by service providers antennas560and574. For example, a frequency converter could be coupled be located between coupler514and the H-port of diplexer522, as well as between coupler514and the H-port of diplexer524. Assembly502does not require a dedicated optical cable strand for operation. For example,FIG.6is a schematic diagram of a portion600of a system for extending a wireline communication network where assembly502is served by an optical cable632which is shared by one or more additional devices (not shown). Optical cable632is an embodiment of wireline cable102ofFIG.1. System portion600further includes wavelength multiplexer676and a wavelength demultiplexer678. Wavelength demultiplexer678separates multiple wavelengths on common optical cable632onto different respective optical cable strands680and682. Strand680carries a wavelength dedicated to assembly502, and an optical coupler684interfaces strand680to a strand630which is communicatively coupled to splitter534. Strand682symbolically represents one or more parallel strands which pass from wavelength demultiplexer678to wavelength multiplexer676without being coupled to splitter534. Wavelength multiplexer676multiplexes the respective wavelengths of strands680and682back onto common optical cable632. Wavelength multiplexer676and a wavelength demultiplexer678could be replaced with respective wavelength selective switches that are capable of achieving similar functionality to wavelength multiplexer676and wavelength demultiplexer678. Optional frequency converters558and572are not shown inFIG.6, but they could be present as indicated inFIG.5. FIG.7is a schematic diagram of a portion700of a system for extending a wireline communication network including an assembly702which is a combination of a communication node and an antenna adapter. Assembly702is another embodiment of communication node104and antenna adapter110, where communication node104and antenna adapter110are combined in a common assembly. Assembly702includes an optical module504, a processor704, digital-to-analog converters706and708, analog-to-digital converters710and712, amplifiers714and716, diplexers718and720, and connectors722and724. Assembly702optionally further includes frequency converters736and748. Frequency converters736and748are included, for example, if frequency of uplink wireless signal128is outside of a range that is compatible with communication node104. Processor704is communicatively coupled to each of receiver536and transmitter538. Digital-to-analog converter706and amplifier714are communicatively coupled in series between processor704and a H-port of diplexer718. Analog-to-digital converter710and optional frequency converter736are communicatively coupled in series between processor704and a L-port of diplexer718. Connector722is communicatively coupled to a S-port of diplexer718. Digital-to-analog converter708and amplifier716are communicatively coupled in series between processor704and a H-port of diplexer720. Analog-to-digital converter712and optional frequency converter748are communicatively coupled in series between processor704and a L-port of diplexer720. Connector724is communicatively coupled to a S-port of diplexer720. Assembly702is configured to support two wireless sectors, but assembly702could be modified to support only a single wireless sector or three or more wireless sectors by removing components or by replicating components as appropriate. Assembly702is generally discussed below in the context of a cable application, i.e. where assembly702is configured to operate as a cable node and comply with a cable communication protocol (e.g. a DOCSIS communication protocol). However, assembly702is not limited to cable applications and could instead be adapted for use with other wireline communication networks, such as by changing the characteristics of amplifiers714and716and/or by changing characteristics of firmware executed by processor704. Optical module504is configured to interface assembly702with strand530of optical cable532, in the same manner as discussed above with respect toFIG.5. Processor704is configured process downlink intermediate electrical signal544from receiver536to generate respective downlink intermediate electrical signals726and728for each wireless sector, where signals726and728are in digital form. For example, processor704is configured to direct downlink information carried by downlink intermediate electrical signal544to the first or second wireless sector, as appropriate, by encoding the data on either signal726or728. Digital-to-analog converter706, analog-to-digital converter710, amplifier714, diplexer718, connector722, and optional frequency converter736support the first wireless sector, and digital-to-analog converter708, analog-to-digital converter712, amplifier716, diplexer720, connector724, and optional frequency converter748support the second wireless sector. Referring to the first wireless sector, digital-to-analog converter706is configured to convert downlink intermediate electrical signal726from digital form to analog form to generate a downlink intermediate electrical signal730. Amplifier714is configured to amplify downlink intermediate electrical signal730to generate a downlink RF electrical signal732, which is an embodiment of RF electrical signal206ofFIG.2. Diplexer718is configured to multiplex downlink RF electrical signal732at its H-port with an uplink RF electrical signal734(discussed below) at its S-port. In some embodiments, uplink and downlink frequencies handled by assembly702are far apart so that diplexer718need not have sharp roll-off characteristics. For example, in particular embodiments, downlink frequencies may be in the range of 400 to 928 MHz, and uplink frequencies may in the range of 40 to 200 MHz. Accordingly, in certain embodiments, diplexer718may be a simple and low-cost diplexer, which promotes low cost of assembly702. Connector722is configured to communicatively couple assembly702to a service provider antenna738, where antenna738is an embodiment of service provider antenna114ofFIG.1. Service provider antenna738is optionally a log-periodic Yagi antenna. Connector722is, for example, a 50 ohm or 75 ohm connector, and in particular embodiments, connector722is a SMA connector or a F-type connector. Service provide antenna738converts downlink RF electrical signal732to downlink wireless signal126ofFIGS.1and2. Assembly702processes an uplink signal from the first wireless sector as follows. Service provider antenna738converts uplink wireless signal128ofFIGS.1and2to uplink RF electrical signal734, which is an embodiment of uplink RF electrical signal216ofFIG.2. Diplexer718de-multiplexes uplink RF electrical signal734at its S-port and provides uplink RF electrical signal734at its L-port. Optional frequency converter736, if present, is configured to shift frequency of uplink RF electrical signal734, e.g. lower frequency of uplink RF electrical signal734, to generate an uplink RF electrical signal734′. Analog-to-digital converter710is configured to convert uplink RF electrical signal734(or uplink RF electrical signal734′) from analog form to digital form to generate an uplink intermediate electrical signal740. Processor704is configured to generate uplink intermediate electrical signal566according to information represented by uplink intermediate electrical signal740, and uplink intermediate electrical signal566is processed by optical module504as discussed above with respect toFIG.5. The circuitry supporting the second wireless sector, i.e. digital-to-analog converter708, analog-to-digital converter712, amplifier716, diplexer720, connector724, and optional frequency converter748operates in the same manner as the circuitry supporting the first wireless sector. Specifically, digital-to-analog converter708is configured to convert downlink intermediate electrical signal728from digital form to analog form to generate a downlink intermediate electrical signal742. Amplifier716is configured to amplify downlink intermediate electrical signal742to generate a downlink RF electrical signal744, which is an embodiment of downlink RF electrical signal206ofFIG.2. Diplexer720is configured to multiplex downlink RF electrical signal744at its H-port with an uplink RF electrical signal746(discussed below) at its S-port. In some embodiments, diplexer720may be a simple and low-cost diplexer for the reasons discussed above with respect to diplexer718. Connector724is configured to communicatively couple assembly702with a service provider antenna750, which is an embodiment of service provider antenna114ofFIG.1. Service provider antenna750has the same configuration as service provider antenna738, and connector724has the same configuration as connector722. Service provider antenna750converts downlink RF electrical signal744to downlink wireless signal126ofFIGS.1and2. Assembly702processes an uplink signal from the second wireless sector as follows. Service provider antenna750converts uplink wireless signal128ofFIGS.1and2to uplink RF electrical signal746, which is an embodiment of uplink RF electrical signal216ofFIG.2. Diplexer720de-multiplexes uplink RF electrical signal746at its S-port to provide uplink RF electrical signal746at its L-port. Optional frequency converter748, if present, is configured to shift frequency of uplink RF electrical signal746, e.g. lower frequency of uplink RF electrical signal746, to generate an uplink RF electrical signal746′. Analog-to-digital converter712is configured to convert uplink RF electrical signal746(or uplink RF electrical signal746′) from analog form to digital form to generate an uplink intermediate electrical signal752. Processor704is configured to generate uplink intermediate electrical signal566according to information represented by uplink intermediate electrical signal752, and uplink intermediate electrical signal566is processed by optical module504in the same manner as discussed above with respect toFIG.5. Assembly702is optionally designed to support specific wireless transmission frequencies, instead of a wide range of wireline transmission frequencies, which may advantageously limit required operating frequency range of assembly702, thereby promoting low cost and simplicity of assembly702. For example, equalizers may not be required due to the relatively narrow range of bandwidth supported by assembly702. Additionally, presence of respective digital-to-analog converters706and708for each sector may eliminate the need for amplitude control because power levels can be independently controlled at the output of digital-to-analog converters706and708. Each wireless sector could be configured to have the same frequency range due to each wireless sector covering a different respective area, which enables frequency reuse. Alternately, processor704could be configured to combine multiple sectors by replicating one signal on each of connectors722, and724, which may be advantageous in applications with low subscriber penetration. AlthoughFIG.7illustrates assembly702as being supported by a dedicated optical cable strand530, assembly702could alternately be supported by a shared optical cable, such as in a manner similar to that discussed above with respect toFIG.6. Additionally, assembly702could be modified to include frequency converters analogous to frequency converters736and748in downlink signal paths, if frequency needs to be shifted before transmission by service providers antennas738and750. For example, a frequency converter could be coupled between digital-to-analog converter706and the H-port of diplexer718, as well as between digital-to-analog converter708and the H-port of diplexer720. Additionally, downlink and uplink wireless signals126and128could be in digital form as well as in analog form, as discussed above. Accordingly, digital-to-analog converters706and708, analog-to-digital converters710and712, and optional frequency converters736and748could be omitted from assembly702. For example,FIG.18is a schematic diagram of a portion1800of a system for extending a wireline communication network including an assembly1802, where assembly1802is an alternate embodiment of assembly702configured for use in applications where downlink and uplink wireless signals126and128are in digital form. Assembly1802is like assembly702except that digital-to-analog converters706and708, analog-to-digital converters710and712, and optional frequency converters736and748are omitted. Amplifier714is configured to amplify downlink intermediate electrical signal726to generate downlink RF electrical signal732, and amplifier716is configured to amplify downlink intermediate electrical signal728to generate downlink RF electrical signal744. Additionally, processor704is configured to directly receive uplink RF electrical signals734and746from diplexers718and720, respectively, in assembly1802. FIG.8is a schematic diagram of an antenna adapter800that is communicatively coupled to two service provider antennas802and804. Antenna adapter800is an embodiment of antenna adapter110ofFIG.1where service provider antenna114is implemented by respective downlink and uplink service provider antennas802and804. Antenna adapter800may be used, for example, to interface a conventional embodiment of communication node104with two service provider antennas. Antenna adapter800includes a connector806, a diplexer808, impedance matching circuitry810, amplifiers812and814, and connectors816and818. Impedance matching circuit810includes network828for downlink signals and network830for uplink signals. A S-port of diplexer808is communicatively coupled to connector806. Network828and amplifier812are communicatively coupled in series between a H-port of diplexer808and connector816. Amplifier814and network830are communicatively coupled in series between connector818and a L-port of diplexer808. Connector806is configured to communicatively couple antenna adapter800to communication node104, e.g. via access cable108ofFIG.1(not shown inFIG.8). In some embodiments, connector806is a F-type connector configured to physically connect to a coaxial electrical cable. Antenna adapter800is configured to receive a downlink access signal820from communication node104via connector806, and antenna adapter800is configured to provide an uplink access electrical signal822to communication node104via connector806. Downlink access electrical signal820and uplink access electrical signal822are embodiments of downlink access electrical signal204and uplink access electrical signal218ofFIG.2, respectively. Diplexer808is configured to de-multiplex downlink access signal820from uplink access signal822at its S-port, and diplexer808is configured to provide downlink access signal820at its H-port. Diplexer808is also configured to multiplex uplink access signal822at its L-port with downlink access signal820at its S-port. Impedance matching circuitry810is configured to perform 75 ohms to 50 ohms impedance matching between communication node104and service provider antennas802and804. Impedance matching circuitry810could be modified to perform different impedance matching without departing from the scope hereof. Additionally, impedance matching circuitry810could be omitted if no impedance matching is required. Network828is configured to transform downlink access signal820to a downlink intermediate electrical signal832, and amplifier812is configured to amplify downlink intermediate electrical signal832to generate a downlink RF electrical signal834, which is an embodiment of downlink RF electrical signal206ofFIG.2. In some embodiments, amplifier812is a narrowband amplifier, e.g. having a range from approximately 400 to 928 MHz. Connector816is configured to communicatively couple antenna adapter800to downlink service provider antenna802, where antenna802is an embodiment of service provider antenna114ofFIG.1. Downlink RF electrical signal834is communicatively coupled to downlink service provider antenna802via connector816. Downlink service provider antenna802converts downlink RF electrical signal834to downlink wireless signal126ofFIGS.1and2. In some embodiments, downlink service provider antenna802has the same configuration as service provider antenna560ofFIG.5. Connector816is configured to physically connect to an instance of antenna cable112ofFIG.1(not shown inFIG.8), and connector816is optionally a SMA connector. Service provider antenna804is an embodiment of service provider antenna114ofFIG.1, and service provider antenna804is configured to convert uplink wireless signal128ofFIGS.1and2to uplink RF electrical signal836, which is an embodiment of uplink RF electrical signal216ofFIG.2. Connector818is configured to communicatively couple uplink service provider antenna804and antenna adapter800, and antenna adapter800receives uplink RF electrical signal836via connector818. Connector818is configured to physically connect to another instance of antenna cable112ofFIG.1(not shown inFIG.8), and connector818is optionally a SMA connector. Amplifier814is configured to amplify uplink RF electrical signal836to generate an intermediate uplink electrical signal838. In some embodiments, amplifier814is a narrowband amplifier, e.g. having a range from approximately 40 to 600 MHz. Amplifier814optionally has automatic gain control to help ensure that uplink access signal822has a magnitude that is compatible with communication node104. Network830is configured to transform uplink intermediate electrical signal838to uplink access signal822, which is provided to the L-port of diplexer808. It should be noted that antenna adapter800is not configured to perform protocol translation. Accordingly, access signals820and822comply with the same communication protocol as RF electrical signals834and836. This lack of communication protocol translation promotes low cost of the antenna adapter, as well as low-latency data transmission latency by antenna adapter800. Additionally, antenna adapter800does not perform frequency shifting, which further helps to achieve low cost. However, some alternate embodiments of antenna adapter800include frequency shifting circuitry or frequency mixing circuitry for downlink and/or uplink signals, such as for applications where wireless signals126and/or128must operate in a different frequency range than corresponding access signals at communication node104. Location of elements within antenna adapter800could be modified without departing from the scope hereof. For example, impedance matching circuitry810could be located between (a) amplifiers812and814and (b) connectors816and818, instead of between diplexer808and amplifiers812and814. As another example, impedance matching circuitry810could be modified to have a single network and be located between connector806and diplexer808. Additionally, antenna adapter800could be modified for use with a single service provider antenna, instead of for use with respective service provider antennas for uplink and downlink. For example,FIG.9is a schematic diagram of an antenna adapter900that is communicatively coupled to a single service provider antenna902. Antenna adapter900is an alternate embodiment of antenna adapter800ofFIG.8that intended for use with a single service provider antenna. Antenna adapter900is like antenna adapter800with the following exceptions: (a) antenna adapter900further includes an additional diplexer908, (b) dual connectors816and818are replaced with a single connector916, and (c) service provider antennas802and804are replaced with a single service provider antenna902for both uplink and downlink. An H-port of diplexer908is configured to receive downlink RF electrical signal834and multiplexes it at its S-port with uplink RF electrical signal836. Diplexer908is also configured to de-multiplex uplink RF electrical signal836and downlink RF electrical signal834at its S-port and provide de-multiplexed RF electrical signal836at its L-port. Connector916is configured to communicatively couple antenna adapter900and service provider antenna902. Service provider antenna902, which is an embodiment of service provider antenna114ofFIG.1, is communicatively coupled to antenna adapter900via connector916. In some embodiments, service provider antenna902has the same configuration as service provider antenna560of FIG. Connector916is configured to physically connect to antenna cable112ofFIG.1(not shown inFIG.9), and connector916is optionally a SMA connector. Furthermore, either of antenna adapter800or900could be modified to additionally include a frequency converter in the downlink signal path and/or uplink signal path, as discussed above. For example,FIG.10is a schematic diagram of an antenna adapter1000that is communicatively coupled to service provider antennas802and804. Antenna adapter1000is an alternate embodiment of antenna adapter800ofFIG.8and further includes a frequency converter1002in the uplink data path. Specifically, frequency converter1002shifts frequency, e.g. decreases frequency, of uplink access signal822to generate uplink access signal822′. Frequency converter1002is included, for example, in cases where frequency of uplink access signal822needs to be shifted for compatibility with communication node104. Discussed below with respect toFIGS.11-15are several example embodiments of antenna adapter120. It is understood, though, antenna adapter120is not limited to these example embodiments. FIG.11is a schematic diagram of an antenna adapter1100that is communicatively coupled to two customer antennas1102and1104. Antenna adapter1100is one embodiment of antenna adapter120ofFIG.1where customer antenna116is implemented by respective downlink and uplink customer antennas1102and1104. Antenna adapter1100may be used, for example, to interface wireline communication device124with two service provider antennas. Antenna adapter1100includes connectors1106,1108, and1110, amplifiers1112and1114, and impedance matching circuitry1116. Impedance matching circuit1116includes a network1126for downlink signals and a network1128for uplink signals. Amplifier1112and network1126are communicatively coupled in series between connector1106and a H-port of diplexer1118. Network1128and amplifier1114are communicatively coupled in series between a L-port of diplexer1118and connector1108. A S-port of diplexer1118is communicatively coupled to connector1110. Customer downlink antenna1102, which is an embodiment of customer antenna116ofFIG.1, is configured to convert downlink wireless signal126ofFIGS.1and2to a downlink RF electrical signal1120, which is an embodiment of downlink RF electrical signal208ofFIG.2. Customer uplink antenna1104, which is an embodiment of customer antenna116ofFIG.1, is configured to convert an uplink RF electrical signal1122, which is an embodiment of uplink RF electrical signal214ofFIG.2, to uplink wireless signal128ofFIGS.1and2. In some embodiments, each of uplink customer antennas1102and1104is capable of transmitting in a range of 5 to 800 MHz. Connector1106is configured to communicatively couple antenna adapter1100to customer uplink antenna1102, e.g. via an instance of antenna cable118(not shown inFIG.11). Connector1108is configured to communicative couple antenna adapter1100to customer uplink antenna1104, e.g. via another instance of antenna cable118(not shown inFIG.11). Each of connectors1106and1108is, for example, a SMA connector. Amplifier1112is configured to convert downlink RF electrical signal1120to a downlink intermediate electrical signal1124. In some embodiments, amplifier1112is a narrowband amplifier, e.g. having a range from approximately 400 to 928 MHz. Amplifier1112optionally has automatic gain control to ensure that a downlink access signal1130(discussed below) has a magnitude compatible with wireline communication device124. Impedance matching circuitry1116is configured to perform 75 ohms to 50 ohms impedance matching between customer antennas1102and1104wireline communication device124. Impedance matching circuitry1116could be configured to perform different impedance matching without departing from the scope hereof. Additionally, impedance matching circuitry1116could be omitted if impedance matching is not required. Network1126is configured to transform downlink intermediate electrical signal1124to a downlink access signal1130, which is an embodiment of downlink access signal210ofFIG.2. Diplexer1118is configured to multiplex downlink access signal1030at its H-port with an uplink access signal1132at its S-port. Diplexer1118is additionally configured to de-multiplex uplink access signal1132from downlink access signal1130at its S-port, to provide de-multiplexed uplink access signal1132at its L-port. Network1128is configured to transform uplink access signal1132to an uplink intermediate electrical signal1134, and amplifier1114is configured to amplify uplink intermediate electrical signal1134to generate uplink RF electrical signal1122. In some embodiments, amplifier1114is a narrowband amplifier, e.g. having a range from approximately 40 to 600 MHz. Wireline communication device124is communicatively coupled to the S-port of diplexer1118by connector1110, e.g. via access cable122ofFIG.1(not shown inFIG.10). In some embodiments, connector1110is a F-type connector configured to physically connect to a coaxial electrical cable. It should be noted that antenna adapter1100is not configured to perform protocol translation. Accordingly, RF electrical signals1120and1122comply with the same communication protocol as access signal1130and1132, which promotes low cost of the antenna adapter, as well as low-latency data transmission latency by antenna adapter1100. Antenna adapter1100could be modified for use with a single customer antenna, instead of for use with respective customer antennas for uplink and downlink. For example,FIG.12is a schematic diagram of an antenna adapter1200that is communicatively coupled to a single customer antenna1202, where customer antenna1202is an embodiment of customer antenna116ofFIG.1. Antenna adapter1200is an alternate embodiment of antenna adapter1100ofFIG.11that intended for use with a single customer antenna. Antenna adapter1200is like antenna adapter1100with the following exceptions: (a) antenna adapter1200further includes an additional diplexer1218, (b) dual connectors1106and1108are replaced with a single connector1206, and (c) customer antennas1102and1104are replaced with single customer antenna1202for both uplink and downlink. A S-port of diplexer1218is communicatively coupled to connector1206. Amplifier1112and network1126are communicatively coupled in series between a H-port of diplexer1218and the H-port of diplexer1118. Network1128and amplifier1114are communicatively coupled in series between the L-port of diplexer1118and a L-port of diplexer1218. Amplifier1114is configured to provide uplink RF electrical signal1112to the L-port of diplexer1218, and diplexer1218is configured to multiplex uplink RF electrical signal1112with downlink RF electrical signal1120at its S-port. Diplexer1218is also configured to de-multiplex downlink RF electrical signal1120from uplink RF electrical signal1122at its S-port, to provide de-multiplexed RF electrical signal1120at its H-port. Connector1206is configured to communicatively couple antenna adapter1200with customer antenna1202, and customer antenna1202is accordingly communicatively coupled to connector1206. In some embodiments, customer antenna1202has the same configuration as customer antennas1102and1104ofFIG.11. Customer antenna1202is configured to convert downlink wireless signal126to downlink RF electrical signal1120, and customer antenna1202is configured to convert uplink RF electrical signal1122to uplink wireless signal128. Connector1206is configured to physically connect to antenna cable118ofFIG.1(not shown inFIG.12), and connector1206is optionally a SMA connector. Locations of elements in antenna adapters1100and1200could be modified without departing from the scope hereof. For example, impedance matching circuitry1116could be replaced with impedance matching circuitry having only a single network and being located between diplexer1118and connector1110.FIG.13is a block diagram of an antenna adapter1300, which is alternate embodiment of antenna adapter1200which has been modified in such manner. Specifically, impedance matching circuitry1116has been replaced with impedance matching circuitry1316having a single network and connected between the S-port of diplexer1118and connector1110. In this embodiment, diplexer1118is configured to multiplex downlink intermediate electrical signal1124at its H-port with uplink intermediate electrical signal1134at its S-port. Additionally, diplexer1118is configured to de-multiplex uplink intermediate electrical signal1134from downlink intermediate electrical signal1124at its S-port, to provide uplink intermediate electrical signal1134at its L-port. As another example, impedance matching circuitry1116could be located between (a) amplifiers1112and1114and (b) connectors1106and1108.FIG.14is a block diagram of an antenna adapter1400, which is alternate embodiment of antenna adapter1100which has been modified in such manner. Specifically, network1126is connected between connector1106and amplifier1112, and network1128is connected between connector1108and amplifier1114. Network1126is configured to transform downlink RF electrical signal1120to a downlink intermediate electrical signal1324, and amplifier1112is configured to amplify downlink intermediate electrical signal1324to generate downlink access signal1130. Additionally, amplifier1114is configured to amplify uplink access signal1132to generate an uplink intermediate electrical signal1334. Network1128is configured to transform uplink intermediate electrical signal1334to uplink RF electrical signal1122. Antenna adapters1100,1200,1300, and1400do not perform frequency shifting, which helps achieve low cost. However, there may be applications where frequency shifting is required, such as where wireless spectrum is unavailable in the frequency range of uplink and/or downlink access signals. Accordingly, any one of antenna adapters1100,1200,1300, and1400may be modified to include a frequency shifter in the uplink path and/or downlink path. For example,FIG.15is a block diagram of an antenna adapter1500, which is alternate embodiment of antenna adapter1100further including a frequency converter1502. Frequency converter1502is configured to shift frequency, e.g. increase frequency, of uplink RF electrical signal1122to generate uplink RF electrical signal1122′. Antenna adapter1500optionally further includes an additional amplifier (not shown) communicatively coupled between frequency converter1502and connector1108to compensate for any degradation of uplink RF electrical signal1122by frequency converter1502. FIG.16is a flow chart of a method1600for operating a wireline communication device on a wireless communication network. In a block1602of method1600, a downlink RF electrical signal is received at a first connector. In one example of block1602, antenna adapter120receives downlink RF electrical signal208at connector136. In a block1604of method1600, the downlink RF electrical signal is converted to a downlink access signal having a format that is compatible with the wireline communication device. In one example of block1604, antenna adapter120converts downlink RF electrical signal208to downlink access signal210. In a block1606of method1600, the downlink access signal is provided to a second connector for transporting to the wireline communication device. In one example of block1606, antenna adapter120provides downlink access signal120to connector134, for transporting to wireline communication device124via access cable122. FIG.17is a flow chart of a method1700for extending a wireline communication network. In a block1702of method1700, a downlink wireline signal is received at a node of the wireline communication network. In one example of block1702, communication node104receives downlink wireline signal202. In a block1704of method1700, the downlink wireline signal is converted to a downlink RF electrical signal. In one example of block1704, communication node104converts downlink wireline signal202to downlink access signal204, and antenna adapter110converts downlink access signal204to downlink RF electrical signal206. In a block1706of method1700, the downlink RF electrical signal is converted to a downlink wireless signal, for transmission to one or more first communication devices which are not physically connected to the wireline communication network. In one example of block1706, service provider antenna114converts downlink RF electrical signal206to downlink wireless signal126, for transmission to wireline communication device124. Referring again toFIG.1, multiple instances of antennas114and116can use one or more common frequency bands for downlink wireless signals126and/or uplink wireless signals128if the antennas are sufficiently geographically far apart so that there is no significant interference between respective wireless signals of the antennas. For example,FIG.19is a block diagram of a system1900for extending a wireline communication network, which is an alternate embodiment of system100ofFIG.1further including a communication node104′, an access cable108′ an antenna adapter110′, an antenna cable112′, a service provider antenna114′, a customer antenna116′, an antenna cable118′, and a customer premises106′. Each prime symbol inFIG.19denotes an additional instance of the element associated with the corresponding reference number. For example, communication node104′ is an additional instance of communication node104. Antennas114and116associated with communication node104are sufficiently geographically far apart from antennas114′ and116′ associated with communication node104′ so that there is no significant interference between (a) wireless signals126and128and (b) wireless signals126′and128′. Consequently, wireless signals126′ and128′ can be in the same frequency band as wireless signals126and128, respectively, thereby enabling spectrum reuse among antenna sets in system1900. Although wireless signals126′ and128′ can be in the same frequency band as wireless signals126and128, corresponding wireline signals and/or access signals may be in different respective frequency bands. For example, a downlink wireline signal on wireline cable102corresponding to downlink wireless signal126may be in a different band than a downlink wireline signal on wireline cable102corresponding to downlink wireless signal126′. Accordingly, some embodiments of nodes104and104′, and/or antenna adapters110and110′, are configured to perform frequency shifting between wireline signals and RF electrical signals, to map wireline signals of different respective frequency bands to wireless signals of a common frequency band, and vice versa. For example, consider a scenario where a downlink wireline signal intended for customer premises106is in a frequency band F1and a downlink wireline signal intended for customer premises106′ is in a frequency band F2that is different from frequency band F1. Communication node104and/or antenna adapter110may be configured to shift frequency of the downlink wireline signal intended for customer premises106from frequency band F1to a frequency band Fc, for transmission by downlink wireless signal126. Additionally, communication node104′ and/or antenna adapter110′ may be configured to shift frequency of the downlink wireline signal intended for customer premises106′ from frequency band F2to frequency band Fc, for transmission by downlink wireless signal126′. Thus, while wireline signals for customer premises106and106′ are in different respective frequency bands F1and F2, wireless signals for customer premises106and106′ are in a common frequency band Fc. Such reuse of spectrum (frequency band Fc) for downlink wireless signal transmission is possible due to significant geographic separation between antenna sets114/116and114′/116′, which prevents significant interference between wireless signals126and126′. Similar mapping may be performed between uplink access signals in different respective frequency bands to uplink wireless signals128and128′ in a common frequency band. Features described above may be combined in various ways without departing from the scope hereof. The following examples illustrate some possible combinations: (A1) A method for operating a wireline communication device on a wireless communication network may include (1) receiving a downlink radio frequency (RF) electrical signal at a first connector, (2) converting the downlink RF electrical signal to a downlink access signal having a format that is compatible with the wireline communication device, and (3) providing the downlink access signal to a second connector for transporting to the wireline communication device. (A2) In the method denoted as (A1), each of the downlink RF electrical signal and the downlink access signal may comply with a common communication protocol. (A3) In the method denoted as (A2), the common communication protocol may be a cable communication protocol. (A4) In the method denoted as (A3), the cable communication protocol may include a Data Over Cable Service Interface Specification (DOCSIS) protocol. (A5) In the method denoted as (A2), the common communication protocol may be a digital subscriber line (DSL) protocol. (A6) In the method denoted as (A2), the common communication protocol may be an optical data transmission protocol. (A7) In the method denoted as (A6), converting the downlink RF electrical signal to the downlink access signal may include converting the downlink RF electrical signal to an optical signal. (A8) In any one of the methods denoted as (A1) through (A7), converting the downlink RF electrical signal to the downlink access signal may include amplifying a downlink electrical signal. (A9) In any one of the methods denoted as (A1) through (A8), converting the downlink RF electrical signal to the downlink access signal may include matching impedance of an antenna generating the downlink RF electrical signal and the wireline communication device. (A10) In any one of the methods denoted as (A1) through (A9), providing the downlink access signal to the second connector may include multiplexing the downlink access signal with an uplink access signal from the wireline communication device. (A11) Any one of methods denoted as (A1) through (A10) may further include (1) receiving an uplink access signal from the wireline communication device; (2) converting the uplink access signal to an uplink RF electrical signal having a format that is compatible with the wireline communication network; and (3) providing the uplink RF electrical signal to the first connector. (A12) In method denoted as (A11), each of the uplink access signal and the uplink RF electrical signal may comply with a common communication protocol. (A13) Any one of the methods denoted as (A1) through (A10) may further include (1) receiving an uplink access signal from the wireline communication device; (2) converting the uplink access signal to an uplink RF electrical signal having a format that is compatible with the wireline communication network; and (3) providing the uplink RF signal to a third connector. (A14) In the method denoted as (A13), each of the uplink access signal and the uplink RF electrical signal may comply with a common communication protocol. (A15) In any one of the methods denoted as (A1) through (A14), the wireline communication device may be one of a cable modem, a digital subscriber line (DSL) modem, an optical network terminal (ONT), and an optical network unit. (B1) An antenna adapter for interfacing a wireline communication device with a wireless communication network may include (1) a first connector configured to communicatively couple the adapter to a first antenna; (2) second connector configured to communicatively couple the adapter to a second antenna; (3) a third connector configured to communicatively couple the adapter to the wireline communication device; (4) a first amplifier being communicatively coupled between the first connector and the third connector; (5) a second amplifier being communicatively coupled between the second connector and the third connector; (6) impedance matching circuitry communicatively coupled between (a) the first and second connectors and (b) the third connector; and (7) a diplexer including a H-port, a L-port, and a S-port, the H-port being communicatively coupled to the first amplifier, the L-port being communicatively coupled to the second amplifier, and the S-port being communicatively coupled to the third connector. (B2) In the antenna adapter denoted as (B1), (1) the impedance matching circuitry may include a first network and a second network; (2) the first network may be communicatively coupled between the first amplifier and the H port of the diplexer; (3) the first amplifier may be communicatively coupled between the first connector and the first network; (4) the second network may be communicatively coupled between the second amplifier and the L-port of the diplexer; and (5) the second amplifier may be communicatively coupled between the second connector and the second network. (B3) In the antenna adapter denoted as (B1), (1) the impedance matching circuitry may be communicatively coupled between the S-port of the diplexer and the third connector; (2) the H-port of the diplexer may be communicatively coupled to the first amplifier; and (3) the L-port of the diplexer may be communicatively coupled to the second amplifier. (C1) An antenna adapter for interfacing a wireline communication device with a wireless communication network may include (1) a first connector configured to communicatively couple the adapter to an antenna; (2) a second connector configured to communicatively the adapter to the wireline communication device; (3) a first diplexer including a first H-port, a first L-port, and a first S-port, the first S-port being communicatively coupled to the first connector; (4) a second diplexer including a second H-port, a second L-port, and a second S-port, the second S-port being communicatively coupled to the second connector; (5) a first amplifier being communicatively coupled between the first and second H-ports; (6) a second amplifier being communicatively coupled between the first and second L-ports; and (7) impedance matching circuitry communicatively coupled between the first and second connectors. (C2) In the antenna adapter denoted as (C1), the impedance matching circuitry may be communicatively coupled between the second S-port and the second connector. (D1) A method for extending a wireline communication network may include (1) receiving a downlink wireline signal at a node of the wireline communication network; (2) converting the downlink wireline signal to a downlink radio frequency (RF) electrical signal; and (3) converting the downlink RF electrical signal to a downlink wireless signal, for transmission to one or more communication devices which are not physically connected to the wireline communication network. (D2) In method denoted as (D1), each of the downlink wireline signal and the downlink RF electrical signal may comply with a common communication protocol. (D3) In the method denoted as (D2), the common communication protocol may be a cable communication protocol. (D4) In method denoted as (D3), the cable communication protocol may include a Data Over Cable Service Interface Specification (DOCSIS) protocol. (D5) In the method denoted as (D2), the common communication protocol may be a digital subscriber line (DSL) protocol. (D6) Any one of the methods denoted as (D1) through (D5) may further include (1) receiving an uplink wireless signal; (2) converting the uplink wireless signal to an uplink RF electrical signal; and (3) converting the uplink RF electrical signal to an uplink wireline signal, for transmission on the wireline communication network. Changes may be made in the above methods, devices, and systems without departing from the scope hereof. It should thus be noted that the matter contained in the above description and shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover generic and specific features described herein, as well as all statements of the scope of the present method and system, which as a matter of language, might be said to fall therebetween. | 80,800 |
11943005 | DETAILED DESCRIPTION As mentioned above, there is currently a large installed base 1G and slower Ethernet networks using Cat5 and Cat5e cables. However, both the need for higher data speeds and the availability of 10 gigabit per second (10G) Ethernet ports have increased significantly in recent years. Thus, the desire to upgrade existing 1 gigabit per second (1G) and slower Ethernet networks is growing. One obstacle to upgrading existing 1G and slower Ethernet networks, however, is the cost of upgrading the cabling required for 10G Ethernet. Cat6 and Cat6a cables are more expensive than Cat5 and Cat5e cables. More importantly, the cost of labor to replace Cat5 and Cat5e cables with Cat6 or Cat6a cables is significant, and the process of cable replacement likely will be very disruptive to users of an Ethernet network, workers of an office building, residents of an apartment building, etc., for example. In many existing Ethernet networks, the amount of data travelling in a first direction (e.g., from a router, switch, hub, etc., to an endpoint) is significantly greater than the amount of data travelling in a second direction (e.g., from the endpoint to the router, switch, hub, etc.). Thus, the need for high-speed data in the first direction is greater than in the second direction in many Ethernet networks. The present application describes embodiments of devices and methods that allow for higher speed transmission in a first direction (e.g., 10 gigabits per second (Gbps)) using existing cables (such as Cat5 and Cat5e cables, or even Cat3 cables) that are not rated for the higher speed; the higher speed transmission in the first direction over existing cables is facilitated, at least in part, by transmission in a second direction at a lower speed (e.g., 0.1 Gbps, 1 Gps, 2.5 Gps, 5 Gps). As is described further below, the use of asymmetric transmission rates mitigates adverse effects of crosstalk between cables (e.g., Cat5 and Cat5e cables). Thus, higher speed transmission in the first direction can be achieved with existing, already installed cables (e.g., Cat5 and Cat5e cables, or even Cat3 cables), i.e., without having to install new cabling. FIG.1is a simplified diagram of an example communication system100, according to an embodiment. The communication system100includes a network device104, such as a router, a switch, a hub, etc., communicatively coupled to a plurality of endpoint devices108(e.g., computers, televisions, gaming systems, medical equipment, etc.) via respective cables112. As an illustrative example, the communication system100is located in an office building, and the endpoint devices108correspond to computers in different workstations (e.g., offices, cubicles, etc.). As another illustrative example, the communication system100is located in a multi-family residential building, and the endpoint devices108correspond to computers, televisions, gaming systems, etc., throughout the residential building. As another illustrative example, the communication system100is located in a healthcare facility, and the endpoint devices108correspond to Medical equipment, computers, televisions, throughout the healthcare facility. The network device104include a plurality of transceivers120, each communicatively coupled to a respective cable112. Similarly, each endpoint108includes a respective transceiver124communicatively coupled to a respective cable112, Although three transceivers120and three endpoints108are illustrated inFIG.1, the communication system100includes other suitable numbers of transceivers120and endpoints108, such as two or more than 3. In some embodiments, a single endpoint108includes multiple transceivers124communicatively coupled to multiple respective cables112. One or more of the cables112are Class C cables (sometimes referred to as a Category 3 (Cat3) cable) or Class Ii) cables (sometimes referred to as a Category 5e (Cat5e) cable) as specified by the ISO/IEC 11801 standard, according to an embodiment. A Class C (Cat3) cable comprises a. plurality of twisted copper wire pairs and is typically rated for certain performance and test requirements up to 16 MHz. A Class D (Cat5e) cable comprises a plurality of twisted copper wire pairs and is typically rated for certain performance and test requirements up to 100 MHz. One or more of the cables112are Category 5 (Cat5) cables specified by an older version of the ISO/IEC 11801 standard and, like Cat5e cables, are rated for certain performance and test requirements up to 100 MHz (according to the older version of the ISO/IEC 11801 standard). Category 3 cables, Category5 cables, and Category 5E cables are sometimes referred to herein as “legacy cables.” In comparison, Class E cables (sometimes referred to as Category 6 (Cat6) cables) as specified by the ISO/IEC 11801 standard and Class EA cables (sometimes referred to as Category 6A (Cat6A) cables) as specified by the ISO/IEC 11801 standard are rated for certain performance and test requirements up to 250 MHz and 500 MHz, respectively. Class F cables (sometimes referred to as Category 7 (Cat7) cables) as specified by the ISO/IEC 11801 standard are rated for certain performance and test requirements up to 600 MHz. On the other hand, a legacy cable may not be rated for any performance or test requirements above 100 MHz according to the ISO/IEC 11801 standard, according to some embodiments. In some embodiments, one or more other cables112are legacy cables that are not rated for any performance or test requirements above 100 MHz. In some embodiments, one or more other cables112are rated for performance or test requirements above 100 MHz. For example, one or more other cables112are Cat6, Cat6a, or Cat7 cables, according to an embodiment. As will be described in more detail below, at least some of the transceivers120(e.g., at least the transceivers120-1,120-2, and120-3) are configured to transmit at a first baud rate while concurrently receiving at a second baud rate that is lower than the first baud rate. Similarly, at least some of the transceivers124(e.g., at least the transceivers124-1,124-2, and124-3) are configured to receive at the first baud rate while concurrently transmitting at the second baud rate. As illustrated inFIG.1, at least cables112-1,112-2, and112-3are bundled together for cable management. The bundling of cables112-1,112-2, and112-3generally increases crosstalk between the cables112-1,112-2, and112-3. For example, transmissions within cable112-1and transmissions within cable112-3both cause crosstalk into cable112-2. Similarly, transmissions within cable12-2cause crosstalk into cable1124and cable112-3. Such crosstalk is sometimes referred to as “alien crosstalk” because the crosstalk experienced by one cable112is caused by transmissions in another cable112, as opposed to crosstalk between different twisted wire pairs within a single cable112. In other embodiments, at least some cables112(e.g., at least cables112-1,112-2, and112-3) are not bundled, but are otherwise deployed in an arrangement that results in alien crosstalk between cables112. For example, cables112that run together in close proximity (while not being bundled with a strap or tie) for a span may experience alien crosstalk. In other embodiments, at least some alien crosstalk occurs because of close proximity between ports of the network device to which respective cables112are connected, as opposed to bundling of cables112or close proximity of cables112. Generally, legacy cables tend to cause and/or experience more alien crosstalk with 10G Ethernet transmissions as compared to Cat6, Cat6A, and Cat7 cables. The largest component of alien crosstalk typically is crosstalk experienced by receive circuitry within a first transceiver (e.g., a transceiver120or a transceiver124) caused by transmissions by one or more second transceivers that are located proximate to the first transceiver, sometimes referred to as “near-end alien crosstalk,” For example, receive circuitry of the transceiver120-1experiences near-end alien crosstalk caused by transmissions by the transceiver120-2within the cable112-2. As another example, receive circuitry of the transceiver120-2experiences near-end alien crosstalk caused by transmissions by the transceiver120-1within the cable112-1and by transmissions by the transceiver120-3within the cable112-3, As another example, receive circuitry of the transceiver120-3experiences near-end alien crosstalk caused by the transmissions by the transceiver120-2within the cable112-2. Other examples of alien crosstalk include: receive circuitry of the transceiver124-1experiences near-end alien crosstalk caused by transmissions by the transceiver124-2within the cable112-2; receive circuitry of the transceiver124-2experiences near-end alien crosstalk caused by transmissions by the transceiver124-4within the cable112-4and by transmissions by the transceiver124-3within the cable112-3; and receive circuity of the transceiver124-3experiences near-end alien crosstalk caused by the transmissions by the transceiver124-2within the cable112-2. A Cat5e cable (or even a Cat5 cable) can be used for a 10G Ethernet link when the length of the cable is relatively short and when alien crosstalk is not an issue, such as when the cable is not bundled with any other Ethernet cables. However, in a network such as illustrated inFIG.1in which multiple network cables112are bundled, or in deployments in which alien crosstalk is otherwise significant, standard 10G Ethernet transmissions over Cat5e or Cat5 cables will typically result in alien crosstalk that significantly degrades performance. FIG.2is a plot of power spectral density (PSD) of alien crosstalk between Cat5e cables versus frequency in a. particular experimental network arrangement. In particular,FIG.2illustrates PSD of alien crosstalk caused by 10G Ethernet transmissions and 1G Ethernet transmissions in the particular experimental network arrangement, Alien crosstalk is highly dependent on physical implementation and traffic characteristics, and general models of alien crosstalk are not well defined. Thus,FIG.2is merely intended to be illustrative of general behavior of alien crosstalk in a particular experimental setting. In the experimental network arrangement corresponding toFIG.2, the PSD of alien crosstalk caused by 1G Ethernet (“1G alien crosstalk”) remains at levels that do not adversely affect other 1G Ethernet transmissions to a significant degree. Additionally, the PSD of 1G alien crosstalk generally decreases as frequency increases, Thus, in the experimental network arrangement corresponding toFIG.2, alien crosstalk caused by 1G Ethernet transmissions tends to not adversely affect either other 1G Ethernet transmissions or other 10G Ethernet transmissions. The PSD of alien crosstalk caused by 10G Ethernet (“10G alien crosstalk”) is approximately constant (e.g., approximately −152.5 dB) for frequencies generally corresponding to 1G Ethernet, but then generally rises as frequency increases. Thus, in contrast to PSD of 1G alien crosstalk, the PSD of 10G alien crosstalk generally increases with frequency in frequencies generally overlapping with 10G Ethernet transmissions. Additionally, as can be seen inFIG.2, PSD of 10G alien crosstalk is significantly greater than the PSD of 1G alien crosstalk for higher frequencies. Referring again toFIG.1, when the transceiver124-2transmits at a baud rate corresponding to 1G Ethernet, alien crosstalk will occur in the cables112-1and112-3. Similarly, when the transceivers124-1and124-3transmit at the baud rate corresponding to 1G Ethernet, alien crosstalk will occur in the cable112-2. However, the PSD of such alien crosstalk remains at levels that do not adversely affect other Ethernet transmissions at higher baud rates to a significant degree. For example, as discussed above with reference toFIG.2, the PSD of 1G alien crosstalk caused by the transmissions of a transceiver124generally decreases as frequency increases. Thus, near end alien crosstalk caused by a transceiver124transmitting at the baud rate corresponding to 1G Ethernet does not adversely affect reception by other transceivers124of Ethernet transmissions at higher baud rates (e.g., corresponding to 10G) to a significant degree. When the transceiver120-2transmits at a baud rate corresponding to 10G Ethernet, alien crosstalk will occur in the cables112-1and112-3. Similarly, when the transceivers120-1and120-3transmit at the baud rate corresponding to 10G Ethernet, alien crosstalk will occur in the cable112-2. At frequencies generally corresponding to 1G Ethernet, the PSD of such alien crosstalk remains at levels that in and of themselves do not adversely affect other Ethernet transmissions to a significant degree. Additionally, because the transmissions by the transceivers124are at the lower baud rate (e.g., corresponding to 1G Ethernet), the signal received by each transceiver120can be lowpass filtered to remove higher frequency components of the 10G alien crosstalk. Thus, the PSD of 10G alien crosstalk caused by the transmissions of the transceivers120can be kept below levels that do not adversely affect reception of the 1G Ethernet transmissions from the transceivers124to a significant degree. Thus, the transceivers120that transmit at the first baud rate while simultaneously receiving at the second baud rate are able to mitigate near end alien crosstalk using lowpass filters caused by the transmissions of other transceivers120. Additionally, although the transceivers124that receive at the higher first baud rate while simultaneously transmitting at the lower second baud rate may experience near end alien crosstalk (e.g., 1G alien crosstalk) caused by the transmissions of other transceivers124, such near end alien crosstalk remains at PSD levels that do not adversely affect reception at the transceivers124to a significant degree. In some embodiments, each of at least some of the transceivers120is configured to transmit using a baud rate corresponding to a minimum bandwidth that exceeds a maximum bandwidth rating of the respective cable112. In some embodiments, each of at least some of the transceivers120is configured to transmit using a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the respective cable112by at least 75 MHz. in other embodiments, each of at least some of the transceivers120is configured to transmit using a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the respective cable112by at least 100 MHz. In other embodiments, each of at least some of the transceivers120is configured to transmit using a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the respective cable112by at least 250 MHz. In some embodiments, each of at least some of the transceivers120additionally is configured to receive at a baud rate corresponding to a minimum bandwidth that is less than or equal to the maximum bandwidth rating of the respective cable112. In some embodiments, each of at least some of the transceivers124is configured to receive at a baud rate corresponding to a minimum bandwidth that exceeds a maximum bandwidth rating of the cable112. In some embodiments, each of at least some of the transceivers124is configured to receive at a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the cable112by at least 75 MHz. In other embodiments, each of at least some of the transceivers124is configured to receive at a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the cable112by at least 100 MHz. In other embodiments, each of at least some of the transceivers124is configured to receive at a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the cable112by at least 250 MHz. In some embodiments, each of at least some of the transceivers124additionally is configured to transmit at a baud rate corresponding to a minimum bandwidth that is less than or equal to the maximum bandwidth rating of the cable112. AlthoughFIG.1was discussed in the context of transmissions in the downlink direction being at the higher first baud rate and transmissions in the uplink direction being at the lower second baud rate, in other embodiments it is useful to have transmissions in the downlink direction being at the lower second baud rate and transmissions in the uplink direction being at the higher first baud rate. For example, in an embodiment, the endpoints108correspond to video cameras (e.g., the communication system100corresponds to a security system) that transmit video data to the network device104in the uplink direction, whereas the network device104transmits a relatively smaller amount of data to the endpoints108in the downlink direction. In such an embodiment, the amount of data travelling in an uplink direction is significantly greater than the amount of data travelling in the downlink direction. Thus, in some embodiments, each transceiver120is configured to transmit at the lower second baud rate and receive at the higher first baud rate; and each transceiver124is configured to transmit at the higher first baud rate and receive at the lower second baud rate. In some embodiments, the network device104includes a controller140that is configured to determine a direction of baud rate asymmetry to be utilized in the network100. For example, the controller140monitors amounts of network traffic in the downlink direction as compared to the uplink direction and determines in which direction (e.g., downlink or uplink) a higher baud rate should be used, according to an embodiment. In such an embodiment, the controller140informs at least the transceivers120(and optionally the transceivers124) of at least in which direction (e.g., downlink or uplink) a higher baud rate should be used. Although the controller140is illustrated as being a component of the network device104, in sonic embodiments the controller140is separate from the network device104and communicatively coupled to the network device. In sonic embodiments, the controller140is omitted from the communication system100. In some embodiments, transceivers120and transceivers140are capable of using a plurality of different baud rates in the downlink direction and/or using a plurality of different baud rates in the uplink direction. In some such embodiments, transceivers120and transceivers140are configured to negotiate with one another regarding baud. rates to use in the uplink direction and the downlink direction with one or more constraints, such as one or more of i) the baud rate in the downlink direction must be higher than the baud rate in the uplink direction, or vice versa; ii) all transceivers120must utilize a same transmission baud rate; iii) all transceivers120must utilize at least a minimum transmission baud rate; iv) all transceivers120must utilize at most a maximum transmission baud rate; v) all transceivers124must utilize a same transmission baud rate; vi) all transceivers124must utilize at least a minimum transmission baud rate; vii) all transceivers124must utilize at most a maximum transmission baud rate; etc. In other embodiments, each of one or more transceivers120is capable of transmitting only at the higher first baud rate and/or is capable of receiving only at the lower second baud rate, or vice versa. Similarly, in some embodiments, each of one or more transceivers124is capable of receiving only at the higher first baud rate and/or is capable of transmitting only at the lower second baud rate, or vice versa. FIG.3is a simplified block diagram of an example transceiver300that is configured to transmit at a first baud rate while simultaneously receiving at a second baud rate that is lower than the first baud rate, according to an embodiment. The transceiver300is utilized for each of at least some of the transceivers120ofFIG.1, according to some embodiments, andFIG.3is described with reference toFIG.1for explanatory purposes. In other embodiments, the transceiver300is utilized in another suitable communication system different from the communication system100ofFIG.1, and/or the some or all of the transceivers120ofFIG.1correspond to a suitable transceiver different from the example transceiver300ofFIG.3. According to an embodiment, the transceiver300is coupled to a cable112, for example via suitable cable connectors (not shown), such as male and female RJ45 connectors, male and female M12 connectors, etc. The transceiver300comprises transmit circuitry304that is configured to transmit at a first baud rate. In some embodiments, the first baud rate corresponds to a signal bandwidth that exceeds a maximum frequency rating of the cable112. In an embodiment, the first baud rate is approximately 800 Megasymbols per second (MSps) (i.e., 800 MSps±8 MSps). In another embodiment, the first baud rate is approximately 400 MSps (i.e., 400 MSps±4 MSps). More generally, a minimum required bandwidth corresponding to the first baud rate exceeds a maximum frequency rating of the cable112, according to some embodiments. For example, the cable112is a legacy cable having a maximum frequency rating that is less than the minimum required bandwidth corresponding to the first baud rate, according to some embodiments. The transceiver300also comprises receive circuitry308that is configured to receive at a second baud rate that is lower than the first baud rate. In an embodiment, the second baud rate is approximately 125 MSps (i.e., 125 MSps±1 MHz). In another embodiment, the second baud rate is approximately 200 MSps (i.e., 200 MSps±2 MSps). In another embodiment in which the first baud rate is approximately 800 MSps, the second baud rate is approximately 400 MSps (i.e., 400 MSps±4 MSps). In some embodiments, a minimum required bandwidth corresponding to the second baud rate is less than or equal to a maximum frequency rating of the cable112, according to some embodiments. For example, the cable112is a legacy cable having a maximum frequency rating that is greater than or equal to the minimum required bandwidth corresponding to the second baud rate, according to some embodiments. The transmit circuitry304transmits at the first baud rate simultaneously with the receive circuitry308receiving at the second baud rate. One transmit circuitry block304and one receive circuitry block308are illustrated inFIG.3to simplify the figure. However, in embodiments in which the cable112includes multiple twisted wire pairs, the transceiver300comprises a respective transmit circuitry block304and a respective receive circuitry block308for each twisted wire pair in the cable112. For instance, each transmit circuitry block304generates a respective transmit signal for a respective twisted wire pair, and each receive circuitry block308processes a respective receive signal from a respective twisted wire pair. Thus, for a cable112that comprises four twisted wire pairs, the transceiver300comprises four transmit circuitry blocks304and four receive circuitry blocks308, according to an embodiment. The transmit circuitry304is coupled to the cable112via a hybrid circuit312, and the receive circuitry308is coupled to the cable112via the hybrid circuit312. The hybrid circuit312is configured to pass a transmit signal generated by the transmit circuitry304to the cable112, and to prevent the transmit signal from passing to the receive circuitry308. Additionally, the hybrid circuit312is configured to pass a receive signal received from the cable112to the receive circuitry308. In an embodiment, the hybrid circuit312is configured to prevent the receive signal from passing to the transmit circuitry304. The transceiver300comprises an echo canceller316that is configured to reduce echo associated with full duplex communications. In an embodiment, the echo canceller316is configured to generate a respective correction signal for each receive circuitry block308. In an embodiment, the echo canceller316is configured to generate the one or more correction signal using respective signals generated by the respective transmit circuitry blocks304. The transmit circuitry304comprises an error correction encoder332that encodes information bits that are to be transmitted (“transmit bits”) via the cable112according to a suitable error correction code to generate encoded transmit bits. In an illustrative embodiment, the error correction encoder332is configured to encode the transmit bits according to a low-density parity check (LDPC) code. In other embodiments, the error correction encoder332is configured to encode the transmit bits according to another suitable error correction code. The transmit circuitry304also comprises a modulation symbol mapper336that is configured to map the encoded transmit bits to modulation symbols. In some embodiments, the modulation symbol mapper336is also configured to implement Tomlinson-Harashima precoding (THP) (“modulation symbol mapper/THP336”). In an embodiment, the modulation symbol mapper336outputs modulation symbols at the first baud rate. The transmit circuitry304further comprises a digital-to-analog converter (DAC)340that is configured to convert the output of the modulation symbol mapper336to an analog transmit signal for transmission via the cable112. The receive circuitry308comprises an analog lowpass filter354coupled to the hybrid circuit512. The receive circuitry308also comprises an analog-to-digital converter (ADC)360coupled to the lowpass filter354, The ADC360is configured to convert an analog receive signal (received via the cable112) to a digital receive signal. In an embodiment, the analog lowpass filter354is an antialiasing filter that is configured to attenuate high frequency components of the receive signal prior to sampling by the ADC360to attenuate aliasing of the high frequency components caused by the sampling process. The receive circuitry308also comprises a summation circuit364that is configured to add a correction signal generated by the echo canceller316to the digital receive signal to mitigate crosstalk from one or more transmits signals generated by the transmit circuitry blocks304. The receive circuitry308further comprises demodulator/equalizer368that is configured to equalize the digital receive signal and to convert modulation symbols to encoded information bits. The receive circuitry308also comprises an error correction decoder372that generates receive bits by decoding, according to the error correction code used by a transmitter, encoded information bits that are output by the demodulator/equalizer368. In an illustrative embodiment, the error correction encoder372is configured to decode the encoded receive bits according to an LDPC code. In other embodiments, the error correction decoder372is configured to decode the encoded receive bits according to another suitable error correction code. The receive circuitry308further comprises a digital lowpass filter384that is configured to attenuate components of alien crosstalk at high frequencies caused by transmissions at the first baud rate in other cables112. Referring toFIGS.1and3, if the transceiver300(FIG.3) corresponds to the transceiver120-2(FIG.1), the digital lowpass filter384is configured to attenuate components of alien crosstalk at high frequencies caused at least by transmissions by the transceiver120-1and the transceiver120-3at the first baud rate in cables112-1and112-3, respectively, according to an illustrative embodiment. Similarly, if the transceiver300(FIG.3) corresponds to the transceiver120-1(FIG.1), the digital lowpass filter384is configured to attenuate components of alien crosstalk at high frequencies caused at least by transmissions by the transceiver120-2at the first baud rate in the cable112-2, according to another illustrative embodiment. Similarly, if the transceiver300(FIG.3) corresponds to the transceiver120-3(FIG.1), the digital lowpass filter384is configured to attenuate components of alien crosstalk at high frequencies caused at least by transmissions by the transceiver120-2at the first baud rate in the cable112-2, according to another illustrative embodiment. In an embodiment, the digital lowpass filter384is configured to significantly attenuate (i.e., at least by −6 dB) at frequencies above a suitable cutoff frequency. In some embodiments, the cutoff frequency will vary depending on the first baud rate and the second baud rate used by the transceiver300. In other embodiments, the cutoff frequency will vary depending on i) the second baud rate, and ii) a third baud rate of another signal being transmitted in another cable (not shown) and that is causing crosstalk in the receive signal received by the receive circuitry308, the other signal being transmitted by another transceiver (not shown) at the third baud rate. In some embodiments in which multiple lowpass filters are included (described further below), the multiple lowpass filters together significantly attenuate at frequencies above the cutoff frequency. In some embodiments, the digital lowpass filter384is coupled between the summation circuit364and the demodulator/equalizer368to filter the digital receive signal prior to the digital receive signal being processed by the demodulator/equalizer368, In some embodiments, the digital lowpass filter384is coupled between the demodulator/equalizer368and the error correction decoder372to filter the digital receive signal prior to the digital receive signal being processed by the error correction decoder372. In some embodiments, the digital lowpass filter384is coupled between the ADC360and the summation circuit364to filter the digital receive signal prior to the digital receive signal being processed by the summation circuit364. in some embodiments, the digital lowpass filter384is implemented as multiple digital lowpass filters located at two or more of the following locations: i) between the ADC360and the summation circuit364, ii) between the summation circuit364and the demodulator/equalizer368, iii) between the demodulator/equalizer368and the error correction decoder372, etc. In some embodiments, the digital lowpass filter384is omitted. For example, the analog lowpass filter354is configured to attenuate components of alien crosstalk at high frequencies to a sufficient degree, at least in some network implementations. As another example, in some network implementations, the level of high frequency components of the alien crosstalk, coupled with the higher robustness of the receive signal at the slower second baud rate (as compared to the transmit signal at the faster first baud rate), is at a level that provides an adequate error rate for the receive signal without requiring the use of the digital lowpass filter384. In operation (in the example network100ofFIG.1, the transceiver300is located at the network device104, according to an embodiment), the transmit circuitry304generates a transmit signal at the first baud rate for transmission via the cable112, and, simultaneously, the receive circuitry308receives and processes a receive signal that was transmitted via the cable112at the second baud rate that is slower than the first baud rate. As discussed above, the largest component of alien crosstalk experienced by the receive circuitry308typically is near-end alien crosstalk caused by transmissions of one or more other transceivers located near the transceiver300, However, because the receive signal was transmitted at the lower second baud rate, the lowpass filter(s)384is able to remove higher frequency components of the near-end alien crosstalk, whereas lower frequency components of the near-end alien crosstalk are at lower PSDs (compared to the higher frequency components of the near-end alien crosstalk) and thus do not adversely affect decoding of the receive signal to a significant degree. In some embodiments in which the digital lowpass filter384is omitted, the analog lowpass filter354is configured to attenuate high frequency components of the alien crosstalk to a sufficient degree. In other embodiments in which the digital lowpass filter384is omitted, the level of high frequency components of the alien crosstalk, coupled with the higher robustness of the receive signal at the slower second baud rate (as compared to the transmit signal at the faster first baud rate), is at a level that provides an adequate error rate for the receive signal. In some embodiments, the transmit circuitry304is configured to transmit using a baud rate corresponding to a minimum bandwidth that exceeds a maximum bandwidth rating of the cable112. In some embodiments, the transmit circuitry304is configured to transmit using a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the cable112by at least 75 MHz. In other embodiments, the transmit circuitry304is configured to transmit using a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the cable112by at least 100 MHz. In other embodiments, the transmit circuitry304is configured to transmit using a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the cable112by at least 250 MHz. In some embodiments, the receive circuitry308additionally is configured to receive at a baud rate corresponding to a minimum bandwidth that is less than or equal to the maximum bandwidth rating of the cable112. In some embodiments, one or more (or all) of the error correction encoder332, the modulation symbol mapper/THP336, the echo canceller316, the digital lowpass filter384(if included), the summation circuit364, the demodulator/equalizer368, and the error correction decoder372are implemented using respective digital circuitry; and/or one or more (or all) of the error correction encoder332, the modulation symbol mapper/THP336, the echo canceller316, the digital lowpass filter384(if included), the summation circuit364, the demodulator/equalizer368, and the error correction decoder372are implemented by one or more digital signal processors (DSPs) (not shown) that execute machine readable instructions stored in one or more memories (not shown) coupled to the one or more DSPs. In some embodiments, the transmit circuitry304is capable of transmitting at a plurality of different baud rates and/or the receive circuitry308is capable of receiving at a plurality of different baud rates. In some such embodiments, the digital lowpass filter384is configurable to implement lowpass filters with different cutoff frequencies appropriate for the baud rates being used by the transmit circuitry304and the receive circuitry308. In embodiments in which the transmit circuitry304is capable of transmitting at a second baud rate that is lower than a first baud rate at which the receive circuitry308is receiving, the receive circuitry308is configurable to deactivate the digital lowpass filter384(e.g., so that a signal passes through the digital lowpass filter384without being modified) or to bypass the digital lowpass filter384(e.g., so that a signal passes around the digital lowpass filter384without being modified). FIG.4is a simplified block diagram of an example transceiver400that is configured to receive at the first baud rate and while simultaneously transmitting at the second baud rate that is lower than the first baud rate, according to an embodiment. The transceiver400is utilized for each of at least some of the transceivers124in the endpoint devices108ofFIG.1, according to some embodiments, andFIG.4is described with reference toFIG.1for explanatory purposes. In other embodiments, the transceiver400is utilized in another suitable communication system different from the communication system100ofFIG.1, and/or the some or all of the transceivers124of Fig,1correspond to a suitable transceiver different from the example transceiver400ofFIG.4. According to an embodiment, the transceiver400is coupled to a cable112, for example via suitable cable connectors (not shown), such as male and female RJ45 connectors, male and female M12 connectors, etc. The transceiver400comprises transmit circuitry404that is configured to transmit at the second baud rate that is lower than the first baud rate. For example, the second baud rate is approximately 125 MSps (i.e., 125 MSps±1 MSps). The transceiver400also comprises receive circuitry408that is configured to receive at the first baud rate that corresponds to a signal bandwidth that exceeds a maximum frequency rating of the cable112. For example, the first baud rate is approximately 800 MSps (i.e., 800 MSps±8 MSps), according to an embodiment. The transmit circuitry404transmits at the second baud rate simultaneously with the receive circuitry408receiving at the first baud rate. One transmit circuitry block404and one receive circuitry block408are illustrated inFIG.4to simplify the figure. However, in embodiments in which the cable112includes multiple twisted wire pairs, the transceiver400comprises a respective transmit circuitry block404and a respective receive circuitry block408for each twisted wire pair in the cable112, according to an embodiment. For instance, each transmit circuitry block404generates a respective transmit signal for a respective twisted wire pair, and each receive circuitry block408processes a respective receive signal from a respective twisted wire pair. Thus, for a cable112that comprises four twisted wire pairs, the transceiver400comprises four transmit circuitry blocks404and four receive circuitry blocks408, according to an embodiment. The transmit circuitry404is coupled to the cable112via a hybrid circuit412, and the receive circuitry408is coupled to the cable112via the hybrid circuit412. The hybrid circuit412is configured to pass a transmit signal generated by the transmit circuitry404to the cable112, and to prevent the transmit signal from passing to the receive circuitry408. Additionally, the hybrid circuit412is configured to pass a receive signal received from the cable112to the receive circuitry408. In an embodiment, the hybrid circuit412is configured to prevent the receive signal from passing to the transmit circuitry404. The transceiver400comprises an echo canceller416that is configured to reduce echo associated with full duplex communications. In an embodiment, the echo canceller416is configured to generate a respective correction signal for each receive circuitry block408. In an embodiment, the echo canceller416is configured to generate the one or more correction signal using respective signals generated by the respective transmit circuitry blocks404. The transmit circuitry404comprises an error correction encoder432that encodes information bits that are to be transmitted (“transmit bits”) via the cable112according to a suitable error correction code to generate encoded transmit bits. In an illustrative embodiment, the error correction encoder432is configured to encode the transmit bits according to an LDPC code. In other embodiments, the error correction encoder432is configured to encode the transmit bits according to a Reed-Solomon code or another suitable error correction code. The transmit circuitry404also comprises a modulation symbol mapper436that is configured to map the encoded transmit bits to modulation symbols. In some embodiments, the modulation symbol mapper436is also configured to implement THP (“modulation symbol mapper/THP436”). In an embodiment, the modulation symbol mapper436outputs modulation symbols at the second baud rate. The transmit circuitry404further comprises a DAC440that is configured to convert the output of the modulation symbol mapper436to an analog transmit signal for transmission via the cable112. The receive circuitry408comprises an ADC460that is configured to convert an analog receive signal (received via the cable112) to a. digital receive signal. The receive circuitry408also comprises a summation circuit464that is configured to add a correction signal generated by the echo canceller416to the digital receive signal to mitigate crosstalkfrom one or more transmits signals generated by the transmit circuitry blocks404. The receive circuitry408further comprises demodulator/equalizer468that is configured to equalize the digital receive signal and to convert modulation symbols to encoded information bits. The receive circuitry408also comprises an error correction decoder472that generates receive bits by decoding, according to the error correction code used by a transmitter, encoded information bits that are output by the demodulator/equalizer468. In an illustrative embodiment, the error correction encoder472is configured to decode the encoded receive bits according to an LDPC code. In another illustrative embodiment, the error correction encoder472is configured to decode the encoded receive bits according to a Reed-Solomon code. In other embodiments, the error correction decoder472is configured to decode the encoded receive bits according to another suitable error correction code. In operation, the transmit circuitry404generates a transmit signal at the second baud rate (which is slower than the first baud rate) for transmission via the cable112, and, simultaneously, the receive circuitry408receives and processes a receive signal that was transmitted via the cable112at the first baud rate. As discussed above, the largest component of alien crosstalk experienced by the receive circuitry408typically is near-end alien crosstalk caused by transmissions of one or more other transceivers located near the transceiver400. However, because signals transmitted by other transceivers located near the transceiver400were transmitted at the lower second baud rate, alien crosstalk caused by such signals do not adversely affect decoding of the receive signal to a significant degree. Additionally, because the transmit signal generated and transmitted by the transmit circuitry404at the lower second baud rate, alien crosstalk caused by the transmit signal do not adversely affect to a significant degree decoding of receive signals at other transceivers located near the transceiver400. In some embodiments, one or more (or all) of the error correction encoder432, the modulation symbol mapper/THP436, the echo canceller416, the summation circuit464, the demodulator/equalizer468, and the error correction decoder472are implemented using respective digital circuitry; and/or one or more (or all) of the error correction encoder432, the modulation symbol mapper/THP436, the echo canceller416, the summation circuit464, the demodulator/equalizer468, and the error correction decoder472are implemented by one or more DSPs (not shown) that execute machine readable instructions stored in one or more memories (not shown) coupled to the one or more DSPs. In some embodiments, the receive circuitry408is configured to receive at a. baud rate corresponding to a minimum bandwidth that exceeds a maximum bandwidth rating of the cable112. In some embodiments, the receive circuitry408is configured to receive at a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the cable112by at least 75 MHz. In other embodiments, the receive circuitry408is configured to receive at a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the cable112by at least 100 MHz. In other embodiments, the receive circuity408is configured to receive at a baud rate corresponding to a minimum bandwidth that exceeds the maximum bandwidth rating of the cable112by at least 250 MHz. In some embodiments, the transmit circuitry404additionally is configured to transmit at a baud rate corresponding to a minimum bandwidth that is less than or equal to the maximum bandwidth rating of the cable112. In some embodiments, the transmit circuitry404is capable of transmitting at a plurality of different baud rates and/or the receive circuitry408is capable of receiving at a plurality of different baud rates. in some such embodiments, the transceiver400includes one or more digital lowpass filters (not shown) similar to the digital lowpass filter384discussed above with reference toFIG.3. In scenarios in which the transmit circuitry404transmits at a second baud rate that is lower than a first baud rate at which the receive circuitry408is receiving, the receive circuitry408is configurable to deactivate the digital lowpass filter(s) (e.g., so that a signal passes through the digital lowpass filter without being modified) or to bypass the digital lowpass filter(s) (e.g., so that a signal passes around the digital lowpass filter384without being modified). Similarly, in scenarios in which the transmit circuitry404transmits at a first baud rate that is higher than a second baud rate at which the receive circuitry408is receiving, the receive circuitry408is configurable to activate the digital lowpass filter(s) to reduce alien cross talk in a manner similar to the digital lowpass filter354discussed above with reference toFIG.3. FIG.5is a flow diagram of an example method500for communicating via a first cable, according to an embodiment. In an embodiment, the method500is implemented by the network device104ofFIG.1, and the method500is described with reference toFIG.1for ease of explanation. In another embodiment, the method500is implemented by one of the endpoint devices108ofFIG.1. In other embodiments, the method500is implemented by a suitable network device different from the network device104and the endpoint devices108ofFIG.1. In an embodiment, the method500is implemented using the transceiver300ofFIG.3, and the method500is described with reference toFIG.3for ease of explanation. in other embodiments, however, the method500is implemented using a suitable transceiver different from the transceiver300ofFIG.3. In some embodiments in which an amount of data transmitted in a downlink direction within a communication network is higher than an amount of data transmitted in an uplink direction within the communication network, the method500is implemented at a transceiver that transmits in the downlink direction. In some embodiments in which an amount of data transmitted in an uplink direction within a communication network is higher than an amount of data transmitted in a downlink direction within the communication network, the method500is implemented at a transceiver that ansmits its the uplink direction. At block504, a first transceiver of a first network device transmits a first signal via the first cable at a first baud rate. The first transceiver transmitting the first signal at block504comprises the transceiver120-2(FIG.1) transmitting a first signal via the cable112-2at the first baud rate, according to an embodiment. The first transceiver transmitting the first signal at block504comprises the transceiver300(FIG.3) transmitting a first signal via the cable112at the first baud rate, according to another embodiment. In an embodiment, the first cable is a first legacy cable that is not rated to support a minimum required bandwidth corresponding to the first baud rate, at least for a length of the first legacy cable and/or for deployments in which alien crosstalk is at issue. In an embodiment, the first cable is a first legacy cable with a maximum frequency rating that is at most 50% of the minimum required bandwidth corresponding to the first baud rate (i.e., the minimum required bandwidth corresponding to the first baud rate is at least 200% more than the maximum frequency rating of the first legacy cable). In other respective embodiments, the first cable is a first legacy cable with a maximum frequency rating of at most 25%, or at most 60% of the minimum required frequency corresponding to the first baud rate (i.e., the first baud rate is at least 400% or 167%, respectively, of the maximum frequency rating of the first legacy cable). In an embodiment, the first cable is a Class D cable according to the current ISO/IEC 11801 Standard or a non-current version of the ISO/fEC 11801 Standard. In another embodiment, the first cable is a Class C cable according to the ISO/IEC 11801 Standard. In another embodiment, the first cable is a Class E cable according to the ISO/IEC 11801 Standard. In an embodiment, the first baud rate is approximately 800 MSps. In an embodiment, the first baud rate corresponds to a first data rate of 10 Gbps. In another embodiment, the first baud rate is approximately 400 MSps. In an embodiment, the first baud rate corresponds to a first data rate of 5 Gbps. At block508, concurrently with transmitting the first signal at block504, the first transceiver receives a second signal via the first cable, the second signal having been transmitted by a second network device at a second baud rate that is lower than both i) the first baud rate and ii) a third baud rate (discussed further below). The first transceiver receiving the second signal at block508comprises the transceiver120-2(FIG.1) receiving a second signal via the cable112-2at the second baud rate, according to an embodiment. The first transceiver receiving the second signal at block508comprises the transceiver300(FIG.3) receiving a second signal via the cable112at the second baud rate, according to another embodiment. In an embodiment, the first cable has a maximum frequency rating that is greater than or equal to a minimum required bandwidth of the second baud rate. In an embodiment, the second baud rate is approximately 100 MSps (i.e., 100 MSps±1 MSps). In another embodiment, the second baud rate is approximately 200 MSps (i.e., 200 MSps±2 MSps). In another embodiment in which the first baud rate is approximately 800 MSps and the third baud rate is also approximately 800 MSps, the second baud rate is approximately 400 MSps (i.e., 400 MSps±4 MSps). In an embodiment, the third baud rate is approximately 800 MSps. In an embodiment, the third baud rate corresponds to a second data rate of 10 Gbps via the multiple second pairs of twisted wires of the second cable. In another embodiment, the third baud rate is approximately 400 MSps. In an embodiment, the third baud rate corresponds to a second data rate of 5 Ghps via the multiple second pairs of twisted wires of the second cable. In some embodiments, the third baud rate is the same as the first baud rate. In other embodiments, the third baud rate is different than the first baud rate. At block516, the first transceiver lowpass filters the second signal received at block508to attenuate crosstalk in the second signal caused by transmission of a third signal at the third baud rate in a second cable. The first transceiver lowpass filtering the second signal at block516comprises the transceiver120-2(FIG.1) lowpass filtering the second signal, according to an embodiment. The first transceiver lowpass filtering the second signal at block516comprises the transceiver300(FIG.1) lowpass filtering the second signal using one or both of i) the analog lowpass filter380and ii) the digital lowpass filter384, according to an embodiment. In an embodiment, the second cable is a second legacy cable that is not rated to support a minimum required bandwidth corresponding to the third baud rate, at least for a length of the second legacy cable and/or for deployments in which alien crosstalk is at issue. In an embodiment, the second cable is a second legacy cable with a maximum frequency rating that is of at most 50% of the minimum required bandwidth corresponding to the third baud rate (i.e., the minimum required bandwidth corresponding to the third baud rate is at least 200% of the maximum frequency rating of the first legacy cable). In other respective embodiments, the second cable is a second legacy cable with a maximum frequency rating of at most 25%, or at most 60% of the minimum required bandwidth corresponding to the third baud rate (i.e., the minimum required bandwidth corresponding to the third baud rate is at least 400% or 167%, respectively, of the maximum frequency rating of the second legacy cable). in an embodiment, the second cable is a Class D cable according to the current ISO/IEC 11801 Standard or a non-current version of the ISO/IEC 11801 Standard. in another embodiment, the second cable is a Class C cable according to the ISO/IEC 11801 Standard. In another embodiment, the second cable is a Class E cable according to the ISO/TEC 11801 Standard. In some embodiments, the third signal is transmitted in the second cable by another communication device separate from the first communication device. In other embodiments, the first communication device transmits the third signal in the second cable. For example, in some embodiments, the method500further comprises: concurrently with transmitting the first signal at block504and receiving the second signal at block508, a second transceiver of the first network device transmitting the third signal at512at the third baud rate, and the second transceiver receiving a fourth signal via the second cable. The fourth signal is transmitted by a third network device at a fourth baud rate that is lower than both i) the first baud rate and ii) a third baud rate; and the second transceiver lowpass filters the fourth signal to attenuate crosstalk in the fourth signal caused by transmission of the first signal in the first cable at block504, according to an embodiment. In one embodiment in which the method500includes the second transceiver of the first network device receiving the fourth signal, the transceiver1204(FIG.1) receives the fourth signal via the cable112-1at the fourth baud rate, according to an embodiment. The second transceiver receiving the fourth signal comprises the transceiver300(FIG.3) receiving a fourth signal via the cable112at the fourth baud rate, according to another embodiment. In an embodiment, the fourth baud rate is approximately 100 MSps (i.e., 100 MSps±1 MSps). In another embodiment, the fourth baud rate is approximately 200 (i.e., 200 MSps±2 MSps). In another embodiment in which the first baud rate is approximately 800 MSps and the third baud rate is also approximately 800 MSps, the fourth baud rate is approximately 400 MHz (i.e., 400 MSps±4 MSps). In some embodiments, the fourth baud rate is the same as the second baud rate. In other embodiments, the fourth baud rate is different than the second baud rate. The second transceiver lowpass filtering the fourth signal comprises the transceiver120-1(FIG.1) lowpass filtering the fourth signal, according to an embodiment. The second transceiver lowpass filtering the fourth signal comprises the transceiver300(FIG.1) lowpass filtering the fourth signal using one or both of i) the analog lowpass filter380and ii) the digital lowpass filter384, according to an embodiment. In some embodiments, transmitting the first signal at block504comprises transmitting the first signal in a downlink direction to the second network device; receiving the second signal at block508comprises receiving the second signal in an uplink direction from the second network device; and the third signal is transmitted in the downlink direction to the third network device. In other embodiments, transmitting the first signal at block504comprises transmitting the first signal in an uplink direction to the second network device; receiving the second signal at block508comprises receiving the second signal in a downlink direction from the second network device; and the third signal is transmitted in the uplink direction to the third network device, FIG.6is a flow diagram of an example method600for communicating via a first cable, according to an embodiment. In an embodiment, the method600is implemented by the endpoint device108-2ofFIG.1, and the method600is described with reference toFIG.1for ease of explanation. In another embodiment, the method600is implemented by the network device104ofFIG.1. In other embodiments, the method600is implemented by a suitable network device different from the network device104and the endpoint devices108ofFIG.1. In an embodiment, the method600is implemented using the transceiver400ofFIG.4, and the method600is described with reference toFIG.4for ease of explanation. In other embodiments, however, the method600is implemented using a suitable transceiver different from the transceiver400ofFIG.4. In some embodiments in which an amount of data transmitted in a downlink direction within a communication network is higher than an amount of data transmitted in an uplink direction within the communication network, the method600is implemented at a transceiver that transmits in the uplink direction. In some embodiments in which an amount of data transmitted in an uplink direction within a communication network is higher than an amount of data transmitted in a downlink direction within the communication network, the method600is implemented at a transceiver that transmits in the downlink direction. At block604, a transceiver of a first network device receives a first signal via the first cable, the first signal having been transmitted by a second network device at a. first baud rate. The transceiver receiving the first signal at block604comprises the transceiver124-2(FIG.1) receiving a first signal via the cable112-2at the first baud rate, according to an embodiment. The transceiver receiving the first signal at block604comprises the transceiver400(FIG.4) receiving a first signal via the cable112at the first baud rate, according to another embodiment. In an embodiment, the first cable is a first legacy cable that is not rated to support the first baud rate, at least for a length of the first legacy cable and/or for deployments in which alien crosstalk is at issue. In an embodiment, the first cable is a first legacy cable with a maximum frequency rating that is of at most 25% of the first baud rate the first baud rate is at least 400% of the maximum frequency rating of the first legacy cable). In other respective embodiments, the first cable is a first legacy cable with a maximum frequency rating of at most 33%, at most 15%, at most 12.5%, or at most 5% of the first baud rate (i.e., the first baud rate is at least 300%, 667%, 800%, or 2000%, respectively, of the maximum frequency rating of the first legacy cable), In an embodiment, the first cable is a Class D cable according to the current ISO/IEC 11801 Standard or a non-current version of the ISO/IEC 11801 Standard. In another embodiment, the first cable is a Class C cable according to the ISO IEC 11801 Standard. In another embodiment, the first cable is a Class E cable according to the ISO/IEC 11801 Standard. In an embodiment, the first baud rate is approximately 800 MSps. In an embodiment, the first baud rate corresponds to a first data rate of 10 Gbps via the multiple first pairs of twisted wires of the first cable. In another embodiment, the first baud rate is approximately 400 MSps. In an embodiment, the first baud rate corresponds to a first data rate of 5 Gbps via the multiple first pairs of twisted wires of the first cable. At block608, concurrently with receiving the first signal at block604, the transceiver transmits a second signal via the first cable at a second baud rate that is lower than the first baud rate to reduce crosstalk from the first cable into one or more second cables. The first transceiver transmitting the second signal at block608comprises the transceiver120-2(FIG.1) transmitting a second signal via the cable112-2at the second baud rate, according to an embodiment. The transceiver transmitting the second signal at block608comprises the transceiver400(FIG.4) transmitting a second signal via the cable112at the second baud rate, according to another embodiment. In an embodiment, the second baud rate is approximately 100 MSps (i.e., 100 MSps±1 MSps). In another embodiment, the second baud rate is approximately 200 MSps (i.e., 200 MSps±2 MSps). In another embodiment in which the first baud rate is approximately 800 MSps, the second baud rate is approximately 400 MSps (i.e., 400 MSps±4 MSps). In an embodiment, the first cable is rated to support the second baud rate. In some embodiments, receiving the first signal at block604comprises receiving the first signal in a downlink direction from the second network device; and transmitting the second signal at block608comprises transmitting the second signal in an uplink direction to the second network device. In other embodiments, receiving the first signal at block604comprises receiving the first signal in an uplink direction from the second network device; and transmitting the second signal at block608comprises transmitting the second signal in a downlink direction to the second network device. As discussed above, transmitting the second signal via the first cable at the second baud rate reduces crosstalk from the first cable into one or more second cables. In some embodiments, at least one of the second cables is coupled to the second network device. In other embodiments, at least one of the second cables is not coupled to second network device, but instead is coupled to a third network device. FIG.7is a flow diagram of another example method700for communicating via a first cable, according to an embodiment. In an embodiment, the method700is implemented by the network device104ofFIG.1, and the method700is described with reference toFIG.1for ease of explanation. In another embodiment, the method700is implemented by one of the endpoint devices108ofFIG.1, In other embodiments, the method700is implemented by a suitable network device different from the network device104and the endpoint devices108ofFIG.1. In an embodiment, the method700is implemented using the transceiver300ofFIG.3, and the method700is described with reference toFIG.3for ease of explanation. In other embodiments, however, the method700is implemented using a suitable transceiver different from the transceiver300ofFIG.3. In some embodiments in which an amount of data transmitted in a downlink direction within a communication network is higher than an amount of data transmitted in an uplink direction within the communication network, the method700is implemented at a transceiver that transmits in the downlink direction. In some embodiments in which an amount of data transmitted in an uplink direction within a communication network is higher than an amount of data transmitted in a downlink direction within the communication network, the method700is implemented at a transceiver that transmits in the uplink direction. At block704, a first transceiver of a first network device transmits a first signal via the first cable at a first baud rate that corresponds to a first minimum required bandwidth, the first minimum required bandwidth exceeding a maximum bandwidth rating of the first cable. The first transceiver transmitting the first signal at block704comprises the transceiver120-2(FIG.1) transmitting a first signal via the cable112-2at the first baud rate, according to an embodiment. The first transceiver transmitting the first signal at block704comprises the transceiver300(FIG.3) transmitting a first signal via the cable112at the first baud rate, according to another embodiment. In an embodiment, the first cable is a first legacy cable that is not rated to support the minimum required bandwidth corresponding to the first baud rate, at least for a length of the first legacy cable and/or for deployments in which alien crosstalk is at issue. In an embodiment, the first cable is a first legacy cable with a maximum frequency rating that is at most 50% of the minimum required bandwidth corresponding to the first baud rate (i.e., the minimum required bandwidth corresponding to the first baud rate is at least 200% more than the maximum frequency rating of the first legacy cable). In other respective embodiments, the first cable is a first legacy cable with a maximum frequency rating of at most 25%. or at most 60% of the minimum required frequency corresponding to the first baud rate (i.e., the first baud rate is at least 400% or 167%, respectively, of the maximum frequency rating of the first legacy cable). In an embodiment, the first cable is a Class D cable according to the current ISO/IEC 11801 Standard or a non-current version of the ISO/IEC 11801 Standard. In another embodiment, the first cable is a Class C cable according to the ISO/IEC 11801 Standard. In another embodiment, the first cable is a Class E cable according to the ISO/IEC 11801 Standard. In an embodiment, the first baud rate is approximately 800 MSps. In an embodiment, the first baud rate corresponds to a first data rate of 10 Gbps. In another embodiment, the first baud rate is approximately 400 MSps. In an embodiment, the first baud rate corresponds to a first data rate of 5 Gbps. At block708, concurrently with transmitting the first signal at block504, the first transceiver receives a second signal via the first cable, the second signal having been transmitted by a second network device at a second baud rate that is lower than both i) the first baud rate and ii) a third baud rate at which a third signal is being transmitted in a second cable that causes crosstalk in the second signal being received via the first cable. In an embodiment, the second baud rate corresponds to a second minimum required bandwidth that is no more than the maximum bandwidth rating of the first cable. The third baud rate corresponds to a third minimum required bandwidth that exceeds a maximum bandwidth rating of the second cable, according to an embodiment. In another embodiment, the third minimum required bandwidth, in addition or alternatively to exceeding the maximum bandwidth rating of the second cable, exceeds the maximum bandwidth rating of the first cable. Reception of the second signal at the second baud rate that is i) lower than the third baud rate, and ii) is no more than the maximum bandwidth rating of the first cable, facilitates mitigation of the crosstalk in the second signal caused by transmission of the third signal in the second cable at the third baud rate. The first transceiver receiving the second signal at block708comprises the transceiver120-2(FIG.1) receiving a. second signal via the cable112-2at the second baud rate, according to an embodiment. The first transceiver receiving the second signal at block708comprises the transceiver300(FIG.3) receiving a second signal via the cable112at the second baud rate, according to another embodiment. In an embodiment, the second baud rate is approximately 100 MSps (i.e., 100 MSps±1 MSps). In another embodiment, the second baud rate is approximately 200 MSps (i.e., 200 MSps±2 MSps). In another embodiment in which the first baud rate is approximately 800 MSps and the third baud rate is also approximately 800 MSps, the second baud rate is approximately 400 MSps (i.e., 400 MSps±4 MSps). In an embodiment, the third baud rate is approximately 800 MSps. In an embodiment, the third baud rate corresponds to a second data rate of 10 Gbps via the multiple second pairs of twisted wires of the second cable. In another embodiment, the third baud rate is approximately 400 MSps. In an embodiment, the third baud rate corresponds to a second data rate of 5 Gbps via the multiple second pairs of twisted wires of the second cable. In some embodiments, the third baud rate is the same as the first baud rate. In other embodiments, the third baud rate is different than the first baud rate. In some embodiments, the method700further includes the first transceiver iowpass filtering the second signal received at block708to attenuate crosstalk in the second signal caused by transmission of the third signal at the third baud rate in the second cable, similar to block516ofFIG.5. In other embodiments, the method700does not require the first transceiver to lowpass filter the second signal received at block708to attenuate crosstalk in the second signal caused by transmission of the third signal at the third baud rate in the second cable. In an embodiment, the second cable is a second legacy cable that is not rated to support a minimum required bandwidth corresponding to the third baud rate, at least for a length of the second legacy cable and/or for deployments in which alien crosstalk is at issue. In an embodiment, the second cable is a second legacy cable with a maximum frequency rating that is of at most 50% of the minimum required bandwidth corresponding to the third baud rate (i.e., the minimum required bandwidth corresponding to the third baud rate is at least 200% of the maximum frequency rating of the first legacy cable). in other respective embodiments, the second cable is a second legacy cable with a maximum frequency rating of at most 25%, or at most 60% of the minimum required bandwidth corresponding to the third baud rate (i.e., the minimum required bandwidth corresponding to the third baud rate is at least 400% or 167%, respectively, of the maximum frequency rating of the second legacy cable). In an embodiment, the second cable is a Class L) cable according to the current ISO/IEC 11801 Standard or a non-current version of the ISO-IEC 11801 Standard. In another embodiment, the second cable is a Class C cable according to the ISO/IEC 11801 Standard. In another embodiment, the second cable is a Class E cable according to the ISO/IEC 11801 Standard. In some embodiments, the third signal is transmitted in the second cable by another communication device separate from the first communication device. In other embodiments, the first communication device transmits the third signal in the second cable. For example, in some embodiments, the method700further comprises: concurrently with transmitting the first signal at block704and receiving the second signal at block708, a. second transceiver of the first network device transmitting the third signal at the third baud rate, and the second transceiver receiving a fourth signal via the second cable. The fourth signal is transmitted by a third network device at a fourth baud rate that is lower than both i) the first baud rate and ii) a third baud rate, according to an embodiment. In some embodiments, the method700further comprises the second transceiver lowpass filtering the fourth signal to attenuate crosstalk in the fourth signal caused by transmission of the first signal in the first cable at block704 In some embodiments, transmitting the first signal at block704comprises transmitting the first signal in a downlink direction to the second network device; receiving the second signal at block708comprises receiving the second signal in an uplink direction from the second network device; and the third signal is transmitted in the downlink direction to the third network device. In other embodiments, transmitting the first signal at block704comprises transmitting the first signal in an uplink direction to the second network device; receiving the second signal at block708comprises receiving the second signal in a downlink direction from the second network device; and the third signal is transmitted in the uplink direction to the third network device. Although embodiments described above utilize cables comprising one or more twisted wire pairs, other embodiments utilize other suitable cables having a metallic transmission medium, such as coaxial cables. In embodiments in which coaxial cables are used, transceivers such as described above are coupled to coaxial cables via suitable cable connectors (not shown), such as Bayorte-Neill-Concelman (BNC) connectors, etc. Embodiment 1: A first network device for communicating via a first cable, comprising: a first transmitter configured to transmit a first signal via, the first cable at a first baud rate that corresponds to a first minimum required bandwidth, the first minimum required bandwidth exceeding a maximum bandwidth rating of the first cable; and a first receiver configured to receive a second signal via the first cable concurrently with transmitting the first signal via the first cable, the second signal having been transmitted by a second network device at a second baud rate that is lower than both i) the first baud rate and ii) a third baud rate at which a third signal is being transmitted in a second cable that causes crosstalk in the second signal being received via the first cable, wherein the second baud rate corresponds to a second minimum required bandwidth that is no more than the maximum bandwidth rating of the first cable, wherein the third baud rate corresponds to a third minimum required bandwidth that exceeds a maximum bandwidth rating of the second cable, and wherein reception of the second signal at the second baud. rate that is i) lower than the third baud rate, and ii) is no more than the maximum bandwidth rating of the first cable, facilitates mitigation of the crosstalk in the second signal caused by transmission of the third signal in the second cable at the third baud rate. Embodiment 2: The first network device of embodiment 1, wherein the third minimum required bandwidth exceeds the maximum bandwidth rating of the first cable. Embodiment 3: The first network device of either of embodiments 1 or 2, further comprising a lowpass filter configured to attenuate the crosstalk in the second signal caused by transmission of the third signal in the second cable at the third baud rate. Embodiment 4: The first network device of embodiment 3, wherein the lowpass filter comprises one or both of: i) one or more digital lowpass filters; and ii) an analog lowpass filter. Embodiment 5: The first network device of any of embodiments 1-3, further comprising: a second transmitter configured to transmit the third signal via the second cable at the third baud rate concurrently with i) transmitting the first signal via. the first cable and ii) receiving the second signal via the first cable; and a second receiver configured to receive a fourth signal via the second cable simultaneously with i) transmitting the first signal via the first cable, ii) receiving the second signal via the first cable, and iii) transmitting the third signal via the second cable, the fourth signal having been transmitted by a third network device at a fourth baud rate that is lower than both i) the first baud rate and ii) the third baud rate. Embodiment 6: The first network device of embodiment 5, further comprising: a first lowpass filter configured to attenuate the crosstalk in the second signal caused by transmission of the third signal in the second cable at the third baud rate; and a second lowpass filter configured to attenuate the crosstalk in the fourth signal caused by transmission of the first signal in the first cable at the first baud rate. Embodiment 7: The first network device of any of embodiments 1-6, wherein: the first transmitter is configured to transmit the first signal at a baud rate of approximately 800 Megasymbols per second (MSps); the first receiver is configured to receive the second signal at a baud rate of at most 400 MSps; and the third signal is transmitted at the baud rate of approximately 800 MSps. Embodiment 8: The first network device of any of embodiments 1-7, wherein: the first transmitter is configured to transmit the first signal to the second network device via the first cable in a downlink direction; the first receiver is configured to receive the second signal from the second network device via the first cable in an uplink direction; and the third signal is transmitted via the second cable in the downlink direction. Embodiment 9: The first network device of any of embodiments 1-7, wherein: the first transmitter is configured to transmit the first signal to the second network device via the first cable in an uplink direction; the first receiver is configured to receive the second signal from the second network device via the first cable in a downlink direction; and the third signal is transmitted via the second cable in the uplink direction. Embodiment 10: A method for communicating via a first cable, the method comprising: transmitting, by a first transceiver of a first network device, a first signal via. the first cable at a first baud rate that corresponds to a first minimum required bandwidth, the first minimum required bandwidth exceeding a maximum bandwidth rating of the first cable; concurrently with transmitting the first signal via the first cable, receiving, by the first transceiver, a second signal via the first cable, the second signal having been transmitted by a second network device at a second baud rate that is lower than both i) the first baud rate and ii) a third baud rate at which a third signal is being transmitted in a second cable that causes crosstalk in the second signal being received via the first cable, wherein the second baud rate corresponds to a second minimum required bandwidth that is no more than the maximum bandwidth rating of the first cable, wherein the third baud rate corresponds to a third minimum required bandwidth that exceeds a maximum bandwidth rating of the second cable, and wherein reception of the second signal at the second baud rate that is i) lower than the third baud rate, and ii) is no more than the maximum bandwidth rating of the first cable, facilitates mitigation of the crosstalk in the second signal caused by transmission of the third signal in the second cable at the third baud rate. Embodiment 11: The method of embodiment 10, wherein the third minimum required bandwidth exceeds the maximum bandwidth rating of the first cable. Embodiment 12: The method of either of embodiments 10 or 11, further comprising: lowpass filtering, at the first transceiver, the second signal to attenuate the crosstalk in the second signal caused by transmission of the third signal in the second cable at the third baud rate. Embodiment 13: The method of embodiment 12, wherein lowpass filtering the second signal to attenuate the crosstalk in the second signal caused by transmission of the third signal in the second cable at the third baud rate comprises one or both of: i) lowpass filtering a digital signal that correspond to the second signal with one or more digital lowpass filters; and ii) lowpass filtering an analog signal that correspond to the second signal with an analog lowpass filter. Embodiment 14: The method of any of embodiments 10-12, further comprising: concurrently with i) transmitting the first signal via the first cable and ii) receiving the second signal via the first cable, transmitting, by a second transceiver of the first network device, the third signal via the second cable at the third baud rate; and concurrently with i) transmitting the first signal via the first cable, ii) receiving the second signal via the first cable, and iii) transmitting the third signal via the second cable, receiving, by the second transceiver, a fourth signal via the second cable, the fourth signal having been transmitted by a third network device at a fourth baud rate that is lower than both i) the first baud rate and ii) the third baud rate. Embodiment 15: The method of embodiment 14, further comprising: lowpass filtering, at the first transceiver, the second signal to attenuate the crosstalk in the second signal caused by transmission of the third signal in the second cable at the third baud rate; and lowpass filtering, at the second transceiver, the fourth signal to attenuate the crosstalk in the fourth signal caused by transmission of the first signal in the first cable at the first baud rate. Embodiment 16: The method of any of embodiments 10-15, wherein: transmitting the first signal via the first cable comprises transmitting the first signal at a baud rate of approximately 800 Megasymbols per second (MSps); receiving the second signal via the first cable comprises receiving the second signal at a baud rate of at most 400 MSps; and the third signal is transmitted via the second cable at the baud rate of approximately 800 MSps. Embodiment 17: The method of any of embodiments 10-16, wherein: transmitting the first signal via the first cable comprises transmitting the first signal to the second network device in a downlink direction; receiving the second signal via the first cable comprises receiving the second signal from the second network device in an uplink direction; and the third signal is transmitted via the second cable in the downlink direction. Embodiment 18: The method of any of embodiments 10-16, wherein: transmitting the first signal via the first cable comprises transmitting the first signal to the second network device in an uplink direction; receiving the second signal via the first cable comprises receiving the second signal from the second network device in a downlink direction; and the third signal is transmitted via, the second cable in the uplink direction. Embodiment 19: A first network interface for communicating via a first cable, comprising: a receiver configured to receive a first signal via the first cable, the first signal having been transmitted by a second network device at a first baud rate; and a transmitter configured to transmit, concurrently with the receiver receiving the first signal at the first baud rate, a second signal via the first cable at a second baud rate that is lower than the first baud rate to reduce crosstalk, caused by transmission of the second signal in the first cable, into one or more second cables. Embodiment 20: The first network interface of embodiment 19, wherein: the receiver configured to receive the first signal at a first baud rate that corresponds to a minimum required bandwidth that exceeds a maximum frequency rating of the first cable; and the transmitter is configured to transmit, concurrently with the receiver receiving the first signal at the first baud rate, the second signal at a second baud rate that corresponds to a minimum required bandwidth that is less than or equal to the maximum frequency rating of the first cable. Embodiment 21: The first network device of either of embodiments 19 or 20, wherein: the receiver is configured to receive the first signal at a baud rate of approximately 800 Megasymbols per second (MSps); and the transmitter is configured to transmit, concurrently with the receiver receiving the first signal at the first baud rate, the second signal at a baud rate of at most 400 MSps. Embodiment 22: The first network device of any of embodiments 19-21, wherein: the receiver is configured to receive the first signal from the second network device via the first cable in a downlink direction; and the transmitter is configured to transmit the second signal to the second network device via the first cable in an uplink direction. Embodiment 23: The first network device of any of embodiments 19-21, wherein: the receiver is configured to receive the first signal from the second network device via the first cable in an uplink direction; and the transmitter is configured to transmit the second signal to the second network device via the first cable in a downlink direction. Embodiment 24: A method for communicating via a first cable, the method comprising: receiving, at a transceiver of a first network device, a first signal via the first cable, the first signal having been transmitted by a second network device at a first baud rate; and concurrently with receiving the first signal via the first cable, transmitting, by the transceiver, a second signal via the first cable at a second baud rate that is lower than the first baud rate to reduce crosstalk, caused by transmission of the second signal in the first cable, into one or more second cables. Embodiment 25: The method of embodiment 24, wherein: receiving the first signal via the first cable comprises receiving the first signal at a first baud rate that corresponds to a minimum required bandwidth that exceeds a maximum frequency ratii g of the first cable; and transmitting the second signal via the first cable comprises transmitting the second signal at a second baud rate that corresponds to a minimum required bandwidth that is less than or equal to the maximum frequency rating of the first cable. Embodiment 26: The method of either of embodiments claim 24 or 25, wherein: receiving the first signal via the first cable comprises receiving the first signal via a first Class D cable that i) complies with the ISO/IEC 11801 Standard for 100 MHz applications and ii) does not comply with the ISO/IEC 11801 Standard for frequencies above 100 MHz applications; and transmitting the second signal via the first cable comprises transmitting the second signal via the first Class D cable at the second baud rate that is lower than the first baud rate to reduce cross talk from the first Class D cable into one or more second Class D cables. Embodiment 27: The method of any of embodiments 24-26, wherein: receiving the first signal via the first cable comprises receiving the first signal at a baud rate of approximately 800 Megasymbols per second (MSps); and transmitting the second signal via the first cable comprises transmitting., concurrently with receiving the first signal at the baud rate of approximately 800 MSps, the second signal at a baud rate of at most 400 MSps. Embodiment 28: The method of any of embodiments 24-26, wherein: receiving the first signal via the first cable comprises receiving the first signal at a baud rate of approximately 400 Megasymbols per second (MSps); and transmitting the second signal via the first cable comprises transmitting, concurrently with receiving the first signal at the baud rate of approximately 400 MSps, the second signal at a baud rate of at most 100 MSps. Embodiment 29: The method of any of embodiments 24-28, wherein: receiving the first signal via the first cable comprises receiving the first signal from the second network device via the first cable in a downlink direction; and transmitting the second signal via the first cable comprises transmitting the second signal to the second network device via the first cable in an uplink direction. Embodiment 30: The method of any of embodiments 24-28, wherein: receiving the first signal via the first cable comprises receiving the first signal from the second network device via the first cable in an uplink direction; and transmitting the second signal via the first cable comprises transmitting the second signal to the second network device via the first cable in a downlink direction. At least some of the various blocks, operations, and technicies described above may be implemented utilizing hardware, a processor executing firmware instructions, a processor executing software instructions, or any combination thereof. When implemented utilizing a processor executing software or firmware instructions, the software or firmware instructions may be stored in any computer readable memory coupled to the processor, such as a RAM, a ROM, a flash memory, etc. The software or firmware instructions may include machine readable instructions that, when executed by one or more processors, cause the one or more processors to perform various acts. When implemented in hardware, the hardware may comprise one or more of discrete components, an integrated circuit, an application-specific integrated circuit (ASIC), a programmable logic device (PLD), etc. While the present invention has been described with reference to specific examples, which are intended to be illustrative only and not to be limiting of the invention, changes, additions and/or deletions may be made to the disclosed embodiments without departing from the scope of the invention. | 87,871 |
11943006 | DETAILED DESCRIPTION OF THE EMBODIMENTS Embodiments to carry out a wireless communication system and a flying object according to the present invention will be described below with reference to attached drawings. Herein, a flying object includes a manned or unmanned rocket, a missile, a manned or unmanned aircraft, an artificial satellite, and the like. First Embodiment A device that performs wireless communication may be arranged in a shield room covered with an electromagnetic wave reflector that blocks wireless communication using electromagnetic wave. A container that covers an internal space as a shield room will be referred to as “shield room forming section” for convenience. It should be noted that a shape of the shield room forming section is arbitrary. In addition, the internal space as the shield room of the shield room forming section may be completely closed, may have some gaps, and furthermore may include a mesh structure sized to block specific communication frequencies. In the present embodiment of wireless communication system, a leaky transmission line is used as a two-way transmission line of electromagnetic waves. That is, for example, a leaky transmission line is provided so as to pass through two shield rooms and a direct two-way wireless communication is performed through the leaky transmission line between two devices arranged inside respective shield rooms. Herein, it is to be noted that performing a two-way wireless communication without using any access point that mediates two devices is expressed as “direct”. A configuration example of a wireless communication system1according to an embodiment will be described with reference toFIG.1.FIG.1is a partial cross-sectional view that shows a configuration example of a wireless communication system1according to an embodiment. Components of the wireless communication system1inFIG.1will be described. The wireless communication system1is provided with a shield room forming section2, a leaky transmission line3, a plurality of devices4, a power supply5and a power supply line50. Herein, the shield room forming section2is provided with a first shield room forming section2A, a second shield room forming section2B and a barrier wall21. The first shield room forming section2A has a first internal space20A therein. Similarly, the second shield room forming section2B has a second internal space20B therein. It should be noted that although a number of shield room forming sections2A and2B included in the shield room forming section2is two in the configuration example shown inFIG.1, it may be three or more. It is needless to say that those numbers are merely examples and do not limit the present embodiment. The leaky transmission line3is provided with a plurality of leakage parts30, two ends and two line terminations391and392. In other words, two ends of the leaky transmission line3are terminated by two line terminations391and392, respectively. Herein, the plurality of leakage parts30include a first leakage part30A, a second leakage part30B and a third leakage part30C. However, when these leakage parts30A,30B and30C are not distinguished, they may be simply referred to as “leakage part(s)”30. It should be noted that the leaky transmission line3may further have a non-leakage part from where no electromagnetic wave leaks. Each of the plurality of devices4is provided with an antenna400and a wireless power receiving unit401. The plurality of devices4includes a first device41, a second device42and a third device43. The first device41is provided with a first antenna410and a first wireless power receiving unit411. Similarly, the second device42is provided with a second antenna420and a second wireless power receiving unit421. In addition, the third device43is provided with a third antenna430and a third wireless power receiving unit431. However, when these devices41,42and43are not distinguished, they may be simply referred to as “device(s)”4. Similarly, when these antennas410,420and430are not distinguished, they may be simply referred to as “antenna(s)”400. In addition, when these wireless power receiving units411,421and431are not distinguished, they may be simply referred to as “wireless power receiving unit(s)”401. The power supply line50is provided with a plurality of wireless power supply units51. The plurality of wireless power supply units51includes a first wireless power supply unit51A, a second wireless power supply unit51B and a third wireless power supply unit51C. However, when these wireless power supply units51A,51B and51C are not distinguished, they may be simply referred to as “wireless power supply unit(s)”51. It should be noted that although there is a variety of power transmitting methods for wireless power supply, such as magnetic field coupling type, electric field coupling type and microwave type, the present embodiment is not limited by them and may be of any type of those methods. In addition, the power supply line50may be a single path or may be branched into a plurality of branch portions. Connections and arrangement of components of the wireless communication system1inFIG.1will be described. In the configuration example inFIG.1, the first shield room forming section2A and the second shield room forming section2B are connected by sharing a part of the respective outer walls. These shared outer walls are the barrier wall21. In other words: the barrier wall21is provided inside the shield room forming section2to divide the internal space in the shield room forming section2into two spaces; a part of the shield room forming section2and the barrier wall21that covers the first internal space20A as a first shield room that is one of the divided internal space is referred to as “the first shield room forming section”2A; and a remaining part thereof that covers the second internal space20B as a second shield room is referred to as “the second shield room forming section”2B. It should be noted that in the present embodiment, as a premise, each of the first internal space20A covered by the first shield room forming section2A and the second internal space20B covered by the second shield room forming section2B is a shield room blocked from electromagnetic waves and no wireless communication can be performed from one internal space to another internal space. Thus, the shield room forming section2, the first shield room forming section2A, the second shield room forming section2B and the barrier wall21may be constituted of an electromagnetic wave reflector that reflects electromagnetic waves. At least, the first internal space20A and the second internal space20B that are covered by the first shield room forming section2A and the second shield room forming section2B, respectively, are preferably covered by an electromagnetic wave reflector. In addition, in this sense, the first shield room forming section2A and the second shield room forming section2B are not necessarily integrated and may exist separately and independently from each other. Furthermore, a combination of a plurality of shield room forming sections that are integrated and a combination of a plurality of shield room forming sections that are separated and independent from each other may simultaneously exist. At that time, the leaky transmission line3may have leakage parts30of a same number as the shield room forming sections2A and2B or more leakage parts30and may have branches. It is needless to say that all ends of the leaky transmission line3are preferably terminated by line terminations, respectively, even if the leaky transmission line3includes branches. The leaky transmission line3may be constituted as a leaky waveguide or may be constituted as a leaky coaxial cable. In any case, a part of the leaky transmission line3is arranged inside the first shield room forming section2A, that is, in a range of the first internal space20A, and another part of the leaky transmission line3is arranged inside the second shield room forming section2B, that is, in a range of the second internal space20B. At that time, the leaky transmission line3may be arranged so as to penetrate through the barrier wall21as shown inFIG.1. Alternatively, the leaky transmission line3may be arranged so as to detour around the barrier wall21(not shown). In addition, there may be a section of non-leakage part that does not radiate electromagnetic waves between each leakage part30. The section of non-leakage part may be constituted as a waveguide or may be constituted as a coaxial cable. A more specific configuration example of a case in which the leaky transmission line3is a leaky waveguide will be described. A general waveguide is a tubular metallic pipe able to propagate electromagnetic waves in longitudinal direction thereof and frequencies of electromagnetic waves with low propagation loss differ in accordance with cross-sectional shape, sizes or the like of the waveguide. A leaky waveguide is a waveguide provided with leakage parts on sides thereof and can radiate a part of electromagnetic waves propagating through the leakage parts. Conversely, a leaky waveguide can propagate electromagnetic waves, that penetrates through a leakage part, along a longitudinal direction. In general, a leakage part of a leaky waveguide is a long and narrow hole opened to penetrate through a side of a metallic pipe and is also referred to as “a slot”. Frequencies, radiation directions and the like of electromagnetic waves that propagate along a leaky waveguide through a leakage part differ in accordance with shape, sizes and the like of the leakage part. It should be noted that in many cases a plurality of slots is provided to a leaky waveguide. In addition, in this sense, it may be considered that leakage parts of a leaky waveguide function as a plurality of antennas provided along the leaky waveguide. A more specific configuration example of a case in which a leaky transmission line3is a leaky coaxial cable will be described. A general coaxial cable is a cable able to propagate electromagnetic waves in a longitudinal direction thereof, in which a circumference of a linear center conductor is covered by a cylindrical dielectric and a circumference of this dielectric is covered by a cylindrical external conductor. The external conductor is preferably further covered by a cylindrical jacket constituted of an insulator. A leaky coaxial cable is a coaxial cable provided with leakage parts on external conductor thereof and can radiate a part of electromagnetic waves propagating through leakage parts. Conversely, a leaky coaxial cable can propagate electromagnetic waves, that penetrates through leakage parts, along the longitudinal direction. In general, a leakage part of a leaky coaxial cable is a long and narrow hole opened to penetrate through the external conductor and is also referred to as “a slot”. It should be noted that in many cases a plurality of slots are provided to a leaky coaxial cable. In addition, as another configuration example, a leaky coaxial cable with an external conductor wound in a spiral with gap around the dielectric also exists. In this case, the gap opened between the spiral external conductor functions as a leakage part. At that time, although the gap is actually constituted in a shape of one spiral, the leaky coaxial cable looks like a plurality of external conductors and a plurality leakage parts arranged alternatively from any point of view and the leaky coaxial cable functions such that a plurality of leakage parts actually exists. In addition, in this sense, it can be also considered that leakage parts of a leaky coaxial cable function as a plurality of antennas provided along the leaky coaxial cable. In the configuration example inFIG.1, the leaky transmission line3penetrates through the barrier wall21and partially penetrates inside the first shield room forming section2A and inside the second shield room forming section2B, respectively. The first device41including the first antenna410is further arranged inside the first shield room forming section2A. Similarly, the second device42including the second antenna420is further arranged inside the second shield room forming section2B, as well. A device4is provided with an antenna400and a wireless power receiving unit401. It should be noted that this means that, as described above, the devices41,42and43are provided with the antennas410,420and430and the wireless power receiving units411,421and431, respectively. Herein, in each device4, the antenna400is connected to a communication circuit that is not illustrated. On the other hand, in each device4, the antenna400is coupled by electromagnetic waves with any one(s) of the plurality of leakage parts30of the leaky transmission line3. Herein, a coupling by electromagnetic waves means that the antenna400and the leakage section30are configured and arranged so as to be wirelessly communicable with each other. Herein, a leakage part30is in electromagnetic wave coupling with the antenna410of the first device41and will be referred to as “a first leakage part”30A. Similarly, “a second leakage part”30B and “a third leakage part”30C are in electromagnetic wave coupling with the antenna420of the second device42and the antenna430of the third device43, respectively. In the configuration example inFIG.1, the first leakage part30A and the third leakage part30C of the leaky transmission line3are arranged inside the first shield room forming section2A and at least the second leakage part30B is arranged inside the second shield room forming section2B. The power supply line50is connected to the power supply5on one hand and is connected to the wireless power supply unit51on the other hand. Although in the configuration example inFIG.1the power supply5is arranged inside the second shield room forming section2B, that is, in the second internal space20B, this is merely a configuration example and does not limit the present embodiment. The power supply5may be arranged inside the first shield room forming section2A, that is, in the first internal space20A, or may be arranged outside the shield room forming section2. A part of the power supply line50is arranged inside the first shield room forming section2A, that is, in the first internal space20A. Another part of the power supply line50is arranged inside the second shield room forming section2B, that is, in the second internal space20B. At that time, the power supply line50may be arranged so as to penetrate through the barrier wall21, as shown inFIG.1. Alternatively, the power supply line50may be arranged so as to detour around the barrier wall21. The plurality of wireless power supply units51and the plurality of wireless power receiving units401are arranged so that the plurality of wireless power receiving units401can receive wireless power supply from the plurality of wireless power supply units51, respectively. In other words, a positional relationship between the first wireless power supply unit51A and the first wireless power receiving unit411is preferably determined so as to enable wireless power supply there between. Similarly, a positional relationship between the second wireless power supply unit51B and the second wireless power receiving unit421is preferably determined so as to enable wireless power supply there between. In addition, a positional relationship between the third wireless power supply unit51C and the third wireless power receiving unit431is preferably determined so as to enable wireless power supply there between. It should be noted that it is needless to say that the wireless power supply unit51is preferably arranged inside the electromagnetic wave reflector, that is, inside the shield room forming section2. Operations of components of the wireless communication system1inFIG.1will be described. At first, the power supply5generates a power to transmit to the wireless power supply unit51through the power supply line50. Each wireless power supply unit51performs wireless power supply to the wireless power receiving units401arranged in a position enabling the wireless power supply. The wireless power receiving units401supply the power wirelessly supplied from the wireless power supply units51to internal circuits of the devices4that are not illustrated. These internal circuits include communication circuits. The internal circuits of the devices4, that are not illustrated, start to operate by the power supplied from the wireless power receiving units401. It should be noted that it is preferable that the devices4are further provided with rechargeable batteries, that are to be charged with the power supplied by the wireless power receiving units401and supply the charged power to the communication circuits, and charge-discharge circuits. The devices4in operation perform, as necessary, transmission and reception of signal through the antennas400. The antennas400enable two-way communication with other devices4through the leakage parts30in electromagnetic wave coupling with the antennas400and the leaky transmission line3. Herein, it is to be noted that when performing wireless communications between a plurality of devices4, the leaky transmission line3functions as a mere two-way propagation path. That is, in a conventional method of using a leaky transmission line3, when performing wireless communication between a plurality of devices4in electromagnetic wave coupling with leakage parts30of a leaky transmission line3, it was common that an access point connected to the leaky transmission line3by wire mediates this wireless communication. In other words, at first, one device4performs communication with the access point and then the access point performs communication with another device4, and thus both devices4could perform communication with each other. However, in the present embodiment, even if two or more devices4are arranged in a same internal space or even if two or more devices4are arranged in a plurality of different internal spaces, respectively, a wireless communication can be performed directly between both devices4. Specifically, in the configuration example inFIG.1, a wireless communication can be performed directly even between a first device41arranged in the first internal space20A and the second device42arranged in the second internal space20B. In addition, a wireless communication can be directly performed between the first device41and the third device43that are arranged in the same first internal space20A, as well. It should be noted that it is needless to say that although a wireless power supply is used in the above description, a similar wireless communication can be performed by supplying the devices4with power by wire, as well. However, by realizing both wireless communication and wireless power supply, installation of the devices4in the shield room forming sections2, assembly of the wireless communication system1, and the like can be greatly simplified. This leads to improvement of productivity. In addition, by using common interfaces for wireless communication and wireless power supply between the plurality of devices4, improvement in degree of freedom in combination of devices4, expandability and the like can be expected as well. A variation example of the present embodiment will be described with reference toFIG.2.FIG.2is a partial cross-sectional view that shows another configuration example of a wireless communication system according to an embodiment. In the variation example shown inFIG.2, the leaky transmission line3and the power supply line50are integrated to the shield room forming section2. In addition, inFIG.2, illustrations of devices4is omitted for a better visual recognition. The leaky transmission line3inFIG.2is integrated to the shield room forming section2, as described above. More specifically, the leaky transmission line3inFIG.2is a leaky waveguide and the metallic pipe thereof is integrated to the shield room forming section2. Therefore, it is preferable that the entire shield room forming section2is made of metal. It should be noted that if the whole of the shield room forming section2is non-metallic, a metal film may be formed on a surface inside or outside the leaky waveguide. Herein, the leakage parts30are constituted as slots that penetrate through the shield room forming section2so that a hollow part of the leaky waveguide is connected to the internal space20. Such a structure can be relatively easily manufactured by using techniques of so-called three-dimensional printers, for example. It should be noted that in case of constituting the leaky transmission line3in the present variation example with a leaky coaxial cable, the following modification may be made, for example. The external conductor of the leaky coaxial cable is considered to be integrated to the shield room forming section2and the center conductor is arranged in a hollow part of the leaky waveguide inFIG.2so as not to be conductive with the shield room forming section2. Furthermore, a remaining space of the hollow part between the center conductor and the shield room forming section2is filled with dielectric. Detailed description about power supply line50is omitted because it is a well-known technique. It should be noted that in the configuration example inFIG.2, since the shield room forming section2is made of metal, it can be used as a ground. In the configuration example inFIG.2, the leaky transmission line3and the power supply line50are arranged so as to protrude outside the shield room forming section2in order to make a shape of the internal space20cylindrical. However, this is a mere example and is not to limit a shape of the wireless communication system1according to the present embodiment. Second Embodiment In the present embodiment, the configuration of the wireless communication system1according to the first embodiment will be applied to a configuration of a flying object. Although it is a repetition of the above described “Background Art”, a configuration example of a flying object according to a related art will be described with reference toFIG.3at first for a better understanding of the present embodiment.FIG.3is a partial cross-sectional view that shows a configuration example of a flying object11according to a related art. Components of the flying object11inFIG.3will be described. The flying object11inFIG.3is provided with a body12, a fuel tank122, a first device14A, a second device14B, a wire harness123and a protective cover124. Connection relationships and positional relationships of the components of the flying object11inFIG.3will be described. The fuel tank122is arranged inside the body12. In the flying object11, the existence of the fuel tank122is very important and in many cases a central part of the body12is occupied by the fuel tank122. In addition, a high symmetry is required for the shape of the fuel tank122. Specifically, it is preferable that the shape of the fuel tank122is almost cylindrical. As a result, the internal space of the body12is physically divided by the fuel tank122into a first internal space120A at the front and a second internal space120B at the rear. Thus, a part of the body12and the fuel tank122that covers the first internal space120A can be considered as a pseudo first shield room forming section12A. Similarly, a part of the body12and the fuel tank122that covers the second internal space120B can be considered as a pseudo second shield room forming section12B. At that time, the first device14A is arranged in the first internal space120A and the second device14B is arranged in the second internal space120B. The first device14A and the second device14B are electrically connected via the wire harness123. The wire harness123that connects the first device14A and the second device14B is arranged outside the body12in order to detour around the fuel tank122. The protective cover124to protect the wire harness123is provided on the outer surface of the flying object11. This is because when the flying object11flies at high speed, high heat is generated on the outer surface of the body12due to aerodynamic heating and the wire harness123needs to be protected from this high heat. In addition, a performance of protecting the wire harness123from outside electromagnetic wave noises is also required of the protective cover124. Next, a flying object11according to the present embodiment will be described with reference toFIG.4.FIG.4is a partial cross-sectional view that shows a configuration example of a flying object11according to an embodiment. Components of the flying object11inFIG.4will be described. The flying object11inFIG.4is provided with a body12, a fuel tank122, a leaky transmission line13, a first device141, a second device142, a power supply15, a power supply line150, a first wireless power supply unit151A and a second wireless power supply unit151B. The leaky transmission line13is provided with leakage parts130A and130B and line terminations1391and1392. The first device141is provided with a first antenna1410and a first wireless power receiving unit1411. Similarly, the second device142is provided with a second antenna1420and a second wireless power receiving unit1421. Connection relationships and positional relationships of components of the flying object11inFIG.4will be described. Similar to the case inFIG.3, the fuel tank122is arranged inside the body12and the internal space of the body12is physically divided by the fuel tank122into the first internal space120A at the front and the second internal space120B at the rear. In addition, a part of the body12and the fuel tank122that covers first internal space120A can be considered as a pseudo first shield room forming section12A. Similarly, a part of the body12and the fuel tank122that covers the second internal space120B can be considered as a pseudo second shield room forming section12B. At that time, the first device141is arranged in the first internal space120A and the second device142is arranged in the second internal space120B. The leaky transmission line13and the power supply line150are integrated to the body12. As the positional relationship of the body12, the leaky transmission line13and the power supply line150inFIG.4is similar to the positional relationship of the shield room forming section2, the leaky transmission line3and the power supply line50shown inFIG.2, further detailed description thereof will be omitted. The first leakage part130A is provided so as to penetrate through a part of the body12that is sandwiched between the leaky transmission line13and the first internal space120A. The first antenna1410is arranged near the first leakage part130A so as to be able to be in electromagnetic wave coupling with the first leakage part130A, so as to enable a wireless communication between the first antenna1410and the first leakage part130A in other words. Similarly, the second leakage part130B is provided so as to penetrate through a part of the body12that is sandwiched between leaky transmission line13and the second internal space120B. The second antenna1420is arranged near the second leakage part130B so as to be able to be in electromagnetic wave coupling with the second leakage part130B, so as to enable a wireless communication between the second antenna1420and the second leakage part130B, in other words. The power supply15is connected to the first wireless power supply unit151A and the second wireless power supply unit151B through the power supply line150. Although the first wireless power supply unit151A and the second wireless power supply unit151B are integrated to the body12in the configuration example inFIG.4, this is merely one configuration example and does not limit configurations of the present embodiment. That is, the power supply15may be arranged in any of the first internal space120A and the second internal space120B. In addition, the first wireless power supply unit151A and the second wireless power supply unit151B may be arranged in the first internal space120A and the second internal space120B, respectively. In any case, the first wireless power supply unit151A is arranged near the first wireless power receiving unit1411so as to be able to wirelessly supply power to the first wireless power receiving unit1411of the first device141. Similarly, the second wireless power supply unit151B is arranged near the second wireless power receiving unit1421so as to be able to wirelessly supply power to the second wireless power receiving unit1421of the second device142. Operations of the components of the flying object11inFIG.4will be described. Similar to the case of the wireless communication system1inFIG.1, at first, the power supply15generates power to transmit to the wireless power supply units151A and151B through the power supply line150. Wireless power supply units151A and151B perform wireless power supply to the wireless power receiving units1411and1412that are arranged at positions where wireless power supply is possible. The wireless power receiving units1411and1421supply the power that is wirelessly supplied from the wireless power supply units151A and151B to internal circuits of the devices141and142that are not illustrated. Those internal circuits include communication circuits. The internal circuits of the devices141and142, that are not illustrated, start and operate with the power supplied by the wireless power receiving units1411and1421. It should be noted that it is preferable that the devices141and142are further provided with rechargeable batteries, that are to be charged with the power supplied by the wireless power receiving units1411and1421and supply the charged power to the internal circuits, and charge-discharge circuits. The devices141and142in operation perform, as necessary, transmission and reception of signals through antennas1410and1420. The antennas1410and1420enable two-way communication between other devices142and141through the leakage parts130A and130B, that are in electromagnetic wave coupling, and the leaky transmission line13. Moreover, further detailed descriptions will be omitted in that leaky transmission line13functions as two-way propagation path, that an access point to mediate a communication is not necessary when a wireless communication is performed between the first device141and the second device142, and that power supply to the first device141and the second device142may be performed by wire, and the like, because the second embodiment is similar to the case of the first embodiment. As effects obtained in the present embodiment, it can be mentioned that, in addition to effects obtained in the first embodiment, the problem in that outer part of the flying object11is exposed to high heat, electromagnetic noises and the like is resolved because the wire harness123of the related art shown inFIG.3is no longer necessary. As a result, the design of the flying object11as a whole becomes easier. In addition, a reliability of the flying object11as a whole is improved because external factors can be reduced. Third Embodiment In the first and second embodiments, it was described that an access point to mediate a communication is not necessary when a wireless communication is performed between a plurality of devices4,141and142. In the present embodiment, it will be described that an access point may be added and that functions can be added by adding an access point. A wireless communication system1according to the present embodiment will be described with reference toFIG.5andFIG.6.FIG.5is a partial cross-sectional view that shows a configuration example of a wireless communication system1according to an embodiment.FIG.6is a partial cross-sectional view that shows another configuration example of a wireless communication system1according to an embodiment. The wireless communication system1according to the configuration example inFIG.5is equivalent to the wireless communication system1inFIG.1with a connection38, a branch33and a line termination393. That is, inFIG.5, the connection38is added between the first line termination391and the second line termination392of the leaky transmission line3. This connection38is a branch point of the leaky transmission line3. Herein, for convenience, a part of the leaky transmission line3from the connection38to the first line termination391will be referred to as “a first branch”31, a part from the connection38to the second line termination392will be referred to as “a second branch”32and a part from the connection38to the third line termination393will be referred to as “a third branch”33. In other words, downstream of the third branch33, there is a third end terminated by the third line termination393. A part of the third branch33that includes an end connected to the connection38is arranged inside the shield room forming section2, while a remaining part including the third line termination393penetrates through the shield room forming section2and is arranged outside the shield room forming section2. The end of the third branch33that is arranged outside the shield room forming section2may be referred to as “an external end”. Similarly, the third line termination393may be referred to as “an external line termination”. Description of features and elements appearing inFIG.5that have been previously described in earlier drawings has been omitted. The wireless communication system1according to the configuration example inFIG.6is equivalent to the wireless communication system1inFIG.5without the third line termination393ofFIG.5removed from the third branch33and with an access point37connected to an end of the third branch33instead. In other words, the third line termination393is detachably attached to the end of the third branch33and can be replaced by the access point37. The access point37is provided with an antenna371. The access point37and the antenna371are arranged outside the shield room forming section2. In other words, the access point37can perform a wireless communication with an arbitrary communication device existing outside the wireless communication system1via the antenna371thereof. On the other hand, the access point37can perform a wireless communication with the device4arranged in the shield room forming section2via the leaky transmission line3. Description of features and elements appearing inFIG.6that have been previously described in earlier drawings has been omitted. In other words, in the wireless communication system1according to the present embodiment, a contactless wireless communication can be performed between a device4existing in an internal space20A or20B shielded by an electromagnetic wave reflector and an arbitrary communication device existing outside the shield room forming section2. The wireless communication system1according to the present embodiment will be described as a specific example when applied to the flying object11inFIG.4in this regard. In general, a flying object11may be subjected to a test before being used. When performing a test, by connecting a relay device corresponding to the access point37to the leaky transmission line3, a wireless communication can be performed between an arbitrary checking device, that is prepared outside the flying object11and connected to the relay device, and the devices141and142via the relay device. As a result, function check, program update and the like can be performed to the devices141and142without physically manipulating the devices141and142inside the body12. It should be noted that after the test is completed the relay device corresponding to the access point37can be removed from the leaky transmission line3and an arbitrary terminating device corresponding to the line termination393can be connected instead as shown inFIG.5. Although the invention made by the inventor(s) has been specifically described above based on embodiments, it is needless to say that the present invention is not limited by the above described embodiments and various modifications can be made thereto without departing from the scope thereof. In addition, each feature described in the above described embodiments can be freely combined as long as there is no technical contradiction. It should be noted that the present application claims priority based on Japanese Patent Application No. 2018-033872 filed on Feb. 27, 2018 and herein incorporates all disclosure thereof by reference. | 36,467 |
11943007 | DESCRIPTION OF THE EMBODIMENTS Reference will now be made in detail to the disclosed embodiments, examples of which are illustrated in the accompanying drawings. Wherever convenient, the same reference numbers will be used throughout the drawings to refer to the same or like parts. FIG.1is a block diagram of an exemplary secure system100for performing one or more operations, consistent with the disclosed embodiments. In one embodiment, system100may include one or more mobile devices110, one or more induction power pads120, one or more user devices130, one or more financial service provider (FSP) servers140, and/or network160. Consistent with disclosed embodiments, user115may be associated with a mobile device110and/or a user device130. The components and arrangement of the components included in system100may vary. Thus, system100may include other components that perform or assist in the performance of one or more processes consistent with the disclosed embodiments. Components of system100may be computing systems configured to provide methods and systems that enable the use of tokens (for example, a secure software and/or hardware mechanism that may be used to authorize operations) to conduct transactions, as well as provision tokens to mobile device110through Bluetooth® or other network connectivity beyond NFC technology, consistent with disclosed embodiments. As further described herein, components of system100may include one or more computing devices (for example, computer(s), server(s), etc.), memory storing data and/or software instructions (for example, database(s), memory device(s), etc.), and other known computing components. In some embodiments, the one or more computing devices may be configured to execute software instructions stored on one or more memory devices to perform one or more operations consistent with the disclosed embodiments. Components of system100may be configured to communicate with one or more other components of system100, including systems associated with mobile device110, user device130, and/or FSP server140. In certain aspects, users may operate one or more components of system100to initiate and provide input for one or more operations consistent with the disclosed embodiments. Mobile device110may be any device configured to be worn or carried by a user, such as a user115. For example, mobile device110may be embedded in or incorporated into a wearable item such as key fob, wristband, purse, jewelry (for example, bracelet, ring, necklace, etc.), eyeglasses, sunglasses, watch, piece of clothing (for example, shirt, shoe, pants, jacket, etc.), etc. Mobile device110may include an attachment device (for example, a clip) to allow it to be attached to a wearable item (for example, belt). Mobile device110may also be embedded in or incorporated into an item that is normally carried by a user or held in the user's pocket (for example, smartphone, wallet, financial card, key, key ring, etc.). In some embodiments, mobile device110may be a component of or incorporated into a commercially available wearable computing device, such as a smartwatch, a pair of smart glasses, etc. As described in greater detail below, mobile device110may be communicatively coupled to user device130using, for example a secure, low power wireless technology, such as Bluetooth® Low Energy (BLE, see, e.g., https://www.bluetooth.com/what-is-bluetooth-technology/how-it-works/low-energy) technology to enable communication between mobile device110and user device130. A detailed explanation of BLE may be found in the Bluetooth® Low Energy Technology Specification version 4.1 and 4.0 and other related BLE specifications, the entire contents of which are incorporated herein by reference. In exemplary embodiments, BLE may operate in the 2.4 GHz industrial, scientific, and medical (ISM Band) band. BLE may support very short data packets (for example, 8 octets minimum up to 27 octets maximum) that are transferred at, for example 1 Mbps. The BLE connections may use advanced sniff-sub rating to achieve ultra-low duty cycles. The BLE technology also may use the adaptive frequency hopping, common to all versions of Bluetooth® technology, to minimize interference from other technologies in the 2.4 GHz ISM Band. The BLE technology may enable efficient multi-path benefits that increase the link budgets and range. The BLE technology also can support connection setup and data transfer as low as 3 ms, allowing an application to form a connection and then transfer authenticated data in few milliseconds for a short communication burst before quickly tearing down the connection. Moreover, increased modulation index provides a possible range for BLE technology of over 100 meters. The BLE technology may use a 24 bit cyclic redundancy check (CRC) on packets to ensure the maximum robustness against interference. The BLE technology may include full Advanced Encryption Standard-128 AES-128) encryption using continuity check message (“CCM”) to provide encryption and authentication of data packets. The BLE technology may be optimized for one-to-one connections while allowing one-to-many connections using, for example, a star topology. It is contemplated that BLE is used for illustrative purpose only. The present disclosure does not limit the wireless protocols used for coupling mobile device110and user device130. For example, mobile device110may also be coupled to user device130using Wi-Fi® based on the IEEE 802.11 standard (operating at 2.4 GHz, 3.6 GHz, 5 GHz, 60 GHz, etc. frequency bands, see, e.g., http://www.wi-fi.org/discover-wi-fi/specifications), or using ZigBee® based on the IEEE 802.15.4 standard (operating at 915 MHz, 2.4 GHz, etc. frequency bands, see, e.g., http://www.zigbee.org/). In exemplary embodiments, mobile device110may have no internal power supply. To activate the BLE communication, mobile device110may be powered through wireless charging. For example, the wireless charging may be in the form of inductive charging that uses an electromagnetic field to transfer energy from induction power pad120to mobile device110. Induction power pad120may include an induction coil configured to create an alternating electromagnetic field in the vicinity of induction power pad120. Correspondingly, mobile device110may include an induction antenna configured to couple with the electromagnetic field and receive the energy in the electromagnetic field. In practice, to receive the induction power, mobile device110may be placed in a close distance to induction power pad120, as specified by the manufacturer of induction power pad120. For example, mobile device110may be directly placed on induction power pad120. Upon receiving the induction power, mobile device110may activate the BLE connectivity and establish the BLE communication with user device130. Subsequently, through the BLE connection, user device130may transmit credentials, including tokens, to mobile device110for use in, for example, conducting a financial transaction. The credential may be pre-stored in user device130, or obtained by user device130from FSP server140through network160. After the credential provisioning is completed, the BLE connection may be disabled. Accordingly, mobile device110is no longer needed to be powered by induction power pad120and can be carried away from induction power pad120. User device130may be one or more computing devices configured to perform one or more operations consistent with disclosed embodiments. User device130may be a desktop computer, a laptop, a server, a mobile device (for example, tablet, smart phone, etc.), or any other type of computing device. For exemplary purposes, aspects of the disclosed embodiments are described with reference to user device130as a mobile client device, such as a smart phone, a tablet, or the like. As mentioned herein, however, the disclosed embodiments are not limited to such examples. For example, user device130could be a laptop, a desktop, or any other device. User device130may include one or more processors configured to execute software instructions stored in memory, such as memory included in user device130. User device130may include software that when executed by a processor performs known Internet-related communications, content display processes, and/or disclosed token provision processes. For instance, user device130may execute browser or related mobile display software that generates and displays interfaces including content on a display device included in, or in communication with, user device130. User device130may be a mobile device that executes mobile device applications and/or mobile device communication software that allows user device130to communicate with other components of system100over network160, and generates and displays content in interfaces via a display device included in user device130. The disclosed embodiments are not limited to any particular configuration of user device130. For instance, user device130may be a mobile device that stores and executes mobile applications that configure the mobile device to receive and/or provide token information. User device130also includes a communication component(s) configured to facilitate communication, wired and/or wirelessly, between user device130and other devices, such as mobile device110and FSP server140. The communication component can access a wireless network based on a communication standard, such as WiFi, 2G, 3G, 4G, 5G, LTE, or a combination thereof. In one exemplary embodiment, the communication component receives a broadcast signal or broadcast associated information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, the communication component further includes a NFC module to facilitate short-range communications. For example, the NFC module may be implemented based on a Near Field Communication (NFC) technology, radio frequency identification (RFID) technology, an infrared data association (IrDA) technology, an ultra-wideband (UWB) technology, a Bluetooth® technology, and other technologies. In particular, consistent with the disclosed embodiments, the communication component can establish a BLE connection with mobile device110, so as to enable the provision of tokens. A financial service provider (not shown) may be an entity that provides, maintains, manages, or otherwise offers financial services. For example, financial service provider may be a bank, credit card issuer, or any other type of financial service entity that generates, provides, manages, and/or maintains financial service accounts for one or more cardholders. Financial service accounts may include, for example, credit card accounts, loan accounts, checking accounts, savings accounts, reward or loyalty program accounts, and/or any other type of financial service account known to those skilled in the art. Financial service provider may include infrastructure and components that are configured to generate and/or provide financial service accounts such as credit card accounts, checking accounts, debit card accounts, loyalty or reward programs, lines of credit, or the like. For example, a financial service provider may include one or more FSP servers140. In one aspect, FSP server140may be one or more computing devices configured to perform one or more operations consistent with disclosed embodiments. For example, FSP server140may be configured to providing provision services for tokens, consistent with disclosed embodiments. In one aspect, FSP server140may be a desktop computer, a server, or any other type of computing device. FSP server140may include one or more processors configured to execute software instructions stored in memory. The one or more processors may be configured to execute software instructions to perform Internet-related communication and financial service-based processes. A user (not shown) may be an entity that offers goods, services, and/or information, such as a retailer (for example, Starbucks® (see, e.g., https://www.starbucks.com/), Macy's® (see, e.g., http://wwwl.macys.com/), Target® (see, e.g., http://www.target.com/), etc.), a grocery store, a service provider (for example, a utility company, etc.), or any other type of entity that offers goods, services, and/or information that users (for example, end-users or other business entities) may purchase, consume, use, etc. In one example, a user may be associated with a user brick-and-mortar location that a user (for example, user115) may physically visit and purchase a product or service. The user may also include back- and/or front-end computing components that store data and execute software instructions to perform operations consistent with disclosed embodiments, such as computers that are operated by employees of the user (for example, back office systems, etc.). The user may include user device150. User device150may include one or more computing systems, such as server(s), desktop computer(s), point-of-sale (POS) device(s), etc., that are configured to execute stored software instructions to perform operations associated with a user, including one or more processes associated with processing purchase transactions, generating transaction data, generating product data (for example, stock-keeping-unit (SKU) data) relating to purchase transactions, etc. User device150may perform one or more operations consistent with the disclosed embodiments. The disclosed embodiments are not limited to any particular configuration of user device150. As one example, user device150may be a POS system like a cash register. User device150may comprise functionality and/or hardware operable to receive wireless communications from mobile device110and/or user device130. For example, user device150may be configured to utilize technologies such as NFC, RFID, infrared, electric field, magnetic fields, or other technologies, in order to initiate and/or process a purchase or other transaction. User device150may also generate and send token authorization requests to systems, such as FSP server140. For example, user device150may receive a token from mobile device110as part of a transaction for services and/or goods rendered, and user device150may send the token (along with other information) to FSP server140to complete a transaction. Thus, user device150may also generate and send transaction requests to FSP server140. Such transaction requests may comply with International-Standardization-for-Organization (ISO) 8583 standards (see, e.g., http s://www.iso.org/obp/ui/#iso:std:iso:8583:-1:ed-1:v1:en). For example, upon receiving financial account information associated with the token, user device150may generate an ISO 8583 message to FSP server140indicating that an account holder would like to make a debit for the purchase price of the rendered good or service. User device150may include a contactless terminal (not shown) comprising any known NFC device designed to communicate (directly or indirectly) with other components of system100. For example, the contactless terminal (CPT) may be a POS terminal, an automated teller machine (ATM), or any other device that is configured to communicate with NFC mobile devices (for example, mobile device110and/or user device130) to facilitate a financial transaction according to disclosed embodiments. Network160may be any type of network configured to provide communications between components of system100. For example, network160may be any type of network (including infrastructure) that provides communications, exchanges information, and/or facilitates the exchange of information, such as the Internet, a Local Area Network (LAN), a Wide Area Network (WAN), a cellular network, IEEE Ethernet 902.3, fiber optics, telephone lines, wireless networks (for example, a Wi-Fi®/802.11 network), NFC, magnetic fields, an optical code scanner, infrared, or other suitable connection(s) that enable the sending and receiving of information between the components of system100. In other embodiments, one or more components of system100may also communicate directly through a dedicated communication link(s). In addition, network160may further include one network, or any number of exemplary types of networks mentioned above, operating as a stand-alone network or hi cooperation with each other. Network160may utilize one or more protocols of one or more communicatively-coupled network elements. Although network160is depicted as a single network, it should be appreciated that according to one or more embodiments, network160may comprise a plurality of interconnected networks, such as, for example, the Internet, a service provider's network, a cable television network, corporate networks, and home networks. FIG.2depicts an exemplary mobile device110, consistent with disclosed embodiments. In some embodiments, mobile device110may include components that may execute one or more processes to receive from user device130a token associated with a financial account. In some embodiments, mobile device110may also include components that may execute one or more processes to initiate a financial transaction by transmitting the token to user device150. As shown inFIG.2, mobile device110may include one or more of a secure element210, a NFC communication component220, a BLE communication component230, a controller240, an indicator interface250, and a wireless power receiver260. Some or all of the components may be combined into one chip, spread among multiple chips or circuits, or any other possible combination. Secure element210may be configured to provide an environment in which processes and data may be securely stored and/or executed. In one embodiment, secure element210may be a separate embedded device that includes a universal integrated circuit card (UICC), a secure digital or other memory card, a Subscriber Identity Module (SIM) card, a microcontroller, a computer processor, or any other possible implementation. In another embodiment, secure element210may be software located in a memory in mobile device110. For example, secure element210may provide delimited memory for applications operating according to disclosed embodiments. In certain embodiments, secure element210may be configured and operate as known secure elements for NFC devices. For example, secure element210may store applications, credentials (for example, tokens), and/or other information associated with secure execution of applications. Secure element210may include one or multiple error detection systems, tamperproof storage modules, execution memory modules. Secure element210may represent multiple secure elements used to isolate various applications and provide additional security. Secure element210may optionally be removable to facilitate ease of use. NFC communication component220may include an antenna and a NFC controller. NFC communication component220and secure element210may be connected, for example, via a Single Wire Protocol (SWP) interface, Signal-In/Signal-Out Connection (S2C) interface, etc. BLE communication component230may include a Bluetooth® radio capable of performing low-energy secure wireless communication with user device130using the BLE technology. This Bluetooth® radio may cooperate with other components of mobile device110, such as controller240, to enable the Bluetooth® communication. BLE communication component230may be capable of decoding data received from user device130. BLE communication component230may also be capable of encoding data to be sent to user device130. BLE communication component230may include one module or multiple modules, and may be optionally combinable with one or both of the secure element210and NFC communication component220. BLE communication component230may be capable of communicating with the user device130by using a host controller interface. For example, and not by way of limitation, BLE communication component230may use a Java™ Contactless Communication API (JSR 257, see, e.g., https://jcp.org/en/jsr/detail?id=257), a Java™ Security and Trust Services API (JSR 177, see, e.g., https://jcp.org/en/jsr/detail?id=177), Security and Trust Services API (SATSA), an ISO/IEC 7816 compatible interface, or any other acceptable means or protocol to communicate with user device130or any other devices. It is contemplated that BLE communication component230is only one example for enabling the communication between mobile device110and user device130. Mobile device110may include other communication components, in place of or in addition to BLE communication component230, to perform any other types of low-energy secure communication with user device130, such as Wi-Fi® or infrared communication. Secure element210, NFC communication component220, and BLE communication component230may be connected in parallel, in series, or any other possible combination. Secure element210and NFC communication component220may each maintain a connection to BLE communication component230, if desired. In some embodiments, only one of secure element210and NFC communication component220may maintain a connection to BLE communication component230to enhance security. Controller240may control various operations of mobile device110. For example, controller240may include specific capabilities to enable Bluetooth® technology, such as, the BLE technology, and cooperate with the other components of mobile device110to communicate with user device130. Controller240may also execute the NFC-related operations. In certain embodiments, controller240may include one or more processors242and memories244for performing functions consistent with the disclosed embodiments. Processor242may include one or more known processing devices, from microcontrollers configured to process simple logic commands, such as PIC™ microcontrollers (see, e.g., http://www.microchip.com/design-centers/microcontrollers), MIPS™ microcontrollers (see, e.g., https://www.imgtec.com/mips/), etc., to more powerful microprocessors including the Pentium™ or Xeon™ family manufactured by Intel™, the Turion™ family manufactured by AMD™, etc. The disclosed embodiments are not limited to any type of processor(s) configured in mobile device110. Memory244may include one or more storage devices configured to store information. For example, in some embodiments, memory244may store instructions that may be executed by a processor, such as processor242. Memory244may store data that may reflect any type of information in any format that system100may use to perform operations consistent with the disclosed embodiments. In some embodiments, processor242may execute one or more programs stored by memory244. For example, processor242may execute a transaction program configured to provide a token stored in secure element210to a user device150(for example, a POS device) when user115operates mobile device110to complete a financial transaction. Indicator interface250may be coupled to an indicator to provide status indications to a user of mobile device110. For example, indicator interface250may operate one or more light-emitting diodes (LEDs) on the surface of mobile device110to provide illuminated status indications. In one embodiment, a solid or flashing green LED indicator may indicate that mobile device110is communicating with user device130and a solid or flashing red LED indicator may indicate that mobile device110is experiencing one or more problems, such as a communication failure, power failure, and the like. Indicator interface250may receive status signals from controller240and/or other components of mobile device110, for example, BLE communication component230, and use those status signals to activate one or more indicators. Wireless power receiver260may include an induction antenna configured to receive power from induction power pad120. Induction power pad120may be any commercially available induction charging pad, such as those employed to wirelessly charge smart phones. Alternatively, induction power pad120may be specially designed for being paired with mobile device110. When mobile device110is brought close to and/or in contact with induction power pad120, the induction antenna in wireless power receiver260may couple with the induction field generated by induction power pad120and collect the energy from the induction field. Wireless power receiver260may also include one or more capacitors and/or inductors, collectively forming the impedance of wireless power receiver260, to facilitate the storing and releasing of the received energy. Wireless power receiver260may be coupled with one or more one or more components of mobile device110and supply the received energy to these components to power various operations by mobile device110. In one embodiment, the received energy may be used to power BLE communication component230and/or controller240to perform the BLE communication with user device130. FIG.3Ais a schematic diagram illustrating an exemplary implementation of wireless powering for provisioning of credential, consistent with the disclosed embodiments. In the example depicted inFIG.3A, mobile device110is a key chain, user device130is a smart phone, and user device150is a contactless POS terminal. Referring toFIG.3A, when the need or desire to provision (or reprovision) a credential (such as, for example, a token) to device110arises, user115places mobile device110on induction power pad120. Wireless power receiver260may sense the induction field generated by induction power pad120and draws energy from the induction field to power BLE communication component230and/or controller240. User device130may also detect the Bluetooth® signal emitted by BLE communication component230and establish a BLE connection with BLE communication component230. User device130may also transmit a token to mobile device110. The token may be obtained by user device130from FSP server140through network160. Alternatively, the token may be pre-stored in or generated by user device130. After successfully receiving the token, controller240may save the token in secure element210for future use. In one embodiment, controller240may generate feedback regarding whether the token has been successfully received and stored. For example, controller240may send a message to user device130reporting the status of the reception and storage of the token in secure element210. For another example, controller240may send a signal to indicator interface250, so that indicator interface250drives an indicator, for example, a LED light, to indicate whether the token is received. User115may move mobile device110away from induction power pad120, for example, after the mobile device110receives the token. Accordingly, BLE communication component230and/or controller240may become deactivated, and the BLE connection between mobile device110and user device130may cut off. For example, when the mobile device100is removed from induction power pad120, BLE communication component230and/or controller240may cease to receive power (or enough power) to continue operations. FIG.3Bis a schematic diagram illustrating an exemplary implementation of mobile using the credential provisioned inFIG.3A, consistent with the disclosed embodiments. Referring toFIG.3B, user115may bring mobile device110close to or in contact with user device150. User device150may include a NFC reader, which may communicate with NFC communication component220by using radio waves or other short-range wireless technology. This way, the token in secure element210may be transmitted to user device150via, for example, NFC communication. For example, in exemplary embodiments, mobile device110may draw power from, for example, the NFC reader associated with user device150in order to perform the NFC communication. Although not enough to power the BLE communication, the typical power settings of user device150may create an induction field capable of driving the NFC communication. Therefore, mobile device110does not require an internal power source for performing either BLE or NFC communications. After receiving the token through the NFC communication, user device110may transmit the token, together with other account and transaction related information, to FSP server140through network160. If the information can be verified, FSP server140may send a confirmation to user device150authorizing the transaction. As illustrated inFIGS.3A and3B, mobile device110may draw power wirelessly from induction power pad120, acquire a token from user device130by wireless communication, and transmit the acquired token to user device150. Embodiments of the disclosed processes do not require mobile device110to carry an internal power source and/or use power/data cables. Therefore, mobile device110can be made smaller and lighter, and may be easier and less expensive to be embedded in other devices/objects, e.g., wearable devices, key fobs, purses, clothing, etc. Moreover, the disclosed processes allow user115or the financial service provider to conveniently provision or reprovision a token to mobile device110, without using batteries or charging/data cables, or physically accessing mobile device110. As such, the disclosed processes not only make mobile device110more user friendly, but also improve the security of mobile technology because any tokens in mobile device110can be conveniently updated as needed and as frequently as possible. FIG.4is a flowchart of a method400performed by secure system100, consistent with disclosed embodiments. For illustrative purposes only, in the following description, both mobile device110and user device130are operated by user115. In step402, mobile device110may be brought within the electromagnetic field of induction power pad120to power one or more components of mobile device110. For example, when mobile device110is placed close to or in contact with induction power pad120, wireless power receiver260may automatically receive power from the electromagnetic field generated by induction power pad120, and use the power to activate BLE communication component230. In step404, mobile device110may establish the BLE connection with user device130. For example, user device130may be BLE-enabled and configured with a mobile application. The mobile application may enable user device130to automatically detect the BLE signals emitted by BLE communication component230and form the BLE connection with mobile device110according to a predetermined communication protocol. In one embodiment, user115may be required to input a password or other credentials in the mobile application to validate the BLE connection, for example, to ensure data security. In step406, user device110may retrieve a token. For example, user115may operate the mobile application installed on user device130to initiate an operation for provisioning a token to mobile device110. The token may include an identifier corresponding to and/or substituting for confidential account information, such as confidential account information that may be transferred in during a swipe transaction of a magnetic-stripe based credit/debit card. User device130may send a request for the token to (or access the token from) FSP server140through network160. Subsequently, FSP server140may generate the token and send the token to user device130. As described above, alternatively, user device130may pre-store and/or generate one or more tokens associated with one or more accounts. The mobile application may display the list of pre-stored tokens on a screen of user device130. User115may select (e.g., on user device130) a token to be provided to mobile device110. In some embodiments, a list of different accounts may be displayed, and a token may be generated based on the selection of an account from the list. In step408, user device110may send the token to mobile device110through the BLE connection. In some embodiments, user115may operate user device130to initiate sending of the retrieved token to mobile device110through the BLE connection. After the token is successfully transmitted to mobile device110, user device130may display a confirmation message. Alternatively, mobile device110may control an indicator, such as a LED indicator on mobile device110, to indicate whether the token is successfully provisioned to mobile110. In some embodiments, mobile device110may store the received token in secure element210for future use. The token may be one or more of single-use token(s), multi-use token(s), token(s) configured for use at a particular user, token(s) configured for use with one or more particular types of transactions, token(s) associated with spending restrictions, etc. In step410, mobile device110may send the token to user device150through a wireless connection, for example, using NFC. This step may be performed, for example, at the time of purchase. In some embodiments, upon receipt of the token, user device150may format the token into a data format consistent with one of several authorization networks. For example, an exemplary 6-digit token may be inserted into one of the “tracks” of data utilized by the Visa® network to transmit and receive transaction data. Also, as noted above, the token provided may also use a format consistent with standard financial card account information, such as the information that would be transferred by a credit card swipe. In step412, user device150may send the token to FSP server140for authorization. For example, user device150may send the token to FSP server140through network160. In one embodiment, the information sent to FSP server140may include the tokenized information representing a financial account with the amount of the transaction and/or other information necessary to process a transaction request. In step414, FSP server140may verify the token and/or transaction. For example, FSP server140may use the token to look up the account of user115and determine whether the transaction should be authorized. FSP server140may check the token against certain parameters to determine, for example, whether the transaction complies with certain parameters, whether the token has expired, etc. In various embodiments, FSP server140may receive and utilize location information or identification information associated with user device130to determine whether to authorize the transaction. For example, FSP server140may receive and utilize the MAC address of user device130and/or the user location to determine whether to authorize the transaction. In step416, if the token and/or transaction can be verified, FSP server140may communicate the authorization to user device150. Otherwise, FSP140may inform user device150that the transaction cannot be authorized. In step418, user device150may process or reject the transaction according to the feedback from FSP server140. The foregoing description has been presented for purposes of illustration. It is not exhaustive and is not limited to the precise forms or embodiments disclosed. Modifications and adaptations of the embodiments will be apparent from consideration of the specification and practice of the disclosed embodiments. For example, the described implementations include hardware and software, but systems and methods consistent with the present disclosure can be implemented as hardware alone. Computer programs based on the written description and methods of this specification are within the skill of a software developer. The various programs or program modules can be created using a variety of programming techniques. For example, program sections or program modules can be designed in or by means of Java, C, C++, assembly language, Python, or any such programming languages. One or more of such software sections or modules can be integrated into a computer system, non-transitory computer-readable media, or existing communications software. Moreover, while illustrative embodiments have been described herein, the scope includes any and all embodiments having equivalent elements, modifications, omissions, combinations (for example, of aspects across various embodiments), adaptations or alterations based on the present disclosure. The elements in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. Further, the steps of the disclosed methods can be modified in any manner, including by reordering steps or inserting or deleting steps. It is intended, therefore, that the specification and examples be considered as exemplary only, with a true scope and spirit being indicated by the following claims and their full scope of equivalents. | 36,796 |
11943008 | DETAILED DESCRIPTION Like features have been designated by like references in the various figures. In particular, the structural and/or functional features that are common among the various embodiments may have the same references and may dispose identical structural, dimensional and material properties. For the sake of clarity, only the operations and elements that are useful to understand the embodiments described herein have been illustrated and described in detail. In particular, the NFC communication protocols and the usual electronic devices or circuits implementing these protocols have not been described as well as the known devices. These protocols are well-known by the one skilled in the art and compatible. In the same manner, the NFC charging, for example according to the WLC specification, and the usual electronic devices or circuits adapted to the NFC charging have not been described, the described embodiments being compatible with NFC charging and with these usual devices. Unless indicated otherwise, when reference is made to two elements connected together, this signifies a direct connection without any intermediate elements other than conductors, and when reference is made to two elements coupled together, this signifies that these two elements can be connected or they can be coupled via one or more other elements. In the following disclosure, unless indicated otherwise, when reference is made to absolute positional qualifiers, such as the terms “front”, “back”, “rear”, “top”, “bottom”, “left”, “right”, etc., or to relative positional qualifiers, such as the terms “above”, “below”, “higher”, “lower”, “behind”, etc., or to qualifiers of orientation, such as “horizontal”, “vertical”, etc., reference is made to the orientation shown in the figures. Unless specified otherwise, the expressions “around”, “approximately”, “substantially” and “in the order of” signify within 10%, and preferably within 5%. In the following disclosure, unless specified otherwise, the expression “NFC communication” means a communication according to the NFC protocols, or said in other words, according to the NFC specification. The expression “NFC charging” means a wireless charging using NFC technologies, preferably a wireless charging according to the WLC specification. The expression “NFC antenna” means the antenna which is used for NFC communications and for NFC charging. The expression “NFC field” means the electromagnetic field used for an NFC communication or for NFC charging between two devices. FIG.1is a schematic rear-view of an NFC-enabled smartphone1configured to wirelessly charge a device via NFC charging. The smartphone1comprises a front face (not visible inFIG.1) having a screen. The smartphone1comprises a back face100, opposite to the front face. The smartphone1comprises an NFC antenna102indicated by dotted lines. The NFC antenna102is disposed inside the smartphone1, between the front face and the back face100of the smartphone1. More precisely, the NFC antenna is disposed on the side of the back face100, for example against the back face100. In other words, the NFC antenna102is disposed behind the back face100. The NFC antenna102is for example disposed in a plane parallel to the back and front faces. In one embodiment, the smartphone1comprises a light source104, preferably a light emitting diode or LED. The light source104is disposed on the back face100. Preferably, the light source104is the flash of an image sensor106of the smartphone1. The image sensor106has an objective disposed in an aperture in the back face100. In one embodiment, the smartphone1comprises a speaker107. In this example, the speaker107is indicated as being disposed on the bottom edge of the smartphone1, but can be disposed in another location (front face, rear face, side edge, top edge . . . ) depending on the model. The speaker107is preferably configured to emit sounds such as music or the voice of a person in phone conversation with the user of the smartphone1. In one embodiment, the smartphone1comprises both the light source104and the speaker107. FIG.2is a schematic front-view of an embodiment of an NFC-enabled device2configured to be charged via NFC charging, for example by the smartphone1inFIG.1. The device2is, for example, an Internet of Things (IoT) device, in this example a smartwatch, although the present disclosure is not limited to a smartwatch2, nor to an IoT device2. For example, the device2could be wireless headphones that need to be charged via NFC charging. The device2comprises a front face200and an NFC antenna202(in dotted lines inFIG.2) disposed behind the front face200. The antenna202is, for example, disposed in a plan approximatively parallel to the front face200. As an example, the front face200may comprise means for displaying information to a user, such as lights, for example LED lights, that may flash, or such as a screen. For example, when device2is a smartwatch, the front face200comprises a screen to display time, and eventually other information. Nevertheless, other devices2may not comprise means for displaying information (specifically a screen). The device2comprises a battery not visible inFIG.2. The device2is configured to charge its battery using NFC charging. Thus, in the following disclosure, unless specified otherwise, charging device2via NFC charging means charging the battery of device2via NFC charging. According to one embodiment, the device2does not have light source, screen or other user interface disposed on its back face, that is to say the face of device2opposite the front face200. FIG.3schematically represents the smartphone1ofFIG.1and the device2ofFIG.2during NFC charging of the device2by the smartphone1. InFIG.3, the smartphone1acts as an NFC transmitter providing an NFC electromagnetic field for charging the device2, which acts as a receiver. During NFC charging, the device2is disposed near the smartphone1, preferably in contact with the smartphone1, such that the front face200of device2(not visible inFIG.3) is facing the back face100of the smartphone1, and such that the antenna102is coupled with the antenna202. In order to maximize the coupling between the antennas102and202, and thus the power transfer from smartphone1to device2, the smartphone1should be aligned with the device2, or, in other words, the antenna102of smartphone1should be aligned with the antenna202of device2. The antennas102and202are said to be aligned for example when, for a given power provided by the smartphone1to its antenna102, the NFC field between device2and smartphone1is at a maximum. However, it is difficult for a user to align the antennas102and202. Indeed, as the device2is disposed on the side of the back face100of the smartphone1, the user does not have access to the screen of the smartphone, which could be used to display information relative to the alignment of the antennas102and202. Further, such information cannot be displayed by the back face of device2when the back face is devoid of screen for displaying such information, which generally the case in practice. For example, the back face of a smartwatch such as the smartwatch2is disposed against the user's wrist while in use, thus does not comprise information display means on the back face. An alignment marker may be added to the back face100of smartphone1to indicate the user where to dispose device2relative to smartphone1, such that the antennas102and202are aligned. However, for esthetic reasons, smartphones manufacturers generally do not want such alignment markers on their products. Further, even if such alignment markers were provided on the back face100of the smartphone1, it cannot be seen by the user when the smartphone1is put in a protective cover, which is mostly the case in practice. There is thus a need to provide a method for NFC charging in which the user is aided with alignment of the NFC antenna102of the smartphone1with the NFC antenna202of device2. It is here proposed to use a smartphone's existing means or devices to help a user during NFC antenna alignment for NFC charging. More precisely, it is here proposed to get, or obtain, by the smartphone, a measured value of a signal representative of the NFC field strength between the smartphone and a device intended to be charged via NFC charging. The smartphone then determines to which range of values the measured value belongs, the range of values being one of a plurality of ranges of values. The smartphone then emits at least one notification signal to the user with a frequency determined by the determined range of values. By doing so, when the user moves the device relative to the smartphone, the user can know if the strength of the NFC field increase or decrease thanks to the frequency variations of the notification signal(s). Thus, the user can move the device relative to the smartphone until the strength of the NFC field between the NFC antennas of the smartphone and the device is at a maximum, or, in other words, until the NFC antennas are aligned. According to an embodiment, the notification signal is a light signal, such as a flashing light, emitted by a light source disposed on the side of the back face of the smartphone, such as the light source104disposed on the rear face100of smartphone1previously described, and/or a sound signal emitted by a speaker of the smartphone, such as the speaker107of the smartphone1previously described. FIG.4represents, in a schematic manner and in the form of blocks, a part of the smartphone1ofFIG.1and a part of the device2ofFIG.2according to an embodiment. Smartphone1comprises the NFC antenna102, schematically represented by a coil inFIG.4, and device2comprises the NFC antenna202, schematically represented by a coil inFIG.4. The NFC antenna102comprises two extremities1021and1022, which are electrically coupled to two corresponding terminals1081and1082of a circuit108by an impedance matching circuit110. The circuit108is an NFC controller. The circuit108is configured to feed the antenna102with an alternating current (AC) signal, preferably a feeding current, so that a corresponding NFC electromagnetic field is emitted by the antenna102. The AC signal feeding the antenna102is provided by terminals1081and1082. The circuit108is further configured to modulate the AC signal provided to the antenna102, so that the NFC electromagnetic field is modulated accordingly and data could be sent to the receiver2. According to one embodiment, the circuit108is configured to measure the feeding current provided to the antenna102by terminals1081and1082. The value of this current is representative of the strength of the NFC field between the smartphone1and the device2, and thus of the position of the antenna202of the device2relative to the antenna102of the smartphone1. Indeed, the position of device2relative to the smartphone1for example affects the impedance seen by the circuit108between terminals1081and1082due to a different loading effect. As a result, the AC signal sent by circuit108changes because voltage between terminals1081and1082is kept constant and voltage, current and impedance are linked together by Ohm's law. Preferably, in this embodiment, the measurement of the feeding current is done with no data exchange between the smartphone1and the device under charge2, or, said in other words, the signal representative of the strength of the NFC field is different from, or not based on, a value measured by the device2and sent to the smartphone using a wireless communication, and in particular a NFC wireless communication using the NFC field. The two extremities1021and1022are further coupled to two terminals1083and1084of the circuit108, for example by capacitive and/or resistive divider. The alternating (AC) voltage received by the terminals1083and1084of the circuit108is thus an image or copy of the AC voltage between the extremities1021and1022of the antenna102. In other words, the AC voltage between terminals1083and1084is representative of the AC voltage between extremities1021and1022of the antenna102. The two terminals1083and1084are coupled to a demodulator circuit (not shown) of the circuit108, for example to an I/Q mixer of this demodulator circuit. The circuit108is configured to demodulate the AC signal available between the extremities1021and1022of the antenna102, in order to receive data sent by the device2using NFC communication, for example by means of load modulation of the device2on the carrier field. In order to demodulate the AC voltage between terminals1083and1084, the circuit108, and more particularly its demodulator circuit, is configured to extract the envelope and, preferably, the phase of this AC voltage. According to one embodiment, the circuit108, and more particularly its demodulator circuit, is configured to measure the voltage between its terminals1083and1084, thus between extremities1021and1022of the antenna102. More precisely, the circuit108, and more particularly its demodulator circuit, is configured to measure the value of the envelope of the AC voltage between terminals1083and1084, the envelope being a voltage. In other words, the circuit108, and more particularly its demodulator circuit, is configured to measure the amplitude of the envelope of the AC voltage between terminals1083and1084. The value of this voltage is representative of the strength of the NFC field between the smartphone1and the device2, and thus of the position of the antenna202of the device2relative to the antenna102of the smartphone1. Preferably, in this embodiment, the measurement of the envelope of the AC voltage is done with no data exchange between the smartphone1and the device under charge2, or, said in other words, the signal representative of the strength of the NFC field is different from, or not based on, a value measured by the device2and sent to the smartphone using a wireless communication, and in particular a NFC wireless communication using the NFC field. According to an embodiment, the smartphone1comprises a processing unit112. The processing unit112is configured to exchange data with the NFC controller108, and with other devices of the smartphone1. According to one embodiment, the circuit112is configured to command the light source104and the speaker107of the smartphone1described previously in relation withFIG.1. Although not shown inFIG.4, the smartphone1comprises other circuits, which are usual circuits well known to a person skilled in the art. The NFC antenna202comprises two extremities2021and2022, which are electrically coupled, preferably connected, to two corresponding terminals2041and2042of a circuit204of the device2. The circuit204is configured to manage NFC communication. In other words, the circuit204is configured to demodulate a signal available between extremities2022and2021of the NFC antenna202, in order to receive data sent by the smartphone using NFC communication protocols. The circuit204is further configured to manage NFC charging. In other words, the circuit204is configured to convert the AC electric signal available between the extremities2021and2022of the NFC antenna202in a direct current (DC) Idc. The current Idc is provided by the circuit204to a circuit206. The circuit206is battery charger which is configured to charge a battery208of the device2from the current Idc. The circuit206provides a charging current Icharg to the battery208. According to one embodiment, the device2, and more particularly its circuit206, is configured to measure the charging current Icharg provided to the battery208. The value of this current is representative of the strength of the NFC field between the smartphone1and the device2, and thus of the position of the antenna202of the device2relative to the antenna102of the smartphone1. According to one embodiment, the device2, and more particularly its circuit204, is configured to send data to the smartphone using NFC communication, for example by retro-modulating the NFC field provided by the smartphone. According to a preferred embodiment, the device2is configured to send to the smartphone1the measured value of the current Icharg, by using NFC communication. Although not shown inFIG.4, the device2comprises other circuits, which are usual circuits well known by the one skilled in the art, for example an NFC chip or tag, an NFC impedance matching circuit, a power management unit, a processing unit or processor or integrated circuit, etc. FIG.5is a flow chart illustrating an embodiment of an NFC charging method, and more precisely of an alignment method of a smartphone and a device intended to be charged by the smartphone via NFC charging. For example, the smartphone corresponds to the smartphone1described in relation withFIG.1, preferably having the part described in relation withFIG.4, and the device to be charged via NFC charging is the device2described in relation withFIG.2, preferably having the part described in relation withFIG.4. At a first step500(block “START CHARGING”), the smartphone1provides an NFC field, both for charging the device2and for communicating with the device2. At this step, the device2is disposed, by a user, near the smartphone1on the back face100of the smartphone1, preferably in contact with the face100, the front face200of the device2facing the back face100of the smartphone1. Thus, the antenna102is coupled with the antenna202. At a next step502(block “GET MEASURED VALUE”), the smartphone1gets or obtains a measured value of a signal representative of the strength of the NFC field between the smartphone1and the device2. According to one embodiment, the signal representative of the strength of the NFC field is the AC voltage between the extremities of the antenna102of the smartphone1, and more particularly the envelope (or amplitude) of this AC voltage. In such embodiment, the measurement is made by the smartphone1itself. For example, the measurement is done by the circuit108(FIG.4), which for example receives, between terminals1083and1084, an image of the AC voltage between the extremities1021and1022of the antenna102. Preferably, the measurement of the amplitude of the AC voltage between terminals1083and1084is done by means an I/Q mixer circuit of the circuit108, which is configured to extract the envelope (or amplitude) of the AC voltage between terminals1083and1084, that is to say to provide a voltage corresponding to the AC voltage envelope. Preferably, in this embodiment, the measurement of the envelope of the AC voltage is done with no data exchange between the smartphone1and the device under charge2, or, said in other words, the signal representative of the strength of the NFC field is different from, or not based on, a value measured by the device2and sent to the smartphone using a wireless communication, and in particular a NFC wireless communication using the NFC field. In this case, the step502of obtaining a measured value of the signal representative of the strength of the NFC field is preferably done with no data exchange between the smartphone1and the device2, or, at least, preferably with no data sent by the device2to the smartphone1using a wireless communication. According to one embodiment, the signal representative of the strength of the NFC field is the current provided by the smartphone1to its antenna102for generating the NFC field. In such an embodiment, the measurement of the value of this current is made by the smartphone1itself, for example by its circuit108(FIG.4). Preferably, in this embodiment, the measurement of the current is done with no data exchange between the smartphone1and the device under charge2, or, said in other words, the signal representative of the strength of the NFC field is different from, or not based on, a value measured by the device2and sent to the smartphone using a wireless communication, and in particular a NFC wireless communication using the NFC field. In this case, the step502of obtaining a measured value of the signal representative of the strength of the NFC field is preferably done with no data exchange between the smartphone1and the device2, or, at least, preferably with no data sent by the device2to the smartphone1using a wireless communication. According to one embodiment, the signal representative of the strength of the NFC field is the charging current provided by the device2to its battery, for example the current Icharg for charging the battery208(FIG.4). In such an embodiment, as it will be described in more detail withFIG.6, the step502comprises a first sub-step wherein the device2measures the current Icharg (or an image of the current Icharg), and a following sub-step wherein the device2sends the measured value of the current Icharg to the smartphone1using NFC communications. As a result, at the end of the step502, the smartphone1has obtained the measured value of the signal representative of strength of the NFC field. The step502is followed by a step504(block “DETERMINE RANGE OF VALUE”). In this step504, the smartphone1determines to which range of values the measured value belongs, the range of values being one of a plurality of ranges of values of the signal representative of the strength of the NFC field. This may be done by the processing unit112(FIG.4) of the smartphone1. For example, the smartphone1, and more particularly its processing unit112, determines to which range of values the measured value belongs by comparing the measured value with thresholds corresponding to the boundaries of these ranges of values. According to an embodiment, the ranges of values, that is to say their boundaries, are stored in a memory (not shown) of the smartphone1. According to an embodiment, each range of values corresponds to different strengths, or intensities or powers, of the NFC field between device2and smartphone1. Thus, depending on which of these ranges of values the measured value belongs, it can be determined whether the smartphone1and the device2are aligned or not, and, when they are not aligned, the position of the device2relative to the position wherein the device2is aligned with the smartphone1(ideal position). Indeed, the further the device2is from the aligned position, the lower the strength of the NFC field. According to an embodiment, these ranges are determined during a design phase of the smartphone1and/or of the device2. For example, the signal representative of the strength of the NFC field is measured during the smartphone1and/or device2design phase, while moving the device2relative to the smartphone1. After measurements are done, different ranges of values of this signal are defined, such that these different ranges of values of the signal correspond to different ranges of strengths of the NFC field, and thus to different ranges of positions of the device2relative to the smartphone1. Then, those ranges of values are recorded into a memory (not shown) of the smartphone1. When implementing the method ofFIG.5, if the measured value of the signal (step502) is in the range of values which comprises the value of the signal corresponding to the ideal position of the device2relative to the smartphone1(step504), the device2and the smartphone1are for example considered to be aligned. As a first example, when the signal representative of the strength of the NFC field is the charging current provided to the battery208of the device2, the determination of these ranges of values comprises: determining the maximum value of the signal when the device2is aligned with the smartphone1; dividing the maximum value to get a plurality of lower values of the signal; and determining the ranges of values using the maximum and the lower values of the signal as boundaries or as central values of the ranges of values, the ranges of values being preferably contiguous. For example, when the maximum value of the charging current is equal to 50 mA, for example four ranges R1, R2, R3and R4of values may be determined as follows:the range R1comprises the values X superior or equal to the maximum value (50 mA≤X);the range R2comprises values X inferior to the maximum value and superior or equal to 40 mA (40 mA≤X<50 mA);the range R3comprises the values X inferior to 40 mA and superior or equal to 20 mA (20 mA≤X<40 mA); andthe range R4comprises the values X inferior to 20 mA (X<20 mA). As a second example, when the signal representative of the strength of the NFC field is the current provided to antenna102of the smartphone1, the determination of these ranges of values comprises: determining the optimum value of the signal when the smartphone1is aligned with a device intended to be NFC charged by the smartphone1; dividing the optimum value to get a plurality of lower values of the signal; and determining the ranges of values using the optimum and the lower values of the signal as boundaries or as central values of the ranges of values, the ranges of values being preferably contiguous. For example, when the optimum value of the current is equal to 200 mA, for example six ranges R1′, R2′, R3′, R4′, R5′ and R6′ of values may be determined as follows:the range R1′ comprises the values X around the optimum value, that is to say between 200 mA+50 mA and 200 mA−50 mA (150 mA≤X<250 mA);the range R2′ comprises the values X between 250 mA and 300 mA (250 mA≤X≤300 mA);the range R3′ comprises the values X superior to 300 mA (300 mA<X);the range R4′ comprises the values X between 150 mA and 100 mA (100 mA≤X<150 mA);the range R5′ comprises the values X between 100 mA and 50 mA (50 mA≤X<100 mA); andthe range R6′ comprises the values X inferior to 50 mA (X<50 mA). As a third example, when the signal representative of the strength of the NFC field is the AC amplitude voltage between the extremities1021and1022of the antenna102of the smartphone1, or, in other words, the AC amplitude voltage between the terminals1083and1084which is an image of the AC amplitude voltage between extremities1021and1022of the antenna102, the determination of these ranges of values comprises:determining the optimum value of the signal when the smartphone1is aligned with a device intended to be NFC charged by the smartphone1;dividing the maximum value to get a plurality of lower values of the signal; anddetermining the ranges of values using the maximum and the lower values of the signal as boundaries or as central values of the ranges of values, the ranges of values being preferably contiguous. For example, when the optimum value of the AC amplitude voltage between terminals1083and1084is equal to 3 V, for example five ranges R1″, R2″, R3″, R4″ and R5″ of values may be determined as follows:the range R1″ comprises the values X around the optimum value, that is to say between 3 V+0.5 V and 3 V−0.5 V (2.5 V≤X≤3.5 V);the range R2″ comprises the values X between 3.5 V and 4.0 V (3.5 V<X≤4.0 V);the range R3″ comprises the values X superior to 4.0 V (4.0 V<X);the range R4″ comprises the values X between 2.5 V and 2.0 V (2.0 V≤X<2.5 V); andthe range R5″ comprises the values X inferior to 2.0 V (X<2.0 V). It is to be noted that for the above range examples, the less than/greater than/equal to signs are merely indicative, and may be modified as needed. At a next step506(block “EMIT SIGNAL”), at least one notification signal is emitted by the smartphone to the user. Each notification signal is periodic and has a frequency determined by the range of values to which belongs the measured value of the signal representative of the NFC field strength. Thus, the user receiving the notification signal(s) may determine whether the device2is aligned with the smartphone1or if he/she should move the device2relative to the smartphone1in order to align the device2with the smartphone1. According to one embodiment, the notification signal is a flashing light emitted by the light source104of the smartphone1. Thus, when the light source104is already provided on the back face100of the smartphone1for other purposes, which is the case in practice, the notification signal can be emitted without adding a specific device to the smartphone1. Further, an advantage of using such a light source104is that it can been seen by the user, even when the device2is disposed on the back face100of the smartphone1, which is not the case of the screen of the front face of the smartphone1. According to one embodiment, the notification signal is a sound emitted by the speaker107of the smartphone1, for example an intermittent periodic sound. Thus, when the speaker107is already provided on the smartphone1for other purposes, which is the case in practice, the notification signal can be emitted without adding a specific device to the smartphone1. Further, an advantage of using such a sound notification signal is that it can been heard by the user, even when the device2is disposed on the back face100of the smartphone1. The two embodiments above may be combined, such that both a light notification signal and a sound notification signal are emitted by the smartphone to the user. At a next step510(block “STOP CHARGING”), it is determined, for example by the smartphone1, if the NFC charging should continue or not. For example, the smartphone1stops providing the NFC field when the smartphone does not detect the device2anymore, or when the smartphone receives from the device2an instruction to stop the NFC charging. If the NFC charging must be stopped (branch Y of block510), the method ends at a step512(block “END CHARGING”). If the NFC charging must continue (branch N of the block510), the method continues at step502. According to an embodiment, until the end of the NFC charging, the steps502,504,506are periodically repeated. For example, the step506can be implemented for a given period of time before moving to step510. That is to say, in step506, according to one embodiment, the notification signal(s) are emitted for a given period of time, for example 5 s, before moving to the next step. According to one embodiment, the frequency of the notification signal(s) varies with the strength of the NFC field between the smartphone and the device, or, in other words, with the range of values to which the measured value belongs. Thus, based on the frequency of the emitted notification signal(s), the user knows that device2approaches, or, on the contrary, moves away from, the ideal position where the device2is aligned with the smartphone1. According to one embodiment, the frequency of the notification signal(s) increases when the position of the device2approaches the ideal position of the device2relative to the smartphone1. Further or alternatively, in one embodiment, when alignment is achieved, the notification signal(s) are continuous for a set amount of time, such as 5 s, and then stop. According to yet another embodiment, the frequency of the notification signal(s) decreases when the position of the device2approaches the ideal position wherein the device2is aligned with the smartphone1. Further or alternatively, in one embodiment, when the measured value belongs to the range of values corresponding to a maximal NFC field strength (alignment is achieved), the notification signal(s) stop, or, in other words, the frequency of the notification signal(s) is null. This prevents the user from being annoyed by continued beeping/flashing lights or sound. Further, as no light or sound is emitted by the smartphone1when the device2and the smartphone1are aligned, the power consumption is reduced compared to a case where a continuous sound and/or light or a high frequency intermittent sound and/or light is emitted when the device2and the smartphone1are aligned. Further or alternatively, in one embodiment, when alignment is achieved, another light (such as if different color LEDs are provided) and/or another tone of beep is emitted for a set amount of time, such as 5 s, and then stops. Although not illustrated inFIG.5, in one embodiment, when alignment is achieved, the step506could be followed by an additional step similar to step510, with the difference that, if the NFC charging is not finished, this additional step is repeated without being followed by step502. Thus, in such an embodiment, after alignment is achieved and until the NFC charging ends, no notification signal is emitted. With the method described above, the user knows if the device2is aligned with the smartphone1, and when they are not aligned, the position of the device2relative to the position where the device2is aligned with the smartphone1. Thus, if the device2is not aligned with the smartphone1, the user can move the device2relative to the smartphone1until he/she receives the notification signal(s) indicating that device2and smartphone1are aligned. For example, referring back to the examples of ranges of values indicated previously, the frequencies of the notification signal(s) may be chosen as follow:the frequency is null for the ranges R1, R1′ and R1″;the frequency is equal to 0.5 Hz for the ranges R2, R2′, R4′, R2″ and R4″;the frequency is equal to 1 Hz for the ranges R3, R3′, R5′ and R3″; andthe frequency is equal to 2 Hz for the ranges R4, R6′ and R5″. The method described in relation withFIG.5allows the device2to be aligned with a smartphone1which provides NFC charging to the device2, without requiring another means of wireless communication such as Bluetooth. FIG.6is a flow charts illustrating an embodiment of step502when the signal representative of strength of the NFC field is the current provided by the device2to its battery208for charging the battery208. In such embodiment, as previously introduced, step502comprises a first sub-step5021(block “MEASURE CHARGING CURRENT”) and a second sub-step S022(block “SEND MEASURED VALUE VIA NFC”). In sub-step5021, the device2measures the value of the charging current provided to its battery208. In sub-step5022, the device2sends the value measured at step S021to the smartphone1, by means of NFC communication. Thus, the smartphone1gets or obtains the measured value. According to one embodiment wherein the signal representative of the strength of the NFC field is the charging current provided to the battery208of the device2further configured to implement sub-steps5021and5022, the device2may be configured to store the plurality of ranges of values of this current and to emit one or more notification signals similar to the one or to those emitted by the smartphone1. In this case, the device2comprises a light source on its back face to emit a light notification signal, and/or a speaker to emit a sound notification signal. In the embodiments described above, the ranges of values are determined during a design phase of the smartphone1and/or the device2. According to a further embodiment, these ranges of values are determined during a configuration phase. This configuration phase is, for example, done before or at the step500. This configuration phase is for example done each time the method ofFIG.5is implemented, or only once for a given pair of a smartphone1and a device2. This configuration phase is preferably done when the ranges of values have not been determined during the design phase of the smartphone1and/or the device2. During this configuration phase, the smartphone1and the device2are disposed as it was described in relation withFIG.3. Further, the user moves the device2relative to the smartphone1, for example over approximatively the whole back face100of the smartphone, while the smartphone1obtains a plurality of measured values of the signal representative of the strength of the NFC field. The smartphone1, and more particularly its processing unit112, then determines the maximal value among the plurality of measured values, and the ranges of values as a function of the maximal value. As an example, the user can be invited by the smartphone1to run the configuration phase, for example by means of sounds, for example emitted by the speaker107, and/or of lights, for example emitted by the light source104, which are different from the notification signal(s) emitted at the step506(FIG.5). During the configuration phase, the smartphone1may indicate the user when he/she has to move the device2relative to the smartphone, for example in order to ensure that the smartphone1has enough time to obtain the measured value for this position of the device2. This indication for example corresponds to sounds, for example emitted by the speaker107, and/or lights, for example emitted by the light source104, which are different from the notification signal(s) emitted at the step506(FIG.5). As an example, the sounds and/or lights emitted for inviting the user to run a configuration phase, and/or for indicating the user to move the device2relative to smartphone1, have frequencies far different from those of the lights and/or sounds emitted during the step506, for example frequencies at least five or ten time lower or higher than those of the notification signal(s). The sounds emitted for inviting the user to run a configuration phase, and/or for indicating the user to move the device2relative to smartphone1, may further or alternatively have tone different from the tone(s) of the sounds emitted during the step506. The lights emitted for inviting the user to run a configuration phase, and/or for indicating the user to move the device2relative to smartphone1, may further or alternatively have color different from the color(s) of the lights emitted during the step506. Various embodiments and variants have been described. Those skilled in the art will understand that certain features of these embodiments can be combined and other variants will readily occur to those skilled in the art. In particular, the present disclosure applies to NFC-enabled devices2other than a smartwatch, which are configured to be charged by the smartphone1using NFC charging. Finally, the practical implementation of the embodiments and variants described herein is within the capabilities of those skilled in the art based on the functional description provided hereinabove. A method for aligning a smartphone1providing NFC wireless power for charging a battery208of a device2, the method may be summarized as including emitting, with a first NFC antenna102of the smartphone1, an NFC field for wirelessly charging the battery208of the device2including a second NFC antenna202; obtaining, with the smartphone1, a measured value of a signal representative of the NFC field strength between the smartphone1and the device2; determining, by the smartphone1, a range of values of a plurality of ranges of values the measured value belongs; and emitting, by the smartphone1, at least one notification signal to a user with a frequency determined by the determined range of values. The smartphone1may include a first face having a screen; and a second face100opposite to the first face, the first NFC antenna102being disposed behind the second face100, wherein, during the NFC charging, the device2is disposed above and facing the second face. Said at least one notification signal may be a light signal emitted by a light source104disposed on the second face100and/or a sound signal emitted by a speaker107of the smartphone1. The frequency may vary with the strength of the NFC field between the smartphone1and the device2. The frequency may decrease when the strength of the NFC field increases, the frequency being preferably null when the measured value belongs to the range of values corresponding to a maximal NFC field strength. The signal representative of the strength of the NFC field may be a feeding current provided by the smartphone1to the first NFC antenna102, and wherein obtaining the measured value includes measuring, with the smartphone1, the feeding current. The signal representative of the strength of the NFC field may be an AC voltage between extremities1021,1022of the first NFC antenna102, and wherein obtaining the measured value includes measuring, with the smartphone1, an envelope of said AC voltage or an envelope of an image of the AC voltage. The signal representative of the strength of the NFC field may be a charging current provided to the battery208of the device2by the second NFC antenna202, and wherein obtaining the measured value includes measuring, with the device2, the charging current and transmitting, by the device2to the smartphone1, the measured value using NFC communication. The steps of obtaining the measured value502, determining the range of values504and emitting said at least one notification signal506may be periodically repeated, preferably until the NFC charging ends. The step504determining said range of values may include comparing said measured value with thresholds corresponding to boundaries of each the ranges of values of the plurality of ranges of values. A smartphone1configured to implement the method, wherein the smartphone1may include a first NFC antenna102and is configured to emit, by means of the first NFC antenna102, an NFC field for wirelessly charging a battery208of a device2including a second NFC antenna202; the smartphone1may be configured to obtain a measured value of a signal representative of the NFC field strength between the smartphone1and the device2; the smartphone1may be configured to determine to which of a plurality of ranges of values said measured value belongs; and the smartphone1may be configured to emit at least one notification signal to a user, with a frequency determined by the determined range of values. The smartphone1may include a first face having a screen and a second face100opposite the first face, wherein the first NFC antenna102is disposed behind the second face, and wherein NFC field emitted by the first NFC antenna102is configured to wirelessly charge the battery208of device2including a second NFC antenna202. The smartphone1may include a light source104disposed on the second face100, said at least one notification signal being a periodic flashing light signal emitted by said light source104, the light source104being preferably a flash of an image captor106of the smartphone1; and/or the smartphone1may include a speaker107, said at least one notification signal being a sound emitted by said speaker107, the speaker107being preferably configured to emit other sounds than the notification signal. The signal representative of the strength of the NFC field may be a charging current provided to the battery208of the device2from the second NFC antenna202, the smartphone1being configured to receive said measured value send by the device1using NFC communication. A device2configured to implement the method, wherein the device2may include a battery208and a second NFC antenna202configured to be coupled with a first NFC antenna102of a smartphone1, the device2being configured to charge the battery208using a NFC field emitted by the first antenna102and received by the second antenna202, to measure a value of a charging current provided to the battery208from the second antenna202and to send the measured value to the smartphone1using NFC communication, the charging current provided to the battery208being the signal representative of the strength of the NFC field between the smartphone1and the device2, the device being preferably an internet of things, IoT, device. The various embodiments described above can be combined to provide further embodiments. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure. | 44,040 |
11943009 | DETAILED DESCRIPTION In the following, a communication barrier arrangement will be described. The same reference numerals will be used to denote the same or similar structural features. In a process control system, it may be necessary for a first process control system device to communicate with a second process control system device via a communication barrier arrangement that isolates the first process control system device from the second process control system device. This may for instance be the case if the second process control system device is provided in an environment from which the first process control system device needs to be isolated, for instance if the environment in which the second process control system device is provided is hazardous. One example of a hazardous environment is an explosive environment. FIG.1schematically shows a simplified process control system10comprising such a first process control systems device PCSD112that communicates with a second process control system device PCSD214via a communication barrier arrangement CBA16, where the second process control system device14and parts of the communication barrier arrangement16are provided in a hazardous environment HE. The first process control system device12may for instance be a controller such as a microcontroller and the second process control system device14may be field device, such as an IO (Input Output) device. It may also be realized as a microcontroller. The communication barrier arrangement16may as an example be an intrinsically safe IO module, for instance for Ex environments according to IEC 60079-11. FIG.2schematically shows the first process control system device12, the second process control system device14as well as a more detailed communication barrier arrangement16. The communication barrier arrangement16comprises a first driving stage DS118, an isolation barrier20, a second driving stage DS222, a protection circuit PRC26and a first signal conditioner SC124. The first driving stage18has a first interface I1 for connection to the first process control system device12. The first driving stage18is also connected to the isolation barrier20. The isolation barrier20has a primary and a secondary side, where the primary side is connected to the first driving stage18and the secondary side is connected to the second driving stage22. The isolation barrier20comprises a first and a second transformer TR1 and TR2, where each transformer has a primary and a secondary winding L1, L2, L3, L4. The first driving stage18is connected to the primary winding L1 of the first transformer TR1 and to the primary winding L2 of the second transformer TR2. The second driving stage22is in turn connected to the secondary winding L3 of the first transformer TR1 and to the secondary winding L4 of the second transformer TR2. The second driving stage22has a first connection terminal CT1 for output of the first signals towards the second process control system device14and for reception of the second signals S2 from the second process control system device. The first connection terminal CT1 is interconnected with a second connection terminal CT2 of the first signal conditioner24via the protection circuit26. The first signal conditioner24thereby has a second connection terminal CT2 for receiving the first signals S1 from the second driving stage22as well as for transmitting the second signals S2 to the second driving stage22. The first signal conditioner24also has a second interface12for delivering the first signals S1 to the second process control system device14as well as for receiving the second signals S2 that are destined for the first process control device12. As can be seen above, the protection circuit26is connected between the first and second connection terminals CT1 and CT2. These connection terminals may be the only connection terminals of the second driving stage22and the first signal conditioner24. Thereby, the signal connection between the first and second connection terminals CT1 and CT2 that passes through the protection circuit26may be the only signal connection between the second driving stage22and the first signal conditioner24. The protection circuit26comprises two components, a resistor R and a first capacitor C1, where the resistor R is connected in parallel with the first capacitor C1. The protection circuit26also has a first side28that is connected to the first connection terminal CT1 and thereby the first side28faces the isolation barrier20. The protection circuit26also has a second side30at an opposite end of the parallel components and this second side30is connected to the second connection terminal CT2. The first communication interface11receives first signals S1 from the first process control system device12that are destined for the second process control system device14as well as delivers second signals S2 to the first process control system device12, where the second signals S2 originate in the second process control system device14. In an analogous manner, the second interface12receives the second signals S2 from the second process control system device14and delivers the first signals S1 to the second process control system device14, where the first signals S1 thus originate in the first process control system device12. The first signals S1 may be universal asynchronous receiver-transmitter (UART) signals, while the second signals S2 may be logic level signals, such as transistor-transistor logic (TTL) level signals. In the isolation barrier20, the first transformer TR1 is provided for transfer of the first signals S1 and the second transformer TR2 is provided for transfer of the second signals S2. In the second driving stage22the first connection terminal CT1 is provided for output of the first signals S1 towards and reception of the second signals S2 from the second process control system device14. In the first signal conditioner24, the second connection terminal CT2 is provided for receiving the first signals S1 from and transmitting the second signals S2 to the second driving stage22. The first signal conditioner24may additionally have a pull up resistor connected to the second connection terminal CT2 for providing a signal level voltage that can be used for outputting the second signals S2. The first signal conditioner24may furthermore comprise processing logic for influencing the voltage on the second connection terminal CT2. It may for this reason be realized as a field-programmable gate array (FPGA) for implementing an UART interface. However, it should be realized that other realizations are also possible, such as an application specific integrated circuit (ASIC). According to aspects of the present disclosure, the first driving stage18is an active driving stage, and the second driving stage22is a passive driving stage, meaning that the first driving stage18needs to be supplied with power for its operation, while the second driving stage22does not need such power. This is inFIG.2indicated through the first driving stage18being connected to a power supply voltage VCC, while the second driving stage22has no such power supply. The isolation barrier20is designed for providing isolation according to the field of application. Thereby the primary and secondary windings of the first and second transformers TR1 and TR2 may be separated by insulation of a thickness that is suitable for the field of application. In the case of use in Ex environments, the insulation may as an example be thicker than 1.o mm. In some such hazardous environments, the isolation barrier20may be subjected to a hazardous voltage, which is typically a high enough voltage to be harmful. It is thereby of interest to protect the isolation barrier20and especially the transformers TR1 and TR2 of the isolation barrier20. The protection circuit26is provided for this reason. A properly designed protection circuit26may provide reliable protection of the isolation barrier20. This protection circuit26may need to have a fairly large resistance, such as a resistance of above 40 kΩ. Furthermore, the operation may lead to the first capacitor C1 being charged. This charging may affect the first signals S1 when they enter the first signal conditioner24. This effect is schematically shown in curve b ofFIG.3, which shows the voltage VCT2at the second connection terminal CT2 when there is a protection circuit, as compared with a corresponding ideal voltage VCT2when there is no protection circuit shown in curve a. The voltage at the second connection terminal CT2 is also the voltage at the second end30of the protection circuit26. The use of a large resistor R leads to the first capacitor C1 being charged without a following discharge. The first capacitor C1 may thus be saturated. Thereby, the information in the signal S1 may become impossible to decode by the first signal conditioner24. Aspects of the present disclosure are directed towards allowing the signals to be detected at the same time as the isolation barrier20is protected. How this can be done will now also be disclosed with reference being made toFIG.4, which shows a flow chart of a number of method steps in a method of operating the communication barrier arrangement16. In the method, the first driving stage18receives the first signals S1 from the first process control system device12, S100, and the first signal conditioner24receives the second signals S2 from the second process control system device14, S102. The first and second signals S1 and S2 are then transferred through the communication barrier arrangement16. The first driving stage18thus transfers the first signals S1 to the second process control system device14via the first transformer TR1, the second driving stage22, the protection circuit26and the first signal conditioner24, step S104. The first signal conditioner24in turn transfers the second signals S2 to the first process control system device12via the protection circuit26, the second driving stage22, the second transformer TR2 and the first driving stage18, S106. In order to enable signal level detection, the first signal conditioner24may investigate the voltage at the first connection terminal CT1, which is also an investigation of the voltage at the first side28of the protection circuit26. The signals on the first connection terminal CT1 may comprise at least one zero voltage level. If now the first signal conditioner24detects that there is supposed to be a zero-voltage level at the first side28of the protection circuit28, S108, i.e. at the first connection terminal CT1, the first signal conditioner24pulls down the voltage at the second side30of the protection circuit26to zero, S110. This pulling down is made through giving the second connection terminal CT2 a zero voltage, for instance through grounding the second connection terminal CT2. The pulling down may be made at the same time as the first connection terminal has the zero-voltage and thereby the first capacitor C1 will be discharged. It is additionally possible that the monitoring is made on the second side of the protection circuit26, i.e. at the second connection terminal CT2. In this case the first signal conditioner24may compare the voltage VCT2at the second connection terminal CT2 with a threshold and pull this voltage VCT2down to zero if the threshold is exceeded. The detection may thus be carried out through comparing the voltage at the second connection terminal CT2 with the threshold and pulling the voltage at this connection terminal to zero if detecting that the threshold is being crossed, i.e. that the voltage passes the threshold. Once the discharge is complete, the voltage may be allowed to rise again until the threshold is again crossed. The threshold may be a threshold below the signal level provided through the use of the pull-up resistor, such as at a fraction of the signal level, for instance at ¼ of the signal level. How this can be carried out can be seen in curve c inFIG.3, where it can also be seen that as soon as the voltage VCT2at the second connection terminal CT2 has reached the threshold, the voltage is pulled down, which occurs when the voltage at the first connection terminal CT1 is zero but the first capacitor C1 has a charge corresponding to the threshold. The voltage is thus forcibly pulled down to zero and thereby the first capacitor C1 is discharged. It can also be seen that it is possible that there are several such discharging cycles in a period of time when the first connection terminal CT1 has a zero voltage. Thereby it is possible to protect the isolation barrier20while at the same time enable detection of the first signals S1. Now aspects of the communication barrier arrangement will be described, where more details about the way that the signals may be transferred will be given. FIG.5schematically shows more details of the communication barrier arrangement16. The first driving stage18comprises a first coding circuit38connected to the primary winding L1 of the first transformer TR1. The first coding circuit38codes the first signals S1 into a carrier CA having a carrier frequency and conveys the carrier CA with the coded first signals S1 to the first signal conditioner24via the first transformer TR1, the second driving stage22and the protection circuit26. The signal conditioner24in turn extracts the first signals S1 from the carrier CA. The coding may be a logical combining of the first signals S1 with the carrier. The first coding circuit38may thereby be a first logical circuit that may be a NOR gate performing a logical NOR operation on the first signals S1 and the carrier CA, which in this case is a high-frequency carrier, such as a high-frequency square wave. This means that the output of the first coding circuit38is a number of pulses of the carrier or a zero-voltage depending on the signs of the first signals S1. Here it should be realized that the first coding circuit may just as well be an AND gate that performs a logical AND operation. The method may therefore additionally comprise coding, in the first driving stage18, the first signals S1 into a carrier CA, where the transferring of the first signals comprises conveying the carrier CA with the coded first signals S1 to the first signal conditioner24via the first transformer TR1 and extracting, in the signal conditioner24, the first signals S1 from the carrier CA. It can also be seen that the second driving stage22comprises a first transistor T1 connected to the first connection terminal CT1. The first transistor T1 has a base or gate connected to the secondary winding L3 of the first transformer TR1, a collector or drain connected to the first connection terminal CT1 and an emitter or source connected to ground. In the present example the transistor is a bipolar transistor, why it has a gate, emitter and collector oriented in the above-mentioned way. There is also a rectifier32connected between the secondary winding L3 of the first transformer TR1 and the first transistor T1. The rectifier32is with advantage realized using one or more diodes. As the first transformer TR1 is connected to the protection circuit26via a diode rectifier and a first transformer with the above-mentioned orientation, the second driving stage22can transfer the carrier with the modulated first signals to the first signal conditioner24without the use of a power supply voltage. In order to transfer the second signals S2 to the first driving stage18, the second driving stage22comprises a switch SW in parallel with the secondary winding L4 of the second transformer TR2, which switch SW is operated using the second connection terminal CT2. The switch SW is thus operated without the use of an external power supply. Thereby also the second signals S2 can be transferred by the second driving stage22without the use of an external power supply. An impedance detector34is also connected to the primary winding L2 of the second transformer TR2 and a second signal conditioner36is connected to the impedance detector34. The impedance detector may be realized as a diode. The second signal conditioner36may be realized as a comparator that compares a detected impedance with an impedance threshold and outputs binary pulses based on the comparison, which binary pulses recreate the second signals. It may output one binary value if the detected impedance is above the threshold and another if the impedance is below the threshold. The transferring of the second signals S2 is in this case made through coding the second signals S2 into the impedance of the second transformer TR2 as impedance variations of the second transformer TR2, where this impedance is the impedance as seen from the primary winding L2 of the second transformer TR2. In the method the communication barrier arrangement16, and in this case the second driving stage22, codes the second signals S2 into the impedance of the second transformer TR2, which coding may be a coding as impedance variations of the second transformer TR2 as seen from the primary winding L2 of the second transformer TR2. In the first driving stage18, the impedance of the second transformer TR2 is then detected at the primary winding L3 and the second signal S2 recreated based on the changes in the detected impedance. The signal is more particularly recreated through the comparing of the measured impedance with the impedance threshold. In order to perform the coding, the second signals S2 at the second connection terminal CT2 are binary with a first and second value, where the signals are applied to the switch SW via the first connection terminal CT1. It is possible that a first binary value of the second signals corresponds to a signal level voltage at the second connection terminal CT2 and that a second binary level of the second signals corresponds to a zero-level voltage at the second connection terminal. The switch SW is then closed when the first binary value appears on the first connection terminal CT1 and opened when the second binary value appears on the first connection terminal CT1, thereby coding the second signals S2 as impedance variations of the second transformer TR2. Furthermore, the first binary value may correspond to a signal level voltage at the second connection terminal CT2 of the first signal conditioner24and the second binary level may correspond to a zero-level voltage at the second connection terminal CT2 of the first signal conditioner24. The switch SW may additionally be realized as a second transistor with the drain and source or collector and emitter connected to the secondary winding L4 of the second transformer TR2 and the gate or base connected to the first connection terminal CT1. In the present case the second transistor is an open drain metal-oxide-semiconductor field-effect transistor (MOSFET) transistor, why it is the drain, source and gate that have the above-mentioned orientation. It is possible to improve the sensitivity of the impedance detection. This can be done through connecting a second capacitor C2 in parallel with the primary winding L2 of the second transformer TR2, which second capacitor C2 has a value selected to tune the resonance frequency of the second transformer TR2 to the carrier frequency. It can finally be seen that the first driving stage also comprises a second logical circuit40connected to the primary winding of the second transformer TR2, where the second logical circuit40, which receives the carrier, is an inverter. It inverts the carrier and supplies it to the second transformer TR2. As can be seen above there is provided communication barrier arrangement, where protection of the isolation barrier is introduced without stopping signal detection. Furthermore, the second driving stage can be made passive, without the requirement of a supply voltage combined with an improved sensitivity in the detection of the second signals. It should here be realized that several variations are possible. It is possible that the rectifier and first transformer of the second driving stage are omitted. Moreover, in some instances, the second signals may not be needed. In this case the switch of the second driving stage and the second transformer could be omitted. Naturally also the impedance detector and the second signal conditioner could be omitted from the first driving stage. Therefore, while the present disclosure has been described with reference to exemplary embodiments, it will be appreciated that the present invention is only limited to the claims. | 20,608 |
11943010 | DETAILED DESCRIPTION FIG.1throughFIG.14, discussed below, and the various, non-limiting embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device. To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a “beyond 4G network” or a “post LTE system.” The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission coverage, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques and the like are discussed in 5G communication systems. In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul communication, moving network, cooperative communication, coordinated multi-points (CoMP) transmission and reception, interference mitigation and cancelation and the like. The discussion of 5G systems and frequency bands associated therewith is for reference as certain embodiments of the present disclosure may be implemented in 5G systems. However, the present disclosure is not limited to 5G systems, or the frequency bands associated therewith, and non-limiting embodiments of the present disclosure may be utilized in connection with any frequency band. For example, aspects of the present disclosure may also be applied to deployment of 5G communication systems, 6G or even later releases which may use terahertz (THz) bands. In 5G or the other wireless systems, mm Wave is a major band on which high throughputs can be achieved. The propagation on the mm Wave bands suffers more significant path loss than that in the sub-6 GHz bands. To compensate the increased path loss, multiple antenna elements can be simultaneously activated to form a narrow beam with high gain. The narrow beamwidth, however, incurs an overhead for aligning the beam direction to the best signal transmission/reception directions. Various embodiments of the present disclosure recognize that, for composite beam operation, the pairing of the narrow beams has to be carefully designed. If the paired beams' angles are close to each other, there can be strong interference to each other, for example the side lobe of one beam could be strong at the main lobe of the other beam. It is noted that a composite beam system can also be implemented with three (or more) narrow beams for a single SSB index. The term “narrow beam” is used here since a large antenna array which is a typical setup for 5G mmWave network deployment is capable of forming narrow beams; however, the various embodiments in this disclosure can be applied to other composite beam systems with any beam width. Many beams, e.g., >100 may be needed to cover a wide angular region. The number of SSB beams, where each beam corresponds to an SSB index, cannot be large, especially in the 5G standalone (SA) system. 5G NR supports at most 64 SSBs for mmWave. Various embodiments of the present disclosure present methods to generate the beam paring for the BS. The methods use input information including the individual beam pattern, the pointing angle of the individual beams. Although mmWave bands are used as example in this disclosure, the non-limiting embodiments in this disclosure can also be applied to other frequency bands as well. Various embodiments of the present disclosure also recognize that formulating a composite beam (CB) pairing enhancement can be used to design an automatic pairing method that finds the optimal pairing that maximizes the intra-pair distance. Large intra-pair distance leads to less interference within the pair. These design specifications can be requirements of the system, for the base station to maintain contact with the UE, or any other feature that would be advantageous to the design of the CBs or a codebook. Moreover, various embodiments of the present disclosure permit the codebook to offer different types, shapes, and powers of CBs to accomplish the objectives of using CBs to cover narrow beam areas or volumes more efficiently. Additionally, various embodiments of the present disclosure also provide for a method of using method to maximize both the intra-pair and inter-pair distance that can overcome error propagation. Large inter-pair distance can reduce the chance of error propagation and adopting a CB codebook with less errors and interference to support mobile UE. Moreover, various embodiments of the present disclosure also provide examples of a composite beam system, where the BS uses two arrays to transmit the two narrow beams at the same time (one array for one narrow beam). One approach to reduce the number of SSB beams is to implement a composite beam system, where the BS transmits two narrow beams simultaneously for one SSB (same SSB index), and thereby halving the number of SSBs for the network. Thus, for a composite beam system, a BS transmits two narrow beams simultaneously for one SSB halving the number of SSBs, where the beam search could be for instance 28 CBs+2 (or 1) NB search. To pair the beams, search accuracy such that, for example, the percentage that the 28+2 (or 1) beam search arrives at the same result as the 56-beam search. The intra-pair distance should be large such that there is less beam pattern distortion when they are transmitted simultaneously. Before further addressing the methods and devices used to effectuate the solutions discussed herein, various physical embodiments are shown inFIGS.1through5below, which describe such various embodiments implemented in wireless communications systems and with the use of orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) communication techniques. The descriptions thereof are not meant to imply physical or architectural limitations to the manner in which different embodiments may be implemented. Different embodiments of the present disclosure may be implemented in any suitably arranged communications system. FIG.1illustrates an example wireless network according to various embodiments of the present disclosure. The non-limiting embodiment of the wireless network shown inFIG.1is for illustration only. Other embodiments of the wireless network100could be used without departing from the scope of this disclosure. As shown inFIG.1, the wireless network includes a gNB101, a gNB102, and a gNB103. The gNB101communicates with the gNB102and the gNB103. The gNB101can also communicate with at least one network130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network. The gNB102provides wireless broadband access to the network130for a first plurality of user equipments (UEs) within a coverage area120of the gNB102. The first plurality of UEs includes a UE111, which may be located in a small business; a UE112, which may be located in an enterprise (E); a UE113, which may be located in a WiFi hotspot (HS); a UE114, which may be located in a first residence (R); a UE115, which may be located in a second residence (R); and a UE116, which may be a mobile device (M), such as a cell phone, a wireless laptop, a wireless PDA, or the like. The gNB103provides wireless broadband access to the network130for a second plurality of UEs within a coverage area125of the gNB103. The second plurality of UEs includes the UE115and the UE116. In some embodiments, one or more of the gNBs101-103may communicate with each other and with the UEs111-116using 5G, LTE, LTE-A, WiMAX, Wi-Fi, or other wireless communication techniques. Depending on the network type, the term “base station” or “BS” can refer to any component (or collection of components) configured to provide wireless access to a network, such as transmit point (TP), transmit-receive point (TRP), an enhanced base station (eNodeB or eNB), a 5G base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wirelessly enabled devices. Base stations may provide wireless access in accordance with one or more wireless communication protocols, e.g., 5G 3GPP new radio interface/access (NR), long term evolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA), Wi-Fi 802.11a/b/g/n/ac, etc. For the sake of convenience, the terms “BS” and “TRP” are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, the term “user equipment” or “UE” can refer to any component such as “mobile station,” “subscriber station,” “remote terminal,” “wireless terminal,” “receive point,” or “user device.” For the sake of convenience, the terms “user equipment” and “UE” are used in this patent document to refer to remote wireless equipment that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a stationary device (such as a desktop computer or vending machine). Dotted lines show the approximate extents of the coverage areas120and125, which are shown as approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with gNBs, such as the coverage areas120and125, may have other shapes, including irregular shapes, depending upon the configuration of the gNBs and variations in the radio environment associated with natural and man-made obstructions. As described in more detail below, one or more of gNB101, gNB102and gNB103include one or more two-dimensional (2D) antenna arrays and utilize paring or grouping of beams transmitted thereby into composite beams as described in various embodiments of the present disclosure. In some embodiments, the network130facilitates communications between at least one server134and various client devices, such as client device136. Server134includes any suitable computing or processing device that can provide computing services for one or more client devices. Server134could, for example, include one or more processing devices, one or more memories storing instructions and data, and one or more network interfaces facilitating communication over the network130. Client device136represents any suitable computing or processing device that interacts with at least one server or other computing device(s) over the network130. In this example, the client device is represented as a desktop computer, but other examples of client devices can include a mobile telephone, laptop computer, or tablet computer. However, any other or additional client devices could be used in the wireless network100. In this example, client devices can communicate indirectly with the network130. For example, some client devices can communicate via one or more base stations, such as cellular base stations or eNodeBs. Also, client devices can communicate via one or more wireless access points (not shown), such as IEEE 802.11 wireless access points. Note that these are for illustration only and that each client device could communicate directly with the network130or indirectly with the network130via any suitable intermediate device(s) or network(s). As described in more detail below, wireless network100can be a 5G communication system in which the BS102can utilize paring or grouping of beams for use in wireless communication. In addition, wireless network100can enable a computing device, such as server134or client device136, to design and disseminate codebooks or elements thereof for composite beams generated offline from communication in the network100. AlthoughFIG.1illustrates one example of a wireless network, various changes may be made toFIG.1. For example, the wireless network could include any number of gNBs and any number of UEs in any suitable arrangement. Also, the gNB101could communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network130. Similarly, each gNB102-103could communicate directly with the network130and provide UEs with direct wireless broadband access to the network130. Further, the gNBs101,102, and/or103could provide access to other or additional external networks, such as external telephone networks or other types of data networks. FIG.2illustrates an exemplary base station example gNB102according to various embodiments of the present disclosure. The non-limiting embodiment of the gNB102illustrated inFIG.2is for illustration only, and the gNBs101and103ofFIG.1could have the same or similar configuration. However, gNBs come in a wide variety of configurations, andFIG.2does not limit the scope of this disclosure to any particular implementation of a gNB. As shown inFIG.2, the gNB102includes multiple antennas205a-205n, multiple radio frequency (RF) transceivers210a-210n, transmit (TX) processing circuitry215, and receive (RX) processing circuitry220. The gNB102also includes a controller/processor225, a memory230, and a backhaul or network interface235. The RF transceivers210a-210nreceive, from the antennas205a-205n, incoming RF signals, such as signals transmitted by UEs in the network100. The RF transceivers210a-210ndown-convert the incoming RF signals to generate intermediate frequency (IF) or baseband signals. The IF or baseband signals are sent to the RX processing circuitry220, which generates processed baseband signals by filtering, decoding, and/or digitizing the baseband or IF signals. The RX processing circuitry220transmits the processed baseband signals to the controller/processor225for further processing. The TX processing circuitry215receives analog or digital data (such as voice data, web data, e-mail, or interactive video game data) from the controller/processor225. The TX processing circuitry215encodes, multiplexes, and/or digitizes the outgoing baseband data to generate processed baseband or IF signals. The RF transceivers210a-210nreceive the outgoing processed baseband or IF signals from the TX processing circuitry215and up-converts the baseband or IF signals to RF signals that are transmitted via the antennas205a-205n. The controller/processor225can include one or more processors or other processing devices that control the overall operation of the gNB102. For example, the controller/processor225could control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceivers210a-210n, the RX processing circuitry220, and the TX processing circuitry215in accordance with well-known principles. The controller/processor225could support additional functions as well, such as more advanced wireless communication functions. That is, the controller/processor225can perform the method in part or in whole described herein, identify inputs, and create the codebook. Also, any of a wide variety of other functions can be supported in the gNB102by the controller/processor225. In some embodiments, the controller/processor225includes at least one microprocessor or microcontroller. In certain embodiments, the controller/processor225could support beam forming or directional routing operations in which outgoing signals from multiple antennas205a-205nare weighted differently to effectively steer the outgoing signals in a desired direction and create and control narrow beans and composite beams. Any of a wide variety of other functions could be supported in the gNB102by the controller/processor225. The controller/processor225is also capable of executing programs and other processes resident in the memory230, such as an operating system (OS). The controller/processor225can move data into or out of the memory230as used by an executing process. The controller/processor225is also capable of determining and/or using composite beams for communications such as SSB transmissions as described in various embodiments of the present disclosure. The controller/processor225is also coupled to the backhaul or network interface235. The backhaul or network interface235allows the gNB102to communicate with other devices or systems over a backhaul connection or over a network. The interface235could support communications over any suitable wired or wireless connection(s). For example, when the gNB102is implemented as part of a cellular communication system (such as one supporting 5G, LTE, or LTE-A), the interface235could allow the gNB102to communicate with other gNBs over a wired or wireless backhaul connection. When the gNB102is implemented as an access point, the interface235could allow the gNB102to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The interface235includes any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or RF transceiver. The memory230is coupled to the controller/processor225. Part of the memory230could include a RAM, and another part of the memory230could include a Flash memory or other read only memory (ROM). In certain embodiments, a plurality of instructions, such as an integer linear programming (ILP) algorithm is stored in memory230. The plurality of instructions is configured to cause the controller/processor225to determine, based on UE reports, composite beams from among a plurality of beams transmitted by the BS102as described in more detail below. AlthoughFIG.2illustrates one example of gNB102, various changes may be made toFIG.2. For example, the gNB102could include any number of each component shown inFIG.2. As a particular example, an access point could include a number of interfaces235, and the controller/processor225could support routing functions to route data between different network addresses. As another particular example, while shown as including a single instance of TX processing circuitry215and a single instance of RX processing circuitry220, the gNB102could include multiple instances of each (such as one per RF transceiver). Also, various components inFIG.2could be combined, further subdivided, or omitted and additional components could be added according to particular needs. FIG.3illustrates an example UE116according to various embodiments of the present disclosure. The non-limiting embodiment of the UE116illustrated inFIG.3is for illustration only, and the UEs111-115ofFIG.1could have the same or similar configuration. However, UEs come in a wide variety of configurations, andFIG.3does not limit the scope of this disclosure to any particular implementation of a UE. As shown inFIG.3, the UE116includes an antenna305, a radio frequency (RF) transceiver310, TX processing circuitry315, a microphone320, and receive (RX) processing circuitry325. The UE116also includes a speaker330, a controller/processor340, an input/output (I/O) interface (IF)345, a touchscreen350(or keypad), a display355, and a memory360. The memory360includes an operating system (OS)361and one or more applications362. The RF transceiver310receives from the antenna305, an incoming RF signal transmitted by a gNB of the network100. The RF transceiver310down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to the RX processing circuitry325, which generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal. The RX processing circuitry325transmits the processed baseband signal to the speaker330(such as for voice data) or to the controller/processor340for further processing (such as for web browsing data). The TX processing circuitry315receives analog or digital voice data from the microphone320or other outgoing baseband data (such as web data, e-mail, or interactive video game data) from the controller/processor340. The TX processing circuitry315encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver310receives the outgoing processed baseband or IF signal from the TX processing circuitry315and up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna305. The controller/processor340can include one or more processors or other processing devices and execute the OS361stored in the memory360in order to control the overall operation of the UE116. For example, the controller/processor340could control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceiver310, the RX processing circuitry325, and the TX processing circuitry315in accordance with well-known principles. In some embodiments, the controller/processor340includes at least one microprocessor or microcontroller. The controller/processor340is also capable of executing other processes and programs resident in the memory360. The controller/processor340can move data into or out of the memory360as used by an executing process. In some embodiments, the controller/processor340is configured to execute the applications362based on the OS361or in response to signals received from gNBs or an operator. The controller/processor340is also coupled to the I/O interface345, which provides the UE116with the ability to connect to other devices, such as laptop computers and handheld computers. The I/O interface345is the communication path between these accessories and the controller/processor340. The controller/processor340is also coupled to the touchscreen350and the display355. The operator of the UE116can use the touchscreen350to enter data into the UE116. The display355may be a liquid crystal display, light emitting diode display, or other display capable of rendering text and/or at least limited graphics, such as from web sites. The memory360is coupled to the controller/processor340. Part of the memory360could include a random-access memory (RAM), and another part of the memory360could include a Flash memory or other read-only memory (ROM). AlthoughFIG.3illustrates one example of UE116, various changes may be made toFIG.3. For example, various components inFIG.3could be combined, further subdivided, or omitted and additional components could be added according to particular needs. As a particular example, the controller/processor340could be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Also, whileFIG.3illustrates the UE116configured as a mobile telephone or smartphone, UEs could be configured to operate as other types of mobile or stationary devices. FIG.4illustrates an example of a computing device400in accordance with various embodiments of this disclosure. In one embodiment, the computing device400is a server, such as server134inFIG.1or a client device, such as client device136inFIG.1. As described in greater detail below, in various embodiments, the computing device400can determine composite beams for use by a BS102based on UE reports. The computing device400may designate these parings, for example, using codebooks generated offline from communication by the BS102. As shown inFIG.4, the computing device400includes a bus system405, which supports communication between at least one processor410, at least one storage device415, at least one communications unit420, and at least one input/output (I/O) unit425. The processor410executes instructions that may be loaded into a memory430. The processor410may include any suitable number(s) and type(s) of processors or other devices in any suitable arrangement. Examples of types of processor410include microprocessors, microcontrollers, digital signal processors, field programmable gate arrays, application specific integrated circuits, and discreet circuitry. The memory430and a persistent storage435are examples of storage devices415, which represent any structure(s) capable of storing and facilitating retrieval of information (such as data, program code, and/or other suitable information on a temporary or permanent basis). The memory430may represent a random-access memory or any other suitable volatile or non-volatile storage device(s). The persistent storage435may contain one or more components or devices supporting longer-term storage of data, such as a ready only memory, hard drive, flash memory, or optical disc. The communications unit420supports communications with other systems or devices. For example, the communications unit420could include a network interface card or a wireless transceiver facilitating communications over the network130. The communications unit420may support communications through any suitable physical or wireless communication link(s). The I/O unit425allows for input and output of data. For example, the I/O unit425may provide a connection for user input through a keyboard, mouse, keypad, touchscreen, or other suitable input device. The I/O unit425may also send output to a display, printer, or other suitable output device. Note that whileFIG.4is described as representing the server134ofFIG.1, the same or similar structure could be used in one or more client devices. For example, client device136can have the same or similar structure as shown inFIG.4. As described in more detail below, a computing device such as server134inFIG.1can be used to design and disseminate codebooks for use by an electronic device, such as UE116and/or BS102for communicating over network100or may be used to store and calculate data used for the implementation of the method described herein, especially in situations where real-time data is not necessary or, on the other hand, where the calculations are more efficiently or effectively done by the networked computing device400. The networked computing device400could also maintain or determine any data or calculations that can be done offline and then transmitted to another component in network100. FIG.5illustrates an example of a transmitter structure500for beamforming according to various embodiments of the present disclosure. The non-limiting embodiment of the transmitter structure500illustrated inFIG.5is for illustration only.FIG.5does not limit the scope of this disclosure to any particular implementation of the transmitter structure500. In certain embodiments, one or more of gNB102or UE116include the transmitter structure500. For example, one or more of antenna205and its associated systems or antenna305and its associated systems can be included in transmitter structure500. Rel.14 LTE and Rel.15 NR support up to 32 Channel State Information Reference Signal (CSI-RS) antenna ports which enable an eNB to be equipped with a large number of antenna elements (such as 64 or 128). In this case, a plurality of antenna elements is mapped onto one CSI-RS port. For mmWave bands, although the number of antenna elements can be larger for a given form factor, the number of CSI-RS ports—which can correspond to the number of digitally precoded ports—tends to be limited due to hardware constraints (such as the feasibility to install a large number of analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) at mmWave frequencies). In the example shown inFIG.5, the transmitter structure500includes analog phase shifters505, an analog beamformer (BF)510, a hybrid BF515, a digital BF520, and one or more antenna arrays525. In this case, one CSI-RS port is mapped onto a large number of antenna elements in antenna arrays525, which can be controlled by the bank of analog phase shifters505. One CSI-RS port can then correspond to one sub-array which produces a narrow analog beam through analog beamforming by analogy BF510. The analog beam can be configured to sweep530across a wider range of angles by varying the phase shifter bank505across symbols or subframes. The number of sub-arrays (equal to the number of RF chains) is the same as the number of CSI-RS ports NCSI-PORT. A digital BF515performs a linear combination across NCSI-PORT analog beams to further increase precoding gain. While analog beams are wideband (hence not frequency-selective), digital precoding can be varied across frequency sub-bands or resource blocks. As operating frequency bands in NR become higher, the UE may include a plurality of antenna arrays525or panels (each panel is able to transmit via one analog beam, e.g., analog BF510) to enhance aspects of multi-beam operation such as coverage enhancement, beam failure event minimization, fast beam switching, and the like. By utilizing the capability of multiple panels, UE116is able to obtain a variety of diversity gains, which comes from dynamic selection of panel(s) with the best quality in terms of performance that systems want to optimize. As an example, a beam corresponds to a spatial transmission/reception filter that is used by the UE116and/or gNB102. In one example, a beam can correspond to a spatial reception filter that is used by the UE116to receive a signal, such as SSB (or SS/PBCH block) and/or a CSI-RS and so on. In another example, a beam can correspond to a spatial transmission filter that is used by the UE116to transmit a reference signal, such as an UL sounding reference signal (SRS) and so on. A beam reporting procedure for a UE can include, for example, a procedure wherein the gNB102configures the UE116with a set of reference signal (RS) resources, such as CSI-RS resources, as well as a configuration for report settings, such that the UE can generate and send UE reports including information indicating beam quality metric(s) measurement(s), such as channel state information (CSI), reference signal received power (RSRP), reference signal received quality (RSRQ), received signal strength indicator (RSSI), signal to noise ratio (SNR), signal to interference and noise ratio (SINR), and so on, as well as information about beam locations, such as, beam pattern, pointing angle of individual beams, etc. In one example, a gNB102can transmit a RS, such as a SSB or a CSI-RS or an SRS with a number of repetitions using a same spatial transmission filter in multiple occasions, so that the gNB102and/or UE116, respectively, can receive the RS with different spatial reception filters, in order to facilitate beam sweeping and identification of a candidate/best beam based on a quality metric, such as RSRP or SINR. Various embodiments of the present disclosure provide for methods and devices to generate beam parings for the BS. The methods use input information including, for example, the individual beam pattern, the pointing angle of the individual beams. Although mmWave bands are used as example in this disclosure, embodiments of the present disclosure can also be applied to other frequency bands as well. FIGS.6A and6Billustrate examples of a composite beam system600with at least two arrays at a BS according to various embodiments of the present disclosure. The system600is for illustration only and other embodiments can be used without departing from the scope of the present disclosure. In these examples, the composite beam system600includes the BS120that uses (at least) two arrays to transmit the two narrow beams at the same time (one array for one narrow beam). These beams are paired to form composite beams. In particular system600includes the BS102, which transmits beams (e.g., beams610-615,620-625, and680-683) from at least two antenna panels601and602, such as antenna panels525fromFIG.5. In the example shown inFIG.6A, beam681and beam682are paired and where arrow683represents the distance of the composite beam-pair. In the example shown inFIG.6B, panel601emits narrow beam coverage650with narrow beams610through615respectively with SSB #0-5, while panel602emits narrow beam coverage660with narrow beams620through625, inclusive, respectively with SSB #0-5 as shown. Shown in this example, is a pairing between beams610and620, with d as the intra-pair distance. In various embodiments, beam pairings are generated to increase (or maximize) the intra-pair distance. In these embodiments, the beams with large angular distance are paired. The angular distance could be defined as the distance between the peak direction of two beams, i.e., the distance between (θi, ϕi) and (θj, ϕj). The distance could be computed as the great-circle distance as follows: dij=arccos([sin θicos ϕi, sin θisin ϕi, cos θi][sin θjcos ϕj, sin θjsin ϕj, cos θj]T) where [⋅]Tstands for the transpose of a vector. Define binary variables zij=0 if beam i and beam j is paired. Otherwise, zij=0. In one example, the beams are paired to increase (or maximize) the minimal intra-pair distance max{zij}mini,j,zij=1dij. In another example, the beams are paired to increase (or maximize) the average intra-pair distance, which is max{zij}𝔼i,j,zij=1dij. In yet another example, the beams are paired to increase (or maximize) the average intra-pair distance and limit the minimal distance to above a threshold T. For example, the problem formulation is: max{zij}𝔼i,j,zij=1dijs.t.,mini,j,zij=1dij>T In another embodiment, the beams with minimal interference are paired. For an assumption that the beam pattern of all the narrow beams is known, Gi(θ, ϕ), 1≤i≤K, where K is the number of beams and Gi(θ, ϕ) is the i-th beam gain at the direction (θ, ϕ). The main lobe of each beam is identified as a region around its peak direction (θi, ϕi). The interference of beam i to beam j at j-th beam's peak direction is thus Gi(θj, ϕj). The interference could also be defined over the main lobe region as well. Denote the interference from beam i to beam j as Ij←i, and binary variables zij=1 if beam i is paired with beam j. In one option, the beams are paired to reduce (or minimize) the maximum interference, for example, based on the following equation: min{zij}maxi,j,zij=1Ij←i. In another example, the beams are paired to minimize the average interference, for example, based on the following equation: min{zij}𝔼i,j,zij=1Ij←i. In yet another example, the beams are paired to minimize the average interference, and limit the maximal interference to below a threshold T. For example, the problem formulation is: min{zij}𝔼i,j,zij=1Ij←is.t.,maxi,j,zij=1Ij←i<T FIGS.7A and7Billustrate examples of beam pairs according to embodiments of the present disclosure. The examples of beam pairs inFIGS.7A and7Bare for illustration only and other embodiments can be used without departing from the scope of the present disclosure. In these examples, the narrow beams are illustrated the angular domain withFIG.7Ashowing pair (i,j) andFIG.7Bshowing pair (k,l) which both are resultant composites of narrow beams with large intra-pair distance but small inter-pair distance. InFIG.7A, beams i and k are adjacent and beams j and beam l are adjacent. InFIG.7B, beams i and l are adjacent, while beams j and k are adjacent. Each circle represents the main lobe of a narrow beam. Beam i and j are paired, and beam k and l are paired inFIGS.7Aand B. In both figures, the pair (i,j) and pair (k,l) have large intra-pair distance, but small inter-pair distance. In various embodiments, the beam pairing is selected or optimized to increase (or maximize) both the intra-pair distance and the inter-pair distance. The increased inter-pair distance might reduce the chance of choosing the wrong narrow beam. The inter-pair distance between two pairs (i,j) and (k,l) could be defined as min(dik+djl, dil+djk). The beam pairing shown inFIGS.7A and7Bmay not be desired when the inter-pair distance is small. In another embodiment, the beam pairing is selected or optimized to reduce (or minimize) both the intra-pair and inter-pair interference. The intra-pair interference between two pairs (i,j) and (k,l) could be max(Ik←i+Il←j, Il←i+Ik←j). FIG.8illustrates an example of a flowchart of a method800for beam pairing based on UE reports according to various embodiments of the present disclosure. The steps of the method800ofFIG.11can be performed by any of the UEs111-116in connection with the BSs101-103ofFIG.1, such as the BS102ofFIG.2. The method800is for illustration only and other embodiments can be used without departing from the scope of the present disclosure. In various embodiments, the beam paring is done by the BS, for example, periodically or dynamically, in an online manner. In other embodiments, the beam paring may be done offline by a computing device for example using simulations with beam parings indicated in codebooks that are sent to the BS for use. One such example of an online manner is illustrated by the method800which begins with the UE reporting to the BS CSI of different beams (step801). In step802, the BS examines the correlation among the beams based on the UE reports. In step803, the BS pairs beams based on the beam correlation. In various embodiments, the online beam pairing is performed to reduce (or minimize) the intra-pair correlation. In one embodiment, the pairing could be paired based on the UE report, and the beam with least correlation are paired. For example, if there are K beams and the reported L1-RSRP or CQI value is x=[x1, x2, x3, . . . , xK]T. If there is not full report from UE (for example, UE only reports the best 4 beams' index and RSRP values), then a default value is assigned to the missing beams. Then, the correlation could be computed as Rxx=𝔼x[xxH]. The average is over all the reports that a BS receives from all the UEs over a sufficient long period (e.g., hours, days). The BS could compute Rxxin a recursive manner. The beam pair with reduced (or minimal) correlation (e.g., which implies that the experienced channels are uncorrelated, or pointing angles are far apart, or the interference between the two beam patterns is small) are paired. The BS could continuously monitor and update the Rxxbased on the online UE report. As such, this online pairing based on the correlation can pair beams to reduce (or minimize) the maximal intra-pair correlation, which may perform better than the angle-based pairing in a non-line of sight (NLOS) environment. In various embodiments, the beams are paired to minimize the sum intra-pair correlation, or minimize the maximal intra-pair correlation, or minimize the sum intra-pair correlation while limiting the maximal intra-pair correlation. FIGS.9A and9Billustrate examples of different numbers of narrow beams in an angular domain according to various embodiments of the present disclosure.FIG.10illustrates an example a size-32 codebook with different pointing angles fromFIG.9Aaccording to various embodiments of the present disclosure.FIG.11illustrates a flowchart of a method1100for beam pairing adapting based on narrow beam usage or distribution according to various embodiments of the present disclosure. The steps of the method1100ofFIG.11can be performed by any of the BSs101-103ofFIG.1, such as the BS102ofFIG.2. The examples illustrated inFIGS.9A-11are for illustration only and other embodiments can be used without departing from the scope of the present disclosure. In various embodiments, online beam pairing adapts to the changes of narrow beam set. The narrow beam set could change due to the cell load, the UE distribution, the tilting angle of the BS, the BS height, etc. For an example, in an urban area, the UE distribution could change a lot during the day and night. Thus, the BS may dynamically change the set of narrow beams to better serve the UE. In another example, the scan range requirement of the BS varies when the BS height changes, for instance, from 10 meters to 30 meters. As a result, the narrow beam set, which is required to cover the scan range, changes with BS height. In various examples, the change of narrow beam set includes, but not limited to: (1) the number of narrow beams increases or decreases or (2) the pointing angles or the covering regions of the narrow beams. As the number of narrow beams changes, some of the beams may not be paired, so a new pairing may be needed. The method1100provides an example of online beam pairing that adapts to the narrow beams' usage and/or distribution. In step1101, the BS (e.g., BS102) monitors the usage and distribution of the narrow beams. In step1102, the BS re-pairs the narrow beams if the usage and/or distribution of the narrow beams change. In step1103, the BS transmits SSBs by the new composite beams. This procedure can be an iterative process in that step1103leads back to step1101as monitoring continues due to changing environments, movement of UEs, etc. In various embodiments, the beam pairing could change as the set of narrow beams change. Once the set of narrow beams changes, the BS can re-pair the narrow beams, following the methods provided in this disclosure. InFIGS.9A and9B, the scan range of the narrow beam codebook expands to cover a larger cell or more UEs with different heights. The number of the narrow beams changes if a higher scan range is needed, for example, where the number of narrow beams increases from 32 inFIG.9A to48inFIG.9B, and a new pairing of narrow beams is then needed. Specifically, inFIG.9A, a size-32 NB codebook with only two rows is displayed while inFIG.9Ba size-48 NB codebook with three rows is displayed. FIG.10is an illustration of another example where the number of NBs does not change, but the pointing angles could change to better serve the UEs. For a size-32 NB codebook, the NB s could be distributed as shown inFIG.10, where the horizontal coverage region is [−30°,30°]. This could happen when the UEs are concentrated in a small angular region, for example, a plaza area. Note that the pointing angles are different fromFIG.9A. Therefore, a different pairing may be needed. In another embodiment, the BS could take into account the beam load when generating the composite beams. In other words, pairing based on the beam load. The beam load might be defined as the number of UE served by the beam, or the number of throughputs delivered by the beam to the served UEs. In one option, the beams with less load are paired, while the beam with high load are not paired. As a result, the load on the composite beams is more balanced. In another option, the beams with less load are grouped into big composite beams that include more than two narrow beams, while the beams with more load are grouped into small composite beams that include two or one narrow beams. In various embodiments, the beam paring is performed using an ILP algorithm. For example, the composite beam design involves a pairing solution that increases (or maximizes) the intra-pair distance to reduce the intra-pair interference when forming composite-beam which can be formulated as an ILP problem, which assumes: the distance between beam i and beam j is dij; zij=1 if beam i and beam j are paired, otherwise zij=0; the objective is to increase (or maximize) the sum of the distance, where dminis a constraint on the minimum intra-pair distance. Given these assumptions, the ILP problem can be formulated based on the following: maxzij∑i,jdijzij(sumofthedistance)s.t.zij=zji,∀i,j(symmetry)∑jzij=1,∀i(paironce)zijdmin≤di,j,∀i,j(minimumdistance)zij=0or1,∀i,j(binary) For example, a MATLAB Mixed-Integer Linear Programming can be adopted to solve this problem, where finding the maximum dminis done by trial and error. Starting from dmin=0, then increase dminuntil the ILP becomes infeasible. In other examples, the ILP can be solved efficiently by available solvers. In another example, a bisection method could be adopted to determine dmin. In various embodiments, the ILP algorithm can also take into account the intra-pair distance. For example, the distance between beam i and beam j is assumed to be dijwhere zij=1 if beam i and beam j is paired, otherwise zij=0. The objective is to increase (or maximize) the sum of the distance, where dminis a constraint on the minimum intra-pair distance; aij=1 if beam i and beam j is adjacent, otherwise aij=0. The additional constraint on the inter-pair distance can be added in the end. The ILP problem can be formulated based on the following: maxzij∑i,jdijzij(sumoftheintra-distance)s.t.zij=zji,∀i,j(symmetry)∑jzij=1,∀i(paironce)zijdmin≤dij,∀i,j(minimumintra-pairdistance)zij=0or1,∀i,j(binary)zij+zkl≤2-aikajl-ailakj∀i,j,k,l(errorpropagation) where the error propagation shown above is also the equation for determining the inter-pair distance. For instance, if there is a choice between two clusters, without this additional check, then if the BS examines the narrow beam closer to a current one, then the RSRP measurement could be noisy, resulting in error. As such, beam section errors could also mount if a first selection is not optimal, propagating errors onward. FIGS.12A and12Billustrate examples of composite beam pairing of 56 narrow beams according to various embodiments of the present disclosure. The examples illustrated inFIGS.12A and12Bare for illustration only and other embodiments can be used without departing from the scope of the present disclosure. FIGS.12A and12Bare examples of the composite beam pairing of 56 narrow beams.FIG.12Ashows inter-pair distance increase (or maximization) per the techniques discussed in this disclosure. In this example, CB 4 and 8 are adjacent pairs.FIG.12Billustrates an example for increases (or maximizes) the inter-pair and intra-pair distance as discussed above. In this example, there are no adjacent pairs. The example pairings ofFIG.12Amay achieve both larger minimum and mean distances than a baseline pairing. The example pairings ofFIG.12Bmay also meet the request to reduce the error propagation as well as achieve a larger minimum distance than a baseline pairing. FIGS.13A and13Billustrate examples of composite beam pairing of 112 narrow beams according to various embodiments of the present disclosure. The examples illustrated inFIGS.13A and13Bare for illustration only and other embodiments can be used without departing from the scope of the present disclosure. FIGS.13A and13Bare examples of the composite beam pairing of 112 narrow beams.FIG.13Ashows inter-pair distance maximization per the techniques discussed in this disclosure. In this example, CB 2 and 3 are adjacent pairs.FIG.12Bincreases (or maximizes) the inter-pair and intra-pair distance. In this example, there are no adjacent pairs. The example pairings ofFIG.13Amay achieve both larger minimum and mean distances than a baseline pairing. The example pairings ofFIG.13Bmay also meet the request to reduce the error propagation as well as achieve a larger minimum distance than a baseline pairing. FIG.14illustrates an example method1400for paring beams according to various embodiments of the present disclosure. The steps of the method1400ofFIG.14can be performed by any of the BSs101-103ofFIG.1, such as the BS102ofFIG.2or by a computing device, such as, server134, client device136, or computing device400(referred to collectively as “the system”). The method1400is for illustration only and other embodiments can be used without departing from the scope of the present disclosure. The method begins with the system identifying, based on one or more UE reports, information on a plurality of narrow beams (step1401). For example, in step1401, the system (e.g., computing device400) may identify this information from offline reports to generate the parings in an offline methodology to provide predefined beam codebooks to a BS (e.g., BS102). In another embodiment, the beam paring may be performed online by BS102. In this example, the BS102may also transmit reference signals on the plurality of narrow beams and receive these UE report(s) from which to determine beam parings. The system then determines beam correlation information for the plurality of narrow beams based on the one or more UE reports (step1402). For example, in step1402, the system may determine information about distances between respective beams in the set of beams as well as other information, such as, signal strengths, beam interference, UE indications of preferred beams, etc. The system then determines pairs of narrow beams from among the plurality of narrow beams based on the correlation information (step1403). Thereafter, for offline paring, the system may generate codebook(s) including the beam parings for use in a wireless communication system. For online paring, the BS may then use one or more of the determined pairs to transmit SSB(s) to UE(s) in the wireless communication system. In step1403, the system may determine pairs of narrow beams a function of a distance between beams in each respective pair of the pairs of narrow beams or intra-pair distance. For example, the system may determine the pairs of narrow beams to have a largest possible distance between the beams in each respective pair of the pairs of narrow beams among the plurality of narrow beams. This may allow for reduced interference between the beams in the respective pairs of narrow beams when transmitted. Additionally or alternatively, in step1403, the system may determine the pairs of narrow beams as a function of a distance between beams in different pairs of the pairs of narrow beams or inter-pair distance. For example, the system may determine the pairs of narrow beams to have a largest possible distance between the different pairs of beams in the pairs of narrow beams. This may allow for reduced correlation between the different pairs of beams. For example, the pairs of the beams may be transmitted in different timeslots, thus not leading to inter-pair interference. However, reducing the correlation or similarity between the pairs may reduce the chance of error propagation between beam pairs. In various embodiments, the system may determine as a function of a distance between beams in each respective pair of the pairs of narrow beams and distance between beams in different pairs of the pairs of narrow beams or both intra and inter pair distance. For example, the system may use an ILP algorithm, such as one discussed above. In various embodiments, the system may also determine the beam correlation information based on identifying a beam load for beams in the plurality of beams as discussed above. Here, the beam load may be based on a number of UEs served by a narrow beam or a throughput to be carried by a narrow beam. The system may determine the pairs of narrow beams comprises selecting beams to pair as a function of the beam load. In various embodiments, the system may also receive updated UE reports including updated information on the plurality of narrow beams, determine information about an updated distribution of beams in the pairs of narrow beams based on the updated UE reports, and determine whether to modify paring of the pairs of narrow beams as a function of comparison of the updated distribution to a threshold values as discussed above, for example, with regard toFIG.11. The above flowcharts illustrate example methods that can be implemented in accordance with the principles of the present disclosure and various changes could be made to the methods illustrated in the flowcharts herein. For example, while shown as a series of steps, various steps in each figure could overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, steps may be omitted or replaced by other steps. Although the figures illustrate different examples of user equipment, various changes may be made to the figures. For example, the user equipment can include any number of each component in any suitable arrangement. In general, the figures do not limit the scope of this disclosure to any particular configuration(s). Moreover, while figures illustrate operational environments in which various user equipment features disclosed in this patent document can be used, these features can be used in any other suitable system. Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. None of the description in this application should be read as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of patented subject matter is defined by the claims. | 53,087 |
11943011 | MODE FOR CARRYING OUT THE INVENTION Hereinafter, modes for carrying out the present technology (hereinafter, referred to as embodiments) will be described. A description will be given in the following order. 1. First Embodiment 2. Second Embodiment 3. Third Embodiment 4. Fourth Embodiment 5. Fifth Embodiment 1. First Embodiment [Wireless Network System] FIG.1is a diagram illustrating a configuration example of a wireless network system according to the embodiment of the present technology. In this wireless network system, a plurality of access points AP #1 (101) and AP #2 (102) and a plurality of communication terminals STA #1 (201), STA #2 (202), and STA #3 (203) are connected to each other. Then, the access points AP #1 (101) and AP #2 (102), as a multi-AP100, are configured to perform joint transmission for a communication terminal group210including a plurality of arbitrary communication terminals. In the APs configuring a multi-AP100, the AP, which acquires a transmission right in advance prior to execution of the joint transmission, is referred to as a sharing AP, and the AP, which does not acquire the transmission right, is referred to as a shared AP. The APs may have the following roles. In other words, in a case where the sharing AP performs, as the multi-AP, a joint operation with the shared AP, after acquiring the transmission right, the sharing AP notifies the shared AP that the sharing AP performs the joint operation within the transmission time acquired by the sharing AP itself. Note that the sharing AP may be referred to as a master AP, and the shared AP may be referred to as a slave AP. Furthermore, the sharing AP and the shared AP are not fixedly determined for the AP, and may be dynamically determined in the multi-AP. For example, the AP that has notified another AP of a request for performing a joint operation may acquire a right to operate as the sharing AP, or may be determined by a magnitude relationship among values of MAC addresses of a plurality of the APs or a user who uses an application for controlling the multi-APs. Furthermore, for example, at a certain time t1, an AP 1 may be the sharing AP and an AP 2 may be the shared AP, and at a different time t2, the AP 1 may be the shared AP and the AP 2 may be the sharing AP. Note that frequency channels used by the multi-AP for transmission to the communication terminals may completely coincide with each other, or may partially coincide with each other. Furthermore, an example in which one shared AP and three communication terminals are provided is illustrated in the drawing, but the number of shared APs and the number of communication terminals may be any number. For example, there may be two shared APs and one communication terminal. In such a configuration, according to the following embodiment, by calculating a weight for each of the APs configuring the multi-AP to perform the joint transmission, the generation efficiency of the weight for performing the joint transmission is improved without the processing of the APs performing notification to each other. However, in a case where each of the APs calculates the weight for performing the joint transmission as in the present embodiment, there is a possibility that the weights are different between the APs and it becomes difficult to appropriately perform the joint transmission, as will be giving an example of a specific algorithm below. [Eigenvalue Decomposition] In the eigenvalue decomposition, an eigenvector u satisfying the following formula is calculated for a square matrix A. Au=λus.t. ∥u∥=1 where ∥u∥ represents a norm of the vector u, and λ represents an arbitrary complex number. In particular, λ is referred to as an eigenvalue. Even when the magnitude (that is, |λ|) of the eigenvalue is the same, the complex phase is different, and thus a complex phase of each element of u is also different. When other CSI estimated by each of the APs on the basis of the information fed back from the terminal is set to A, a vector obtained by multiplying the eigenvector u obtained by the eigenvalue decomposition by a constant can be used as a weight vector of the CJT applied to the entire multi-AP (hereinafter, “multi-AP-CJT weight”). Each of the APs applies some rows of the calculated multi-AP-CJT weight as its own weight. However, since the complex phases of the eigenvalues do not coincide with each other between the APs that calculates u, each of the APs calculates different u. Therefore, the multi-AP-CJT weight assumed by the each of the APs is different, and there is a possibility that an appropriate CJT weight is not applied to the entire multi-AP as it is. Although the case where the eigenvector is directly used as the CJT weight has been described here, the same applies to the CJT weight calculated by a minimize maximum square error (MMSE) method. [Gram-Schmidt Orthonormalization Method] The Gram-Schmidt orthonormalization method is a method of orthogonalizing a plurality of vectors to each other, and can be used particularly in a case where a plurality of streams is transmitted. Specifically, a reference vector (ak) is selected from a plurality of vectors a1, a2, . . . , and aN, and a correlation component with the reference vector akis subtracted from a different arbitrary vector (a1). Subsequently, a correlation component with akand alis further subtracted from a different vector (am, m≠k, l), and thereafter, a similar calculation is performed. Therefore, obtained vectors b1, b2, . . . , bNare orthogonalized to each other. At this time, the generated vectors orthogonalized to each other have different properties depending on the order of the reference vector and the vectors selected thereafter. The vectors obtained by multiplying the eigenvectors for A fed back from the terminal by arbitrary constants with respect to the vectors b1, b2, . . . , and bNobtained by the Gram-Schmidt orthonormalization method on the basis of a1, a2, . . . , and aNcan be used as weights in the CJT. However, in a case where weights for performing simultaneous communication to a plurality of users are calculated by each of the APs in the CJT, it is not guaranteed that the order of the reference vector and the order of a vector selected thereafter coincides with each other as described above, and thus, there is a possibility that a desired weight is not applied to the entire multi-AP as in the case of the eigenvalue decomposition described above. Therefore, in the following embodiment, in a case where each of the APs configuring the multi-AP calculates a CJT weight, an information notification regarding a parameter necessary for matching the multi-AP-CJT weights calculated by the APs is performed between the APs, and an operation (hereinafter, weight synchronization) for matching the weights of the multi-AP-CJT calculated between the APs is performed. As a result, in a case where each AP calculates the CJT weight, even in a case where details of an algorithm that can be applied to the calculation of the multi-AP-weight is different in each AP, it is possible to accurately calculate the weight with which the CJT can be performed, and in addition to this, it is possible to perform the CJT with a small overhead as compared with the method of the related art. Furthermore, since each AP calculates the CJT weight, each of the APs configuring the multi-AP simultaneously transmits, to the terminal, a reference signal for the terminal to estimate CSI, and notifies (hereinafter, explicitly feeds back) each AP of the estimation result. Then, an information notification (feedback information synchronization) for confirming that the estimation results notification of which is performed coincide with each other between the APs is performed. Then, in addition to this, notification of information regarding whether or not to perform a calculation algorithm for the multi-AP-CJT weight in each AP, such as eigenvalue decomposition, a Gram-Schmidt orthonormalization method, and numerical operations independently specified by AP vendors, is performed between the APs, and an algorithm used at the time of calculating the multi-AP-CJT weight is synchronized between the APs. According to this, the amount of information necessary for weight synchronization in each AP is reduced. [Device Configuration] FIG.2is a diagram illustrating a configuration example of a wireless communication device300according to the embodiment of the present technology. The wireless communication device300described herein includes the access points AP #1 (101) and AP #2 (102) described above and the communication terminals STA #1 (201) to STA #3 (203). For example, the wireless communication device300may be a wireless communication module or an integrated circuit, which is mounted on the AP or the terminal. The wireless communication device300includes a communication unit310, a control unit321, a power supply unit322, and an antenna319. There may be provided a plurality of communication units310. The communication unit310includes a wireless control unit311, a data processing unit312, a modulation and demodulation unit313, a signal processing unit314, a channel estimation unit315, a wireless interface unit316, and an amplifier unit317. The wireless interface unit316, the amplifier unit317, and the antenna319may be formed as one set, and one or more sets may be a component. Furthermore, a function of the amplifier unit317may be included in the wireless interface unit316. The communication unit310is realized by, for example, a large scale integration (LSI). At the time of transmission in which data is input from the higher layer, the data processing unit312generates a packet for wireless transmission from the data, performs processing such as addition of a header for media access control (MAC) or addition of an error detection code, and supplies the processed data to the modulation and demodulation unit313. On the other hand, at the time of reception in which there is an input from the modulation and demodulation unit313, MAC header analysis, packet error detection, reorder processing, and the like are performed, and the processed data is provided to the higher layer of its own protocol. The wireless control unit311exchanges information between the units. Furthermore, parameter setting in the modulation and demodulation unit313and the signal processing unit314, packet scheduling in the data processing unit312, parameter setting and transmission power control of the modulation and demodulation unit313, the signal processing unit314, the wireless interface unit316, and the amplifier unit317are performed. At the time of transmission, the modulation and demodulation unit313encodes, interleaves, and modulates the input data from the data processing unit312on the basis of the encoding scheme and modulation scheme set by the wireless control unit311, generates a data symbol stream, and supplies the data symbol stream to the signal processing unit314. At the time of reception, processing reverse to that at the time of transmission is performed on the input from the signal processing unit314, and data is supplied to the data processing unit312or the wireless control unit311. At the time of transmission, the signal processing unit314performs signal processing for spatial separation on the input from the modulation and demodulation unit313as necessary, and supplies the obtained one or more transmission symbol streams to each wireless interface unit316. Note that transmission (hereinafter, cyclic shift delay (CSD)) may be applied by assigning an arbitrary delay amount to each antenna319without performing the spatial separation. Furthermore, at the time of reception, the signal processing unit314performs signal processing on the received symbol stream input from each wireless interface unit316, performs spatial decomposition of the stream as necessary, and supplies the result to the modulation and demodulation unit313. The channel estimation unit315calculates complex channel gain information of the channel from a preamble portion and a training signal portion of the input signals from the wireless interface units316. The calculated complex channel gain information is used for demodulation processing in the modulation and demodulation unit313and spatial processing in the signal processing unit314via the wireless control unit311. At the time of transmission, the wireless interface unit316converts the input from the signal processing unit314into an analog signal, performs filtering, up-conversion to a carrier frequency, and phase control, and transmits the analog signal to the antenna319or the amplifier unit317. At the time of reception, reverse processing is performed on the input from the antenna319or the amplifier unit317, and data is supplied to the signal processing unit314and the channel estimation unit315. At the time of transmission, the amplifier unit317amplifies the analog signal input from the wireless interface unit316to predetermined power, and transmits the amplified analog signal to the antenna319. At the time of reception, a signal input from the antenna319is amplified to predetermined power and output the signal to the wireless interface unit316. All or a part of the amplifier unit317in at least one of a function at the time of transmission or a function at the time of reception may be included in the wireless interface unit316. Furthermore, all or a part of the amplifier unit317in at least one of the function at the time of transmission or the function at the time of reception may be a component outside the communication unit310. The control unit321controls the wireless control unit311and the power supply unit322. Furthermore, the control unit321may perform at least a part of the operation of the wireless control unit311instead of the wireless control unit311. The power supply unit322includes a battery power supply or a fixed power supply, and supplies power to each unit of the wireless communication device300. In this configuration, the wireless control unit311and the control unit321control each unit to perform the following operations. [Operation] FIG.3is a sequence diagram illustrating an operation example of a wireless network system according to a first embodiment of the present technology. Here, there is a plurality of communication terminals STAs, one sharing AP and one shared AP. Although this example indicates a case where capability exchange and feedback information synchronization are performed earlier than AP #1, some or all of these may be performed earlier than AP #2. Furthermore, similarly, this example indicates a case where algorithm synchronization, weight synchronization information, and weight calculation are performed by the AP #1, but some or all of these may be performed by the AP #2. Furthermore, for example, in performing the feedback information synchronization to be described later, the feedback information synchronization may be performed by the AP that has acquired the transmission right earlier. Furthermore, each sequence may be implemented as one sequence formed by collecting some of the sequences or the sequences may be partially omitted as necessary. For example, notification of information notification of which is performed in the capability exchange and algorithm synchronization may be collectively performed as one frame. [Capability Exchange] First, the AP #1 and the AP #2 perform notification of information regarding the capability of the AP #1 and the AP #2 to each other. This is referred to as capability exchange811and capability exchange812. The capability herein refers to whether or not joint sounding or joint transmission to be described later is performed or the type of algorithm that can be used at the time of the weight calculation, but is not limited thereto. Whether or not the algorithm for weight calculation is performed may vary depending on the device. Therefore, notification of an algorithm implemented among generally known algorithms such as eigenvalue decomposition and a Gram-Schmidt orthonormalization method may be performed in the capability exchange811and capability exchange812. Furthermore, instead of the generally known algorithm as described above, notification of an algorithm independently implemented by a vendor may be performed. The capability exchange811and capability exchange812may be performed by being included in, for example, a beacon signal periodically transmitted by each AP or an information notification (association) for connection for the APs to operate as a multi-AP. FIG.4is a diagram illustrating a configuration example of a frame notification of which is performed in capability exchange811and capability exchange812according to the embodiment of the present technology. The notification frame of the capability exchange811and capability exchange812is configured by an “element ID”, an “Extremely High Throughput (EHT) capability element”, and a “vendor-specific element”, but the components are not limited thereto. Note that the order of the “EHT capability element” and the “vendor-specific element” may not be as described above. The “Element ID” includes information indicating the type of immediately subsequent element. The “EHT capability element” includes information indicating whether or not the CJT can be performed and whether or not joint sounding to be described later can be performed. The “vendor-specific element” includes information indicating a manufacturing vendor of the device and information regarding a vendor-specific numerical calculation algorithm. The “element ID” is information necessary for identifying an immediately subsequent element at the time of reception, and includes information capable of uniquely indicating the type of immediately subsequent element. Note that identification may be performed using arbitrary information included in the subsequent element. The “EHT capability element” includes at least one of the fields of a “length”, “joint transmission capability”, and “joint sounding capability”. The “length” includes information indicating a bit length of the “EHT capability element”. The “joint transmission capability” includes information indicating whether or not CJT can be performed for a device that transmits a main frame. The “joint sounding capability” includes information indicating whether or not joint sounding can be performed for the device that transmits a main frame. The “vendor-specific element” includes at least one of fields of a “length”, an “organization identifier”, and a “vendor-specific content”. The “length” includes information indicating a bit length of the “vendor-specific element”. The “organization identifier” includes information indicating a vendor of the device that transmits a main frame. The “vendor-specific content” includes information regarding a vendor-specific numerical calculation algorithm for the device that transmits a main frame. [Algorithm Synchronization] Next, the AP performs an information notification for determining an algorithm to be used when performing the CJT. This is referred to as algorithm synchronization815. In the algorithm synchronization815, on the basis of information notification of which is performed in the capability exchange811and capability exchange812, notification of information indicating an algorithm commonly used by both the APs in the weight calculation of the CJT is performed. At this time, as illustrated in the drawing, the AP #1 performs the algorithm synchronization815for the AP #2, and thus an algorithm used for calculating the weight of the CJT is designated. Then, an acknowledgement Ack816in response to this is performed, and thus the algorithm notification of which is performed in the algorithm synchronization815may be used in the weight calculation of the CJT. Furthermore, in the algorithm synchronization815, the AP #1 may perform notification of information indicating a candidate of an algorithm to be used for calculating the weight of the CJT, and perform notification of information indicating an algorithm to be performed for this by the AP #2. Note that, in this case, since notification of the algorithm that can be performed between the APs is performed to each other, when it is determined that a transmission source terminal can perform the joint sounding and joint transmission when the algorithm synchronization815is performed, the capability exchange811and capability exchange812do not need to be performed in advance. Note that, in this example, the algorithm synchronization815is started from the AP #1, but may be started from the AP #2. FIG.5is a diagram illustrating a configuration example of a frame notification of which is performed in the algorithm synchronization815according to the embodiment of the present technology. A notification frame of this algorithm synchronization815includes a “category”, an “action”, and a “CJT algorithm”, but components are not limited to these. The “category” and the “action” include information indicating that the subsequent “CJT algorithm” exists by combining the information included in both the category and the action. The “CJT algorithm” includes information regarding an algorithm in weight calculation of the CJT. The “category” includes information indicating that subsequent information is the “CJT algorithm”. The “action” may include information indicating from where notification of a main frame is performed among the algorithm synchronization815, feedback information synchronization841to be described later, and weight synchronization854. Specifically, in particular, the “action” may store information as below. That is, “00” indicates that the main frame is sent in the algorithm synchronization815, “01” indicates that the main frame is sent in the feedback information synchronization841, and “10” indicates that the main frame is sent in the weight synchronization854. The “CJT algorithm” includes one or more subfields of a “length”, a “vendor information flag”, a “single user algorithm”, a “multi-user algorithm”, and a “vendor algorithm”. The “length” includes information indicating a bit length of the “CJT algorithm”. The “vendor information flag” includes information indicating that the “vendor algorithm” is included in the “CJT algorithm”. The “single user algorithm” (SU algorithm) includes information regarding an algorithm in the weight calculation when the transmission is performed only to one terminal in the CJT. The “multi-user algorithm” (MU algorithm) includes information regarding an algorithm in the weight calculation when the transmission is performed to a plurality of the terminals in the CJT. The “vendor algorithm” includes information regarding an algorithm determined by a specific vendor in the weight calculation at the time of performing the CJT. As a specific example, information may be stored in these subfields as below. For example, the “vendor information flag” shows “one” when the “vendor algorithm” is included in the “CJT algorithm”, but otherwise, the “vendor information flag” shows “zero”. Furthermore, for example, in the “single user algorithm”, when the multi-AP-CJT weight when transmission is performed only to one terminal in the CJT is “00”, it is indicated that a unit matrix is applied; when the multi-AP-CJT weight when transmission is performed only to one terminal in the CJT is “01”, it is indicated that a discrete Fourier transformation (DFT) matrix is applied; and when the multi-AP-CJT weight when transmission is performed only to one terminal in the CJT is “10”, it is indicated that a singular vector obtained by singular value decomposition (SVD) or an eigenvector obtained by eigenvalue decomposition (EVD) is applied to a propagation channel matrix H between the multi-AP and the terminal. Furthermore, for example, in the “multi-user algorithm”, when the multi-AP-CJT weight when transmission is performed to a plurality of the terminals in the CJT is “00”, it is indicated that a vector obtained with zero forcing (ZF) criteria is applied; when the multi-AP-CJT weight when transmission is performed to a plurality of the terminals in the CJT is “01”, a vector obtained by minimize maximum square error (MMSE) criteria is applied; and when the multi-AP-CJT weight when transmission is performed to a plurality of the terminals in the CJT is “10”, a vector obtained by a Gram-Schmidt orthonormalization method is applied. Note that the DFT matrix is represented by the following Formula 1. [Mathematicalformula1]Q=[W00W01…W0NDFT-1W10W11…W1NDFT-1⋮⋮⋱⋮WNDFT-10WNDFT-11…WNDFT-1NDFT-1],Formula1s.t.Wab=e-y~πaNDFTb,NDFT∈Z′where Z+represents a set of all positive integers. Furthermore, W(fl)represented in the following Formula 2 indicates an example of a vector of MMSE criteria applied to a frequency fl at the time of transmission to a certain desired terminal STAk. [Mathematicalformula2]w(f1)∝max·eigenvector{(σN2I+H(f1)H~H(f1)~)-1(hk(f1)Hhk(f1))}Formula2whereH(fl)indicates a propagation channel matrix at a frequency flbetween the multi-AP and the terminal;hk(fl)indicates a channel matrix between the multi-AP and the terminal STAkin H(fl);H˜(fl)indicates a matrix obtained by removing hk(fl)in H(fl);l indicates a unit matrix;σN2indicates an average value of noise power between all the antennas that can be measured in the terminal STAk;AHindicates a complex conjugate transpose matrix of a matrix A; andmax.eigenvector {A} indicates an eigenvector having the maximum eigenvalue among eigenvectors of a matrix A. Note that the vector of the ZF criteria is, for example, represented by the following Formula 3, similarly to the vector of the MMSE criteria. [Mathematicalformula3]w(f1)∝max·eigenvector{(σN2I+H(f1)H~H(f1)~)-1(hk(f1)Hhk(f1))}Formula3 Furthermore, w(fl)represented by the following Formula 5 is an example of a vector in a Gram-Schmidt orthonormalization method. Here, hk(fl)indicates a channel matrix at a frequency flbetween the multi-AP and the terminal STAk, H(fl)=[(h1(fl))T, (h2(fl))T, . . . , (hN(fl))T]Tindicates a propagation matrix, and [a1, a2, . . . , aN] indicates an integer sequence obtained by rearranging a consecutive integer sequence from one to N in arbitrary order. At this time, arbitrary ham(fl)is converted into matrices h˜am(fl)orthogonalized to each other by the following Formula 4. [Mathematicalformula4]w∝h~am(f1)s.t.h~am(f1)=[h~am(f1,1)h~am(f1,1)…h~am(f1,Nm)h~am(f1,Nm)],h~am(f1,j)=h~am(f1,j)-∑1=1m-1∑p=1N1h~a1(f1,p)Hham(f1,j)h~a1(f1,p)Formula4 where j indicates an arbitrary integer from one to Nm; a(fl, c)and b˜(fl, c)respectively indicates the c-th column vectors of a(fl)and b˜(fl)with respect to a matrix represented by a(fl)or b˜(fl); and Nmindicates the number of columns of ham(fl)or h˜am(fl). [Joint Sounding] In order to calculate the weight of the CJT, the AP #1 and the AP #2 transmit a reference signal for the terminal to estimate channel state information, that is, perform joint sounding821. In the joint sounding821, reference signals orthogonal to each other in a frequency domain may be transmitted by the AP #1 and the AP #2, but the reference signals need to be transmitted so as to obtain channel state information with each transmission antenna that transmits the joint sounding821and a correlation between a transmission antenna and a reception antenna. Note that notification of the reference signal for performing frequency synchronization and time synchronization between the APs may be performed for the AP #1 and the AP #2 immediately before the joint sounding821is performed. The joint sounding821is performed, and a terminal serving as a desired destination terminal performs estimation822of channel state information on the basis of the received reference signal. [Trigger and Feedback] The terminal for which the joint sounding821is performed performs feedback824which is a notification of information regarding the estimated channel to the AP #1 and the AP #2. The feedback824may be performed for each terminal in a time-division manner, or may be performed by a plurality of the terminals simultaneously in a frequency-division manner. In this example, immediately before the feedback824, it is indicated that trigger823, which is an information notification that the terminal induces the feedback to be performed, is performed, but it does not necessarily need to be performed. However, in a case where the feedback824is performed by frequency multiplexing of a plurality of the terminals, such as orthogonal frequency division multiple access (OFDMA) as defined in IEEE 802.11, a notification regarding the feedback824of the terminal may be performed as the trigger823immediately before the feedback824. [Feedback Information Synchronization and Weight Calculation] The multi-AP, for which the feedback824is performed by the terminal, performs information notification regarding feedback information synchronization841and feedback information synchronization842in order to confirm whether there is a difference in information regarding the channel, notification of which is performed in the feedback824. As in this example, when the AP #1 performs the feedback information synchronization841for the AP #2, the AP #2 is notified of information regarding the channel held by the AP #1. Thereafter, the AP #2 notifies the AP #1 of information indicating a difference between the information regarding the channel held by the AP #1 notification of which is performed and the information regarding the channel held by the AP #2 itself in the feedback information synchronization842. As in this example, the AP #1, for which the feedback information synchronization842is performed by the AP #2, performs weight calculation851of the multi-AP-CJT for the channel state information commonly held by the multiple APs. The weight calculation851may be performed on the basis of the methods shown in Formulas 2 to 4 described above, but is not limited thereto. Here, for example, in a case where notification of the feedback824from a certain terminal is performed to the AP #1 but cannot be received by the AP #2, the channel state information held by the multi-APs does not coincide with each other. In the weight calculation of the multi-AP-CJT, a weight for an arbitrary terminal is required so as not to interfere with other terminals at the time of transmission. Therefore, when the information regarding the channel held by each AP does not coincide with each other, the weight calculated by each AP is different. The feedback information synchronization841and feedback information synchronization842are performed to avoid this. Furthermore, for example, in a case where notification of information indicating a singular vector of a channel matrix is performed to the channel with the multi-AP in the feedback824from each terminal, each AP manages the singular vectors in order by using a matrix or the like, but this order may be different between the APs. In the weight calculation of the multi-AP-CJT, the eigenvalue decomposition, or the Gram-Schmidt orthonormalization method is performed for an ordered singular vector group (hereinafter, a singular matrix), but in a case where the singular matrix is different between the APs, the weight calculated in each AP is different. The feedback information synchronization841and feedback information synchronization842are performed to avoid this. Note that, in this example, the feedback information synchronization841is started from the AP #1, but may be started from the AP #2. FIG.6is a diagram illustrating a configuration example of a frame notified in the feedback information synchronization841and the feedback information synchronization842according to the embodiment of the present technology. Notification frames of the feedback information synchronization841and the feedback information synchronization842include a “category”, an “action”, and “feedback information”, but components are not limited to these. The “category” and the “action” are similar to those in the algorithm synchronization815described above. The “feedback information” includes information regarding channel state information between the AP performing notification of the main frame and the terminal. The “feedback information” includes at least one of subfields of a “direction”, a “weight synchronization flag”, the “number of terminals”, and “terminal information”. The “direction” includes information indicating whether or not feedback information synchronization has been performed precedingly. The “weight synchronization flag” includes information indicating whether or not weight synchronization can be performed according to the information included in the “direction”, or information indicating whether or not there is subsequent information in the “feedback information”. The “number of terminals” (STA number) includes information indicating the number of subsequent “terminal information” subfields. The “terminal information” (STA Information #1 to #NSTA) includes information regarding a channel between a certain terminal and the multi-AP, the information held by the AP that transmits the main frame according to information included in the “direction”, or information regarding a difference from the channel state information notification of which is performed in the preceding feedback information synchronization. Note that the “terminal information” includes at least one of an association identifier (AID) or an SS number. The AID includes information uniquely indicating the terminal indicated in the “terminal information” subfield. Furthermore, the SS number includes information indicating a spatial stream (SS) of the channel state information. As a specific example, information may be stored in the “feedback information” as below. Note that a case where the AP #1 performs the “feedback information synchronization” for the AP #2, and immediately thereafter, the AP #2 performs the “feedback information synchronization” for the AP #1 will be described below. However, the same applies to a case where the AP #1 and the AP #2 are switched. When the AP #1 performs the feedback information synchronization841for the AP #2, “direction”=“one” is set in the “feedback information” notification of which is performed. At this time, in a case where it is requested that the AP #1 performs the weight synchronization854, “weight synchronization flag”=“one” is set, and otherwise, “weight synchronization flag”=“zero” is set. Furthermore, when “weight synchronization flag”=“zero” is set, the “number of terminals” and the “terminal information” do not exist subsequently, but in a case where “weight synchronization flag”=“one” is set, the “number of terminals” and the “terminal information” exist subsequently. In the “terminal information”, the “AID” of each terminal included in the channel state information between the multi-AP and the terminal, which is obtained by the AP #1 by the joint sounding is stored. However, the “AID” indicated in each “terminal information” is different from each other. On the other hand, the AP #2 for which the AP #1 has performed the feedback information synchronization841with “direction”=“one” notifies the AP #1 of the feedback information synchronization842with “direction”=“zero”. At this time, in a case where the AP #1 performs, for the AP #2, the feedback information synchronization841with “direction”=“one” and “weight synchronization flag”=“one” precedingly, when there is a terminal that is not included in the channel state information between the multi-AP and the terminal, which is held by the AP #2 itself, among the “AIDS” indicated by the “terminal information” in the feedback information synchronization841, the AP #2 sets “weight synchronization flag”=“one”, stores an “AID” of the terminal in each “terminal information”, and stores the number of the corresponding terminals in the “number of terminals”. In other cases, the main frame with “weight synchronization flag”=“zero” is transmitted, but the “number of terminals” and the “terminal information” should not exist. In a case where the AP #2 performs the feedback information synchronization842with “direction”=“zero” for the AP #1, and when “weight synchronization flag”=“zero” in the frame notification of which is performed is set, the AP #1, which has performed, for the AP #2, the feedback information synchronization841with “direction”=“one”, performs the weight calculation851of the multi-AP-CJT by using the channel state information between the multi-AP and the terminal, which is held by the AP #1 itself. On the other hand, in a case where “weight synchronization flag”=“one” is set, the channel state information of the terminal having the “AID” notification of which is performed in the “terminal information” may not be used when the weight calculation of the multi-AP-CJT is performed. Furthermore, notification of the channel state information between the terminal indicated by the “AID” and the multi-AP may be performed to the AP #2. [Weight Synchronization Information and Weight Synchronization] The AP, which has performed the weight calculation851, notifies the other APs configuring the multi-AP of weight synchronization information852regarding the weight calculated by the AP itself. This example shows a case where the AP #1 performs the weight synchronization information852for the AP #2, and the AP #2 needs to calculate the CJT weight on the basis of the channel state information held by the AP #2 itself after the weight synchronization information852is performed. However, as described above, in the multi-AP-CJT weight, the calculation result of the AP #1 and the calculation result of the AP #2 are in a relationship multiplied by a complex constant. Therefore, the AP #2 performs the weight synchronization854which is an operation for synchronizing with the “multi-AP-CJT weight” calculated by the AP #1 on the basis of the information regarding the weight the AP #1 generates on the basis of the weight synchronization information852. Note that, in this example, it has been described that the AP #2, for which the weight synchronization information852is performed, calculates the “multi-AP-CJT weight” in the weight synchronization854, but the calculation may not be performed only in the weight synchronization854. For example, when the weight calculation851is performed by the AP #1, the AP #2 may also calculate the “multi-AP-CJT weight” on the basis of the information held by the AP #2 itself, and after the weight synchronization information852is performed, the AP #2 may perform the weight calculation and the calculation for correction again. The operation of the weight synchronization854will be described below. Here, the AP #1 obtains the feedback information of STA #1 to STA #(k+1), and the AP #2 obtains the feedback information of STA #1 to STA #k and STA #(k+2) by the joint sounding821. wm(1)(fl)indicates “multi-AP-CJT weight” with respect to STAmand a frequency f1, which is generated by the AP #1 with its own numerical algorithm on the basis of the feedback information, and wm(2)(fl)indicates the “multi-AP-CJT weight” similarly generated by the AP #2 with its own algorithm. Each AP generates wm(fl)with an algorithm as shown in Formulas 2 to 4, but may be generated by another algorithm. Here, among all the “multi-AP-CJT weights” generated by the AP #1 and the AP #2 on the basis of the feedback information held by the AP #1 and the AP #2 themselves, the “multi-AP-CJT weights” of the terminals (that is, STAs #1 to #k) commonly held by the AP #1 and the AP #2 are represented by in Formulas 5 and 6, respectively. That is, W(1)(fl)calculated by Formula 5 is a weight held by the sharing AP (AP #1), and W(2)(fl)calculated by Formula 6 is a weight held by the shared AP (AP #2). [Mathematicalformula5]W(1)(f1)=[wa1(1)(f1)wa2(1)(f1)…wak(1)(f1)]=[γa1(f1)⋱γak(f1)][ua1(t)(f1)ua2(t)(f1)…uak(1)(f1)]Formula5s.t.ai∈{1,2,…,k}[Mathematicalformula6]W(2)(f1)=[wb1(2)(f1)wb2(2)(f1)…wbk(2)(f1)]=[γb1(f1)⋱γbk(f1)][ub1(2)(f1)ub2(2)(f1)…ubk(2)(f1)]Formula6s.t.bi∈{1,2,…,k} where for wam(1)(fl)and wbm(2)(fl), matrices obtained by normalizing column vectors are represented as uam(1)(fl)and ubm(2)(fl), respectively, and γam(fl)and γbm(fl)represent diagonal matrices obtained by multiplying each column of uam(1)(fl)and ubm(2)(fl)by a constant. The AP #1 and the AP #2 each calculate “multi-AP-CJT weight” wm(fl), but wm(1)(fl)and wm(2)(fl)have a relationship multiplied by a complex constant with each other by using a numerical calculation algorithm as shown in Formulas 5 and 6, or have a degree of freedom such that the order of column vectors is different although column vectors of wm(1)(fl)and wm(2)(fl)are the same. Specifically, even when a1(1)=b1(2) is satisfied with respect to ua1(1)(fl)and ub1(2)(fl)represented by Formulas 5 and 6, there is a case where the order of the column vectors is different from each other, or the column vectors do not completely coincide with each other, for example, an arbitrary θ1and an imaginary unit j are multiplied by ejθ1. [Mathematicalformula7][γa1(f1)⋱γak(f1)][Θa1(f1)⋱Θak(f1)]C[γb1(f1)-1⋱γbk(f1)-1]W(2)(f1)=[γa1(f1)⋱γak(f1)][Θa1(f1)⋱Θak(f1)]C[ub1(2)(f1)ub2(2)(f1)…ubk(2)(f1)]=[γa1(f1)⋱γak(f1)][ub1(2)(f1)ub2(2)(f1)…ubk(2)(f1)]=W(1)(f1)Formula7 Here, a matrix C is a permutation matrix that performs an operation of rearranging [ub1(2)(fl)ub2(2)(fl). . . ubk(2)(fl)] in order of the same column vector as a stream intended by each column vector of [ua1(2)(fl)ua2(2)(fl). . . uak(2)(fl)]. Furthermore, θa1(fl)indicates a diagonal matrix, and each diagonal component is represented by ejθfor any different complex phase θ. In general, uan(1)(fl)and ubm(2)(fl)are obtained in a numerical calculation, have a relationship multiplied by a complex constant as described above, and notification of θam(fl), γam(fl), γbm(fl), and c (m∈{a1, . . . ak}), which are coefficients for correcting this, are performed among the multiple APs. Therefore, the “multi-AP-CJT weight” generated in each AP can be matched. FIG.7is a diagram illustrating a configuration example of a frame notification of which is performed in the weight synchronization information852according to the embodiment of the present technology. In the weight synchronization information852, notification of a parameter for synchronization with the “multi-AP-CJT weight” held by a notification source AP is performed when the AP notification of which is performed calculates the “multi-AP-CJT weight”. Note that a calculation example of the weight synchronization854is shown in the above-described Formula 7, but is not limited thereto. A notification frame of the weight synchronization information852includes a “category”, an “action”, and “synchronization information”, but components are not limited to these. The “category” and the “action” are similar to those in the algorithm synchronization815described above. The “synchronization information” includes information indicating a parameter necessary for the AP notified of the main frame to perform the weight synchronization854. The “synchronization information” includes one or more of the “number of terminals”, “quantization granularity”, “spatial stream order information”, a “power”, and a “complex phase”. Note that, hereinafter, for convenience, an AP to which notification of the weight synchronization information852is performed is set to the AP #1, and an AP to which the weight synchronization information852is to be sent is set to the AP #2. However, the AP #2 may perform notification of the weight synchronization information852, and the destination target of the notification may be set to the AP #1. The “number of terminals” (STA number) includes information indicating the number of desired terminals the AP #1 sets as the destination in the CJT. The “quantization granularity” includes a value indicating resolution of values included in the subsequent “power” and “complex phase”. The “spatial stream order information” (spatial stream order information #1 to #NSTA) includes information regarding the “multi-AP-CJT weight” for the different NSTAterminals, which is calculated by the AP #1. The “power” (power #1 to #NSS) includes information regarding the magnitude of the “multi-AP-CJT weight” for different NSSstreams, which is calculated by the AP #1. The “complex phase” (complex phases #1 to #NSS) includes information regarding the magnitude of the “multi-AP-CJT weight” for different NSSstreams, which is calculated by the AP #1. Note that the information included in the “number of terminals” may be a value indicating “NSTA” which is the number of fields of the subsequent “spatial stream order information”. Furthermore, the “quantization granularity” may include at least one of “magnitude” or “phase”. The “magnitude” includes a value indicating the resolution of the value included in the “power”. The “phase” includes a value indicating the resolution of the value included in the “complex phase”. Note that the “magnitude” and the “phase” are not defined, and the resolution of the value included in the “power” and the resolution included in the “complex phase” may be indicated as one value. Furthermore, the “spatial stream order information” includes at least one of an “AID”, a “band width”, an “SS number”, or “spatial stream order”. The “AID” includes information indicating a terminal which is a target of the information regarding the channel indicated in each “spatial stream order information”. The “band width” (BW) includes information indicating the number of “subcarriers” included in the frequency channel and the subsequent “complex phase”. The “SS number” includes information indicating “NSS” which is the number of “spatial stream order” in the same “spatial stream order information”. The “spatial stream order” (spatial stream order #1 to #N33) includes information indicating a position of the feedback vector between the AP that transmits the main frame and the terminal indicated by the “AID” in the channel matrix. Furthermore, the “complex phase” includes “subcarrier”. The “subcarrier” (subcarriers #1 to #Nf) includes information regarding a complex phase of an element of the feedback vector. As a specific example, information may be stored in the “synchronization information” as below. Hereinafter, a case where the AP #1 notifies the AP #2 of the weight synchronization information852will be described, but the same applies to a case where the AP #2 notifies the AP #1 of the weight synchronization information852. In the feedback information synchronization841and the feedback information synchronizations842, when the “multi-AP-CJT weight” W(1)(fl)at a certain frequency f1calculated by the AP #1 is represented by Formula 5 described above, information indicating “k” is stored in the “number of terminals”, information indicating a minimum unit or resolution expressed by the subsequent “power” or “complex phase” is stored in the “quantization granularity”, and information regarding a terminal STAito which ui(1)(fl)is applied is stored in “spatial stream order #i”. In particular, in the “spatial stream order #i”, a bit string calculated from a MAC address of the terminal STAiis indicated in the “AID”; information indicating the frequency channel of the terminal STAiapplied at the time of the CJT and information indicating the number Nf(i) of fields of the “subcarrier” included in the “complex phase #i” are indicated in the “band width”; information indicating the number of columns of the matrix of uai(1)is indicated in the “SS number”; and information indicating a column number of each column vector of ui(1)(fl)for [ua1(1)(fl)ua2(1)(fl). . . uak(1)(fl)] in Formula 5 is indicated in “spatial stream order information #1 to #NSS(i)”. Furthermore, the “power” includes information regarding diag [γa1(1)(fl)γa2(1)(fl). . . γak(1)(fl)], and the “complex phase #i” includes information regarding ui(1)(fl)at the frequency fi. Here, diag [x] represents a diagonal matrix having each element of the vector x as a diagonal component. As a specific example, information indicating a complex phase for an element of the first row in each column vector of ui(1)(fl)is stored in the “complex phase #i”, and when a (m, m)-th component of diag [γa1(fl)γa2(fl). . . γak(1)(fl)] is set to Aγ(fl)(m, m), information indicating a value represented by the following Formula 8 is stored in the “power #m”. [Mathematicalformula8]1Nf∑k=1Nf❘"\[LeftBracketingBar]"γ(fk)(m,m)❘"\[RightBracketingBar]"2Formula8 At this time, for example, when an arbitrary “subcarrier” of the “complex phase #i” is represented by Nbbits and a value of the i-th bit in the “subcarrier” is X(i), the complex phase may be interpreted as in the following Formula 9. [Mathematicalformula9]K2Nb∑i=1Nb2(i-1)δ(X(i)),s.t.δ(x)={1,x=00,x≠0Formula9 At this time, information indicating “Nb” or “K” may be included in the “quantization granularity”. Furthermore, bit information stored in the “power” may be interpreted in a similar manner to Formula 9. [Joint Transmission] After the AP #2 performs the weight synchronization854, the AP #1 and the AP #2 perform joint transmission (JT)859for the communication terminal group210. In this joint transmission859, either coherent JT (CJT) in which the AP #1 and AP #2 serving as one virtual AP perform transmission or non coherent JT (NCJT) in which the AP #1 and the AP #2 form streams independently of each other and perform transmission may be performed. The AP that performs the joint transmission859needs to align a transmission timing between the APs. Therefore, immediately before the joint transmission859is performed, the AP #1 or the AP #2 may notify an AP performing the joint transmission859that the joint transmission859is performed. As a specific example, a trigger frame indicating a start time of the joint transmission859may be transmitted, and the joint transmission859may be performed at the time indicated by the trigger frame. As described above, in the first embodiment of the present technology, the AP #1 and the AP #2, which perform the joint transmission859, calculate weights, respectively, and one of the AP #1 and the AP #2 notifies the other of the AP #1 and the AP #2 of a parameter necessary for synchronization with the weight synchronization information852to perform the weight synchronization854. Therefore, the mismatch of the weights between the APs can be resolved, and the joint transmission859can be performed. 2. Second Embodiment FIG.8is a sequence diagram illustrating an operation example of a wireless network system according to the second embodiment of the present technology. In the first embodiment described above, the reference signal is transmitted from the multi-AP by the joint sounding821, and notification of the feedback information based on the reference signal is performed from the communication terminal group210by explicit feedback. On the other hand, in the second embodiment, arbitrary APs configuring the multi-AP perform a sounding trigger832for the communication terminal group210. With this as a trigger, the communication terminal group210notified of the sounding trigger832performs UL_NDP833for the multi-AP and transmits a reference signal. In this manner, each AP estimates CSI with the terminal by using the reference signal of the UL_NDP833induced by the sounding trigger832. Here, a multi-AP trigger831, the sounding trigger832, and the UL_NDP833, which are the differences from the first embodiment described above, will be described. Note that, in this example, a case where the sounding trigger832is performed by each of the APs (AP #1 and AP #2) configuring the multi-AP is described, but the sounding trigger is not necessarily performed by all the APs, and may be performed by either the AP #1 or the AP #2. In this case, the multi-AP trigger831may not be performed. [Multi-AP Trigger] In a case where a plurality of the APs configuring the multi-AP simultaneously performs the sounding trigger832, in the multi-AP trigger831, a reference signal for performing frequency synchronization and time synchronization between the APs is performed. In this example, a case where the AP #1 performs the multi-AP trigger831for the AP #2 is described, but the AP #2 may perform the multi-AP trigger for the AP #1. [Sounding Trigger] Arbitrary APs configuring the multi-AP perform the sounding trigger832for requesting an arbitrary communication terminal group210to perform the UL_NDP833. [UL_NDP] In the sounding trigger832, the communication terminal group210, which has been notified of a request of performing UL_NDP833, performs the UL_NDP833for the multi-AP. The frame notification of which is performed by the UL_NDP833may be a null data packet (NDP) defined in IEEE 802.11. Note that, in a case where the sounding trigger832includes information indicating that a plurality of terminals simultaneously performs the UL_NDP833, it may be determined that the terminal, which has received the sounding trigger832, performs the UL_NDP833only in a case where the frequency synchronization can be performed for an arbitrary AP of the multi-AP within 350 Hz. As described above, according to the second embodiment of the present technology, the channel state information can be estimated in each AP by causing the communication terminal group210to transmit the known signal by the UL_NDP833when the sounding is performed. 3. Third Embodiment FIG.9is a sequence diagram illustrating an operation example of a wireless network system according to the third embodiment of the present technology. In the first embodiment described above, the feedback information synchronization841and the feedback information synchronization842are performed bidirectionally between the AP #1 and the AP #2, but in the third embodiment, feedback information synchronization844is performed in one direction only from the AP #2. Then, prior to the feedback information synchronization844, a feedback information synchronization request843, which is an information notification requesting the AP #1 to perform the feedback information synchronization844for the AP #2, is performed. However, the feedback information synchronization request843may be performed by the AP #2 so as to be in the same direction as that in the first embodiment described above, and thereafter, the AP #1 may perform the feedback information synchronization844for the AP #2. FIG.10is a diagram illustrating a configuration example of a frame notification of which is performed in the feedback information synchronization request843according to the embodiment of the present technology. The notification frame of the feedback information synchronization request843is used to notify a destination terminal of a request of performing the feedback information synchronization844. The main frame includes “frame control”, a “length”, and a “synchronization request”. The “frame control” includes information indicating that the main frame is a frame notification of which is performed as the feedback information synchronization request843. The “length” includes information regarding a bit length of the main frame. The “synchronization request” includes information indicating a request of performing the feedback information synchronization844. Note that in the “frame control”, it may be indicated that the main frame is a frame notification of which is performed as the feedback information synchronization request843together with values of other fields. As a specific example, the “synchronization request” may indicate “one” in a case where the destination terminal is requested to perform the feedback information synchronization844, and otherwise, may indicate “zero”. As described above, according to the third embodiment of the present technology, another AP can perform the feedback information synchronization844for the AP that has performed the feedback information synchronization request843. 4. Fourth Embodiment FIG.11is a sequence diagram illustrating an operation example of a wireless network system according to the fourth embodiment of the present technology. In the fourth embodiment, advanced algorithm synchronization817obtained by extending the algorithm synchronization815in the first embodiment described above is performed. That is, in the notification of information regarding whether or not the calculation algorithm for the CJT weight in each AP can be performed, the amount of information necessary for weight synchronization is further reduced by further specifying details of calculation for an algorithm such as eigenvalue decomposition or a Gram-Schmidt orthonormalization method. Note that in the fourth embodiment, since a highly accurate value can be obtained by an advanced algorithm, both the weight synchronization information852and the weight synchronization854, which are illustrated in the drawing, do not necessarily need to be performed. [Capability Exchange] In the fourth embodiment, in addition to the first embodiment described above, the AP #1 and the AP #2 notify each other of information indicating whether or not the “multi-AP-CJT weight” can be calculated on the basis of the information notification of which is performed in the advanced algorithm synchronization817through the capability exchange811and capability exchange812. FIG.12is a diagram illustrating a configuration example of a frame notification of which is performed in the capability exchange811and capability exchange812according to the fourth embodiment of the present technology. In the notification frames of the capability exchange811and capability exchange812in the fourth embodiment, in the “advanced weight synchronization”, notification of information indicating whether or not the “multi-AP-CJT weight” can be calculated is performed to each other on the basis of the information notification of which is performed in the advanced algorithm synchronization817. For example, “one” may be indicated when calculation is possible, and otherwise, “zero” may be indicated. Note that not only “one” may indicate that calculation is possible, but also details regarding the numerical calculation algorithm such as eigenvalue decomposition or a Gram-Schmidt orthonormalization method may be specified. In this case, the advanced algorithm synchronization817may not be performed as long as necessary information is transmitted. [Advanced Algorithm Synchronization] The AP #1 performs the advanced algorithm synchronization817as a notification of information regarding an algorithm (eigenvalue decomposition, a Gram-Schmidt orthonormalization method, or the like) used in calculation of the “multi-AP-CJT weight”. Unlike the algorithm synchronization815of the first embodiment described above, notification of information regarding reducing the amount of information notification of which is performed in the weight synchronization information852is performed to the algorithm to be used. As a specific example, for the eigenvalue decomposition and the Gram-Schmidt orthonormalization method, notification of the following information is performed. For example, in the eigenvalue decomposition used when the “multi-AP-CJT weight” is calculated, notification that an eigenvector for an eigenvalue having a complex phase designated in the advanced algorithm synchronization817is calculated is performed. Furthermore, in the Gram-Schmidt orthonormalization method used when calculating the “multi-AP-CJT weight”, notification of the order of the vectors to be calculated at the time of calculation is performed. For example, the feedback vector notification of which is performed in the feedback824may be notified of information indicating that the calculation is performed in ascending order of the “AID”. FIG.13is a diagram illustrating a configuration example of a frame notification of which is performed in the advanced algorithm synchronization817according to the fourth embodiment of the present technology. Hereinafter, only a difference from a field configuration in the algorithm synchronization815of the first embodiment described above will be described. “Algorithm details” includes information regarding numerical calculation algorithms such as eigenvalue decomposition and a Gram-Schmidt orthonormalization method. The “algorithm details” include, for example, at least one of “GS order” or an “SV/EV complex phase”. The “GS Order” includes order of vectors to be calculated at the time of calculation in the Gram-Schmidt orthonormalization method. As described above, the feedback vector notification of which is performed in the feedback824may be notified of information indicating that the calculation is performed in ascending order of the “AID”. The “SV/EV complex phase” includes information indicating a complex phase of an eigenvalue corresponding to an eigenvector obtained by eigenvalue decomposition or a complex phase of a singular value corresponding to a singular vector obtained by singular value decomposition. As described above, according to the fourth embodiment of the present technology, by performing algorithm synchronization assuming a highly accurate value in the advanced algorithm synchronization817, it is possible to omit the subsequent weight synchronization854. 5. Fifth Embodiment FIG.14is a sequence diagram illustrating an operation example of a wireless network system according to the Fifth embodiment of the present technology. The fifth embodiment is different from the first embodiment described above in that the communication terminal group210performs a CJT request819for the AP #1 or the AP #2, and that a notification regarding whether or not a CJT request819can be performed is performed between the multi-AP and the communication terminal group210by capability exchange813and capability exchange814. In this example, a case where the communication terminal group210performs the CJT request819for the AP #1 is described, but the CJT request may be performed for the AP #2 or for both the AP #1 and the AP #2. Furthermore, although the communication terminal group210performs the capability exchange813and capability exchange814for the AP #1, the capability exchange813and capability exchange814may be performed for the AP #2 or for both the AP #1 and the AP #2. Note that the order of the sequences in the example of the drawing may not be as illustrated in the drawing. For example, the CJT request819may be performed immediately before the feedback information synchronization841, and the capability exchange813and capability exchange814between the AP #1 and the communication terminal group210may be performed after the algorithm synchronization815. Hereinafter, matters related to the CJT request819, which is a difference from the first embodiment, will be described. [Capability Exchange] In the fifth embodiment, similarly to the first embodiment described above, between the APs configuring the multi-AP, the capability exchange811and capability exchange814are performed as the notification of capability of the devices itself, and the APs configuring an arbitrary multi-AP and an arbitrary terminal perform the capability exchange811and capability exchange814are performed as the notification of capability of the devices itself. FIG.15is a diagram illustrating a configuration example of a frame notification of which is performed in the capability exchange811and capability exchange814according to the fifth embodiment of the present technology. Hereinafter, a “joint transmission request”, which is a difference from the first embodiment, will be described. The “joint transmission request” (JT Request) includes information indicating whether or not the CJT request819to be described later can be performed. As a specific example, information may be stored in the “joint transmission request” as below. “00” indicates that the terminal performing notification of the main frame cannot perform both transmission and reception of the CJT request819, “01” indicates that the terminal notifying the main frame can perform only transmission of the CJT request819, “10” indicates that the terminal notifying the main frame can perform only reception of the CJT request819, and “11” indicates that the terminal notifying the main frame can perform both transmission and reception of the CJT request819. [CJT Request] In the multi-AP for which the CJT can be performed, an arbitrary communication terminal group210performs the CJT request819, which is a notification of a request of performing the CJT, for at least one AP configuring the multi-AP. The trigger for performing the CJT request819may be a time at which a user using the terminal performs setting to make the CJT request819performed by using an application mounted on the terminal. As a specific example, in a case where the terminal is a smartphone, it is assumed that a data rate mode can be designated by an application on the smartphone. The data rate mode that can be designated include a “normal data rate mode” in which a request not to perform the CJT is performed for the multi-AP, a “high data rate mode” in which a request of performing the CJT is performed for the multi-AP, and a “default mode” in which a request of performing the CJT is not performed for the multi-AP. In this case, after the user operating the smartphone selects a mode other than the “default mode” at an arbitrary timing, the terminal may perform the CJT request819when the transmission right has been acquired. FIG.16is a diagram illustrating a configuration example of a frame notification of which is performed in the CJT request819according to the fifth embodiment of the present technology. The main frame includes “frame control” and a “CJT request”, but the components may not be limited to these. The “frame control” includes information indicating that the main frame is a frame to be notified as the CJT request819. The “CJT request” includes information regarding a request of performing CJT. As a specific example, the “CJT request” may store the following information. That is, in a case where the “CJT request” indicates “zero”, the terminal performing notification of the main frame requests the destination AP not to perform the CJT. Furthermore, in a case where the “CJT request” indicates “one”, the terminal performing notification of the main frame requests the destination AP to perform the CJT. [Feedback] The feedback824is similar to that of the first embodiment described above. However, in the CJT request819, the terminal that has perform the request notification indicating that the CJT is not performed does not need to perform the feedback824. [Feedback Information Synchronization] The feedback information synchronization841and feedback information synchronization842are similar to those of the first embodiment described above. However, in the CJT request819, it is not necessary to perform notification of information regarding a terminal that has performed a request not to perform the CJT. As a specific example, in the “terminal information” in the field configuration of the feedback information synchronization841and feedback information synchronization842, which are illustrated inFIG.6, information regarding the terminal that has performed a request not to perform the CJT is not stored. As described above, according to the fifth embodiment of the present technology, by transmitting the CJT request819to the multi-AP from the terminal side, it is possible to request the use of joint transmission with a high data rate. Furthermore, the terminal notifies a request to perform or not to perform the CJT, and thus it is possible to reduce the amount of information required for the feedback information synchronization841and feedback information synchronization842, and the weight synchronization854. Note that the above-described embodiments describe examples for embodying the present technology, and the matters in the embodiment and the matters specifying the invention in the claims have a correspondence relationship. Similarly, the matters specifying the invention in the claims and the matters in the embodiments of the present technology denoted by the same names as the matters specifying the invention have a correspondence relationship. However, the present technology is not limited to the embodiments, and can be embodied by making various modifications to the embodiments without departing from the gist thereof. Furthermore, the processing procedure described in the above-described embodiment may be regarded as a method including these series of procedures, and may be regarded as a program for causing a computer to execute these series of procedures or a recording medium storing the program. As the recording medium, for example, a compact disc (CD), a mini disc (MD), a digital versatile disc (DVD), a memory card, a Blu-ray (registered trademark) disc, or the like can be used. Note that the effects described in the present specification are merely examples and are not limited, and other effects may be provided. Note that the present technology can also have the following configurations. (1) A wireless base station including:a wireless control unit that generates information regarding channel state information between a terminal which is a destination when performing joint transmission together with another wireless base station and a plurality of wireless base stations which is a transmission source of the joint transmission; anda communication unit that transmits the information regarding the channel state information to the another wireless base station. (2) The wireless base station according to (1), in whichthe wireless control unit generates capability information regarding a communication scheme that is capable of being implemented by the wireless base station in the joint transmission and capability information regarding an algorithm that is capable of being performed by the wireless base station in weight calculation of the joint transmission, andthe communication unit transmits the capability information to the another wireless base station. (3) The wireless base station according to (2), in whichthe capability information includes at least one of a preset algorithm or an independently defined algorithm, as an algorithm that is capable of being performed in the weight calculation of the joint transmission. (4) The wireless base station according to any one of (1) to (3), in whichthe wireless control unit generates use algorithm information regarding an algorithm used by the wireless base station in weight calculation of the joint transmission, andthe communication unit transmits the use algorithm information to the another wireless base station. (5) The wireless base station according to (4), in whichthe use algorithm information includes at least one of information indicating an algorithm of weight calculation in a case where one terminal is set as a destination in the joint transmission, information indicating an algorithm of weight calculation in a case where a plurality of terminals is set as a destination in the joint transmission, or information indicating that a specific algorithm is used among independently defined algorithms. (6) The wireless base station according to (4) or (5), in whichthe use algorithm information includes any one of information regarding a complex phase of an eigenvector calculated in eigenvalue decomposition and information regarding operation order in a Gram-Schmidt orthonormalization method. (7) The wireless base station according to any one of (1) to (6), in whichthe wireless control unit generates weight synchronization information regarding a calculation result of a weight used by the wireless base station in the joint transmission, andthe communication unit transmits the weight synchronization information to the another wireless base station. (8) The wireless base station according to (7), in whichthe weight synchronization information includes quantization granularity, spatial stream order information, a power, and a complex phase. (9) The wireless base station according to any one of (1) to (8), in whichin a case where a request for the joint transmission is received from the terminal which is a destination of the joint transmission, the wireless control unit generates information regarding the channel state information between a specific terminal that transmits the request for the joint transmission and the plurality of wireless base stations that performs the joint transmission, andthe communication unit transmits information regarding the channel state information with only the specific terminal to the another wireless base station. (10) A wireless base station including:a communication unit that receives information necessary for performing joint transmission together with another wireless base station from the another wireless base station; anda wireless control unit that generates a weight of the joint transmission on the basis of information necessary for performing the joint transmission. (11) The wireless base station according to (10), in whichthe wireless control unit generates capability information regarding a communication scheme that is capable of being implemented by the wireless base station in the joint transmission and capability information regarding an algorithm that is capable of being performed by the wireless base station in weight calculation of the joint transmission, andthe communication unit transmits the capability information to the another wireless base station. (12) The wireless base station according to (10) or (11), in whichthe communication unit receives use algorithm information regarding an algorithm used by the another wireless base station in weight calculation of the joint transmission from the another wireless base station, andthe wireless control unit generates a weight of the joint transmission on the basis of the use algorithm information. (13) The wireless base station according to (12), in whichthe use algorithm information includes any one of information regarding a complex phase of an eigenvector calculated in eigenvalue decomposition and information regarding operation order in a Gram-Schmidt orthonormalization method. (14) The wireless base station according to any one of (10) to (13), in whichthe communication unit receives weight synchronization information regarding a calculation result of a weight used by the another wireless base station in the joint transmission from the another wireless base station, andthe wireless control unit generates the weight of the joint transmission on the basis of the weight synchronization information. (15) The wireless base station according to any one of (10) to (14), in whichthe wireless control unit generates information regarding channel state information between a plurality of wireless base stations which is a transmission source of the joint transmission and the terminal which is a destination, in accordance with a request for information regarding channel state information from the another wireless base station, andthe communication unit transmits the information regarding the channel state information to the another wireless base station. (16) The wireless base station according to (15), in whichin a case where a request for the joint transmission is received from the terminal which is a destination of the joint transmission, the wireless control unit generates information regarding the channel state information between a specific terminal that transmits the request for the joint transmission and the plurality of wireless base stations that performs the joint transmission, andthe communication unit transmits information regarding the channel state information with only the specific terminal to the another wireless base station. REFERENCE SIGNS LIST 100Multi-access point (multi-AP)101,102Access point (AP)201to203Communication terminal (STA)210Communication terminal group (STAs)300Wireless communication device310Communication unit311Wireless control unit312Data processing unit313Modulation and demodulation unit314Signal processing unit315Channel estimation unit316Wireless interface unit317Amplifier unit319Antenna321Control unit322Power supply unit811to814Capability exchange815Algorithm synchronization817Advanced algorithm synchronization819CJT request821Joint sounding822Channel estimation823Trigger824Feedback831Multi-AP trigger832Sounding trigger841,842,844Feedback information synchronization843Feedback information synchronization request851Weight calculation852Weight synchronization information854Weight synchronization859Joint transmission | 77,092 |
11943012 | DETAILED DESCRIPTION Reference will now be made in detail to several embodiments. While the subject matter will be described in conjunction with the alternative embodiments, it will be understood that they are not intended to limit the claimed subject matter to these embodiments. On the contrary, the claimed subject matter is intended to cover alternative, modifications, and equivalents, which may be included within the spirit and scope of the claimed subject matter as defined by the appended claims. Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. However, it will be recognized by one skilled in the art that embodiments may be practiced without these specific details or with equivalents thereof. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects and features of the subject matter. Portions of the detailed description that follow are presented and discussed in terms of a method. Although steps and sequencing thereof are disclosed in a figure herein (e.g.,FIGS.10and11) describing the operations of this method, such steps and sequencing are exemplary. Embodiments are well suited to performing various other steps or variations of the steps recited in the flowchart of the figure herein, and in a sequence other than that depicted and described herein. Some portions of the detailed description are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that can be performed on computer memory. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. A procedure, computer-executed step, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout, discussions utilizing terms such as “accessing,” “configuring,” “coordinating,” “storing,” “transmitting,” “authenticating,” “identifying,” “requesting,” “reporting,” “determining,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. Novel Sounding Protocol for Map Wireless Networks As used herein, the term “EHT” may refer generally to a recent generation of wireless communication (Wi-Fi) known as Extremely High Throughput (EHT) and is defined according to the IEEE 802.11be standards. The term station (STA) refers generally to an electronic device capable of sending and receiving data over Wi-Fi that is not operating as an access point (AP). Embodiments of the present invention provide an apparatus and method for a MAP wireless network that includes a collaborative channel sounding measurement phase to determine channel state information between devices (e.g., the channel state between an STA and a collaborative AP) for efficient configuration of the MAP wireless network and to improve the performance of the MAP wireless networks. For example, when an AP obtains a transmission opportunity (TXOP), the AP as a TXOP holder can share a portion (e.g., a resource unit (RU)) of the bandwidth allocated by the TXOP with one or more other collaborative APs. The RU can share in the spatial domain, frequency domain, or time domain. In one example, collaborative beamforming is used to nullify the interference between collaborative APs so that the APs can simultaneously transmit data substantially without interference. With regard toFIG.1, an exemplary MAP wireless network100is depicted according to embodiments of the present invention. When a wireless AP obtains a TXOP frame, the wireless AP (e.g., the TXOP holder) can share a portion of the RU of the bandwidth granted by the TXOP with one or more other collaborative APs within the TXOP. Collaborative beamforming is one approach to enable sharing the RU in the spatial domain. The wireless AP and wireless STAs associated with collaborative APs can simultaneously transmit by applying collaborative beamforming where the interferences between channels nullify each other (e.g., nulling), and the beamforming is performed based on a sounding phase performed by the collaborative APs. The sounding protocol can include a collaborative sounding measurement phase and a collaborative sounding feedback report phase, using Null Data Packets (NDPs), for example, as described herein according to embodiments of the present invention. FIG.1depicts downlink (DL) transmissions between collaborative AP1 and AP2 services wireless stations STA1, STA2, STA3, and STA4. In this example, AP1, STA1, and STA2 belong to a first basic service set (BSSID1), and AP2, STA3, and STA4 belong to a second basic service set (BSSID2). The first basic service set and the second basic service set can be considered one basic service set; however, the first basic service set is associated with a first BSSID and the second basic service set is associated with a second BSSID. The dashed lines represent potential interference between channels. The solid lines represent downlink data transmissions. It is appreciated that the APs and the STAs can also be configured to perform beamforming for cooperative uplink (UL) transmissions. Multi-AP Collaborative Sounding Measurement Phase for Map Wireless Networks FIG.2depicts an exemplary data transmission and timing diagram200for performing a collaborative sounding measurement phase of a collaborative sounding protocol in a MAP wireless network according to embodiments of the present invention. As depicted inFIG.2, the collaborative sounding protocol includes a measurement phase and a feedback report phase performed using null data packet announcement (NDPA) frames205and215and null data packet (NDP) frames210and220transmitted between exemplary wireless AP1 and wireless AP2. The NDPA frames210and220include a Collaborative BSSID subfield for identifying a basic service set (BSS) serviced by wireless AP1 or wireless AP2. For example, an AP can set the Collaborative BSSID subfield to the BSSID of the corresponding collaborative AP when the wireless AP (e.g., wireless AP1) triggers the collaborative sounding sequence with the corresponding collaborative AP (e.g., wireless AP2). When an STA serviced by wireless AP1 or wireless AP2 receives an NDPA (e.g., NDPA205or215), the STA measures the subsequent NDP (e.g., NDP210or220), and calculates the data channel beamforming feedback (BF) if the NDPA is sent from the wireless AP associated with the STA and the Association ID (AID)11 subfield of the STA Info field of the received NDPA matches the AID of the STA. In this case, the data channel BF represents the channel state between the STA and its associated AP. Otherwise, if the NDPA is not sent from the wireless AP associated with the STA, and the Collaborative BSSID subfield of the STA Info field of the received NDPA matches the BSSID of the wireless AP associated with the STA, the STA measures the subsequent NDP and calculates the interference channel beamforming feedback (BF). The interference channel BF represents the channel state (e.g., interference) between the STA and its collaborative AP (e.g., the wireless AP with that is not associated with the STA, and the NDPA received from the wireless AP indicates the Collaborative BSSID subfield of the STA Info field to the STA's associated AP). Interference channel BF is also known as the inter-BSS BF because it indicates the channel state between the AP of the BSS of which the STA is not a member and the STA. According to some embodiments, all STAs associated with the collaborative AP calculate the interference channel beamforming feedback (BF). FIG.3depicts an exemplary data transmission and timing diagram300for performing a collaborative sounding measurement phase of a collaborative sounding protocol in a MAP wireless network according to embodiments of the present invention. Similar to the embodiment depicted inFIG.2, the collaborative sounding protocol includes a measurement phase and a feedback report phase performed using null data packet announcement (NDPA) frames305and310, and null data packet (NDP) frames315and320transmitted between exemplary wireless APs AP1 and wireless AP2. However, in the embodiment depicted inFIG.3, wireless AP2 transmits NDPA frame310after wireless AP1 transmits NDPA305and before wireless AP1 transmits NDP frame315. The NDPA frames305and310include a Collaborative BSSID subfield, and wireless AP1 and wireless AP2 set the Collaborative BSSID subfield to the BSSID of the corresponding collaborative AP when the AP triggers the collaborative sounding sequence with the collaborative AP. When an STA receives the NDPA (e.g., NDPA305or310), the STA measures the subsequent NDP (e.g.,315or320) and calculates the data channel BF if the NDPA is sent from its associated AP and the AID11 subfield of the STA Info field of the received NDPA matches the STA's AID. The data channel BF represents the channel state between the STA and its associated AP. Otherwise, if the NDPA is not sent from its associated AP but the Collaborative BSSID subfield of the STA Info field of the received NDPA matches the BSSID of its associated AP, the STA (that is identified as the beam-formed STA based on the preceding or subsequent NDPA) measures the subsequent NDP and calculates the interference channel BF. This interference channel BF represents the channel state (e.g., interference) between the STA and its collaborative AP. Specifically, when a wireless STA STA1 receives the first NDPA sent from its associated AP (e.g., wireless AP1) and the AID11 subfield of the STA Info field of the first NDPA matches wireless STA1's AID, wireless STA1 measures the first NDP and calculates the data channel beamforming feedbacks (BF). When another wireless STA STA3 receives the first NDPA sent from non-associated AP (e.g., wireless AP1) but the Collaborative BSSID subfield of the STA Info field of the first NDPA is matched with the BSSID of its associated wireless AP (e.g., wireless AP2), wireless STA3 waits for the second NDPA to be sent from its associated AP. When wireless STA1 receives the second NDPA sent from a non-associated AP (e.g., wireless AP2), and the Collaborative BSSID subfield of the STA Info field of the second NDPA matches the BSSID of its associated AP, wireless STA1 measures the second NDP and calculates the interference channel BF. Because wireless STA1 already received the first NDPA and the AID11 subfield of the STA Info field of the first NDPA matches wireless STA1's AID, wireless STA1 is confirmed as the target STA of the collaborative beam-formed transmission. Moreover, when wireless STA3 receives the second NDPA sent from its associated AP (e.g., wireless AP2) and the AID11 subfield of the STA Info field of the second NDPA matches wireless STA3's AID, and wireless STA3 measures the second NDP and calculates the data channel BF. Because wireless STA3 has already received the first NDPA and the Collaborative BSSID subfield matches the BSSID of its associated AP (e.g., wireless AP2), wireless STA3 is confirmed as the target STA of the collaborative beam-formed transmission, and it measures the second NDP and calculates the interference channel BF. For associating an NDP with an NDPA, the SIG field of the NDP includes the partial BSSID subfield. The partial BSSID field is set to the partial information of the BSSID of the wireless AP included in the associated NDPA. For example, the partial BSSID subfield of the SIG field of the first NDP can be set according to the partial information of the BSSID of the AP (e.g., wireless AP1) included in the first NDPA. The partial BSSID subfield of the SIG field of the second NDP can be according to the partial information of the BSSID of the AP (e.g., wireless AP2) included in the second NDPA. FIG.4depicts an exemplary data transmission and timing diagram400for performing a simultaneous collaborative sounding measurement phase of a collaborative sounding protocol in a MAP wireless network according to embodiments of the present invention. Similar to the embodiment depicted inFIG.3, the collaborative sounding protocol includes a measurement phase and a feedback report phase performed using null data packet announcement (NDPA) and null data packet (NDP) frames transmitted between wireless AP1 and wireless AP2. However, in the embodiment depicted inFIG.4, wireless AP1 and wireless AP2 transmit NDP frames405and410simultaneously. For example, NDPs405and410can be multiplexed in the frequency domain so that the NDP405uses odd subcarriers and NDP410uses even subcarriers. FIG.5depicts an exemplary data transmission and timing diagram500for performing a collaborative sounding measurement phase of a collaborative sounding protocol in a MAP wireless network according to embodiments of the present invention. Similar to the embodiments depicted inFIG.2, the collaborative sounding protocol includes a measurement phase and a feedback report phase performed using NDPA and NDP frames transmitted between wireless AP1 and wireless AP2. However, in this embodiment, the NDPA frames510and520and NDP frames515and525are preceded by a cooperative NDPA (C-NDPA) frame505. As depicted inFIG.5, wireless AP1 transmits C-NDPA505frame to a collaborative wireless AP (e.g., wireless AP2), and the C-NDPA505frame identifies the target stations of the collaborative beam-formed transmission which are associated with the wireless AP (e.g., wireless AP1). The NDPAs510and520include the Collaborative BSSID subfield and the AP sets the Collaborative BSSID subfield to the BSSID of the collaborative AP when the AP triggers the collaborative sounding sequence with the collaborative AP. When the STA receives an NDPA, the STA measures the subsequent NDP and calculates the data channel beamforming feedback (BF) if the NDPA is sent from its associated AP and the AID11 subfield of the STA Info field of the received NDPA is matched with the STA's AID. The data channel BF represents the channel state between the STA and its associated AP. Otherwise if the NDPA is not sent from its associated AP but the Collaborative BSSID subfield of the STA Info field of the received NDPA is matched with the BSSID of its associated AP, the STA that is identified as the beam-formed STA based on the preceding or subsequent NDPA measures the subsequent NDP and calculates the interference channel BF. Interference channel BF represents the channel state between the STA and its collaborative AP. According to some embodiments, an NDPA includes one or more Collaborative STA Info fields, and the Collaborative STA Info fields include the Collaborative BSSID subfield. The Collaborative BSSID subfield is set to the BSSID of the collaborative wireless AP when the wireless AP triggers the collaborative sounding sequence with the collaborative wireless AP. The wireless AP sets the AID11 subfield of the Collaborative STA Info field to the AID of the target station of the collaborative beam-formed transmission which is associated with the collaborative wireless AP. When the STA receives the NDPA, the STA measures the subsequent NDP and calculates the data channel BF if the NDPA is sent from its associated AP and the AID11 subfield of the STA Info field of the received NDPA is matched with the STA's AID. The data channel BF represents the channel state between the STA and its associated AP. Otherwise, if the NDPA is not sent from its associated AP, the Collaborative BSSID subfield of the Collaborative STA Info field of the received NDPA is matched with the BSSID of its associated AP, and the AID11 subfield of the Collaborative STA Info field is matched with the STA's AID, the STA measures the subsequent NDP and calculates the interference channel BF. In this case, the interference channel BF represents the channel state between the STA and its collaborative AP. Multi-AP Collaborative Sounding Beamforming Feedback Phase for Map Wireless Networks With regard toFIG.6, an exemplary data transmission and timing diagram600for performing a collaborative sounding beamforming feedback phase of a collaborative sounding protocol using Indirect Interference Channel Beamforming Feedback in a MAP wireless network is depicted according to embodiments of the present invention. The collaborative sounding beamforming feedback phase follows a collaborative sounding measurement phase, for example, one of the collaborative sounding measurement phases depicted inFIGS.2-5according to embodiments of the present invention. The collaborative sounding beamforming feedback phase includes an STA associated with an AP transmitting a BF Report frame that contains both Data Channel (D-CH) BF and interference channel (I-CH) BF responsive to a Beamforming Feedback Report (BFRP) trigger frame sent by a wireless AP. The BR Report frame can be transmitted using an HE TB PPDU format, for example. When the wireless AP receives BF Report frames, the wireless AP transmits the I-CH BF to a collaborative wireless AP. Specifically, in the example depicted inFIG.6, Direct Interference Channel Beamforming Feedback is performed in a collaborative sounding beamforming feedback phase between wireless AP1 and wireless AP2. Wireless AP1 transmits a BFRP Trigger frame605that is received by STAs associated with wireless AP1, including wireless STA1 and wireless STA2. Wireless AP2 transmits a BFRP Trigger frame610that is received by STAs associated with wireless AP2, including wireless STA3 and wireless STA4. The STAs send BF Report frames620including both D-CH BF and I-CH BF to their associated AP responsive to the BFRP trigger frames605and610. For example, wireless AP1 receives a BF Report from wireless STA1 and wireless STA2, and wireless AP2 receives a BF Report from wireless STA3 and wireless STA4. Wireless AP1 then transmits BF Report625including the I-CH BF of STA1 and STA2 to the wireless AP2, and wireless AP2 transmits BF Report630including the I-CH BF of STA3 and STA4 to wireless AP1. With regard toFIG.7, an exemplary data transmission and timing diagram700for performing a collaborative sounding beamforming feedback phase of a collaborative sounding protocol in a MAP wireless network using Direct Interference Channel Beamforming Feedback is depicted according to embodiments of the present invention. The collaborative sounding beamforming feedback phase follows a collaborative sounding measurement phase, for example, one of the collaborative sounding measurement phases depicted inFIGS.2-5according to embodiments of the present invention. As depicted inFIG.7, a BFRP Trigger frame705is transmitted from wireless AP1 and is received by STAs associated with wireless AP1. Wireless STA1 and wireless STA2 associated with wireless AP1 transmit BF Report frames710and715including D-CH BF. Any of the BF Report frames depicted inFIG.7can be transmitted using an HE TB PPDU format, for example. The BFRP Trigger frame705is also received by STAs associated with a collaborative AP (e.g., wireless AP2). After receiving the BFRP Trigger frame from wireless AP1, wireless STA3 and wireless STA4 associated with wireless AP2 transmit BF Report frames720and725that include I-CH BF. The Trigger Dependent User Info subfield of the BFRP Trigger frame can include the collaborative BSSID subfield. When the collaborative BSSID subfield matches the BSSID of its associated wireless AP, and the AID11 subfield of the User Info field of the received BFRP Trigger frame matches wireless STA's AID, the wireless STA transmits the BF Report frame that contains only the I-CH BF. A BFRP Trigger frame730is also transmitted from wireless AP2 and an analogous process is performed to receive BF Report frames from the STAs. Specifically, the BFRP Trigger frame730is received by wireless STA3 and wireless STA4 associated with wireless AP2, and wireless STA3 and wireless STA4 transmit BF Report frames745and750including D-CH BF. Wireless STA1 and wireless STA2 associated with wireless AP1 transmit BF Report frames735and740that include I-CH BF. The Trigger Dependent User Info subfield of the BFRP Trigger frame can include the collaborative BSSID subfield. When the collaborative BSSID subfield matches the BSSID of its associated wireless AP, and the AID11 subfield of the User Info field of the received BFRP Trigger frame matches wireless STA's AID, the wireless STA transmits the BF Report frame that contains only the I-CH BF. With regard toFIG.8, an exemplary data transmission and timing diagram800for performing a collaborative sounding beamforming feedback phase of a collaborative sounding protocol in a MAP wireless network using Broadcast Interference Channel Beamforming Feedback is depicted according to embodiments of the present invention. The collaborative sounding beamforming feedback phase follows a collaborative sounding measurement phase, for example, one of the collaborative sounding measurement phases depicted inFIGS.2-5according to embodiments of the present invention. As depicted inFIG.8, a BFRP Trigger frame805is transmitted from wireless AP1 and is received by a wireless STA associated with wireless AP1. The wireless STA transmits a BF Report frame responsive to BFRP Trigger frame805including BF from within the BSS associated with the wireless STA (intra BSS BF) and BF from a neighboring (e.g., cooperative) BSS (inter BSS BF). The BF Report frames can be broadcast using a SU PPDU format, for example, and can be received by an associated AP and collaborative APs. The intra BSS BF inter BSS BF includes both D-CH BF and I-CH BF. The I-CH BF includes the BSSID of the collaborative AP used to carry the inference channel feedback. When the wireless AP receives the BF Report frame, the AP stores the D-CH BF if the AP requested the BF Report frame. Otherwise, if the AP did not request the BF Report frame, the AP stores the I-CH BF when the AP's BSSID matches the BSSID information of the I-CH BF. The above collaborative sounding beamforming feedback phase is performed first by wireless AP1 and repeated by wireless AP2 for its associated wireless STAs. Specifically, as depicted inFIG.8, wireless AP1 broadcasts BFRP805, and STA1 responds with BF Report810. Wireless AP1 requested the BF Report810and therefore stores the D-CH BF included in BF Report810. Wireless AP1 broadcasts BFRP815, and STA2 responds with BF Report820. Wireless AP1 requested the BF Report820and therefore stores the D-CH BF included in BF Report820. Wireless AP2 also receives BF Report810and820. AP2 did not request BF Report frames810and820and therefore wireless AP2 stores the I-CH BF included in the report frames810and820when wireless AP2's BSSID matches the BSSID information of the I-CH BF. The same process is repeated for BFRPs825and835broadcast by wireless AP2. Specifically, wireless AP2 broadcasts BFRPs825, and STA3 responds with BF Report830. Wireless AP2 requested the BF Report830and therefore stores the D-CH BF included in BF Report830. Wireless AP2 broadcasts BFRP835, and STA4 responds with BF Report840. Wireless AP2 requested the BF Report840and therefore stores the D-CH BF included in BF Report840. Wireless AP1 also receives BF Report830and840. AP2 did not request BF Report frames830and840and therefore wireless AP2 stores the I-CH BF included in the report frames830and840when wireless AP1's BSSID matches the BSSID information of the I-CH BF. With regard toFIG.9, an exemplary data transmission and timing diagram900for performing a collaborative sounding beamforming feedback phase of a collaborative sounding protocol in a MAP wireless network using Hybrid Interference Channel Beamforming Feedback is depicted according to embodiments of the present invention. The collaborative sounding beamforming feedback phase follows a collaborative sounding measurement phase, for example, one of the collaborative sounding measurement phases depicted inFIGS.2-5according to embodiments of the present invention. As depicted inFIG.9, a BFRP Trigger frame905is transmitted from wireless AP1 and is received by STAs associated with wireless AP1. The STAs associated with wireless AP1 transmit BF Report frames including both the D-CH BF and I-CH BF. Wireless STAs associated with a collaborative AP (e.g., wireless AP2) receive the BFRP Trigger frame and transmits the BF Report frame that contains only the I-CH BF. The BF Report frames can be transmitted using an HE TB PPDU format, for example. The wireless AP receives the BF Report frames, and the wireless AP sends the I-CH BF to the collaborative AP. The I-CH BF can also contain other information for scheduling the collaborative beam-formed transmission. Specifically, as depicted inFIG.9, wireless AP2 transmits BFRP Trigger frame905that is received by its associated wireless STAs (e.g., wireless STA3 and wireless STA4). STA3 and STA4 transmit BF Report frames910and915, respectively, and BF Report frames910and915include both D-CH BF and I-CH BF because wireless STA3 and wireless STA4 are associated with wireless AP2. AP1 transmits BFRP Trigger frame920that is received by its associated wireless STAs (e.g., wireless STA1 and wireless STA2). STA3 and STA4 transmit BF Report frames930and935, respectively, and BF Report frames930and935include both D-CH BF and I-CH BF because wireless STA1 and wireless STA2 are associated with wireless AP1. AP2 transmits the I-CH BF of STA3 and STA4 in BF Report925that is received by AP1. AP1 transmits the I-CH BF of STA1 and STA2 in BF Report940that is received by AP2. FIG.10is a flow chart of an exemplary sequence of computer implemented steps of a process1000for performing collaborative sounding beamforming feedback according to embodiments of the present invention. The process1000can be performed after a collaborative sounding measurement phase, for example, as described above with reference toFIGS.2-5. At step1005, a wireless AP transmits a BFRP trigger frame from a first wireless AP associated with a first BSS to wireless STAs of the first BSS. At step1010, BF reports are received from wireless STAs of the first BSS. The BF reports are transmitted responsive to the BFRP trigger frame and include interference channel BF and data channel BF of the first wireless STA and the second wireless STA. At step1015, a BF report is generated that includes the interference channel BF of the wireless STAs as reported in step1010. At step1020, the BF report that includes the interference channel BF of the wireless STAs is transmitted to a collaborative AP that services wireless STAs of a different BSS. At step1025, a BF report is received from the collaborative AP that includes interference channel BF of the wireless STAs associated with the second BSS. At step1030, the wireless AP is configured for collaborative beamforming to mitigate interference of wireless STAs associated with the second BSS according to the BF reports. FIG.11is a flow chart of an exemplary sequence of computer implemented steps of a process1100for performing collaborative sounding beamforming feedback according to embodiments of the present invention. The process1100can be performed after a collaborative sounding measurement phase, for example, as described above with reference toFIGS.2-5. At step1105, a wireless AP associated with a first BSS transmitting a BFRP trigger frame to wireless STAs of the first BSS and to wireless STAs of a second BSS. At step1110, BF reports are received at the wireless AP from the wireless STAs of the first BSS. The first BF reports are transmitted responsive to the BFRP trigger frame and include data channel BF of the wireless STAs of the first BSS. At step1115, a BF reports are received at the wireless AP from the wireless STAs of the second BSS. The BF reports are transmitted responsive to the BFRP trigger frame and include interference channel BF of the wireless STAs of the second BSS. According to some embodiments, step1115includes a respective wireless STA matching a collaborative BSSID subfield with the BSSID of an AP associated with the second BSS, and matching an AID11 subfield of the received BFRP Trigger frame with the respective wireless STA's AID. At step1120, the wireless AP is configured according to the BF reports received from the wireless STAs of the first BSS and the wireless STAs of the second BSS. It is appreciated that the above steps can be repeated by a collaborative AP so that the collaborative AP can be configured for collaborative beamforming according to BF reports received from the wireless STAs of the first BSS and the wireless STAs of the second BSS. Exemplary Computer Controlled System Embodiments of the present invention are drawn to electronic systems for a performing collaborative sounding protocol in a MAP wireless network. The following discussion describes one such exemplary electronic system or computer system that can be used as a platform for implementing embodiments of the present invention. The exemplary computer system1212can be a wireless AP or a wireless STA, for example. In the example ofFIG.12, the exemplary computer system or wireless device includes a central processing unit (such as a processor or a CPU)1201for running software applications and optionally an operating system. Read-only memory1202and random access memory1203store applications and data for use by the CPU1201. Data storage device1204provides non-volatile storage for applications and data and may include fixed disk drives, removable disk drives, flash memory devices, and CD-ROM, DVD-ROM or other optical storage devices. The optional user inputs1206and1207comprise devices that communicate inputs from one or more users to the computer system1212(e.g., mice, joysticks, cameras, touch screens, and/or microphones). A communication or network interface408includes a plurality of transceivers and allows the computer system1212to communicate with other computer systems, networks, or devices via an electronic communications network, including wired and/or wireless communication and including an Intranet or the Internet (e.g., 802.11 wireless standard). According to embodiments of the present invention, the communication or network interface1208can operate multiple transceivers simultaneously. The communication or network interface1208can further include a cooperative management unit for coordinating the data sent and/or received by the transceivers. Moreover, the network interface1208can be configured to perform a collaborative sounding protocol in a MAP wireless network to determine channel state information with neighboring BSSs and APS of the MAP wireless network. The sounding protocol can include a collaborative sounding measurement phase and a collaborative sounding feedback report phase, using NDPs, for example, as described herein according to embodiments of the present invention. The network interface1208can be configured to perform collaborative beamforming according to the results of the sounding protocol. The optional display device1210may be any device capable of displaying visual information in response to a signal from the computer system1212and may include a flat panel touch sensitive display, for example, and may be remotely disposed. The components of the computer system1212, including the CPU1201, memory1202/1203, data storage1204, user input devices1206, and graphics subsystem1205may be coupled via one or more data buses. Some embodiments may be described in the general context of computer-executable instructions, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments. Embodiments of the present invention are thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the following claims. | 33,511 |
11943013 | DETAILED DESCRIPTION Aspects of the present disclosure relate to a system and method for wireless inter-networking between a wireless wide area network (WWAN) and a local area network (WLAN) employing one or more extended range wireless inter-networking devices. Aspects of the present disclosure also apply to other connected inter-networking devices such as smartphones, and other data devices in general. Aspects of the present disclosure further include a portable wireless access point configured for extended range communications, which may include a high power user equipment (“HPUE”) as disclosed herein. Embodiments of the system and method are directed toward a high powered wireless interconnect device that may include high efficiency circuitry (e.g., utilizing 25% and above efficient amplifiers) to make it possible to implement in a personal, portable, and/or in-vehicle form factor, which may provide reasonable battery life, size, weight, and thermal dissipation. For instance, a traditional amplifier is in the 10-15% efficient range. However, to illustrate, an “out-of-spec” or high power transmission, as described below may result in excessive power consumption and heat generation. To illustrate, a six times increase in battery power may be required to support just a doubling of power transmitted, as needed for the high power/extended range communications. As it stands, under normal (standard, in-range) WWAN operations, personal mobile devices can become uncomfortably hot and battery life unduly short, particularly with user equipment already having many use cycles. Briefly described and generally, the disclosure includes an inter-networking device and system where a WWAN modem is integrated with an efficient radio frequency (RF) front-end (RFFE) having the appropriate capability to meet stringent wireless requirements in a fashion that increases network performance without degradation to the performance of either the wireless network system, neighboring wireless equipment, and its own receive performance (include drawing of antenna and filtering of RFFE to avoid desense and enable high power). The higher performance modem is integrated seamlessly at the RF section and the appropriate protocol level to ensure network control performance is seamless and avoids improper interactions within the system at all protocol layers. It may also include other WWAN operational bands (e.g., multi-band) that may or may not be of higher power and integrate seamlessly, whether under local control or through a handoff process under network control. Included within this disclosure are antenna configurations beneficial for performance without creating self-interference. Various aspects of the novel systems, devices, and methods are described more fully hereinafter with reference to the accompanying drawings. The detailed description set forth herein, in connection with the appended drawings, is intended as a description of various configurations and embodiments, and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. In particular, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. FIG.1schematically illustrates an extended range wireless or high power inter-networking system (“inter-networking system”), according to one embodiment of the disclosure. Here, an inter-networking system100is shown according to one exemplary embodiment. As shown, the inter-networking system100may include a device for wireless inter-networking, or high power user equipment (“HPUE”)200, a WLAN300, and a WWAN400. The HPUE200may be configured to communicably couple with WLAN300and WWAN400simultaneously. The WLAN300is broadly understood to include a wireless computer network that links two or more devices using a wireless distribution method (often spread-spectrum or OFDM radio) within a limited area such as a building, home, school, or field, to name a few. The WLAN300may be configured to provide a connection to a private intranet and/or the wider Internet. According to one embodiment, WLAN300may be based on IEEE 802.11 standards (e.g., Wi-Fi). The WWAN400is broadly understood to include a wireless network covering a larger or wider area in size than the WLAN300. Further, WWAN400may differ from WLAN300by using mobile telecommunication cellular network technologies such as LTE, WiMAX, UMTS, CDMA2000, GSM, cellular digital packet data and Mobitex to transfer data. It can also use Local Multipoint Distribution Service (LMDS) or Wi-Fi to provide Internet access. Further, it may connect to/from anywhere within the regional boundaries of such service. Various computers can have integrated WWAN capabilities. According to one embodiment, the WWAN400may also be any closed network that covers a large geographic area (e.g., a mesh network or mobile ad hoc network (MANET) with nodes on building, tower, trucks, and planes). FIG.2schematically illustrates the extended range wireless inter-networking system ofFIG.1. Here, the inter-networking system100is shown with additional exemplary infrastructure. In particular and as shown, the HPUE200may be configured to communicate voice, text, streamed content, and/or packet data over the WLAN300with at least one of a computer (e.g., laptop)310, a mobile communication device (e.g., smart phone)320, a handheld computer (e.g., tablet)330, and a networking device (e.g., wireless router, Bluetooth sensor nodes, etc.)340. It is understood that other WLAN-enabled devices are contemplated. Likewise, the HPUE200may be further configured to communicate voice, text, streamed content, and/or packet data over the WWAN400via a base station410. According to one preferred embodiment, the WLAN300may operate over the IEEE 802.11 standards. According to another preferred embodiment, the WWAN400may operate over Band 14 of the LTE standard. According to yet another preferred embodiment, the HPUE200may be configured to emit a Class 1 high power transmission over the WWAN400, where the transmit power exceeds that used by standard cellular devices, for example, by a factor of 6 (e.g., 8 dB), which is the maximum permitted by the standards and regulatory bodies. It should be noted that current communication chipsets may experience premature wear, damage, and even failure upon reception of its own transmissions at these elevated, high power levels. As such and as described below, the HPUE200may incorporate the efficient RFFE having appropriate (i.e., for the particular application) extra protection so as to not blow out commercial receiver, for example, during extended range, high power transmissions. However, to increase network performance without degradation to the performance of either the wireless network system, neighboring wireless equipment, and its own receive performance, added impedance (e.g., addition of a 13 dB pad) is limited or balanced to not render base station transmissions overly attenuated while recognizing power coming back while in the high power mode of operation. For example, the HPUE200may be configured to maintain a balanced link budget (or imbalanced) through its operational range. The link budget referred to herein is the difference in power loss allowed for the downlink transmission versus the uplink transmission. Also as discussed below, the HPUE200may incorporate a rejection filter (discussed below) in its WWAN radio that is be specifically tuned to that of the power transmitted (including non-linear harmonics and VSWR issues in transmit chain). According to yet another preferred embodiment, the WLAN300and/or the WWAN400may separately or jointly incorporate encryption and authentication features. According to one preferred embodiment, the WLAN300may be configured to operate in an infrastructure and/or ad hoc mode. In ad hoc mode, mobile units may transmit directly peer-to-peer. In infrastructure mode, mobile units may communicate through an access point that serves as a bridge to other networks (such as Internet or LAN). For example, according to a preferred embodiment, the HPUE200may be configured to communicably couple with WLAN300and WWAN400simultaneously, and operate as a “hotspot” between the WWAN400and end user devices310,320,330,340over the WLAN300. The WLAN300may be configured as a virtual private network (VPN) and/or may include other security features. FIG.3schematically illustrates an extended range wireless inter-networking device, according to one embodiment of the disclosure. Here, the HPUE200is shown according to one exemplary embodiment. As shown, the HPUE200may include a support structure or chassis (e.g., a substrate, PCB, housing210, etc.), and affixed or otherwise coupled to the support structure (hereinafter housing210) the HPUE200may further include a power supply212, a processor214, a memory216, a WLAN radio220, and a WWAN radio240. According to one embodiment, the HPUE200may further include a location radio218including but not limited to a location radio adapted for a global navigation satellite system (GNSS) such as United States' Global Positioning System (GPS), Russia's GLONASS, China's BeiDou Navigation Satellite System (BDS) and the European Union's Galileo, etc. or any other Real-time locating systems (RTLS). According to one embodiment, the HPUE200may further include an n-axis accelerometer219. This may provide the benefit of providing inertial navigation enhancing resolution and reliability of the location radio218, for example. Aspects of the disclosure may include a plurality of different housings210. In particular, by applying the teachings disclosed herein, it may be possible to tailor the HPUE200to have a form factor unique to its application. For example, and as discussed further below, the housing210may be configured as a handheld device or as an extended battery life device. Also for example, the housing210may be configured as a ruggedized case, a waterproof case, and/or a modular/MIL-STD case, and/or include a vehicular mount and/or vehicular interfaces such as to external antennas and to a Controller Area Network (CAN Bus), etc., and any combination thereof. Further, as discussed throughout, it is contemplated that the HPUE200may designed to be used in adverse environments, for example by first responders, police, and military. The power supply212may be configured to power at least one of the processor214, the memory216, the location radio218, the n-axis accelerometer219, the WLAN radio220, and the WWAN radio240. The power supply212may be embodied as an energy storage (e.g. rechargeable battery), or as part of an external power supply (e.g., AC wall power, DC car adapter, etc.). The processor214may be communicably coupled to at least one of the memory216, the location radio218, the n-axis accelerometer219the WLAN radio220, and the WWAN radio240. The HPUE200may be configured to communicably couple with WLAN300(FIG.2) and WWAN400(FIG.2) simultaneously. In particular, the WLAN radio220, is broadly understood to include any RF equipment configured to communicate over a desired WLAN, such as WLAN300, for example. Similarly, the WWAN radio240is broadly understood to include any RF equipment configured to communicate over a desired WWAN, such as WWAN400, for example. Further, and as discussed in detail below, the WWAN radio240may be configured to communicate over greater ranges and greater attenuation than conventional WWAN radios. According to one embodiment, the WLAN radio220may include a WLAN transceiver/MODEM222communicably coupled to a WLAN antenna (e.g., MIMO antenna)224, together configured to communicate over the WLAN300. According to one embodiment, WLAN radio220may be embodied as or otherwise include a personal area network (PAN) radio. According to one embodiment, WWAN radio240may include a first WWAN transceiver/MODEM, a high power port communicably coupled to the first WWAN transceiver/MODEM, and configured as a duplex chain including a high power amplifier, a frequency duplexer, and a high power antenna, and a diversity port communicably coupled to the first WWAN transceiver/MODEM, and configured as a complementary receive path including a rejection filter and a diversity antenna. As shown, a WWAN transceiver/MODEM242may be communicably coupled to a full duplex (transmit and receive) high power port244and to a half-duplex (receive) diversity port245, together configured to communicate over WWAN400. The high power port244may be configured as a duplex chain including a high power amplifier252, a high power port frequency duplexer254, and an antenna (high power port antenna256). The high power amplifier252may be configured to further amplify a transmission from the WWAN transceiver/MODEM242upstream of the high power port frequency duplexer254. The high power amplifier252provides a fixed or adjustable gain to the uplink transmit signal such that the energy radiated from the antenna port256is sufficient to have an extended range. To illustrate, standard mode WWAN communications are limited in their transmission power, where the current maximum levels allowed are in 100's of milliwatts range (e.g., 0.300 watts). In contrast, the permissible amount of transmit power currently permitted by the standards for Band 14 is 1.25 watts to the antenna256. However, one drawback associated with high power transmissions is the issue is that higher powers create significant issues with battery consumption (due to low efficiency amplifiers traditionally used), out of band issues due to non-linear amplification, and also with raised power levels. Further, traditionally, the receive chain would be designed to not expect that much extra power coupling in, so the diversity chain becomes less sensitive. According to one embodiment, high power amplifier252of the high power port244may be configured to transmit greater than 0.3 watts, 0.5 watts, 1.0 watts, and/or 1.25 watts to the high power antenna256. Alternately, high power amplifier252of the high power port244may be configured to transmit to the high power antenna256in a range of 0.3 watts to 2.0 watts, 0.5 watts to 1.25 watts, of 0.5 watts to 1.0 watts, for example. The diversity port245may be configured as a complementary receive path including a rejection filter257and a diversity antenna259. The rejection filter257provides protection to the conventional implementations of the WWAN transceiver/MODEM242by reducing the energy level seen by the diversity port245from the transmitted signals out of the high power port antenna256sufficiently such that these higher transmitted powers avoid temporary or permanent performance degradation of the WWAN transceiver/MODEM242. In operation, the separate high power transmit and receive paths between the WWAN transceiver/MODEM242and the high power antenna256may be duplexed via the high power port frequency duplexer254. Further, transmissions to the high power antenna256from the WWAN transceiver/MODEM242may be amplified via the high power amplifier252, extending the transmission range. Also, receptions from the high power antenna256may be communicated directly to the WWAN transceiver/MODEM242on an isolated receive path. More particularly, For example, the frequency duplexer254may be functionally coupled to and between the high power amplifier252and the high power antenna256, and is further functionally coupled to the receive port237(FIG.4) of the WWAN transceiver/MODEM242, the frequency duplexer254may be configured to isolate the receive port237of the WWAN transceiver/MODEM242from transmissions of the high power amplifier252. Advantageously, the inter-networking device (HPUE200) may extend network connectivity over the WWAN400by having a high power transmit chain that more closely balances the communications link. Conventional transceivers require additional external functionality to meet full performance requirements that are possible in a wireless network. Here, the radio frequency (RF) front end (RFFE) (high power port244and diversity port245) provides a method to integrate high power capability into the inter-networking device while maintaining transmit and receive performance levels. Advantageously, the RFFE uses techniques illustrated here and discussed further below permit conventional RF transceiver devices and technologies to be used. However, as illustrated, adding the high-power amplifier252in the chain may obligate the use of a more stringent duplexer and receive filtering when compared to architectures found in most frequency division duplexing devices. In general, the efficient RFFE should be understood to be able to support any and all WWAN radio constellations, able to support all WWAN power levels, able to pass without external circuitry all regulatory requirements, able to versatile in support for enhanced operations such as MIMO, diversity, able to be frequency nimble, versatile and independent, able to sustain MDS through all transmit power levels, reduction of AGC and AFC scintillation that causes issues in the demod, etc. According to one embodiment, and as discussed above, the rejection filter257of the WWAN radio240may be configured to maintain a preferred link budget (i.e., preferring the HPUE200) through an operational range of the high power amplifier252. For example, the WWAN radio240of the HPUE200may utilize a rejection filter257configured to maintain a preferred link budget of approximately 4 decibel (dB) or less. Furthermore, the high power port frequency duplexer254can be selected or otherwise be configured to handle the higher power output from the amplifier chain and reject the transmit power energy sufficiently on the receive chain of the high power port frequency duplexer254such that the WWAN transceiver/MODEM242will be able to meet performance requirements and avoid damage or signal degradation. For example, modern-day integrated transceiver devices are extremely sensitive, and expect to receive signal levels below the microwatt range. Transceiver input signal levels in the 10's of microwatts can cause performance degradation, and levels in the milliwatt range can cause permanent damage to the transceiver. Conventional frequency duplexers used in most cellphones reduce the transmit energy to the transceiver by less than a factor of one million. In addition to the fact these duplexers cannot handle the power levels on the transmit input, this energy reduction into the transceiver will degrade the receiver performance. When using high power, the energy reduction must be much greater than this and may be on the order of a factor of 10 millionth or more. The high power port frequency duplexer254also may restrict other out-of-band emissions to include harmonics and noise that may interfere with external or internal functions. The bandstop filter reduces the transmit energy in the receive chain such that 7 integrated circuit transceiver solutions can be used without causing damage to the device. FIG.4schematically illustrates a detail section of the extended range wireless inter-networking device ofFIG.3, according to one embodiment of the disclosure. As above, the WWAN radio240may include the WWAN transceiver/MODEM242the high power port244and the diversity port245. According to one embodiment, the WWAN transceiver/MODEM242may include a WWAN MODEM, a WWAN transceiver, and a multi-mode power amplifier, the WWAN MODEM functionally coupled to the WWAN transceiver, the WWAN transceiver including a transmit port, a receive port, and a diversity receive port, the transmit port functionally coupled to the multi-mode power amplifier, said multi-mode power amplifier functionally coupled to the high power amplifier, the receive port functionally coupled to the frequency duplexer, the diversity receive port functionally coupled to the rejection filter. In particular and as shown, the WWAN transceiver/MODEM242may include a WWAN MODEM232, a WWAN transceiver234, and a multi-mode power amplifier236. The WWAN MODEM232may be functionally coupled to the WWAN transceiver234. The WWAN transceiver234may have a transmit port235and a receive port237, as well as a diversity receive port239. As shown, the transmit port235may be functionally coupled to the multi-mode power amplifier236, which may be functionally coupled to the high power amplifier252. Similarly, the receive port237may be functionally coupled to the high power port frequency duplexer254. Similarly, the diversity receive port239may be functionally coupled to the rejection filter257or the diversity antenna259. According to one embodiment, the WWAN transceiver/MODEM242may be embodied in a single package, including the WWAN MODEM232, the WWAN transceiver234, and the multi-mode power amplifier236, using conventional technology, as discussed above. According to another embodiment, the WWAN MODEM232, the WWAN transceiver234, and the multi-mode power amplifier236may be embodied as discrete components, and may be further embodied using conventional components. Beneficially, the WWAN radio240as described herein may provide for improved performance. It should be understood that operation of the WWAN radio240at high power, may also require significant limiter and rejection filtering, which decreases sensitivity. However, the decrease in sensitivity of the receiver, may diminish reception or ultimately lead to a reduction in the range that the WWAN radio240could operate. Thus, as discussed above, if one overly rejects the incoming signal without regard for the amount of amplification the effect, unbalances the link budget and tilts the shortfall to be downlink (rather the previously corrected uplink unbalance). Here, aspects of the WWAN radio240, together or in isolation, address these problems. First, the WWAN radio240may incorporate the efficient RFFE disclosed herein and be appropriately balanced for performance/capability without degradation and include drawing of antenna and filtering of RFFE to avoid desense and enable the extended range benefits associated with high power transmissions. Second, as discussed above, rejection filtering if too strong makes the receiver believe the signal is further away than it truly is, and here the WWAN radio240may incorporate the rejection filter specifically tuned to that of the power transmitted (including non-linear harmonics and VSWR issues in transmit chain). Third, as discussed above the WWAN radio240may incorporate various embodiments of the WWAN transceiver/MODEM242. Further, the WWAN radio240may include a higher performance modem. For example, the WWAN transceiver/MODEM242may be selected or otherwise configured to be able to meet regulatory requirements of multiple bands while transmitting up to 8 dB above standard max RF power levels which results in a doubling of the acceptable performance range before LOS, to provide expanded coverage and range while being power efficient to allow for operation for duration of work shift event, and to operate with WWANs to select best performance trading off power and operational speed with coverage and range needed Beneficially, the WWAN radio240as described herein may provide for improved thermal control. As above, high power operation typically results higher heat and power consumption, which typically results in shortened battery life. This may be a problem especially when the HPUE200(FIG.2), for example, acting as a mobile gateway, could be body worn creating a personal area network (PAN). With the First Responders there is a need to provide data and voice coverage into remote locations previously not accessible using traditional WWAN techniques. Merely using a more powerful transmitter in the WWAN radio240might provide extended range transmissions, but, as discussed above, this may significantly increase the heat generated by the device. Furthermore, additional heat dissipation techniques are not typically available on body mounted devices, this additional heat may become intolerable to a wearer, and even arrive to the point of degrading the electronics by surpassing operational tolerances of the ICs (e.g., during persistent operations). Here, aspects of the WWAN radio240, together or in isolation, address these problems typically associated with power increase scaling. First, the WWAN radio240may incorporate efficient power amplifier(s) (e.g., 25% or greater efficiency) that balances a reduced power consumption and waste heat generation with the desired increased performance. Second and as discussed below (FIG.6), the WWAN radio240may incorporate close loop controls (e.g., feedback monitoring/control of amplification and/or output). These features the WWAN radio240, together or in isolation, may advantageously minimize the battery life degradation, and also minimize the costly components of a multi-stage power amplifier and secondary amplification at the antenna. Furthermore, the embodiment goes beyond traditional design implementation to focus on the high power transmissions and anticipated signal reception to provide enhanced filtering for the receive chain to ensure the modem optimizes signal power to correctly balance the link budget saving power, battery life and minimizing heat and protecting circuits. FIG.5schematically illustrates a detail section of an extended range wireless inter-networking device, according to another embodiment of the disclosure. In particular, the HPUE may include a MIMO WWAN radio540. Here, “MIMO” is used for clarity as well to relate to Multiple-Input-Multiple-Output where multiple antennas are used at both the source (transmitter) and the destination (receiver). The antennas at each end of the communications circuit are combined to minimize errors and optimize data speed. MIMO operation may incorporate just one additional duplexed transmit and receive pair or a multiple of duplexed transmit and receive pairs. The diagram assumes all duplexed channels will include a MIMO high power amplifier552it does not preclude only using a subset of the MIMO transmit chains in a high power mode. There may be a no diversity receive ports, a single diversity receive port, or a multiple diversity receive ports. Similar to above, a MIMO WWAN radio540, shown here, may include the WWAN MODEM232communicably coupled to a MIMO WWAN transceiver534configured for MIMO communications (e.g., including the transmit port235, the receive port237, and the diversity receive port239, as well as at least one MIMO transmit port535and at least one MIMO receive port537). Also as above, the WWAN modem, WWAN transceiver, and multi-mode amplifiers may be discrete or packaged together. Further, the MIMO WWAN radio540may include the diversity port245having the rejection filter257and a diversity antenna259as discussed above. According to the illustrated embodiment, the MIMO WWAN radio540may also include the multi-mode power amplifier236and at least one MIMO multi-mode power amplifier536, each functionally coupled and configure to amplify its respective duplex chain. It will be appreciated by one skilled in the telecommunications art that the MIMO components may represent 1-to-N duplex chains. According to the illustrated embodiment, the MIMO WWAN radio540may further include a MIMO high power port544downstream of the packaged or discrete multi-mode amplifiers236,536, the MIMO high power port544being configured to for MIMO communications. In particular, the MIMO high power port544may be configured as 2-to-N duplex chains including a first duplex chain including the high power amplifier252, the high power port frequency duplexer254, and the high power port antenna256, and 1-to-N additional duplex chains of, for example, including a MIMO high power amplifier552, a MIMO frequency duplexer554and a MIMO high power port antenna556. Each duplex chain may be configure as discussed above and integrated into the MIMO architecture of MIMO WWAN radio540. FIG.6schematically illustrates a detail section of an extended range wireless inter-networking device, according to another embodiment of the disclosure. In particular, the HPUE may include an efficient WWAN radio640. Here, “efficient” is used for clarity as well to relate to an amplifier that provides the high output power using a low amount of additional power to provide such an amplification while still maintaining the stringent spectral requirements that the standards and regulatory bodies require. There are various techniques that can be employed to attain such efficiency. Such embodiments may include the use of techniques to decrease the peak power consumption of the signal and applying techniques to track the amplitude of the amplifier such that the minimal amount of power is lost to thermal energy with minimal impact to the transmit performance of the signal. Similar to above, the efficient WWAN radio640may include the WWAN MODEM232, the WWAN transceiver234, and the multi-mode power amplifier236, which may be discrete or packaged. Likewise, efficient WWAN radio640may include the diversity port245having the rejection filter257and a diversity antenna259. According to the illustrated embodiment, the efficient WWAN radio640may further include an efficient high power port644configured to for efficient communications. In particular, the efficient high power port644may be configured as a duplex chain including the high power port frequency duplexer254and the high power port antenna256, as discussed above. Further, the efficient high power port644may include an efficient high power amplifier652and a waveform processor655. For example, as shown here the efficient high power amplifier652includes a feedback loop configured to monitor an output of the efficient high power amplifier (e.g., incorporating the waveform processor655). Further, the feedback loop is configured to modify the output in response to the feedback loop. According to one embodiment, the efficient high power amplifier652may be a single stage amplifier, or alternately a multistage amplifier. The efficient high power amplifier652may be functionally coupled to the multi-mode power amplifier236, and configured to further amplify transmissions output from the multi-mode power amplifier236. Also, the waveform processor655may be functionally coupled to the multi-mode power amplifier236and the efficient high power amplifier253. Further, waveform processor655may be configured to reduce the peak amplitude requirements of the amplifier, track the signal amplitude to permit the high power amplifier652to attain a high efficiency ratio, and/or modify the signal such that the amplifier operates at a high efficiency while maintaining the required linearity and spectral requirements mandated by the standards and regulatory bodies. The waveform process may do this analyzing the signal and dynamically modifying it to meet the efficiency and spectral requirements. Another embodiment may also integrate the amplifier output fed back to the waveform processor to make the analysis and adjustments of the signal. FIG.7schematically illustrates an extended range wireless inter-networking system, according to another embodiment of the disclosure. Here, an inter-networking system101is shown according to one exemplary embodiment, and including a HPUE201configured to communicate with multiple channels, multiple networks, and/or across diverse technologies. To illustrate, similar to above, the HPUE201may be configured to communicably couple with multiple end user devices310,320,330via the WLAN300. Further, the HPUE201may be configured to communicably couple with a plurality of WWANs (e.g., WWAN1401, WWAN2402, and WWAN3403) simultaneously, and simultaneously with the multiple end user devices310,320,330. Thus, inter-networking system101may include at least a two WWANs (e.g., WWAN1401and WWAN2402) with the HPUE201being configured to communicate at least one base station of each, and according to a two separate WWAN communication protocols (e.g., a cellular network standard/protocol and public safety band standard/protocol). Similarly, and according to one embodiment, the HPUE201may be further configured to communicably couple with the multiple end user devices310,320,330via a plurality of WLANs (not shown). As discussed below, WWAN1401, WWAN2402, and WWAN3403are broadly contemplated, and may each include any one of diverse channels within a network (e.g., Public Safety band and carrier communications band of an end user device), diverse networks (e.g., different carrier networks), and/or diverse WWAN technologies (e.g., LTE, WiMAX, UMTS, CDMA2000, GSM, 5G, etc.). According to one embodiment, WWAN1401may be a public band (e.g., LTE Public Safety Band 14) and WWAN1402may be a carrier communications band of the end user device310(e.g., Verizon LTE network, AT&T 5G network, etc.). FIG.8schematically illustrates an extended range wireless inter-networking device, according to another embodiment of the disclosure. In particular, an exemplary HPUE201is shown including two distinct transmission ports. Here, the HPUE201may include the housing210, the power supply212, the processor214, the memory216, the WLAN radio220, as discussed above, and may also include a WWAN radio840as discussed further below. According to one embodiment, the HPUE201may further include the location radio218and/or the n-axis accelerometer219as discussed above. The HPUE201may be configured to communicably couple with WLAN300(FIG.7) and a plurality of WWANs401,402,403(FIG.7) individually and/or simultaneously. According to one embodiment, WWAN radio840may include a multi-band WWAN chipset842(e.g., transceiver/MODEM/multi-mode amplifier) communicably coupled to a full duplex (transmit and receive) high power port244, to a half-duplex (receive) diversity port245, as discussed above, and to a full duplex (transmit and receive) standard power port844, together configured to communicate over one or more of WWAN1401, WWAN2402, and WWAN3403. It should be understood that the high power port244is conveniently selected for illustration purposes, and may be substituted by the MIMO High Power Port544(FIG.5) or the Efficient High Power Port644(FIG.6), each discussed above. It should be further understood that additional WWAN radios may include a traditional WWAN chipset e.g., additional/second WWAN transceiver/MODEM/multi-mode amplifier1043(FIG.10), communicably coupled to, and configured as a standard duplex chain including a standard frequency duplexer1054(FIG.10), and a standard power port antenna856(FIG.10). Accordingly, communications over the standard power port844may approximate those of current WWAN communications, whereas the high power port244(and other embodiments) may provide the benefits of communications over greater ranges and greater attenuation than conventional WWAN radios, as well as additional benefits discussed herein. In one embodiment, the traditional WWAN standard power port844may include a standard power port rejection filter857configured to exclude the high power port energy received on the standard power port antenna856. For example and as discussed above, the standard power port844may be configured to transmit at a first maximum power level (e.g. below 0.3 watts), and the high power port may be adapted and configured to transmit at a second maximum power level, said second maximum power level being greater than said first maximum power level, for example by a factor of greater than six (e.g., >8 dB), or alternately a factor equal to or greater than four. FIG.9schematically illustrates a detail section of the extended range wireless inter-networking device ofFIG.8, according to one embodiment of the disclosure. As above, the WWAN radio840may include the WWAN transceiver/MODEM842, the standard power port844, the high power port244, and the diversity port245, where the standard power port844approximates state of the art equipment and the high power port244provides enhanced connectivity, with each utilizing the diversity port245in reception. According to one embodiment, the WWAN transceiver/MODEM842may include a WWAN MODEM232, a WWAN transceiver834, a multi-mode power amplifier836, and a standard frequency duplexer854. The WWAN MODEM232may be functionally coupled to the WWAN transceiver834. As above, the WWAN transceiver834may have a transmit port235, a first receive port237(part of the high power port244), and a diversity receive port239. However, the WWAN transceiver834may also have a second receive port837as part of the standard power port844). The two receive ports may be configured internal to the WWAN transceiver834where the transceiver has one or more additional ports to support such an input or the signals may be switched just external to the WWAN transceiver834. An alternate embodiment of the transmit chain from the WWAN transceiver834may have two transmit ports where a separate one is routed to the amplifier stages using the transmit port235on the high power port and an additional standard power transmit port routed to its own amplifier. Other architectures are contemplated, for example, most cellphone implementations have a multi-mode amplifier, and the transceiver may use the same transmit port, though some implementations have multiple ports going into the amplifier, and some have multiple amplifiers. As shown, the multi-mode power amplifier836may be functionally coupled to both the standard frequency duplexer854(standard transmissions) and the high power amplifier252(boosted transmissions). Also, the first receive port237may be functionally coupled to the high power port frequency duplexer254of the high power port244, and the second receive port837may be functionally coupled to the standard frequency duplexer854of the standard power port844. Further, the diversity receive port239may be functionally coupled to the rejection filter257. In the standard embodiment, the multi-mode amplifier836has two output ports where one is routed to the standard frequency duplexer854and the other is routed to the high power amplifier252. One alternate embodiments may share the multi-mode amplifier836output with a switch to direct the amplified output accordingly. Another embodiment may have transceiver ports and amplifiers. As above, according to one embodiment, the WWAN transceiver/MODEM842may embodied in a single package, including the WWAN MODEM232, the WWAN transceiver834, and the multi-mode power amplifier836. According to another embodiment, the WWAN MODEM232, the WWAN transceiver834, and the multi-mode power amplifier836may be embodied as discrete components. According to yet another embodiment, the WWAN transceiver/MODEM842may be modified from conventional components/chipsets to integrate the high power port244. In such an embodiment, the WWAN transceiver834may have multiple ports to support these multiple paths. FIG.10schematically illustrates an extended range wireless inter-networking device, according to another embodiment of the disclosure. In particular, an exemplary HPUE203is shown including two distinct WWAN transceiver/MODEMs, and for use in an inter-networking system such as inter-networking system101. As above, the HPUE203may include the housing210, the power supply212, the processor214, the memory216, the WLAN radio220, as discussed above, and may also include a WWAN radio1040as discussed further below. According to one embodiment, the HPUE203may further include the location radio218and/or the n-axis accelerometer219as discussed above. Also as above, the HPUE203may be configured to communicably couple with WLAN300(FIG.7) and a plurality of WWANs401,402,403(FIG.7) individually and/or simultaneously. According to one embodiment, WWAN radio1040may include a high power port WWAN transceiver/MODEM as discussed above (here, high power port WWAN transceiver/MODEM1042) and a standard power port1044including an additional WWAN transceiver/MODEM1043. As above, the high power port WWAN transceiver/MODEM1042may be communicably coupled to the full duplex high power port244and to a half-duplex (receive) diversity port1045(discussed further below). Similarly, the standard power port WWAN transceiver/MODEM1043may be communicably coupled to a full duplex (transmit and receive) standard power port1044including a standard frequency duplexer1054and the standard power port antenna856, akin to the RFFE of a conventional mobile wireless communication device. According to one embodiment, at least one of the high power port244and the standard power port1044may be configured as a MIMO port such as the MIMO high power port544(FIG.5) discussed above. Also, according to another embodiment, the high power port244may be configured as the efficient high power port644(FIG.6). According to yet another embodiment, the standard power port WWAN transceiver/MODEM1043and the standard power port1044may be embodied as a RFFE of a conventional mobile wireless communication device (e.g., mobile communication device320inFIG.2), while the HPUE203is further modified to include a high power port such as the high power port244, the MIMO high power port544, and/or the efficient high power port644. According to yet another embodiment, the diversity antenna259in one embodiment may be used or otherwise shared for both the WWAN transceiver/MODEM1042and the WWAN transceiver/MODEM1043diversity inputs. As shown, the diversity port1045may further include a shared rejection filter1057similar to above. Alternately, the WWAN radio1040may utilize two separate antenna and diversity receive paths. Both WWAN transceiver/MODEMs may operate simultaneously in an independent fashion, separately under user or processor control, or through coordination by a radio control processor which may be processor214. The output streams from the WWAN radio1040may have two separate streams or be combined to have one individual data stream. FIG.12schematically illustrates an extended range wireless inter-networking device, according to another embodiment of the disclosure. Here, a high power user equipment (“HPUE”) is shown as a portable wireless access point2000configured for extended range communications, according to one exemplary embodiment. It should be appreciated that many, if not all components and features disclosed above are similarly applicable here, however, for clarity, new reference numbers are used. As shown, the portable wireless access point2000may include a wireless wide area network (WWAN) interface2400and a wireless local area network (WLAN) interface2200communicably coupled together via an inter-networker2500, such that a WLAN user (e.g., via mobile communication device) may access a WWAN via the portable wireless access point2000. As mentioned above, aspects of the WLAN interface2200may be similar to the WLAN radio220discussed above (and vis versa). Likewise, aspects of the WWAN interface2400may be similar to the WWAN radio240discussed above (and vis versa). The portable wireless access point2000may further include a user interface2600configured to initiate and terminate operation of the portable wireless access point2000. According to one preferred embodiment, the user interface2600may be a simplified user control configured to merely allow the user to command the portable wireless access point2000between an operational state and an inoperable state (e.g., “on and off” switch/control). Further, the user interface2600may include display configured to indicate the status of the portable wireless access point2000. (e.g., LED off, LED on, LED flashing on). In some embodiments, the status may represent a data connection status as discussed below. According to one embodiment, the portable wireless access point2000may further include a plurality of antennas2700. In particular, the plurality of antennas2700may include one or more antennas configured for each wireless network, or a subset thereof. For example, the plurality of antennas2700may include at least one of: one or more WLAN antennas, one or more WWAN antennas, and one or more diversity antennas. In addition, the plurality of antennas2700may include one or more location antennas configured for a location radio. One or more of the plurality of antennas may be integrated into its associated radio or communicably coupled as a separate component, for example, via a wireless or (preferably) a wired connection. The portable wireless access point2000may further include an enclosure2100configured to house at least one of the WWAN interface2400, the WLAN interface2500, and the inter-networker2500. According to one preferred embodiment, as shown, the enclosure2100may house all three of the WWAN interface2400, the WLAN interface2200, and the inter-networker2500. According to one embodiment, the user interface2600may be affixed to the enclosure2100. Further, the user interface2600may be located and/or operable externally of the enclosure2100. Alternately, the user interface2600may be may be located and/or operable internally and accessible wirelessly and/or via opening at least a portion of the enclosure2100. According to one embodiment the enclosure2100may be ruggedized and/or made to meet one or more environmental standards related to outdoor use or use in rugged/harsh environments. FIG.13schematically illustrates an extended range wireless inter-networking device, showing an alternate arrangement of its enclosure, according to one embodiment of the disclosure. In particular, a portable wireless access point2001may be similar to the portable wireless access point2000above (and going forward), however including an enclosure2101that is generally accessible by a user. In particular, enclosure may generally be an enclosed structure, yet include at least opening or access port. For example, the enclosure2101may be embodied as a clamshell case that is pivotably accessible via a case fastener (e.g., a conventional toolless fastener such as a draw latch) and at least one case hinge (pivot hinge2110). In this arrangement, an upper section may be lifted up (e.g., while resting on a flat surface, as shown) and pivoting away from a lower section, and exposing or otherwise providing access to the user interface2600. Thus, as illustrated, the user interface2600may be located internally of and/or operable from within the enclosure2100, limiting its access to first opening at least a portion of the enclosure2101. According to one embodiment, the enclosure2101may be segmented or otherwise arranged to provide varying degrees of access based on a use requirement. In particular, the enclosure2101may include (1) an operator section2107that is generally unsecured, or merely secured against access via one or more toolless fasteners, (2) a maintenance section2108that is lightly secured, or generally secured against access via a one or more fasteners that require a standard tool (e.g., screwdriver) to open, and (3) a protected section2109that is highly secured against access, requiring a unique security device (e.g., key) or destruction of the enclosure2101for access (e.g., embedded within one or more walls of the case. For example, with regard to the operator section2107, the user interface2600may be readily accessible by releasing a quick release fastener and opening a top half or access panel of the enclosure2101. According to one embodiment, portions of the enclosure2101may include indica within the operator section2107, directed toward the user. In particular, internal portions of the enclosure2101may include written communications or other indicia, such as access point name and password(s), use instructions, warnings, ownership and proprietary information, and the like. Also for example, with regard to the maintenance section2108, a lower half (ref., when the enclosure2101is sitting flat on a horizontal surface) of the clamshell may be configured to house modular, plug-and-play components that are field replaceable (e.g., WWAN interface2400, WLAN interface2200, the inter-networker2500, and/or a power supply2120). Similarly, an upper half (ref., when the enclosure2101is sitting flat on a horizontal surface) of the clamshell may also be configured to house modular, plug-and-play components that are field replaceable (e.g., antennas2700). Beneficially, this separation may provide for improved antenna performance and reduced RF interaction with other onboard electronics. Further, one or both of the lower half and the upper half may be internally enclosed by an internal access panel2105such that the access panel2105must also be removed after accessing the operator section2107(e.g., after opening the clamshell case). Preferably, the access panel2105may be secured in place by screws or other fasteners that are not toollessly removable. Each modular, plug-and-play component may be removably affixed to portions of the enclosure2100within the maintenance section2108and appropriately coupleable to each other (e.g., power, communications, signaling, etc.) and/or coupleable to external ports via conventional interconnections (e.g., Ethernet cables, USB cables, AC power cables, DC power cables, etc.). According to one embodiment, one or both access panels2105may be configured so as to electromagnetically shield modular components within each upper and lower half, respectively, and/or to enhance antenna performance (e.g., creating a ground plane, aid directionality, reduce interference, etc.). Also for example, with regard to the protected section2109, an upper wall (ref., when the enclosure2101is sitting flat on a horizontal surface) of the clamshell may be configured to house components that are generally not field replaceable, contain permanent identifying information (e.g., NFC/RFID tags, embedded antennas, etc.), and/or require special/authorized access to modify (e.g., SIM card, memory cards, user interface, etc.). These areas may be sealed within the enclosure2101or may be physically secured by a locking plate2106, for example requiring a non-standard tool or key for user access. As illustrated (right hand side), this may be an alternate embodiment of the upper half of the enclosure2101wherein the locking plate2106is permanently fixed or only removable via key or a limited access tool. As above, the locking plate2106may be configured so as to electromagnetically shield modular components within at least of the upper and lower half, and/or to enhance antenna performance. Returning toFIG.12, as shown, the enclosure2100may include or otherwise support and house: a power supply2120configured to power onboard components via a power distribution network2126; an environment control subsystem2130configured to maintain an operating environment within the enclosure2100; and/or the plurality of antennas2700configured for each wireless network, or a subset thereof and/or a location radio (as discussed above). The enclosure2100may further include a variety of physical interfaces, including but not limited to at least one of a power input port2111, a power output port2112, a cooling inlet2113, a cooling outlet2114, a communication port2116, and an antenna port2118. The power input port2111, the power output port2112, the communication port2116, and the antenna port2118may be any conventional port configured to interface with a standardized or proprietary connector, as appropriate. To illustrate, the power input port2111may include a conventional DC power jack, the power output port2112may include a USB-type slot, the communication port2116may include an Ethernet receptacle, and the antenna port2118may include a coaxial cable receptacle, to name a few. Further, each port may be located in any convenient location (e.g. all on one side, all inputs on one side and all outputs on an opposite side, proximate its connected module, etc.) Similarly, the cooling inlet(s) and outlet(s) may be made and positioned for performance, use case, or any other desirable criteria, as discussed further below. FIG.14schematically illustrates a detail section of the extended range wireless inter-networking device ofFIG.12, showing aspects of the power supply, according to one embodiment of the disclosure. As shown, the power supply2120may generally include an energy storage2122electronically coupled to the power distribution network2126(FIG.12). For example, the energy storage2122may include a battery (e.g., rechargeable Li-Ion battery) configured to receive, store, and deliver DC power (e.g., 12 VDC). According to one embodiment, the energy storage2122may be embodied as a power pack configured to receive and store DC power, and to deliver DC and/or AC power. It should be appreciated that the power supply2120may include additional conventional components and features as appropriate, and which are well-known in the art. The power supply2120may further include a power converter2124electronically coupled between the energy storage2122and the power distribution network2126. In particular, the power converter2124may be configured to convert power delivered by the energy storage2122to any onboard need via any conventional means. For example, the power converter2124may include DC-to-DC converter configured to buck/boost battery voltage as appropriate. Also for example, the power converter2124may include an DC-to-AC converter (inverter) configured to meet any onboard AC requirement. Also for example, the power converter2124may include any combination of one or more converters (converters, inverters, and rectifiers). According to one embodiment, the power converter2124may include an AC-to-DC converter (rectifier/AC adapter) configured to convert standard AC power to meet an onboard requirement such as onboard bus power (e.g., 120 VAC-to-12 VDC). This may be particularly beneficial where the energy storage2122is embodied as a conventional, and modular power pack configured to receive and store DC power, and to deliver AC power. The power supply2120may further include a charger2121electronically coupled between an external power supply99and the energy storage2122. In particular, the charger2121may be configured to convert offboard AC power (e.g., wall power) to DC power for charging the energy storage2122. Beneficially, in this way the portable wireless access point2000may be recharged by merely plugging it into a conventional wall outlet. According to one embodiment, the power supply2120may be further configured to power the power distribution network2126directly by the external power supply99(e.g., bypassing one or more components of the power supply2120and/or bypassing but with a parallel battery charge). As shown, the power distribution network2126may include a direct current (“DC”) circuit2126D and/or an alternating current (“AC”) circuit2126A. In particular and as described above, where the energy storage2122is a battery, the power converter2124may include a DC-to-DC converter configured to convert DC power from a battery voltage (e.g., 3.7 VDC, 6 VDC, 12 VDC etc.) to: a DC bus voltage (e.g., 5 VDC, 12 VDC, 24 VDC, etc.); one or more discrete or localized onboard DC voltages; and/or one or more offboard DC voltages; and to power one or more components over the DC circuit2126D. Further, the power converter2124may include a DC-to-AC converter configured to convert DC power at a battery voltage to AC power at: an AC bus voltage (e.g., 120 VAC); one or more onboard AC voltages; and/or one or more offboard AC voltages; and to power one or more components over the AC circuit2126A. The power supply2120may be configured to interface with the power input port2111and/or the power output port2112(FIG.12). In particular, the power supply2120may be configured to be charged and/or directly powered via the power input port2111. Similarly, the power supply2120may be configured to power and/or charge external devices via the power output port2112. As disclosed above, the power input port2111may include an onboard charger or other electronics, where appropriate, to conform available external power99(FIG.12) to the requirements of the power supply2120. FIG.15schematically illustrates a detail section of the extended range wireless inter-networking device ofFIG.12, showing aspects of the plurality of antennas, according to one embodiment of the disclosure. As above, the WLAN interface2200(FIG.12) may include or otherwise be electronically coupled to one or more WLAN antennas2720, included the plurality of antennas2700. Also as above, the WWAN interface2400(FIG.12) may include or otherwise be electronically coupled to one or more standard port WWAN antennas2730, one or more high power port WWAN antennas2740, one or more diversity port WWAN antennas2750, and one or more location antennas2780, included the plurality of antennas2700. According to one preferred embodiment, the plurality of antennas2700may include three LTE antennas, two Wi-Fi antennas, and one GPS antenna. Preferably, the plurality of antennas2700will be embodied as an independent module embedded or otherwise attached to the enclosure2100(FIG.12), remote from their respective radios. Further, the plurality of antennas2700may be electronically coupled back to their respective radios located elsewhere in the enclosure2100, via cabling and connectors. According to one embodiment, one or more of the plurality of antennas2700may be active and powered via the power supply2120(FIG.12). Preferably, one or more of the plurality of antennas2700may be high-gain antennas that utilize being remote from their respective radio modules for increased size and directionality. For example, one or more of the plurality of antennas2700may be located in or proximate a surface of the enclosure2100that is outward facing, larger than their respective radio modules, and/or shielded from other electronics. According to one embodiment, one or more of the plurality of antennas2700may be removable or otherwise extendable from the enclosure2100. FIG.16schematically illustrates a detail section of the extended range wireless inter-networking device ofFIG.12, showing aspects of the environment control subsystem, according to one embodiment of the disclosure. As above, the enclosure2100(FIG.12) may include or otherwise support and house the environment control system2130configured to maintain a desired operating environment (e.g., maintain a desired thermal range) within the enclosure2100. In particular, the environment control system2130may be arranged as an open-loop cooling system (i.e., ingesting ambient air into and exhausting heated air from the enclosure2100to the environment) and/or as a closed-loop cooling system (i.e., exhausting heated air or otherwise expelling heat from the environment control system2130to the environment via a heat exchanger). According to one embodiment, the environment control system2130may include one or more sensors2134(e.g., temperature sensors, humidity, etc.), a local controller2136, and any other conventional components or features. For example, the local controller2136may be configured to engage or otherwise operate the environment control system2130once a threshold condition is sensed by one or more sensors2134(e.g., temperature or humidity out of acceptable limits). While the sensor(s)2134and local controller2136are illustrated for clarity as independent items, it is understood that one or more components of the environment control system2130may be embedded in another component or otherwise be a shared resource (e.g. the local controller2136and sensor2134may integrated into a fan unit or the inter-networker2500). According to one embodiment, the cooling inlet2113and/or the cooling outlet2114may include filters (e.g., membrane filters) and covers (e.g., dust covers, water seals, etc.) configured to maintain the interior of the enclosure2100free of debris, contaminants, and other harmful substances, during operation and storage, respectively. In some embodiments, the covers of the cooling inlet2113and/or the cooling outlet2114may seal the interior of the enclosure2100when installed. According to one preferable embodiment, the environment control system2130will be arranged as an open-loop cooling system. For example, the environment control system2130may merely include at least one fan fluidly coupled to at least one of the cooling inlet2113and the cooling outlet2114, where the fan is configured to pump cooler air from the environment into the enclosure2100and/or heated air from the enclosure2100to the environment, respectively. According to one embodiment, the environment control system2130may be arranged as a closed-loop cooling system where the environment control system2130further includes a heat exchanger2132fluidly interspersed between the cooling inlet2113and the cooling outlet2114. In particular, the heat exchanger2132may be configured to receive heat from the enclosure2100via the environment control system2130, and the environment control system2130is then configured to expel heat to the environment, without introducing ambient air into the rest of the enclosure2100, beyond the environment control system2130. FIG.17schematically illustrates a detail section of the extended range wireless inter-networking device ofFIG.12, showing aspects of the WLAN interface, according to one embodiment of the disclosure. As above, the portable wireless access point2000(FIG.12) may include the WLAN interface2200communicably coupled together with the WWAN interface2400(FIG.12) via the inter-networker2500(FIG.12). Further, the WLAN interface2200may be similar to or otherwise include aspects similar to the WLAN radio220described above. Generally, the WLAN interface2200may be arranged as a conventional WLAN router, including a WLAN transceiver/MODEM2220similar to the WLAN transceiver/MODEM222described above. Further, the WLAN interface2200may include a communication port2212(e.g., Ethernet port), a power port2214(e.g., DC jack), or a combination thereof as a communication port configured to receive power (e.g., PoE port). Preferably, the WLAN interface2200will be embodied as an integrated WiFi radio module (e.g., having its own housing, with connections for power and for communications). In this way the WLAN interface2200may be mounted to the enclosure2100as a plug-and-play device requiring only a power and data connection to the inter-networker2500(e.g., an Ethernet connection). According to one embodiment, the WLAN interface2200may be powered directly by the DC circuit2126D of the power distribution network2126(e.g., via a DC power cable and connector), or indirectly by the DC circuit2126D, for example via a DC power cable and connector to the inter-networker2500. According to another embodiment, the WLAN interface2200may be powered directly by the external power99(e.g., via a DC power cable and connector). According to yet another embodiment, the WLAN interface2200may be powered and communicably coupled via a combined communication and power supply interface (not shown). In particular, the WLAN interface2200may be powered and communicably coupled to the inter-networker2500via a Power-over-Ethernet connection (PoE) connection or a USB type connection. According to one embodiment, the WLAN interface2200may include or otherwise be electronically coupled to one or more WLAN antennas2720(FIG.15) included the plurality of antennas2700, where the one or more WLAN antennas2720are similar to the various WLAN antennas224discussed above. Preferably, the one or more WLAN antennas2720will be embedded or otherwise encased in enclosure2100but outside of the housing of WLAN interface2200, and communicable coupled via one or more antenna ports2216. Similarly, one or more WLAN antennas2720may be located remotely from the enclosure2100(e.g., vehicle antenna, building antenna, antenna of a separate portable wireless access point2000), and coupled via antenna cabling to the one or more antenna ports2216. According to one embodiment, the housing of the WLAN interface2200may include heat exchanging/radiating features (e.g., fins, pins, heatsink, etc.) configured to transfer heat from the WLAN interface2200to a coolant fluid (e.g., cooling air) flowing within or through the enclosure2100. FIG.18schematically illustrates a detail section of the extended range wireless inter-networking device ofFIG.12, showing aspects of a WWAN interface, according to one embodiment of the disclosure. As above, the portable wireless access point2000(FIG.12) may include the WLAN interface2200(FIG.12) communicably coupled together with the WWAN interface2400via the inter-networker2500(FIG.12). Generally, the WWAN interface2400may be arranged as a WWAN radio, similar to or otherwise including aspects similar to the WWAN radio840described above. Further, the WWAN interface2400may include a communication port2412(e.g., USB type port), a power port2414(e.g., DC jack), or a combination thereof (e.g., USB type port or PoE port). Preferably, the WWAN interface2400will be embodied as an integrated module (e.g., having its own housing, with connections for power and for communications). According to one embodiment, the WWAN interface2400may be powered directly or indirectly (e.g., through the inter-networker2500) by the DC circuit2126D of the power distribution network2126. Further, the WWAN interface2400may be communicably coupled to the inter-networker2500(e.g., via a USB-type or other data connection). Alternately, the WWAN interface2400may be communicably coupled and powered via a combined communication and power supply interface such as a USB type connection or a PoE connection without requiring a direct power connection. According to one embodiment, the WWAN interface2400may be selectably configured for the option of separate power and communications, or of combined power and communication. Said selection may be user based or automatic, such as whether or not a combined power and communications connection is made, for example. According to one embodiment and as illustrated, the WWAN interface2400may include a multi-band WWAN chipset2420(e.g., transceiver/MODEM/multi-mode amplifier or equivalent), similar to the multi-band WWAN chipset842discussed above. The multi-band WWAN chipset2420may be communicably coupled to a full duplex high power port2440(similar to high power port244discussed above) and to a full duplex standard power port2430(similar to standard power port844discussed above). According to one embodiment, the WWAN interface2400may further include a half-duplex (receive) diversity port2450(similar to diversity port245discussed above). Alternately, the WWAN interface2400may include a plurality of WWAN transceiver/MODEMs, as in the alternate embodiments disclosed above. For example, the WWAN interface2400may include a high power port WWAN transceiver/MODEM (such as WWAN transceiver/MODEM1042above) communicably coupled to the high power port2440(and alternately communicably coupled to the diversity port2450), and further include a standard power port WWAN transceiver/MODEM (such as WWAN transceiver/MODEM1043above) communicably coupled to the standard power port2430. This may provide the same or similar additional benefits and functionality discussed above. The high power port2440and the standard power port2430may be configured to communicate over one or more of WWAN1401, WWAN2402, and WWAN3403(see ref.,FIG.7) or one or more bands within a single WWAN. Further, the high power port2440may be adapted to operate at the same or similar higher power levels for high power communications (relative to the standard power communications of the standard power port2430), discussed above and throughout. For example, the high power port2440may be configured to operate at Class 1 levels, while the standard power port2430may be configured to operate at Class 3 levels. According to one embodiment, the high power port2440may be configured to communicate as a Power Class 1 mobile radio over a public safety network (e.g., Band 14 at 1.25 W output power), and the standard power port2430may be configured to communicate as a Power Class 3 mobile radio over a standard mobile communication network (e.g., Bands 2, 4, 5, 12, 17, 29, 30, and 66 at 200 mW). According to one embodiment, the WWAN interface2400may further include or otherwise be electronically coupled to the one or more antennas2700(FIG.15). In particular, the standard power port2430may be electronically coupled to one or more standard port WWAN antennas2730(FIG.15), the high power port2440may be electronically coupled to one or more high power port WWAN antennas2740(FIG.15), and the diversity port2450may be electronically coupled to one or more high power port WWAN antennas2750(FIG.15). The standard port WWAN antenna2730, the high power port WWAN antenna2740, and the high power port WWAN antenna2750may be included the plurality of antennas2700, where the one or more WWAN antennas2730,2740,2750are similar to the various WWAN antennas259,256,856discussed above. Preferably, the one or more WWAN antennas2730,2740,2750will be embedded or otherwise encased in enclosure2100(FIG.12) but outside of the housing of WWAN interface2400, and communicable coupled via one or more antenna ports2416. According to one embodiment, the WWAN interface2400may further include a location radio2480similar to the location radio218discussed above. Likewise, the location radio2480may include or otherwise be electronically coupled to one or more location antennas2780(FIG.15). According to one embodiment, the WWAN interface2400may further include an n-axis accelerometer2490similar to the n-axis accelerometer219discussed above. According to one embodiment, the housing of the WWAN interface2400may include heat exchanging/radiating features (e.g., fins, pins, heatsink, etc.) configured to transfer heat from the WWAN interface2400to a coolant fluid (e.g., cooling air) flowing within or through the enclosure2100. Beneficially, these features may improve thermal conductivity between the WWAN interface2400and the environment control subsystem2130(FIG.12), thus improving performance of WWAN interface2400(particularly during high power port communications). FIG.19schematically illustrates a detail section of the portable wireless access point ofFIG.12, showing aspects of a distributed WWAN interface, according to alternate embodiment of the disclosure. In particular, here the functionality of the high power port has been removed from the housing of the WWAN interface2400(FIG.18) and is shown as a connectable module (or “sleeve”). As shown, the WWAN interface2401may include the same or similar components and features as the WWAN interface2400above (e.g., power, communications, and antenna ports, logic, additional radios, TxRx/MODEM, etc.), however the components and features associated with a conventional WWAN device (e.g., the standard port2430) may be segregated and packaged as a first module (i.e., a standard power WWAN module2402), and the components and features associated with high power communications may be combined and packaged as a second module (i.e., a high power WWAN sleeve2403). The high power WWAN sleeve2403may be communicably coupled to and powered by the standard power WWAN module2402. In particular, the high power WWAN sleeve2403may include and be arranged as a host for the high power port2440. The high power port2440electronically coupled to one or more high power port WWAN antennas2740via one or more antenna ports2416. According to one embodiment and as shown, the high power port2440may be coupled to the multi-band WWAN chipset2420of the standard power WWAN module2402. Alternately, the high power port2440may include its own dedicated transceiver/MODEM (not shown). Further, the high power port2440may include any appropriate local logic and power electronics2471for interfacing with the standard power WWAN module2402. According to the illustrated embodiment, the high power port2440may interface with the standard power WWAN module2402via the local logic and power electronics2470of the standard power WWAN module2402. This may be beneficial where the standard power WWAN module2402and the high power WWAN sleeve2403are singly coupled via a combined communication and power supply interface. Alternately, the high power port2440may interface directly with the multi-band WWAN chipset2420of the standard power WWAN module2402. This may be beneficial where a dedicated port is provided. For example, where the standard power WWAN module2402is merely a conventional wireless communication device, this dedicated port may be structured as or otherwise analogous to an RF test port. It should be understood that many different interfacing routes are available, which may be selected based on equipment available and/or specific use case/application. For example, according to one embodiment the high power WWAN sleeve2403may be embedded into or otherwise combined with the inter-networker2500(or an adaption thereof). Beneficially, full functionality of both the high power port2440and the inter-networker2500may complement or otherwise be added to a conventional wireless communication device. FIGS.20-22schematically illustrates a detail section of the extended range wireless inter-networking device ofFIG.12, showing aspects of an inter-networker, according to different variations of the disclosure. As above, the portable wireless access point2000(FIG.12) may include the WLAN interface2200(FIG.12) communicably coupled together with the WWAN interface2400(FIG.12) via the inter-networker2500. Generally, the inter-networker2500may be arranged as data converter between WWAN and WLAN communications (e.g., between LTE communications and Ethernet communications), and as an integrator or overall controller of the portable wireless access point2000. Also, the inter-networker2500may be similar to or otherwise include aspects similar to at least one of the power supply212, the processor214, and the memory216described above. Preferably, the inter-networker2500will be embodied as an integrated module (e.g., having its own housing, with connections for power and for communications). For example, one or more components of the inter-networker2500may be housed in a single unit (preferably ruggedized), such as being mounted to a mounting plate, and covered with a casing. The inter-networker2500may be configured to communicably couple to the WLAN interface2200and communicably couple to the WWAN interface2400. Also, the inter-networker2500may be powered directly or indirectly by the DC circuit2126D of the power distribution network2126. Alternately, the inter-networker2500may be powered by the WLAN interface2200(e.g., via an offboard power supply). In addition, the inter-networker2500may be further configured to power one or both of the WWAN interface2400and WLAN interface2200. For example, the inter-networker2500may be configured to power one or both of the WWAN interface2400and the WLAN interface2200via a dedicated power supply (see e.g., DC power supply to WWAN interface2400inFIG.20). Also for example, the inter-networker2500may be configured to power one or both of the WWAN interface2400and the WLAN interface2200via a combined data/power supply (e.g., to WWAN interface2400via USB connection, to WLAN interface2200via a PoE connection, etc.). According to one embodiment, the inter-networker2500may include or otherwise incorporate an Ethernet injector configured to deliver both power and data concurrently via twisted pair Ethernet cabling. In addition, the inter-networker2500may be further configured receive power via the same connection as well, respectively. According to one embodiment, the inter-networker2500may include one or more communication ports, power ports, or combinations thereof. In particular, the inter-networker2500may include a LAN communication port2522, a WAN communication port2524, and a power input port2572. In addition, the inter-networker2500may further include a power output port2574. Each of the LAN communication port2522and the WAN communication port2524may be configured as a purely communication port, or as both a communication and power port, as discussed above. According to one preferred embodiment, each port may be configured to be coupled to a standardized connector. For example, the LAN communication port2522may include a RJ-45 connector and the WAN communication port2524may include a USB-type connector. Also for example, the power input port2572and the power output port2574may each include a DC power jack. In this way, the inter-networker2500may be integrated into the portable wireless access point2000as a plug-and-play module that merely needs to be mounted and plugged in. According to one embodiment and as illustrated, the inter-networker2500may include a WAN-to-LAN module2520and a system controller2540. These may be embodied as software, hardware, firmware, or any combination thereof. Further, while the WAN-to-LAN module2520and the system controller2540are illustrated here as separate items, this is done merely for improved clarity. It should be understood that the WAN-to-LAN module2520and the system controller2540may be embodied as illustrated, combined together, one may be a submodule within the other, or any combination thereof. The WAN-to-LAN module2520may include and/or utilize a processor/microcontroller programmed or otherwise configured to seamlessly integrate WAN and LAN communications between the modems of the WWAN interface2400and the WLAN interface2220, respectively. For example, the WAN-to-LAN module2520may preferably be programmed or otherwise be configured to convert communications between USB 3.0 between Gigabit Ethernet. The system controller2540may be configured to provide for offboard controller communications, such as network management (particularly over a WWAN). Examples of network management may include remote provisioning, subscription management, and cloud data analytics, to name a few. Further, the system controller2540may be configured to provide for onboard controller communications, such as status reporting, environment control, power control, port control/access/communications, etc. Onboard controller communications may be communicated over a dedicated link (e.g., direct communications with the user interface2600as shown), or over a shared resource (e.g., bus communications over the LAN communication port2522with the user interface2600not shown). According to one embodiment the system controller2540may also include/integrate, power, and/or otherwise support/complement the WAN-to-LAN module2520. For example, the WAN-to-LAN module2520may merely be a module of the system controller2540). According to one embodiment, the inter-networker2500may be configured to regulate power between a power supply and the electronics of at least one of the WWAN interface2400and the WLAN interface2200. In particular, the inter-networker2500may further include a power converter (i.e., power conditioner2570) configured to convert a supply voltage from, for example, the power distribution network2126(FIG.12), a combined data and power connection, a standard external power supply, etc., to an operational voltage of the WWAN interface2400. Beneficially, in this arrangement, the inter-networker2500may be sufficiently modular to operate the WWAN interface2400independently of the power supply2120(FIG.12), for example, when mounted together as a kit on a portable mounting bracket. As an independent module, the inter-networker2500and the WWAN interface2400may merely require a standard DC input and provide a data connection for a conventional WLAN modem or WLAN modem/router For example, the power conditioner2570may include a DC-to-DC (buck-boost) converter configured convert a range of diverse supply voltages (e.g., between 7 VDC and 48 VDC) to one or more predefined operational voltages (e.g., standard 5 VDC or 12 VDC). Further, the power conditioner2570may configured dynamically convert a range of supply voltages (e.g., between 9 VDC and 36 VDC) to one or more onboard operational voltages of the inter-networker2500. Similarly, and as shown inFIG.22, the power conditioner2570may include a transformer and associated circuitry to separate power from communications in a combined communication and power supply interface (e.g., via a PoE connection). According to one embodiment, the inter-networker2500may include a power output port2574configured to supply sole, selectable, or supplemental power. For example, as shown inFIG.20, the power output port may2574be configured to provide sole DC power to the WWAN interface2400. Also for example, as shown inFIGS.21and22, the WAN communication port2524may be configured as combined communication and power supply interface. In this configuration, the power output port2574may be combined with or functionally replaced by WAN communication port2524. Alternately, the power output port2574may be added to provide supplemental (or primary) DC power to the WWAN interface2400. According to one embodiment, the inter-networker2500may include a user interface2560. The user interface may be embodied as a variable indicator light configured to indicate a device and/or connection status to a user. For example, the user interface2560may be a multi-color LED where blue indicates “initialization”; flashing red indicates “data connection error” (e.g., to check that a properly provisioned SIM has been inserted); solid red indicates “no SIM installed”; flashing green indicates “connecting”; and solid green indicates “attached to the network”. According to one embodiment, the housing of the inter-networker2500may include heat exchanging/radiating features (e.g., fins, pins, heatsink, etc.) configured to transfer heat from the inter-networker2500to a coolant fluid (e.g., cooling air) flowing within or through the enclosure2100. Beneficially, these features may improve thermal conductivity between the inter-networker2500and the environment control subsystem2130(FIG.12), thus improving performance of the inter-networker2500. Beneficially, while here the inter-networker2500is illustrated as communicably coupled with the WLAN interface2220, the inter-networker2500may also operate in tandem with any standard routers, gateways, and switches (particularly when the LAN communication port2522includes an Ethernet connection), further providing for a high-speed connection to other associated LAN devices. FIG.23schematically illustrates an extended range wireless inter-networking device adapted as a portable wireless access point, showing the WLAN interface remote form the enclosure, according to an alternate embodiment of the disclosure. As above, a portable wireless access point2002may include a WLAN interface2203communicably coupled together with the WWAN interface2400via the inter-networker2500. Here, however, the WLAN interface2203is independent of or otherwise not mounted to the enclosure2102. As shown, the WLAN interface2203may be plugged into and powered by the power port output2112of enclosure2102(e.g., DC power jack). Further, the WLAN interface2203may be plugged into the communication port2116of the of enclosure2102(e.g., Ethernet jack) and communicably coupled to the inter-networker2500, providing the requisite data connection for operation. Beneficially, portable wireless access point2002may provide a portable data connection that can be used with any standard routers, gateways, and switches, as discussed above. According to one embodiment, portable wireless access point2002may include a second WLAN interface (not shown) mounted to the enclosure2102and connected as discussed above. Alternately, the WLAN interface2203may be powered directly by external power99, and may further be communicably coupled to and power the inter-networker2500, and/or other components onboard the enclosure2103via a combined communication and power supply interface (e.g., via a PoE connection a USB type connection). This may be particularly advantageous in embodiments where the WLAN interface2202is a standalone WiFi modem/router with PoE capacity and has access to wall power. FIG.24is a flow chart of an exemplary method2900for inter-networked communications, according to one embodiment of the disclosure. The method2900may include the following steps or variants there of: Providing2910a portable wireless access point (such as portable wireless access point2000above); Powering up2920the portable wireless access point via a user interface (e.g., pressing an “on/off” button); Establishing2930a WWAN link between the portable wireless access point and at least one WWAN; Providing2940a data connection to a WLAN MODEM of the portable wireless access point; Establishing2950a WLAN link between the portable wireless access point and at least one wireless communication device; Providing2960ongoing inter-networked communications between the at least one wireless communication device and the WWAN via the WWAN link and the WLAN link of the portable wireless access point. The method2900may further include the step of accessing2922the user interface, as a prerequisite to its use in step2920. For example, this step may require opening the case or enclosure of the portable wireless access point, or merely opening an access port to the user interface. The method2900may further include selecting2932between a first WWAN band and a second WWAN band. For example, this may include selecting between a standard or individual communication band and a public communications band (e.g., Band 14). Also, the method2900may further include switching2934between the first WWAN band and the second WWAN band. For example, this may include switching between the standard or individual communication band and the public communications band based on WWAN signal strength, radio selected, priority of communications, etc., just to name a few. According to one embodiment, these steps may be at least partially integrated into step2930. According to one embodiment, at least one of these steps may be performed prior to step2940. In addition, the method2900may further include selecting2936between a first WWAN radio and a second WWAN radio. For example, this may include selecting between a high power port (e.g., high power port2440) and a standard power port (e.g., standard power port2430) of the WWAN radio. Also, the method2900may further include switching2938between the first WWAN radio and the second WWAN radio. For example, this may include switching between the high power port and the standard power port based on WWAN signal strength, band selected, priority of communications, etc., just to name a few. According to one embodiment, at least one of these steps may be performed prior to step2940. The method2900may further include communicating a data connection status to a user2942once a data connection is available (and/or other related states as discussed above). The method2900may further include powering down2970the portable wireless access point via a user interface (e.g., pressing the “on/off” button a second time). While the steps of method2900have been discussed in a logical order of operation, it should be understood that that this is not limiting and variations to the presented order are both possible and anticipated. Similarly, it should be understood that one or more steps may be repeated in the process of following the method2900. INDUSTRIAL APPLICABILITY The present disclosure generally pertains to a system and method for wireless inter-networking between a wireless wide area network (WWAN) and a local area network (WLAN) and/or personal area network (PAN) employing one or more extended range wireless inter-networking devices, and is applicable to the use, operation, maintenance, repair, and improvement of wireless communication devices and associated infrastructure. The inter-networking system embodiments described herein may be suited for wireless communications for any number of industrial applications, such as, but not limited to, various aspects of the military, police and first response, and the wireless communication industry in general, to name a few examples. Furthermore, the described embodiments are not limited to use in conjunction with a particular type of WLAN or WWAN technology. There are numerous inter-networking configurations and combinations that are applicable here. For example, it should be understood by one having ordinary skill in the art that, in view of the above discussion, a method1100for inter-networking a mobile device and a remote base station. Referring toFIG.11, showing a flow chart of an exemplary method for inter-networking a mobile device and a remote base station, the method1100may include the following steps or variants there of: providing1110, a wireless local area network (WLAN); providing1120a first wireless wide area network (WWAN); providing1130a high power user equipment (e.g., HPUE200or HPUE201) configured to wirelessly communicate with the WLAN and the first WWAN, and further configured to communicably couple the mobile device with the first WWAN via the WLAN; communicating1140with the mobile device over the WLAN via the WWAN radio; and communicating1150with the remote base station in a boosted mode over the WWAN via the high power port of the WWAN radio, the boosted mode including transmissions, for example, greater than 0.5 watts. Further, the method1100may include providing1160a second WWAN including an in-range base station; and communicating1170with the in-range base station in a standard mode over the second WWAN via the high power port of the WWAN radio, the standard mode limiting transmissions to less than 0.5 watts, for example. While all features and benefits might not be achieved in every embodiment of the disclosure, some benefits may include doubling the range of Public Safety Band 14 wireless broadband equipment and allowing any Wi-Fi-enabled device to connect to the wireless network in even the most remote and difficult environments. Further, a benefit that may not be readily apparent, the disclosed high power user equipment (e.g., HPUE200or HPUE201) may serve as a “base station” for many end user devices310,320,330,340over the WLAN300where a mobile chipset (e.g., WWAN transceiver/MODEM242,1042,1043) the be effectively utilized as a base station. Whether it's in the deepest levels of structures or in the most remote outdoor areas, applying the teachings herein, a user may be able to stay connected with all the advanced broadband services currently in use. Further, smartphone, tablet, and IoT devices may continue work in even the most remote and difficult areas, and may achieve mission-critical levels of communications readiness and reliability. In addition, wireless hotspots, routers, smartphones and other similar devices might now stay connected at nearly twice the distance from the base station as well as deep inside underground and concrete structures. Furthermore, the disclosed innovations discovered by the inventors may offer these benefits without significantly increasing the size, power consumption, or thermal dissipation of the user equipment. While wireless hotspots connect over the wireless wide area network such as a cellular or WiMAX network, and have a range and speed limitation caused by having a lower power transmitter (found in most commercial handsets), here, with the addition of the high power transmitter on the wide area network side, the range for any given data rate can be extended, and the network capacity can be expanded by having an adequate signal to noise ratio offered by the higher TX power. Thus, the hotspot or HPUE may provide inter-networking between a wireless wide area network (WWAN) and the local or personal area network in a modest form factor that may be generally mobile and portable. Such an inter-networking device that possesses the high power and more reliable front end that maximizes the ability to transmit data to the network station while minimizing the interference may ensure reliable reception, and increase the devices' range, connection reliability, data rates, and network resiliency. These characteristics are essential for critical communications capabilities. Similarly, existing wireless interconnect devices, such as a variety of hotspot products, provide inter-networking between wireless wide area networks (WWAN), such as cellular-based networks, and local or personal wireless networks (WLAN/WPAN). These existing interconnect devices have range and data rate limitations caused the limited power that they transmit to the WWAN. Higher power transmission from the disclosed HPUE or interconnect devices may extend the range and data rates possible. However, for personal/pedestrian or in-vehicle interconnect devices, the need to operate for long periods of time from a reasonable sized battery constrains the amount of transmission power they can transmit. As a result, the long-range capabilities of the disclosed innovations may make it possible to include a wide range of additional capabilities and use these with reliable connections at long range, for example as an integrated services platform. Some of these additional capabilities may include: Seamless local communications during loss of WWAN backhaul; Network services such as DHCP, DNS, caching; IMS server for voice and video applications; Voice services; Internal support of voice services to WWAN; Attachment over LAN or PAN or direct connect; Group channel change capability for voice, video, or other service groupings; Store-and-forward server for data, voice, and video; Geographic Information System (GIS) server; Computer Aided Dispatch (CAD) server; Audio commands; Audio record and playback and store-and-forward; Security server; Interface to biometrics sensors; Core network services; Includes device management method (e.g., OMA, Motorola device management, SNMP, TR-069); Includes mass storage for database or store-and-forward applications; Includes an application operating system (e.g., Android, Windows, etc.); Multiple-SIM; just to name a few. Some additional applications and uses may include Enhanced inter-networking devices including: WLAN 802.11, PAN Bluetooth, others, Wired, Data, voice, and video support, Local sensors and control, Works with a plurality of connected devices, Includes GPIO/serial interface for control and monitor functions, Real-time clock with long term battery, With MIMO and diversity, Internal antenna and external antenna connection, Multiple band operation on WWAN and WLAN, Connects to a plurality of WWAN, User interface to set configuration parameters, Adaptive radiation levels and shape depending on SAR environment. Additionally, embedded location capability may include GPS, accelerometer, beacons, triangulation, 802.11, other location technologies, and combinations of any or all of the above. Further, additional features may include device security and pairing in order to: Integrate methods of physical verification of identity, RFID, NFC, Fingerprint, Key fob, Entry verification of identity such as UI or voice-based, Identity association with user, Remote monitoring and control of device configuration and operation through wired or wireless connection, Link level security (e.g., SSL, VPN), Physical anti-tamper and tamper detection methods including protection against SIM swapping. In addition, different form factors are contemplated, such as: Fixed vehicle, wall, or tabletop mounting; Portable wearable, belt, holster mount; Hybrid composed of portable device removable from fixed mounting solution; Vehicle mount with antenna, power, vehicle bus, controls, sensors tied in and removable unit converts to internal antenna control without additional direct wired vehicle connectivity; and Vehicle voice input over wired or wireless connection Some embodiments may include Internal alerts for: Remote alert control for user notification; Local control based upon one or more sensor triggers; Integral sensors to detect excessive heat or other environmental effect; External sensors to include body-worn, critical personal support equipment, and operator identity paired with a particular user device; and Ability for remote triggering of alert levels; to name a few. Further aspects of the disclosure may include a device for wireless inter-networking, the device comprising: a means for increasing the RF transmission power of a full-duplex wireless device that transmits and receives on a wireless wide area network (WWAN) with a base station using consumer-level integrated circuits by 1) connecting a RF power amplifier to the transmit signal from the WWAN modem transceiver to boost the total transmitted power, 2) providing a high power, bandwidth-limiting RF combining duplexer function that combines the transmit output signal of the high efficiency RF power amplifier with the received RF signal and connecting the combined RF output of this duplexer to a transmit/receive antenna for transmission to a base station, 3) providing an isolation filtering function to limit feedback of the high power transmit signal to a diversity receiver antenna, if applicable. According to one embodiment, the RF amplifier has a high efficiency power amplifier. According to one embodiment, the high efficiency RF power amplifier has fixed gain. According to one embodiment, the fixed gain high efficiency RF power amplifier has gain set high enough so that the amplifier stage in the modem transceiver is backed off to reduce its noise levels so that the combined out-of-band noise contribution of the staged amplifiers is reduced in order to meet regulatory requirements. According to one embodiment, the RF power amplifier has variable gain that is varied as part of the overall power control methods of the WWAN operation. According to one embodiment, multiple frequency channels may be transmitted, simultaneously or one at a time, from the modem/RF function and in which one or more of these channels is transmitted at higher power while other frequency channel transmissions are made without the additional RF power amplification. In this case, the high power transmission signals may be transmitted on an antenna separate from the antenna used for the non-high power transmission signal. According to one embodiment, the inter-networking device is a wireless cellular handset. According to one embodiment, the inter-networking device is a wireless computing device including tablets, computers, etc. According to one embodiment, the inter-networking device is a WWAN connection dongle. According to one embodiment, the inter-networking device is a wireless router. According to one embodiment, the inter-networking device may include a transmission power level measurement method that monitors the RF power at the output of RF power amplifier and provides this measurement information to the wireless modem function for calibration and power control purposes. According to one embodiment, the inter-networking device may include means for filtering the high power RF signals to prevent interference with other RF functions on the device including GPS, Wi-Fi, and Bluetooth signals. According to one embodiment, the inter-networking device may include a filtering function that reduces interference with other RF signals, including the received WWAN signals, is implemented using frequency rejection band stop filter circuits. According to one embodiment, the inter-networking device may include a filtering function that reduces interference with other RF signals, including the received WWAN signals, is implemented using frequency rejection antenna subsystem. According to one embodiment, the inter-networking device may support operation on a WWAN network that requires a subscriber identification module (SIM) According to one embodiment, the inter-networking device may support operation on multiple WWAN networks that requires more than one subscriber identification module (SIM) According to one embodiment, the inter-networking device may be a battery operated portable device, wherein the battery is rechargeable, and/or the battery is replaceable According to one embodiment, the inter-networking device may include means for increasing the RF transmission power from a commercially available modem/transceiver circuit module of a full-duplex portable wireless device that transmits and receives on a wireless wide area network (WWAN) with a base station by 1) connecting a high efficiency RF power amplifier to the transmit signal from the modem/transceiver module to boost the total transmitted power, 2) providing a high power, bandwidth-limiting RF combining duplexer function that combines the transmit output signal of the high efficiency RF power amplifier with the received RF signal and connecting the combined RF output of this duplexer to a transmit/receive antenna for transmission to a base station, 3) providing an isolation filtering function to limit feedback of the high power transmit signal to a diversity receiver antenna, if applicable. According to one embodiment, the inter-networking device may include a WWAN modem integrated on a module having ports for an external transmit, receive, and power monitor function enabling a higher power external amplifier separate from the conventional amplifiers used in cellular user equipment. Further the inter-networking device may include a duplexed or multiple duplexed ports for standard power transmissions output to the antenna subsystem in addition to the high power ports. The disclosure has been sufficiently described so that a person of ordinary skill in the art can reproduce and obtain the results mentioned in the present disclosure. However, any skilled person in the field of the art of the present disclosure may be able to make modifications not described in the present application. Notwithstanding, if these modifications require a structure or manufacturing process not described in the present disclosure, the modifications should be understood to be within the scope of the claimed | 102,513 |
11943014 | DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS The following describes the technical solutions in this application with reference to the accompanying drawings. The technical solutions in the embodiments of this application may be applied to various communications systems such as a global system for mobile communications (GSM), a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS) system, a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD) system, a universal mobile telecommunications system (UMTS), a worldwide interoperability for microwave access (WiMAX) communications system, a fifth generation (5G) system or a new radio (NR) system, vehicle-to-X (V2X), long term evolution-vehicle (LTE-V), an Internet of vehicles, machine type communication (MTC), an Internet of things (IoT), long term evolution-machine (LTE-M), and machine to machine (M2M), where V2X may include vehicle to network (V2N), vehicle to vehicle (V2V), vehicle to infrastructure (V2I), vehicle to pedestrian (V2P), or the like. For ease of understanding the embodiments of this application, a communications system shown inFIG.1is first used as an example to describe in detail a communications system to which the embodiments of this application are applicable.FIG.1is a schematic diagram of a communications system100to which a coefficient indication method for constructing a precoding matrix according to an embodiment of this application is applicable. As shown inFIG.1, the communications system100may include at least one network device, for example, a network device110shown inFIG.1. The communications system100may further include at least one terminal device, for example, a terminal device120shown inFIG.1. The network device110may communicate with the terminal device120through a radio link. A plurality of antennas may be configured for each communications device such as the network device110or the terminal device120. For each communications device in the communications system100, the plurality of configured antennas may include at least one transmit antenna configured to send a signal and at least one receive antenna configured to receive a signal. Therefore, the communications devices in the communications system100, for example, the network device110and the terminal device120, may communicate with each other by using a multi-antenna technology. It should be understood that, the network device in the communications system may be any device that has a wireless transceiver function. The network device includes but is not limited to an evolved NodeB (eNB), a radio network controller (RNC), a NodeB (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (for example, a home evolved NodeB or a home NodeB, HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (Wi-Fi) system, a wireless relay node, a wireless backhaul node, a transmission point (TP), a transmission reception point (TRP), or the like, or may be a gNB or a transmission point (TRP or TP) in a 5G system, for example, an NR system, or one antenna panel or a group of antenna panels (including a plurality of antenna panels) of a base station in a 5G system, or may be a network node, for example, a baseband unit (BBU) or a distributed unit (DU), that constitutes a gNB or a transmission point. In some deployments, the gNB may include a centralized unit (CU) and the DU. The gNB may further include an active antenna unit (AAU). The CU implements some functions of the gNB, and the DU implements some functions of the gNB. For example, the CU is responsible for processing a non-real-time protocol and a non-real-time service, and implements functions of a radio resource control (RRC) layer and a packet data convergence protocol (PDCP) layer. The DU is responsible for processing a physical layer protocol and a real-time service, and implements functions of a radio link control (RLC) layer, a media access control (MAC) layer, and a physical (PHY) layer. The AAU implements some physical layer processing functions, radio frequency processing, and a function related to an active antenna. Information at the RRC layer is eventually converted into information at the PHY layer, or is converted from information at the PHY layer. Therefore, in this architecture, higher layer signaling such as RRC layer signaling may also be considered as being sent by the DU or sent by the DU and the AAU. It may be understood that the network device may be a device including one or more of a CU node, a DU node, and an AAU node. In addition, the CU may be classified into a network device in an access network (RAN), or may be classified into a network device in a core network (CN). This is not limited in this application. It should be further understood that the terminal device in the wireless communications system may also be referred to as user equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communications device, a user agent, or a user apparatus. The terminal device in the embodiments of this application may be a mobile phone, a tablet computer (pad), a computer having a wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in telemedicine (remote medical), a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a mobile terminal disposed in a vehicle, or the like. An application scenario is not limited in the embodiments of this application. It should be further understood thatFIG.1is merely a simplified schematic diagram used as an example for ease of understanding. The communications system100may further include another network device or another terminal device, which is not shown inFIG.1. For ease of understanding the embodiments of this application, the following briefly describes a processing process of a downlink signal at the physical layer before the downlink signal is sent. It should be understood that, the processing process of the downlink signal described below may be performed by the network device, or may be performed by a chip disposed in the network device. For ease of description, these devices are collectively referred to as network devices below. The network device may process a codeword on a physical channel. The codeword may be a coded bit obtained through coding (for example, including channel coding). The codeword is scrambled (scrambling) to generate a scrambled bit. Modulation mapping is performed on the scrambled bit, to obtain a modulated symbol. The modulated symbol is mapped to a plurality of layers through layer mapping. The layer is also referred to as a transport layer. A modulated symbol obtained through the layer mapping is precoded, to obtain a precoded signal. The precoded signal is mapped to a plurality of resource elements (REs) through RE mapping. These REs are then transmitted through an antenna port after orthogonal multiplexing (OFDM) modulation is performed on the REs. It should be understood that, the processing process of the downlink signal described above is merely an example for description, and this shall not constitute any limitation on this application. For a specific processing process of the downlink signal, refer to the conventional technology. For brevity, detailed descriptions of the specific process are omitted herein. For ease of understanding the embodiments of this application, the following first briefly describes terms used in the embodiments of this application. 1. Precoding technology: The precoding technology is a signal processing manner in a physical layer processing process. For example, when a channel state is known, the network device may process a to-be-sent signal by using a precoding matrix that adapts to the channel state, thereby reducing complexity of eliminating inter-channel impact by a receiving device. Therefore, after the to-be-sent signal is precoded, quality (for example, a signal to interference plus noise ratio (SINR)) of a received signal can be improved. A sending device and a plurality of receiving devices can implement transmission on a same time-frequency resource by using the precoding technology. That is, multi-user multiple-input multiple-output (MU-MIMO) is implemented. It should be understood that related descriptions of the precoding technology in this specification are merely examples for ease of understanding, and are not intended to limit the protection scope of the embodiments of this application. In a specific implementation process, the sending device may alternatively perform precoding in another manner. For example, when channel information (for example, but not limited to a channel matrix) cannot be learned of, precoding is performed by using a preset precoding matrix or through weighted processing. For brevity, specific content of the precoding manner is not further described in this specification. 2. Channel reciprocity: In a time division duplex (TDD) mode, on uplink and downlink channels, signals are transmitted on a same frequency domain resource and on different time domain resources. Within relatively short time (for example, channel propagation coherence time), it may be considered that signals on the uplink and downlink channels experience same channel fading. This is reciprocity between the uplink and downlink channels. Based on the reciprocity between the uplink and downlink channels, the network device may measure the uplink channel based on an uplink reference signal, for example, a sounding reference signal (SRS). In addition, the downlink channel may be estimated based on the uplink channel, so that a precoding matrix used for downlink transmission can be determined. However, in a frequency division duplex (FDD) mode, because a frequency band interval between the uplink and downlink channels is far greater than a coherence bandwidth, and the uplink and downlink channels do not have complete reciprocity, the precoding matrix that is used for downlink transmission and that is determined by using the uplink channel may not adapt to the downlink channel. However, in the FDD mode, the uplink and downlink channels still have partial reciprocity, for example, angle reciprocity and delay reciprocity. Therefore, an angle and a delay may also be referred to as reciprocity parameters. When a signal is transmitted through a radio channel, the signal may arrive at a receive antenna through a plurality of paths from a transmit antenna. A multipath delay spread causes frequency selective fading, that is, a change of a channel in frequency domain. A delay is transmission time of a radio signal on different transmission paths, is determined by a distance and a speed, and is irrelevant to a frequency domain of the radio signal. Therefore, delays on the uplink and downlink channels in the FDD mode may be considered to be the same, in other words, reciprocal. In addition, an angle may be an angle of arrival (AOA) at which a signal arrives at a receive antenna through a radio channel, or may be an angle of departure (AOD) at which a signal is transmitted by using a transmit antenna. In the embodiments of this application, the angle may be an angle of arrival at which an uplink signal arrives at the network device, or may be an angle of departure at which the network device transmits a downlink signal. Because of reciprocity of transmission paths of the uplink and downlink channels at different frequencies, an angle of arrival of an uplink reference signal and an angle of departure of a downlink reference signal may be considered to be reciprocal. Therefore, it may be considered that the delays and the angles on the uplink and downlink channels in the FDD mode have reciprocity. In the embodiments of this application, each angle may be represented by using one angle vector, and each delay may be represented by using one delay vector. Therefore, in the embodiments of this application, one angle vector may represent one angle, and one delay vector may represent one delay. 3. Reference signal (RS) and precoded reference signal: The reference signal may also be referred to as a pilot, a reference sequence, or the like. In the embodiments of this application, the reference signal may be a reference signal used for channel measurement. For example, the reference signal may be a channel state information reference signal (CSI-RS) or a sounding reference signal (SRS). It should be understood that the reference signals listed above are merely examples, and this shall not constitute any limitation on this application. This application does not exclude a possibility that another reference signal is defined in a future protocol to implement a same or similar function. The precoded reference signal may be a reference signal obtained by precoding the reference signal. In the embodiments of this application, the precoding may specifically include beamforming and/or phase rotation. Beamforming may be implemented, for example, by precoding a reference signal based on one or more angle vectors. Phase rotation may be implemented, for example, by precoding a reference signal based on one or more delay vectors. In the embodiments of this application, for ease of distinguishing and description, a reference signal obtained through precoding, for example, beamforming and/or phase rotation, is referred to as a precoded reference signal; and a reference signal that is not precoded is referred to as a reference signal for short. In the embodiments of this application, precoding the downlink reference signal based on the one or more angle vectors may also be referred to as loading the one or more angle vectors to the downlink reference signal. Precoding the downlink reference signal based on the one or more delay vectors may also be referred to as loading the one or more delay vectors to the downlink reference signal. 4. Port: The port is also referred to as an antenna port. The port may be understood as a virtual antenna identified by a receiving device. Optionally, the port may be a transmit antenna port. For example, a reference signal of each port may be a reference signal that is not precoded, or may be a precoded reference signal obtained by precoding a reference signal based on one delay vector. A quantity of ports may be a quantity of transmit antenna ports or a quantity of transmit antennas. The transmit antenna port may be an actual independent transceiver unit (TxRU). Optionally, the port is a reference signal port after beamforming. For example, a reference signal of each port may be a precoded reference signal obtained by precoding a reference signal based on one angle vector, or may be a precoded reference signal obtained by precoding a reference signal based on one angle vector and one delay vector. A quantity of ports may be a quantity of reference signal ports or a quantity of angle vectors. It may be understood that, a quantity of reference signal ports after beamforming may be less than a quantity of transmit antenna ports. A signal of each port may be transmitted by using one or more RBs. In different embodiments shown below, the port sometimes refers to a transmit antenna port, and sometimes refers to a reference signal port. A specific meaning expressed by the port may be determined based on a specific embodiment. 5. Angle vector: The angle vector may be understood as a precoding vector used to perform beamforming on a reference signal. A transmitted reference signal may have specific spatial directivity through beamforming. Therefore, a process of precoding a reference signal based on an angle vector may also be considered as a space domain precoding process. A quantity of ports of a precoded reference signal obtained by precoding a reference signal based on one or more angle vectors is the same as a quantity of the angle vectors. When the quantity of the angle vectors is less than a quantity of transmit antennas, dimension reduction of antenna ports can be implemented through space domain precoding, thereby reducing pilot overheads. A length of the angle vector may be T, T is a quantity of transmit antenna ports in one polarization direction, and T≥1 and T is an integer. Optionally, the angle vector is obtained from a discrete Fourier transform (DFT) matrix, for example, vi1,i2[ui2ej2πi1O1I1ui2…ej2πi1(I1-1)O1I1ui2]Tui2={[1ej2πi2O2I2…ej2πi2(I2-1)O2I2]I2>11I2=1. I1is a quantity of antenna ports in a same polarization direction that are included in each column (or row) in an antenna array, and I2is a quantity of antenna ports in a same polarization direction that are included in each row (or column) in the antenna array. In the embodiments, T=I1×I2. O1and O2are oversampling factors. i1and i2satisfy that 0≤i1≤(O1×I1−1) and 0≤i2≤(O2×I2−1). Optionally, the angle vector is a steering vector of a uniform linear array (ULA), for example, a(θk)=[1ej2πλcosθkd⋮ej2πλcosθk(T-1)d]. θkis an angle, and k=1, 2, . . . , or K. K indicates the quantity of the angle vectors, λ is a wavelength, and d is an antenna spacing. The steering vector may indicate a phase difference between responses of angles of arrival of a path on different antennas. The steering vector a(θk) and a vector Vi1,i2, in the DFT matrix satisfy that cosθkd=i1O1I1. Optionally, the angle vector is a steering vector of a uniform plane array (UPA). The steering vector may be, for example, a steering vector that includes information about a horizontal angle and a pitch angle, for example, a(θk,φk)=[ej2πλukρ1ej2πλukρ2⋮ej2πλukρT]. θkis the horizontal angle; θkis the pitch angle; ρtis three-dimensional coordinates of a tthtransmit antenna port, and t=1, 2, . . . , or T; and ukis a unit spherical basis vector corresponding to a kthangle: uk=[sin φkcos φksin φksin φkcos φk]. For ease of description below, the angle vector is denoted as a(θk). It is assumed that the transmit antenna is a single-polarized antenna; the quantity of transmit antennas is T; and a quantity of frequency domain units is N, N≥1, and N is an integer. In this case, for a receive antenna, a channel may be a matrix whose dimensions are N×T. If space domain precoding is performed on a reference signal based on one angle vector, the angle vector may be loaded to the reference signal. Because dimensions of the angle vector are T×1, for a receive antenna, dimensions of a precoded channel may be N×1. That is, a received precoded reference signal may be represented as a matrix whose dimensions are N×1. Because the reference signal to which the angle vector is loaded may be transmitted to the terminal device through a downlink channel, a channel measured by the terminal device based on the received precoded reference signal is equivalent to a channel to which the angle vector is loaded. For example, a downlink channel V to which the angle vector a(θk) is loaded may be represented as Va(θk). Therefore, if space domain precoding is performed on a reference signal based on one angle vector, for each frequency domain unit on each receive antenna, dimensions of a channel estimated based on a precoded reference signal may be 1×1. It should be understood that, the angle vector is a form that is proposed in this application and that is used to represent an angle. The angle vector is named merely for ease of distinguishing from the delay vector described below, and this shall not constitute any limitation on this application. This application does not exclude a possibility that another name is defined in a future protocol to represent a same or similar meaning. It should be further understood that, merely for ease of understanding, the foregoing shows a possible implementation of precoding the reference signal based on the angle vector, but this shall not constitute any limitation on this application. This application does not exclude a possibility of precoding the reference signal based on the angle vector in another manner. A process in which the network device performs space domain precoding on the reference signal is implemented inside a device. This is not limited in this application. 6. Frequency domain unit: The frequency domain unit is a unit of a frequency domain resource, and may represent different frequency domain resource granularities. The frequency domain unit may include, for example, but not limited to, a subband, a resource block (RB), a resource block group (RBG), and a precoding resource block group (PRG). In the embodiments of this application, the network device may determine, based on a feedback of the terminal device, a precoding matrix corresponding to each frequency domain unit. In embodiments shown below, for ease of understanding and description, an RB is used as an example of a frequency domain unit to describe a channel measurement method provided in the embodiments of this application. For example, when an RB is used as an example of a frequency domain unit, it may be considered that each frequency domain unit includes only one RB used to carry a reference signal. Actually, each frequency domain unit may include one or more RBs used to carry a reference signal. When each frequency domain unit includes a plurality of RBs used to carry a reference signal, the network device may load a delay vector to the plurality of RBs used to carry a reference signal in each frequency domain unit. For brevity, in the following, it is assumed that each frequency domain unit includes only one RB used to carry a reference signal unless otherwise specified. 7. Delay vector: The delay vector is a vector that is proposed in this application and that may be used to indicate a change rule of a channel in frequency domain. As described above, a multipath delay causes frequency selective fading. It can be learned from Fourier transform that a time delay of a signal in time domain may be equivalent to a phase gradient in frequency domain. For example, for a signal g(t), the signal may be transformed in frequency domain through Fourier transform: F(g(t))=∫−∞+∞g(t)ejωdt; and for a signal g(t−t0), the signal may be transformed in frequency domain through Fourier transform: F(g(t−t0))=∫−∞+∞g(t)ejωdt=ejω0F(g(t)). ω is a frequency variable, different frequencies correspond to different phase rotations, and t and t−t0indicate delays. A signal of the two delays may be represented as x(t=g(t)+g(t−t0), and therefore, a function X(ω)=g(ω)(1+ejω0) of the frequency variable may be obtained. Assuming that g(ω)≡1, X(ω)=1+ejω0may be obtained. Therefore, signals of two different delays cause frequency selective fading. Because a phase change of a channel in each frequency domain unit is related to a delay, a change rule of the phase of the channel in each frequency domain unit may be represented by using a delay vector. In other words, the delay vector may be used to represent a delay characteristic of the channel. That the reference signal is precoded based on the delay vector may essentially mean that phase rotation is performed on each frequency domain unit in frequency domain based on an element in the delay vector, to pre-compensate, by using the precoded reference signal, a frequency selective characteristic caused by the multipath delay. Therefore, a process of precoding the reference signal based on the delay vector may be considered as a frequency domain precoding process. Precoding a reference signal based on different delay vectors is equivalent to performing phase rotation on each frequency domain unit of a channel based on the different delay vectors. In addition, phase rotation angles of a same frequency domain unit may be different. To distinguish between different delays, the network device may precode a reference signal based on each of L delay vectors. Optionally, a length of the delay vector is N, N is a quantity of frequency domain units that are in a frequency domain bandwidth occupied by a CSI measurement resource and that are used to carry a reference signal (for example, the precoded reference signal in the embodiments), N≥1, and N is an integer. Optionally, an lthdelay vector in the L delay vectors may be represented as b(τl), and b(τl)=[e-j2πf1τle-j2πf2τl⋮e-j2πfNτl].l=1,2,…,orL; L may indicate a quantity of delay vectors; and f1, f2, . . . , and fNrepresent carrier frequencies of the first, the second, . . . , and an Nthfrequency domain unit, respectively. Optionally, the delay vector is obtained from a DFT matrix, for example, uk=[1ej2πkOfN…ej2πk(N-1)OfN]T. Each vector in the DFT matrix may be referred to as a DFT vector. Ofis an oversampling factor, and Of≥1; and k is an index of the DFT vector, and satisfies that 0≤k≤Of×N−1 or 1−Of×N≤k≤0 For example, when k<0, b(τl) and the vector ukin the DFT matrix may satisfy: b(τl)=ukβlandΔfτl=kOfN, where βl=e−j2πflτl, Δf=fn−fn+1, and 1≤n≤N−1. For ease of description below, the delay vector is denoted as b(τl). If one frequency domain unit is one RB, or one frequency domain unit includes one RB used to carry a reference signal, the delay vector may be loaded to N RBs used to carry a reference signal. For example, it is assumed that N=4, and a delay vector corresponding to a port is b(τl)=[e-j2πf1τle-j2πf2τle-j2πf3τle-j2πf4τl]. The delay vector may be loaded to four RBs used to carry a reference signal. It should be understood that, the four RBs may be four consecutive RBs, that is, each RB is one frequency domain unit. Alternatively, the four RBs may be four RBs discretely distributed in a frequency domain resource, that is, each RB is an RB that is in a frequency domain unit to which each RB belongs and that is used to carry a reference signal. A relationship between the four RBs is not limited in this application. It is assumed that the four RBs are an RB #1, an RB #2, an RB #3, and an RB #4 respectively. If a reference signal is precoded based on the delay vector b(τl), a precoded reference signal carried on the RB #1 may be obtained at least by precoding the reference signal based on an element e−j2πflτl; a precoded reference signal carried on the RB #2 may be obtained at least by precoding the reference signal based on an element e−j2πflτl; a precoded reference signal carried on the RB #3 may be obtained at least by precoding the reference signal based on an element e−j2πflτl; and a precoded reference signal carried on the RB #4 may be obtained at least by precoding the reference signal based on an element e−j2πflτl. The term “at least” is used because the reference signal of the port may be precoded based only on a delay vector, or may be precoded based on a delay vector and an angle vector. For brevity, descriptions of a same or similar case are omitted below. If one frequency domain unit is a plurality of RBs, or one frequency domain unit includes a plurality of RBs used to carry a reference signal, the delay vector may be loaded to the plurality of RBs used to carry a reference signal. For example, it is assumed that each frequency domain unit includes two RBs used to carry a reference signal, N=4, and a delay vector corresponding to a port is b(τl)=[e-j2πf1τle-j2πf2τle-j2πf3τle-j2πf4τl]. The delay vector may be loaded to eight RBs used to carry a reference signal. Two RBs in a same frequency domain unit may correspond to a same element. It is assumed that the eight RBs in the four frequency domain units are respectively an RB #1 and an RB #2 that belong to a frequency domain unit #1, an RB #3 and an RB #4 that belong to a frequency domain unit #2, an RB #5 and an RB #6 that belong to a frequency domain unit #3, and an RB #7 and an RB #8 that belong to a frequency domain unit #4. If a reference signal is precoded based on the delay vector b(τl), precoded reference signals carried on the RB #1 and the RB #2 may be obtained at least by precoding the reference signal based on an element e−j2πflτl; precoded reference signals carried on the RB #3 and the RB #4 may be obtained at least by precoding the reference signal based on an element e−j2πflτl; precoded reference signals carried on the RB #5 and the RB #6 may be obtained at least by precoding the reference signal based on an element e−j2πflτl; and precoded reference signals carried on the RB #7 and the RB #8 may be obtained at least by precoding the reference signal based on an element e−j2πflτl. The reference signals obtained after the frequency domain precoding correspond to a same port. Certainly, each frequency domain unit may alternatively include an RB used to carry reference signals of a plurality of ports. For example, when each frequency domain unit includes two RBs used to carry a reference signal, the two RBs may correspond to a same port. As described above, signals are obtained by performing precoding based on a same delay vector. Alternatively, the two RBs may correspond to two ports. For example, signals are obtained by performing precoding based on two different delay vectors. This is not limited in this application. It should be understood that, merely for ease of understanding frequency domain precoding, the foregoing shows a correspondence between the elements in the delay vector and the RBs in each frequency domain unit. However, this is merely an example of a possible implementation of precoding a reference signal based on a delay vector, and this shall not constitute any limitation on this application. The correspondence between the elements in the delay vector and the RBs in each frequency domain unit shall not constitute any limitation on this application. In addition, this application does not exclude a possibility of precoding the reference signal based on the delay vector in another manner either. A process in which the network device performs frequency domain precoding on the reference signal is implemented inside the device. This is not limited in this application. The frequency domain bandwidth occupied by the CSI measurement resource may be understood as a bandwidth used to transmit a reference signal, and the reference signal may be a reference signal used for channel measurement, for example, a CSI-RS. Signaling used to indicate the frequency domain bandwidth occupied by the CSI measurement resource may be, for example, a CSI-bandwidth occupation range (CSI-Frequency Occupation). The frequency domain bandwidth occupied by the CSI measurement resource may also be referred to as a pilot transmission bandwidth or a measurement bandwidth. For ease of description below, the frequency domain bandwidth occupied by the CSI measurement resource is referred to as the measurement bandwidth for short. It should be understood that, the length N of the delay vector is merely a possible design, and this shall not constitute any limitation on this application. Lengths of different delay vectors are defined below with reference to different embodiments. Detailed descriptions thereof are omitted herein. It is assumed that the transmit antenna is a single-polarized antenna, the quantity of transmit antennas is T, and the quantity of frequency domain units is N. In this case, for a receive antenna, a downlink channel may be represented as a matrix whose dimensions are N×T. If frequency domain precoding is performed on a reference signal based on a delay vector, N elements in the delay vector may be respectively loaded to reference signals carried on a plurality of RBs in the N frequency domain units. Because the reference signal to which the delay vector is loaded may be transmitted to the terminal device through the downlink channel, a channel measured by the terminal device based on the received precoded reference signal is equivalent to a channel to which the delay vector is loaded. For example, a channel V(n)of an nthRB to which an nthelement in the delay vector is loaded may be represented as V(n)e−j2πflτl. It should be noted that, frequency domain precoding may be performed on the reference signal based on the delay vector before resource mapping, or after resource mapping. This is not limited in this application. It should be understood that, the delay vector is a form that is proposed in this application and that is used to represent a delay. The delay vector is named merely for ease of distinguishing from the angle, and this shall not constitute any limitation on this application. This application does not exclude a possibility that another name is defined in a future protocol to represent a same or similar meaning. 8. Angle-delay pair: The angle-delay pair may be a combination of one angle vector and one delay vector. Each angle-delay pair may include one angle vector and one delay vector. Each angle-delay pair may be uniquely determined by using one angle vector and one delay vector. It should be understood that, the angle-delay pair may be understood as a representation form of a spatial-frequency basic unit determined by using one angle vector and one delay vector, but the angle-delay pair may not necessarily be a unique representation form. For example, the angle-delay pair may alternatively be represented as a spatial-frequency component matrix or a spatial-frequency component vector described below. 9. Spatial-frequency component matrix: One spatial-frequency component matrix may be determined by using one angle-delay pair. In other words, a spatial-frequency component matrix may be uniquely determined by using one angle vector and one delay vector. A spatial-frequency component matrix and an angle-delay pair may be mutually converted. One spatial-frequency component matrix may be determined, for example, by a product of one angle vector and a conjugate transpose of one delay vector, for example, a(θk)×b(τl)H, and have dimensions of T×N. It should be understood that, the spatial-frequency component matrix may be understood as another representation form of a spatial-frequency basic unit determined by using one angle vector and one delay vector. For example, the spatial-frequency basic unit may alternatively be represented as a spatial-frequency component vector. For example, the spatial-frequency component vector is determined by using a Kronecker product of one angle vector and one delay vector. It should be further understood that, a specific form of the spatial-frequency basic unit is not limited in this application. Various possible forms determined by a person skilled in the art based on a same concept by using one angle vector and one delay vector shall all fall within the protection scope of this application. In addition, if definitions of the angle vector and the delay vector are different from those listed above, an operation relationship among the spatial-frequency component matrix, the angle vector, and the delay vector, and an operation relationship among the spatial-frequency component vector, the angle vector, and the delay vector may also be different. The operation relationship among the spatial-frequency component matrix, the angle vector, and the delay vector, and the operation relationship among the spatial-frequency component vector, the angle vector, and the delay vector are not limited in this application. 10. Spatial-frequency matrix: In the embodiments of this application, the spatial-frequency matrix is an intermediate quantity used to determine a precoding matrix. For each frequency domain unit, the precoding matrix may usually be a matrix whose dimensions are T×Z. Z represents a quantity of transport layers, and Z is an integer greater than or equal to 1. In the embodiments of this application, the spatial-frequency matrix may be determined based on each receive antenna, or may be determined based on each transport layer. If the spatial-frequency matrix is determined based on a receive antenna, the spatial-frequency matrix may be referred to as a spatial-frequency matrix corresponding to the receive antenna. The spatial-frequency matrix corresponding to the receive antenna may be used to construct a downlink channel matrix of each frequency domain unit, to determine a precoding matrix corresponding to each frequency domain unit. For example, a channel matrix corresponding to a frequency domain unit may be a conjugate transpose of a matrix constructed by using column vectors that correspond to a same frequency domain unit and that are in spatial-frequency matrices corresponding to receive antennas. For example, an nthcolumn vector in the spatial-frequency matrix corresponding to each receive antenna is extracted, and a matrix whose dimensions are T×R may be obtained by arranging the column vectors from left to right in a sequence of the receive antennas. R indicates a quantity of the receive antennas, and R is an integer greater than or equal to 1. After a conjugate transpose of the matrix is obtained, a channel matrix V(n)of an nthfrequency domain unit may be obtained. A relationship between the channel matrix and the spatial-frequency matrix is described in detail below, and detailed descriptions of the relationship between the channel matrix and the spatial-frequency matrix are omitted herein. If the spatial-frequency matrix is determined based on a transport layer, the spatial-frequency matrix may be referred to as a spatial-frequency matrix corresponding to the transport layer. The spatial-frequency matrix corresponding to the transport layer may be directly used to determine a precoding matrix corresponding to each frequency domain unit. For example, a precoding matrix corresponding to a frequency domain unit may be constructed by using column vectors that correspond to a same frequency domain unit and that are in spatial-frequency matrices corresponding to transport layers. For example, an nthcolumn vector in the spatial-frequency matrix corresponding to each transport layer is extracted, and a matrix whose dimensions are T×Z may be obtained by arranging the column vectors from left to right in a sequence of the transport layers. Z indicates a quantity of the transport layers, and Z is an integer greater than or equal to 1. The matrix may be used as a precoding matrix W(n)of an nthfrequency domain unit. A specific process of determining the precoding matrix based on the spatial-frequency matrix is described in detail in the following embodiments, and detailed descriptions of the specific process are omitted herein. It should be noted that a precoding matrix determined according to a channel measurement method provided in the embodiments of this application may be a precoding matrix directly used for downlink data transmission. Alternatively, some beamforming methods, for example, including zero forcing (ZF), a minimum mean-squared error (MMSE), and a maximum signal-to-leakage-and-noise ratio (SLNR), may be used, to obtain a precoding matrix finally used for downlink data transmission. This is not limited in this application. All precoding matrices below may be precoding matrices determined based on the channel measurement method provided in this application. In the embodiments of this application, the spatial-frequency matrix may be determined by using one or more angle-delay pairs. For example, the spatial-frequency matrix may be a weighted sum of one or more spatial-frequency component matrices. The spatial-frequency matrix may alternatively be converted into a form of a spatial-frequency vector, and the spatial-frequency vector may alternatively be a weighted sum of one or more spatial-frequency component vectors. A type II codebook feedback manner is defined in the NR protocol TS38.214. An example of a feedback in the type II codebook feedback manner when a rank is 1 is shown below: W=W1W2=[a0v0a1v1a2v2a3v3a4v0a5v1a6v2a7v3][c0c1c2c3c4c5c6c7]T=[a0c0v0+a1c1v1+a2c2v2+a3c3v3a4c4v0+a5c5v1+a6c6v2+a7c7v3]. W represents a to-be-fed-back precoding matrix in two polarization directions in one subband at one transport layer. W1may be fed back by using a wideband, and W2may be fed back by using a subband. υ0to υ3are beam vectors included in W1, and the plurality of beam vectors may be indicated by using, for example, an index of a combination of the plurality of beam vectors. In the precoding matrix shown above, beam vectors in the two polarization directions are the same, and the beam vectors υ0to υ3are all used. a0to a7are wideband amplitude coefficients included in W1, and may be indicated by using quantized values of the wideband amplitude coefficients. c0to c7are subband coefficients included in W2, and each subband coefficient may include a subband amplitude coefficient and a subband phase coefficient. For example, c0to c7may include subband amplitude coefficients α0to α7and subband phase coefficients φ0to φ7, respectively, and may be indicated by using quantized values of the subband amplitude coefficients α0to α7and quantized values of the subband phase coefficients φ0to φ7, respectively. Because the terminal device feeds back the amplitude coefficient and the phase coefficient based on each subband, relatively high feedback overheads are caused. Therefore, a feedback manner that is based on continuity in frequency domain and frequency selective fading caused by a multipath delay and in which a delay vector is used to describe a frequency domain change rule is proposed. The delay vector may also be understood as a vector used to indicate a delay characteristic of a channel. The spatial-frequency matrix described above is an intermediate quantity that is proposed based on the continuity in frequency domain and that is used to construct a precoding matrix. A spatial-frequency matrix H may satisfy: H=SCFH. S represents a matrix constructed by using one or more (for example, K) angle vectors, for example, S=[a(θ1) a(θ2) . . . a(θK)]; F represents a matrix constructed by using one or more (for example, L) delay vectors, for example, F=[b(τ1) b(τ2) . . . b(τL)]; and C represents a coefficient matrix constructed by using a weighting coefficient corresponding to each of the K angle vectors and each of the L delay vectors. In the FDD mode, because of reciprocity between delays and angles on uplink and downlink channels, a spatial-frequency matrix HULobtained through uplink channel measurement may be expressed as HUL=SCULFH, and a spatial-frequency matrix HDLobtained through downlink channel measurement may be expressed as HDL=SCDLFH. Therefore, in the embodiments of this application, a coefficient matrix CDLcorresponding to the downlink channel is determined and fed back through downlink channel measurement, to determine a precoding matrix that adapts to the downlink channel. The foregoing formula HDL=SCDLFHis further transformed to obtain SHHDL=CDLFH, and (HDLHS)H=CDLFHis further obtained and is further transformed to obtain a coefficient matrix CDL=(HDLHS)HF. HDLHis a spatial-frequency matrix determined by using an actual channel, and HDLHS is an actual channel on which space domain precoding is performed. Each element in the coefficient matrix CDLmay be determined by multiplying one row in (HDLHS)Hby one column in F. In other words, each element in the coefficient matrix CDLmay be obtained by multiplying one row in a conjugate transpose (HDLHS)Hof the actual channel HDLHS by one column in F, or multiplying a conjugate transpose of one column in the actual channel HDLHS by one column in F. Therefore, in the embodiments of this application, the spatial-frequency matrix HDLdetermined based on the weighting coefficient of each angle-delay pair fed back by the terminal device may be obtained by using the conjugate transpose of the actual channel. In other words, the spatial-frequency matrix in the embodiments of this application may alternatively be obtained by a conjugate transpose (namely, VH) of the actual channel V. From another perspective, in the embodiments of this application, it is defined that the spatial-frequency component matrix is determined by a(θk)×b(τl)H. Therefore, it may be determined that dimensions of the spatial-frequency matrix HDLare a quantity of transmit antennas×a quantity of frequency domain units, for example, dimensions of a spatial-frequency matrix corresponding to the downlink channel are T×N. In the following embodiments, unless otherwise specified, the spatial-frequency matrix is the matrix HDLwhose dimensions are T×N described above. However, this is not necessarily a spatial-frequency matrix determined by using an actual channel. Generally, dimensions of a channel matrix are defined as a quantity of receive antennas×a quantity of transmit antennas. For example, dimensions of the downlink channel are R×T. Dimensions of the spatial-frequency matrix determined by using the channel matrix are N×T, which are exactly opposite to the dimensions T×N of the foregoing spatial-frequency matrix HDL. Therefore, in the embodiments of this application, the actual channel may be a conjugate transpose of a channel matrix determined by using the foregoing spatial-frequency matrix HDL. A downlink channel matrix determined by using the spatial-frequency matrix HDLmay be a conjugate transpose of the actual channel. Further, a precoding matrix may be determined by using the spatial-frequency matrix HDL. The precoding matrix of the nthfrequency domain unit may be constructed by the nthcolumn vector in the spatial-frequency matrix corresponding to each transport layer. For example, SVD is performed on the channel matrix. A conjugate transpose of a precoding matrix may be obtained by performing SVD on a channel matrix V. However, if SVD is performed on a conjugate transpose of the channel matrix, that is, SVD is performed on VH, the precoding matrix may be exactly obtained. Therefore, in the embodiments of this application, the spatial-frequency matrix HDLdetermined by using the conjugate transpose of the actual channel may be used to directly determine the precoding matrix corresponding to each frequency domain unit. A detailed process of determining the channel matrix and the precoding matrix by using the spatial-frequency matrix HDLis described in detail in the following embodiments, and detailed descriptions of the specific process are omitted herein. It should be understood that, a relationship between the actual channel and the spatial-frequency matrix HDLis not fixed. Different definitions of the spatial-frequency matrix and the spatial-frequency component matrix may change the relationship between the actual channel and the spatial-frequency matrix HDL. For example, the spatial-frequency matrix HDLmay be obtained based on the conjugate transpose of the actual channel, or may be obtained based on a transpose of the actual channel. When the spatial-frequency matrix and the spatial-frequency component matrix are defined differently, operations performed by the network device when the delay and the angle are loaded are also different, and operations performed by the terminal device when the terminal device performs channel measurement and provides a feedback correspondingly change. However, these are only implementation behaviors of the terminal device and the network device, and this shall not constitute any limitation on this application. In the embodiments of this application, merely for ease of understanding, a case in which the spatial-frequency matrix is obtained based on the conjugate transpose of the actual channel is shown. The definition of the channel matrix, the dimensions and the definition of the spatial-frequency matrix, and a transformation relationship between the channel matrix and the spatial-frequency matrix are not limited in this application. Similarly, a transformation relationship between the spatial-frequency matrix and the precoding matrix is not limited in this application either. 11. Antenna-delay pair: The antenna-delay pair may be a combination of one transmit antenna port and one delay vector. Each antenna-delay pair may include one transmit antenna port and one delay vector. Transmit antenna ports and/or delay vectors included in any two antenna-delay pairs are different. In other words, each antenna-delay pair may be uniquely determined by using one transmit antenna port and one delay vector. It should be understood that, the antenna-delay pair may be understood as a representation form of a spatial-frequency basic unit determined by using one transmit antenna port and one delay vector, but is not necessarily a unique representation form. A representation form of a combination of a transmit antenna port and a delay vector is not limited in this application. In addition, for ease of understanding the embodiments of this application, the following descriptions are provided. First, for ease of understanding, the following briefly describes main parameters in this application. P: P is a quantity of angle-delay pairs used by the network device to precode the reference signal, that is, a quantity of ports of a precoded reference signal sent by the network device by using a transmit antenna in one polarization direction, and P is an integer greater than 1. Q: Q is a quantity of some ports selected by the terminal device from the P ports. In correspondence to P, the Q ports are some ports determined by the terminal device from the P ports based on a precoded reference signal sent by a transmit antenna in one polarization direction. P>Q≥1, and Q is an integer. N: N is a quantity of frequency domain units, and N is an integer greater than or equal to 1. T: T is a quantity of transmit antenna ports in a polarization direction, and T is an integer greater than or equal to 1. K: K is a quantity of angle vectors, and K is an integer greater than or equal to 1. L: L is a quantity of delay vectors, and L is an integer greater than or equal to 1. R: R is a quantity of receive antennas, and R is an integer greater than 1. Z: Z is a quantity of transport layers, and Z is an integer greater than or equal to 1. J: J is a quantity of polarization directions of a transmit antenna, and J is an integer greater than 1. Second, in the embodiments of this application, for ease of description, when numbering is involved, numbers may be consecutive and start from 1. For example, the L angle vectors may include the first angle vector to an Lthangle vector, and the K delay vectors may include the first delay vector to a Kthdelay vector. Certainly, a specific implementation is not limited thereto. For example, numbers may alternatively be consecutive and start from 0. For example, the L angle vectors may include the zeroth angle vector to an (L−1)thangle vector, and the K delay vectors may include the zeroth delay vector to a (K−1)thdelay vector. It should be understood that, the foregoing descriptions are all provided for ease of describing the technical solutions provided in the embodiments of this application, but are not intended to limit the scope of this application. Third, in this application, transformation of a matrix and a vector is involved in many places. For ease of understanding, unified descriptions are provided herein. An upper corner mark T indicates a transpose. For example, ATindicates a transpose of a matrix (or vector) A. An upper corner mark * represents a conjugate. For example, A* represents a conjugate of the matrix (or vector) A. An upper corner mark H represents a conjugate transpose. For example, AHrepresents a conjugate transpose of the matrix (or vector) A. For brevity, descriptions of a same or similar case are omitted below. Fourth, in the embodiments shown below, an example in which both the angle vector and the delay vector are column vectors is used to describe the embodiments provided in this application. However, this shall not constitute any limitation on this application. Based on a same concept, a person skilled in the art may further figure out more possible representations. Fifth, in this application, “being used to indicate” may include “being used to directly indicate” and “being used to indirectly indicate”. When a piece of indication information is described as being used to indicate A, the indication information may directly indicate A or indirectly indicate A, but it does not necessarily indicate that the indication information carries A. Information indicated by the indication information is referred to as to-be-indicated information. In a specific implementation process, the to-be-indicated information may be indicated in a plurality of manners, for example, but not limited to, a manner of directly indicating the to-be-indicated information. For example, the to-be-indicated information is indicated by using the to-be-indicated information or an index of the to-be-indicated information. Alternatively, the to-be-indicated information may be indirectly indicated by indicating other information, and there is an association relationship between the other information and the to-be-indicated information. Alternatively, only a part of the to-be-indicated information may be indicated, and the other part of the to-be-indicated information is already known or pre-agreed on. For example, specific information may alternatively be indicated by using an arrangement sequence of a plurality of pieces of information that is pre-agreed on (for example, stipulated in a protocol), to reduce indication overheads to some extent. In addition, a common part of all pieces of information may be further identified and indicated in a unified manner, to reduce indication overheads caused by separately indicating same information. For example, a person skilled in the art should understand that a precoding matrix includes precoding vectors, and each precoding vector in the precoding matrix may have a same part in terms of composition or another attribute. In addition, a specific indication manner may alternatively be various existing indication manners, for example, but not limited to, the foregoing indication manners and various combinations thereof. For details of various indication manners, refer to the conventional technology. Details are not described in this specification. It can be learned from the foregoing descriptions that, for example, when a plurality of pieces of information of a same type need to be indicated, manners of indicating different information may be different. In a specific implementation process, a required indication manner may be selected according to a specific requirement. The selected indication manner is not limited in the embodiments of this application. In this way, the indication manner in the embodiments of this application should be understood as covering various methods that can enable a to-be-indicated party to learn of the to-be-indicated information. In addition, the to-be-indicated information may have another equivalent form. For example, a row vector may be represented as a column vector; a matrix may be represented by using a transposed matrix of the matrix; the matrix may alternatively be represented in a form of a vector or an array; and the vector or the array may be formed by connecting row vectors or column vectors in the matrix. The technical solutions provided in the embodiments of this application should be understood as covering various forms. For example, some or all features in the embodiments of this application should be understood as covering various representations of the features. The to-be-indicated information may be sent as a whole, or may be divided into a plurality of pieces of sub-information for separate sending. In addition, sending periodicities and/or sending occasions of the sub-information may be the same or may be different. A specific sending method is not limited in this application. The sending periodicities and/or the sending occasions of the sub-information may be predefined, for example, predefined according to a protocol, or may be configured by a transmit end device by sending configuration information to a receive end device. The configuration information may include, for example, but not limited to, one or a combination of at least two of radio resource control signaling, media access control (MAC) layer signaling, and physical layer signaling. The radio resource control signaling includes, for example, radio resource control (RRC) signaling. The MAC layer signaling includes, for example, a MAC control element (CE). The physical layer signaling includes, for example, downlink control information (DCI). Sixth, definitions listed in this application for many features (for example, a Kronecker product, a channel state information (CSI) report, a precoding matrix indicator (PMI), an RB, an angle, and a delay) are merely used to explain functions of the features by using an example. For detailed content thereof, refer to the conventional technology. Seventh, the terms “first”, “second”, and various numbers in the following embodiments are merely used for distinguishing for ease of description, and are not intended to limit the scope of the embodiments of this application. For example, the terms are used to distinguish between different indication information. Eighth, in the embodiments shown below, “being pre-obtained” may include “being indicated by a network device by using signaling” or “being predefined”, for example, “being defined in a protocol”. The “predefinition” may be implemented in a manner in which corresponding code, a table, or other related indication information may be prestored in a device (for example, including a terminal device and a network device). A specific implementation of the “predefinition” is not limited in this application. Ninth, “storage” in the embodiments of this application may be storage in one or more memories. The one or more memories may be separately disposed, or may be integrated into an encoder or a decoder, a processor, or a communications apparatus. Alternatively, some of the one or more memories may be separately disposed, and some of the one or more memories are integrated into a decoder, a processor, or a communications apparatus. A type of the memory may be a storage medium in any form, and this is not limited in this application. Tenth, a “protocol” in the embodiments of this application may be a standard protocol in the communications field, for example, may include an LTE protocol, an NR protocol, and a related protocol applied to a future communications system. This is not limited in this application. Eleventh, “at least one” indicates one or more, and “a plurality of” indicates two or more. The term “and/or” describes an association relationship between associated objects and represents that three relationships may exist. For example, A and/or B may represent the following cases: Only A exists, both A and B exist, and only B exists, where A and B may be singular or plural. The character “/” generally indicates an “or” relationship between the associated objects. The term “at least one of the following items (pieces)” or a similar expression thereof means any combination of these items, including any combination of singular items (pieces) or plural items (pieces). For example, at least one of a, b, and c may represent: a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c each may be singular or plural. Twelfth, in the embodiments of this application, descriptions such as “when”, “in a case”, and “if” mean that a device (for example, the terminal device or the network device) performs corresponding processing in an objective situation, and are not intended to limit time, and the device (for example, the terminal device or the network device) is not required to perform a determining action during implementation, and do not mean any other limitation. The following describes in detail the channel measurement method provided in the embodiments of this application with reference to the accompanying drawings. It should be understood that, the method provided in the embodiments of this application may be applied to a system in which communication is performed by using a multi-antenna technology, for example, the communications system100shown inFIG.1. The communications system may include at least one network device and at least one terminal device. The network device and the terminal device may communicate with each other by using the multi-antenna technology. It should be further understood that, a specific structure of an execution body of the method provided in the embodiments of this application is not specifically limited in the embodiments shown below, provided that a program that records code of the method provided in the embodiments of this application can be run to perform communication according to the method provided in the embodiments of this application. For example, the execution body of the method provided in the embodiments of this application may be the terminal device or the network device, or a functional module that can invoke and execute the program in the terminal device or the network device. Without loss of generality, interaction between the network device and the terminal device is used as an example below to describe in detail the channel measurement method provided in the embodiments of this application. In an implementation, the network device may precode a downlink reference signal based on a predetermined angle vector and delay vector, so that the terminal device estimates and feeds back, based on a received precoded reference signal, a plurality of weighting coefficients corresponding to a plurality of angle-delay pairs. The network device may determine, based on the plurality of angle-delay pairs and the plurality of weighting coefficients fed back by the terminal device, a precoding matrix that adapts to a downlink channel. In another implementation, the network device may precode a downlink reference signal based on a predetermined delay vector, so that the terminal device estimates and feeds back, based on a received precoded reference signal, a plurality of weighting coefficients corresponding to a plurality of antenna-delay pairs. The network device may determine, based on the plurality of antenna-delay pairs and the plurality of weighting coefficients fed back by the terminal device, a precoding matrix that adapts to a downlink channel. For ease of understanding, in embodiments shown below, a precoded reference signal sent by a transmit antenna in one polarization direction is first used as an example to describe in detail a specific process in which the terminal device performs channel measurement and provides a feedback based on a precoded reference signal received by one receive antenna. Then, a transmit antenna in one polarization direction is extended to transmit antennas in a plurality of polarization directions, and one receive antenna is extended to a plurality of receive antennas, to describe in detail a specific process in which the terminal device feeds back Q ports and Q corresponding weighting coefficients to the network device. Then, the feedback based on the receive antenna is changed into a feedback based on the transport layer, to further describe a specific process in which the terminal device feeds back the Q ports and the Q corresponding weighting coefficients to the network device based on the transport layer. Finally, a specific process in which the network device determines a precoding matrix is separately described in detail for two cases: a feedback based on the receive antenna and a feedback based on a receive transport layer. It should be understood that, when the embodiments of this application are described based on one polarization direction for the terminal device, the polarization direction may be any one of one or more polarization directions of a transmit antenna that are configured by the network device. In other words, for a precoded reference signal transmitted by a transmit antenna in any polarization direction, the terminal device may perform channel measurement based on the method provided in the embodiments of this application, or the network device may determine a precoding matrix based on the method provided in the embodiments of this application. It should be further understood that, when the embodiments of this application are described based on one receive antenna for the terminal device, the receive antenna may be any one of one or more receive antennas that are configured for the terminal device. In other words, for a precoded reference signal received by any receive antenna, the terminal device may perform channel measurement based on the method provided in the embodiments of this application, or the network device may determine a precoding matrix based on the method provided in the embodiments of this application. It should be further understood that, a quantity of polarization directions of a transmit antenna that are configured by the network device is not limited in this application. For example, there may be one polarization direction, namely, a single polarization direction, or there may be a plurality of polarization directions, for example, dual polarization directions. A quantity of receive antennas that are configured for the terminal device is not limited in this application either. For example, there may be one or more receive antennas. FIG.2is a schematic flowchart of a channel measurement method200according to an embodiment of this application from a perspective of device interaction. As shown in the figure, the method200may include operation210to operation270. The following describes the operations in the method200in detail. Step210: A terminal device receives precoded reference signals of P ports, where the precoded reference signals of the P ports correspond to P angle-delay pairs. Correspondingly, a network device sends the precoded reference signals of the P ports, where the precoded reference signals of the P ports correspond to the P angle-delay pairs. Specifically, each of the P angle-delay pairs includes one angle vector and one delay vector. In other words, each angle-delay pair is a combination of one angle vector and one delay vector. One angle vector and one delay vector can uniquely determine an angle-delay pair. In this embodiment, the P angle-delay pairs may be obtained by combining K (where K is a positive integer) angle vectors and L (where L is a positive integer) delay vectors. In other words, a plurality of combinations of angle vectors and delay vectors may be obtained based on the K angle vectors and the L delay vectors. The plurality of combinations are different from each other. Angle vectors and/or delay vectors in any two of the plurality of combinations are different. The plurality of combinations may include the P angle-delay pairs. The P angle-delay pairs correspond to the precoded reference signals of the P ports. The precoded reference signal of each port may correspond to one angle-delay pair. The precoded reference signal of each port may be obtained by precoding a reference signal based on an angle vector and a delay vector in a corresponding angle-delay pair. In a possible implementation, the network device may traverse the K angle vectors and the L delay vectors, to obtain K×L combinations of angle vectors and delay vectors, or K×L angle-delay pairs. That is, P=K×L. That is, the network device may precode the reference signal based on each of the K angle vectors and each of the L delay vectors. When precoding the reference signal based on a kth(1≤k≤K, and k is an integer) angle vector in the K angle vectors, the network device may traverse each of the L delay vectors to precode the reference signal. Alternatively, when precoding the reference signal based on an lth(1≤l≤L, and l is an integer) delay vector in the L delay vectors, the network device may traverse each of the K angle vectors to precode the reference signal. In other words, the K angle vectors may be considered as being shared by all the delay vectors, and the L delay vectors may also be considered as being shared by all the angle vectors. That is, the K angle vectors and the L delay vectors are shared by each other. In another possible implementation, delay vectors corresponding to at least two angle vectors are different. When precoding the reference signal based on a kthangle vector in the K angle vectors, the network device may traverse each of Lk(1≤Lk≤L, and Lkis an integer) delay vectors corresponding to the kthangle vector, to precode the reference signal. That is, P= ∑k=1KLk. The Lkdelay vectors may be some or all of the L delay vectors, that is, Lk≤L. L in the L delay vectors may satisfy that L≤∑k=1KLk. Herein, that the delay vectors corresponding to the at least two angle vectors are different may mean that delay vectors corresponding to at least two of the K angle vectors are different, and delay vectors respectively corresponding to other angle vectors may be the same or may be different. This is not limited in this application. In other words, delay vectors corresponding to angle vectors are partially or completely different. That delay vectors corresponding to two angle vectors are different may mean that the delay vectors corresponding to the two angle vectors are completely different, that is, the delay vectors corresponding to the two angle vectors are not repeated, or have no intersection. For example, a delay vector corresponding to an angle vector a(θ1) includes b(τ2), and delay vectors corresponding to an angle vector a(θ1) include b(τ1) and b(τ3). That delay vectors corresponding to two angle vectors are different may alternatively mean that the delay vectors corresponding to the two angle vectors are partially different, that is, the delay vectors corresponding to the two angle vectors are partially repeated but are not completely the same, or the delay vectors corresponding to the two angle vectors have an intersection but are not completely the same. For example, delay vectors corresponding to a(θ1) include b(τ2) and b(τ3), and delay vectors corresponding to an angle vector a(θ2) include b(τ1) and b(τ3). When delay vectors corresponding to any two of the K angle vectors are not repeated, L=∑k=1KLk. When delay vectors corresponding to two or more of the K angle vectors are partially repeated, L<∑k=1KLk. Therefore, the network device may obtain ∑k=1KLk combinations of angle vectors and delay vectors based on the K angle vectors and the L delay vectors. In still another possible implementation, angle vectors corresponding to at least two delay vectors are different. When precoding the reference signal based on an lthdelay vector in the L delay vectors, the network device may traverse each of Kl(1≤Kl≤K, and Klis an integer) angle vectors corresponding to the lthdelay vector, to precode the reference signal. That is, P= ∑l=1LKl. The Klangle vectors may be some or all of the K angle vectors, that is, Kl≤K. K in the K angle vectors may satisfy that K≤∑l=1LKl. Herein, that the angle vectors corresponding to the at least two delay vectors are different may mean that angle vectors corresponding to at least two of the L delay vectors are different, and angle vectors respectively corresponding to other delay vectors may be the same or may be different. This is not limited in this application. In other words, angle vectors corresponding to delay vectors are partially or completely different. That angle vectors corresponding to two delay vectors are different may mean that the angle vectors corresponding to the two delay vectors are completely different, that is, the angle vectors corresponding to the two delay vectors are not repeated, or have no intersection. For example, an angle vector corresponding to a delay vector b(τ1) includes a(θ2), and an angle vector corresponding to a delay vector b(τ2) includes a(θ1). That angle vectors corresponding to two delay vectors are different may alternatively mean that the angle vectors corresponding to the two delay vectors are partially different, that is, the angle vectors corresponding to the two delay vectors are partially repeated but are not completely the same, or the angle vectors corresponding to the two delay vectors have an intersection but are not completely the same. For example, an angle vector corresponding to a delay vector b(τ1) includes a(θ2), and angle vectors corresponding to a delay vector b(τ2) include a(θ1) and a(θ2). When angle vectors corresponding to any two of the L delay vectors are not repeated, K=∑l=1LKl. When angle vectors corresponding to two or more of the L delay vectors are partially repeated, K<∑l=1LKl. Therefore, the network device may obtain ∑l=1LKl combinations of angle vectors and delay vectors based on the K angle vectors and the L delay vectors. It should be understood that, the foregoing lists a correspondence between an angle vector and a delay vector merely for ease of understanding. However, this shall not constitute any limitation on this application. The correspondence between an angle vector and a delay vector is not limited in this application. For ease of understanding,FIG.3shows an example in which a plurality of ports correspond to a plurality of angle-delay pairs. As shown inFIG.3, a plurality of RBs shown inFIG.3carry reference signals of four ports, that is, P=4. For example, the reference signals of the four ports may be obtained through precoding based on one delay vector and four angle vectors, that is, L=1 and K=4. Alternatively, the reference signals of the four ports may be obtained through precoding based on two delay vectors and two angle vectors, that is, L=2 and K=2. Alternatively, the reference signals of the four ports may be obtained through precoding based on four delay vectors and one angle vector, that is, L=4 and K=1. Alternatively, the reference signals of the four ports may be obtained through precoding based on two angle vectors and two delay vectors corresponding to each angle vector, that is, L=2 and K1=K2=2. Alternatively, the reference signals of the four ports may be obtained through precoding based on two delay vectors and two angle vectors corresponding to each delay vector, that is, K=2 and L1=L2=2. This is not limited in this application. It should be understood that, the four RBs shown inFIG.3are an example of a reference signal resource. The four RBs may be considered as a same reference signal resource. However, this is merely an example, and this shall not constitute any limitation on a quantity of RBs included in the reference signal resource. It should be further understood that, a quantity of ports is relative to the reference signal resource, and is irrelevant to the quantity of RBs included in the reference signal resource. The reference signal resource may include more or fewer RBs. The precoded reference signals of the four ports may alternatively be carried on more or fewer RBs, and a quantity of ports corresponding to the precoded reference signal carried on each RB may be P. As shown in the figure, precoded reference signals of a same port occupy a same RE in all the RBs, in other words, relative positions of resources occupied by the precoded reference signals of the same port in all the RBs are the same. REs occupied by precoded reference signals of different ports in a same RB may be different, for example, may be distinguished in a frequency division multiplexing (FDM) or time division multiplexing (TDM) manner. Alternatively, REs occupied by precoded reference signals of different ports in a same RB may be the same, for example, may be distinguished in a code division multiplexing (CDM) manner. The figure is merely an example, and shows an example in which a port #1 and a port #2 are distinguished from a port #3 and a port #4 through FDM, and the port #1 and the port #3 are distinguished from the port #2 and the port #4 through TDM. It should be understood that,FIG.3is merely an example for ease of understanding, and does not completely show all REs in one RB. A quantity of REs in each RB is not limited in this application. In addition, a quantity of ports corresponding to a precoded reference signal carried on each RB and a specific resource multiplexing manner of the precoded reference signals of the ports are not limited in this application. It should be further understood that, the four RBs shown inFIG.3may be four consecutive RBs, or may be four RBs discretely distributed in a frequency domain resource. This is not limited in this application. In other words, one RB may be one frequency domain unit, or one RB may be a part of the frequency domain unit. Because of reciprocity between angles and delays on uplink and downlink channels, optionally, the K angle vectors and the L delay vectors may all be determined by the network device based on uplink channel measurement. Specifically, the network device may determine K (where K≥1, and K is an integer) angles and L (where L≥1, and L is an integer) delays based on an uplink channel matrix obtained through pre-estimation. The K angles may be represented by using the K angle vectors. The L delays may be represented by using the L delay vectors. The uplink channel matrix may be a weighted sum of K×L spatial-frequency matrices determined by using the K angle vectors and the L delay vectors. For ease of description below, it is assumed that P=K×L, and P is a positive integer. For example, the K angle vectors may be K stronger angle vectors determined from a predefined angle vector set. The K angle vectors may be jointly determined for the L delay vectors, or may be separately determined for each of the L delay vectors. This is not limited in this application. Optionally, each angle vector in the angle vector set is obtained from a DFT matrix. For example, the K angle vectors may be determined by performing DFT on the uplink channel matrix. Optionally, each angle vector in the angle vector set is a steering vector. For example, the L delay vectors may be L stronger delay vectors determined from a predefined delay vector set. The L delay vectors may be jointly determined for the K angle vectors, or may be separately determined for each of the K angle vectors. This is not limited in this application. Optionally, each delay vector in the delay vector set is obtained from a DFT matrix. For example, the L delay vectors may be determined by performing DFT on the uplink channel matrix. For example, the network device may determine, by using a joint angle and delay estimation (JADE) algorithm in the conventional technology, the K angle vectors and one or more stronger delay vectors corresponding to each angle vector. Specifically, the estimation algorithm may be, for example, a multiple signal classification algorithm (MUSIC), a Bartlett algorithm, or an estimation of signal parameters via rotation invariant technique algorithm (ESPRIT). Alternatively, the network device may perform DFT on a spatial-frequency matrix that is determined based on uplink channel measurement, to determine the K angle vectors and the L delay vectors. A specific method for determining the K angle vectors and the L delay vectors by the network device is not limited in this application. An example in which DFT is performed on the spatial-frequency matrix is used. It is assumed that both the angle vector and the delay vector are obtained from the DFT matrices. For example, the predefined angle vector set may be a vector set including a plurality of vectors in a space-domain DFT matrix. For ease of distinguishing, the vector set is referred to as an angle vector set Us, and Us=[us,1us,2. . . us,T]. For example, the predefined delay vector set may be a vector set including a plurality of vectors in a frequency-domain DFT matrix. For ease of distinguishing, the vector set is referred to as a delay vector set Uf, and Uf=[uf,1uf,2. . . uf,N]. The network device may determine an uplink channel through channel estimation, and further determine a spatial-frequency matrix HULof the uplink channel. The network device may perform space-domain DFT transform and frequency-domain DFT transform on the spatial-frequency matrix HULthat is obtained through uplink channel estimation, to obtain a coefficient matrix CULas follows: CUL=UsHHULUf. For ease of understanding, dimensions of the spatial-frequency matrix HULof the uplink channel are kept consistent with dimensions of a spatial-frequency matrix HDLof a downlink channel herein. The foregoing has described the dimensions of the spatial-frequency matrix of the downlink channel and a relationship between the dimensions and the downlink channel. The dimensions of the spatial-frequency matrix HULdetermined by using the uplink channel may be N×T. It should be understood that, the dimensions of the spatial-frequency matrix HULof the uplink channel and the calculation formula used to determine the coefficient matrix CULthat are shown herein are merely examples, and this shall not constitute any limitation on this application. If different dimensions are defined for the spatial-frequency matrix HUL, calculation formulas used to determine the coefficient matrix CULare also different. The network device may determine K stronger rows from the coefficient matrix CUL. The K stronger rows may be used to determine the K angle vectors. For example, the network device may determine, based on a quadratic sum of moduli of elements in each row in the coefficient matrix CUL, K rows with larger quadratic sums of the moduli. The K rows with the larger quadratic sums of the moduli may be used to determine the K angle vectors. Positions of the K rows in the coefficient matrix CULmay be used to determine positions of the K angle vectors in the angle vector set. For example, row sequence numbers of the K rows in the coefficient matrix CULmay be column sequence numbers of the K angle vectors in the angle vector set. Therefore, the K angle vectors may be determined. The K angle vectors are angle vectors selected from the angle vector set and used to precode a downlink reference signal. The network device may determine, based on a quadratic sum of moduli of elements in each column in the coefficient matrix CUL, L columns with larger quadratic sums of the moduli. The L columns with the larger quadratic sums of the moduli may be used to determine the L delay vectors. Positions of the L columns in the coefficient matrix CULmay be used to determine positions of the L delay vectors in the delay vector set. For example, column sequence numbers of the L columns in the coefficient matrix CULmay be column sequence numbers of the L delay vectors in the delay vector set. Therefore, the L delay vectors may be determined. The L delay vectors are delay vectors selected from the delay vector set and used to decode the downlink reference signal. Alternatively, the network device may determine one or more stronger delay vectors based on each of the K stronger rows in the coefficient matrix CUL. For example, for a kthrow in the K rows, the network device may determine, based on a square of a modulus of each element, one or more elements with squares of moduli being greater than a preset value, for example, Lkelements. The preset value may be, for example, a predefined value. For example, the preset value may be 80% of a quadratic sum of the moduli of the elements in this column. The Lkelements with the squares of the moduli being greater than the preset value may be used to determine Lkdelay vectors. For example, columns in which the Lkelements with the squares of the moduli being greater than the preset value are located in the coefficient matrix CULmay be used to determine positions of the Lkdelay vectors in the predefined delay vector set. For example, column sequence numbers of the Lkelements in the coefficient matrix CULmay be column sequence numbers of the Lkdelay vectors in the delay vector set. For the K angle vectors, a total quantity of delay vectors may be L. The L delay vectors are delay vectors selected from the delay vector set. It should be understood that, merely for ease of understanding, the foregoing lists several possible methods that may be used by the network device to determine the K angle vectors and the L delay vectors. However, this shall not constitute any limitation on this application. A specific implementation of determining the K angle vectors and the L delay vectors by the network device is not limited in this application. In addition, for example, the uplink channel matrix may be obtained by the network device through estimation based on an uplink reference signal, for example, an SRS, that is received in advance, or obtained based on a correctly decoded data signal. This is not limited in this application. For a specific method for obtaining the uplink channel matrix through estimation by the network device based on the uplink reference signal, refer to the conventional technology. For brevity, detailed descriptions of the specific method are omitted herein. In an FDD mode, angles and delays on uplink and downlink channels may be reciprocal. Therefore, the K angle vectors and the L delay vectors that are obtained through uplink channel measurement may be loaded to the downlink reference signal, so that the terminal device performs downlink channel measurement based on the received precoded reference signal. Certainly, the K angle vectors obtained through uplink channel measurement may alternatively be loaded to the downlink reference signal, or the L delay vectors obtained through uplink channel measurement may alternatively be loaded to the downlink reference signal. In this embodiment, a case in which the K angle vectors and the L delay vectors are loaded to the downlink reference signal is mainly described in detail. It should be understood that, determining the K angle vectors and the L delay vectors based on uplink channel measurement is not a unique implementation. For example, the K angle vectors and the L delay vectors may be predefined, for example, defined in a protocol; or may be determined by the network device through statistics collection based on a result fed back in one or more previous downlink channel measurements. A manner of obtaining the K angle vectors and the L delay vectors is not limited in this application. The network device may precode the downlink reference signal such as a CSI-RS based on the K angle vectors and the L delay vectors, to obtain a precoded reference signal. The precoded reference signal obtained by the network device through precoding based on the K angle vectors and the L delay vectors may be sent by using a transmit antenna in one polarization direction, or may be sent by using transmit antennas in a plurality of polarization directions. This is not limited in this application. Optionally, when the network device sends, by using the transmit antennas in the plurality of polarization directions, the precoded reference signal obtained through precoding based on the K angle vectors and the L delay vectors, a quantity of ports of the precoded reference signal may be multiplied. For example, when the transmit antenna is in a single polarization direction, a quantity of ports of the sent precoded reference signal is P; when the transmit antenna is in dual polarization directions, a quantity of ports of the sent precoded reference signal is 2P. The network device may transmit the precoded reference signal by using a preconfigured reference signal resource. When receiving the precoded reference signal from the network device, the terminal device may determine a time-frequency resource of the precoded reference signal of each port based on a predefined pilot pattern, and may receive the precoded reference signal of each port on the corresponding time-frequency resource. The terminal device may perform channel measurement based on the received reference signal of each port. A port that can be identified by the terminal device is a port corresponding to the reference signal. Therefore, the terminal device may perform channel estimation and measurement based on each port. Step220: The terminal device generates first indication information, where the first indication information is used to indicate Q ports in the P ports. Specifically, the P ports correspond to the P angle-delay pairs described above. The Q ports are some of the P ports, Q<P, and Q is a positive integer. In other words, the terminal device may indicate some of the Q ports to the network device. The Q ports may be stronger ports in the P ports. The terminal device may perform downlink channel measurement based on the received reference signals of the P ports, estimate channels of the P ports, and feed back the Q stronger ports to the network device. A weighted sum of the P angle-delay pairs obtained by the terminal device by performing channel measurement based on the reference signals of the P ports may be used to determine a downlink channel. In the P angle-delay pairs, impact of an angle-delay pair with a larger weighting coefficient on feedback precision is greater than impact of an angle-delay pair with a smaller weighting coefficient on the feedback precision. Therefore, the terminal device may select, from the P angle-delay pairs, Q angle-delay pairs with larger weighting coefficients for a feedback, thereby helping reduce feedback overheads while ensuring the feedback precision. It should be noted that, when receiving the precoded reference signal and performing channel measurement based on the received precoded reference signal, the terminal device may perform receiving and measurement based on different port numbers. The terminal device does not learn of or does not need to learn of angle vectors and delay vectors that are used by the network device to precode the reference signal. When precoding the reference signal, the network device may determine a correspondence among each angle vector, a delay vector, and a port. In addition, when the reference signal is transmitted, a correspondence between each port and a time-frequency resource may also be learned of. Therefore, the terminal device indicates the Q ports to the network device, and the network device may determine Q corresponding angle-delay pairs based on the Q ports. A value of Q may be predefined, for example, defined in a protocol; or may be preconfigured by the network device, for example, indicated by the network device in advance by using signaling; or may be determined by the terminal device. This is not limited in this application. If the value of Q is determined by the terminal device, the terminal device may further indicate the value of Q by using the first indication information. Optionally, the first indication information is further used to indicate the value of Q. If the value of Q is indicated by the network device, the network device and the terminal device may pre-agree on whether the terminal device reports a corresponding quantity of ports according to an indication of the network device. For example, the network device and the terminal device may pre-agree on that the terminal device may further determine the quantity of reported ports according to the indication of the network device. In this case, the network device may indicate a maximum value Q0of Q in advance by using signaling, and the terminal device may report the Q ports based on Q0, where Q≤Q0, and Q0is a positive integer. Optionally, the method further includes: The network device sends third indication information, where the third indication information is used to indicate the maximum value Q0of Q. Correspondingly, the terminal device receives the third indication information, where the third indication information is used to indicate the maximum value Q0of Q. If the terminal device further determines the value of Q based on the maximum value Q0, the terminal device may indicate the value of Q by using the first indication information. Certainly, Q may alternatively be equal to Q0. This is not limited in this application. For another example, the network device and the terminal device may pre-agree on that the terminal device needs to report a corresponding quantity of ports according to the indication of the network device. That is, the network device may indicate the value of Q in advance by using signaling, and the terminal device reports the Q ports. Optionally, the method further includes: The network device sends third indication information, where the third indication information is used to indicate the value of Q. Correspondingly, the terminal device receives the third indication information, where the third indication information is used to indicate the value of Q. For ease of distinguishing and description, the Q ports that need to be fed back to the network device and that are determined by the terminal device based on the received reference signals of the P ports are denoted as target ports below. It should be understood that, P and Q are merely examples for ease of distinguishing and understanding, and specific values of P and Q are not limited in this application. The following describes in detail a specific process in which the terminal device determines the Q target ports from the P ports. As described above, the P ports correspond to the P angle-delay pairs. Weighting coefficients of the P angle-delay pairs may be determined based on the precoded reference signals of the P ports. The terminal device may perform channel measurement based on the precoded reference signals of the P ports, determine the weighting coefficients of the P angle-delay pairs corresponding to the P ports, and further determine the Q target ports from the P ports. Because the network device precodes the reference signal based on the P angle-delay pairs including the K angle vectors and the L delay vectors, a precoded reference signal carried on each frequency domain unit (for example, an RB) may correspond to the P ports. A pthport in the P ports corresponds to a pthangle-delay pair. A precoded reference signal of the pthport is obtained by precoding the reference signal based on an angle vector and a delay vector in the pthangle-delay pair. It is assumed that the pthangle-delay pair includes the km angle vector in the K angle vectors and the lthdelay vector in the L delay vectors. In this case, the precoded reference signal of the pthport may be obtained by precoding the reference signal based on the kthangle vector and the lthdelay vector. In other words, the precoded reference signal corresponding to the pthport may be used to determine a weighting coefficient of an angle-delay pair including the kthangle vector and the lthdelay vector, that is, may be used to determine a weighting coefficient of the pthangle-delay pair. Therefore, the terminal device may determine the weighting coefficient of the corresponding angle-delay pair based on the precoded reference signal of each port. If a reference signal received by the terminal device is a reference signal that is not precoded, for each receive antenna, dimensions of a downlink channel may be N×T. Dimensions of a downlink channel on one frequency domain unit that is received by using one receive antenna may be 1×T. In this embodiment of this application, because the network device precodes the reference signal based on the angle vector and the delay vector, and dimensions of each angle vector may be T×1, after the reference signal is precoded by using the angle vector and the delay vector, dimensions of a downlink channel on each frequency domain unit that is received by the terminal device through each receive antenna may be 1×1. An estimation value of the downlink channel whose dimensions are 1×1 is a channel estimation value obtained by performing channel estimation on the precoded reference signal on one frequency domain unit. For the precoded reference signal of the pthport, the terminal device may determine the weighting coefficient of the pthangle-delay pair based on N 1×1 downlink channels received on N frequency domain units. The weighting coefficient of the pthangle-delay pair may be obtained by performing superposition summation on N channel estimation values on the N frequency domain units. It is assumed that an estimation value that is of a downlink channel and that is obtained by the terminal device by performing channel estimation on the precoded reference signal of the pthport is denoted as yn(p). In this case, a sum of a plurality of estimation values that are obtained by the terminal device by performing channel estimation on the precoded reference signal of the pthport on the N frequency domain units may be represented as ∑n=1Nyn(p).∑n=1Nyn(p) is the weighting coefficient of the pthangle-delay pair. Based on the foregoing method, the terminal device may determine, based on the received precoded reference signals of the P ports, the P weighting coefficients corresponding to the P angle-delay pairs. Based on the P weighting coefficients, the terminal device may further determine the Q stronger ports in the P ports, and determine the Q stronger ports as the Q target ports to be fed back to the network device. A weighting coefficient of any one of the Q angle-delay pairs corresponding to the Q target ports is greater than or equal to a weighting coefficient of an angle-delay pair corresponding to any one of the remaining P-Q ports. After determining the Q target ports, the terminal device may generate the first indication information to indicate the Q target ports. In an implementation, when the first indication information is used to indicate the Q target ports, the first indication information is specifically used to indicate indexes of the Q angle-delay pairs corresponding to the Q target ports. As described above, the P angle-delay pairs may be obtained by combining the K angle vectors and the L delay vectors. Although the terminal device does not learn of angle vectors and delay vectors that are specifically included in the P angle-delay pairs, the terminal device may learn that there is a one-to-one correspondence between ports and angle-delay pairs. If the angle vectors and the delay vectors that are included in these angle-delay pairs are separately distinguished by using indexes, a combination of an index of one angle vector and an index of one delay vector may be used to uniquely indicate one port. It should be understood that, herein, the index of the angle vector is not an index of the angle vector in the angle vector set, and the index of the delay vector is not an index of the delay vector in the delay vector set. Instead, different index values are defined for the K angle vectors and the L delay vectors that are used for precoding, for distinguishing. Optionally, each of the P angle-delay pairs may be indicated by using a two-dimensional index (k, l). k=1, 2, . . . , or K; and l=1, 2, . . . , or L. For ease of understanding,FIG.4shows a correspondence between P angle-delay pairs and P groups of two-dimensional indexes. As shown inFIG.4, a quantity K of angle vectors is 6, a quantity L of delay vectors is 4, and a quantity P of angle-delay pairs is 24. A total of six indexes 1 to 6 on a horizontal axis are in a one-to-one correspondence with the six angle vectors, and a total of four indexes 1 to 4 on a vertical axis are in a one-to-one correspondence with the four delay vectors. Therefore, one angle-delay pair can be uniquely determined by using one index on the horizontal axis and one index on the vertical axis. For example, the indexes 1 to 6 on the horizontal axis sequentially correspond to the first angle vector to the sixth angle vector in the six angle vectors. The indexes 1 to 4 on the vertical axis sequentially correspond to the first delay vector to the fourth delay vector in the four delay vectors. In this case, an index (1, 1) may represent an angle-delay pair including the first angle vector in the six angle vectors and the first delay vector in the four delay vectors, and an index (3, 4) may represent an angle-delay pair including the third angle vector in the six angle vectors and the fourth delay vector in the four delay vectors. For brevity, examples are not listed one by one herein. It should be noted that, the P angle-delay pairs are not necessarily obtained by combining the K angle vectors and the L delay vectors in pairs, that is, P does not necessarily satisfy that P=K×L. For example, if P=∑k=1KLk, L may be a total quantity of delay vectors that form P delay vector pairs, and the L delay vectors are different from each other. That is, L≤∑k=1KLk. For another example, if P=∑l=1LKl, K may be a total quantity of angle vectors that form P angle vector pairs, and the K angle vectors are different from each other. That is, K≤∑l=1LKl. However, it may be understood that regardless of a relationship among P, L, and M, the terminal device may indicate, by using the foregoing two-dimensional indexes, the Q angle-delay pairs corresponding to the Q target ports. For ease of understanding, the following describes in detail a specific method for indicating the Q angle-delay pairs by using the two-dimensional indexes with reference toFIG.4. As shown inFIG.4, 24 angle-delay pairs are shown in the figure, where shaded grids represent the Q determined angle-delay pairs corresponding to the Q target ports, and Q=12. When the first indication information is used to indicate the 12 angle-delay pairs, for example, two-dimensional indexes (1, 2), (1, 4), (2, 2), (2, 4), (3, 1), (3, 2), (4, 4), (5, 1), (5, 2), (5, 3), (6, 2), and (6, 4) may be used for indication. It should be understood that,FIG.4is merely an example, and this shall not constitute any limitation on this application. The specific values of P and Q and a sequence of the Q two-dimensional indexes are not limited in this application. It should be further understood that,FIG.4is merely an example for ease of understanding, and this shall not constitute any limitation on this application. A correspondence between an angle vector and an index and a correspondence between a delay vector and an index are not necessarily those shown inFIG.4. For example, the angle vector may correspond to the index on the vertical axis, and the delay vector may correspond to the index on the horizontal axis. For another example, a correspondence between the K angle vectors and the K indexes and a correspondence between the L delay vectors and the L indexes are not necessarily those listed above. The angle-delay pair may be indicated by using the two-dimensional index, provided that the network device and the terminal device can define the correspondence between an angle vector and an index and the correspondence between a delay vector and an index according to a same rule. A correspondence between each angle vector and an index and a correspondence between each delay vector and an index are not limited in this application. Actually, indicating the Q angle-delay pairs by using the two-dimensional indexes is merely a possible implementation, and the Q angle-delay pairs may alternatively be indicated by using one-dimensional indexes. Optionally, each of the P angle-delay pairs may be indicated by using a one-dimensional index p. p=1, 2, . . . , or P. A person skilled in the art may understand that the two-dimensional index (k, l) and the one-dimensional index p may be mutually converted. For example, the L rows are sequentially arranged from left to right from the first row to an Lthrow, or the K columns are sequentially arranged from top to bottom from the first column to a Kthcolumn, to obtain the one-dimensional indexes. One angle-delay pair may be uniquely indicated by using each one-dimensional index, provided that the network device and the terminal device can define the correspondence between an angle-delay pair and an index according to a predefined rule. A correspondence between each angle-delay pair and an index is not limited in this application. It should be understood that, the two-dimensional index and the one-dimensional index that are listed above are merely a possible implementation in which the terminal device indicates the Q angle-delay pairs. Based on a same concept, the terminal device may alternatively indicate the Q angle-delay pairs by using a bitmap. In this case, the first indication information may include a bitmap whose length is P, to correspond to the P ports, or correspond to the P angle-delay pairs. Each bit corresponds to one port, or each bit corresponds to one angle-delay pair. A bit is set to “0” or “1” to indicate whether a corresponding port (or angle-delay pair) belongs to the Q target ports (or angle-delay pairs), so that the Q target ports (or angle-delay pairs) are indicated. In an implementation, when the first indication information is used to indicate the Q target ports, the first indication information is specifically used to indicate port numbers of the Q target ports. Because the network device may notify the terminal device in advance by using signaling of a time-frequency resource for transmitting the reference signal and a port number for the transmitted reference signal, the terminal device may directly feed back the port numbers of the Q target ports to the network device after determining the Q stronger target ports. It should be understood that, indicating the Q target ports by using the indexes of the corresponding angle-delay pairs and indicating the Q target ports by using the port numbers are merely two possible implementations provided in this application, and this shall not constitute any limitation on this application. A specific implementation of indicating the Q target ports by the terminal device is not limited in this application. It should be noted that, a specific process in which the terminal device generates the first indication information is described in detail above by using one polarization direction and one receive antenna as an example. In other words, the Q ports may be determined based on a precoded reference signal that is sent by a transmit antenna in one polarization direction and that is received by one receive antenna. However, this shall not constitute any limitation on this application. Alternatively, the network device may send precoded reference signals by using transmit antennas in a plurality of polarization directions. Alternatively, the terminal device may receive the precoded reference signals based on a plurality of receive antennas, and generate the first indication information based on the plurality of receive antennas. When transmit antennas in a plurality of polarization directions are configured for the network device, the polarization direction described in the foregoing embodiment may be any one of the plurality of polarization directions. When transmit antennas in a plurality of polarization directions are configured for the network device, the terminal device may separately determine one or more stronger ports based on a precoded reference signal sent by a transmit antenna in each of the plurality of polarization directions, or may jointly determine one or more stronger ports based on precoded reference signals sent by the transmit antennas in the plurality of polarization directions. The one or more stronger ports that are determined by the terminal device based on the precoded reference signals sent by the transmit antennas in the plurality of polarization directions are the target port described above. It should be noted that, the terminal device may map the identified port to the polarization direction according to a predefined rule. For example, when the transmit antenna is in dual polarization directions, a quantity of ports of received reference signals is 2P. The terminal device may map the first P ports to a first polarization direction, and map the last P ports to a second polarization direction. Therefore, when the terminal device determines a target port based on a precoded reference signal sent by a transmit antenna in one or more polarization directions, it may be considered that the terminal device determines the target port based on a precoded reference signal of a port corresponding to the one or more polarization directions. For brevity, descriptions of a same or similar case are omitted below. It is assumed that transmit antennas in J polarization directions are configured for the network device, where J is an integer greater than 1. The network device may precode, based on the angle vector and the delay vector that are included in each of the P angle-delay pairs, a reference signal sent by a transmit antenna in each polarization direction, to obtain precoded reference signals of J×P ports. Certainly, when the network device sends precoded reference signals by using the transmit antennas in the J polarization directions, quantities of angle-delay pairs corresponding to precoded reference signals sent by transmit antennas in at least two polarization directions may alternatively be different. For example, a precoded reference signal sent by a transmit antenna in a jth(where 1≤j≤J, and j is a positive integer) polarization direction may be obtained by precoding the reference signal based on angle vectors and delay vectors in P; angle-delay pairs. That is, the precoded reference signal sent by the transmit antenna in the jthpolarization direction corresponds to Pj(where Pjis a positive integer) ports. Generally, ports corresponding to precoded reference signals sent by transmit antennas in any two polarization directions may be the same, that is, Pj=P. Therefore, a total quantity of ports may be J×P. For the jthpolarization direction, the terminal device may determine Qj(where Qjis a positive integer) target ports based on received precoded reference signals of the Pjports. The Qjtarget ports are an example of the Q target ports described above. A value of j is traversed from 1 to J, so that one or more target ports corresponding to each of the J polarization directions may be determined. Optionally, target ports determined by the terminal device based on precoded reference signals sent by transmit antennas in any two polarization directions are the same. The terminal device may determine Q target ports based on a precoded reference signal sent by a transmit antenna in any polarization direction. That is, when the value of j is any one of 1 to J, that Qj=Q can be satisfied. The Q target ports may be Q stronger ports determined by performing channel measurement based on the precoded reference signals sent by the transmit antennas in the J polarization directions, or may be Q ports determined by performing channel measurement based on a precoded reference signal sent by a transmit antenna in one polarization direction. This is not limited in this application. When Q same target ports are determined by the terminal device based on precoded reference signals sent by transmit antennas in any two of the J polarization directions, the first indication information may indicate the Q target ports once, or the first indication information includes only one piece of indication information used to indicate the Q target ports. It should be understood that, a specific method for determining, by the terminal device based on the precoded reference signals sent by the transmit antennas in the J polarization directions, the Q stronger target ports from the P ports is similar to the foregoing listed specific method for determining, based on a precoded reference signal sent by a transmit antenna in one polarization direction, the Q stronger target ports from the P ports. For brevity, details are not described herein again. Optionally, target ports determined by the terminal device based on precoded reference signals sent by transmit antennas in at least two polarization directions are different. That target ports determined by the terminal device based on precoded reference signals sent by transmit antennas in at least two of the J polarization directions are different may mean that target ports determined by the terminal device based on precoded reference signals sent by transmit antennas in some of the J polarization directions are different; or may mean that target ports determined by the terminal device based on precoded reference signals sent by transmit antennas in all of the J polarization directions are different. That target ports determined based on precoded reference signals sent by transmit antennas in two polarization directions are different may mean that the target ports determined based on the precoded reference signals sent by the transmit antennas in the two polarization directions are completely different, that is, the target ports determined based on the precoded reference signals sent by the transmit antennas in the two polarization directions are not repeated, or have no intersection. That target ports determined based on precoded reference signals sent by transmit antennas in two polarization directions are different may alternatively mean that the target ports determined based on the precoded reference signals sent by the transmit antennas in the two polarization directions are partially different, that is, the target ports determined based on the precoded reference signals sent by the transmit antennas in the two polarization directions are partially repeated but are not completely the same, or the target ports determined based on the precoded reference signals sent by the transmit antennas in the two polarization directions have an intersection but are not completely the same. Certainly, when the target ports determined based on the precoded reference signals sent by the transmit antennas in the two polarization directions are different, quantities of target ports determined based on the precoded reference signals sent by the transmit antennas in the two polarization directions may be the same or may be different. This is not limited in this application. When the target ports determined by the terminal device based on the precoded reference signals sent by the transmit antennas in at least two of the J polarization directions are different, the first indication information may separately indicate a target port corresponding to each polarization direction, or the first indication information may include indication information of one or more target ports corresponding to each of the J polarization directions. When a plurality of receive antennas are configured for the terminal device, the receive antenna described in the foregoing embodiment may be any one of the plurality of receive antennas of the terminal device. When the plurality of receive antennas are configured for the terminal device, the terminal device may separately determine one or more stronger ports based on each of the plurality of receive antennas, or may jointly determine one or more stronger ports based on the plurality of receive antennas. The one or more stronger ports that are determined by the terminal device based on the plurality of receive antennas are the target port described above. It is assumed that R receive antennas are configured for the terminal device, where R is an integer greater than 1. The terminal device may determine Qrtarget ports based on precoded reference signals of the P ports that are received by an rthreceive antenna in the R receive antennas. r=1, 2, . . . , or R; and Qris an integer. Optionally, target ports determined by the terminal device based on precoded reference signals received by any two of the R receive antennas are the same. The terminal device may determine Q target ports based on any receive antenna. That is, when a value of r is any one of 1 to R, that Qr=Q is satisfied. The Q target ports may be Q stronger ports determined by performing channel measurement based on precoded reference signals received by the R receive antennas, or may be Q stronger ports determined by performing channel measurement based on a precoded reference signal received by a specific receive antenna. This is not limited in this application. When Q same target ports are determined by the terminal device based on precoded reference signals received by any two of the R receive antennas, the first indication information may indicate the Q target ports once, or the first indication information includes only one piece of indication information used to indicate the Q target ports. It should be understood that, a specific method for determining, by the terminal device based on the precoded reference signals received by the plurality of receive antennas, the Q stronger target ports from the P ports is similar to the foregoing listed specific method for determining, based on a precoded reference signal received by one receive antenna, the Q stronger target ports from the P ports. For brevity, details are not described herein again. Optionally, target ports determined by the terminal device based on precoded reference signals received by at least two of the R receive antennas are different. The terminal device may determine the Qrstronger target ports based on the precoded reference signal received by the rthreceive antenna. That target ports determined by the terminal device based on precoded reference signals received by at least two of the R receive antennas are different may mean that target ports determined by the terminal device based on precoded reference signals received by some of the R receive antennas are different, or may mean that target ports determined by the terminal device based on precoded reference signals received by all of the R receive antennas are different. That target ports determined based on precoded reference signals received by two receive antennas are different may mean that the target ports determined based on the precoded reference signals received by the two receive antennas are completely different, that is, the target ports determined based on the precoded reference signals received by the two receive antennas are not repeated, or have no intersection. That target ports determined based on precoded reference signals received by two receive antennas are different may alternatively mean that the target ports determined based on the precoded reference signals received by the two receive antennas are partially different, that is, the target ports determined based on the precoded reference signals received by the two receive antennas are partially repeated but are not completely the same, or the target ports determined based on the precoded reference signals received by the two receive antennas have an intersection but are not completely the same. Certainly, when the target ports determined based on the precoded reference signals received by the two receive antennas are different, quantities of target ports determined based on the precoded reference signals received by the two receive antennas may be the same or may be different. This is not limited in this application. When the target ports determined by the terminal device based on the precoded reference signals received by at least two of the R receive antennas are different, the first indication information may separately indicate a target port corresponding to each receive antenna, or the first indication information may include indication information of one or more target ports corresponding to each of the R receive antennas. The foregoing specific method for determining the Q target ports in operation220is based on a receive antenna. Actually, the terminal device is not limited to determining the target port based on each receive antenna, and the terminal device may alternatively determine the target port based on a transport layer. An example in which a quantity of polarization directions is J and a quantity of receive antennas is R is still used. The terminal device may construct a coefficient matrix based on J×R×P weighting coefficients corresponding to the J polarization directions and the R receive antennas. The coefficient matrix may be a matrix with J×P rows and R columns, and elements in each column may be J×P weighting coefficients corresponding to one receive antenna. An example of the coefficient matrix is shown below: [α1,1α1,2…α1,R⋮⋮…⋮αP,1αP,2…αP,RαP+1,1αP+1,2…αP+1,R⋮⋮…⋮α2P,1α2P,2…α2P,R]. The coefficient matrix shows an example in which the quantity J of polarization directions is equal to 2. The first row to a Pthrow in the coefficient matrix may include weighting coefficients corresponding to one polarization direction, and αp,rmay represent a weighting coefficient corresponding to the pthangle-delay pair and the rthreceive antenna in the first polarization direction. A (P+1)throw to a 2Pthrow in the coefficient matrix may include weighting coefficients corresponding to another polarization direction, and αP+p,rmay represent a weighting coefficient corresponding to the pthangle-delay pair and the rthreceive antenna in the second polarization direction. p=1, 2, . . . , or P; and r=1, 2, . . . , or R. The terminal device may perform singular value decomposition (SVD) on the coefficient matrix to obtain a weighting coefficient corresponding to a transport layer. Assuming that a quantity of transport layers is Z, weighting coefficients corresponding to the Z transport layers may include Z×2P weighting coefficients. The first column to a Pt column of the Z×2P weighting coefficients correspond to one polarization direction, and a (P+1)thcolumn to a 2Pthcolumn of the Z×2P weighting coefficients correspond to another polarization direction. Each row of the Z×2P weighting coefficients corresponds to one transport layer. That is, 2P weighting coefficients in each row are weighting coefficients of 2P angle-delay pairs determined based on one transport layer. For each transport layer, the terminal device may select some stronger weighting coefficients from weighting coefficients corresponding to each polarization direction, and feed back ports corresponding to the weighting coefficients to the network device. For example, for a zthtransport layer, the terminal device may select Qz(where Qzis a positive integer) stronger ports based on weighting coefficients of P ports corresponding to the zthtransport layer to be reported to the network device. The Qzstronger ports are an example of the target ports described above. A value of z is traversed from 1 to Z, so that one or more target ports corresponding to each of the Z transport layers may be determined. Optionally, target ports fed back by the terminal device based on any two of the Z transport layers are the same. The terminal device may determine Q ports based on any transport layer. That is, when the value of z is any one of 1 to Z, that Qz=Q is satisfied. The Q ports may be Q stronger ports determined by performing channel measurement based on precoded reference signals received at the Z transport layers, or may be Q stronger ports determined by performing channel measurement based on a precoded reference signal received at a specific transport layer. This is not limited in this application. When Q same target ports are determined by the terminal device based on any two of the Z transport layers, the first indication information may indicate the Q target ports once, or the first indication information includes only one piece of indication information used to indicate the Q target ports. It should be understood that, a specific method for determining, by the terminal device based on a plurality of transport layers, the Q stronger target ports from the P ports is similar to the foregoing listed specific method for determining, based on one transport layer, the Q stronger target ports from the P ports. For brevity, details are not described herein again. Optionally, target ports determined by the terminal device based on at least two of the Z transport layers are different. The terminal device may determine Qzstronger target ports based on a Zthtransport layer. That target ports determined by the terminal device based on at least two of the Z transport layers are different may mean that target ports determined by the terminal device based on some of the Z transport layers are different, or may mean that target ports determined by the terminal device based on all of the Z transport layers are different. That target ports determined based on two transport layers are different may mean that the target ports determined based on two transport layers are completely different, that is, the target ports determined based on the two transport layers are not repeated, or have no intersection. That target ports determined based on two transport layers are different may alternatively mean that the target ports determined based on the two transport layers are partially different, that is, the target ports determined based on the two transport layers are partially repeated but are not completely the same, or the target ports determined based on the two transport layers have an intersection but are not completely the same. Certainly, when the target ports determined based on the two transport layers are different, quantities of target ports determined based on the two transport layers may be the same or may be different. This is not limited in this application. When the target ports determined by the terminal device based on at least two of the Z transport layers are different, the first indication information may separately indicate a target port corresponding to each transport layer, or the first indication information may include indication information of one or more target ports corresponding to each of the Z transport layers. It should be understood that, a specific method for determining, by the terminal device based on a weighting coefficient, one or more target ports from the P ports has been described in detail above. For brevity, details are not described herein again. Step230: The terminal device sends the first indication information. Correspondingly, the network device receives the first indication information. Specifically, the terminal device may send the first indication information to the network device by using a pre-allocated physical uplink resource, for example, a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). For example, the first indication information may be carried in a CSI report, or may be carried in other existing or newly added signaling. Specific signaling used to carry the first indication information is not limited in this application. It should be understood that, for a specific process in which the terminal device sends the first indication information by using the physical uplink resource, refer to the conventional technology. For brevity, detailed descriptions of the specific process are omitted herein. Step240: The network device determines, based on the first indication information, the Q angle-delay pairs corresponding to the Q ports. As described above, when precoding the reference signal, the network device may determine the correspondence among each angle vector, a delay vector, and a port. In addition, when the reference signal is transmitted, the correspondence between each port and a time-frequency resource may also be learned of. Therefore, the terminal device indicates the Q ports (that is, the target ports in operation220) to the network device, and the network device may determine the Q corresponding angle-delay pairs based on the Q ports. Based on the foregoing solution, precoding the reference signal by the network device based on the angle vector and the delay vector is equivalent to precoding the reference signal in space domain and frequency domain. A delay vector is introduced for a reference signal. A change of a channel in a plurality of frequency domain units may be represented by using a delay vector, and a reference signal is precoded based on the delay vector, so that the terminal device does not need to separately feed back the target port based on each frequency domain unit. Therefore, the feedback overheads can be reduced. After determining the Q angle-delay pairs, the network device may precode, based only on the Q angle-delay pairs, a reference signal to be sent next time, or may continue to precode, based on the P angle-delay pairs, a reference signal to be sent next time. This is not limited in this application. In an embodiment, the network device may precode, based on P1angle-delay pairs (namely, an example of the P angle-delay pairs) in a periodicity (for example, denoted as a periodicity #1) of predetermined duration, a reference signal that is sent for the first time in the periodicity #1, to obtain and send precoded reference signals of P1ports (namely, an example of the P ports). The network device may precode, by using Q1corresponding angle-delay pairs (namely, an example of the angle-delay pairs corresponding to the Q target ports) based on Q1ports (namely, an example of the Q target ports) indicated by the terminal device by using indication information #1 (namely, an example of the first indication information), a reference signal to be sent next time or reference signals to be subsequently sent for a plurality of times. The network device may precode, in a next periodicity (for example, denoted as a periodicity #2) based on P2angle-delay pairs (namely, another example of the P angle-delay pairs), a reference signal that is sent for the first time in the periodicity #2, to obtain and send precoded reference signals of P2ports. The network device may precode, by using Q2corresponding angle-delay pairs (namely, another example of the angle-delay pairs corresponding to the Q target ports) based on Q2ports (namely, another example of the Q target ports) indicated by the terminal device by using indication information #2 (namely, another example of the first indication information), a reference signal to be sent next time or reference signals to be subsequently sent for a plurality of times. By analogy, the network device may precode reference signals in a plurality of periodicities according to the foregoing method. For brevity, details are not described herein. Based on the foregoing solution, the network device may first precode the reference signal by using a plurality of angle-delay pairs, so that the terminal device performs channel measurement. Then, the network device may precode the reference signal based on a feedback of the terminal device by using a stronger angle-delay pair in the downlink channel. Because a weighting coefficient of a stronger angle-delay pair has greater impact on the feedback precision, the feedback overheads can be reduced while the feedback precision is ensured, and a compromise between the feedback precision and the feedback overheads can be reached. As described above, the network device may precode the downlink reference signal based on reciprocity between uplink and downlink channels and based on one or more stronger angle vectors and one or more stronger delay vectors that are determined through uplink channel measurement, to send the precoded reference signal to the terminal device, so that the terminal device performs downlink channel measurement. For example, based on uplink channel measurement, the network device may determine two stronger angle vectors a(θ2) and a(θ4) from a plurality of predefined angle vectors, and determine two stronger delay vectors b(τ1) and b(τ3) from a plurality of predefined delay vectors. However, actually, based on downlink channel measurement, two stronger angle vectors a(θ2) and a(θ3) and two strong delayer vectors b(τ3) and b(τ4) are determined. The network device constructs four angle-delay pairs: (a(θ2), b(τ1)), (a(θ4), b(τ1)), (a(θ2), b(τ3)), and (a(θ4), b(τ3)) based on the angle vectors a(θ2) and a(θ4) and the delay vectors b(τ1) and b(τ3). If the network device precodes the reference signal based on the angle vectors and the delay vectors in the four angle-delay pairs, the feedback precision of the terminal device may be limited. However, in the method provided in this application, the network device may precode the reference signal in advance by using a plurality of angle-delay pairs, and after obtaining a stronger angle-delay pair that is in the downlink channel and that is fed back by the terminal device through measurement, the network device may select some stronger angle-delay pairs from the plurality of angle-delay pairs, to precode a reference signal to be sent next time, so as to perform downlink channel measurement. For example, the network device may precode the reference signal in advance based on a plurality of (for example, 16) angle-delay pairs determined by using the four angle vectors and the four delay vectors, where the plurality of angle-delay pairs may include a combination of any one of a(θ1) to a(θ4) and any one of b(τ1) to b(τ4). After the terminal device feeds back the stronger angle-delay pair based on downlink channel measurement, the network device may mainly load an angle-delay pair used to next precode the reference signal to a stronger angle-delay pair in the downlink channel. For the foregoing four angle-delay pairs, the four angle-delay pairs include (a(θ2), b(τ3)), (a(θ3), b(τ3)), (a(θ2), b(τ4)), and (a(θ3), b(τ4)). Therefore, the network device may mainly load the angle-delay pair used to precode the reference signal to a stronger angle-delay pair in the downlink channel. Because the network device precodes the reference signal by using the plurality of angle-delay pairs in advance, a stronger angle-delay pair in the downlink channel determined by the terminal device may fall within a range of the plurality of angle-delay pairs with a higher probability. Therefore, on one hand, this helps obtain relatively high feedback precision, and on the other hand, feedback overheads caused by a next feedback of a weighting coefficient by the terminal device can be reduced. In addition, after determining the Q target ports from the P ports based on the weighting coefficients of the P angle-delay pairs, the terminal device may further indicate the weighting coefficients of the angle-delay pairs corresponding to the Q target ports. Optionally, the method200further includes: Step250: The terminal device generates second indication information, where the second indication information is used to indicate the weighting coefficients of the Q angle-delay pairs, and the Q angle-delay pairs and the weighting coefficients corresponding to the Q angle-delay pairs are used to determine a precoding matrix. For example, the terminal device may indicate the weighting coefficients of the Q angle-delay pairs in a normalized manner. For example, the terminal device may determine a weighting coefficient with a largest modulus (for example, denoted as a maximum weighting coefficient) from the Q weighting coefficients, and indicate a position of the maximum weighting coefficient in the Q weighting coefficients. The terminal device may further indicate relative values of Q−1 remaining weighting coefficients relative to the maximum weighting coefficient. The terminal device may indicate the Q−1 weighting coefficients by using quantized value indexes of the relative values. For example, the network device and the terminal device may predefine a one-to-one correspondence between a plurality of quantized values and a plurality of indexes, and the terminal device may feed back the relative values of the weighting coefficients relative to the maximum weighting coefficient to the network device based on the one-to-one correspondence. Because the terminal device quantizes the weighting coefficients, and a quantized value may be the same as or close to an actual value, the quantized value is referred to as a quantized value of the weighting coefficient. When generating the second indication information used to indicate the weighting coefficients of the Q angle-delay pairs, the terminal device may generate, according to a pre-agreed sequence, quantized information of the Q weighting coefficients corresponding to the Q angle-delay pairs. For example, refer toFIG.4. In a sequence from the first row to the Lthrow and a sequence from the first column to the Kthcolumn for each row, or in a sequence from the first column to the Kthcolumn and a sequence from the first row to the Lt row for each column, the terminal device may arrange the Q weighting coefficients corresponding to the Q angle-delay pairs into an ordered array, and separately indicate the weighting coefficients in the ordered array by using the second indication information. The network device may interpret the second indication information according to a same rule, to determine a correspondence between each weighting coefficient and an angle-delay pair. It should be understood that, the foregoing description with reference toFIG.4is merely an example for ease of understanding and description, and does not indicate that the terminal device generates the arrangement relationship shown inFIG.4or an arrangement relationship similar to that shown inFIG.4when generating the second indication information. It should be further understood that, the terminal device may generate the second indication information according to a rule pre-agreed on with the network device or a predefined rule. The network device may interpret the second indication information according to a same rule. Therefore, the network device may determine the Q weighting coefficients corresponding to the Q angle-delay pairs. The rule listed above with reference toFIG.4is merely an example, and specific content of the rule is not specified in this application. It should be noted that, when the terminal device indicates the Q weighting coefficients in the normalized manner, the terminal device may not directly indicate the quantized values of the Q weighting coefficients. For example, for the maximum weighting coefficient, the position of the maximum weighting coefficient in the Q weighting coefficients or a position of the maximum weighting coefficient in the P weighting coefficients may be indicated. For another example, for a weighting coefficient whose quantized value is zero, a position of the weighting coefficient in the Q weighting coefficients may also be indicated. In other words, the second indication information directly or indirectly indicates the Q weighting coefficients. Any implementation in which the network device can restore the Q weighting coefficients based on the second indication information falls within the protection scope of this application. It should be further understood that, the normalization mentioned above may be determining the maximum weighting coefficient by using each receive antenna as a unit, to perform normalization within a range of quantized information corresponding to each receive antenna. However, this shall not constitute any limitation on this application. For example, in this embodiment, the terminal device may alternatively determine the maximum weighting coefficient by using a plurality of receive antennas, one polarization direction, a plurality of polarization directions, or one port as a unit, to perform normalization within a range of quantized information corresponding to the plurality of receive antennas, each polarization direction, the plurality of polarization directions, or the port. It should be understood that, the foregoing listed manner of indicating each weighting coefficient in the normalized manner is merely a possible implementation, and this shall not constitute any limitation on this application. A specific manner of indicating the weighting coefficient by the terminal device is not limited in this application. For example, a quantized value index of each of the Q weighting coefficients may also be indicated. It should be noted that, a specific process in which the terminal device generates the second indication information is described in detail above by using one polarization direction and one receive antenna as an example. In other words, the weighting coefficients of the Q angle-delay pairs corresponding to the Q target ports may be determined based on a precoded reference signal that is sent by a transmit antenna in one polarization direction and that is received by one receive antenna. However, this shall not constitute any limitation on this application. As described above, when transmit antennas in a plurality of polarization directions are configured for the network device, the polarization direction described in the foregoing embodiment may be any one of the plurality of polarization directions. In other words, the terminal device may determine, based on the foregoing method, the weighting coefficient based on a precoded reference signal sent by the transmit antenna in each polarization direction. As described in operation220, it is assumed that the transmit antennas in the J polarization directions are configured for the network device, where J is an integer greater than 1. The terminal device may determine, based on the precoded reference signal sent by the transmit antenna in the jthpolarization direction, the Q target ports corresponding to the jthpolarization direction. If the quantity of receive antennas is 1 and the quantity of the polarization direction is J, where J is an integer greater than 1, the second indication information may be used to indicate J groups of weighting coefficients corresponding to the J polarization directions, and a jthgroup of weighting coefficients may include Qjweighting coefficients. Herein, one group of weighting coefficients corresponding to one polarization direction is one or more weighting coefficients determined by performing channel measurement based on a precoded reference signal transmitted in the polarization direction. Optionally, the second indication information includes J sets of indication information, and each set of indication information corresponds to one polarization direction. Each set of indication information is used to indicate one or more weighting coefficients corresponding to the polarization direction. The terminal device may indicate, in the normalized manner by using each polarization direction as a unit, the one or more weighting coefficients corresponding to each polarization direction. Optionally, when the second indication information is used to indicate a plurality of weighting coefficients in the J polarization directions, the normalized manner may also be used for indication by using the J polarization directions as a unit. That is, a maximum weighting coefficient may be determined from the plurality of weighting coefficients corresponding to the J polarization directions, and a position of the maximum weighting coefficient may be indicated. The terminal device may further determine relative values of the remaining weighting coefficients relative to the maximum weighting coefficient, and indicate the remaining weighting coefficients by using quantized value indexes of the relative values. It should be understood that, a specific method for performing, by the terminal device, normalization within a range of quantized information in a plurality of polarization directions is the same as that for performing normalization within a range of quantized information in one polarization direction. For brevity, details are not described herein again. It should be further understood that, when indicating the weighting coefficients in the plurality of polarization directions in the normalized manner, the terminal device may sequentially indicate the weighting coefficients in a pre-agreed sequence. For example, weighting coefficients other than a normalization coefficient may be sequentially indicated in a predefined indication sequence of the J polarization directions. A sequence in which the terminal device indicates the weighting coefficients is not limited in this application, provided that the network device can restore, based on the second indication information, the plurality of weighting coefficients corresponding to the J polarization directions. It should be noted that, merely for ease of description and understanding, the foregoing defines the weighting coefficient corresponding to each polarization direction as a group of weighting coefficients. However, this shall not constitute any limitation on this application. When indicating the weighting coefficient by using the second indication information, the terminal device does not necessarily indicate, in a form of a group, the weighting coefficient corresponding to each polarization direction. The “group” is merely a logical concept, and this shall not constitute any limitation on a field actually included in the second indication information or a specific manner of indicating the weighting coefficient. As described above, when the plurality of receive antennas are configured for the terminal device, the receive antenna described in the foregoing embodiment may be any one of the plurality of receive antennas of the terminal device. When the plurality of receive antennas are configured for the terminal device, the terminal device may report the weighting coefficient based on each of the plurality of receive antennas. As described in operation220, it is assumed that the R receive antennas are configured for the terminal device, where R is an integer greater than 1. The terminal device may feed back the Qrtarget ports based on the received precoded reference signals of the P ports and the rthreceive antenna in the R receive antennas. r=1, 2, . . . , or R; and Qris an integer. If the quantity of polarization directions is 1 and the quantity of receive antennas is R, where R is an integer greater than 1, the second indication information may be used to indicate R groups of weighting coefficients corresponding to the R receive antennas, and an rthgroup of weighting coefficients may include Qrweighting coefficients. Herein, one group of weighting coefficients corresponding to one receive antenna may be a weighting coefficient determined by performing channel measurement based on a precoded reference signal received by the receive antenna. Optionally, the second indication information includes R sets of indication information, and each set of indication information corresponds to one receive antenna. Each set of indication information is used to indicate one or more weighting coefficients corresponding to one receive antenna. The terminal device may indicate, in the normalized manner by using each receive antenna as a unit, the one or more weighting coefficients corresponding to each receive antenna. Optionally, when the second indication information is used to indicate a plurality of weighting coefficients corresponding to the R receive antennas, the normalized manner may also be used for indication by using the plurality of receive antennas as a unit. That is, a maximum weighting coefficient may be determined from the plurality of weighting coefficients corresponding to the R receive antennas, and a position of the maximum weighting coefficient may be indicated. The terminal device may further determine relative values of the remaining weighting coefficients relative to the maximum weighting coefficient, and indicate the remaining weighting coefficients by using quantized value indexes of the relative values. It should be understood that, a specific method for performing, by the terminal device, normalization within a range of quantized information of a plurality of receive antennas is the same as that for performing normalization within a range of quantized information of one receive antenna. For brevity, details are not described herein again. It should be further understood that, when indicating the weighting coefficients of the plurality of receive antennas in the normalized manner, the terminal device may sequentially indicate the weighting coefficients in a pre-agreed sequence. For example, weighting coefficients other than a normalization coefficient may be sequentially indicated in a predefined indication sequence of the R receive antennas. A sequence in which the terminal device indicates the weighting coefficients is not limited in this application, provided that the network device can restore, based on the second indication information, the plurality of weighting coefficients corresponding to the R receive antennas. It should be noted that, merely for ease of description and understanding, the foregoing defines the weighting coefficient corresponding to each receive antenna as a group of weighting coefficients. However, this shall not constitute any limitation on this application. When indicating the weighting coefficient by using the second indication information, the terminal device does not necessarily indicate, in a form of a group, the weighting coefficient corresponding to each receive antenna. The “group” is merely a logical concept, and this shall not constitute any limitation on a field actually included in the second indication information or a specific manner of indicating the weighting coefficient. If the quantity of receive antennas is R and the quantity of polarization directions is J, the second indication information may be used to indicate a plurality of weighting coefficients corresponding to the J polarization directions and the R receive antennas. A weighting coefficient corresponding to one polarization direction and one receive antenna may be a weighting coefficient determined by performing channel measurement based on a precoded reference signal that is sent by a transmit antenna in the polarization direction and that is received by the receive antenna. Optionally, when the second indication information is used to indicate the plurality of weighting coefficients corresponding to the J polarization directions and the R receive antennas, the normalized manner may be used for indication by using one polarization direction and the R receive antennas as a unit. When the second indication information is used to indicate the plurality of weighting coefficients corresponding to the J polarization directions and the R receive antennas, the normalized manner may also be used for indication by using one polarization direction and the R receive antennas as a unit. For example, the second indication information includes J sets of indication information, and each set of indication information corresponds to one polarization direction and the R receive antennas. Each set of indication information is used to indicate a plurality of weighting coefficients corresponding to the polarization direction and the R receive antennas. Optionally, when the second indication information is used to indicate the plurality of weighting coefficients corresponding to the J polarization directions and the R receive antennas, the normalized manner may also be used for indication by using the J polarization directions and one receive antenna as a unit. For example, the second indication information includes R sets of indication information, and each set of indication information corresponds to one receive antenna and J polarization directions. Each set of indication information is used to indicate a plurality of weighting coefficients corresponding to the receive antenna and the J polarization directions. Optionally, when the second indication information is used to indicate the plurality of weighting coefficients corresponding to the J polarization directions and the R receive antennas, the normalized manner may also be used for indication by using one polarization direction and one receive antenna as a unit. For example, the second indication information includes J×R sets of indication information, and each set of indication information corresponds to one polarization direction. Each set of indication information is used to indicate one or more weighting coefficients corresponding to the polarization direction and one receive antenna. A unit for normalization and a specific indication manner are not limited in this application. It should be understood that, a specific method for indicating the plurality of weighting coefficients by the terminal device in the normalized manner has been described in detail above. For brevity, details are not described herein again. It should be further understood that, when indicating the weighting coefficients of the plurality of polarization directions and the plurality of receive antennas in the normalized manner, the terminal device may sequentially indicate the weighting coefficients in a pre-agreed sequence. For example, weighting coefficients other than a normalization coefficient may be sequentially indicated in a predefined indication sequence of the J polarization directions and the R receive antennas. A sequence in which the terminal device indicates the weighting coefficients is not limited in this application, provided that the network device can restore, based on the second indication information, the plurality of weighting coefficients of the J polarization directions and the R receive antennas. It should be further understood that, indication of the weighting coefficients in the normalized manner is merely a possible implementation, and this shall not constitute any limitation on this application. A specific manner of indicating the weighting coefficients by using the second indication information is not limited in this application. It should be noted that, merely for ease of description and understanding, the foregoing defines the weighting coefficient corresponding to each polarization direction and/or each receive antenna as a group of weighting coefficients. However, this shall not constitute any limitation on this application. When indicating the weighting coefficient by using the second indication information, the terminal device does not necessarily indicate, in a form of a group, the weighting coefficient corresponding to each polarization direction and/or each receive antenna. The “group” is merely a logical concept, and this shall not constitute any limitation on a field actually included in the second indication information or a specific manner of indicating the weighting coefficient. When the weighting coefficient is fed back based on the receive antenna, the terminal device may further indicate the quantity of receive antennas. Optionally, the method200further includes: The terminal device sends fourth indication information, where the fourth indication information is used to indicate the quantity of receive antennas. Correspondingly, the network device receives the fourth indication information. The fourth indication information and the second indication information may be carried in same signaling, for example, a precoding matrix indicator (PMI) or a CSI report, for sending, or may be sent by using different signaling. This is not limited in this application. It should be understood that, the quantity of receive antennas of the terminal device may alternatively be predefined, for example, defined in a protocol. In this case, the terminal device may not indicate the quantity of receive antennas by using additional signaling. Actually, the terminal device is not limited to feeding back the weighting coefficient based on each receive antenna, and the terminal device may alternatively feed back the weighting coefficient based on a transport layer. After determining, based on the foregoing method, the weighting coefficient corresponding to each polarization direction and each receive antenna, the terminal device may further process the weighting coefficient, to obtain a weighting coefficient fed back based on each transport layer. When the terminal device indicates, by using the second indication information, the weighting coefficients corresponding to the Z transport layers, the normalized manner may also be used for indication. For example, the terminal device may indicate, in the normalized manner by using one transport layer as a unit, one or more weighting coefficients corresponding to each transport layer. Alternatively, the terminal device may indicate, in the normalized manner by using the Z transport layers as a unit, a plurality of weighting coefficients corresponding to the Z transport layers. It should be understood that, indication of the weighting coefficients in the normalized manner is merely a possible implementation, and this shall not constitute any limitation on this application. A specific manner of indicating the weighting coefficients by using the second indication information is not limited in this application. It should be further understood that, a specific method for feeding back the weighting coefficient by the terminal device based on the transport layer is similar to the foregoing specific method for feeding back the weighting coefficient based on the receive antenna. The specific method for feeding back the weighting coefficient by the terminal device based on the receive antenna has been described in detail above. For brevity, details are not described herein again. When the weighting coefficient is fed back based on the transport layer, the terminal device may further indicate the quantity of transport layers. Optionally, the method200further includes: The terminal device sends fifth indication information, where the fifth indication information is used to indicate the quantity of transport layers. Correspondingly, the network device receives the fifth indication information. Optionally, the fifth indication information is a rank indicator (RI). It should be understood that, the RI is merely an example of the fifth indication information, and this shall not constitute any limitation on this application. A specific form of the fifth indication information is not limited in this application. It should be further understood that, the fifth indication information and the second indication information may be carried in same signaling, for example, a CSI report, for sending, or may be sent by using different signaling. This is not limited in this application. It should be further understood that, the method for constructing a coefficient matrix and performing SVD on the coefficient matrix to determine a weighting coefficient corresponding to each transport layer that is listed above is merely an example, and this shall not constitute any limitation on this application. A specific method for determining the weighting coefficient of each transport layer is not limited in this application. Optionally, the method200further includes: Step260: The terminal device sends the second indication information. Correspondingly, in operation260, the network device receives the second indication information. Specifically, the terminal device may send the second indication information to the network device by using a pre-allocated physical uplink resource. The second indication information and the first indication information may be carried in same signaling, for example, a CSI report, for sending, or may be carried in different signaling for sending. This is not limited in this application. It should be understood that, for a specific process in which the terminal device sends the second indication information by using the physical uplink resource, refer to the conventional technology. For brevity, detailed descriptions of the specific process are omitted herein. Step270: The network device determines the precoding matrix based on the second indication information. As described above, the terminal device may feed back the weighting coefficient based on the receive antenna, or may feed back the weighting coefficient based on the transport layer. The network device may determine the precoding matrix based on the second indication information and based on different feedback granularities. If the terminal device feeds back the weighting coefficient based on the receive antenna, the weighting coefficient indicated by the second indication information may include a weighting coefficient corresponding to one or more receive antennas. The network device may reconstruct a downlink channel based on the weighting coefficient corresponding to each receive antenna and the angle-delay pair corresponding to each weighting coefficient, to further determine a precoding matrix of each RB (namely, an example of the frequency domain unit). Herein, it should be noted that, when the terminal device feeds back the weighting coefficient by using the second indication information based on the receive antenna, the target port fed back by the terminal device by using the first indication information is also fed back based on the receive antenna. The network device may determine, based on the target port indicated by the terminal device in the first indication information, the angle-delay pair corresponding to each weighting coefficient, or determine the correspondence between each angle-delay pair and a weighting coefficient. Specifically, one polarization direction of a transmit antenna is used as an example. The terminal device may feed back one or more weighting coefficients based on each receive antenna. For ease of description below, it is assumed that the terminal device feeds back Q weighting coefficients based on each receive antenna. The Q weighting coefficients corresponding to each receive antenna may correspond to the Q ports indicated by the second indication information, that is, are in a one-to-one correspondence with the Q angle-delay pairs corresponding to the Q ports. The network device may construct, based on the Q weighting coefficients corresponding to each receive antenna and an angle vector and a delay vector that are included in each of the Q angle-delay pairs, a spatial-frequency matrix corresponding to each receive antenna. In this embodiment, a spatial-frequency matrix corresponding to the rthreceive antenna may be determined by using the Q angle-delay pairs and Q weighting coefficients corresponding to the rthreceive antenna. The Q angle-delay pairs may be used to construct Q spatial-frequency component matrices. As described above, the spatial-frequency component matrix a(θk)×b(τl)Hmay be constructed by using the kthangle vector a(θk) in the K angle vectors and the lthdelay vector b(τl) in the L delay vectors. The spatial-frequency matrix HDL(r)corresponding to the rthreceive antenna may be a weighted sum of the Q spatial-frequency component matrices. That is, HDL(r)=∑l=1L∑k=1Kαk,l(r)a(θk)×b(τl)H. αk,l(r)represents a weighting coefficient that is fed back based on the rthreceive antenna and that corresponds to the kthangle vector and the lthdelay vector. Dimensions of the spatial-frequency matrix may be T×N. It is assumed that in the calculation formula of the spatial-frequency matrix HDL(r), the K angle vectors and the L delay vectors are shared by each other. When delay vectors corresponding to at least two angle vectors are different, the foregoing formula may be transformed into: HDL(r)=∑lk=1Lk∑k=1Kαk,lk(r)a(θk)×b(τlk)H. Alternatively, when angle vectors corresponding to at least two delay vectors are different, the foregoing formula may be transformed into: HDL(r)=∑l=1L∑kl=1Klαkl,l(r)a(θkl)×b(τl)H. For ease of description, HDL(r)=∑l=1L∑k=1Kαk,l(r)a(θk)×b(τl)H is used as an example for description below. It may be understood that regardless of whether delay vectors corresponding to angle vectors are the same, or whether angle vectors corresponding to delay vectors are the same, determining of the precoding matrix is not affected. It should be noted that, for ease of understanding, the foregoing uses one polarization direction of the transmit antenna as an example to describe a specific process of determining the spatial-frequency matrix corresponding to the receive antenna. However, this shall not constitute any limitation on this application. When the quantity of polarization directions of the transmit antenna is greater than 1, the network device may still determine, based on the foregoing method, the spatial-frequency matrix corresponding to each receive antenna. For example, when the quantity of polarization directions of the transmit antenna is 2, the spatial-frequency matrix corresponding to the rthreceive antenna may be determined by using the following calculation formula: HDL(r)=[∑l=1L∑k=1Kαk,l,1(r)a(θk)×b(τl)H∑l=1L∑k=1Kαk,l,2(r)a(θk)×b(τl)H]. αk,l,1(r)represents a weighting coefficient that is fed back based on the rthreceive antenna and that corresponds to the kthangle vector and the lthdelay vector in the first polarization direction; and αk,l,2(r)represents a weighting coefficient that is fed back based on the rthreceive antenna and that corresponds to the kthangle vector and the lthdelay vector in the second polarization direction. It should be understood that, the foregoing calculation formula of the spatial-frequency matrix HDL(r)that is defined for the two polarization directions is merely an example, and this shall not constitute any limitation on this application. For example, quantities of delay vectors and/or angle vectors loaded in different polarization directions may be the same or may be different, and delay vectors and/or angle vectors loaded in different polarization directions may be the same or may be different. For the R receive antennas, the network device may determine spatial-frequency matrices HDL(1)and HDL(2)to HDL(R)based on the Q weighting coefficients corresponding to each receive antenna. Therefore, the network device may determine a downlink channel matrix corresponding to each RB. An nthRB in N RBs is used as an example. The network device may determine a conjugate transpose (V(n))Hof a downlink channel matrix corresponding to the nthRB. The matrix (V(n))Hmay be determined by using an nthcolumn vector in each of the R spatial-frequency matrices HDL(1)and HDL(2)to HDL(R)that are respectively determined based on the R receive antennas. For example, an nthcolumn in HDL(1)is used as the first column in the matrix (V(n))H, an nthcolumn in HDL(2)is used as the second column in the matrix (V(n))H, and by analogy, an nthcolumn in HDL(R)may be used as an rthcolumn in the matrix (V(n))H. Therefore, a matrix (V(n))Hmay be obtained, to determine a downlink channel matrix V(n)corresponding to the nthRB. The downlink channel matrix corresponding to each RB may be determined based on the foregoing method. The network device may further determine the precoding matrix of each RB based on the downlink channel matrix of each RB. For example, the network device may determine the precoding matrix by performing SVD on the downlink channel matrix or a covariance matrix of the channel matrix, or may determine the precoding matrix by performing eigenvalue decomposition (EVD) on a covariance matrix of the downlink channel matrix. It should be understood that, for a specific manner of determining the precoding matrix by the network device based on the channel matrix, refer to the conventional technology. A manner of determining the precoding matrix is not limited in this application. It should be further understood that, merely for ease of understanding, the foregoing shows a specific process in which the network device determines the downlink channel matrix based on the spatial-frequency matrix, to further determine the precoding matrix. However, this shall not constitute any limitation on this application. Alternatively, the network device may directly determine the precoding matrix based on the spatial-frequency matrix. If the terminal device feeds back the weighting coefficient based on the transport layer, the weighting coefficient indicated by the second indication information may include a weighting coefficient of one or more transport layers. The network device may determine, based on the weighting coefficient corresponding to each transport layer and the angle-delay pair corresponding to each weighting coefficient, a spatial-frequency matrix corresponding to each transport layer, to further determine the precoding matrix of each RB. Herein, it should be noted that, when the terminal device feeds back the weighting coefficient by using the second indication information based on the transport layer, the target port fed back by the terminal device by using the first indication information is also fed back based on the transport layer. The network device may determine, based on the target port indicated by the terminal device in the first indication information, the angle-delay pair corresponding to each weighting coefficient, or determine the correspondence between each angle-delay pair and a weighting coefficient. Specifically, one polarization direction of a transmit antenna is used as an example. The terminal device may feed back one or more weighting coefficients based on each transport layer. For ease of description below, it is assumed that the terminal device feeds back Q weighting coefficients based on each transport layer. The Q weighting coefficients corresponding to each transport layer may correspond to the Q ports indicated by the second indication information, that is, are in a one-to-one correspondence with the Q angle-delay pairs corresponding to the Q ports. The network device may construct, based on the Q weighting coefficients corresponding to each transport layer and an angle vector and a delay vector that are included in each of the Q angle-delay pairs, a precoding vector corresponding to the transport layer. In this embodiment, a spatial-frequency matrix HDL(z)corresponding to the zthtransport layer may be determined by using the Q angle-delay pairs and Q weighting coefficients corresponding to the zthtransport layer. The Q angle-delay pairs may be used to construct Q spatial-frequency component matrices. A precoding vector corresponding to the zthtransport layer may be a weighted sum of the Q spatial-frequency component matrices. That is, HDL(z)=∑l=1L∑k=1Kαk,l(z)a(θk)×b(τl)H. αk,l(r)represents a weighting coefficient that is fed back based on the rthreceive antenna and that corresponds to the kthangle vector and the lthdelay vector. Dimensions of the spatial-frequency matrix may be T×N. It is assumed that in the calculation formula of the spatial-frequency matrix HDL(z), the K angle vectors and the L delay vectors are shared by each other. When delay vectors corresponding to at least two angle vectors are different, the foregoing formula may be transformed into: HDL(z)=∑lk=1Lk∑k=1Kαk,lk(r)a(θk)×b(τlk)H. Alternatively, when angle vectors corresponding to at least two delay vectors are different, the foregoing formula may be transformed into: HDL(z)=∑l=1L∑kl=1Klαkl,l(z)a(θkl)×b(τl)H. For ease of description, HDL(z)=∑l=1L∑k=1Kαk,l(z)a(θk)×b(τl)H is used as an example for description below. It may be understood that regardless of whether delay vectors corresponding to angle vectors are the same, or whether angle vectors corresponding to delay vectors are the same, determining of the precoding matrix is not affected. It should be noted that, for ease of understanding, the foregoing uses one polarization direction of the transmit antenna as an example to describe a specific process of determining the spatial-frequency matrix corresponding to the receive antenna. However, this shall not constitute any limitation on this application. When the quantity of polarization directions of the transmit antenna is greater than 1, the network device may still determine, based on the foregoing method, the spatial-frequency matrix corresponding to each transport layer. For example, if the quantity of polarization directions is 2, the spatial-frequency matrix corresponding to the zthtransport layer may be determined by using the following calculation formula: HDL(z)=[∑l=1L∑k=1Kαk,l,1(z)a(θk)×b(τl)H∑l=1L∑k=1Kαk,l,2(z)a(θk)×b(τl)H]. αk,l,1(z)represents a weighting coefficient that is fed back based on the zthtransport layer and that corresponds to the kthangle vector and the lthdelay vector in the first polarization direction; and αk,l,2(z)represents a weighting coefficient that is fed back based on the zthtransport layer and that corresponds to the kthangle vector and the lthdelay vector in the second polarization direction. It should be understood that, the foregoing calculation formula of the spatial-frequency matrix HDL(z)that is defined for the two polarization directions is merely an example, and this shall not constitute any limitation on this application. For example, quantities of delay vectors and/or angle vectors loaded in different polarization directions may be the same or may be different, and delay vectors and/or angle vectors loaded in different polarization directions may be the same or may be different. For the Z transport layers, the network device may determine, based on the Q weighting coefficients corresponding to each transport layer, spatial-frequency matrices HDL(1)and HDL(2)to HDL(Z)corresponding to the transport layers. Therefore, the network device may determine a precoding matrix W(n)corresponding to each RB. The precoding matrix W(n)corresponding to the nthRB may be constructed by using an nthcolumn vector in each of the Z spatial-frequency matrices HDL(1)and HDL(2)to HDL(Z)that are respectively determined based on the Z transport layers. For example, an nthcolumn in HDL(1)is used as the first column in the downlink channel matrix W(n), an nthcolumn in HDL(2)is used as the second column in the downlink channel matrix W(n), and by analogy, an nthcolumn in HDL(z)is used as a zthcolumn in the downlink channel matrix W(n). The precoding matrix corresponding to each RB may be determined based on the foregoing method. It should be understood that, merely for ease of understanding, the foregoing uses the spatial-frequency component matrix as an example to describe in detail a specific process in which the network device determines the precoding matrix. However, this shall not constitute any limitation on this application. Alternatively, the network device may determine Q spatial-frequency component vectors based on the Q angle-delay pairs, to further determine the precoding matrix. A person skilled in the art may construct Q spatial-frequency basic units in different forms based on the Q angle-delay pairs, to further determine the precoding matrix. A manner of constructing the Q spatial-frequency basic units in different forms based on the Q angle-delay pairs, to further determine the precoding matrix based on a weighted sum of the Q spatial-frequency basic units shall fall within the protection scope claimed in this application. It should be further understood that, the foregoing is merely an example, and shows a possible implementation in which the network device determines the precoding matrix based on the second indication information. However, this shall not constitute any limitation on this application. A specific implementation in which the network device determines the precoding matrix based on the second indication information is not limited in this application. Based on a same concept, a person skilled in the art performs transformation or equivalent replacement on the foregoing listed matrix operation, and a method for determining a precoding matrix shall fall within the protection scope of this application. It should be further understood that, the precoding matrix determined above is a precoding matrix corresponding to an RB. The RB is an example of the frequency domain unit. The precoding matrix corresponding to the RB may be a precoding matrix determined at a granularity of a size of the RB based on a channel matrix corresponding to the RB, or a precoding matrix determined based on a precoded reference signal received on the RB, and may be used to precode data transmitted by using the RB. A downlink channel corresponding to the RB may be a downlink channel determined based on the precoded reference signal received on the RB, and may be used to determine the precoding matrix corresponding to the RB. It should be understood that, merely for understanding and description, the foregoing uses the RB as an example of the frequency domain unit to describe in detail a specific process in which the network device restores the precoding matrix corresponding to the frequency domain unit. However, this shall not constitute any limitation on this application. As described above, the granularity of the frequency domain unit is not limited to the RB. When the granularity of the frequency domain unit is relatively large, for example, when the frequency domain unit is a subband, a PRG, or a PRB, the network device may determine the precoding matrix for the frequency domain unit based on the precoding matrix corresponding to each RB in each frequency domain unit. If each frequency domain unit includes one RB used to carry a reference signal, the network device may use a precoding matrix corresponding to the RB as a precoding matrix corresponding to the frequency domain unit to which the RB belongs. If each frequency domain unit includes a plurality of RBs used to carry a reference signal, the network device may perform, for example, SVD after averaging correlation matrices of precoding matrices corresponding to a plurality of RBs in a same frequency domain unit, to determine a precoding matrix corresponding to the frequency domain unit. For another example, the network device may use an average of precoding matrices corresponding to a plurality of RBs in a same frequency domain unit as a precoding matrix corresponding to the frequency domain unit. It should be understood that, for a specific method for determining, by the network device, the precoding matrix of the frequency domain unit based on the precoding matrices corresponding to the plurality of RBs in the frequency domain unit, refer to the conventional technology, and the method is not limited to the foregoing listed method. A specific method for determining, by the network device, the precoding matrix for the frequency domain unit based on the precoding matrices corresponding to the plurality of RBs in the frequency domain unit is not limited in this application. It should be further understood that, the weighting coefficient that is mentioned in the foregoing descriptions and that corresponds to an angle vector and a delay vector is a weighting coefficient corresponding to an angle-delay pair including the angle vector and the delay vector. For example, the weighting coefficient corresponding to the kthangle vector and the lthdelay vector is the weighting coefficient corresponding to the angle-delay pair including the kthangle vector and the lthdelay vector. For brevity, examples are not described one by one herein. In this embodiment of this application, the network device precodes a downlink reference signal based on a predetermined angle vector and delay vector, so that the terminal device performs downlink channel measurement based on the precoded reference signal. Therefore, the terminal device may not need to feed back a space domain vector and a frequency domain vector (for example, the foregoing angle vector and delay vector), but only needs to feed back a weighting coefficient corresponding to each angle-delay pair, thereby greatly reducing the feedback overheads of the terminal device. In addition, based on the reciprocity between the uplink and downlink channels, the network device may load the angle vector and the delay vector that are determined through uplink channel measurement to the downlink reference signal, so that a process of measuring a downlink channel by the terminal device can be simplified. Therefore, complexity of calculation by the terminal device in the channel measurement process is reduced. Moreover, a precoding matrix is constructed through linear superposition of a plurality of space domain vectors and a plurality of frequency domain vectors, so that the precoding matrix determined by the network device can adapt to the downlink channel, thereby still ensuring relatively high feedback precision while reducing the feedback overheads. In addition, the terminal device may feed back some stronger ports based on the received precoded reference signal. Because of the correspondence among a port, an angle vector, and a delay vector, the network device may choose to mainly load, based on a feedback of the terminal device, the angle vector and the delay vector that are used for precoding to a stronger angle vector and delay vector in the downlink channel. In addition, because a stronger angle vector and a stronger delay vector have greater impact on the feedback precision in a process of constructing the precoding matrix, and a weaker angle vector and a weaker delay vector have less impact on the feedback precision in the process of constructing the precoding matrix, discarding of some weaker angle vectors and some weaker delay vectors has little impact on the feedback precision, and therefore, a compromise between the feedback overheads and the feedback precision can be reached. It should be understood that, in this embodiment of this application, merely for ease of understanding, a specific process of performing downlink channel measurement and determining the precoding matrix when the spatial-frequency matrix is obtained based on a conjugate transpose of an actual channel is shown. However, this shall not constitute any limitation on this application. A relationship between the actual channel and the spatial-frequency matrix HDLis not fixed. Different definitions of the spatial-frequency matrix and the spatial-frequency component matrix may change the relationship between the actual channel and the spatial-frequency matrix HDL. For example, the spatial-frequency matrix HDLmay be obtained based on the conjugate transpose of the actual channel, or may be obtained based on a transpose of the actual channel. When a relationship between the spatial-frequency matrix and the channel matrix is defined differently, operations performed by the network device when the delay and the angle are loaded are also different, and operations performed by the terminal device when the terminal device performs channel measurement and provides a feedback correspondingly change. However, these are only implementation behaviors of the terminal device and the network device, and this shall not constitute any limitation on this application. The definition of the channel matrix, the dimensions and the definition of the spatial-frequency matrix, and a transformation relationship between the channel matrix and the spatial-frequency matrix are not limited in this application. Similarly, a transformation relationship between the spatial-frequency matrix and the precoding matrix is not limited in this application either. In the method embodiment provided above, the channel measurement method provided in this application is described in detail by using an example in which the reference signal is precoded based on the angle vector and the delay vector. However, this shall not constitute any limitation on this application. Alternatively, the network device may precode the reference signal based on only the delay vector, so that the terminal device performs downlink channel measurement based on the precoded reference signal. For ease of understanding, in embodiments shown below, a precoded reference signal sent by a transmit antenna in one polarization direction is first used as an example to describe in detail a specific process in which the terminal device performs channel measurement and provides a feedback based on a precoded reference signal received by one receive antenna. Then, a transmit antenna in one polarization direction is extended to transmit antennas in a plurality of polarization directions, and one receive antenna is extended to a plurality of receive antennas, to describe in detail a specific process in which the terminal device feeds back Q ports and Q corresponding weighting coefficients to the network device. Then, a feedback based on the receive antenna is changed into a feedback based on the transport layer, to further describe a specific process in which the terminal device feeds back the Q ports and the Q corresponding weighting coefficients to the network device based on the transport layer. Finally, a specific process in which the network device determines a precoding matrix is separately described in detail for two cases: a feedback based on the receive antenna and a feedback based on the receive transport layer. It should be understood that, when the embodiments of this application are described based on one polarization direction for the terminal device, the polarization direction may be any one of one or more polarization directions of a transmit antenna that are configured by the network device. In other words, for a precoded reference signal transmitted by a transmit antenna in any polarization direction, the terminal device may perform channel measurement based on the method provided in the embodiments of this application, or the network device may determine a precoding matrix based on the method provided in the embodiments of this application. It should be further understood that, when the embodiments of this application are described based on one receive antenna for the terminal device, the receive antenna may be any one of one or more receive antennas that are configured for the terminal device. In other words, for a precoded reference signal received by any receive antenna, the terminal device may perform channel measurement based on the method provided in the embodiments of this application, or the network device may determine a precoding matrix based on the method provided in the embodiments of this application. It should be further understood that, a quantity of polarization directions of a transmit antenna that are configured by the network device is not limited in this application. For example, there may be one polarization direction, namely, a single polarization direction, or there may be a plurality of polarization directions, for example, dual polarization directions. A quantity of receive antennas that are configured for the terminal device is not limited in this application either. For example, there may be one or more receive antennas. FIG.5is a schematic flowchart of a channel measurement method500according to another embodiment of this application from a perspective of device interaction. As shown in the figure, the method500may include operation510to operation570. The following describes the operations in the method500in detail. Step510: A terminal device receives precoded reference signals of P ports, where the precoded reference signals of the P ports correspond to P antenna-delay pairs. Correspondingly, a network device sends the precoded reference signals of the P ports, where the precoded reference signals of the P ports correspond to the P antenna-delay pairs. Specifically, each of the P antenna-delay pairs includes one transmit antenna and one delay vector, or each antenna-delay pair is a combination of one transmit antenna and one delay vector. One transmit antenna and one delay vector can uniquely determine an antenna-delay pair. In this embodiment, the P antenna-delay pairs may be obtained by combining L delay vectors and T transmit antennas. In other words, a plurality of combinations of delay vectors and transmit antennas may be obtained based on the L delay vectors and the T transmit antennas. The plurality of combinations are different from each other. Delay vectors and/or transmit antennas in any two of the plurality of combinations are different. The plurality of combinations may include the foregoing P antenna-delay pairs. T is a quantity of transmit antenna ports in one polarization direction, and T is a positive integer. The P antenna-delay pairs correspond to the precoded reference signals of the P ports. The precoded reference signal of each port may correspond to one antenna-delay pair. The precoded reference signal of each port may be obtained by precoding, based on a delay vector included in the corresponding antenna-delay pair, a reference signal sent by a transmit antenna included in the antenna-delay pair. The network device precodes, based on the L delay vectors, a reference signal sent by a transmit antenna, that is, does not perform space domain precoding but performs only frequency domain precoding on the reference signal. Because space domain precoding is not performed on the reference signal, before the reference signal is precoded based on the delay vector, the reference signal may correspond to T transmit antenna ports. A precoded reference signal obtained by performing frequency domain precoding on a reference signal by the network device based on one or more delay vectors may correspond to one or more groups of ports. Each group of ports may correspond to precoded reference signals obtained by precoding reference signals of the T transmit antenna ports based on a same delay vector. Each group of ports may include a maximum of T ports, and the T ports may correspond to the T transmit antenna ports. Therefore, a precoded reference signal of each port may correspond to one delay vector and one transmit antenna port. In other words, each port may be a combination of a delay vector and a transmit antenna port. In a possible implementation, the network device may traverse the L delay vectors, to obtain T×L different combinations, or T×L antenna-delay pairs. In other words, a total of T×L combinations of delay vectors and different transmit antenna ports may be obtained by loading the L delay vectors to reference signals of different transmit antenna ports. In another possible implementation, delay vectors corresponding to at least two transmit antenna ports are different. A reference signal transmitted by the network device through a lth(1≤t≤T) transmit antenna port in the T transmit antenna ports may be obtained through precoding based on Lt(1≤Lt≤L, and Ltis an integer) delay vectors. That is, P=∑t=1TLt. The Ltdelay vectors may be some or all of the L delay vectors, that is, Lt≤L. L in the L delay vectors may satisfy that L≤∑t=1TLt. Herein, that delay vectors corresponding to at least two transmit antenna ports are different may mean that delay vectors corresponding to at least two of the T transmit antenna ports are different, and delay vectors corresponding to the other transmit antenna ports may be the same or may be different. This is not limited in this application. In other words, delay vectors corresponding to the transmit antenna ports are partially or completely different. That delay vectors corresponding to two transmit antenna ports are different may mean that the delay vectors corresponding to the two transmit antenna ports are completely different, that is, the delay vectors corresponding to the two transmit antenna ports are not repeated, or have no intersection. For example, a delay vector corresponding to a transmit antenna port #1 includes b(τ2), and delay vectors corresponding to a transmit antenna port #2 include b(τ1) and b(τ3). That delay vectors corresponding to two transmit antenna ports are different may alternatively mean that the delay vectors corresponding to the two transmit antenna ports are partially different, that is, the delay vectors corresponding to the two transmit antenna ports are partially repeated but are not completely the same, or the delay vectors corresponding to the two transmit antenna ports have an intersection but are not completely the same. For example, a delay vector corresponding to a transmit antenna port #1 includes b(τ2), and delay vectors corresponding to a transmit antenna port #2 include b(τ1), b(τ2), and b(τ3). When delay vectors corresponding to any two of the T transmit antenna ports are not repeated, L=∑t=1TLt. When delay vectors corresponding to two or more of the T transmit antenna ports are partially repeated, L<∑t=1TLt. Therefore, the network device may obtain ∑t=1TLt combinations of angle vectors and delay vectors based on the T transmit antenna ports and the L delay vectors. It should be understood that, the foregoing lists a correspondence between a transmit antenna port and a delay vector merely for ease of understanding. However, this shall not constitute any limitation on this application. The correspondence between a transmit antenna port and a delay vector is not limited in this application. Because of reciprocity between delays on uplink and downlink channels, the L delay vectors may all be determined based on uplink channel measurement. A specific method for determining the L stronger delay vectors by the network device based on uplink channel measurement has been described in detail in the foregoing method200. For brevity, details are not described herein again. It should be understood that, determining the L delay vectors based on uplink channel measurement is not a unique implementation; and the L delay vectors may be, for example, predefined, for example, defined in a protocol, or may be determined through statistics collection based on a result fed back in one or more previous downlink channel measurements. This is not limited in this application. In an FDD mode, delays on uplink and downlink channels may be reciprocal. Therefore, the L delay vectors that are obtained through uplink channel measurement may be loaded to a downlink reference signal, so that the terminal device performs downlink channel measurement based on the received precoded reference signal. The network device may precode the downlink reference signal such as a CSI-RS based on the L delay vectors, to obtain a precoded reference signal. The network device may transmit the precoded reference signal by using a preconfigured reference signal resource. Step520: The terminal device generates sixth indication information, where the sixth indication information is used to indicate Q ports in the P ports. Specifically, the P ports correspond to the P antenna-delay pairs described above. The Q ports are some of the P ports, Q<P, and Q is a positive integer. In other words, the terminal device may indicate some of the Q ports to the network device. The Q ports may be stronger ports in the P ports. The terminal device may perform downlink channel measurement based on the received reference signals of the P ports, estimate channels of the P ports, and feed back the Q stronger ports to the network device. A weighted sum of the P antenna-delay pairs obtained by the terminal device by performing channel measurement based on the reference signals of the P ports may be used to determine a downlink channel. In the P antenna-delay pairs, impact of an antenna-delay pair with a larger weighting coefficient on feedback precision is greater than impact of an antenna-delay pair with a smaller weighting coefficient on the feedback precision. Therefore, the terminal device may select, from the P antenna-delay pairs, Q antenna-delay pairs with larger weighting coefficients for a feedback, thereby helping reduce feedback overheads while ensuring the feedback precision. It should be noted that, when receiving the precoded reference signal and performing channel measurement based on the received precoded reference signal, the terminal device may perform receiving and measurement based on different port numbers. The terminal device does not learn of or does not need to learn of antenna vectors and delay vectors that are used by the network device to precode the reference signal. When precoding the reference signal, the network device may determine a correspondence among each antenna vector, a delay vector, and a port. In addition, when the reference signal is transmitted, a correspondence between each port and a time-frequency resource may also be learned of. Therefore, the terminal device indicates the Q ports to the network device, and the network device may determine Q corresponding antenna-delay pairs based on the Q ports. A value of Q may be predefined, for example, defined in a protocol; or may be preconfigured by the network device, for example, indicated by the network device in advance by using signaling; or may be determined by the terminal device. This is not limited in this application. If the value of Q is determined by the terminal device, the terminal device may further indicate the value of Q by using the sixth indication information. Optionally, the sixth indication information is further used to indicate the value of Q. If the value of Q is indicated by the network device, the network device and the terminal device may pre-agree on whether the terminal device reports a corresponding quantity of ports according to an indication of the network device. For example, the network device and the terminal device may pre-agree on that the terminal device may further determine the quantity of reported ports according to the indication of the network device. In this case, the network device may indicate a maximum value Q0of Q in advance by using signaling, and the terminal device may report the Q ports based on Q0, where Q≤Q0, and Q0is a positive integer. Optionally, the method further includes: The network device sends third indication information, where the third indication information is used to indicate the maximum value Q0of Q. Correspondingly, the terminal device receives the third indication information, where the third indication information is used to indicate the maximum value Q0of Q. If the terminal device further determines the value of Q based on the maximum value Q0, the terminal device may indicate the value of Q by using the sixth indication information. Certainly, Q may alternatively be equal to Q0. This is not limited in this application. For another example, the network device and the terminal device may pre-agree on that the terminal device needs to report a corresponding quantity of ports according to the indication of the network. That is, the network device may indicate the value of Q in advance by using signaling, and the terminal device reports the Q ports. Optionally, the method further includes: The network device sends third indication information, where the third indication information is used to indicate the value of Q. Correspondingly, the terminal device receives the third indication information, where the third indication information is used to indicate the value of Q. For ease of distinguishing and description, the Q ports that need to be fed back to the network device and that are determined by the terminal device based on the received reference signals of the P ports are denoted as target ports below. It should be understood that, P and Q are merely examples for ease of distinguishing and understanding, and specific values of P and Q are not limited in this application. The following describes in detail a specific process in which the terminal device determines the Q target ports from the P ports. As described above, the P ports correspond to the P antenna-delay pairs. Weighting coefficients of the P antenna-delay pairs may be determined based on the precoded reference signals of the P ports. The terminal device may perform channel measurement based on the precoded reference signals of the P ports, determine the weighting coefficients of the P antenna-delay pairs corresponding to the P ports, and further determine the Q target ports from the P ports. Because the network device precodes the reference signal based on the P antenna-delay pairs including K transmit antenna ports and the L delay vectors, a precoded reference signal carried on each RB may correspond to the P ports. Apt port in the P ports corresponds to a pthantenna-delay pair. A precoded reference signal of the pthport is obtained by precoding the reference signal based on a transmit antenna port and a delay vector in the pthantenna-delay pair. It is assumed that the pthantenna-delay pair includes the lthtransmit antenna port in the T transmit antenna ports and an lthdelay vector in the L delay vectors. In this case, the precoded reference signal of the pthport may be obtained by precoding the reference signal based on the lthtransmit antenna port and the lthdelay vector. In other words, the precoded reference signal corresponding to the pf port may be used to determine a weighting coefficient of an antenna-delay pair including the lthtransmit antenna port and the lthdelay vector, that is, may be used to determine a weighting coefficient of the pthantenna-delay pair. Therefore, the terminal device may determine the weighting coefficient of the corresponding antenna-delay pair based on the precoded reference signal of each port. As described above, if precoding on a reference signal is not considered, for each receive antenna, dimensions of a downlink channel may be N×T. Dimensions of a downlink channel on one RB that is received by using one receive antenna may be 1×T. Because the network device precodes the reference signal based on the delay vector, dimensions of a downlink channel received by the terminal device through each receive antenna may be 1×P. An estimation value of the downlink channel whose dimensions are 1×P is a channel estimation value obtained by performing channel estimation on the precoded reference signal on one RB. P elements in the downlink channel may correspond to P antenna-delay pairs. A pthelement may represent a channel estimation value obtained by performing channel estimation on a precoded reference signal corresponding to the pthantenna-delay pair on one RB. Because the precoded reference signal corresponds to the P antenna-delay pairs, a precoded reference signal carried on each RB may correspond to the P ports. The precoded reference signal corresponding to the pthport in the P ports may be a precoded reference signal that is obtained by precoding the reference signal based on one delay vector (for example, the lthdelay vector) and that is sent through one transmit antenna port (for example, the lthtransmit antenna port). In other words, the precoded reference signal corresponding to the pthport may be used to determine the weighting coefficient of the antenna-delay pair including the lthdelay vector and the lthtransmit antenna port, that is, may be used to determine a weighting coefficient of the pthantenna-delay pair. Therefore, the P ports are in a one-to-one correspondence with the P antenna-delay pairs. It should be understood that, a correspondence among the pthport, the lthdelay vector, and the lthtransmit antenna port that is listed above is merely an example, and this shall not constitute any limitation on this application. The terminal device does not learn of a correspondence among each port, a delay vector, and a transmit antenna port. The terminal device only needs to receive a reference signal and perform channel estimation based on a time-frequency resource corresponding to each port. For the precoded reference signal of the pthport, the terminal device may determine, based on downlink channels received on N RBs, the weighting coefficient of the pthantenna-delay pair. The weighting coefficient of the pthantenna-delay pair may be a pthelement in a channel estimation value that is obtained by performing superposition summation on N channel estimation values on the N RBs and whose dimensions are 1×P. It is assumed that an estimation value that is of a downlink channel and that is obtained by the terminal device by performing channel estimation on the precoded reference signal of the pthport is denoted as yn(p). In this case, a sum of a plurality of estimation values that are obtained by the terminal device by performing channel estimation on the precoded reference signals of the P ports on the N RBs may be represented as ∑n=1Nyn(p).∑n=1Nyn(p) may be a vector whose dimensions are 1×P, and the vector includes P weighting coefficients corresponding to the P antenna-delay pairs. It may be understood that a pthelement in the vector is the weighting coefficient of the pthantenna-delay pair, and the weighting coefficient of the pthantenna-delay pair is determined by using the precoded reference signal that is obtained through precoding based on the lthdelay vector and that is transmitted through the lthtransmit antenna port. Because the P ports include L groups of ports corresponding to the L delay vectors, the P weighting coefficients may be understood as L groups of weighting coefficients corresponding to the L delay vectors. Each group of weighting coefficients may include T weighting coefficients corresponding to a maximum of T transmit antenna ports. When each group of ports includes T ports and corresponds to T transmit antenna ports, each of the L groups of weighting coefficients may include T weighting coefficients. In this case, the P weighting coefficients may be represented as, for example, a form of a matrix whose dimensions are T×L or L×T. The weighting coefficient that is in the P weighting coefficients and that corresponds to the lthtransmit antenna port and the lthdelay vector may be denoted as αt,l. When delay vectors corresponding to at least two transmit antenna ports are different, transmit antenna ports corresponding to the at least two delay vectors are also different. In this case, each group of weighting coefficients includes a maximum of T weighting coefficients. In this case, there are Ltdelay vectors corresponding to the lthtransmit antenna port in the P weighting coefficients, and a weighting coefficient corresponding to the lthtransmit antenna port and an llthdelay vector may be denoted as αt,lt. Based on the foregoing method, the terminal device may determine, based on the received precoded reference signals of the P ports, the P weighting coefficients corresponding to the P antenna-delay pairs. Based on the P weighting coefficients, the terminal device may further determine the Q stronger ports in the P ports, and determine the Q stronger ports as the Q target ports to be fed back to the network device. A weighting coefficient of any one of the Q antenna-delay pairs corresponding to the Q target ports is greater than or equal to a weighting coefficient of an antenna-delay pair corresponding to any one of the remaining P-Q ports. After determining the Q target ports, the terminal device may generate the sixth indication information to indicate the Q target ports. In an implementation, when the sixth indication information is used to indicate the Q target ports, the sixth indication information is specifically used to indicate indexes of the Q antenna-delay pairs corresponding to the Q target ports. As described above, the P antenna-delay pairs may be obtained by combining the L delay vectors and the T transmit antenna ports. Although the terminal device does not learn of transmit antenna ports and delay vectors that are specifically included in the P antenna-delay pairs, the terminal device may learn that there is a one-to-one correspondence between ports and antenna-delay pairs. If the transmit antenna ports and the delay vectors that are included in these antenna-delay pairs are separately distinguished by using indexes, a combination of an index of one transmit antenna port and an index of one delay vector may be used to uniquely indicate one port. It should be understood that, herein, the index of the transmit antenna port is not a port number of the transmit antenna port, and the index of the delay vector is not an index of the delay vector in a delay vector set. Instead, different index values are defined for the L delay vectors and the T transmit antenna ports that are used for precoding, for distinguishing. Optionally, each of the P antenna-delay pairs may be indicated by using a two-dimensional index (t, l). t=1, 2, . . . , or T; and l=1, 2, . . . , or L. In the foregoing method200, a specific method for indicating, by the sixth indication information, the index of the angle-delay pair by using the two-dimensional index is described in detail with reference toFIG.4. In this embodiment, a specific method for indicating the antenna-delay pair by using the two-dimensional index is similar to the method, except that the angle vector is replaced with the transmit antenna port. For brevity, details are not described herein again. In addition, the two-dimensional index (t, l) may alternatively be converted into a one-dimensional index p. p=1, 2, . . . , or P. A specific method for converting the two-dimensional index into the one-dimensional index has been described in detail in the foregoing method200. For brevity, details are not described herein again. In an implementation, when the sixth indication information is used to indicate the Q target ports, the sixth indication information is specifically used to indicate port numbers of the Q target ports. Because the network device may notify the terminal device in advance by using signaling of a time-frequency resource for transmitting the reference signal and a port number for the transmitted reference signal, the terminal device may directly feed back the port numbers of the Q target ports to the network device after determining the Q stronger target ports. It should be understood that, indicating the Q target ports by using the indexes of the corresponding antenna-delay pairs and indicating the Q target ports by using the port numbers are merely two possible implementations provided in this application, and this shall not constitute any limitation on this application. A specific implementation of indicating the Q target ports by the terminal device is not limited in this application. It should be noted that, a specific process in which the terminal device generates the sixth indication information is described in detail above by using one polarization direction and one receive antenna as an example. In other words, the Q ports may be determined based on a precoded reference signal that is sent by a transmit antenna in one polarization direction and that is received by one receive antenna. However, this shall not constitute any limitation on this application. Alternatively, the network device may send precoded reference signals by using transmit antennas in a plurality of polarization directions. Alternatively, the terminal device may receive the precoded reference signals based on a plurality of receive antennas, and generate the sixth indication information based on the plurality of receive antennas. When transmit antennas in a plurality of polarization directions are configured for the network device, the polarization direction described in the foregoing embodiment may be any one of the plurality of polarization directions. When transmit antennas in a plurality of polarization directions are configured for the network device, the terminal device may separately determine one or more stronger ports based on a precoded reference signal sent by a transmit antenna in each of the plurality of polarization directions, or may jointly determine one or more stronger ports based on precoded reference signals sent by the transmit antennas in the plurality of polarization directions. The one or more stronger ports that are determined by the terminal device based on the precoded reference signals sent by the transmit antennas in the plurality of polarization directions are the target port described above. When a plurality of receive antennas are configured for the terminal device, the receive antenna described in the foregoing embodiment may be any one of the plurality of receive antennas of the terminal device. When the plurality of receive antennas are configured for the terminal device, the terminal device may separately determine one or more stronger ports based on each of the plurality of receive antennas, or may jointly determine one or more stronger ports based on the plurality of receive antennas. The one or more stronger ports that are determined by the terminal device based on the plurality of receive antennas are the target port described above. Specific content indicated by the first indication information in different cases has been described in detail in the foregoing method200. In this embodiment, specific content indicated by the sixth indication information in different cases may be similar to the specific content indicated by the first indication information. For brevity, details are not described herein again. As described above, when generating the sixth indication information, the terminal device is not limited to determining the target port based on each receive antenna, and the terminal device may alternatively determine the target port based on a transport layer. A specific method for determining the target port by the terminal device based on each transport layer has been described in detail in the foregoing method200. For brevity, details are not described herein again. In addition, when the terminal device indicates the target port based on each transport layer, specific content indicated by the sixth indication information in different cases may also be similar to the specific content indicated by the first indication information. For brevity, details are not described herein again. Step530: The terminal device sends the sixth indication information. Correspondingly, the network device receives the sixth indication information. Step540: The network device determines the Q antenna-delay pairs corresponding to the Q ports (that is, the Q target ports in the foregoing operation520) based on the sixth indication information. It should be understood that, specific processes of operation530and operation540are similar to specific processes of operation230and operation240in the foregoing method200, except that the angle-delay pair is replaced with the antenna-delay pair, and the angle vector is replaced with the transmit antenna port. For brevity, details are not described herein again. Based on the foregoing solution, precoding the reference signal by the network device based on the delay vector is equivalent to precoding the reference signal in frequency domain. A delay vector is introduced for a reference signal. A change of a channel in a plurality of frequency domain units may be represented by using a delay vector, and a reference signal is precoded based on the delay vector, so that the terminal device does not need to separately feed back the target port based on each frequency domain unit. Therefore, the feedback overheads can be reduced. After determining the Q antenna-delay pairs, the network device may precode, based only on the delay vectors included in the Q antenna-delay pairs, a reference signal to be sent next time, or may continue to precode, based on the delay vectors included in the P antenna-delay pairs, a reference signal to be sent next time. This is not limited in this application. In an embodiment, the network device may precode, based on delay vectors in P1antenna-delay pairs (namely, an example of the P antenna-delay pairs) in a periodicity (for example, denoted as a periodicity #1) of predetermined duration, a reference signal that is sent for the first time in the periodicity #1, to obtain and send precoded reference signals of P1ports (namely, an example of the P ports). The network device may precode, by using delay vectors in Q1corresponding antenna-delay pairs (namely, an example of the antenna-delay pairs corresponding to the Q target ports) based on Q1ports (namely, an example of the Q target ports) indicated by the terminal device by using indication information #1 (namely, an example of the sixth indication information), a reference signal to be sent next time or reference signals to be subsequently sent for a plurality of times. The network device may precode, in a next periodicity (for example, denoted as a periodicity #2) based on delay vectors in P2antenna-delay pairs (namely, another example of the P antenna-delay pairs), a reference signal that is sent for the first time in the periodicity #2, to obtain and send precoded reference signals of P2ports. The network device may precode, by using delay vectors in Q2corresponding antenna-delay pairs (namely, another example of the antenna-delay pairs corresponding to the Q target ports) based on Q2ports (namely, another example of the Q target ports) indicated by the terminal device by using indication information #2 (namely, another example of the sixth indication information), a reference signal to be sent next time or reference signals to be subsequently sent for a plurality of times. By analogy, the network device may precode reference signals in a plurality of periodicities according to the foregoing method. For brevity, details are not described herein again. Based on the foregoing solution, the network device may first precode, by using a plurality of delay vectors, the reference signal sent by each transmit antenna, so that the terminal device performs channel measurement. Then, based on a stronger antenna-delay pair in the downlink channel that is fed back by the terminal device, the network device may precode, by using a delay vector in the stronger antenna-delay pair, a reference signal sent by a transmit antenna included in the stronger antenna-delay pair. Because a weighting coefficient of a stronger antenna-delay pair has greater impact on the feedback precision, the feedback overheads can be reduced while the feedback precision is ensured, and a compromise between the feedback precision and the feedback overheads can be reached. Because the network device precodes the reference signal by using the plurality of antenna-delay pairs in advance, a stronger antenna-delay pair in the downlink channel determined by the terminal device may fall within a range of the plurality of antenna-delay pairs with a higher probability. Therefore, on one hand, this helps obtain relatively high feedback precision, and on the other hand, feedback overheads caused by a next feedback of a weighting coefficient by the terminal device can be reduced. Optionally, the method500further includes: Step550: The terminal device generates seventh indication information, where the seventh indication information is used to indicate the weighting coefficients of the Q antenna-delay pairs corresponding to the Q target ports. Optionally, the method500further includes: Step560: The terminal device sends the seventh indication information. Correspondingly, in operation560, the network device receives the seventh indication information. It should be understood that, specific processes of operation550and operation560are similar to specific processes of operation250and operation260in the foregoing method200, except that the angle-delay pair is replaced with the antenna-delay pair, and the angle vector is replaced with the transmit antenna port. For brevity, details are not described herein again. Optionally, the method500further includes: Step570: The network device determines a precoding matrix based on the seventh indication information. As described above, the terminal device may feed back the weighting coefficient based on the receive antenna, or may feed back the weighting coefficient based on the transport layer. The network device may determine the precoding matrix based on the seventh indication information and based on different feedback granularities. If the terminal device feeds back the weighting coefficient based on the receive antenna, the weighting coefficient indicated by the seventh indication information may include a weighting coefficient corresponding to one or more receive antennas. The network device may reconstruct a downlink channel based on a weighting coefficient corresponding to each receive antenna and an antenna-delay pair corresponding to each weighting coefficient, to further determine a precoding matrix of each RB. Herein, it should be noted that, when the terminal device feeds back the weighting coefficient by using the seventh indication information based on the receive antenna, the target port fed back by the terminal device by using the first indication information is also fed back based on the receive antenna. The network device may determine, based on the target port indicated by the terminal device in the first indication information, the antenna-delay pair corresponding to each weighting coefficient, or determine the correspondence between each antenna-delay pair and a weighting coefficient. Specifically, one polarization direction of a transmit antenna is used as an example. The terminal device may feed back one or more weighting coefficients based on each receive antenna. For ease of description below, it is assumed that the terminal device feeds back Q weighting coefficients based on each receive antenna. The Q weighting coefficients corresponding to each receive antenna may be in a one-to-one correspondence with the Q antenna-delay pairs. Because space domain precoding is not performed on the reference signal, the network device may construct, based on the Q weighting coefficients corresponding to each receive antenna and one or more delay vectors that are in the Q antenna-delay pairs and that correspond to each transmit antenna port, a spatial-frequency matrix corresponding to each receive antenna, and reconstruct, based on the spatial-frequency matrix corresponding to each receive antenna, a downlink channel matrix corresponding to each RB, to further determine the precoding matrix corresponding to each RB. It may be understood that because the Q weighting coefficients are in a one-to-one correspondence with the Q antenna-delay pairs, the Q weighting coefficients are also in a one-to-one correspondence with the delay vectors included in the Q antenna-delay pairs. There are Ltdelay vectors corresponding to the lthtransmit antenna port in the T transmit antenna ports, and the delay vector corresponding to the lthtransmit antenna port is denoted as b(τlt), where lt=1, 2, . . . , or Lt. A spatial-frequency matrix HDL(r)corresponding to an rthreceive antenna may be a matrix whose dimensions are T×N, a lthrow in the spatial-frequency matrix may be a spatial-frequency vector ht(r), and ht(r)=∑lt=1Ltαt,lt(r)(b(τlt))H. Therefore, a spatial-frequency matrix corresponding to the rthreceive antenna may be obtained: HDL(r)=[h1(r)h2(r)⋮hT(r)].αt,lt(r) represents a weighting coefficient that is fed back based on the rthreceive antenna and that corresponds to the lthtransmit antenna port and the ltthdelay vector. It may be understood that if any two of the T transmit antenna ports correspond to the L same delay vectors, the spatial-frequency vector ht(r)may be expressed as ht(r)=∑l=1Lαt,l(r)(b(τl))H.αt,l(r) represents the weighting coefficient corresponding to the lthtransmit antenna port and the lthdelay vector. For ease of description, ht(r)=∑l=1Lαt,l(r)(b(τl))H is used as an example for description below. It may be understood that, regardless of whether delay vectors corresponding to transmit antenna ports are the same, determining of the precoding matrix is not affected. It should be noted that, for ease of understanding, the foregoing uses one polarization direction of the transmit antenna as an example to describe a specific process of determining the spatial-frequency matrix corresponding to the receive antenna. However, this shall not constitute any limitation on this application. When the quantity of polarization directions of the transmit antenna is greater than 1, the network device may still determine, based on the foregoing method, the spatial-frequency matrix corresponding to each receive antenna. For example, the quantity of polarization directions is 2. Each spatial-frequency vector in the spatial-frequency matrix that corresponds to the rthreceive antenna in a first polarization direction may be determined by using a calculation formula ht,1(r)=∑l=1Lαt,l,1(r)(b(τl))H. Each spatial-frequency vector in the spatial-frequency matrix that corresponds to the rthreceive antenna in the second polarization direction may be determined by using a calculation formula ht,2(r)=∑l=1Lαt,l,2(r)(b(τl))H. ht,1(r)represents a spatial-frequency vector that is fed back based on the rthreceive antenna in the first polarization direction; αt,l,1(r)represents a weighting coefficient that is fed back based on the rthreceive antenna and that corresponds to the lthtransmit antenna port and the lthdelay vector in the first polarization direction; ht,2(r)represents a spatial-frequency vector that is fed back based on the rthreceive antenna in the second polarization direction; and αt,l,2(r)represents a weighting coefficient that is fed back based on the rthreceive antenna and that corresponds to the lthtransmit antenna port and the lthdelay vector in the second polarization direction. It should be understood that, the foregoing calculation formulas of the spatial-frequency vectors ht,1(r)and ht,2(r)that are defined for the two polarization directions are merely examples, and this shall not constitute any limitation on this application. For example, quantities of delay vectors and/or angle vectors loaded in different polarization directions may be the same or may be different, and delay vectors and/or angle vectors loaded in different polarization directions may be the same or may be different. For the R receive antennas, the network device may determine spatial-frequency matrices HDL(1)and HDL(2)to HDL(R)based on the Q weighting coefficients corresponding to each receive antenna. Therefore, the network device may determine a downlink channel matrix corresponding to each RB. It should be understood that, a specific process in which the network device determines, based on the spatial-frequency matrix corresponding to each receive antenna, the downlink channel matrix corresponding to each RB has been described in detail in the foregoing method200. For brevity, details are not described herein again. It should be noted that, as described above, a channel matrix determined based on a spatial-frequency matrix obtained by performing weighted summation on the angle-delay pairs is a conjugate transpose of an actual channel matrix. The network device may further determine the precoding matrix of each RB based on the downlink channel matrix corresponding to each RB. For example, the network device may determine the precoding matrix by performing SVD on the downlink channel matrix or a covariance matrix of the channel matrix, or may determine the precoding matrix by performing eigenvalue decomposition (EVD) on a covariance matrix of the downlink channel matrix. It should be understood that, for a specific manner of determining the precoding matrix by the network device based on the channel matrix, refer to the conventional technology. A manner of determining the precoding matrix is not limited in this application. It should be further understood that, merely for ease of understanding, the foregoing shows a specific process in which the network device determines the downlink channel matrix based on the spatial-frequency matrix, to further determine the precoding matrix. However, this shall not constitute any limitation on this application. Alternatively, the network device may directly determine the precoding matrix based on the spatial-frequency matrix. For example, the matrix V(n)may be determined based on the spatial-frequency matrix, and the network device may determine the precoding matrix in a manner of performing SVD on (V(n))*(V(n))Tand then taking a right eigenvector. If the terminal device feeds back the weighting coefficient based on the transport layer, the weighting coefficient indicated by the seventh indication information may include a weighting coefficient of one or more transport layers. The network device may determine, based on a weighting coefficient corresponding to each transport layer and an antenna-delay pair corresponding to each weighting coefficient, a spatial-frequency matrix corresponding to each transport layer, to further determine a precoding matrix of each RB. Herein, it should be noted that, when the terminal device feeds back the weighting coefficient by using the seventh indication information based on the transport layer, the target port fed back by the terminal device by using the first indication information is also fed back based on the transport layer. The network device may determine, based on the target port indicated by the terminal device in the first indication information, the antenna-delay pair corresponding to each weighting coefficient, or determine the correspondence between each antenna-delay pair and a weighting coefficient. Specifically, one polarization direction of a transmit antenna is used as an example. The terminal device may feed back one or more weighting coefficients based on each transport layer. For ease of description below, it is assumed that the terminal device feeds back Q weighting coefficients based on each transport layer. The Q weighting coefficients corresponding to each transport layer may be in a one-to-one correspondence with the Q antenna-delay pairs. The network device may construct, based on the Q weighting coefficients corresponding to each transport layer and one or more delay vectors that are in the Q antenna-delay pairs and that correspond to each transmit antenna port, a spatial-frequency matrix corresponding to the transport layer. There are Ltdelay vectors corresponding to the lthtransmit antenna port in the T transmit antenna ports, and the delay vector corresponding to the lthtransmit antenna port is denoted as b(τlt), where lt=1, 2, . . . , or Lt. The spatial-frequency matrix HDL(z)corresponding to the zthtransport layer may be a matrix whose dimensions are T×N, a lthrow in the spatial-frequency matrix may be a spatial-frequency vector ht(z), and ht(z)=∑lt=1Ltαt,lt(z)(b(τlt))H. Therefore, the spatial-frequency matrix corresponding to the zthtransport layer may be obtained: HDL(z)=[h1(z)h2(z)⋮hT(z)] αt,lt(z)represents a weighting coefficient that is fed back based on the zthtransport layer and that corresponds to the lthtransmit antenna port and the llthdelay vector. It may be understood that if any two of the T transmit antenna ports correspond to the L same delay vectors, the spatial-frequency vector ht(z)may be expressed as ht(z)=∑l=1Lαt,l(z)(b(τl))H. αt,l(z)represents a weighting coefficient that is fed back based on the zthtransport layer and that corresponds to the lthtransmit antenna port and the lthdelay vector. For ease of description, ht(z)=∑l=1Lαt,l(z)(b(τl))H is used as an example for description below. It may be understood that, regardless of whether delay vectors corresponding to transmit antenna ports are the same, determining of the precoding matrix is not affected. It should be noted that, for ease of understanding, the foregoing uses one polarization direction of the transmit antenna as an example to describe a specific process of determining the spatial-frequency matrix corresponding to the receive antenna. However, this shall not constitute any limitation on this application. When the quantity of polarization directions of the transmit antenna is greater than 1, the network device may still determine, based on the foregoing method, the spatial-frequency matrix corresponding to each receive antenna. For example, the quantity of polarization directions is 2. Each spatial-frequency vector in the spatial-frequency matrix that corresponds to the zthtransport layer in the first polarization direction may be determined by using a calculation formula ht,1(z)=∑l=1Lαt,l,1(z)(b(τl))H. Each spatial-frequency vector in the spatial-frequency matrix that corresponds to the zthtransport layer in the second polarization direction may be determined by using a calculation formula ht,2(z)=∑l=1Lαt,l,2(z)(b(τl))H. ht,1(z)represents a spatial-frequency vector that is fed back based on the zthtransport layer in the first polarization direction; αt,l,1(z)represents a weighting coefficient that is fed back based on the zthtransport layer and that corresponds to the lthtransmit antenna port and the lthdelay vector in the first polarization direction; ht,2(z)represents a spatial-frequency vector that is fed back based on the zthtransport layer in the second polarization direction; and αt,l,2(z)represents a weighting coefficient that is fed back based on the zthtransport layer and that corresponds to the lthtransmit antenna port and the lthdelay vector in the second polarization direction. It should be understood that, the foregoing calculation formulas of the spatial-frequency vectors ht,1(z)and ht,2(z)that are defined for the two polarization directions are merely examples, and this shall not constitute any limitation on this application. For example, quantities of delay vectors and/or angle vectors loaded in different polarization directions may be the same or may be different, and delay vectors and/or angle vectors loaded in different polarization directions may be the same or may be different. For the Z transport layers, the network device may determine, based on the Q weighting coefficients corresponding to each transport layer, spatial-frequency matrices HDL(1)and HDL(2)to HDL(Z)corresponding to the transport layers. Therefore, the network device may determine a precoding matrix corresponding to each RB. It should be understood that, a specific process in which the network device determines, based on the spatial-frequency matrix corresponding to each transport layer, the precoding matrix corresponding to each RB has been described in detail in the foregoing method200. For brevity, details are not described herein again. It should be further understood that, the foregoing is merely an example, and shows a possible implementation in which the network device determines the precoding matrix based on the seventh indication information. However, this shall not constitute any limitation on this application. A specific implementation in which the network device determines the precoding matrix based on the seventh indication information is not limited in this application. Based on a same concept, a person skilled in the art performs transformation or equivalent replacement on the foregoing listed matrix operation, and a method for determining a precoding matrix shall fall within the protection scope of this application. It should be further understood that, the precoding matrix determined above is a precoding matrix corresponding to an RB. Herein, the RB is an example of a frequency domain unit. The precoding matrix corresponding to the RB may be a precoding matrix determined at a granularity of the RB based on a channel matrix corresponding to the RB, or a precoding matrix determined based on a precoded reference signal received on the RB, and may be used to precode data transmitted by using the RB. A downlink channel corresponding to the RB may be a downlink channel determined based on the precoded reference signal received on the RB, and may be used to determine the precoding matrix corresponding to the RB. It should be understood that, merely for understanding and description, the foregoing uses the RB as an example of the frequency domain unit to describe in detail a specific process in which the network device restores the precoding matrix corresponding to the frequency domain unit. However, this shall not constitute any limitation on this application. As described above, the granularity of the frequency domain unit is not limited to the RB. When the granularity of the frequency domain unit is relatively large, for example, when the frequency domain unit is a subband, a PRG, or a PRB, the network device may determine the precoding matrix for the frequency domain unit based on the precoding matrix corresponding to each RB in each frequency domain unit. A specific method for determining, by the network device, the precoding matrix of each frequency domain unit based on the precoding matrix corresponding to each RB in the frequency domain unit has been described in detail in the foregoing method200. For brevity, details are not described herein again. It should be further understood that, the weighting coefficient that is mentioned above and that corresponds to a transmit antenna port and a delay vector is a weighting coefficient corresponding to an antenna-delay pair including the transmit antenna port and the delay vector. For example, the weighting coefficient corresponding to the lthtransmit antenna port and the lthdelay vector is the weighting coefficient corresponding to the antenna-delay pair including the lthtransmit antenna port and the lthdelay vector. For brevity, examples are not described one by one herein. In this embodiment of this application, the network device may precode a downlink reference signal based on a predetermined delay, so that the terminal device performs downlink channel measurement based on the precoded reference signal. Therefore, the terminal device may not need to feed back a frequency domain vector (for example, the foregoing delay vector), but only needs to feed back a weighting coefficient corresponding to each antenna-delay pair, thereby greatly reducing the feedback overheads of the terminal device. In addition, based on reciprocity between the uplink and downlink channels, the network device may load a delay vector determined through uplink channel measurement to the downlink reference signal, so that a downlink channel measurement process of the terminal device is simplified. Therefore, complexity of calculation by the terminal device in the channel measurement process is reduced. Moreover, a precoding matrix is constructed through linear superposition of a plurality of frequency domain vectors, so that the precoding matrix determined by the network device can adapt to the downlink channel, thereby still ensuring relatively high feedback precision while reducing the feedback overheads. In addition, the terminal device may feed back some stronger ports based on the received precoded reference signal. Because of the correspondence among a port, an angle vector, and a delay vector, the network device may choose to mainly load, based on a feedback of the terminal device, the delay vector used for precoding to several stronger delay vectors in the downlink channel. Because a stronger delay vector has greater impact on the feedback precision in a process of constructing the precoding matrix, and a weaker delay vector has less impact on the feedback precision in the process of constructing the precoding matrix, discarding of some weaker delay vectors has little impact on the feedback precision, and therefore, a compromise between the feedback overheads and the feedback precision can be reached. It should be understood that, in this embodiment of this application, merely for ease of understanding, a specific process of performing downlink channel measurement and determining the precoding matrix when the spatial-frequency matrix is obtained based on the conjugate transpose of the actual channel is shown. However, this shall not constitute any limitation on this application. A relationship between the actual channel and the spatial-frequency matrix HDLis not fixed. Different definitions of the spatial-frequency matrix and the spatial-frequency component matrix may change the relationship between the actual channel and the spatial-frequency matrix HDL. For example, the spatial-frequency matrix HDLmay be obtained based on the conjugate transpose of the actual channel, or may be obtained based on a transpose of the actual channel. When a relationship between the spatial-frequency matrix and the channel matrix is defined differently, operations performed by the network device when the delay and the angle are loaded are also different, and operations performed by the terminal device when the terminal device performs channel measurement and provides a feedback correspondingly change. However, these are only implementation behaviors of the terminal device and the network device, and this shall not constitute any limitation on this application. The definition of the channel matrix, the dimensions and the definition of the spatial-frequency matrix, and a transformation relationship between the channel matrix and the spatial-frequency matrix are not limited in this application. Similarly, a transformation relationship between the spatial-frequency matrix and the precoding matrix is not limited in this application either. It should be further understood that, sequence numbers of the processes do not mean execution sequences in the foregoing embodiments. The execution sequences of the processes should be determined based on functions and internal logic of the processes, and this shall not constitute any limitation on the implementation processes of the embodiments of this application. The foregoing describes in detail, with reference toFIG.2toFIG.5, the precoding vector indication and determining method provided in the embodiments of this application. The following describes in detail communications apparatuses provided in the embodiments of this application with reference toFIG.6toFIG.8. FIG.6is a schematic block diagram of a communications apparatus1000according to an embodiment of this application. As shown in the figure, the communications apparatus1000may include a transceiver unit1100and a processing unit1200. In a possible design, the communications apparatus1000may correspond to the terminal device in the foregoing method embodiments, for example, may be the terminal device, or may be a chip disposed in the terminal device. Specifically, the communications apparatus1000may correspond to the terminal device in the method200or the method500according to the embodiments of this application. The communications apparatus1000may include units configured to perform the method performed by the terminal device in the method200inFIG.2or the method500inFIG.5. In addition, the units in the communications apparatus1000and the foregoing other operations and/or functions are separately intended to implement corresponding procedures of the method200inFIG.2or the method500inFIG.5. When the communications apparatus1000is configured to perform the method200inFIG.2, the transceiver unit1100may be configured to perform operation210, operation230, and operation260in the method200, and the processing unit1200may be configured to perform operation220and operation250in the method200. When the communications apparatus1000is configured to perform the method500inFIG.5, the transceiver unit1100may be configured to perform operation510, operation530, and operation560in the method500, and the processing unit1200may be configured to perform operation520and operation550in the method500. It should be understood that, a specific process in which each unit performs the foregoing corresponding operation is described in detail in the foregoing method embodiments. For brevity, details are not described herein again. It should be further understood that, when the communications apparatus1000is the terminal device, the transceiver unit1100in the communications apparatus1000may correspond to a transceiver2020in a terminal device2000shown inFIG.7, and the processing unit1200in the communications apparatus1000may correspond to a processor2010in the terminal device2000shown inFIG.7. It should be further understood that, when the communications apparatus1000is the chip disposed in the terminal device, the transceiver unit1100in the communications apparatus1000may be an input/output interface. In another possible design, the communications apparatus1000may correspond to the network device in the foregoing method embodiments, for example, may be the network device, or a chip disposed in the network device. Specifically, the communications apparatus1000may correspond to the network device in the method200or the method500according to the embodiments of this application. The communications apparatus1000may include units configured to perform the method performed by the network device in the method200inFIG.2or the method500inFIG.5. In addition, the units in the communications apparatus1000and the foregoing other operations and/or functions are separately intended to implement corresponding procedures of the method200inFIG.2or the method500inFIG.5. When the communications apparatus1000is configured to perform the method200inFIG.2, the transceiver unit1100may be configured to perform operation210, operation230, and operation260in the method200, and the processing unit1200may be configured to perform operation270in the method200. When the communications apparatus1000is configured to perform the method500inFIG.5, the transceiver unit1100may be configured to perform operation510, operation530, and operation560in the method500, and the processing unit1200may be configured to perform operation570in the method500. It should be further understood that, when the communications apparatus1000is the network device, the transceiver unit in the communications apparatus1000may correspond to an RRU3100in a network device3000shown inFIG.8, and the processing unit1200in the communications apparatus1000may correspond to a BBU3200or a processor3202in the network device3000shown inFIG.8. It should be further understood that, when the communications apparatus1000is the chip disposed in the network device, the transceiver unit1100in the communications apparatus1000may be an input/output interface. FIG.7is a schematic diagram of a structure of the terminal device2000according to an embodiment of this application. The terminal device2000may be applied to the system shown inFIG.1, to perform functions of the terminal device in the foregoing method embodiments. As shown in the figure, the terminal device2000includes the processor2010and the transceiver2020. Optionally, the terminal device2000further includes a memory2030. The processor2010, the transceiver2020, and the memory2030may communicate with each other through an internal connection path, to transfer a control signal and/or a data signal. The memory2030is configured to store a computer program. The processor2010is configured to invoke the computer program from the memory2030and run the computer program, to control the transceiver2020to receive or send a signal. Optionally, the terminal device2000may further include an antenna2040, configured to send, by using a radio signal, uplink data or uplink control signaling output by the transceiver2020. The processor2010and the memory2030may be integrated into one processing apparatus. The processor2010is configured to execute program code stored in the memory2030to implement the foregoing functions. During specific implementation, the memory2030may alternatively be integrated into the processor2010, or may be independent of the processor2010. The processor2010may correspond to the processing unit inFIG.6. The transceiver2020may correspond to the transceiver unit1100inFIG.6. The transceiver2020may include a receiver (or referred to as a receiver or a receiver circuit) and a transmitter (or referred to as a transmitter or a transmitter circuit). The receiver is configured to receive a signal, and the transmitter is configured to transmit a signal. It should be understood that, the terminal device2000shown inFIG.7can implement the processes of the terminal device in the method embodiment shown inFIG.2orFIG.5. Operations and/or functions of the modules in the terminal device2000are separately intended to implement corresponding procedures in the foregoing method embodiments. For details, refer to the descriptions in the foregoing method embodiments. To avoid repetition, detailed descriptions are properly omitted herein. The processor2010may be configured to perform an action that is implemented inside the terminal device and that is described in the foregoing method embodiments, and the transceiver2020may be configured to perform an action of receiving or sending that is performed by the terminal device from or to the network device and that is described in the foregoing method embodiments. For details, refer to the descriptions in the foregoing method embodiments. Details are not described herein again. Optionally, the terminal device2000may further include a power supply2050, configured to supply power to various devices or circuits in the terminal device. In addition, to improve the functions of the terminal device, the terminal device2000may further include one or more of an input unit2060, a display unit2070, an audio circuit2080, a camera2090, a sensor2100, and the like, and the audio circuit may further include a speaker2082, a microphone2084, and the like. FIG.8is a schematic diagram of a structure of the network device according to an embodiment of this application, for example, may be a schematic diagram of a structure of a base station. The base station3000may be applied to the system shown inFIG.1, to perform functions of the network device in the foregoing method embodiments. As shown in the figure, the base station3000may include one or more radio frequency units, for example, one or more remote radio units (RRUs)3100, and one or more baseband units (BBUs) (which may also be referred to as distributed units (DUs))3200. The RRU3100may be referred to as a transceiver unit, and corresponds to the transceiver unit1100inFIG.6. Optionally, the transceiver unit may also be referred to as a transceiver, a transceiver circuit, a transceiver, or the like, and may include at least one antenna3101and a radio frequency unit3102. Optionally, the transceiver unit may include a receiving unit and a sending unit. The receiving unit may correspond to a receiver (or referred to as a receiver or a receiver circuit), and the sending unit may correspond to a transmitter (or referred to as a transmitter or a transmitter circuit). The RRU3100is mainly configured to: receive and send a radio frequency signal, and perform conversion between the radio frequency signal and a baseband signal. For example, the RRU3100is configured to send indication information to a terminal device. The BBU3200is mainly configured to: perform baseband processing, control the base station, and so on. The RRU3100and the BBU3200may be physically disposed together, or may be physically disposed separately; to be specific, the base station is a distributed base station. The BBU3200is a control center of the base station, may also be referred to as a processing unit, may correspond to the processing unit1200inFIG.6, and is mainly configured to implement a baseband processing function, for example, channel coding, multiplexing, modulation, or spreading. For example, the BBU (the processing unit) may be configured to control the base station to perform an operation procedure related to the network device in the foregoing method embodiments, for example, to generate the foregoing indication information. In an example, the BBU3200may include one or more boards, and a plurality of boards may jointly support a radio access network (such as an LTE network) having a single access standard, or may separately support radio access networks (such as an LTE network, a 5G network, or another network) having different access standards. The BBU3200further includes a memory3201and a processor3202. The memory3201is configured to store necessary instructions and data. The processor3202is configured to control the base station to perform a necessary action, for example, configured to control the base station to perform an operation procedure related to the network device in the foregoing method embodiments. The memory3201and the processor3202may serve one or more boards. In other words, a memory and a processor may be independently disposed on each board, or a plurality of boards may share a same memory and a same processor. In addition, a necessary circuit may be further disposed on each board. It should be understood that, the base station3000shown inFIG.8can implement the processes of the network device in the method embodiment inFIG.2orFIG.5. Operations and/or functions of the modules in the base station3000are separately intended to implement corresponding procedures in the foregoing method embodiments. For details, refer to the descriptions in the foregoing method embodiments. To avoid repetition, detailed descriptions are properly omitted herein. The BBU3200may be configured to perform an action that is implemented inside the network device and that is described in the foregoing method embodiments, and the RRU3100may be configured to perform an action of receiving or sending that is performed by the network device from or to the terminal device and that is described in the foregoing method embodiments. For details, refer to the descriptions in the foregoing method embodiments. Details are not described herein again. An embodiment of this application further provides a processing apparatus, including a processor and an interface. The processor is configured to perform the communication method in any one of the foregoing method embodiments. It should be understood that, the processing apparatus may be a chip. For example, the processing apparatus may be a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-a-chip (SoC), a central processing unit (CPU), a network processor (NP), a digital signal processor (DSP), a micro controller unit (MCU), a programmable logic device (PLD), or another integrated chip. In an implementation process, operations in the foregoing methods may be implemented by using a hardware integrated logic circuit in the processor, or by using instructions in a form of software. The operations of the methods disclosed with reference to the embodiments of this application may be directly performed by a hardware processor, or may be performed by a combination of hardware and software modules in the processor. The software module may be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, or a register. The storage medium is located in the memory, and the processor reads information in the memory and completes the operations in the foregoing methods in combination with hardware of the processor. To avoid repetition, details are not described herein again. It should be noted that, the processor in the embodiments of this application may be an integrated circuit chip, and has a signal processing capability. In an implementation process, operations in the foregoing method embodiments may be implemented by using a hardware integrated logic circuit in the processor, or by using instructions in a form of software. The foregoing processor may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or another programmable logic device, a discrete gate or a transistor logic device, or a discrete hardware component. The processor may implement or perform the methods, operations, and logical block diagrams that are disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like. The operations of the methods disclosed with reference to the embodiments of this application may be directly performed and completed by a hardware decoding processor, or may be performed and completed by a combination of hardware and software modules in a decoding processor. The software module may be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, or a register. The storage medium is located in the memory, and the processor reads information in the memory and completes the operations in the foregoing methods in combination with hardware of the processor. It may be understood that the memory in the embodiments of this application may be a volatile memory or a non-volatile memory, or may include a volatile memory and a non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), used as an external cache. By way of example but not limitative description, many forms of RAMs may be used, for example, a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDR SDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synchronous link dynamic random access memory (SLDRAM), and a direct rambus random access memory (DR RAM). It should be noted that the memories in the systems and methods described in this specification include but are not limited to these memories and any memory of another suitable type. According to the methods provided in the embodiments of this application, this application further provides a computer program product. The computer program product includes computer program code. When the computer program code is run on a computer, the computer is enabled to perform the method in either of the embodiments shown inFIG.2andFIG.5. According to the methods provided in the embodiments of this application, this application further provides a computer-readable medium. The computer-readable medium stores program code. When the program code is run on a computer, the computer is enabled to perform the method in either of the embodiments shown inFIG.2andFIG.5. According to the methods provided in the embodiments of this application, this application further provides a system. The system includes the foregoing one or more terminal devices and the foregoing one or more network devices. All or some of the foregoing embodiments may be implemented by using software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, the embodiments may be implemented completely or partially in a form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on the computer, the procedures or the functions according to the embodiments of this application are all or partially generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or another programmable apparatus. The computer instruction may be stored in a computer-readable storage medium or may be transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instruction may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (for example, a coaxial cable, an optical fiber, or a digital subscriber line (DSL)) or wireless (for example, infrared, radio, or microwave) manner. The computer-readable storage medium may be any usable medium accessible by a computer, or a data storage device, such as a server or a data center, integrating one or more usable media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, or a magnetic tape), an optical medium (for example, a high-density digital video disc (DVD)), a semiconductor medium (for example, a solid-state disc (SSD)), or the like. The network device and the terminal device in the foregoing apparatus embodiments completely correspond to the network device and the terminal device in the method embodiments. A corresponding module or unit performs a corresponding operation. For example, the transceiver unit (transceiver) performs a receiving or sending operation in the method embodiments, and a operation other than the sending operation and the receiving operation may be performed by the processing unit (processor). For a function of a specific unit, refer to a corresponding method embodiment. There may be one or more processors. Terms such as “component”, “module”, and “system” used in this specification are used to indicate computer-related entities, hardware, firmware, combinations of hardware and software, software, or software being executed. For example, a component may be, but is not limited to, a process that runs on a processor, a processor, an object, an executable file, a thread of execution, a program, and/or a computer. As shown in figures, both a computing device and an application that runs on a computing device may be components. One or more components may reside within a process and/or a thread of execution, and a component may be located on one computer and/or distributed between two or more computers. In addition, these components may be executed from various computer-readable media that store various data structures. The components may communicate by using a local and/or remote process and according to, for example, a signal having one or more data packets (for example, data from two components interacting with another component in a local system, in a distributed system, and/or across a network such as the Internet interacting with other systems by using the signal). A person of ordinary skill in the art may be aware that, in combination with the examples described in the embodiments disclosed in this specification, units and algorithm operations may be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by the hardware or the software depends on particular applications and design constraints of the technical solutions. A person skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of this application. It may be clearly understood by a person skilled in the art that, for the purpose of convenient and brief description, for a detailed working process of the foregoing system, apparatus, and unit, refer to a corresponding process in the foregoing method embodiments, and details are not described herein again. In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiments are merely examples. For example, the unit division is merely logical function division and may be other division during actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual coupling or direct coupling or communication connections may be implemented by using some interfaces. The indirect coupling or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms. The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions of the embodiments. In addition, functional units in the embodiments of this application may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units may be integrated into one unit. When the functions are implemented in the form of a software functional unit and sold or used as an independent product, the functions may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of this application essentially, or the part contributing to the conventional technology, or some of the technical solutions may be implemented in a form of a software product. The computer software product is stored in a storage medium, and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform all or some of the operations of the methods described in the embodiments of this application. The storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc. The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims. | 266,725 |
11943015 | DETAILED DESCRIPTION Massive MIMO (Multiple Input, Multiple Output) technology is used for advanced transmission standards like the 5G mobile communication standard. It can offer narrow beam forming (that is, well-directed narrow transmit and receive beams), and hence the possibility to address many user devices per base station. It can also offer a way to defer attacks on the security of the transmitted messages. Massive MIMO is based on a large number, e.g. several hundred, of different power amplifiers and antennas. This is suitable for 5G base stations, but may be too much overhead for applications in which a similar degree of secure authentication is required or desired—e.g. domestic WLAN stations, WLAN hot spots, vehicle-to-everything (V2X) base stations, micro-cell base stations in future cellular network transmission standards or domestic cordless phone base stations. Examples disclosed herein can extend and modify the massive MIMO concept from several hundreds of small antennas to one single, long antenna which consists of a concatenation of many small sub-antennas. As will be described in detail below, the intended signal for these sub-antennas is sequentially fed into the long antenna; due to propagation delay, at a certain point of time, the intended signal is present at each sub-antenna and the single, long antenna transmits a directional beamformed signal. Such a system can require standard RF transmitter hardware—one amplifier, one antenna—yet still offer the advantages of massive MIMO that include narrow beamforming. This can save energy and allow addressing many user devices by a single base station. In this way, the cost and complexity of using many (perhaps several hundred) RF amplifiers is avoided. An additional advantage is that one or more of the systems disclosed herein can be well suited for state-of-the-art ways of Physical Layer Security to protect a secure authentication. Target applications can therefore include secure authentication by low data-rate cryptographic challenge/response handshake. The systems can be used stand-alone, or in additional to existing security/authentication methods. FIG.1shows a simplified MIMO system100, in which signals that represent a symbol (e.g. one bit modulated on an RF carrier frequency) are transmitted via several antennas102. The system100includes a driver/amplifier104for each antenna102. A phase adjustment block106sets the phase ϕn of each driver/amplifier104such that at a known position of a receiver108, the signals transmitted from the antennas102superimpose constructively. That is, the phase adjustment block106sets the relative phase shift of the drivers/amplifiers104to provide beamforming in a required direction. InFIG.1, a data source110creates data words that are to be transmitted by the antennas102. For example, each data word can be 10 bits wide for a 1024-QAM (quadrature amplitude modulation) signal. Further details of such signals will be described below with reference toFIGS.6aand6b. The phase adjustment block106receives a position indicator112that describes the position of the designated receiver108. It will be appreciated that the phase adjustment block106can receive the position indicator112from a processing block/module that is internal to the MIMO system100or external from the MIMO system. The position indicator112can be determined by processing a signal that is received from the designated receiver108. Also, the position indicator112can be retrieved from memory, for instance in environments where the antennas102and designated receiver108are in fixed positions (such as an office or manufacturing environment). The phase adjustment block106then calculates, according to the position of designated receiver108as defined by the position indicator112, a setting ϕnfor a phase shifter of each driver/amplifier104. The phase shifter settings ϕn result in each antenna102transmitting a signal with a phase such that at the designated receiver108, the field strength is expected to be at its maximum. This is because (ideally) the signals transmitted by each of the antennas102interfere constructively at that point. Assuming far-field conditions, the complex amplitude VRxreceived at the position of the receiver108as shown inFIG.1can be calculated as a function of the distances d(n) from antenna102to the designated receiver108, and the carrier frequency's wavelength λ. For convenience, the transmit power as well as the transmission factor from antenna to the designated receiver108are assumed to be unity. VRx=∑ne-jd(n)λ The MIMO system100ofFIG.1can be used for narrow beamforming. A significant drawback is the huge number of components and associated Bill of Material (BOM) due to the large number of drivers/amplifiers104and antennas102. This holds especially for the massive MIMO used e.g. in the 5G cellular network transmission standard. FIG.2shows a transmitted signal Tx214with the different symbols D1. . . D7that are sequentially transmitted by the MIMO system ofFIG.1.FIG.2also shows the received signal Rx216with the respective symbols as received at the designated receiver inFIG.1. As can be seen, there is only a short time interval between the received symbols, when the received symbol is undefined (marked by the striped boxes218). FIG.3shows an example embodiment of a communications system300, which, as described below, provides similar functionality to the MIMO system that is shown inFIG.1. The example ofFIG.3can be referred to as a space-continuous MIMO system. The system300includes an antenna320that comprises a plurality of serially connected sub-antenna elements322. In the example ofFIG.3there are seven sub-antenna elements322, although it will be appreciated that any number of sub-antenna elements322can be used. The sub-antenna elements322can be considered as part of a single “long antenna” that replaces the multiple small antennas102that are shown inFIG.1. Such examples can be considered as having a “long” antenna because it is longer than would be required for a single antenna (one that does not have a plurality of sub-antenna elements) to transmit signals at the same frequency. The system300also includes a signal generator324that provides an electrical transmission signal to the antenna320for propagating along the sub-antenna elements322. Each sub-antenna element322has a proximal and distal end—the proximal end being electrically closest to a signal generator324that provides the transmission signal; and the distal end being electrically furthest away from the signal generator324. Therefore, a sub-antenna element322receives the transmission signal at its proximal end, the transmission signal propagates through the sub-antenna element322towards its distal end, and then the transmission signal exits the sub-antenna element322at its distal end. The sub-antenna elements322are connected serially in that the distal end of a sub-antenna element is galvanically connected in series to the proximal end of the next sub-antenna element in the series. The transmission signal comprises a plurality of serial symbol packets (not shown inFIG.3) each with a defined phase such that when the serial symbol packets align with predefined ones of the sub-antenna elements322, the specified phase shifts cause the antenna320to provide a beamformed signal. The data in each symbol packet can be configured to be aligned with a single one of the plurality of sub-antenna elements322, in order to contribute to the beamformed signal that is provided by the antenna320. When a symbol packet is not aligned with its predefined sub-antenna element322, it does not contribute to a beamformed signal that is directed towards the designated receiver308. In this way, the antenna320is serially fed with signals such that at some instants in time (due to the propagation delay in the antenna320) each of the sub-antenna elements322receives a signal similar to the signal of the corresponding antenna of a multi-antenna array inFIG.1. Therefore, the system300ofFIG.3can achieve a transmission pattern that is similar to the MIMO system ofFIG.1such that the respective signals constructively interfere at the intended position (the designated receiver position308) at a designated time. As shown inFIG.3, the signal generator324receives a symbol from a symbol generator326. The symbol generator326, in turn, receives data from a data source310and generates the symbols according to any method known in the art. The symbols can simply be bits in some examples. In other examples, as described below, the symbols may be QAM symbols. The signal generator324includes a phase adjustment block306, which is different to the corresponding block in the system ofFIG.1. InFIG.1the phase adjustment block provides phase values to each of the drivers/amplifiers in parallel with each other, and the phase shift of each driver/amplifier stays constant during the transmission of each symbol. Whereas the phase adjustment block306ofFIG.3provides phase values for each of the sub-antenna elements322serially to the antenna320such that a plurality of different phase values are provided to the antenna320for the transmission of a single symbol. The phase adjustment block306ofFIG.3receives a symbol from the symbol generator326, and also receives a position indicator312. As above, the position indicator312can describe the position of the designated receiver308relative to the antenna320. Then, for each of the serially connected sub-antenna elements322, the phase adjustment block306determines a serial symbol packet based on the symbol received from the symbol generator326. The phase adjustment block306sets the phase of the serial symbol packet based on the received position indicator312. This description assumes, for ease of reading, that the difference in travel times from each sub-antenna element322to the designated receiver308is negligible. If this is not the case, then the phase adjustment block306can correct the phase of the symbol packets for the respective sub-antennas322to account for the travel time difference. In this example, the signal generator324also includes a single driver/amplifier304that drives the entire antenna320, and therefore also drives each of the sub-antenna elements322. This is in contrast to the system ofFIG.1that required a plurality of drivers/amplifiers. The signal generator324(in this example, the driver/amplifier304of the signal generator324) can then provide the serial symbol packets to the antenna320. Again assuming far-field conditions, the complex amplitude VRxreceived at the position of the receiver308as shown inFIG.3can be calculated as a function of the distances d(n) and the wavelength λ. For convenience, the transmit power and the attenuation across the path from the antenna320to the designated receiver308are again assumed to be unity. VRx=∑ne-jd(n)λ FIG.4shows schematically how an antenna420that is similar to the antenna ofFIG.3can be used to provide a beamformed signal. The antenna420ofFIG.4includes five sub-antenna elements422a-e. The left-hand side ofFIG.4schematically shows six instances of a transmission signal that can be present on the antenna420at six instances in time, t1-t6, as the transmission signal propagates along the antenna. At t1, the transmission signal428that is present on the antenna420includes five serial symbol packets, D1a-D1e, that are aligned with respective sub-antenna elements422a-eof the antenna420. The phase adjustment block of the system has set the phase of each of these five serial symbol packets, D1a-D1e, such that when they are aligned with the respective sub-antenna elements422a-ethe respective phase shifts causes the antenna to provide a beamformed signal that represents the first symbol, D1, and is directed to the designated receiver. At time t2, the transmission signal430has propagated along the antenna420from t1such that a newly received symbol packet, D2a, for a second symbol is now aligned with the first sub-antenna element422eof the antenna420. The symbol packets for the first symbol, D1, have propagated along the antenna420such that the first symbol packet, D1a, has dropped off the end of the antenna420(i.e., it has been absorbed by a termination resistor). The second packet for the first symbol, D1b, is therefore aligned with the last sub-antenna element422a. At t2, the antenna420does not provide a complete beamformed signal directed to the designated receiver because the sub-antenna elements422a-ereceive symbol packets that relate to a mixture of symbols (D1and D2) at t2. At times t3to t5, a newly received symbol packet for the second symbol, D2, is provided to the antenna420by the signal generator and is aligned with the first sub-antenna element422e. Also, the earliest symbol packet for the preceding symbol drops off the end of the antenna420in the same way as described for t2. At time t6, the last symbol packet, D1e, for the preceding symbol, D1, has dropped off the end of the antenna420. Therefore, at t6the transmission signal432that is present on the antenna420includes five serial symbol packets of the second symbol, D2a-D2e, that are aligned with respective sub-antenna elements422a-eof the antenna420. The phase adjustment block of the system has set the phase of each of these five serial symbol packets, D2a-D2e, such that when they are aligned with the respective sub-antenna elements422a-ethe respective phase shifts causes the antenna to provide a beamformed signal that represents the second symbol, D2, and is directed to the designated receiver. In this way, the phase shift of the transmission signal fed into the antenna420varies during the symbol transmission. At one or more instants in time each sub-antenna element422a-egets its signal with the correct phase shift for a given symbol and the antenna420provides a beamformed signal. The antenna420can be considered as having a plurality of galvanically concatenated sub-antennas elements; with each sub-antenna element performing a similar function as a single antenna in the massive MIMO system ofFIG.1. Each a symbol packet can represent one or a plurality of carrier frequency wavelets. It will be appreciated that the time between each of t1-t6shown inFIG.4corresponds to the time it takes for a symbol packet to propagate along the antenna420from one sub-antenna element422a-eto the next. FIG.5shows a transmitted signal514Tx with the different symbols D1. . . D7that are sequentially transmitted by the system ofFIG.3. As will be appreciated fromFIG.4in particular, each of the symbols includes a plurality of symbol packets that have a phase setting that is specific to that symbol packet for the given symbol, and is different to a phase setting for the symbol packets of the same symbol that are intended for the other sub-antenna elements. When each of the symbol packets of a given symbol are aligned with the appropriate sub-antenna elements, they have respective phase differences with the symbol packets on the other sub-antenna elements that results in constructive interference between the signals transmitted by the sub-antenna elements at the designated receiver position. FIG.5also shows the received signal Rx516with the respective symbols as received at the designated receiver inFIG.3. As can be seen, the received symbols are valid only for a very short time, and there is a relatively long time interval between adjacent symbols that are received at the designated receiver, where the symbol is undefined, as illustrated by the striped boxes518. These periods of time that the symbol is undefined at the designated receiver are caused by the time taken for the symbol packets of the transmission signal to propagate along the antenna until they are correctly aligned with their intended sub-antenna elements. With reference to the example ofFIG.4, the symbol will be undefined at the designated receiver at times t2, t3, t4and t5. It will therefore be appreciated fromFIGS.4and5that the system ofFIG.3will reduce the achievable data rate, when compared with the system ofFIG.1. This is a compromise that results from the use of a single independent antenna having multiple sub-antenna elements. In some applications, the reduction in components and complexity when compared with the system ofFIG.1can be a sufficiently strong benefit to warrant the trade-off with achievable data rate. Furthermore, the reduced data rate can provide an advantage in that it can strongly increase the Physical Layer Security. This is because an attacker (who may also be referred to as an eavesdropper) has less time of signal validity. The attacker may not be able to readily derive the moment that a received signal is valid, especially if he/she does not know the intended location of the designated receiver, whereas a legitimate receiver can derive the moment when the signal is valid (as will be discussed in more detail below with reference toFIG.7). Physical Layer Security can be advantageous in the context of protecting wireless communication from a mobile phone base station to user devices. In such applications, the phases of the symbol packets are modified in a way that is only known by the legitimate receiver, hence only the legitimate receiver can reconstruct the intended signal with its full amplitude. An attacker, who does not know how the phases of the symbol packets have been shifted, however, can only reconstruct a signal that is much below the ambient noise floor, and hence cannot be used to retrieve the desired information. In this way, the transmitted message can be protected with a security level that is comparable to state-of-the-art hard cryptography, e.g. RSA or AES encryption. Therefore, examples disclosed herein can provide a niche-application for authentication. This may especially be the case in future transmission technologies (particularly those that use high-frequency signals, where the dimensions of the antenna can be kept small), for stand-alone technologies, or to synergistically complement other authentication mechanisms. Examples disclosed herein can be suitable for authentication/secure exchange of challenge/response words. FIG.6ashows a symbol in the context of a Quadrature Amplitude Modulation (QAM) transmission—the symbol has a certain amplitude for the I-component and an amplitude for the Q-component. Depending on the signal-to-noise ratio and the requirements for Bit Error Rate, a symbol can be approximately one carrier frequency wavelet long, or comprise several carrier wavelets. The combination of I and Q amplitudes encodes the intended data word; in advanced QAM coding schemes there may be e.g. 210or even 212different symbols, so that 10 or even 12 bits per symbol can be transferred. QAM is identified as one example type of symbol because it includes many modulation schemes like Binary Phase Shift Keying (BPSK), Amplitude Shift Keying (ASK) or Amplitude Modulation (AM). Nonetheless, as indicated above, any type of symbol can be used in systems disclosed herein, with any type of modulation of encoding. FIG.6bshows an example symbol generator for QAM, that can be used as part of a communications system as disclosed herein. The data word to be transmitted is split into one half that is fed into the I-DAC, and another half that is fed into the Q-DAC. The data are converted to analog values, filtered and mixed with the original or 90° phase-shifted PLL-generated RF carrier signal, and finally they are added. FIG.7shows a transmitted signal714Tx and a corresponding received signal Rx716that are the same as shown inFIG.5. As discussed above, each received symbol is valid for only a relatively short time compared withFIG.2. FIG.7also shows the signal amplitude734of the received signal RX716at the designated receiver. As can be seen fromFIG.7, the signal amplitude734is sufficiently high only for a short time interval, compared to the whole duration of each symbol. This is because the signals of the sub-antenna elements interfere constructively only in this short time interval. At all other times, the signal amplitude734is very low; at these times, the signals from the sub-antenna elements interfere constructively and destructively. This allows for a mechanism to synchronize the receiver to this short interval of validity. One way to achieve such a synchronization is using a standard PLL mechanism. As the symbol rate is assumed to be fixed and constant, the frequency range of the PLL's VCO can and should be relatively narrow. Turning now to the antenna, it will be appreciated that it can be implemented in any of a number of different ways in order to provide the plurality of sub-antenna elements that are described herein. It could simply be a single wire (which may or may not be orientated in a straight line), with the sub-antenna elements being defined as particular regions of the wire. The sub-antenna elements may be spaced apart along the antenna, or they may be defined as adjacent regions of the antenna. The antenna may optionally be provided with delay elements or resonators between successive sub-antenna elements. Depending on the carrier frequency, these can be implemented as a simple delay line (high frequency), or e.g. an inductor (lower frequency). An advantage of including this functionality is that the symbol at each sub-antenna element can “stay” there for a longer time, before it starts propagating into the next sub-antenna element. The appropriate design of the antenna/sub-antenna elements will depend on factors such as carrier frequency and the intended range of the signals to be transmitted by the antenna (e.g. in the 1 km range for telecom applications, but only in the 10 m range for in-house wireless networks). The antenna may be a continuous single wire or a dipole antenna. The antenna and/or sub-antenna elements may also be realized in stripline or microstrip/microstrip patch technology. For very short wavelengths, it may also be realized in antenna-in-package technology, i.e. integrated into the ICs package. For achieving a high antenna efficiency, a resonant antenna can be particularly well-suited. FIG.8shows an example embodiment of an antenna consisting of three orthogonal segments, which can be used for 3D beamforming. In this example, the antenna is provided as a wire, but not orientated in a straight line (on which the sub-antennas are lined up). Instead, the antenna is divided into multiple segments that are not parallel with each other. For instance, the segments can be orthogonal to each other. In this example, the antenna includes three mutually orthogonal segments. Each segment can include a plurality of sub-antenna elements. This can allow for a better 3D beamforming, i.e. narrower transmit and receive lobes, with the advantage of higher security (as discussed above). Examples disclosed herein can also consume lower energy than systems known in the art. This is because the transmit lobe can be narrower, and hence the transmit energy is concentrated in a smaller cross section. One or more of the systems disclosed herein can be implemented using a plurality of antennas, with each antenna comprising a plurality of sub-antenna elements. Such systems can include a signal generator that is configured to provide a transmission signal to each of the plurality of the antennas for propagating along the sub-antenna elements, such that each of the plurality of antennas provides a beamformed signal that is directed to the same designated receiver. FIG.9shows an example embodiment of a communications system900in which two antennas920a,920bare used instead of only one. Although it will be appreciated that any number of antennas920a,920bcan be used to suit a particular application. For instance, 3, 5, 10 or more antennas920a,920bcan be used as part of the same communications system. Using a plurality of antennas920a,920bcan provide substantially better beamforming, and thus higher security and lower transmit energy. As shown inFIG.9, the system900includes a signal generator924that has a plurality of phase adjustment blocks906a,906b. Each of the phase adjustment blocks906a,906breceives the same symbol, in this example from the same symbol generator926. Each phase adjustment block906a,906balso receives a position indicator912that represents that same position in space of a designated receiver. In some examples, each phase adjustment block906a,906bmay receive a position indicator912that represents a relative direction to the designated receiver from the respective antenna920a,920b. In such examples, the position indicators912that are provided to each phase adjustment block906a,906bwill be different because their respective antennas will be in different positions with respect to the designated receiver. In another example, each phase adjustment block906a,906bcan receive the same position indicator912that represents a point in space of the designated receiver; for instance relative to a predetermined reference point, or using any known coordinate system such as GPS. In such examples, the phase adjustment block906a,906bcan determine an antenna-specific-position-indicator for the respective antenna based on the known position of the sub-antenna elements, such that the antenna-specific-position-indicator can be used by the phase adjustment block906a,906bto set the phase of the symbol packets that will be provided to that antenna to achieve the required beamforming direction. In a yet further example, any of the signal generators disclosed herein can add noise to the transmitted signal that is provided to the antenna, such as artificial pseudo-random noise or true random noise (e.g. thermal noise). This can provide an additional degree of Physical Layer Security because it can be more difficult for an eavesdropper to identify the transmitted signal. In a yet further example, the sub-antenna elements of any of the systems described herein could be asymmetric with respect to each other. For instance, the sub-antenna elements do not necessarily need to all have the same length. Therefore, the symbol packets also do not necessarily all need to have the same duration. That is, at least one of the sub-antenna elements can have a different length to another of the sub-antenna elements, and at least one of the symbol packets can have a different duration to another of the symbol packets. Such an example can make it even more difficult for an eavesdropper to intercept the symbols if he/she does not have details of the asymmetry that is present in the sub-antenna elements and the symbol packets. Whereas an intended receiver would have details of the asymmetry, and therefore would be able to accurately decode the symbols from the received signal. FIG.10shows schematically an example embodiment of a method according to the present disclosure. The method is for providing a transmission signal to an antenna that comprises a plurality of serially connected sub-antenna elements. The method can be performed by any of the signal generators disclosed herein. At step1050, the method includes receiving a symbol, for example from a symbol generator. At step1052, the method receives a position indicator for a designated receiver, as described above. At step1054, the method determines the transmission signal by: for each of the serially connected sub-antenna elements: (i) determining a serial symbol packet based on the received symbol, and (ii) setting the phase of the serial symbol packet based on the received position indicator. The method sets the phase such that when the symbol packets align with predefined ones of the sub-antenna elements, the antenna provides a beamformed signal. At step1056, the method provides the serial symbol packets to the antenna serially as the transmission signal. Examples disclosed herein relate to a massive MIMO data transmission system that uses an antenna that includes many sub-antennas, which are functionally similar to the individual antennas used in the massive MIMO system ofFIG.1. These examples can be particularly well-suited for low data rate transmission of secure authentication messages, especially challenge/response words. Advantageously, such examples provide at least the high degree of Physical Layer Security as is achieved by a massive MIMO such as the one ofFIG.1, and the same high degree of beamforming, but with a substantially reduced bill of materials and fewer components. Applications of the examples disclosed herein include integrated circuits (ICs) and systems for wireless data transmission, especially if the advantages of massive MIMO are beneficial (high directivity of the transmit/receive lobe, hence a high energy efficiency, efficiency of the used bandwidth, and additionally Physical Layer Security), and the additional advantage of space-continuous MIMO shall be used (reduced BOM). Particularly suitable applications include secure networks, e.g. domestic WLAN stations, WLAN hot spots, vehicle-to-everything (V2X) base stations, micro-cell base stations in future cellular network transmission standards or domestic cordless phone base stations, body-area networks, point-to-point connections similar to Bluetooth, Home IoT networks similar to ZigBee, etc. Examples disclosed herein are suitable for use in a high frequency technology standard for mobile telecommunications. For instance, standards that operate at 60 GHz, 90 GHz, 100 GHz or even higher. At such frequencies the required lengths for the sub-antenna elements can be sufficiently small to provide 2 or 3 carrier frequency wavelets for each sub-antenna element, while still, achieving an overall antenna length that will not be too long for many applications. The instructions and/or flowchart steps in the above figures can be executed in any order, unless a specific order is explicitly stated. Also, those skilled in the art will recognize that while one example set of instructions/method has been discussed, the material in this specification can be combined in a variety of ways to yield other examples as well, and are to be understood within a context provided by this detailed description. In some example embodiments the set of instructions/method steps described above are implemented as functional and software instructions embodied as a set of executable instructions which are effected on a computer or machine which is programmed with and controlled by said executable instructions. Such instructions are loaded for execution on a processor (such as one or more CPUs). The term processor includes microprocessors, microcontrollers, processor modules or subsystems (including one or more microprocessors or microcontrollers), or other control or computing devices. A processor can refer to a single component or to plural components. In other examples, the set of instructions/methods illustrated herein and data and instructions associated therewith are stored in respective storage devices, which are implemented as one or more non-transient machine or computer-readable or computer-usable storage media or mediums. Such computer-readable or computer usable storage medium or media is (are) considered to be part of an article (or article of manufacture). An article or article of manufacture can refer to any manufactured single component or multiple components. The non-transient machine or computer usable media or mediums as defined herein excludes signals, but such media or mediums may be capable of receiving and processing information from signals and/or other transient mediums. Example embodiments of the material discussed in this specification can be implemented in whole or in part through network, computer, or data based devices and/or services. These may include cloud, internet, intranet, mobile, desktop, processor, look-up table, microcontroller, consumer equipment, infrastructure, or other enabling devices and services. As may be used herein and in the claims, the following non-exclusive definitions are provided. In one example, one or more instructions or steps discussed herein are automated. The terms automated or automatically (and like variations thereof) mean controlled operation of an apparatus, system, and/or process using computers and/or mechanical/electrical devices without the necessity of human intervention, observation, effort and/or decision. It will be appreciated that any components said to be coupled may be coupled or connected either directly or indirectly. In the case of indirect coupling, additional components may be located between the two components that are said to be coupled. In this specification, example embodiments have been presented in terms of a selected set of details. However, a person of ordinary skill in the art would understand that many other example embodiments may be practiced which include a different selected set of these details. It is intended that the following claims cover all possible example embodiments. | 33,049 |
11943016 | DESCRIPTION OF EXAMPLE EMBODIMENTS Overview Briefly, multi-user multiple-input multiple-output (MU-MIMO) techniques are employed, and in particular the spatial dimension aspects of those techniques. Shield nodes are controlled to transmit in a way to obscure the downlink streams transmitted by a wireless access point that are intended for a particular client device to anything outside of the shielded area, and also to obscure uplink streams from one or more client devices to the wireless access point to anything outside of the shielded area but allowing the uplink streams to be well received by the wireless access point. In one form, a method is provided that is performed by a serving wireless access point capable of wireless communication with one or more wireless client devices within a physical space within which a plurality of shield wireless transceiver devices are positioned around a perimeter of, or in an arrangement within, the physical space. Each of the shield wireless transceiver devices includes one or more directional antennas pointing outward from the physical space so that transmissions from respective shield wireless transceiver devices are strongest in a predetermined area within the physical space or outside of the physical space where shielding is to be achieved for transmissions between the serving wireless access point and the one or more wireless client devices. The method includes, for a downlink transmission to be sent from the serving wireless access point to a first wireless client device of the one or more wireless client devices: sending a multi-user multiple-input multiple-output (MU-MIMO) transmission that includes a stream containing downlink traffic intended for the first wireless client device; and causing one or more first shield wireless transceiver devices of the plurality of shield wireless transceiver devices to send a downlink cover transmission while the downlink traffic is being transmitted to the first wireless client device that creates interference with reception of the downlink traffic outside of the physical space of the downlink traffic transmitted to the first wireless client device. The method also includes, for an uplink transmission to be sent from the first wireless client device of the one or more wireless client devices to the serving wireless access point: transmitting a MU-MIMO uplink trigger frame that subsequently causes the first wireless client device and one or more second shield wireless transceiver devices of the plurality of shield wireless transceiver devices to initiate a MU-MIMO uplink transmission such that the one or more second shield wireless transceiver devices send an uplink cover transmission outside the physical space while the first wireless client device sends an uplink transmission to the serving wireless access point to create interference with reception outside of the physical space of the uplink transmission from the first wireless client device to the serving wireless access point. Example Embodiments Presented herein are techniques to shield transmissions from being received and the information contained in them recovered by unwanted devices. This may desirable when one or more client devices are connected to a wireless network that is operating in a physical space in which over-the-air transmissions could be received outside the physical space, or outside of a particular sub-region of the physical space. Such a situation is more prevalent as more people work from home and use wireless networks in their apartment or house. However, this situation may also occur in enterprise/business offices environments where it may be desirable to prevent unauthorized reception of wireless transmissions outside of a conference room, factory floor or other workspace. Reference is now made toFIGS.1A and1B. These figures illustrate a system100that can provide an active radio frequency (RF) wireless shield outside of a physical space to be protected. The system100includes a data serving wireless access point (AP)110and a plurality of coordinated wireless nodes, called shield nodes. In the example arrangement shown inFIGS.1A and1B, there are 10 shield nodes120(1)-120(10) positioned around a perimeter of a physical space130to be protected. This is meant to be a non-limiting example as the number of shield nodes and their positions may vary depending on the size and shape of the physical space. The shield nodes may have semi-directional antennas pointing outward so that their transmissions are the strongest in the direction of areas where is desired to prevent snooping. The serving AP110has connectivity to a local area network/wide-area network (LAN/WAN)125, through any suitable gateway, broadband Internet Service Provider (ISP) modem, etc. (not shown inFIGS.1A and1B, for simplicity). There are one or more client devices140(1)-140(M) shown inside the physical space130. The downlink transmissions from the serving AP110to the client devices140(1)-140(M) and the uplink transmissions from the client devices140(1)-140(M) to the serving AP110are to be protected by creating the active RF wireless shield outside the physical space using the shield nodes120(1)-120(10). The client devices140(1)-140(M) may be laptop computers with wireless network connectivity, Smartphones, desktop computers with wireless network connectivity, video conference endpoints, or any suitable end user device that may receive downlink traffic from the serving AP and send uplink traffic to the serving AP. The serving AP110includes a plurality of antennas112that are used for steering of transmissions, as described further below. The shield nodes120(1)-120(10) may include one or a plurality of antennas122, but noteworthy is that the one or more antennas122of the shield nodes are directional antennas that are configured to have a transmit beam pattern outward from the physical space130. This is best shown inFIG.1B, where the transmit beam pattern150(1)-150(10) is shown for the respective shield nodes120(1)-120(10). The shapes and dimensions of the transmit beam patterns150(1)-150(10) are only examples and not meant to be limiting. Again, the shield nodes120(1)-120(1) are wireless transceiver devices configured to be positioned around a perimeter of, or in an arrangement within, the physical space130, wherein each of the shield wireless transceiver devices includes one or more directional antennas122pointing outward from the physical space130so that transmissions from respective shield nodes are strongest in a predetermined area within the physical space or outside of the physical space130where shielding is to be achieved for transmissions between the serving AP110and the one or more wireless client devices140(1)-140(M). The serving AP110coordinates operation of the shield nodes120(1)-120(10) to create an active wireless shield coincident in time with uplink and downlink transmissions between the serving AP110and one or more client devices140(1)-140(M). The goal is that the intended recipient of a downlink transmission (e.g., one or more of the client devices140(1)-140(M) or of an uplink transmission (the serving AP110) will be able to receive and decode the transmission, but any device outside of the physical space130will not be able to decode the transmission because the signal-to-interference ratio of those transmissions outside the physical space will be too poor. In one embodiment, multi-user multiple-input multiple-output (MU-MIMO) techniques of the IEEE 802.11ax standard are employed, and in particular the spatial dimension aspects of those techniques. The shield nodes transmit in a way to obscure the downlink streams that are designated for a particular client device to anything outside of the shielded area, and also to obscure uplink streams from one or more client devices inside the shielded area to anything outside of the shielded area but allowing the uplink streams to be well received by the serving AP110. The assumption is that a snooping device is going to be outside the perimeter of the physical space130. Thus, the transmit beam patterns from the shielding nodes are directed outward of the perimeter of the physical space130where the shielding transmissions are the strongest as indicated inFIG.1B, and inside the shielded space there will be some interference from the shielding transmissions, but it will be much lower (e.g., 20 dB lower). Moreover, the shielding transmissions sent by the shield nodes120(1)-120(10) may be steered in such a way that they are nulled at the serving AP110(in the case of a shielded uplink transmission) or at the client device (in the case of a shielded downlink transmission) so the serving AP110and client device experience as little interference as possible from the shielding transmissions. The shielded device (one or more of the client devices140(1)-140(M) or the serving AP110) is ignorant to what is going on with the shielding transmissions. The shield nodes120(1)-120(10) can be a part of the network infrastructure such as 802.11 stations (STAs) that are capable of acting as both an AP and a client), or off-the-shelf clients, or a mix. Again, the purpose of the shield nodes is to provide cover for uplink and downlink physical layer protocol data units (PPDUs) by transmitting over top of them while the serving AP110and the client device exchange protected data. The shield nodes may be arranged/configured to operate as “uplink shields,” as “downlink shields” or as both. Uplink shield nodes act as client-type devices during coordinated MU-MIMO uplink events and are triggered by the serving AP110. Downlink shield nodes act as AP-type devices and transmit during downlink transmission events. A given shield node could be configured to serve as an uplink shield and a downlink shield, if it has two radios (one in STA mode and another in AP mode) or a single radio running software that can support both acting as a client and AP in downlink and uplink. In any case, the shield nodes may be wall-powered or battery powered, and may (or may not be) associated to the serving AP110and have established some configuration with the serving AP so that they are able to coordinate with the traffic exchanges to transmit at the same time as an uplink transmission or a downlink transmission in order to provide active RF shielding. As shown inFIGS.1A and1B, the shield nodes have semi-directional antennas122that are focused outward. The shield nodes could further have multiple antennas that allow for the use of beam steering techniques to null any of the shielding transmissions at the client device or at the serving AP to be sure there is minimal or no negative impact at these intended devices. In one example of a deployment, shield nodes may be arranged such that uplink shield nodes are interleaved with downlink shield nodes. For example, shield nodes120(1),120(3),120(5),120(7) and120(9) are uplink shield nodes, and shield nodes120(2),120(4),120(6),120(8) and120(1) are downlink shield nodes. This is only an example, however. Reference is now made toFIG.2, which shows a block diagram of a shield node200(representative of any of the shield nodes shown inFIGS.1A and1B), according to an example embodiment. The shield node200includes one or more semi-directionally antennas210(1)-210(K). The shield node could be MIMO devices so that they can participate in MU-MIMO. To this end, there a transmitter220(1) and a receiver230(1) associated with antenna210(1) and a transmitter and a receiver220(K) and a receiver230(K) associated with antenna210(K). A baseband processor (modem)240is connected to the transmitters220(1)-220(K) and to the receiver230(1)-230(K). There may be multiple baseband processors in a shield node if the shield node is to serve as a shield node in both STA mode and AP mode. The baseband processor240is configured to perform the baseband modulation signal processing and baseband demodulation signal processing. The baseband processor240may be configured to perform MU-MIMO uplink and downlink signal processing. A controller250is provided to performing overall control of the shield node, based on software instructions stored in memory260for control logic270. The controller250may be a microcontroller, a microprocessor or a digital signal processor. Turning now toFIG.3, a block diagram is shown of a serving AP300. The serving AP is fully MU-MIMO capable (pursuant to IEEE 802.11ax) may also configured to coordinate transmissions according to the techniques for IEEE 802.11be. To this end, the serving AP300includes a plurality of antennas310(1)-310(J). There is a transmitter320(1) and a receiver330(1) associated with antenna310(1) and a transmitter and a receiver320(J) and a receiver330(J) associated with antenna310(J). A baseband processor (modem)340is connected to the transmitters320(1)-320(J) and to the receivers320(1)-320(J). The baseband processor340is configured to perform the baseband modulation signal processing and baseband demodulation signal processing. The baseband processor340is configured to perform MU-MIMO uplink and downlink signal processing. A controller350is coupled to the baseband processor340and performs higher level control functions of the serving AP300. The controller350may be a microprocessor, microcontroller or digital signal processor. A memory360stores instructions for serving AP control logic370that the controller350executes to perform the control functions of the serving AP. The serving AP300coordinates all downlink and uplink events. The serving AP300also provides the shielding transmissions to the shield nodes. The serving AP300also runs a power calibration process, described below. These functions of the serving AP300are performed under control and execution by the controller350of the serving AP control logic370, and in coordination with operations performed by the baseband processor340. FIG.4illustrates a flow chart depicting a process400by which the various entities in a wireless network interact to initialize operations to protect transmissions to/from a wireless client device. Reference may also be made toFIGS.1A and1Bfor purposes of the description ofFIG.4. At410, the serving AP powers on. At420, a client device associates to the serving AP. At this point, the client device is associated in a so-called “unprotected mode” insofar as the shield nodes have not yet been powered up and configured. At430, the shield nodes that serve as uplink shield nodes power and associate to the serving AP. At440, the shield nodes that serve as downlink shield nodes power on and are configured as slave APs to the serving AP. This may be achieved according to the procedures of IEEE 802.11be. At450, downlink and uplink traffic transmissions are executed and protected by the shield nodes. Details are presented below for how coordination is achieved among the shield nodes to provide cover for downlink transmissions and for uplink transmissions. Downlink Shielding When a downlink transmission is to be sent, the serving AP does a MU-MIMO transmission to the target wireless client device (for the downlink data traffic intended for the target wireless device) and to some other destinations, such as to uplink shield nodes, but the stream(s) of this MU-MIMO transmission that are not destined to the target wireless client device are just for convenience to complete the MU-MIMO transmission; they do not carry any real information or data. However, the data streams in the MU-MIMO transmission to the uplink shield devices are just random streams meant and may provide some amount of PHY-layer cover (additional to that provided by the DL shield nodes, as described below) so that a snooping device cannot decode the downlink data traffic intended for the target wireless client. The serving AP may perform beam steering of its transmission so that the target wireless client device is the only device to which the MU-MIMO transmission is steered to properly. The streams that are sent to the UL shield nodes may be sent at a higher transmit power level than that which is sent to the target client device, again, to provide some additional PHY-layer cover. These transmissions may be coordinated according to the procedures of IEEE 802.11be coordinated transmit operations. The serving AP acts as a master AP and the downlink shield nodes act as slave APs, and send random “canned” or bogus data to non-existent clients directed outside the physical space by the semi-directional antennas of the downlink shield nodes, as shown inFIG.1B. During the same transmit opportunity (Tx Op), the downlink shield nodes can also transmit and null their interfering/cover transmissions to the target wireless client device in order to avoid or minimize interfering with the target wireless client device's reception of the downlink transmission from the serving AP. More specifically, in one embodiment, in coordinating the timing of downlink shield node transmissions, one of the downlink shield nodes may be designated to operation in AP mode. That designated shield node, called AP_downlink_shield or AP_ds, and the serving AP use spatial reuse techniques. The AP_ds waits for the serving AP to send an AP trigger frame. This causes the AP_ds to send its own AP trigger frame to the downlink shield nodes. The AP_ds keeps track of any Clear-to-Send to Self (CTS2self) or any other indicator of Network Allocation Vector/Transmit Opportunity (NAV/TxOP) timing and uses that for controlling the TxOp of the downlink shields. In another embodiment, IEEE 802.11be is proposing a more coordinated/cooperative AP mechanism that employs TxOp coordination. In this case, downlink shield nodes would coordinate their transmissions with the downlink TxOps of the serving AP. A MAC-layer mechanism may be employed for the serving AP to coordinate TxOp sharing with other APs. While the foregoing describes the shielded area being outside a physical space, there may be some applications/situations where it is desired to do some shielding interference inside the physical space, but away from the target/intended recipients within that physical space. A subset of the shield nodes could have their semi-directional antennas adjusted to achieve a beam pattern to cover some portion of the internal space where shielding is desired. This may be the case when there are one or more “guest” user devices in the physical space, and it is desired to prevent those devices from being able to decode transmissions between a client device and AP elsewhere in the physical space. Uplink Shielding A conventional MU-MIMO UL trigger may be used to solicit an uplink transmission from a wireless client device and all the UL shield nodes and timing should work out properly. UL shield nodes would be associated to the AP and they would establish themselves as UL shield nodes for the purposes of UL PHY cover. The UL shield nodes are later included in MU UL triggered PPDUs per the procedures of IEEE 802.11ax UL MU-MIMO. The serving AP sends an UL trigger frame for an MU-MIMO uplink. The uplink shield nodes and the wireless client device transmit on top of each other. The uplink shield nodes can transmit at a higher transmit power since their beams are pointing outward/away from the physical space (and thus away from the serving AP that is the intended recipient). The wireless client device generally transmits an omni-directional beam and can transmit at a lower transmit power. Again, the transmissions from the uplink shield devices provide PHY layer cover for the wireless client device's uplink transmission so that devices outside the physical space are unable to receive and decode the uplink transmission from the wireless client device. Reference is now made toFIG.5for a more detailed description of an example transmission sequence500made in a network environment. In the example ofFIG.5, there is a serving AP, two client devices (Client 1 and Client 2), a plurality of downlink (DL) shield nodes (e.g., four DL shield nodes) and a plurality of UL shield nodes (e.g., four UL shield nodes). Moving from left to right, the serving AP sends a MU-MIMO downlink transmission that includes downlink traffic505to Client 1, as well as MU traffic to, for example, UL shield nodes, though that is not required. At the same time, the serving AP coordinates the DL shield nodes to transmit, at510, for PHY-layer cover over the downlink transmission to Client 1. At515, Client 1 sends an uplink block acknowledgement (ACK) to the serving AP. To shield this uplink transmission, at520, the UL shield nodes also are coordinated to transmit at the same time that the uplink block ACK is transmitted by Client 1. At525, the serving AP transmits an uplink trigger frame. The uplink trigger frame is received by devices in the network, and in this example, Client 1 has data queued up to send. At530, Client 1 and at535, UL shield nodes perform a MU-MIMO uplink transmission. The UL shield nodes transmit on top of the uplink transmission530to provide PHY layer cover for the Client 1 uplink transmission outside the physical space. As explained above, the UL shield nodes can transmit at a higher transmit power since their beams are pointing outward/away from the physical space (and thus away from the serving AP that is the intended recipient). No nulling/steering of the transmissions made by the UL shield nodes is needed. Client 1 generally transmits an omni-directional beam and can transmit at a lower transmit power. At540, the serving AP transmits a downlink block ACK steered to Client 1 to acknowledge reception of the uplink transmission at530from Client 1. The serving AP coordinates with the DL shield nodes to cause them to send transmissions, at545, to achieve cover for the serving AP's ACK transmitted to Client 1, similar to how the serving AP transmits the downlink transmission at505to Client 1. Next, at550, the serving AP transmits a MU-MIMO downlink transmission that includes downlink traffic550to Client 2, as well as MU traffic to, for example, UL shield nodes, though, again, that is not required. At the same time, the serving AP coordinates the DL shield nodes to transmit, at555, for PHY-layer cover over the downlink transmission to Client 2. At560, Client 2 sends an uplink block ACK to the serving AP. To shield this uplink transmission from Client 2, at565, the UL shield nodes also are coordinated to transmit at the same time that the uplink block ACK is transmitted by Client 1. At570, the serving AP again transmits an uplink trigger frame. The uplink trigger frame is received by devices in the network, and in this example, Client 2 has data queued up to send. At575, Client 2 and at580, UL shield nodes perform a MU-MIMO uplink transmission. The UL shield nodes transmit on top of the uplink transmission575to provide PHY layer cover for the Client 2 uplink transmission outside the physical space. No nulling/steering of the transmissions made by the UL shield nodes is needed. Client 2 can transmit an omni-directional beam and can transmit at a lower transmit power. At590, the serving AP transmits a downlink block ACK steered to Client 2 to acknowledge reception of the uplink transmission at575from Client 2. The serving AP coordinates with the DL shield nodes to cause them to send transmissions, at595, to achieve cover for the serving AP's ACK transmitted to Client 2. Power Calibration Taking into account the antenna patterns of the shield nodes and the beamforming that they do to help null the shielding transmissions toward the intended recipients of a data traffic transmission (to have minimum interference at the intended recipient device(s)), the shield nodes will contribute some level of interference at the recipient device(s). Presented here is a scheme to determine how to adjust a power level of the shielding/cover transmissions and/or power level of the data traffic transmissions to minimize interference impact of the shielding transmissions at the intended recipient devices. The procedures of IEEE 802.11ax include the ability of an AP to inform a client as to what power level the client should use to transmit an uplink to the AP. This power calibration process can be run once at the beginning and intermittently throughout service in the shielded space. The following is a process to estimate how much greater the transmit power can be can be for the streams to/from shield nodes as compared to the power of the shielded data stream. This power difference is computed by an intermittent calibration sequence that determines the Receive Signal Strength Information (RSSI) difference between all shield nodes and the intended clients. These power levels ensure that the data to/from the intended target client has enough margin for decoding to be performed. The data rates used to/from the intended client device can be lowered, if desired, so that the power differential can be increased without leading to increased packet errors. The calibration procedure involves channel sounding to each shield node on a periodic basis, every N milliseconds, such as 100-5000 milliseconds (ms). This is used for MU-MIMO steering as it would typically be used, as well as to understand current inter-device RSSI levels. For any given uplink/downlink, the total power used in the stream to/from the intended device is sent at power1 (as a function of data rate) and the power used by all other streams is sent at power_max, such that: power1(client,data_rate)=RSSI(shield)−RSSI(client)+decodingMargin_dB(data_rate)+power_max+steering_gainDb; where, RSSI(client) is the RSSI associated with reception at the AP of a transmission from that particular client; RSSI(shield) is the aggregate RSSI at the AP of all the shield nodes that would participate in that transmission event; decodingMarginDb(data_rate) is the signal-to-noise ratio (SNR) required to decode a packet at the data rate, data_rate; power_max is the max power to be sent per stream; and steering_gainDb is a typical beamforming/nulling gain achieved by the system. Referring toFIG.6,FIG.6illustrates a high-level hardware block diagram of a networking device600that may be configured to perform operations of the techniques presented herein, such as operations performed by a wireless access point. In at least one embodiment, the networking device600may be any apparatus that may include one or more processor(s)602, one or more memory element(s)604, storage606, a bus608, one or more network processor unit(s)610interconnected with one or more network input/output (I/O) interface(s)612, one or more I/O interface(s)614, and control logic620. In various embodiments, instructions associated with logic for networking device600can overlap in any manner and are not limited to the specific allocation of instructions and/or operations described herein. In at least one embodiment, processor(s)602is/are at least one hardware processor configured to execute various tasks, operations and/or functions for networking device600as described herein according to software and/or instructions configured for networking device600. Processor(s)602(e.g., a hardware processor) can execute any type of instructions associated with data to achieve the operations detailed herein. In one example, processor(s)602can transform an element or an article (e.g., data, information) from one state or thing to another state or thing. Any of potential processing elements, microprocessors, digital signal processor, baseband signal processor, modem, PHY, controllers, systems, managers, logic, and/or machines described herein can be construed as being encompassed within the broad term ‘processor’. In at least one embodiment, memory element(s)604and/or storage606is/are configured to store data, information, software, and/or instructions associated with networking device600, and/or logic configured for memory element(s)604and/or storage606. For example, any logic described herein (e.g., control logic620) can, in various embodiments, be stored for networking device600using any combination of memory element(s)604and/or storage606. Note that in some embodiments, storage606can be consolidated with memory element(s)604(or vice versa), or can overlap/exist in any other suitable manner. In at least one embodiment, bus608can be configured as an interface that enables one or more elements of networking device600to communicate in order to exchange information and/or data. Bus608can be implemented with any architecture designed for passing control, data and/or information between processors, memory elements/storage, peripheral devices, and/or any other hardware and/or software components that may be configured for networking device600. In at least one embodiment, bus608may be implemented as a fast kernel-hosted interconnect, potentially using shared memory between processes (e.g., logic), which can enable efficient communication paths between the processes. In various embodiments, network processor unit(s)610may enable communication between networking device600and other systems, entities, etc., via network I/O interface(s)612(wired and/or wireless) to facilitate operations discussed for various embodiments described herein. In various embodiments, network processor unit(s)610can be configured as a combination of hardware and/or software, such as one or more Ethernet driver(s) and/or controller(s) or interface cards, wireless receivers/transmitters/transceivers, baseband processor(s)/modem(s), and/or other similar network interface driver(s) and/or controller(s) now known or hereafter developed to enable communications between networking device600and other systems, entities, etc. to facilitate operations for various embodiments described herein. In various embodiments, network I/O interface(s)612can be configured as one or more Ethernet port(s), Fibre Channel ports, any other I/O port(s), and/or antenna(s)/antenna array(s) now known or hereafter developed. Thus, the network processor unit(s)610and/or network I/O interface(s)612may include suitable interfaces for receiving, transmitting, and/or otherwise communicating data and/or information in a network environment. I/O interface(s)614allow for input and output of data and/or information with other entities that may be connected to networking device600. For example, I/O interface(s)614may provide a connection to external devices such as a keyboard, keypad, a touch screen, and/or any other suitable input and/or output device now known or hereafter developed. In some instances, external devices can also include portable computer readable (non-transitory) storage media such as database systems, thumb drives, portable optical or magnetic disks, and memory cards. In still some instances, external devices can be a mechanism to display data to a user, such as, for example, a monitor, a display screen, or the like. In various embodiments, control logic620can include instructions that, when executed, cause processor(s)602to perform operations, which can include, but not be limited to, providing overall control operations of host device; interacting with other entities, systems, etc. described herein; maintaining and/or interacting with stored data, information, parameters, etc. (e.g., memory element(s), storage, data structures, databases, tables, etc.); combinations thereof; and/or the like to facilitate various operations for embodiments described herein. The programs described herein (e.g., control logic620) may be identified based upon application(s) for which they are implemented in a specific embodiment. However, it should be appreciated that any particular program nomenclature herein is used merely for convenience; thus, embodiments herein should not be limited to use(s) solely described in any specific application(s) identified and/or implied by such nomenclature. In various embodiments, any entity or apparatus as described herein may store data/information in any suitable volatile and/or non-volatile memory item (e.g., magnetic hard disk drive, solid state hard drive, semiconductor storage device, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM), application specific integrated circuit (ASIC), etc.), software, logic (fixed logic, hardware logic, programmable logic, analog logic, digital logic), hardware, and/or in any other suitable component, device, element, and/or object as may be appropriate. Any of the memory items discussed herein should be construed as being encompassed within the broad term ‘memory element’. Data/information being tracked and/or sent to one or more entities as discussed herein could be provided in any database, table, register, list, cache, storage, and/or storage structure: all of which can be referenced at any suitable timeframe. Any such storage options may also be included within the broad term ‘memory element’ as used herein. Note that in certain example implementations, operations as set forth herein may be implemented by logic encoded in one or more tangible media that is capable of storing instructions and/or digital information and may be inclusive of non-transitory tangible media and/or non-transitory computer readable storage media (e.g., embedded logic provided in: an ASIC, digital signal processing (DSP) instructions, software [potentially inclusive of object code and source code], etc.) for execution by one or more processor(s), and/or other similar machine, etc. Generally, memory element(s)604and/or storage606can store data, software, code, instructions (e.g., processor instructions), logic, parameters, combinations thereof, and/or the like used for operations described herein. This includes memory element(s)604and/or storage606being able to store data, software, code, instructions (e.g., processor instructions), logic, parameters, combinations thereof, or the like that are executed to carry out operations in accordance with teachings of the present disclosure. In some instances, software of the present embodiments may be available via a non-transitory computer useable medium (e.g., magnetic or optical mediums, magneto-optic mediums, CD-ROM, DVD, memory devices, etc.) of a stationary or portable program product apparatus, downloadable file(s), file wrapper(s), object(s), package(s), container(s), and/or the like. In some instances, non-transitory computer readable storage media may also be removable. For example, a removable hard drive may be used for memory/storage in some implementations. Other examples may include optical and magnetic disks, thumb drives, and smart cards that can be inserted and/or otherwise connected to a host device for transfer onto another computer readable storage medium. Reference is now made toFIG.7, which illustrates a flow chart for a method700, according to an example embodiment. Reference is also made toFIGS.1A and1Bfor purposes of the description ofFIG.7. The method700may be performed by a serving wireless access point that is capable of wireless communication with one or more wireless client devices within a physical space within which a plurality of shield wireless transceiver devices are positioned around a perimeter of, or in an arrangement within, the physical space. As depicted inFIGS.1A and1B, each of the shield wireless transceiver devices includes one or more directional antennas pointing outward from the physical space so that transmissions from respective shield wireless transceiver devices are strongest in a predetermined area within the physical space or outside of the physical space where shielding is to be achieved for transmissions between the serving wireless access point and the one or more wireless client devices. For a downlink transmission to be sent from the serving wireless access point to a first wireless client device of the one or more wireless client devices, the method700performs operations710and720. At operation710, the method700includes sending a multi-user multiple-input multiple-output (MU-MIMO) transmission that includes a stream containing downlink traffic intended for the first wireless client device. At operation720, the method700includes causing one or more first shield wireless transceiver devices of the plurality of shield wireless transceiver devices to send a downlink cover transmission while the downlink traffic is being transmitted to the first wireless client device that creates interference with reception of the downlink traffic outside of the physical space of the downlink traffic transmitted to the first wireless client device. For an uplink transmission to be sent from the first wireless client device of the one or more wireless client devices to the serving wireless access point, the method includes, at operation730, transmitting a MU-MIMO uplink trigger frame that subsequently causes the first wireless client device and one or more second shield wireless transceiver devices of the plurality of shield wireless transceiver devices to initiate a MU-MIMO uplink transmission such that the one or more second shield wireless transceiver devices send an uplink cover transmission outside the physical space while the first wireless client device sends an uplink transmission to the serving access point to create interference with reception outside of the physical space of the uplink transmission from the first wireless client device to the serving wireless access point. Variations and Implementations Embodiments described herein may include one or more networks, which can represent a series of points and/or network elements of interconnected communication paths for receiving and/or transmitting messages (e.g., packets of information) that propagate through the one or more networks. These network elements offer communicative interfaces that facilitate communications between the network elements. A network can include any number of hardware and/or software elements coupled to (and in communication with) each other through a communication medium. Such networks can include, but are not limited to, any local area network (LAN), virtual LAN (VLAN), wide area network (WAN) (e.g., the Internet), software defined WAN (SD-WAN), wireless local area (WLA) access network, wireless wide area (WWA) access network, metropolitan area network (MAN), Intranet, Extranet, virtual private network (VPN), Low Power Network (LPN), Low Power Wide Area Network (LPWAN), Machine to Machine (M2M) network, Internet of Things (IoT) network, Ethernet network/switching system, any other appropriate architecture and/or system that facilitates communications in a network environment, and/or any suitable combination thereof. Networks through which communications propagate can use any suitable technologies for communications including wireless communications (e.g., 4G/5G/nG, IEEE 802.11 (e.g., Wi-Fi®/Wi-Fi6®), IEEE 802.16 (e.g., Worldwide Interoperability for Microwave Access (WiMAX)), Radio-Frequency Identification (RFID), Near Field Communication (NFC), Bluetooth™, mm.wave, Ultra-Wideband (UWB), etc.), and/or wired communications (e.g., T1 lines, T3 lines, digital subscriber lines (DSL), Ethernet, Fibre Channel, etc.). Generally, any suitable means of communications may be used such as electric, sound, light, infrared, and/or radio to facilitate communications through one or more networks in accordance with embodiments herein. Communications, interactions, operations, etc. as discussed for various embodiments described herein may be performed among entities that may directly or indirectly connected utilizing any algorithms, communication protocols, interfaces, etc. (proprietary and/or non-proprietary) that allow for the exchange of data and/or information. In various example implementations, any entity or apparatus for various embodiments described herein can encompass network elements (which can include virtualized network elements, functions, etc.) such as, for example, network appliances, forwarders, routers, servers, switches, gateways, bridges, loadbalancers, firewalls, processors, modules, radio receivers/transmitters, or any other suitable device, component, element, or object operable to exchange information that facilitates or otherwise helps to facilitate various operations in a network environment as described for various embodiments herein. Note that with the examples provided herein, interaction may be described in terms of one, two, three, or four entities. However, this has been done for purposes of clarity, simplicity and example only. The examples provided should not limit the scope or inhibit the broad teachings of systems, networks, etc. described herein as potentially applied to a myriad of other architectures. Communications in a network environment can be referred to herein as ‘messages’, ‘messaging’, ‘signaling’, ‘data’, ‘content’, ‘objects’, ‘requests’, ‘queries’, ‘responses’, ‘replies’, etc. which may be inclusive of packets. As referred to herein and in the claims, the term ‘packet’ may be used in a generic sense to include packets, frames, segments, datagrams, and/or any other generic units that may be used to transmit communications in a network environment. Generally, a packet is a formatted unit of data that can contain control or routing information (e.g., source and destination address, source and destination port, etc.) and data, which is also sometimes referred to as a ‘payload’, ‘data payload’, and variations thereof. In some embodiments, control or routing information, management information, or the like can be included in packet fields, such as within header(s) and/or trailer(s) of packets. Internet Protocol (IP) addresses discussed herein and in the claims can include any IP version 4 (IPv4) and/or IP version 6 (IPv6) addresses. To the extent that embodiments presented herein relate to the storage of data, the embodiments may employ any number of any conventional or other databases, data stores or storage structures (e.g., files, databases, data structures, data or other repositories, etc.) to store information. Note that in this Specification, references to various features (e.g., elements, structures, nodes, modules, components, engines, logic, steps, operations, functions, characteristics, etc.) included in ‘one embodiment’, ‘example embodiment’, ‘an embodiment’, ‘another embodiment’, ‘certain embodiments’, ‘some embodiments’, ‘various embodiments’, ‘other embodiments’, ‘alternative embodiment’, and the like are intended to mean that any such features are included in one or more embodiments of the present disclosure, but may or may not necessarily be combined in the same embodiments. Note also that a module, engine, client, controller, function, logic or the like as used herein in this Specification, can be inclusive of an executable file comprising instructions that can be understood and processed on a server, computer, processor, machine, compute node, combinations thereof, or the like and may further include library modules loaded during execution, object files, system files, hardware logic, software logic, or any other executable modules. It is also noted that the operations and steps described with reference to the preceding figures illustrate only some of the possible scenarios that may be executed by one or more entities discussed herein. Some of these operations may be deleted or removed where appropriate, or these steps may be modified or changed considerably without departing from the scope of the presented concepts. In addition, the timing and sequence of these operations may be altered considerably and still achieve the results taught in this disclosure. The preceding operational flows have been offered for purposes of example and discussion. Substantial flexibility is provided by the embodiments in that any suitable arrangements, chronologies, configurations, and timing mechanisms may be provided without departing from the teachings of the discussed concepts. As used herein, unless expressly stated to the contrary, use of the phrase ‘at least one of’, ‘one or more of’, ‘and/or’, variations thereof, or the like are open-ended expressions that are both conjunctive and disjunctive in operation for any and all possible combination of the associated listed items. For example, each of the expressions ‘at least one of X, Y and Z’, ‘at least one of X, Y or Z’, ‘one or more of X, Y and Z’, ‘one or more of X, Y or Z’ and ‘X, Y and/or Z’ can mean any of the following: 1) X, but not Y and not Z; 2) Y, but not X and not Z; 3) Z, but not X and not Y; 4) X and Y, but not Z; 5) X and Z, but not Y; 6) Y and Z, but not X; or 7) X, Y, and Z. Each example embodiment disclosed herein has been included to present one or more different features. However, all disclosed example embodiments are designed to work together as part of a single larger system or method. This disclosure explicitly envisions compound embodiments that combine multiple previously-discussed features in different example embodiments into a single system or method. Additionally, unless expressly stated to the contrary, the terms ‘first’, ‘second’, ‘third’, etc., are intended to distinguish the particular nouns they modify (e.g., element, condition, node, module, activity, operation, etc.). Unless expressly stated to the contrary, the use of these terms is not intended to indicate any type of order, rank, importance, temporal sequence, or hierarchy of the modified noun. For example, ‘first X’ and ‘second X’ are intended to designate two ‘X’ elements that are not necessarily limited by any order, rank, importance, temporal sequence, or hierarchy of the two elements. Further as referred to herein, ‘at least one of’ and ‘one or more of’ can be represented using the ‘(s)’ nomenclature (e.g., one or more element(s)). In summary, a system provided that includes a master wireless access point device and several shield wireless transceiver devices (nodes). The master wireless access point device sends downlink transmissions to and receives uplink transmissions from both an intended target client device and the shield nodes. MU-MIMO uplink and downlink techniques are used to mask the transmissions (data streams) to the intended target client device and from the target client device to the master wireless access point device. In some aspects, the techniques described herein relate to a system including: a serving wireless access point configured for wireless communication with one or more wireless client devices within a physical space; and a plurality of shield wireless transceiver devices configured to be positioned around a perimeter of, or in an arrangement within, the physical space, wherein each of the shield wireless transceiver devices includes one or more directional antennas pointing outward from the physical space so that transmissions from respective shield wireless transceiver devices are strongest in a predetermined area within the physical space or outside of the physical space where shielding is to be achieved for transmissions between the serving wireless access point and the one or more wireless client devices; wherein the serving wireless access point is configured, for a downlink transmission to a first wireless client device of the one or more wireless client devices, to: send a multi-user multiple-input multiple-output (MU-MIMO) transmission that includes a stream containing downlink traffic intended for the first wireless client device; and cause one or more first shield wireless transceiver devices of the plurality of shield wireless transceiver devices to send a downlink cover transmission while the downlink traffic is being transmitted to the first wireless client device that creates interference with reception of the downlink traffic outside of the physical space of the downlink traffic transmitted to the first wireless client device; wherein the serving wireless access point is configured, for an uplink transmission from the first wireless client device of the one or more wireless client devices, to: transmit a MU-MIMO uplink trigger frame that subsequently causes the first wireless client device and one or more second shield wireless transceiver devices of the plurality of shield wireless transceiver devices to initiate a MU-MIMO uplink transmission such that the one or more second shield wireless transceiver devices send an uplink cover transmission outside the physical space while the first wireless client device sends an uplink transmission to the serving wireless access point to create interference with reception outside of the physical space of the uplink transmission from the first wireless client device to the serving wireless access point. In some aspects, for the downlink transmission, the serving wireless access point is configured to perform beam steering so that the first wireless client device is the only intended recipient device to which the MU-MIMO transmission is steered. In some aspects, for the downlink transmission, the serving wireless access point is configured to act as a master access point and to coordinate with the one or more first shield wireless transceiver devices to act as slave access points and to cause the one or more first shield wireless transceiver devices to transmit the downlink cover transmission that carries random or bogus data directed towards non-existent clients outside the physical space via the directional antennas of the one or more first shield wireless transceiver devices. In some aspects, the serving wireless access point is configured to coordinate with the one or more first shield wireless transceiver devices to null the downlink cover transmission to the first wireless client device in order to avoid or minimize interfering with reception by the first wireless client device of the downlink traffic from the serving wireless access point. In some aspects, for the downlink transmission, the serving wireless access point is configured to send, as part of the MU-MIMO transmission, one or more random data streams to one or more second shield wireless transceiver devices of the plurality of shield wireless transceiver devices. In some aspects, the serving wireless access point is configured to send the one or more random data streams as part of the MU-MIMO transmission with a higher transmit power level than a power level for the stream that contains the downlink traffic intended for the first wireless client device. In some aspects, the one or more second shield wireless transceiver devices send the uplink cover transmission with a higher transmit power than a transmit power used by the first wireless client device in sending the uplink transmission to the serving wireless access point. In some aspects, the serving wireless access point is further configured to perform a calibration procedure to determine a transmit power to be used for transmissions to or from a given wireless client device of the one or more wireless client devices in order to achieve a desired decoding margin at the given wireless client device or at the serving wireless access point. In some aspects, the serving wireless access point is configured to compute the transmit power as a function of data rate, power(client, data_rate) to be used for transmissions to or from the given wireless client device using a computation: power(client, data_rate)=RSSI(shield)−RSSI(client)+decodingMargin_dB(data_rate)+power_max+steering_gainDb, where RSSI(client) is received signal strength information associated with reception at the serving wireless access point of a transmission event from the given wireless client device, RSSI(shield) is an aggregate RSSI at the serving wireless access point of all shield wireless transceiver devices that would participate in the transmission event, decodingMarginDb(data_rate) is a signal-to-noise ratio (SNR) to decode a packet at the data rate, power_max is a maximum power to be sent per stream, and steering_gainDb is a beamforming/nulling gain. In some aspects, the techniques described herein relate to a method performed by a serving wireless access point capable of wireless communication with one or more wireless client devices within a physical space within which a plurality of shield wireless transceiver devices are positioned around a perimeter of, or in an arrangement within, the physical space, wherein each of the shield wireless transceiver devices includes one or more directional antennas pointing outward from the physical space so that transmissions from respective shield wireless transceiver devices are strongest in a predetermined area within the physical space or outside of the physical space where shielding is to be achieved for transmissions between the serving wireless access point and the one or more wireless client devices, the method including: for a downlink transmission to be sent from the serving wireless access point to a first wireless client device of the one or more wireless client devices: sending a multi-user multiple-input multiple-output (MU-MIMO) transmission that includes a stream containing downlink traffic intended for the first wireless client device; and causing one or more first shield wireless transceiver devices of the plurality of shield wireless transceiver devices to send a downlink cover transmission while the downlink traffic is being transmitted to the first wireless client device that creates interference with reception of the downlink traffic outside of the physical space of the downlink traffic transmitted to the first wireless client device; for an uplink transmission to be sent from the first wireless client device of the one or more wireless client devices to the serving wireless access point: transmitting a MU-MIMO uplink trigger frame that subsequently causes the first wireless client device and one or more second shield wireless transceiver devices of the plurality of shield wireless transceiver devices to initiate a MU-MIMO uplink transmission such that the one or more second shield wireless transceiver devices send an uplink cover transmission outside the physical space while the first wireless client device sends an uplink transmission to the serving wireless access point to create interference with reception outside of the physical space of the uplink transmission from the first wireless client device to the serving wireless access point. In some aspects, the method further includes: performing beam steering so that the first wireless client device is the only intended recipient device to which the MU-MIMO transmission is steered; and coordinating with the one or more first shield wireless transceiver devices to act as slave access points and to cause the one or more first shield wireless transceiver devices to transmit the downlink cover transmission that carries random or bogus data directed towards non-existent clients outside the physical space via the directional antennas of the one or more first shield wireless transceiver devices. In some aspects, the method further includes: coordinating with the one or more first shield wireless transceiver devices to null the downlink cover transmission to the first wireless client device in order to avoid or minimize interfering with reception by the first wireless client device of the downlink traffic from the serving wireless access point. In some aspects, for the downlink transmission, the serving wireless access point sends, as part of the MU-MIMO transmission, one or more random data streams to one or more second shield wireless transceiver devices of the plurality of shield wireless transceiver devices. In some aspects, the method further includes: performing a calibration procedure to determine a transmit power to be used for transmissions to or from a given wireless client device of the one or more wireless client devices in order to achieve a desired decoding margin at the given wireless client device or at the serving wireless access point. In some aspects, performing the calibration procedure includes: computing the transmit power as a function of data rate, power(client, data_rate) to be used for transmissions to or from the given wireless client device using a computation: power(client, data_rate)=RSSI(shield)−RSSI(client)+decodingMargin_dB(data_rate)+power_max+steering_gainDb, where RSSI(client) is received signal strength information associated with reception at the serving wireless access point of a transmission event from the given wireless client device, RSSI(shield) is an aggregate RSSI at the serving wireless access point of all shield wireless transceiver devices that would participate in the transmission event, decodingMarginDb(data_rate) is a signal-to-noise ratio (SNR) to decode a packet at the data rate, power_max is a maximum power to be sent per stream, and steering_gainDb is a beamforming/nulling gain. In some aspects, the techniques described herein relate to an apparatus including: a plurality of radio transceivers that provide wireless communication with one or more wireless client devices within a physical space, wherein a plurality of shield wireless transceiver devices are positioned around a perimeter of, or in an arrangement within, the physical space, wherein each of the shield wireless transceiver devices includes one or more directional antennas pointing outward from the physical space so that transmissions from respective shield wireless transceiver devices are strongest in a predetermined area within the physical space or outside of the physical space where shielding is to be achieved for transmissions between the apparatus and the one or more wireless client devices; a baseband processor coupled to the plurality of radio transceivers; and a controller coupled to the baseband processor, wherein the controller is configured, for a downlink transmission to a first wireless client device of the one or more wireless client devices, to cause the apparatus to: send a multi-user multiple-input multiple-output (MU-MIMO) transmission that includes a stream containing downlink traffic intended for the first wireless client device; and cause one or more first shield wireless transceiver devices of the plurality of shield wireless transceiver devices to send a downlink cover transmission while the downlink traffic is being transmitted to the first wireless client device that creates interference with reception of the downlink traffic outside of the physical space of the downlink traffic transmitted to the first wireless client device; wherein the controller is configured, for an uplink transmission from the first wireless client device of the one or more wireless client devices, to cause the apparatus to: transmit a MU-MIMO uplink trigger frame that subsequently causes the first wireless client device and one or more second shield wireless transceiver devices of the plurality of shield wireless transceiver devices to initiate a MU-MIMO uplink transmission such that the one or more second shield wireless transceiver devices send an uplink cover transmission outside the physical space while the first wireless client device sends an uplink transmission to the apparatus to create interference with reception outside of the physical space of the uplink transmission from the first wireless client device to the apparatus. In some aspects, for the downlink transmission, the controller configures the apparatus to serve as a master access point and to coordinate with the one or more first shield wireless transceiver devices to act as slave access points and to cause the one or more first shield wireless transceiver devices to transmit the downlink cover transmission that carries random or bogus data directed towards non-existent clients outside the physical space via the directional antennas of the one or more first shield wireless transceiver devices. In some aspects, the controller is configured to cause the apparatus to coordinate with the one or more first shield wireless transceiver devices to null the downlink cover transmission to the first wireless client device in order to avoid or minimize interfering with reception by the first wireless client device of the downlink traffic from the apparatus. In some aspects, the controller is configured to perform a calibration procedure to determine a transmit power to be used for transmissions to or from a given wireless client device of the one or more wireless client devices in order to achieve a desired decoding margin at the given wireless client device or at the apparatus. In some aspects, the controller is configured to compute the transmit power as a function of data rate, power(client, data_rate) to be used for transmissions to or from the given wireless client device based on a computation: power(client, data_rate)=RSSI(shield)−RSSI(client)+decodingMargin_dB(data_rate)+power_max+steering_gainDb, where RSSI(client) is received signal strength information associated with reception at apparatus of a transmission event from the given wireless client device, RSSI(shield) is an aggregate RSSI at the apparatus of all shield wireless transceiver devices that would participate in the transmission event, decodingMarginDb(data_rate) is a signal-to-noise ratio (SNR) to decode a packet at the data rate, power_max is a maximum power to be sent per stream, and steering_gainDb is a beamforming/nulling gain. In some aspects, the techniques relate to relate one or more non-transitory computer readable storage media encoded with instructions that, when executed by a processor in a serving wireless access point that includes a plurality of radio transceivers that provide wireless communication with one or more wireless client devices within a physical space, wherein a plurality of shield wireless transceiver devices are positioned around a perimeter of, or in an arrangement within, the physical space, wherein each of the shield wireless transceiver devices includes one or more directional antennas pointing outward from the physical space so that transmissions from respective shield wireless transceiver devices are strongest in a predetermined area within the physical space or outside of the physical space where shielding is to be achieved for transmissions between the apparatus and the one or more wireless client devices; a baseband processor coupled to the plurality of radio transceivers; and a control processor coupled to the baseband processor, wherein the control processor executes the instructions to perform operations including: for a downlink transmission to a first wireless client device of the one or more wireless client devices, cause the serving wireless access point to: send a multi-user multiple-input multiple-output (MU-MIMO) transmission that includes a stream containing downlink traffic intended for the first wireless client device; and cause one or more first shield wireless transceiver devices of the plurality of shield wireless transceiver devices to send a downlink cover transmission while the downlink traffic is being transmitted to the first wireless client device that creates interference with reception of the downlink traffic outside of the physical space of the downlink traffic transmitted to the first wireless client device; for an uplink transmission from the first wireless client device of the one or more wireless client devices, to cause the serving wireless access point to: transmit a MU-MIMO uplink trigger frame that subsequently causes the first wireless client device and one or more second shield wireless transceiver devices of the plurality of shield wireless transceiver devices to initiate a MU-MIMO uplink transmission such that the one or more second shield wireless transceiver devices send an uplink cover transmission outside the physical space while the first wireless client device sends an uplink transmission to the serving wireless access point to create interference with reception outside of the physical space of the uplink transmission from the first wireless client device to the serving wireless access point. One or more advantages described herein are not meant to suggest that any one of the embodiments described herein necessarily provides all of the described advantages or that all the embodiments of the present disclosure necessarily provide any one of the described advantages. Numerous other changes, substitutions, variations, alterations, and/or modifications may be ascertained to one skilled in the art and it is intended that the present disclosure encompass all such changes, substitutions, variations, alterations, and/or modifications as falling within the scope of the appended claims. | 64,844 |
11943017 | DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Technical solutions provided in embodiments of this application may be applied to various communications systems, such as a 5G communications system, a future evolved system, or a plurality of harmonized communications systems, and may also be applied to an existing communications system or the like. The technical solutions provided in this application may be applied to a plurality of scenarios, for example, machine-to-machine (M2M), macro-micro communications, enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (uRLLC), and massive machine-type communications (mMTC) scenarios. These scenarios may include, but are not limited to, a scenario of communication between terminals, a scenario of communication between network devices, a scenario of communication between a network device and a terminal, and the like. The following uses the application scenario of communication between a network device and a terminal as an example for description. FIG.1is a schematic diagram of a communications system applicable to an embodiment of this application. The communications system may include one or more network devices10(only one is shown) and one or more terminals20connected to each network device10.FIG.1is merely a schematic diagram, and does not constitute a limitation on an applicable scenario of the technical solutions provided in this application. The network device10may be a transmission reception point (TRP), a base station, a relay station, an access point, or the like. The network device10may be a network device in a 5G communications system or a network device in a future evolved network, or may be a wearable device, a vehicle-mounted device, or the like. Alternatively, the network device10may be a base transceiver station (base transceiver station, BTS) in a global system for mobile communications (GSM) system or a code division multiple access (CDMA) network, or may be an NB (NodeB) in wideband code division multiple access (WCDMA), or may be an eNB or eNodeB (evolutional NodeB) in long term evolution (LTE). Alternatively, the network device10may be a radio controller in a cloud radio access network (CRAN) scenario. The terminal20may be user equipment (UE) or client premises equipment (CPE), an access terminal, a UE unit, a UE station, a mobile station, a mobile console, a remote station, a remote terminal, a mobile device, a UE terminal, a wireless communications device, a UE agent, a UE apparatus, or the like. The access terminal may be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having a wireless communication function, a computing device, another processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal in a 5G network, a terminal in a future evolved public land mobile network (PLMN), or the like. Each network element inFIG.1may be implemented by using a communications device200inFIG.2. The communications device200includes at least one processor201, a communications line202, a memory203, and at least one communications interface204. The processor201may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to control program execution of the solutions of this application. The communications line202may include a channel, to transfer information between the foregoing components. The communications interface204uses any apparatus such as a transceiver to communicate with another device or a communications network such as an Ethernet, a RAN, or a wireless local area network (WLAN). The memory203may be, but is not limited to, a read-only memory (ROM) or another type of static storage device capable of storing static information and instructions, a random access memory (RAM) or another type of dynamic storage device capable of storing information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or another compact disc storage, an optical disc storage (including a compact disc, a laser disc, an optical disc, a digital versatile disc, and a blue-ray disc, or the like), a magnetic disk storage medium or another magnetic storage device, or any other medium that can be used to carry or store expected program code in a form of instructions or a data structure and can be accessed by a computer. The memory may exist independently, and is connected to the processor by using the communications line202. Alternatively, the memory may be integrated with the processor. The memory provided in this embodiment of this application may generally be non-volatile. The memory203is configured to store computer-executable instructions for executing the solutions of this application, and the processor201controls execution of the instructions. The processor201is configured to execute the computer-executable instructions stored in the memory203, to implement a method provided in the following embodiment of this application. Optionally, the computer-executable instructions in this embodiment of this application may also be referred to as application program code. This is not specifically limited in this embodiment of this application. During specific implementation, in an embodiment, the communications device200may include a plurality of processors, for example, the processor201and a processor207shown inFIG.2. Each of these processors may be a single-CPU processor, or may be a multi-CPU processor. The processor herein may be one or more devices, circuits, and/or processing cores configured to process data (for example, computer program instructions). During specific implementation, in an embodiment, the communications device200may further include an output device205and an input device206. The output device205communicates with the processor201, and may display information in a plurality of manners. For example, the output device205may be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device206communicates with the processor201, and may receive user input in a plurality of manners. For example, the input device206may be a mouse, a keyboard, a touchscreen device, or a sensing device. It should be noted that any technical solution provided in the embodiments of this application may be applied to a downlink transmission scenario, and may also be applied to an uplink transmission scenario. In an application scenario of downlink transmission, a transmit end device may be a network device, and a receive end device may be a terminal. A device of a structure similar to that inFIG.2is applied. A type of the communications device200is not limited in this embodiment of this application. It should be noted that the technical solutions provided in the embodiments of this application may be applied to a downlink transmission scenario, and may also be applied to an uplink transmission scenario. In an application scenario of downlink transmission, a transmit end device may be a network device, and a receive end device may be a terminal. In an application scenario of uplink transmission, a transmit end device may be a terminal, and a receive end device may be a network device. For any one of the following embodiments, after a transmit end device (or a receive end device) is replaced with a network device, a network device in this embodiment and the replaced network device may represent a same network device. After the transmit end device (or the receive end device) is replaced with a terminal, a terminal in this embodiment and the replaced terminal may represent a same terminal. A unified explanation is provided herein, and it is not repeated below. The technical solutions provided in the embodiments of this application may be applied to a time division duplex (TDD) system, and may also be applied to a frequency division duplex system. The technical solutions provided in the embodiments of this application are described by using an example in which a network device schedules a terminal, and the terminal spatially multiplexes a plurality of data streams. In addition, a manner of multiplexing a transmission resource (for example, a time-frequency resource or a space resource) between the terminal and another terminal is not limited in the embodiments of this application. It should be noted that, unless otherwise described, diagonal elements of a matrix in the embodiments of this application are all elements on a main diagonal of the matrix. A unified explanation is provided herein, and it is not repeated below. FIG.3is a schematic flowchart of a precoding method according to an embodiment of this application. In this embodiment, the method is performed by a transmit end device. The method shown inFIG.3may include the following steps. S101: Obtain a channel matrix H, and perform SVD on the channel matrix H, to decompose the channel matrix into a product of a matrix U, a matrix Σ, and a matrix VH, that is, H=UΣVH. The matrix VHis a conjugate transpose matrix of a matrix V, both the matrix U and the matrix V are unitary matrices, and the matrix Σ is a diagonal matrix. For a specific implementation process of S101, refer to a conventional technology. Details are not described herein. If an n-order complex matrix A meets AHA=AAH=E, the matrix A is a unitary matrix. AHis a conjugate transpose matrix of the matrix A. E is an identity matrix. The diagonal matrix is a matrix in which all elements other than elements on a main diagonal are 0, and the elements on the diagonal may be 0 or non-zero values. S102: Transform the matrix U, the matrix Σ, and the matrix VHto obtain a matrix Q, a matrix R, and a matrix PH, so that H=QRPH. The matrix PHis a conjugate transpose matrix of a matrix P, both the matrix Q and the matrix P are unitary matrices, and the matrix R is an upper triangular matrix. The upper triangular matrix is a square matrix in which all elements below a main diagonal are zeros. The matrix P is a precoding matrix. Generally, one column vector in the precoding matrix corresponds to one data stream, and the column vector is used to precode data in the data stream. Based on this, when applied to the technical solution provided in this embodiment of this application, in an example, a quantity of columns of the precoding matrix P may be a quantity of data streams that is determined by a network device for a terminal in a current scheduling periodicity. The column vector herein may be replaced with a row vector, and correspondingly, the quantity of columns may be replaced with a quantity of rows. All data streams corresponding to the precoding matrix P may correspond to a same codeword, or may correspond to a plurality of different codewords. In addition, a quantity of data streams corresponding to a same codeword is not limited in this embodiment of this application. For example, it is stipulated in a 5G NR protocol that when a quantity of data streams is less than or equal to 4, a same codeword is used. A value of each diagonal element of the matrix R represents an equivalent channel gain of a data stream. Optionally, a ratio of at least two diagonal elements of the matrix R is a target ratio, and the target ratio is determined based on a code rate. The code rate is a concept in channel coding and decoding, and is used to indicate redundancy of channel coding. A value of the code rate ranges from 0 to 1. Generally, a smaller code rate indicates higher redundancy of channel coding, and a larger code rate indicates lower redundancy of coding. Optionally, a larger code rate indicates that the target ratio is closer to 1:1: . . . :1. In other words, values of A1, A2, . . . and At are closer to each other. Similarly, a smaller code rate indicates that the target ratio is farther from 1:1: . . . :1. In other words, values of A1, A2, . . . and At are more different from each other. This helps improve overall performance of a plurality of data streams corresponding to a same codeword. The “at least two diagonal elements” may be a plurality of any diagonal elements of the matrix R. Optionally, the “at least two diagonal elements” are the first to tthdiagonal elements in the matrix R, t≤K, and K is a quantity of diagonal elements of the matrix R. Both t and K are integers. The following descriptions are all made by using an example in which the at least two diagonal elements are the first to tthdiagonal elements in the matrix R. For example, if a ratio of the first to tthdiagonal elements of the matrix R is r1,1:r2,2:rk,k:⋯:rt,t=A1:A2:⋯:Ak:⋯:At, where rk,kis a kthdiagonal element of the matrix R, 1≤k≤t, and k is an integer, rk,k=Akθ, where θ is determined based on a non-zero singular value obtained through SVD on the channel matrix H. For example, θ is obtained based on an average value, that is, (√j=1′λj)1/t, of products of the first t non-zero singular values obtained through SVD on the channel matrix H, where λjis a jthnon-zero singular value obtained through SVD on the channel matrix H, and j=1, 2, . . . , t. For example, θ=(1∏j=1tAj)1/t(∏j=1tλj)1/t, Certainly, this embodiment of this application is not limited thereto. In some embodiments of this application, a ratio of all the diagonal elements of the matrix R is a target ratio. That is, t=K. A manner of obtaining the target ratio is not limited in this embodiment of this application. For example, the target ratio may be determined based on overall performance of a plurality of data streams corresponding to a single codeword. A manner of obtaining the target ratio is not limited in this embodiment of this application. For example, the target ratio may be predefined, or may be determined by the transmit end device based on a channel decoder model. The target ratio varies with different code rates. Optionally, a non-zero singular value obtained through SVD on the channel matrix H and a diagonal element in a diagonal matrix (that is, the matrix Σ) obtained through SVD on the channel matrix H meet the following condition: {λ1>σ1λ2<σ2<λ1λ2σ1⋮λt-1<σt-1<λ1λ2⋯λt-1σ1σ2⋯σt-1, where λkis a kthnon-zero singular value obtained through SVD on the channel matrix H, σkis Akθ, and 1≤k≤t≤K. Certainly, this embodiment of this application is not limited thereto. S101and S102are a specific implementation of “obtaining a channel matrix H, and decomposing the channel matrix H to obtain QRPH”. Certainly, during specific implementation, this embodiment of this application is not limited thereto. In this embodiment of this application, a process of decomposing the channel matrix to obtain QRPHmay be referred to as performing diagonal element arbitrary ratio decomposition (DEAR) on the channel matrix. S103: Precode to-be-sent data based on the matrix P. The to-be-sent data is to-be-sent data in a plurality of data streams corresponding to the matrix P. In the precoding method provided in this embodiment of this application, a ratio of at least two diagonal elements of the matrix R obtained by decomposing the channel matrix can be the target ratio. In this way, through precoding with the precoding method provided in this embodiment of this application, equivalent channel gains of a plurality of spatially multiplexed data streams can meet a ratio. In other words, performance of the plurality of spatially multiplexed data streams can be adjusted to the target ratio. Therefore, by rationally setting the target ratio, overall performance of data streams corresponding to a codeword can be improved. For example, four data streams are spatially multiplexed. The target ratio may be set, so that performance differences between the four data streams are small, thereby improving overall performance. In some implementations, assuming that K diagonal elements in the matrix R meet the target ratio, that is, t=K, S102may include: first, using the matrix Σ as an initial matrix R0of the matrix R, using the matrix U as an initial matrix Q0of the matrix Q, and using the matrix V as an initial matrix P0of the matrix P; and then, assigning σkto a kthdiagonal element rk,kin a matrix Rk−1, and traversing each value of k=1, 2, . . . , K−1, where σkis Akθ, so that diagonal elements of the matrix R are A1θ, A2θ, . . . , and AKθ. In other words, the diagonal elements of the matrix R meet the target ratio A1:A2: . . . :AK. In addition, in a process of traversing each value of k=1, 2, . . . , K−1, a submatrix formed by an intersection of kthand (k+1)throws and kthand (k+1)thcolumns is implemented as an upper triangular matrix, to obtain the matrix R (denoted by a matrix Rk), the matrix Q (denoted by a matrix Qk), and the matrix P (denoted by a matrix Pk) that make the equation H=QRPHtrue. It may be understood that RK−1, QK−1, and PK−1obtained when k=K−1 are the matrix R, the matrix Q, and the matrix P, respectively. Optionally, steps performed in traversing each value of k=1, 2, . . . , K−1 may include the following steps 1 to 4. Step 1: Find a diagonal element rp,pfrom a matrix Rk−1based on a magnitude relationship between σkand a kthdiagonal element rk,kin the matrix Rk−1, where k<p≤K, p is an integer, and σkis Akθ; if rk,k≥σk, rp,p≤σk; and if rk,k<σk, rp,p>σk. rp,pmay be any element meeting the condition “k<p≤K; if rk,k≥σk, rp,p≤σk; and if rk,k<σk, rp,p>σk, or may be an element with a smallest value of p that meets the condition. Step 2: Switch diagonal elements rk+1,k+1and rp,pin the matrix Rk−1, to obtain a matrix Rre_k, switch a (k+1)thcolumn of elements and a pthcolumn of elements in a matrix Qk−1to obtain a matrix Qre_k, and switch a (k+1)thcolumn of elements and a pthcolumn of elements in a matrix Pk−1to obtain a matrix Pre_k. Assuming that rk+1,k+1=a and rp,p=b, that is, in the matrix Rk−1, an (k+1)thdiagonal element is a and a pthdiagonal element is b, after rk+1,k+1and rp,pare switched, rk+1,k+1=b and rp,p=a, that is, in the matrix Rre_k, an (k+1)thdiagonal element is b, and a pthdiagonal element is a. Similarly, a meaning of switching two columns of elements may be obtained. It may be understood that elements (including two elements or two columns of elements) in a matrix may be switched by multiplying the matrix by a “permutation matrix”. For a specific implementation thereof, refer to a conventional technology. Details are not described herein. A sequence of performing the three switching operations in step 2 is not limited in this embodiment of this application. A principle of “switching diagonal elements rk+1,k+1and rp,pin the matrix Rk−1” in step 2 is as follows: Steps 1 to 4 are performed at this time to assign σkto the element rk,kin the matrix Rk−1and ensure H=QkRkPkH. Therefore, if rk,k≥σk, the (k+1)thdiagonal element in the matrix Rkis made less than or equal to σk, so that H=QkRkPkH. Similarly, if rk,k<σk, the (k+1)thdiagonal element in the matrix Rkis made greater than σk, so that H=QkRkPkH. The “switching a (k−1)thcolumn of elements and a pthcolumn of elements in a matrix Qk−1, and switching a (k−1)thcolumn of elements and a pthcolumn of elements in a matrix Pk−1” in step 2 helps H=QkRkPkH. Step 3: Construct a matrix G1and a matrix G2based on σkand a kthdiagonal element and a (k+1)thdiagonal element in the matrix Rre_k, where the matrix G1and the matrix G2make a submatrix (referred to as a target submatrix below, where the target submatrix is a 2*2 submatrix) formed by an intersection of kthand (k+1)throws and kthand (k+1)thcolumns in G2TRre_kG1be an upper triangular matrix, a first diagonal element ((that is, the kthdiagonal element in Rre_k, where the element is also a kthdiagonal element in the matrix Rk) of the submatrix is σk, and G2Tis a transpose matrix of the matrix G2. The kthdiagonal element in the matrix Rre_kis the kthdiagonal element in the matrix Rk−1(that is, rk,k). The (k+1)thdiagonal element in the matrix Rre_kis the pthdiagonal element in the matrix Rk−1(that is, rp,p). Therefore, it can be learned that step 3 may be performed immediately after step 1. In other words, a sequence of performing step 2 and step 3 is not limited in this embodiment of this application. Step 4: Obtain a matrix Rkbased on a formula Rk=G2TRre_kG1, obtain a matrix Qkbased on a formula Qk=Qre_kG2, and obtain a matrix Pkbased on a formula Pk=Pre_kG1. Subsequently, a matrix RK−1obtained after steps 1 to 4 are performed at a (K−1)thtime may be used as the matrix R, a matrix QK−1obtained after steps 1 to 4 are performed at the (K−1)thtime may be used as the matrix Q, and a matrix PK−1obtained after steps 1 to 4 are performed at the (K−1)thtime may be used as the matrix P. It may be understood that the foregoing description of the specific implementation of S102is described based on an example in which the diagonal elements of the matrix R are to meet the target ratio. In actual implementation, if the ratio of the first to tthdiagonal elements of the matrix R is to be implemented as the target ratio, where t≤K, t is an integer, and K is the quantity of diagonal elements of the matrix R, the transmit end device may perform the foregoing steps 1 to 4 only t−1 times. Optionally, the first t columns of a matrix Pt−1obtained after the (t−1)thtime may be used as a precoding matrix. Optionally, when step 3 is performed, the matrix G1and the matrix G2may be constructed based on the following formulas: G1=1σk[cδ1sδ2-sδ2cδ1]andG2=[cs-sc].c=σk2-δ22δ12-δ22,s=1-c2, δ1is the kthdiagonal element in the matrix Rre_k(that is, the kthdiagonal element rk,kin the matrix Rk−1), and δ2is the (k+1)thdiagonal element in the matrix Rre_k(that is, the pthdiagonal element rp,pin the matrix Rk−1). The following analyzes rationality of constructing the matrix G1and the matrix G2in this optional implementation. In order that the target submatrix is an upper triangular matrix in which a first diagonal element is σk, the following formula may be obtained through Givens rotation: 1σk[cδ1sδ2-sδ2cδ1][δ1δ2][cs-sc]=[σkx0y] where a right side of the equation is the target submatrix, y is the (k+1)thdiagonal element in the matrix Rre_k, that is, the pthdiagonal element rp,pin the matrix Rk−1, and a value of x is determined by a formula on a left side of the equation. Based on this, it can be learned that the target submatrix may be constructed by constructing G1=1σk[cδ1sδ2-sδ2cδ1]andG2=[cs-sc] based on σkand a kthdiagonal element (that is, δ1) and a (k−1)thdiagonal element (that is, δ2) in the matrix Rre_k. It may be understood that this optional implementation is merely an implementation of constructing a target submatrix, and the target submatrix may be constructed in another manner. FIG.4is a schematic interaction diagram of an information transmission method according to an embodiment of this application. The method shown inFIG.4includes the following steps. S201: A receive end device sends receiving capability information to a transmit end device, where the receiving capability information is used to indicate that the receive end device supports a non-linear receiving algorithm. For example, the non-linear receiving algorithm includes an SIC algorithm, an MLD algorithm, or the like. In this embodiment of this application, a message in which the receiving capability information is carried is not specifically limited. For example, if the transmit end device is a network device, and the receive end device is a terminal, the receiving capability information may be carried in RRC signaling, MAC signaling, or DCI. For another example, if the transmit end device is a terminal, and the receive end device is a network device, the receiving capability information may be carried in RRC signaling, MAC signaling, or UCI. It may be understood that, because the receiving capability information of the receive end device generally remains unchanged in a period of time, optionally, the receiving capability information may be generally carried in RRC signaling or MAC signaling for transmission. It may be understood that the receive end device may support one or more receiving algorithms, which may include a non-linear receiving algorithm, and may also include a linear receiving algorithm. For example, the receive end device supports MLD, SIC, minimum mean square error (MMSE), and interference rejection combining (interference rejection combining, IRC) algorithms. For another example, the receive end device supports only an MMSE algorithm. In an implementation, the receiving capability information in S201is specifically used to indicate information that the receive end device supports a non-linear receiving algorithm. For example, assuming that the receiving capability information of the receive end device is carried in RRC signaling, a flag bit may be set in the RRC signaling. If the receive end device supports a non-linear receiving algorithm, the flag is set to 1. If the receive end device supports a linear receiving algorithm, the flag is set to 0. Certainly, this embodiment of this application is not limited thereto. In another implementation, the receiving capability information in S201is specifically used to indicate identification information of a non-linear receiving algorithm supported by the receive end device. For example, the receiving capability information may be used to indicate that the receive end device supports two non-linear receiving algorithms: MLD and SIC. S202: The transmit end device precodes to-be-sent data based on the receiving capability information by using the precoding method (the precoding method shown inFIG.3) provided in the embodiments of this application. It may be understood that, if the receive end device receives data by using a non-linear receiving algorithm, when precoding to-be-sent data, the transmit end device may retain some inter-stream interference, and the inter-stream interference may be reduced or eliminated when the receive end device executes the non-linear receiving algorithm. The inter-stream interference may be represented in that a matrix R (that is, the matrix R described above) obtained by decomposing a channel matrix is an upper triangular matrix, and does not need to be a diagonal matrix. Therefore, the transmit end device may precode the to-be-sent data by using the precoding method provided in the embodiments of this application. S203: The transmit end device sends the precoded to-be-sent data. If the transmit end device is a network device, and the receive end device is a terminal, S203may include: sending, by the transmit end device, the precoded to-be-sent data through a physical downlink shared channel (PDSCH). Alternatively, if the transmit end device is a terminal, and the receive end device is a network device, S203may include: sending, by the transmit end device, the precoded to-be-sent data through a physical uplink shared channel (PUSCH). S204: The transmit end device sends indication information to the receive end device, where the indication information is used to indicate that the transmit end device precodes the to-be-sent data by using the precoding method (the precoding method shown inFIG.3) provided in the embodiments of this application. If the transmit end device is a network device, and the receive end device is a terminal, the indication information is carried in radio resource control RRC signaling, media access control MAC signaling, or downlink control information DCI. Alternatively, if the transmit end device is a terminal, and the receive end device is a network device, the indication information is carried in RRC signaling, MAC signaling, or uplink control information UCI. A sequence of performing S203and S204is not limited in this embodiment of this application. For example, S203may be performed before S204, or S204may be performed before S203, or S203and S204may be performed at the same time. S205: The receive end device receives the precoded to-be-sent data from the transmit end device based on the indication information by using the non-linear receiving algorithm supported by the receive end device. For example, received data is equalized based on the non-linear receiving algorithm supported by the receive end device, so that data streams mixed together at the transmit end device are separated into independent data streams, and inter-stream interference is reduced or eliminated in this process. Subsequently, operations such as demodulation and channel decoding may be performed on each data stream. S204and S205are optional steps. If S204and S205are not performed, in an implementation, when the receive end device supports only the non-linear receiving algorithm, the receive end device may directly receive the data by using the supported receiving algorithm. In another implementation, when the receive end device further supports the linear receiving algorithm, the receive end device may compare a performance gain of receiving the data by using the non-linear receiving algorithm with a performance gain of receiving the data by using the linear receiving algorithm, to choose to receive the data by using the non-linear receiving algorithm. Certainly, this embodiment of this application is not limited thereto. For example, the receive end device may alternatively receive the data by using the non-linear receiving algorithm in the following method shown inFIG.5. It may be understood that, in the precoding method provided above, a matrix R obtained by decomposing a channel matrix is an upper triangular matrix. In other words, after a plurality of data streams are encoded by using the precoding method, inter-stream interference is caused. In this embodiment, the receive end device may cooperate to receive the data by using the non-linear receiving algorithm, to reduce or eliminate the inter-stream interference, thereby improving a probability of correct demodulation of multi-stream data. In addition, when the transmit end device uses the precoding method provided above, inter-stream interference is allowed, and the inter-stream interference may be reduced or eliminated by the receive end device. Therefore, when information transmission is performed by using this embodiment, a quantity of spatially multiplexed streams of a multi-antenna system can be increased, thereby providing a system capacity. FIG.5is a schematic interaction diagram of an information transmission method according to an embodiment of this application. The method shown inFIG.5includes the following steps. S301: A receive end device sends receiving capability information to a transmit end device, where the receiving capability information is used to indicate that the receive end device supports a non-linear receiving algorithm. For a specific implementation of S301, refer to S201. Details are not described herein again. S302: The transmit end device sends indication information to the receive end device based on the receiving capability information, where the indication information is used to indicate the receive end device to receive data by using the non-linear receiving algorithm. The non-linear receiving algorithm may include an SIC algorithm, an MLD algorithm, or the like. In an implementation, the indication information is specifically used to indicate the receive end device to receive data by using a non-linear receiving algorithm instead of a linear receiving algorithm. In other words, in this embodiment of this application, the transmit end device is supported in configuring, for the receive end device, whether the receive end device is to receive data by using a non-linear receiving algorithm. The method may be applied to a scenario in which the receive end device supports a linear receiving algorithm and a non-linear receiving algorithm. Based on the scenario, the receive end device may support one or more non-linear receiving algorithms. In another implementation, the indication information is specifically used to indicate a non-linear receiving algorithm to be used by the receive end device to receive data. This manner may be applied to a scenario in which the receive end device supports at least two non-linear receiving algorithms. S303: The receive end device receives data from the transmit end device based on the indication information by using the non-linear receiving algorithm. Optionally, the data is data obtained by the transmit end device by performing precoding by using the precoding method provided in the embodiments of this application. If the transmit end device is a network device, and the receive end device is a terminal, the indication information is carried in RRC signaling, MAC signaling, or DCI. Alternatively, if the transmit end device is a terminal, and the receive end device is a network device, the indication information is carried in RRC signaling, MAC signaling, or uplink control information UCI. In this embodiment, the transmit end device sends the indication information to the receive end device, to indicate the non-linear receiving algorithm to be used by the receive end device. This helps the receive end device to select a proper receiving algorithm, thereby improving a data demodulation probability. The method may be used in combination with the precoding method provided in the embodiments of this application, to reduce or eliminate inter-stream interference generated by the transmit end device by performing precoding by using the precoding method provided in the embodiments of this application, thereby improving a probability of correct demodulation of multi-stream data. The solutions provided in the embodiments of this application are mainly described above from a perspective of a method. To implement the foregoing functions, corresponding hardware structures and/or software modules for performing the functions are included. A person skilled in the art should easily be aware that, in combination with units and algorithm steps of the examples described in the embodiments disclosed in this specification, this application may be implemented by using hardware or a combination of hardware and computer software. Whether a function is performed by using hardware or hardware driven by computer software depends on particular applications and design constraints of the technical solutions. A person skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of this application. In the embodiments of this application, function module division may be performed on the precoding apparatus, the transmit end device, or the receive end device based on the foregoing method examples. For example, each function module may be obtained through division corresponding to each function, or two or more functions may be integrated into one processing module. The integrated module may be implemented in a form of hardware, or may be implemented in a form of a software functional module. It should be noted that, in the embodiments of this application, module division is an example, and is merely logical function division. In actual implementation, another division manner may be used. FIG.6is a schematic structural diagram of a precoding apparatus60according to an embodiment of this application. In an example, the precoding apparatus60may be a transmit end device (for example, a network device or a terminal). In an example, the precoding apparatus60may be configured to perform the precoding method shown inFIG.3. The precoding apparatus60may include a processing unit601and a sending unit602. The processing unit601is configured to decompose a channel matrix into a product of a matrix Q, a matrix R, and a matrix PH, where the matrix PHis a conjugate transpose matrix of a matrix P, both the matrix Q and the matrix P are unitary matrices, and the matrix R is an upper triangular matrix. The sending unit602is configured to precode to-be-sent data based on the matrix P. For example, with reference toFIG.3, the processing unit601may be configured to perform S102, and the sending unit602may be configured to perform S103. Optionally, a ratio of at least two diagonal elements of the matrix R is a target ratio, and the target ratio is determined based on a code rate. Optionally, if a ratio of diagonal elements of the matrix R is r1,1:r2,2: . . . :rk,k: . . . :rt,t=A1:A2: . . . :Ak: . . . :At, where rk,kis a kthdiagonal element of the matrix R, 1≤k≤t≤K, both k and t are integers, and K is a quantity of diagonal elements of the matrix R, rk,k=Akθ, where θ is determined based on a non-zero singular value obtained through SVD on the channel matrix. Optionally, θ=(1∏j=1tAj)1/t(∏j=1tλj)1/t, where λjis a jthnon-zero singular value obtained through SVD on the channel matrix, and j=1, 2, . . . , t. Π represents a product operation. Optionally, t≥2, and a non-zero singular value obtained through SVD on the channel matrix and a diagonal element in a diagonal matrix obtained through SVD on the channel matrix meet the following condition: {λ1>σ1λ2<σ2<λ1λ2σ1⋮λt-1<σt-1<λ1λ2⋯λt-1σ1σ2⋯σt-1, where λkis a kthnon-zero singular value obtained through SVD on the channel matrix, σkis Akθ, and 1≤k≤t≤K. Optionally, the processing unit601is specifically configured to: perform SVD on the channel matrix, to decompose the channel matrix into a product of a matrix U, a matrix Σ, and a matrix VH, where the matrix VHis a conjugate transpose matrix of a matrix V, both the matrix U and the matrix V are unitary matrices, and the matrix Σ is a diagonal matrix; and transform the matrix U, the matrix Σ, and the matrix VHto obtain the matrix Q, the matrix R, and the matrix PH. For example, with reference toFIG.3, the processing unit601may be configured to perform S101and S102. Optionally, the target ratio is a ratio of the first to tthdiagonal elements in the matrix R, where 1≤k≤t≤K, both k and t are integers, and K is a quantity of diagonal elements of the matrix R. Based on this, when transforming the matrix U, the matrix Σ, and the matrix VHto obtain the matrix Q, the matrix R, and the matrix PH, the processing unit601is specifically configured to:first, use the matrix Σ as an initial matrix R0of the matrix R;then, traverse each value of k=1, 2, . . . , t−1, where 1≤k≤t≤K, both k and t are integers, and K is the quantity of diagonal elements of the matrix R; and perform the following steps 1 to 4:step 1: finding a diagonal element rp,pfrom a matrix Rk−1based on a magnitude relationship between σkand a kthdiagonal element rk,kin the matrix Rk−1, where k<p≤K, p is an integer, and σkis Akθ; if rk,k≥σk, rp,p≤σk; and if rk,k<σk, rp,p>σk;step 2: switching diagonal elements rk+1,k+1and rp,pin the matrix Rk−1, to obtain a matrix Rre_k;step 3: constructing a matrix G1and a matrix G2based on σkand a kthdiagonal element and a (k+1)thdiagonal element in the matrix Rre_k, where the matrix G1and the matrix G2make a submatrix formed by an intersection of kthand (k+1)throws and kthand (k+1)thcolumns in G2TRre_kG1be an upper triangular matrix, a first diagonal element of the submatrix is σk, and G2Tis a transpose matrix of the matrix G2; andstep 4: obtaining a matrix Rkbased on a formula Rk=G2TRre_kG1; andnext, use, as the matrix R, a matrix Rt−1obtained after steps 1 to 4 are performed at a (t−1)thtime. Optionally, when constructing the matrix G1and the matrix G2based on k and the kthdiagonal element and the (k+1)thdiagonal element in the matrix Rre_k, the processing unit601is specifically configured to: construct the matrix G1and the matrix G2based on the following formula: G1=1σk[cδ1sδ2-sδ2cδ1]andG2=[cs-sc], where c=σk2-δ22δ12-δ22,s=1-c2, δ1is the kthdiagonal element in the matrix Rre_k, and δ2is the (k+1)thdiagonal element in the matrix Rre_k. Optionally, when transforming the matrix U, the matrix Σ, and the matrix VHto obtain the matrix Q, the matrix R, and the matrix PH, the processing unit601is specifically further configured to: use the matrix U as an initial matrix Q0of the matrix Q and use the matrix V as an initial matrix P0of the matrix P; and in a process of performing steps 1 to 4 at a kthtime: switch a (k+1)thcolumn of elements and a pthcolumn of elements in a matrix Qk−1to obtain a matrix Qre_k, and switch a (k+1)thcolumn of elements and a pthcolumn of elements in a matrix Pk−1to obtain a matrix Pre_k; obtain a matrix Qkbased on a formula Qk=Qre_kG2, and obtain a matrix Pkbased on a formula Pk=Pre_kG1; and use, as the matrix Q, a matrix Qt−1obtained after steps 1 to 4 are performed at the (t−1)thtime, and use, as the matrix P, a matrix Pt−1obtained after steps 1 to 4 are performed at the (t−1)thtime. For explanations of related content, descriptions of beneficial effects, and the like in any precoding apparatus60provided above, refer to the foregoing corresponding method embodiment. Details are not described herein again. In an example, with reference to the communications device shown inFIG.2, the processing unit601may be implemented by using the processor201or the processor207inFIG.2. The sending unit602may be implemented by using the communications interface204inFIG.2. FIG.7is a schematic structural diagram of a transmit end device70according to an embodiment of this application. In an example, the transmit end device70may be configured to perform a step performed by the transmit end device in the method inFIG.4orFIG.5. The transmit end device70may include a receiving unit701, a processing unit702, and a sending unit703. The receiving unit701is configured to receive receiving capability information from a receive end device, where the receiving capability information is used to indicate that the receive end device supports a non-linear receiving algorithm. The processing unit702is configured to precode to-be-sent data based on the receiving capability information by using any precoding method (the precoding method shown inFIG.3) provided in the embodiments of this application. The sending unit703is configured to send the precoded to-be-sent data. For example, with reference toFIG.4, the receiving unit701may be configured to perform a receiving step corresponding to S201, the processing unit702may be configured to perform S202, and the sending unit703may be configured to perform S203. Optionally, the sending unit703is further configured to send indication information to the receive end device, where the indication information is used to indicate that the transmit end device precodes the to-be-sent data by using any precoding method (the precoding method shown inFIG.3) provided in the embodiments of this application. For example, with reference toFIG.4, the sending unit703may be configured to perform S204. Optionally, the sending unit703is further configured to send indication information to the receive end device, where the indication information is used to indicate the receive end device to receive the to-be-sent data by using the non-linear receiving algorithm. For example, with reference toFIG.5, the sending unit703may be configured to perform S302. Optionally, if the transmit end device is a network device, and the receive end device is a terminal, any one piece of the foregoing indication information is carried in RRC signaling, MAC signaling, or DCI. Alternatively, if the transmit end device is a terminal, and the receive end device is a network device, any one piece of the foregoing indication information is carried in RRC signaling, MAC signaling, or UCI. Optionally, the non-linear receiving algorithm includes an SIC algorithm or an MLD algorithm. For explanations of related content, descriptions of beneficial effects, and the like in any transmit end device70provided above, refer to the foregoing corresponding method embodiment. Details are not described herein again. In an example, with reference to the communications device shown inFIG.2, the processing unit702may be implemented by using the processor201or the processor207inFIG.2. The receiving unit701and the sending unit703may be implemented by using the communications interface204inFIG.2. FIG.8is a schematic structural diagram of a receive end device80according to an embodiment of this application. In an example, the receive end device80may be configured to perform a step performed by the transmit end device in the method inFIG.4orFIG.5. The receive end device80may include a receiving unit801and a processing unit802. Optionally, the receive end device80may further include a sending unit803. In a first embodiment, the receiving unit801is configured to receive indication information sent by a transmit end device, where the indication information is used to indicate that the transmit end device precodes to-be-sent data by using any precoding method (the precoding method shown inFIG.3) provided in the embodiments of this application. The processing unit802is configured to receive the precoded to-be-sent data based on the indication information by using a non-linear receiving algorithm supported by the receive end device. For example, with reference toFIG.4, the receiving unit801may be configured to perform a receiving step corresponding to S204, and the processing unit802is configured to perform S205. Optionally, the sending unit803is configured to send receiving capability information to the transmit end device, where the receiving capability information is used to indicate that the receive end device supports the non-linear receiving algorithm. For example, with reference toFIG.4, the sending unit803may be configured to perform S201. Optionally, the non-linear receiving algorithm includes an SIC algorithm, an MLD algorithm, or the like. In a second embodiment, the receiving unit801is configured to receive indication information sent by a transmit end device, where the indication information is used to indicate the receive end device to receive data by using a non-linear receiving algorithm. The processing unit802is configured to receive data from the transmit end device based on the indication information by using the non-linear receiving algorithm. For example, with reference toFIG.5, the receiving unit801may be configured to perform a receiving step corresponding to S302, and the processing unit802may be configured to perform S303. Optionally, the sending unit803is configured to send receiving capability information to the transmit end device, where the receiving capability information is used to indicate that the receive end device supports the non-linear receiving algorithm. For example, with reference toFIG.5, the sending unit803may be configured to perform S301. Optionally, the non-linear receiving algorithm includes an SIC algorithm, an MLD algorithm, or the like. For explanations of related content, descriptions of beneficial effects, and the like in any receive end device80provided above, refer to the foregoing corresponding method embodiment. Details are not described herein again. In an example, with reference to the communications device shown inFIG.2, the processing unit802may be implemented by using the processor201or the processor207inFIG.2. The receiving unit801and the sending unit803may be implemented by using the communications interface204inFIG.2. An embodiment of this application further provides a communications system. The communications system may include any precoding apparatus60provided above and a receive end device that receives data precoded by the precoding apparatus60. An embodiment of this application further provides a communications system. The communications system may include any transmit end device70provided above and a corresponding receive end device80provided above. An embodiment of this application further provides a communications system. The communications system may include any receive end device80in the second embodiment provided above and a transmit end device that communicates with the receive end device80to complete configuration of a receiving algorithm used by the receive end device. All or some of the foregoing embodiments may be implemented by using software, hardware, firmware, or any combination thereof. When a software program is used to implement the embodiments, the embodiments may be implemented completely or partially in a form of a computer program product. The computer program product includes one or more computer instructions. When the computer-executable instructions are loaded and executed on a computer, the procedure or functions according to the embodiments of this application are all or partially generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or another programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or may be transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (for example, a coaxial cable, an optical fiber, or a digital subscriber line (DSL)) or wireless (for example, infrared, radio, or microwave) manner. The computer-readable storage medium may be any usable medium accessible by a computer, or a data storage device, such as a server or a data center, integrating one or more usable media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, or a magnetic tape), an optical medium (for example, a DVD), a semiconductor medium (for example, a solid-state drive (SSD)), or the like. Although this application is described with reference to the embodiments, in a process of implementing this application that claims protection, a person skilled in the art may understand and implement another variation of the disclosed embodiments by viewing the accompanying drawings, disclosed content, and the accompanying claims. In the claims, “comprising” does not exclude another component or another step, and “a” or “one” does not exclude a meaning of plurality. A single processor or another unit may implement several functions enumerated in the claims. Some measures are recorded in dependent claims that are different from each other, but this does not mean that these measures cannot be combined to produce a better effect. Although this application is described with reference to specific features and the embodiments thereof, clearly, various modifications and combinations may be made to them without departing from the spirit and scope of this application. Correspondingly, the specification and accompanying drawings are merely example description of this application defined by the appended claims, and are considered as any of or all modifications, variations, combinations or equivalents that cover the scope of this application. Clearly, a person skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. This application is intended to cover these modifications and variations of this application provided that they fall within the scope of protection defined by the following claims and their equivalent technologies. | 51,586 |
11943018 | DETAILED DESCRIPTION In some wireless communications systems such as multiple-input multiple-output (MIMO) systems, a base station and user equipment (UE) may use multiple antennas to achieve improved system performance, including improved system capacity (e.g., more UEs per cell) and improved coverage, as well as improved service provisioning, for example, higher per-UE data rates. The availability of multiple antennas at the base station and UE can also be used in different manners to achieve different objectives. For example, multiple antennas at the base station or UE can be used to provide additional diversity against fading on a radio channel, or to shape an overall antenna beam (e.g., transmit beam or receive beam respectively), or to create multiple parallel communication radio channels over a radio interface. This provides the possibility for increased bandwidth utilization without a corresponding reduction in power efficiency. A base station and UE, in a MIMO system, may use multiple antennas for uplink (UL) and downlink (DL) communications. In some cases, the antennas of the base station or UE may be partially coherent. That is, different groups of antennas may be coherent or noncoherent. In the case that antennas of a first group of antennas is coherent with other antennas of that first group, and the antennas of a second group of antennas is coherent with other antennas of that second group, but the antennas of the second group are not coherent (noncoherent) with the antennas of the first group, the two groups of antennas may be said to be partially coherent. In other examples, three or more such groups of antennas may exist or be used, each group having two or more coherent antennas. In some techniques, a group of antennas that are coherent may be restricted from simultaneous transmissions with another group of antennas that are coherent, where the first group is noncoherent with the second group, limiting the base station's or UE's resource utilization (e.g., transmit power utilization). According to the techniques described herein, a UE (or a base station) may be configured to support simultaneous UL (or DL) transmissions by partially coherent antennas, in particular where antennas within each group are coherent, but the antennas are noncoherent between different groups. In some cases, a base station may configure a UE to use both a closed-loop MIMO scheme and a transparent diversity scheme to support simultaneous transmission across groups of antennas that may be partially coherent and realizing the benefits associated with it (e.g., efficient resource utilization, spectral diversity, etc.). For example, a UE may receive an indication, in a downlink control information (DCI) message or via radio resource control (RRC) signaling, that the UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme for UL transmission using a number of antenna ports associated with a number of groups of antenna ports. Following the reception of the indication, the UE may apply both the closed-loop MIMO scheme and the transparent diversity scheme among the antenna ports within each group of the number of groups of antenna ports. That is, the closed-loop MIMO scheme may be applied within each group of antenna ports, and the transparent diversity scheme may be applied among the antenna ports in different groups of antenna ports. The order of applying the closed-loop MIMO scheme and a transparent diversity scheme may be different. In an example, the UE may first apply the closed-loop MIMO scheme and following with the transparent diversity scheme to the antenna ports within each group of the number of groups of antenna ports. Alternatively, in another example, the UE may first apply the transparent diversity scheme and then the closed-loop MIMO scheme to the antenna ports within each group of the number of groups of antenna ports. In some cases, first applying the transparent diversity scheme to the antenna ports among different groups of antenna ports may result in a number of virtual antenna ports. That is, applying the transparent diversity scheme to the antenna ports across different groups of antenna ports first may be to virtually combine multiple noncoherent antennas into a virtual antenna port. By applying a hybrid closed-loop MIMO scheme, as well as a transparent diversity scheme, the UE may fully realize its resources and decrease instances of unused resources. Additionally, by configuring the UE with the above scheme (e.g., hybrid closed-loop MIMO plus transparent diversity scheme) may result in improved spatial diversity for the MIMO system. Aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are also illustrated by and described with reference to block diagrams, tables, and process flows. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to hybrid closed-loop MIMO and transparent diversity schemes. FIG.1illustrates an example of a wireless communications system100that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The wireless communications system100includes base stations105, UEs115, and a core network130. In some examples, the wireless communications system100may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some cases, wireless communications system100may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices. Base stations105may wirelessly communicate with UEs115via one or more base station antennas. Base stations105described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation Node B or giga-nodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or some other suitable terminology. Wireless communications system100may include base stations105of different types (e.g., macro or small cell base stations). The UEs115described herein may be able to communicate with various types of base stations105and network equipment including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like. Each base station105may be associated with a particular geographic coverage area110in which communications with various UEs115is supported. Each base station105may provide communication coverage for a respective geographic coverage area110via communication links125, and communication links125between a base station105and a UE115may utilize one or more carriers. Communication links125shown in wireless communications system100may include uplink transmissions from a UE115to a base station105, or downlink transmissions from a base station105to a UE115. Downlink transmissions may also be called forward link transmissions while uplink transmissions may also be called reverse link transmissions. The geographic coverage area110for a base station105may be divided into sectors making up only a portion of the geographic coverage area110, and each sector may be associated with a cell. For example, each base station105may provide communication coverage for a macro cell, a small cell, a hot spot, or other types of cells, or various combinations thereof. In some examples, a base station105may be movable and therefore provide communication coverage for a moving geographic coverage area110. In some examples, different geographic coverage areas110associated with different technologies may overlap, and overlapping geographic coverage areas110associated with different technologies may be supported by the same base station105or by different base stations105. The wireless communications system100may include, for example, a heterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different types of base stations105provide coverage for various geographic coverage areas110. The term “cell” refers to a logical communication entity used for communication with a base station105(e.g., over a carrier), and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) operating via the same or a different carrier. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband Internet-of-Things (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of devices. In some cases, the term “cell” may refer to a portion of a geographic coverage area110(e.g., a sector) over which the logical entity operates. UEs115may be dispersed throughout the wireless communications system100, and each UE115may be stationary or mobile. A UE115may also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client. A UE115may also be a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE115may also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, or the like, which may be implemented in various articles such as appliances, vehicles, meters, or the like. Some UEs115, such as MTC or IoT devices, may be low cost or low complexity devices, and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station105without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of the information or present the information to humans interacting with the program or application. Some UEs115may be designed to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging. Some UEs115may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously). In some examples half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for UEs115include entering a power saving “deep sleep” mode when not engaging in active communications, or operating over a limited bandwidth (e.g., according to narrowband communications). In some cases, UEs115may be designed to support critical functions (e.g., mission critical functions), and a wireless communications system100may be configured to provide ultra-reliable communications for these functions. In some cases, a UE115may also be able to communicate directly with other UEs115(e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol). One or more of a group of UEs115utilizing D2D communications may be within the geographic coverage area110of a base station105. Other UEs115in such a group may be outside the geographic coverage area110of a base station105, or be otherwise unable to receive transmissions from a base station105. In some cases, groups of UEs115communicating via D2D communications may utilize a one-to-many (1:M) system in which each UE115transmits to every other UE115in the group. In some cases, a base station105facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between UEs115without the involvement of a base station105. Base stations105may communicate with the core network130and with one another. For example, base stations105may interface with the core network130through backhaul links132(e.g., via an S1, N2, N3, or other interface). Base stations105may communicate with one another over backhaul links134(e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations105) or indirectly (e.g., via core network130). The core network130may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network130may be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one Packet Data Network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs115served by base stations105associated with the EPC. User IP packets may be transferred through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation as well as other functions. The P-GW may be connected to the network operators IP services. The operators IP services may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet-Switched (PS) Streaming Service. At least some of the network devices, such as a base station105, may include subcomponents such as an access network entity, which may be an example of an access node controller (ANC). Each access network entity may communicate with UEs115through a number of other access network transmission entities, which may be referred to as a radio head, a smart radio head, or a transmission/reception point (TRP). In some configurations, various functions of each access network entity or base station105may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., a base station105). Wireless communications system100may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves may penetrate structures sufficiently for a macro cell to provide service to UEs115located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter range (e.g., less than 100 km) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz. Wireless communications system100may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band. The SHF region includes bands such as the 5 GHz industrial, scientific, and medical (ISM) bands, which may be used opportunistically by devices that can tolerate interference from other users. Wireless communications system100may also operate in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, wireless communications system100may support millimeter wave (mmW) communications between UEs115and base stations105, and EHF antennas of the respective devices may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE115. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. Techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body. In some cases, wireless communications system100may utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communications system100may employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz ISM band. When operating in unlicensed radio frequency spectrum bands, wireless devices such as base stations105and UEs115may employ listen-before-talk (LBT) procedures to ensure a frequency channel is clear before transmitting data. In some cases, operations in unlicensed bands may be based on a CA configuration in conjunction with CCs operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of both. In some examples, base station105or UE115may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, MIMO communications, or beamforming. For example, wireless communications system100may use a transmission scheme between a transmitting device (e.g., a base station105) and a receiving device (e.g., a UE115), where the transmitting device is equipped with multiple antennas and the receiving devices are equipped with one or more antennas. MIMO communications may employ multipath signal propagation to increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream, and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) where multiple spatial layers are transmitted to multiple devices. In some cases, base stations105and/or UEs115may perform open-loop MIMO or closed-loop MIMO. In MIMO, the transmitter (e.g., the UE115for uplink, and the base station105for downlink) may use a precoding matrix to match (or attempt to match) a spatial channel experienced between the UE115and the base station105. In closed-loop MIMO, the precoding matrix may be changed based on feedback signaling from the UE115to the base station105. That is, in closed-loop MIMO the base stations105may use channel information (e.g., obtained via measurements) to select a precoding matrix. In an example, base station105may select or change a precoding matrix based on channel state information (CSI) report received from a UE115. An indication of which precoding matrix for the UE115to use may be indicated to a UE115, for example, in DCI. In open-loop MIMO, feedback signaling is not provided by the base station105nor UEs115to determine the channel information. In some cases, base stations105and/or UEs115may apply a diversity scheme. Examples of diversity schemes include cyclic delay diversity (CDD), frequency switch transmit diversity (FSTD), space-frequency block coding (SFBC), and space-time block coding (STBC). In a transparent diversity scheme, a transmitter may apply a diversity scheme at the transmitter, the specific parameters associated with the diversity scheme being unknown to the receiver (and thus transparent to the receiver). For uplink, a UE115may apply a diversity scheme whose parameters are not known to the base station105. In the case of a transparent diversity scheme including cyclic delay diversity, a UE115may apply a phase shift θ, the value of which is unknown to the base station105. Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station105or a UE115) to shape or steer an antenna beam (e.g., a transmit beam or receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying predetermined amplitude and phase offsets to signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation). In one example, a base station105may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE115. For instance, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station105multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station105or a receiving device, such as a UE115) a beam direction for subsequent transmission and/or reception by the base station105. Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station105in a single beam direction (e.g., a direction associated with the receiving device, such as a UE115). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions. For example, a UE115may receive one or more of the signals transmitted by the base station105in different directions, and the UE115may report to the base station105an indication of the signal it received with a highest signal quality, or an otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted in one or more directions by a base station105, a UE115may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE115), or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device). A receiving device (e.g., a UE115, which may be an example of a mmW receiving device) may try multiple receive beams when receiving various signals from the base station105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets applied to signals received at a set of antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at a set of antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive beams or receive directions. In some examples a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). The single receive beam may be aligned in a beam direction determined based on listening according to different receive beam directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based on listening according to multiple beam directions). In some cases, the antennas of a base station105or UE115may be located within one or more antenna arrays, which may support MIMO operations, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, antennas or antenna arrays associated with a base station105may be located in diverse geographic locations. A base station105may have an antenna array with a number of rows and columns of antenna ports that the base station105may use to support beamforming of communications with a UE115. Likewise, a UE115may have one or more antenna arrays that may support various MIMO or beamforming operations. In some cases, wireless communications system100may be a packet-based network that operate according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may in some cases perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use hybrid automatic repeat request (HARM) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE115and a base station105or core network130supporting radio bearers for user plane data. At the Physical (PHY) layer, transport channels may be mapped to physical channels. In some cases, UEs115and base stations105may support retransmissions of data to increase the likelihood that data is received successfully. HARQ feedback is one technique of increasing the likelihood that data is received correctly over a communication link125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., signal-to-noise conditions). In some cases, a wireless device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval. Time intervals in LTE or NR may be expressed in multiples of a basic time unit, which may, for example, refer to a sampling period of Ts= 1/30,720,000 seconds. Time intervals of a communications resource may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be expressed as Tf=307,200 Ts. The radio frames may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into 2 slots each having a duration of 0.5 ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). Excluding the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases, a subframe may be the smallest scheduling unit of the wireless communications system100, and may be referred to as a transmission time interval (TTI). In other cases, a smallest scheduling unit of the wireless communications system100may be shorter than a subframe or may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) or in selected (CCs) component carriers using sTTIs). In some wireless communications systems, a slot may further be divided into multiple mini-slots containing one or more symbols. In some instances, a symbol of a mini-slot or a mini-slot may be the smallest unit of scheduling. Each symbol may vary in duration depending on the subcarrier spacing or frequency band of operation, for example. Further, some wireless communications systems may implement slot aggregation in which multiple slots or mini-slots are aggregated together and used for communication between a UE115and a base station105. The term “carrier” refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over a communication link125. For example, a carrier of a communication link125may include a portion of a radio frequency spectrum band that is operated according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a pre-defined frequency channel (e.g., an E-UTRA absolute radio frequency channel number (EARFCN)), and may be positioned according to a channel raster for discovery by UEs115. Carriers may be downlink or uplink (e.g., in an FDD mode), or be configured to carry downlink and uplink communications (e.g., in a TDD mode). In some examples, signal waveforms transmitted over a carrier may be made up of multiple sub-carriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or DFT-s-OFDM). The organizational structure of the carriers may be different for different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR, etc.). For example, communications over a carrier may be organized according to TTIs or slots, each of which may include user data as well as control information or signaling to support decoding the user data. A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling that coordinates operation for the carrier. In some examples (e.g., in a carrier aggregation (CA) configuration), a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, control information transmitted in a physical control channel may be distributed between different control regions in a cascaded manner (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces). A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system100. For example, the carrier bandwidth may be one of a number of predetermined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some examples, each served UE115may be configured for operating over portions or all of the carrier bandwidth. In other examples, some UEs115may be configured for operation using a narrowband protocol type that is associated with a predefined portion or range (e.g., set of subcarriers or resource blocks (RBs)) within a carrier (e.g., “in-band” deployment of a narrowband protocol type). In a system employing MCM techniques, a resource element may include one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme). Thus, the more resource elements that a UE115receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE115. In MIMO systems, a wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers), and the use of multiple spatial layers may further increase the data rate for communications with a UE115. Devices of the wireless communications system100(e.g., base stations105or UEs115) may have a hardware configuration that supports communications over a particular carrier bandwidth, or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system100may include base stations105and/or UEs115that can support simultaneous communications via carriers associated with more than one different carrier bandwidth. Wireless communications system100may support communication with a UE115on multiple cells or carriers, a feature which may be referred to as CA or multi-carrier operation. A UE115may be configured with multiple downlink CCs and one or more uplink CCs according to a CA configuration. CA may be used with both FDD and TDD component carriers. In some cases, wireless communications system100may utilize enhanced component carriers (eCCs). An eCC may be characterized by one or more features including wider carrier or frequency channel bandwidth, shorter symbol duration, shorter TTI duration, or modified control channel configuration. In some cases, an eCC may be associated with a CA configuration or a dual connectivity configuration (e.g., when multiple serving cells have a suboptimal or non-ideal backhaul link). An eCC may also be configured for use in unlicensed spectrum or shared spectrum (e.g., where more than one operator is allowed to use the spectrum). An eCC characterized by wide carrier bandwidth may include one or more segments that may be utilized by UEs115that are not capable of monitoring the whole carrier bandwidth or are otherwise configured to use a limited carrier bandwidth (e.g., to conserve power). In some cases, an eCC may utilize a different symbol duration than other CCs, which may include use of a reduced symbol duration as compared with symbol durations of the other CCs. A shorter symbol duration may be associated with increased spacing between adjacent subcarriers. A device, such as a UE115or base station105, utilizing eCCs may transmit wideband signals (e.g., according to frequency channel or carrier bandwidths of 20, 40, 60, 80 MHz, etc.) at reduced symbol durations (e.g., 16.67 microseconds). A TTI in eCC may include of one or multiple symbol periods. In some cases, the TTI duration (that is, the number of symbol periods in a TTI) may be variable. Wireless communications systems such as an NR system may utilize any combination of licensed, shared, and unlicensed spectrum bands, among others. The flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums. In some examples, NR shared spectrum may increase spectrum utilization and spectral efficiency, specifically through dynamic vertical (e.g., across the frequency domain) and horizontal (e.g., across the time domain) sharing of resources. A base station105and UE115may use multiple antennas for UL and DL communications. In some cases, the antennas of the base station105or UE115may be partially coherent. That is, different groups of antennas may be coherent or noncoherent. In the case that one group of antennas is coherent and another group is also coherent, but noncoherent with the first group of antennas, the two groups of antennas may be said to be partially coherent. In some techniques, a group of antennas that are coherent may be restricted from simultaneous transmissions with another group of antennas that are coherent where the antennas of the groups are noncoherent between them, limiting the base station's105or UE's115resource utilization (e.g., transmit power utilization). According to the techniques described herein, a UE115(or a base station105in some examples) may be configured to support simultaneous UL (or DL) transmissions on groups of antennas (e.g., multiple groups (e.g., pairs, triplets, etc.) of coherent antennas) that may be partially coherent within their group, but noncoherent with antennas of another antenna group. In some cases, a base station105may configure a UE115to use both a closed-loop MIMO scheme and a transparent diversity scheme to support simultaneous transmission across groups of antennas that may be partially coherent, and realizing the benefits associated with it (e.g., efficient resource utilization, spectral diversity, etc.). FIG.2illustrates an example of a wireless communications system200that supports hybrid closed-loop MIMO and transparent diversity schemes in NR in accordance with various aspects of the present disclosure. In some examples, the wireless communications system200may implement aspects of the wireless communications system100. The wireless communications system200may include a base station105-aand a UE115-a, which may be examples of the corresponding devices described with reference toFIG.1. For example, the wireless communications system200may be an NR MIMO system. The base station105-amay perform a communication procedure (e.g., an RRC procedure, such as a cell acquisition procedure, random access procedure, RRC connection procedure, RRC configuration or reconfiguration procedure, etc.) with the UE115-a. The base station105-aand UE115-amay be configured with multiple antennas, which may be used for directional or beamformed transmissions. As part of the communication procedure, the base station105-amay identify that the UE115-ais to use both a closed-loop MIMO scheme and a transparent diversity scheme for UL transmissions. In some examples, the UE115-amay determine a UE capability, which may include an indication of groups of antenna ports and information corresponding to coherence and non-coherence. For example, a UE capability may indicate that a group of antenna ports related to UL transmit beam210-amay be coherent or a group of antenna ports related to UL transmit beam210-bmay be noncoherent, or both. This UE capability may be provided to the base station105-aduring the communication procedure, which the base station105-amay use to identify that the UE115-ais to use both the closed-loop MIMO scheme and the transparent diversity scheme for UL transmissions. Following this identification operation, the base station105-amay provide an indication (e.g., in control information) to the UE115-ato use both the closed-loop MIMO scheme and the transparent diversity scheme for UL transmissions. In an example, the base station105-amay provide the indication via RRC signaling205. Alternatively, the base station105-amay provide the indication in DCI message on a physical downlink control channel (PDCCH). In some cases, the indication may provide an order for performing the closed-loop MIMO scheme and the transparent diversity scheme. An example order may include performing the closed-loop MIMO scheme at a first time and performing the transparent diversity scheme at a second time after the first time. Another example order may include performing the transparent diversity scheme at a first time and then the closed-loop MIMO scheme at a second time after the first time. In some cases, as part of the communication procedure, the base station105-amay also configure the UE115-awith one or more transmission parameters for an UL transmission (e.g., a data stream) associated with at least one of the UL transmit beam210-aor the UL transmit beam210-b, for example. A transmission parameter may include a modulation coding scheme (MCS), a rank indicator (RI), a precoder (e.g., precoding matrix indicator (PMI)), resource allocation (e.g., time and frequency resources), or the like. A transmission parameter may additionally, or alternatively be based on a rank of an UL transmission. In some cases, an UL transmission may include a set of data streams corresponding to a set of layers. For example, an UL transmission may be a rank-1 (i.e., one layer of data) or a rank-2 (i.e., two layers of data) or a higher rank (i.e., rank-4, rank-4, etc.). In this example, a precoder for an UL transmission may be selected based on the rank of the UL transmission. In some cases, each group of antennas ports may have different transmission parameters. For example, the base station105-amay schedule a first precoder matrix for a first group of antenna ports that may be coherent and a second precoder matrix that is different from the first precoder matrix for a second group of antenna ports that may be coherent, where the first group of antenna ports may be noncoherent with the second group of antenna ports. The precoder for an UL transmission may be selected according to a closed-loop precoding scheme or an open-loop precoding scheme. In a closed-loop precoding scheme, the base station105-amay select a suitable transmission rank and a corresponding precoder matrix based on measurements on reference signals (RSs) transmitted from the UE115-a(e.g., demodulation reference signals (DMRSs), sounding reference signals (SRSs)). The base station105-amay explicitly signal to the UE115-aa selected rank and corresponding precoder matrix for an UL transmission. For example, the base station105-amay transmit information (e.g., control information) that identifies the transmission rank, as well as the selected precoder matrix in a DCI message to the UE115-a. In some cases, to reduce the signaling between the base station105-aand the UE115-afor both DL and UL transmissions, a codebook may be configured for each transmission rank for a given number of antenna ports. In this case, both the base station105-awhen selecting an actual precoder matrix to use for UL transmission from the UE115-a, and the UE115-awhen generating the uplink signal, may select a precoder matrix from the corresponding codebook. As such, in either case that an UL transmission is a rank-1 or rank-2, the UL transmission may be closed-loop multiplexed according to the selected precoder matrix. Alternatively, in an open-loop precoding scheme, the UE115-amay not rely on signaling from the base station105-ato select precoder matrix. The UE115-amay receive the indication (e.g., in control information) to use both the closed-loop MIMO scheme and the transparent diversity scheme for UL transmissions, for example, via RRC signaling205or in a DCI message carried on a PDCCH. With reference to the transmission parameters, the UE115-amay also receive information corresponding to one or more precoder matrices for precoding an UL transmission (i.e., performing closed-loop MIMO). For example, the UE115-amay identify a first precoder matrix for precoding UL data on a first group of antenna ports (e.g., corresponding to UL transmit beam210-a) and identify a second precoder matrix for precoding UL data on a second group of antenna ports (e.g., corresponding to UL transmit beam210-b). In some examples, the first group of antenna ports and the second group of antenna ports may have the same precoder matrix. In some cases, the phase coherence can be maintained between antenna ports (e.g., antennas) included in each antenna port group (e.g., antenna group). The first group of antenna ports and the second group of antenna ports may be partially coherent. For example, the first group of antenna ports may be coherent with each other antenna port of the first group of antenna ports and noncoherent with the second group of antenna ports. The second group of antenna ports may be coherent with each other antenna port of the second group of antenna ports and noncoherent with the first group of antenna ports. After precoding the different groups of antenna ports, the UE115-amay apply a transparent diversity scheme among each antenna port of the groups. An example of a transparent diversity scheme may include a small cyclic delay diversity (CDD), which applies cyclic shifts to different antenna ports. As a result, CDD may be applicable to OFDM-based and DFTS-OFDM-based transmissions. In this case when the UE115-afirst perform closed-loop MIMO and then CDD, the UE115-amay be capable of simultaneous UL transmissions on both UL transmit beam210-aand210-b. That is, UE115-ais capable of transmitting same UL data on both UL transmit beam210-aand210-b. Alternatively, in the case that the UE115-afirst performs CDD and then closed-loop MIMO, similar benefits such as spectral diversity may be realized. Except that when the UE115-aperforms the closed-loop MIMO, it is performed on virtual antenna ports. That is, the CDD is applied among the antenna ports in different antenna groups to virtually combine multiple noncoherent antennas into groups of virtual antenna ports and perform the UL transmission using the groups of virtual antenna ports. In some cases, the small delay CDD may be zero. That is, the UE115-amay apply a small delay CDD with zero cyclic shift (e.g., in time domain) or zero phase shift (e.g., in frequency domain) as part of the transparent diversity scheme. The UE115-amay apply the same scheme for DMRS transmissions and data (e.g., the same scheme for a DMRS transmission as the scheme used for the corresponding uplink data). In the UL, the UE115-amay transmit DMRS at the same time as the PUSCH and PUCCH, as a phase reference for use in channel estimation. The UE115-amay also transmit SRS at times configured by the base station105-a, as a power reference in support frequency-dependent scheduling and precoder selection. In some cases, the UE115-amay apply the transparent diversity scheme among (e.g., virtually combine) each antenna port of a first group of antenna ports and a corresponding antenna port of a second group of antenna ports to generate a set of virtual SRS ports, and transmit an SRS separately for each of the set of virtual antenna ports. By applying a hybrid closed-loop MIMO and transparent diversity scheme, the UE115-amay fully utilize its resources and decrease instances of unused resources. Additionally, configuring the UE115-awith the above scheme (e.g., hybrid closed-loop MIMO plus transparent diversity scheme) may result in improved spatial diversity for the wireless communications system200. FIG.3Aillustrates an example of a block diagram300-athat supports hybrid closed-loop MIMO and transparent diversity schemes in NR in accordance with various aspects of the present disclosure. In some examples, the block diagram300-amay implement aspects of the wireless communications systems100and200. For example, the block diagram300-amay depict performing a closed-loop MIMO scheme following with a transparent diversity scheme. In this example, a UE may sound all antenna ports separately and select precoders based on the sounding from all the antenna ports. The block diagram300-amay include operations between a UE and a base station, which may be examples of the corresponding devices described with reference toFIGS.1and2. The operations depicted in block diagram300-amay be transmitted in a different order than the exemplary order shown, or the operations performed may be performed in different orders or at different times. Some operations may also be left out of the block diagram300-a, or other operations may be added to the block diagram300-a. A UE, which may be an example of the corresponding device described with reference toFIGS.1and2may use multiple antennas to realize multiple parallel data streams, so as to increase a data rate and realize spectral diversity. In the depicted example, a UE may include a layer mapper310, a precoding block315-a, a precoding block315-b, an SCDD block320. A base station, which may be an example of the corresponding device described with reference toFIGS.1and2may also use multiple antennas to realize multiple parallel data streams, so as to increase a data rate and realize spectral diversity. In the depicted example, the base station may include a layer de-mapper325, and a channel estimator330. At the UE, the layer mapper310may receive modulated symbol stream (e.g., a data stream) for UL transmission. For example, the modulated symbol stream may be a sequence of UL modulated symbols (e.g., x0, x1, x2, . . . ). The layer mapper310may map the modulated symbols (e.g., x0, x1, x2, . . . ) to one or more layers, where the number of layers corresponds to the selected rank. In some examples, a transmission rank may be greater than 1. The layer mapper310may map the modulated symbols to two or more layers for transmission. In a two layer example (e.g., rank 2 transmission), half of the modulated symbols (e.g., x0, x2, x4, . . . ) may be mapped to layer 1 for transmission, and the other half of the modulated symbols (e.g., x1, x3, x5, . . . ) may be mapped to layer 2 for transmission (e.g., as further illustrated and described with reference toFIGS.4A and4B). The precoding block315-aand the precoding block315-bmay receive the modulated symbols and pre-code each symbol based on a precoder matrix. The precoder matrix may be selected by the base station and provided to the UE. For example, two precoders (precoder matrices) for two different groups of antenna ports (e.g., antenna group305-aand antenna group305-b) may be [g0g1]and[g2g3], where g0, g1, g2, and g3are elements of the respective precoders. The output from the precoding block315-aand the precoding block315-bfor each symbol of the modulated symbols may be pre-coded with the corresponding precoder matrix. For a first symbol x0, for example, the output from the precoding block315-amay be g0x0and g1x0and the precoding block315-bmay be g2x0and g3x0. The precoding block315-aand the precoding block315-bmay forward the pre-coded symbols to the SCDD block320to apply transparent diversity. For example, the SCDD block320may apply CDD to the pre-coded symbols. In some examples, the SCDD block320may only apply CDD to introduce a delay between pre-coded symbols corresponding to antenna ports that are noncoherent. For example, the SCDD block320may apply CDD (e.g., phase-shift in the frequency domain) the pre-coded symbols associated with the antenna ports of antenna group305-brelative to antenna ports of antenna group305-abecause such antenna ports may be noncoherent with the antenna ports of antenna group305-a. A phase-shift in the frequency domain may result in a cyclic-shift in the time domain. The output signals from SCDD block320may then be mapped to antenna ports in the antenna group305-aand antenna group305-b. FIG.3Billustrates an example of a table300-bthat supports hybrid closed-loop MIMO and transparent diversity schemes in NR in accordance with various aspects of the present disclosure. In some examples, the block diagram300-bmay represent aspects of the block diagram300-a. For example, the block diagram300-bmay depict an output signal after performing a closed-loop MIMO scheme following with a transparent diversity scheme for antenna ports Ant0, Ant1, Ant2, and Ant3over the course of four frequency tones. With reference toFIG.3A, antenna port0and antenna port1may belong to antenna group305-a. The antenna port0and antenna port1may also be coherent. The antenna port2and antenna port3may belong to antenna group305-b. The antenna ports of antenna group305-amay be noncoherent with the antenna ports of antenna group305-b, such that antenna port0and antenna port2may be noncoherent, antenna port1and antenna port3may be noncoherent, and so on. As depicted inFIG.3B, the output signal corresponding to the modulated symbol stream may be mapped to different frequency tones and different antenna ports of each antenna group305-aand305-b. For example, antenna port0may transmit g0x0on a first frequency tone, g0x1on a second frequency tone, g0x3on a third frequency tone, and g0x3on a fourth frequency tone, and antenna port1may transmit g1x0on a first frequency tone, g1x1on a second frequency tone, g1x3on a third frequency tone, and g1x3on a fourth frequency tone. The modulated symbols mapped to antenna port2and antenna port3may have a phase-shift associated with them, as a result of applying CDD because the antenna port2and antenna port3being noncoherent with the antenna port0and antenna port1. For example, antenna port2may transmit g2x0on a first frequency tone, g2x1ejθon a second frequency tone, g2x2e2jθon a third frequency tone, and g2x3e3jθon a fourth frequency tone, and antenna port3 may transmit g3x0on a first frequency tone, g3x1ejθon a second frequency tone, g3x2e2jθon a third frequency tone, and g3x3e3jθon a fourth frequency tone. As a result, the data stream may be transmitted using both antenna group305-aand305-bsimultaneously. With reference toFIG.3A, at the base station, the channel estimator330may calculate a channel estimation corresponding to a resource allocation of the UE. The layer de-mapper325may perform the complementary operation of the layer mapper310by extracting data symbols from one or more layers, if applicable. By applying a hybrid scheme including a closed-loop MIMO scheme and a transparent diversity scheme, a UE may fully utilize its resources and provide a single layer UL transmission, while improving spatial diversity for a wireless communications system. FIG.4Aillustrates an example of a block diagram400-athat supports hybrid closed-loop MIMO and transparent diversity schemes in NR in accordance with various aspects of the present disclosure. In some examples, the block diagram400-amay implement aspects of the wireless communications systems100and200. For example, the block diagram400-amay depict performing a transparent diversity scheme following a closed-loop MIMO scheme. The block diagram400-amay include operations between a UE and a base station, may be examples of the corresponding devices described with reference toFIGS.1and2. The operations depicted in block diagram400-amay be transmitted in a different order than the exemplary order shown, or the operations performed may be performed in different orders or at different times. Some operations may also be left out of the block diagram400-a, or other operations may be added to the block diagram400-a. A UE, which may be an example of the corresponding device described with reference toFIGS.1and2may use multiple antennas to realize multiple parallel data streams, so as to increase a data rate and realize spectral diversity. In the depicted example, a UE may include a layer mapper410, a precoding block415-a, a precoding block415-b, an SCDD block420. A base station, which may be an example of the corresponding device described with reference toFIGS.1and2may also use multiple antennas to realize multiple parallel data streams, so as to increase a data rate and realize spectral diversity. In the depicted example, the base station may include a layer de-mapper425and a channel estimator430. At the UE, the layer mapper410may receive a data stream for UL transmission, for example a sequence of modulated UL symbols (e.g., x0, x1, x2, . . . ). The layer mapper410may map the modulated symbols to one or more layers, where the number of layers depends on a rank. In some examples, a transmission rank may be greater than 1. The layer mapper410may map the modulated symbols (e.g., x0, x1, x2, . . . ) to two or more layers for transmission where, a first data stream on a first layer may be a sequence of modulated symbols (e.g., a0, a1, a2, . . . ) and a second data stream on the second layer may be another sequence of modulated symbols (e.g., b0, b1, b2, . . . ). In a two-layer example (e.g., rank 2 transmission), the first data stream may be mapped to layer 1 for transmission, and the second data stream may be mapped to layer 2 for transmission. The precoding block415-aand the precoding block415-bmay receive modulated symbols of the data streams and pre-code the modulated symbols based on a precoder matrix. The precoder matrix may be selected by the base station and provided to the UE. For example, two precoder matrices for two different groups of antenna ports (e.g., antenna group405-aand antenna group405-b) may be [g00g01g10g11]and[g20g21g30g31], where g00, g01, g10, g11, g20, g21, g30and g30are elements of the respective precoders. The output from the precoding block415-aand the precoding block415-bfor each symbols of the data streams may be pre-coded with the corresponding precoder matrix. For a first symbol a0and first symbol b0, for example from the first data stream and the second data stream, the output from the precoding block415-amay be g00a0+g01b0and g10a0+g11b0and the precoding block415-bmay be g20a0+g21b0, g30a0+g31b0. The precoding block415-aand the precoding block415-bmay provide the pre-coded symbols to the SCDD block320to apply transparent diversity. For example, the SCDD block320may apply CDD to the pre-coded symbols. In some examples, the SCDD block320may only apply CDD to introduce a delay between pre-coded symbols corresponding to antenna ports that are noncoherent. For example, the SCDD block320may apply CDD (e.g., phase-shift in the frequency domain) the pre-coded symbols associated with the antenna ports of antenna group405-brelative to antenna ports of antenna group405-abecause such antenna ports may be noncoherent with the antenna ports of antenna group305-a. The output signal from SCDD block320may then be mapped to antenna ports in the antenna group405-aand antenna group405-b. FIG.4Billustrates an example of a table400-bthat supports hybrid closed-loop MIMO and transparent diversity schemes in NR in accordance with various aspects of the present disclosure. In some examples, the block diagram400-bmay represent aspects of the block diagram400-a. For example, the block diagram400-bmay depict an output signal after performing a closed-loop MIMO scheme following with a transparent diversity scheme for antenna ports Ant0, Ant1, Ant2, and Ant3over the course of four tones. With reference toFIG.4A, antenna port0and antenna port1may belong to antenna group405-a. The antenna ports of antenna group405-amay be noncoherent with the antenna ports of antenna group405-b, such that antenna port0and antenna port2may be noncoherent, antenna port1and antenna port3may be noncoherent, and so on. As depicted inFIG.4B, the output signals corresponding to the data streams may be mapped to different frequency tones and different antenna ports of each antenna group405-aand405-b. For example, antenna port0may transmit g00a0+g01b0on a first frequency tone, g00a1+g01b1on a second frequency tone, g00a2+g01b2on a third frequency tone, and g00a3+g01b3on a fourth frequency tone, and antenna port1may transmit g10a0+g11b0on a first frequency tone, g10a1+g11b1on a second frequency tone, g10a2+g11b2on a third frequency tone, and g10a3+g11b3on a fourth frequency tone. The symbols mapped to antenna port2and antenna port3may have a phase-shift associated with them, as a result of applying CDD because the antenna port2and antenna port3being noncoherent with the antenna port0and antenna port1. For example, antenna port2may transmit g20a0+g21b0on a first frequency tone, (g20a1+g21b1)ejθon a second frequency tone, (g20a2+g21b2)e2jθon a third frequency tone, and (g20a3+g21b3)e3jθon a fourth frequency tone, and antenna port 3 may transmit g30a0+g31b0on a first frequency tone, (g30a1+g31b1)ejθon a second frequency tone, (g30a2+g31b2)e2jθon a third frequency tone, and (g30a3+g31b3)e3jθon a fourth frequency tone. As a result, the data stream may be transmitted using both antenna group405-aand405-bsimultaneously. With reference toFIG.4A, at the base station, the channel estimator430may calculate a channel estimation corresponding to a resource allocation of the UE. The layer de-mapper425may perform the complementary operation of the layer mapper410by extracting symbols from one or more layers. By applying a hybrid closed-loop MIMO and transparent diversity scheme, a UE may fully utilize its resources and provide multiple layer UL transmissions, while improving spatial diversity for a wireless communications system. FIG.5illustrates an example of a block diagram500that supports hybrid closed-loop MIMO and transparent diversity schemes in NR in accordance with various aspects of the present disclosure. In some examples, the block diagram500may implement aspects of the wireless communications systems100and200. For example, the block diagram500may depict performing a transparent diversity scheme following with a closed-loop MIMO scheme. In this example, a UE may sound two virtual antenna ports separately and select a precoder based on the sounding from the two virtual antenna ports. The block diagram500may include operations between a UE and a base station, which may be examples of the corresponding devices described with reference toFIGS.1and2. The operations depicted in block diagram500may be transmitted in a different order than the exemplary order shown, or the operations performed may be performed in different orders or at different times. Some operations may also be left out of the block diagram500, or other operations may be added to the block diagram500. A UE, which may be an example of the corresponding device described with reference toFIGS.1and2may use multiple antennas to realize multiple parallel data streams, so as to increase a data rate and realize spectral diversity. In the depicted example, a UE may include a layer mapper510, an SCDD block515, and a precoding block520. A base station, which may be an example of the corresponding device described with reference toFIGS.1and2may also use multiple antennas to realize multiple parallel data streams, so as to increase a data rate and realize spectral diversity. In the depicted example, the base station may include a layer de-mapper525and a channel estimator530. At the UE, the layer mapper510may receive a data stream for UL transmission. For example, the data stream may be a sequence of UL symbols (e.g., x0, x1, x2, . . . ), which may be modulated. The layer mapper may map the modulated symbols to one or more layers, where the number of layers depends on a rank. The layer mapper510may forward the pre-coded symbols to the SCDD block515for transparent diversity. The SCDD block515may apply CDD to the symbols to generate a set of virtual antenna ports (e.g., virtual antenna port group505-aand virtual antenna port group505-b), which may be referred to as a virtual antenna port group or a virtual antenna group. In some examples, the SCDD block515may only apply CDD to symbols from antenna ports that are noncoherent, for example, the SCDD block515may apply CDD (e.g., phase-shift in the frequency domain) among symbols associated with antenna port0and antenna port2, and among symbols associated with antenna port1and antenna port3because antenna port0and antenna port2are noncoherent pair of antenna ports, and antenna port1and antenna port3are a noncoherent pair of antenna ports. The output signal (e.g., including phase-shifted bits) from SCDD block515associated with the virtual antenna ports (e.g., virtual antenna port group505-aand virtual antenna port group505-b) may then be provided to the precoding block520. The output signal from SCDD block515associated with virtual antenna port group505-amay be for antenna port1x0, x1, x2, . . . , and antenna port1x0, x1, x2, . . . , and the output signal from SCDD block515associated with virtual antenna port group505-bmay for antenna port2x0, x1ejθ, x2e2jθ, . . . , and for antenna port3x0, x1ejθ, x2e2jθ. The precoding block520may receive modulated symbols of the data stream and pre-code each symbol based on a precoder matrix. That is, the precoding block520may apply a precoder on the virtual antenna ports (e.g., virtual antenna port group505-aand virtual antenna port group505-b) to obtain a pre-coded data stream for each virtual antenna port. The pre-coded output signal for each virtual antenna port may be for antenna port1g0x0, g0x1, g0x2, . . . , antenna port1g1x0, g1x1, g1x2, . . . , for antenna port2g0x0, g0x1ejθ, g0x2e2jθ, . . . , and for antenna port3g1x0, g1x1ejθ, g1x2e2jθ. The precoder matrix may be selected by the base station and provided to the UE. The pre-coded data streams including the symbols (e.g., x0, x1, x2, . . . ) may then be mapped to antenna ports in the virtual antenna port group505-aand virtual antenna port group505-b, or both. At the base station, the channel estimator530may calculate a channel estimation corresponding to a resource allocation of the UE. The layer de-mapper525may perform the complementary operation of the layer mapper510by extracting symbols from one or more layers. By applying a transparent diversity scheme to symbols of a data stream and then applying hybrid closed-loop MIMO scheme, may allow a UE to utilize different antenna ports across different groups of virtual antenna ports, while improving spatial diversity for a wireless communications system. FIG.6illustrates an example of a process flow600that supports hybrid closed-loop MIMO and transparent diversity schemes in NR in accordance with various aspects of the present disclosure. In some examples, the process flow600may implement aspects of the wireless communications system100and200. Base station105-band UE115-bmay be examples of the corresponding devices described with reference toFIGS.1and2. In the following description of the process flow600, the operations between the base station105-band the UE115-bmay be transmitted in a different order than the exemplary order shown, or the operations performed by the base station105-band the UE115-bmay be performed in different orders or at different times. Some operations may also be left out of the process flow600, or other operations may be added to the process flow600. In some examples, the process flow600may commence with the base station105-bestablishing a connection with the UE115-b(e.g., performing a cell acquisition procedure, a random access procedure, an RRC connection procedure, an RRC configuration procedure). At605, the base station105-amay identify UE capability associated with UE115-b. the UE capability may include an indication of groups of antenna ports and information corresponding to coherence and non-coherence corresponding to different groups of antenna ports. In some examples, the UE capability may be reported to the base station105-aduring an RRC procedure. At610, the base station105-bmay select a mode for the UE115-abased on the UE capability. For example, the base station105-bmay select a mode that indicates for the UE115-bto use both a closed-loop MIMO scheme and a transparent diversity scheme for UL transmissions. At615, the base station105-bmay transmit RRC signaling (e.g., an RRC message) to the UE115-b. At620, the UE115-bmay identify the mode based on the RRC signaling. At625, the base station105-bmay transmit a DCI message to the UE115-b. In some examples, the DCI message may carry the indication to use both a closed-loop MIMO scheme and a transparent diversity scheme for UL transmissions. The DCI message at620, or another DCI message, may indicate rank associated with the uplink data for which the closed MIMO scheme is to be applied at635. Additionally or alternatively, the DCI message at620, or another DCI message, may indicate one or more precoders to be applied at635for the closed-loop MIMO scheme. At630, the UE115-bmay identify the rank and precoder based on the DCI message. At635, the UE115-bmay apply a closed-loop MIMO scheme among antenna ports within each group of a set of antenna ports. At640, the UE115-bmay apply a transparent diversity scheme among the antenna ports belonging to different group of the set of antenna ports. At645, the UE115-bmay simultaneously transmit data using the antenna ports within each group of the set of antenna ports. In other examples, for example with reference to the features of block diagram500, the630may occur before625. FIG.7shows a block diagram700of a device705that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The device705may be an example of aspects of a UE115as described herein. The device705may include a receiver710, a UE communications manager715, and a transmitter720. The device705may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver710may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to hybrid closed-loop MIMO and transparent diversity scheme in NR, etc.). Information may be passed on to other components of the device705. The receiver710may be an example of aspects of the transceiver920described with reference toFIG.9. The receiver710may utilize a single antenna or a set of antennas. The UE communications manager715may receive, from a base station, an indication that the UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme for transmissions of uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports, generate, from the uplink data, a set of output signals corresponding to the set of antenna ports based on applying the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports, and transmit the set of output signals using the set of antenna ports. The actions performed by the UE communications manager715as described herein may be implemented to realize one or more potential advantages. One implementation may allow a UE115to reduce signaling latency by fully utilizing its resources and decrease instances of wasted (e.g., unused) resources. Another implementation may provide improved quality and reliability of service at the UE115, as latency and the number of separate resources allocated to the UE115may be reduced. The UE communications manager715may be an example of aspects of the UE communications manager910described herein. The UE communications manager715, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the UE communications manager715, or its sub-components may be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. The UE communications manager715, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the UE communications manager715, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the UE communications manager715, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. The transmitter720may transmit signals generated by other components of the device705. In some examples, the transmitter720may be collocated with a receiver710in a transceiver module. For example, the transmitter720may be an example of aspects of the transceiver920described with reference toFIG.9. The transmitter720may utilize a single antenna or a set of antennas. FIG.8shows a block diagram800of a device805that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The device805may be an example of aspects of a device705or a UE115as described herein. The device805may include a receiver810, a UE communications manager815, and a transmitter840. The device805may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver810may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to hybrid closed-loop MIMO and transparent diversity scheme in NR, etc.). Information may be passed on to other components of the device805. The receiver810may be an example of aspects of the transceiver920described with reference toFIG.9. The receiver810may utilize a single antenna or a set of antennas. The receiver810may receive, from a base station, an indication that the UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme for transmissions of uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports. In some examples, the receiver810may receive DCI indicating a rank associated with the uplink data to which the closed-loop MIMO scheme is to be applied. In some examples, the receiver810may receive DCI indicating at least one precoder to be applied in the closed-loop MIMO scheme. The UE communications manager815may be an example of aspects of the UE communications manager715as described herein. Based applying both a closed-loop MIMO scheme and a transparent diversity scheme to one antenna pair that is coherent and another antenna pair that is noncoherent, a processor of a UE115(e.g., controlling the receiver810, the transmitter840, or the transceiver920as described with reference toFIG.9) may be able fully utilize its resources. Further, the processor of UE115may receive an indication that indicates when the hybrid scheme should be applied. As such, when the hybrid scheme indication is received, the processor may apply the hybrid scheme to two or more antenna groups and be capable of using more or all of the allocated transmit power by using both antenna groups contemporaneously. The UE communications manager815may include a signal generator820, a closed-loop MIMO component825, a diversity component830, and a precoder835. The UE communications manager815may be an example of aspects of the UE communications manager910described herein. The signal generator820may generate, from the uplink data, a set of output signals corresponding to the set of antenna ports based on applying the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. The closed-loop MIMO component825may apply the closed-loop MIMO scheme to the uplink data among the antenna ports within each group of the set of groups of antenna ports. In some examples, the closed-loop MIMO component825may apply the closed-loop MIMO scheme to an output of the applied transparent diversity scheme. In some examples, the closed-loop MIMO component825may apply the closed-loop MIMO scheme to the set of virtual antenna port. In some examples, the closed-loop MIMO component825may apply the closed-loop MIMO scheme and the transparent diversity scheme applied to the uplink data to a DMRS associated with the uplink data. In this case, the receiver810may not need to know the specific parameters associated with the diversity scheme (e.g., the phase θ applied in the small delay CDD scheme, as described with reference toFIGS.3and4) to decode the uplink data. That is, the diversity scheme applied at the UE may be “transparent” to the receiver810at the base station. The diversity component830may apply, to an output of the applied closed-loop MIMO scheme, the transparent diversity scheme among the groups of antenna ports. In some examples, the diversity component830may apply, to the uplink data, the transparent diversity scheme among the antenna ports of the set of groups of antenna ports. In some examples, the diversity component830may apply the transparent diversity scheme among each antenna port of a first group of antenna ports and a corresponding antenna port of a second group of antenna ports to generate a set of virtual antenna ports. In some examples, the diversity component830may apply the transparent diversity scheme among (e.g., virtually combine) each antenna port of a first group of antenna ports and a corresponding antenna port of a second group of antenna ports to generate a set of virtual SRS ports. The precoder835may pre-code, for a first group of the set of groups of antenna ports, the uplink data according to a first precoder. In some examples, the precoder835may pre-code, for a second group of the set of groups of antenna ports, the uplink data according to a second precoder different from the first precoder. The transmitter840may transmit signals generated by other components of the device805. In some examples, the transmitter840may be collocated with a receiver810in a transceiver module. For example, the transmitter840may be an example of aspects of the transceiver920described with reference toFIG.9. The transmitter840may utilize a single antenna or a set of antennas. The transmitter840may transmit the set of output signals using the set of antenna ports. In some examples, the transmitter840may transmit an SRS separately for each of the set of virtual antenna ports. In some examples, the transmitter840may transmit the DMRS using the set of antenna ports. In some examples, the transmitter840may transmit an SRS separately for each of the set of antenna ports. For example, the transmitter840may transmit SRS for each virtual antenna port if the transparent diversity is applied prior to closed-loop MIMO. The transmitter840may transmits SRS for reach antenna port if the transparent diversity scheme is applied after the closed-loop MIMO scheme. FIG.9shows a diagram of a system900including a device905that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The device905may be an example of or include the components of device705, device805, or a UE115as described herein. The device905may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a UE communications manager910, an I/O controller915, a transceiver920, an antenna925, memory930, and a processor940. These components may be in electronic communication via one or more buses (e.g., bus945). The UE communications manager910may receive, from a base station, an indication that the UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme for transmissions of uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports, generate, from the uplink data, a set of output signals corresponding to the set of antenna ports based on applying the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports, and transmit the set of output signals using the set of antenna ports. The I/O controller915may manage input and output signals for the device905. The I/O controller915may also manage peripherals not integrated into the device905. In some cases, the I/O controller915may represent a physical connection or port to an external peripheral. In some cases, the I/O controller915may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In other cases, the I/O controller915may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller915may be implemented as part of a processor. In some cases, a user may interact with the device905via the I/O controller915or via hardware components controlled by the I/O controller915. The transceiver920may communicate bi-directionally, via one or more antennas, wired, or wireless links as described herein. For example, the transceiver920may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver920may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. In some cases, the wireless device may include a single antenna925. However, in some cases the device may have more than one antenna925, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The memory930may include random-access memory (RAM) and read-only memory (ROM). The memory930may store computer-readable, computer-executable code935including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory930may contain, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices. The processor940may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor940may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor940. The processor940may be configured to execute computer-readable instructions stored in a memory (e.g., the memory930) to cause the device905to perform various functions (e.g., functions or tasks supporting hybrid closed-loop MIMO and transparent diversity scheme in NR). The code935may include instructions to implement aspects of the present disclosure, including instructions to support hybrid closed-loop MIMO schemes and transparent diversity schemes. The code935may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code935may not be directly executable by the processor940but may cause a computer (e.g., when compiled and executed) to perform functions described herein. FIG.10shows a block diagram1000of a device1005that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The device1005may be an example of aspects of a base station105as described herein. The device1005may include a receiver1010, a base station communications manager1015, and a transmitter1020. The device1005may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver1010may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to hybrid closed-loop MIMO and transparent diversity scheme in NR, etc.). Information may be passed on to other components of the device1005. The receiver1010may be an example of aspects of the transceiver1220described with reference toFIG.12. The receiver1010may utilize a single antenna or a set of antennas. The base station communications manager1015may identify that a UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme to transmit uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports and transmit, to the UE, an indication that the UE is to use the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. The base station communications manager1015may be an example of aspects of the base station communications manager1210described herein. The base station communications manager1015, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the base station communications manager1015, or its sub-components may be executed by a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. The base station communications manager1015, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the base station communications manager1015, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the base station communications manager1015, or its sub-components, may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. The transmitter1020may transmit signals generated by other components of the device1005. In some examples, the transmitter1020may be collocated with a receiver1010in a transceiver module. For example, the transmitter1020may be an example of aspects of the transceiver1220described with reference toFIG.12. The transmitter1020may utilize a single antenna or a set of antennas. FIG.11shows a block diagram1100of a device1105that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The device1105may be an example of aspects of a device1005or a base station105as described herein. The device1105may include a receiver1110, a base station communications manager1115, and a transmitter1130. The device1105may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver1110may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to hybrid closed-loop MIMO and transparent diversity scheme in NR, etc.). Information may be passed on to other components of the device1105. The receiver1110may be an example of aspects of the transceiver1220described with reference toFIG.12. The receiver1110may utilize a single antenna or a set of antennas. The base station communications manager1115may be an example of aspects of the base station communications manager1015as described herein. The base station communications manager1115may include a scheme component1120and a precoder selection component1125. The base station communications manager1115may be an example of aspects of the base station communications manager1210described herein. The scheme component1120may identify that a UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme to transmit uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports. The precoder selection component1125may select a precoder for the UE to apply in the closed-loop MIMO scheme. The transmitter1130may transmit signals generated by other components of the device1105. In some examples, the transmitter1130may be collocated with a receiver1110in a transceiver module. For example, the transmitter1130may be an example of aspects of the transceiver1220described with reference toFIG.12. The transmitter1130may utilize a single antenna or a set of antennas. The transmitter1130may transmit, to the UE, an indication that the UE is to use the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. The transmitter1130may transmit, to the UE, an indication that the UE is to use the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. In some examples, the transmitter1130may transmit an indication that the uplink data is to be precoded for a first group of the set of groups of antenna ports according to a first precoder, and the uplink data is to be precoded for a second group of the set of groups antenna ports according to a second precoder different from the first precoder. In some examples, the transmitter1130may transmit radio resource control signaling that includes the indication that the UE is to use the closed-loop MIMO scheme and the transparent diversity scheme. In some examples, the transmitter1130may transmit DCI indicating a rank associated with the uplink data to which the closed-loop MIMO scheme is to be applied. In some examples, the transmitter1130may transmit DCI indicating at least one precoder for the UE to apply in the closed-loop MIMO scheme. In some examples, the transmitter1130may transmit an indication of the selected precoder to the UE. FIG.12shows a diagram of a system1200including a device1205that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The device1205may be an example of or include the components of device1005, device1105, or a base station105as described herein. The device1205may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a base station communications manager1210, a network communications manager1215, a transceiver1220, an antenna1225, memory1230, a processor1240, and an inter-station communications manager1245. These components may be in electronic communication via one or more buses (e.g., bus1250). The base station communications manager1210may identify that a UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme to transmit uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports and transmit, to the UE, an indication that the UE is to use the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. The network communications manager1215may manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communications manager1215may manage the transfer of data communications for client devices, such as one or more UEs115. The transceiver1220may communicate bi-directionally, via one or more antennas, wired, or wireless links as described herein. For example, the transceiver1220may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver1220may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. In some cases, the wireless device may include a single antenna1225. However, in some cases the device may have more than one antenna1225, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The memory1230may include RAM, ROM, or a combination thereof. The memory1230may store computer-readable code1235including instructions that, when executed by a processor (e.g., the processor1240) cause the device to perform various functions described herein. In some cases, the memory1230may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. The processor1240may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor1240may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor1240. The processor1240may be configured to execute computer-readable instructions stored in a memory (e.g., the memory1230) to cause the device1205to perform various functions (e.g., functions or tasks supporting hybrid closed-loop MIMO and transparent diversity scheme in NR). The inter-station communications manager1245may manage communications with other base station105, and may include a controller or scheduler for controlling communications with UEs115in cooperation with other base stations105. For example, the inter-station communications manager1245may coordinate scheduling for transmissions to UEs115for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager1245may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations105. The code1235may include instructions to implement aspects of the present disclosure, including instructions to support hybrid closed-loop MIMO and transparent diversity scheme in NR. The code1235may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code1235may not be directly executable by the processor1240but may cause a computer (e.g., when compiled and executed) to perform functions described herein. FIG.13shows a flowchart illustrating a method1300that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The operations of method1300may be implemented by a UE115or its components as described herein. For example, the operations of method1300may be performed by a UE communications manager as described with reference toFIGS.7through9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, a UE may perform aspects of the functions described herein using special-purpose hardware. At1305, the UE may receive, from a base station, an indication that the UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme for transmissions of uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports. The operations of1305may be performed according to the methods described herein. In some examples, aspects of the operations of1305may be performed by a receiver as described with reference toFIGS.7through9. At1310, the UE may generate, from the uplink data, a set of output signals corresponding to the set of antenna ports based on applying the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. The operations of1310may be performed according to the methods described herein. In some examples, aspects of the operations of1310may be performed by a signal generator as described with reference toFIGS.7through9. At1315, the UE may transmit the set of output signals using the set of antenna ports. The operations of1315may be performed according to the methods described herein. In some examples, aspects of the operations of1315may be performed by a transmitter as described with reference toFIGS.7through9. FIG.14shows a flowchart illustrating a method1400that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The operations of method1400may be implemented by a UE115or its components as described herein. For example, the operations of method1400may be performed by a UE communications manager as described with reference toFIGS.7through9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, a UE may perform aspects of the functions described herein using special-purpose hardware. At1405, the UE may receive, from a base station, an indication that the UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme for transmissions of uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports. The operations of1405may be performed according to the methods described herein. In some examples, aspects of the operations of1405may be performed by a receiver as described with reference toFIGS.7through9. At1410, the UE may apply the closed-loop MIMO scheme to the uplink data among the antenna ports within each group of the set of groups of antenna ports. The operations of1410may be performed according to the methods described herein. In some examples, aspects of the operations of1410may be performed by a closed-loop MIMO component as described with reference toFIGS.7through9. At1415, the UE may apply, to an output of the applied closed-loop MIMO scheme, the transparent diversity scheme among the groups of antenna ports. The operations of1415may be performed according to the methods described herein. In some examples, aspects of the operations of1415may be performed by a diversity component as described with reference toFIGS.7through9. At1420, the UE may generate, from the uplink data, a set of output signals corresponding to the set of antenna ports based on applying the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. The operations of1420may be performed according to the methods described herein. In some examples, aspects of the operations of1420may be performed by a signal generator as described with reference toFIGS.7through9. At1425, the UE may transmit the set of output signals using the set of antenna ports. The operations of1425may be performed according to the methods described herein. In some examples, aspects of the operations of1425may be performed by a transmitter as described with reference toFIGS.7through9. FIG.15shows a flowchart illustrating a method1500that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The operations of method1500may be implemented by a UE115or its components as described herein. For example, the operations of method1500may be performed by a UE communications manager as described with reference toFIGS.7through9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, a UE may perform aspects of the functions described herein using special-purpose hardware. At1505, the UE may receive, from a base station, an indication that the UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme for transmissions of uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports. The operations of1505may be performed according to the methods described herein. In some examples, aspects of the operations of1505may be performed by a receiver as described with reference toFIGS.7through9. At1510, the UE may apply, to the uplink data, the transparent diversity scheme among the antenna ports of the set of groups of antenna ports. The operations of1510may be performed according to the methods described herein. In some examples, aspects of the operations of1510may be performed by a diversity component as described with reference toFIGS.7through9. At1515, the UE may apply the closed-loop MIMO scheme to an output of the applied transparent diversity scheme. The operations of1515may be performed according to the methods described herein. In some examples, aspects of the operations of1515may be performed by a closed-loop MIMO component as described with reference toFIGS.7through9. At1520, the UE may generate, from the uplink data, a set of output signals corresponding to the set of antenna ports based on applying the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. The operations of1520may be performed according to the methods described herein. In some examples, aspects of the operations of1520may be performed by a signal generator as described with reference toFIGS.7through9. At1525, the UE may transmit the set of output signals using the set of antenna ports. The operations of1525may be performed according to the methods described herein. In some examples, aspects of the operations of1525may be performed by a transmitter as described with reference toFIGS.7through9. FIG.16shows a flowchart illustrating a method1600that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The operations of method1600may be implemented by a UE115or its components as described herein. For example, the operations of method1600may be performed by a UE communications manager as described with reference toFIGS.7through9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, a UE may perform aspects of the functions described herein using special-purpose hardware. At1605, the UE may receive, from a base station, an indication that the UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme for transmissions of uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports. The operations of1605may be performed according to the methods described herein. In some examples, aspects of the operations of1605may be performed by a receiver as described with reference toFIGS.7through9. At1610, the UE may apply the transparent diversity scheme among (e.g., virtually combine) each antenna port of a first group of antenna ports and a corresponding antenna port of a second group of antenna ports to generate a set of virtual antenna ports. The operations of1610may be performed according to the methods described herein. In some examples, aspects of the operations of1610may be performed by a diversity component as described with reference toFIGS.7through9. At1615, the UE may apply the closed-loop MIMO scheme to the set of virtual antenna port. The operations of1615may be performed according to the methods described herein. In some examples, aspects of the operations of1615may be performed by a closed-loop MIMO component as described with reference toFIGS.7through9. At1620, the UE may generate, from the uplink data, a set of output signals corresponding to the set of antenna ports based on applying the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. The operations of1620may be performed according to the methods described herein. In some examples, aspects of the operations of1620may be performed by a signal generator as described with reference toFIGS.7through9. At1625, the UE may transmit the set of output signals using the set of antenna ports. The operations of1625may be performed according to the methods described herein. In some examples, aspects of the operations of1625may be performed by a transmitter as described with reference toFIGS.7through9. FIG.17shows a flowchart illustrating a method1700that supports hybrid closed-loop MIMO and transparent diversity scheme in NR in accordance with aspects of the present disclosure. The operations of method1700may be implemented by a base station105or its components as described herein. For example, the operations of method1700may be performed by a base station communications manager as described with reference toFIGS.10through12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described herein. Additionally or alternatively, a base station may perform aspects of the functions described herein using special-purpose hardware. At1705, the base station may identify that a UE is to use both a closed-loop MIMO scheme and a transparent diversity scheme to transmit uplink data using a set of antenna ports that include a set of groups of antenna ports, antenna ports within each group of antenna ports being phase coherent with each other antenna port belonging to the group of antenna ports and being phase incoherent with the antenna ports belonging to at least one other group of antenna ports. The operations of1705may be performed according to the methods described herein. In some examples, aspects of the operations of1705may be performed by a scheme component as described with reference toFIGS.10through12. At1710, the base station may transmit, to the UE, an indication that the UE is to use the closed-loop MIMO scheme for the set of groups of antenna ports and the transparent diversity scheme among antenna ports belonging to different groups of antenna ports. The operations of1710may be performed according to the methods described herein. In some examples, aspects of the operations of1710may be performed by a transmitter as described with reference toFIGS.10through12. It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined. Techniques described herein may be used for various wireless communications systems such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and other systems. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases may be commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from the organization named “3rd Generation Partnership Project” (3GPP). CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies. While aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR applications. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs115with service subscriptions with the network provider. A small cell may be associated with a lower-powered base station105, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency bands as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell, for example, may cover a small geographic area and may allow unrestricted access by UEs115with service subscriptions with the network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs115having an association with the femto cell (e.g., UEs115in a closed subscriber group (CSG), UEs115for users in the home, and the like). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells, and may also support communications using one or multiple component carriers. The wireless communications system100or systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations105may have similar frame timing, and transmissions from different base stations105may be approximately aligned in time. For asynchronous operation, the base stations105may have different frame timing, and transmissions from different base stations105may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an exemplary step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.” In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label. The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “exemplary” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples. The description herein is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein. | 120,388 |
11943019 | DETAILED DESCRIPTION The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims. It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be understood that when an element such as a layer, region, or substrate is referred to as being “on” or extending “onto” another element, it can be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or extending “directly onto” another element, there are no intervening elements present. Likewise, it will be understood that when an element such as a layer, region, or substrate is referred to as being “over” or extending “over” another element, it can be directly over or extend directly over the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly over” or extending “directly over” another element, there are no intervening elements present. It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Relative terms such as “below” or “above” or “upper” or “lower” or “horizontal” or “vertical” may be used herein to describe a relationship of one element, layer, or region to another element, layer, or region as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including” when used herein specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Aspects disclosed in the detailed description include systems and methods for low-power multi-antenna synchronization. In particular, a computing device, such as an Internet of Things (IoT) computing device, may include a transceiver operating using BLUETOOTH LOW ENERGY (BLE) with multiple antennas. In an exemplary aspect, each of a plurality of antennas is coupled to a respective edge detection circuit. When an incoming signal is detected by one of the edge detection circuits, circuitry associated with others of the multiple antennas may be placed in a low-power mode while circuitry associated with the detecting edge detection circuit attempts to synchronize with the incoming signal to see if the incoming signal is a signal of interest. By placing portions of the circuitry in low-power or sleep modes, power savings are achieved. As noted above, there has been a movement to BLE for IoT devices. Instead of using the lower data rates associated with BLE to extend range, one option is to use a multi-antenna system to take advantage of spatial diversity. One low-power approach to implementing such a multi-antenna system would be to borrow from the teachings of the '981 patent where a single radio frequency front end (RFFE) uses time-multiplexing to switch between antennas. Data collected from each antenna is analyzed to select a best antenna for signal reception. Such approach may work for angle of arrival applications where a lengthy tone is appended to the end of a packet, and the antenna is switched during the tone so that phase measurements may be made on each antenna. In other applications, where such a tone is not present, BLE has a comparatively short non-repeating synchronization word, which makes synchronization difficult using a time-multiplexing antenna approach given settling transients whenever switching between antennas occurs. Additionally, this approach does not allow for antenna combining techniques to maximize the range of the system. In most diversity systems, each antenna may have some form of correlation-based synchronization circuitry, which provides information about the signal being received at the respective antenna. Based on this information, an antenna may be selected, or a combination of signals may be made. The correlation circuitry consumes power. For such a system, more antennas mean more correlation circuitry, and therefore higher power consumption. Exemplary aspects of the present disclosure provide systems and methods to help reduce power consumption for multi-antenna systems such as an IoT system that uses BLE. In particular, exemplary aspects of the present disclosure leave correlation circuitry in a low-power mode until such a time as a signal of interest is detected. An antenna with the most interesting signal is selected and the signal of interest is provided to newly-awakened correlation circuitry. By delaying activation of the correlation circuitry, power consumption is reduced. In this regard,FIG.1is a block diagram of a receiver100with antennas102(1)-102(2). While the entirety of the description contained herein focuses on two-antenna systems, it should be appreciated that the teachings of the present disclosure are applicable to systems with more than two antennas. The antennas102(1)-102(2) may be coupled to respective analog-to-digital converters (ADCs)104(1)-104(2). In an exemplary aspect, the ADCs104(1)-104(2) may process in-phase (I) and quadrature (Q) portions of the signals. Immediately before, or immediately after the ADCs104(1)-104(2) other digital signal processing (DSP) blocks to condition the signal for detection (e.g., a channel select filter) may be provided as illustrated by DSPs106A(1),106B(1),106A(2),106B(2). Respective nodes108(1)-108(2) exist after the ADCs104(1)-104(2) (and perhaps after the DSPs106B(1)-106B(2)). The signals from the antennas102(1)-102(2) are split at the respective nodes108(1)-108(2). Respective first portions of the signals are provided to buffers110(1)-110(2). The buffers110(1)-110(2) may be sized large (or long) enough to account for the expected delay of the edge detection circuits120(1)-120(2)(described below) so that data arriving just prior to the edge detection can be used for synchronization. The buffers110(1)-110(2) are coupled to a multiplexer (MUX)112. The MUX112is coupled to a synchronization circuit114. The synchronization circuit114may be coupled to and controlled by a control circuit116. The synchronization circuit114drains data from one or more of the buffers110(1)-110(2) and uses this data to determine if the signal of interest is an actual signal to be received. The control circuit116may also be coupled to and control the MUX112. In an exemplary aspect, the synchronization circuit114may conform to the teachings of U.S. Pat. No. 10,667,102, which is hereby incorporated by reference in its entirety. Respective second portions of the signals are provided from the nodes108(1)-108(2) to respective received signal strength indicator (RSSI) circuits118(1)-118(2). The respective RSSI circuits118(1)-118(2) are coupled to respective edge detection circuits120(1)-120(2). The edge detection circuits120(1)-120(2) are coupled to an antenna selection circuit122. While shown as a distinct circuit inFIG.1, the antenna selection circuit122may be part of the control circuit116. FIG.2provides a flowchart of a process200for the receiver100in use. The process200starts with the synchronization circuit114turned off or placed in a low-power mode (block202). Additionally, the MUX112may likewise be turned off or placed in a low-power mode (block204). In other words, both antenna paths may be active, but the synchronization hardware is turned off. Electromagnetic waves and noise may impinge on the antennas102(1)-102(2) creating a current therein (block206), which may be conditioned by the DSPs106(1)-106(2) and converted into a digital signal by the respective ADCs104(1)-104(2)(block208). Such digital signals are stored in the buffers110(1)-110(2) (block210). The digital signals are also processed by the RSSI circuits118(1)-118(2), and the output provided to the edge detection circuits118(1)-118(2) to search for sudden signal energy indicative of a possible signal of interest (block212) relative to an existing environment (e.g., background noise, known received signals not of interest (e.g., out of bandwidth), or the like). As better explained with reference toFIG.3below, the edge detection circuits120(1)-120(2) determine if a signal edge is detected (block214). If the answer to block214is no, then the process200returns to block206. If, however, a signal edge is detected at block214, then the antenna selection circuit122selects an antenna102(2)-102(2) with the largest signal increase (block216). By performing antenna selection prior to synchronization, only a single correlation and synchronization circuit114needs to be active during synchronization, reducing power consumption compared with typical antenna diversity systems. The control circuit116then turns on the synchronization circuit114(block218) and the data stored in the buffer110(1)-110(2) corresponding to the selected antenna102(2)-102(2) is provided to the synchronization circuit114by the MUX112. As noted, the buffer110(1)-110(2) may contain data exceeding a time to edge detection and selection. The synchronization circuit114then uses a correlation algorithm to perform single antenna correlation calculations on the signal to synchronize to a packet (block220). The synchronization circuit114(or the control circuit116) determines if a packet was found before a time out occurs (block222). If a time out occurs, the synchronization circuit114will stop searching for new packets, complete any existing computations in progress, and the process200returns to block206. Note that if another edge is detected before the time out, the process200may reset the timer associated with the time out. If, however, a packet is found at block222, the process200concludes with single antenna detection (block224) and signal processing. In an exemplary aspect, the time out may be approximately one hundred fifty microseconds (150 μs). 150 μs corresponds to a minimum time between packet transmissions for BLE. Approximately, as used herein means within five percent (5%). While approximately 150 μs is contemplated, it should be appreciated that even lower timeouts can be used in specific applications or to trade off reliability and power consumption. In general, timeouts should be set as short as possible to minimize power consumption, but long enough to account for the time between the start of a packet transmission and when a worst-case device can actually synchronize to the packet. The timeout may also need to account for pre-packet transmissions including time needed to ramp up a power amplifier or for analog frequency synthesizers to settle. Time outs should additionally be chosen to be long enough that the long-term average will have time to converge to a new level reflecting the new signal environment. It should be appreciated that the time outs may be programmed as needed during installation or manufacture. Note that optionally any non-selected antenna path (e.g., ADC, buffer, and DSP circuits) may be turned off while the synchronization circuit114operates. Powering down a non-selected antenna path may save power, but also may hinder the diversity reception if conditions change to make the non-selected antenna path the better receiving path. FIG.3illustrates an edge detection circuit120. The edge detection circuit120receives a signal from an associated RSSI circuit118. The RSSI circuit118may average a magnitude of an I and Q sample over a short period of time, then adjust the result with the current gain setting of an associated RFFE. The results may be down-sampled before sending to the edge detection circuit120. In the edge detection circuit120, a first circuit300forms a short-term moving average, which may cover, for example, 6 μs. A second circuit302forms a long-term moving average, which may cover, for example 16 μs. In an exemplary aspect, the edge detection circuit120may have a sampling rate of one megahertz (1 MHz). A difference is taken by a difference circuit304. The difference is, effectively, an indication of how strong a signal (the short-term average) is over a general noise level (the long-term average). This difference is compared to a threshold by a comparator306, and if the threshold is exceeded, a signal onset detected signal is provided to the antenna selection circuit122. There are other ways exemplary aspects of the present disclosure may be implemented. One alternate exemplary receiver400is illustrated inFIG.4. The receiver400has antennas402(1)-402(2). The antennas402(1)-402(2) may be coupled to respective ADCs404(1)-404(2). In an exemplary aspect, the ADCs404(1)-404(2) may process I and Q portions of the signals. DSP blocks to condition the signal for detection (e.g., a channel select filter) may be provided (not shown) on either side of the ADCs404(1)-402(2). Respective nodes408(1)-408(2) exist after the ADCs404(1)-404(2). The signals from the antennas402(1)-402(2) are split at the respective nodes408(1)-408(2). Respective first portions of the signals are provided to buffers410(1)-410(2). The buffers410(1)-410(2) are coupled to respective synchronization circuits414(1)-414(2). The synchronization circuits414(1)-414(2) may be coupled to and controlled by a control circuit416. Respective second portions of the signals are provided from the nodes408(1)-408(2) to respective RSSI circuits418(1)-418(2). The respective RSSI circuits418(1)-418(2) are coupled to respective edge detection circuits420(1)-420(2). The edge detection circuits420(1)-420(2) may be identical to the edge detection circuit120ofFIG.3and may be coupled to an antenna selection circuit422, which may be a logical OR circuit. While shown as a distinct circuit inFIG.4, the antenna selection circuit422may be part of the control circuit416. In the receiver400, both synchronization circuits414(1)-414(2) are initially in a sleep or low-power mode, but may be activated together when one or the other edge detection circuit420(1)-420(2) detects a signal. The synchronization circuits414(1)-414(2) may then operate to facilitate creating a combined signal, thereby taking advantage of the diversity options available from the antennas402(1)-402(2). This approach achieves better performance, albeit at the cost of greater power consumption. While not optimal for battery-operated IoT devices, a mains-supplied IoT device (e.g., a refrigerator, set-top box, or the like) may find such design compromise acceptable. This approach may also do a better job of selecting a better antenna because the antenna selection may be based on the correlation calculations rather than merely edge detection. Finally, this approach can be used for more advanced multiple input-multiple output (MIMO) processing techniques, including space time coding, where the transmitting system encodes information across multiple antennas. As another option that could be implemented by either the receiver100or the receiver400, the control circuit116or416may initially select an antenna based on the output from the edge detection circuits120,420(1)-420(2), but, if ambiguity or uncertainty occurs, activate the correlation-based synchronization. This approach achieves excellent antenna selection performance while also generally reducing power consumption in most cases. Another alternate receiver500is illustrated inFIG.5. The receiver500may be a single antenna receiver having only an antenna502. The antenna502may be coupled to an ADC504. In an exemplary aspect, the ADC504may process I and Q portions of the signals. Immediately before, or immediately after the ADC504other DSP blocks to condition the signal for detection (e.g., a channel select filter) may be provided. A node508may exist after the ADC504. The signal from the antenna502is split at the node508. A first portion of the signal is provided to a buffer510. The buffer510is coupled to a synchronization circuit514. The synchronization circuit514may be coupled to and controlled by a control circuit516. A second portion of the signal is provided from the nodes508to an RSSI circuit518. The RSSI circuit518is coupled to an edge detection circuit520, which may be identical to the edge detection circuit120. The edge detection circuit520may be coupled to the control circuit516. Similar to the discussion above, the synchronization circuit514may remain in a sleep or low-power mode until activated by the control circuit516based on an indication that a signal has been received and detected by the edge detection circuit520. This arrangement still provides power savings for the receiver500relative to a system that uses the synchronization circuit to detect signals. It is also noted that the operational steps described in any of the exemplary aspects herein are described to provide examples and discussion. The operations described may be performed in numerous different sequences other than the illustrated sequences. Furthermore, operations described in a single operational step may actually be performed in a number of different steps. Additionally, one or more operational steps discussed in the exemplary aspects may be combined. It is to be understood that the operational steps illustrated in the flowchart diagrams may be subject to numerous different modifications as will be readily apparent to one of skill in the art. Those of skill in the art will also understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | 20,507 |
11943020 | DETAILED DESCRIPTION The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to limit the scope of the disclosure. Rather, the detailed description includes specific details for the purpose of providing a thorough understanding of the inventive subject matter. It will be apparent to those skilled in the art that these specific details are not required in every case and that, in some instances, well-known structures and components are shown in block diagram form for clarity of presentation. This disclosure relates generally to providing or participating in communication as between two or more wireless devices in one or more wireless communications systems, also referred to as wireless communications networks. In various aspects, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, 5th Generation (5G) or new radio (NR) networks (sometimes referred to as “5G NR” networks/systems/devices), as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably. A CDMA network, for example, may implement a radio technology such as universal terrestrial radio access (UTRA), cdma2000, and the like. UTRA includes wideband-CDMA (W-CDMA) and low chip rate (LCR). CDMA2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA network may, for example implement a radio technology such as GSM. 3GPP defines standards for the GSM EDGE (enhanced data rates for GSM evolution) radio access network (RAN), also denoted as GERAN. GERAN is the radio component of GSM/EDGE, together with the network that joins the base stations (for example, the Ater and Abis interfaces) and the base station controllers (A interfaces, etc.). The radio access network represents a component of a GSM network, through which phone calls and packet data are routed from and to the public switched telephone network (PSTN) and Internet to and from subscriber handsets, also known as user terminals or user equipments (UEs). A mobile phone operator's network may comprise one or more GERANs, which may be coupled with Universal Terrestrial Radio Access Networks (UTRANs) in the case of a UMTS/GSM network. An operator network may also include one or more LTE networks, and/or one or more other networks. The various different network types may use different radio access technologies (RATs) and radio access networks (RANs). An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and Global System for Mobile Communications (GSM) are part of universal mobile telecommunication system (UMTS). In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named “3rd Generation Partnership Project” (3GPP), and cdma2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). These various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the universal mobile telecommunications system (UMTS) mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces. 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. To achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (IoTs) with an ultra-high density (e.g., ˜1M nodes/km2), ultra-low complexity (e.g., ˜10s of bits/sec), ultra-low energy (e.g., ˜10+ years of battery life), and deep coverage with the capability to reach challenging locations; (2) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ˜99.9999% reliability), ultra-low latency (e.g., ˜1 ms), and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., ˜10 Tbps/km2), extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates), and deep awareness with advanced discovery and optimizations. 5G NR devices, networks, and systems may be implemented to use optimized OFDM-based waveform features. These features may include scalable numerology and transmission time intervals (TTIs); a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD)/frequency division duplex (FDD) design; and advanced wireless technologies, such as massive multiple input, multiple output (MIMO), robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3 GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz, for example over 1, 5, 10, 20 MHz, and the like bandwidth. For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz bandwidth. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz bandwidth. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz bandwidth. The scalable numerology of 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with uplink/downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive uplink/downlink that may be flexibly configured on a per-cell basis to dynamically switch between uplink and downlink to meet the current traffic needs. For clarity, certain aspects of the apparatus and techniques may be described below with reference to exemplary LTE implementations or in an LTE-centric way, and LTE terminology may be used as illustrative examples in portions of the description below; however, the description is not intended to be limited to LTE applications. Indeed, some aspects of the present disclosure are concerned with shared access to wireless spectrum between networks using different radio access technologies or radio air interfaces, such as those of 5G NR. Moreover, it should be understood that, in operation, wireless communication networks adapted according to the concepts herein may operate with any combination of licensed or unlicensed spectrum depending on loading and availability. Accordingly, it will be apparent to one of skill in the art that the systems, apparatus and methods described herein may be applied to other communications systems and applications than the particular examples provided. While aspects and aspects are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, aspects and/or uses may come about via integrated chip aspects and/or other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregated, distributed, or OEM devices or systems incorporating one or more described aspects. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described aspects. It is intended that innovations described herein may be practiced in a wide variety of implementations, including both large/small devices, chip-level components, multi-component systems (e.g. RF-chain, communication interface, processor), distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution. FIG.1shows wireless network100for communication according to some aspects. Wireless network100may, for example, comprise a 5G wireless network. As appreciated by those skilled in the art, components appearing inFIG.1are likely to have related counterparts in other network arrangements including, for example, cellular-style network arrangements and non-cellular-style-network arrangements (e.g., device to device or peer to peer or ad hoc network arrangements, etc.). Wireless network100illustrated inFIG.1includes a number of base stations105and other network entities. A base station may be a station that communicates with the UEs and may also be referred to as an evolved node B (eNB), a next generation eNB (gNB), an access point, and the like. Each base station105may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a base station and/or a base station subsystem serving the coverage area, depending on the context in which the term is used. In implementations of wireless network100herein, base stations105may be associated with a same operator or different operators (e.g., wireless network100may comprise a plurality of operator wireless networks), and may provide wireless communications using one or more of the same frequencies (e.g., one or more frequency bands in licensed spectrum, unlicensed spectrum, or a combination thereof) as a neighboring cell. In some examples, an individual base station105or UE115may be operated by more than one network operating entity. In other examples, each base station105and UE115may be operated by a single network operating entity. A base station may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, and the like). A base station for a macro cell may be referred to as a macro base station. A base station for a small cell may be referred to as a small cell base station, a pico base station, a femto base station or a home base station. In the example shown inFIG.1, base stations105dand105eare regular macro base stations, while base stations105a-105care macro base stations enabled with one of 3 dimension (3D), full dimension (FD), or massive MIMO. Base stations105a-105ctake advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. Base station105fis a small cell base station which may be a home node or portable access point. A base station may support one or multiple (e.g., two, three, four, and the like) cells. Wireless network100may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. In some scenarios, networks may be enabled or configured to handle dynamic switching between synchronous or asynchronous operations. UEs115are dispersed throughout the wireless network100, and each UE may be stationary or mobile. It should be appreciated that, although a mobile apparatus is commonly referred to as user equipment (UE) in standards and specifications promulgated by the 3rd Generation Partnership Project (3GPP), such apparatus may also be referred to by those skilled in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. Within the present document, a “mobile” apparatus or UE need not necessarily have a capability to move, and may be stationary. Some non-limiting examples of a mobile apparatus, such as may comprise aspects of one or more of UEs115, include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a laptop, a personal computer (PC), a notebook, a netbook, a smart book, a tablet, and a personal digital assistant (PDA). A mobile apparatus may additionally be an “Internet of things” (IoT) or “Internet of everything” (IoE) device such as an automotive or other transportation vehicle, a satellite radio, a global positioning system (GPS) device, a logistics controller, a drone, a multi-copter, a quad-copter, a smart energy or security device, a solar panel or solar array, municipal lighting, water, or other infrastructure; industrial automation and enterprise devices; consumer and wearable devices, such as eyewear, a wearable camera, a smart watch, a health or fitness tracker, a mammal implantable device, gesture tracking device, medical device, a digital audio player (e.g., MP3 player), a camera, a game console, etc.; and digital home or smart home devices such as a home audio, video, and multimedia device, an appliance, a sensor, a vending machine, intelligent lighting, a home security system, a smart meter, etc. In one aspect, a UE may be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE may be a device that does not include a UICC. In some aspects, UEs that do not include UICCs may also be referred to as IoE devices. UEs115a-115dof the aspect illustrated inFIG.1are examples of mobile smart phone-type devices accessing wireless network100A UE may also be a machine specifically configured for connected communication, including machine type communication (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT) and the like. UEs115e-115killustrated inFIG.1are examples of various machines configured for communication that access wireless network100. A mobile apparatus, such as UEs115, may be able to communicate with any type of the base stations, whether macro base stations, pico base stations, femto base stations, relays, and the like. InFIG.1, a lightning bolt (e.g., communication link) indicates wireless transmissions between a UE and a serving base station, which is a base station designated to serve the UE on the downlink and/or uplink, or desired transmission between base stations, and backhaul transmissions between base stations. Backhaul communication between base stations of wireless network100may occur using wired and/or wireless communication links. In operation at wireless network100, base stations105a-105cserve UEs115aand115busing 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. Macro base station105dperforms backhaul communications with base stations105a-105c, as well as small cell, base station105f. Macro base station105dalso transmits multicast services which are subscribed to and received by UEs115cand115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts. Wireless network100of aspects supports mission critical communications with ultra-reliable and redundant links for mission critical devices, such UE115e, which is a drone. Redundant communication links with UE115einclude from macro base stations105dand105e, as well as small cell base station105f. Other machine type devices, such as UE115f(thermometer), UE115g(smart meter), and UE115h(wearable device) may communicate through wireless network100either directly with base stations, such as small cell base station105f, and macro base station105e, or in multi-hop configurations by communicating with another user device which relays its information to the network, such as UE115fcommunicating temperature measurement information to the smart meter, UE115g, which is then reported to the network through small cell base station105f. Wireless network100may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as in a vehicle-to-vehicle (V2V) mesh network between UEs115i-115kcommunicating with macro base station105e. FIG.2shows a block diagram of a design of a base station105and a UE115, which may be any of the base stations and one of the UEs inFIG.1. For a restricted association scenario (as mentioned above), base station105may be small cell base station105finFIG.1, and UE115may be UE115cor115D operating in a service area of base station105f, which in order to access small cell base station105f, would be included in a list of accessible UEs for small cell base station105f. Base station105may also be a base station of some other type. As shown inFIG.2, base station105may be equipped with antennas234athrough234t, and UE115may be equipped with antennas252athrough252rfor facilitating wireless communications. At the base station105, a transmit processor220may receive data from a data source212and control information from a controller/processor240. The control information may be for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid-ARQ (automatic repeat request) indicator channel (PHICH), physical downlink control channel (PDCCH), enhanced physical downlink control channel (EPDCCH), MTC physical downlink control channel (MPDCCH), etc. The data may be for the PDSCH, etc. The transmit processor220may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor220may also generate reference symbols, e.g., for the primary synchronization signal (PSS) and secondary synchronization signal (SSS), and cell-specific reference signal. Transmit (TX) multiple-input multiple-output (MIMO) processor230may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to modulators (MODs)232athrough232t. Each modulator232may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator232may additionally or alternatively process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators232athrough232tmay be transmitted via the antennas234athrough234t, respectively. Base station105may include communication unit246and communicate to network controller200(e.g., a RAN or core network component) via communication unit246. Network controller200may include communication unit294, controller/processor290, and memory292. At the UE115, the antennas252athrough252rmay receive the downlink signals from the base station105and may provide received signals to the demodulators (DEMODs)254athrough254r, respectively. Each demodulator254may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator254may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector256may obtain received symbols from demodulators254athrough254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor258may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE115to a data sink260, and provide decoded control information to a controller/processor280. On the uplink, at the UE115, a transmit processor264may receive and process data (e.g., for the physical uplink shared channel (PUSCH)) from a data source262and control information (e.g., for the physical uplink control channel (PUCCH)) from the controller/processor280. Transmit processor264may also generate reference symbols for a reference signal. The symbols from the transmit processor264may be precoded by TX MIMO processor266if applicable, further processed by the modulators254athrough254r(e.g., for SC-FDM, etc.), and transmitted to the base station105. At base station105, the uplink signals from UE115may be received by antennas234, processed by demodulators232, detected by MIMO detector236if applicable, and further processed by receive processor238to obtain decoded data and control information sent by UE115. Processor238may provide the decoded data to data sink239and the decoded control information to controller/processor240. Controllers/processors240and280may direct the operation at base station105and UE115, respectively. Controller/processor240and/or other processors and modules at base station105and/or controller/processor28and/or other processors and modules at UE115may perform or direct the execution of various processes for the techniques described herein, such as to perform or direct the execution illustrated inFIGS.5and6, and/or other processes for the techniques described herein. Memories242and282may store data and program codes for base station105and UE115, respectively. Scheduler244may schedule UEs for data transmission on the downlink and/or uplink. Wireless communications systems operated by different network operating entities (e.g., network operators) may share spectrum. In some instances, a network operating entity may be configured to use an entirety of a designated shared spectrum for at least a period of time before another network operating entity uses the entirety of the designated shared spectrum for a different period of time. Thus, in order to allow network operating entities use of the full designated shared spectrum, and in order to mitigate interfering communications between the different network operating entities, certain resources (e.g., time) may be partitioned and allocated to the different network operating entities for certain types of communication. For example, a network operating entity may be allocated certain time resources reserved for exclusive communication by the network operating entity using the entirety of the shared spectrum. The network operating entity may also be allocated other time resources where the entity is given priority over other network operating entities to communicate using the shared spectrum. These time resources, prioritized for use by the network operating entity, may be utilized by other network operating entities on an opportunistic basis if the prioritized network operating entity does not utilize the resources. Additional time resources may be allocated for any network operator to use on an opportunistic basis. Access to the shared spectrum and the arbitration of time resources among different network operating entities may be centrally controlled by a separate entity, autonomously determined by a predefined arbitration scheme, or dynamically determined based on interactions between wireless nodes of the network operators. In some cases, UE115and base station105may operate in a shared radio frequency spectrum band, which may include licensed or unlicensed (e.g., contention-based) frequency spectrum. In an unlicensed frequency portion of the shared radio frequency spectrum band, UEs115or base stations105may traditionally perform a medium-sensing procedure to contend for access to the frequency spectrum. For example, UE115or base station105may perform a listen before talk (LBT) procedure such as a clear channel assessment (CCA) prior to communicating in order to determine whether the shared channel is available. A CCA may include an energy detection procedure to determine whether there are any other active transmissions. For example, a device may infer that a change in a received signal strength indicator (RSSI) of a power meter indicates that a channel is occupied. Specifically, signal power that is concentrated in a certain bandwidth and exceeds a predetermined noise floor may indicate another wireless transmitter. A CCA also may include detection of specific sequences that indicate use of the channel. For example, another device may transmit a specific preamble prior to transmitting a data sequence. In some cases, an LBT procedure may include a wireless node adjusting its own backoff window based on the amount of energy detected on a channel and/or the acknowledge/negative-acknowledge (ACK/NACK) feedback for its own transmitted packets as a proxy for collisions. Referring toFIGS.3A and3B, examples of antenna arrays are illustrated.FIG.3Acorresponds to a diagram illustrating a complex antenna array. The antenna array may be suitable for mm wave communications, full duplex operations (e.g., simultaneous transmission and reception), or both. In the example ofFIG.3A, the antenna array has transmission (TX) and reception/receiving (RX) antenna panels or elements that are separated and isolated from each other. To illustrate, the antenna panels are spaced apart from each other and have structure blocking a transmission path between the two antenna panels. In some implementations and operating modes, a pair of TX and RX antenna panels/elements may simultaneously transmit and receive data, such as at least partially overlapping in time, frequency, or both. FIG.3Bcorresponds to a diagram illustrating simultaneous operation and clutter interference on one side of the antenna array ofFIG.3A. InFIG.3B, the antenna elements of the TX and/or RX antenna panels form transmission nulls to reduce interference. Transmission nulls correspond to an intentional suppression of an antenna response in one or more particular directions, such as reduced, low, or no energy sidelobes. As illustrated inFIG.3B, the antenna array of node N1is operating in a full duplex mode with node N2. Outgoing and incoming transmissions have a particular main direction (e.g., spatial direction) or focus of radiative energy from the antennas. To produce such a main direction (e.g., spatial angle), the antenna panel also emits sidelobes or radiative energy in additional directions fanning out from the main direction. This sidelobe energy may cause interference. As shown in the example ofFIG.3B, the sidelobe energy or signals may reflect off of objects, such as C1and C2. When reflected transmission sidelobe energy is directed back at the RX antenna panel, which is active to receive an RX transmission, the transmission sidelobe energy causes interference called clutter interference (or clutter echo). This reflected transmission energy may clutter, distort, or disguise incoming transmissions from node N2. In conventional operations, such as sub mm wave operations and frequencies, clutter interference is not usually the biggest cause of self-interference (e.g., reduced SINR). Usually, array leakage is the largest contributor of self-interference. However, in mm wave operations and frequencies, array leakage (e.g., direct leakage) has been found to be lower and clutter interference (e.g., echo or indirect interference) has been found to cause a significant or majority amount of self-interference. For example, the size of the antenna elements for mm wave frequency and directional nature of the mm wave operations reduces array leakage. Reducing and mitigating clutter interference is a key challenge in enabling full duplex operating in mm wave. One proposed technique for reducing clutter interference involves measuring interference at one node, reporting the measured interference to another node, and making a determination based on the measurements. Such “closed loop” clutter interference mitigation techniques may be suitable for certain conditions and utilize additional processing and signaling overhead. Open loop clutter mitigation techniques have also been proposed. FIGS.4A and4Billustrate an example of transmission null sweeping.FIG.4Aillustrates a first transmission null andFIG.4Billustrates a second and different transmission null. InFIG.4A, the transmitting antenna generates a first transmission null that reduces or cancels clutter echo or feedback (clutter reflections) for object C1, such as reduces or cancels the generation of clutter reflections. InFIG.4B, the transmitting antenna generates a second transmission null that reduces or cancels clutter echo or feedback (clutter reflections) for object C2. As shown inFIGS.4A and4B, the receiving antenna may also form transmission nulls (e.g., reception nulls) in addition to or in the alternative of. In the examples shown inFIGS.4A and4B, the receiving antenna transmission nulls (e.g., reception nulls) also reduce or cancel the pickup of clutter reflections. Various null-forming procedures may be performed, including receive null-forming procedures (e.g., transmission beam if fixed and repeated, and multiple receive beams associated with a prior receive beam are used for measurements), transmit null-forming procedures (e.g., multiple transmit beams associated with a prior transmit beam are used, and receive beam is fixed and repeated), joint transmit and receive null-forming procedures (e.g., transmission and measurements over multiple self-interference (SI) resources with different choices of transmit and receive beams associated with, e.g., spatially QCL'd, with a pair of prior transmit and receive beams), or iterative null-forming procedures (e.g., start with a receive or transmit null-forming procedure, and then switch to the other null-forming procedure type, if needed). In some conventional wireless devices, as a baseline, for any beam, multiple spatially QCL'ed beams with different null-forming (e.g., suppression of different side-lobes and the amount of suppression) are pre-configured and stored at the wireless device. The wireless device has to go over the list and do measurements to find a good candidate. In some designs, multiple beams can be created on-the-fly and based on the prior measurements. In other designs, the wireless device may have performed prior measurements (e.g., detecting clutters, their directions and strengths), and may utilize this information to find/create a proper null-forming configuration. Aspects of the disclosure are directed to selectively performing a receive null-forming procedure on the first beam, a transmit null-forming procedure on the second beam, or a combination thereof. In particular, the selective nature of the null-forming procedure(s) performed on the beam(s) is based upon dynamic null-forming procedure information at the wireless device (e.g., receive from external network entity and/or based in part upon measurements at the wireless device itself) rather than a pre-stored null-forming configuration. Such an implementation may provide various technical advantages, including more precise null-forming, faster null-forming, network-coordinated null forming (e.g., so transmission part of null forming procedures can be monitored by other wireless entities, for positioning, power control, etc.), and so on. FIG.5illustrates an exemplary process500of wireless communications according to an aspect of the disclosure. The process500ofFIG.5is performed by a first wireless device, which may correspond to BS105or UE115. The process500ofFIG.5is specific to the scenario where a directional association (e.g., transmit or receive) of a set of beams is already determined, and the first wireless device is attempting to identify null-forming procedure(s) to perform on at least one beam in the set of beams with the known directional association. At502, the first wireless device (e.g., controller/processor240, controller/processor280, etc.) determines that a first beam of the first wireless device is associated with a receive direction and that a second beam is associated with a transmit direction. The determination of502can be performed in a variety of ways (e.g., configured by a network entity, carried over from a previously used beam directional association, etc.). At504, the first wireless device (e.g., controller/processor240, controller/processor280, etc.) determines null-forming procedure information associated with null-forming at the first wireless device, the null-forming associated with steering the first beam, the second beam, or both, away from one or more external sources of self-interference, the null-forming procedure information (i) based on one or more measurements performed at the first wireless device, (ii) received from a first network entity, or (iii) a combination thereof. The determined null-forming procedure information is dynamic in nature, in contrast to the pre-stored null-forming configuration used in some conventional null-forming procedures. At506, the first wireless device (e.g., controller/processor240, controller/processor280, etc.) optionally determines one of a receive null-forming procedure or a transmit null-forming procedure based on an efficiency metric (e.g., based on which of the receive or transmit null-forming procedure is determined to be likely to be more efficient in terms of null-forming on respective beams). In some designs, this optional determination may factor into a subsequent selection at508with regard to which null-forming procedure(s) to perform (and/or an order in which to perform the null-forming procedure(s)). At508, the first wireless device (e.g., controller/processor240, controller/processor280, etc.) selects, based on the null-forming procedure information, a receive null-forming procedure on the first beam, a transmit null-forming procedure on the second beam, or a combination thereof. In some designs, the selected null-forming procedure may comprise a receive null-forming procedure only (e.g., with an optional transmit null-forming procedure being performed later for iterative execution), a transmit null-forming procedure only (e.g., with an optional receive null-forming procedure being performed later for iterative execution), or a joint receive/transmit null-forming procedure. In some designs, the selection at510may be based at least in part upon historical measurement information at the first wireless device. For example, the first wireless device may have some prior information related to measurements or detection of clutter echo (e.g., direction/strength) of clutter (e.g., which may likewise impact the optional determination at506). In some designs, the selection at508is based on the optional determination at506. In some designs, the selection of508may be limited in part by a beam-specific null-forming procedure capacity of the first wireless device (e.g., only select beam-specific null-forming procedures known to be supported by the first wireless device), a directional-specific null-forming procedure capacity of the first wireless device (e.g., only select beam-specific null-forming procedures in a direction that is known to be supported by the first wireless device), or a combination thereof. In some designs, the selection at510may be based on one or more selection criteria received from a second network entity (e.g., which may be the same or different from the first network entity). At510, in some designs, the selected null-forming procedure may comprise a transmit null-forming procedure, which comprises transmitting a plurality of signals on a plurality of different transmit beams (e.g., where the plurality of different transmit beams are spatially QCL'ed), and measuring the plurality of signals on the same receive beam. In an example, at510, the first wireless device (e.g., antenna(s)252a. . .252r, modulators254a. . .254r, Tx MIMO processor266, transmit processor264, etc.) may optionally coordinate with a second wireless device to facilitate the second wireless device to perform one or more measurements in association with one or more transmissions by the first wireless device in association with the transmit null-forming procedure. For example, to facilitate the optional coordination at510, the first wireless device may transmit an indication of one or more resources or configurations associated with the transmission of the plurality of signals. As an example, this optional coordination may facilitate the second wireless device to measure the signal(s) (e.g., for power control, for positioning, etc.). Hence, a null-forming procedure need not be performed strictly for the purpose of null-forming, but can rather be opportunistically leveraged to facilitate other functions as well. At512, the first wireless device (e.g., antenna(s)252a. . .252r, demodulators254a. . .254r, Rx MIMO processor256, receive processor258, etc., and/or antenna(s)252a. . .252r, modulators254a. . .254r, Tx MIMO processor266, transmit processor264, etc.) performs the selected null-forming procedure. As noted above, the selected null-forming procedure may comprise a receive null-forming procedure only (e.g., with an optional transmit null-forming procedure being performed later for iterative execution), a transmit null-forming procedure only (e.g., with an optional receive null-forming procedure being performed later for iterative execution), or a joint receive/transmit null-forming procedure. At514, the first wireless device (e.g., controller/processor240, controller/processor280, etc.) optionally determines to initiate another null-forming procedure after the selected null-forming procedure has at least started (e.g., iterative null-forming). For example, assume that the selected null-forming procedure comprises a receive null-forming procedure. At some point during or after the receive null-forming procedure, the first wireless device may determine that the self-interference resulting from the receive null-forming procedure is insufficient (e.g., SI remains above a threshold, such as an SINR threshold), which results in a determination at514to perform a transmit null-forming procedure in an iterative manner. In some designs, a receive null-forming procedure may be performed first as part of an iterative null-forming procedure because receive null-forming may be transparent to other wireless devices (i.e., less overall overhead). In another example, assume that the selected null-forming procedure comprises a transmit null-forming procedure. At some point during or after the transmit null-forming procedure, the first wireless device may determine that the self-interference resulting from the transmit null-forming procedure is insufficient (e.g., SI remains above a threshold, such as an SINR threshold), which results in a determination at514to perform a receive null-forming procedure in an iterative manner. In some designs, a transmit null-forming procedure may be performed first as part of an iterative null-forming procedure because transmit null-forming is typically more efficient than receive null-forming (e.g., because there are less constraints on the side-lobe suppression that can be achieved on the transmit side). In some designs related to receive null-forming, the received signals on multiple antenna elements may be combined in the first wireless device to effectively create null-forming (e.g., to suppress the signal received in some directions) and hence it is subject to some hardware limitations such as the dynamic range of the low noise amplifiers (LNAs). At516, the first wireless device (e.g., antenna(s)252a. . .252r, modulators254a. . .254r, Tx MIMO processor266, transmit processor264, etc., or antenna(s)234a. . .234r, modulators232a. . .232r, Tx MIMO processor230, transmit processor220, controller/processor240, etc.) optionally reports an indication of the selection of508and/or one or more results associated with the selected null-forming procedure performed at512(and/or514) to a second network entity (e.g., same or different from first network entity, possibly to a different logical component of same network entity or of the first wireless device itself). In some designs, the optional reporting at516is triggered periodically or semi-persistently, in response to a request from the network entity, in an event-triggered manner (e.g., the result(s) indicate a new beam configuration for the first wireless device, etc.), or a combination thereof. In some designs, the report at516may indicate the type of null-forming procedure(s) performed (e.g., transmit, receive, iterative, or joint null-forming procedure) at512and/or514. FIG.6illustrates an exemplary process600of wireless communications according to another aspect of the disclosure. The process600ofFIG.6is performed by a first wireless device, which may correspond to BS105or UE115. In contrast to the process500ofFIG.5, the process600ofFIG.6is specific to the scenario where a directional association (e.g., transmit or receive) of a set of beams need not be known prior to execution (e.g., although this is a possibility), and in at least some designs the process600ofFIG.6may facilitate a selection of the directional associations (e.g., transmit or receive) for the set of beams. At602, the first wireless device (e.g., controller/processor240, controller/processor280, etc.) determines null-forming procedure information associated with null-forming at the first wireless device, the null-forming associated with steering a first beam, a second beam, or both, away from one or more external sources of self-interference, the null-forming procedure information (i) based on one or more measurements performed at the first wireless device, (ii) received from a first network entity, or (iii) a combination thereof. The determined null-forming procedure information is dynamic in nature, in contrast to the pre-stored null-forming configuration used in some conventional null-forming procedures. At604, the first wireless device (e.g., controller/processor240, controller/processor280, etc.) optionally determines one of a receive null-forming procedure or a transmit null-forming procedure based on an efficiency metric (e.g., based on which of the receive or transmit null-forming procedure is determined to be likely to be more efficient in terms of null-forming on respective beams). In some designs, this optional determination may factor into a subsequent selection at606with regard to which null-forming procedure(s) to perform (and/or an order in which to perform the null-forming procedure(s)). At606, the first wireless device (e.g., controller/processor240, controller/processor280, etc.) selects, based on the null-forming procedure information, based on the null-forming procedure information, a receive or transmit null-forming procedure on the first beam, a receive or transmit null-forming procedure on the second beam, or a combination thereof. In some designs, the selected null-forming procedure may comprise a receive null-forming procedure only (e.g., with an optional transmit null-forming procedure being performed later for iterative execution), a transmit null-forming procedure only (e.g., with an optional receive null-forming procedure being performed later for iterative execution), or a joint receive/transmit null-forming procedure. In some designs, the selection at606may be based at least in part upon historical measurement information at the first wireless device. For example, the first wireless device may have some prior information related to measurements or detection of clutter echo (e.g., direction/strength) of clutter (e.g., which may likewise impact the optional determination at604). In some designs, the selection at606is based on the optional determination at604. In some designs, the selection of606may be limited in part by a beam-specific null-forming procedure capacity of the first wireless device (e.g., only select beam-specific null-forming procedures known to be supported by the first wireless device), a directional-specific null-forming procedure capacity of the first wireless device (e.g., only select beam-specific null-forming procedures in a direction that is known to be supported by the first wireless device), or a combination thereof. In some designs, the selection at606may be based on one or more selection criteria received from a second network entity (e.g., which may be the same or different from the first network entity). At608, in some designs, the selected null-forming procedure may comprise a transmit null-forming procedure, which comprises transmitting a plurality of signals on a plurality of different transmit beams (e.g., where the plurality of different transmit beams are spatially QCL'ed), and measuring the plurality of signals on the same receive beam. In an example, at608, the first wireless device (e.g., antenna(s)252a. . .252r, modulators254a. . .254r, Tx MIMO processor266, transmit processor264, etc.) may optionally coordinate with a second wireless device to facilitate the second wireless device to perform one or more measurements in association with one or more transmissions by the first wireless device in association with the transmit null-forming procedure. For example, to facilitate the optional coordination at608, the first wireless device may transmit an indication of one or more resources or configurations associated with the transmission of the plurality of signals. As an example, this optional coordination may facilitate the second wireless device to measure the signal(s) (e.g., for power control, for positioning, etc.). Hence, a null-forming procedure need not be performed strictly for the purpose of null-forming, but can rather be opportunistically leveraged to facilitate other functions as well. At610, the first wireless device (e.g., antenna(s)252a. . .252r, demodulators254a. . .254r, Rx MIMO processor256, receive processor258, etc., and/or antenna(s)252a. . .252r, modulators254a. . .254r, Tx MIMO processor266, transmit processor264, etc.) performs the selected null-forming procedure. As noted above, the selected null-forming procedure may comprise a receive null-forming procedure on the first beam only, or a transmit null-forming procedure on the first beam only, a receive null-forming procedure on the second beam only, a transmit null-forming procedure on the second beam only, or a receive null-forming procedure on the first beam and the transmit null-forming procedure to be performed jointly, or a receive null-forming procedure on the first beam and a transmit null-forming procedure to be performed iteratively. At612, the first wireless device (e.g., controller/processor240, controller/processor280, etc.) optionally selects based on one or more results associated with the performed null-forming procedure(s) from610, the first beam as a receive beam and the second beam as a transmit beam, or the second beam as the receive beam and the first beam as the transmit beam. For example, if receive null-forming on one of the beams is determined to be more successful than transmit null-forming on that same beam, then that beam may be selected as a receive beam and the other beam may be selected as a transmit beam. Alternatively, if transmit null-forming on one of the beams is determined to be more successful than receive null-forming on that same beam, then that beam may be selected as a transmit beam and the other beam may be selected as a receive beam. At614, the first wireless device (e.g., antenna(s)252a. . .252r, modulators254a. . .254r, Tx MIMO processor266, transmit processor264, etc., or antenna(s)234a. . .234r, modulators232a. . .232r, Tx MIMO processor230, transmit processor220, controller/processor240, etc.) optionally reports an indication of the selection of606and/or one or more results associated with the selected null-forming procedure performed at606and/or the optional selection at612to a second network entity (e.g., same or different from first network entity, possibly to a different logical component of same network entity or of the first wireless device itself). In some designs, the optional reporting at614is triggered periodically or semi-persistently, in response to a request from the network entity, in an event-triggered manner (e.g., the result(s) indicate a new beam configuration for the first wireless device, etc.), or a combination thereof. In some designs, the report at614may indicate the type of null-forming procedure(s) performed (e.g., transmit, receive, iterative, or joint null-forming procedure) at610, and/or the optional beam directional associations selected at612. Referring toFIGS.5-6, in some designs, as noted above, the selected null-forming procedure may comprise a receive null-forming procedure. The receive null-forming procedure may comprise transmission, by the first wireless device, of a plurality of signals on the same transmit beam, and measuring, by the first wireless device, the plurality of signals on a plurality of different receive beams. In an example, the plurality of different receive beams may be spatially QCL'ed (e.g., QCL'd type D). Referring toFIGS.5-6, in some designs, as noted above, the selected null-forming procedure may comprise a transmit null-forming procedure. The transmit null-forming procedure may comprise transmission, by the first wireless device, of a plurality of signals on a plurality of different transmit beams, and measuring, by the first wireless device, of the plurality of signals on the same receive beam. In an example, the plurality of different transmit beams may be spatially QCL'ed (e.g., QCL'd type D). Referring toFIGS.5-6, in some designs, as noted above, the at least one null-forming procedure may comprise a transmit null-forming procedure and a receive null-forming procedure. In some designs, the transmit null-forming procedure and the receive null-forming procedure are performed iteratively (e.g., one after the other, with the latter null-forming procedure being conditionally performed based on one or more results from the first null-forming procedure). For example, if the initial null-forming procedure provides sufficient results, then another null-forming procedure may not be necessary. In other designs, the transmit null-forming procedure and the receive null-forming procedure are performed jointly (e.g., concurrently). In accordance with a joint null-forming procedure (e.g., transmission and measurements over multiple self-interference (SI) resources with different choices of transmit and receive beams associated with, e.g., spatially QCL'd, with a pair of prior transmit and receive beams). Referring toFIGS.5-6, in some designs, as noted above, the selection at508ofFIG.5or606ofFIG.6may be based upon historical measurement information at the first wireless device, such as measurements or detection of clutter echo (e.g., direction/strength) of clutter. In a specific example, the first wireless device may use the historical measurement information to select one or multiple choices of null-formed beams (e.g., associated with either or both of the original beams) for further self-interference measurements and/or down-selection. In another specific example, the first wireless device may determine which of the two original beams can achieve a more efficient null-forming performance. For example, assume that the first wireless device determines that receive null-forming is more efficient on the second beam. In this case, the first wireless device may start with receive null-forming on the second beam. If sufficient self-interference mitigation is achieved based on the receive null-forming on the second beam, then the null-forming on the second beam can stop. However, if sufficient self-interference mitigation is achieved based on the receive null-forming on the second beam, then the null-forming can continue with transmit null-forming on the second beam and/or null-forming of the first beam (e.g., iterative mode). For example, with reference toFIGS.4A-4B, the main lobe of one beam (e.g., the first beam) may partially excite clutter C2, for which proper transmit null-forming cannot be achieved. In this case, the first beam (e.g., left-side ofFIGS.4A-4B) may be dynamically switched (or selected) as a receive beam rather than a transmit beam. Referring toFIGS.5-6, in some designs, another entity (e.g., a network entity, parent node, control node, etc.) may provide the first wireless device with various configuration information, including but not limited to:an instruction specifying the null-forming selection to be made at508ofFIG.5or606ofFIG.6,an indication that the first wireless device is responsible for making the null-forming selection to be made at508ofFIG.5or606ofFIG.6(e.g., which may later be indicated to the network entity at516ofFIG.5or614ofFIG.6), oran express assignment of a directional association (e.g., transmit or receive) to adopt on which beam (e.g., first beam or second beam or both), ora desired quality threshold to be achieved (e.g., threshold on SI-RSRP, or SINR), based on which the first wireless device may decide its mode on respective beam(s), orany combination thereof. FIG.7is a conceptual data flow diagram700illustrating the data flow between different means/components in exemplary apparatuses702and780in accordance with an aspect of the disclosure. The apparatus702may be a wireless device (e.g., BS105or UE115) in communication with an apparatus780, which may be a network device (e.g., BS105, such as a different logical component of BS105in a scenario where the wireless device702corresponds to BS105, or another network entity such as network controller130). The apparatus702includes a transmission component704, which may correspond to transmitter circuitry in BS105or UE115as depicted inFIG.2, including controller/processor280, antenna(s)252a. . .252r, modulators(s)254a. . .254r, TX MIMO processor266, TX processor264, or antenna(s)234a. . .234r, modulators232a. . .232r, Tx MIMO processor230, transmit processor220, controller/processor240, etc. The apparatus702further includes null-forming component706, which may correspond to processor circuitry in BS105or UE115as depicted inFIG.2, including controller/processor240, controller/processor280, etc. The apparatus702further includes a reception component708, which may correspond to receiver circuitry in BS105or UE115as depicted inFIG.2, including controller/processor280, antenna(s)252a. . .252r, demodulators(s)254a. . .254r, MIMO detector256, RX processor258, or antenna(s)234a. . .234r, demodulators232a. . .232r, Rx MIMO processor236, receive processor238, etc. The apparatus780includes a reception component782, which may correspond to receiver circuitry in BS105or network device130as depicted inFIG.2, including controller/processor240, antenna(s)234a. . .234r, demodulators(s)232a. . .232r, MIMO detector236, RX processor238, communication unit246, or communication unit294. The apparatus780further includes an optional null-forming control component784, which may correspond to processor circuitry in BS105or network device130as depicted inFIG.2, including controller/processor240or controller/processor290. The apparatus780further includes a transmission component786, which may correspond to transmission circuitry in BS105or network device130as depicted inFIG.2, including e.g., controller/processor240, antenna(s)234a. . .234r, modulators(s)232a. . .232r, Tx MIMO processor230, TX processor220, communication unit246, or communication unit294. Referring toFIG.7, the transmission component704optionally transmits null-forming procedure information to the reception component708, which may then be factored into a null-forming procedure selection by the null-forming component706. This aspect is optional because the null-forming procedure information may at least partially be derived by the null-forming component706itself (e.g., based on historical measurement information at the apparatus702). The null-forming component706directs the transmission component704and the reception component786to perform null-forming procedure(s) which involve transmission of null-forming signals, which may be measured by the reception component708and may optionally be measured at the reception component782as well via optional coordination that is facilitated by optional transmission of a null-forming indication from the transmission component704to the reception component782. The transmission component704optionally transmits null-forming procedure selection information (e.g., which null-forming procedure(s) were performed on which beam(s)) and/or result(s) associated with the null-forming procedure(s). One or more components of the apparatus702and apparatus780may perform each of the blocks of the algorithm in the aforementioned flowcharts ofFIGS.5-6. As such, each block in the aforementioned flowcharts ofFIGS.5-6may be performed by a component and the apparatus702and apparatus780may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. FIG.8is a diagram800illustrating an example of a hardware implementation for an apparatus702employing a processing system814. The processing system814may be implemented with a bus architecture, represented generally by the bus824. The bus824may include any number of interconnecting buses and bridges depending on the specific application of the processing system814and the overall design constraints. The bus824links together various circuits including one or more processors and/or hardware components, represented by the processor804, the components704,706and708, and the computer-readable medium/memory806. The bus824may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. The processing system814may be coupled to a transceiver810. The transceiver810is coupled to one or more antennas820. The transceiver810provides a means for communicating with various other apparatus over a transmission medium. The transceiver810receives a signal from the one or more antennas820, extracts information from the received signal, and provides the extracted information to the processing system814, specifically the reception component708. In addition, the transceiver810receives information from the processing system814, specifically the transmission component704, and based on the received information, generates a signal to be applied to the one or more antennas820. The processing system814includes a processor804coupled to a computer-readable medium/memory806. The processor804is responsible for general processing, including the execution of software stored on the computer-readable medium/memory806. The software, when executed by the processor804, causes the processing system814to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory806may also be used for storing data that is manipulated by the processor804when executing software. The processing system814further includes at least one of the components704,706and708. The components may be software components running in the processor804, resident/stored in the computer readable medium/memory806, one or more hardware components coupled to the processor804, or some combination thereof. The processing system814may be a component of the BS105or UE115ofFIG.2and may include the memory242or282, and/or at least one of the TX processor220or264, the RX processor238or258, and the controller/processor240or280. In one configuration, the apparatus702(e.g., a UE or BS) for wireless communication includes means for determining that a first beam of the first wireless device is associated with a receive direction and that a second beam is associated with a transmit direction, means for determining null-forming procedure information associated with null-forming at the first wireless device, the null-forming associated with steering the first beam, the second beam, or both, away from one or more external sources of self-interference, the null-forming procedure information (i) based on one or more measurements performed at the first wireless device, (ii) received from a first network entity, or (iii) a combination thereof, means for selecting, based on the null-forming procedure information, a receive null-forming procedure on the first beam, a transmit null-forming procedure on the second beam, or a combination thereof, and means for performing the selected null-forming procedure. In another configuration, the apparatus702(e.g., a UE or BS) for wireless communication includes means for determining null-forming procedure information associated with null-forming at the first wireless device, the null-forming associated with steering a first beam, a second beam, or both, away from one or more external sources of self-interference, the null-forming procedure information (i) based on one or more measurements performed at the first wireless device, (ii) received from a first network entity, or (iii) a combination thereof, means for selecting, based on the null-forming procedure information, a receive or transmit null-forming procedure on the first beam, a receive or transmit null-forming procedure on the second beam, or a combination thereof, and means for performing the selected null-forming procedure. The aforementioned means may be one or more of the aforementioned components of the apparatus702and/or the processing system814of the apparatus702configured to perform the functions recited by the aforementioned means. As described supra, the processing system814may include the memory242or282, and/or at least one of the TX processor220or264, the RX processor238or258, and the controller/processor240or280. Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps (e.g., the logical blocks inFIGS.5-6) described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. Skilled artisans will also readily recognize that the order or combination of components, methods, or interactions that are described herein are merely examples and that the components, methods, or interactions of the various aspects of the present disclosure may be combined or performed in ways other than those illustrated and described herein. The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In the detailed description above it can be seen that different features are grouped together in examples. This manner of disclosure should not be understood as an intention that the example clauses have more features than are explicitly mentioned in each clause. Rather, the various aspects of the disclosure may include fewer than all features of an individual example clause disclosed. Therefore, the following clauses should hereby be deemed to be incorporated in the description, wherein each clause by itself can stand as a separate example. Although each dependent clause can refer in the clauses to a specific combination with one of the other clauses, the aspect(s) of that dependent clause are not limited to the specific combination. It will be appreciated that other example clauses can also include a combination of the dependent clause aspect(s) with the subject matter of any other dependent clause or independent clause or a combination of any feature with other dependent and independent clauses. The various aspects disclosed herein expressly include these combinations, unless it is explicitly expressed or can be readily inferred that a specific combination is not intended (e.g., contradictory aspects, such as defining an element as both an insulator and a conductor). Furthermore, it is also intended that aspects of a clause can be included in any other independent clause, even if the clause is not directly dependent on the independent clause. Implementation examples are described in the following numbered clauses: Clause 1. A method of operating a first wireless device, comprising: determining that a first beam of the first wireless device is associated with a receive direction and that a second beam is associated with a transmit direction; determining null-forming procedure information associated with null-forming at the first wireless device, the null-forming associated with steering the first beam, the second beam, or both, away from one or more external sources of self-interference, the null-forming procedure information (i) based on one or more measurements performed at the first wireless device, (ii) received from a first network entity, or (iii) a combination thereof; selecting, based on the null-forming procedure information, a receive null-forming procedure on the first beam, a transmit null-forming procedure on the second beam, or a combination thereof; and performing the selected null-forming procedure. Clause 2. The method of clause 1, wherein the first wireless device corresponds to a user equipment (UE), or wherein the first wireless device corresponds to a base station. Clause 3. The method of any of clauses 1 to 2, wherein the selecting selects the receive null-forming procedure as the selected null-forming procedure. Clause 4. The method of clause 3, further comprising: determining to initiate the transmit null-forming procedure on the second beam after the receive null-forming procedure on the first beam has at least started. Clause 5. The method of any of clauses 1 to 4, wherein the selecting selects the transmit null-forming procedure as the selected null-forming procedure. Clause 6. The method of clause 5, further comprising: determining to initiate the receive null-forming procedure on the first beam after the transmit null-forming procedure on the second beam has at least started. Clause 7. The method of any of clauses 5 to 6, further comprising: coordinating with a second wireless device to facilitate the second wireless device to perform one or more measurements in association with one or more transmissions by the first wireless device in association with the transmit null-forming procedure. Clause 8. The method of any of clauses 1 to 7, wherein the selecting is based at least in part upon historical measurement information at the first wireless device. Clause 9. The method of any of clauses 1 to 8, further comprising: determining, prior to the selecting, one of the receive null-forming procedure or the transmit null-forming procedure based on an efficiency metric, wherein the selecting selects the null-forming procedure determined to be more efficient as the selected null-forming procedure. Clause 10. The method of any of clauses 1 to 9, wherein the selecting is limited in part by a beam-specific null-forming procedure capacity of the first wireless device, a directional-specific null-forming procedure capacity of the first wireless device, or a combination thereof. Clause 11. The method of any of clauses 1 to 10, wherein the selecting is based on one or more selection criteria received from a second network entity. Clause 12. The method of any of clauses 1 to 11, further comprising: reporting an indication of the selection and/or one or more results associated with the selected null-forming procedure to a second network entity. Clause 13. A method of operating a first wireless device, comprising: determining null-forming procedure information associated with null-forming at the first wireless device, the null-forming associated with steering a first beam, a second beam, or both, away from one or more external sources of self-interference, the null-forming procedure information (i) based on one or more measurements performed at the first wireless device, (ii) received from a first network entity, or (iii) a combination thereof; selecting, based on the null-forming procedure information, a receive or transmit null-forming procedure on the first beam, a receive or transmit null-forming procedure on the second beam, or a combination thereof; and performing the selected null-forming procedure. Clause 14. The method of clause 13, further comprising: selecting, based on one or more results associated with the performing: the first beam as a receive beam and the second beam as a transmit beam, or the second beam as the receive beam and the first beam as the transmit beam. Clause 15. The method of any of clauses 13 to 14, wherein the first wireless device corresponds to a user equipment (UE), or wherein the first wireless device corresponds to a base station. Clause 16. The method of any of clauses 13 to 15, wherein the selecting selects the receive null-forming procedure on the first beam only, or wherein the selecting selects the transmit null-forming procedure on the first beam only, or wherein the selecting selects the receive null-forming procedure on the second beam only, or wherein the selecting selects the transmit null-forming procedure on the second beam only, or wherein the selecting the selects the receive null-forming procedure on the first beam and the transmit null-forming procedure to be performed jointly, or wherein the selecting the selects the receive null-forming procedure on the first beam and the transmit null-forming procedure to be performed iteratively. Clause 17. The method of any of clauses 13 to 16, further comprising: coordinating with a second wireless device to facilitate the second wireless device to perform one or more measurements in association with one or more transmissions by the first wireless device in association with the performing. Clause 18. The method of any of clauses 13 to 17, wherein the selecting is based at least in part upon historical measurement information at the first wireless device. Clause 19. The method of any of clauses 13 to 18, further comprising: determining, prior to the selecting, one of the receive null-forming procedure or the transmit null-forming procedure based on an efficiency metric, wherein the selecting is performed for the respective beams based on which null-forming procedure is determined to be more efficient as the selected null-forming procedure. Clause 20. The method of any of clauses 13 to 19, wherein the selecting is limited in part by a beam-specific null-forming procedure capacity of the first wireless device, directional-specific null-forming procedure capacity of the first wireless device, or a combination thereof. Clause 21. The method of any of clauses 13 to 20, wherein the selecting is based on one or more selection criteria received from a second network entity. Clause 22. The method of any of clauses 13 to 21, further comprising: reporting an indication of the selection and/or one or more results associated with the performing to a second network entity Clause 23. An apparatus comprising a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, the memory, the at least one transceiver, and the at least one processor configured to perform a method according to any of clauses 1 to 22. Clause 24. An apparatus comprising means for performing a method according to any of clauses 1 to 22. Clause 25. A non-transitory computer-readable medium storing computer-executable instructions, the computer-executable comprising at least one instruction for causing a computer or processor to perform a method according to any of clauses 1 to 22. The steps of a method or algorithm described in connection with the disclosure herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. In one or more exemplary designs, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. Computer-readable storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, a connection may be properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL), then the coaxial cable, fiber optic cable, twisted pair, or DSL, are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), hard disk, solid state disk, and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. As used herein, including in the claims, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) or any of these in any combination thereof. The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | 79,943 |
11943021 | While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the present disclosure to the particular forms disclosed, but on the contrary, the intention of the present disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure. Note that corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS Examples of the present disclosure will now be described more fully with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be implemented in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known structures, and well-known technologies are not described in detail. The UE (User Equipment) according to the present disclosure includes but not limited to a terminal having a wireless communication function such as a mobile terminal, a computer, a vehicle equipment and the like. Further, the UE according to the present disclosure may further be UE itself or a component therein such as a chip. In addition, the base station according to the present disclosure may be, for example, eNB (evolution Node Base Station) or a component in the eNB such as the chip. TXRU (transceiver unit) is a radio transceiver unit with an independent phase and amplitude.FIG.1andFIG.2illustrate two examples of a relationship between a TXRU and an antenna. InFIG.1andFIG.2, q is a Tx signal vector at M same polarization antenna units in one column, w and W are wideband TXRU virtual weight vector and matrix respectively, x is TXRU signal vector at MTXRUTXRUs. The parameter MTXRUindicates the number of TXRUs in each dimension of a polarization direction of each column in the antenna array. In 2D antenna array, the number of antennas may be represented by (M, N, P), where M is the number of antennas having a same polarization direction in each column, N is the number of columns of the antenna array, and P is the number of dimension of antenna polarization direction.FIG.3illustrates cross-polarized 2D antenna array. As shown inFIG.3, the antenna array includes multiple antenna units which are in M rows and N columns and have a two-dimension polarization direction. In the antenna unit as shown inFIG.3, one polarization direction is represented by a solid line, and another polarization direction is represented by a dotted line. In conjunction with a conception of TXRU, the number of antennas (M, N, P) may be converted into the number of TXRUs (MTXRU, N, P). A value of MTXRUis agreed on in the field of wireless communication technology currently. Further, setting of TXRU is also agreed on in the field of wireless communication technology currently, as shown in Table 1. TABLE 1antenna configuration structureN = 1N = 2N = 4M = 84TXRU (1D)8TXRU (1D/2D)8TXRU (2D)16TXRU (2D)32TXRU (2D)64TXRU (2D)M = 48TXRU (1D/2D)16TXRU (2D)32TXRU (2D) As can be seen from Table 1 that, there are multiple combinations of antenna arrays in 3D MIMO (3-Dimension Multiple-Input Multiple-Output) system. Moreover, the number of TXRUs may be changed from 4 to 64, and same number of TXRUs corresponds to different antenna configurations. Different antenna configurations result in different features of physical channels, in this case, the base station should select different codebooks to reflect the feature of the physical channels. In addition, different antenna configurations may affect a manner of transmitting a reference signal by a base station and a manner of a UE measuring and feeding back the feature of a wireless channel. Hence, in order to improve transmission efficiency, it is necessary to notify the antenna configuration of the base station to the UE. Hence, the disclosure proposes a new base-station-to-UE antenna configuration transmission design to serve for 2D antenna array and 3D MIMO system. FIG.4illustrates a structure of an electronic device400in a wireless communication system according to an embodiment of the present disclosure. As shown inFIG.4, the electronic device400may include a processing circuit410. It is to be noted that, the electronic device400may either include one processing circuit410or multiple processing circuits410. Additionally, the electronic device400may further include an antenna array420, a communication unit430and the like. The processing circuit410may be configured to execute the operation of: determining a corresponding TXRU configuration based on an antenna array420corresponding to the electronic device400. As mentioned above, each TXRU is related to a group of antenna units having a same polarization direction, the antenna array includes multiple antenna units which are in M rows and N columns and have a P-dimension polarization direction, where M, N and P are natural numbers. It may be realized by those skilled in the art that, the processing circuit410may include various discrete functional units to perform a variety of different functions and/or operations. It is to be noted that these functional units may be physical entities or logical entities, and different units may be implemented by the same physical entity. For example, the processing circuit410may include a determination unit (not shown in the drawings) which can determine a corresponding TXRU configuration based on the antenna array420. Further, processing circuit410may be configured to execute the operation of: adding antenna configuration information into a RRC (Radio Resource Control) signaling for a UE in the wireless communication system, where the antenna configuration information is used to obtain the number of the TXRUs in the antenna array420. Correspondingly, the processing circuit410may include an adding unit (not shown in the drawings) for adding the antenna configuration information into the RRC signaling. With the electronic device400according to an embodiment of the present disclosure, the antenna configuration information may be transmitted via the RRC signaling and used to obtain the number of the TXRUs in the antenna array420. Since notification is performed via the RRC signaling, broadcast resource may be saved, and a UE supporting TXRU transmission is notified and unnecessary analysis of the conventional UE is reduced. Accordingly, effective transmission of TXRU configuration information is implemented. FIG.5illustrates an example of TXRU configuration in an antenna array. As shown inFIG.5, in antenna array configuration (8, 4, 2, 16), the antenna array includes multiple antenna units which are in 8 rows and 4 columns and have a two-dimension polarization direction, and includes 16 TXRUs. It is to be noted that, since same polarization directions in each dashed box belong to same TXRU and the antenna array has a two-dimension polarization direction, each dashed box corresponds to two TXRUs. Similarly, in antenna array configuration (8, 4, 2, 32), the antenna array includes multiple antenna units which are in 8 rows and 4 columns and have a two-dimension polarization direction, and includes 32 TXRUs. In antenna array configuration (8, 4, 2, 64), the antenna array includes multiple antenna units which are in 8 rows and 4 columns and have a two-dimension polarization direction, and includes 64 TXRUs. As can be seen fromFIG.5, in 2D antenna array, the antenna arrays may have different numbers of TXRUs although antenna array configuration (M, N, P) are the same. Hence, effective transmission of TXRU configuration information is necessary. According to a preferred embodiment of the present disclosure, the antenna configuration information may be used to obtain at least information on a parameter MTXRUto indicate the number of TXRUs in each dimension of a polarization direction of each column in the antenna array420. In other words, the parameter MTXRUrefers to the number of TXRUs in each dimension of a polarization direction of each column in the antenna array420. FIG.6illustrates another example of TXRU configuration in an antenna array. As shown inFIG.6, in antenna array configuration (8, 4, 2, 2), the antenna array includes multiple antenna units which are in 8 rows and 4 columns and have a two-dimension polarization direction, and the number of TXRUs in each dimension of a polarization direction of each column in the antenna array is 2. It is to be noted that, since same polarization directions in each dashed box belong to same TXRU and the antenna array has a two-dimension polarization direction, each dashed box corresponds to two TXRUs. Similarly, in antenna array configuration (8, 4, 2, 4), the antenna array includes multiple antenna units which are in 8 rows and 4 columns and have a two-dimension polarization direction, and the number of TXRUs in each dimension of a polarization direction of each column in the antenna array is 4. In antenna array configuration (8, 4, 2, 8), the antenna array includes multiple antenna units which are in 8 rows and 4 columns and have a two-dimension polarization direction, and the number of TXRUs in each dimension of a polarization direction of each column in the antenna array is 8. It is to be noted that, indications of the parameters MTXRU, M, N and P of antenna array configuration may have various sequences so long as the sequence is uniform in advance on both sending and receiving end. A sequence of the parameters in an example ofFIG.6is (M, N, P, MTXRU), and a parameter sequence (MTXRU, M, N, P) is taken as an example in subsequent description. According to a preferred embodiment of the present disclosure, a numerical range of the parameter MTXRUmay at least include 1, 2, 4 and 8 and a value of the parameter MTXRUis less than or equal to a value of the parameter M. The numerical range of the parameter MTXRUand a relationship between the numerical range of the parameter MTXRUand the parameter M can be obtained based on the antenna configuration structure in Table 1. According to a preferred embodiment of the present disclosure, the RRC signaling may contain information on the number of antenna ports usable for a 3D MIMO (3-Dimension Multiple-Input Multiple-Output)/FD MIMO (Full-Dimension Multiple-Input Multiple-Output) system to indicate the number of the TXRUs. Since the number of TXRUs is the same as the number of antenna ports, the information on the number of antenna ports may be used in the 3D MIMO/FD MIMO system to indicate the number of TXRUs in a case that the RRC signaling contains the information. According to a preferred embodiment of the present disclosure, the antenna configuration information may explicitly or implicitly contain information on an antenna configuration parameter. Next, firstly, it is described in detail the case that the antenna configuration information explicitly contains information on an antenna configuration parameter. It is known for the inventor that, as a part of radio resource control information, an antenna notification information unit (antennainfo information elements) is defined in the RRC information unit. A process and a structure of the antenna notification information unit are as follows. --ASN1STARTAntennaInfoCommon ::=SEQUENCE {antennaPortsCountENUMERATED {an1, an2, an4, spare1}}AntennaInfoDedicated ::= SEQUENCE {transmissionModeENUMERATED {tm1, tm2, tm3, tm4, tm4, tm5, tm6,tm7, tm8-v1320},codebookSubsetRestrictionCHOICE {n2TxAntenna-tm3BIT STRING (SIZE (2)),n2TxAntenna-tm3BIT STRING (SIZE (4)),n2TxAntenna-tm4BIT STRING (SIZE (6)),n2TxAntenna-tm4BIT STRING (SIZE (64)),n2TxAntenna-tm5BIT STRING (SIZE (4)),n2TxAntenna-tm5BIT STRING (SIZE (16)),n2TxAntenna-tm6BIT STRING (SIZE (4)),n2TxAntenna-tm6BIT STRING (SIZE (16))} OPTIONAL,-- Cond TMue-TransmitAntennaSelectionCHOICE{releaseNULL,setupENUMERATED {closedLoop, openLoop}}}AntennaInfoDedicated-v1320 ::= SEQUENCE {codebookSubsetRestriction-v1320CHOICE {n2TxAntenna-tm8-r9BIT STRING (SIZE (6)),n4TxAntenna-tm8-r9BIT STRING (SIZE (32))} OPTIONAL-- Cond TM8}AntennaInfoDedicated-r10 ::= SEQUENCE {transmissionMode-r10ENUMERATED {tm1, tm2, tm3, tm4, tm5, tm6, tm7, tm8-v1320,tm9-v1020, tm10-v1130, spare6, spare5, spare4,spare3, spare2, spare1},codebookSubsetRestriction-r10BIT STRING OPTIONAL,-- Cond TMXue-TransmitAntennaSelectionCHOICE{releaseNULL,setupENUMERATED {closedLoop, openLoop}}}AntennaInfoDedicated-v12xx ::=SEQUENCE {alternativeCodebookEnabledFor4TX-r12 ENUMERATED {true} OPTIONAL--Cond TMY}--ASN1STOP It can be seen that, in above antenna notification information unit, contents being notified to a UE include the number of antenna ports, a transmission mode and a corresponding codebook subset restriction. The antenna notification information should be transmitted to the UE in a process that the UE performs random access since the antenna notification information unit is a part of radio resource control (RRC) information unit. The UE transmits RRC connection request signaling to a base station on a random access channel to establish RRC connection in the process that the UE performs random access. Then the base station transmits RRC connection establishment signaling to the UE on a forward access channel including the antenna notification information unit. Additionally, the codebook subset restriction may also be transmitted in CSI-Process information unit. In this case, the codebook subset restriction may still be transmitted in CSI process information unit. Moreover, in order to keep integrity of current antenna notification information unit, it is hoped that only antenna communication information is added without changing existing information unit. According to a preferred embodiment of the present disclosure, the antenna configuration parameter in the antenna configuration information may include one or more of: the parameter MTXRU, a parameter M, a parameter N, a parameter P and a combination thereof. Preferably, the antenna configuration parameter may include the parameter MTXRU, the parameter M, the parameter N and the parameter P. Additionally, according to a preferred embodiment of the present disclosure, the processing circuit410(for example, the adding unit included in the processing circuit410) may add the antenna configuration information into an antenna notification information unit or a CSI-RS (channel state information reference signal) configuration information unit in the RRC signaling. Specifically, for example, a unit called antennaNumberCount may be added into AntennaInfoDedicated-r13. The unit contains four parameters (MTXRU, M, N, P). To meet antenna configuration in Table 1, M may be equal to 4 or 8, N may be equal to 1, 2 or 4, P may be equal to 1 or 2, and a corresponding MTXRUmay be obtained form Table 1. Since the part is new-added content, the unit should occur after conventional content, the changed antenna notification information unit is as follows. ......AntennaInfoDedicated-r13 ::=SEQUENCE {antennaNumberCountMENUMERATED {an4, an8}antennaNumberCountNENUMERATED {an1,an2,an4}antennaNumberCountPENUMERATED {an1,an2}antennaNumberConutMTXRU ENUMERATED{TXRU1,TXRU2,TXRU4,TXRU8}} An actual value of the antenna configuration parameter or a function of the actual value may be represented by a predetermined bit number when the base station notifies the parameters to the UE. For example, the antenna parameters are indicated by 1 bit or 2 bits, or the actual values of the antenna parameters are transmitted. Further, the base station may also transmit the parameters in form of log2(MTXRU, M, N, P) since the antenna parameters are in form of exponential of 2. Moreover, for the parameter sequence (MTXRU, M, N, P), the base station may use a parameter M/MTXRUto replace the parameter MTXRUor M. In this case, the parameter may be transmitted separately in a case that the parameter M/MTXRUis constant in a system, thereby system overhead is reduced. Moreover, in a case that the number of antennas in a TXRU is constant, the UE can obtain the total number of antennas in the system based on the number of TXRUs, thus only two parameters are required to be transmitted in the parameter sequence (M, N, P). Another method for obtaining the number of TXRUs is defining a new part called CSI-RS-Config-r13 in CSI-RS-Config information unit, and the part includes antennaPortsCount-r13. The number of TXRUs can be obtained from the new part since the number of TXRUs is equal to the number of antenna ports. The changed CSI-RS-Config information unit is as follows. CSI-RS-Config-r10 ::=SEQUENCE {......CSI-RS-Config2-r12 ::=SEQUENCE {......CSI-RS-Config-r13 ::=SEQUENCE {csi-RS-r13CHOICH {releaseNULL,setupSEQUENCE {antennaPortsCount-r13ENUMERATED {an4, an8, an16, an32, an64,spare3, spare2, spare1},......}}zeroTxPowerCSI-RS-r13 CHOICH{......} The user can obtain the number of the TXRUs based on antennaPortsCount-r13. Accordingly, in the scheme, the parameter sequence (MTXRU, M, N, P) may be simplified into (M, N, P), and the antenna parameter may be obtained after knowing the number of the TXRUs. Moreover, the parameter sequence (M, N, P) may also be explicitly transmitted in CSI-RS-Config-r13. Next, it is described in detail the case that the antenna configuration information implicitly contains information on an antenna configuration parameter. According to a preferred embodiment of the present disclosure, the processing circuit410(for example, the adding unit included in the processing unit410) may add the antenna configuration information by using a codebook subset restriction in the RRC signaling. More preferably, the processing circuit410(for example, the adding unit included in the processing unit410) may express the antenna configuration information by adding a predetermined bit number into a bit string for selecting a codebook in the codebook subset restriction. Alternatively, the processing circuit410(for example, the adding unit included in the processing unit410) may express the antenna configuration information by adding a codebook index into the codebook subset restriction. Specifically, a new transmission mode is provided in the present disclosure and different antenna configurations are distinguished based on the codebook subset restriction. Firstly, it is provided a new transmission mode for vertical beamforming/FD MIMO system. The new transmission mode defines a codebook subset restriction including information on the number of the antennas and the number of the TXRUs. In the conventional antenna notification information unit, it can be seen that, in codebookSubsetRestriction part, transmission conditions are distinguished based on the number of the antenna ports. Hence, in the new transmission mode, the transmission conditions can still be distinguished based on the number of the antenna ports. It can be said that the transmission conditions are distinguished based on the number of the TXRUs since the number of the antenna ports is equal to the number of the TXRUs. As can be seen from Table 1, the number of the TXRUs may be equal to 4, 8, 16, 32 or 64. Moreover, different antenna configuration states under the same number of TXRUs can be distinguished by adding several bits into a bit string for selecting a codebook. The changed antenna information transmission unit is as follows. AntennaInfoDedicated-r10 ::= SEQUENCE {transmissionMode-r10ENUMERATED {tm1, tm2, tm3, tm4, tm5, tm6, tm7, tm8-v1320,tm9-v1020, tm10-v1130, tm11-v13xx, spare5, spare4,spare3, spare2, spare1 },codebookSubsetRestriction-r10BIT STRING OPTIONAL, -- Cond TMXue-TransmitAntennaSelectionCHOICE{releaseNULL,setupENUMERATED {closedLoop, openLoop}}}......AntennaInfoDedicated-v13xx ::=SEQUENCE {codebookSubsetRestriction-v13xxCHOICE {n4TxAntenna-tm11-r13BIT STRING (SIZE (96)),n8TxAntenna-tm11-r13BIT STRING (SIZE (112)),n16TxAntenna-tm11-r13BIT STRING (SIZE (219)),n32TxAntenna-tm11-r13BIT STRING (SIZE (437)),n64TxAntenna-tm11-r13BIT STRING (SIZE (872)),} OPTIONAL} Several bits are added to front of the bit string to distinguish different antenna configurations since the same number of the TXRUs may correspond to different antenna configurations in Table 1. The UE should extract the added bit based on the number of the antenna ports and determine antenna configuration upon reception of the bit string. It is assumed that a length of a bit string is 96 in a case of 4 antenna ports. Moreover, in Table 1, the number of the added bits is 0 since there is only one antenna configuration in a case of 4 TXRUs. It is assumed that a length of a bit string is 109 in a case of 8 antenna ports. The number of the added bits is 3 since there are 5 antenna configurations for 8 TXRUs in Table 1. For cases of 16, 32 and 64 antenna ports, it is assumed that patterns of organization of bit mapping tables under these three cases are similar to a case of 8 antenna ports, only a scale of the bit mapping table is bigger. It can be seen from Table 1 that, the number of the added bits are 1, 1 and 0 for 16, 32 and 64 antenna ports respectively. Hence, the lengths of bit string corresponding to three cases should be 219, 437 and 872. A relationship between the added bits and the antenna configuration is as shown in Table 2. TABLE 2correspondence between the added bit and antenna configurationantennaadded bit stringconfiguration4 TXRU—(8, 2, 1)8 TXRU000(8, 2, 2)001(8, 4, 1)010(8, 4, 2)011(4, 4, 1)100(4, 4, 2)16 TXRU0(8, 4, 2)1(4, 4, 2)32 TXRU0(8, 4, 2)1(4, 4, 2)64 TXRU—(8, 4, 2) Another method for designing codebook subset restriction is firstly designing a codebook index for distinguishing antenna configurations, then selecting a corresponding code from a bit mapping table of the codebook subset restriction. The changed antenna notification information unit is as follows. AntennaInfoDedicated-r10 ::= SEQUENCE {transmissionMode-r10ENUMERATED {tm1, tm2, tm3, tm4, tm5, tm6, tm7, tm8-v1320,tm9-v1020, tm10-v1130, tm11-v13xx, spare5, spare4, spare3,spare2, spare1},codebookSubsetRestriction-r10BIT STRING OPTIONAL, -- Cond TMXue-TransmitAntennaSelectionCHOICE{releaseNULL,setupENUMERATED {closedLoop, openLoop}}}......AntennaInfoDedicated-v13xx ::=SEQUENCE {codebookSelectionIndex ENUMERATED{index1, index2, index3, index4,index5, index6, spare2, spare1},codebookSubsetRestriction-v13xxCHOICE {n4TxAntenna-tm11-r13BIT STRING (SIZE (96)),n8TxAntenna-tm11-r13BIT STRING (SIZE (109)),n16TxAntenna-tm11-r13BIT STRING (SIZE (218)),n32TxAntenna-tm11-r13BIT STRING (SIZE (436)),n64TxAntenna-tm11-r13BIT STRING (SIZE (872)),} OPTIONAL} In the design, the codebook subset restriction is used to select code rather than distinguishing antenna configurations, hence, the part of adding bit in previous design is no longer needed. In Table 1, there are 6 types of different antenna configurations regardless of the number of TXRUs, hence, there are 6 indexes in codebook selection. A correspondence between the codebook selection index and the antenna configuration is as shown in Table 3. TABLE 3correspondence between codebook selectionindex and antenna configurationcodebook selectionantennaindexconfiguration000(8, 2, 1)001(8, 2, 2)010(8, 4, 1)011(8, 4, 2)100(4, 4, 1)101(4, 4, 2) As described above, selection of antenna configuration and CSI-RS transmission mechanism are different in two schemes. In a first scheme, the parameter sequence (MTXRU, M, N, P) can be obtained directly, the antenna configuration is (M, N, P). Moreover, a total number of the TXRUs is known as (MTXRU×N×P) based on the parameters MTXRUand N, hence, the number of CSI-RSs is (MTXRU×N×P). The CSI-RSs are distributed in MTXRUrows and N columns and a P-dimension polarization direction. However, in a second scheme, the number of the TXRUs may be obtained based on the codebook subset restriction. The antenna configuration may be obtained from Table 2 or Table 3. The number of CSI-RSs NCSI-RS(that is equal to the number of the TXRUs) and distribution of CSI-RSs may be determined based on the total number of the TXRUs and the antenna configuration (M, N, P).FIG.9is an example of 8CSI-RS distributed in 2 rows and 4 columns, which is used for 2D antenna array with the antenna parameters (1, 8, 4, 2), (2, 8, 4, 1), (1, 4, 4, 2) and (2, 4, 4, 1). It is to be noted that, according to an embodiment of the present disclosure, the wireless communication system as described above may be a LTE-A (Long Term Evolution-Advanced) cellular communication system, the electronic device400may be a base station in the wireless communication system, and the electronic device400may further include an antenna array420, a communication unit430and the like. For example, the communication unit430may transmit RRC signaling to a UE in the wireless communication system. The electronic device on a base-station side in the wireless communication system is described as above. Next, an electronic device on a UE side in the wireless communication system is described in detail.FIG.7illustrates a structure of an electronic device700in a wireless communication system according to an embodiment of the present disclosure. As shown inFIG.7, the electronic device700may include a processing circuit710. It is to be noted that, the electronic device700may either include one processing circuit710or multiple processing circuits710. Additionally, the electronic device700may further include a communication unit720and the like. The processing circuit710may extract antenna configuration information from an RRC signaling from a base station in the wireless communication system. As mentioned above, similarly, the processing circuit710may also include various discrete functional units to perform a variety of different functions and/or operations. These functional units may be physical entities or logical entities, and different units may be implemented by the same physical entity. For example, the processing circuit710may include an extraction unit (not shown in the drawings) which may extract antenna configuration information from an RRC signaling from a base station in the wireless communication system. As mentioned above, the antenna configuration information may be used to obtain the number of TXRUs in an antenna array of the base station. Similarly, each TXRU is related to a group of antenna units having a same polarization direction, the antenna array includes multiple antenna units which are in M rows and N columns and have a P-dimension polarization direction, where M, N and P are natural numbers. Preferably, the antenna configuration information may be used to obtain at least information on a parameter MTXRUto indicate the number of TXRUs in each dimension of a polarization direction of each column in the antenna array. Preferably, a numerical range of the parameter MTXRUat least includes 1, 2, 4 and 8 and a value of the parameter MTXRUis less than or equal to a value of a parameter M. Preferably, the processing circuit710(for example, an extraction unit included in the processing circuit710) may further extract, from the RRC signaling, information on the number of antenna ports usable for a 3D MIMO/FD MIMO system to determine the number of the TXRUs. Preferably, the antenna configuration parameter may include the parameter MTXRU, a parameter M, a parameter N and a parameter P. Preferably, the processing circuit710may decode at least one of an antenna notification information unit, a CSI-RS configuration information unit and a codebook subset restriction information unit in the RRC signaling to obtain the antenna configuration information. Correspondingly, the processing circuit710may include a parsing unit (not shown in the drawings) which can execute the preceding parsing operation. Preferably, the processing circuit710may select at least one of a CSI (channel state information) feedback codebook and a CSI feedback scheme based on the antenna configuration information. More preferably, the processing circuit710may select both of a CSI feedback codebook and a CSI feedback based on the antenna configuration information. Correspondingly, the processing circuit710may include a selection unit (not shown in the drawings) which can execute the preceding selection operation. It is to be noted that, according to an embodiment of the present disclosure, the wireless communication system as described above may be a LTE-A cellular communication system, the electronic device700may be a UE in the wireless communication system, and the electronic device700may further include a receiver (for example, the communication unit720) to receive the RRC signaling. The electronic device in the wireless communication system according to an embodiment of the present disclosure is described as above. Next, a method for performing wireless communication in a wireless communication system according to an embodiment of the present disclosure is described in detail. The method for performing wireless communication in a wireless communication system according to an embodiment of the present disclosure may include: determining a corresponding TXRU configuration based on an antenna array corresponding to an electronic device in the wireless communication system, where each TXRU is related to a group of antenna units having a same polarization direction, the antenna array includes multiple antenna units which are in M rows and N columns and have a P-dimension polarization direction, where M, N and P are natural numbers. The method may further include adding antenna configuration information into a RRC signaling for a user equipment in the wireless communication system, where the antenna configuration information is used to obtain the number of TXRUs in the antenna array. Preferably, the antenna configuration information may be used to obtain at least information on a parameter MTXRUto indicate the number of TXRUs in each dimension of a polarization direction of each column in the antenna array. Preferably, a numerical range of the parameter MTXRUat least includes 1, 2, 4 and 8 and a value of the parameter MTXRUis less than or equal to a value of a parameter M. Preferably, the RRC signaling may contain information on the number of antenna ports usable for a 3D MIMO/FD MIMO system to indicate the number of the TXRUs. Preferably, the antenna configuration information may explicitly contain information on an antenna configuration parameter. Preferably, the antenna configuration parameter may include one or more of: the parameter MTXRU, a parameter M, a parameter N, a parameter P and a combination thereof. More preferably, the antenna configuration parameter may include the parameter MTXRU, the parameter M, the parameter N and the parameter P. Preferably, the antenna configuration information may be added into an antenna notification information unit or a CSI-RS configuration information unit in the RRC signaling. Preferably, an actual value of the antenna configuration parameter or a function of the actual value may be represented by a predetermined bit number. Preferably, the antenna configuration information may implicitly contain information on an antenna configuration parameter. Preferably, the antenna configuration information may be added by using a codebook subset restriction in the RRC signaling. Preferably, the antenna configuration information may be expressed by adding a predetermined bit number into a bit string for selecting a codebook in the codebook subset restriction. Preferably, the antenna configuration information may be expressed by adding a codebook index into the codebook subset restriction. In another aspect, a method for performing wireless communication in a wireless communication system according to an embodiment of the present disclosure may include: extracting antenna configuration information from an RRC signaling from a base station in the wireless communication system. As mentioned above, the antenna configuration information may be used to obtain the number of transceiver units TXRUs in an antenna array of the base station, where each TXRU is related to a group of antenna units having a same polarization direction, the antenna array includes multiple antenna units which are in M rows and N columns and have a P-dimension polarization direction, where M, N and P are natural numbers. Preferably, the antenna configuration information may be used to obtain at least information on a parameter MTXRUto indicate the number of TXRUs in each dimension of a polarization direction of each column in the antenna array. Preferably, a numerical range of the parameter MTXRUat least includes 1, 2, 4 and 8 and a value of the parameter MTXRUis less than or equal to a value of a parameter M. Preferably, information on the number of antenna ports usable for a 3D MIMO/FD MIMO system may further be extracted from the RRC signaling, to determine the number of the TXRUs. Preferably, the antenna configuration parameter may include the parameter MTXRU, a parameter M, a parameter N and a parameter P. Preferably, at least one of an antenna notification information unit, a CSI-RS configuration information unit and a codebook subset restriction information unit in the RRC signaling may be decoded to obtain the antenna configuration information. Preferably, at least one of a CSI feedback codebook and a CSI feedback scheme may be selected based on the antenna configuration information. More preferably, both a CSI feedback codebook and a CSI feedback may be selected based on the antenna configuration information. Various specific embodiments of the above steps of a method for performing wireless communication in a wireless communication system is described in detail as above, which is not described here. Next, a signal interaction process between a base-station side and a user side in a wireless communication system according to an embodiment of the present disclosure is described in detail in conjunction withFIG.8. FIG.8is a sequence diagram of a method for performing wireless communication in a wireless communication system according to an embodiment of the present disclosure. As show inFIG.8, in step S101, the user transmits an RRC connection request signaling to a base station to establish RRC connection. In step S102, the base station transmits an RRC connection establishment signaling to the user, which includes an antenna notification information unit and a codebook subset restriction. The base station may select a first scheme or a second scheme to transmit the antenna configuration information during transmission. In the first scheme, the parameter sequence (MTXRU, M, N, P) is transmitted explicitly. In the second scheme, the parameter sequence (MTXRU, M, N, P) may be obtained based on the codebook subset restriction and the added bit or a codebook selection index. In step S103, the user determines CSI feedback scheme and a codebook based on the antenna configuration information. The CSI feedback scheme should be applicable to MTXRU×P×N CSI feedbacks. In step S104, the user transmits an RRC connection establishment complete signaling to the base station. In step S105, the base station transmits CSI-RS to the user. In step S106, the user estimates the channel and calculates CSI feedback information based on the CSI feedback scheme and the codebook. The number of CSI-RSs should be MTXRU×P×N and the user can calculate corresponding CSI feedback information. In step S107, the user transmits the CSI feedback information to the base station. In step S108, the base station obtains the channel feedback and performs radio resource management and pre-encoding. Finally, in step S109, steps S105to S108are repeated. A process from transmitting the CSI-RS signaling to the base station performing radio resource management and pre-encoding may be performed periodically. Next, an operation mode of the present disclosure is described in conjunction with an example in which the base-station antenna configurations are (1, 8, 4, 2) and (2, 4, 4, 1) and the base station transmits 8 CSI-RS by using 8 antenna ports inFIG.9. In a case of the antenna configuration being (1, 8, 4, 2), it is assumed that the antenna configuration is transmitted explicitly by using the first scheme. In AntennaInfoDedicated-r13, values corresponding to the antenna configuration parameters should be as follows: antennaNumberCountM=8, antennaNumberCountN=4, antennaNumberCountP=2, antennaNumberCountMTXRU=1. The base station transmits the parameter values to the user so that the user can obtain that the antenna configuration of the base station is (1, 8, 4, 2), and the signalings are as follows. ......AntennaInfoDedicated-r13 ::=SEQUENCE {antennaNumberCountM8antennaNumberCountN4antennaNumberCountP2antennaNumberConutMTXRU1} Similarly, signaling being transmitted by the base station are as follows in a case that the antenna configuration is (2, 4, 4, 1). ......AntennaInfoDedicated-r13 ::=SEQUENCE {antennaNumberCountM4antennaNumberCountN4antennaNumberCountP1antennaNumberConutMTXRU2} Alternatively, the base station selects the second scheme to transmit the antenna configuration implicitly. The base station should select to transmit n8TXAntenna-tm11-r13 in codebooksubsetrestriction-v13xx since the number of the antenna ports of the base station is 8. Since the antenna configuration parameter is (8, 4, 2), based on Table 2, in a case of 8TXRU, the added bits should be 010 (or a codebook selection index is used, and in this case the index should be 011). Accordingly, the user can determine that the antenna parameter configuration is (8, 4, 2) based on the information. And the user has obtained that the number of the TXRUs of the base station is 8, and the user can know that an overall antenna configuration of the base station is (1, 8, 4, 2). The signaling are as follows. AntennaInfoDedicated-r10 ::= SEQUENCE {transmissionMode-r10ENUMERATEDtm1, tm2, tm3, tm4, tm5, tm6, tm7, tm8-v1320,tm9-v1020, tm10-v1130, tm11-v13xx, spare5, spare4,spare3, spare2, spare1},codebookSubsetRestriction-r10BIT STRING OPTIONAL,--Cond TMXue-TransmitAntennaSelectionCHOICE{releaseNULL,setupENUMERATED {closedLoop, openLoop}}}......AntennaInfoDedicated-v13xx ::=SEQUENCE {codebookSubsetRestriction-v13xxCHOICE{n8TxAntenna-tm11-r13BIT STRING (SIZE (112)),} OPTIONAL} Similarly, the added bits should be 011 (or a codebook selection index is used, and in this case the index should be 110) in a case that the antenna configuration is (2, 4, 4, 1), the signaling being transmitted by the base station are as follows. AntennaInfoDedicated-r10 ::= SEQUENCEtransmissionMode-r10ENUMERATED {tm1, tm2, tm3, tm4, tm5, tm6, tm7, tm8-v1320,tm9-v1020, tm10-v1130, tm11-v13xx, spare5, spare4,spare3, spare2, spare1},codebookSubsetRestriction-r10BIT STRING OPTIONAL,--Cond TMXue-TransmitAntennaSelectionCHOICE{releaseNULL,setupENUMERATED {closedLoop, openLoop}}}......AntennaInfoDedicated-v13xx ::=SEQUENCE {codebookSubsetRestriction-v13xxCHOICE {n8TxAntenna-tm11-r13BIT STRING (SIZE (112)),} OPTIONAL} The user selects a corresponding codebook to perform CSI feedback upon reception of such two antenna configurations of base station. In a case that the antenna configuration on a base-station side is (1, 8, 4, 2), for example, the user equipment determines that there are 8 TXRUs in a same horizontal direction, which is the same as the assumed antenna configuration of current Rel-12, and the user equipment selects to use a codebook of 8 antenna ports in TM10, that is codebook(1,8,4,2)=codebook8-tm10 Correspondingly, the user equipment feeds back a code index being selected from the codebook (for example, PMI) to the base station. In a case that the antenna configuration on the base-station side is (2, 4, 4, 1), for example, the user equipment determines that there are two sets of TXRUs with different heights. Each set contains 4 TXRUs corresponding to 4 antenna ports, thus two sets of codebooks of 4 antenna ports are selected. Further, since two sets of TXRUs have offset phase due to height difference. The two sets of codebooks have relevance, for example, the user equipment takes a codebook of 4 antenna ports in TM 10 as a first set of codebook, and obtains a second set of codebook by adding oddest phase θ to a code in the codebook of 4 antenna ports in TM10, that is codebook(2,4,4,1)=(codebook4-tm10codebook4-tm10ejθ) correspondingly, the user equipment feeds back the code index being selected from the above codebook (for example, PMI) and the offset phase to the base station. As can be seen that, the user selects different CSI feedback codebooks based on the antenna configuration on the base-station side in a case that antenna configurations especially TXRU configurations on the base-station side are different. Moreover, in the example, in a process of determining the CSI codebook feedback on a user side, the user actually uses two parameters of MTXRUand the number of ports on the base-station side. The base-station side only needs to transmit MTXRUand N×P signaling without independent information on M, N and P. Moreover, the base station can allow the user to determine a corresponding antenna codebook only by transmitting one of MTXRUand N×P since a total number of TXRUs on the base-station side can be determined based on the number of antenna ports. Hence, in practice, the base station should transmit all or a part of the transmission parameter sequence (MTXRU, M, N, P) to the user, and signaling overhead of the system can be reduced. In practice, the user transmits an RRC connection request signaling to the base station to establish RRC connection, and the base station transmits an RRC connection establishment signaling to the user, in which the base station can select the first scheme or the second scheme as above described to add related information on antenna configuration into the RRC connection establishment signaling. The user determines a scheme and a codebook for CSI feedback based on the received antenna configuration information, then the user transmits an RRC connection establishment complete signaling to the base station. Thereafter, the base station transmits CSI-RS as shown inFIG.9to the user in a case that the base station needs to perform channel estimation. The user performs channel measurement upon reception of the CSI-RS, then determines CSI feedback information based on the determined the scheme and the codebook for CSI feedback and transmits to the base station. The base station completes channel estimation after obtaining CSI feedback, and performs a corresponding radio resource management and pre-encoding. According to an embodiment of the present disclosure, in a new design of antenna configuration notification, the number of antennas and the number of the TXRUs on the base-station side are notified to the UE. Being inspired by the description of the number of antennas and the number of TXRUs in 2D antenna array, the parameter sequence (MTXRU, M, N, P) is enough to notify all antenna configurations to the UE. According to an embodiment of the present disclosure, the antenna configuration information is transmitted from the base station to the UE by using change in the antenna notification information unit and other related information unit, thereby optimizing CSI feedback mechanism in the 3D MIMO system, and improving transmission performance of 3D MIMO system. According to an embodiment of the present disclosure, a user in the 3D MIMO system can determine antenna configuration of the base station. In the 3D MIMO system, an original notification unit used for 1D antenna array information is no longer applicable since a 2D antenna array is used. The antenna notification information unit is necessary in radio resource management. The two schemes according to the present disclosure are applicable to the antenna notification information unit in the 3D MIMO system. According to an embodiment of the present disclosure, CSI feedback flow in the 3D MIMO system can be completed. Original CSI feedback flow is not applicable to the 3D MIMO system since a new perpendicular dimension is introduced into the 3D MIMO system. To implement CSI feedback flow in the 3D MIMO system, the user needs to determine antenna configuration on the base-station side, and an antenna notification mechanism designed according to the present disclosure can realize the objective, thereby completing CSI feedback flow in the 3D MIMO system. According to an embodiment of the present disclosure, the antenna configuration notification scheme according to the present disclosure is a necessary part of the 3D MIMO system, thereby perfecting the 3D MIMO system. According to an embodiment of the present disclosure, the schemes include explicit and implicit modes, and a relationship between antenna configuration parameters to be indicated is taken into full consideration. Hence, the scheme according to the present disclosure has better flexibility, low signaling overhead and small change in standard, and it is easy to extend to use the scheme according to the present disclosure in future different antenna number combinations. The technology of the present disclosure can be applied to various products. For example, the base station mentioned in the present disclosure may be implemented as any type of an evolved node B (eNB), such as a macro eNB and a small eNB. The small eNB may be an eNB which covers a cell smaller than a macro cell, such as a pico eNB, a micro eNB and a home (femto) eNB. Alternatively, the base station may be implemented as any other type of a base station, such as a Node B and a base transceiver station (BTS). The base station may include: a main body (also referred to as a base station device) configured to control the wireless communication, and one or more remote radio header (RRH) provided at a different site from the main body. Further, various types of terminals may be served as a base station by performing the function of the base station temporarily or semi-permanently. For example, the UE mentioned in the present disclosure may be implemented as a mobile terminal (such as an smart phone, a panel personal computer (PC), a notebook PC, a portable game terminal, a portable/dongle mobile router and a digital camera device) or an on-board terminal (such as a car navigation device). The UE may also be implemented as a terminal for performing machine to machine (M2M) communication, which is also referred to as a machine-type communication (MTC) terminal. Further, the UE may be a wireless communication module mounted on each of the above terminals (such as the integrated circuit module including a single chip). FIG.10is a block diagram illustrating a first example of a schematic configuration of an eNB to which the technology according to the present disclosure is applicable. An eNB1000includes one or more antennas1010and a base station device1020. The base station device1020and each antenna1010may be connected with each other via RF cable. Each of the antennas1010includes one or more antenna elements (such as the multiple antenna elements included in the multiple-input multiple-output (MIMO) antenna), and is used for transmitting and receiving the wireless signal by the base station device1020. As show inFIG.10, the eNB1000may include multiple antennas1010. For example, the multiple antennas1010may be compatible with the multiple frequency bands used by the eNB1000. The eNB1000may also include a single antenna1010althoughFIG.10shows an example of the eNB1000including multiple antennas1010. The base station device1020includes a controller1021, a memory1022, a network interface1023and a wireless communication interface1025. For example, the controller1021may be a CPU or DSP, and performs various functions of higher layers of the base station device1020. For example, the controller1021generates a data packet based on the data in the signal processed by the wireless communication interface1025, and transfers the generated packet via the network interface1023. The controller1021may bundle data from multiple baseband processors to generate bundled packet, and transfers the generated bundled packet. The controller1021may have logical function to perform the control such as radio resource control, radio bearer control, mobility management, admission control and scheduling. The control may be performed in conjunction with the neighboring eNB or a core network node. The memory1022includes RAM and ROM, and stores the program to be performed by the controller1021and various types of control data (such as a terminal list, transmission power data and scheduling data). The network interface1023is a communication interface for connecting the base station device1020to the core network1024. The controller1021may communication with the core network node or another eNB via the network interface1023. In this case, the eNB1000and the core network node or other eNB may be connected with each other via a logic interface (such as S1 interface and X2 interface). The network interface1023may also be a wired communication interface or a wireless communication interface for wireless backhaul routing. If the network interface1023is a wireless communication interface, the network interface1023may use a higher frequency band for wireless communication as compared with that used by the wireless communication interface1025. The wireless communication interface1025supports any cellular communication scheme (such as the long term evolution (LTE) and the LTE-Advanced), and provides a wireless connection to a terminal located in the cell of the eNB1000via the antenna1010. The wireless communication interface1025may generally include for example a base band (BB) processor1026and a RF circuit1027. The BB processor1026may perform for example encoding/decoding, modulation/demodulation and multiplexing/de-multiplexing, and performs various types of signal processes of the layer (for example L1, media access control (MAC), radio link control (RLC) and packet data convergence protocol (PDCP)). Instead of the controller1021, the BB processor1026may have some or all of the above logical functions. The BB processor1026may be a memory storing the communication control program, or a module including a processor and related circuit configured to perform the program. The updating program may change the function of the BB processor1026. The module may be a card or blade inserted into the slot of the base station device1020. Alternatively, the module may be a chip mounted on the card or the blade. The RF circuit1027may include for example a mixer, a filter and an amplifier, and transmit and receive the wireless signal via the antenna1010. As shown inFIG.10, the wireless communication interface1025may include multiple BB processors1026. For example, the multiple BB processors1026may be compatible with the multiple frequency bands used by the eNB1000. As shown inFIG.10, the wireless communication interface1025may include multiple RF circuits1027. For example, the multiple RF circuits1027may be compatible with multiple antenna elements. Although an example in which the wireless communication interface1025includes multiple BB processors1026and multiple RF circuits1027is shown inFIG.10, the wireless communication interface1025may include a single BB processor1026and a single RF circuit1027. FIG.11is a block diagram illustrating a second example of a schematic configuration of an eNB to which the technology according to the disclosure is applicable. An eNB1130includes one or more antennas1140, a base station device1150and a RRH1160. The RRH1160and each antenna1140may be connected with each other via RF cable. The base station device1150and the RRH1160may be connected with each other via a high-speed line such as optical fiber. Each of the antennas1140includes one or more antenna element (such as the multiple antenna elements included in the MIMO antenna), and is used for transmitting and receiving the wireless signal by the RRH1160. As show inFIG.11, the eNB1130may include multiple antennas1140. For example, the multiple antennas1140may be compatible with the multiple frequency bands used by the eNB1130. The eNB1130may also include a single antenna1140althoughFIG.11shows an example of the eNB1130including multiple antennas1140. The base station device1150includes a controller1151, a memory1152, a network interface1153, a wireless communication interface1155and a connection interface1157. The controller1151, the memory1152and the network interface1153are the same as the controller1021, the memory1022and the network interface1023as described inFIG.10. The wireless communication interface1155supports any cellular communication scheme (such as LTE and LTE-Advanced), and provides wireless communication to a terminal positioned in a sector corresponding to the RRH1160via the RRH1160and the antenna1140. The wireless communication interface1155may typically include, for example, a BB processor1156. The BB processor1156is the same as the BB processor1026described with reference toFIG.10, except that the BB processor1156is connected to the RF circuit1164of the RRH1160via the connection interface1157. The wireless communication interface1155may include the multiple BB processors1156, as illustrated inFIG.11. For example, the multiple BB processors1156may be compatible with multiple frequency bands used by the eNB1130. AlthoughFIG.11illustrates the example in which the wireless communication interface1155includes the multiple BB processors1156, the wireless communication interface1155may also include a single BB processor1156. The connection interface1157is an interface for connecting the base station device1150(wireless communication interface1155) to the RRH1160. The connection interface1157may also be a communication module for communication in the above-described high speed line that connects the base station device1150(wireless communication interface1155) to the RRH1160. The RRH1160includes a connection interface1161and a wireless communication interface1163. The connection interface1161is an interface for connecting the RRH1160(wireless communication interface1163) to the base station device1150. The connection interface1161may also be a communication module for communication in the above-described high speed line. The wireless communication interface1163transmits and receives wireless signals via the antenna1140. The wireless communication interface1163may typically include, for example, the RF circuit1164. The RF circuit1164may include, for example, a mixer, a filter, and an amplifier, and transmits and receives wireless signals via the antenna1140. The wireless communication interface1163may include multiple RF circuits1164, as illustrated inFIG.11. For example, the multiple RF circuits1164may support multiple antenna elements. AlthoughFIG.11illustrates the example in which the wireless communication interface1163includes the multiple RF circuits1164, the wireless communication interface1163may also include a single RF circuit1164. In the eNB1000and the eNB1130illustrated inFIGS.10and11, the communication unit430described by usingFIG.4may be implemented by the wireless communication interface1025, and the wireless communication interface1155and/or the wireless communication interface1163. At least a part of the functions may also be implemented by the controller1021and the controller1151. FIG.12is a block diagram illustrating an example of a schematic configuration of a smartphone1200to which the technology according to the present disclosure is applicable. The smartphone1200includes a processor1201, a memory1202, a storage1203, an external connection interface1204, a camera1206, a sensor1207, a microphone1208, an input device1209, a display device1210, a speaker1211, a wireless communication interface1212, one or more antenna switches1215, one or more antennas1216, a bus1217, a battery1218, and an auxiliary controller1219. The processor1201may be, for example, a CPU or a system on a chip (SoC), and controls functions of an application layer and another layer of the smartphone1200. The memory1202includes RAM and ROM, and stores a program that is executed by the processor1201and data. The storage1203may include a storage medium such as a semiconductor memory and a hard disk. The external connection interface1204is an interface for connecting an external device (such as a memory card and a universal serial bus (USB) device) to the smartphone1200. The camera1206includes an image sensor (such as a charge coupled device (CCD) and a complementary metal oxide semiconductor (CMOS)), and generates a captured image. The sensor1207may include a group of sensors such as a measurement sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor. The microphone1208converts sounds that are inputted to the smartphone1200to audio signals. The input device1209includes, for example, a touch sensor configured to detect touch on a screen of the display device1210, a keypad, a keyboard, a button, or a switch, and receives an operation or an information inputted from a user. The display device1210includes a screen (such as a liquid crystal display (LCD) and an organic light-emitting diode (OLED) display), and displays an output image of the smartphone1200. The speaker1211converts audio signals that are outputted from the smartphone1200to sounds. The wireless communication interface1212supports any cellular communication scheme (such as LET and LTE-Advanced), and performs wireless communication. The wireless communication interface1212may typically include, for example, a BB processor1213and an RF circuit1214. The BB processor1213may perform, for example, encoding/decoding, modulating/demodulating, and multiplexing/demultiplexing, and performs various types of signal processing for wireless communication. Meanwhile, the RF circuit1214may include, for example, a mixer, a filter, and an amplifier, and transmits and receives wireless signals via the antenna1216. The wireless communication interface1212may be a chip module having the BB processor1213and the RF circuit1214integrated thereon. The wireless communication interface1212may include multiple BB processors1213and multiple RF circuits1214, as illustrated inFIG.12. AlthoughFIG.12illustrates the example in which the wireless communication interface1212includes the multiple BB processors1213and the multiple RF circuits1214, the wireless communication interface1212may also include a single BB processor1213or a single RF circuit1214. Furthermore, in addition to a cellular communication scheme, the wireless communication interface1212may support another type of wireless communication scheme such as a short-distance wireless communication scheme, a near field communication scheme, and a radio local area network (LAN) scheme. In that case, the wireless communication interface1212may include the BB processor1213and the RF circuit1214for each wireless communication scheme. Each of the antenna switches1215switches connection destinations of the antennas1216among multiple circuits (such as circuits for different wireless communication schemes) included in the wireless communication interface1212. Each of the antennas1216includes a single or multiple antenna elements (such as multiple antenna elements included in an MIMO antenna), and is used for the wireless communication interface1212to transmit and receive wireless signals. The smartphone1200may include the multiple antennas1216, as illustrated inFIG.12. AlthoughFIG.12illustrates the example in which the smartphone1200includes the multiple antennas1216, the smartphone1200may also include a single antenna1216. Furthermore, the smartphone1200may include the antenna1216for each wireless communication scheme. In that case, the antenna switches1215may be omitted from the configuration of the smartphone1200. The bus1217connects the processor1201, the memory1202, the storage1203, the external connection interface1204, the camera1206, the sensor1207, the microphone1208, the input device1209, the display device1210, the speaker1211, the wireless communication interface1212, and the auxiliary controller1219to each other. The battery1218supplies power to blocks of the smartphone1200illustrated inFIG.12via feeder lines, which are partially shown as dashed lines in the drawing. The auxiliary controller1219operates a minimum necessary function of the smartphone1200, for example, in a sleep mode. In the smartphone1200illustrated inFIG.12, the communication unit720described by usingFIG.7may be implemented by the wireless communication interface1212. At least a part of the functions may also be implemented by the processor1201or the auxiliary controller1219. FIG.13is a block diagram illustrating an example of a schematic configuration of a car navigation device1320to which the technology according to the present disclosure is applicable. The car navigation device1320includes a processor1321, a memory1322, a global positioning system (GPS) module1324, a sensor1325, a data interface1326, a content player1327, a storage medium interface1328, an input device1329, a display device1330, a speaker1331, a wireless communication interface1333, one or more antenna switches1336, one or more antennas1337, and a battery1338. The processor1321may be, for example, a CPU or a SoC, and controls a navigation function and another function of the car navigation device1320. The memory1322includes RAM and ROM, and stores a program that is executed by the processor1321, and data. The GPS module1324uses GPS signals received from a GPS satellite to measure a position (such as latitude, longitude, and altitude) of the car navigation device1320. The sensor1325may include a group of sensors such as a gyro sensor, a geomagnetic sensor, and an air pressure sensor. The data interface1326is connected to, for example, an in-vehicle network1341via a terminal that is not shown, and acquires data generated by the vehicle, such as vehicle speed data. The content player1327reproduces content stored in a storage medium (such as a CD and a DVD) that is inserted into the storage medium interface1328. The input device1329includes, for example, a touch sensor configured to detect touch on a screen of the display device1330, a button, or a switch, and receives an operation or an information inputted from a user. The display device1330includes a screen such as a LCD or an OLED display, and displays an image of the navigation function or content that is reproduced. The speaker1331outputs sounds of the navigation function or the content that is reproduced. The wireless communication interface1333supports any cellular communication scheme (such as LTE and LTE-Advanced), and performs wireless communication. The wireless communication interface1333may typically include, for example, a BB processor1334and an RF circuit1335. The BB processor1334may perform, for example, encoding/decoding, modulating/demodulating, and multiplexing/demultiplexing, and performs various types of signal processing for wireless communication. Meanwhile, the RF circuit1335may include, for example, a mixer, a filter, and an amplifier, and transmits and receives wireless signals via the antenna1337. The wireless communication interface1333may also be one chip module that has the BB processor1334and the RF circuit1335integrated thereon. The wireless communication interface1333may include multiple BB processors1334and multiple RF circuits1335, as illustrated inFIG.13. AlthoughFIG.13illustrates the example in which the wireless communication interface1333includes the multiple BB processors1334and the multiple RF circuits1335, the wireless communication interface1333may also include a single BB processor1334or a single RF circuit1335. Furthermore, in addition to a cellular communication scheme, the wireless communication interface1333may support another type of wireless communication scheme such as a short-distance wireless communication scheme, a near field communication scheme, and a wireless LAN scheme. In that case, the wireless communication interface1333may include the BB processor1334and the RF circuit1335for each wireless communication scheme. Each of the antenna switches1336switches connection destinations of the antennas1337among multiple circuits (such as circuits for different wireless communication schemes) included in the wireless communication interface1333. Each of the antennas1337includes a single or multiple antenna elements (such as multiple antenna elements included in an MIMO antenna), and is used for the wireless communication interface1333to transmit and receive wireless signals. The car navigation device1320may include multiple antennas1337, as illustrated inFIG.13. AlthoughFIG.13illustrates the example in which the car navigation device1320includes the multiple antennas1337, the car navigation device1320may also include a single antenna1337. Furthermore, the car navigation device1320may include the antenna1337for each wireless communication scheme. In that case, the antenna switches1336may be omitted from the configuration of the car navigation device1320. The battery1338supplies power to blocks of the car navigation device1320illustrated inFIG.13via feeder lines that are partially shown as dashed lines in the drawing. The battery1338accumulates power supplied form the vehicle. In the car navigation device1320illustrated inFIG.13, the communication unit720described by usingFIG.7may be implemented by the wireless communication interface1333. At least a part of the functions may also be implemented by the processor1321. The technology of the present disclosure may also be realized as an in-vehicle system (or a vehicle)1340including one or more blocks of the car navigation device1320, the in-vehicle network1341, and a vehicle module1342. The vehicle module1342generates vehicle data (such as vehicle speed, engine speed, and trouble information), and outputs the generated data to the in-vehicle network1341. In the system and method of the present disclosure, it will be apparent that the components or steps may be decomposed and/or recombined. These decomposition and/or recombination shall be considered as equivalent to the present disclosure. Also, the steps of executing the above-described series of processes can be naturally performed in chronological order in the described order, but need not necessarily be performed in chronological order. Some steps may be performed in parallel or independently from each other. While the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, it is to be understood that the above-described embodiments are merely illustrative of the present disclosure and are not to be construed as limiting the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made in the above-described embodiments without departing from the spirit and scope of the present disclosure. Accordingly, the scope of the disclosure is to be limited only by the appended claims and their equivalents. | 68,187 |
11943022 | DETAILED DESCRIPTION The following description and the drawings sufficiently illustrate specific aspects to enable those skilled in the art to practice them. Other aspects may incorporate structural, logical, electrical, process, and other changes. Portions and features of some aspects may be included in, or substituted for, those of other aspects. Aspects set forth in the claims encompass all available equivalents of those claims. FIG.1is a functional block diagram illustrating a system according to some aspects. The system100may include multiple UEs110,140. In some aspects, one or both the UEs110,140may be communication devices that communicate with each other directly (e.g., via P2P or other short range communication protocol) or via one or more short range or long range wireless networks130. The UEs110,140may, for example, communicate wirelessly locally, for example, via one or more BSs132(also called BS nodes), WiFi access points (APs)160or directly using any of a number of different techniques, such as WiFi, Bluetooth or Zigbee, among others. The BS132may contain one or more micro, pico or nano base stations. The BS132may be, for example, evolved NodeBs (eNBs) or next (5th) generation NodeBs (gNBs). The UEs110,140may also communicate through the network130via Third Generation Partnership Project Long Term Evolution (3GPP LTE) protocols and LTE advanced (LTE-A) protocols, 4G protocols or NR protocols. Examples of UEs110,140include, but are not limited to, mobile devices such as portable handsets, smartphones, tablet computers, laptop computers, wearable devices, sensors and devices in vehicles, such as cars, trucks or drones. The UEs110,140may communicate with each other and/or with one or more servers150. The particular server(s)150may depend on the application used by the UEs110,140. The network130may contain network devices such as an access point for WiFi networks, a base station (which may be e.g., an eNB or gNB), gateway (e.g., a serving gateway and/or packet data network gateway), a Home Subscriber Server (HSS), a Mobility Management Entity (MME) for LTE networks or an Access and Mobility Function (AMF), etc., for NG networks. The network130may also contain various servers that provide content or other information related to user accounts. FIG.2illustrates a block diagram of a communication device in accordance with some aspects. Some of the elements shown inFIG.2may not be present depending on the type of the device. In some aspects, the communication device200may be a UE such as a drone, a specialized computer, a personal or laptop computer (PC), a tablet PC, a personal digital assistant (PDA), a mobile telephone, a smart phone, a web appliance (e.g., camera, doorbell, security apparatus), or other user-operated communication device. In some aspects, the communication device200may be a UE embedded within another, non-communication based device such as a vehicle (e.g., car) or home appliance (e.g., refrigerator). In some aspects, the communication device200may be a network-operated device, such as an AP, an eNB, a gNB, a to network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules and components are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations. Accordingly, the term “module” (and “component”) is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time. The communication device200may include a hardware processor202(e.g., a central processing unit (CPU), a GPU, a hardware processor core, or any combination thereof), a main memory204and a static memory206, some or all of which may communicate with each other via an interlink (e.g., bus)208. The main memory204may contain any or all of removable storage and non-removable storage, volatile memory or non-volatile memory. The communication device200may further include a display unit210such as a video display, an alphanumeric input device212(e.g., a keyboard), and a user interface (UI) navigation device214(e.g., a mouse). In an example, the display unit210, input device212and UI navigation device214may be a touch screen display. The communication device200may additionally include a storage device (e.g., drive unit)216, a signal generation device218(e.g., a speaker), a network interface device220, and one or more sensors, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The communication device200may further include an output controller, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.). The storage device216may include a non-transitory machine readable medium222(hereinafter simply referred to as machine readable medium) on which is stored one or more sets of data structures or instructions224(e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions224may also reside, completely or at least partially, within the main memory204, within static memory206, and/or within the hardware processor202during execution thereof by the communication device200. While the machine readable medium222is illustrated as a single medium, the term “machine readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions224. The term “machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the communication device200and that cause the communication device200to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks. The instructions224may further be transmitted or received over a communications network using a transmission medium226via the network interface device220utilizing any one of a number of transfer protocols (e.g., frame relay, interne protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks. Communications over the networks may include one or more different protocols, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi, IEEE 802.16 family of standards known as WiMax, IEEE 802.15.4 family of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, a next generation (NG)/5thgeneration (5G) standards among others. In an example, the network interface device220may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the transmission medium226. As above, until recently, UEs disposed at elevated locations of over about 100 m above ground level were limited geographically and in mobility. This is to say that such UEs were disposed primarily in cities (with taller buildings) and the mobility limited to a particular building. This permitted base stations to provide communication support primarily to ground level devices, leaving UEs at elevated altitudes to connect via, for example, WiFi APs, and providing more limited coverage to such UEs. For typical UEs, this may be sufficient, especially when beamforming is not employed, and quality of service issues do not arise, as mobility-related issues usually do not arise within buildings. However, the rapid expansion in the use of unmanned aerial vehicles (UAVs), also known as drones, has led to issues with communications between the drones and terrestrial systems. For example, to extend the safety and reliability of drone operation beyond visual line-of-sight (LoS) range, it may be desirable to extend the existing cellular network into an infrastructure that achieves key performance indicators for reliable drone operation and management. While, as above, networks provide good coverage to terrestrial users with high throughput and reliable handover, the channel, interference, and mobility environments of drones may be different from that of typical terrestrial UEs. The situations for drones are more challenging for current systems at least in part because the main lobe of the existing BS points toward ground UEs. Thus, drones may only be able to be served by the BS with sidelobes, which are narrower and carry less power than the main lobe. Drones may also receive a greater number of signals from different BSs due to LoS propagation (the lack of objects impeding BS transmissions), leading to a much harsher interference condition than that of typical ground UEs. In particular, the situation degenerates with increasing drone altitude, to the extent that a large number of dead zones (coverage holes) may be created with respect to drones in high altitude, e.g., above a predetermined height (above ground level) such as 100 m. Note that throughout the description, transmission of the various signals includes generation and encoding of the signals from the transmitting device and reception of the various signals includes decoding and storage of the received signals. The existence of coverage holes raises several technical issues to solve. These issues include, for example, drone mobility and severe interference by ground UE communications. Mobility involves a UE engaging in a 3GPP handover procedure that includes multiple signals between various devices, such as transmission of a measurement report by the UE to the BS (measuring the cell reference signal (CRS) of various BSs) and in response a Radio Resource Control (RRC) Connection Reconfiguration message by the BS to the UE, transmission of a handover request and response between the source and target BS, exchange of a path switch request and response between the target BS and the mobility management entity (MME), and exchange of user plane request and response between the MME and serving gateway (S-GW). Of the above communications associated with the 3GPP handover process, the over the air communications between the UE and BS may be problematic for drones. In particular, a 20˜30% handover failure ratio exists for high-altitude drones (above 100 m) due to the coverage holes in the existing cellular network. For drones to comply with the handover procedure, the drones should be able to receive signals on data and control channels, and simultaneously measure CRS signal strength of multiple candidate cells. In particular, for mobility support, UEs may perform measurement on the signal strength of the neighboring cells and report a set of Radio Resource Management (RRM) measurements of the neighboring cells to the serving cell. Each RRM measurement may include Reference Signal Received Power (RSRP) and/or Reference Signal Received Quality (RSRQ), among others, of the CRS of each neighboring cell. This measurement may be performed before the UE switches from a source serving cell to a target serving cell during actual handover. Most drones, however, include a single omni-directional antenna, and may thus be unable to measure the CRS of one or more of the cells due to the poor signal-to-interference ratio (SINR) at high altitude. In particular, the UE should be able to complete downlink synchronization (DL sync) based on the primary synchronization signal (PSS) and secondary synchronization signal (SSS) for multiple candidate cells and proceed to measure the characteristics, e.g., the RSRP on the CRS of the candidate cells. Such PSS/SSS signals are designed to be robust enough for all typical ground UEs to successfully decode them. However, drones are subject to very low SINR mainly because of downtilting and a significant amount of LoS inter-cell interference so that drones often cannot detect the PSS/SSS signals, even if the SNR of the PSS/SSS signals would otherwise be detectable by low altitude/ground level UEs. While analog/RF beamforming may be applied to enhance a particular cell/direction, such solutions may be unable to provide large enough degrees of freedom in receive beamforming directions to enable simultaneous data reception and multicell measurement. Moreover, because of enhanced LoS propagation above the predetermined height (say, the BS height), the cell signals reaching a drone may be stronger than those reaching the same drone at ground level. This means that conventional multi-cell measurement may lead to excessive reports, which may in turn result in incomplete handover of high-speed drones. In some aspect, Full Dimension Multiple-Input-Multiple-Output (FD-MIMO) may be used at the BS and/or directional beamforming at the drone to mitigate or eliminate the above mobility issue and enhance the data rate. FD-MIMO may enable the BS to beamform in both the horizontal and vertical direction so that the BS can cover anywhere in a 3D space. The use of directional beamforming at drones can be of use to reduce the high handover failure ratio to a tolerable level. FD-MIMO assumes that DL sync of the drone by the BS, as well as decoding of the Physical Downlink Control Channel (PDCCH) have already been performed. Whether or not these have been accomplished, mobility related signals and channels, however, such as the PSS, SSS, CRS, Physical Broadcast Channel (PBCH), Physical Random Access Channel (PRACH), and PDCCH are not beamformed, resulting in the coverage holes. Therefore, multicell measurement for mobility may become a bottleneck in FD-MIMO systems without further development. Directional beamforming, on the other hand, may be implemented by analog/RF beamforming, without impact on cellular standards and modem implementation. While directional beamforming can boost drone data throughput and improve handover performance for drones along a particular direction, this may be insufficient to provide large enough degrees of freedom in receive beamforming directions so as to enable simultaneous data reception and multicell measurement. The insufficiency may be due to multicell measurement with sidelobes at the drone (sidelobe-to-sidelobe link), where one sidelobe is on the BS side and the other sidelobe is on the drone side. Instead, a different beamforming solution and architecture design may be used for simultaneous data reception and multicell measurement at the drones for mobility. Receive beamforming at the drones may permit boosting the SINR of the PSS/SSS and the CRS. To complete a parallel cell search within the predetermined time period, in some aspects a receive beamforming architecture for simultaneously monitoring multiple directions has been developed that takes advantage of synchronization done in the time domain. To this end, receive beamforming may performed before fast Fourier transform (FFT) processing, unlike normal digital beamforming. This may permit drones capable of simultaneously receiving signals from multiple receive directions to perform other cell searches based on the PSS/SSS. The drones may be able to perform multiple receive beamforming for multicell measurement for mobility and simultaneously to receive the PDSCH from the serving cell and transmit the associated PUSCH. In review, DL sync is a three-stage procedure which may be performed when the UE is switched on or when the UE loses synchronization. In the first stage, the UE retrieves the fractional frequency offset (FFO) and acquires coarse information about the orthogonal frequency-division multiplexing (OFDM) symbol timing. This operation is typically accomplished in the time domain using a cyclic prefix (CP)-based delay correlation method. After FFO correction and CP removal, the resulting samples are converted in the frequency domain using a discrete Fourier transform (DFT) unit. The second stage detects the position of the PSS within the received DL signal and recovers the Zadoff-Chu (ZC) root index. These tasks can be accomplished either in the time or frequency domain, and may provide subframe timing information as well as the sector ID. In the third stage, the SSS is used to obtain the cell ID group and the frame boundary. As the SSS is located in the symbol immediately preceding the PSS, the latter is normally used as a phase reference to perform coherent detection of the SSS in the frequency domain. The integer frequency offset (IFO) can be estimated either in the second or third step by evaluating the frequency domain shift of the received PSS or SSS at the DFT output. The UE may generally perform filtering to extract 62 PSS/SSS subcarriers out of the entire whole band. This filtering may be performed in the time domain. For the time-domain correlator to successfully detect the PSS and retrieve the FFO and coarse timing in the 1ststage, The SINR of the PSS should be reasonably good, such as being above about −6 dB. Since this is not the case with high-altitude drones, a two-dimensional (or one-dimensional) beamforming network before PSS/SSS detector in the time domain.FIG.3illustrates a receiver in accordance with some aspects. In particular,FIG.3shows a high level block diagram of a fully digital beamforming architecture for multi-cell DL sync and CRS measurement. The receiver300may be incorporated in a drone or other high-altitude UE. Some components used in the receiver300shown inFIG.3may not be shown for convenience. The receiver300may receive CRS via Nrmultiple omni-directional antenna elements310a-310m. The signals received at the antennas310a-310mmay be received at an analog front end (which may include amplifiers, filters, buffers and downconversion circuitry, for example)302and each of the resulting analog signals digitalized at an analog-to-digital converter (ADC)304to produce a Nr dimensional vector. The vector may be supplied to the 2D beamforming network306, which may produce NmRFRx beamformed signals, where NRFis the number of Rx beams that point in different directions. Each of the NRFRx beamformed signals from the 2D beamforming network306may be supplied to the input of a PSS/SSS detector308a-308n, where the coarse timing and FFO of the particular signal are determined. Once NSSdifferent cells are detected out of the NRFbeamformed signals, the detected signals are then fed to an FFT block312a-312nand a fine timing/frequency offset sync block that determines fine timing and the IFO of the received signals. Since a portion of synchronization is done in the time domain, the receive beamforming may thus be performed before the FFT operation. The RSRP and/or RSRQ may then be measured at an RRM block314a-314nbased on the CRS received in the frequency domain. Although not shown, the drone can send an LTE measurement report containing the RSRP/RSRQ for mobility support. In addition, PDCCH/PDSCH reception (demodulation and decoding) and PUCCH/PUSCH transmission may be conducted using one of the NRFbeamformed signals, at the same time as the multicell measurement. The PDCCH/PDSCH reception may use similar components as the measurement, in which the beamformed signal of the serving cell supplied from the beamforming network306is provided directly to an FFT312zof the FFT block and the output of the FFT312demodulated by a demodulator316and decoded by a decoder318. FIG.4illustrates a block diagram of a controller for a beamforming network in accordance with some aspects. As above, some components of the controller inFIG.4may not be shown for convenience. Assuming the number of PSS/SSS detectors, NRF, is insufficient relative to multiple directions to search for a meaningful measurement report, a beam controller may be used to adjust the directions to search. Similar toFIG.3, the output signals from beamforming network406may processed to determine the coarse timing and FFO408. Based on the coarse timing and FFO of the signals, a controller410may provide feedback to the beamforming network406to adjust the beam direction. The controller410should be able to quickly decide based on the correlator output which beam direction does not point toward strong neighboring cells and to discard that beam and switch to another beam. If a strong correlation is indicated, the signals may be supplied to the FFT block412and then the IFO determined414. For time-domain beamforming methods, either a codebook-based approach or adaptive approach may be used. In some aspects, the Unmanned Traffic Management (UTM) (or Unmanned Aircraft Systems (UAS) Traffic Management) information may be used to control the beamforming network. The UTM may be available at the BS. The UTM may include the 3D position, speed, and navigation information of each drone served by the BS. This may enable the BS to provide the relevant UTM to the drone. The UTM may permit the drone to adjust the receive beam directions of candidate neighboring cells for mobility support by higher layer signaling. FIG.5illustrates a hybrid beamformer in accordance with some aspects. The hybrid beamformer500contains the same elements as the fully digital beamforming architecture ofFIG.3and the controller ofFIG.4. However, the beamformer500is different—unlike the fully digital beamforming architecture, in which the beamforming network is disposed after the ADC, the beamforming network506is disposed between the AFE502and the ADC504. Thus, the hybrid beamformer500employs analog beamforming rather than the digital beamforming ofFIG.3. LikeFIG.4, however, the beamforming network506is controlled by a digital feedback signal from the beam controller510as determined by the coarse timing and FFO of the digitized beamformed signals. The structure of the synchronization signals detected by the drone are different depending on whether the 3GPP system is an LTE/4G or a 5G NR system. When 5G NR systems are employed for communication between the BS and drone, if an outage in the DL sync signals occurs a substantial bottleneck may result because of the limited Sync Signal (SS) blocks supported by the 5G NR system. FIG.6illustrates a 5G NR synchronization signal block structure in accordance with some aspects. Each slot in the 5G NR system may include 14 OFDM symbols. The time domain transmission pattern of the NR SS blocks may be cell-specific rather than being UE-specific. The time domain transmission pattern may also be dependent on the subcarrier spacing and frequency range, as well as other parameters. The NR SS blocks may be disposed in the center frequencies of the bandwidth used by the cell for communication. In particular, as shown inFIG.6, the 5G NR system only supports at most 4 SS blocks for a frequency range below 3 GHz, 8 SS blocks for a frequency range between 3 GHz and below 6 GHz and 64 SS blocks for a frequency range between 6 GHz and 52.6 GHz. An SS block includes the PSS, SSS and PBCH. A SS burst represents one or more SS block(s). A SS burst set includes of one or more SS burst(s) with a configurable transmission period. In some aspects, the default transmission period may be 20 ms. As shown, the SS block consists of 240 contiguous subcarriers (20 RBs) and 4 OFDM symbols. Beam sweeping may be employed in 5G NR for SS block transmissions. In this case, multiple SS blocks may be transmitted periodically at about 20 ms intervals. In addition, the transmission of SS blocks within a single SS burst set may be limited to a subset of time in the transmission period (e.g., a 5 ms window in the transmission period). The frequency location of the SS block may be configured by higher-layer (RRC) signaling to support a sparser search raster in order to detect the SS block. However, the sparseness of the SS block transmission in 5G NR systems may cause issues that are exacerbated at the lower frequencies. In particular, the wideband SINR distribution of 4 SS blocks at a carrier frequency 2 GHz shows more than 12% drones are out of sync. Compared to the outage probability of ground UEs, a 12% sync outage is significant. In short, 4 SS beams may be insufficient to support drones as well as ground UEs. A repetition and/or accumulation scheme (coverage enhancement) may be used to boost the channel quality of handover-related signals and channels for drones. Drones with poor channel quality (e.g., SINR below −10 dB) can establish a DL sync to neighboring cells and transmit the measurement report to the serving cell (and/or one or more of the neighboring cells, which may be coupled to the serving cell via an X2 or Xn interface). However, to provide a measurement report, a drone may measure a large number of candidate cells with multiple SS beams, which repeats every 20 ms as a default for initial access. Thus, it may take a substantial amount of time for the drone to accumulate each SS block over, say, 10 periods (200 ms). This latency continues to add for each step in the handover procedure (from measurement control to transmission of an RRC Connection Reconfiguration Complete message). The use of coverage enhancement may thus increase the latency for the entire handover procedure including measurement report, yielding a significant impact on handover performance. Instead of, or in addition to, the use of the coverage enhancement technique, a UE-specific SS block configuration may be used to support reliable mobility performance of drones while maintaining limited search complexity. By leveraging vertical separation between drones and ground UEs, the SS blocks for a UE to search may be restricted in vertical domain to retain the same number of SS blocks per UE, but with less DL sync outage probability of drones because of better vertical beams. Furthermore, the UE-specific SS block configuration can significantly reduce the UE complexity in terms of initial access above 6 GHz. In advance of using the UE-specific SS block, the network may identify drones and their altitudes, keeping track via the UTM information above. Below 6 GHz, the mobility support for drones can be improved by increasing the number of SS blocks in the vertical domain. If, for example, 8 SS blocks are able to be used below 3 GHz instead of the 4 SS blocks currently specified in NR, the computational complexity of UE may be increased in terms of initial access. It would be desirable, however, to keep at least the same complexity as the case of 4 SS blocks as well as achieving a better mobility support of drones with more vertical beams. This can be achieved by noticing that most drones fly above the height of the BS (e.g., 25 m or 15 m), whereas ground UEs are most likely to be below the BS height.FIG.7illustrates a spatial separation between ground UEs and drones in the vertical domain in accordance with some aspects. As shown inFIG.7, the vertical separation between ground UEs702and drones704may be leveraged to introduce UE-specific SS blocks that are dependent on the vertical sector720,730occupied by the ground UE702or drone704. In particular, a restriction may be imposed on SS blocks for a UE to search for mobility or measurement purposes. For instance, if 2 horizontal SS beams and 4 vertical SS beams712a-712dare transmitted by the BS710, the ground UEs702may be restricted to only search/measure neighboring cells based on the lower 2 vertical SS beams712c,712dand the drones704may be restricted to only search/measure the upper 2 vertical SS beams712a,712b. As above, for 5G NR systems, the numerology and pattern (or position) of the SS burst set may depend only on the carrier frequency for initial access so that the SS block configuration is cell-specific and does not change over time. To retain the number of SS blocks per UE as well as to enhance the mobility performance of drones, for drone mobility, the SS block configuration may be altered to be UE-specific and may change semi-statically. For instance, in the RRC connected mode, a UE (either drones or ground UEs) can be informed by higher-layer signaling to limit its search/measurement to restricted SS blocks as increasing the number of SS blocks used concurrently increases the UE complexity in terms of cell search, radio link failure recovery, measurement report, etc. Either static or semi-static higher-layer signaling of the SS block may be used. To use static signaling, the RRC signaling does not change in the connected mode. Semi-static signaling, while more complicated, may be useful if the drone varies in height to transition between the vertical sectors (e.g., from high altitude to below the BS height). Semi-static signaling may combine RRC signaling and Medium Access Control (MAC) Control Element (CE) signaling, where the latter can change the SS block restriction patterns in the RRC connected mode, depending on the UE height information. Such UE height information can be given by a height-triggered measurement report from corresponding UEs. In some aspects, an on/off bitmap may be used for the SS block restriction pattern. Let N1and N2denote the number of SS beams in the 1stdimension (e.g., horizontal domain) and the 2nddimension (e.g., vertical domain), respectively. Taking the signaling overhead into account, different control can be effected over the SS block restriction pattern in the different domains. For instance, several bitmaps of length {1, N1, N2, N1*N2} may be defined. For a one-bit signal, a subset of SS beams may be predetermined for a certain UE to search or measure. For the bitmap of length N1(or N2), the BS may restrict the SS beams for a UE to a subset of SS beams only in the 1st(or 2nd) dimension. For a bitmap of length N1*N2, the BS may arbitrarily turn a particular SS beam on/off in both 1stand 2nddimensions. Drones are likely to experience LoS channel propagation so that a good SS beam for a certain drone may not change dynamically and may also be predictable, unlike ground UEs. Accordingly, a flexible SSB restriction pattern may be useful. The above bitmap may be provided when the drone is in the RRC Connected mode. In some aspects, similar signaling may be provided to the drone when in Idle mode to instruct the drone to search or measure a particular subset of SS blocks. In some aspects, the BS may use information about SS block usage to further reduce the search/measurement burden on the drones. In particular, one or more SS blocks, which are dependent on the positions of the UEs and the corresponding SS block restriction, may be unused by the BS. Given this information, the BS can inform the UEs via higher layer signaling regarding which SS blocks among the available SS blocks are actually transmitted. This may permit the UEs to perform rate matching for the PDSCH and PDCCH. To utilize the above SSB restriction, the information exchange may be performed among neighboring BSs in terms of a UE-specific SS block restriction as well as a cell-specific SSB configuration through higher-layer signaling via, e.g., via an X2/Xn interface or air interface among the BSs. As an alternative, UTM information may be used to provide a SS block restriction. In this case, the BS can deactivate the upper vertical SS beams when there is no drone that is present or expected in the upper vertical sector, according to the UTM information. In some aspects, the BS can also inform a UE of the foregoing SS block restriction patterns based on the UTM information. By doing so, SS block resources may be saved by deactivating some of the signaling, allowing data to be sent if desired. To provide beamforming, multiple antennas may be used by both the BS and the drone. Further, wireless systems operating above 6 GHz enable deployment of a massive number of antennas at the BS and user equipment (UE). To reduce RF power consumption and cost efficiency, these systems generally employ fully analog or hybrid digital analog (HDA) transceiver architectures. Adaptive beamforming techniques may be used at such frequencies to overcome high signal attenuation. Channel state information (CSI) may be used to implement adaptive beamforming. In a wideband communication channel having multiple antenna elements, the CSI may fluctuate in space, time and frequency, and therefore CSI may be measured in all three dimensions. The BSs may periodically may transmit known reference symbols (RS) (also referred to as pilots) so that the CSI can be estimated at each receiving node using the pilots. Unfortunately, as the number of antennas increases the feasibility of measuring the CSI between each transmit-receive antenna pair. In addition, mmWave systems may utilize a large signal bandwidth (e.g., 1 GHz), which means large number of RSs may be used to acquire CSI for the entire bandwidth. For highly mobile UEs such as drones, the CSI acquisition latency is thus a useful performance metric. In sub 6 GHz systems (sub mmWave systems), orthogonal RSs are used to measure CSI variations, where each transmit antenna sends its unique RS signature comprising symbols distributed densely in time and frequency. Both frequency division multiplexing (FDM) and code-division multiplexing (CDM) based orthogonal RSs have been used. Further to this, channel sounding and channel estimation may be split into two steps. In the channel sounding step, beam sweeping/synchronization is performed between the transmitter (BS) and receiver nodes (UE/drone). In the channel estimation step, orthogonal RSs are transmitted between each pair of transmit and receive beams and channel estimation is performed using the methods described above. The use of multiple steps for beam management and channel estimation, however, may significantly increase the latency. Instead, a combined beam management and channel estimation technique may be used. A transceiver may detect optimal beamforming vectors as defined by a codebook and estimate the multi-path channel coefficients for each beamforming vector. The channel estimate may be used to determine a CSI feedback message that includes the channel quality indicator (CQI), Pre-coding Matrix Indicator (PMI), Rank Indicator (RI), among others. In particular, the inherent propagation characteristics of the mmWave channel may be exploited. FIG.8illustrates a mmWave channel in accordance with some aspects. In particular,FIG.8shows a schematic of mmWave signal propagation showing signals arrive through sparse cluster of channel taps existing along several angular directions. The mmWave channel can be represented under a sparsifying basis (e.g., a DFT codebook) as a sparse multi-path multi-angular wireless channel. Each angular direction may represent signals arriving from/to a cluster of scatterers. The overall delay spread of the channel may be large. But, as shown a mmWave channel carries signals only along a few angular directions and has a very small delay spread at each angular direction. As illustrated, mmWave channels exhibit almost flat frequency response along each angular direction. These properties are used to enable each receiving node to receive a signal with fully-analog random beamforming and subsequently perform channel estimation along each signal bearing Angle of Arrival (AoA) direction. The AoA is the angle between the reception direction of a reference signal from a linear antenna array and the normal axis of the array. In some cases, the Time Difference of Arrival (TDOA) may be measured at individual elements of the array. The received AP signal between successive antenna elements may be phase-shifted, and the degree of phase shift may depend on the AoA, the antenna element spacing, and the carrier frequency. By measuring the phase shift and using known characteristics, the AoA can be determined. This may provide significant reduction in sounding codewords used for beam selection and channel estimation. The system may be modeled as a wireless network with a receiving node equipped with a large number of antennas NRand a transmitting node equipped with a large number of antennas NT. Assuming OFDM transmission in which bandwidth B GHz is divided into N equi-spaced sub-carriers, the wireless channel on sub-carrier k is given by the matrix H[k]∈NR×NT. Note, however, that the scheme described herein is not limited to OFDM based systems. For example, this scheme is applicable to single carrier FDM systems. A mathematical framework is described for channel estimation and beam management in which the measurements overhead is significantly reduced compared to state-of-the art solutions. The RS used may be 5G pilot signals (e.g., SS block or CSI-RS). Reduction of measurement overhead is achieved by exploiting the inherent sparse structure of wireless channels above 6 GHz. In some aspects, beamforming alignment may be based on calculations at the receive node only. The technique described may enable joint detection of Rx beams and estimation of multipath channel impulse response.FIG.9illustrates a flow diagram for compressed CSI acquisition protocol in accordance with some aspects. As shown inFIG.9, the transmitting and receiving nodes are assigned RS sub-carrier groups (as described by the underlying standard). The RS signal parameters, including the sub-carrier ID, the group IDs and the ZC sequence IDs are exchanged between the transmitting and receiving nodes. Each RS sub-carrier group has P frequency locations that are uniformly spaced across the entire bandwidth used by the cell. Each RS sub-carrier group may be assigned to different transmitting nodes. For example, a transmitting node assigned to the i-th RS sub-carrier group may transmit symbols Xi=[Xi0, Xi1, . . . Xip−1], where ikis the k-th randomly generated sub-carrier location in the RS sub-carrier group. Next, each receiving node having NRantenna elements may use M random beamformers. Each random beamformer may be a NR×1 vector of independent random phases generated using NRphase shifters. In one example, each set of random phase shifters could be circularly symmetric complex Gaussian vectors. Note that M<NR, which is sub-Nyquist sampling in the AoA space. In an alternative, a receive measurement codebook can also be designed based on criterion like weighted pseudo random beamforming with adaptive weight updates that are provided by the base station and are adaptive to channel conditions of the sub-carrier group. Similar to the receive codebook, a transmit codebook may use a small (<NT) number of random transmit beamformers. For simplifying the mathematical formulation, without loss of generality, it is assumed that each transmitting node uses an optimal transmit beamformer wi∈NT×1. Then the mmWave channel from the i-th transmitting node to the receiving node is given by hi[k]=Hi[k]wi, which is a NR×1 vector channel on sub-carrier k. Channel sounding may be performed on M consecutive OFDM symbols, where each OFDM symbol is N samples long with an inter sub-carrier frequency δf and signal bandwidth N δf. A different random beamformer φm∈NR×1may be used by the receiving node in each OFDM symbol. Next, the received signal in the ik-th sub-carrier of the m-th OFDM/SC-FDMA symbol may be given by: ym[ik]=φmH(hi[ik]Xik+nm[ik]),k=0, . . . ,P−1 Channel estimation may be performed using M×P samples of received signal received during M OFDM/SC-FDMA symbols. An alternative representation of the frequency domain received signal from all M OFDM symbols may be given as: (y0(i0)…yM-1(i0)⋮…⋮y0(iP-1)…yM-1(iP-1))=(Xi0…Xi0·e-j2πNi0(D-1)⋮…⋮XiP-1…XiP-1·e-j2πNiP-1(D-1))×(h~0,0…h~NR-1,0⋮…⋮h~0,D-1…h~NR-1,D-1)×(b0,0…b0,NR-1⋮…⋮bR-1,0…hNR-1,NR-1)×(φ0,0…φ0,M-1⋮…⋮φNR-1,0…φNR-1,M-1)+(n0(i0)…nM-1(i0)⋮…⋮n0(iP-1)…nM-1(iP-1)) Where: X=Δ(Xi0…Xi0·e-j2πNi0(D-1)⋮…⋮XiP-1…XiP-1·e-j2πNiP-1(D-1)) is a P×D reference symbol matrix with each column representing a rotation corresponding to the channel tap arriving at that delay, H~=Δ(h~0,0…h~NR-1,0⋮…⋮h~0,d-1…h~NR-1,d-1) is a D×NRchannel tap matrix, where the j-th row represents the channel tap arriving at the j-th sample delay from NRangular directions, and B=Δ(b0,0…b0,NR-1⋮…⋮bR-1,0…hNR-1,NR-1) is a NR×NRsparsifying angular basis. In one example B is a DFT matrix, Φ=Δ(φ0,0…φ0,M-1⋮…⋮φNr-1,0…φNR-1,M-1) is a NR×M random beamformer matrix, and Z=Δ(n0(i0)…nM-1(i0)⋮…⋮n0(iP-1)…nM-1(iP-1)) is a P×M receiver noise matrix. As described earlier and depicted inFIG.8, the channel tap matrix {tilde over (H)} may be a sparse in row and column space. Therefore, random sampling may be performed along the row space of {tilde over (H)} at a sub-Nyquist sampling rate. More specifically, for the random sampling in the row space of {tilde over (H)} M randomly beamformed OFDM symbols may be used to recover NR>M number of angular positions. Next, the Kronecker product representation of the matrix equation vec(ABC)=(CT⊗A)B=vec(D) may be used to rewrite the received signal in the measurement phase as: y=((BΦ)T⊗X){tilde over (h)}+ñ Where y=vec(Y) is a (P M)×1 vector obtained from columns-wise stacking sub-carriers Y, {tilde over (h)}=vec({tilde over (H)}) is a (NRD)×1 vector obtained from columns-wise stacking channel matrix {tilde over (H)}, and ñ=vec(Z) is a (P M)×1 vector obtained from columns-wise stacking noise matrix Z. Estimation of NR×D elements of vectorized channel {tilde over (h)} may be performed using P×M number of received measurements contained in vectorized signal y. Established compressed sensing theory has shown (P×M)≈K log(NR×D), where K is the sparsity parameter defining the number of non-zero (or, almost zero) elements in vectorized channel {tilde over (h)}. Therefore, pilot signal overhead scales logarithmically with respect to the product of number of receive antennas and the signal bandwidth that dictates the number of channel taps. A beamformed mmWave channel is typically very sparse as signals arrive from a few clusters. Therefore, a huge saving is provided in terms of using pilot resources for acquiring CSI. In addition, for a given number of measurements, a degree of freedom is provided in distributing power across pilot tones. Sparse signal estimation techniques like least absolute shrinkage and selection operator (LASSO) can be applied to perform the estimation of {tilde over (h)}. For simulation results, a low complexity sparse-reconstruction algorithm has been used based on reduced sub-set least squared followed by zero-attracting least mean absolute deviation. The compressed measurements y can also be used to infer system parameters like the best analog beamforming vectors or for a given analog beamforming vector the effective analog beamformed channel, which may be used for co-phasing or digital precoding/receive combining. Beam detection and effective channel estimation can be performed as described above. Simulation Results TABLE 1Simulation ParametersISD100mCarrier Frequency73GHzBandwidth1GHzBS Transmit power40dBmCable Loss3dBChannel Model3GPPNumber of Sub-carriers2048Number of pilot sub-carriers128 (At Nyquist rate)Pilot power boostingNoneNumber of Receive Antennas at UE32Receive BeamformerFully analogue using randomcodebookNumber of Transmit Antennas at BS256Transmit BeamformerFully digital using SVD precoder The random measurement codebook at the receiver contains M measurement codewords. Each codeword is generated by 32 phase shifters when number of receive antennas is 32. Each phase shift is uniformly and independently distributed. Also, P=128 reference symbols are transmitted in frequency domain at the Nyquist sampling rate of the channel in each OFDM symbol. The frequency location of RSs is equally spaced across 1 GHz bandwidth. The estimated channel power for the center sub-carrier obtained at different angle of arrivals for M=16 measurement codewords and M=32 measurement codewords was used. For performance benchmarking, frequency domain channel estimation method was used as a baseline. The channel is LoS and there is one strongest AoA. The simulation showed that the above sparse channel estimation method quite accurately estimates the strongest angle AoA. Although the baseline method also achieved largest channel power at the correct AoA, baseline method inaccurately estimated relatively higher channel power at multiple angle of arrivals. This affects the overall normalized mean square error (NMSE) performance of per antenna element mmWave channel. More precisely, the NMSE of proposed channel estimation method was at 5.8%, while the baseline had 25% NMSE. Thus, channel estimation may be used to detect an optimal beam from a (large) beamforming codebook that is able to differ from a measurement beamforming codebook used to measure the pilot signals. The estimation algorithm may have parameters that are optimized beforehand using a machine learning or other algorithm and that depend on the measurement beams. Note that the codebooks may be deterministic and designed offline. Such codebooks may be loaded when desired or when a predetermined condition is met, such as after a predetermined time period, or when the propagation environment changes by more than a predetermined threshold (e.g., the SNR/RSRP/RSRQ changes). Beam tracking in mmWave applications may encounter further problems. Applications that involve channel variations such as those in high-speed autonomous applications, mobile environments etc. may be particularly problematic. This is particularly challenging in hybrid architectures in which the number of RF chains is limited and hence the device does not have full access to all the antenna outputs. Non-blind beam tracking may use pilot signals that are transmitted to acquire the beam direction. Acquisition of the beam direction using non-blind beam tracking may involve Tx scanning across the beam space and Rx feedback. However, non-blind algorithms incur cost in terms of both bandwidth and time resources and do not track well in high-speed applications. Blind algorithms such as Constant Modulus Algorithms (CMA) rely on the signal profile may instead be used for beam tracking but primarily deal with initial beam access and pilots for continuous tracking. In autonomous applications, while tracking may be used when blockages occur, and vehicles move at high speed (compared to handheld UEs), CMA-based algorithms do not work well for OFDM signals that have high peak-to-average power ratio (PAPR). Further, CMA-based algorithms incur larger costs in the case of hybrid beamforming in which access to the signal is only available after beamforming rather than having access to all outputs of the antennas. A blind beam tracking technology is presented for use by, among others, hybrid architectures. Specifically, a blind angle locked loop (ALL) algorithm is described for beam tracking using hybrid architectures. The ALL algorithm assumes that at least one other RF chain (in addition to the main beam chain) is available for tracking. By determining the energy change in the direction of the beam between the addition RF chain and the main beam chain, the main beam may be adapted to track any changes in the signal. This avoids the use of pilots or can be used for tracking in between the time arrivals of the pilots and is effective in low SNR conditions. Moreover, timing synchronization and FFT processing may be avoided as the ALL algorithm is a time domain algorithm. In addition, the ALL algorithm is able to track from time sample to time sample, the adaption consequently occurs with every time sample. Note that it is assumed that the initial beam direction is acquired and this technique used to track the beam when there is relative motion between the Tx and Rx. FIG.10illustrates a block diagram for hybrid Radio Frequency (RF) beamforming in accordance with some aspects. In the following equations, a flat fading channel to begin with is assumed. yk(t)=hkx(t)+n(t) where yk(t) is the signal received at the k-th antenna (Nr inFIGS.3and4), hkis the channel response of the kth channel on which the desired signal (x(t)) is transmitted and n(t) is the noise on the channel. In vector form this can be written as: y(t)=hx(t)+n(t)h=∑mgma(θm)a(θ)=[1ejπsin(θ)Λej(K-1)πsin(θ)]T where a(θ) is a scaling vector and gmis the complex channel gain assuming that the initial beam is obtained through pilots or other beam access procedures such as sector sweep. θ=maxθaH(θ)h2 For tracking, two other RF chains may be used: W=[w−a(θ)w+] The digital signal at the output of these RF chains is given by: r(t)=WHy(t) The weight matrix W and the AoA change detector f(r) may be desired to detect the direction of the beam change: θ=θ+μf(r) where μ is the update factor, which may be dependent on noise and speed (for example, for faster tracking μ is larger, for a noisy environment μ is smaller). The weight vectors and update algorithm may be designed as follows: w−=a(θ−δ),w+=a(θ+δ) where δ are the tracking angles. The change detector function is: f(r)=sign(|r3(t)|−|r1(t)|) where r3and r1are the digital signals associated with w+and w−, respectively. The beam angle is then tracked in a closed loop manner using the update equation: θ=θ+μf(r) Using the above blind ALL algorithm permits tracking under both high (20 dB) and low (−10 dB) SNR conditions. Simulations performed using 8 antennas with an FFT size of 2048 show tracking within about 1° for high SNR with a 0.1° AoA sample step over 2500 samples and within about 2° for low SNR with a 0.01° AoA sample step over 2500 samples. As above, a beamforming network may be used to provide the above beam tracking. As described above, the beamforming network may be controlled in some aspects using UTM information stored in the BS. However, UTM information can be intentionally corrupted. For example, malicious drones can incorrectly report their positions, causing performance degradations and posing security risks. Incorrect position estimates can moreover cause instability issues. To provide interference mitigation, security and location precision without any communication overhead or increased hardware complexity, a technique is provided that extracts maximal information from observed signals without the use of RSs. To accomplish this, let yk(t) be the received signal at antenna k, at time tin a drone with multiple antennas. This can be represented as follows: yk(t)=hkHs(t)+n where, as above, hkis the channel response, s(t) is the source signal at time t and n is noise. Note that this is a vector since multiple sources could be active at any time. Depending on the problem being solved, these sources could be different entities. In the communication case, s is the set of desired sources and the interfering sources. In the case of location estimation, s could be any arbitrary signal transmitted from a node when the AoA from that node is of interest or could be RS from a GPS or ranging transmitter if the AoA and time of arrival of the signal from this source is of interest. For the below, no assumptions of pilots or knowledge of RSs were made. The different problems of interest in the drone scenario are described and the above equation modified suitably to match to the corresponding scenario and the corresponding algorithms showcased. For interference mitigation, the open sky environment for drone poses serious interference challenges due to the environment having limited obstruction and thus free-space propagation. Thus, a drone may see multiple interfering signals in addition to its desired signal of interest. One objective is to mitigate the power of the interfering signals. Let N be the number of antennas at the desired drone, MDthe number of desired signal streams and MIthe number of interfering signal streams. Equation (1) can be written as follows: YN×T=HS(MD+M1)×T+n where Y is the observed signal stream from the N antennas for a time duration T, H is the channel matrix that is assumed to be unknown and S is the set of all received signal streams given as follows: S=(SDSI) where SDof size MD×T is the desired stream and SIof size MI×T the interfering stream. The weight vectors W=w1. . . wMDare determined such that: wiHY≈αiSDi+noise,i=1, . . . ,MD Each of the sources is assumed to be non-Gaussian. The algorithm could be applied in any dimension where the sources are likely more non-Gaussian. For example in the FFT domain for OFDM-like signals. However, the sum of a set of non-Gaussian variables is more Gaussian than each of the individual variables. Hence, by maximizing a measure of non-Gaussianity, the individual sources may be able to be extracted. To that extent, the following optimization problem is solved to extract the sources of interest: wopt=arg maxE{|G(wHY)|2} where E is the expectation value and G is the non-Gaussian measure (e.g., 4thorder or entropy cumulative).FIG.11illustrates a non-Gaussian optimization method in accordance with some aspects. The algorithm shown inFIG.11describes a block method to solve this optimization problem (assume the input data is whitened): first, observations are made at operation 1102: YN×T=HSN×T+n. Next, at operation 1104 the W matrix is initialized W=I. Then, iteration is performed for each row at operation 1106 wi∈W until convergence. The iteration includes solving: wij+1=−E{G*(z)G*(z)Y}+E{G′(z)G′*(z)}wij+E(yyT)E{G*(z)G″(z)}wij* for each row and then orthonormalizing the rows to get a unitary W. For drones, this can be further optimized based on a partial knowledge of who the interferers are. Since the propagation environment is largely LOS and the drone uses a linear antenna array, then the channel matrix can be represented by an array matrix. Let the scaling vector a(θ): a(θ)=[1eja sin(θ). . . ej(N−1) a sin(θ)] At each location in space, a database can be built with potential interferers that can be updated with multiple drones traversing that area. If the interferers are the static BSs, since the position of the BSs are fixed, and the drone location is fixed an estimate of the angles from the BSs can be obtained. The channel matrix thus roughly has the following form: H({a(θk)})≈[g1a(θ1)gaa(θ2) . . .gMDM1a(θMF+M1)] where giis a complex scaling factor. The above interference mitigation algorithm is an iterative solution to a non-convex optimization problem and hence can benefit from a good initial point. This initial point can be made a function of the known interfering source array vectors: W0=f({a(θk)}) An example of such a function could be: W0=H({a(θk)})−1 Once the above algorithm has been executed, the drone also has an estimate of the interfering directions which could be sent back to the network to update the database. In some aspects, the network may store the weight vectors W as a function of the location in a database and a drone in the future can use these weights as the initial point for the iterative algorithm.FIG.12illustrates another non-Gaussian optimization method in accordance with some aspects in which the weights are stored. Thus, as shown inFIG.12, the network may maintain interferer information in a database at operation 1202. The interferer information may include interferer locations liand the interferer angles {θk(li)} and/or the weight vectors Wt(li) at time t. The drone may query the database at operation 1204 for the most recently stored angles and the weight vectors. At operation 1206, the drone may use the information obtained from the database to initialize the weight vector W0=func(Wt(Wt(li), {θk(li)}). The drone may then at operation 1208 execute the algorithm shown inFIG.11to estimate W. At operation 1210, the drone may use the estimated W to mitigate the interference. After mitigating the interference from the interferers, the drone may at operation 1212 feed back W to the network to update the database for the next time increment. In addition to mitigating interference, the drone may also estimate the AoA for localization and security authentication. Assuming that there is a single drone that is transmitting, and that the signal is received by neighboring drones and base stations, the signal received at any particular base station/drone can be written as follows: yk(t)=hks(t)+n Assuming a LOS channel and a linear array, hk=βjα(k−1)sin(θ) where θ is the AoA at the destination node. Here β captures any phase calibration and channel phase that is introduced. When wk=ejα(k−1)sin({circumflex over (θ)}) θ may be estimated, and {circumflex over (θ)} here is the estimate of the AoA. Let r(t)=Σkwk*yk(t). It can be seen that, when the AoA estimate is equal to the true AoA, then the power of the resulting signal r(t) is maximized. Therefore, the following optimization problem may be solved to solve for the angles. maxθ^E(r(t)2) This problem can be solved as shown inFIG.13.FIG.13illustrates an Angle of Arrival (AoA) optimization method in accordance with some aspects. Let ϕk=∠wk. Then, as shown inFIG.13, at operation 1302, wkis initialized (initially set to zero). At operation 1304, maxθ^E(r(t)2) is then solved using the following updates: ϕk=ϕk+μ∠{zk(t)r(t)}θ^=1N-1∑asinϕkα(k-1)ϕk=α(k-1)sin(θ^) Thus, the AoA arrival can be blindly determined at the neighboring drones and the base stations. This may be used to estimate the position of the transmitting drone. This provides for an independent location estimate of the target drone that can be used to authenticate its location for security purposes and determine whether the drone is not intruding any restricted airspaces.FIG.14illustrates an interference mitigation method in accordance with some aspects. To determine the position of a target drone, at operation 1402, each drone in the vicinity of the target drone may estimate the AoA of the target drone based on the observed signals from the target drone. In some aspects, only drones that have received an observed signal from the target drone having a signal quality (e.g., SNR, RSRP, RSRQ) above a predetermined threshold may estimate the AoA. At operation 1404, each drone may report its own position and the estimated AoA of the target drone to the serving BS. At operation 1406, other BSs may also compute their AoA estimates with respect to the target drone. At operation 1408, the network may collect the AoA estimates and position estimates of the neighboring drones and also that of the BSs. The network may at operation 1410 analyze the positions and the AoA estimates collected to estimate the position of the target drone independent of the position the target drone reports. The independently estimated position can also be reported back to the drone to improve its position estimate and, in some aspects, may not provide a report if the position estimated by the target drone and the independently estimated position are within a predetermined tolerance. This can also be used for security authentication purposes to verify that a drone is not maliciously reporting incorrect positions. In the latter case, the network may make such a determination based on the difference between the position reported by the drone and that independently determined exceeding a predetermined threshold difference (e.g., 1 m or 10 m). If the threshold is exceeded, the network may report the drone to a monitoring agency, such as a nearby police station and/or ignore transmissions from/to the drone. Although an aspect has been described with reference to specific example aspects, it will be evident that various modifications and changes may be made to these aspects without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof show, by way of illustration, and not of limitation, specific aspects in which the subject matter may be practiced. The aspects illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other aspects may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various aspects is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. The Abstract of the Disclosure is provided to comply with 37 C.F.R. § 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single aspect for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed aspects require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed aspect. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate aspect. | 63,872 |
11943023 | DETAILED DESCRIPTION Hereinafter, various example embodiments will be described in greater detail with reference to the accompanying drawings. FIG.1is a block diagram illustrating an electronic device101in a network environment100according to various embodiments. Referring toFIG.1, the electronic device101in the network environment100may communicate with an electronic device102via a first network198(e.g., a short-range wireless communication network), or an electronic device104or a server108via a second network199(e.g., a long-range wireless communication network). According to an embodiment, the electronic device101may communicate with the electronic device104via the server108. According to an embodiment, the electronic device101may include a processor120, memory130, an input device150, a sound output device155, a display device160, an audio module170, a sensor module176, an interface177, a haptic module179, a camera module180, a power management module188, a battery189, a communication module190, a subscriber identification module (SIM)196, or an antenna module197. In various embodiments, at least one (e.g., the display device160or the camera module180) of the components may be omitted from the electronic device101, or one or more other components may be added in the electronic device101. In various embodiments, some of the components may be implemented as single integrated circuitry. For example, the sensor module176(e.g., a fingerprint sensor, an iris sensor, or an illuminance sensor) may be implemented as embedded in the display device160(e.g., a display). The processor120may execute, for example, software (e.g., a program140) to control at least one other component (e.g., a hardware or software component) of the electronic device101coupled with the processor120, and may perform various data processing or computation. According to an embodiment, as at least part of the data processing or computation, the processor120may load a command or data received from another component (e.g., the sensor module176or the communication module190) in volatile memory132, process the command or the data stored in the volatile memory132, and store resulting data in non-volatile memory134. According to an embodiment, the processor120may include a main processor121(e.g., a central processing unit (CPU) or an application processor (AP)), and an auxiliary processor123(e.g., a graphics processing unit (GPU), an image signal processor (ISP), a sensor hub processor, or a communication processor (CP)) that is operable independently from, or in conjunction with, the main processor121. Additionally or alternatively, the auxiliary processor123may be adapted to consume less power than the main processor121, or to be specific to a specified function. The auxiliary processor123may be implemented as separate from, or as part of the main processor121. The auxiliary processor123may control at least some of functions or states related to at least one component (e.g., the display device160, the sensor module176, or the communication module190) among the components of the electronic device101, instead of the main processor121while the main processor121is in an inactive (e.g., sleep) state, or together with the main processor121while the main processor121is in an active state (e.g., executing an application). According to an embodiment, the auxiliary processor123(e.g., an image signal processor or a communication processor) may be implemented as part of another component (e.g., the camera module180or the communication module190) functionally related to the auxiliary processor123. The memory130may store various data used by at least one component (e.g., the processor120or the sensor module176) of the electronic device101. The various data may include, for example, software (e.g., the program140) and input data or output data for a command related thereto. The memory130may include the volatile memory132or the non-volatile memory134. The program140may be stored in the memory130as software, and may include, for example, an operating system (OS)142, middleware144, or an application146. The input device150may receive a command or data to be used by other component (e.g., the processor120) of the electronic device101, from the outside (e.g., a user) of the electronic device101. The input device150may include, for example, a microphone, a mouse, a keyboard, or a digital pen (e.g., a stylus pen). The sound output device155may output sound signals to the outside of the electronic device101. The sound output device155may include, for example, a speaker or a receiver. The speaker may be used for general purposes, such as playing multimedia or playing record, and the receiver may be used for an incoming calls. According to an embodiment, the receiver may be implemented as separate from, or as part of the speaker. The display device160may visually provide information to the outside (e.g., a user) of the electronic device101. The display device160may include, for example, a display, a hologram device, or a projector and control circuitry to control a corresponding one of the display, hologram device, and projector. According to an embodiment, the display device160may include touch circuitry adapted to detect a touch, or sensor circuitry (e.g., a pressure sensor) adapted to measure the intensity of force incurred by the touch. The audio module170may convert a sound into an electrical signal and vice versa. According to an embodiment, the audio module170may obtain the sound via the input device150, or output the sound via the sound output device155or a headphone of an external electronic device (e.g., an electronic device102) directly (e.g., wiredly) or wirelessly coupled with the electronic device101. The sensor module176may detect an operational state (e.g., power or temperature) of the electronic device101or an environmental state (e.g., a state of a user) external to the electronic device101, and then generate an electrical signal or data value corresponding to the detected state. According to an embodiment, the sensor module176may include, for example, a gesture sensor, a gyro sensor, an atmospheric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor. The interface177may support one or more specified protocols to be used for the electronic device101to be coupled with the external electronic device (e.g., the electronic device102) directly (e.g., wiredly) or wirelessly. According to an embodiment, the interface177may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, a secure digital (SD) card interface, or an audio interface. A connecting terminal178may include a connector via which the electronic device101may be physically connected with the external electronic device (e.g., the electronic device102). According to an embodiment, the connecting terminal178may include, for example, a HDMI connector, a USB connector, a SD card connector, or an audio connector (e.g., a headphone connector). The haptic module179may convert an electrical signal into a mechanical stimulus (e.g., a vibration or a movement) or electrical stimulus which may be recognized by a user via his tactile sensation or kinesthetic sensation. According to an embodiment, the haptic module179may include, for example, a motor, a piezoelectric element, or an electric stimulator. The camera module180may capture a still image or moving images. According to an embodiment, the camera module180may include one or more lenses, image sensors, image signal processors, or flashes. The power management module188may manage power supplied to the electronic device101. According to an embodiment, the power management module188may be implemented as at least part of, for example, a power management integrated circuit (PMIC). The battery189may supply power to at least one component of the electronic device101. According to an embodiment, the battery189may include, for example, a primary cell which is not rechargeable, a secondary cell which is rechargeable, or a fuel cell. The communication module190may support establishing a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device101and the external electronic device (e.g., the electronic device102, the electronic device104, or the server108) and performing communication via the established communication channel. The communication module190may include one or more communication processors that are operable independently from the processor120(e.g., the application processor (AP)) and supports a direct (e.g., wired) communication or a wireless communication. According to an embodiment, the communication module190may include a wireless communication module192(e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module194(e.g., a local area network (LAN) communication module or a power line communication (PLC) module). A corresponding one of these communication modules may communicate with the external electronic device via the first network198(e.g., a short-range communication network, such as Bluetooth™, wireless-fidelity (Wi-Fi) direct, or infrared data association (IrDA)) or the second network199(e.g., a long-range communication network, such as a cellular network, the Internet, or a computer network (e.g., LAN or wide area network (WAN)). These various types of communication modules may be implemented as a single component (e.g., a single chip), or may be implemented as multi components (e.g., multi chips) separate from each other. The wireless communication module192may identify and authenticate the electronic device101in a communication network, such as the first network198or the second network199, using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the subscriber identification module196. The antenna module197may transmit or receive a signal or power to or from the outside (e.g., the external electronic device) of the electronic device101. According to an embodiment, the antenna module197may include an antenna including a radiating element including a conductive material or a conductive pattern formed in or on a substrate (e.g., PCB). According to an embodiment, the antenna module197may include a plurality of antennas. In such a case, at least one antenna appropriate for a communication scheme used in the communication network, such as the first network198or the second network199, may be selected, for example, by the communication module190(e.g., the wireless communication module192) from the plurality of antennas. The signal or the power may then be transmitted or received between the communication module190and the external electronic device via the selected at least one antenna. According to an embodiment, another component (e.g., a radio frequency integrated circuit (RFIC)) other than the radiating element may be additionally formed as part of the antenna module197. At least some of the above-described components may be coupled mutually and communicate signals (e.g., commands or data) therebetween via an inter-peripheral communication scheme (e.g., a bus, general purpose input and output (GPIO), serial peripheral interface (SPI), or mobile industry processor interface (MIPI)). According to an embodiment, commands or data may be transmitted or received between the electronic device101and the external electronic device104via the server108coupled with the second network199. Each of the electronic devices102and104may be a device of a same type as, or a different type, from the electronic device101. According to an embodiment, all or some of operations to be executed at the electronic device101may be executed at one or more of the external electronic devices102,104, or108. For example, if the electronic device101should perform a function or a service automatically, or in response to a request from a user or another device, the electronic device101, instead of, or in addition to, executing the function or the service, may request the one or more external electronic devices to perform at least part of the function or the service. The one or more external electronic devices receiving the request may perform the at least part of the function or the service requested, or an additional function or an additional service related to the request, and transfer an outcome of the performing to the electronic device101. The electronic device101may provide the outcome, with or without further processing of the outcome, as at least part of a reply to the request. To that end, a cloud computing, distributed computing, or client-server computing technology may be used, for example. FIG.2is a block diagram200illustrating an example configuration of an example electronic device101in a network environment including a plurality of cellular networks according to various embodiments. Referring toFIG.2, an electronic device101may include a first communication processor (e.g., including processing circuitry)212, a second communication processor (e.g., including processing circuitry)214, a first radio frequency integrated circuit (RFIC)222, a second RFIC224, a third RFIC226, a fourth RFIC228, a first radio frequency front end (RFFE)232, a second RFFE234, a first antenna module242, a second antenna module244, and an antenna248. The electronic device101may further include a processor (e.g., including processing circuitry)120and a memory130. The second network199may include a first cellular network292and a second cellular network294. According to an embodiment, the electronic device may further include at least one of the parts shown inFIG.1and the second network199may further include at least one another network. According to an embodiment, the first communication processor212, the second communication processor214, the first RFIC222, the second RFIC224, the fourth RFIC228, the first RFFE232, and the second RFFE234may form at least a portion of a wireless communication module192. According to an embodiment, the fourth RFIC228may be omitted or may be included as a portion of the third RFIC226. The first communication processor212may include various communication circuitry and can support establishment of a communication channel with a band to be used for wireless communication with the first cellular network292and legacy network communication through the established communication channel. According to various embodiments, the first cellular network may be a legacy network including a 2G, 3G, 4G, or Long-Term Evolution (LTE) network. The second communication processor214may include various communication circuitry and can support establishment of a communication channel corresponding to a designated band (e.g., about 6 GHz˜about 60 GHz) of a band to be used for wireless communication with the second cellular network294and 5G network communication through the established communication channel. According to various embodiments, the second cellular network294may be a 5G network that is defined in 3GPP. Further, according to an embodiment, the first communication processor212or the second communication processor214can support establishment of a communication channel corresponding to another designated band (e.g., about 6 GHz or less) of a band to be used for wireless communication with the second cellular network294and 5G network communication through the established communication channel. According to an embodiment, the first communication processor212and the second communication processor214may be implemented in a single chip or a single package. According to various embodiments, the first communication processor212or the second communication processor214may be disposed in a single chip or a single package together with the processor120, the auxiliary processor123, or the communication module190. According to an embodiment, the first communication processor212and the second communication processor214is directly or indirectly connected by an interface (not shown), thereby being able to provide or receive data or control signal in one direction or two directions. The first RFIC222, in transmission, can converts a baseband signal generated by the first communication processor212into a radio frequency (RF) signal of about 700 MHz to about 3 GHz that is used for the first cellular network292(e.g., a legacy network). In reception, an RF signal can be obtained from the first cellular network292(e.g., a legacy network) through an antenna (e.g., the first antenna module242) and can be preprocessed through an RFFE (e.g., the first RFFE232). The first RFIC222can covert the preprocessed RF signal into a baseband signal so that the preprocessed RF signal can be processed by the first communication processor212. The second RFIC224can convert a baseband signal generated by the first communication processor212or the second communication processor214into an RF signal in a Sub6 band (e.g., about 6 GHz or less) (hereafter, 5G Sub6 RF signal) that is used for the second cellular network294(e.g., a 5G network). In reception, a 5G Sub6 RF signal can be obtained from the second cellular network294(e.g., a 5G network) through an antenna (e.g., the second antenna module244) and can be preprocessed through an RFFE (e.g., the second RFFE234). The second RFIC224can convert the processed 5G Sub6 RF signal into a baseband signal so that the processed 5G Sub6 RF signal can be processed by a corresponding communication processor of the first communication processor212or the second communication processor214. The third RFIC226can convert a baseband signal generated by the second communication processor214into an RF signal in a 5G Above6 band (e.g., about 6 GHz˜about 60 GHz) (hereafter, 5G Above6 RF signal) that is used for the second cellular network294(e.g., a 5G network). In reception, a 5G Above6 RF signal can be obtained from the second cellular network294(e.g., a 5G network) through an antenna (e.g., the antenna248) and can be preprocessed through the third RFFE236. The third RFIC226can covert the preprocessed 5G Above6 RF signal into a baseband signal so that the preprocessed 5G Above6 RF signal can be processed by the first communication processor214. According to an embodiment, the third RFFE236may be provided as a portion of the third RFIC226. The electronic device101, according to an embodiment, may include a fourth RFIC228separately from or as at least a portion of the third RFIC226. In this case, the fourth RFIC228can convert a baseband signal generated by the second communication processor214into an RF signal in an intermediate frequency band (e.g., about 9 GHz˜about 11 GHz) (hereafter, IF signal), and then transmit the IF signal to the third RFIC226. The third RFIC226can convert the IF signal into a 5G Above6 RF signal. In reception, a 5G Above6 RF signal can be received from the second cellular network294(e.g., a 5G network) through an antenna (e.g., the antenna248) and can be converted into an IF signal by the third RFIC226. The fourth RFIC228can covert the IF signal into a baseband signal so that IF signal can be processed by the second communication processor214. According to an embodiment, the first RFIC222and the second RFIC224may be implemented as at least a portion of a single chip or a single package. According to an embodiment, the first RFFE232and the second RFFE234may be implemented as at least a portion of a single chip or a single package. According to an embodiment, at least one of the first antenna module242or the second antenna module244may be omitted, or may be combined with another antenna module and can process RF signals in a plurality of bands. According to an embodiment, the third RFIC226and the antenna248may be disposed on a substrate, thereby being able to form a third antenna module246. For example, the wireless communication module192or the processor120may be disposed on a first substrate (e.g., a main PCB). In this case, the third RFIC226may be disposed in a partial area (e.g., the bottom) and the antenna248may be disposed in another partial area (e.g., the top) of a second substrate (e.g., a sub PCB) that is different from the first substrate, thereby being able to form the third antenna module246. By disposing the third RFIC226and the antenna248on the same substrate, it is possible to reduce the length of the transmission line therebetween. Accordingly, it is possible to reduce a loss (e.g., attenuation) of a signal in a high-frequency band (e.g., about 6 GHz˜about 60 GHz), for example, which is used for 5G network communication, due to a transmission line. Accordingly, the electronic device101can improve the quality and the speed of communication with the second cellular network294(e.g., 5G network). According to an embodiment, the antenna248may be an antenna array including a plurality of antenna elements that can be used for beamforming. In this case, the third RFIC226, for example, as a portion of the third RFFE236, may include a plurality of phase shifters238corresponding to the antenna elements. In transmission, the phase shifters238can convert the phase of a 5G Above6 RF signal to be transmitted to the outside of the electronic device101(e.g., to a base station of a 5G network) through the respectively corresponding antenna elements. In reception, the phase shifters238can convert the phase of a 5G Above6 RF signal received from the outside through the respectively corresponding antenna element into the same or substantially the same phase. This enables transmission or reception through beamforming between the electronic device101and the outside. The second cellular network294(e.g., a 5G network) may be operated independently from (e.g., Stand-Along (SA)) or connected and operated with (e.g., Non-Stand Alone (NSA)) the first cellular network292(e.g., a legacy network). For example, there may be only an access network (e.g., a 5G radio access network (RAN) or a next generation RAN (NG RAN)) and there is no core network (e.g., a next generation core (NGC)) in a 5G network. In this case, the electronic device101can access the access network of the 5G network and then can access an external network (e.g., the internet) under control by the core network (e.g., an evolved packed core (EPC)) of the legacy network. Protocol information (e.g., LTE protocol information) for communication with a legacy network or protocol information (e.g., New Radio (NR) protocol information) for communication with a 5G network may be stored in the memory230and accessed by another part (e.g., the processor120, the first communication processor212, or the second communication processor214). FIG.3is a diagram illustrating an example operation for connecting wireless communication between a base station320and an electronic device101in a network using directional beams for wireless connection according to various embodiments. According to an embodiment, the base station (gNB(gNodeB), a transmission reception point (TRP))320may perform a beam detection operation with the electronic device101to connect the wireless communication. In the illustrated embodiment, to achieve the beam detection, the base station320may perform transmission beam sweeping330at least one time by transmitting a plurality of transmission beams, for example, first to fifth transmission beams335-1to335-5of different directions, in sequence. According to an embodiment, the first to fifth transmission beams335-1to335-5may include at least one synchronization sequences (SS)/physical broadcast channel (PBCH) block (SS/PBCH Block). The SS/PBCH Block may be used to periodically measure a channel of the electronic device110or beam intensity. In an embodiment, the first to fifth transmission beams335-1to335-5may include at least one channel state information-reference signal (CSI-RS). The CSI-RS may be a criterion/reference signal flexibly set by the base station320, and may be transmitted periodically/semi-persistently or aperiodically. The electronic device101may measure the channel, beam intensity using the CSI-RS. According to an embodiment, the transmission beams may form a radiation pattern having a selected beam width. For example, the transmission beams may have a broad radiation pattern having a first beam width, or a sharp radiation pattern having a second beam width which is narrower than the first beam width. For example, the transmission beams including the SS/PBCH Block may have a broader radiation pattern than that of the transmission beams including the CSI-RS. According to an embodiment, the electronic device101may perform reception beam sweeping340while the base station320is performing the transmission beam sweeping330. For example, the electronic device101may fix a first reception beam345-1in a first direction and may receive a signal of the SS/PBCH Block transmitted with at least one of the first to fifth transmission beams335-1to335-5while the base station220is performing the first transmission beam sweeping330. The electronic device101may fix a second reception beam345-2in a second direction and may receive a signal of the SS/PBCH Block transmitted with the first to fifth transmission beams335-1to335-5while the base station320is performing the second transmission beam sweeping330. As described above, the electronic device101may select a reception beam (for example, the second reception beam345-2) and a transmission beam (for example, the third transmission beam335-3) that enable communication, based on a result of receiving a signal through the reception beam sweeping340. According to an embodiment, when the transmission and reception beams that enable communication are determined as described above, the base station320and the electronic device101may transmit and/or receive basic information of setting a cell, and may set information of additional beam management based on the basic information. For example, the beam management information may include detailed information on the set beam, setting information regarding the SS/PBCH Block, CSI-RS or additional reference signal. According to an embodiment, the electronic device101may continuously monitor the channel and the beam intensity using at least one of the SS/PBCH Block, the CSI-RS included in the transmission beams. The electronic device101may adaptively select a beam having good beam quality using the monitoring operation. Selectively, when communication is disconnected due to movement of the electronic device101or interruption of the beams, the electronic device may perform the above-described beam sweeping operation again and may determine a beam for communication. FIG.4is a block diagram illustrating an example configuration of an electronic device101for 5G network communication according to various embodiments. The electronic device101may include various components shown inFIG.4, but for brief explanation,FIG.4illustrates that the electronic device includes a processor (e.g., including processing circuitry)120, a second communication processor (e.g., including processing circuitry)214, a fourth RFIC228, at least one third antenna module246. For example, the processor120may be an application processor (AP), and the second communication processor214may be a modulator-demodulator (MODEM). Referring toFIG.4, the third antenna module246may include first to fourth phase shifters213-1to213-4, and/or first to fourth antenna elements217-1to217-4. Each one of the first to fourth antenna elements217-1to217-4may be electrically connected with individual one of the first to fourth phase shifters213-1to213-4. The first to fourth antenna elements217-1to217-4may form at least one antenna array215. According to an embodiment, the second communication processor214may control phases of signals transmitted and/or received through the first to fourth antenna elements217-1to217-4, by controlling the first to fourth phase shifters213-1to213-4, and accordingly, may generate a transmission beam and/or a reception beam in a selected direction. According to an embodiment, the third antenna module246may form a beam251of a broad radiation pattern (hereinafter, a “broad beam”) or a beam253of a sharp radiation pattern (hereinafter, a “sharp beam”) mentioned above, according to the number of antenna elements used. For example, the third antenna module246may form the sharp beam253when all of the first to fourth antenna elements217-1to217-4are used, and may form the broad beam251when only the first antenna element217-1and the second antenna element217-2are used. Since the broad beam251has a wider coverage than the sharp beam253but has a lower antenna gain, the broad beam251may be more effective in beam detection. On the other hand, since the sharp beam253has a narrower coverage than the broad beam251but has a higher antenna gain, the sharp beam253can enhance communication performance. According to an embodiment, the second communication processor214may utilize a sensor module176(for example, a nine-axis sensor, a grip sensor, or a GPS) for beam detection. For example, the electronic device101may adjust a beam detection position and/or a beam detection period based on a position and/or movement of the electronic device101using the sensor module176. In another example, when the electronic device101is gripped by a user, an antenna module having better communication performance may be selected from the plurality of third antenna modules246by identifying a part gripped by the user. According to various embodiments, an intermediate frequency integrated circuit (IFIC) (not shown) included in the electronic device101may convert a baseband signal of the second communication processor214into an interband signal, and a radio frequency integrated circuit (RFIC) mounted in the third antenna module246may convert an intermediate frequency (IF) into a target frequency band (for example, 28 GHz, 39 GHz). According to various embodiments, the processor120and the second communication processor214may be one component, or the IFIC (not shown) and the third RFIC226may be one component, and the third RFIC226and the third antenna module246may be separated as other components. FIG.5is a block diagram illustrating an example configuration of an electronic device500for controlling a plurality of antenna modules according to various embodiments. Referring toFIG.5, the electronic device500according to an embodiment may include a plurality of antenna modules, and the number of the plurality of antenna modules is not limited, and for example, the electronic device may include three antenna modules. The electronic device500(for example, the electronic device101ofFIG.1) may include a processor (e.g., including processing circuitry)502(for example, the processor120ofFIG.1and/or the second communication processor ofFIG.2), a first antenna module (e.g., including at least one antenna)504(for example, the third antenna module246ofFIG.2), a second antenna module (e.g., including at least one antenna)506, a third antenna module (e.g., including at least one antenna)508, and/or a memory510(for example, the memory130ofFIG.1). According to an embodiment, the processor502may include various processing circuitry and control overall operations of the electronic device500. For example, the processor502may control at least one other component (for example, a hardware or software component) connected to the processor502, and may perform various data processing or computation. According to an embodiment, the processor502may load a command or data received from another component into the memory as at least part of the data processing or computation, and may process the command or data stored in the memory and may store resulting data in the memory. According to an embodiment, the processor502may receive state information of the first antenna module504, the second antenna module506, and/or the third antenna module508in the electronic device500, and may activate at least one antenna module of the first antenna module504, the second antenna module506, or the third antenna module508based on the state information. The processor502may control to perform beam sweeping with respect to the at least one activated antenna module, and may determine a beam of the strongest signal strength based on the beam sweeping. The processor502may set a beam that each of the antenna modules has, by changing a register value of a phase shifter included in each of the antenna modules. The processor502may pre-store a setting value of the phase shifter in the memory510to set a beam that each of the antenna modules has. In various embodiments of the disclosure, the beam sweeping controlled by the processor502may be variable. For example, the processor502may change an order of beams for beam sweeping. In addition, the processor502may control to skip at least one beam of a beam set of performing beam sweeping, and to perform beam sweeping. According to an embodiment, the first antenna module504, the second antenna module506, or the third antenna module508may each include at least one antenna and perform communication with a base station through beams in respective directions of the electronic device500. The first antenna module504, the second antenna module506, or the third antenna module508may have at least one beam. For example, the first antenna module504, the second antenna module506or the third antenna module508may include a plurality of active elements such as a phase shifter or a power amplifier, a plurality of antenna elements and/or an RFIC. The first antenna module504, the second antenna module506, or the third antenna module508may control phases of signals transmitted and/or received through the plurality of antenna elements, by controlling the plurality of phase shifters, and accordingly, may generate a transmission beam and/or a reception beam in a selected direction. According to an embodiment, the antenna module may form a beam of a broad radiation pattern or a beam of a sharp radiation pattern according to the number of antenna elements. Since the broad beam (for example, the broad beam251ofFIG.4) has a wider coverage than the sharp beam (for example, the sharp beam253ofFIG.4), but has a lower antenna gain, the broad beam may be more effective in beam detection. On the other hand, since the sharp beam has a narrower coverage than the broad beam, but has a higher antenna gain, the sharp beam can enhance communication performance. According to an embodiment, the memory510may store various data used by at least one component (for example, the processor502) of the electronic device500. The data may include, for example, state information of each of the plurality of antenna modules (for example, the first antenna module504, the second antenna module506, and the third antenna module508), beam set information regarding the plurality of antenna modules, information of an optimal beam determined through beam sweeping, and input data or output data related to a relevant command. FIGS.6A,6B and6Care diagrams illustrating an example structure of the third antenna module246according to various embodiments. FIG.6Aillustrates an embodiment of a structure of the third antenna module246described with reference toFIG.2, for example.FIG.6Ais a perspective view of the third antenna module246seen from one side, andFIG.6Bis a perspective view of the third antenna module246seen from the other side.FIG.6Cis a cross-sectional view of the third antenna module246taken on line A-A′. Referring toFIGS.6A,6B and6C, in an embodiment, the third antenna module246may include a printed circuit board610, an antenna array630, a radio frequency integrate circuit (RFIC)652, a power manage integrate circuit (PMIC)654, and a module interface (not shown). Selectively, the third antenna module246may further include a shielding member690. In various embodiments, at least one of the above-mentioned components may be omitted or at least two of the components may be integrally formed with each other. According to an embodiment, the printed circuit board610may include a plurality of conductive layers and a plurality of non-conductive layers which are stacked alternately with the conductive layers. The printed circuit board610may provide electric connection between the printed circuit board610and/or various electronic components disposed on the outside using wires and conductive vias formed on the conductive layer. According to an embodiment, the antenna array630(for example, the antenna248ofFIG.2) may include a plurality of antenna elements632,634,636or638disposed to form directional beams. The antenna elements may be formed, for example, on a first surface of the printed circuit board610. According to an embodiment, the antenna array630may be formed inside the printed circuit board610. According to embodiments, the antenna array630may include a plurality of antenna arrays of the same or different shapes or types (for example, a dipole antenna array and/or a patch antenna array). According to an embodiment, the RFIC652(for example, the third RFIC226ofFIG.2) may be disposed on another area (for example, a second surface opposite to the first surface) of the printed circuit board610that is spaced apart from the antenna array. The RFIC may be configured to process a signal of a selected frequency band which is transmitted/received through the antenna array630. According to an embodiment, the RFIC652may convert a baseband signal acquired from a communication processor (not shown) into an RF signal of a designated band when transmitting signals. The RFIC652may convert an RF signal received through the antenna array630into a baseband signal when receiving signals, and may transmit the baseband signal to the communication processor. According to an embodiment, the RFIC652may up-convert an IF signal (for example, about 9 GHz to about 11 GHz) acquired from an intermediate frequency integrate circuit (IFIC) (for example, the fourth RFIC228ofFIG.2) into an RF signal of a selected band when transmitting signals. The RFIC652may down-convert an RF signal acquired through the antenna array630into an IF signal when receiving signals, and may transmit the IF signal to the IFIC. According to an embodiment, the PMIC654may be disposed on another area (for example, the second surface) of the printed circuit board610spaced apart from the antenna array. The PMIC may receive a voltage from a main PCB (not shown), and may provide necessary power to various components (for example, the RFIC652) on the antenna module. According to an embodiment, the shielding member690may be disposed on part (for example, the second surface) of the printed circuit board610to electromagnetically shield at least one of the RFIC652or the PMIC654. According to an embodiment, the shielding member690may include a shield can. In various embodiments, the third antenna module246may be electrically connected with another printed circuit board (for example, a main circuit board) through the module interface although this is not illustrated in the drawing. The module interface may include a connection member, for example, a coaxial cable connector, a board-to-board connector, an interposer, or a flexible printed circuit board (FPCB). The RFIC652and/or the PMIC654of the antenna module may be electrically connected with the printed circuit board through the connection member. FIG.7is a block diagram illustrating an example configuration of an antenna module included in the electronic device500according to various embodiments. The first antenna module504may include various components, and is illustrated inFIG.7as including a printed circuit board (PCB)702(for example, the printed circuit board610ofFIG.6), a connector704, a sensor706and/or a radio frequency integrated circuit (RFIC)708(for example, the third RFIC226ofFIG.2) for brief explanation. Referring toFIG.7, the PCB702according to an embodiment may be a board that configures an electronic circuit to connect an electronic component such as a resistor, a condenser, or an integrated circuit. The connector704may connect the PCB703and a main PCB. The sensor706may detect an operation state (for example, power or temperature) of the first antenna module504, and may generate an electric signal or a data value corresponding to the detected state. According to an embodiment, the sensor706may include, for example, a grip sensor and/or a temperature sensor. The RFIC708may be an RF circuit that is implemented on one semiconductor chip using an active element and a passive element. For example, the sensor706mounted on the first antenna module504may measure a temperature of the first antenna module504, and may transmit data regarding the measured temperature to the processor502. In various embodiments, the sensor706may be included in other components than the antenna module504or may be included as a separate component in the electronic device500. According to various example embodiments, an electronic device500(for example, the electronic device101ofFIG.1) may include: a plurality of antenna modules, each including at least one antenna; a memory (for example, the memory130ofFIG.1); and a processor (for example, the processor120ofFIG.1and/or the second communication processor214ofFIG.2), and the processor may be configured to: identify that a first antenna module (for example, the first antenna module504ofFIG.5) among the plurality of antenna modules (for example, the first antenna module504ofFIG.5, the second antenna module506ofFIG.5, the third antenna module508ofFIG.5) is unusable; change a first beam set of the plurality of antenna modules to a second beam set including at least one sub beam to cover at least part of a coverage of the first antenna module; and control the electronic device to perform communication based on the second beam set. According to various example embodiments, the at least one sub beam may include a beam of a usable antenna module among the plurality of antenna modules that covers at least part of the coverage of at least one antenna module identified as being unusable among the plurality of antenna modules. According to various example embodiments, the processor may be configured to receive information regarding a temperature of each of the plurality of antenna modules from the plurality of antenna modules, and determine whether the temperature of each of the plurality of antenna modules exceeds a specified first threshold value, based on the information regarding the temperature. According to various example embodiments, the processor may be configured to identify that the first antenna module is usable; change the second beam set to the first beam set, and control the electronic device to perform communication based on the first beam set, wherein the first beam set may be configured as a plurality of main beams of the respective plurality of antenna modules. According to various example embodiments, the processor may be configured to determine whether a temperature of the first antenna module is less than a specified second threshold value, based on the information regarding the temperature. According to various example embodiments, the plurality of main beams may have a higher effective isotropic radiated power (EIRP) gain with respect to a specific coverage than the at least one sub beam. According to various example embodiments, the processor may be configured to control the electronic device to: perform beam sweeping based on the first beam set; and perform communication using a beam determined based on the beam sweeping. According to various example embodiments, the first threshold value may be larger than the second threshold value. According to various example embodiments, the processor may be configured to control the electronic device to: perform beam sweeping based on the second beam set, and perform communication using a beam determined based on the beam sweeping. According to various example embodiments, the second beam set may correspond to a beam table in which a value of a beam of each of the plurality of antenna modules optimized for a coverage of another antenna module is pre-stored. FIG.8is a graph and diagram illustrating comparison of a radiation pattern of a main beam of an antenna module and a radiation pattern of a sub beam of another antenna module according to various embodiments. An electronic device500illustrated inFIG.8may include a first antenna module504which manages a main beam504-1and a sub beam504-2, a second antenna module506which manages a main beam506-1without managing a sub beam, and a third antenna module508which manages a main beam508-1and a sub beam508-2. Referring toFIG.8, each of the first antenna module504, the second antenna module506, and the third antenna module508according to an embodiment may perform communication using at least one main beam504-1,506-1,508-1facing their respective coverage regions. For example, the first antenna module504may cover a left region of the electronic device500using at least one main beam504-1. The second antenna module506may cover an upper region of the electronic device500using at least one main beam506-1. The third antenna module508may cover a right region of the electronic device500using at least one main beam508-1. The left region of the electronic device500may be covered using at least one sub beam508-2of the third antenna module508, in addition to the at least one main beam504-1of the first antenna module504. The upper region of the electronic device500may be covered using at least one sub beam504-2of the first antenna module504or at least one sub beam508-2of the third antenna module508, in addition to the at least one main beam506-1of the second antenna module506. The right region of the electronic device500may be covered using the at least one sub beam504-2of the first antenna module504in addition to the at least one main beam508-1of the third antenna module508. The main beam may be a beam that has a higher EIRP gain for a specific coverage than a sub beam, and may include a beam of an antenna module facing the specific coverage. For example, at least one main beam for the left region of the electronic device500may include a beam of the first antenna module504. The sub beam may be a beam that has a lower EIRP gain for a specific coverage than a main beam, and may include a beam of another antenna module covering at least part of the specific coverage. For example, at least one sub beam for the left region of the electronic device500may include a beam of the second antenna module506or a beam of the third antenna module508. According to an embodiment, the main beam and the sub beam covering the upper region of the electronic device500will be described. In the upper region of the electronic device500, a radiation pattern810of the main beam506-1of the second antenna module506, which covers the upper region of the electronic device500, may have a narrower beam width than a radiation pattern820of the sub beam504-2of the first antenna module504or the sub beam508-2of the third antenna module508, which covers the upper region of the electronic device500. Referring to the graph830illustrating EIRP regarding the main beam and the sub beam covering the upper region of the electronic device500according to angles, in a section from about −40° to about 40°, EIRP832of the main beam of the second antenna module506, which covers the upper region of the electronic device500, may be higher than EIRP831of the sub beam504-2of the first antenna module504or the sub beam508-2of the third antenna module508, which covers the upper region of the electronic device500. From the upper region of the electronic device500to a side region, there may be a region in which the EIRP832of the main beam of the second antenna module506, which covers the upper region of the electronic device500, is lower than the EIRP831of the sub beam504-2of the first antenna module504or the sub beam508-2of the third antenna module508, which covers the upper region of the electronic device500, in a section lower than about −40° or a section exceeding about 40°. FIG.9is a flowchart900illustrating example operations for controlling a plurality of antenna modules when at least one antenna module is unusable in the electronic device500according to various embodiments. An operating entity of the flowchart900illustrated inFIG.9may be understood as the electronic device500or a component (for example, the processor502) of the electronic device500. Referring toFIG.9, in operation901, the electronic device500according to an embodiment may identify that a certain antenna module among the plurality of antenna modules is unusable. The electronic device500may receive state information from the sensor706included in each of the plurality of antenna modules. The state information may include information regarding a temperature of the antenna module. For example, the electronic device500may receive the state information including the information regarding the temperature of the antenna module from the sensor706included in each of the plurality of antenna modules. The electronic device500may compare the temperature of each of the plurality of antenna modules and a first threshold value, and may determine an antenna module the temperature of which exceeds the first threshold value as an unusable antenna module. In various embodiments, the electronic device500may identify that at least one antenna module used for current communication among the plurality of antenna modules is unusable. For example, the electronic device500may receive state information including information regarding a temperature of at least one antenna module from the sensor706included in the at least one antenna module used for current communication among the plurality of antenna modules. The electronic device500may compare the temperature of the at least one antenna module used for current communication among the plurality of antenna modules and the first threshold value, and may determine the at least one antenna module the temperature of which exceeds the first threshold value as an unusable antenna module. In various embodiments, when the sensor is included in other components than the antenna module in the electronic device500, or is included as a separate component in the electronic device500, the electronic device500may receive state information of each of the plurality of antenna modules from the sensor. For example, the electronic device500may receive the state information including information regarding the temperature of each of the plurality of antenna modules from the sensor. According to an embodiment, in operation903, the electronic device500may change a beam set used for current communication (for example, a beam set used for beam sweeping) from a first beam set of the plurality of antenna modules to a second beam set. The second beam set may be, for example, a beam set that includes at least one sub beam to cover at least part of a coverage of at least one unusable antenna module among the plurality of antenna modules. The first beam set may include at least one main beam for each of the plurality of antenna modules in the electronic device500. The main beam may be a beam that has a higher EIRP gain with respect to a specific coverage than a sub beam, and may include a beam of an antenna module facing the specific coverage. The second beam set may include at least one sub beam for at least one usable antenna module among the plurality of antenna modules in the electronic device500, and the sub beam may be a beam that has a lower EIRP gain with respect to a specific coverage than a main beam, and may include a beam of another antenna module that covers at least part of a coverage of an antenna module identified as being unusable. Information regarding the first beam set and/or the second beam set may be pre-stored in the memory510of the electronic device500. For example, the information regarding the first beam set and/or the second beam set may be pre-stored in the memory510of the electronic device500in the form of a beam table. According to an embodiment, in operation905, the electronic device500may perform communication based on the second beam set. The electronic device500may determine a beam capable of covering the coverage of the antenna module identified as being unusable, based on the second beam set. The electronic device500may perform communication using the determined beam. For example, the electronic device500may perform beam sweeping based on the beam table including the information regarding the main beam and the sub beam regarding at least one usable antenna module, and may determine an optimal beam to cover the coverage of the antenna module identified as being unusable. FIG.10Ais a flowchart1000illustrating example operations for determining an optimal beam when at least one antenna module is unusable in the electronic device500according to various embodiments.FIG.10Bis a diagram illustrating regions covered by main beams and sub beams of the plurality of antenna modules in the electronic device500according to various embodiments. Herein, a beam that has a maximum of the EIRP average regarding a specific coverage among a plurality of beams equally supporting the specific coverage may be referred to as a main beam, and the other beams may be referred to as sub beams. An operating entity of the flowchart1000illustrated inFIG.10Amay be understood as the electronic device500or a component of the electronic device500(for example, the processor502or the second communication processor214ofFIG.2). Referring toFIG.10A, in operation1001, the electronic device500according to an embodiment may monitor whether each of the plurality of antenna modules is usable. For example, the electronic device500may monitor whether each of the plurality of antenna modules is usable in the middle of performing communication. The electronic device500may monitor whether each of the plurality of antenna modules is usable prior to performing communication. The electronic device500may receive state information regarding each antenna module from a sensor (for example, the sensor706ofFIG.7) included in each of the plurality of antenna modules (for example, the first antenna module504, the second antenna module506, the third antenna module508). The state information may be atmospheric pressure, acceleration, temperature, humidity or illuminance regarding the antenna module. For example, the electronic device500may receive information regarding a temperature of the antenna module from the sensor included in each of the plurality of antenna modules. In various embodiments, when the sensor is included in other components than the antenna module in the electronic device500or is included as a separate component in the electronic device500, the electronic device500may receive state information of each of the plurality of antenna modules from the sensor. For example, the electronic device500may receive the state information including information regarding a temperature of each of the plurality of antenna modules from the sensor. According to an embodiment, in operation1003, the electronic device500may determine whether a certain antenna module among the plurality of antenna modules is unusable. For example, the electronic device500may determine whether the temperature of each antenna module, received from the sensor (for example, the sensor706ofFIG.7), exceeds a predetermined first threshold value. The electronic device500may determine at least one antenna module the temperature of which exceeds the predetermined first threshold value as at least one unusable antenna module. According to an embodiment, when the at least one antenna module is determined as being unusable (Yes in operation1003), in operation1005, the electronic device500may change a beam set used for current communication from a first beam set of the plurality of antenna modules to a second beam set that includes at least one sub beam to cover at least part of a coverage of the at least one unusable antenna module among the plurality of antenna modules. For example, when the electronic device500is allowed to perform communication only within the coverage of the at least one unusable antenna module in the electronic device500, the coverage may not be covered by the first beam set of the electronic device500, and accordingly, the electronic device may change the first beam set to the second beam set capable of covering the coverage. According to an embodiment, when the at least one antenna module is not determined as being unusable (No in operation1003), the electronic device500may monitor whether each of the plurality of antenna modules is usable in operation1001. For example, the first beam set may be a beam set that is used when all of the plurality of antenna modules in the electronic device500are usable, and may be configured as a main beam of each of the plurality of antenna modules. Hereinafter, various embodiments of the operation of changing the first beam set to the second beam set will be described. Information regarding the first beam set may be a beam table in which a value of a beam optimized for the coverage of each antenna module is pre-stored as a phase modulator register value. Information regarding the second beam set may be a beam table in which a value of a beam optimized for a coverage of another antenna module in each antenna module is pre-stored as a phase modulator register value. TABLE 1AntennaCoveragemoduleABCDEFGHIM1MB11MB12MB13SB11M2SB21MB21MB22MB23SB22M3SB31SB32MB31MB32MB33 Referring toFIG.10Band table1, each antenna module in the electronic device500may have three main beam identifiers (IDs). The electronic device500may cover coverages A to C with three main beams MB11, MB12, MB13of the first antenna module504M1, may cover coverages D to F with three main beams MB21, MB22, MB23of the second antenna module506M2, and may cover coverages G to I with three main beams MB31, MB32, MB33of the third antenna module508M3. According to an embodiment, each antenna module in the electronic device500may have at least one sub beam ID. The electronic device500may cover the coverage C with a sub beam SB11of the second antenna module506, may cover the coverage D with a sub beam SB21of the first antenna module504, may cover the coverage E with the sub beam SB21of the first antenna module504or a sub beam SB31of the third antenna module508, may cover the coverage F with a sub beam SB32of the third antenna module508, and may cover the coverage G with a sub beam SB22of the second antenna module506. The main beam and the sub beam for one antenna module may have different beam directions, and the numbers of main beams and sub beams or beam widths of the main beam and the sub beam are not limited. According to an embodiment, the electronic device500may use a beam setting value regarding each beam ID as a phase modulator register value of the antenna module corresponding to the corresponding beam, based on a beamforming schedule, while initiating communication or performing communication. TABLE 2UsableantennaCoveragemoduleABCDEFGHIM1, M2,MB11MB12MB13MB21MB22MB23MB31MB32MB33M3M1, M3MB11MB12MB13SB11SB31SB32MB31MB32MB33M3SB31SB32MB31MB32MB33 Referring to table2, the first beam set used when all of the first antenna module504M1, the second antenna module506M2, and the third antenna module508M3are usable according to an embodiment may include the three main beams of the first antenna module504, the three main beams of the second antenna module506, and the three main beams of the third antenna module508, and for example, information regarding the first beam set may be pre-stored in the memory510in the form of a beam table. According to an embodiment, when at least one antenna module is determined as being unusable, the electronic device500may change the first beam set to the second beam set which includes at least one sub beam capable of covering a coverage of the at least one unusable antenna module. According to an embodiment, when the second antenna module506is unusable, the second beam set may include the sub beam SB11of the first module and the sub beams SB31, SB32of the third module to cover the coverages D to F of the unusable second antenna module506. According to an embodiment, when the first antenna module504and the second antenna module506are unusable, the second beam set may include the sub beams SB31, SB32of the third antenna module508to cover the coverage E and the coverage F which are at least part of the coverages A to F of the first antenna module504and the second antenna module506, which are unusable. For example, information regarding the second beam set may be pre-stored in the memory510in the form of a beam table. According to various embodiments, the number of beams of the second beam set may be smaller than the number of beams of the first beam set, based on the numbers of main beams and sub beams of each antenna module. For example, if each of the four antenna modules has four main beams and one sub beam, the electronic device500may use 16 main beams when the four antenna modules are normally operated. When it is identified that one antenna module is unusable, the electronic device500may use 12 main beams and 3 sub beams with respect to all of the three antenna modules. The total number of beams used when a normal operation is performed is 16, and the total number of beams used when one antenna module becomes unusable is 15. That is, the number of beams for beam sweeping by the electronic device500may be reduced. In various embodiments, the number of beams for beam sweeping may be variable. According to an embodiment, in operation1007, the electronic device500may perform beam sweeping based on the second beam set. Referring table2, when the second antenna module506M2in the electronic device500is unusable, the electronic device500may perform beam sweeping with respect to the sub beam SB11of the first antenna module504and the sub beams SB31, SB32of the third antenna module508to cover the coverages D to F of the second antenna module506, the main beams MB11, MB12, MB13of the first antenna module504, and the main beams MB31, MB32, MB33of the third antenna module508, which are the second beam set. According to an embodiment, the electronic device500may perform beam sweeping according to each antenna module, or may perform beam sweeping according to a predetermined order regarding an index of each beam. According to an embodiment, in operation1009, the electronic device500may perform communication with a beam which is determined through beam sweeping. For example, the electronic device500may determine a beam having a strongest signal strength by measuring a strength of a base station signal received with each beam through beam sweeping, and may perform communication with the determined beam. In an embodiment, when the electronic device500monitors whether each of the plurality of antenna modules is usable prior to performing communication, the electronic device500may perform beam sweeping without using at least one unusable antenna module when beam-sweeping, although this is not illustrated. For example, the electronic device may change the first beam set of the plurality of antenna modules to the second beam set including at least one sub beam to cover at least part of the coverage of the unusable antenna module, and may perform beam sweeping using the second beam set. The electronic device500may determine a beam to use for communication based on a result of beam sweeping. The electronic device500may monitor whether each of the plurality of antenna modules is usable in the middle of performing communication using the determined beam (for example, operation1001). FIG.11is a flowchart illustrating example operations for determining an optimal beam when the plurality of antenna modules become usable in the electronic device500according to various embodiments. An operating entity of the flowchart1100illustrated inFIG.11may be understood as the electronic device500or a component (for example, the processor502) of the electronic device500.FIG.11illustrates an example of an operation after it is identified that at least one antenna module in the electronic device500is unusable. Referring toFIG.11, in operation1101, the electronic device1100according to an embodiment may monitor whether each of the plurality of antenna modules is usable. The electronic device1100may receive state information regarding each antenna module from a sensor (for example, the sensor706ofFIG.7) included in each of the plurality of antenna modules (for example, the first antenna module504, the second antenna module506, the third antenna module508). The state information may be atmospheric pressure, acceleration, temperature, humidity or illuminance information regarding the antenna module. For example, the electronic device500may receive information regarding a temperature of the antenna module from the sensor included in each of the plurality of antenna modules. According to an embodiment, in operation1103, the electronic device500may determine whether an unusable antenna module is in the usable state again. For example, the electronic device500may determine whether the temperature of each antenna module received from the sensor (for example, the sensor706ofFIG.7) is less than a predetermined second threshold value. The electronic device500may determine at least one antenna module the temperature of which is less than the predetermined second threshold value as a usable antenna module. According to an embodiment, the first threshold value for determining an unusable antenna module may be greater than the second threshold value for determining a usable antenna module. According to an embodiment, the electronic device500may compare a temperature of a corresponding antenna module and the first threshold value when the corresponding antenna module is a usable antenna module, and may compare a temperature of a corresponding antenna module and the second threshold value when the corresponding antenna module is an unusable antenna module. According to an embodiment, when it is determined that the unusable antenna module becomes usable again, the electronic device500may change the beam set used for current communication from the second beam set to the first beam set including at least one main beam for the plurality of modules in operation1105. The first beam set may be a beam set that is used when all of the plurality of antenna modules in the electronic device500are usable, and may be configured as a main beam of each of the plurality of antenna modules. Information regarding the first beam set may be a beam table in which a value of a beam optimized for a coverage of each antenna module is pre-stored as a phase modulator register value. Referring to table2, since all of the antenna modules are usable, the first beam set may include three main beams for each of the first antenna module504M1, the second antenna module506M2, and the third antenna module508M3, and information regarding the first beam set may be pre-stored in the memory510in the form of a beam table. When the unusable antenna module is not identified as being usable, the electronic device500may monitor whether each of the plurality of antenna modules is usable in operation1101. According to an embodiment, in operation1107, the electronic device500may perform beam sweeping based on the first beam set. Referring to table2, the electronic device500may perform beam sweeping with respect to the three main beams MB11, MB12, MB13of the first antenna module504M1, the three main beams MB21, MB22, MB23of the second antenna module506M2, and the three main beams MB31, MB32, MB33of the third antenna module508M3, which are the first beam set. According to an embodiment, in operation1109, the electronic device500may perform communication with a beam determined through beam sweeping. For example, the electronic device500may determine a beam of a strongest signal strength by measuring a strength of a base station signal received with each beam through beam sweeping, and may perform communication with the determined beam. According to various example embodiments, a method of operating an electronic device500(for example, the electronic device101ofFIG.1) may include: identifying that a first antenna module (for example, the first antenna module504ofFIG.5) among a plurality of antenna modules (for example, the first antenna module504ofFIG.5, the second antenna module506ofFIG.5, the third antenna module508ofFIG.5) is unusable; changing a first beam set of the plurality of antenna modules to a second beam set including at least one sub beam to cover at least part of a coverage of the first antenna module; and performing communication based on the second beam set. According to various example embodiments, the at least one sub beam may include a beam of a usable antenna module among the plurality of antenna modules that covers at least part of the coverage of at least one antenna module identified as being unusable among the plurality of antenna modules. According to various example embodiments, identifying that the first antenna module among the plurality of antenna modules is unusable may include: receiving information regarding a temperature of each of the plurality of antenna modules from the plurality of antenna modules; and determining whether the temperature of each of the plurality of antenna modules exceeds a specified first threshold value, based on the information regarding the temperature. According to various example embodiments, the method may further include: identifying that the first antenna module is usable; changing the second beam set to the first beam set; and performing communication based on the first beam set, and the first beam set may be configured as a plurality of main beams for the respective plurality of antenna modules. According to various example embodiments, identifying that the first antenna module among the plurality of antenna modules is usable may include determining whether a temperature of the first antenna module is less than a specified second threshold value, based on the information regarding the temperature. According to various example embodiments, the plurality of main beams may have a higher effective isotropic radiated power (EIRP) gain with respect to a specific coverage than the at least one sub beam. According to various example embodiments, performing communication based on the first beam set may include: performing beam sweeping based on the first beam set; and performing communication using a beam determined based on the beam sweeping. According to various example embodiments, the first threshold value may be larger than the second threshold value. According to various example embodiments, performing communication based on the second beam set may include: performing beam sweeping based on the second beam set; and performing communication using a beam determined based on the beam sweeping. FIG.12is a graph1200illustrating effective isotropic radiated power (EIRP) regarding an entire coverage according to different operating methods of an electronic device controlling a plurality of antenna modules, as a cumulative distribution function (CDF), according to various embodiments.FIGS.13A,13B and13Care diagrams illustrating examples of communicating using a main beam or a sub beam regarding a plurality of antenna modules in an electronic device according to various embodiments. According to an embodiment, the electronic device500may include a first antenna module504, a second antenna module506, and a third antenna module508, and each antenna module may perform communication through four main beams and one sub beam. Referring toFIG.12, the graph1200illustrating the CDF regarding the EIRP may indicate EIRP performance regarding all directions of the electronic device500. Referring toFIG.13A, Case11301is a case where communication is performed through main beams1to12for the plurality of antenna modules (the first antenna module504, the second antenna module506, the third antenna module508) in the electronic device500. When all of the plurality of antenna modules are usable, a beam sweeping order may be variable and is not limited. For example, the electronic device500may perform beam sweeping according to each antenna module or may perform beam sweeping according to an order predetermined for an index of each beam (see, e.g., graph1201ofFIG.12). Referring toFIG.13B, Case21302is a case where communication is performed through main beams1to4and9to12for at least one usable antenna module (the first antenna module504and the third antenna module508) when at least one antenna module (the second antenna module506) is unusable (see, e.g., graph1202ofFIG.12). Referring toFIG.13C, Case31303is a case where communication is performed through main beams1to4and9to12and sub beams5′,8′ for at least one usable antenna module (the first antenna module504and the third antenna module508) when at least one antenna module (second antenna module506) is unusable (see, e.g., graph1203ofFIG.12). As in Case21302and Case31303, when at least one antenna module of the plurality of antenna modules is unusable, beam sweeping may be performed without using the at least one unusable antenna module. A beam sweeping order may be variable and is not limited. For example, the electronic device500may perform beam sweeping according to each usable antenna module, or may omit the at least one unusable antenna module from a predetermined order for the index of each beam and may perform beam sweeping. Referring to the graph1300illustrating the CDF regarding the EIRP, the EIRP at CDF 0.5 and 1 in Case1301is higher than that in Case21302and Case31303, and accordingly, Case1supports higher EIRP with respect to an entire coverage compared to Case21302and Case31303, and Case31303has higher EIRP in the entire CDF area compared to Case21302, and accordingly, may support higher EIRP with respect to the entire coverage compared to Case21302. Through the graph1300, it can be seen that additionally managing a sub beam for each antenna module is effective for the electronic device500. The electronic device according to various embodiments may be one of various types of electronic devices. The electronic devices may include, for example, a portable communication device (e.g., a smartphone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, a home appliance, or the like. According to an embodiment of the disclosure, the electronic devices are not limited to those described above. It should be appreciated that various embodiments of the present disclosure and the terms used therein are not intended to limit the technological features set forth herein to particular embodiments and include various changes, equivalents, or replacements for a corresponding embodiment. With regard to the description of the drawings, similar reference numerals may be used to refer to similar or related elements. It is to be understood that a singular form of a noun corresponding to an item may include one or more of the things, unless the relevant context clearly indicates otherwise. As used herein, each of such phrases as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B, or C,” “at least one of A, B, and C,” and “at least one of A, B, or C,” may include any one of, or all possible combinations of the items enumerated together in a corresponding one of the phrases. As used herein, such terms as “1st” and “2nd,” or “first” and “second” may be used to simply distinguish a corresponding component from another, and does not limit the components in other aspect (e.g., importance or order). It is to be understood that if an element (e.g., a first element) is referred to, with or without the term “operatively” or “communicatively”, as “coupled with,” “coupled to,” “connected with,” or “connected to” another element (e.g., a second element), the element may be coupled with the other element directly (e.g., wiredly), wirelessly, or via a third element. As used herein, the term “module” may include a unit implemented in hardware, software, or firmware, or any combination thereof, and may interchangeably be used with other terms, for example, “logic,” “logic block,” “part,” or “circuitry”. A module may be a single integral component, or a minimum unit or part thereof, adapted to perform one or more functions. For example, according to an embodiment, the module may be implemented in a form of an application-specific integrated circuit (ASIC). Various embodiments as set forth herein may be implemented as software (e.g., the program140) including one or more instructions that are stored in a storage medium (e.g., internal memory136or external memory138) that is readable by a machine (e.g., the electronic device101). For example, a processor (e.g., the processor120) of the machine (e.g., the electronic device101) may invoke at least one of the one or more instructions stored in the storage medium, and execute it, with or without using one or more other components under the control of the processor. This allows the machine to be operated to perform at least one function according to the at least one instruction invoked. The one or more instructions may include a code generated by a complier or a code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Wherein, the “non-transitory” storage medium is a tangible device, and may not include a signal (e.g., an electromagnetic wave), but this term does not differentiate between where data is semi-permanently stored in the storage medium and where the data is temporarily stored in the storage medium. According to an embodiment, a method according to various embodiments of the disclosure may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or be distributed (e.g., downloaded or uploaded) online via an application store (e.g., PlayStore™), or between two user devices (e.g., smart phones) directly. If distributed online, at least part of the computer program product may be temporarily generated or at least temporarily stored in the machine-readable storage medium, such as memory of the manufacturer's server, a server of the application store, or a relay server. According to various embodiments, each component (e.g., a module or a program) of the above-described components may include a single entity or multiple entities. According to various embodiments, one or more of the above-described components may be omitted, or one or more other components may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into a single component. In such a case, according to various embodiments, the integrated component may still perform one or more functions of each of the plurality of components in the same or similar manner as they are performed by a corresponding one of the plurality of components before the integration. According to various embodiments, operations performed by the module, the program, or another component may be carried out sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations may be executed in a different order or omitted, or one or more other operations may be added. While the disclosure has been illustrated and described with reference to various example embodiments, it will be understood that the various example embodiments are intended to be illustrative, not limiting. It will be further understood by those skilled in the art that various changes in form and detail may be made without departing from the true spirit and full scope of the disclosure, including the appended claims and their equivalents. It will also be understood that any of the embodiment(s) described herein may be used in conjunction with any other embodiment(s) described herein. | 80,914 |
11943024 | DETAILED DESCRIPTION The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of various embodiments. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the various embodiments may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the various embodiments with unnecessary detail. For the purposes of the present document, the phrase “A or B” means (A), (B), or (A and B). The following is a glossary of terms that may be used in this disclosure. The term “circuitry” as used herein refers to, is part of, or includes hardware components such as an electronic circuit, a logic circuit, a processor (shared, dedicated, or group) or memory (shared, dedicated, or group), an Application Specific Integrated Circuit (ASIC), a field-programmable device (FPD) (e.g., a field-programmable gate array (FPGA), a programmable logic device (PLD), a complex PLD (CPLD), a high-capacity PLD (HCPLD), a structured ASIC, or a programmable system-on-a-chip (SoC)), digital signal processors (DSPs), etc., that are configured to provide the described functionality. In some embodiments, the circuitry may execute one or more software or firmware programs to provide at least some of the described functionality. The term “circuitry” may also refer to a combination of one or more hardware elements (or a combination of circuits used in an electrical or electronic system) with the program code used to carry out the functionality of that program code. In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuitry. The term “processor circuitry” as used herein refers to, is part of, or includes circuitry capable of sequentially and automatically carrying out a sequence of arithmetic or logical operations, or recording, storing, or transferring digital data. The term “processor circuitry” may refer an application processor, baseband processor, a central processing unit (CPU), a graphics processing unit, a single-core processor, a dual-core processor, a triple-core processor, a quad-core processor, or any other device capable of executing or otherwise operating computer-executable instructions, such as program code, software modules, or functional processes. The term “interface circuitry” as used herein refers to, is part of, or includes circuitry that enables the exchange of information between two or more components or devices. The term “interface circuitry” may refer to one or more hardware interfaces, for example, buses, I/O interfaces, peripheral component interfaces, network interface cards, or the like. The term “user equipment” or “UE” as used herein refers to a device with radio communication capabilities and may describe a remote user of network resources in a communications network. The term “user equipment” or “UE” may be considered synonymous to and may be referred to as client, mobile, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, reconfigurable mobile device, etc. Furthermore, the term “user equipment” or “UE” may include any type of wireless/wired device or any computing device including a wireless communications interface. The term “computer system” as used herein refers to any type interconnected electronic devices, computer devices, or components thereof. Additionally, the term “computer system” or “system” may refer to various components of a computer that are communicatively coupled with one another. Furthermore, the term “computer system” or “system” may refer to multiple computer devices or multiple computing systems that are communicatively coupled with one another and configured to share computing or networking resources. The term “resource” as used herein refers to a physical or virtual device, a physical or virtual component within a computing environment, or a physical or virtual component within a particular device, such as computer devices, mechanical devices, memory space, processor/CPU time, processor/CPU usage, processor and accelerator loads, hardware time or usage, electrical power, input/output operations, ports or network sockets, channel/link allocation, throughput, memory usage, storage, network, database and applications, workload units, or the like. A “hardware resource” may refer to compute, storage, or network resources provided by physical hardware element(s). A “virtualized resource” may refer to compute, storage, or network resources provided by virtualization infrastructure to an application, device, system, etc. The term “network resource” or “communication resource” may refer to resources that are accessible by computer devices/systems via a communications network. The term “system resources” may refer to any kind of shared entities to provide services, and may include computing or network resources. System resources may be considered as a set of coherent functions, network data objects, or services accessible through a server where such system resources reside on a single host or multiple hosts and are clearly identifiable. The term “channel” as used herein refers to any transmission medium, either tangible or intangible, which is used to communicate data or a data stream. The term “channel” may be synonymous with or equivalent to “communications channel,” “data communications channel,” “transmission channel,” “data transmission channel,” “access channel,” “data access channel,” “link,” “data link,” “carrier,” “radio-frequency carrier,” or any other like term denoting a pathway or medium through which data is communicated. Additionally, the term “link” as used herein refers to a connection between two devices for the purpose of transmitting and receiving information. The terms “instantiate,” “instantiation,” and the like as used herein refers to the creation of an instance. An “instance” also refers to a concrete occurrence of an object, which may occur, for example, during execution of program code. The term “connected” may mean that two or more elements, at a common communication protocol layer, have an established signaling relationship with one another over a communication channel, link, interface, or reference point. The term “network element” as used herein refers to physical or virtualized equipment or infrastructure used to provide wired or wireless communication network services. The term “network element” may be considered synonymous to or referred to as a networked computer, networking hardware, network equipment, network node, virtualized network function, or the like. The term “information element” refers to a structural element containing one or more fields. The term “field” refers to individual contents of an information element or a data element that contains content. An information element may include one or more additional information elements. Embodiments of the present disclosure describe a UE implementing one or more beamforming schemes including, for example, a channel-based beamforming scheme and a codebook-based beamforming scheme. Various embodiments describe control signaling and beam management operations corresponding to the UE implementing the one or more beamforming schemes. FIG.1illustrates a network environment100in accordance with some embodiments. The network environment100may include a UE104and a gNB108. The gNB108may be a base station that provides a wireless access cell, for example, a 3GPP New Radio (NR) cell, through which the UE104may communicate with the gNB108. The UE104and the gNB108may communicate over an air interface compatible with 3GPP technical specifications, such as those that define Fifth Generation (5G) NR system standards. The gNB108may transmit information (for example, data and control signaling) in the downlink direction by mapping logical channels on the transport channels, and transport channels onto physical channels. The logical channels may transfer data between a radio link control (RLC) and media access control (MAC) layers; the transport channels may transfer data between the MAC and PHY layers, and the physical channels may transfer information across the air interface. The physical channels may include a physical broadcast channel (PBCH); a physical downlink control channel (PDCCH); and a physical downlink shared channel (PDSCH). The PBCH may be used to broadcast system information that the UE104may use for initial access to a serving cell. The PBCH may be transmitted along with physical synchronization signals (PSS) and secondary synchronization signals (SSS) in a synchronization signal (SS)/PBCH block. The SS/PBCH blocks (SSBs) may be used by the UE104during a cell search procedure and for beam selection. The PDSCH may be used to transfer end-user application data, signaling radio bearer (SRB) messages, system information messages (other than, for example, MIB), and paging messages. The PDCCH may transfer downlink control information (DCI) that is used by a scheduler of the gNB108to allocate both uplink and downlink resources. The DCI may also be used to provide uplink power control commands, configure a slot format, or indicate that preemption has occurred. The gNB108may also transmit various reference signals to the UE104. The reference signals may include demodulation reference signals (DMRSs) for the PBCH, PDCCH, and PDSCH. The UE104may compare a received version of the DMRS with a known DMRS sequence that was transmitted to estimate an impact of the propagation channel. The UE104may then apply an inverse of the propagation channel during a demodulation process of a corresponding physical channel transmission. The reference signals may also include channel state information-reference signals (CSI-RS). The CSI-RS may be a multi-purpose downlink transmission that may be used for CSI reporting, beam management, connected mode mobility, radio link failure detection, beam failure detection and recovery, and fine-tuning of time and frequency synchronization. Transmissions that use different antenna ports may experience different radio channels. However, in some situations different antenna ports may share common radio channel characteristics. For example, different antenna ports may have similar Doppler shifts, Doppler spreads, average delay, delay spread, or spatial receive parameters (for example, properties associated with a downlink received signal angle of arrival at a UE). Antenna ports that share one or more of these large-scale radio channel characteristics may be said to be quasi co-located (QCL) with one another, 3GPP has specified four types of QCL to indicate which particular channel characteristics are shared. In QCL Type A, antenna ports share Doppler shift, Doppler spread, average delay, and delay spread. In QCL Type B, antenna ports share Doppler shift and Doppler spread are shared. In QCL Type C, antenna ports share Doppler shift and average delay. In QCL Type D, antenna ports share spatial receiver parameters. The gNB108may provide transmission configuration indicator (TCI) state information to the UE104to indicate QCL relationships between antenna ports used for reference signals (for example, synchronization signal/PBCH or CSI-RS) and downlink data or control signaling, for example, PDSCH or PDCCH. The gNB108may use a combination of RRC signaling, MAC control element signaling, and DCI to inform the UE104of these QCL relationships. The UE104and the gNB108may perform beam management operations to identify and maintain desired beams for transmission in the uplink and downlink directions. The beam management may be applied to both PDSCH and PDCCH in the downlink direction and PUSCH and PUCCH in the uplink direction. The UE104may select a beam to receive downlink transmissions based on beam management-reference signals (BM-RSs), which may include SSBs and CSI-RS for BMs. The UE104, while in a radio resource control (RRC)-idle mode, may perform an initial acquisition during a random-access procedure using SSBs and physical random access channel (PRACH) preambles to establish uplink and downlink beam pairs. These initial beam pairs may correspond to relatively wide beams. The UE104may then enter an RRC-connected mode and initiate beam refinement procedures to select beams that are more directional and have higher gain. The beam refinement procedures may be based on CSI-RS. In various embodiments, the gNB108may configure the UE104with one or more CSI-RS resource sets. Each resource set may include one or more CSI-RS resources. A single resource set may be configured with a sequence of up to 64 CSI-RS resource identities. The resource set configuration may include a flag to indicate whether repetition is enabled. If the gNB108sets the repetition flag to “ON,” then all the CSI-RSs belonging to the resource set may be transmitted using the same beam; for example, they may be transmitted using the same spatial domain filter. In some embodiments, the gNB108may use the repetition flag during beam management procedures to change a beam selection for the purposes of beam refinement, which may be referred to as a P-2 BM procedure, or to improve a downlink UE receive beam, which may be referred to as a P-3 BM procedure. For the P-3 BM procedure, the gNB108may transmit repetitions of the CSI-RS using a beam selected during the P-2 BM procedure. This may provide the UE104with sufficient time to switch between its own beam positions and identify the best beam to pair with the beam selected by the gNB108. In various embodiments, both digital and analog beamforming concepts may be performed by the UE104and the gNB108. However, digital beamforming may utilize more radio-frequency chains, which may lead to increased power consumption. Therefore, in some embodiments, the UE104may rely primarily on analog beamforming, which may improve coverage and provide a desirable link budget, especially when a good gNB/UE beam pair is used. An analog beamforming weight (W) could be considered as an Nant×Npmatrix for the UE104, where Nantindicates a number of antenna elements and Npindicates a number of radio-frequency (RF) chains. In various embodiments, the UE104may determine the beamforming weight W using a codebook-based beamforming scheme or a channel-based beamforming scheme. In the codebook scheme, W may be selected from a codebook stored at the UE104that includes a list of matrices that could be used as beamforming weights. The UE may pre-store the codebook without any measurement. The codebook may include different kinds of beams from different horizontal and vertical directions. One typical example is a discrete Fourier transform (DFT)-based codebook, where each beam weight for each antenna element (m,n) could be generated as wm,n(θ,φ)=1MNexp{-j2πλ[(m-1)dvcosθ+(n-1)dHsinφ]}, where θ is the vertical transmission direction, φ is the horizontal direction, M is the number of antenna elements in vertical domain, N is the number of antenna elements in horizontal domain, λ is waveform length, and dvis the vertical antenna spacing, dHis the horizontal antenna spacing. The UE104may need to measure a number symbols of beam management reference signal (BM-RS). The UE104does not need to know the effective channel, it only needs to measure the RSRP from each BM-RS. For each measurement, UE selects one beam from the codebook. In one example, for a four-antenna UE with one RF chain, the codebook size and number of symbols of BM-RS that need to be measured may be 16. In the channel-based scheme, the UE104does not need to pre-store any codebook. Instead, the UE104may calculate an effective channel matrix after multiple measurement instances to derive a beamforming weight W using, for example, singular value decomposition (SVD). The channel matrix may be obtained by a measurement of M=ceil(NantNp) symbols of BM-RS within a time window. The time window may be a maximum time window in which a relationship (for example, coherency) between resources used for channel-based beamforming calculations may apply. This time window may be reported by a UE capability report. In one example, for a four-antenna UE with one RF chain, a BM-RS resource may include M-4 symbols within a time window to allow the UE104to reconstruct the channel. Thus, a different number of symbols may be needed for different schemes. FIG.2illustrates a channel-based beamforming operation200in accordance with some embodiments. This embodiment, the UE104may have four antenna elements with one port. At204, the operation200may include applying different sequences from a predefined matrix (which may be stored in memory of the UE) as the weight to receive different symbols of a BM-RS and get estimated channels. The predefined matrix may be, for example, a normalized Hadamard matrix as follows: W′=[0.50.50.50.50.5-0.50.5-0.50.50.5-0.50.50.5-0.5-0.5-0.5]. A first weight, W′(:,1) may be provided to a BM RS received on a first symbol (BM RS symbol 1); a second weight W′(:,2) may be provided to a BM RS received on a second symbol (BM RS symbol 2); a third weight W′(:,3) may be provided to a BM RS received on a third symbol (BM RS symbol 3); and a fourth weight W′(:,4) may be provided to a BM RS received on a fourth symbol (BM RS symbol 4). In this manner, M instances of the channels (H1-H4) may be obtained. At208, the operation may include constructing the combined channel from the M instances of the channel obtained at204. The combined channel may be given by H=[H1; H2; H3; H4]. At212, the operation may include calculating an eigenvector based on the combined channel and predefined matrix. In some embodiments, the eigenvector may be obtained by multiplying the predefined matrix W′ by the combined channel H. The UE104may use the eigenvector for the beamforming weight W to provide the analog beam for receiving downlink communications from the gNB108. Thus, in contrast to the codebook-based approach, the channel-based beamforming scheme relies on a contemporaneous construction of a channel by measuring BM-RS within a time window. The advantages and challenges for each of these beamforming schemes may be different. For example, advantages of the codebook-based scheme may include that beamforming gain may be included in each measurement; there is no additional timing requirement for BM-RS; and the UE104may receive another signal multiplexed in the same symbol in a frequency division multiplexing (FDM) manner. Challenges for the codebook-based scheme may include more number of symbols may be required and the selected beam may not be the best (as the beamforming weight is selected from a predefined number of matrices in the codebook). Advantages of the channel-based scheme may include that a less number of symbols carrying the BM-RS are required and the selected beam may be closer to an optimized beam as compared to a beam selected from the codebook-based scheme, which could improve system performance. Challenges of the channel-based scheme may include that beamforming gain is not included in each measurement, and the UE may not be able to receive another signal multiplexed in the same symbol in FDM manner. The desired beamforming scheme for different scenarios may be different. For example, in a low-SINR case, codebook-based beamforming may be more desirable because the beamforming gain added to each measurement may provide more accurate measurements. In a high-SINR case, channel-based beamforming may be more desirable as the measurements may not require the beamforming gain and the optimized beam may increase the system performance. Providing the use of different beamforming schemes may improve network efficiencies; however, it may also be important to coordinate operation between the UE104and the gNB108to ensure the gNB108is aware of the beamforming scheme used by the UE104for beam management. This may allow the gNB to provide downlink signaling that properly supports the selected beamforming scheme. For example, the gNB108may need to configure BM-RS for UE beam tracking differently based on the different beamforming schemes. If the UE104uses channel-based beamforming scheme, the gNB108may only need to configure four OFDM symbols with BM-RS (assuming four antenna elements and one RF chain). If, however, the UE104uses codebook-based beamforming scheme, the gNB108may need to configure 16 OFDM symbols with the BM-RS. As another example, if the channel-based beamforming is used, the gNB108may configure the BM-RS mapping pattern with a burst-like pattern. For example, a BM-RS resource may be configured with the desired number of OFDM symbols so that the BM-RS is transmitted within the time window. The BM-RS may be mapped to resource elements (REs) of the desired number of OFDM symbols based on the same or different RE mappings. In some embodiments, the gNB108may configure TCI information differently based on the type of beamforming scheme used by the UE104. For example, in some embodiments, the gNB108may configure TCIs to provide a plurality of reference signals with a QCL or port association that allows the UE104to use measurements from the plurality of reference signals for the channel determination of the channel-based beamforming scheme. Thus, in these embodiments, the gNB108may determine aspects of a TCI state, for example, effective time. QCL type, etc., based on whether the UE104is using the channel-based beamforming scheme. In some embodiments, the gNB108may determine whether a measurement restriction is valid or not based on the beamforming scheme used by the UE104. Consider, for example, a time restriction for channel measurements. A UE configured with this parameter, through a CSI report configuration information element, may derive channel measurements for computing CSI reported in a slot may be based on only a most recent occasion of a non-zero power CSI-RS. This may be referred to as one-shot reporting. In some embodiments, the gNB108may not configure the UE104with one-shot reporting if the UE104uses a channel-based beamforming scheme since the UE104may need to measure a resource multiple times to get the beamforming weight. In some embodiments, the gNB108may schedule a downlink channel differently based on which beamforming scheme is used by the UE104. For different schemes, whether the UE104can receive signals multiplexed with the BM-RS in FDM manner could be different. For example, for codebook-based scheme, the UE104may still be able to receive both signals. However, for channel-based scheme, the UE104may not be able to receive both signals. Therefore, if the UE104uses a codebook-based scheme, the gNB108may multiplex some signals in a same symbol with a BM-RS. However, if the UE104uses a channel-based scheme, the gNB108may not multiplex other signals in the same symbol with the BM-RS. Various embodiments describe processes that may be employed to maintain the same understanding between the gNB108and the UE104on the beamforming schemes. Aspects include reports from the UE104on beamforming scheme, and control signaling to/from the gNB108for beamforming scheme selection. In general, the UE104may only support one beamforming scheme, or may support both beamforming schemes. If the UE supports both beamforming schemes, the scheme may be switched in a dynamic or semi-static manner. Switching or otherwise selecting a beamforming scheme to be implemented at the UE104may be done at the initiative of the UE104or the gNB108. If the UE104only supports one beamforming scheme, there may be two alternatives in order to provide a common understanding of beamforming capabilities between the UE104and the gNB108. The first alternative embodiment may include the UE104reporting the beamforming scheme, for example, codebook-based or channel-based, by a UE capability report. In some embodiments, the gNB108may send a capability inquiry to the UE104to request the UE104to send capability information. The UE104may respond by sending a UE capability report to provide information requested by the gNB108. In some embodiments, the UE capability report may include a beamforming scheme identifier (ID) to identify either the codebook-based beamforming scheme or the channel-based beamforming scheme. The gNB108may determine the supported beamforming scheme based on the beamforming scheme ID included in the UE capability report. In some embodiments, a default beamforming scheme (for example, codebook-based beamforming scheme) may be applied. Both the gNB108and the UE104may have knowledge of which beamforming scheme is to be considered the default beamforming scheme. Therefore, if the UE104supports the default beamforming scheme, there is no need to provide the report. If, on the other hand, the UE104supports the non-default beamforming scheme, the UE104may generate and send the UE capability report as described above. The second alternative embodiment may include the gNB108determining the beamforming scheme supported based on other, contextual information in a UE capability report. For example, the gNB108may determine the supported beamforming scheme based on whether the UE104supports measurement restriction for RSRP/SINR measurement. If the UE104supports the measurement restriction, the gNB108may determine that codebook-based beamforming scheme is used. Otherwise, the gNB108may determine that channel-based beamforming scheme is used. In another example of using contextual information in the UE capability report to determine the supported beamforming scheme, the gNB108may determine whether the UE104reports the maximum time window for a BM-RS burst. If the UE104reports this feature, the gNB108may determine that channel-based beamforming scheme is used. Otherwise, the gNB108may determine that codebook-based beamforming scheme is used. For UEs that support both beamforming schemes, the following options may be provided for beamforming scheme selection and reporting. In some embodiments, different beamforming schemes may be used for different types of BM-RS. This may be due to different coverage for the different types of BM-RSS. For example, the gNB108may use a wide beam to transmit SSB and narrow beams to transmit CSI-RSS. Therefore, in this example, it may be more applicable to use a codebook-based scheme for SSB and a channel-based beamforming scheme for CSI-RSS. The UE104may report the beamforming scheme for each type of BM-RS by RRC signaling, for example, the UE capability report. In some embodiments, the BM-RSs include: SSB for L1-RSRP/L1-SINR report; CSI-RS in a resource set without repetition (for example, repetition=off); CSI-RS in a resource set with repetition (for example, repetition=on); SSB/CSI-RS for beam failure detection; and SSB/CSI-RS for radio link monitoring. In some embodiments, the UE104may report an update or selection of a beamforming scheme by a MAC CE. This information may be periodically updated and, therefore, may be considered as a semi-static configuration of the beamforming scheme. FIG.3illustrates an uplink and downlink communication sequence in accordance with some embodiments. At304, the UE104may send a scheduling request (SR) to the gNB108to request uplink resources for a MAC CE to provide beamforming scheme update information. The SR may be a dedicated SR configured by RRC signaling for beamforming scheme update information. In other embodiments, the SR may be normal SR or the UE104may use a PRACH preamble transmission. At308, the UE104may receive an indication of an uplink grant from the gNB108. The uplink grant may schedule uplink resources for the UE104to transmit a MAC CE The MAC CE may identify the beamforming scheme to be used by the UE104along with related information including, for example, a serving cell or serving cell list index, and a maximum number of receive beams of the UE104. The maximum number of receive beams in the MAC CE may override any maxNumberOfRX Beams previously reported in a UE capability. The UE104may transmit the MAC CE at312. In some embodiments, the UE104may transmit the MAC CE with a hybrid automatic repeat request (HARQ) process ID that may allow a receiver to check for errors in received data and, if detected, buffer the data and request a retransmission from the sender. At316, the UE104may receive a response to the MAC CE from the gNB108. The response could be an uplink grant for a new transmission for the same HARQ process ID that was used to transmit the MAC CE. Alternatively, the response could be a reconfiguration of some RRC parameters. The reconfiguration of the RRC parameters may facilitate the selected beamforming scheme as well as provide an acknowledgement/approval that the UE104may switch to the selected beamforming scheme. In some embodiments, a default beamforming scheme may be pre-defined as, for example, codebook-based or channel-based. The MAC CE may then be used to change the default scheme if needed. At320, which may be K symbols after the UE104receives the gNB response at316, the UE104can start to apply the new beamforming scheme. In some embodiments, K may be predefined or reported by UE capability. In some embodiments, the gNB108may determine which beamforming scheme is to be used by the UE104in the event the UE104supports more than one beamforming scheme. The gNB108may signal which beamforming scheme to use using higher-layer signaling including, for example, RRC or MAC CE. In some embodiments, the beamforming scheme may be configured per bandwidth part, per serving cell, per serving cell group, or per UE. In embodiments in which the beamforming scheme is configured the same for more than one UE, the gNB108may incorporate the configuration information into system information or other broadcast control signaling. In some embodiments the beamforming scheme may be configured for all types of BM-RSs, configured for each type of BM-RS, or configured for sets of BM-RS types. In the event the gNB108instructs the UE104to use a particular beamforming scheme, the beamforming scheme may be implemented a period of time after the instruction. This period of time or action time may be predefined, reported by UE capability, or included within the control signaling that provides the instructions. Similar to embodiments described above, in this embodiment one beamforming scheme may be determined to be the default scheme (for example, codebook-based beamforming or channel-based beamforming) to be applied in the absence of other signaling or indication. In some embodiments, the UE104or the gNB108may determine an appropriate beamforming scheme based on network conditions. For example, in some embodiments the UE104may be configured with or otherwise determine RSRP/SINR thresholds that are relevant to the beamforming scheme determination. The UE104may report these thresholds to the gNB108. Alternatively, the threshold may be predefined and known by both the UE104and the gNB108. The UE104and the gNB108may both know that if the channel is in a first state, for example, the channel metrics are below the thresholds, the UE104is to use a first beamforming scheme. And if the channel is in a second state, for example, the channel metrics are above the thresholds, the UE104is to use a second beamforming scheme. The UE104may periodically perform channel state measurements to determine the channel metrics (as part of a typical CSI feedback process) and may provide the reports to the gNB108regarding the measurements. In this manner, both the UE104and the gNB108may know which beamforming scheme is to be used. For example, in some embodiments, the beamforming scheme may be switched based on Layer 3 (L3)-RSRP or L3-SINR reports. If the reports indicate that RSRP/SINR are above a threshold known to both the UE104and the gNB108, the channel-based scheme may be used. Otherwise, the codebook-based scheme may be used. In some embodiments, an action time may be associated with the reports. For example, the beamforming scheme may be updated at the UE104K symbols after a first report that indicates RSRP/SINR as above a threshold. The value K may be predefined or based on a UE capability report. FIG.4may include an operation flow/algorithmic structure400in accordance with some embodiments. The operation flow/algorithmic structure400may be performed or implemented by a UE such as, for example, UE104or800; or components thereof, for example, baseband processor804A. The operation flow/algorithmic structure400may include, at404, determining a beamforming scheme supported by the UE. The beamforming scheme may be a channel-based beamforming scheme or a codebook-based beamforming scheme. In some embodiments, one beamforming scheme may be supported by the UE. In other embodiments, both beamforming schemes may be supported by the UE. The operation flow/algorithmic structure400may further include, at408, generating a capability report or MAC CE to include information about the beamforming scheme supported by the UE. In some embodiments, the information may include a beamforming scheme identifier to explicitly identify a beamforming scheme. In other embodiments, the information may be a parameter that is associated with a particular beamforming scheme. For example, the parameter may be a measurement restriction parameter that is associated with codebook-based beamforming scheme or a timing window parameter for a BM-RS burst that may be associated with a channel-based beamforming scheme. In some embodiments, the UE may generate a capability report to indicate whether it supports one or two beamforming schemes and, if so, which ones. In some embodiments, the UE may generate a MAC CE to update a beamforming scheme that is employed by the UE. A MAC CE may be generated after, for example, a network condition has been detected that prompts a change in the beamforming scheme. In some embodiments, the capability report or MAC CE may include a beamforming scheme supported for each of a number of BM-RS types. The BM-RS types may include an SSB for L1 RSRP/SINR report; CSI-RS in a resource set with or without repetition; an SSB/CSI-RS for beam failure detection; or an SSB/CSI-RS for radio link monitoring. The operation flow/algorithmic structure400may further include, at412, transmitting the capability report or MAC CE to a gNB. In some embodiments, the capability report may be transmitted in response to a capability inquiry from the gNB. In some embodiments, the MAC CE may be transmitted after the gNB has granted uplink resources for the transmission based on an earlier transmitted SR or PRACH preamble. FIG.5may include an operation flow/algorithmic structure500in accordance with some embodiments. The operation flow/algorithmic structure500may be performed or implemented by a UE such as, for example, UE104or800; or components thereof, for example, baseband processor804A. In some embodiments, the operation flow/algorithmic structure500may be performed or implemented by a UE that is capable of implementing a plurality of beamforming schemes. The operation flow/algorithmic structure500may include, at504, detecting a network condition or configuration. The network condition may be associated with a channel state. For example, channel metrics such as RSRP/SINR being greater than or less than a predetermined threshold. The configuration may be an instruction from a gNB to implement a particular beamforming scheme. Alternatively, the configuration may be an indication of a default beamforming scheme. The operation flow/algorithmic structure500may further include, at508, selecting a beamforming scheme based on the network condition or configuration. For example, if the UE detects that RSRP/SINR is less than a predetermined threshold, the UE may select codebook-based beamforming scheme. Alternatively, if the UE detects that the RSRP/SINR is greater than the predetermined threshold, the UE may select channel-based beamforming scheme. For another example, the UE may the beamforming scheme indicated by a configuration instruction or default configuration. In some embodiments, the operation flow/algorithmic structure500may further include transmitting an indication of the selected beamforming scheme to the gNB. The indication may be included in a UE capability report or a MAC CE as described elsewhere herein. The operation flow/algorithmic structure500may further include, at512, determining beamforming weight based on the beamforming scheme. In the event channel-based beamforming scheme is selected, the UE may determine channel estimates using a prestored matrix and reference signals received on a plurality of OFDM symbols of a BM-RS resource; construct a channel from the channel estimates; and determine a beamforming weight based on the channel and the prestored matrix. In the event codebook-based beamforming scheme is selected, the UE may access the codebook to determine which of a plurality of matrices provide the highest quality reception, and use the selected matrix for the beamforming weight. FIG.6may include an operation flow/algorithmic structure600in accordance with some embodiments. In some embodiments, the operation flow/algorithmic structure600may be performed or implemented by a gNB, for example, gNB108or900; or components thereof, for example, baseband processor904A. The operation flow/algorithmic structure600may include, at604, processing a report to determine the UE supports one or more beamforming schemes. In various embodiments, the report may be a UE capability report or a MAC CE as described herein. If the report includes a UE capability report, the gNB may determine the one or more beamforming scheme supported by the UE based on an explicit indication in the report, for example, a beamforming scheme identifier, or based on an implicit indication, for example, a parameter associated with one beamforming scheme, but not the other. The operation flow/algorithmic structure600may further include, at608, determining the UE is to use a selected beamforming scheme. In some embodiments, the determination may be based on a signaling event, for example, the UE indicating that it is to use a beamforming scheme. In other embodiments, the determination may be based on an absence of a signaling event in which case the gNB may determine the UE is to use a default beamforming scheme. The operation flow/algorithmic structure600may further include, at612, configuring the BM-RS based on selected beamforming scheme. In some embodiments, the configuring of the BM-RS may include a serving cell configuration, a reference signal resource configuration, a TCI state configuration, etc. The gNB may configure the reference signals to appropriately support the beamforming scheme that is to be used by the UE. For example, in the event the UE is to use a channel-based beamforming scheme, the gNB may ensure they reference signal resources configured with a plurality of OFDM symbols that carry a sufficient number of BM-RS within a timing window. FIG.7illustrates receive components70) of the UE104in accordance with some embodiments. The receive components700may include an antenna panel704that includes a number of antenna elements. The panel704is shown with four antenna elements, but other embodiments may include other numbers. The antenna panel704may be coupled to analog beamforming (BF) components that include a number of phase shifters708(1)-708(4). The phase shifters708(1)-708(4) may be coupled with a radio-frequency (RF) chain712. The RF chain712may amplify a receive analog RF signal, downconverts the RF signal to baseband, and convert the analog baseband signal to a digital baseband signal that may be provided to a baseband processor for further processing. In various embodiments, control circuitry, which may reside in a baseband processor, may provide BF weights (for example W1-W4), which may represent phase shift values, to the phase shifters708(1)-708(4) to provide a receive beam at the antenna panel704. These BF weights may be determined based on the channel-based beamforming scheme (as described inFIG.2, for example) or codebook-based beamforming scheme described herein. FIG.8illustrates a UE800in accordance with some embodiments. The UE800may be similar to and substantially interchangeable with UE104ofFIG.1. Similar to that described above with respect to UE104, the UE800may be any mobile or non-mobile computing device, such as, for example, mobile phones, computers, tablets, industrial wireless sensors (for example, microphones, carbon dioxide sensors, pressure sensors, humidity sensors, thermometers, motion sensors, accelerometers, laser scanners, fluid level sensors, inventory sensors, electric voltage/current meters, actuators, etc.) video surveillance/monitoring devices (for example, cameras, video cameras, etc.) wearable devices; or relaxed-IoT devices. In some embodiments, the UE may be a reduced capacity UE or NR-Light UE. The UE800may include processors804, RF interface circuitry808, memory/storage812, user interface816, sensors820, driver circuitry822, power management integrated circuit (PMIC)824, and battery828. The components of the UE800may be implemented as integrated circuits (ICs), portions thereof, discrete electronic devices, or other modules, logic, hardware, software, firmware, or a combination thereof. The block diagram ofFIG.8is intended to show a high-level view of some of the components of the UE800. However, some of the components shown may be omitted, additional components may be present, and different arrangement of the components shown may occur in other implementations. The components of the UE800may be coupled with various other components over one or more interconnects832, which may represent any type of interface, input/output, bus (local, system, or expansion), transmission line, trace, optical connection, etc. that allows various circuit components (on common or different chips or chipsets) to interact with one another. The processors804may include processor circuitry such as, for example, baseband processor circuitry (BB)804A, central processor unit circuitry (CPU)804B, and graphics processor unit circuitry (GPU)804C. The processors804may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions, such as program code, software modules, or functional processes from memory/storage812to cause the UE800to perform operations as described herein. In some embodiments, the baseband processor circuitry804A may access a communication protocol stack836in the memory/storage812to communicate over a 3GPP compatible network. In general, the baseband processor circuitry804A may access the communication protocol stack to: perform user plane functions at a PHY layer, MAC layer, RLC layer, PDCP layer, SDAP layer, and PDU layer: and perform control plane functions at a PHY layer, MAC layer. RLC layer, PDCP layer, RRC layer, and a non-access stratum “NAS” layer. In some embodiments, the PHY layer operations may additionally/alternatively be performed by the components of the RF interface circuitry808. The baseband processor circuitry804A may generate or process baseband signals or waveforms that carry information in 3GPP-compatible networks. In some embodiments, the waveforms for NR may be based cyclic prefix OFDM (CP-OFDM) in the uplink or downlink, and discrete Fourier transform spread OFDM (DFT-S-OFDM) in the uplink. The baseband processor circuitry804A may also access group information from memory/storage812to determine search space groups in which a number of repetitions of a PDCCH may be transmitted. The memory/storage812may include any type of volatile or non-volatile memory that may be distributed throughout the UE800. In some embodiments, some of the memory/storage812may be located on the processors804themselves (for example, L1 and L2 cache), while other memory/storage812is external to the processors804but accessible thereto via a memory interface. The memory/storage812may include any suitable volatile or non-volatile memory such as, but not limited to, dynamic random-access memory (DRAM), static random-access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read only memory (EEPROM), Flash memory, solid-state memory, or any other type of memory device technology. The RF interface circuitry808may include transceiver circuitry and radio frequency front module (RFEM) that allows the UE800to communicate with other devices over a radio access network. The RF interface circuitry808may include various elements arranged in transmit or receive paths. These elements may include, for example, switches, mixers, amplifiers, filters, synthesizer circuitry, control circuitry, etc. In the receive path, the RFEM may receive a radiated signal from an air interface via an antenna826and proceed to filter and amplify (with a low-noise amplifier) the signal. The signal may be provided to a receiver of the transceiver that downconverts the RF signal into a baseband signal that is provided to the baseband processor of the processors804. In the transmit path, the transmitter of the transceiver upconverts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM may amplify the RF signal through a power amplifier prior to the signal being radiated across the air interface via the antenna826. In various embodiments, the RF interface circuitry808may be configured to transmit/receive signals in a manner compatible with NR access technologies. The antenna826may include a number of antenna elements that each convert electrical signals into radio waves to travel through the air and to convert received radio waves into electrical signals. The antenna elements may be arranged into one or more antenna panels. The antenna826may have antenna panels that are omnidirectional, directional, or a combination thereof to enable beamforming and multiple input, multiple output communications. The antenna826may include microstrip antennas, printed antennas fabricated on the surface of one or more printed circuit boards, patch antennas, phased array antennas, etc. The antenna826may have one or more panels designed for specific frequency bands including bands in FR1 or FR2. The user interface circuitry816includes various input/output (I/O) devices designed to enable user interaction with the UE800. The user interface816includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting an input including, inter alia, one or more physical or virtual buttons (for example, a reset button), a physical keyboard, keypad, mouse, touchpad, touchscreen, microphones, scanner, headset, or the like. The output device circuitry includes any physical or virtual means for showing information or otherwise conveying information, such as sensor readings, actuator position(s), or other like information. Output device circuitry may include any number or combinations of audio or visual display, including, inter alia, one or more simple visual outputs/indicators (for example, binary status indicators such as light emitting diodes (LEDs) and multi-character visual outputs, or more complex outputs such as display devices or touchscreens (for example, liquid crystal displays (LCDs), LED displays, quantum dot displays, projectors, etc.), with the output of characters, graphics, multimedia objects, and the like being generated or produced from the operation of the UE800. The sensors820may include devices, modules, or subsystems whose purpose is to detect events or changes in its environment and send the information (sensor data) about the detected events to some other device, module, subsystem, etc. Examples of such sensors include, inter alia, inertia measurement units comprising accelerometers, gyroscopes, or magnetometers; microelectromechanical systems or nanoelectromechanical systems comprising 3-axis accelerometers, 3-axis gyroscopes, or magnetometers; level sensors; flow sensors: temperature sensors (for example, thermistors); pressure sensors; barometric pressure sensors; gravimeters: altimeters; image capture devices (for example, cameras or lensless apertures); light detection and ranging sensors; proximity sensors (for example, infrared radiation detector and the like), depth sensors, ambient light sensors, ultrasonic transceivers; microphones or other like audio capture devices: etc. The driver circuitry822may include software and hardware elements that operate to control particular devices that are embedded in the UE800, attached to the UE800, or otherwise communicatively coupled with the UE800. The driver circuitry822may include individual drivers allowing other components to interact with or control various input/output (I/O) devices that may be present within, or connected to, the UE800. For example, driver circuitry822may include a display driver to control and allow access to a display device, a touchscreen driver to control and allow access to a touchscreen interface, sensor drivers to obtain sensor readings of sensor circuitry820and control and allow access to sensor circuitry820, drivers to obtain actuator positions of electro-mechanic components or control and allow access to the electro-mechanic components, a camera driver to control and allow access to an embedded image capture device, or audio drivers to control and allow access to one or more audio devices. The PMIC824may manage power provided to various components of the UE800. In particular, with respect to the processors804, the PMIC824may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. In some embodiments, the PMIC824may control, or otherwise be part of, various power-saving mechanisms of the UE800. For example, if the platform UE is in an RRC_Connected state, where it is still connected to the RAN node as it expects to receive traffic shortly, then it may enter a state known as Discontinuous Reception Mode (DRX) after a period of inactivity. During this state, the UE800may power down for brief intervals of time and thus save power. If there is no data traffic activity for an extended period of time, then the UE800may transition off to an RRC_Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The UE800goes into a very low power state and it performs paging where again it periodically wakes up to listen to the network and then powers down again. The UE800may not receive data in this state; in order to receive data, it must transition back to RRC_Connected state. An additional power saving mode may allow a device to be unavailable to the network for periods longer than a paging interval (ranging from seconds to a few hours). During this time, the device is totally unreachable to the network and may power down completely. Any data sent during this time incurs a large delay and it is assumed the delay is acceptable. A battery828may power the UE800, although in some examples the UE800may be mounted deployed in a fixed location, and may have a power supply coupled to an electrical grid. The battery828may be a lithium ion battery or a metal-air battery, such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, and the like. In some implementations, such as in vehicle-based applications, the battery828may be a typical lead-acid automotive battery. FIG.9illustrates a gNB900in accordance with some embodiments. The gNB node900may similar to and substantially interchangeable with gNB98. The gNB900may include processors904, RF interface circuitry908, core network (CN) interface circuitry912, and memory/storage circuitry916. The components of the gNB900may be coupled with various other components over one or more interconnects928. The processors904, RF interface circuitry908, memory/storage circuitry916(including communication protocol stack910), antenna924, and interconnects928may be similar to like-named elements shown and described with respect toFIG.11. The CN interface circuitry912may provide connectivity to a core network, for example, a 5thGeneration Core network (5GC) using a 5GC-compatible network interface protocol such as carrier Ethernet protocols, or some other suitable protocol. Network connectivity may be provided to/from the gNB900via a fiber optic or wireless backhaul. The CN interface circuitry912may include one or more dedicated processors or FPGAs to communicate using one or more of the aforementioned protocols. In some implementations, the CN interface circuitry912may include multiple controllers to provide connectivity to other networks using the same or different protocols. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. For one or more embodiments, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, or methods as set forth in the example section below. For example, the baseband circuitry, as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below. For another example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below in the example section. EXAMPLES In the following sections, further exemplary embodiments are provided. Example 1 includes a method of operating a UE, the method comprising: determining a beamforming scheme supported by the UE, the beamforming scheme to include a channel-based beamforming scheme or a codebook-based beamforming scheme; generating a capability report or media access control (MAC) control element (CE) to include information about the beamforming scheme supported by the UE; and transmitting the capability report or MAC CE to a gNB. Example 2 includes a method of example 1 or some other example herein, wherein the information includes a beamforming scheme identifier corresponding to the beamforming scheme. Example 3 includes method of example 1 or some other example herein, wherein the information is to indicate a parameter that is associated with the beamforming scheme. Example 4 includes a method of example 3 or some other example herein, wherein the parameter is a measurement restriction parameter for reference signal receive power (RSRP) or signal to interference and noise ratio (SINR) and is associated with the codebook-based beamforming scheme. Example 5 includes a method of example 3 or some other example herein, wherein the parameter is a timing window parameter for a beamforming management reference signal burst that is associated with the channel-based beamforming scheme. Example 6 includes a method of example 1 or some other example herein, wherein the information includes a beamforming scheme supported for individual beam management-reference signal (BM-RS) types. Example 7 includes a method of example 6 or some other example herein, wherein the individual BM-RSs include a synchronization signal and physical broadcast channel block (SSB) for Layer 1 reference signal receive power (RSRP) or signal to interference and noise ratio (SINR) report; channel state information-reference signal (CSI-RS) in a resource set with repetition; CSI-RS in a resource set without repetition; SSB/CSI-RS for beam failure detection; or SSB/CSI-RS for radio link monitoring. Example 8 includes a method of operating a UE, the method comprising: detecting a network condition or configuration; selecting, based on the network condition or configuration, a beamforming scheme from a channel-based beamforming scheme and a codebook-based beamforming scheme; and determining a beamforming weight to control the antenna panel based on the beamforming scheme. Example 9 includes the method of example 8 or some other example herein, further comprising: transmitting a media access control (MAC) control element (CE) with an indication of the beamforming scheme selected. Example 10 includes the method of example 9 or some other example herein, wherein the MAC CE includes an indication of a serving cell, a serving cell list, or a maximum number of receive beams. Example 11 includes the method of example 9 or some other example herein, further comprising: transmitting a scheduling request or physical random access channel (PRACH) preamble to obtain an uplink grant for the MAC CE. Example 12 includes the method of example 9 or some other example herein, further comprising: processing a response to the MAC CE: and applying the beamforming scheme a predetermined number of symbols after the response. Example 13 includes the method of example 12 or some other example herein, further comprising: transmitting the MAC CE with a hybrid automatic repeat request (HARQ) process identifier, wherein the response includes an uplink grant to schedule a transmission with the HARQ process identifier. Example 14 includes the method of example 12 or some other example herein, wherein the response includes a reconfiguration of radio resource control parameters. Example 15 includes the method of example 12 or some other example herein, wherein the predetermined number of symbols is based on a UE capability. Example 16 includes the method of example 8 or some other example herein, further comprising: receiving a control signal that includes the configuration; and selecting the beamforming scheme based on the configuration, wherein the control signal includes a radio resource control (RRC) signal or a media access control (MAC) control element (CE). Example 17 include the method of example 16 or some other example herein, wherein the configuration is to configure the beamforming scheme for a bandwidth part, a serving cell, a serving cell group, or a specific UE. Example 18 include the method of example 8 or some other example herein, further comprising: measuring a channel quality metric; comparing the channel quality metric to a predetermined threshold; and selecting the beamforming scheme based on comparison of the channel quality metric to the predetermined threshold. Example 19 includes a method of operating a gNB, the method comprising: processing a report received from a UE to determine one or more beamforming schemes supported by the UE, the report to include a UE capability report or a media access control (MAC) control element (CE) and the one or more beamforming schemes to include a channel-based beamforming scheme or codebook-based beamforming scheme: determining that the UE is to use a beamforming scheme selected from the one or more beamforming schemes: and configuring beam management-reference signals (BM-RS) based on the beamforming scheme to be used by the LE. Example 20 includes the method of example 19 or some other example herein, wherein processing the report comprises determining a plurality of beamforming schemes supported by the UE, and the method further comprises: transmitting, to the UE, an indication to use the beamforming scheme. Example 21 may include an apparatus comprising means to perform one or more elements of a method described in or related to any of examples 1-20, or any other method or process described herein. Example 22 may include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of examples 1-20, or any other method or process described herein. Example 23 may include an apparatus comprising logic, modules, or circuitry to perform one or more elements of a method described in or related to any of examples 1-20, or any other method or process described herein. Example 24 may include a method, technique, or process as described in or related to any of examples 1-20, or portions or parts thereof. Example 25 may include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform the method, techniques, or process as described in or related to any of examples 1-20, or portions thereof. Example 26 may include a signal as described in or related to any of examples 1-20, or portions or parts thereof. Example 27 may include a datagram, information element, packet, frame, segment, PDU, or message as described in or related to any of examples 1-20, or portions or parts thereof, or otherwise described in the present disclosure. Example 28 may include a signal encoded with data as described in or related to any of examples 1-20, or portions or parts thereof, or otherwise described in the present disclosure. Example 29 may include a signal encoded with a datagram, IE, packet, frame, segment, PDU, or message as described in or related to any of examples 1-64, or portions or parts thereof, or otherwise described in the present disclosure. Example 30 may include an electromagnetic signal carrying computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors is to cause the one or more processors to perform the method, techniques, or process as described in or related to any of examples 1-20, or portions thereof. Example 31 may include a computer program comprising instructions, wherein execution of the program by a processing element is to cause the processing element to carry out the method, techniques, or process as described in or related to any of examples 1-20, or portions thereof. Example 32 may include a signal in a wireless network as shown and described herein. Example 33 may include a method of communicating in a wireless network as shown and described herein. Example 34 may include a system for providing wireless communication as shown and described herein. Example 35 may include a device for providing wireless communication as shown and described herein. Any of the above-described examples may be combined with any other example (or combination of examples), unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments. Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. | 64,269 |
11943025 | DETAILED DESCRIPTION The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any action or feature illustrated by dashed lines should be regarded as optional. FIG.3is a schematic diagram illustrating a communication network100where embodiments presented herein can be applied. The communications network100could be a third generation (3G) telecommunications network, a fourth generation (4G) telecommunications network, or a fifth (5G) telecommunications network and support any 3GPP telecommunications standard, where applicable. The communications network100comprises a network apparatus200configured to provide network access to at least one terminal device150in a radio access network110. The radio access network110is operatively connected to a core network120. The core network120is in turn operatively connected to a service network130, such as the Internet. The terminal device150is thereby enabled to, via the network apparatus200, access services of, and exchange data with, the service network130. The network apparatus200comprises, is collocated with, is integrated with, or is in operational communications with, a TRP140. The network apparatus200(via its TRP140) and the terminal device150are configured to communicate with each other in beams. In the illustrative example ofFIG.1, beam160is the beam currently being used by the TRP140142for communication with the terminal device150, and beam170is the beam currently being used by the terminal device150for communication with the antenna panel142. The TRP140comprises an antenna panel (not shown inFIG.3) that is divided into subpanels. In some examples, per symbol of a transmission time interval, each subpanel is configured to generate either exactly one double-polarized beam or exactly two beams having orthogonal polarization with respect to each other. Examples of network apparatuses200are radio base stations, base transceiver stations, Node Bs, evolved Node Bs, g NBs, access points, access nodes, and backhaul nodes. Examples of terminal devices150are wireless devices, mobile stations, mobile phones, handsets, wireless local loop phones, user equipment (UE), smartphones, laptop computers, tablet computers, network equipped sensors, network equipped vehicles, and so-called Internet of Things devices. As noted above there is a need for improved time-domain beamformed communication. In more detail, different subpanels142a,142bcovering the same frequency spectrum would not enable improved beamforming gain since data streams from different subpanels do not add up coherently (due to lack of synchronization between the subpanels142a,142b). The embodiments disclosed herein therefore relate to mechanisms for controlling transmission from an antenna panel142. In order to obtain such mechanisms, there is provided a network apparatus200, a method performed by the network apparatus200, a computer program product comprising code, for example in the form of a computer program, that when run on a network apparatus200, causes the network apparatus200to perform the method. FIG.4is a flowchart illustrating embodiments of methods for controlling transmission from an antenna panel142. The methods are performed by the network apparatus200. The methods are advantageously provided as computer programs1020. S102: The network apparatus200performs time-domain beamformed communication with terminal devices150served by the network apparatus200using the antenna panel142split into N>1 subpanels142a,142b. Each subpanel142a,142bhas its own two input ports. Each subpanel142a,142bis fed by its own signals via the input ports. Each subpanel142a,142bis configured to generate beams by application of antenna element weights to its antenna elements144. The subpanels142a,142bare at least phase-wise synchronized with each other. When one and the same signal is fed into the input ports of all the subpanels142a,142b, signals as transmitted from the subpanels142a,142badd up coherently to represent a 1-layer transmission by a time reference being shared between the subpanels142a,142b. The time-domain beamformed communication is performed by the network apparatus200using from 1 to 2N layers per symbol of a transmission time interval according to a mapping between the input ports and the signals as transmitted from the subpanels142a,142b. The subpanels are synchronized so that that one unique signal fed into the different input ports of all the subpanels result in streams adding up coherently. Based on the subpanel division (and phase-wise synchronization), multi-port CSI-RS (i.e., more than 2 ports) is enabled to support multi-layer SU-MIMO (i.e., more than 2 transmission layers). As will be further disclosed below, the same phase-wise synchronized subpanels142a,142bmight be also used for single-layer transmissions without loss of transmission power or beamforming gain, by feeding the same signal into all ports of all subpanels142a,142b. This is useful for common channels (i.e., channels whose content is shared among two or more terminal devices150) such as the physical broadcast channel (PBCH). All in all, depending on deployment, the subpanels142a,1402bare by the network apparatus200configured to co-operate to support e.g. either a split spectrum (typically for two-layer transmissions per frequency chunk) or a contiguous spectrum (typically for transmissions with more than two transmission layers). The number of transmission layers, the power and the frequency range can thereby be traded against each other. Embodiments relating to further details of time-domain beamforming from an antenna panel142as performed by the network apparatus200will now be disclosed with continued reference toFIG.4. At least some of the below embodiment show how a configuration with two subpanels142a,142bcan offer transmissions with the number of layers exceeding two, whilst still maintaining the full power budget and beamforming gain for single-layer transmissions. Hence, in some examples, N=2. However, the below embodiments are also applicable for N>2 whilst still offering the same benefits. Parallel reference is made toFIG.5which schematically illustrates two subpanels142a,142bconfigured for beamformed communication with a terminal device150according to an embodiment. In order to provide the full beamforming gain for a one-layer transmission, the antenna weights defined for the one-antenna panel case (shown inFIG.1). According to an embodiment, the antenna element weights are thus reused between the subpanels142a,142b. Thereby, all subpanels142a,142bare, according to the antenna element weights, identically weighted. According to another example, the antenna weights of the antennas in the upper half of the antenna panel inFIG.1apply to subpanel142ainFIG.5, and the antenna weights of the antennas in the lower half of the antenna panel inFIG.1apply to subpanel142binFIG.5. Thus, in another embodiment, the antenna weights of the antenna panel as undivided apply also to the antenna panel as divided into the subpanels142a,142b. Together they combine to exactly represent the one-layer transmission ofFIG.1. In more detail,FIG.5illustrates an example of one-layer transmissions for a 2-subpanel. The same signal s is injected into all the ports of the subpanels142a,142b. The different subpanels142a,142bare fully synchronized and thereby enabled to provide the full beamforming gain. Application of any precoder prior to the input ports that provides equal amount of power to the input ports is acceptable. Hence, according to an embodiment, the network apparatus200is configured to perform (optional) action S104as part performing the time-domain beamformed communication in action S104: S104: The network apparatus200provides one and the same antenna port of a one-port CSI-RS port to all input ports. The one-port CSI-RS is then transmitted in a first set of beams. The two subpanels142a,142ballow for more beams, one per polarization and subpanel142a,142b. This might be exploited to prepare for multi-layer SU-MIMO with up to 2N transmission layers. The subpanels142a,142balso allow for receiving up to 2N layers from the terminal device150(as for reception of a 2N-layer physical uplink shared channel (PUSCH) instance from the terminal device150). Generally, the more subpanels142a,142bare used, the more layers can be supported (N per subpanel). In some aspects the terminal device150reports back measurements of the strongest beams in the first set of beams, based on one-port CSI-RS resources. The port of the CSI-RS could be implemented using the same precoder as for the one-layer transmission. Hence, according to an embodiment, the network apparatus200is configured to perform (optional) action S106as part performing the time-domain beamformed communication in action S102: S106: The network apparatus200receives, from one of the terminal devices served by the network apparatus200, first feedback. The first feedback at least identifies which beam in the first set of beams was received with highest power by the terminal device. This first feedback might be classified as a ‘cri-RSRP’ measurement in the technical specification 3GPP TS 38.214 entitled “NR; Physical layer procedures for data”, version 15.7.0 or in the technical specification 3GPP TS 38.331 entitled “NR; Radio Resource Control (RRC); Protocol specification”, version 15.7.0 and reported as Uplink Control Information (UCI) as described in the technical specification 3GPP TS 38.212 entitled “NR; Multiplexing and channel coding”, version 15.7.0. By means of radio resource control (RRC) configuration the number of (strongest) beams reported can be configured using the parameter nrofReportedRS (ranging from 1 to 4). Formally the UCI would then contain each of the (strongest) beams (in terms of RSRP); the strongest beam is presented with its CSI-RS Resource Indicator (CRI) and its associated RSRP and the next strongest beams are presented with their respective CRI and their respective differential RSRP (i.e., the difference to the RSRP of the strongest beam). Parallel reference is made toFIG.6which schematically illustrates two subpanels142a,142bconfigured for beamformed communication with a terminal device150according to an embodiment. In more detail,FIG.6illustrates an example of a 2N-port CSI-RS, where N=2. A beamformed 2N-port CSI-RS might be transmitted upon the network apparatus200receiving the first feedback from the terminal device150in S106but might also be transmitted in other scenarios. Hence, according to an embodiment, the network apparatus200is configured to perform (optional) action S108as part performing the time-domain beamformed communication in action S102: S108: The network apparatus200provides one unique antenna port of a 2N-port CSI-RS to each of the input ports. The 2N-port CSI-RS are then transmitted in a second set of beams selected according to the first feedback. FIG.6shows how the different CSI-RS ports Pimap to the different input streams siof the subpanels142a,142b. The ports P0and P1are transmitted on beam160a, whereas the ports P2and P3are transmitted on beam160b. This allows the terminal device150to report channel information for this combined beamform. Hence, according to an embodiment, the network apparatus200is configured to perform (optional) action Silo as part performing the time-domain beamformed communication in action S102: S110: The network apparatus200receives, from this one of the terminal devices150, second feedback. The second feedback comprises channel information, such as RI, PMI and/or CQI, relating to the second set of beams. The channel information at least indicates how many transmission layers to be used for communication with this one of the terminal devices150. Since the inclusion of several beams in the second set of beams opens up for more spatial layers the terminal device150may report an RI exceeding 2. Upcoming transmissions of physical downlink shared channel (PDSCH) instances might then be on more than 2 layers according to the channel information, see S116below. It might be assumed that the PDSCH transmissions are all subject to the same port-to-antenna mapping as used for CSI-RS before application of that precoder that is indicated by the PMI. Parallel reference is made toFIG.7which schematically illustrates two subpanels142a,142bconfigured for beamformed communication with a terminal device150according to an embodiment. In more detail,FIG.7illustrates an example of an N-port CSI-RS where N=2. Hence, according to an embodiment, the network apparatus200is configured to perform (optional) action S112as part performing the time-domain beamformed communication in action S102: S112: The network apparatus200provides an M-port CSI-RS, where M≤N, and where each antenna port is associated with N subpanels142a,142b. One input port only from each subpanel142a,142bis assigned to the antenna ports. The M-port CSI-RS is then transmitted in a third set of beams selected according to the first or second feedback. In some examples, M=2. Such an M-port CSI-RS might be transmitted in parallel to the 2N-port CSI-RS transmissions (but on other time occasions). As a non-limiting example, if the reported CSI feedback for the 2N-port CSI-RS indicates that transmission is not spectrally efficient, fallback can be made to PDSCH transmissions based on CSI feedback from the M-port CSI-RS. As for the above embodiments, for the one-layer transmission it is possible to reuse the antenna weights defined for an M-port CSI-RS in a setup where half the number of subpanels is used. According to the illustrative example ofFIG.7, port P0is mapped to inputs s0and s2, where s0is subject to antenna weights re-used from the upper half of the one-antenna panel case, and where s2is subject to antenna weights re-used from the lower half of the one-antenna panel case. A similar mapping applies to P1with regards to s1and s3. This allows the terminal device150to report channel information for this c third set of beams. According to an embodiment, the network apparatus200is configured to perform (optional) action S114as part performing the time-domain beamformed communication in action S102: S114: The network apparatus200receives, from this one of the terminal devices150, third feedback. The third feedback comprises channel information, such as RI, PMI and/or CQI, relating to the third set of beams. The channel information at least indicating how many transmission layers to be used for communication with this one of the terminal devices150. Note that there is no normalization inFIG.7. The normalization can be viewed as implemented from the splitting of the antenna panel142into subpanels142a,142bsince one data stream is only allocated to one subpanel. The normalization (of the square root of two) inFIG.5can be understood as from a two-step reasoning: firstly there are two ports as shown inFIG.7(with no normalization); secondly the one layer is mapped onto the two ports with the typical normalization of the square root of two. The two-subpanel configuration handles a one-layer transmission the same way as a one-antenna panel configuration. Communication with the terminal device150might then be performed based on either the feedback to the 2N-port CSI-RS or the feedback to the M-port CSI-RS. Hence, according to an embodiment, the network apparatus200is configured to perform (optional) action S116as part performing the time-domain beamformed communication in action S102: S116: The network apparatus200performs S116time-domain beamformed communication with said one of the terminal devices150according to the channel information. The beamformed communication is then performed using as many transmission layers as indicated by the channel information. FIG.8schematically illustrates, in terms of a number of functional units, the components of a network apparatus200according to an embodiment. Processing circuitry210is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product1010(as inFIG.10), e.g. in the form of a storage medium230. The processing circuitry210may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA). Particularly, the processing circuitry210is configured to cause the network apparatus200to perform a set of operations, or actions, as disclosed above. For example, the storage medium230may store the set of operations, and the processing circuitry210may be configured to retrieve the set of operations from the storage medium230to cause the network apparatus200to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry210is thereby arranged to execute methods as herein disclosed. The storage medium230may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory. The network apparatus200may further comprise a communications interface220at least configured for communications with other entities, functions, nodes, devices, and apparatuses of the communication network100. As such the communications interface220may comprise one or more transmitters and receivers, comprising analogue and digital components. The processing circuitry210controls the general operation of the network apparatus200e.g. by sending data and control signals to the communications interface220and the storage medium230, by receiving data and reports from the communications interface220, and by retrieving data and instructions from the storage medium230. Other components, as well as the related functionality, of the network apparatus200are omitted in order not to obscure the concepts presented herein. FIG.9schematically illustrates, in terms of a number of functional modules, the components of a network apparatus200according to an embodiment. The network apparatus200ofFIG.9comprises a communication module210aconfigured to perform action S102. The network apparatus200ofFIG.9may further comprise a number of optional functional modules, such as any of a provide module210bconfigured to perform action S104, a receive module210cconfigured to perform action S106, a provide module210dconfigured to perform action S108, a receive module210econfigured to perform action S110, a provide module210fconfigured to perform action S112, a receive module210gconfigured to perform action S114, and a communication module210hconfigured to perform action S116. In general terms, each functional module210a-210hmay in one embodiment be implemented only in hardware and in another embodiment with the help of software, i.e., the latter embodiment having computer program instructions stored on the storage medium230which when run on the processing circuitry makes the network apparatus200perform the corresponding actions mentioned above in conjunction withFIG.9. It should also be mentioned that even though the modules correspond to parts of a computer program, they do not need to be separate modules therein, but the way in which they are implemented in software is dependent on the programming language used. Preferably, one or more or all functional modules210a-210hmay be implemented by the processing circuitry210, possibly in cooperation with the communications interface220and/or the storage medium230. The processing circuitry210may thus be configured to from the storage medium230fetch instructions as provided by a functional module210a-210hand to execute these instructions, thereby performing any actions as disclosed herein. The network apparatus200may be provided as a standalone device or as a part of at least one further device. For example, the network apparatus200may be provided in a node of the radio access network or in a node of the core network. Alternatively, functionality of the network apparatus200may be distributed between at least two devices, or nodes. These at least two nodes, or devices, may either be part of the same network part (such as the radio access network or the core network) or may be spread between at least two such network parts. In general terms, instructions that are required to be performed in real time may be performed in a device, or node, operatively closer to the cell than instructions that are not required to be performed in real time. Thus, a first portion of the instructions performed by the network apparatus200may be executed in a first device, and a second portion of the of the instructions performed by the network apparatus200may be executed in a second device; the herein disclosed embodiments are not limited to any particular number of devices on which the instructions performed by the network apparatus200may be executed. Hence, the methods according to the herein disclosed embodiments are suitable to be performed by a network apparatus200residing in a cloud computational environment. Therefore, although a single processing circuitry210is illustrated inFIG.8the processing circuitry210may be distributed among a plurality of devices, or nodes. The same applies to the functional modules210a-210hofFIG.9and the computer program1020ofFIG.10. FIG.10shows one example of a computer program product1010comprising computer readable storage medium1030. On this computer readable storage medium1030, a computer program1020can be stored, which computer program1020can cause the processing circuitry210and thereto operatively coupled entities and devices, such as the communications interface220and the storage medium230, to execute methods according to embodiments described herein. The computer program1020and/or computer program product1010may thus provide means for performing any actions as herein disclosed. In the example ofFIG.10, the computer program product1010is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product1010could also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program1020is here schematically shown as a track on the depicted optical disk, the computer program1020can be stored in any way which is suitable for the computer program product1010. FIG.11is a schematic diagram illustrating a telecommunication network connected via an intermediate network420to a host computer430in accordance with some embodiments. In accordance with an embodiment, a communication system includes telecommunication network410, such as a 3GPP-type cellular network, which comprises access network411, such as radio access network110inFIG.3, and core network414, such as core network120inFIG.3. Access network411comprises a plurality of radio access network nodes412a,412b,412c, such as NBs, eNBs, gNBs (each corresponding to the network apparatus200ofFIG.3) or other types of wireless access points, each defining a corresponding coverage area, or cell,413a,413b,413c. Each radio access network nodes412a,412b,412cis connectable to core network414over a wired or wireless connection415. A first UE491located in coverage area413cis configured to wirelessly connect to, or be paged by, the corresponding network node412c. A second UE492in coverage area413ais wirelessly connectable to the corresponding network node412a. While a plurality of UE491,492are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole terminal device is connecting to the corresponding network node412. The UEs491,492correspond to the terminal device150ofFIG.3. Telecommunication network410is itself connected to host computer430, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer430may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections421and422between telecommunication network410and host computer430may extend directly from core network414to host computer430or may go via an optional intermediate network420. Intermediate network420may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network420, if any, may be a backbone network or the Internet; in particular, intermediate network420may comprise two or more sub-networks (not shown). The communication system ofFIG.11as a whole enables connectivity between the connected UEs491,492and host computer430. The connectivity may be described as an over-the-top (OTT) connection450. Host computer430and the connected UEs491,492are configured to communicate data and/or signaling via OTT connection450, using access network411, core network414, any intermediate network420and possible further infrastructure (not shown) as intermediaries. OTT connection450may be transparent in the sense that the participating communication devices through which OTT connection450passes are unaware of routing of uplink and downlink communications. For example, network node412may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer430to be forwarded (e.g., handed over) to a connected UE491. Similarly, network node412need not be aware of the future routing of an outgoing uplink communication originating from the UE491towards the host computer430. FIG.12is a schematic diagram illustrating host computer communicating via a radio access network node with a UE over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with an embodiment, of the UE, radio access network node and host computer discussed in the preceding paragraphs will now be described with reference toFIG.12. In communication system500, host computer510comprises hardware515including communication interface516configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system500. Host computer510further comprises processing circuitry518, which may have storage and/or processing capabilities. In particular, processing circuitry518may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer510further comprises software511, which is stored in or accessible by host computer510and executable by processing circuitry518. Software511includes host application512. Host application512may be operable to provide a service to a remote user, such as UE530connecting via OTT connection550terminating at UE530and host computer510. The UE530corresponds to the terminal device150ofFIG.3. In providing the service to the remote user, host application512may provide user data which is transmitted using OTT connection550. Communication system500further includes radio access network node520provided in a telecommunication system and comprising hardware525enabling it to communicate with host computer510and with UE530. The radio access network node520corresponds to the network apparatus200ofFIG.3. Hardware525may include communication interface526for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system500, as well as radio interface527for setting up and maintaining at least wireless connection570with UE530located in a coverage area (not shown inFIG.12) served by radio access network node520. Communication interface526may be configured to facilitate connection560to host computer510. Connection560may be direct or it may pass through a core network (not shown inFIG.12) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware525of radio access network node520further includes processing circuitry528, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Radio access network node520further has software521stored internally or accessible via an external connection. Communication system500further includes UE530already referred to. Its hardware535may include radio interface537configured to set up and maintain wireless connection570with a radio access network node serving a coverage area in which UE530is currently located. Hardware535of UE530further includes processing circuitry538, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE530further comprises software531, which is stored in or accessible by UE530and executable by processing circuitry538. Software531includes client application532. Client application532may be operable to provide a service to a human or non-human user via UE530, with the support of host computer510. In host computer510, an executing host application512may communicate with the executing client application532via OTT connection550terminating at UE530and host computer510. In providing the service to the user, client application532may receive request data from host application512and provide user data in response to the request data. OTT connection550may transfer both the request data and the user data. Client application532may interact with the user to generate the user data that it provides. It is noted that host computer510, radio access network node520and UE530illustrated inFIG.12may be similar or identical to host computer430, one of network nodes412a,412b,412cand one of UEs491,492ofFIG.11, respectively. This is to say, the inner workings of these entities may be as shown inFIG.12and independently, the surrounding network topology may be that ofFIG.11. InFIG.12, OTT connection550has been drawn abstractly to illustrate the communication between host computer510and UE530via network node520, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE530or from the service provider operating host computer510, or both. While OTT connection550is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network). Wireless connection570between UE530and radio access network node520is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE530using OTT connection550, in which wireless connection570forms the last segment. More precisely, the teachings of these embodiments may reduce interference, due to improved classification ability of airborne UEs which can generate significant interference. A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection550between host computer510and UE530, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection550may be implemented in software511and hardware515of host computer510or in software531and hardware535of UE530, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection550passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software511,531may compute or estimate the monitored quantities. The reconfiguring of OTT connection550may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect network node520, and it may be unknown or imperceptible to radio access network node520. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer's510measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software511and531causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection550while it monitors propagation times, errors etc. The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims. | 34,259 |
11943026 | DESCRIPTION OF EMBODIMENTS Embodiments of this application may be applied to a wireless communication system. The wireless communication system may be a new radio (NR) system in the 5th generation (5G) mobile communication system, or may be a future new wireless communication system. This is not limited in this application. The embodiments of this application specifically relate to a network device and a terminal device. The network device is an access device used by the terminal device to access the mobile communication system in a wireless manner, and may be a NodeB, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in the 5G mobile communication system, a base station in a future mobile communication system, an access node in a Wi-Fi system, or the like. A specific technology and a specific device form used by the network device are not limited in the embodiments of this application. The terminal device may also be referred to as a terminal (Terminal), user equipment (UE), a mobile station (MS), a mobile terminal (MT), or the like. The terminal device may be a mobile phone, a tablet (Pad), a computer with a wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote surgery (remote medical surgery), a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, or the like. A specific technology and a specific device form used by the terminal device are not limited in the embodiment of this application. For example, the wireless communication system is a long term evolution (LIE) system. In the LTE system, a reference signal sent by the terminal device to the network device may be an SRS, and the network device may perform related measurement based on the SRS to obtain CSI. For example, the network device performs channel quality estimation based on the SRS to obtain CSI. For example, the network device may estimate uplink channel quality by measuring the SRS, to perform uplink AMC and uplink frequency selective scheduling. The network device may further measure uplink timing of the terminal device, deliver a TA command, ensure an uplink synchronization status of the terminal device, and calculate a downlink beamforming weight by using the SRS. In a plurality of cells, due to signal interference between different cells, SRS interference is severe in an area in which signals of the different cells overlap. Consequently, SRS measurement is inaccurate. Therefore, how to allocate, to the terminal device, a transmission resource for transmitting an SRS plays a decisive role in maintaining uplink synchronization, ensuring uplink frequency selective scheduling, and the like for the terminal device. To better understand a method for obtaining channel state information, an apparatus, and a computer storage medium disclosed in the embodiments of this application, the following first describes the method for obtaining channel state information in the embodiments of this application.FIG.1is a schematic flowchart of a method for obtaining channel state information according to an embodiment of this application. The method includes but is not limited to the following steps. Step S101: A network device allocates, to a terminal device according to a preset rule, a transmission resource for transmitting an SRS in a cell to which the terminal device belongs. Transmission resources for transmitting SRSs in different cells do not overlap at all or partially overlap. The transmission resource includes a time domain resource, a frequency domain resource, a carrier domain resource, or a code domain resource. For example, time domain resources for transmitting the SRSs in the different cells do not completely overlap (for example, terminal devices in the different cells transmit the SRSs on different SRS symbols). For another example, frequency domain resources for transmitting the SRSs in the different cells do not completely overlap (for example, terminal devices in the different cells transmit the SRSs on different sub-bands). For another example, carrier domain resources for transmitting the SRSs in the different cells do not completely overlap (for example, terminal devices in the different cells transmit the SRSs on different subcarriers). For another example, code domain resources for transmitting the SRSs in the different cells do not completely overlap (for example, terminal devices in the different cells transmit the SRSs on different orthogonal codes (Cyclic Shift sequences)). In this embodiment, the terminal device may use all other frequency domain resources, carrier domain resources, or code domain resources in the time domain resources allocated by the network device to the cell to which the terminal device belongs, and does not cause interference to another neighboring cell. In an implementation, when the allocation is performed according to an SRS time domain (SRS symbol) allocation scheme, the network device allocates, in different subframe SRS resources of an entire frame, different SRS symbol resources to cells having different PCIs. When the allocation is performed according to an SRS resource frequency domain (SRS sub-band) allocation scheme, SRSs in a system bandwidth of the entire cell are divided into different sub-bands. A frequency of a first sub-band is less than a frequency of a second sub-band. The frequency of the second sub-band is less than a frequency of a third sub-band. The frequency of the third sub-band is less than a frequency of a fourth sub-band. A frequency domain relationship between other sub-bands is deduced by analogy. When the allocation is performed according to an SRS carrier domain (SRS Comb) allocation scheme, in carrier domain resources in a system bandwidth of the entire cell, different SRS carrier domain resources are numbered based on physical resource blocks RBs, and system SRS resources are allocated to cells having different PCIs. When the allocation is performed according to an SRS resource code domain (SRS Cyclic Shift sequence) allocation scheme, in SRS code domain resources in a system bandwidth of the entire cell, different SRS code domain resources are numbered based on SRS orthogonal code Cyclic Shift serial numbers, and system SRS resources are allocated to cells having different PCIs. In an implementation, the time domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap. In a part in which the time domain resources for transmitting the SRSs in the different cells completely overlap, frequency domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap. In a part in which the frequency domain resources for transmitting the SRSs in the different cells completely overlap, carrier domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap. In a part in which the carrier domain resources for transmitting the SRSs in the different cells completely overlap, code domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap. In this embodiment, the terminal device included in each cell may use a part of or all transmission resources in a sub-band range that is allocated by the network device for the cell. If a quantity of access users in the cell is very large and exceeds a sub-band range allocated to the cell, to avoid interference to another cell, subcarriers or code channels on an expanded resource are staggered as much as possible. Based on this, even if a same resource block (RB) is allocated to different cells, subcarriers in the RB allocated to the different cells are staggered as much as possible. Even if a same subcarrier is allocated to different cells, code channels in the subcarrier allocated to the different cells are staggered as much as possible, to reduce inter-cell SRS interference. In an implementation, the network device may determine a quantity of cells in which the transmission resource needs to be currently allocated, and allocate, to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs. For example, a same SRS allocation algorithm may be used within a cell and between cells to ensure that transmission resources allocated to different cells are staggered as much as possible. In an implementation, the network device divides a PCI of the cell to which the terminal device belongs by the quantity of cells to obtain a remainder, determines, based on the remainder, the cell to which the terminal device belongs as a target cell, and allocates, to the terminal device, the transmission resource for transmitting the SRS in the target cell. The target cell is a first cell, a second cell, or a third cell. The first cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a first value. The second cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a second value. The third cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a third value. A transmission resource for transmitting an SRS in the first cell, a transmission resource for transmitting an SRS in the second cell, and a transmission resource for transmitting an SRS in the third cell do not overlap at all or partially overlap. In this embodiment, the network device may group jointly allocated cells into a cell cluster, and formulate a joint allocation principle to jointly allocate transmission resources to a plurality of cells, to reduce SRS interference between different cells as much as possible, and improve transmission resource utilization. For example, in a 3-sector networking scenario, transmission resources in different cells may be staggered according to PCI mod 3. In the jointly allocated cell cluster, different transmission resources are initially allocated in different cells. If a quantity of time domain SRS symbols of a system frame is sufficient for staggering the transmission resources in the different cells, the transmission resources in the different cells are first staggered in time domain (SRS symbol). If the transmission resources in the different cells cannot be staggered in time domain, the transmission resources in the different cells are staggered in frequency domain (SRS sub-band). If the transmission resources in the different cells cannot be staggered in frequency domain, the transmission resources in the different cells are staggered in carrier domain (SRS subcarrier Comb). If the transmission resources in the different cells cannot be staggered in carrier domain, the transmission resources in the different cells are staggered in code domain (SRS orthogonal code). For example, the quantity of cells is 3. A cell identifier of the first cell is 0. A cell identifier of the second cell is 1. A cell identifier of the third cell is 2. The transmission resource for transmitting the SRS in the first cell is the first subframe to the fourth subframe in the system frame. The transmission resource for transmitting the SRS in the second cell is the fourth subframe to the seventh subframe in the system frame. The transmission resource for transmitting the SRS in the third cell is the seventh subframe to the tenth subframe in the system frame. The network device may obtain the PCI of the cell to which the terminal device belongs. If the remainder obtained by dividing the PCI of the cell to which the terminal device belongs by the quantity of cells is 0, the network device may determine that the cell to which the terminal device belongs is the first cell, and further allocate, to the terminal device, the transmission resource for transmitting the SRS. The allocated transmission resource is the first subframe to the fourth subframe in the system frame. In an implementation, the network device may determine a quantity of intra-frequency neighboring cells, and allocate, to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs. The intra-frequency neighboring cells include the cell to which the terminal device belongs, and the intra-frequency neighboring cells have a same spectrum. In an implementation, the network device may divide a PCI of the cell to which the terminal device belongs by the quantity of cells to obtain a remainder, determine, based on the remainder, the cell to which the terminal device belongs as a target cell, and allocate, to the terminal device, the transmission resource for transmitting the SRS in the target cell. The target cell is a first cell, a second cell, or a third cell. The first cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a first value. The second cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a second value. The third cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a third value. A transmission resource for transmitting an SRS in the first cell is a first sub-band or a second sub-band. A transmission resource for transmitting an SRS in the second cell is the second sub-band or a third sub-band. A transmission resource for transmitting an SRS in the third cell is the third sub-band or a fourth sub-band. For example, if there are three intra-frequency neighboring cells, SRS resource allocation of the three cells may be staggered based on remainders obtained by dividing PCIs of the cells by 3. A cell for which PCI mod 3=0 preferentially uses sub-bands 0 and 1 in a system full band. A cell for which PCI mod 3=1 preferentially uses sub-bands 1 and 2 in a system SRS full-band resource. A cell for which PCI mod 3=2 preferentially uses sub-bands 2 and 3 in the system SRS full-band resource. In an implementation, the network device divides a physical cell identifier PCI of the cell to which the terminal device belongs by the quantity of cells to obtain a remainder, determines, based on the remainder, the cell to which the terminal device belongs as a target cell, and allocates, to the terminal device, the transmission resource for transmitting the SRS in the target cell. The target cell is a fourth cell or a fifth cell. The fourth cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a first value. The fifth cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a second value. A transmission resource for transmitting an SRS in the fourth cell is a fifth sub-band or a sixth sub-band. A transmission resource for transmitting an SRS in the fifth cell is a seventh sub-band or an eighth sub-band. The fifth sub-band and the seventh sub-band are obtained based on a quantity of frequency domain resources included in the system bandwidth. A frequency of the fifth sub-band is less than a frequency of the seventh sub-band. The sixth sub-band is a part of the fifth sub-band, and the eighth sub-band is a part of the seventh sub-band. For example, if there are two intra-frequency neighboring cells, SRS resource allocation of the two cells may be staggered based on remainders obtained by dividing PCIDs of the cells by 2. A cell for which PCI mod 2=0 preferentially uses an upper half sub-band or an upper 1/4 sub-band of the system bandwidth. A cell for which PCI mod 2=1 preferentially uses a lower half sub-band or a lower 1/4 sub-band of the system bandwidth. In an implementation, the network device sends first configuration information to the terminal device, where the first configuration information is used to indicate the terminal device to regularly transmit, based on a configuration periodicity, the SRS on the allocated transmission resource. In an implementation, the network device sends second configuration information to the terminal device, where the second configuration information is used to indicate that the transmission resource allocated to the terminal device is a resource other than a transmission resource corresponding to a periodically transmitted SRS in the system bandwidth. In this embodiment, SRS transmission includes periodic SRS transmission and aperiodic SRS transmission based on a user feedback frequency. When the terminal device accesses a network, the network device notifies the terminal device by using signaling. A periodic SRS needs to be sent by the terminal based on the configuration periodicity, and an aperiodic SRS needs to be sent by the terminal based on triggering by the network device. In an implementation, the periodic SRS and the aperiodic SRS cooperate with each other. The aperiodic SRS may be configured at an SRS sub-band position that is not detected by using the periodic SRS, so that the terminal device can quickly report information about the position that is not detected by using the periodic SRS. When resources are sufficient, the aperiodic SRS can be used to indicate full-band SRS sounding. An aperiodic SRS bandwidth and a frequency hopping bandwidth of a user are allocated based on a size of an RB of a service of the user. Uplink and downlink scheduling is preferentially performed at a place in which an SRS sounding position is allocated. If there is a burst service to be processed and a volume of the service is heavy, the uplink and downlink scheduling can be performed at a place in which no SRS sounding position is allocated. For example, the network device may schedule the terminal device in a MIMO mode that does not require a BF weight. If the terminal device supports the aperiodic SRS, the network device may use a data volume prediction manner during scheduling. Based on a case in which an uplink or downlink data volume in an uplink or downlink buffer is very large, a case in which a frequency domain start position or a bandwidth of scheduled data may need to exceed a sub-band position that is originally detected by using the periodic SRS, a frequency domain position that is not detected by using the SRS, or a case in which a time of previous sounding exceeds a validity period, the network device indicates, by using an uplink/downlink scheduling indication (Downlink Control Information, DCI), the terminal to trigger aperiodic reporting, and supplementarily detects a position that is not detected by the terminal by using the periodic SRS. In an implementation, when a quantity of users included in the cell to which the terminal device belongs or a type of a service that needs to be currently processed by the terminal device changes, the network device dynamically adjusts the transmission resource allocated to the terminal device. For example, when SRS resources allocated to the cell according to an SRS resource allocation principle are insufficient, the SRS resources may be expanded, that is, allocation is allowed to be performed according to an SRS resource allocation principle of another neighboring cell. For example, after a time domain resource, a frequency domain resource, a carrier domain resource, and a code domain resource of an initially allocated SRS are all allocated in sequence, the SRS is sequentially expanded in time domain, in frequency domain, in carrier domain, and in code domain. For example, if the SRS cannot be expanded in time domain, the SRS is preferentially expanded in a frequency domain sub-band, and then expanded sequentially in carrier domain and in code domain. That is, an SRS frequency domain resource sub-band allocated in another cell is allowed to be used, and expansion may be subsequently performed in carrier domain and in code domain, to ensure that a user accesses a network. In each cell, user SRSs are allocated according to a rule, to stagger the user SRSs as much as possible. To reduce inter-cell SRS interference, an example in which frequency domain SRSs are allocated in a staggering manner is used herein for description and taken as a reference for allocation of SRSs in other domain in a staggering manner. In this embodiment, due to a change in a type of the service or an increase in the quantity of users in the cell, more transmission resources are needed. When the transmission resource is expanded to an area outside the cell in which the transmission resource is allocated, to avoid interference, expanded areas in different cells need to be staggered as much as possible. For example, in different cells, transmission resources are staggered in code domain. A subcarrier 0/1 and a code channel 0/1/2/3 in an RB are preferentially allocated in a cell for which PCI mod 3=0. A subcarrier 2/3 and a code channel 4/5/6/7 in the RB are preferentially allocated in a cell for which PCI mod 3=1. A subcarrier 4/5 and a code channel 8/9/10/11 in the RB are preferentially allocated in a cell for which PCI mod 3=2. Step S102: The terminal device transmits the SRS on the allocated transmission resource. Step S103: The network device performs channel quality estimation based on the SRS to obtain CSI. In this embodiment of this application, the transmission resources for transmitting the SRSs in the different cells do not completely overlap, thereby ensuring that the transmission resources allocated by the network device to the different cells are staggered as much as possible. Therefore, SRS interference between the cells can be reduced, and cell performance can be improved. FIG.2is another schematic flowchart of a method for obtaining channel state information according to an embodiment of this application. The method includes but is not limited to the following steps. Step S201: A network device determines a service that needs to be currently processed by a terminal device. Step S202: The network device determines, based on a correspondence between a service and a transmission resource for transmitting an SRS, a transmission resource corresponding to the service. In an implementation, the network device may determine, based on indication information of the service that needs to be currently processed by the terminal device, a type of the service, where the indication information includes a QCI or an SPID of the service. The network device may further determine, based on a correspondence between a type of a service and a transmission resource for transmitting an SRS, the transmission resource corresponding to the type of the service. The QCI is a scale value. The QCI (such as a packet loss rate or a packet delay budget) may be used to measure a specific packet forwarding behavior to be provided to a service data flow (SDF). The QCI may further be used for a guaranteed bit rate (GBR) bearer and a non-guaranteed bit rate (Non-GBR) bearer, and is used to specify a control bearer-level packet forwarding manner (such as a scheduling weight, an admission threshold, a queue management threshold, or a link layer protocol configuration) defined in an access node. Based on user information mapped by using the SPID, the network device may use a terminal device-specific camping policy and inter-frequency inter-RAT handover policy, to ensure that the terminal device camps on or is handed over to an appropriate frequency/RAT based on subscription information of the terminal device, thereby ensuring optimal user experience. In an implementation, when a latency requirement level of the service that needs to be currently processed by the terminal device is greater than a first-level threshold, the network device determines that a configuration periodicity of the SRS is less than a preset periodicity threshold; and when the latency requirement level of the service that needs to be currently processed by the terminal device is less than or equal to the first-level threshold, the network device determines that the configuration periodicity of the SRS is greater than or equal to the preset periodicity threshold. For example, the network device may determine, based on an indication, such as the QCI or the SPID, of the service, the type of the service that needs to be currently processed by the terminal device. For example, the type of the service may be enhanced machine type communication (eMTC) or a kids watch. Services of different types have different service features. For a service with a small service volume, the transmission resource allocated by the network device may be within a specified range of a full bandwidth. For a service with a large volume and a high delay requirement, the transmission resource allocated by the network device may be a full bandwidth. In an implementation, the network device determines a service volume based on uplink send buffer data fed back by the terminal device or a downlink send buffer data volume. The network device further determines, based on a correspondence between a service volume and a transmission resource for transmitting an SRS, the transmission resource corresponding to the service volume. In an implementation, when a frequency domain resource block resource requirement level of the service that needs to be currently processed by the terminal device is less than or equal to a second-level threshold, the network device determines that a sub-band included in the transmission resource is less than or equal to a preset quantity threshold; and when the frequency domain resource block resource requirement level of the service that needs to be currently processed by the terminal device is greater than the second-level threshold, the network device determines that the sub-band included in the transmission resource is greater than or equal to the preset quantity threshold. For example, when the service volume is large, a transmission resource including a large sub-band (where the large sub-band includes several small sub-bands in frequency domain) may be allocated. When the service volume is small, a transmission resource including a small sub-band may be allocated. For example, services such as semi-persistent voice scheduling and machine-to-machine communication require a relatively small frequency domain resource, and a frequency domain resource corresponding to a transmission resource block size of the service may be allocated. In an implementation, when the service volume changes, the network device dynamically adjusts the transmission resource allocated to the terminal device. A resource volume of an adjusted transmission resource is directly proportional to the service volume. For example, if determining that the service volume increases, the network device may adjust a size of a periodic SRS frequency hopping bandwidth by using a radio resource control (RRC) signaling message. For example, the transmission resource allocated to the terminal device is adjusted from a 1/4 full-band frequency hopping bandwidth to a 1/2 full-band frequency hopping bandwidth or a full-band frequency hopping bandwidth. For another example, when a large SRS sub-band needs to be allocated due to an increase in the service volume, and an SRS frequency-domain transmission resource is idle, the network device may allocate the large SRS sub-band to the terminal device, and may trigger, by using a scheduling indication, reporting of an SRS sub-band with a large aperiodic SRS frequency-domain transmission resource, or reconfigure, by using signaling, an SRS sub-band with a large periodic SRS frequency-domain transmission resource, or even allocate an entire frequency domain sub-band (namely, all frequency domain SRS bandwidths) of the entire cell. When the service volume decreases, a small periodic SRS frequency domain bandwidth may be reconfigured for a user by using signaling. In this embodiment, an appropriate user SRS frequency-domain transmission resource is adjusted based on the service volume, to obtain a status of a frequency domain channel for transmitting the required service, so that user data can be better transmitted in a downlink or scheduled in an uplink at the frequency domain position. Space domain multiplexing is performed, by using a beamforming (BF) technology and a multiple-input multiple-output (MIMO) technology, on a same time-frequency resource allocated by the network device in the cell. In an implementation, the network device may further send first configuration information to the terminal device, where the first configuration information is used to indicate the terminal device to regularly transmit, based on a configuration periodicity, the SRS on the allocated transmission resource. In an implementation, the network device may further send second configuration information to the terminal device, where the second configuration information is used to indicate that the transmission resource allocated to the terminal device is a resource other than a transmission resource corresponding to a periodically transmitted SRS in a system bandwidth. In an implementation, the network device may dynamically adjust and allocate, based on a service feature, an SRS bandwidth and a periodicity that satisfy a size of a user service bandwidth. For example, for a latency-sensitive service, the network device may allocate a short SRS periodicity, and for a latency-insensitive service, the network device may allocate a long SRS periodicity. Step S203: The terminal device transmits the SRS on the allocated transmission resource. Step S204: The network device performs channel quality estimation based on the SRS to obtain CSI. In this embodiment of this application, the network device may configure, based on the service feature, the transmission resource required by the service, and sounding does not need to be performed on a transmission resource that is not required by the service, so that the network device and the terminal device can use CSI of an air interface in a more timely manner, and latest channel quality information can be fully used during uplink and downlink scheduling, thereby improving spectral efficiency of the cell. In addition, when a cell bandwidth is larger in a future 5G scenario, a transmission resource required by a service may be allocated to improve resource utilization. In another method for obtaining channel state information, a smaller frequency domain bandwidth indicates a more similar channel characteristic obtained through SRS sounding than a channel characteristic obtained through SRS sounding by using a larger frequency domain bandwidth. For example, during determining multi-user space domain multiplexing pairing scheduling by using multi-user beamforming of downlink scheduling and uplink virtual MIMO, a channel statistical characteristic is used to calculate a statistical weight. If the user statistical weight can more accurately comply with user channel information, when the statistical weight used during pairing scheduling is closer to an instantaneous weight, selected paired users are more accurate, interference between the paired users is lower, and a cell throughput is higher. During a scheduling process, a user ensures, in the foregoing manner, that there is corresponding channel information during the scheduling. For example, when some terminal devices do not support an aperiodic SRS, a service whose type is an urgent and burst service or a service whose service volume increases and exceeds an RB allocated for SRS sounding, and scheduling needs to be performed in a current subframe, downlink scheduling may be performed by using statistical channel information, or performed temporarily by using a DCI message in a diversity mode of a common MIMO transmission mode without depending on the channel information, and uplink scheduling may be performed by using the statistical channel information. In this embodiment, SRS sounding is preferentially performed on the transmission resource allocated by the network device during the uplink and downlink scheduling. When there is a burst service to be processed, the terminal device is allowed to transmit the SRS on a non-allocated transmission resource. In a beamforming transmission mode that requires a channel state, transmitted data may be weighted by using a statistical weight of an allocated SRS frequency-domain transmission resource, and a user in a MIMO mode may directly perform uplink and downlink scheduling transmission in a system full band. The foregoing describes in detail the methods in the embodiments of this application. The following provides related apparatuses in the embodiments of this application. FIG.3is a schematic diagram of a structure of a communication apparatus according to an embodiment of this application. The communication apparatus is configured to perform the steps performed by the network device in the method embodiment corresponding toFIG.1. The communication apparatus may include:a sending unit301, configured to allocate, to a terminal device according to a preset rule, a transmission resource for transmitting an SRS in a cell to which the terminal device belongs, where transmission resources for transmitting SRSs in different cells do not overlap at all or partially overlap, and the transmission resource includes a time domain resource, a frequency domain resource, a carrier domain resource, or a code domain resource;a receiving unit302, configured to receive the SRS transmitted by the terminal device on the allocated transmission resource; anda processing unit303, configured to perform channel quality estimation based on the received SRS to obtain channel state information CSI. In an implementation, that a sending unit301allocates, to a terminal device according to a preset rule, a transmission resource for transmitting an SRS in a cell to which the terminal device belongs includes:determining a quantity of cells in which the transmission resource needs to be currently allocated; andallocating, to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs. In an implementation, that the sending unit301allocates, to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs includes:dividing a physical cell identifier PCI of the cell to which the terminal device belongs by the quantity of cells, to obtain a remainder;determining, based on the remainder, the cell to which the terminal device belongs as a target cell, where the target cell is a first cell, a second cell, or a third cell; the first cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a first value, the second cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a second value, and the third cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a third value; and a transmission resource for transmitting an SRS in the first cell, a transmission resource for transmitting an SRS in the second cell, and a transmission resource for transmitting an SRS in the third cell do not overlap at all or partially overlap; andallocating, to the terminal device, the transmission resource for transmitting the SRS in the target cell. In an implementation, that the sending unit301determines a quantity of cells in which the transmission resource needs to be currently allocated includes:determining a quantity of intra-frequency neighboring cells, where the intra-frequency neighboring cells include the cell to which the terminal device belongs, and the intra-frequency neighboring cells have a same spectrum. In an implementation, that the sending unit301allocates, to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs includes:dividing a PCI of the cell to which the terminal device belongs by the quantity of cells, to obtain a remainder;determining, based on the remainder, the cell to which the terminal device belongs as a target cell, where the target cell is a first cell, a second cell, or a third cell; the first cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a first value, the second cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a second value, and the third cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a third value; and a transmission resource for transmitting an SRS in the first cell is a first sub-band or a second sub-band, a transmission resource for transmitting an SRS in the second cell is the second sub-band or a third sub-band, and a transmission resource for transmitting an SRS in the third cell is the third sub-band or a fourth sub-band; andallocating, to the terminal device, the transmission resource for transmitting the SRS in the target cell. In an implementation, that the sending unit301allocates, to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs includes:dividing a physical cell identifier PCI of the cell to which the terminal device belongs by the quantity of cells, to obtain a remainder;determining, based on the remainder, the cell to which the terminal device belongs as a target cell, where the target cell is a fourth cell or a fifth cell; the fourth cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a first value, and the fifth cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a second value; and a transmission resource for transmitting an SRS in the fourth cell is a fifth sub-band or a sixth sub-band, a transmission resource for transmitting an SRS in the fifth cell is a seventh sub-band or an eighth sub-band, the fifth sub-band and the seventh sub-band are obtained based on a quantity of frequency domain resources included in a system bandwidth, a frequency of the fifth sub-band is less than a frequency of the seventh sub-band, the sixth sub-band is a part of the fifth sub-band, and the eighth sub-band is a part of the seventh sub-band; and allocating, to the terminal device, the transmission resource for transmitting the SRS in the target cell. In an implementation, that transmission resources for transmitting SRSs in different cells do not overlap at all or partially overlap includes:time domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap;in a part in which the time domain resources for transmitting the SRSs in the different cells completely overlap, frequency domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap;in a part in which the frequency domain resources for transmitting the SRSs in the different cells completely overlap, carrier domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap; andin a part in which the carrier domain resources for transmitting the SRSs in the different cells completely overlap, code domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap. In an implementation, the sending unit301is further configured to send first configuration information to the terminal device, where the first configuration information is used to indicate the terminal device to regularly transmit, based on a configuration periodicity, the SRS on the allocated transmission resource. In an implementation, the sending unit301is further configured to send second configuration information to the terminal device, where the second configuration information is used to indicate that the transmission resource allocated to the terminal device is a resource other than a transmission resource corresponding to a periodically transmitted SRS in the system bandwidth. In an implementation, the processing unit303is further configured to: when a quantity of users included in the cell to which the terminal device belongs or a type of a service that needs to be currently processed by the terminal device changes, dynamically adjust the transmission resource allocated to the terminal device. It should be noted that, for content that is not mentioned in the embodiment corresponding toFIG.3and a specific implementation of steps performed by the units, refer to the embodiment shown inFIG.1and the foregoing content. Details are not described herein again. FIG.3is a schematic diagram of a structure of a communication apparatus according to an embodiment of this application. The communication apparatus is configured to perform the steps performed by the network device in the method embodiment corresponding toFIG.2. The communication apparatus may include:a processing unit303, configured to determine a service that needs to be currently processed by a terminal device, wherethe processing unit303is further configured to determine, based on a correspondence between a service and a transmission resource for transmitting a sounding reference signal SRS, a transmission resource corresponding to the service;a sending unit301, configured to allocate the transmission resource to the terminal device; anda receiving unit302, configured to receive the SRS transmitted by the terminal device on the allocated transmission resource, wherethe processing unit303, further configured to perform channel quality estimation based on the received SRS to obtain channel state information CSI. In an implementation, that the processing unit303determines, based on a correspondence between a service and a transmission resource for transmitting an SRS, a transmission resource corresponding to the service includes:determining, based on indication information of the service that needs to be currently processed by the terminal device, a type of the service, where the indication information includes a quality of service class identifier QCI or a subscriber profile identifier SPID of the service; anddetermining, based on a correspondence between a type of a service and a transmission resource for transmitting an SRS, the transmission resource corresponding to the type of the service. In an implementation, that the processing unit303determines, based on a correspondence between a type of a service and a transmission resource for transmitting an SRS, the transmission resource corresponding to the type of the service includes:when a latency requirement level of the service that needs to be currently processed by the terminal device is greater than a first-level threshold, determining, by the network device, that a configuration periodicity of the SRS is less than a preset periodicity threshold; andwhen the latency requirement level of the service that needs to be currently processed by the terminal device is less than or equal to the first-level threshold, determining that the configuration periodicity of the SRS is greater than or equal to the preset periodicity threshold. In an implementation, that the processing unit303determines, based on a correspondence between a service and a transmission resource for transmitting a sounding reference signal SRS, a transmission resource corresponding to the service includes:determining a service volume based on uplink send buffer data fed back by the terminal device or a downlink send buffer data volume; anddetermining, based on a correspondence between a service volume and a transmission resource for transmitting an SRS, the transmission resource corresponding to the service volume. In an implementation, that the processing unit303determines, based on a correspondence between a service volume and a transmission resource for transmitting an SRS, the transmission resource corresponding to the service volume includes:when a frequency domain resource block resource requirement level of the service that needs to be currently processed by the terminal device is less than or equal to a second-level threshold, determining that a sub-band included in the transmission resource is less than or equal to a preset quantity threshold; andwhen the frequency domain resource block resource requirement level of the service that needs to be currently processed by the terminal device is greater than the second-level threshold, determining that the sub-band included in the transmission resource is greater than or equal to the preset quantity threshold. In an implementation, the processing unit303is further configured to: when the service volume changes, dynamically adjust the transmission resource allocated to the terminal device. A resource volume of an adjusted transmission resource is directly proportional to the service volume. In an implementation, the sending unit301is further configured to send first configuration information to the terminal device, where the first configuration information is used to indicate the terminal device to regularly transmit, based on a configuration periodicity, the SRS on the allocated transmission resource. In an implementation, the sending unit301is further configured to send second configuration information to the terminal device, where the second configuration information is used to indicate that the transmission resource allocated to the terminal device is a resource other than a transmission resource corresponding to a periodically transmitted SRS in a system bandwidth. It should be noted that, for content that is not mentioned in the embodiment corresponding toFIG.3and a specific implementation of steps performed by the units, refer to the embodiment shown inFIG.2and the foregoing content. Details are not described herein again. In an implementation, related functions implemented by the units inFIG.4may be implemented in combination with a processor and a communication interface.FIG.4is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present invention. The communication apparatus includes a processor401, a memory402, and a communication interface403. The processor401, the memory402, and the communication interface403are connected through one or more communication buses. The processor401is configured to support the communication apparatus in performing the method inFIG.1. The processor401may be a central processing unit (CPU), a network processor (NP), a hardware chip, or any combination thereof. The memory402is configured to store program code or the like. The memory402may include a volatile memory, for example, a random access memory (RAM). The memory402may also include a non-volatile memory, for example, a read-only memory (ROM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD). The memory402may further include a combination of the foregoing types of memories. The communication interface403is configured to send and receive data. In this embodiment of the present invention, the communication apparatus includes a plurality of communication interfaces, and a communication interface configured to send data and a communication interface configured to receive data may be different communication interfaces. The processor401may invoke the program code stored in the memory402, to perform the following operations:allocating, through the communication interface403, to a terminal device according to a preset rule, a transmission resource for transmitting a sounding reference signal SRS in a cell to which the terminal device belongs, where transmission resources for transmitting SRSs in different cells do not overlap at all or partially overlap, and the transmission resource includes a time domain resource, a frequency domain resource, a carrier domain resource, or a code domain resource;receiving, through the communication interface403, the SRS transmitted by the terminal device on the allocated transmission resource; andperforming channel quality estimation based on the received SRS to obtain channel state information CSI. In an implementation, that the processor401allocates, through the communication interface403, to a terminal device according to a preset rule, a transmission resource for transmitting an SRS in a cell to which the terminal device belongs includes:determining a quantity of cells in which the transmission resource needs to be currently allocated; andallocating, to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs. In an implementation, that the processor401allocates, through the communication interface403, to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs includes:dividing a physical cell identifier PCI of the cell to which the terminal device belongs by the quantity of cells, to obtain a remainder;determining, based on the remainder, the cell to which the terminal device belongs as a target cell, where the target cell is a first cell, a second cell, or a third cell; the first cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a first value, the second cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a second value, and the third cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a third value; and a transmission resource for transmitting an SRS in the first cell, a transmission resource for transmitting an SRS in the second cell, and a transmission resource for transmitting an SRS in the third cell do not overlap at all or partially overlap; andallocating, to the terminal device, the transmission resource for transmitting the SRS in the target cell. In an implementation, that the processor401determines a quantity of cells in which the transmission resource needs to be currently allocated includes:determining a quantity of intra-frequency neighboring cells, where the intra-frequency neighboring cells include the cell to which the terminal device belongs, and the intra-frequency neighboring cells have a same spectrum. In an implementation, the allocating, by the processor401to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs through the communication interface403includes:dividing a PCI of the cell to which the terminal device belongs by the quantity of cells, to obtain a remainder;determining, based on the remainder, the cell to which the terminal device belongs as a target cell, where the target cell is a first cell, a second cell, or a third cell; the first cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a first value, the second cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a second value, and the third cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a third value; and a transmission resource for transmitting an SRS in the first cell is a first sub-band or a second sub-band, a transmission resource for transmitting an SRS in the second cell is the second sub-band or a third sub-band, and a transmission resource for transmitting an SRS in the third cell is the third sub-band or a fourth sub-band; andallocating, to the terminal device, the transmission resource for transmitting the SRS in the target cell. In an implementation, the allocating, by the processor401to the terminal device based on the quantity of cells, the transmission resource for transmitting the SRS in the cell to which the terminal device belongs through the communication interface403includes:dividing a physical cell identifier PCI of the cell to which the terminal device belongs by the quantity of cells, to obtain a remainder;determining, based on the remainder, the cell to which the terminal device belongs as a target cell, where the target cell is a fourth cell or a fifth cell; the fourth cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a first value, and the fifth cell is a cell for which the remainder obtained by dividing the PCI by the quantity of cells is a second value; and a transmission resource for transmitting an SRS in the fourth cell is a fifth sub-band or a sixth sub-band, a transmission resource for transmitting an SRS in the fifth cell is a seventh sub-band or an eighth sub-band, the fifth sub-band and the seventh sub-band are obtained based on a quantity of frequency domain resources included in a system bandwidth, a frequency of the fifth sub-band is less than a frequency of the seventh sub-band, the sixth sub-band is a part of the fifth sub-band, and the eighth sub-band is a part of the seventh sub-band; andallocating, to the terminal device, the transmission resource for transmitting the SRS in the target cell. In an implementation, that transmission resources for transmitting SRSs in different cells do not overlap at all or partially overlap includes:time domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap;in a part in which the time domain resources for transmitting the SRSs in the different cells completely overlap, frequency domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap;in a part in which the frequency domain resources for transmitting the SRSs in the different cells completely overlap, carrier domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap; andin a part in which the carrier domain resources for transmitting the SRSs in the different cells completely overlap, code domain resources for transmitting the SRSs in the different cells do not overlap at all or partially overlap. In an implementation, the processor401may further perform the following operation through the communication interface403:sending first configuration information to the terminal device, where the first configuration information is used to indicate the terminal device to regularly transmit, based on a configuration periodicity, the SRS on the allocated transmission resource. In an implementation, the processor401may further perform the following operation through the communication interface403:sending second configuration information to the terminal device, where the second configuration information is used to indicate that the transmission resource allocated to the terminal device is a resource other than a transmission resource corresponding to a periodically transmitted SRS in the system bandwidth. In an implementation, the processor401may further perform the following operation:when a quantity of users included in the cell to which the terminal device belongs or a type of a service that needs to be currently processed by the terminal device changes, dynamically adjusting the transmission resource allocated to the terminal device. It should be noted that, for content that is not mentioned in the embodiment corresponding toFIG.4and a specific implementation of steps performed by the components, refer to the embodiment shown inFIG.1and the foregoing content. Details are not described herein again. In an implementation, the processor401is configured to support the communication apparatus in performing the method inFIG.2. The processor401may invoke the program code stored in the memory402, to perform the following operations:determining a service that needs to be currently processed by a terminal device;determining, based on a correspondence between a service and a transmission resource for transmitting a sounding reference signal SRS, a transmission resource corresponding to the service;allocating the transmission resource to the terminal device through the communication interface403; andreceiving, through the communication interface403, the SRS transmitted by the terminal device on the allocated transmission resource; andperforming channel quality estimation based on the received SRS to obtain channel state information CSI. In an implementation, that the processor401determines, based on a correspondence between a service and a transmission resource for transmitting an SRS, a transmission resource corresponding to the service includes:determining, based on indication information of the service that needs to be currently processed by the terminal device, a type of the service, where the indication information includes a quality of service class identifier QCI or a subscriber profile identifier SPID of the service; anddetermining, based on a correspondence between a type of a service and a transmission resource for transmitting an SRS, the transmission resource corresponding to the type of the service. In an implementation, the determining, by the processor401based on a correspondence between a type of a service and a transmission resource for transmitting an SRS, the transmission resource corresponding to the type of the service includes:when a latency requirement level of the service that needs to be currently processed by the terminal device is greater than a first-level threshold, determining that a configuration periodicity of the SRS is less than a preset periodicity threshold; andwhen the latency requirement level of the service that needs to be currently processed by the terminal device is less than or equal to the first-level threshold, determining that the configuration periodicity of the SRS is greater than or equal to the preset periodicity threshold. In an implementation, that the processor401determines, based on a correspondence between a service and a transmission resource for transmitting a sounding reference signal SRS, a transmission resource corresponding to the service includes:determining a service volume based on uplink send buffer data fed back by the terminal device or a downlink send buffer data volume; anddetermining based on a correspondence between a service volume and a transmission resource for transmitting an SRS, the transmission resource corresponding to the service volume. In an implementation, that the processor401determines, based on a correspondence between a service volume and a transmission resource for transmitting an SRS, the transmission resource corresponding to the service volume includes:when a frequency domain resource block resource requirement level of the service that needs to be currently processed by the terminal device is less than or equal to a second-level threshold, determining that a sub-band included in the transmission resource is less than or equal to a preset quantity threshold; andwhen the frequency domain resource block resource requirement level of the service that needs to be currently processed by the terminal device is greater than the second-level threshold, determining that the sub-band included in the transmission resource is greater than or equal to the preset quantity threshold. In an implementation, the processor401may further perform the following operation:when the service volume changes, dynamically adjusting the transmission resource allocated to the terminal device. A resource volume of an adjusted transmission resource is directly proportional to the service volume. In an implementation, the processor401may further perform the following operation through the communication interface403:sending first configuration information to the terminal device, where the first configuration information is used to indicate the terminal device to regularly transmit, based on a configuration periodicity, the SRS on the allocated transmission resource. In an implementation, the processor401may further perform the following operation through the communication interface403:sending second configuration information to the terminal device, where the second configuration information is used to indicate that the transmission resource allocated to the terminal device is a resource other than a transmission resource corresponding to a periodically transmitted SRS in a system bandwidth. It should be noted that, for content that is not mentioned in the embodiment corresponding toFIG.4and a specific implementation of steps performed by the components, refer to the embodiment shown inFIG.2and the foregoing content. Details are not described herein again. The foregoing descriptions are merely specific implementations of the present invention, but are not intended to limit the protection scope of the present invention. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims. | 61,577 |
11943027 | DETAILED DESCRIPTION OF THE EMBODIMENTS The following describes the solutions with reference to the accompanying drawings. The solutions in embodiments may be applied to various communications systems, such as a global system for mobile communications (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS), a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD) system, a universal mobile telecommunications system (UMTS), a worldwide interoperability for microwave access (WiMAX) communications system, a future 5th generation (5G) system, or a new radio (NR) system. A terminal device in the embodiments may be as user equipment, an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile console, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communications device, a user agent, or a user apparatus. The terminal device may alternatively be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having a wireless communication function, a computing device or another processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a future 5G network, a terminal device in a future evolved public land mobile network (PLMN), or the like. This is not limited in the embodiments. The network device in the embodiments may be a device used to communicate with the terminal device. The network device may be a base transceiver station (base transceiver station, BTS) in a global system for mobile communications (global system for mobile communications, GSM) system or a code division multiple access (code division multiple access, CDMA) system, or may be a NodeB (NodeB, NB) in a wideband code division multiple access (wideband code division multiple access, WCDMA) system, or may be an evolved NodeB (evolved NodeB, eNB or eNodeB) in an LTE system, or may be a radio controller in a cloud radio access network (cloud radio access network, CRAN) scenario, or the network device may be a network device such as a relay station, an access point, a vehicle-mounted device, a wearable device, and a network device in a 5G network or a network device in a future evolved PLMN network. This is not limited in the embodiments. It should be understood that the =solutions provided in the embodiments may be applied to various communications systems, for example, a 5G mobile communications system. The 5G mobile communications system described includes a non-standalone (NSA) 5G mobile communications system and/or a standalone (SA) 5G mobile communications system. The solutions provided may be further applied to a future communications system, such as a sixth-generation mobile communications system. In the embodiments, the terminal device or the network device includes a hardware layer, an operating system layer that runs above the hardware layer, and an application layer that runs above the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and a memory (also referred to as a main memory). The operating system may be any one or more computer operating systems that process a service by using a process, for example, a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a windows operating system. The application layer includes applications such as a browser, an address book, word processing software, and instant messaging software. In addition, a specific structure of an entity for performing the method provided in the embodiments is not limited in the embodiments, provided that a program that records code of the method provided in the embodiments can be run to perform communication based on the method provided in the embodiments. For example, the method provided in the embodiments may be performed by the terminal device or the network device, or a function module that is in the terminal device or the network device and that can invoke a program and execute the program. In addition, aspects or features may be implemented as a method, an apparatus, or a product that uses standard programming and/or engineering technologies. The term “product” covers a computer program that can be accessed from any computer-readable component, carrier, or medium. For example, the computer-readable medium may include but is not limited to a magnetic storage component (for example, a hard disk, a floppy disk, or a magnetic tape), an optical disc (for example, a compact disc (CD), a digital versatile disc (DVD), a smart card, and a flash memory component (for example, an erasable programmable read-only memory (EPROM), a card, a stick, or a key drive). In addition, various storage media described may indicate one or more devices and/or other machine-readable media that are configured to store information. The term “machine-readable medium” may include but is not limited to a radio channel and various other media that can store, contain, and/or carry instructions and/or data. FIG.1is a schematic diagram of a communications system according to the embodiments n. The communications system inFIG.1may include at least one terminal device (for example, a terminal device10, a terminal device20, a terminal device30, a terminal device a terminal device50, and a terminal device60) and a network device70. The network device70is configured to provide a communication service for the terminal device and access a core network. The terminal device may access a network by searching for a synchronization signal, a broadcast signal, and the like that are sent by the network device70, to communicate with the network. InFIG.1, the terminal device10, the terminal device20, the terminal device the terminal device40, and the terminal device60may perform uplink and downlink transmission with the network device70. For example, the network device70may send a downlink signal to the terminal device10, the terminal device20, the terminal device30, the terminal device40, and the terminal device60, and may also receive uplink signals sent by the terminal device10, the terminal device20, the terminal device30, the terminal device40, and the terminal device60. In addition, the terminal device40, the terminal device50, and the terminal device60may also be considered as a communications system. The terminal device60may send a downlink signal to the terminal device40and the terminal device50, and may also receive uplink signals sent by the terminal device40and the terminal device50. The terminal device60and the network device70in the figure are used as examples for description. The network device70and the terminal device60may use different types of reference signals to complete data transmission, where one type of reference signal is used for channel state measurement or channel quality measurement, so that the network device70schedules, based on a current channel state or current channel quality, a transmission resource to be used by the terminal device60, to transmit data through a channel with relatively good channel quality. For example, the terminal device60may receive a channel state information reference signal (CSI-RS) from the network device700, and measure channel quality of the CSI-RS, to obtain channel state information ( ). There are two types of CSI-RS. One is zero power (ZP) CSI-RS that is used for interference measurement. The other is a non-zero power (NZP) CSI-RS that is used for channel state measurement and channel estimation. In a 5G mobile communications system, the NZP CSI-RS may be further used for interference measurement and layer 1 (L1) reference signal received power (reference signal received power, RSRP) measurement, where L1-RSRP is used to determine an L1 signal to interference plus noise ratio (SINR), so that the network device70and the terminal device60select a beam of relatively good channel quality from a plurality of beams based on an L1-SINR corresponding to the beam. The CSI may include at least one of a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), a synchronization signal/physical broadcast channel block (SSB) resource indicator (SSBRI), a layer indicator (layer indicator, LI), a rank indicator (RI), L1-RSRP, and an L1-SINR. The CSI may be sent by the terminal device60to the network device70through a physical uplink control channel (PUCCH) or a physical uplink shared channel ( ). The network device70may configure at least one type of CSI report configuration for the terminal device60by using higher layer signaling (CSI-Report Config), and configure at least one type of CSI-RS resource configuration for the terminal device60by using higher layer signaling (CSI-Resource Config). The CSI report configuration is used to indicate a reporting type of the CSI, and the reporting type of the CSI includes periodic reporting, semi-persistent reporting, and aperiodic reporting. The CSI-RS resource configuration is used to indicate a CSI-RS resource. The CSI-RS resource includes a periodic CSI-RS resource, a semi-persistent CSI-RS resource, and an aperiodic CSI-RS resource, and is used by the terminal device60to report the CSI. The periodic CSI-RS resource may be used for periodic reporting or semi-persistent reporting or aperiodic reporting, the semi-persistent CSI-RS resource may be used for semi-persistent reporting or aperiodic reporting, and the aperiodic CSI-RS resource can only be used for aperiodic reporting. An example in which each CSI-RS resource configuration includes only one CSI-RS resource set is used as an example below to describe a CSI-RS resource configuration method. Configuration Method 1 The network device70may configure two resource configurations for the terminal device60. One resource configuration is used to configure a transmission resource required for channel measurement, such as a first reference signal resource set. For ease of description, a reference signal resource in the first reference signal resource set is referred to as a channel measurement resource (CMR). The CMR may be an SSB resource, or may be an NZP CSI-RS resource. The other resource configuration is used to configure a transmission resource required for interference measurement, such as a second reference signal resource set. For ease of description, a reference signal resource in the second reference signal resource set is referred to as an interference measurement resource (interference measurement resource, IMR). The IMR may be a CSI interference measurement (CSI-IM) resource, or may be an NZP CSI-RS resource. Configuration Method 2 The network device70may configure three resource configurations for the terminal device60. A first resource configuration is used to configure a CMR, and the CMR may be an SSB resource or an NZP CSI-RS resource. A second resource configuration and a third resource configuration are used to configure an IMR, the second resource configuration is used to configure a CSI-IM resource, and the third resource configuration is used to configure an NZP CSI-RS resource. Optionally, the CSI-IM resource may be used to measure inter-cell interference, and the NZP CSI-RS resource may be used to measure multi-user (MU) interference in a cell, or interference between a plurality of coordination sets (in other words, TRP) during NCJT, or interference between a plurality of beams/transport streams/transport layers in the user. The terminal device60measures a reference signal on the foregoing resource to obtain channel state information. Configuration Method 3 The network device70may configure two resource configurations for the terminal device60. Both the two resource configurations are used to configure a transmission resource required for channel measurement, such as a first reference signal resource set and a second reference signal resource set. The terminal device60measures at least one reference signal in the first reference signal resource set and at least one reference signal in the second reference signal resource set to obtain two pieces of channel state information. When a reference signal carried on a CMR in the first reference signal resource set is used as a non-interference signal, and a reference signal carried on a CMR in the second reference signal resource set is used as an interference signal, one piece of channel state information is measured. When the reference signal carried on the CMR in the first reference signal resource set is used as an interference signal, and the reference signal carried on the CMR in the second reference signal resource set is used as a non-interference signal, the other piece of channel state information is measured. For a beam training procedure, several preferred beams need to be selected from a plurality of beams. Therefore, a quantity of CMR resources needs to be greater than one. Each CMR resource needs to have a corresponding IMR resource. If the terminal device measures communication quality of the plurality of beams based on the foregoing different configuration methods of the network device, and reports channel state information of the beams to the network device, resource overheads are huge and a measurement process is relatively complex. For each resource used as a signal, the network device may configure a plurality of resources that interfere with the resource. However, when configuring an interference resource, the network device cannot learn whether the terminal device can simultaneously receive a configured resource used as a signal and a configured resource used as interference. If the terminal device cannot simultaneously receive the resource used as a signal and the resource used as interference, the measured channel state information is inaccurate (for example, measured interference is excessively large and channel quality is excessively small). In view of this, an embodiment provides a channel state information transmission method. In a process of measuring channel state information, a terminal device can determine a reference signal used as a signal and a reference signal used as interference that are simultaneously received, and when reporting the channel state information to a network device, the terminal device may report a resource index of the reference signal used as a signal, a resource index of the reference signal used as interference, and measured channel quality information. In other words, in this embodiment, the terminal device may select, based on a resource configuration of the network device, a resource used as interference, and does not need to measure channel quality based on the configuration of the network device, thereby avoiding measurement of channel quality information between a resource used as a signal and the resource used as interference that cannot be simultaneously received, to recommend a relatively good transmission manner for data transmission, so that the network device obtains accurate channel state information. It should be noted that one or more pieces of channel state information or beam information (for example, including a resource index and corresponding channel quality information) reported by the terminal device to the network device based on a plurality of reference signals may be selected and reported by the terminal device, may be reported based on an instruction principle of the network device, or may be reported based on a protocol-predefined rule. For example, the terminal device may report beam/channel state information of relatively good channel quality, or the terminal device may report beam information/channel state information of relatively poor channel quality. This is not limited in the embodiments. The following describes the embodiments in detail with reference to an example. It should be noted that this is merely to help a person of ordinary skill in the art better understand the embodiments, but does not limit the scope of the embodiments. It should be understood that, in the embodiments, “first”, “second”, “third”, “fourth”, and the like are merely intended to indicate different objects, and do not indicate other limitations on the indicated objects. For ease of understanding, the following describes items related to the embodiments: 1. Beam: The beam is a type of communication resource. The beam may be a wide beam, a narrow beam, or another type of beam. A technology of forming the beam may be a beamforming technology or another technical means. The beamforming technology may be a digital beamforming technology, an analog beamforming technology, and a hybrid digital/analog beamforming technology. Different beams may be considered as different resources. Same information or different information may be sent by using different beams. Optionally, a plurality of beams that have a same communication feature or similar communication features may be considered as one beam. One beam may include one or more antenna ports that are configured to transmit a data channel, a control channel, a sounding signal, and the like. For example, a transmit beam may indicate distribution of signal strength formed in different spatial directions after a signal is transmitted through an antenna, and a receive beam may indicate distribution of signal strength, in different spatial directions, of a wireless signal received from the antenna. It may be understood that one or more antenna ports that form one beam may also be considered as one antenna port set. Beams may be classified into a transmit beam and a receive beam of the network device and a transmit beam and a receive beam of the terminal device. The transmit beam of the network device is used to describe beamforming information on a transmit side of the network device, a receive beam of a base station is used to describe beamforming information on a receive side of the network device, the transmit beam of the terminal device is used to describe beamforming information on a transmit side of the terminal device, and the receive beam of the terminal is used to describe beamforming information on a receive side of the terminal device. In other words, the beam is used to describe beamforming information. The beam may correspond to a time resource and/or a space resource and/or a frequency domain resource. Optionally, the beam may further correspond to a reference signal resource (for example, a beamforming reference signal resource) or beamforming information. Optionally, the beam may further correspond to information associated with a reference signal resource of the network device. A reference signal may be a CSI-RS, an SSB, a DMRS, a phase tracking signal (PTRS), a tracking signal (TRS), or the like, and the information associated with the reference signal resource may be a reference signal resource identifier, QCL information (such as type-D QCL), or the like. The reference signal resource identifier corresponds to a transmit/receive beam pair previously established based on measurement of the reference signal resource. By using this reference signal resource index, the terminal may infer beam information. Optionally, the beam may further correspond to a spatial domain filter (spatial filter) and a spatial domain transmission filter. 2. Quasi Co-Location (QCL) Information Quasi co-site/quasi co-location QCL assumption information may also be referred to as co-location assumption information. The QCL information is used to assist in describing beamforming information and a receiving procedure on a receive side of the terminal device. The QCL information is used to indicate a QCL relationship between two types of reference signals. A target reference signal may be generally a demodulation reference signal (DMRS), a channel state information reference signal (CSI-RS), or the like. A referenced reference signal or a source reference signal may be generally a channel state information reference signal (-RS), a tracking reference signal (TRS), a synchronous signal/broadcast channel block (synchronous signal/PBCH block, SSB), or the like. It should be understood that spatial characteristic parameters of two reference signals or channels that meet the QCL relationship are the same. Therefore, a spatial characteristic parameter of the target reference signal may be inferred based on a resource index of the source reference signal. The spatial characteristic parameter includes one or more of the following parameters:an angle of incidence (AoA), a dominant angle of incidence AoA, an average angle of incidence, a power angular spectrum (PAS) of an angle of incidence, an angle of departure (AoD), a dominant angle of departure, an average angle of departure, a power angular spectrum of an angle of departure, terminal transmit beamforming, terminal receive beamforming, spatial channel correlation, base station transmit beamforming, base station receive beamforming, an average channel gain, an average channel delay, delay spread, Doppler spread, Doppler frequency shift (Doppler shift), a spatial receive parameter (spatial Rx parameters), and the like. These spatial characteristic parameters describe a spatial channel characteristic between an antenna port of the source reference signal and an antenna port of the target reference signal, and help the terminal device complete a receive-side beamforming or receive-side processing process based on the QCL information. It should be understood that the terminal may receive the target reference signal based on receive beam information of the source reference signal indicated by the QCL information. To reduce QCL information indication overheads of a network device side to a terminal device side, in an optional implementation, the network device side may indicate that a demodulation reference signal of a PDCCH or a PDSCH and one or more of a plurality of reference signal resources previously reported by the terminal device meet the QCL relationship. For example, the reference signal may be a channel state information reference signal (CSI-RS). Herein, an index of each reported CSI-RS resource corresponds to one transmit/receive beam pair previously established based on measurement of the CSI-RS resource. It should be understood that receive beam information of two reference signals or channels that meet the QCL relationship is the same, so that the UE may infer receive beam information of the PDCCH or the PDSCH based on the reference signal resource index. In an existing standard, four types of QCL are defined. The base station may simultaneously configure one or more types of QCL for the UE, such as QCL types A+D and C+D.QCL types A: Doppler shift, Doppler spread, average delay, delay spread;QCL types B: Doppler shift, Doppler spread;QCL types C: average delay, Doppler shift;QCL types D: Spatial Rx parameter. Optionally, the QCL relationship in the embodiments may mainly be QCL types D. It should be understood that spatial characteristic parameters of two reference signals or channels that meet spatial correlation information are the same. Therefore, a spatial characteristic parameter of the target reference signal may be inferred based on the resource index of the source reference signal. The spatial characteristic parameter includes one or more of the following parameters:an angle of incidence (AoA), a dominant angle of incidence AoA, an average angle of incidence, a power angular spectrum (PAS) of an angle of incidence, an angle of departure (AoD), a dominant angle of departure, an average angle of departure, a power angular spectrum of an angle of departure, terminal transmit beamforming, terminal receive beamforming, spatial channel correlation, base station transmit beamforming, base station receive beamforming, an average channel gain, an average channel delay, delay spread, Doppler spread, Doppler frequency shift (Doppler shift), a spatial receive parameter (spatial Rx parameters), and the like. These spatial characteristic parameters describe a spatial channel characteristic between the antenna port of the source reference signal and the antenna port of the target reference signal, and help the terminal device complete a transmit-side beamforming or transmit-side processing process based on the spatial correlation information. It should be understood that the terminal may transmit the target reference signal based on transmit beam information of the source reference signal indicated by the spatial correlation information. FIG.2is a schematic flowchart of a channel state information transmission method according to an embodiment. The method inFIG.2may be applied to a network architecture inFIG.1. The method inFIG.2includes the following steps. 210: Receive N reference signal groups, where N is an integer greater than or equal to 2. In this embodiment, a terminal device may receive the N reference signal groups based on N reference signal resource sets configured by a network device. The terminal device may receive one group of reference signals at one reference signal resource set configured by the network device, in other words, the terminal device receives the N reference signal resource sets configured by the network device, and the terminal device may receive the N reference signal groups at the N reference signal resource sets. For example, the network device configures the N reference signal resource sets, and the N reference signal resource sets include at least one resource set used for channel measurement. In other words, the terminal device receives the N reference signal groups at the N resource sets, and the N reference signal groups may include at least one reference signal group used for channel measurement. For example, the network device configures the N reference signal resource sets, and all the N resource sets are resource configurations used for channel measurement. In other words, the terminal device receives the N reference signal groups, and all the N reference signal groups may be reference signal groups used for channel measurement. For example, the network device configures the N reference signal resource sets, and the N reference signal resource sets include at least one resource set used for channel (or signal) measurement and at least one resource set used for interference measurement. In other words, the terminal device receives the N reference signal groups, and the N reference signal groups include at least one reference signal group used for channel measurement and at least one reference signal group used for interference measurement. In a possible implementation, the network device configures the N reference signal resource sets, and the N reference signal resource sets include at least one resource set used for channel (or signal) measurement and at least one resource set used for interference measurement. The reference signal resource set used for channel measurement and the reference signal set used for interference measurement may belong to different resource configurations. For example, resource configurations of N reference signals include that a reference signal resource in a first resource set is a CMR and a reference signal resource in a second resource set is an IMR. The CMR may be an NZP CSI-RS or an SSB, and the IMR may be a CSI-IM or an NZP CSI-RS. In other words, the first resource set and the second resource set may be different resource configurations. It should be understood that, in this embodiment, the terminal device may receive the N reference signal groups based on the N reference signal resource sets configured by the network device. Different resource sets may be resources used as a signal or may be resources used as interference. 220: Send channel state information, where the channel state information includes a first resource index, a second resource index, and first channel quality information, the first resource index is a resource index of a first reference signal, the second resource index is a resource index of a second reference signal, the first reference signal and the second reference signal are reference signals in different groups in the N reference signal groups, and the first channel quality information is obtained by using the first reference signal as a signal and the second reference signal as interference. In this embodiment, the terminal device receives the N reference signal groups based on the N reference signal resource sets configured by the network device, selects a signal used as a signal and a signal used as interference from the N reference signal groups, measures channel quality information, and reports the channel quality information to the network device. It should be understood that, in this embodiment, the second resource index may include resource indexes of one or more second reference signals, and a reference signal used as an interference item is referred to as the second reference signal. It should be further understood that, optionally, a quantity of first resource indexes and a quantity of second resource indexes may be configured by the network device, or may be predefined in a protocol, or may be reported by the terminal device. In another optional implementation, a sum of a quantity of first resource indexes and a quantity of second resource indexes may be configured by the base station, or may be predefined in a protocol, or may be reported by the terminal device. The quantity of first resource indexes may be configured by the base station, predefined in a protocol, or reported by the terminal device. Optionally, a reference signal corresponding to the first resource index and a reference signal corresponding to the second resource index are reference signals that are simultaneously received by the terminal device and/or simultaneously sent by the network device. It should be understood that, in this embodiment, “simultaneously” means receiving at a same moment, receiving at overlapping moments, receiving in a same time unit, or receiving in at least one overlapping time unit, and M reference signals overlap in at least one time unit. The time unit may be one or more radio frames, one or more subframes, one or more timeslots, one or more mini-slots, one or more orthogonal frequency division multiplexing (OFDM) symbols defined in an LTE system or a 5G NR system, or may be a time window including a plurality of frames or subframes, for example, a system information (SI) window. The following embodiment is described by using an example in which simultaneously received reference signals are reference signals received on one or more OFDM symbols. This is not limited in the embodiments. For example, the reported channel state information may include one first resource index, one second resource index, and the first channel quality information; or the reported channel state information may include one first resource index, two second resource indexes, and the first channel quality information. The first resource index may be a resource index of a first reference signal used as a signal, and the second index may be a resource index of a second reference signal used as interference. The embodiments set no limitation on the quantity of second resource indexes. It should be noted that the first channel quality information may be an SINR (such as an L1-SINR), a CQI, RSRQ, an SNR, or other information that can indicate a channel state/channel quality. In a possible implementation, the terminal device may receive first configuration information sent by the network device, and the first configuration information may indicate that all the N resource sets are CMRs, in other words, all the N resource sets are resource sets used for channel measurement. In other words, the first configuration information may indicate that the N reference signal groups received by the terminal device are reference signal groups used for channel measurement. Descriptions are provided below by using an example in which the network device configures two resource sets. It should be understood that the network device may configure the N resource sets for the terminal device, where N is an integer greater than 2. For example, as shown inFIG.3, the network device configures two reference signal resource sets including a resource set 1 and a resource set 2. Both the resource set 1 and the resource set 2 are resource sets used for channel measurement, and the resource set 1 and the resource set 2 may belong to different resource configurations. For example, the resource set 1 may be an NZP CSI-RS resource, and the resource set 2 may be an SSB resource. Alternatively, the resource set 1 may be an SSB resource, and the resource set 2 may be an NZP CSI-RS resource. In other words, the two reference signal resource sets configured by the network device may belong to different resource configurations. For example, as shown inFIG.4, the network device configures two reference signal resource sets including a resource set 1 and a resource set 2. Both the resource set 1 and the resource set 2 are resource sets used for channel measurement, and the resource set 1 and the resource set 2 may belong to a same resource configuration. For example, both the resource set 1 and the resource set 2 may be NZP CSI-RS resources; or both the resource set 1 and the resource set 2 may be SSB resources. In other words, the two reference signal resource sets configured by the network device may belong to a same resource configuration. In other words, the terminal device may receive the first configuration information sent by the network device, and the first configuration information may indicate that all the N resource sets are CMRs. For example, the first configuration information may indicate the two resource sets shown inFIG.3orFIG.4. For example, the terminal device may receive the first configuration information sent by the network device, and the first configuration information indicates that all the N resource sets are resources used for channel measurement, in other words, the terminal device receives N reference signal groups that are all used for channel measurement. The terminal device determines one reference signal group from the N reference signal groups and determines the first reference signal from the one reference signal group, and the terminal device may determine one or more second reference signals used as interference from N−1 reference signal groups based on the first reference signal. The first reference signal is used as a signal item and the one or more second reference signals are used as interference items to measure the channel quality information. Optionally, the terminal device may determine, from the N−1 reference signal groups based on the first reference signal, one or more second reference signals that may be received simultaneously with the first reference signal, where the N−1 reference signal groups do not include a reference signal group in which the first reference signal is located. In a possible implementation, when the first configuration information indicates that a reference signal resource set in which the second reference signal is located is a reference signal resource set used for channel measurement, the terminal device may report the second channel quality information. For example, when all the N resource sets configured by the network device are CMRs, in other words, all the N reference signal groups received by the terminal device are reference signal groups used for channel measurement, the terminal device further sends the second channel quality information to the network device, where the second channel quality information is channel quality measured by using the second reference signal as a signal item and the first reference signal as an interference item for the second reference signal. The network device may configure the N resource sets for the terminal device, where N is a positive integer greater than or equal to 2. An example in which the network device configures two resource sets for the terminal device is used for description. The network device may configure the first resource set as a resource set used for channel measurement. Optionally, when resource configuration information sent by the network device to the terminal device indicates that the second resource set is used for channel measurement, the terminal device may report the second channel quality information, where the second channel quality information is determined by using the second reference signal as a signal item and the first reference signal as an interference item for the second reference signal. Optionally, when the resource configuration information sent by the network device to the terminal device indicates that the second resource set is used for interference measurement, the terminal device may not report the second channel quality information. For example, the terminal device receives the N resource sets configured by the network device, in other words, receives the N reference signal groups. The terminal device may select A RSs from the N RS sets, where A is less than or equal to N, and the A RSs are separately from different RS sets, in other words, a maximum of one RS is selected for each RS set. The UE measures channel quality information by using one RS in the A RSs as a signal item and another RS in the A RSs as an interference item. For example, the terminal device receives an RS set 1 and an RS set 2 that are used for channel quality information measurement, where the RS set 1 includes L1 reference signals, and the RS set 2 includes L2 reference signals. L1 may be equal to L2, or L1 may not be equal to L2. The terminal device may select a first reference signal from the RS set 1 as a signal item, and the terminal device may then select a reference signal RS X1 from the RS set 2 as an interference item, to obtain the channel quality information through calculation. For example, an L1-SINR 1 may be obtained through calculation. It should be noted that the terminal device may select, from the RS set 2, a reference signal that can be received simultaneously with the reference signal used as a signal item. The UE may sequentially poll each reference signal in the RS set 1 to calculate an L1-SINR, to obtain a total of L1 L1-SINRa. Optionally, the UE may further obtain L1 or L2 L1-SINRb by using a reference signal in the RS set 2 as a signal item and a reference signal in the RS set 1 as an interference item. For example, the UE may select B reference signals with largest L1-SINRa and a measurement result from the L1 reference signals, or the UE selects, from the L1 reference signals, K reference signals with a corresponding largest average value or equivalent value of L1-SINRa and L1-SINRb and a measurement result, and reports the K reference signals and the measurement result to the network device. In other words, when both the RS set 1 and the RS set 2 are resources used for channel quality information measurement, the UE may report the first channel quality information and the second channel quality information. The first channel quality information may be channel quality measured by using a reference signal in the RS set 1 as a signal term and a reference signal in the RS set 2 as an interference term. The second channel quality information may be channel quality measured by using a reference signal in the RS set 2 as a signal term and a reference signal in the RS set 1 as an interference term. Optionally, the UE may further send first identifier information and/or second identifier information, where the first identifier information is used to indicate an identifier of the reference signal group in which the first reference signal is located, and the second identifier information is used to indicate an identifier of a reference signal group in which the second reference signal is located. For example, when all the N resource sets are CMRs, the first resource index and the second resource index that are reported by the UE may be from different RS sets. Optionally, the UE may further report an ID of a corresponding set in which the first resource index is located and/or an ID of a corresponding set in which the second resource index is located. In a possible implementation, the terminal device may receive second configuration information sent by the network device, and the second configuration information may indicate that M resource sets in the N resource sets are CMRs and N-M resource sets are IMRs. In other words, the second configuration information may indicate that the N reference signal groups include M channel measurement reference signal groups and N-M interference measurement reference signal groups, where N is greater than or equal to 2, M is less than or equal to N, and M may be equal to 1. Descriptions are provided by using an example in which the network device configures two resource sets. It should be understood that the network device may configure the N resource sets for the terminal device, where N is an integer greater than 2. Optionally, the terminal device may select one first reference signal from the first resource set, select one or more second reference signals from the second resource set, and report a resource index of the first reference signal, resource indexes of the one or more second reference signals, and the first channel quality information to the network device. Optionally, the terminal device may select a first reference signal used as a signal item from the first resource set, and select one or more second reference signals used as interference items from the first resource set and the second resource set. Further, optionally, one or more second reference signals that are selected by the terminal device from the first resource set and that are used as interference items are different from the first reference signal. In a possible implementation, the terminal device may select a reference signal used as an interference item from the first resource set for measurement of MU interference, and/or inter-TRP interference, and/or interference between a plurality of beams, and may select a reference signal used as an interference item from the second resource set for measurement of inter-cell interference. In a possible implementation, the terminal device may select a reference signal used as an interference item from the first resource set for measurement of MU interference, inter-TRP interference, or interference between a plurality of beams, and may select a reference signal used as an interference item from the second resource set for interference measurement of inter-cell interference, MU interference, or inter-TRP interference. This may also be understood as that the reference signal used as the interference item is selected from the first resource set to measure a part of interference, and the reference signal used as the interference item is selected from the second resource set to measure the other part of interference. Types of interference measured by using at least two reference signals selected from different sets as interference items may be different or not entirely the same. In a possible implementation, the terminal device may select a reference signal used as an interference item from the first resource set for measurement of inter-cell interference and/or MU interference/coordinating set interference/inter-beam interference, and may select a reference signal used as an interference item from the second resource set for measurement of inter-cell interference or inter-beam interference. It should be understood that, optionally, the inter-beam interference may also be referred to as interference between a plurality of transmission streams or interference between a plurality of transmission layers, and may be interference between a plurality of transmit beams of the network device when the plurality of transmit beams serve a same terminal device. The MU interference may be interference between a plurality of users transmitted in pairs on a same time-frequency resource (or may be understood as interference caused to a terminal device when a network device serves another terminal device). The inter-TRP interference is interference between a plurality of TRPs in a coordinating set when the plurality of TRPs serve a same terminal device (or may be understood as interference caused by a TRP to a terminal device when another TRP serves the terminal device). In another possible implementation, optionally, the terminal device may further select a third reference signal used as an interference item from a third resource set. With reference to the foregoing method, the terminal device may determine the channel quality information (for example, the first channel quality information) based on the first reference signal, the second reference signal, and the third reference signal, and a resource index of the third reference signal may be not reported. For example, the third resource set may be a zero-power ZP resource configuration. For example, as shown inFIG.5, the network device configures two reference signal resource sets including a resource set 1 and a resource set 2. The resource set 1 may be a resource set used for channel measurement, and the resource set 2 may be a resource set used for interference measurement, in other words, M may be equal to 1. In other words, the UE may receive the N resource sets configured by the network device. The N resource sets include at least one resource set that belongs to a resource configuration used for channel (or signal) measurement, and the N resource sets include at least one resource set that belongs to a resource configuration used for interference measurement. It should be understood thatFIG.5is an example for description when N=2. For example, the terminal device may receive the second configuration information sent by the network device, and the second configuration information indicates that M resource sets in the N resource sets are resources used for channel measurement and N-M resource sets are resources used for interference measurement. In other words, the N reference signal groups received by the terminal device include M channel measurement reference signal groups and N-M interference measurement reference signal groups. The terminal device determines one reference signal group from the M reference signal groups and determines the first reference signal from the one reference signal group, and the terminal device may determine one or more second reference signals used as interference from the N-M reference signal groups based on the first reference signal. The first reference signal is used as a signal item and the one or more second reference signals are used as interference items to measure the channel quality information. For example, the UE may receive the N resource sets configured by the network device, in other words, receive the N reference signal groups. The UE includes a CMR RS sets and b IMR RS sets in the N RS sets. The UE calculates the channel quality information by using one RS in the a RS sets as a signal item and one or more RSs in the other b RS sets as interference items. Optionally, the UE may further send third identifier information, and the third identifier information is used to indicate an identifier of a reference signal group in which the second reference signal is located. In other words, when the N resource sets include an IMR, the second resource index reported by the UE may be from different RS sets. In this case, the UE further needs to report an ID of a corresponding set in which the second resource index is located. For example, the network device may configure three resource sets. For example, the three resource sets separately correspond to three TRPs. The UE may select two TRPs or three TRPs of NCJT. The UE needs to obtain a plurality of pieces of channel quality information through measurement based on different transmission assumptions, and report the plurality of pieces of channel quality information to the network device, to recommend a transmission manner or a serving TRP used during data transmission. In this embodiment, the UE may report the first resource index, the second resource index, and the first channel quality information to the network device. For example, the UE may report CRI 1+IMR 1+L1-SINR 1, where the CRI 1 is a reference signal in a resource set used for channel measurement, the IMR 1 is a reference signal in a resource set used for interference measurement, and the L1-SINR 1 is calculated based on a signal measured on the CRI 1 and interference measured on the IMR 1. Optionally, the UE may report CRI 1+CRI 2+L1-SINR 1+L1-SINR 2 based on different resource configurations of the network device, where the CRI 1 is a reference signal in the first resource set, the CRI 2 is a reference signal in the second resource set, the L1-SINR 1 is calculated based on a signal measured on the CRI 1 and interference measured on the CRI 2, and the L1-SINR 2 is calculated based on a signal measured on the CRI 2 and interference measured on the CRI 1. Optionally, the UE may report CRI 1+CRI 2+CRI 3+L1-SINR 1+L1-SINR 2+L1-SINR 3, where the L1-SINR 1 may be obtained based on a signal measured on the CRI 1 and interference measured on the CRI 2 and the CRI 3, the L1-SINR 2 may be obtained based on a signal measured on the CRI 2 and interference measured on the CRI 1 and the CRI 3, and the L1-SINR 3 may be obtained based on a signal measured on the CRI 3 and interference measured on the CRI 1 and the CRI 2. In a possible implementation, when the network device configures group based beam reporting, the UE may report the first resource index, the second resource index, and the channel quality information to the network device based on the foregoing method. In a possible implementation, when the network device configures non-group based beam reporting, the UE may measure the channel quality information based on the foregoing method. When performing reporting to the network device, the UE may not report a resource ID of the reference signal used as an interference item, but use, as an interference item used for calculating an L1-SINR, an average value of interference measured on an IMR resource corresponding to the CMR. For example, L1-SINR 1=L1-RSRP 5/average (L1-RSRP 1+L1-RSRP 2+L1-RSRP 3). In this embodiment, when measuring the channel state information, the terminal device can determine a reference signal used as a signal and a reference signal used as interference that are simultaneously received, and when reporting the channel state information to the network device, the terminal device may report a resource index of the reference signal used as a signal, a resource index of the reference signal used as interference, and the measured channel quality information. In other words, in this embodiment, the terminal device may select, based on the resource configuration of the network device, a resource used as interference, and does not need to measure channel quality based on the configuration of the network device, thereby avoiding measurement of channel quality information between a resource used as a signal and a resource used as interference that cannot be simultaneously received, and improving resource utilization efficiency. In an optional implementation, the terminal device may report one or more pieces of channel state information, for example, K pieces of channel state information, where K is an integer greater than or equal to 1. An amount of channel state information reported by the terminal device may be configured by the network device, or predefined in a protocol, or reported by the terminal device. In a possible implementation, the K pieces of channel state information may be mapped and encoded in the following bit sequence, and when the channel state information includes the first resource index, the second resource index, and the first channel quality information, for example, the channel state information may be reported by using the following method 1 and method 2. Manner 1: all first resource indexes→all second resource indexes→all first channel quality. In other words, first, all the first resource indexes are mapped, and then all the second resource indexes are mapped, and finally all the first channel quality is mapped. It should be understood that all the first resource indexes, all the second resource indexes, and all the first channel quality are a first resource index, a second resource index, and first channel quality that are in the K pieces of channel state information. Manner 2: first resource index 1→second resource index 1→ . . . →first resource index K→second resource index K→ . . . →first channel quality 1→ . . . →first channel quality K. In other words, resource indexes in all the channel state information are first sequentially mapped, and then channel quality in all the channel state information is sequentially mapped. It should be noted that K first resource indexes may be different, and K second resource indexes may be the same. Optionally, a first piece of channel state information may be first mapped, and then a second piece of channel state information is mapped, and then other channel state information may be sequentially mapped. For example, the manner 1 is shown in Table 1, and the manner 2 is shown in Table 2. TABLE 1CSI report numberCSI domainCCSI report #nFirst resource index 1First resource index 2. . .First resource index KSecond resource index 1Second resource index 2. . .Second resource index NFirst channel quality 1First channel quality 2. . .First channel quality K TABLE 2CSI report numberCSI domainCSI report #nFirst resource index 1Second resource index 1First resource index 2Second resource index 2. . .. . .First resource index NSecond resource index NFirst channel quality 1First channel quality 2. . .First channel quality N When the channel state information may include the first resource index, the second resource index, the first channel quality information, and the second channel quality, the channel state information is reported by using the following method 3 and method 4. Manner 3: all first resource indexes→all second resource indexes→all first channel quality→all second channel quality. In other words, first, all the first resource indexes are encoded, and then all the second resource indexes are encoded, and then all the first channel quality is encoded, and finally all the second channel quality is encoded. Manner 4: first resource index 1→second resource index 1→ . . . →first resource index K→second resource index K→first channel quality 1→second channel quality 1→ . . . →first channel quality K→second channel quality K. In other words, first resource indexes and second resource indexes in all the channel state information are first sequentially mapped, and then first channel quality and second channel quality in all the channel state information are sequentially mapped. The manner 3 is shown in Table 3, and the manner 4 is shown in Table 4. TABLE 3CSI report numberCSI domainCCSI report #nFirst resource index 1First resource index 2. . .First resource index KSecond resource index 1Second resource index 2. . .Second resource index KFirst channel quality 1First channel quality 2. . .First channel quality KSecond channel quality 1Second channel quality 2. . .Second channel quality K TABLE 4CCSI report numberCSI domainCCSI report #nFirst resource index 1Second resource index 1First resource index 2Second resource index 2. . .. . .First resource index KSecond resource index KFirst channel quality 1Second channel quality 1First channel quality 2Second channel quality 2. . .. . .First channel quality KSecond channel quality K Optionally, a first piece of channel state information may be first mapped, and then a second piece of channel state information is mapped, and then other channel state information may be sequentially mapped. Optionally, the channel quality information may be reported in a non-differential manner or reported in a differential manner. When the differential manner is used for reporting, there are the following several methods: Differential method 1: Channel quality in a group is differentiated, for example, for each piece of channel state information, if the channel state information includes first channel quality and second channel quality, the first channel quality and the second channel quality are reported in a differential manner. For example, the second signal channel quality is reported by using a difference value and by using the first channel quality as a reference. In other words, the terminal device reports the first channel quality and a difference value between the first channel quality and the second channel quality. Optionally, channel quality as a reference value may be a maximum value or a minimum value in the first channel quality and the second channel quality, an average value of the first channel quality and the second channel quality, or the like. Differential method 2: Channel quality of a same type is differentiated, for example, in the K pieces of channel state information, first channel quality is reported in a differential manner, for example, first channel quality 1 is used as a reference value, and first channel quality 2 to first channel quality K are reported in a differential manner. In other words, the terminal device reports the first channel quality 1 and difference values between each of the first channel quality 1 to K and the first channel quality 1. There is a similar method for second channel quality. For example, second channel quality 1 is used as a reference value, and second channel quality 2 to second channel quality K are reported in a differential manner. In other words, the terminal device reports the second channel quality 1 and difference values between each of the second channel quality 1 to K and the second channel quality 1. Optionally, channel quality as a reference value may be a maximum value or a minimum value in all channel quality or the channel quality of the same type, an average value of all channel quality or the channel quality of the same type, or the like. Differential method 3: All channel quality is differentiated, for example, the K pieces of channel quality information include first channel quality and second channel quality. One of the channel quality is used as a reference value, and the other channel quality is reported in a differential manner. A difference value between the reference channel quality and the other channel quality is reported. Optionally, channel quality as a reference value may be a maximum value or a minimum value in all channel quality or channel quality of a same type, an average value of all channel quality or channel quality of a same type, or the like. It should be understood that, optionally, the difference value means a difference or a ratio between two quantities. It should also be understood that, optionally, a manner in which the terminal device reports the channel state information may be indicated by the network device, or reported by the terminal device, or predefined in a protocol. It should be further understood that, in the foregoing method for reporting the channel state information by the terminal device, the network device may decode the channel state information based on the foregoing method. A decoding manner may be predefined, or may be configured by the network device, or may be reported by the terminal device. FIG.6is a schematic flowchart of a channel state information transmission method according to an embodiment. The method inFIG.6may be applied to a network architecture inFIG.1. The method inFIG.6includes the following steps. 310: A terminal receives X reference signals, where X is a positive integer. 320: Send third channel quality information of Y reference signals in the X reference signals, where X and Y are positive integers, and Y is less than or equal to X. It should be noted that, in this embodiment, the third channel quality information may be RSRP. The third channel quality information may be alternatively information such as signal power/signal energy/signal strength. For example, before the terminal device receives the X reference signals, the terminal device may receive first report configuration information, and the first report configuration information may be configuration information sent by one network device, or may be configuration information sent by a plurality of different network devices. The first configuration information may indicate a first resource configuration and a first report quantity, first resource configuration information may indicate resources of the X reference signals, and first to-be-reported channel quality information is the third channel quality information. In other words, the terminal device may receive resource configuration information of X reference signals sent by one network device, to receive the X reference signals. Alternatively, resource configuration information sent by a plurality of network devices to the terminal device indicates the resources of the X reference signals. For example, a report configuration may include the following fields: CSI-ReportConfig ::=SEQUENCE {reportConfigIdCSI-ReportConfigId,carrierServCellIndexOPTIONAL, -- Need SresourcesForChannelMeasurementCSI-ResourceConfigId,csi-IM-ResourcesForInterferenceCSI-ResourceConfigIdOPTIONAL, -- Need Rnzp-CSI-RS-ResourcesForInterferenceCSI-ResourceConfigIdOPTIONAL, -- Need RreportQuantityCHOICE {noneNULL,cri-RI-PMI-CQINULL,cri-RI-i1NULL,cri-RI-CQINULL,cri-RSRPNULL,ssb-Index-RSRPNULL,cri-L1-SINRNULL,ssb-Index-L1-SINRNULL,......},...... } CSI-ReportConfig may represent report configuration information, reportQuantity may represent a report quantity, cri-RSRP may represent a type of third channel quality, cri-L1-SINR may represent a type of fourth channel quality information, and CSI-ResourceConfigId may be used to indicate resource configuration information, for example, resourcesForChannelMeasurement is used to indicate the first resource configuration, csi-IM-ResourcesForInterference may indicate a second resource configuration, and nzp-CSI-RS-ResourcesForInterference may also indicate the second resource configuration. Optionally, the terminal device may receive first report configuration information sent by a first network device, and the first report configuration information indicates the resources of the X reference signals. Alternatively, the terminal device may receive first report configuration information separately sent by a first network device and a second network device, and a sum of resources indicated by the two pieces of first report configuration information is the resources of the X reference signals. In other words, the terminal device may receive one or more pieces of first report configuration information. For example, the terminal device may determine the resources of the X reference signals based on the received first report configuration information, and receive the X reference signals. The first report quantity indicated in the first report configuration information is the third channel quality information, in other words, a type of the first to-be-reported channel quality may be RSRP. The terminal device may measure RSRP of the received X reference signals, and determine Y reference signals with relatively good RSRP in the X reference signals. The terminal device sends the RSRP of the Y reference signals to the network device. It should be noted that the terminal device determines Y reference signals of relatively good channel quality based on the measured RSRP of the X reference signals, and reports the Y reference signals to the network device. Resource configurations of the X reference signals may be from one network device, or may be from configuration performed by a plurality of network devices on the terminal device. Therefore, the reported Y reference signals may be resources configured by one network device, or may be resources configured by different a plurality of network devices. Optionally, the network device receives the third channel quality information of the Y reference signals reported by the terminal device, and sends second report configuration information to the terminal device. The second report configuration information indicates a second resource configuration and a second report quantity, the second resource configuration indicates resources of L reference signals and resources of Q third reference signals, the L reference signals are reference signals used for channel measurement, the third reference signals are reference signals used for interference measurement, the second report quantity is fourth channel quality information, and Q is a positive integer. 330: Send fourth channel quality information of P reference signals, where the fourth channel quality information of the P reference signals is obtained based on the third channel quality information of the Y reference signals. In this embodiment, the second report configuration and the first report configuration meet an association relationship, in other words, the terminal device may receive the X reference signals, select Y better reference signals by measuring L1-RSRP of the X reference signals and report the Y better reference signals to the network device, and then report the channel quality information of the P reference signals based on L1-RSRP of the Y reference signals, for example, report L1-SINR of the P reference signals based on the L1-RSRP of the Y reference signals, to determine a better reference signal. The association relationship of the two report configurations is established, so that resource overheads can be effectively reduced, reporting overheads can be reduced, and computational complexity can be reduced. Optionally, in this embodiment, the fourth channel quality information may be any one of the following: a signal to interference plus noise ratio, a signal-to-noise ratio, a channel quality indicator, and reference signal received quality. It should be noted that the terminal device receives the second report configuration information, and the second configuration information indicates the resources of the L reference signals and the resources of the Q third reference signals. The terminal device may send the fourth channel quality information of the P reference signals in the L reference signals based on the third channel quality information for sending the Y reference signals. In other words, an intersection set of the L reference signals and the Y reference signals is a non-empty subset, and the P reference signals are a subset of the L reference signals. For example, in a beam training process, X=64, Y=8, L=4, and P=2. In other words, the terminal device may receive 64 reference signals based on a resource configuration, and the terminal device may determine eight reference signals with relatively good RSRP from the 64 reference signals. Resources of four reference signals may be configured in the second configuration information received by the terminal device, in other words, channel quality information of the four reference signals may be measured, and a signal to interference plus noise ratio, a signal-to-noise ratio, a channel quality indicator, reference signal received quality, or the like may be measured. The terminal device may send two better reference signals to the network device based on a measurement result. Optionally, the terminal device further needs to report reference signal resource indexes corresponding to the two reference signals. For example, the second report configuration and the first report configuration meet a first association relationship, in other words, the first report configuration may be indexed based on the second report configuration, and a second report quantity indicated by the second report configuration may be obtained based on the first report quantity. In other words, the first association relationship may indicate that the fourth channel quality information of the P reference signals is determined based on the third channel quality information of the Y reference signals. Optionally, the first association relationship may be an association relationship predefined in a protocol or configured by the network device. For example, the second report configuration information may include the identification information indicating the first report configuration information. For example, the identification information in the second report configuration information may indicate a first report configuration index (report config ID). For example, the identification information in the second report configuration information may indicate a first resource configuration index (resource config ID). For example, the second resource configuration and the first resource configuration meet a second association relationship, in other words, the first resource configuration may be indexed based on the second resource configuration, and the second association relationship may indicate that the fourth channel quality information of the P reference signals is sent based on the third channel quality information of the Y reference signals. For example, the second association relationship may be an association relationship that is indicated by the second resource configuration information and that is of a transmission time sequence of the P reference signals and/or the Q third reference signals and the X reference signals. For example, the sending fourth signal quality information of P reference signals includes the following. The terminal device receives a second report configuration, where the second report configuration information indicates a second resource configuration and a second report quantity, the second resource configuration indicates the resources of the L reference signals and the resources of the Q third reference signals, the L reference signals are reference signals used for channel measurement, the third reference signals are reference signals used for interference measurement, the second report quantity indicates a type of the fourth channel quality information, and Q is a positive integer. The P reference signals are a subset of the L reference signals. The second report configuration and the first report configuration meet the first association relationship, or the second resource configuration and the first resource configuration meet the second association relationship. The terminal device may send the fourth signal quality information of the P reference signals based on the second report configuration and the first association relationship, or the terminal device may send the fourth signal quality information of the P reference signals based on the second report configuration and the second association relationship. Optionally, the second association relationship may be an association relationship predefined in a protocol or configured by the network device. Optionally, all or some of the L reference signals and all or some of the X reference signals meet a QCL relationship, and/or all or some of the Q third reference signals and all or some of the X reference signals meet a QCL relationship. Optionally, that one or more of the L reference signals and one or more of the X reference signals meet the QCL relationship may be predefined or may be indicated by using signaling (for example, one of RRC signaling, MAC CE signaling, and DCI signaling). For example, that one of the L reference signals and one of the X reference signals meet the QCL relationship may be predefined; or that one of the L reference signals and a plurality of reference signals in the X reference signals meet the QCL relationship may be predefined. For example, it is assumed that the L reference signals are four reference signals, the X reference signals are four reference signals, and that a first reference signal in the L reference signals and a first reference signal in the X reference signals meet the QCL relationship is predefined, or that a first reference signal in the L reference signals and a first reference signal and a second reference signal in the X reference signals meet the QCL relationship is predefined. Optionally, that one or more of the Q third reference signals and one or more of the X reference signals meet the QCL relationship may be predefined or may be indicated by using signaling (for example, one of RRC signaling, MAC CE signaling, and DCI signaling). For example, that one of the Q third reference signals and one of the X reference signals meet the QCL relationship may be predefined; or that one of the Q third reference signals and a plurality of reference signals in the X reference signals meet the QCL relationship may be predefined. For example, it is assumed that the Q third reference signals are four third reference signals, the X reference signals are four reference signals, and that a first third reference signal in the Q third reference signals and a first reference signal in the X reference signals meet the QCL relationship may be predefined, or that a first third reference signal in the Q third reference signals and a first reference signal and a second reference signal in the X reference signals meet the QCL relationship may be predefined. Optionally, a reference signal that is in the L reference signals and that has a same resource identifier as a reference signal in the X reference signals meets the QCL relationship, and/or a reference signal that is in the Q third reference signals and that has a same resource identifier as a reference signal in the X reference signals meets the QCL relationship. Quasi co-site/quasi co-location QCL assumption information may also be referred to as co-location assumption information. The QCL information is used to assist in describing beamforming information and a receiving procedure on a receive side of the terminal device. For example, the UE receives resource config b1 sent by the network device, measures L1-RSRP of the reference signal in the resource config b1, and reports Y best reference signals and corresponding L1-RSRP. The UE receives resource config b2 sent by the network device, and the resource config b2 and the resource config b1 are in a second association relationship. The UE measures an L1-SINR of the reference signal based on the second association relationship and the resource config b2, and reports P reference signals and corresponding L1-SINRs. For example, that the first report quantity is L1-RSRP and the second report quantity is an L1-SINR is used as an example for description. As shown inFIG.7, the UE receives a first report configuration Report Config ID X, where the first report configuration may indicate that the first report quantity is L1-RSRP, and the first report configuration is associated with or includes at least one resource configuration (resource config a1), and the at least one resource config includes or indicates at least one reference signal resource set. As shown inFIG.7, a first resource set indicated by the first report configuration includes the resources of the X reference signals. The resources of the X reference signals may be a CSI-RS 5, a CSI-RS 6, a CSI-RS 7, a CSI-RS 8, a CSI-RS 9, a CSI-RS 10, and a CSI-RS 11. The terminal device may measure L1-RSRP of the X reference signals to determine Y best reference signals, such as the CSI-RS 5, the CSI-RS 6, the CSI-RS 7, and the CSI-RS 8. The terminal device reports the four reference signals to the network device, and the network device sends a second report configuration Report Config ID Y to the terminal device. The second report configuration may indicate that a type of the second report quantity is an L1-SINR, and indicate the second resource configuration (resource config a2). The second resource configuration (resource config a2) may include a resource used for channel measurement and a resource used for interference measurement. For example, the CSI-RS 5 and the CSI-RS 6 may be CMRs, and the CSI-RS 7 and the CSI-RS 8 may be IMRs. The second report configuration and the first report configuration are in an association relationship. L1-RSRP measured in the first report configuration may be indexed by using the association relationship, and the L1-SINR is determined based on the measured L1-RSRP. Optionally, a correspondence between a reference signal in the CMR and a reference signal in the IMR may be a QCL relationship configured by the network device, or the UE may determine, based on a reference signal in the CMR, reference signals in the IMR that can be simultaneously received and that are used as interference items. In other words, after receiving the second report configuration information, the terminal device may select a reference signal used as a signal item and an interference signal used as an interference item, and report the fourth channel quality information. Optionally, the resources of the L reference signals in the second resource configuration indicated by the second report configuration may be a subset of the Y reference signals. As shown inFIG.7, a resource of a reference signal that is included in the CMR resource set and that is indicated by the second report configuration is a subset of the resources of the reported Y reference signals. Optionally, the resources of the L reference signals in the second resource configuration indicated by the second report configuration may include another resource configured by a network. For example, the CMR resource set indicated by the second configuration may further include a resource CSI-RS 12 configured by the network device, as shown inFIG.7. In other words, the resources of the L reference signals in the second resource configuration may include resources of some Y reference signals, or may include some resources configured by the network device. In other words, an intersection set of the resources of the L reference signals and the resources of the Y reference signals is a non-empty subset. Optionally, there is an association relationship between a Report Config ID X including L1-RSRP and a Report Config ID Y including an L1-SINR, and the association relationship is configured by the base station by using signaling. For example, the Report Config ID X including the L1-RSRP is associated with the Report Config ID Y including the L1-SINR. Optionally, Resource Config a1 and Resource Config a2 meet a first time sequence relationship. For example, a time interval (start time, end time, and the like) for sending or reporting Resource Config a1 and Resource Config a2 is less than or equal to a first threshold K. The first threshold may be reported based on a capability of the UE, or predefined in a protocol, or configured by the base station. Optionally, a reference signal in the resource config a1 may be a periodic reference signal or a half-periodic reference signal (for example, may be a CSI-RS or an SSB). Optionally, a reference signal sent in the resource config a2 is an aperiodic reference signal (for example, may be a CSI-RS). The reference signal is mainly a reference signal used for interference measurement, in other words, an IMR reference signal in the resource config a2 may be an aperiodic reference signal. Optionally, all or some reference signals in the resource config a2 may be indicated but not sent. Optionally, a reference signal CMR that is in the resource config a2 and that is used for channel measurement is indicated but not sent. In other words, after the second report configuration information is received, it may indicate that a reference signal in a CMR resource set does not need to be sent again. Optionally, one or more resource sets may be configured in the resource config a2. When a plurality of resource sets are configured in the resource config a2, the plurality of resource sets may include at least one CMR resource set and at least one IMR resource set, or all the plurality of resource sets may be CMR resource sets. Optionally, only Q third reference signal resources may be configured for the second resource configuration in this embodiment. Optionally, in this case, the terminal device obtains the fourth channel quality information based on the Y reference signals and the Q third reference signals. Optionally, a reference signal IMR that is in the resource config a2 and that is used for interference measurement may be sent, in other words, the terminal device may receive a reference signal in a resource set that is used for interference measurement and that is indicated in the second report configuration. Optionally, a periodicity of the X reference signals indicated by the first resource configuration is less than a periodicity of the Q reference signals indicated by the second resource. In the foregoing method, overheads can be further reduced, and a reporting delay can be shortened. For example, L1-SINR=S/I, where a signal item S may be directly obtained from previously reported L1-RSRP by using the foregoing association relationship, and an interference item may be obtained by measuring an interference resource IMR indicated by the second report configuration Report Config ID Y. In other words, optionally, in this embodiment, the terminal device may first receive the first report configuration information sent by the network device; based on the first report configuration information, the terminal device may receive the X reference signals, measure the third channel quality information (for example, L1-RSRP) of the X reference signals, and report the third channel quality information of the Y reference signals of relatively good channel quality to the network device; and then the terminal device may receive the second report configuration information sent by the network device, and the terminal device may send the fourth channel quality information (for example, L1-SINRs) of the P reference signals based on the second report configuration information. Optionally, the first report configuration information and the second report configuration information may be one or more pieces of configuration information sent by the network device. Optionally, the network device may configure at least two report configurations (Report config). The at least two report configurations have the following features: In the at least two pieces of report configuration information, a report quantity (reportQuantity) is configured as L1-RSRP in at least one report config (collectively referred to as report config a1), and a report quantity (reportQuantity) is configured as an L1-SINR in at least one report config (collectively referred to as report config a2). Optionally, in the at least two pieces of report configuration information, a report quantity includes at least one resource configuration (collectively referred to as resource config b1) associated with or included in report config (report configuration) of the L1-RSRP, and the at least one resource config includes or indicates at least one reference signal resource set. Optionally, the at least one reference signal resource set is a resource set (for example, a CMR RS set 1) used for channel measurement. Optionally, in the at least two report configurations, a report quantity includes at least one resource configuration (collectively referred to as resource config b2) associated with or included in the report config of the L1-SINR, and the at least one resource config includes or indicates at least one reference signal resource set. Optionally, at least one resource set (for example, a CMR RS set 2) used for channel measurement and at least one resource set (an IMR RS set 3) used for interference measurement are included. Optionally, at least one resource set (such as an RS set 2, or an RS set 2 and an RS set 3) used for channel measurement is included. In this embodiment, the second report configuration and the first report configuration meet an association relationship, in other words, the terminal device may receive the X reference signals, select the Y better reference signals by measuring the L1-RSRP of the X reference signals and report the Y better reference signals to the network device, and then report the channel quality information of the P reference signals based on the L1-RSRP of the Y reference signals. For example, the L1-SINR of the P reference signals is reported based on the L1-RSRP of the Y reference signals, to determine a better reference signal. The association relationship of the two report configurations is established, so that resource overheads can be effectively reduced, reporting overheads can be reduced, and computational complexity can be reduced. It should be understood that, sequence numbers of the foregoing processes do not mean execution sequences. The execution sequences of the processes should be determined based on functions and internal logic of the processes and should not be construed as any limitation on the implementation processes of the embodiments. The channel state information transmission method according to the embodiments is described in detail above. The terminal device recommends a preferred transmission manner for data transmission, so that the network device obtains accurate channel state information, thereby improving accuracy of the channel state information reported by the terminal device. It should be understood that the terminal device and the network device in the embodiments may perform the foregoing methods in the embodiments. In other words, for a specific working process of the following products, refer to a corresponding process in the foregoing method embodiments. The following describes in detail a channel state information transmission apparatus with reference toFIG.8toFIG.11. FIG.8is a schematic block diagram of a channel state information transmission apparatus according to an embodiment. As shown inFIG.8, the apparatus500may include a sending unit510and a receiving unit520. In a possible implementation, the apparatus500may correspond to the terminal device in the foregoing method embodiments, for example, may be the terminal device, or may be a chip disposed in the terminal device. The apparatus500can perform the steps performed by the terminal device inFIG.2. The receiving unit520is configured to receive N reference signal groups, where N is an integer greater than or equal to 2. The sending unit510is configured to send channel state information, where the channel state information includes a first resource index, a second resource index, and first channel quality information, the first resource index is a resource index of a first reference signal, the second resource index is a resource index of a second reference signal, the first reference signal and the second reference signal are reference signals in different groups in the N reference signal groups, and the first channel quality information is obtained by using the first reference signal as a signal and the second reference signal as interference. It should be understood that the apparatus500may further include a processing unit, and the processing unit may be configured to control the receiving unit520and the sending unit510to perform related steps. In this embodiment, the terminal device may determine, based on a receiving status of the N reference signal groups, a reference signal used as a signal item and a reference signal used as an interference item, thereby avoiding a problem that when a network device configures an interference resource, because the network device cannot learn of a receiving status of the terminal device, the network device configures a non-interference beam as the interference resource, and consequently channel state information reported by the terminal device is inaccurate. The terminal device may report a resource index of the reference signal used as the signal item, a resource index of the reference signal used as the interference item, and measured channel quality information, so that accuracy of the channel state information reported by the terminal device can be improved. Optionally, the processing unit is configured to determine first reference signals in the N reference signal groups. The processing unit is further configured to determine second reference signals in the N reference signal groups based on the first reference signals. Optionally, the receiving unit520is further configured to receive first configuration information, where the first configuration information indicates that the N reference signal groups are channel measurement reference signal groups. The sending unit510is further configured to send second channel quality information, where the second channel quality information is obtained by using the second reference signal as a signal and the first reference information as interference. Optionally, the sending unit510is further configured to send first identifier information and/or second identifier information, where the first identifier information is used to indicate an identifier of a reference signal group in which the first reference signal is located, and the second identifier information is used to indicate an identifier of a reference signal group in which the second reference signal is located. Optionally, the receiving unit520is further configured to receive second configuration information, where the second configuration information indicates that the N reference signal groups include M channel measurement reference signal groups and N-M interference measurement reference signal groups, and M is a positive integer less than N. The processing unit is configured to determine the first reference signal in the M reference signal groups. The processing unit is further configured to determine the second reference signal in the N-M reference signal groups based on the first reference signal. Optionally, the sending unit210510is further configured to send third identifier information, where the third identifier information is used to indicate an identifier of a reference signal group in which the second reference signal is located. In a possible implementation, the apparatus500may correspond to the terminal device in the foregoing method embodiments, for example, may be the terminal device, or may be a chip disposed in the terminal device. The apparatus500can perform the steps performed by the terminal device inFIG.6. The receiving unit520is configured to receive X reference signal. The sending unit510is configured to send third channel quality information of Y reference signals in the X reference signals, where X and Y are positive integers, and Y is less than or equal to X. The sending unit510is further configured to send fourth channel quality information of P reference signals, where the fourth channel quality information of the P reference signals is obtained based on the third channel quality information of the Y reference signals, and P is a positive integer. It should be understood that the apparatus500may further include a processing unit, and the processing unit may be configured to control the receiving unit520and the sending unit510to perform related steps. In this embodiment, the terminal device may receive the X reference signals, select Y better reference signals by measuring third channel quality information of the X reference signals and report the Y better reference signals to a network device, and then report the fourth channel quality information of the P reference signals based on the third channel quality information of the Y reference signals, to determine a better reference signal. In this embodiment, resource overheads can be effectively reduced, reporting overheads can be reduced, and computational complexity can be reduced. Optionally, the receiving unit520is further configured to receive first report configuration information, where the first report configuration information indicates a first resource configuration and a first report quantity, the first resource configuration indicates resources of the X reference signals, and the first report quantity indicates a type of the third channel quality information. Optionally, the receiving unit520is further configured to receive second report configuration information, where the second report configuration information indicates a second resource configuration and a second report quantity, the second resource configuration indicates resources of L reference signals and resources of Q third reference signals, the L reference signals are reference signals used for channel measurement, the third reference signals are reference signals used for interference measurement, the second report quantity indicates a type of the fourth channel quality information, the P reference signals are a subset of the L reference signals, and L and Q are positive integers. Optionally, the P reference signals are a subset of the Y reference signals. Optionally, the receiving unit520is further configured to receive the Q third reference signals. Optionally, the second report configuration information and the first report configuration information meet a first association relationship, and/or the second resource configuration and the first resource configuration meet a second association relationship. Optionally, the first association relationship is that the second report configuration information includes identification information indicating the first report configuration information. Optionally, the second association relationship is one of the following relationships:A transmission time interval between the L reference signals and/or the Q third reference signals and the X reference signals is less than a preset threshold;the L reference signals and/or the Q third reference signals and the X reference signals meet a quasi co-site/quasi co-location QCL relationship; or the resources of the L reference signals and/or the resources of the Q third reference signals are subsets of the resources of the X reference signals. Optionally, the fourth channel quality information is any one of the following: a signal to interference plus noise ratio, a signal-to-noise ratio, a channel quality indicator, and reference signal received quality. It should be understood that the apparatus500according to this embodiment may correspond to the method performed by the terminal device in the foregoing method embodiments. In addition, the foregoing and other management operations and/or functions of the units/modules in the apparatus500are separately used to implement corresponding steps of the method performed by the first terminal device in the foregoing method embodiments, and therefore, can also achieve the beneficial effects in the foregoing method embodiments. For brevity, details are not described herein again. It should be further understood that the units/modules in the apparatus500may be implemented in a form of software and/or hardware. This is not limited. In other words, the apparatus500is presented in a form of functional modules. The “unit” herein may be an application specific integrated circuit (ASIC), a circuit, a processor and a memory that execute one or more software or firmware programs, an integrated logic circuit, and/or another component that can provide the foregoing functions. The apparatus500in the foregoing solutions may have a function of implementing corresponding steps performed by the terminal device in the foregoing methods. The function may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or the software includes one or more modules corresponding to the foregoing function. For example, the sending unit may be replaced with a transmitter, the receiving unit may be replaced with a receiver, and another unit such as a determining unit may be replaced with a processor, to respectively perform a sending operation, a receiving operation, and a related processing operation in the method embodiments. In this embodiment, the apparatus inFIG.8may alternatively be a chip or a chip system, for example, a system on chip (SoC). Correspondingly, the receiving unit and the sending unit may be a transceiver circuit of the chip. This is not limited herein. FIG.9is a schematic block diagram of a channel state information transmission apparatus according to an embodiment. As shown inFIG.9, the apparatus600may include a sending unit610and a receiving unit620. In a possible implementation, the apparatus600may correspond to the network device in the foregoing method embodiments, for example, may be the network device, or may be a chip disposed in the network device. The apparatus600can perform the steps performed by the network device inFIG.2. The sending unit610is configured to send N reference signal groups, where N is an integer greater than or equal to 2. The receiving unit620is configured to receive channel state information, where the channel state information includes a first resource index, a second resource index, and first channel quality information, the first resource index is a resource index of a first reference signal, the second resource index is a resource index of a second reference signal, the first reference signal and the second reference signal are reference signals in different groups in the N reference signal groups, and the first channel quality information is obtained by using the first reference signal as a signal and the second reference signal as interference. It should be understood that the apparatus600may further include a processing unit, and the processing unit may be configured to control the receiving unit620and the sending unit610to perform related steps. In this embodiment, the network device may receive the first resource index, the second resource index, and the first channel quality information that are sent by a terminal device. The terminal device may determine, based on a receiving status of the N reference signal groups, a reference signal used as a signal item and a reference signal used as an interference item, thereby avoiding a problem that when the network device configures an interference resource, because the network device cannot learn of a receiving status of the terminal device, the network device configures a non-interference beam as the interference resource, and consequently channel state information reported by the terminal device is inaccurate. The terminal device may report a resource index of the reference signal used as the signal item, a resource index of the reference signal used as the interference item, and measured channel quality information, so that accuracy of the channel state information reported by the terminal device can be improved. Optionally, the sending unit610is further configured to send first configuration information, where the first configuration information indicates that the N reference signal groups are channel measurement reference signal groups. The receiving unit620is further configured to receive second channel quality information, where the second channel quality information is obtained by using the second reference signal as a signal and the first reference information as interference. Optionally, the receiving unit620is further configured to receive first identifier information and/or second identifier information, where the first identifier information is used to indicate an identifier of a reference signal group in which the first reference signal is located, and the second identifier information is used to indicate an identifier of a reference signal group in which the second reference signal is located. Optionally, the sending unit610is further configured to send second configuration information, where the second configuration information indicates that the N reference signal groups include M channel measurement reference signal groups and N-M interference measurement reference signal groups, and M is a positive integer less than N. Optionally, the receiving unit620is further configured to receive third identifier information, where the third identifier information is used to indicate an identifier of a reference signal group in which the second reference signal is located. In a possible implementation, the apparatus600may correspond to the network device in the foregoing method embodiments, for example, may be the network device, or may be a chip disposed in the network device. The apparatus600can perform the steps performed by the network device inFIG.6. The sending unit610is configured to send X reference signals. The receiving unit620is configured to receive third channel quality information of Y reference signals in the X reference signals, where X and Y are positive integers, and Y is less than or equal to X. The receiving unit620is further configured to receive fourth channel quality information of P reference signals, where the fourth channel quality information of the P reference signals is obtained based on the third channel quality information of the Y reference signals, and P is a positive integer. It should be understood that the apparatus600may further include a processing unit, and the processing unit may be configured to control the receiving unit620and the sending unit610to perform related steps. In this embodiment, the network device may send the X reference signals to a terminal device, and the terminal device selects Y better reference signals by measuring third channel quality information of the X reference signals and report the Y better reference signals to the network device, and then reports the fourth channel quality information of the P reference signals based on the third channel quality information of the Y reference signals, to determine a better reference signal. In this embodiment, resource overheads can be effectively reduced, reporting overheads can be reduced, and computational complexity can be reduced. Optionally, the sending unit610is further configured to send first report configuration information, where the first report configuration information indicates a first resource configuration and a first report quantity, the first resource configuration indicates resources of the X reference signals, and the first report quantity indicates a type of the third channel quality information. Optionally, the sending unit610is further configured to send second report configuration information, where the second report configuration information indicates a second resource configuration and a second report quantity, the second resource configuration indicates resources of L reference signals and resources of Q third reference signals, the L reference signals are reference signals used for channel measurement, the third reference signals are reference signals used for interference measurement, the second report quantity indicates a type of the fourth channel quality information, the P reference signals are a subset of the L reference signals, and L and Q are positive integers. Optionally, the P reference signals are a subset of the Y reference signals. Optionally, the sending unit610is further configured to send the Q third reference signals. Optionally, the second report configuration information and the first report configuration information meet a first association relationship, and/or the second resource configuration and the first resource configuration meet a second association relationship. Optionally, the first association relationship is that the second report configuration information includes identification information indicating the first report configuration information. Optionally, the second association relationship is one of the following relationships:A transmission time interval between the L reference signals and/or the Q third reference signals and the X reference signals is less than a preset threshold;the L reference signals and/or the Q third reference signals and the X reference signals meet a quasi co-site/quasi co-location QCL relationship; orthe resources of the L reference signals and/or the resources of the Q third reference signals are subsets of the resources of the X reference signals. Optionally, the fourth channel quality information is any one of the following: a signal to interference plus noise ratio, a signal-to-noise ratio, a channel quality indicator, and reference signal received quality. It should be understood that the apparatus600according to this embodiment may correspond to the method performed by the network device in the foregoing method embodiments. In addition, the foregoing and other management operations and/or functions of the units/modules in the apparatus600are separately used to implement corresponding steps of the method performed by the network device in the foregoing method embodiments, and therefore, can also achieve the beneficial effects in the foregoing method embodiments. For brevity, details are not described herein again. It should be further understood that the units/modules in the apparatus600may be implemented in a form of software and/or hardware. This is not limited. In other words, the apparatus600is presented in a form of functional modules. The “unit” herein may be an ASIC, a circuit, a processor and a memory that execute one or more software or firmware programs, an integrated logic circuit, and/or another component that can provide the foregoing functions. The apparatus600in the foregoing solutions has a function of implementing corresponding steps performed by the network device in the foregoing methods. The function may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or the software includes one or more modules corresponding to the foregoing function. For example, the sending unit may be replaced with a transmitter, the receiving unit may be replaced with a receiver, and another unit such as a determining unit may be replaced with a processor, to respectively perform a sending operation, a receiving operation, and a related processing operation in the method embodiments. In this embodiment, the apparatus inFIG.9may alternatively be a chip or a chip system, for example, a, SoC. Correspondingly, the receiving unit and the sending unit may be a transceiver circuit of the chip. This is not limited herein. FIG.10is a schematic structural diagram of an apparatus800according to an embodiment. The apparatus800may be a terminal device, and is applied to the system shown inFIG.1, to perform a function of the terminal device in the foregoing method embodiments. As shown inFIG.10, the terminal device800includes a processor810and a transceiver820. Optionally, the terminal device800further includes a memory830. The processor810, the transceiver802, and the memory830may communicate with each other through an internal connection path, and transfer a control signal and/or a data signal. The memory2030is configured to store a computer program. The processor810is configured to: invoke the computer program from the memory830and run the computer program, to control the transceiver820to receive/send a signal. Optionally, the apparatus800may further include an antenna840, configured to send, by using a radio signal, uplink data or uplink control signaling output by the transceiver820. The processor810and the memory830may be integrated into one processing apparatus. The processor810is configured to execute program code stored in the memory830to implement the foregoing functions. During implementation, the memory830may alternatively be integrated into the processor810, or may be independent of the processor810. The processor810may correspond to the processing unit in the apparatus500. The transceiver820may correspond to the receiving unit520and the sending unit510inFIG.8, and may also be referred to as a communications unit. The transceiver820may include a receiver (which is also referred to as a receiver or a receiver circuit) and a transmitter (which is also referred to as a transmitter or a transmitter circuit). The receiver is configured to receive a signal, and the transmitter is configured to transmit a signal. It should be understood that, the terminal device800shown inFIG.10can implement processes related to the terminal device in the method embodiments inFIG.2andFIG.6. Operations and/or functions of the modules in the terminal device800are separately intended to implement corresponding procedures in the foregoing method embodiments. For details, refer to the descriptions in the foregoing method embodiments. To avoid repetition, detailed descriptions are properly omitted herein. The processor810may be configured to perform an action that is implemented inside the terminal device and that is described in the foregoing method embodiments, and the transceiver820may be configured to perform an action of receiving or sending that is performed by the terminal device from or to the network device and that is described in the foregoing method embodiments. For details, refer to the descriptions in the foregoing method embodiments. Details are not described herein again. Optionally, the terminal device800may further include a power supply850, configured to supply power to various components or circuits in the terminal device. In addition, to further improve functions of the apparatus, the apparatus800may further include one or more of an input unit860, a display unit870, an audio circuit880, a camera890, a sensor810, and the like, and the audio circuit may further include a loudspeaker882, a microphone884, and the like. It should be noted that the terminal device800may be the terminal device in any one of the foregoing method embodiments, to implement the steps or functions of the terminal device in any one of the foregoing implementations. FIG.11is a schematic structural diagram of an apparatus900according to an embodiment. For example,FIG.11may be a schematic structural diagram of a network device. The network device900may be applied to the system shown inFIG.1, to perform a function of the network device in the foregoing method embodiments. As shown in the figure, for example, the network device900may include one or more radio frequency units, for example, a remote radio unit (RRU)910and one or more baseband units (BBU) (which may also be referred to as a digital unit (DU))920. The RRU910may be referred to as a communications unit or a transceiver unit, and corresponds to the sending unit610and the receiving unit620inFIG.9. Optionally, the transceiver unit910may also be referred to as a transceiver, a transceiver circuit, a transceiver, or the like, and may include at least one antenna911and a radio frequency unit912. Optionally, the transceiver unit910may include a receiving unit and a sending unit. The receiving unit may correspond to a receiver (which is also referred to as a receiver or a receiver circuit), and the sending unit may correspond to a transmitter (which is also referred to as a transmitter or a transmitter circuit). The RRU910is mainly configured to: receive/send a radio frequency signal, and perform conversion between a radio frequency signal and a baseband signal. For example, the RRU910is configured to send first information to a terminal device. The BBU920is mainly configured to: perform baseband processing, control the network device, and the like. The RRU910and the BBU920may be physically disposed together, or may be physically separated, namely, a distributed base station. The BBU920is a control center of the network device, and may also be referred to as a processing unit. The BBU920may correspond to the processing unit included in the apparatus600, and is mainly configured to implement a baseband processing function, for example, channel coding, multiplexing, modulation, or spreading. For example, the BBU (the processing unit) may be configured to control the base station to perform an operation procedure related to the network device in the foregoing method embodiments, for example, to generate the foregoing indication information. In an example, the BBU920may include one or more boards, and a plurality of boards may jointly support a radio access network (for example, an LTE network) having a single access standard, or may separately support radio access networks (for example, an LTE network, a 5G network, or another network) having different access standards. The BBU920further includes a memory921and a processor922. The memory921is configured to store necessary instructions and data. The processor922is configured to control the network device to perform a necessary action, for example, configured to control the network device to perform an operation procedure related to the network device in the foregoing method embodiments. The memory921and the processor922may serve one or more boards. In other words, a memory and a processor may be independently disposed on each board. Alternatively, a plurality of boards may share a same memory and a same processor. In addition, a necessary circuit may further be disposed on each board. It should be understood that the network device900shown inFIG.11can implement processes related to the network device in the method embodiments inFIG.2andFIG.6. Operations and/or functions of the modules in the network device900are separately intended to implement corresponding procedures in the foregoing method embodiments. For details, refer to the descriptions in the foregoing method embodiments. To avoid repetition, detailed descriptions are properly omitted herein. The BBU920may be configured to perform an action that is implemented inside the network device and that is described in the foregoing method embodiments, and the RRU910may be configured to perform an action of receiving or sending that is performed by the network device from or to the terminal device and that is described in the foregoing method embodiments. For details, refer to the descriptions in the foregoing method embodiments. Details are not described herein again. An embodiment further provides a processing apparatus including a processor and an interface. The processor is configured to perform the method in any one of the foregoing method embodiments. It should be understood that, the processing apparatus may be a chip. For example, the processing apparatus may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a SoC, a CPU, a network processor (NP), a digital signal processing circuit (DSP), a microcontroller unit (MCU), a programmable controller (PLD), or another integrated chip. In an implementation process, steps in the foregoing methods can be implemented by using a hardware integrated logical circuit in the processor, or by using instructions in a form of software. The steps of the methods disclosed with reference to the embodiments may be directly performed by a hardware processor, or may be performed by using a combination of hardware in the processor and a software module. The software module may be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, or a register. The storage medium is located in the memory, and the processor reads information in the memory and completes the steps in the foregoing methods in combination with hardware of the processor. To avoid repetition, details are not described herein again. It should be noted that the processor in the embodiments may be an integrated circuit chip and have a signal processing capability. In an implementation process, steps in the foregoing method embodiments can be implemented by using a hardware integrated logical circuit in the processor, or by using instructions in a form of software. The processor may be a general-purpose processor, a DSP, an ASIC, an FPGA or another programmable logic device, a discrete gate or a transistor logic device, or a discrete hardware component. The processor may implement or perform the methods, the steps, and logical block diagrams that are disclosed in the embodiments. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor or the like. Steps of the methods disclosed with reference to the embodiments may be directly executed and accomplished by using a hardware decoding processor, or may be executed and accomplished by using a combination of hardware in the decoding processor and a software module. The software module may be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, or a register. The storage medium is located in the memory, and the processor reads information in the memory and completes the steps in the foregoing methods in combination with hardware of the processor. It may be understood that the memory in this embodiment may be a volatile memory or a nonvolatile memory or may include a volatile memory and a nonvolatile memory. The nonvolatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), used as an external cache. Through example but not limitative description, many forms of RAMs may be used, for example, a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDR SDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synchlink dynamic random access memory (SLDRAM), and a direct rambus dynamic random access memory (DR RAM). It should be noted that the memory of the systems and methods include, but are not limited to, these and any memory of another proper type. According to the methods provided in the embodiments, there is further provided a computer program product. The computer program product includes computer program code. When the computer program code is run on a computer, the computer is enabled to perform the method in the embodiment shown inFIG.2. According to the methods provided in the embodiments, the embodiments further provide a computer-readable medium. The computer-readable medium stores program code. When the program code is run on a computer, the computer is enabled to perform the method in the embodiment shown inFIG.2orFIG.6. According to the methods provided in the embodiments, the embodiments further provide a system. The system includes the foregoing one or more terminal devices and the foregoing one or more network devices. All or some of the foregoing embodiments may be implemented by using software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or some of the embodiments may be implemented in a form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the procedure or functions according to the embodiments are all or partially generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or another programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or may be transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (for example, a coaxial cable, an optical fiber, or a digital subscriber line (DSL)) or wireless (for example, infrared, radio, or microwave) manner. The computer-readable storage medium may be any usable medium accessible by a computer, or a data storage device, such as a server or a data center, integrating one or more usable media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, or a magnetic tape), an optical medium (for example, a high-density digital video disc (DVD), a semiconductor medium (for example, a solid-state drive (SSD)), or the like. The network device and the terminal device in the foregoing apparatus embodiments exactly correspond to the network device and the terminal device in the method embodiments. A corresponding module or unit performs a corresponding step. For example, a communications unit (a transceiver) performs a receiving step or a sending step in the method embodiments, and a processing unit (a processor) may perform a step other than the sending step and the receiving step. For a function of a specific unit, refer to a corresponding method embodiment. There may be one or more processors. In the embodiments, “at least one” means one or more, and “a plurality of” means two or more. The term “and/or” describes an association relationship between associated objects, and represents that three relationships may exist. For example, A and/or B may represent the following cases: only A exists, both A and B exist, and only B exists, where A and B may be singular or plural. The character “I” usually represents an “or” relationship between the associated objects. “At least one (piece) of the following” or a similar expression thereof means any combination of these items, including any combination of singular items (pieces) or plural items (pieces). For example, at least one (piece) of a, b, or c may indicate the following cases: a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c may be singular or plural. A person of ordinary skill in the art may be aware that, in combination with the examples described in the embodiments, method steps and units may be implemented by electronic hardware, computer software, or a combination thereof. To clearly describe the interchangeability between the hardware and the software, the foregoing has generally described steps and compositions of each embodiment based on functions. Whether the functions are performed by hardware or software depends on particular applications and design constraint conditions of the solutions. A person of ordinary skill in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of the embodiments. The terms such as “component”, “module”, and “system” are used to indicate computer-related entities, hardware, firmware, combinations of hardware and software, software, or software being executed. For example, a component may be, but is not limited to, a process that runs on a processor, a processor, an object, an executable file, a thread of execution, a program, and/or a computer. As shown in figures, both a computing device and an application that runs on a computing device may be components. One or more components may reside within a process and/or a thread of execution, and a component may be located on one computer and/or distributed between two or more computers. In addition, these components may be executed from various computer-readable media that store various data structures. For example, the components may perform communication by using a local and/or remote process and based on, for example, a signal having one or more data packets (for example, data from two components interacting with another component in a local system, a distributed system, and/or across a network such as the Internet interacting with other systems by using the signal). A person of ordinary skill in the art may be aware that, various illustrative logical blocks and steps that are described with reference to the embodiments disclosed may be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by using hardware or software depends on particular applications and design constraint conditions of the solutions. A person of ordinary skill in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope. It may be clearly understood by a person of ordinary skill in the art that, for the purpose of convenient and brief description, for a detailed working process of the foregoing system, apparatus, and unit, refer to a corresponding process in the foregoing method embodiments. Details are not described herein again. In the several embodiments provided, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiment is merely an example. For example, the unit division is merely logical function division and may be other division in actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communications connections may be implemented through some interfaces. The indirect couplings or communications connections between the apparatuses or units may be implemented in electrical, mechanical, or other forms. The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located at one position, or may be distributed on a plurality of network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions of the embodiments. In addition, functional units in the embodiments may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units are integrated into one unit. In the foregoing embodiments, all or some of functions of the functional units may be implemented by software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or some of the embodiments may be implemented in a form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, the procedure or functions according to the embodiments are all or partially generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or another programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or may be transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (for example, a coaxial cable, an optical fiber, or a digital subscriber line (DSL)) or wireless (for example, infrared, radio, or microwave) manner. The computer-readable storage medium may be any usable medium accessible by a computer, or a data storage device, such as a server or a data center, integrating one or more usable media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, or a magnetic tape), an optical medium (for example, a DVD), a semiconductor medium (for example, a solid-state drive (solid state disk, SSD)), or the like. When the functions are implemented in a form of a software functional unit and sold or used as an independent product, the functions may be stored in a computer-readable storage medium. Based on such an understanding, the solutions essentially, or the part contributing to the current technology, or some of the solutions may be implemented in a form of a software product. The computer software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform all or some of the steps of the methods described in the embodiments. The foregoing storage medium includes: any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc. The foregoing descriptions are merely implementations, and are non-limiting. Any variation or replacement readily figured out by a person of ordinary skill in the art within the scope of the embodiments shall fall within the scope of the embodiments. | 129,840 |
11943028 | DETAILED DESCRIPTION Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details. The described features generally relate to communicating channel state information (CSI) feedback for sidelink (SL) communications according to a CSI transmission timeline, which may be based on a number of slots, symbols, etc. For example, SL communications can refer to device-to-device (D2D) communication among devices (e.g., user equipment (UEs)) in a wireless network. In a specific example, SL communications can be defined for vehicle-based communications, such as vehicle-to-vehicle (V2V) communications, vehicle-to-infrastructure (V2I) communications (e.g., from a vehicle-based communication device to road infrastructure nodes), vehicle-to-network (V2N) communications (e.g., from a vehicle-based communication device to one or more network nodes, such as a base station), a combination thereof and/or with other devices, which can be collectively referred to as vehicle-to-anything (V2X) communications. In V2X communications, vehicle-based communication devices can communicate with one another and/or with infrastructure devices over a SL channel. For example, a slot can include a collection of multiple symbols, where the multiple symbols can be one of orthogonal frequency division multiplexing (OFDM) symbols, single carrier-frequency division multiplexing (SC-FDM) symbols, or other types of symbols. In an example, the number of symbols in a slot may vary based on a cyclic prefix (CP) length defined for the symbols. A mini-slot, in an example, can include a portion of a slot, and thus a slot can include multiple mini-slots. In one example, UE can transmit SL communications in the slot or mini-slot, where a transmission time interval (TTI) can be the slot, the mini-slot, or each symbol within the slot or mini-slot. In addition, the UE can transmit SL communications over a channel defined by time resources and frequency resources, where the frequency resources can include a channel in multiple physical resource blocks (PRBs), a sub-channel of the channel, etc., and/or may be defined over a period of time (e.g., slot, symbol, etc.). The PRBs can include a collection of subcarriers or resource elements of a symbol. Continued support and implementation of SL communications is provided in fifth generation (5G) new radio (NR) communication technologies. In 5G NR, there is a mapping between physical sidelink shared channel (PSSCH) and corresponding physical sidelink feedback channel (PSFCH) resources for transmitting feedback for the PSSCH. The mapping can be based on one or more of the starting sub-channel of PSSCH, which can be configured based on an information element sl-PSFCH-CandidateResourceType configured as startSubCH, the number of subchannels in a PSSCH, which can be configured based on an information element sl-PSFCH-CandidateResourceType configured as allocSubCH, the slot containing PSSCH (e.g., an index of the slot), the source identifier of the source node (e.g., UE) transmitting PSSCH, or the destination identifier of the destination node (e.g., UE) receiving the PSSCH. In addition, for example, the number of available PSFCH resources can be equal to or greater than the number of UEs in groupcast. In 5G NR, for example, a base station or SL transmitting (Tx) UE can configure one or more sidelink receiving (Rx) UEs with parameters for determining PSFCH resources, including periodPSFCHresource, which can indicate PSFCH periodicity, in number of slots, in a resource pool, and may be set to 0, 1, 2, or 4, where 0 can indicate that PSFCH transmissions from a UE in the resource pool are disabled. In this example, the parameters may also include MinTimeGapPSFCH, which can indicate a minimum time gap, represented in number of slots, between a last slot of the PSSCH reception and a first slot that includes PSFCH resources of the resource pool, which can allow the SL Rx UE time to receive and process the PSSCH and generate feedback before transmission. In this example, the parameters may also include one or more of rbSetPSFCH indicating a set of MPRB,setPFSCHPRBs in a resource pool for PSFCH transmission, numSubchannel indicating a number of Nsubchsub-channels for the resource pool, or NPRB,setPFSCHindicating a number of PSSCH slots associated with a PSFCH slot, which can be determined by periodPSFCHresource. In this example, MPRB,setPFSCH=α·Nsubch·NPSSCHPFSCH, and Msubch,slotPFSCH=MPRB,setPFSCHNsubch·NPSSCHPFSCH. Currently, in 5G NR (e.g., in V2X), there is a minimum time gap MinTimeGapPSFCH for the UE to send hybrid automatic repeat/request (HARQ)-acknowledgement (ACK) of a PSSCH signal, where the UE uses the next available PSFCH resource after MinTimeGapPSFCH slots to send the feedback, where currently the minimum value is 2 slots. HARQ-ACK, as generally referred to herein, can include transmission of ACK or negative-ACK (NACK) as HARQ feedback over associated resources. Similarly, for CSI that is going to be sent on a periodic carrier such as PSFCH or certain period resources (e.g., allocated PSSCH) to feedback CSI, a minimum CSI computation timeline can be configured so that the SL Rx UEs can determine whether their corresponding CSI is included in the CSI carrier or not. CSI from PSSCH can help in 1) avoiding automatic gain control (AGC) distortion at the SL Rx UE in multiple-user (MU)-multiple-input multiple-output (MIMO) scenarios by controlling the two SL Tx UEs power levels. For example, a SL Rx UE computes power levels (such as demodulation reference signal (DMRS) reference signal received power (RSRP) to balance the received signals from both MU-MIMO links, and feeds back this CSI to SL Tx UEs. CSI from PSSCH can also help in 2) performing link adaptation to change modulation and coding scheme (MCS), especially in retransmission (e.g., the SL Tx UE can reserve 2 future resources for retransmission of a current transport block (TB) for transmitting based on feedback from the SL Rx UE). In an example, a SL Rx UE can use aperiodic CSI (A-CSI) reporting in PSFCH where the SL Rx UE can report CSI faster than media access control-control element (MAC-CE) in layer 2 (L2) and the processing can be faster since PSFCH is layer 1 (L1). As PSFCH has certain periodicity and is configurable per a resource pool, there are some timeline considerations that can be taken into account for CSI (regardless of the CSI source being CSI-RS or PSSCH). For example, a minimum computation time for CSI can be considered at least partly based on UE capability. Aspects described herein relate to timeline considerations for CSI (generated by either PSSCH or CSI-RS) carried by the PSFCH, and/or considerations for reserved resources CSI and maintained quasi-colocation (QCL) and phase coherency. In aspects described herein, a SL Rx UE can receive PSSCH (or other sidelink communications, such as physical sidelink control channel (PSCCH), CSI-RS, etc.) from a SL Tx UE, and can transmit CSI feedback based on the PSSCH (or other sidelink communications), the corresponding DMRS or log likelihood ratios (LLRs), etc. based on a CSI transmission timeline. In some aspects, the CSI transmission timeline can include, or be defined according to, a minimum time gap for transmitting CSI in PSFCH resources after receiving the PSSCH (or other sidelink communications) for which feedback is being provided. In addition, the CSI transmission timeline may include, or be defined according to, an aging parameter that can expire the CSI transmission if PSFCH resources occur too long of a time after receiving the PSSCH (or other sidelink communications) for which feedback is being provided. In some aspects, collision between CSI feedback from one SL Rx UE and hybrid automatic repeat/request (HARD) feedback from another SL Rx UE can be handled by providing separate CSI feedback resources in the resource pool. In some aspects, a base station can configure the resource pool, and can notify the SL Rx UEs (e.g., via SL Tx UEs or otherwise) of the PSFCH resources (e.g., generally and/or specifically for CSI feedback). The aspects described herein can allow for SL Rx UEs to receive aperiodic CSI-RSs from SL Tx UEs and report feedback within a time that is useful for the SL Tx UE to modify communication parameters to improve communications between the SL Tx UE and the SL Rx UE. Enabling useful and efficient reporting of CSI feedback, in this regard, can improve communication quality and/or throughput for SL devices, which can improve user experience, etc. The described features will be presented in more detail below with reference toFIGS.1-15. As used in this application, the terms “component,” “module,” “system” and the like are intended to include a computer-related entity, such as but not limited to hardware, software, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components can communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets, such as data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms “system” and “network” may often be used interchangeably. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and A are commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM™, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies, including cellular (e.g., LTE) communications over a shared radio frequency spectrum band. The description below, however, describes an LTE/LTE-A system for purposes of example, and LTE terminology is used in much of the description below, although the techniques are applicable beyond LTE/LTE-A applications (e.g., to fifth generation (5G) new radio (NR) networks or other next generation communication systems). The following description provides examples, and is not limiting of the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in other examples. Various aspects or features will be presented in terms of systems that can include a number of devices, components, modules, and the like. It is to be understood and appreciated that the various systems can include additional devices, components, modules, etc. and/or may not include all of the devices, components, modules etc. discussed in connection with the figures. A combination of these approaches can also be used. FIG.1is a diagram illustrating an example of a wireless communications system and an access network100. The wireless communications system (also referred to as a wireless wide area network (WWAN)) can include base stations102, UEs104, an Evolved Packet Core (EPC)160, and/or a 5G Core (5GC)190. The base stations102may include macro cells (high power cellular base station) and/or small cells (low power cellular base station). The macro cells can include base stations. The small cells can include femtocells, picocells, and microcells. In an example, the base stations102may also include gNBs180, as described further herein. In one example, some nodes of the wireless communication system may have a modem240and communicating component242for transmitting or receiving CSI over a physical feedback channel, such as PSFCH, according to a CSI transmission timeline, as described further herein. In addition, some nodes may have a modem340and configuring component342for configuring UEs with resources or resource pools, CSI transmission timelines, etc. for transmitting or receiving CSI over the physical feedback channel, as described herein. Though UEs104-aand104-bis shown as having the modem240and communicating component242and a base station102is shown as having the modem340and configuring component342, this is one illustrative example, and substantially any node or type of node may include a modem240and communicating component242and/or a modem340and configuring component342for providing corresponding functionalities described herein. The base stations102configured for 4G LTE (which can collectively be referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC160through backhaul links132(e.g., using an S1 interface). The base stations102configured for 5G NR (which can collectively be referred to as Next Generation RAN (NG-RAN)) may interface with 5GC190through backhaul links184. In addition to other functions, the base stations102may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations102may communicate directly or indirectly (e.g., through the EPC160or 5GC190) with each other over backhaul links134(e.g., using an X2 interface). The backhaul links134may be wired or wireless. The base stations102may wirelessly communicate with one or more UEs104. Each of the base stations102may provide communication coverage for a respective geographic coverage area110. There may be overlapping geographic coverage areas110. For example, the small cell102′ may have a coverage area110′ that overlaps the coverage area110of one or more macro base stations102. A network that includes both small cell and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group, which can be referred to as a closed subscriber group (CSG). The communication links120between the base stations102and the UEs104may include uplink (UL) (also referred to as reverse link) transmissions from a UE104to a base station102and/or downlink (DL) (also referred to as forward link) transmissions from a base station102to a UE104. The communication links120may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations102/UEs104may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (e.g., for x component carriers) used for transmission in the DL and/or the UL direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). In another example, certain UEs (e.g., UE104-aand104-b) may communicate with each other using device-to-device (D2D) communication link158. The D2D communication link158may use the DL/UL WWAN spectrum. The D2D communication link158may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR. The wireless communications system may further include a Wi-Fi access point (AP)150in communication with Wi-Fi stations (STAs)152via communication links154in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs152/AP150may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. The small cell102′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell102′ may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP150. The small cell102′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. In addition, in this regard, UEs104-a,104-bcan use a portion of frequency in the 5 GHz unlicensed frequency spectrum in communicating with the small cell102′, with other cells, with one another using sidelink communications, etc. The UEs104-a,104-b, small cell102′, other cells, etc. can use other unlicensed frequency spectrums as well, such as a portion of frequency in the 60 GHz unlicensed frequency spectrum. A base station102, whether a small cell102′ or a large cell (e.g., macro base station), may include an eNB, gNodeB (gNB), or other type of base station. Some base stations, such as gNB180may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, and/or near mmW frequencies in communication with the UE104. When the gNB180operates in mmW or near mmW frequencies, the gNB180may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band has extremely high path loss and a short range. The mmW base station180may utilize beamforming182with the UE104to compensate for the extremely high path loss and short range. A base station102referred to herein can include a gNB180. The EPC160may include a Mobility Management Entity (MME)162, other MMES164, a Serving Gateway166, a Multimedia Broadcast Multicast Service (MBMS) Gateway168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway172. The MME162may be in communication with a Home Subscriber Server (HSS)174. The MME162is the control node that processes the signaling between the UEs104and the EPC160. Generally, the MME162provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway166, which itself is connected to the PDN Gateway172. The PDN Gateway172provides UE IP address allocation as well as other functions. The PDN Gateway172and the BM-SC170are connected to the IP Services176. The IP Services176may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BM-SC170may provide functions for MBMS user service provisioning and delivery. The BM-SC170may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway168may be used to distribute MBMS traffic to the base stations102belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. The 5GC190may include an Access and Mobility Management Function (AMF)192, other AMFs193, a Session Management Function (SMF)194, and a User Plane Function (UPF)195. The AMF192may be in communication with a Unified Data Management (UDM)196. The AMF192can be a control node that processes the signaling between the UEs104and the 5GC190. Generally, the AMF192can provide QoS flow and session management. User Internet protocol (IP) packets (e.g., from one or more UEs104) can be transferred through the UPF195. The UPF195can provide UE IP address allocation for one or more UEs, as well as other functions. The UPF195is connected to the IP Services197. The IP Services197may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The base station may also be referred to as a gNB, Node B, evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. The base station102provides an access point to the EPC160or 5GC190for a UE104. Examples of UEs104include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a positioning system (e.g., satellite, terrestrial), a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, robots, drones, an industrial/manufacturing device, a wearable device (e.g., a smart watch, smart clothing, smart glasses, virtual reality goggles, a smart wristband, smart jewelry (e.g., a smart ring, a smart bracelet)), a vehicle/a vehicular device, a meter (e.g., parking meter, electric meter, gas meter, water meter, flow meter), a gas pump, a large or small kitchen appliance, a medical/healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs104may be referred to as IoT devices (e.g., meters, pumps, monitors, cameras, industrial/manufacturing devices, appliances, vehicles, robots, drones, etc.). IoT UEs may include machine type communications (MTC)/enhanced MTC (eMTC, also referred to as category (CAT)-M, Cat M1) UEs, NB-IoT (also referred to as CAT NB1) UEs, as well as other types of UEs. In the present disclosure, eMTC and NB-IoT may refer to future technologies that may evolve from or may be based on these technologies. For example, eMTC may include FeMTC (further eMTC), eFeMTC (enhanced further eMTC), mMTC (massive MTC), etc., and NB-IoT may include eNB-IoT (enhanced NB-IoT), FeNB-IoT (further enhanced NB-IoT), etc. The UE104may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. In an example, UE104-acan be a SL transmitting UE that can transmit SL communications to a receiving UE104-b. In this example, the SL transmitting UE104-acan transmit, to the SL receiving UE104-b, sidelink communications, and the SL receiving UE104-bcan transmit CSI to the SL transmitting UE104-a, where the CSI can be derived from sidelink communications received from the SL transmitting UE104-a. In an example, SL receiving UE104-bcan transmit the CSI over a physical feedback channel, such as PSFCH. As feedback resources may be periodically scheduled and/or configurable per resource pool, SL receiving UE104-bcan transmit the CSI according to a CSI transmission timeline to allow the SL receiving UE104-benough time to process the sidelink communications and generating the CSI. In addition, SL receiving UE104-bcan transmit the CSI in consideration of an expiration timer for the CSI to ensure the CSI is used by the SL transmitting UE104-a. In addition, in an example, base station102can configure the SL transmitting UE104-aand/or SL receiving UE104-bwith resource pools, CSI transmission timelines, and/or other parameters for communicating the SL communications and/or the corresponding CSI. Turning now toFIGS.2-15, aspects are depicted with reference to one or more components and one or more methods that may perform the actions or operations described herein, where aspects in dashed line may be optional. Although the operations described below inFIGS.4-6are presented in a particular order and/or as being performed by an example component, it should be understood that the ordering of the actions and the components performing the actions may be varied, depending on the implementation. Moreover, it should be understood that the following actions, functions, and/or described components may be performed by a specially programmed processor, a processor executing specially programmed software or computer-readable media, or by any other combination of a hardware component and/or a software component capable of performing the described actions or functions. Referring toFIG.2, one example of an implementation of UE104may include a variety of components, some of which have already been described above and are described further herein, including components such as one or more processors212and memory216and transceiver202in communication via one or more buses244, which may operate in conjunction with modem240and/or communicating component242for transmitting or receiving CSI over a physical feedback channel, such as PSFCH, according to a CSI transmission timeline, as described herein. In an aspect, the one or more processors212can include a modem240and/or can be part of the modem240that uses one or more modem processors. Thus, the various functions related to communicating component242may be included in modem240and/or processors212and, in an aspect, can be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors212may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiver processor, or a transceiver processor associated with transceiver202. In other aspects, some of the features of the one or more processors212and/or modem240associated with communicating component242may be performed by transceiver202. Also, memory216may be configured to store data used herein and/or local versions of applications275or communicating component242and/or one or more of its subcomponents being executed by at least one processor212. Memory216can include any type of computer-readable medium usable by a computer or at least one processor212, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, memory216may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining communicating component242and/or one or more of its subcomponents, and/or data associated therewith, when UE104is operating at least one processor212to execute communicating component242and/or one or more of its subcomponents. Transceiver202may include at least one receiver206and at least one transmitter208. Receiver206may include hardware and/or software executable by a processor for receiving data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). Receiver206may be, for example, a radio frequency (RF) receiver. In an aspect, receiver206may receive signals transmitted by at least one base station102or a SL transmitting UE. Additionally, receiver206may process such received signals, and also may obtain measurements of the signals, such as, but not limited to, Ec/Io, signal-to-noise ratio (SNR), reference signal received power (RSRP), received signal strength indicator (RSSI), etc. Transmitter208may include hardware and/or software executable by a processor for transmitting data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). A suitable example of transmitter208may including, but is not limited to, an RF transmitter. Moreover, in an aspect, UE104may include RF front end288, which may operate in communication with one or more antennas265and transceiver202for receiving and transmitting radio transmissions, for example, receiving wireless communications transmitted by at least one base station102or a SL transmitting UE, transmitting wireless communications to at least one base station102or a SL receiving UE, etc. RF front end288may be connected to one or more antennas265and can include one or more low-noise amplifiers (LNAs)290, one or more switches292, one or more power amplifiers (PAs)298, and one or more filters296for transmitting and receiving RF signals. In an aspect, LNA290can amplify a received signal at a desired output level. In an aspect, each LNA290may have a specified minimum and maximum gain values. In an aspect, RF front end288may use one or more switches292to select a particular LNA290and its specified gain value based on a desired gain value for a particular application. Further, for example, one or more PA(s)298may be used by RF front end288to amplify a signal for an RF output at a desired output power level. In an aspect, each PA298may have specified minimum and maximum gain values. In an aspect, RF front end288may use one or more switches292to select a particular PA298and its specified gain value based on a desired gain value for a particular application. Also, for example, one or more filters296can be used by RF front end288to filter a received signal to obtain an input RF signal. Similarly, in an aspect, for example, a respective filter296can be used to filter an output from a respective PA298to produce an output signal for transmission. In an aspect, each filter296can be connected to a specific LNA290and/or PA298. In an aspect, RF front end288can use one or more switches292to select a transmit or receive path using a specified filter296, LNA290, and/or PA298, based on a configuration as specified by transceiver202and/or processor212. As such, transceiver202may be configured to transmit and receive wireless signals through one or more antennas265via RF front end288. In an aspect, transceiver may be tuned to operate at specified frequencies such that UE104can communicate with, for example, one or more base stations102or one or more cells associated with one or more base stations102, one or more other UEs in SL communications, etc. In an aspect, for example, modem240can configure transceiver202to operate at a specified frequency and power level based on the UE configuration of the UE104and the communication protocol used by modem240. In an aspect, modem240can be a multiband-multimode modem, which can process digital data and communicate with transceiver202such that the digital data is sent and received using transceiver202. In an aspect, modem240can be multiband and be configured to support multiple frequency bands for a specific communications protocol. In an aspect, modem240can be multimode and be configured to support multiple operating networks and communications protocols. In an aspect, modem240can control one or more components of UE104(e.g., RF front end288, transceiver202) to enable transmission and/or reception of signals from the network based on a specified modem configuration. In an aspect, the modem configuration can be based on the mode of the modem and the frequency band in use. In another aspect, the modem configuration can be based on UE configuration information associated with UE104as provided by the network during cell selection and/or cell reselection. In an aspect, communicating component242can optionally include one or more of a CSI component252for generating CSI for transmitting to a UE in SL communications or processing CSI received from a UE in SL communications, a timeline component254for determining a CSI transmission timeline by which to transmit or receive the CSI, and/or an expiring component256for determining whether CSI is expired prior to transmitting or receiving the CSI, as described herein. In an aspect, the processor(s)212may correspond to one or more of the processors described in connection with the UE inFIG.15. Similarly, the memory216may correspond to the memory described in connection with the UE inFIG.15. Referring toFIG.3, one example of an implementation of base station102(e.g., a base station102and/or gNB180, as described above) may include a variety of components, some of which have already been described above, but including components such as one or more processors312and memory316and transceiver302in communication via one or more buses344, which may operate in conjunction with modem340and configuring component342for configuring UEs with resources or resource pools, CSI transmission timelines, etc. for transmitting or receiving CSI over the physical feedback channel, as described herein. The transceiver302, receiver306, transmitter308, one or more processors312, memory316, applications375, buses344, RF front end388, LNAs390, switches392, filters396, PAs398, and one or more antennas365may be the same as or similar to the corresponding components of UE104, as described above, but configured or otherwise programmed for base station operations as opposed to UE operations. In an aspect, configuring component342can optionally include a timeline configuring component352for configuring one or more UEs with a CSI transmission timeline or other parameters related to transmitting CSI over a physical sidelink channel, as described herein. In an aspect, the processor(s)312may correspond to one or more of the processors described in connection with the base station inFIG.15. Similarly, the memory316may correspond to the memory described in connection with the base station inFIG.15. FIG.4illustrates a flow chart of an example of a method400for transmitting, by a SL receiving UE, CSI to a SL transmitting UE that transmits SL communications to the SL receiving UE. In an example, a UE (e.g., UE104-b, as a SL receiving UE in sidelink communications) can perform the functions described in method400using one or more of the components described inFIGS.1and2. In method400, at Block402, a SL receiving UE104-bcan receive, from a transmitting UE in SL communications, a SL transmission. In an aspect, communicating component242, e.g., in conjunction with processor(s)212, memory216, transceiver202, etc., can receive, from the transmitting UE (e.g., SL transmitting UE104-a) in SL communications, the SL transmission. For example, a base station102can configure resources or a resource pool for SL communications. In this example, the SL transmitting UE104-acan transmit SL communications over the resources, or SL resources selected from the resource pool, and SL receiving UE104-bcan receive the SL communications over the resources. The SL communications can include data transmitted over a PSSCH, control data for the PSSCH data transmitted over a PSCCH, a DMRS or LLRs for the data transmitted over the PSSCH (or DMRS or LLRs for the control data transmitted over PSCCH), a CSI-RS or other reference signal, etc. In method400, at Block404, the SL receiving UE104-bcan generate CSI for the SL transmission. In an aspect, CSI component252, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, etc., can generate the CSI for the SL transmission. For example, CSI component252can generate the CSI based on the received SL transmission to indicate a channel state determined from signal properties of the SL transmission. In an example, CSI component252can generate the CSI for the SL transmitting UE104-ato use in adjusting parameters for transmitting SL communications to the SL receiving UE104-b, granting SL resources to the SL receiving UE104-b, and/or the like. In method400, at Block406, the SL receiving UE104-bcan transmit, to the transmitting UE and based on a CSI transmission timeline, the CSI over a PSFCH. In an aspect, CSI component252, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, timeline component254, etc., can transmit, to the transmitting UE (e.g., SL transmitting UE104-a) and based on the CSI transmission time, which can be determined by timeline component254, the CSI over a PSFCH. For example, as transmission of SL communications and reporting of corresponding CSI may be periodic, CSI component252can transmit the CSI based on a CSI transmission timeline that allows sufficient time to process received SL communications and generate CSI and/or can allow for determining a next opportunity for transmitting the CSI over the feedback channel (e.g., PSFCH). In one example, in transmitting the CSI at Block406, optionally at Block408, the SL receiving UE104-bcan transmit the CSI in PSFCH resources that are after a minimum time gap from resources over which the SL transmission is received. In an aspect, CSI component252, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, timeline component254, etc., can transmit the CSI in the PSFCH resources that are after a minimum time gap from resources over which the SL transmission is received. For example, CSI component252can determine the PSFCH resources based on information received from the SL transmitting UE104-a, base station102, etc., which may indicate resources for transmitting PSFCH. For example, CSI component252can determine the PSFCH resources as occurring from at least an offset from receiving the SL communications (e.g., a slot offset of a number of slots from a slot during which the SL communications are received). In addition, in an example, timeline component254can determine the CSI transmission timeline for transmitting the CSI, which may be based on the minimum time gap, based on other considerations, such as determining resources after the minimum time gap that are indicated as, or otherwise reserved for, transmitting CSI (whether over PSFCH or other resources), etc. In an example, the minimum time gap may be similar to (e.g., equal to), less than, or greater than a feedback minimum time gap for transmitting HARQ feedback for the SL communications, as described further herein. In an example, a timeline for CSI from a physical channel can be defined so that the UEs (e.g., the SL receiving UE104-band/or SL transmitting UE104-a) can determine if a CSI is transmitted in a next available CSI carrier (e.g., which may include the next available PSFCH resources) or not. For example, the physical channel may include PSSCH and/or corresponding DMRS or LLRs, CSI-RS, etc. In an example, if the CSI carrier is PSFCH (e.g., if timeline component254determines that the CSI carrier is PSFCH, such as next PSFCH resources), a MinTimeGap_CSI_in_PSFCH can be set or determined as a function of the SL receiving UE104-bcapability to compute the CSI from PSSCH or from CSI-RS (which may be of different minimum time in general). For example, for PSSCH-based CSI, timeline component254can set or determine the minimum time gap as MinTimeGap_CSI_in_PSFCH_PSSCH_based. For example, if CSI is from a DMRS or LLRs associated with the PSSCH (or associated with a corresponding PSCCH), the minimum time gap MinTimeGap_CSI_in_PSFCH_PSSCH_based may be lower than the feedback timing gap (e.g., HARQ-ACK MinTimeGapPSFCH). For example, DMRS or LLRs may be from sidelink control information (SCI)-1(PSCCH) or from PSSCH or both. In another example, if CSI is from PSSCH data tones (and/or decoder statistics, which may include a number of iterations, input/output LLRs, number of unsatisfied parity checks, etc.), MinTimeGap_CSI_in_PSFCH_PSSCH_based may be higher than the feedback timing gap (e.g., HARQ-ACK MinTimeGapPSFCH). In another example, for CSI-RS-based CSI (where CSI is from CSI-RS), the minimum time gap for reporting CSI via PSFCH, MinTimeGap_CSI_in_PSFCH_CSI-RS_based, can be larger than MinTimeGap_CSI_in_PSFCH_PSSCH_based for PSSCH-based CSI. As CSI is transmitted in PSFCH, and PSFCH has certain periodicity, timeline component254can determine the timeline for transmitting PSFCH, as opposed to conventional CSI transmitted in MAC-CE, where there may not be a minimum time gap for CSI computation based on CSI-RS. In method400, optionally at Block410, the SL receiving UE104-bcan determine whether CSI is expired, and/or can transmit the CSI based on determining that CSI is not expired. In an aspect, expiring component256, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, etc., can determine whether the CSI is expired and/or can transmit the CSI based on determining that the CSI is not expired. For example, as the resources over which to transmit CSI may be periodic, the CSI may become stale and may be expired so that the SL transmitting UE104-adoes not process or consider old CSI. In an example, CSI aging can be taken into account by considering an expiry/bound time. For example, SL receiving UE104-bcan use a CSI expiration timer parameter, CSI_PSSCH_expiry_timer, to determine whether the CSI is expired. For example, expiring component256can initialize a CSI expiration timer based on the parameter value, and if the CSI expiration timer expires, CSI component252can determine to not transmit the CSI. In an example, CSI_PSSCH_expiry_timer may be the same as, or may have the same value as. the CSI-RS-based CSI parameter sl-LatencyBound-CSI-Report, and thus may be this parameter or a newly defined parameter. In an example, SL receiving UE104-bcan use sl-LatencyBound-CSI-Report to determine whether to discard the CSI generated from PSSCH (e.g., at Block404). In another example, CSI component252can cancel or expire the CSI transmission by configuration where the base station102(e.g., using downlink control information (DCI) or radio resource control (RRC)/MAC-CE signaling) or the SL transmitting UE104-a(e.g., using SCI) can indicate to the SL receiving UE104-bwhen a CSI is to be cancelled. For example, this information can be in terms of time slots (e.g., as indicated by a parameter, such as CSI_PSSCH_expiry_timer), which may be set using PC-5-RRC, PC5-MAC-CE, DCI (e.g., from base station102) or SCI (e.g., from the SL transmitting UE104-a), etc. In yet another example, expiration of CSI can be associated with PSFCH periodicity per resource pool. In this example, CSI may be determined as expired, or otherwise to be cancelled, if the periodicity of PSFCH is higher than X slots, where X can be configured by the base station102, SL transmitting UE104-a, etc. using PC5-RRC, PC5-MAC-CE, DCI, SCI, etc. In yet another example, expiration time may be dynamic in a way that CSI is determined to be expired or otherwise is cancelled immediately if it cannot be sent on the same PSFCH resource that carries the HARQ-ACK (e.g., based on the minimum time gap). In method400, optionally at Block412, the SL receiving UE104-bcan receive one or more parameters related to expiring CSI. In an aspect, expiring component256, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, etc., can receive the one or more parameters (e.g., from SL transmitting UE104-a, base station102, etc.) related to expiring CSI. For example, the one or more parameters can include a value for initializing the CSI expiration timer for aperiodic CSI reporting, such as sl-LatencyBound-CSI-Report, which may be defined for legacy UEs that may not support transmitting CSI over PSFCH resources, or a more general parameter, such as a CSI_PSSCH_expiry_timer, etc. In another example, the one or more parameters may include the PSFCH periodicity per resource pool or parameters for determining when to expire CSI based on the PSFCH periodicity. In another example, the one or more parameters may include an indication to expire CSI if it cannot be sent on the same PSFCH resource that carries the HARQ-ACK. In an example, expiring component256can receive the one or more parameters in RRC signaling, MAC-CE, DCI, SCI, etc., as described above and further herein. FIGS.7-10illustrate various examples of transmitting CSI based on a minimum time gap and/or an expiration timer. FIG.7illustrates an example of a CSI transmission timeline700where CSI can be transmitted in PSFCH resources. According to CSI transmission timeline700, a SL receiving UE104-bcan receive a SL communication702for which HARQ-ACK and CSI can be generated. Based on PSFCH resources704occurring after the feedback minimum time gap, MinTimeGapPSFCH, SL receiving UE104-bcan transmit the HARQ-ACK for the SL communication702in PSFCH resources704. For CSI, however, as the PSFCH resources do not occur after the minimum time gap for transmitting CSI, MinTimeGap_CSI_in_PSFCH, SL receiving UE104-bcan refrain from transmitting CSI in PSFCH resources704and can instead wait for PSFCH resources706occurring after MinTimeGap_CSI_in_PSFCH. This can be despite another SL communication having been received at708. In addition, SL receiving UE104-bcan determine to transmit CSI in PSFCH resources706based on the expiration timer, CSI_PSSCH_expiry_timer, having not expired before PSFCH resources706. FIG.8illustrates an example of a CSI transmission timeline800where CSI is not transmitted in PSFCH resources. According to CSI transmission timeline800, a SL receiving UE104-bcan receive a SL communication802for which HARQ-ACK and CSI can be generated. Based on PSFCH resources804occurring after the feedback minimum time gap, MinTimeGapPSFCH, SL receiving UE104-bcan transmit the HARQ-ACK for the SL communication802in PSFCH resources804. For CSI, however, as the PSFCH resources do not occur after the minimum time gap for transmitting CSI, MinTimeGap_CSI_in_PSFCH, SL receiving UE104-bcan refrain from transmitting CSI in PSFCH resources804and can instead wait for PSFCH resources806occurring after MinTimeGap_CSI_in_PSFCH. This can be despite another SL communication having been received at808. SL receiving UE104-bcan determine, however, to refrain from transmitting CSI in PSFCH resources806based on the expiration timer, CSI_PSSCH_expiry_timer, expiring before PSFCH resources806. In this example, SL receiving UE104-bcan cancel or delete, etc., the CSI. FIG.9illustrates an example of a CSI transmission timeline900where CSI can be transmitted in PSFCH resources earlier than HARQ-ACK feedback. According to CSI transmission timeline900, a SL receiving UE104-bcan receive a SL communication902for which HARQ-ACK and CSI can be generated. Based on PSFCH resources904occurring after the minimum time gap, MinTimeGap_CSI_in_PSFCH, SL receiving UE104-bcan transmit the CSI for the SL communication902in PSFCH resources904. For HARQ-ACK, however, as the PSFCH resources do not occur after the feedback minimum time gap, MinTimeGapPSFCH SL receiving UE104-bcan refrain from transmitting HARQ-ACK in PSFCH resources904and can instead wait for PSFCH resources906occurring after MinTimeGapPSFCH. FIG.10illustrates an example of a CSI transmission timeline1000where CSI can be transmitted in PSFCH resources along with HARQ-ACK feedback. According to CSI transmission timeline1000, a SL receiving UE104-bcan receive a SL communication1002for which HARQ-ACK and CSI can be generated. Based on PSFCH resources1004occurring after the minimum time gap, MinTimeGap_CSI_in_PSFCH, and feedback minimum time gap, MinTimeGapPSFCH, SL receiving UE104-bcan transmit the CSI and HARQ-ACK for the SL communication1002in PSFCH resources1004, without necessarily transmitting in PDFCH resources1008. In some examples, it may be possible that CSI transmitted in PSFCH resources by one SL receiving UE104-bmay collide with HARQ-ACK transmitted in the same PSFCH resource by another SL receiving UE.FIG.11illustrates an example of a CSI transmission timeline1100where one UE can transmit CSI in PSFCH resources that collides with another UE transmitting HARQ-ACK feedback in the PSFCH resources. According to CSI transmission timeline1100, a SL receiving UE104-b(e.g., UE1) can receive a SL communication1102for which HARQ-ACK and CSI can be generated. Based on PSFCH resources1104occurring after the feedback minimum time gap, MinTimeGapPSFCH, SL receiving UE104-bcan transmit the HARQ-ACK for the SL communication1102in PSFCH resources1104. For CSI, however, as the PSFCH resources do not occur after the minimum time gap for transmitting CSI, MinTimeGap_CSI_in_PSFCH, SL receiving UE104-bcan refrain from transmitting CSI in PSFCH resources1104and can instead wait for PSFCH resources1108occurring after MinTimeGap_CSI_in_PSFCH. In an example, however, PSFCH resources1108may be used by a second UE (e.g., UE2) for transmitting HARQ-ACK feedback for another SL communication1106received by the second UE. This can generate a collision between the CSI and HARQ-ACK transmissions of UE1 and UE2. To avoid such collision, in an example, PSFCH resources used for CSI may be separately configured, where the UEs can use these separately configured resources to send CSI reports. For example, the separately configured PSFCH resources can have their own periodicity and/or configuration parameters per resource pool (e.g., separate from the periodicity and/or configuration parameters of PSFCH resources for HARQ-ACK or other feedback). In method400, optionally at Block414, the SL receiving UE104-bcan receive a configuration defining one or more parameters of PSFCH resources over which to transmit CSI. In an aspect, CSI component252, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, timeline component254, etc., can receive the configuration (e.g., from SL transmitting UE104-a, base station102, etc.) defining the one or more parameters of PSFCH resources over which to transmit CSI. As described, for example, the configuration can indicate the PSFCH resources for CSI separately (e.g., as separated in time) from PSFCH resources for HARQ-ACK. An example is illustrated inFIG.12. FIG.12illustrates an example of a CSI transmission timeline1200where one UE can transmit CSI in PSFCH resources that are separately configured for CSI. According to CSI transmission timeline1200, a SL receiving UE104-b(e.g., UE1) can receive a SL communication1202for which HARQ-ACK and CSI can be generated. Based on PSFCH resources1204occurring after the feedback minimum time gap, MinTimeGapPSFCH, SL receiving UE104-bcan transmit the HARQ-ACK for the SL communication1202in PSFCH resources1204. For CSI, however, as the PSFCH resources do not occur after the minimum time gap for transmitting CSI, MinTimeGap_CSI_in_PSFCH, SL receiving UE104-bcan refrain from transmitting CSI in PSFCH resources1204and can instead wait for later occurring PSFCH resources, which can include PSFCH resources1206that are separately configured for transmitting CSI. In this example, PSFCH resources1208can be configured for transmitting HARQ-ACK, and PSFCH resource1206can be configured separately from the HARQ-ACK PSFCH resources for transmitting CSI. In an example, using the separately configured PSFCH resources1206can avoid collision with PSFCH resources1208used by a second UE (e.g., UE2) for transmitting HARQ-ACK feedback for another SL communication1210received by the second UE. FIG.13illustrates an example of resource allocations1300,1310that define PSFCH resources for CSI that are separate from PSFCH resources for HARQ-ACK. For example, resource allocation1300includes a plurality of symbols in a slot, including two symbols1302reserved for PSFCH, with gap symbols on either side, where gap symbols may not include transmissions. When defining PSFCH resources for CSI, the PSFCH resources1302can be maintained so legacy UEs that may not have the capability to transmit CSI over PSFCH can use the PSFCH resources for HARQ-ACK, and UEs configured for transmitting CSI over PSFCH can use newly defined PSFCH resources for CSI. Resource allocation1310illustrates one example of PSFCH resources for CSI including symbols1302for PSFCH for HARQ-ACK, which may include one AGC symbol, and also symbols1312for PSFCH for CSI, which may also include one AGC symbol. In an example, CSI component252can receive the configuration defining the one or more parameters of the PSFCH resources for CSI (e.g., an indication of symbols over which to transmit CSI in PSFCH) from the base station102or SL transmitting UE104-a, which may be received in RRC signalling, MAC-CE, DCI, SCI, etc. In method400, optionally at Block416, the SL receiving UE104-bcan receive, from the transmitting UE, a retransmission of the SL transmission having a same phase coherency and QCL (e.g., as the SL transmission received at Block402). In an aspect, CSI component252, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, timeline component254, etc., can receive, from the transmitting UE (e.g., SL transmitting UE104-a), the retransmission of the SL transmission having the same phase coherency and QCL. For example, the SL transmitting UE104-acan maintain the phase coherency and QCL across the SL transmission and one or multiple retransmissions of the same TB. This may be based on a capability of the SL transmitting UE104-aof maintaining QCL and phase coherency. In an example, the SL transmitting UE104-amay indicate that retransmissions are to have the same phase coherency and QCL in the first slot carrying the TB. In examples described above, the SL receiving UE104-bcan cancel CSI when the CSI is not transmitted before a retransmission of a TB. In the above example, if second transmission starts before the PSFCH scheduled to be used to carry the CSI, then this CSI can be canceled and perhaps replaced with the new CSI obtained from the new PSSCH. In one example, transmitting the CSI can be based on determining that transmitting the CSI for the sidelink transmission can occur before receiving the retransmission of the sidelink transmission. FIG.14illustrates an example of a CSI transmission timeline1400where phase coherency and QCL can be maintained over sidelink transmissions. According to CSI transmission timeline1400, a SL receiving UE104-bcan receive a SL communications1402,1404,1406of the same TB using the same phase coherency and/or QCL across the SL communications1402,1404,1406. In this regard, for example, CSI may remain valid over the SL communications that use the same phase coherency and/or QCL, which can allow for later reporting without necessarily expiring the CSI. FIG.5illustrates a flow chart of an example of a method500for receiving, by a SL transmitting UE, CSI from a SL receiving UE that receives SL communications from the SL transmitting UE. In an example, a UE (e.g., UE104-a, as a SL transmitting UE in sidelink communications) can perform the functions described in method500using one or more of the components described inFIGS.1and2. In method500, at Block502, a SL transmitting UE104-acan transmit, to a receiving SL UE in SL communications, a SL transmission. In an aspect, communicating component242, e.g., in conjunction with processor(s)212, memory216, transceiver202, etc., can transmit, to the receiving UE (e.g., SL receiving UE104-b) in SL communications, the SL transmission. For example, a base station102can configure resources or a resource pool for SL communications. In this example, the SL transmitting UE104-acan transmit SL communications over the resources, or SL resources selected from the resource pool, and SL receiving UE104-bcan receive the SL communications over the resources. The SL communications can include data transmitted over a PSSCH, control data for the PSSCH data transmitted over a PSCCH, a DMRS or LLRs for the data transmitted over the PSSCH (or DMRS or LLRs for the control data transmitted over PSCCH), a CSI-RS or other reference signal, etc., as described. In method500, at Block504, the SL transmitting UE104-acan receive, from the receiving UE and based on a CSI transmission timeline, the CSI over a PSFCH. In an aspect, CSI component252, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, timeline component254, etc., can receiving, from the receiving UE (e.g., SL receiving UE104-b) and based on the CSI transmission time, which can be determined by timeline component254, the CSI over a PSFCH. For example, as transmission of SL communications and reporting of corresponding CSI may be periodic, CSI component252can receive the CSI based on a CSI transmission timeline that allows sufficient time for the SL receiving UE104-bto process received SL communications and generate CSI and/or can allow for determining a next opportunity for receiving the CSI over the feedback channel (e.g., PSFCH). In one example, in receiving the CSI at Block504, optionally at Block506, the SL transmitting UE104-acan receive the CSI in PSFCH resources that are after a minimum time gap from resources over which the SL transmission is transmitted. In an aspect, CSI component252, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, timeline component254, etc., can receive the CSI in the PSFCH resources that are after a minimum time gap from resources over which the SL transmission is transmitted. For example, CSI component252can determine the PSFCH resources based on information transmitted to the SL receiving UE104-bby the SL transmitting UE104-a, base station102, etc., which may indicate resources for reporting CSI over PSFCH. For example, CSI component252can determine the PSFCH resources as occurring from at least an offset from transmitting the SL communications (e.g., a slot offset of a number of slots from a slot during which the SL communications are transmitted). In addition, in an example, timeline component254can determine the CSI transmission timeline for transmitting the CSI, which may be based on the minimum time gap, based on other considerations, such as determining resources after the minimum time gap that are indicated as, or otherwise reserved for, receiving CSI (whether over PSFCH or other resources), etc. In an example, the minimum time gap may be similar to (e.g., equal to), less than, or greater than a feedback minimum time gap for receiving HARQ feedback for the SL communications, as described above. In an example, a timeline for CSI from a physical channel can be defined so that the UEs (e.g., the SL receiving UE104-band/or SL transmitting UE104-a) can determine if a CSI is transmitted in a next available CSI carrier (e.g., which may include the next available PSFCH resources) or not, as described. For example, the physical channel may include PSSCH and/or corresponding DMRS or LLRs, CSI-RS, etc. In an example, the minimum time gap can include one or more of a MinTimeGap_CSI_in_PSFCH, MinTimeGap_CSI_in_PSFCH_PSSCH_based, MinTimeGap_CSI_in_PSFCH_CSI-RS_based, etc., as described above. As described above, for example, the minimum time gap may be configured for the SL receiving UE104-b(e.g., by SL transmitting UE104-a, base station102, etc.). Where SL transmitting UE104-aconfigures the minimum time gap, it can be configured using SCI transmitted to the SL receiving UE104-b. In method500, optionally at Block508, the SL transmitting UE104-acan determine whether CSI is expired, and/or can receive the CSI based on determining that CSI is not expired. In an aspect, expiring component256, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, etc., can determine whether the CSI is expired and/or can receive the CSI based on determining that the CSI is not expired. For example, as the resources over which to transmit CSI may be periodic, the CSI may become stale and may be expired so that the SL transmitting UE104-adoes not process or consider old CSI. As described above, for example, this may be based on a CSI expiration timer, such as CSI_PSSCH_expiry_timer, which may be configured for the SL receiving UE104-b(e.g., by SL transmitting UE104-a, base station102, etc.). Where SL transmitting UE104-aconfigures the CSI expiration timer, it can be configured using SCI transmitted to the SL receiving UE104-b. In method500, optionally at Block510, the SL transmitting UE104-acan transmit one or more parameters related to expiring CSI. In an aspect, expiring component256, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, etc., can transmit the one or more parameters (e.g., to SL receiving UE104-b) related to expiring CSI. For example, the one or more parameters can include a value for initializing the CSI expiration timer (e.g., sl-LatencyBound-CSI-Report, CSI_PSSCH_expiry_timer, etc.). In another example, the one or more parameters may include the PSFCH periodicity per resource pool or parameters for determining when to expire CSI based on the PSFCH periodicity. In another example, the one or more parameters may include an indication to expire CSI if it cannot be sent on the same PSFCH resource that carries the HARQ-ACK. In an example, expiring component256can transmit the one or more parameters in RRC signaling, MAC-CE, DCI, SCI, etc., as described above and further herein. In method500, optionally at Block512, the SL transmitting UE104-acan transmit a configuration defining one or more parameters of PSFCH resources over which to transmit CSI. In an aspect, CSI component252, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, timeline component254, etc., can transmit the configuration (e.g., to SL receiving UE104-b) defining the one or more parameters of PSFCH resources over which to transmit CSI. As described, for example, the configuration can indicate the PSFCH resources for CSI separately from PSFCH resources for HARQ-ACK. In method500, optionally at Block514, the SL transmitting UE104-acan transmit, to the receiving UE, a retransmission of the SL transmission having a same phase coherency and QCL (e.g., as the SL transmission transmitted at Block502). In an aspect, CSI component252, e.g., in conjunction with processor(s)212, memory216, transceiver202, communicating component242, timeline component254, etc., can transmit, to the receiving UE (e.g., SL receiving UE104-b), the retransmission of the SL transmission having the same phase coherency and QCL. For example, the SL transmitting UE104-acan maintain the phase coherency and QCL across the SL transmission and one or multiple retransmissions of the same TB, as described. In an example, this may be based on a capability of the SL transmitting UE104-aof maintaining QCL and phase coherency, which may be indicated in the first slot carrying the TB. FIG.6illustrates a flow chart of an example of a method600for configuring SL UEs to communicate CSI using PSFCH resources. In an example, a base station (e.g., base station102) can perform the functions described in method600using one or more of the components described inFIGS.1and3. In method600, at Block602, the base station102can generate a configuration indicating resources to use in communicating CSI for sidelink transmission over a PSFCH. In an aspect, configuring component342, e.g., in conjunction with processor(s)312, memory316, transceiver302, timeline configuring component352, etc., can generate the configuration indicating resources to use in communicating CSI for sidelink transmissions over a PSFCH. For example, configuring component342can generate the configuration to indicate resources or a resource pool for PSFCH and/or whether the resources or resource pool can be used for CSI. In another example, configuring component342can generate the configuration to indicate resources for HARQ-ACK, or other feedback, and separate PSFCH resources for CSI. In addition, for example, timeline configuring component352can include, in the configuration or a separate configuration, one or more parameters related to a CSI transmission timeline for transmitting CSI in PSFCH resources, such as a minimum time gap, a CSI expiration timer value, etc. As described above, the expiration time may be defined for aperiodic CSI reporting (e.g., a sl-LatencyBound-CSI-Report, or another parameter). In another example, the expiration time may correspond to a periodicity for transmitting over the PSFCH per resource pool available for sidelink transmissions. In another example, the configuration can indicate PSFCH resources reserved for transmitting the CSI over the PSFCH that are separated, in time, from feedback PSFCH resources reserved for transmitting HARQ-ACK feedback for the sidelink transmissions, where the feedback PSFCH resources may include PSFCH resources indicated in a last two symbols of a slot corresponding to the sidelink transmissions, and the PSFCH resources for CSI may be other symbols in the slot. In method600, at Block604, the base station102can transmit the configuration to at least one transmitting UE and/or one receiving UE that communicate with one another in sidelink communications. In an aspect, configuring component342, e.g., in conjunction with processor(s)312, memory316, transceiver302, etc., can transmit the configuration to at least one transmitting UE and/or receiving UE that communicate with one another in sidelink communications. In this example, the SL transmitting UE104-aand/or SL receiving UE104-b, as described above, can receive the configuration and determine one or more of resources or a resource pool for communicating CSI over PSFCH resources, a CSI transmission timeline based on which to transmit CSI over PSFCH resources, an expiration time for expiring CSI that is to be transmitted over PSFCH resources, etc. FIG.15is a block diagram of a MIMO communication system1500including a base station102and a UE104, in accordance with various aspects of the present disclosure. The MIMO communication system1500may illustrate aspects of the wireless communication access network100described with reference toFIG.1. The base station102may be an example of aspects of the base station102described with reference toFIG.1. In addition, the UE104can communicate with another UE over sidelink resources using similar functionality described herein with respect to UE104and base station102communications, and as such, base station102could be another UE104having a communicating component242. The base station102may be equipped with antennas1534and1535, and the UE104may be equipped with antennas1552and1553. In the MIMO communication system1500, the base station102may be able to send data over multiple communication links at the same time. Each communication link may be called a “layer” and the “rank” of the communication link may indicate the number of layers used for communication. For example, in a 2×2 MIMO communication system where base station102transmits two “layers,” the rank of the communication link between the base station102and the UE104is two. At the base station102, a transmit (Tx) processor1520may receive data from a data source. The transmit processor1520may process the data. The transmit processor1520may also generate control symbols or reference symbols. A transmit MIMO processor1530may perform spatial processing (e.g., precoding) on data symbols, control symbols, or reference symbols, if applicable, and may provide output symbol streams to the transmit modulator/demodulators1532and1533. Each modulator/demodulator1532through1533may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator/demodulator1532through1533may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a DL signal. In one example, DL signals from modulator/demodulators1532and1533may be transmitted via the antennas1534and1535, respectively. The UE104may be an example of aspects of the UEs104described with reference toFIGS.1-2. At the UE104, the UE antennas1552and1553may receive the DL signals from the base station102and may provide the received signals to the modulator/demodulators1554and1555, respectively. Each modulator/demodulator1554through1555may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each modulator/demodulator1554through1555may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector1556may obtain received symbols from the modulator/demodulators1554and1555, perform MIMO detection on the received symbols, if applicable, and provide detected symbols. A receive (Rx) processor1558may process (e.g., demodulate, deinterleave, and decode) the detected symbols, providing decoded data for the UE104to a data output, and provide decoded control information to a processor1580, or memory1582. The processor1580may in some cases execute stored instructions to instantiate a communicating component242(see e.g.,FIGS.1and2). On the uplink (UL), at the UE104, a transmit processor1564may receive and process data from a data source. The transmit processor1564may also generate reference symbols for a reference signal. The symbols from the transmit processor1564may be precoded by a transmit MIMO processor1566if applicable, further processed by the modulator/demodulators1554and1555(e.g., for SC-FDMA, etc.), and be transmitted to the base station102in accordance with the communication parameters received from the base station102. At the base station102, the UL signals from the UE104may be received by the antennas1534and1535, processed by the modulator/demodulators1532and1533, detected by a MIMO detector1536if applicable, and further processed by a receive processor1538. The receive processor1538may provide decoded data to a data output and to the processor1540or memory1542. The processor1540may in some cases execute stored instructions to instantiate a configuring component342(see e.g.,FIGS.1and3). The components of the UE104may, individually or collectively, be implemented with one or more application specific integrated circuits (ASICs) adapted to perform some or all of the applicable functions in hardware. Each of the noted modules may be a means for performing one or more functions related to operation of the MIMO communication system1500. Similarly, the components of the base station102may, individually or collectively, be implemented with one or more ASICs adapted to perform some or all of the applicable functions in hardware. Each of the noted components may be a means for performing one or more functions related to operation of the MIMO communication system1500. The following aspects are illustrative only and aspects thereof may be combined with aspects of other embodiments or teaching described herein, without limitation. Aspect 1 is a method for wireless communication by a receiving UE in sidelink communications including receiving, from a transmitting UE in sidelink communications, a sidelink transmission, generating CSI for the sidelink transmission, and transmitting, to the transmitting UE and based on a CSI transmission timeline, the CSI over a PSFCH. In Aspect 2, the method of Aspect 1 includes where the CSI transmission timeline is associated with a minimum time gap for transmitting the CSI after receiving the sidelink transmission, and where transmitting the CSI includes transmitting the CSI in PSFCH resources that are after the minimum time gap from resources over which the sidelink transmission is received. In Aspect 3, the method of Aspect 2 includes where the sidelink transmission is at least one of a PSSCH or PSCCH transmission, where generating the CSI is based on a DMRS or one or more LLRs of the PSSCH or PSCCH transmission, and where the minimum time gap is less than a feedback minimum time gap for transmitting HARQ feedback for the PSSCH or PSCCH transmission. In Aspect 4, the method of any of Aspects 2 or 3 includes where the sidelink transmission is at least one of a PSSCH or PSCCH transmission, and where the minimum time gap is greater than a feedback minimum time gap for transmitting HARQ feedback for the PSSCH or PSCCH transmission. In Aspect 5, the method of any of Aspects 1 to 4 includes where the sidelink transmission is a CSI-RS. In Aspect 6, the method of any of Aspects 1 to 5 includes where transmitting the CSI is based on an expiration time not expiring before transmitting the CSI. In Aspect 7, the method of Aspect 6 includes where the expiration time is defined for aperiodic CSI reporting. In Aspect 8, the method of any of Aspects 6 or 7 includes receiving an indication of the expiration time from the transmitting UE or from a base station in control information signaling, RRC signaling, or MAC-CE signaling. In Aspect 9, the method of any of Aspects 6 to 8 includes where the expiration time corresponds to a periodicity for transmitting over a PSFCH per resource pool available for sidelink transmissions. In Aspect 10, the method of any of Aspects 6 to 9 includes where the expiration time corresponds to a next PSFCH resource that carries HARQ feedback for the sidelink transmission. In Aspect 11, the method of any of Aspects 1 to 10 includes where PSFCH resources reserved for transmitting the CSI over the PSFCH are separated, in time, from feedback PSFCH resources reserved for transmitting HARQ feedback for the sidelink transmission. In Aspect 12, the method of Aspect 11 includes receiving a configuration defining one or more parameters of the PSFCH resources that is separate from a feedback configuration defining one or more other parameters of the feedback PSFCH resources, where the one or more parameters include at least a periodicity of the PSFCH resources per resource pool. In Aspect 13, the method of any of Aspects 11 or 12 includes where the feedback PSFCH resources are defined in a last two symbols of a slot corresponding to the sidelink transmission, and where the PSFCH resources are defined in one or more other symbols of the slot. In Aspect 14, the method of any of Aspects 1 to 13 includes receiving, from the transmitting UE, a retransmission of the sidelink transmission includes where the sidelink transmission and the retransmission have a same phase coherency and quasi-colocation. In Aspect 15, the method of Aspect 14 includes where transmitting the CSI is based on determining that transmitting the CSI for the sidelink transmission can occur before receiving the retransmission of the sidelink transmission. Aspect 16 is a method for wireless communication by a transmitting UE in sidelink communications including transmitting, to a receiving UE in sidelink communications, a sidelink transmission, and receiving, from the receiving UE and based on a CSI transmission timeline, the CSI over a PSFCH. In Aspect 17, the method of Aspect 16 includes where the CSI transmission timeline is associated with a minimum time gap for transmitting the CSI after receiving the sidelink transmission, and where receiving the CSI includes receiving the CSI in PSFCH resources that are after the minimum time gap from resources over which the sidelink transmission is transmitted. In Aspect 18, the method of Aspect 17 includes where the sidelink transmission is at least one of a PSSCH or PSCCH transmission, where the CSI transmission timeline is based on a DMRS or one or more LLRs of the PSSCH or PSCCH transmission, and where the minimum time gap is less than a feedback minimum time gap for transmitting HARQ feedback for the PSSCH or PSCCH transmission. In Aspect 19, the method of any of Aspects 17 to 18 includes where the sidelink transmission is at least one of a PSSCH or PSCCH transmission, and where the minimum time gap is greater than a feedback minimum time gap for transmitting HARQ feedback for the PSSCH or PSCCH transmission. In Aspect 20, the method of any of Aspects 16 to 19 includes where the sidelink transmission is a CSI-RS. In Aspect 21, the method of any of Aspects 16 to 20 includes where receiving the CSI is based on determining that an expiration time does not expire before the receiving UE transmitted the CSI. In Aspect 22, the method of Aspect 21 includes where the expiration time is defined for aperiodic CSI reporting. In Aspect 23, the method of any of Aspects 21 or 22 includes transmitting an indication of the expiration time to the receiving UE in control information signaling. In Aspect 24, the method of any of Aspects 21 to 23 includes where the expiration time corresponds to a periodicity for transmitting over a PSFCH per resource pool available for sidelink transmissions. In Aspect 25, the method of any of Aspects 21 to 24 includes where the expiration time corresponds to a next PSFCH resource that carries HARQ feedback for the sidelink transmission. In Aspect 26, the method of any of Aspects 16 to 25 includes where PSFCH resources reserved for transmitting the CSI over the PSFCH are separated, in time, from feedback PSFCH resources reserved for transmitting HARQ feedback for the sidelink transmission. In Aspect 27, the method of Aspect 26 includes transmitting, to the receiving UE, a configuration defining one or more parameters of the PSFCH resources that is separate from a feedback configuration defining one or more other parameters of the feedback PSFCH resources, where the one or more parameters include at least a periodicity of the PSFCH resources per resource pool. In Aspect 28, the method of any of Aspects 26 or 27 includes where the feedback PSFCH resources are defined in a last two symbols of a slot corresponding to the sidelink transmission, and where the PSFCH resources are defined in one or more other symbols of the slot. In Aspect 29, the method of any of Aspects 16 to 28 includes transmitting, to the receiving UE, a retransmission of the sidelink transmission, where the sidelink transmission and the retransmission have a same phase coherency and quasi-colocation. In Aspect 30, the method of Aspect 29 includes where receiving the CSI is based on determining that receiving the CSI for the sidelink transmission can occur before transmitting the retransmission of the sidelink transmission. Aspect 31 is a method for wireless communication by a base station including generating a configuration indicating resources to use in communicating CSI for sidelink transmissions over a PSFCH, and transmitting the configuration to at least one transmitting UE and one receiving UE that communicate with one another in sidelink communications. In Aspect 32, the method of Aspect 31 includes where the configuration indicates a minimum time gap for transmitting the CSI over the PSFCH after receiving a sidelink transmission based on which the CSI is generated. In Aspect 33, the method of any of Aspects 31 or 32 includes where the configuration indicates an expiration time before which the CSI can be transmitted over the PSFCH after receiving a sidelink transmission based on which the CSI is generated. In Aspect 34, the method of Aspect 33 includes where the expiration time is defined for aperiodic CSI reporting. In Aspect 35, the method of any of Aspects 33 or 34 includes where the expiration time corresponds to a periodicity for transmitting over the PSFCH per resource pool available for sidelink transmissions. In Aspect 36, the method of any of Aspects 31 to 35 includes where the configuration indicates PSFCH resources reserved for transmitting the CSI over the PSFCH that are separated, in time, from feedback PSFCH resources reserved for transmitting HARQ feedback for the sidelink transmissions. In Aspect 37, the method of Aspect 36 includes where the feedback PSFCH resources are indicated in a last two symbols of a slot corresponding to the sidelink transmissions, and where the PSFCH resources are indicated in one or more other symbols of the slot. In Aspect 38, the method of any of Aspects 31 to 37 includes where transmitting the configuration comprises transmitting the configuration using downlink control information signaling, RRC signaling, or MAC-CE signaling. Aspect 39 is an apparatus for wireless communication including a transceiver, a memory configured to store instructions, and one or more processors communicatively coupled with the memory and the transceiver, where the one or more processors are configured to execute the instructions to cause the apparatus to perform one or more of the methods of any of Aspects 1 to 37. Aspect 40 is an apparatus for wireless communication including means for performing one or more of the methods of any of Aspects 1 to 37. Aspect 41 is a computer-readable medium including code executable by one or more processors for wireless communications, the code including code for performing one or more of the methods of any of Aspects 1 to 37. The above detailed description set forth above in connection with the appended drawings describes examples and does not represent the only examples that may be implemented or that are within the scope of the claims. The term “example,” when used in this description, means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and apparatuses are shown in block diagram form in order to avoid obscuring the concepts of the described examples. Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, computer-executable code or instructions stored on a computer-readable medium, or any combination thereof. The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a specially programmed device, such as but not limited to a processor, a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination thereof designed to perform the functions described herein. A specially programmed processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A specially programmed processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The functions described herein may be implemented in hardware, software, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a non-transitory computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a specially programmed processor, hardware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Moreover, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase, for example, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, for example the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (A and B and C). Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media. The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the common principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Furthermore, although elements of the described aspects and/or embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect and/or embodiment may be utilized with all or a portion of any other aspect and/or embodiment, unless stated otherwise. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | 90,238 |
11943029 | DETAILED DESCRIPTION Some embodiments of the present invention are described in detail with reference to the accompanying drawings. A detailed description to be disclosed along with the accompanying drawings are intended to describe some embodiments of the present invention and are not intended to describe a sole embodiment of the present invention. The following detailed description includes more details in order to provide full understanding of the present invention. However, those skilled in the art will understand that the present invention may be implemented without such more details. In some cases, in order to avoid that the concept of the present invention becomes vague, known structures and devices are omitted or may be shown in a block diagram form based on the core functions of each structure and device. In this specification, a base station has the meaning of a terminal node of a network over which the base station directly communicates with a device. In this document, a specific operation that is described to be performed by a base station may be performed by an upper node of the base station according to circumstances. That is, it is evident that in a network including a plurality of network nodes including a base station, various operations performed for communication with a device may be performed by the base station or other network nodes other than the base station. The base station (BS) may be substituted with another term, such as a fixed station, a Node B, an eNB (evolved-NodeB), a Base Transceiver System (BTS), or an access point (AP). Furthermore, the device may be fixed or may have mobility and may be substituted with another term, such as User Equipment (UE), a Mobile Station (MS), a User Terminal (UT), a Mobile Subscriber Station (MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), a Wireless Terminal (WT), a Machine-Type Communication (MTC) device, a Machine-to-Machine (M2M) device, or a Device-to-Device (D2D) device. Hereinafter, downlink (DL) means communication from an eNB to UE, and uplink (UL) means communication from UE to an eNB. In DL, a transmitter may be part of an eNB, and a receiver may be part of UE. In UL, a transmitter may be part of UE, and a receiver may be part of an eNB. Specific terms used in the following description have been provided to help understanding of the present invention, and the use of such specific terms may be changed in various forms without departing from the technical sprit of the present invention. The following technologies may be used in a variety of wireless communication systems, such as Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), and Non-Orthogonal Multiple Access (NOMA). CDMA may be implemented using a radio technology, such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented using a radio technology, such as Global System for Mobile communications (GSM)/General Packet Radio Service (GPRS)/Enhanced Data rates for GSM Evolution (EDGE). OFDMA may be implemented using a radio technology, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is part of a Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of an Evolved UMTS (E-UMTS) using evolved UMTS Terrestrial Radio Access (E-UTRA), and it adopts OFDMA in downlink and adopts SC-FDMA in uplink. LTE-Advanced (LTE-A) is the evolution of 3GPP LTE. Embodiments of the present invention may be supported by the standard documents disclosed in at least one of IEEE 802, 3GPP, and 3GPP2, that is, radio access systems. That is, steps or portions that belong to the embodiments of the present invention and that are not described in order to clearly expose the technical spirit of the present invention may be supported by the documents. Furthermore, all terms disclosed in this document may be described by the standard documents. In order to more clarify a description, 3GPP LTE/LTE-A is chiefly described, but the technical characteristics of the present invention are not limited thereto. General System to which the Present Invention May be Applied FIGS.1A and1Bshow the structure of a radio frame in a wireless communication system to which an embodiment of the present invention may be applied. 3GPP LTE/LTE-A support a radio frame structure type 1 which may be applicable to Frequency Division Duplex (FDD) and a radio frame structure which may be applicable to Time Division Duplex (TDD). The size of a radio frame in the time domain is represented as a multiple of a time unit of T_s=1/(15000*2048). A UL and DL transmission includes the radio frame having a duration of T_f=307200*T_s=10 ms. FIG.1Aexemplifies a radio frame structure type 1. The type 1 radio frame may be applied to both of full duplex FDD and half duplex FDD. A radio frame includes 10 subframes. A radio frame includes 20 slots of T_slot=15360*T_s=0.5 ms length, and 0 to 19 indexes are given to each of the slots. One subframe includes consecutive two slots in the time domain, and subframe i includes slot 2i and slot 2i+1. The time required for transmitting a subframe is referred to as a transmission time interval (TTI). For example, the length of the subframe i may be 1 ms and the length of a slot may be 0.5 ms. A UL transmission and a DL transmission I the FDD are distinguished in the frequency domain. Whereas there is no restriction in the full duplex FDD, a UE may not transmit and receive simultaneously in the half duplex FDD operation. One slot includes a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols in the time domain and includes a plurality of Resource Blocks (RBs) in a frequency domain. In 3GPP LTE, OFDM symbols are used to represent one symbol period because OFDMA is used in downlink. An OFDM symbol may be called one SC-FDMA symbol or symbol period. An RB is a resource allocation unit and includes a plurality of contiguous subcarriers in one slot. FIG.1Bshows frame structure type 2. A type 2 radio frame includes two half frame of 153600*T_s=5 ms length each. Each half frame includes 5 subframes of 30720*T_s=1 ms length. In the frame structure type 2 of a TDD system, an uplink-downlink configuration is a rule indicating whether uplink and downlink are allocated (or reserved) to all subframes. Table 1 shows the uplink-downlink configuration. TABLE 1Downlink-Uplink-to-UplinkDownlinkSwitch-pointSubframe numberconfigurationperiodicity012345678905 msDSUUUDSUUU15 msDSUUDDSUUD25 msDSUDDDSUDD310 msDSUUUDDDDD410 msDSUUDDDDDD510 msDSUDDDDDDD65 msDSUUUDSUUD Referring to Table 1, in each subframe of the radio frame, ‘13’ represents a subframe for a DL transmission, ‘U’ represents a subframe for UL transmission, and ‘S’ represents a special subframe including three types of fields including a Downlink Pilot Time Slot (DwPTS), a Guard Period (GP), and a Uplink Pilot Time Slot (UpPTS). A DwPTS is used for an initial cell search, synchronization or channel estimation in a UE. A UpPTS is used for channel estimation in an eNB and for synchronizing a UL transmission synchronization of a UE. A GP is duration for removing interference occurred in a UL owing to multi-path delay of a DL signal between a UL and a DL. Each subframe i includes slot 2i and slot 2i+1 of T_slot=15360*T_s=0.5 ms. The UL-DL configuration may be classified into 7 types, and the position and/or the number of a DL subframe, a special subframe and a UL subframe are different for each configuration. Table 2 represents configuration (length of DwPTS/GP/UpPTS) of a special subframe. TABLE 2Normal cyclic prefixExtended cyclic prefixin downlinkin downlinkUpPTSUpPTSSpecialNormalExtendedNormalExtendedsubframecyclic prefixcyclic prefixcyclic prefixcyclic prefixconfigurationDwPTSin uplinkin uplinkDwPTSin uplinkin uplink06592 · Ts2192 · Ts2560 · Ts7680 · Ts2192 · Ts2560 · Ts119760 · Ts20480 · Ts221952 · Ts23040 · Ts324144 · Ts25600 · Ts426336 · Ts7680 · T,4384 · Ts5120 · Ts56592 · Ts4384 · Ts5120 · Ts20480 · Ts619760 · Ts23040 · T,721952 · Ts———824144 · Ts——— The structure of a radio subframe according to the example ofFIGS.1A and1Bare just an example, and the number of subcarriers included in a radio frame, the number of slots included in a subframe and the number of OFDM symbols included in a slot may be changed in various manners. FIG.2is a diagram illustrating a resource grid for one downlink slot in a wireless communication system to which an embodiment of the present invention may be applied. Referring toFIG.2, one downlink slot includes a plurality of OFDM symbols in a time domain. It is described herein that one downlink slot includes 7 OFDMA symbols and one resource block includes 12 subcarriers for exemplary purposes only, and the present invention is not limited thereto. Each element on the resource grid is referred to as a resource element, and one resource block (RB) includes 12×7 resource elements. The number of RBs N{circumflex over ( )}DL included in a downlink slot depends on a downlink transmission bandwidth. The structure of an uplink slot may be the same as that of a downlink slot. FIG.3shows the structure of a downlink subframe in a wireless communication system to which an embodiment of the present invention may be applied. Referring toFIG.3, a maximum of three OFDM symbols located in a front portion of a first slot of a subframe correspond to a control region in which control channels are allocated, and the remaining OFDM symbols correspond to a data region in which a physical downlink shared channel (PDSCH) is allocated. Downlink control channels used in 3GPP LTE include, for example, a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), and a physical hybrid-ARQ indicator channel (PHICH). A PCFICH is transmitted in the first OFDM symbol of a subframe and carries information about the number of OFDM symbols (i.e., the size of a control region) which is used to transmit control channels within the subframe. A PHICH is a response channel for uplink and carries an acknowledgement (ACK)/not-acknowledgement (NACK) signal for a Hybrid Automatic Repeat Request (HARQ). Control information transmitted in a PDCCH is called Downlink Control Information (DCI). DCI includes uplink resource allocation information, downlink resource allocation information, or an uplink transmission (Tx) power control command for a specific UE group. FIG.4shows the structure of an uplink subframe in a wireless communication system to which an embodiment of the present invention may be applied. Referring toFIG.4, the uplink subframe may be divided into a control region and a data region in a frequency domain. A physical uplink control channel (PUCCH) carrying uplink control information is allocated to the control region. A physical uplink shared channel (PUSCH) carrying user data is allocated to the data region. In order to maintain single carrier characteristic, one UE does not send a PUCCH and a PUSCH at the same time. A Resource Block (RB) pair is allocated to a PUCCH for one UE within a subframe. RBs belonging to an RB pair occupy different subcarriers in each of 2 slots. This is called that an RB pair allocated to a PUCCH is frequency-hopped in a slot boundary. Multi-Input Multi-Output (MIMO) A MIMO technology does not use single transmission antenna and single reception antenna that have been commonly used so far, but uses a multi-transmission (Tx) antenna and a multi-reception (Rx) antenna. In other words, the MIMO technology is a technology for increasing a capacity or enhancing performance using multi-input/output antennas in the transmission end or reception end of a wireless communication system. Hereinafter, MIMO is called a “multi-input/output antenna.”. More specifically, the multi-input/output antenna technology does not depend on a single antenna path in order to receive a single total message and completes total data by collecting a plurality of data pieces received through several antennas. As a result, the multi-input/output antenna technology can increase a data transfer rate within a specific system range and can also increase a system range through a specific data transfer rate. It is expected that an efficient multi-input/output antenna technology will be used because next-generation mobile communication requires a data transfer rate much higher than that of existing mobile communication. In such a situation, the MIMO communication technology is a next-generation mobile communication technology which may be widely used in mobile communication UE and a relay node and has been in the spotlight as a technology which may overcome a limit to the transfer rate of another mobile communication attributable to the expansion of data communication. Meanwhile, the multi-input/output antenna (MIMO) technology of various transmission efficiency improvement technologies that are being developed has been most in the spotlight as a method capable of significantly improving a communication capacity and transmission/reception performance even without the allocation of additional frequencies or a power increase. FIG.5shows the configuration of a known MIMO communication system. Referring toFIG.5, if the number of transmission (Tx) antennas is increased to N_T and the number of reception (Rx) antennas is increased to N_R at the same time, a theoretical channel transmission capacity is increased in proportion to the number of antennas, unlike in the case where a plurality of antennas is used only in a transmitter or a receiver. Accordingly, a transfer rate can be improved, and frequency efficiency can be significantly improved. In this case, a transfer rate according to an increase of a channel transmission capacity may be theoretically increased by a value obtained by multiplying the following rate increment R_i by a maximum transfer rate R_o if one antenna is used. Ri=min(NT,NR) [Equation 1] That is, in an MIMO communication system using 4 transmission antennas and 4 reception antennas, for example, a quadruple transfer rate can be obtained theoretically compared to a single antenna system. Such a multi-input/output antenna technology may be divided into a spatial diversity method for increasing transmission reliability using symbols passing through various channel paths and a spatial multiplexing method for improving a transfer rate by sending a plurality of data symbols at the same time using a plurality of transmission antennas. Furthermore, active research is being recently carried out on a method for properly obtaining the advantages of the two methods by combining the two methods. Each of the methods is described in more detail below. First, the spatial diversity method includes a space-time block code-series method and a space-time Trelis code-series method using a diversity gain and a coding gain at the same time. In general, the Trelis code-series method is better in terms of bit error rate improvement performance and the degree of a code generation freedom, whereas the space-time block code-series method has low operational complexity. Such a spatial diversity gain may correspond to an amount corresponding to the product (N_T×N_R) of the number of transmission antennas (N_T) and the number of reception antennas (N_R). Second, the spatial multiplexing scheme is a method for sending different data streams in transmission antennas. In this case, in a receiver, mutual interference is generated between data transmitted by a transmitter at the same time. The receiver removes the interference using a proper signal processing scheme and receives the data. A noise removal method used in this case may include a Maximum Likelihood Detection (MLD) receiver, a Zero-Forcing (ZF) receiver, a Minimum Mean Square Error (MMSE) receiver, Diagonal-Bell Laboratories Layered Space-Time (D-BLAST), and Vertical-Bell Laboratories Layered Space-Time (V-BLAST). In particular, if a transmission end can be aware of channel information, a Singular Value Decomposition (SVD) method may be used. Third, there is a method using a combination of a spatial diversity and spatial multiplexing. If only a spatial diversity gain is to be obtained, a performance improvement gain according to an increase of a diversity disparity is gradually saturated. If only a spatial multiplexing gain is used, transmission reliability in a radio channel is deteriorated. Methods for solving the problems and obtaining the two gains have been researched and may include a double space-time transmit diversity (double-STTD) method and a space-time bit interleaved coded modulation (STBICM). In order to describe a communication method in a multi-input/output antenna system, such as that described above, in more detail, the communication method may be represented as follows through mathematical modeling. First, as shown inFIG.5, it is assumed that N_T transmission antennas and NR reception antennas are present. First, a transmission signal is described below. If the N_T transmission antennas are present as described above, a maximum number of pieces of information which can be transmitted are N_T, which may be represented using the following vector. s=└s1,s2, . . . ,sNT[Equation 2] Meanwhile, transmission power may be different in each of pieces of transmission information s_1, s_2, . . . , s_NT. In this case, if pieces of transmission power are P_1, P_2, . . . , P_NT, transmission information having controlled transmission power may be represented using the following vector. ŝ=[ŝ1,ŝ2, . . . ,ŝNT]T=[P1s1,P2s2, . . . ,PNTsNT]T[Equation 3] Furthermore, transmission information having controlled transmission power in the Equation 3 may be represented as follows using the diagonal matrix P of transmission power. s^=[P10P2⋱0PNT][s1s2⋮sNT]=Ps[Equation4] Meanwhile, the information vector having controlled transmission power in the Equation 4 is multiplied by a weight matrix W, thus forming N_T transmission signals x_1, x_2, . . . , x_NT that are actually transmitted. In this case, the weight matrix functions to properly distribute the transmission information to antennas according to a transport channel condition. The following may be represented using the transmission signals x_1, x_2, . . . , x_NT. x=[x1x2⋮xi⋮xNT]=[w11w12…w1NTw21w22…w2NT⋮⋱wi1wi2…wiNT⋮⋱wNT1wNT2…wNTNT][s^1s^2⋮s^j⋮s^NT]=Ws^=WPs[Equation5] In this case, w_ij denotes weight between the i-th transmission antenna and the j-th transmission information, and W is an expression of a matrix of the weight. Such a matrix W is called a weight matrix or precoding matrix. Meanwhile, the transmission signal x, such as that described above, may be considered to be used in a case where a spatial diversity is used and a case where spatial multiplexing is used. If spatial multiplexing is used, all the elements of the information vector s have different values because different signals are multiplexed and transmitted. In contrast, if the spatial diversity is used, all the elements of the information vector s have the same value because the same signals are transmitted through several channel paths. A method of mixing spatial multiplexing and the spatial diversity may be taken into consideration. In other words, the same signals may be transmitted using the spatial diversity through 3 transmission antennas, for example, and the remaining different signals may be spatially multiplexed and transmitted. If N_R reception antennas are present, the reception signals y_1, y_2, . . . , y_NR of the respective antennas are represented as follows using a vector y. y=[y1,y2, . . . ,yNR]T[Equation 6] Meanwhile, if channels in a multi-input/output antenna communication system are modeled, the channels may be classified according to transmission/reception antenna indices. A channel passing through a reception antenna i from a transmission antenna j is represented as h_ij. In this case, it is to be noted that in order of the index of h_ij, the index of a reception antenna comes first and the index of a transmission antenna then comes. Several channels may be grouped and expressed in a vector and matrix form. For example, a vector expression is described below. FIG.6is a diagram showing a channel from a plurality of transmission antennas to a single reception antenna. As shown inFIG.6, a channel from a total of N_T transmission antennas to a reception antenna i may be represented as follows. hiT=└hi1,hi2, . . . ,hiNT┘ [Equation 7] Furthermore, if all channels from the N_T transmission antenna to NR reception antennas are represented through a matrix expression, such as Equation 7, they may be represented as follows. H=[h1Th2T⋮hiT⋮hNRT]=[h11h12…h1NTh21h22…h2NT⋮⋱hi1hi2…hiNT⋮⋱hNR1hNR2…hNRNT][Equation8] Meanwhile, Additive White Gaussian Noise (AWGN) is added to an actual channel after the actual channel experiences the channel matrix H. Accordingly, AWGN n_1, n_2, . . . , n_NR added to the N_R reception antennas, respectively, are represented using a vector as follows. n=[n1,n2, . . . ,nNR]T[Equation 9] A transmission signal, a reception signal, a channel, and AWGN in a multi-input/output antenna communication system may be represented to have the following relationship through the modeling of the transmission signal, reception signal, channel, and AWGN, such as those described above. y=[y1y2⋮yi⋮yNR]=[h11h12…h1NTh21h22…h2NT⋮⋱hi1hi2…hiNT⋮⋱hNR1hNR2…hNRNT][x1x2⋮xj⋮xNT]+[n1n2⋮ni⋮nNR]=Hx+n[Equation10] Meanwhile, the number of rows and columns of the channel matrix H indicative of the state of channels is determined by the number of transmission/reception antennas. In the channel matrix H, as described above, the number of rows becomes equal to the number of reception antennas N_R, and the number of columns becomes equal to the number of transmission antennas N_T. That is, the channel matrix H becomes an N_R×N_T matrix. In general, the rank of a matrix is defined as a minimum number of the number of independent rows or columns. Accordingly, the rank of the matrix is not greater than the number of rows or columns. As for figural style, for example, the rank H of the channel matrix H is limited as follows. rank(H)≤min(NT,NR[Equation 11] Furthermore, if a matrix is subjected to Eigen value decomposition, a rank may be defined as the number of Eigen values that belong to Eigen values and that are not 0. Likewise, if a rank is subjected to Singular Value Decomposition (SVD), it may be defined as the number of singular values other than 0. Accordingly, the physical meaning of a rank in a channel matrix may be said to be a maximum number on which different information may be transmitted in a given channel. In this specification, a “rank” for MIMO transmission indicates the number of paths through which signals may be independently transmitted at a specific point of time and a specific frequency resource. The “number of layers” indicates the number of signal streams transmitted through each path. In general, a rank has the same meaning as the number of layers unless otherwise described because a transmission end sends the number of layers corresponding to the number of ranks used in signal transmission. Reference Signal (RS) In a wireless communication system, a signal may be distorted during transmission because data is transmitted through a radio channel. In order for a reception end to accurately receive a distorted signal, the distortion of a received signal needs to be corrected using channel information. In order to detect channel information, a method of detecting channel information using the degree of the distortion of a signal transmission method and a signal known to both the transmission side and the reception side when they are transmitted through a channel is chiefly used. The aforementioned signal is called a pilot signal or reference signal (RS). Furthermore recently, when most of mobile communication systems transmit a packet, they use a method capable of improving transmission/reception data efficiency by adopting multiple transmission antennas and multiple reception antennas instead of using one transmission antenna and one reception antenna used so far. When data is transmitted and received using multiple input/output antennas, a channel state between the transmission antenna and the reception antenna must be detected in order to accurately receive the signal. Accordingly, each transmission antenna must have an individual reference signal. In a mobile communication system, an RS may be basically divided into two types depending on its object. There are an RS having an object of obtaining channel state information and an RS used for data demodulation. The former has an object of obtaining, by a UE, to obtain channel state information in the downlink. Accordingly, a corresponding RS must be transmitted in a wideband, and a UE must be capable of receiving and measuring the RS although the UE does not receive downlink data in a specific subframe. Furthermore, the former is also used for radio resources management (RRM) measurement, such as handover. The latter is an RS transmitted along with corresponding resources when an eNB transmits the downlink. A UE may perform channel estimation by receiving a corresponding RS and thus may demodulate data. The corresponding RS must be transmitted in a region in which data is transmitted. A downlink RS includes one common RS (CRS) for the acquisition of information about a channel state shared by all of UEs within a cell and measurement, such as handover, and a dedicated RS (DRS) used for data demodulation for only a specific UE. Information for demodulation and channel measurement can be provided using such RSs. That is, the DRS is used for only data demodulation, and the CRS is used for the two objects of channel information acquisition and data demodulation. The reception side (i.e., UE) measures a channel state based on a CRS and feeds an indicator related to channel quality, such as a channel quality indicator (CQI), a precoding matrix index (PMI) and/or a rank indicator (RI), back to the transmission side (i.e., an eNB). The CRS is also called a cell-specific RS. In contrast, a reference signal related to the feedback of channel state information (CSI) may be defined as a CSI-RS. The DRS may be transmitted through resource elements if data on a PDSCH needs to be demodulated. A UE may receive information about whether a DRS is present through a higher layer, and the DRS is valid only if a corresponding PDSCH has been mapped. The DRS may also be called a UE-specific RS or demodulation RS (DMRS). FIGS.7A and7Billustrate reference signal patterns mapped to downlink resource block pairs in a wireless communication system to which the present invention may be applied. Referring toFIGS.7A and7B, a downlink resource block pair, that is, a unit in which a reference signal is mapped, may be represented in the form of one subframe in a time domain X 12 subcarriers in a frequency domain. That is, in a time axis (an x axis), one resource block pair has a length of 14 OFDM symbols in the case of a normal cyclic prefix (CP) (FIG.7A) and has a length of 12 OFDM symbols in the case of an extended cyclic prefix (CP) (FIG.7B). In the resource block lattice, resource elements (REs) indicated by “0”, “1”, “2”, and “3” mean the locations of the CRSs of antenna port indices “0”, “1”, “2”, and “3”, respectively, and REs indicated by “D” mean the location of a DRS. If an eNB uses a single transmission antenna, reference signals for a single antenna port are arrayed. If an eNB uses two transmission antennas, reference signals for two transmission antenna ports are arrayed using a time division multiplexing (TDM) scheme and/or a frequency division multiplexing (FDM) scheme. That is, different time resources and/or different frequency resources are allocated in order to distinguish between reference signals for two antenna ports. Furthermore, if an eNB uses four transmission antennas, reference signals for four transmission antenna ports are arrayed using the TDM and/or FDM schemes. Channel information measured by the reception side (i.e., UE) of a downlink signal may be used to demodulate data transmitted using a transmission scheme, such as single transmission antenna transmission, transmission diversity, closed-loop spatial multiplexing, open-loop spatial multiplexing or a multi-user-multi-input/output (MIMO) antenna. If a multi-input multi-output antenna is supported, when a RS is transmitted by a specific antenna port, the RS is transmitted in the locations of resource elements specified depending on a pattern of the RS and is not transmitted in the locations of resource elements specified for other antenna ports. That is, RSs between different antennas do not overlap. In an LTE-A system, that is, an advanced and developed form of the LTE system, the design is necessary to support a maximum of eight transmission antennas in the downlink of an eNB. Accordingly, RSs for the maximum of eight transmission antennas must be also supported. In the LTE system, only downlink RSs for a maximum of four antenna ports has been defined. Accordingly, if an eNB has four to a maximum of eight downlink transmission antennas in the LTE-A system, RSs for these antenna ports must be additionally defined and designed. Regarding the RSs for the maximum of eight transmission antenna ports, the aforementioned RS for channel measurement and the aforementioned RS for data demodulation must be designed. One of important factors that must be considered in designing an LTE-A system is backward compatibility, that is, that an LTE UE must well operate even in the LTE-A system, which must be supported by the system. From an RS transmission viewpoint, in the time-frequency domain in which a CRS defined in LTE is transmitted in a full band every subframe, RSs for a maximum of eight transmission antenna ports must be additionally defined. In the LTE-A system, if an RS pattern for a maximum of eight transmission antennas is added in a full band every subframe using the same method as the CRS of the existing LTE, RS overhead is excessively increased. Accordingly, the RS newly designed in the LTE-A system is basically divided into two types, which include an RS having a channel measurement object for the selection of MCS or a PMI (channel state information-RS or channel state indication-RS (CSI-RS)) and an RS for the demodulation of data transmitted through eight transmission antennas (data demodulation-RS (DM-RS)). The CSI-RS for the channel measurement object is characterized in that it is designed for an object focused on channel measurement unlike the existing CRS used for objects for measurement, such as channel measurement and handover, and for data demodulation. Furthermore, the CSI-RS may also be used for an object for measurement, such as handover. The CSI-RS does not need to be transmitted every subframe unlike the CRS because it is transmitted for an object of obtaining information about a channel state. In order to reduce overhead of a CSI-RS, the CSI-RS is intermittently transmitted on the time axis. In the LTE-A system, a maximum of eight transmission antennas are supported in the downlink of an eNB. In the LTE-A system, if RSs for a maximum of eight transmission antennas are transmitted in a full band every subframe using the same method as the CRS in the existing LTE, RS overhead is excessively increased. Accordingly, in the LTE-A system, an RS has been separated into the CSI-RS of the CSI measurement object for the selection of MCS or a PMI and the DM-RS for data demodulation, and thus the two RSs have been added. The CSI-RS may also be used for an object, such as RRM measurement, but has been designed for a main object for the acquisition of CSI. The CSI-RS does not need to be transmitted every subframe because it is not used for data demodulation. Accordingly, in order to reduce overhead of the CSI-RS, the CSI-RS is intermittently transmitted on the time axis. That is, the CSI-RS has a period corresponding to a multiple of the integer of one subframe and may be periodically transmitted or transmitted in a specific transmission pattern. In this case, the period or pattern in which the CSI-RS is transmitted may be set by an eNB. In order to measure a CSI-RS, a UE must be aware of information about the transmission subframe index of the CSI-RS for each CSI-RS antenna port of a cell to which the UE belongs, the location of a CSI-RS resource element (RE) time-frequency within a transmission subframe, and a CSI-RS sequence. In the LTE-A system, an eNB has to transmit a CSI-RS for each of a maximum of eight antenna ports. Resources used for the CSI-RS transmission of different antenna ports must be orthogonal. When one eNB transmits CSI-RSs for different antenna ports, it may orthogonally allocate the resources according to the FDM/TDM scheme by mapping the CSI-RSs for the respective antenna ports to different REs. Alternatively, the CSI-RSs for different antenna ports may be transmitted according to the CDM scheme for mapping the CSI-RSs to pieces of code orthogonal to each other. When an eNB notifies a UE belonging to the eNB of information on a CSI-RS, first, the eNB must notify the UE of information about a time-frequency in which a CSI-RS for each antenna port is mapped. Specifically, the information includes subframe numbers in which the CSI-RS is transmitted or a period in which the CSI-RS is transmitted, a subframe offset in which the CSI-RS is transmitted, an OFDM symbol number in which the CSI-RS RE of a specific antenna is transmitted, frequency spacing, and the offset or shift value of an RE in the frequency axis. A CSI-RS is transmitted through one, two, four or eight antenna ports. Antenna ports used in this case are p=15, p=15, 16, p=15, . . . , 18, and p=15, . . . , 22, respectively. A CSI-RS may be defined for only a subcarrier interval Δf=15 kHz. In a subframe configured for CSI-RS transmission, a CSI-RS sequence is mapped to a complex-valued modulation symbol a k,l{circumflex over ( )}(p) used as a reference symbol on each antenna port p as in Equation 12. [Equation12]ak,l(p)=wl″·rl,ns(m′)k=k′+12m+{-0forp∈{15,16},normalcyclicprefix-6forp∈{17,18},normalcyclicprefix-1forp∈{19,20},normalcyclicprefix-7forp∈{21,22},normalcyclicprefix-0forp∈{15,16},extendedcyclicprefix-3forp∈{17,18},extendedcyclicprefix-6forp∈{19,20},extendedcyclicprefix-9forp∈{21,22},extendedcyclicprefixl=l′+{l″CSIreferencesignalconfigurations0-19,normalcyclicprefix2l″CSIreferencesignalconfigurations20-31,normalcyclicprefixl″CSIreferencesignalconfigurations0-27,extendedcyclicprefixwl″={1p∈{15,17,19,21}(-1)l″p∈{16,18,20,22}l″=0,1m=0,1,…,NRBDL-1m′=m+⌊NRBmax,DL-NRBDL2⌋ In Equation 12, (k′,l′) (wherein k′ is a subcarrier index within a resource block and l′ indicates an OFDM symbol index within a slot.) and the condition of n_s is determined depending on a CSI-RS configuration, such as Table 3 or Table 4. Table 3 illustrates the mapping of (k′,l′) from a CSI-RS configuration in a normal CP. TABLE 3CSI referenceNumber of CSI reference signals configuredsignal1 or 248configuration(k′,l′)nsmod 2(k′,l′)nsmod 2(k′,l′)nsmod 2Frame structure type 1 and 20(9,5)0(9,5)0(9,5)01(11,2)1(11,2)1(11,2)12(9,2)1(9,2)1(9,2)13(7,2)1(7,2)1(7,2)14(9,5)1(9,5)1(9,5)15(8,5)0(8,5)06(10,2)1(10,2)17(8,2)1(8,2)18(6,2)1(6,2)19(8,5)1(8,5)110(3,5)011(2,5)012(5,2)113(4,2)114(3,2)115(2,2)116(1,2)117(0,2)118(3,5)119(2,5)1Frame structure type 2 only20(11,1)1(11,1)1(11,1)121(9,1)1(9,1)1(9,1)122(7,1)1(7,1)1(7,1)123(10,1)1(10,1)124(8,1)1(8,1)125(6,1)1(6,1)126(5,1)127(4,1)128(3,1)129(2,1)130(1,1)131(0,1)1 Table 4 illustrates the mapping of (k′,l′) from a CSI-RS configuration in an extended CP. TABLE 4CSI referenceNumber of CSI reference signals configuredsignal1 or 248configuration(k′,l′)nsmod 2(k′,l′)nsmod 2(k′,l′)nsmod 2Frame structure type 1 and 20(11,4)0(11,4)0(11,4)01(9,4)0(9,4)0(9,4)02(10,4)1(10,4)1(10,4)13(9,4)1(9,4)1(9,4)14(5,4)0(5,4)05(3,4)0(3,4)06(4,4)1(4,4)17(3,4)1(3,4)18(8,4)09(6,4)010(2,4)011(0,4)012(7,4)113(6,4)114(1,4)115(0,4)1Frame struc16(11,1)1(11,1)1(11,1)117(10,1)1(10,1)1(10,1)118(9,1)1(9,1)1(9,1)119(5,1)1(5,1)120(4,1)1(4,1)121(3,1)1(3,1)122(8,1)123(7,1)124(6,1)125(2,1)126(1,1)127(0,1)1 Referring to Table 3 and Table 4, in the transmission of a CSI-RS, in order to reduce inter-cell interference (ICI) in a multi-cell environment including a heterogeneous network (HetNet) environment, a maximum of 32 different configurations (in the case of a normal CP) or a maximum of 28 different configurations (in the case of an extended CP) are defined. The CSI-RS configuration is different depending on the number of antenna ports and a CP within a cell, and a neighboring cell may have a maximum of different configurations. Furthermore, the CSI-RS configuration may be divided into a case where it is applied to both an FDD frame and a TDD frame and a case where it is applied to only a TDD frame depending on a frame structure. (k′,l′) and n_s are determined depending on a CSI-RS configuration based on Table 3 and Table 4, and time-frequency resources used for CSI-RS transmission are determined depending on each CSI-RS antenna port. FIGS.8A to8Care diagrams illustrating resources to which reference signals are mapped in a wireless communication system to which the present invention may be applied. Particularly,FIGS.8A to8Cillustrate CSI-RS patterns for cases in which the number of CSI-RS antenna ports is 1 or 2, 4 and 8 in a subframe to which a normal CP is applied. FIG.8Ashows twenty types of CSI-RS configurations available for CSI-RS transmission by one or two CSI-RS antenna ports,FIG.8Bshows ten types of CSI-RS configurations available for four CSI-RS antenna ports, andFIG.8Cshows five types of CSI-RS configurations available for eight CSI-RS antenna ports. As described above, radio resources (i.e., an RE pair) in which a CSI-RS is transmitted are determined depending on each CSI-RS configuration. If one or two antenna ports are configured for CSI-RS transmission with respect to a specific cell, the CSI-RS is transmitted on radio resources on a configured CSI-RS configuration of the twenty types of CSI-RS configurations shown inFIG.8A. Likewise, when four antenna ports are configured for CSI-RS transmission with respect to a specific cell, a CSI-RS is transmitted on radio resources on a configured CSI-RS configuration of the ten types of CSI-RS configurations shown inFIG.8B. Furthermore, when eight antenna ports are configured for CSI-RS transmission with respect to a specific cell, a CSI-RS is transmitted on radio resources on a configured CSI-RS configuration of the five types of CSI-RS configurations shown inFIG.8C. A CSI-RS for each antenna port is subjected to CDM (Code Division Multiplexing) for every two antenna ports (i.e., {15,16}, {17,18}, {19,20} and {21,22}) on the same radio resources and transmitted. For example, in the case of antenna ports 15 and 16, CSI-RS complex symbols for the respective antenna ports 15 and 16 are the same, but are multiplied by different types of orthogonal code (e.g., Walsh code) and mapped to the same radio resources. The complex symbol of the CSI-RS for the antenna port 15 is multiplied by [1, 1], and the complex symbol of the CSI-RS for the antenna port 16 is multiplied by [1 −1] and mapped to the same radio resources. The same is true of the antenna ports {17,18}, {19,20} and {21,22}. A UE may detect a CSI-RS for a specific antenna port by multiplying code by which a transmitted symbol has been multiplied. That is, a transmitted symbol is multiplied by the code [1 1] multiplied in order to detect the CSI-RS for the antenna port 15, and a transmitted symbol is multiplied by the code [1 −1] multiplied in order to detect the CSI-RS for the antenna port 16. Referring toFIGS.8A to8C, in the case of the same CSI-RS configuration index, radio resources according to a CSI-RS configuration having a large number of antenna ports include radio resources having a small number of CSI-RS antenna ports. For example, in the case of a CSI-RS configuration 0, radio resources for the number of eight antenna ports include both radio resources for the number of four antenna ports and radio resources for the number of one or two antenna ports. FIGS.9A to9Cillustrate resources to which reference signals are mapped in a wireless communication system to which the present invention is applicable. Particularly,FIGS.9A to9Cshow CSI-RS patterns for cases in which the number of CSI-RS antenna ports is 1 or 2, 4 and 8 in a subframe to which an extended CP is applied. FIG.9Ashows 16 CSI-RS configurations which can be used for CSI-RS transmission through 1 or 2 CSI-RS antenna ports,FIG.9Bshows 8 CSI-RS configurations which can be used for CSI-RS transmission through 4 CSI-RS antenna ports, andFIG.9Cshows 4 CSI-RS configurations which can be used for CSI-RS transmission through 8 CSI-RS antenna ports. In this manner, radio resources (i.e., RE pairs) for CSI-RS transmission are determined depending on each CSI-RS configuration. When one or two antenna ports are set for CSI-RS transmission for a specific cell, CSI-RSs are transmitted on radio resources according to a set CSI-RS configuration among the 16 CSI-RS configurations shown inFIG.9A. Similarly, when 4 antenna ports are set for CSI-RS transmission for a specific cell, CSI-RSs are transmitted on radio resources according to a set CSI-RS configuration among the 8 CSI-RS configurations shown inFIG.9B. Further, when 8 antenna ports are set for CSI-RS transmission for a specific cell, CSI-RSs are transmitted on radio resources according to a set CSI-RS configuration among the 4 CSI-RS configurations shown inFIG.9C. A plurality of CSI-RS configurations may be used in a single cell. Only zero or one CSI-RS configuration may be used for a non-zero power (NZP) CSI-RS and zero or multiple CSI-RS configurations may be used for a zero power (ZP) CSI-RS. For each bit set to 1 in a zero-power (ZP) CSI-RS (‘ZeroPowerCSI-RS) that is a bitmap of 16 bits configured by a high layer, a UE assumes zero transmission power in REs (except a case where an RE overlaps an RE assuming a NZP CSI-RS configured by a high layer) corresponding to the four CSI-RS columns of Table 3 and Table 4. The most significant bit (MSB) corresponds to the lowest CSI-RS configuration index, and next bits in the bitmap sequentially correspond to next CSI-RS configuration indices. A CSI-RS is transmitted only in a downlink slot that satisfies the condition of (n_s mod 2) in Table 3 and Table 4 and a subframe that satisfies the CSI-RS subframe configurations. In the case of the frame structure type 2 (TDD), a CSI-RS is not transmitted in a special subframe, a synchronization signal (SS), a subframe colliding against a PBCH or SystemInformationBlockType1 (SIB 1) Message transmission or a subframe configured to paging message transmission. Furthermore, an RE in which a CSI-RS for any antenna port belonging to an antenna port set S (S={15}, S={15,16}, S={17,18}, S={19,20} or S={21,22}) is transmitted is not used for the transmission of a PDSCH or for the CSI-RS transmission of another antenna port. Time-frequency resources used for CSI-RS transmission cannot be used for data transmission. Accordingly, data throughput is reduced as CSI-RS overhead is increased. By considering this, a CSI-RS is not configured to be transmitted every subframe, but is configured to be transmitted in each transmission period corresponding to a plurality of subframes. In this case, CSI-RS transmission overhead can be significantly reduced compared to a case where a CSI-RS is transmitted every subframe. A subframe period (hereinafter referred to as a “CSI transmission period”) T CSI-RS and a subframe offset Δ_CSI-RS for CSI-RS transmission are shown in Table 5. Table 5 illustrates CSI-RS subframe configurations. TABLE 5CSI-RSCSI-RS subframeCSI-RS-periodicity TCSI-RSoffset ΔCSI-RSSubframeConfig ICSI-RS(subframes)(subframes)0-45ICSI-RS5-1410ICSI-RS− 515-3420ICSI-RS− 1535-7440ICSI-RS− 3575-15480ICSI-RS− 75 Referring to Table 5, CSI-RS periodicity TCSI-RS and a subframe offset ΔCSI-RS are determined depending on CSI-RS subframe configuration ICSI-RS. The CSI-RS subframe configuration in Table 5 may be set to one of the aforementioned ‘SubframeConfig’ field and ‘zeroTxPowerSubframeConfig’ field. The CSI-RS subframe configuration may be separately set for an NZP CSI-RS and a ZP CSI-RS. A subframe including a CSI-RS satisfies Equation 13. (10nf+└ns/2┘−ΔCSI_RS)modTCSI_RS=0 [Equation 13] In Equation 13, TCSI-RS indicates CSI-RS periodicity, ΔCSI-RS indicates a subframe offset value, of denotes a system frame number, and ns denotes a slot number. In the case of a UE for which transmission mode 9 is set with respect to a serving cell, a single CSI-RS resource configuration may be set for the UE. In the case of a UE for which transmission mode 10 is set with respect to the serving cell, one or more CSI-RS resource configurations may be set for the UE. CSI-RS Configuration In the current LTE standard, CSI-RS configuration parameters include antennaPortsCount, subframeConfig, resourceConfig, etc. These parameters indicate the number of antenna ports used to transmit CSI-RS, the period and offset of a subframe for transmitting CSI-RS, and a transmitted RE location (frequency and OFDM symbol index) in the corresponding subframe. Particularly, when a base station delivers specific CSI-RS configuration to a UE, it delivers the following parameters/information.antennaPortsCount: A parameter representing the number of antenna ports used for transmission of CSI reference signals (e.g., 1 CSI-RS port, 2 CSI-RS ports, 4 CSI-RS ports, 8 CSI-RS ports, etc.).resourceConfig: A parameter associated with the location of resources allocated for CSI-RS.subframeConfig: A parameter associated with the period and offset of a subframe for transmitting CSI-RS.p-C: Regarding UE assumption on reference PDSCH transmitted power for CSI feedback CSI-RS, Pc is the assumed ratio of PDSCH EPRE to CSI-RS EPRE when UE derives CSI feedback and takes values in the range of [−8, 15] dB with 1 dB step size.zeroTxPowerResourceConfigList: A parameter associated with zero-power CSI-RS configuration.zeroTxPowerSubframeConfig: A parameter associated with the period and offset of a subframe for transmitting zero-power CSI-RS. Massive MIMO A MIMO system having a plurality of antennas may be called a massive MIMO system and attracts attention as a means for improving spectral efficiency, energy efficiency and processing complexity. Recently, the massive MIMO system has been discussed in order to meet requirements for spectral efficiency of future mobile communication systems in 3GPP. Massive MIMO is also called full-dimension MIMO (FD-MIMO). LTE release-12 and following wireless communication systems consider introduction of an active antenna system (AAS). Distinguished from conventional passive antenna systems in which an amplifier capable of adjusting the phase and magnitude of a signal is separated from an antenna, the AAS is configured in such a manner that each antenna includes an active element such as an amplifier. The AAS does not require additional cables, connectors and hardware for connecting amplifiers and antennas and thus has high energy efficiency and low operation costs. Particularly, the AAS supports electronic beam control per antenna and thus can realize enhanced MIMO for forming accurate beam patterns in consideration of a beam direction and a beam width or 3D beam patterns. With the introduction of enhanced antenna systems such as the AAS, massive MIMO having a plurality of input/output antennas and a multi-dimensional antenna structure is also considered. For example, when a 2D antenna array instead of a conventional linear antenna array is formed, a 3D beam pattern can be formed using active antennas of the AAS. FIG.10illustrates a 2D AAS having 64 antenna elements in a wireless communication system to which the present invention is applicable. FIG.10illustrates a normal 2D antenna array. A case in which Nt=Nv·Nh antennas are arranged in a square form, as shown inFIG.10, may be considered. Here, Nh indicates the number of antenna columns in the horizontal direction and Nv indicates the number of antenna rows in the vertical direction. When the aforementioned 2D antenna array is used, radio waves can be controlled in both the vertical direction (elevation) and the horizontal direction (azimuth) to control transmitted beams in a 3D space. A wavelength control mechanism of this type may be referred to as 3D beamforming. FIG.11illustrates a system in which an eNB or a UE has a plurality of transmission/reception antennas capable of forming AAS based 3D beams in a wireless communication system to which the present invention is applicable. FIG.11schematizes the above-described example and illustrates a 3D MIMO system using a 2D antenna array (i.e., 2D-AAS). From the viewpoint of transmission antennas, quasi-static or dynamic beam formation in the vertical direction as well as the horizontal direction of beams can be performed when a 3D beam pattern is used. For example, application such as sector formation in the vertical direction may be considered. From the viewpoint of reception antennas, a signal power increase effect according to an antenna array gain can be expected when a received beam is formed using a massive reception antenna. Accordingly, in the case of uplink, an eNB can receive signals transmitted from a UE through a plurality of antennas, and the UE can set transmission power thereof to a very low level in consideration of the gain of the massive reception antenna. FIG.12illustrates a 2D antenna system having cross polarization in a wireless communication system to which the present invention is applicable. 2D planar antenna array model considering polarization may be schematized as shown inFIG.12. Distinguished from conventional MIMO systems using passive antennas, systems based on active antennas can dynamically control gains of antenna elements by applying a weight to an active element (e.g., amplifier) attached to (or included in) each antenna element. Since a radiation pattern depends on antenna arrangement such as the number of antenna elements and antenna spacing, an antenna system can be modeled at an antenna element level. The antenna arrangement model as shown inFIG.12may be represented by (M, N, P) which corresponds to parameters characterizing an antenna arrangement structure. M indicates the number of antenna elements having the same polarization in each column (i.e., in the vertical direction) (i.e., the number of antenna elements having +45° slant in each column or the number of antenna elements having −45° slant in each column). N indicates the number of columns in the horizontal direction (i.e., the number of antenna elements in the horizontal direction). P indicates the number of dimensions of polarization. P=2 in the case of cross polarization as shown inFIG.11, whereas P=1 in the case of co-polarization. An antenna port may be mapped to a physical antenna element. The antenna port may be defined by a reference signal associated therewith. For example, antenna port 0 may be associated with a cell-specific reference signal (CRS) and antenna port 6 may be associated with a positioning reference signal (PRS) in the LTE system. For example, antenna ports and physical antenna elements may be one-to-one mapped. This may correspond to a case in which a single cross-polarization antenna element is used for downlink MIMO or downlink transmit diversity. For example, antenna port 0 may be mapped to a single physical antenna element, whereas antenna port 1 may be mapped to another physical antenna element. In this case, two downlink transmissions are present in terms of a UE. One is associated with a reference signal for antenna port 0 and the other is associated with a reference signal for antenna port 1. Alternatively, a single antenna port may be mapped to multiple physical antenna elements. This may correspond to a case in which a single antenna port is used for beamforming. Beamforming can cause downlink transmission to be directed to a specific UE by using multiple physical antenna elements. This can be accomplished using an antenna array composed of multiple columns of multiple cross-polarization antenna elements in general. In this case, a single downlink transmission derived from a single antenna port is present in terms of a UE. One is associated with a CRS for antenna port 0 and the other is associated with a CRS for antenna port 1. That is, an antenna port represents downlink transmission in terms of a UE rather than substantial downlink transmission from a physical antenna element in an eNB. Alternatively, a plurality of antenna ports may be used for downlink transmission and each antenna port may be multiple physical antenna ports. This may correspond to a case in which antenna arrangement is used for downlink MIMO or downlink diversity. For example, antenna port 0 may be mapped to multiple physical antenna ports and antenna port 1 may be mapped to multiple physical antenna ports. In this case, two downlink transmissions are present in terms of a UE. One is associated with a reference signal for antenna port 0 and the other is associated with a reference signal for antenna port 1. In FD-MIMO, MIMO precoding of a data stream may be subjected to antenna port virtualization, transceiver unit (TXRU) virtualization and an antenna element pattern. In antenna port virtualization, a stream on an antenna port is precoded on TXRU. In TXRU virtualization, a TXRU signal is precoded on an antenna element. In the antenna element pattern, a signal radiated from an antenna element may have a directional gain pattern. In conventional transceiver modeling, static one-to-on mapping between an antenna port and TXRU is assumed and TXRU virtualization effect is integrated into a (TXRU) antenna pattern including both the effects of the TXRU virtualization and antenna element pattern. Antenna port virtualization may be performed through a frequency-selective method. In LTE, an antenna port is defined along with a reference signal (or pilot). For example, for transmission of data precoded on an antenna port, a DMRS is transmitted in the same bandwidth as that for a data signal and both the DMRS and the data signal are precoded through the same precoder (or the same TXRU virtualization precoding). For CSI measurement, a CSI-RS is transmitted through multiple antenna ports. In CSI-RS transmission, a precoder which characterizes mapping between a CSI-RS port and TXRU may be designed as an eigen matrix such that a UE can estimate a TXRU virtualization precoding matrix for a data precoding vector. 1D TXRU virtualization and 2D TXRU virtualization are discussed as TXRU virtualization methods, which will be described below with reference to the drawings. FIGS.13A and13Billustrate transceiver unit models in a wireless communication system to which the present invention is applicable. In 1D TXRU virtualization, M_TXRU TXRUs are associated with M antenna elements in a single-column antenna arrangement having the same polarization. In 2D TXRU virtualization, a TXRU model corresponding to the antenna arrangement model (M, N, P) ofFIG.12may be represented by (M_TXRU, N, P). Here, M_TXRU denotes the number of 2D TXRUs present in the same column and the same polarization, and M_TXRU≤M all the time. That is, a total number of TXRUs is M_TXRU×N×P. TXRU virtualization models may be divided into TXRU virtualization model option-1: sub-array partition model as shown inFIG.12(a)and TXRU virtualization model option-2: full-connection model as shown inFIG.12(b)according to correlation between antenna elements and TXRU. Referring toFIG.13A, antenna elements are partitioned into multiple antenna element groups and each TXRU is connected to one of the groups in the case of the sub-array partition model. Referring toFIG.13B, multiple TXRU signals are combined and delivered to a single antenna element (or antenna element array) in the case of the full-connection model. InFIGS.13A and13B, q is a transmission signal vector of M co-polarized antenna elements in a single column, w is a wideband TXRU virtualization weight vector, W is a wideband TXRU virtualization weight matrix, and x is a signal vector of M_TXRU TXRUs. Here, mapping between antenna ports and TXRUs may be 1-to-1 or 1-to-many mapping. FIGS.13A and13Bshow an example of TXRU-to-antenna element mapping and the present invention is not limited thereto. The present invention may be equally applied to mapping between TXRUs and antenna elements realized in various manners in terms of hardware. Definition of CSI (Channel-State Information)-Reference Signal (CSI-RS) For a serving cell and UE configured in transmission mode 9, the UE can be configured with one CSI-RS resource configuration. For a serving cell and UE configured in transmission mode 10, the UE can be configured with one or more CSI-RS resource configuration(s). The following parameters for which the UE shall assume non-zero transmission power for CSI-RS are configured via higher layer signaling for each CSI-RS resource configuration:CSI-RS resource configuration identifier (if the UE is configured in transmission mode 10)Number of CSI-RS ports.CSI RS ConfigurationCSI RS subframe configuration I_(CSI-RS).UE assumption on reference PDSCH transmitted power for CSI feedback (P_c) (if the UE is configured in transmission mode 9).UE assumption on reference PDSCH transmitted power for CSI feedback (P_c) for each CSI process, if the UE is configured in transmission mode 10. If CSI subframe sets C_(CSI,0) and C_(CSI,1) are configured by higher layers for a CSI process, P_c is configured for each CSI subframe set of the CSI process.Pseudo-random sequence generator parameter (n_ID)CDM type parameter, if the UE is configured with higher layer parameter CSI-Reporting-Type, and CSI-reporting-Type is set to ‘CLASS A’ for a CSI process.Higher layer parameter qcl-CRS-Info-r11 for QCL type B UE assumption of CRS antenna ports and CSI-RS antenna ports with the following parameters, if the UE is configured in transmission mode 10:qcl-ScramblingIdentity-r11.crs-PortsCount-r11.mbsfn-SubframeConfigList-r11.P_c is the assumed ratio of PDSCH EPRE to CSI-RS EPRE (Energy Per Resource Element) when UE derives CSI feedback and takes values in the range of [−8, 15] dB with 1 dB step size, where the PDSCH EPRE corresponds to the number of symbols for which the ratio of the PDSCH EPRE to the cell-specific RS EPRE. A UE should not expect the configuration of CSI-RS and PMCH in the same subframe of a serving cell. For frame structure type 2 serving cell and 4 CRS ports, the UE is not expected to receive a CSI RS Configuration index belonging to the set [20-31] for the normal CP case or the set [16-27] for the extended CP case. A UE may assume the CSI-RS antenna ports of a CSI-RS resource configuration are quasi co-located (QCL) with respect to delay spread, Doppler spread, Doppler shift, average gain, and average delay. A UE configured in transmission mode 10 and with QCL type B may assume the antenna ports 0-3 associated with qcl-CRS-Info-r11 corresponding to a CSI-RS resource configuration and antenna ports 15-22 corresponding to the CSI-RS resource configuration are quasi co-located (QCL) with respect to Doppler shift, and Doppler spread. If a UE is configured in transmission mode 10 with higher layer parameter CSI-Reporting-Type, CSI-Reporting-Type is set to ‘CLASS B’, and the number of CSI-RS resources configured for a CSI process is 1 or more, and QCL type B is configured, the UE is not expected to receive CSI-RS resource configurations for the CSI process that have different values from the higher layer parameter qcl-CRS-Info-r11. In subframes configured for CSI-RS transmission, the reference signal sequence rl,ns(m) shall be mapped to complex-valued modulation symbols ak,l(p)used as reference symbols on antenna port p. The mapping depends on the higher layer parameter CDMType. If CDMType does not correspond to CDM4, mapping may be done according to the following Equation 14: [Equation14]ak,l(p′)=wl″·rl,ns(m′)k=k′+12m+{-0forp′∈{15,16},normalcyclicprefix-6forp′∈{17,18},normalcyclicprefix-1forp′∈{19,20},normalcyclicprefix-7forp′∈{21,22},normalcyclicprefix-0forp′∈{15,16},extendedcyclicprefix-3forp′∈{17,18},extendedcyclicprefix-6forp′∈{19,20},extendedcyclicprefix-9forp′∈{21,22},extendedcyclicprefixl=l′+{l″CSIreferencesignalconfigurations0-19,normalcyclicprefix2l″CSIreferencesignalconfigurations20-31,normalcyclicprefixl″CSIreferencesignalconfigurations0-27,extendedcyclicprefixwl″={1p′∈{15,17,19,21}(-1)l″p′∈{16,18,20,22}l″=0,1m=0,1,…,NRBDL-1m′=m+⌊NRBmax,DL-NRBDL2⌋ If CDMType corresponds to CDM4, mapping may be done according to the following Equation 15. ak,l(p′)=wp′(i)·rl,ns(m′)k=k′+12m+{k″forp′∈{15,16,19,20},normalcyclicprefix,NportsCSI=8k″+6forp′∈{17,18,21,22},normalcyclicprefix,NportsCSI=86k″forp′∈{15,16,17,18},normalcyclicprefix,NportsCSI=4l=l′+{l″CSIreferencesignalconfigurations0-19,normalcyclicprefix2l″CSIreferencesignalconfigurations20-31,normalcyclicprefixl″=0,1k″=0,1i=2k″+l″m=0,1,…,NRBDL-1m′=m+⌊NRBmax,DL-NRBDL2⌋[Equation15]where wp′(i) is determined by the following Table 6. Table 6 represents the sequence wp′(i) for CDM4. TABLE 6p′NCSIports = 4NCSIports = 8[wp′(0) wp′(1) wp′(2) wp′(3)]1515, 17[1 1 1 1]1616, 18[1 −1 1 −1]1719, 21[1 1 −1 −1]1820, 22[1 −1 −1 1] OFDM Numerology As more and more communication devices demand larger communication capacity, there is a need for improved mobile broadband communication compared to existing RAT (Radio Access Technology). Also, massive MTC (Machine Type Communications), which provides various services by connecting many devices and objects, is one of the major issues to be considered in the next generation communication. In addition, a communication system design considering a service/UE sensitive to reliability and latency in the next-generation communication is being discussed. The introduction of next-generation RAT, which takes enhanced mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) into account, is being discussed. In the present invention, this technology is referred to as new RAT for simplicity. The new RAT system uses an OFDM transmission scheme or a similar transmission scheme. Typically, it has the OFDM numerology of the following Table 3. TABLE 3ParameterValueSubcarrier-spacing (Δf)60kHzOFDM symbol length16.33μsCyclic Prefix(CP) length1.30 μs/1.17 μssSystem bandwidth80MHz(No. of available subcarriers)1200Subframe length0.25msNumber of OFDM symbols per subframe14symbols Self-Contained Subframe Structure In order to minimize the latency of data transmission in the TDD system in the new fifth-generation RAT, a self-contained subframe structure is considered, in which a control channel and a data channel are time-divison-multiplexed (TDM). FIG.14illustrates a self-contained subframe structure to which the present invention is applicable. InFIG.14, the hatched area represents the transmission region of a physical channel PDCCH carrying DCI, and the black area represents the transmission region of a physical channel PUCCH for carrying UCI (Uplink Control Information). Here, the DCI is control information that the eNB transmits to the UE. The DCI may include information on cell configuration that the UE should know, DL specific information such as DL scheduling, and UL specific information such as UL grant. The UCI is control information that the UE transmits to the eNB. The UCI may include a HARQ ACK/NACK report on the DL data, a CSI report on the DL channel status, and/or a scheduling request (SR). InFIG.14, the area that is not hatched or black may be used for transmission of a physical channel PDSCH carrying downlink data, or may be used for transmission of a physical channel PUSCH carrying uplink data. According to the self-contained subframe structure, DL transmission and UL transmission may be sequentially performed in one subframe, whereby DL data may be transmitted and UP ACK/NACK may be received within the subframe. As a result, the time taken to retransmit data when a data transmission error occurs may be reduced, thereby minimizing the latency of final data transfer. In the self-contained subframe structure, a time gap for switching from a transmission mode to a reception mode or vice versa is required for the eNB and the UE. To this end, some OFDM symbols at the time of switching from DL to UL in the subframe structure are set as a guard period (GP). This subframe type may be referred to as a ‘self-contained SF’. Analog Beamformin! In millimeter wave (mmW), the wavelength is shortened, and thus a plurality of antenna elements may be installed in the same area. For example, a total of 64 (8×8) antenna elements may be installed in a 5-by-5 cm panel in a 30 GHz band with a wavelength of about 1 cm in a 2-dimensional array at intervals of 0.5λ (wavelength). Therefore, in mmW, increasing the coverage or the throughput by increasing the beamforming (BF) gain using multiple antenna elements is taken into consideration. If a transceiver unit (TXRU) is provided for each antenna element to enable adjustment of transmit power and phase, independent beamforming is possible for each frequency resource. However, installing TXRU in all of the about 100 antenna elements is less feasible in terms of cost. Therefore, a method of mapping a plurality of antenna elements to one TXRU and adjusting the direction of a beam using an analog phase shifter is considered. This analog beamforming method may only make one beam direction in the whole band, and thus may not perform frequency selective beamforming (BF), which is disadvantageous. Hybrid BF with B TXRUs that are fewer than Q antenna elements as an intermediate form of digital BF and analog BF may be considered. In the case of hybrid BF, the number of directions in which beams may be transmitted at the same time is limited to B or less, which depends on the method of connecting B TXRUs and Q antenna elements. Moreover, hybrid beamforming, a combination of digital beamforming and analog beamforming, is suggested where multiple antennas are used in the new RAT system. Here, the analog beamforming (or RF beamforming) refers to performing precoding (or combining) at the RF end. In the hybrid beamforming, the baseband end and the RF end each perform precoding (or combining), which has the benefit of achieving performance close to digital beamforming while reducing the number of RF chains and the number of D (digital)/A (analog) (or A/D) converters. For convenience, the hybrid beamforming structure may be represented by N transceiver units (TXRUs) and M physical antennas. Then, digital beamforming for L data layers to be transmitted by the transmitting end may be represented by N by L matrices, and thereafter N converted digital signals are converted into analog signals through the TXRUs and then analog beamforming is applied to represent them by M by N matrices. FIG.15is a schematic diagram of a hybrid beamforming structure from the perspective of TXRUs and physical antennas. InFIG.15, the number of digital beams is L, and the number of analog beams is N. The New RAT system is designed in such a way that the base station changes analog beamforming for each symbol, thereby supporting more efficient beamforming for a UE located in a particular area. Furthermore, inFIG.15, when N particular TXRUs and M RF antennas are defined by a single antenna panel, the New RAT system may deploy a plurality of antenna panels to which hybrid beamforming may be applied individually. When the base station uses multiple analog beams, each UE may require different analog beams for their signal reception. Thus, for synchronization signals, system information, and paging, beam sweeping may be taken into consideration so that the multiple analog beams to be used by the base station in a particular subframe (SF) are changed for each symbol to allow every UE to have an opportunity to receive. FIG.16is a schematic diagram of a beam sweeping operation for synchronization signals and system information in a DL transmission process. InFIG.16, physical resources (or physical channels) on which the system information in the New RAT system is transmitted by broadcasting are termed xPBCH (physical broadcast channels). Referring toFIG.16, analog beams that belong to different antenna panels within one symbol may be simultaneously transmitted. To measure a channel for each analog beam, as shown inFIG.16, an approach for introducing a beam RS (BRS), which is an RS that is transmitted using a single analog beam (corresponding to a specific antenna panel), is being discussed. The BRS may be defined for a plurality of antenna ports, and each antenna port of the BRS may correspond to a single analog beam. In this case, unlike the BRS, a synchronization signal or xPBCH may be transmitted using all analog beams in an analog beam group so that a certain UE may receive it properly. RRM Measurement in LTE LTE systems support RRM operations for power control, scheduling, cell search, cell re-selection, handover, radio link or connection monitoring, connection establish/re-establish, etc. In this case, the serving cell may request the UE for the RRM measurement information for the RRM operations. For example, the UE may measure cell search information for each cell, reference signal received power (RSRP), reference signal received quality (RSRQ), etc., and may report the measurement result. Specifically, in an LTE system, the UE may receive “measConfig” as a higher-layer signal for RRM measurement from the serving cell. In this case, the UE may measure RSRP or RSRQ according to the “measConfig” information. In this case, RSRP, RSRQ, and RSSI according to the TS 36.214 document for LTE systems can be defined as follows: [RSRP] Reference signal received power (RSRP) is defined as the linear average over the power contributions (in [W]) of the resource elements that carry cell-specific RSs (CRs) within the considered measurement frequency bandwidth. For RSRP determination, CRS R0 shall be used according to TS 36.211 [3]. If the UE can reliably detect that R1 is available, it may use R1 in addition to R0 to determine RSRP. The reference point for the RSRP shall be the antenna connector of the UE. If receiver diversity is in use by the UE, the reported value shall not be lower than the corresponding RSRP of any of the individual diversity branches. [RSRQ] Reference Signal Received Quality (RSRQ) is defined as the ratio N×RSRP/(E-UTRA carrier RSSI), where N is the number of RBs of the E-UTRA carrier RSSI measurement bandwidth. The measurements in the numerator and denominator shall be made over the same set of resource blocks. E-UTRA Carrier Received Signal Strength Indicator (RSSI) comprises the linear average of the total received power (in [W]) observed/measured by the UE, only in OFDM symbols containing reference symbols for antenna port 0, in the measurement bandwidth, over N number of resource blocks from all sources (including co-channel serving and non-serving cells), channel interference, thermal noise etc. If higher-layer signaling indicates certain subframes for performing RSRQ measurements, then RSSI is measured over all OFDM symbols in the indicated subframes. The reference point for the RSRQ shall be the antenna connector of the UE. If receiver diversity is in use by the UE, the reported value shall not be lower than the corresponding RSRQ of any of the individual diversity branches. [RSSI] The received wide band power, including thermal noise and noise generated in the receiver, within the bandwidth defined by the receiver pulse shaping filter. The reference point for the measurement shall be the antenna connector of the UE. If receiver diversity is in use by the UE, the reported value shall not be lower than the corresponding UTRA carrier RSSI of any of the individual receive antenna branches. In accordance with the above-mentioned definitions, the UE configured to operate in the LTE system may measure the RSRP through IE (information element)-associated with Allowed Measurement Bandwidth (AMB) transmitted in SIB3 (System Information Block Type 3) in the case of Intra-Frequency measurement, or may measure the RSRP at one bandwidth selected from among 6 RB (Resource Block), 15 RB, 25 RB, 50 RB, 75 RB, and 100 RB through allowed measurement bandwidth (AMB) transmitted in SIBS (System Information Block Type 5) in the case of Inter-frequency measurement. Alternatively, if the information element (IE) is not present, the UE configured to operate in the LTE system may measure the RSRP in a frequency bandwidth of the entire DL system as a default. In this case, if the UE receives the allowed measurement bandwidth, the UE may assume that the corresponding value is a maximum measurement bandwidth, such that the UE can freely measure the RSRP value within the corresponding value. However, if the serving cell transmits the IE defined as WB (wideband)-RSRQ and sets the allowed measurement bandwidth to SORB or higher, the UE must calculate the RSRP value regarding the entire allowed measurement bandwidth. Meanwhile, RSSI may be measured in the frequency bandwidth allocated to the receiver of the UE according to the RSSI bandwidth definition. FIG.17illustrates a panel antenna array to which the present invention is applicable. Referring toFIG.17, the panel antenna array consists of Mg panels in the horizontal domain and Ng panels in the vertical domain, and each panel may consist of M columns and N rows. Particularly, the panels as used herein are illustrated with respect to X-pol (cross polarization) antennas. Accordingly, the total number of antenna elements inFIG.17may be 2*M*N*Mg*Ng. Port Layout Codebooks may be defined as various types. In NR (New RAT), there are mainly two types of codebooks: Type 1 codebook and Type2 codebook. Further, each type may be sub-divided depending on whether it is a codebook for a single panel or a codebook for multi-panels (e.g., Type 1 single/multi-panel codebook and Type 2 single/multi-panel codebook). For Type 1 single panel codebook, W1 may be defined by the following Equation 16. Here, W1 denotes a first PMI having long-term, wideband, and beam selection characteristics. W1=[B100B2],Bi=[b0i,…,bL-1i][Equation16] At least for rank 1 and rank 2, the number (L) of candidate DFT (Discrete Fourier Transform) beams in B (or Bi) in W1 may be 1, 2, 4 and/or 7. The L value may be configured by the network (e.g., base station). For L>1, L beams may be selected freely by the UE. Alternatively, at least one beam group pattern may be defined, and an example of such a beam group pattern will be described below with reference toFIGS.18and19. The beam group pattern may be configured by the network (e.g., base station). A beam pattern may be reported by the UE. Alternatively, L beams may be selected freely by gNB. Selection of L beams may apply to rank 1 and rank 2 alike or differently. For L=1, W1 may be defined by the following Equation 17: W1=[v00v][Equation17] FIG.18illustrates candidate beam group patterns for L=2 in a 2D port layout applicable to the present invention. In this drawing, patterned squares represent L selected beams. FIG.19illustrates candidate beam group patterns for L=4 in a 2D port layout applicable to the present invention. In this drawing, patterned squares represent L selected beams. In a 1D port layout, a beam group pattern includes a row of beams for L>1 that are uniformly and/or non-uniformly separated by d. For L>1, a single value or multiple values may be supported for d1 and d2. Proposal of Codebooks in NR In wireless communication systems using panel array antennas, including New RAT, narrow beams are formed as beamforming using massive antennas is performed, and the implementation of a panel antenna array may eliminate linear increments between antenna ports. Thus, the performance of a DFT-based codebook, used in LTE, LTE-A, etc., may be degraded. Accordingly, the present invention proposes a codebook structure suitable for a panel array antenna. Firstly, a 2D DFT beam to be applied to a 2D antenna array within one panel may be defined by Equation 18: Wm1,m2=vm1⊗um2N1N2vm1=[1exp(j2πm1o1N1)…exp(j2πm1(N1-1)o1N1)]Tum2=[1exp(j2πm2o2N2)…exp(j2πm2(N2-1)o2N2)]T[Equation18]where m1 and m2 represent the indices of a 1D-DFT codebooks in first and domains, respectively, N1 and N2 represent the numbers of antenna ports per pol in first and second dimensions in a panel, and o1 and o2 represent the oversampling factors in first and second dimensions in a panel. InFIG.17, M and N represent antenna elements (hereinafter, M is referred to as a first domain (horizontal) parameter, and N is referred to as a second domain (vertical) parameter, for convenience of explanation). According to the results of performing antenna virtualization on a plurality of antenna elements according to a specific vector and then performing antenna element-to-port mapping, the number of ports in the first and second domains is defined by N1 and N2, respectively. When N1′ and N2′ are defined as the number of ports per panel, the total number (Ntot) of antenna ports to be considered in the present invention is defined as P*Mg*Ng*N1′*N2′, and P may be set to 2 in the case of an X-pol antenna and 1 in the case of a co-pol antenna. FIG.20is a view illustrating a non-uniform array according to an exemplary embodiment of the present invention. Referring toFIG.20, vertical virtualization on a panel array with 32 elements (i.e., M=4, N=2, P=2) for each panel results in P=2, N1′=4, N2′=1, Mg=2, Ng=2, which is a total of 32 ports. While antenna ports may correspond to antenna elements by antenna virtualization, the antenna ports in the present invention, after the virtualization of a single antenna element or multiple antenna elements, are generally referred to as an “antenna port” for convenience of explanation. Antenna port information for beamforming (e.g., {N1, N2, O1 and O2}, and/or {Mg, Ng, N1′, N2′, O1 and/or O2}) may be signaled by higher-layer signaling or agreed in advance between the UE and the network. The Ntot value may vary, but should conform to a codebook structure that is integrally applicable to antenna ports supported in LTE systems, such as 2, 4, 8, 12, 16, 20, 24, 28, and 32-ports. To this end, the present invention considers a multi-stage codebook structure, and an example of triple stages is as shown in the following Equation 19: W=W1*W2*W3 [Equation 19]where a particular codebook matrix may be replaced with W1 (first PMI) or W2 (second PMI) in a dual-stage codebook structure used in LTE and LTE-A. A 3GPP Rel-13 codebook follows dual structures of Rel-10 and Rel12 codebooks. That is, a final codebook is formed by multiplying W1 and W2, with W1 having the long-term, wideband, and beam group selection characteristics and W2 having the short-term, subband, and beam selection and co-phasing characteristics. The difference with the Rel-10 and Rel-12 codebooks is that, since an antenna port layout to be considered includes two dimensions, the beams in the codebooks are described as a Kronecker product of a vertical beam and a horizontal beam. A 3GPP Rel-13 1-2 codebook may be expressed by the following Equation 20: W=W1W2Wm1,m2,n(1)=12N1N2[vm1⊗um2φnvm1⊗um2],φn=exp(j2πn4),n=0,1,2,3,Wm1,m2,n(2)=12N1N2[vm1⊗um2vm1⊗um2φnvm1-φnvm1⊗um2],φn=exp(j2πn4),n=0,1vm1=[1exp(j2πm1o1N1)…exp(j2πm1(N1-1)o1N1)]Tum2=[1exp(j2πm2o2N2)…exp(j2πm2(N2-1)o2N2)]T[Equation20]where W{circumflex over ( )}(1) represents the final form of the rank 1 codebook, and W{circumflex over ( )}(2) represents the final form of the rank 2 codebook.Here, N1 and N2 are the number of antenna ports per polarization in 1st and 2nd dimensions, and o1 and o2 are the oversampling factors in first and second dimensions. m1 and m2 represent methods of selecting a DFT vector in horizontal and vertical (or first and second) domains. A particular W1 (i.e., first PMI) 2D beam group (i.e., Codebook Configs 1 to 4) may be created through ml (for rank 2, ml and ml′) and m2 (for rank 2, m2 and m2′). The subscript n represents co-phasing. That is, the 3GPP Rel-13 codebook can be viewed as a two-dimensional extension of 8Tx(8 port transfer) codebook of Rel-10 using a Kroneckerk product. Proposal 1) Analog Codebook This proposal proposes a method for reporting CSI information for analog beamforming using a codebook. In an embodiment, one (e.g., W1) of the multi-stages of Equation 19 performs the function/role of codeword selection corresponding to Tx/Rx analog beamforming, or an analog codebook may be generated by a single codebook matrix. In analog beamforming, an analog codebook may be configured by a weighting vector for TXRU virtualization. Using a 2D sub-array model in FD-MIMO, it may be configured by the following Equation 21: vl,i=1Lexp(-j2πλ(l-1)dHsinϑi)forl=l,…,L,o=1,…,o1TXRULwk,o=1Kexp(-j2πλ(k-1)dVcosθetilt,o)fork=1,…,K,o=1,…,o2TXRUK[Equation21]where dv and dH are the spacing between each antenna element, λ is the carrier frequency, K is the number of antenna elements in the N1 domain per TXRU, L is the number of antenna elements in the N2 domain per TXRU, O_1TXRU and O_2TXRU are the oversampling factors of 1-DFT beams formed by the elements in each domain of TXRU, the length of wo is given by K=M/N1′, and the length of vi is given by L=N/N2′. ϑi, θetilt,oare specific directivity angles in N1 and N2 domains, respectively, and may be expressed by scan and tilt angles if N1 is a horizontal domain and N2 is a vertical domain. Accordingly, the final form of a Tx analog beam may be determined as in Equation 22: Wk⊗Vl[Equation 22] Equation 22 corresponds to when antenna element indexing for virtualization is performed first in the N2 direction. If antenna element indexing for virtualization is performed first in the N2 direction, Equation 22 may be transformed into the following Equation 23: Vl⊗Wk[Equation 23] An analog beam may be directed in 2D as described above, or may be directed only in 1D direction by using a vector for horizontal or vertical virtualization alone. In the present invention, exemplary embodiments will be described with respect to, but not limited to, 2D analog beams based on Equation 22 for convenience of explanation. Each vector in Equation 21 may be expressed in the same manner by DFT beams in Equation 18 by a mathematical relationship. For example, Equation 21 may be transformed into the following Equation 24 by expressing each vector by tilting. θtilt=cos-1(-m1λo2,TXRUKdv)[Equation24] Using Equation 24, Equation 21 may be expressed by the following Equation 25: vl=1L[1exp(j2πlo1,TXRUL)…exp(j2πl(L-1)o1,TXRUL)]Twk=1K[1exp(j2πko2,TXRUK)…exp(j2πk(K-1)o2,TXRUK)]T[Equation25]where k=0, . . . , o_(K−1), 1=0, . . . , o_(L−1). Then, the maximum size of an analog codebook may be represented by multiplying L*O_1TXRU and K*O_2TXRU. In the analog codebook, the resulting tilting angle and the scan angle may be configured by uniformly configuring all azimuth angles and zenith angles (e.g., Equation 26, and the above example assume that the zenith angle ranges from −pi to pi and the azimuth angle ranges from −pi/3 to pi/3), and by uniformly dividing the boundary of analog beams by the number of analog beams as in θ1≤θtilt≤θ2and ϑ1≤ϑscan≤ϑ2. In this case, the base station may inform the UE of the number of analog beams used and/or the boundary value of the angle of analog beams by RRC. ϑscan,1=-π3+2π3o1,TXRULl(1=1,…o1,TXRUL),θtilt,k=πo2,TXRUKk(k=1,…o2,TXRUK)[Equation26] The above-explained analog codebook for antenna virtualization may be divided into two types of codebooks: Selection Codebook NP (Non-Precoded) CSI-RS Based Analog Codebook Hereinafter, the selection codebook and the NP CSI-RS based analog codebook will be proposed. In an analog beam selection codebook, particular N_A analog beamforming beams (e.g., the N_A value may be set to L*O_1TXRU*K*O_2TXRU or set/defined to a specific value the base station informs the UE of) may be mapped to N_A CSI-RS ports (or specific ports for analog beamforming), and the UE may report a (selected) PMI using a port selection codebook. The UE may report a number of beams pre-agreed with the base station (or indicated by the base station), including the best beam, the first and second best beams, or the best and worst beams. To this end, the base station may indicate information such as K, O_1TXRU, L, O_2TXRU, etc. or the N_A value to the UE through higher-layer signaling or may pre-agree with the UE about this. The tilting angle or scan angle mainly used for the UE may be limited depending on the UE's channel environment. Thus, to reduce the overhead of analog beam sweeping, the base station may inform the UE of the number of analog beams used for beam sweeping and/or the number of analog beams to be reported by higher-layer signaling or pre-agree with the UE about this. When the selection codebook is used, a single analog beam is mapped to a single antenna port and transmitted, and the UE configures a selection vector by the codebook and report it to the base station. That is, in this case, the codebook is configured by an analog beam selection vector, and the codeword is as shown in Equation 27, and the UE reports the i index of Equation 27 to the base station. ei=[0,…1︸i,…,0]T,wherei=1,…,NA[Equation27] Using Equation 27, the best Tx analog beam reporting codebook may be expressed as in Equation 28: Wanalog,Tx,i=[ei]∈CNA×1[Equation 28] In this case, the number of feedback bits in the codebook is |log2NA|. For example, for N_A=32, a total of 5 bits of a feedback payload is required. When the UE additionally reports the best beam or the worst beam, the UE may be newly defined and used as an indicator indicating the number of beams to be reported, or an RI in an LTE system may be newly defined and used as an indicator indicating the number of beams. For example, when the first beam is selected as the best beam and the fourth beam is selected as the worst beam, the UE may report, to the base station, RI=2 and a PMI index corresponding to Wanalog,Tx2=[e1, e4]∈CNA×2, obtained by applying the first beam and the fourth beam to Equation 28. And/or, the UE may assume a rank 1 restriction on each beam and report a PMI with a different period and/or offset. In this case, the number of feedback bits to be reported is ┌log2(NA(NA−1))┐. And/or, the UE may use the codebook for the purpose of indicating the range of a TX analog beam (e.g., for the purpose of indicating θ1and θ2in θ1≤θtilt≤θ2). While this embodiment has been exemplified with respect to vertical tilting/domain, the present invention is not limited thereto and this codebook may be used for the purpose of indicating horizontal tilting/domain or 2-D tilting/domains where both horizontal and vertical tilting/domains are used. Moreover, in this embodiment, the UE may be understood/interpreted as providing the base station with information on an analog codebook subset restriction, and this may be applicable to digital codebooks. In analog beam sweeping, the payload size may not be a big problem because of the long term and wideband characteristics. Thus, when the analog beam selection codebook is used, analog beams may be fed back in a linear combination as shown in Equation 29 may be considered for more precise feedback. 1∑i∈Slciei∑i∈Slciei[Equation29]where Slis a set of 1-th beams participating in beam combining, and ci is a combination coefficient which may have a particular complex value and be configured by ci,j,k=ai,jexp(jϕi,k). At least some of the elements of Sl, ai,j, ϕi,kmay be pre-agreed between the base station and the UE, and the base station may indicate them to the UE by RRC. For example, if the total number of analog beams used for Tx beam sweeping is 4 and the number of beams participating in combining is 2, Sl∈{(1,2), (1,3), (1,4), (2,3), (2,4), (3,4)}, ai,j={1, 0.5, 0.25, 0}, ϕi,k={1, j, −1, −j} may be established. In the above example, the number of required feedback bits is 3+2+2=7, and at least some of the feedback elements/content may be joint-encoded and fed back/reported. And/or, each element/content may be fed back with a different period and/or different feedback granularity/unit (e.g., Wideband (WB)/Subband (SB)). A combining codebook, in comparison with a codebook only using a selection through Equation 27, has the advantage of being capable of implementing an analog codebook with a relatively higher granularity. If the UE is located in an environment with a lot of interference (e.g., at a cell boundary), performance degradation may get severe due to interference from an analog beam transmitted from an interfering TRP (Transmission Reception Point). In this case, the UE may measure the interference by the codebook and report to the base station information (e.g., {0.5,0.25,0.125,0}*P, where P is transmitted power) on the reduced power level due to the interference, along with/simultaneously with the corresponding codeword. The foregoing embodiment has been described with respect to a Tx beam sweeping operation of the base station. However, if the UE performs Rx beam sweeping, the UE may report information about this to the base station to let the base station know the UE's UL beamforming information. That is, similarly to Equation 25, an Rx analog beam may be represented by Equation 30: ra=1A[1exp(j2πao1r,TXRUA)…exp(j2πa(A-1)oo1r,TXRUA)]T,a=0,…,o1r,TXRUA-1sb=1B[1exp(j2πbo2r,TXRUB)…exp(j2πb(B-1)oo2r,TXRUB)]T,b=0,…,o2r,TXRUB-1[Equation30]where A and B represent the numbers of antenna elements in first and second domains of the UE's TXRU, and o1r,TXRUand o2r,TXRUrepresent the oversampling factors in first and second domains of an analog DFT codebook. The final 2D (or 1D) DFT beam may be expressed as a Kronecker product ra⊗sbor Sb⊗rausing Equation 30, as in Equation 22. For configuring a UL codebook, the UE may additionally give feedback to the base station about information of A, B, o1r,TXRU, and o2r,TXRUor the number of Rx beamforming. And/or, the UE may additionally give feedback to the base station about the port index direction (that is, ra⊗sbor sb⊗ra) or pre-agree with the base station about it. The entire size (Nrx,tot) of the Rx analog beamforming codebook may be ‘A*B*o1r,TXRU*o2r,TXRU’, and the UE's Rx beamforming selection codebook may be represented by Equation 31: Wanalog,Rx,j=[ej]∈CNA,RX×1[Equation 31]where N_(A,RX) represents the number of Rx beamforming. Among all the analog codebooks of Wanalog,Tx⊗Wanalog,Rx, Tx-Rx beam pair codebooks, for example, may be reported collectively or independently, and may have different feedback periods, offsets, and/or feedback granularities/units (e.g., wideband/suband/partial-band). Alternatively, RI may be used in order for the UE to indicate Rx beamforming. For example, if RI=2 is reported, the base station may recognize that Rx beamforming is reported (along with Tx beamforming), and may calculate each Tx-Rx beamforming by the codebooks of Wanalog,Tx⊗Wanalog,Rx. In the above-described analog beamforming selection codebook, complexity increases linearly according to the number of analog beamformed ports. That is, for N_A=128, the number of CSI-RS ports required for one resource is 128, and it may be inefficient to transmit all these many ports in each PRB pair. Accordingly, CSI-Rs Comb-type transmission may be taken into consideration, in which all analog beamformed CSI-RS ports are divided into N sub-port groups and the N sub-port groups are mapped one-to-one to N PRB pairs so that the N sub-port groups are transmitted to every N PRB pairs (i.e., CSI-RS ports required for one resource are divided and transmitted across N PRB pairs). For example, for N_A=128 and N=4, ports corresponding to 0th to 31th beams may be transmitted in 0, 4, 8, . . . PRB-pairs (i.e., 4n PRB-pairs (n=0,1,2 . . . )), ports corresponding to 32th to 63th beams may be transmitted in 1, 5, 9, . . . PRB-pairs (i.e., 4n+1 PRB-pairs (n=0,1,2 . . . )), ports corresponding to 64th to 95th beams may be transmitted in 2, 6, 10, . . . PRB-pairs (i.e., 4n+2 PRB-pairs (n=0,1,2 . . . )), and ports corresponding to 96th 127th beams may be transmitted in 3, 7, 11, . . . PRB-pairs (i.e., 4n+3 PRB-pairs (n=0,1,2 . . . )). Alternatively, ports (32 ports in the above example) corresponding/included in each sub-port group may be transmitted with different time offsets and/or periods for each sub-port group (and/or for each port in each sub-port group). To reduce overhead in terms of the UE's reporting, port selection may be performed by using RI for the purpose of indicating the above-mentioned time offset and/or frequency offset. For example, if the best analog beam is the 64th beam in the above example, the UE may report RI=3 and PMI=1(Wanalog,Tx,1=[e1]∈C32×1) to the base station. The above-described selection-based codebook may be used solely for the purpose of beam management, and may have a higher priority level than other CSIs (e.g., i1(first PMI), i2(second PMI), RI, CQI and/or CRI). Also, if the beam gain is lower than or equal to a particular threshold, the UE may trigger CSI-RS port transmission for the selection codebook or report a beam index (e.g., the second best beam index) different from the beam index reported immediately before reference resource reception. Hereinafter, an NP CSI-RS based analog codebook will be described. In beam sweeping, as the number of beams increases (i.e., as K, L, o1, and o2 increase), a larger number of OFDM symbols used for beam sweeping and/or more CSI-RS ports are required and the complexity of calculation by the UE increases much. If the total number of antenna elements or K*L is equal to the number of CSI-RSs supported in NR, the UE may measure channels and report the best analog beam and/or digital beam by using NP CSI-RS (i.e., through 1:1 element-to-port mapping). In an example, Equation 32 may be configured as a final codebook by using Equation 19. In this case, when the UE reports an analog codebook, the analog codebook may be reported based on a multi-stage codebook (e.g., triple-stages as in Equation 32), and the analog codebook may be used as one component of the multi-stage codebook. W=WaW1W2=[Wa1000⋱000Wa,Nports]︸AnalogcodebookW1W2︸Digitaldualstagecodebook[Equation32] Analog codebooks (Wai∈CNA×1(i=1, . . . , Nports, where Nportsis the number of digital ports)) positioned in the diagonal term of the first matrix of Equation 32 may be configured by Equation 22 or 23, and W1 and W2 may be an LTE codebook or a digital codebook to be described later. Moreover, for Wa1= . . . =Wa1Nports, the same analog beam is applied to all digital ports, in which case the UE may only give feedback/report of the PMI of a representative analog beam for all the ports. However, it should be noted that, for more precise CSI feedback, the UE may perform feedback/report assuming Wa1≠ . . . ≠Wa1Nportsusing different analog beams for every port. In this case, there may be a disadvantage that the number of feedback bits increases by N_ports, as compared to using the same analog beam for every port. However, PMI (i.e., Wa) feedback on analog beams has a very long term characteristic (e.g., an integer multiple of digital W1 or RI), and the overhead increase may not be that large from the entire system perspective. Accordingly, for efficient use of the codebook, the base station may transmit NP CSI-RS in K*L ports in the first CSI-RS resource according to the UE's analog codebook feedback period, assuming that the same analog beam applies to every port. In this case, the UE may report the best analog beam index to the base station, and, with this, the base station may transmit, to the UE, N_ports CSI-RS using analog beamforming (corresponding to the analog beam index reported by the UE) for the second CSI-RS resource. The UE may give report/feedback (i.e., digital codebook feedback) to the base station about the RI, PMI and/or CQI for/corresponding to N_ports. The aforementioned two resources (i.e., the first and second CSI-RS resources) may have different periods and/or offsets. If collision occurs between the two resources, the resource for analog beamforming (i.e., the resource for determining an analog beam; the first CSI-RS resource in the above example) has a higher priority level. Alternatively, to apply a codebook with high granularity, the base station may transmit CSI-RS using K*L*N_ports NP CSI-RS ports in one resource, and the UE may report the best PMI, CQI and/or RI to the base station based on the CSI-RS. Proposal 2) Digital Codebook In the New RAT, LTE codebooks or class A codebook may be re-used. Such codebooks have a dual-stage structure, and examples of this structure include Rel-10 8Tx, Rel-12 4Tx, Rel-13 12Tx, 16Tx, Rel-14 20-, 24-, 28-, and 32Tx codebooks. In the dual-stage structure (i.e., W=W1*W2), W1 serves to determine a specific number of beam groups with the long-term/wideband characteristics, and W2 serves to select beams within a beam group with the short-term/subband characteristics, determined as W1, and perform co-phasing under an X-pol antenna situation. Preferably, codebooks used in the New RAT are configured within one framework, and it is expected that configuring a codebook with configuration information such as parameters N1 and N2 for configuring a TX port and o1 and o2 for configuring a codebook will make it easy to maintain scalability and implement the UE. In an LTE 2-port codebook, rank 1 is configured by QPSK (quadrature phase-shift keying) (indices 0,1,2, and 3 of Table 4), and rank 2 is configured by QPSK (indices 0,1, and 2 of Table 4). However, if analog beams are applied to ports to make the beams sharper, it may be better to increase beam granularity in terms of performance. Accordingly, the present invention proposes to configure a 2-port codebook of rank 1 and rank 2 using 8-PSK for co-phasing, as in Table 4, in order to increase 2-port granularity. TABLE 4CodebookNumber of layers υindex12012[11]12[1001]112[1-1]12[111-1]212[1j]12[11j-j]312[1-j]122[221+j-1-j]412[21+j]122[221-j-1+j]512[21-j]—612[2-1+j]—712[2-1-j]— And/or, the base station may configure a codebook bit field for the UE to set whether the final codebook is QPSK or 8-PSK. For example, if the UE is given a 2-bit field from the base station, the UE may use the codebooks of the indices 0 to 3 in Table 4, and if the UE is given a 3-bit field from the base station, the UE may use the codebooks of the indices 0 to 7 in Table 4. This may be used for a purpose similar to a codebook subset restriction. While the existing codebook subset restriction cannot reduce feedback bits, the above proposed method may reduce feedback bits to thereby reduce uplink overhead. In another embodiment, if different analog beamforming is performed for each port and there are many antenna elements for virtualization that constitute a single analog beam to form very sharp beams, the codebook performance improvement caused by digital codebook application is expected to be not very high. In this case, it may be more efficient to apply different beams to two ports and select only a particular port. In this case, a 2-port codebook configuration may be proposed as in Table 5. TABLE 5CodebookNumber of layers υindex120[10]12[1001]1[01] In the proposal according to Table 5, no PMI feedback (i.e., beam selection) is required for rank 2. In another embodiment, a codebook having codewords with different magnitudes for different ports may be configured, and an example of this is as shown in Equation 33: 11+a2[1αϕn]forRank112+2a2[1aaϕn-ϕn]forRank2[Equation33] As exemplified in Equation 33, in a 2-port codebook, a port may have a particular magnitude that is equal to or smaller than that of another port. For example, in Equation 33, α={1,0.5,0.25,0} If α is 1, the codebook has the characteristics of the codebook exemplified in Table 4, and if α is 0, the codebook is similar to the port selection codebook exemplified in Table 5. α may be applied for each wideband or partial-band, and the reporting period is long-term. In Equation 33, ϕn=exp(−j2πn/4) for n=0, 1, 2, 3, ϕn=exp(−j2πn/8) for n=0, 1, . . . , 7 corresponding to the phase may be set to QPSK or 8-PSK according to the range of the n value. Accordingly, the base station may inform the UE of specific information corresponding to the a value and/or ϕnco-phasing size by RRC or pre-agree with the UE. Alternatively, the base station may signal/configure bit fields for the amplitude and co-phase of the codebook for the UE individually or integrally and set them for the UE. For example, if the bit field size of the amplitude is set to 1 bit, α={1,0.5} or α={1,0}, and the base station may set the co-phase bit field size to 2 bits and inform the UE of information on co-phasing based on QPSK. The above-explained codebook may assume X-pol and be more suitable when the same analog beam is configured/applied for each port. On the other hand, if different analog beams are configured/applied for each port, it may be ambiguous to know which port is given a better beam gain due to the differences in beam gain. Thus, a codebook having such a structure as in Equation 34, which is a more generalized form of the proposed codebook, may be suggested. According to this codebook, the power amplitude codebook of each port may be configured independently, thereby improving performance gain. 1α2+β2[αβϕn]forRank112(α2+β2)[αββϕn-αϕn]forRank2[Equation34] In the codebook according to Equation 34, the values of parameters (α,β,ϕn) (and/or each parameter set and/or set size) may be set by RRC or pre-agreed between the base station and the UE. Alternatively, when the UE reports a port index with a relatively high gain in 1 bit to the base station to reduce the feedback bits of a α,β, the base station may set the amplitude coefficient of the corresponding reported port to ‘1’. In this case, the UE reports only the amplitude coefficient information of the other one port to the base station, and as a result, the feedback bits are reduced. For example, in a case where the UE gives feedback/report of a port index with a high gain as the second port, β=1 is determined/set, and α may be determined/set to a value the UE reports to the base station, within an amplitude set (e.g., α={1, 0.5, 0.25, 0}) pre-agreed between the base station and the UE. To apply the aforementioned 2-port codebooks to a unified framework of the dual-stage structure, W1 (matrix) may be assumed as a square matrix (I), and the codebooks of Table 4 or Table 5 may be applied as W2 (matrix) (i.e., W=W1*W2=I*W2). In another method, the aforementioned analog beam selection codebooks may be used for W1, and W2 may be configured as in Table 4 and Table 5 so that codebooks are defined/applied in the form of W=W1*W2=Wa*W2. For Wa, the aforementioned Tx analog codebook configuration may be used. In another method, Wa may be N_(a,Tx) analog beam selection codebooks. For example, for N_(a,Tx)=4, selection codebooks of Wa may be configured/defined as (ei, ej)∈{(i,j)|(1, 1),(2, 2),(3, 3),(4, 4), (1,2),(1,3),(1,4), (2,3), (2,4),(3,4)}, or a set of some of them to adjust to the payload size for example, (ei,ej)∈{(i,j)|(1,1), (2, 2),(3, 3), (4,4),(1,2),(1,4), (2,3), (2,4)}, a beam selection combination of LTE-A rank 2 codebooks. Alternatively, for N_(a,Tx)=4, selection codebooks of Wa may be specialized for Table 5 and configured/defined/transmitted by using different beams for different ports (in the above example, (ei,ej)∈{(i,j)|(1,2),(1,3),(1,4),(2,3),(2,4),(3,4)}). In another method for configuring a 2-port codebook, W2 in W=Wa*W2 may be configured by a linear combining codebook. For example, W2 may be configured as in 1c22+c22([c10]+[0c2]), and c1 and c2 have a complex value. The base station may configure which of the aforementioned codebooks the UE will use/apply by RRC. Proposal 3) Panel-Based Codebook One of the new characteristics of the New RAT is to support a multi-panel antenna array consisting of multiple antennas as shown inFIG.20. In this case, as shown inFIG.20, unless the spacing between panels is set in such a manner that the spacing between all antenna elements is constant, the characteristics (i.e., uniform increments) of DFT codebooks which the existing LTE is based on, are not met, thereby leading to performance degradation. To solve this, the present invention proposes a method (proposal 3-1) that performs compensation between each panel and/or a method (proposal 3-2) that selects a specific panel(s) and configures a digital codebook. 3-1) Compensation Between Panels For convenience of explanation, this embodiment will be described with reference toFIG.20. InFIG.20, ports may be configured for each panel by 4-element vertical antenna virtualization, with each panel (panels 1 through 4) including 8 ports, and therefore a total of 32 digital ports are configured. 32 ports are supported in eFD-MIMO, and class A codebooks may be used. In this case, the final codebook may be as in Equation 35: W=WcW1W2=[00]︸Wc[00]︸W1[ei2ϕnei2]︸W2[Equation35] where {tilde over (W)}c∈CN1N2is a diagonal matrix and serves to perform codebook compensation control (i.e., compensation matrix/codebook), w1∈C2N1N2×2NW1 W1 of a dual-stage codebook in a LTE system, N_W1 corresponds to the number of beam groups of W1, and W2∈C2W1×rankis W2 of the dual-stage codebook in the LTE system and serves to perform beam selection and co-phasing. Referring toFIG.20, assuming that (N1′=4, N2′=1) N2 direction is a vertical direction, We may be configured as in Equation 36: =[00],=[1α1α1α1α],=[βγβγβγβγ][Equation36]where α, β, γ refer to compensation terms/compensators/correctors (hereinafter, ‘correctors’) of panels 2, 3, and 4 (with respect to panel 1)—for example, they may have a particular complex value such as QPSK{1,−1,j,−j} (and/or BPSK (binary phase-shift keying)). These correctors may be used to compensate for the phase and/or amplitude between panels, and the UE may signal the correctors (e.g., α, β, γ) and give report/feedback to the base station by CSI (e.g., PMI in CSI). In this case, the UE may give report/feedback indicating that a corrector is WB (Wideband) and/or SB (Subband) according to the RRC mode setting (e.g., modes 1 and 2) by the base station (that is, the UE reports to the base station about a corrector (hereinafter, described as “WB and/or SB panel corrector’) selected/derived/acquired for Wideband and/or Subband according to the mode setting). If γ can be expressed by a function of α and β due to the characteristics of a linear planar array (for example, γ=α*β), the UE may not give feedback on γ and therefore the feedback overhead is reduced. The above concept may be expanded to designate one representative panel corrector value for each domain. In the above example, α may be designated as a vertical panel reference corrector, and β may be designated as a horizontal panel reference corrector, and the correctors for the other panels may be expressed by a function of α and/or β. For example, if panel 5 exists at the right side of panel 3 ofFIG.20, the phase corrector (compensation value) of panel 5 may be expressed by a function of α, as in f(a)=α2, for example. Although the corrector may have maximum performance when feedback is given in SB and/or short-term periods, the feedback overhead may be saved by giving report/feedback in the same period as W1 PMI or in integer multiples thereof. The configuration of a matrix (compensation matrix) for the corrector may affect the method of indexing between all the panels and ports. Therefore, the port indexing direction may be pre-agreed between the base station and the UE or indicated to the UE by higher-layer signalling. In another compensation method, compensation may be performed on a port or panel sub group in a panel that maintains the linear increments between antenna ports. This can be mathematically expressed by Equation 37: W=WcW1W2=[I0…00αIβI⋱γI⋮⋮⋱IαIβI00…0γI][W~10…00W~2W~3⋱W~4⋮⋮⋱W~1W~2W~300…0W~4][e1e2e3e4ϕne1ϕne2ϕne3ϕne4][Equation37]where Wc∈CN1N2×N1N2, ∈CN1′N2′×NW1′ is defined as a W1 fat matrix configured by the number of ports set within one panel, and I∈CN′1N′2×N′1N′2. Also, W2 is a matrix that performs beam selection and co-phasing for each panel, which has been described assuming rank 1 in the above example but not limited thereto and may be expanded to a general W2 expression. In the example described above and example to be described later, the co-phase is described as configured/reported alike for each panel for convenience of explanation, but it is needless to say that the co-phase may be configured/reported independently for each panel for performance improvement. According to the method according to Equation 37, the following two cases may be taken into consideration: i) {tilde over (W)}1≠{tilde over (W)}2≠{tilde over (W)}3≠{tilde over (W)}4and ii) {tilde over (W)}1={tilde over (W)}2={tilde over (W)}3={tilde over (W)}4. i) As exemplified inFIG.20, for example, an 8-port codebook is used for each panel, and different W1 beam groups are assumed for each panel. Thus, codebook granularity increases significantly, thereby increasing performance gain. However, the calculation complexity and the number of feedback bits may increase in proportion to the number of panels, as compared to ii). There is an advantage that complexity and the number of feedback bits can be reduced because of the use of a representative W1 beam group for each panel. In this case, as is the case with the codebooks of Equation 35 and/or 36, α, β, γ for panel compensation may have a particular complex value such as QPSK {1, −1, j, −j}, and their feedback periods may be equal to a W1 PMI period or integer multiples of the W1 PMI period. According to the method according to Equation 37, an 8-port codebook is assumed for each panel, and Equation 37 may also apply to two 16-port panel sub-groups consisting of panels 1 and 2 and panels 3 and 4, respectively, inFIG.20. To this end, the UE may additionally report information on the panel sub-groups to the base station. For example, if the base station informs the UE of the number of panels of each panel sub-group and the number of panels along the horizontal or vertical direction in each panel sub-group, then the UE may select a specific panel sub-group and report it to the base station. This sub panel group (i.e., the sub panel group reported by the UE) may be used for each digital codebook application, or may be used for the purpose of indicating a group to which the same analog beam is applied. In a case where digital precoding is configured for each panel or for each sub panel group as in Equation 37, it may be desirable that port indexing is performed preferentially on “ports having the same polarization within one panel” in order to facilitate codebook configuration. 3-2) Panel/Sub Panel Group Selection Codebook When different analog beamforming is performed/applied for each panel or for each sub panel group, it may be desirable to select a panel or sub panel group corresponding to the best analog beam and give CSI feedback. To this end, the We matrix in Equation 37 may be modified into a selection matrix as shown in Equation 38 and used. Ws=[ρI0…00αIβIγI⋮⋮⋱ρIαIβI00…0γI]∈CN1N2×N1N2,ρ,α,β,γ∈{0,1}[Equation38]where I∈CCN1′N2′×N1′N2′. If only one among ρ, α, β, and γ has a value of 1, single panel selection is performed (2-bit feedback is required in the above example), and if two or more among ρ, α, β, and γ have a value of 1, multi-panel selection is performed (4-bit feedback is required in the above example). In the latter case, the UE may expect that the same analog beam will be transmitted through the selected multi-panels. Hence, when a PMI for panel selection is reported to the base station, the base station will find out that the UE is using only the ports in the panels corresponding to the reported PMI, and will activate the corresponding ports and deactivate the other ports for the corresponding UE and use them for other UEs' transmissions. In the above example, assuming that two panels are selected, a total of 2*2*N1′*N2′ ports are activated. In this case, the UE may apply a digital codebook corresponding to the 2*2*N1′*N2′ ports and give a PMI/CQI/RI report. If a non-uniform port layout is configured by the UE's panel selection, a codebook, combined with the above-explained method of compensation between ports, may be applied/used for performance improvement. When describing this embodiment in association with the base station's capability, if the base station has good calibration between panels, it may be desirable for it to perform digital beamforming using all of the 2*2*N1′*N2′ ports. On the contrary, if the base station has no good calibration between panels, it may be desirable for it to perform digital beamforming on 2*N1′*N2′ ports or NP*2*N1′*N2′ ports corresponding to one panel or a specific NP number of panels. That is, a non-calibrated base station may indicate to the UE to configure/apply the panel selection codebook so as to prevent digital beamforming through port aggregation between panels. Alternatively, the UE, if it has a sufficiently high gain by analog beamforming thanks to a good geometry, may not highly require digital beamforming, and the UE may select a preferred panel(s) by using a panel selection codebook in order to reduce the complexity of codebook calculation. To make the aforementioned panel selection codebook work properly, the base station may inform the UE of information about at least one among N1, N2, N1′, and N2′ by RRC or pre-agree with the UE. Moreover, the aforementioned codebooks may be used individually or in combination. In the latter case, for example, an analog beam selection codebook and a panel selection codebook may be used in combination. This example may apply when different analog beams are applied to different panels. 3-3) Panel/Sub Panel Group Combination Codebook When a panel linear combination codebook is configured by modifying the aforementioned selection codebook, We may be configured by Equation 39. Wc=[ρIαIβIγI00000000ρIαIβIγI]∈C2N1N2×N1N2=[ρIαIβIγI00000000ρIαIβIγI][W~10…00W~2W~3⋱W~4⋮⋮⋱W~1W~2W~300…0W~4][e1e2e3e4ϕne1ϕne2ϕne3ϕne4]=[ρW~1e1+αW~2e2+e3+e4ϕn(ρW~1e1+αW~2e2+e3+e4][Equation39] Referring to Equation 39, the length of a column in the dimension of the final codebook is set to 2*N1′*N2′, and this may be understood/interpreted that analog and digital beamformed vectors with the length of 2*N1′*N2′ for each port are combined. In the above method, the values of ρ, α, β, and γ may be expressed by ρ=aexp(kjψa), α=abexp(kjψb), β=acexp(kjψc), γ=adexp(kjψd), for example. In this case, the amplitude component (aa, ab, ac, ad) and the phase component (ψa,ψb,ψc,ψd) may be reported independently or integrally. In an independent report, for example, the UE may report the amplitude component as wideband (or partial-band)/long-term and the phase component as wideband/subband, individually. Because a combination is done, the amplitude (a) may be set to one of the values {1,0.5,0.25,0}, and the phase (ψ) may be set to one of the values QPSK {1,−1,j,−j}. To save the payload size, the number of combined panels may be limited to a specific number, and this number of panels may be signalled by RRC (or MAC (Medium Access Control) CE (Control Element)) or may be pre-agreed between the UE and the base station. That is, in the above example, if the number of combined panels is assumed to be 2, the UE may report the power index 0 for the least preferred two panel indices or may select two panels first at the front end of the panel combination codebook. That is, in a case where two beams out of four panel beams are combined, if indices are allocated for each combination of panels, as in {(1,2), (1,3), (1,4), (2,3), (2,4), (3,4)}, the UE may first report a particular index selected by them to the base station and then perform the panel combination codebook for the selected panels. Moreover, it may be inefficient to report each value corresponding all power combining coefficients. Thus, the power combining coefficient for a particular panel (i.e., a panel with the highest beam gain or the first panel as default) may be assumed/set to be a specific value, and the UE may report only the power combining coefficient for the other combined beam. For example, if the power of the first panel is assumed to be ‘1’, the UE may report the amplitude values of α, β, and γ corresponding to the other panel. In the panel combination codebook proposed above, the base station may configure whether the UE will use the same codebook or phase compensation (WB and/or SB) for each panel or different codebooks or phase combinations for each panel. In the case of a codebook with different beam groups for each polarization, if the above-explained panel compensation codebook is applied, the values of ρ, α, β, and γ may be set/applied independently for each polarization. That is, ρ_1, α_1, β_1, and γ_1 for the first polarization and ρ_2, α_2, β_2, and γ_2 for the second polarization—i.e., a total of 8 independent variables—may be used to perform panel compensation. Similarly to the method proposed above, a codebook for indicating/reporting a differential in compensation value between a panel and a reference panel may be considered/proposed. The proposed compensation codebook may be extensively applied as an SB panel correction codebook, as well as a WB panel correction codebook. This may increase the payload for SB CSI feedback, but a panel calibration codebook may be applied for each SB, which reflects frequency selectivity better and therefore leads to a very large improvement in performance. However, to solve the problem of the payload increase, the feedback granularity/unit/size/bit-width of the SB panel corrector may be set/defined differently from the feedback granularity/unit/size/bit-width of the WB panel corrector. Particularly, to reduce feedback overhead, the feedback granularity/unit/size/bit-width of the SB panel corrector may be set/defined to be smaller than the feedback granularity/unit/size/bit-width of the WB panel corrector (that is, the feedback granularity of the SB panel corrector is lower than the feedback granularity of the WB panel corrector). For example, the feedback granularity/unit/size/bit-width of the WB panel corrector may be set to 2 bits (in QPSK), and the feedback granularity/unit/size/bit-width of the SB panel corrector may be set to 1 bit (in BPSK). In this case, the UE may give the base station a recommendation/feedback about whether to use the WB and/or SB panel correction codebook. And/or, the base station may configure whether or not the UE uses the WB and/or SB panel correction codebook by RRC configuration. For example, the application of the WB panel correction codebook may be defined as a first mode, and the application of both the WB and SB panel correction codebooks may be defined as a second mode, and the base station may indicate to the UE which mode to apply through specific RRC signalling (e.g., ‘CodebookMode’). When the first mode is set, the UE may report to the base station the WB panel corrector selected/derived based on QPSK in a 2-bit size by CSI (particularly, PMI). When the second mode is set, the UE may report to the base station the WB panel corrector selected/derived based on QPSK in a 2-bit size and the SB panel corrector selected/derived based on BPSK in a 1-bit size by CSI (particularly, PMI). In the second mode, the WB panel corrector may be used to compensate for the overall co-phase, and the SB panel corrector may be used to compensate for the overall co-phase, and the SB panel corrector may be used to finely compensate for the co-phase. Alternatively, whether to use the WB panel correction codebook or the SB panel correction codebook may be tied to the number (=Mg*Ng) of panels of the base station. For example, for Mg*Ng=4, the number N_W1 of beams of W1 in a digital codebook may be set/applied to 1, and, for Mg*Ng=2, the number N_W2 of beams of W1 in a digital codebook may be set/applied to 2 (N_W1=2). While the proposed codebook has been described with respect to DL, it is not limited thereto but may be readily and extensively applicable to UL codebook configuration. Hereinafter, Type 1 codebook configuration assuming a single panel will be described. First of all, the use of the same beam group will be described, which may be expressed as in Equation 40: W1=[B00B][Equation40]where W1 performs beam grouping with WB/long-term characteristics in the dual-stage codebook. In this case, B∈CN1N2×L, and B may have L values (e.g., L=1,2,4,7, . . . ). Although N_W1 has been used before indicating the number of beam groups of W1, it will be hereinafter replaced with L. Now, a description will be given of a case where the UE selects L beams. The UE may freely and explicitly indicate L beams being used to the base station in an explicit fashion (e.g., in bitmap form or by indicating the beam index). In this case, the number of required bits is L*N1*N2*O1*O2 or ┌log2(LN1N2O1O2)┐, and there is a problem that the feedback bits increase as L and the number of Tx antenna ports increases. Accordingly, the UE may freely select beams within a specific GoB (Grid of Beams) as a way to cut down the number of feedback bits. An example of this will be described below with reference toFIG.21. FIG.21is a view illustrating GoB for N1=4, O1=4, N2=2, and O2=4 according to an exemplary embodiment of the present invention. Referring toFIG.21, when a beam selection window of 4 by 6 is configured, the UE may freely select L−1 beams within this window. In this case, the UE may give feedback about the position of a primary/leading beam2101and the window size of 4 by 6. In another method, an exemplary embodiment ofFIG.22may be applied. FIG.22is a view illustrating a window configuration method for N1=4, O1=4, N2=2, and O2=4 according to an exemplary embodiment of the present invention. Referring toFIG.22, the entire GoB is divided into windows of a size recommended/fed back by the base station or UE, and the UE may give feedback on the index (position) of a window and/or information on the selection of L beams freely selected within that window.FIG.22illustrates the existence of 8 windows of 4 by 6. According to the configuration, adjacent windows may overlap. In this case, the base station may configure information on the positions and/or size of the windows for the UE. If the UE selects L beams used for W1, as proposed above, high feedback bitrate is required. Thus, feedback information (e.g., information on the selection of L beams) may be limited to using PUCCH reporting, rather than using PUSCH reporting. Hereinafter, different diagonal matrices forming W1 (i.e., different beam groups used for each polarization) will be described, which can be expressed as in Equation 41. W1=[B100B2][Equation41]where B1≠B2, and B1 and B2 may have different dimensions. Bi∈CN1N2×Li(i=1,2) is defined, Lirepresents the number of beams in a beam group of i-slant (e.g., i=1 H slant, and i=2 V slant), and L1 and L2 may have different values (e.g., L1=1, and L2=2). The base station may pre-agree with the UE about the L1 and L2 values, or may configure these values for the UE by a higher layer (e.g., RRC or MAC CE). Alternatively, the UE may give the base station a recommendation/feedback about information on the L1 and L2 values. Configuring W1 as above has the advantage of applying the best codeword for each polarization but has the disadvantage of significantly increasing the feedback overhead of W1. Accordingly, an exemplary embodiment for solving these disadvantages will be proposed. Firstly, L1=L2(i.e., if the number of vertical beams and the number of horizontal beams are equal) will be described. In this case, W2 for rank 1 codebook configuration will be proposed as in Equation 42. W2=[eiϕnej][Equation42] where i≠j, i, j∈{1, . . . , L} and ϕn={1, j, −1, −j} are defined, and eirepresents a selection vector whose length is L and whose ith element has a value of 1 and the other elements has a value of 0. In this case, i and j must be reported individually, and twice as much feedback overhead is consumed for beam selection as compared to when the same beam group is used. For this design, i, j, and co-phase values may be reported as SB. To reduce the SB feedback overhead for beam selection, L1=L2=1 should be satisfied. In this case, W2 may be set to W2=[1ϕn] In another method, the UE may give report/feedback about i11 and i12 for B1 and give additional report/feedback about the differential between B1 and B2. Here, i11 and i12 represent the first and second domain indices of W1 PMI as in LTE codebooks. That is, the UE may give feedback/report to the base station about how far B2 is spaced apart from the leading beam indices i11 and i12 of B1 in the first and second domains. For example, when the leading beam index (i11, i12) of B1 is (10,2) and a value corresponding to (2.4) as the differential of B1 is additionally reported/fed back to the base station, the base station may recognize the leading beam (i11, i12) of B2 as (12,6) and configure B2. In this method of indicating the differential between B1 (index) and B2 (index), the differential may be agreed between the UE and the base station as a specific value for each domain, or the base station may configure the differential for the UE, or the UE may give report/feedback to the base station. To reduce the report/feedback overhead, the UE may give feedback only about information on the specific domain (e.g., first or second domain). In this case, the base station may configure the specific domain for the UE, or the UE may inform the base station of the specific domain. The rank 2 codebook configuration may be expressed as in Equation 43: W2=[eiekϕnej-ϕnel][Equation43] As can be seen from Equation 43, variables of i, j, k, and l should meet the following conditions to maintain the orthogonality for each layer in the rank 2 codebook. 1. ei=ek, ej=el: In this case, the codebook indicates that the same beam is selected for each polarization when configuring a layer. When configuring the codebook, ϕnmay be limited to ϕn={1,j}, for example. In this case, beams forming the codebook may be normalized to 1. 2. {ei≠ek},{ej≠el}: In this case, B1 of W1 should be configured for each polarization so that beams selected by i and k are orthogonal to each other, and B2 of W1 should be configured for each polarization so that beams selected by j and l are orthogonal to each other. That is, beam groups of B1 and B2 of W1 should consist of beams orthogonal to each other. Alternatively, if there are some non-orthogonal beams, the codebook may be configured by pairing orthogonal beams in the above method. For example, for B1=[b0b1bO1b1+O1], assuming that b0, bO1are orthogonal to each other and b1, b1+O1are orthogonal to each other b0, bO1and b1, b1+O1may be paired according to the above second method—that is, pairing may be done two times in total. In this method, co-phase of ϕn={1,j,−1,−j} may be used. Hereinafter, L1≠L2will be discussed. In this case, a codebook may be configured by extensively applying the above method proposed for L1=L2. As a special example of L1≠L2, L1=1 will be described first. In this case, the rank 1 configuration of W2 is as shown in Equation 44: W2=[1ϕnei][Equation44] In this case, beam selection and co-phasing are possible for beams corresponding to one slant. Thus, a PMI may be determined/indicated independently for each polarization, thereby increasing codebook granularity and improving performance. In this case, ϕn={1, j, −1, −j} may be used. When designing the codebook as above, the codebook may be configured in such a way that B1⊂B2is established (that is, L beams of B2 always include B1) to form a super-set of LTE Class A codebook Config 1. Alternatively, the UE may recommend information on B2 to the base station. Similarly, rank 2 codebook may be configured as in Equation 45: W2=[11ϕnei-ϕnej][Equation45] For ei=ej, ϕn={1, j} may be used, and for ei≠ej, if beams selected as i and j are orthogonal to each other, ϕn={1, j, −1, −j} may be used. Alternatively, co-phase with the same granularity may be applied to both of the two cases. In the above-explained method, WB co-phase for beams of B2may be reported along with the B2 index. That is, {tilde over (B)}2=ψnB2may be set, and W1 may be configured as in Equation 46. W1=[B100B~2][Equation46]where ψnis a WB co-phase value, for example, ψn={1, j, −1, −j}. In this case, SB co-phase may be configured as in ϕn={1+j2,1-j2,-1+j2,-1-j2}, for example, to have a different co-phase from WB, thereby increasing codebook granularity. To save SB feedback bits, the UE may report 2-level co-phase by using 1-bit co-phase (e.g.,ϕn={1,1+j2}). The proposed method is readily applicable to B1=B2and B1 and B2 of W1 may be configured/applied independently for each band (or band group). As described above, similarly to the method of using different beam groups for each polarization, the SB size may be reduced to increase the accuracy of SB PMI. Once the SB size is reduced, PMI per SB can be more accurate but feedback overhead increases. Accordingly, the base station may configure, for the UE, whether to reduce the SB size and/or use a codebook of B1≠B2. A new codebook may be configured by combining the above-proposed codebook designs. FIG.23is a flowchart illustrating a method for a UE to report CSI according to an exemplary embodiment of the present invention. Regarding this flowchart, the foregoing embodiments/descriptions may apply equally or similarly, and redundant explanation will be omitted. First of all, the UE may measure a CSI-RS transmitted from the base station through multiple panels (S2310). Next, the UE may report to the base station CSI generated based on the CSI-RS measurement (S2320). In this case, if the UE reports a WB panel corrector and SB panel corrector for the multiple panels as the CSI (according to the CSI settings by the base station), the WB panel corrector and the SB panel corrector may be reported with different bit widths. Here, the WB panel corrector may correspond to a beam/codebook phase corrector for each panel derived/determined/selected based on the measurement of CSI-RS (resources) for WB, and the SB panel corrector may correspond to a beam/codebook phase corrector for each panel derived/determined/selected based on the measurement of CSI-RS (resources) for SB (or for each SB). That is, the WB panel corrector and the SB panel corrector may be used for phase correction between the multiple panels. The number of panels may be set by higher-layer signalling. Particularly, the bit width of the SB panel corrector may be shorter than the bit width of the WB panel corrector—for example, the bit width of the SB panel corrector may be set to 1 bit, and the bit width of the WB panel corrector may be set to 2 bits. Thus, the WB panel corrector may be reported based on QPSK, and the SB panel corrector may be reported based on BPSK. If the UE reports only the WB panel corrector as the CSI, the WB panel corrector may be reported with a bit width of 2 bits. Whether to report both the WB panel corrector and the SB panel corrector or only the WB panel corrector may be determined according to the mode set by the base station (e.g., the mode set by RRC signalling). For example, if the base station indicates mode ‘1’ to the UE, the UE may recognize that only the WB panel corrector is reported, and if the base station indicates mode ‘2’, the UE may recognize that both the WB panel corrector and the SB panel corrector are reported. The WB panel corrector and the SB panel corrector may be included in a PMI within the CSI when reported. Also, the WB panel corrector and the SB panel corrector may be reported independently for each of the plurality of panels. General Devices to which the Present Invention is Applicable FIG.24illustrates a block diagram of a wireless communication system according to an exemplary embodiment of the present invention. Referring toFIG.24, the wireless communication system includes a base station2410and a plurality of UEs2420located within the region of the base station2410. The base station2410includes a processor2411, a memory2412, and an RF (radio frequency) unit2413. The processor2411implements the functions, processes and/or methods proposed above. The layers of wireless interface protocol may be implemented by the processor2411. The memory2412is connected to the processor2411, and stores various types of information for driving the processor2411. The RF unit2413is connected to the processor2411, and transmits and/or receives radio signals. The UE2420includes a processor2421, a memory2422, and an RF unit2423. The processor2421implements the functions, processes and/or methods proposed above. The layers of wireless interface protocol may be implemented by the processor2421. The memory2422is connected to the processor2421, and stores various types of information for driving the processor2421. The RF unit2423is connected to the processor2421, and transmits and/or receives radio signals. The memories2412and2422may be located interior or exterior to the processors2411and2421, and may be connected to the processors2411and2421by well-known various means. In addition, the base station2410and/or the UE2420may have a single antenna or multiple antennas. The above-described embodiments correspond to combinations of elements and features of the present invention in prescribed forms. And, the respective elements or features may be considered as selective unless they are explicitly mentioned. Each of the elements or features can be implemented in a form failing to be combined with other elements or features. Moreover, it is able to implement an embodiment of the present invention by combining elements and/or features together in part. A sequence of operations explained for each embodiment of the present invention can be modified. Some configurations or features of one embodiment can be included in another embodiment or can be substituted for corresponding configurations or features of another embodiment. And, it is apparently understandable that an embodiment is configured by combining claims failing to have relation of explicit citation in the appended claims together or can be included as new claims by amendment after filing an application. In the present description, “A and/or B” can be interpreted as “at least one of A and B”. The embodiments of the present invention may be implemented by various means, for example, hardware, firmware, software and the combination thereof. In the case of the hardware, an embodiment of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), a processor, a controller, a micro controller, a micro processor, and the like. In the case of the implementation by the firmware or the software, an embodiment of the present invention may be implemented in a form such as a module, a procedure, a function, and so on that performs the functions or operations described so far. Software codes may be stored in the memory, and driven by the processor. The memory may be located interior or exterior to the processor, and may exchange data with the processor with various known means. It will be understood to those skilled in the art that various modifications and variations can be made without departing from the essential features of the inventions. Therefore, the detailed description is not limited to the embodiments described above, but should be considered as examples. The scope of the present invention should be determined by reasonable interpretation of the attached claims, and all modification within the scope of equivalence should be included in the scope of the present invention. A variety of embodiments of the present invention have been described in the best mode for carrying out the invention. While the present invention has been described mainly with respect to an example of application of 3GPP LTE/LTE-A systems, it may be applied to various wireless communication systems, in addition to the 3GPP LTE/LTE-A systems. | 138,583 |
11943030 | DETAILED DESCRIPTION The following description contains specific information related to implementations of the present disclosure. The drawings and their accompanying detailed description are merely directed to implementations. However, the present disclosure is not limited to these implementations. Other variations and implementations of the present disclosure will be obvious to those skilled in the art. Unless noted otherwise, like or corresponding elements among the drawings may be indicated by like or corresponding reference numerals. Moreover, the drawings and illustrations in the present disclosure are generally not to scale and are not intended to correspond to actual relative dimensions. For the purpose of consistency and ease of understanding, like features may be identified (although, in some examples, not shown) by the same numerals in the drawings. However, the features in different implementations may be different in other respects and shall not be narrowly confined to what is shown in the drawings. The phrases “in one implementation,” or “in some implementations,” may each refer to one or more of the same or different implementations. The term “coupled” is defined as connected whether directly or indirectly through intervening components and is not necessarily limited to physical connections. The term “comprising” means “including, but not necessarily limited to” and specifically indicates open-ended inclusion or membership in the so-described combination, group, series or equivalent. The expression “at least one of A, B and C” or “at least one of the following: A, B and C” means “only A, or only B, or only C, or any combination of A, B and C.” The terms “system” and “network” may be used interchangeably. The term “and/or” is only an association relationship for describing associated objects and represents that multiple relationships may exist such that A and/or B may indicate that A exists alone, A and B exist at the same time, or B exists alone. The character “/” generally represents that the associated objects are in an “or” relationship. For the purposes of explanation and non-limitation, specific details such as functional entities, techniques, protocols, and standards are set forth for providing an understanding of the present disclosure. In other examples, detailed description of well-known methods, technologies, systems, and architectures are omitted so as not to obscure the description with unnecessary details. Persons skilled in the art will recognize that any network function(s) or algorithm(s) disclosed may be implemented by hardware, software or a combination of software and hardware. Disclosed functions may correspond to modules which may be software, hardware, firmware, or any combination thereof. A software implementation may include computer executable instructions stored on a computer readable medium such as memory or other type of storage devices. One or more microprocessors or general-purpose computers with communication processing capability may be programmed with corresponding executable instructions and perform the disclosed network function(s) or algorithm(s). The microprocessors or general-purpose computers may include Applications Specific Integrated Circuitry (ASIC), programmable logic arrays, and/or using one or more Digital Signal Processor (DSPs). Although some of the present disclosure is directed to software installed and executing on computer hardware, alternative implementations as firmware or as hardware or combination of hardware and software are well within the scope of the present disclosure. The computer readable medium includes but is not limited to Random Access Memory (RAM), Read Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), flash memory, Compact Disc Read-Only Memory (CD-ROM), magnetic cassettes, magnetic tape, magnetic disk storage, or any other equivalent medium capable of storing computer-readable instructions. A radio communication network architecture such as a Long Term Evolution (LTE) system, an LTE-Advanced (LTE-A) system, an LTE-Advanced Pro system, or a 5G NR Radio Access Network (RAN) typically includes at least one base station (BS), at least one UE, and one or more optional network elements that provide connection within a network. The UE communicates with the network such as a Core Network (CN), an Evolved Packet Core (EPC) network, an Evolved Universal Terrestrial RAN (E-UTRAN), a 5G Core (5GC), or an internet via a RAN established by one or more BSs. A UE may include but is not limited to a mobile station, a mobile terminal or device, or a user communication radio terminal. The UE may be portable radio equipment that includes but is not limited to a mobile phone, a tablet, a wearable device, a sensor, a vehicle, or a Personal Digital Assistant (PDA) with wireless communication capability. The UE is configured to receive and transmit signals over an air interface to one or more cells in a RAN. The BS may be configured to provide communication services according to at least a Radio Access Technology (RAT) such as Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM) that is often referred to as 2G, GSM Enhanced Data rates for GSM Evolution (EDGE) RAN (GERAN), General Packet Radio Service (GPRS), Universal Mobile Telecommunication System (UMTS) that is often referred to as 3G based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), LTE, LTE-A, evolved LTE (eLTE) that is LTE connected to 5GC, NR (often referred to as 5G), and/or LTE-A Pro. However, the scope of the present disclosure is not limited to these protocols. The BS may include but is not limited to a node B (NB) in the UMTS, an evolved node B (eNB) in LTE or LTE-A, a radio network controller (RNC) in UMTS, a BS controller (BSC) in the GSM/GERAN, a ng-eNB in an E-UTRA BS in connection with 5GC, a next generation Node B (gNB) in the 5G-RAN, or any other apparatus capable of controlling radio communication and managing radio resources within a cell. The BS may serve one or more UEs via a radio interface. The BS is operable to provide radio coverage to a specific geographical area using a plurality of cells forming the RAN. The BS supports the operations of the cells. Each cell is operable to provide services to at least one UE within its radio coverage. Each cell (often referred to as a serving cell) provides services to serve one or more UEs within its radio coverage such that each cell schedules the downlink (DL) and optionally uplink (UL) resources to at least one UE within its radio coverage for DL and optionally UL packet transmissions. The BS can communicate with one or more UEs in the radio communication system via the plurality of cells. A cell may allocate sidelink (SL) resources for supporting Proximity Service (ProSe) or Vehicle to Everything (V2X) service. Each cell may have overlapped coverage areas with other cells. As discussed previously, the frame structure for NR supports flexible configurations for accommodating various next generation (e.g., 5G) communication requirements such as Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), and Ultra-Reliable and Low-Latency Communication (URLLC), while fulfilling high reliability, high data rate and low latency requirements. The Orthogonal Frequency-Division Multiplexing (OFDM) technology in the 3rd Generation Partnership Project (3GPP) may serve as a baseline for an NR waveform. The scalable OFDM numerology such as adaptive sub-carrier spacing, channel bandwidth, and Cyclic Prefix (CP) may also be used. Two coding schemes are considered for NR, specifically Low-Density Parity-Check (LDPC) code and Polar Code. The coding scheme adaption may be configured based on channel conditions and/or service applications. At least DL transmission data, a guard period, and an UL transmission data should be included in a transmission time interval (TTI) of a single NR frame. The respective portions of the DL transmission data, the guard period, and the UL transmission data should also be configurable based on, for example, the network dynamics of NR. SL resources may also be provided in an NR frame to support ProSe services or V2X services. In one implementation, a UE may be equipped with multiple antenna panels to enable high frequency band communication via beamforming. An antenna panel may contain a group of antenna elements and may be an operational unit for controlling a spatial filter for transmission. In one implementation, the antennal panels in the UE may be indexed to facilitate signaling between the UE and a network (NW). In one implementation, the UE may transmit, to a BS (e.g., a gNB), a UE capability message that includes at least one of the number of the antenna panels and the maximum number of the antenna panels that can be activated simultaneously. In one implementation, the UE may report to the BS a number X representing the number of the antenna panels. In one implementation, the UE may report a number Y representing the maximum number of antenna panels that can be activated at the same time, where X may be greater than or equal to Y. In one implementation, the UE may report a number Z representing the number of antenna panels used for transmission or reception, where Y may be greater than or equal to Z. Each of the Z panels may be connected to a transceiver chain. In one implementation, X may be a positive integer greater than 1. X, Y, Z are positive integers where X>1, Y 1, and Z 1. The UE capability message may include at least one of the numbers X, Y, and Z. In one implementation, X and Y may be greater than 1 and Z may be equal to 1. In this case, multiple panels are implemented on the UE and multiple panels can be activated at the same time but only one panel can be used for transmission. Several implementations will be provided to achieve a panel switch operation that allows selecting one panel among the Y panels and enabling flexible scheduling decisions. In one implementation, selection of the Y panels from the X panels may be based on UE implementation when only Y is signaled to the BS. As a result, the signaling for panel selection and the signaling for panel state update between the BS and the UE may be based on the Y UE panels. FIG.1includes a diagram100illustrating multiple antenna panels and panel activation/deactivation according to an example implementation of the present disclosure. As illustrated in the left-hand side ofFIG.1, the BS110is aware of four UE panels132,134,136and138equipped at the UE120. The symbol ‘x’ illustrated in each of the panels132,134,136and138may represent a cross-polarized antenna. The BS110may provide configuration for individual panels, such as channel state information reference signal (CSI-RS) resources and sounding reference signal (SRS) resources. It should be noted that while the BS110provides configurations for up to four panels, how to map individual configurations to individual physical panels may depend on the UE implementation. Nevertheless, the UE120may not change the mapping for active panels once the mapping is performed. The mapping may be performed again when inactive panels are to be activated. The four active panels may be dynamically/semi-statically indicated for transmission and/or reception. In the right-hand side ofFIG.1, panel #1132and panel #2134are to be deactivated. After their deactivation, the dynamic and/or semi-static indication may be limited to panel #3136and panel #4138. In the following disclosure, the dynamic and/or semi-static indication of panel selection may also be referred to as fast panel switch or panel switch. In one implementation, panel selection indicated by the BS110may use a bitmap. The bitmap may include one bit for each of the panels132,134,136and138to indicate an activation status of the panels. For example, in the left-hand side ofFIG.1, the BS110may transmit a message that includes a bitmap {1111} to the UE120to indicate that all the four panels132,134,136and138are to be activated. The UE120may use the panel #4138for transmission and reception. In the right-hand side ofFIG.1, the BS110may transmit another message that includes a bitmap {0011} to the UE120to indicate that panel #1132and panel #2134are to be deactivated, and thus panel #3136and panel #4138remain activated. The UE120may also use the panel #4138for transmission and reception after receiving the bitmap {0011} from the BS110. Case 1: Panel Switch Operation Case 1-1: Panel Activation Request In one implementation, the UE may receive, from the BS, a panel activation request that indicates at least one of the antenna panels to be activated, or remain activated if the indicated at least one antenna panel was already activated. The panel activation request may be a complete signaling or a delta signaling. For example, the panel activation request may be a bitmap that includes one bit for each UE panel to indicate an activation/deactivation status of each UE panel. One example panel activation request having a bitmap form may be {1010}, indicating the first and the third panels are to be activated, or remain activated if they were activated already. The panel activation request may also carry an index to indicate which UE panel(s) is/are to be activated. One example panel activation request having at least one index may be {#1, #3} indicating the first and the third panels are to be activated. The panel activation request may be carried in a downlink control information (DCI) format or a medium access control (MAC) control element (CE). In one implementation, a subset of panels may be configured by radio resource control (RRC) signaling. A MAC CE may be then used for activating panels within the subset. In one implementation, the UE may further send a confirmation message after receiving the panel activation request. The confirmation message may be subject to an activation latency of the panel. For example, the UE may send the confirmation message to the BS after the indicated panel(s) is already activated (or turned on) based on the panel activation request. The confirmation message may be subject to an activation latency, which may be specified or (pre-)configured. The confirmation message may be sent after a pre-specified operation. In one implementation, the confirmation message is sent after a hybrid automatic repeat request (HARQ) acknowledgement (ACK) feedback corresponding to a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH) associated with the panel activation request is sent. The transmission of the confirmation message may be further subject to a latency from the HARQ-ACK feedback. The latency may be specified or (pre-)configured. In one implementation, the confirmation message may be a panel state report that indicates an activation state of the antenna panels. The UE may transmit the panel state report in response to the panel activation request. FIG.2is a flowchart of a method200for panel activation according to an example implementation of the present disclosure. In action202, the UE may receive, from the BS, a panel activation request that indicates at least one of the antenna panels to be activated. In action204, the UE may transmit, to the BS, a panel state report in response to the panel activation request. In one implementation, the panel state report may be carried in a MAC CE. The panel state report may use complete signaling or delta signaling. In one implementation, the panel state report may indicate whether each of the antenna panels is activated or deactivated, such as a bitmap including one bit for each panel. In another implementation, the panel state report may indicate which additional panel(s) is activated. In one implementation, the confirmation message or the panel state report may be a MAC CE with a predefined logical channel identifier (LCID), format or identifier. The content of the MAC CE may contain information of currently activated panels as confirmation. The information carried by the MAC CE may be the panel index(s) of activated panel(s) or may be the number of the activated panels. The content of the MAC CE may be a fixed size of zero bits. The MAC CE may be a fixed size format or a variable size format. The content of the MAC CE may include an identifier of activated and/or deactivated panel(s). The content of the MAC CE may include a bitmap for indicating activated and/or deactivated panel(s). It should be noted that when the payload size of the MAC CE is zero bit, the LCID and optionally some reserved bits still exist. The MAC CE having a zero-bit payload may indicate that the UE simply follows the panel activation request without alternating it. In one implementation, the UE may decide not to follow the panel activation request strictly. For example, the UE may decide to deactivate a panel that is indicated by the panel activation request. In this case, the confirmation message or the panel state report may also include information of the cause of UE's decision, such as “low UE battery.” Case 1-2: Panel Deactivation Request In one implementation, the UE may receive, from the BS, a panel deactivation request that indicates at least one of the antenna panels to be deactivated, or remain deactivated if the indicated at least one antenna panel was already deactivated. The panel deactivation request may be a complete signaling or a delta signaling, similar to the implementations provided in Case 1-1. The panel deactivation request may be carried in a DCI format or a MAC CE. In one embodiment, the UE may further send a confirmation message after receiving the panel deactivation request. The confirmation message may be subject to a deactivation latency of the panel. For example, the UE may send the confirmation message to the BS after the indicated panel(s) is already deactivated (or turned off) based on the panel deactivation request. In one implementation, the confirmation message may be a panel state report that indicates an activation state of the antenna panels. The UE may transmit the panel state report in response to the panel deactivation request. Implementations of the confirmation message or the panel state report may be referred to those mentioned in Case 1-1. In one implementation, the panel activation request and the panel deactivation request may be implemented in a same message. For example, the same message includes a bitmap for indicating activated and/or deactivated panel(s) simultaneously. Case 1-3: Panel Switch Indication In one implementation, the UE may receive a panel switch indication from the BS. The panel switch indication may indicate which panel(s) is going to be used for transmission/reception by the UE. The panel switch indication may include a panel index or a mapped CSI-RS/SRS configuration ID. The BS may provide the panel switch indication via DCI/RRC/MAC CE explicitly or in an implicit way. Examples of the implicit way may include indication based on the traffic type, radio network temporary identifier (RNTI), or control resource set (CORESET). Case 1-4: Panel State Report A panel state report may indicate an activation state of the antenna panels, such as indicating whether each of the antenna panels is activated or deactivated. The panel state report sent from the UE may inform the BS which UE panels are active for panel switch operation. In one implementation, the panel state report may be used as a means for UE to request the BS for activating a different subset of UE panels. In one implementation, the panel state report may be transmitted by the UE when the activation state changes. For example, the latest active panel index(s) (or the latest inactive panel index(s)) may be reported when there is a change in the activation state. In one implementation, the UE may deactivate (turn off) a panel that is indicated as inactive in the panel state report after at least one of the following conditions is met:(a) the UE receives a DCI format indicating to flush a buffer of a HARQ process that was used for transmission of the panel state report. For example, the UE receives a DCI format that indicates a toggled new data indicator (NDI) value and a HARQ process ID associated with the transmission of the panel state report.(b) the UE receives a confirmation message (e.g., a MAC CE with a predefined LCID/format/identifier) from the BS in response to the panel state report. The content of the MAC-CE may contain information of currently activated panels as confirmation. The information may be panel index(s) of activated panel or may be a count on the active panels. The panel state report may be transmitted periodically, aperiodically, semi-persistently, or event-triggered. In one implementation, the UE may receive, from the BS, a configuration that indicates a periodic transmission of the panel state report. In this case, the report may be initiated by the UE according to the reporting configuration. In one implementation, the UE may receive, from the BS, an activation that indicates a semi-persistent transmission of the panel state report. In one implementation, the UE may receive, from the BS, a request for the panel state report. In this case, the report may be queried by the BS via a panel state report request message, which may provide corresponding reporting resources. In one implementation, the panel state report may be transmitted after/during a beam failure recovery procedure. It should be noted that for panel related signaling mentioned above, a panel index may be used. Association between the index and a corresponding configuration may not be changed before the corresponding panel is deactivated and/or the corresponding RRC configuration has been removed. The panel index may be an explicit ID or an implicit ID that is associated with other ID, such as synchronization signal block (SSB) ID, CSI-RS resource ID, CSI-RS resource set ID, SRS resource ID, SRS resource set ID, Transmission Configuration Indication (TCI) state, etc. The TCI state may correspond to DL direction or UL direction. Case 2: Panel Timer In one implementation, a panel timer may be configured for each active panel. In one implementation, a panel timer may be configured for multiple active panels.FIG.3is a flowchart of a method300for panel timer control according to an example implementation of the present disclosure. In action302, the UE may activate one or more panel timers when more than one of the antenna panels are activated. In action304, the UE may deactivate at least one of the antenna panels when one of the panel timers expires or is stopped. In action306, the UE may transmit, to a BS, a panel state report that indicates an activation state of the antenna panels. In one implementation, each of the panel timers may be associated with one antennal panel or multiple antenna panels. An antenna panel may be deactivated when its associated panel timer expires or is stopped. In one implementation, the UE may also activate a panel timer when one of the antenna panels is activated in action302. In one implementation, the UE may transmit the panel state report when one of the panel timers expires or is stopped. In one implementation, a power headroom report may be triggered when one of the panel timers expires or is stopped. Case 2-1: Starting or Re-Starting the Panel Timer The panel timer may be started or re-started when at least one of the following conditions is met:(a) when an antenna panel corresponding to the panel timer is activated by either the BS or the UE;(b) when a transmission or a reception takes place from an antenna panel corresponding to the panel timer, such as receiving a DL/UL scheduling on a PDCCH or a PDSCH, or transmitting a physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH);(c) when a random access channel (RACH) procedure is completed from one of the antenna panels;(d) when a beam failure recovery (BFR) procedure is completed from one of the antenna panels, such as receiving a response from the BS for beam failure recovery request transmission; and(e) when a panel is indicated as active in the panel state report and/or a corresponding confirmation message is received from the BS. It should be noted the above conditions (c) and (d) may be applied to (1) the panel that performs the RACH procedure or the BFR procedure or (2) all active panels of the concerned serving cell. That is, if the RACH or BFR procedure is completed from one of the antenna panels, in one implementation the panel timer associated with the antenna panel may be started, while in another implementation all panel timers associated with all active panels of the concerned serving cell may be started. Case 2-2: Stopping the Panel Timer The panel timer may be stopped (or suspended) when at least one of the following conditions is met:(a) when an antenna panel corresponding to the panel timer is deactivated by either the BS or the UE;(b) when a RACH procedure is initiated;(c) when a beam failure is detected;(d) when the UE switches to an initial bandwidth part (BWP), such as when a BWP inactivity timer expires; and(e) when the UE goes to an idle state or an inactive state. In one implementation, after the panel timer is suspended, the panel timer may be resumed when the RACH procedure is completed. In one implementation, the panel timer may be stopped or re-started depending on different discontinuous reception (DRX) states. Case 2-3: Fallback Panel In one implementation, among all the antenna panels of the UE, there may be a fallback panel. The above-mentioned timer mechanism may not be applicable to the fallback panel. The fallback panel may keep activated. That is, in one implementation the UE does not turn off the fallback panel. In one implementation, there may be no panel timer associated with the fallback panel. FIG.4is a flowchart of a method400for antenna panel control with respect to a fallback panel according to an example implementation of the present disclosure. In action402, the UE may select one of the antenna panels as a fallback panel. In one implementation, the UE may select the fallback panel based on a configuration from the BS. That is, the fallback panel may be (pre-)configured by the BS. For example, the configuration may indicate a specific panel or a specific panel index as the fallback panel. In one implementation, the BS or the UE may statically designate one panel as the fallback panel, such as panel #0. In one implementation, the BS or the UE may assign one of the currently activated panels as the fallback panel, such as the panel having the smallest index among the activated panels. In action404, the UE may activate the fallback panel and deactivate all the other antenna panels. In one implementation, the fallback panel may be a default panel that is always active. In one implementation, parameters related to timer configurations for all configured panels may be the same. There may be only one set of timer configuration applicable to all configured panels. Case 3: Panel State Misalignment Between BS and UE Based on the implementation of signaling mechanism for the activation state of the antenna panels, e.g., which panels are active and which panels are inactive, there may be occasions that the BS and the UE have different understanding about the activation state of the antenna panels. Such situation may be referred to as panel state misalignment between the BS and the UE. When there is panel state misalignment, the BS may indicate to the UE a panel for transmission/reception but the indicated panel is currently not active. For example, the UE may receive, from the BS, a panel switch indication that indicates an inactive antenna panel for transmission by the UE. The panel state misalignment occasions may include:(a) Semi-persistent (SP) or aperiodic (AP) SRS transmission whose spatial relation is associated with an inactive panel;(b) PUCCH transmission whose active spatial relation is associated with an inactive panel; and(c) PUSCH transmission whose indicated spatial relation reference is associated with an inactive panel. The spatial relation reference may be determined by uplink control information (UCI) or a default behavior when an SRS resource indicator (SRI) field is not present in the UCI. It is noted that the spatial relation reference is provided by an RRC parameter spatialRelationInfo for different signal/channels in NR Rel-15/16. The spatial relation reference may be provided by another approach, e.g., an UL TCI framework similar to a DL TCI framework, but same information is delivered. Several implementations are provided below for dealing with the panel state misalignment. It should be noted that the UE may adopt one or a combination of the following implementations. Different implementations may be applicable to different occasions. Case 3-1: UE Ignores the Indicated Transmission Occasion The UE may drop a transmission occasion indicated by the panel switch indication that indicates an inactive panel for transmission. Case 3-1 may be applicable to, but not limited to, the occasion (a) (SP/AP SRS transmission). Case 3-2: UE Selects a Panel from Active Ones for Transmission Case 3-2 may be applicable to, but not limited to, the occasion (b) (PUCCH transmission) and/or the occasion (c) (PUSCH transmission). The UE may perform a measurement or rely on a previous measurement result to select a panel among the activated panels. In one implementation, the UE may select a panel that has a measured metric better than a threshold, which may be a predefined or (pre-)configured value. The measured metric may be Layer 1 Signal to Interference plus Noise Ratio (L1-SINR), Layer 1 Reference Signal Received Power (L1-RSRP), Layer 1 Received Signal Strength Indicator (L1-RSSI), Block Error Rate (BLER), etc. In one implementation, the UE may ignore the indicated transmission if the measured metrics of all the activated panels are worse than the threshold. Case 3-3: UE Triggers a Panel State Report to BS The UE may transmit the panel state report after receiving the panel switch indication that indicates an inactive panel for transmission. Implementations on the panel state report may be referred to in Case 1.FIG.5is a flowchart of a method500for handling panel state misalignment according to an example implementation of the present disclosure. In action502, the UE receives, from a BS, a panel switch indication that indicates an inactive panel for transmission. In action504, the UE transmits, to the BS, a panel state report after receiving the panel switch indication.FIG.5illustrates an implementation of an event-triggered panel state report. In one implementation, the UE may fallback to one-panel operation. For example, the UE may leave only one active panel (e.g., the fallback panel mentioned in Case 2-3) and turn off the others. That is, the UE may keep the fallback panel active or activate the fallback panel, and deactivate all the other antenna panels. The one active panel may be up to UE selection or may be configured. For example, the one active panel maybe the panel without timer configuration. In one implementation, the fallback behavior (e.g., only one panel is activated) may last until a confirmation message in response to the panel state report is received by the UE. In one implementation, the UE may fallback to all-panel operation. For example, the UE may turn on all panels and apply corresponding resource mapping if configured. It should be noted that the all-panel operation may be subject to a UE capability constraint. For example, the all-panel operation may mean that all the Y panels are used, where the parameter Y is the maximum number of antenna panels that can be activated at the same time. Case 3-4: UE Triggers a Beam Failure Recovery Procedure The UE may trigger a beam failure recovery procedure when there is panel state misalignment assuming the beam failure detection criteria is fulfilled. Case 3-5: UE Activates the Indicated Inactive Panel for Transmission, if a Scheduling Delay is Larger than a Panel Activation Latency The UE may activate the inactive antenna panel indicated by the panel switch indication after determining that a scheduling delay for a PUSCH transmission is longer than a panel activation latency for activating the inactive antenna panel.FIG.6includes a diagram600illustrating a scheduling delay according to an example implementation of the present disclosure. The BS transmits to the UE a PDCCH602carrying a panel switch indication that indicates an inactive panel for transmission. The PDCCH602schedules a PUCSH604transmission via a currently inactive panel. The scheduling delay may be the duration between the PDCCH602and the PUSCH604. The panel activation latency may be the time the UE takes to activate an inactive panel. If the scheduling delay is longer than the activation latency, the UE may activate the inactive panel indicated in the PDCCH602for transmitting the PUSCH604. The beam indicated in the PDCCH602may be used for transmitting the PUSCH604. A panel state report may be further transmitted due to the change of the panel activation state. On the other hand, if the scheduling delay is shorter than the activation latency, the UE may not be able to turn on the inactive panel when the PUSCH604starts. The beam indicated in the PDCCH602may not be used for transmitting the PUSCH604. In this case, the UE may adopt behaviors described in Cases 3-1 through 3-4. In one implementation, the physical panel to be activated may be the latest one that was associated with the indicated panel index. In one implementation, the physical panel to be activated may be up to UE implementation. It should be noted that implementations described in Cases 3-1 through 3-5 may be logically combined. In one implementation, the UE may receive AP SRS transmission whose spatial relationship is not associated with an active panel. In this case, the UE may ignore the transmission (Case 3-1) and trigger a panel state report to the BS (Case 3-3). In one implementation, the UE may receive an UL grant for PUSCH transmission whose spatial relationship is not associated with an active panel. In this case, the UE may transmit the PUSCH with another UE panel that is currently active (Case 3-2) and trigger a panel state report to the BS (Case 3-3). The “another UE panel that is currently active” may be up to UE selection. In one implementation, the UE may receive a SP/AP SRS activation MAC CE containing spatial relationship not referring to an active panel. The UE may activate an inactive panel and use the newly active panel for SP/AP SRS transmission (Case 3-5). The “newly active panel” may be the latest one that was associated with the indicated panel index or may be up to UE selection. The UE may further trigger a panel state report to the BS (Case 3-3), where the active panel information in the panel state report may include the “newly active panel”. FIG.7is a block diagram illustrating a node700for wireless communication according to the present disclosure. As illustrated inFIG.7, the node700may include a transceiver720, a processor728, a memory734, one or more presentation components738, and at least one antenna736. The node700may also include an RF spectrum band module, a BS communications module, a network communications module, and a system communications management module, Input/Output (I/O) ports, I/O components, and a power supply (not shown). Each of the components may directly or indirectly communicate with each other over one or more buses740. The node700may be a UE or a BS that performs various functions disclosed with reference toFIGS.1through6. The transceiver720has a transmitter722(e.g., transmitting/transmission circuitry) and a receiver724(e.g., receiving/reception circuitry) and may be configured to transmit and/or receive time and/or frequency resource partitioning information. The transceiver720may be configured to transmit in different types of subframes and slots including but not limited to usable, non-usable and flexibly usable subframes and slot formats. The transceiver720may be configured to receive data and control channels. The node700may include a variety of computer-readable media. Computer-readable media may be any available media that may be accessed by the node700and include both volatile and non-volatile media, removable and non-removable media. The computer-readable media may include computer storage media and communication media. Computer storage media include both volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or data. Computer storage media include RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices. Computer storage media do not include a propagated data signal. Communication media typically embody computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and include any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. Communication media include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the previously listed components should also be included within the scope of computer-readable media. The memory734may include computer-storage media in the form of volatile and/or non-volatile memory. The memory734may be removable, non-removable, or a combination thereof. Example memory includes solid-state memory, hard drives, optical-disc drives, etc. As illustrated inFIG.7, the memory734may store computer-readable, computer-executable instructions732(e.g., software codes) that are configured to cause the processor728to perform various disclosed functions with reference toFIGS.1through6. Alternatively, the instructions732may not be directly executable by the processor728but be configured to cause the node700(e.g., when compiled and executed) to perform various functions disclosed herein. The processor728(e.g., having processing circuitry) may include an intelligent hardware device, e.g., a Central Processing Unit (CPU), a microcontroller, an ASIC, etc. The processor728may include memory. The processor728may process the data730and the instructions732received from the memory734, and information transmitted and received via the transceiver720, the base band communications module, and/or the network communications module. The processor728may also process information to be sent to the transceiver720for transmission via the antenna736to the network communications module for transmission to a core network. One or more presentation components738present data to a person or another device. Examples of presentation components738include a display device, a speaker, a printing component, and a vibrating component. In view of the present disclosure, it is obvious that various techniques may be used for implementing the concepts in the present disclosure without departing from the scope of those concepts. Moreover, while the concepts have been disclosed with specific reference to certain implementations, a person of ordinary skill in the art may recognize that changes may be made in form and detail without departing from the scope of those concepts. As such, the described implementations are to be considered in all respects as illustrative and not restrictive. It should also be understood that the present disclosure is not limited to the particular implementations disclosed and many rearrangements, modifications, and substitutions are possible without departing from the scope of the present disclosure. | 40,426 |
11943031 | DETAILED DESCRIPTION Some wireless communications systems may support beam selection and refinement as part of a beam switch procedure during wireless communications between a user equipment (UE) and a network entity. The beam switch procedure may involve delays (e.g., timings) between operations, which may give the UE time for performing operations associated with the beam switch procedure. The delays may be specific to a UE and may be based on the capability of the UE. For example, a slower, less complex, or power-saving UE may report a slow capability, associated with longer delays during beam switch procedures. Alternatively, a UE may prioritize performance and low latency and may report a fast capability, associated with shorter delays during beam switch procedures. However, wireless communications systems support fixed delays, and the UE may not be allowed to switch capabilities and use different delays as parameters at the UE change. For instance, a UE may switch from a power-saving mode to a high performance mode but may not be able to report a faster capability associated with shorter delays thus experiencing higher latency. Similarly, a UE that has switched from a high performance mode to a power saving mode may not be able to report a slower capability associated with longer delays and may experience higher power consumption. Thus, UEs may be unable to accommodate for different user needs, hampering the user experience. According to one or more aspects of the present disclosure, the UE may dynamically change and report beam switching delay capabilities. For example, the UE may update the capability to a network entity periodically when the complexity, power, or memory needs of the UE change. Additionally, or alternatively, the UE may update the capability upon being triggered by the network entity, during a time scheduled by the network entity, upon the expiration of a timer, etc. The capabilities may be or may include explicit values for beam switching delay, or an index selecting values from a table previously configured (e.g., pre-configured) for the UE, for example. In some cases, the UE may indicate more than one capability in a message (e.g., a fast and slow capability), and the network entity may indicate the UE to assume beam switching delay values corresponding to one of the capabilities until a next indication, for a predefined time, or until some event, for example. Accordingly, the UE may avoid higher power consumption or high latency scenarios caused by fixed beam switching delay capabilities. One or more aspects depicted herein further provide that the UE may report capability values associated with a time delay between a transmitted channel state information reference signal (CSI-RS) with repetition and the UE being ready for a downlink transmission using a beam selected based on the CSI-RS. This capability may indicate to a network entity to avoid scheduling downlink messages following the CSI-RS but prior to the expiration of the time delay. Thus, the UE can assume that no message will be transmitted and may avoid buffering until after the delay, leading to decreased power consumption. Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are additionally described in the context of process flow and diagrams. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to dynamic beam switching delay capability. FIG.1illustrates an example of a wireless communications system100that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The wireless communications system100may include one or more network entities105, one or more UEs115, and a core network130. In some examples, the wireless communications system100may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating in accordance with other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein. The network entities105may be dispersed throughout a geographic area to form the wireless communications system100and may include devices in different forms or having different capabilities. In various examples, a network entity105may be referred to as a network element, a mobility element, a radio access network (RAN) node, or network equipment, among other nomenclature. In some examples, network entities105and UEs115may wirelessly communicate via one or more communication links125(e.g., a radio frequency (RF) access link). For example, a network entity105may support a coverage area110(e.g., a geographic coverage area) over which the UEs115and the network entity105may establish one or more communication links125. The coverage area110may be an example of a geographic area over which a network entity105and a UE115may support the communication of signals according to one or more radio access technologies (RATs). The UEs115may be dispersed throughout a coverage area110of the wireless communications system100, and each UE115may be stationary, or mobile, or both at different times. The UEs115may be devices in different forms or having different capabilities. Some example UEs115are illustrated inFIG.1. The UEs115described herein may be able to communicate with various types of devices, such as other UEs115or network entities105, as shown inFIG.1. As described herein, a node of the wireless communications system100, which may be referred to as a network node, or a wireless node, may be a network entity105(e.g., any network entity described herein), a UE115(e.g., any UE described herein), a network controller, an apparatus, a device, a computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, a node may be a UE115. As another example, a node may be a network entity105. As another example, a first node may be configured to communicate with a second node or a third node. In one aspect of this example, the first node may be a UE115, the second node may be a network entity105, and the third node may be a UE115. In another aspect of this example, the first node may be a UE115, the second node may be a network entity105, and the third node may be a network entity105. In yet other aspects of this example, the first, second, and third nodes may be different relative to these examples. Similarly, reference to a UE115, network entity105, apparatus, device, computing system, or the like may include disclosure of the UE115, network entity105, apparatus, device, computing system, or the like being a node. For example, disclosure that a UE115is configured to receive information from a network entity105also discloses that a first node is configured to receive information from a second node. In some examples, network entities105may communicate with the core network130, or with one another, or both. For example, network entities105may communicate with the core network130via one or more backhaul communication links120(e.g., in accordance with an S1, N2, N3, or another interface protocol). In some examples, network entities105may communicate with one another over a backhaul communication link120(e.g., in accordance with an X2, Xn, or other interface protocol) either directly (e.g., directly between network entities105) or indirectly (e.g., via a core network130). In some examples, network entities105may communicate with one another via a midhaul communication link162(e.g., in accordance with a midhaul interface protocol) or a fronthaul communication link168(e.g., in accordance with a fronthaul interface protocol), or any combination thereof. The backhaul communication links120, midhaul communication links162, or fronthaul communication links168may be or include one or more wired links (e.g., an electrical link, an optical fiber link), one or more wireless links (e.g., a radio link, a wireless optical link), among other examples or various combinations thereof. A UE115may communicate with the core network130through a communication link155. One or more of the network entities105described herein may include or may be referred to as a base station140(e.g., a base transceiver station, a radio base station, an NR base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB), a 5G NB, a next-generation eNB (ng-eNB), a Home NodeB, a Home eNodeB, or other suitable terminology). In some examples, a network entity105(e.g., a base station140) may be implemented in an aggregated (e.g., monolithic, standalone) base station architecture, which may be configured to utilize a protocol stack that is physically or logically integrated within a single network entity105(e.g., a single RAN node, such as a base station140). In some examples, a network entity105may be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture), which may be configured to utilize a protocol stack that is physically or logically distributed among two or more network entities105, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, a network entity105may include one or more of a central unit (CU)160, a distributed unit (DU)165, a radio unit (RU)170, a RAN Intelligent Controller (RIC)175(e.g., a Near-Real Time RIC (Near-RT RIC), a Non-Real Time RIC (Non-RT RIC)), a Service Management and Orchestration (SMO)180system, or any combination thereof Δn RU170may also be referred to as a radio head, a smart radio head, a remote radio head (RRH), a remote radio unit (RRU), or a transmission reception point (TRP). One or more components of the network entities105in a disaggregated RAN architecture may be co-located, or one or more components of the network entities105may be located in distributed locations (e.g., separate physical locations). In some examples, one or more network entities105of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU), a virtual DU (VDU), a virtual RU (VRU)). The split of functionality between a CU160, a DU165, and an RU170is flexible and may support different functionalities depending upon which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combinations thereof) are performed at a CU160, a DU165, or an RU170. For example, a functional split of a protocol stack may be employed between a CU160and a DU165such that the CU160may support one or more layers of the protocol stack and the DU165may support one or more different layers of the protocol stack. In some examples, the CU160may host upper protocol layer (e.g., layer 3 (L3), layer 2 (L2)) functionality and signaling (e.g., Radio Resource Control (RRC), service data adaption protocol (SDAP), Packet Data Convergence Protocol (PDCP)). The CU160may be connected to one or more DUs165or RUs170, and the one or more DUs165or RUs170may host lower protocol layers, such as layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU160. Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU165and an RU170such that the DU165may support one or more layers of the protocol stack and the RU170may support one or more different layers of the protocol stack. The DU165may support one or multiple different cells (e.g., via one or more RUs170). In some cases, a functional split between a CU160and a DU165, or between a DU165and an RU170may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU160, a DU165, or an RU170, while other functions of the protocol layer are performed by a different one of the CU160, the DU165, or the RU170). A CU160may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU160may be connected to one or more DUs165via a midhaul communication link162(e.g., F1, F1-c, F1-u), and a DU165may be connected to one or more RUs170via a fronthaul communication link168(e.g., open fronthaul (FH) interface). In some examples, a midhaul communication link162or a fronthaul communication link168may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities105that are in communication over such communication links. In wireless communications systems (e.g., wireless communications system100), infrastructure and spectral resources for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, providing an IAB network architecture (e.g., to a core network130). In some cases, in an IAB network, one or more network entities105(e.g., IAB nodes104) may be partially controlled by each other. One or more IAB nodes104may be referred to as a donor entity or an IAB donor. One or more DUs165or one or more RUs170may be partially controlled by one or more CUs160associated with a donor network entity105(e.g., a donor base station140). The one or more donor network entities105(e.g., IAB donors) may be in communication with one or more additional network entities105(e.g., IAB nodes104) via supported access and backhaul links (e.g., backhaul communication links120). IAB nodes104may include an IAB mobile termination (IAB-MT) controlled (e.g., scheduled) by DUs165of a coupled IAB donor. An IAB-MT may include an independent set of antennas for relay of communications with UEs115, or may share the same antennas (e.g., of an RU170) of an IAB node104used for access via the DU165of the IAB node104(e.g., referred to as virtual IAB-MT (vIAB-MT)). In some examples, the IAB nodes104may include DUs165that support communication links with additional entities (e.g., IAB nodes104, UEs115) within the relay chain or configuration of the access network (e.g., downstream). In such cases, one or more components of the disaggregated RAN architecture (e.g., one or more IAB nodes104or components of IAB nodes104) may be configured to operate according to the techniques described herein. In the case of the techniques described herein applied in the context of a disaggregated RAN architecture, one or more components of the disaggregated RAN architecture may be configured to support dynamic beam switching delay capability as described herein. For example, some operations described as being performed by a UE115or a network entity105(e.g., a base station140) may additionally, or alternatively, be performed by one or more components of the disaggregated RAN architecture (e.g., IAB nodes104, DUs165, CUs160, RUs170, RIC175, SMO180). A UE115may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE115may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE115may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples. The UEs115described herein may be able to communicate with various types of devices, such as other UEs115that may sometimes act as relays as well as the network entities105and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown inFIG.1. The UEs115and the network entities105may wirelessly communicate with one another via one or more communication links125(e.g., an access link) over one or more carriers. The term “carrier” may refer to a set of RF spectrum resources having a defined physical layer structure for supporting the communication links125. For example, a carrier used for a communication link125may include a portion of a RF spectrum band (e.g., a bandwidth part (BWP)) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system100may support communication with a UE115using carrier aggregation or multi-carrier operation. A UE115may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers. Communication between a network entity105and other devices may refer to communication between the devices and any portion (e.g., entity, sub-entity) of a network entity105. For example, the terms “transmitting,” “receiving,” or “communicating,” when referring to a network entity105, may refer to any portion of a network entity105(e.g., a base station140, a CU160, a DU165, a RU170) of a RAN communicating with another device (e.g., directly or via one or more other network entities105). Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may refer to resources of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, in which case the symbol period and subcarrier spacing may be inversely related. The quantity of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both) such that the more resource elements that a device receives and the higher the order of the modulation scheme, the higher the data rate may be for the device. A wireless communications resource may refer to a combination of an RF spectrum resource, a time resource, and a spatial resource (e.g., a spatial layer, a beam), and the use of multiple spatial resources may increase the data rate or data integrity for communications with a UE115. The time intervals for the network entities105or the UEs115may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of Ts=1/(Δfmax·Nf) seconds, where Δfmaxmay represent the maximum supported subcarrier spacing, and Nfmay represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023). Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a quantity of slots. Alternatively, each frame may include a variable quantity of slots, and the quantity of slots may depend on subcarrier spacing. Each slot may include a quantity of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some wireless communications systems100, a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., Nf) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation. A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system100and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., a quantity of symbol periods in a TTI) may be variable. Additionally, or alternatively, the smallest scheduling unit of the wireless communications system100may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)). Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a set of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs115. For example, one or more of the UEs115may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to an amount of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs115and UE-specific search space sets for sending control information to a specific UE115. In some examples, a network entity105(e.g., a base station140, an RU170) may be movable and therefore provide communication coverage for a moving coverage area110. In some examples, different coverage areas110associated with different technologies may overlap, but the different coverage areas110may be supported by the same network entity105. In some other examples, the overlapping coverage areas110associated with different technologies may be supported by different network entities105. The wireless communications system100may include, for example, a heterogeneous network in which different types of the network entities105provide coverage for various coverage areas110using the same or different radio access technologies. Some UEs115may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception concurrently). In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs115include entering a power saving deep sleep mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs115may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs)) within a carrier, within a guard-band of a carrier, or outside of a carrier. The wireless communications system100may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system100may be configured to support ultra-reliable low-latency communications (URLLC). The UEs115may be designed to support ultra-reliable, low-latency, or critical functions. Ultra-reliable communications may include private communication or group communication and may be supported by one or more services such as push-to-talk, video, or data. Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, and ultra-reliable low-latency may be used interchangeably herein. In some examples, a UE115may be able to communicate directly with other UEs115over a device-to-device (D2D) communication link135(e.g., in accordance with a peer-to-peer (P2P), D2D, or sidelink protocol). In some examples, one or more UEs115of a group that are performing D2D communications may be within the coverage area110of a network entity105(e.g., a base station140, an RU170), which may support aspects of such D2D communications being configured by or scheduled by the network entity105. In some examples, one or more UEs115in such a group may be outside the coverage area110of a network entity105or may be otherwise unable to or not configured to receive transmissions from a network entity105. In some examples, groups of the UEs115communicating via D2D communications may support a one-to-many (1:M) system in which each UE115transmits to each of the other UEs115in the group. In some examples, a network entity105may facilitate the scheduling of resources for D2D communications. In some other examples, D2D communications may be carried out between the UEs115without the involvement of a network entity105. The core network130may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network130may be an evolved packet core (EPC) or 5G core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs115served by the network entities105(e.g., base stations140) associated with the core network130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to IP services150for one or more network operators. The IP services150may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet-Switched Streaming Service. The wireless communications system100may operate using one or more frequency bands, which may be in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, which may be referred to as clusters, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs115located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz. The wireless communications system100may utilize both licensed and unlicensed RF spectrum bands. For example, the wireless communications system100may employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. While operating in unlicensed RF spectrum bands, devices such as the network entities105and the UEs115may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples. A network entity105(e.g., a base station140, an RU170) or a UE115may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a network entity105or a UE115may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a network entity105may be located in diverse geographic locations. A network entity105may have an antenna array with a set of rows and columns of antenna ports that the network entity105may use to support beamforming of communications with a UE115. Likewise, a UE115may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally, or alternatively, an antenna panel may support RF beamforming for a signal transmitted via an antenna port. Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a network entity105, a UE115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation). A network entity105or a UE115may use beam sweeping techniques as part of beamforming operations. For example, a network entity105(e.g., a base station140, an RU170) may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a network entity105multiple times along different directions. For example, the network entity105may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions along different beam directions may be used to identify (e.g., by a transmitting device, such as a network entity105, or by a receiving device, such as a UE115) a beam direction for later transmission or reception by the network entity105. Some signals, such as data signals associated with a particular receiving device, may be transmitted by transmitting device (e.g., a transmitting network entity105, a transmitting UE115) along a single beam direction (e.g., a direction associated with the receiving device, such as a receiving network entity105or a receiving UE115). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted along one or more beam directions. For example, a UE115may receive one or more of the signals transmitted by the network entity105along different directions and may report to the network entity105an indication of the signal that the UE115received with a highest signal quality or an otherwise acceptable signal quality. In some examples, transmissions by a device (e.g., by a network entity105or a UE115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or beamforming to generate a combined beam for transmission (e.g., from a network entity105to a UE115). The UE115may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured set of beams across a system bandwidth or one or more sub-bands. The network entity105may transmit a reference signal (e.g., a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)), which may be precoded or unprecoded. The UE115may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted along one or more directions by a network entity105(e.g., a base station140, an RU170), a UE115may employ similar techniques for transmitting signals multiple times along different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE115) or for transmitting a signal along a single direction (e.g., for transmitting data to a receiving device). A receiving device (e.g., a UE115) may perform reception operations in accordance with multiple receive configurations (e.g., directional listening) when receiving various signals from a receiving device (e.g., a network entity105), such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may perform reception in accordance with multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration may be aligned along a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR), or otherwise acceptable signal quality based on listening according to multiple beam directions). Wireless communications system100may support beam selection and refinement as part of a beam switch procedure during wireless communication between a UE115and a network entity105. The beam switch procedure may include delays (e.g., timings) in between operations. The UE115may use the delay to perform operations associated with the beam switch procedure. The delays or the time between beam switch operations may be specific to a UE115and may be based on the capability of the UE115. For example, a slower, less complex, or power-saving UE115may report a slow capability, leading to longer delays during beam switch procedures. Alternatively, a UE115may prioritize performance and low latency and may report a fast capability, leading to shorter delays during beam switch procedures. However, if a wireless communications system100operates using fixed delays, the UE115may not be able to switch capabilities and use different delays as parameters at the UE change. Additionally, or alternatively, different UEs115may not be able to report different delay values. Thus, the wireless communications system100may be unable to accommodate for different user needs, hampering the user experience. In some examples, the UE115may select a spatial filter to receive downlink messages following a reference signal transmission (e.g., a CSI-RS) with repetition as part of a receive beam refinement procedure (e.g., a P-3 procedure). The processing and selection time for the UE115may be relatively quick and may be absorbed into a cyclic prefix length time. However, the UE115may take additional time to perform processing and selection in some cases, such as when the UE115supports beam switching between multiple antenna panels or the network entity105and the UE115are communicating according to a relatively high subcarrier spacing that may be associated with a relatively short cyclic prefix length. This may lead to decreased performance by the UE115. In some implementations according to aspects of the present disclosure, wireless communications system100may support a UE115dynamically changing and reporting beam switching delay capabilities. For example, the UE115may update the capability to a network entity periodically when the complexity, power, or memory needs of the UE115change. Additionally, or alternatively, the UE115may update the capability upon being triggered by a network entity105, during a time scheduled by the network entity105, or upon the expiration (e.g., expiry) of a timer, etc. The capabilities may be or may include explicit values for beam switching delay, or an index selecting values from a table previously configured (e.g., pre-configured) to the UE115, for example. In some cases, the UE115may indicate more than one capability in a message (e.g., a fast capability or a slow capability), and the network entity105may indicate the UE115to assume beam switching delay values corresponding to one of the capabilities until a next indication, for a predefined time, or until some event, for example. Accordingly, the UE115may avoid higher power consumption or high latency scenarios caused by fixed beam switching delay capabilities. The wireless communications system100may support a UE115reporting capability values associated with a time delay between a transmitted reference signal (e.g., a CSI-RS) with repetition and the UE115being ready for a downlink transmission using a beam selected based on the reference signal. This capability may indicate to a network entity105to avoid scheduling downlink messages following the reference signal transmission but prior to the expiration of the time delay. Thus, the UE115can assume no message will be transmitted and may avoid buffering until after the delay, leading to decreased power consumption. FIG.2illustrates an example of a wireless communications system200that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The wireless communications system200may implement or be implemented to realize aspects of the wireless communications system100. For example, the wireless communications system200may illustrate communications between a UE115-aand a network entity105-a, which may be examples of corresponding devices described herein, including with reference toFIG.1. Further, the UE115-aand the network entity105-amay communicate messages using communication links210, which may be examples of a communication link125described herein, with reference toFIG.1. The UE115-aand the network entity105-amay also support beamformed communications. For example, the UE115-aand the network entity105-amay transmit and receive messages using one or more respective beams205selected and refined, for example, in accordance with a beam switch procedure (e.g., a beam selection procedure). The UE115-aand the network entity105-amay support performing beam switch procedures (e.g., events) according to various UE capability values230and beam switching delay times235. For example, the beam switch procedure may involve a transmit beam selection step (e.g., a P-1 procedure), a downlink transmit beam refinement step (e.g., a P-2 procedure), and a UE115-areceive beam refinement step (e.g., a P-3 procedure), and there may be beam switching delay times235throughout these steps to allow time for the UE115-ato read and process downlink control information (DCI) received from the network entity105-a. In some cases, the UE115-amay support transmitting a capability report215to the network entity105-aindicating (e.g., containing, comprising, etc.) one or more capability value230pertaining to supporting one or more beam switch delay times235. For example, the UE may include a capability value230corresponding to a fast beam switch capability (e.g., for high-performance and low latency operations) associated with shorter beam switch delay times235, and a capability value230corresponding to a slow beam switch capability (e.g., for power-saving) associated with longer beam switch delay times235. In some cases, the UE115-amay be configured to transmit a capability report215periodically (e.g., according to a timing or expiration of a timer). Additionally, or alternatively, the UE115-amay be configured to transmit a capability report215as the complexity, power, latency, or memory needs change at the UE115-a, and the UE115-adecides to switch to a different capability. For example, as the UE115-adetermines to switch from a fast beam switch capability to a slow beam switch capability to conserve power, the UE115-amay transmit a capability report215including a capability value230corresponding to the slow beam switch capability. In some cases, the network entity105-amay trigger the UE115-ato transmit a capability report215by transmitting a capability request220. Additionally, or alternatively, the network entity105-amay schedule a time for the UE115-ato transmit the capability report215and indicate the time to the UE115-ain the capability request220. In some cases, the UE115-amay transmit the capability report215after a timer indicated in the capability request220by the network entity105-ais elapsed. In some cases, the network entity105-amay configure one or more times for the UE115-ato transmit the capability report215as part of a scheduling pattern. In some examples, the network entity105-amay transmit a confirmation225in response to receiving the capability report215. Thus, the UE115-amay transmit multiple capability values pertaining to the UE115-a's support of different beam switching delay times for selection of a reception beam at the UE115-a, the different beam switching delay times each associated with a same type of beam switching event. The UE115-amay transmit the capability report215in an uplink message, which may be, for example, a physical uplink shared channel transmission, a physical uplink control channel transmission, a random access channel transmission, a sounding reference signal, etc. The capability report215may include multiple capability values230, each associated with one or more beam switch delay times235. For example, the UE115-amay transmit two capability values230corresponding to a fast and a slow capability, and each may be associated with a different value (e.g., an index corresponding to a table value) for a beam switch delay time235corresponding to a time between a DCI containing a transmission configuration indicator and the UE115-abeing ready to receive a physical downlink shared channel transmission from the network entity105-aduring a beam switch event. In response to the capability report215, the network entity105-amay indicate or request the UE115-ato assume one of the indicated capability values. The indication may be valid until the network entity105-atransmits a next indication to the UE115-a. Alternatively, the indication may be valid until the expiration of a timer (e.g., indicated by the network entity105-a) or until a predefined event (e.g., a scheduling pattern, internal event at the UE115-a, etc.). The beam switch delay times235may correspond to one or more values for the UE115-ato perform operations relating to a beam switch event. For example, a beam switch delay time235may be the time between reception of a DCI including a transmission configuration indicator and the UE115-abeing ready to receive a physical downlink shared channel transmission from the network entity105-ato the UE115-a; time for the UE115-ato become ready to receive an aperiodic channel state information reference signal (CSI-RS) following a DCI trigger; and the time between a downlink reference signal (e.g., a CSI-RS, a synchronization signal block (SSB) reference signal, etc.) and an uplink beam report from the UE115-a, among other examples. In some examples, the UE115-amay be configured (e.g., pre-configured by the network entity105-a) with a table containing multiple options for each of multiple beam switch delay times235. Each option may be associated with an index, which the UE115-amay include in the capability report215in order to indicate desired beam switch delay times235corresponding to a capability value230. Alternatively, the UE115-amay indicate the explicit values for the desired beam switch delay times235. In some examples, the UE115-amay transmit a capability report215indicating a capability value230associated with one or more beam switch delay times235corresponding to the time between a CSI-RS with repetition (e.g., repetition set to ON) during a beam training session (e.g., for P-3, the receive beam refinement step) and the UE115-abeing ready to receive a downlink transmission using the selected receive beam. The capability may be dependent on a subcarrier spacing (SCS) associated with transmissions between the UE115-aand the network entity105-a, a number of antenna panels available at the UE115-a, a periodicity of the CSI-RS (e.g., periodic, aperiodic, or semi-persistent), a slot or sub-slot resolution for transmissions, a symbol or sub-symbol resolution for transmissions (e.g., for higher SCS, the capability may be based on a half symbol if a single carrier waveform is used), a number of CSI-RS resources used during the beam training session, or any combination thereof. In response to the capability report215, the network entity105-amay refrain from transmitting a downlink message before the beam switch delay time235. The network entity105-amay configure the UE115-awith a delay so that the UE115-amay assume that no downlink message will be scheduled before this delay elapses after the CSI-RS with repetition. Therefore, the UE115-amay refrain from buffering and listening for downlink messages using the selected beam until the delay elapses. FIG.3illustrates an example of a process flow300that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The process flow300may implement aspects of the wireless communications system100and the wireless communications system200. For example, the process flow300may illustrate communications between a UE115-band a network entity105-b, which may be examples of corresponding devices described herein, including with reference toFIGS.1and2. In some examples, the UE115-bmay dynamically report capability reports associated with a beam switching procedure to the network entity105-b. In the following description of the process flow300, the operations may be performed (e.g., reported or provided) in a different order than the order shown. Specific operations also may be left out of the process flow300, or other operations may be added to the process flow300. Further, although some operations or signaling may be shown to occur at different times for discussion purposes, these operations may actually occur at the same time. At305, the network entity105-bmay request the UE115-bto transmit a capability report. The network entity105-bmay configure the UE115-bwith a delay or timer, such that after the configured timer elapses following the capability request, the UE115-amay transmit the capability report. Additionally, or alternatively, the network entity105-amay configure the UE115-bwith a scheduling pattern for transmitting capability reports. At310, the UE115-bmay transmit a capability report indicating a first capability value (i.e., value 1) associated with one or more beam switch delay times supported by the UE115-b. The capability report may indicate the beam switch delay times by including one or more indexes associated with a table including values for the beam switch delay times corresponding to the beam switch event. Additionally, or alternatively, the UE115-bmay include explicit values for the beam switch delay times in the capability report. In some examples, the UE115-bmay transmit the capability report in response to a capability request form the network entity105-b. Alternatively, the UE115-bmay transmit the capability report as part of a periodic transmission, or in response to the complexity, power, latency, or memory needs of the UE115-bchanging. At315, the network entity105-bmay send a confirmation in response to the capability report. For example, the network entity105-bmay indicate the UE115-ato assume beam switch delay times associated with the predetermined capability value 1. In some cases, the UE115-amay assume the beam switch delay times associated with the predetermined capability value 1 without receiving a confirmation from the network entity105-b. At320, the network entity105-band the UE115-bmay engage in a beam switch event. For example, the beam switching event may be a transmit beam selection step (e.g., P-1), a downlink transmit beam refinement step (e.g., P-2), a UE115-areceive beam refinement step (e.g., P-3), or a combination thereof. The beam switch event may incorporate the beam switch delay times to allow time for the UE115-ato perform operations associated with the beam switch event. For example, a beam switch delay time may be a delay between the UE115-breceiving a message (e.g., DCI) from the network entity105-band the UE115-bswitching beams. The UE115-band the network entity105-bmay perform the beam switch event according to the beam switch delay times corresponding to the capability value 1 indicated in the capability report. At325, the UE115-bmay determine a change in complexity, power, latency, memory needs, or other parameters, and switch to a second capability for performing beam switch events. For example, the UE115-bmay enter a power-saving mode and switch to a slow capability associated with longer beam switch delay times which may reduce power consumption. The longer beam switch delay times may allow for reduced processing power and cycles, reduced buffering needs, and micro-sleep during the delays at the UE115-bleading to reduced memory and power consumption. Alternatively, the UE115-bmay enter a high-performance or low-latency mode and prioritize faster procedures over power savings. In this case, the second capability may be associated with shorter beam switch delay times to decrease latency. At330, the UE115-bmay transmit a second capability report indicating a second capability value (i.e., value 2) associated with one or more beam switch delay times supported by the UE115-b. The capability report may indicate the beam switch delay times by including one or more indexes associated with a table containing values for the beam switch delay times corresponding to the beam switch event. Additionally, or alternatively, the UE115-bmay include explicit values for the beam switch delay times in the capability report. In some examples, the UE115-bmay transmit the capability report in response to a capability request form the network entity105-b. Alternatively, the UE115-bmay transmit the capability report as part of a periodic transmission, or in response to the complexity, power, latency, or memory needs of the UE115-bchanging. At335, the network entity105-band the UE115-bmay engage in a second beam switch event. For example, the beam switching event may be a transmit beam selection step (e.g., P-1), a downlink transmit beam refinement step (e.g., P-2), a UE115-areceive beam refinement step (e.g., P-3), or a combination thereof. The beam switch event may incorporate the second beam switch delay times to allow time for the UE115-ato perform operations associated with the beam switch event. FIG.4illustrates an example of a process flow400that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The process flow400may implement aspects of the process flow300, the wireless communications system100, and the wireless communications system200. For example, the process flow300may illustrate communications between a UE115-cand a network entity105-c, which may be examples of corresponding devices described herein, including with reference toFIGS.1,2and3. In some examples, the UE115-cmay dynamically report capability reports associated with a beam switching procedure to the network entity105-c. In the following description of the process flow400, the operations may be performed (e.g., reported or provided) in a different order than the order shown. Specific operations also may be left out of the process flow400, or other operations may be added to the process flow400. Further, although some operations or signaling may be shown to occur at different times for discussion purposes, these operations may actually occur at the same time. At405, the UE115-cmay transmit a capability report indicating (e.g., containing, comprising, etc.) multiple capability values (i.e., value 1 and value 2), where each capability value is associated with one or more beam switch delay times supported by the UE115-c. For example, value 1 may correspond to a fast capability associated with shorter beam switch delay times, while value 2 may correspond to a slow capability associated with longer beam switch delay times. The capability report may indicate the one or more beam switch delay times by including one or more indexes associated with a table containing values for the beam switch delay times corresponding to a beam switch event. Additionally, or alternatively, the UE115-cmay include explicit values for the beam switch delay times in the capability report. In some examples, the UE115-cmay transmit the capability report in response to a capability request form the network entity105-cscheduling a capability report. Alternatively, the UE115-cmay transmit the capability report as part of a periodic transmission, or in response to the complexity, power, latency, or memory needs of the UE115-cchanging. At410, the network entity105-cmay indicate the UE115-cto assume the beam switch delay times associated with capability value 1. The network entity105-cmay determine to indicate the value 1 based on the current needs (e.g., complexity, power, latency, or memory needs) of the system or the UE115-c. The indication may be valid until the network entity105-ctransmits a following indication to the UE115-c. Alternatively, the indication may be valid until the expiration (e.g., expiry) of a timer (e.g., indicated by the network entity105-c) or until a predefined event (e.g., a scheduling pattern, internal event at the UE115-c, etc.). The network entity105-cmay configure the UE114cwith a timing415, so that the UE115-cmay assume the beam switch delay times after the timing415has elapsed following the capability indication. At420, the UE115-cmay assume the beam switch delay times associated with capability value 1 for beam switch events. The UE115-cmay assume the beam switch delay times after the timing415has elapsed. At425, the network entity105-cand the UE115-cmay engage in a beam switch event. For example, the beam switching event may be a transmit beam selection step (e.g., P-1), a downlink transmit beam refinement step (e.g., P-2), a UE115-areceive beam refinement step (e.g., P-3), or a combination thereof. The beam switch event may incorporate the beam switch delay times to allow time for the UE115-ato perform operations associated with the beam switch event. For example, a beam switch delay time may be a delay between the UE115-creceiving a message (e.g., DCI) from the network entity105-cand the UE115-cswitching beams. The UE115-cand the network entity105-cmay perform the beam switch event according to the beam switch delay times corresponding to the capability value 1 indicated in the capability indication. FIG.5illustrates an example of a process flow500that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The process flow500may implement aspects of process flows300and400, and wireless communications systems100and200. For example, the process flow500may illustrate communications between a UE115-dand a network entity105-d, which may be examples of corresponding devices described herein. In some examples, the UE115-dand the network entity105-dmay operate according to a capability associated with a beam switch delay time515corresponding to the time between transmission of a reference signal (e.g., CSI-RS) with repetition (e.g., repetition set to ON) during a beam training session (e.g., for a P-3 procedure) and the UE115-dbeing ready to receive a downlink transmission using the selected receive beam. Transmitting the reference signal with repetition may involve the network entity105-dtransmitting multiple reference signals with a common transmit beam505in quick succession. The beam used for the repeated transmission may be a transmit beam505-aselected in a previous beam switch event (e.g., during a P-2 event). The UE115-dmay sweep receive beams510and select a receive beam510-abased on the transmission of the reference signal with repetition. The network entity105-dmay refrain from transmitting a downlink message before the beam switch delay time515elapses. The network entity105-dmay configure the UE115-dwith the beam switch delay time515so that the UE115-dmay assume that no downlink message will be scheduled before this delay elapses after the reference signal with repetition. Therefore, the UE115-dmay refrain from buffering and listening for downlink messages using the selected beam until the delay elapses. The capability and the beam switch delay time515may be dependent on a subcarrier spacing (SCS) associated with transmissions between the UE115-dand the network entity105-d, a number of antenna panels available at the UE115-d, a periodicity of the reference signal (e.g., periodic, aperiodic, or semi-persistent), a slot or sub-slot resolution for transmissions, a symbol or sub-symbol resolution for transmissions (e.g., for higher SCS, the capability may be based on a half symbol if a single carrier waveform is used), a number of reference signal resources used during the beam training session, or any combination thereof. After the beam switch delay time515elapses, the UE115-dmay be ready to begin receiving downlink messages according to the selected receive beam510-a. FIG.6illustrates an example of a process flow600that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The process flow600may implement aspects of process flows300and400, wireless communications systems100and200, and process flow500. For example, the process flow600may illustrate communications between a UE115-3and a network entity105-3, which may be examples of corresponding devices described herein. In some examples, the UE115-emay dynamically report capability reports associated with a beam switching procedure to the network entity105-e. In the following description of the process flow600, the operations may be performed (e.g., reported or provided) in a different order than the order shown. Specific operations also may be left out of the process flow600, or other operations may be added to the process flow600. Further, although some operations or signaling may be shown to occur at different times for discussion purposes, these operations may actually occur at the same time. At605, the network entity105-emay transmit a control message (e.g., DCI) to the UE115-e. The control message may indicate (e.g., schedule) the UE115-eof an upcoming reference signal transmission with repetition and, in some cases, a subsequent message. In some examples, the control message may indicate to the UE115-eof a timing615during which the UE115-ecan assume that no messages will be transmitted by the network entity105-ein accordance with a capability of the UE115-eas described herein, with reference toFIG.5. For example, the capability and the timing620may be dependent on a subcarrier spacing (SCS) associated with transmissions between the UE115-eand the network entity105-e, a number of antenna panels available at the UE115-e, a periodicity of the reference signal (e.g., periodic, aperiodic, or semi-persistent), a slot or sub-slot resolution for transmissions, a symbol or sub-symbol resolution for transmissions (e.g., for higher SCS, the capability may be based on a half symbol if a single carrier waveform is used), a number of reference signal resources used during the beam training session, or any combination thereof. At610, the network entity105-emay transmit the reference signal (e.g., a CSI-RS) with repetition, which may involve the network entity105-etransmitting multiple reference signals with a common transmit beam in quick succession. The beam used for the repeated transmission may be a transmit beam selected in a previous beam switch event (e.g., during a P-2 event). The UE115-emay sweep receive beams and select a receive beam based on the transmission of the reference signal with repetition. The network entity105-emay refrain from transmitting any messages to the UE115-euntil the timing615has elapsed. As such, the UE115-emay avoid buffering and listening for messages using the selected receive beam until the timing615has elapsed. At620, the network entity105-emay transmit a message (e.g., a PDSCH) to the UE115-eusing the transmit beam after the timing615has elapsed. The UE115-emay receive the message using the selected receive beam. FIG.7shows a block diagram700of a device705that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The device705may be an example of aspects of a UE115as described herein. The device705may include a receiver710, a transmitter715, and a communications manager720. The device705may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver710may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to dynamic beam switching delay capability). Information may be passed on to other components of the device705. The receiver710may utilize a single antenna or a set of multiple antennas. The transmitter715may provide a means for transmitting signals generated by other components of the device705. For example, the transmitter715may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to dynamic beam switching delay capability). In some examples, the transmitter715may be co-located with a receiver710in a transceiver module. The transmitter715may utilize a single antenna or a set of multiple antennas. The communications manager720, the receiver710, the transmitter715, or various combinations thereof or various components thereof may be examples of means for performing various aspects of dynamic beam switching delay capability as described herein. For example, the communications manager720, the receiver710, the transmitter715, or various combinations or components thereof may support a method for performing one or more of the functions described herein. In some examples, the communications manager720, the receiver710, the transmitter715, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a digital signal processor (DSP), a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some examples, a processor and memory coupled with the processor may be configured to perform one or more of the functions described herein (e.g., by executing, by the processor, instructions stored in the memory). Additionally, or alternatively, in some examples, the communications manager720, the receiver710, the transmitter715, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by a processor. If implemented in code executed by a processor, the functions of the communications manager720, the receiver710, the transmitter715, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting a means for performing the functions described in the present disclosure). In some examples, the communications manager720may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver710, the transmitter715, or both. For example, the communications manager720may receive information from the receiver710, send information to the transmitter715, or be integrated in combination with the receiver710, the transmitter715, or both to obtain information, output information, or perform various other operations as described herein. The communications manager720may support wireless communication at a UE in accordance with examples as disclosed herein. For example, the communications manager720may be configured as or otherwise support a means for transmitting, to a network entity and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The communications manager720may be configured as or otherwise support a means for receiving, from the network entity, a first downlink message that triggers the beam switching event. The communications manager720may be configured as or otherwise support a means for switching to the reception beam based on receiving the first downlink message. Additionally, or alternatively, the communications manager720may support wireless communication at a UE in accordance with examples as disclosed herein. For example, the communications manager720may be configured as or otherwise support a means for transmitting, to a network entity and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. The communications manager720may be configured as or otherwise support a means for receiving, from the network entity, the channel state information signal with repetition. The communications manager720may be configured as or otherwise support a means for switching to the reception beam based on receiving the channel state information signal with repetition. By including or configuring the communications manager720in accordance with examples as described herein, the device705(e.g., a processor controlling or otherwise coupled with the receiver710, the transmitter715, the communications manager720, or a combination thereof) may support techniques for reducing power consumption or latency at the UE. FIG.8shows a block diagram800of a device805that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The device805may be an example of aspects of a device705or a UE115as described herein. The device805may include a receiver810, a transmitter815, and a communications manager820. The device805may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver810may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to dynamic beam switching delay capability). Information may be passed on to other components of the device805. The receiver810may utilize a single antenna or a set of multiple antennas. The transmitter815may provide a means for transmitting signals generated by other components of the device805. For example, the transmitter815may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to dynamic beam switching delay capability). In some examples, the transmitter815may be co-located with a receiver810in a transceiver module. The transmitter815may utilize a single antenna or a set of multiple antennas. The device805, or various components thereof, may be an example of means for performing various aspects of dynamic beam switching delay capability as described herein. For example, the communications manager820may include a capability component825, a beam switch component830, or any combination thereof. The communications manager820may be an example of aspects of a communications manager720as described herein. In some examples, the communications manager820, or various components thereof, may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver810, the transmitter815, or both. For example, the communications manager820may receive information from the receiver810, send information to the transmitter815, or be integrated in combination with the receiver810, the transmitter815, or both to obtain information, output information, or perform various other operations as described herein. The communications manager820may support wireless communication at a UE in accordance with examples as disclosed herein. The capability component825may be configured as or otherwise support a means for transmitting, to a network entity and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The beam switch component830may be configured as or otherwise support a means for receiving, from the network entity, a first downlink message that triggers the beam switching event. The beam switch component830may be configured as or otherwise support a means for switching to the reception beam based on receiving the first downlink message. Additionally, or alternatively, the communications manager820may support wireless communication at a UE in accordance with examples as disclosed herein. The capability component825may be configured as or otherwise support a means for transmitting, to a network entity and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. The beam switch component830may be configured as or otherwise support a means for receiving, from the network entity, the channel state information signal with repetition. The beam switch component830may be configured as or otherwise support a means for switching to the reception beam based on receiving the channel state information signal with repetition. FIG.9shows a block diagram900of a communications manager920that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The communications manager920may be an example of aspects of a communications manager720, a communications manager820, or both, as described herein. The communications manager920, or various components thereof, may be an example of means for performing various aspects of dynamic beam switching delay capability as described herein. For example, the communications manager920may include a capability component925, a beam switch component930, a delay component935, a selection component940, a timer component945, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses). The communications manager920may support wireless communication at a UE in accordance with examples as disclosed herein. The capability component925may be configured as or otherwise support a means for transmitting, to a network entity and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The beam switch component930may be configured as or otherwise support a means for receiving, from the network entity, a first downlink message that triggers the beam switching event. In some examples, the beam switch component930may be configured as or otherwise support a means for switching to the reception beam based on receiving the first downlink message. In some examples, the delay component935may be configured as or otherwise support a means for performing the beam switching event in accordance with a first beam switching delay time of the different beam switching delay times, where the beam switching event includes receiving, at a time that is the first beam switching delay time after receiving the first downlink message, a second downlink message using the selected reception beam at the UE. In some examples, the first downlink message includes a downlink control information signal including a transmission configuration indicator information, and the second downlink message includes a physical downlink shared channel. In some examples, the first downlink message includes a downlink control information signal and the second downlink message includes an aperiodic channel state information reference signal. In some examples, the selection component940may be configured as or otherwise support a means for transmitting, at a time that is the first beam switching delay time after receiving the first downlink message, an indication of the selected reception beam at the UE, where the first downlink message includes at least one of a downlink reference signal, a synchronization signal block, a channel state information reference signal, or a combination thereof. In some examples, to support transmitting the set of multiple UE capability values, the delay component935may be configured as or otherwise support a means for periodically transmitting the set of multiple UE capability values pertaining to support, by the UE, of different beam switching delay times for selection of the reception beam at the UE. In some examples, the capability component925may be configured as or otherwise support a means for determining a change in one or more parameters at the UE, where transmitting the set of multiple UE capability values is based on the change in the one or more parameters at the UE. In some examples, the delay component935may be configured as or otherwise support a means for receiving, from the network entity, a request for a predetermined beam switching delay value, where transmitting the set of multiple UE capability values is based on receiving the request for the predetermined beam switching delay value. In some examples, the timer component945may be configured as or otherwise support a means for determining an expiry of a timer, where transmitting the set of multiple UE capability values is in response to the expiry of the timer. In some examples, the selection component940may be configured as or otherwise support a means for receiving a first capability selection message indicating a first beam switching delay time of the different beam switching delay times. In some examples, the delay component935may be configured as or otherwise support a means for communicating with the network entity in accordance with the first beam switching delay time based on receiving the first capability selection message. In some examples, the selection component940may be configured as or otherwise support a means for receiving a second capability selection message indicating a second beam switching delay time of the different beam switching delay times, where the second beam switching delay time is different from the first beam switching delay time. In some examples, the delay component935may be configured as or otherwise support a means for communicating with the network entity in accordance with the second beam switching delay time based on receiving the second capability selection message. In some examples, communicating with the network entity includes communicating with the network entity a predetermined time after the receiving the first capability selection message. In some examples, the set of multiple UE capability values indicates a set of multiple indices from a pre-configured table. In some examples, the one or more uplink messages include at least one of a physical uplink shared channel, a physical uplink control channel, a random access channel, a sounding reference signal, or a combination thereof. In some examples, the uplink message includes at least one of a physical uplink shared channel, a physical uplink control channel, a random access channel, a sounding reference signal, or a combination thereof. Additionally, or alternatively, the communications manager920may support wireless communication at a UE in accordance with examples as disclosed herein. In some examples, the capability component925may be configured as or otherwise support a means for transmitting, to a network entity and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. In some examples, the beam switch component930may be configured as or otherwise support a means for receiving, from the network entity, the channel state information signal with repetition. In some examples, the beam switch component930may be configured as or otherwise support a means for switching to the reception beam based on receiving the channel state information signal with repetition. In some examples, the delay component935may be configured as or otherwise support a means for receiving, from the network entity, a delay parameter indicating a time period after the channel state information signal. In some examples, the delay component935may be configured as or otherwise support a means for assuming an absence of downlink messages during the time period after receiving the channel state information signal based on the delay parameter. In some examples, the UE capability value is based on a subcarrier spacing, a number of antenna panels at the UE, a periodicity of the channel state information signal, a slot resolution, a symbol resolution, a number of channel state information reference signal resources used in a beam training session, or a combination thereof. FIG.10shows a diagram of a system1000including a device1005that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The device1005may be an example of or include the components of a device705, a device805, or a UE115as described herein. The device1005may communicate (e.g., wirelessly) with one or more network entities105, one or more UEs115, or any combination thereof. The device1005may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager1020, an input/output (I/O) controller1010, a transceiver1015, an antenna1025, a memory1030, code1035, and a processor1040. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus1045). The I/O controller1010may manage input and output signals for the device1005. The I/O controller1010may also manage peripherals not integrated into the device1005. In some cases, the I/O controller1010may represent a physical connection or port to an external peripheral. In some cases, the I/O controller1010may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. Additionally, or alternatively, the I/O controller1010may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller1010may be implemented as part of a processor, such as the processor1040. In some cases, a user may interact with the device1005via the I/O controller1010or via hardware components controlled by the I/O controller1010. In some cases, the device1005may include a single antenna1025. However, in some other cases, the device1005may have more than one antenna1025, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver1015may communicate bi-directionally, via the one or more antennas1025, wired, or wireless links as described herein. For example, the transceiver1015may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver1015may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas1025for transmission, and to demodulate packets received from the one or more antennas1025. The transceiver1015, or the transceiver1015and one or more antennas1025, may be an example of a transmitter715, a transmitter815, a receiver710, a receiver810, or any combination thereof or component thereof, as described herein. The memory1030may include random access memory (RAM) and read-only memory (ROM). The memory1030may store computer-readable, computer-executable code1035including instructions that, when executed by the processor1040, cause the device1005to perform various functions described herein. The code1035may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code1035may not be directly executable by the processor1040but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the memory1030may contain, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices. The processor1040may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor1040may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor1040. The processor1040may be configured to execute computer-readable instructions stored in a memory (e.g., the memory1030) to cause the device1005to perform various functions (e.g., functions or tasks supporting dynamic beam switching delay capability). For example, the device1005or a component of the device1005may include a processor1040and memory1030coupled with or to the processor1040, the processor1040and memory1030configured to perform various functions described herein. The communications manager1020may support wireless communication at a UE in accordance with examples as disclosed herein. For example, the communications manager1020may be configured as or otherwise support a means for transmitting, to a network entity and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The communications manager1020may be configured as or otherwise support a means for receiving, from the network entity, a first downlink message that triggers the beam switching event. The communications manager1020may be configured as or otherwise support a means for switching to the reception beam based on receiving the first downlink message. Additionally, or alternatively, the communications manager1020may support wireless communication at a UE in accordance with examples as disclosed herein. For example, the communications manager1020may be configured as or otherwise support a means for transmitting, to a network entity and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. The communications manager1020may be configured as or otherwise support a means for receiving, from the network entity, the channel state information signal with repetition. The communications manager1020may be configured as or otherwise support a means for switching to the reception beam based on receiving the channel state information signal with repetition. By including or configuring the communications manager1020in accordance with examples as described herein, the device1005may support techniques for improved communication reliability, reduced latency, reduced power consumption, improved coordination between devices, longer battery life, or a combination thereof. In some examples, the communications manager1020may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver1015, the one or more antennas1025, or any combination thereof. Although the communications manager1020is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager1020may be supported by or performed by the processor1040, the memory1030, the code1035, or any combination thereof. For example, the code1035may include instructions executable by the processor1040to cause the device1005to perform various aspects of dynamic beam switching delay capability as described herein, or the processor1040and the memory1030may be otherwise configured to perform or support such operations. FIG.11shows a block diagram1100of a device1105that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The device1105may be an example of aspects of a network entity105as described herein. The device1105may include a receiver1110, a transmitter1115, and a communications manager1120. The device1105may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver1110may provide a means for obtaining (e.g., receiving, determining, identifying) information such as user data, control information, or any combination thereof (e.g., I/Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack). Information may be passed on to other components of the device1105. In some examples, the receiver1110may support obtaining information by receiving signals via one or more antennas. Additionally, or alternatively, the receiver1110may support obtaining information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. The transmitter1115may provide a means for outputting (e.g., transmitting, providing, conveying, sending) information generated by other components of the device1105. For example, the transmitter1115may output information such as user data, control information, or any combination thereof (e.g., I/Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack). In some examples, the transmitter1115may support outputting information by transmitting signals via one or more antennas. Additionally, or alternatively, the transmitter1115may support outputting information by transmitting signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter1115and the receiver1110may be co-located in a transceiver, which may include or be coupled with a modem. The communications manager1120, the receiver1110, the transmitter1115, or various combinations thereof or various components thereof may be examples of means for performing various aspects of dynamic beam switching delay capability as described herein. For example, the communications manager1120, the receiver1110, the transmitter1115, or various combinations or components thereof may support a method for performing one or more of the functions described herein. In some examples, the communications manager1120, the receiver1110, the transmitter1115, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a DSP, a CPU, an ASIC, an FPGA or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some examples, a processor and memory coupled with the processor may be configured to perform one or more of the functions described herein (e.g., by executing, by the processor, instructions stored in the memory). Additionally, or alternatively, in some examples, the communications manager1120, the receiver1110, the transmitter1115, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by a processor. If implemented in code executed by a processor, the functions of the communications manager1120, the receiver1110, the transmitter1115, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting a means for performing the functions described in the present disclosure). In some examples, the communications manager1120may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver1110, the transmitter1115, or both. For example, the communications manager1120may receive information from the receiver1110, send information to the transmitter1115, or be integrated in combination with the receiver1110, the transmitter1115, or both to obtain information, output information, or perform various other operations as described herein. The communications manager1120may support wireless communication at a network entity in accordance with examples as disclosed herein. For example, the communications manager1120may be configured as or otherwise support a means for receiving, from a UE and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The communications manager1120may be configured as or otherwise support a means for transmitting, to the UE, a first downlink message that triggers the beam switching event. The communications manager1120may be configured as or otherwise support a means for communicating with the UE in accordance with one of the different beam switching delay times based on transmitting the first downlink message. Additionally, or alternatively, the communications manager1120may support wireless communication at a network entity in accordance with examples as disclosed herein. For example, the communications manager1120may be configured as or otherwise support a means for receiving, from a UE and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. The communications manager1120may be configured as or otherwise support a means for transmitting, to the UE, the channel state information signal with repetition. The communications manager1120may be configured as or otherwise support a means for communicating with the UE in accordance with one of the one or more beam switching delay times based on transmitting the channel state information signal with repetition. By including or configuring the communications manager1120in accordance with examples as described herein, the device1105(e.g., a processor controlling or otherwise coupled with the receiver1110, the transmitter1115, the communications manager1120, or a combination thereof) may support techniques for reduced power consumption or latency, and more efficient utilization of communication resources. FIG.12shows a block diagram1200of a device1205that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The device1205may be an example of aspects of a device1105or a network entity105as described herein. The device1205may include a receiver1210, a transmitter1215, and a communications manager1220. The device1205may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver1210may provide a means for obtaining (e.g., receiving, determining, identifying) information such as user data, control information, or any combination thereof (e.g., I/Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack). Information may be passed on to other components of the device1205. In some examples, the receiver1210may support obtaining information by receiving signals via one or more antennas. Additionally, or alternatively, the receiver1210may support obtaining information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. The transmitter1215may provide a means for outputting (e.g., transmitting, providing, conveying, sending) information generated by other components of the device1205. For example, the transmitter1215may output information such as user data, control information, or any combination thereof (e.g., I/Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack). In some examples, the transmitter1215may support outputting information by transmitting signals via one or more antennas. Additionally, or alternatively, the transmitter1215may support outputting information by transmitting signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter1215and the receiver1210may be co-located in a transceiver, which may include or be coupled with a modem. The device1205, or various components thereof, may be an example of means for performing various aspects of dynamic beam switching delay capability as described herein. For example, the communications manager1220may include a capability component1225, a beam switch component1230, a communication component1235, or any combination thereof. The communications manager1220may be an example of aspects of a communications manager1120as described herein. In some examples, the communications manager1220, or various components thereof, may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver1210, the transmitter1215, or both. For example, the communications manager1220may receive information from the receiver1210, send information to the transmitter1215, or be integrated in combination with the receiver1210, the transmitter1215, or both to obtain information, output information, or perform various other operations as described herein. The communications manager1220may support wireless communication at a network entity in accordance with examples as disclosed herein. The capability component1225may be configured as or otherwise support a means for receiving, from a UE and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The beam switch component1230may be configured as or otherwise support a means for transmitting, to the UE, a first downlink message that triggers the beam switching event. The beam switch component1230may be configured as or otherwise support a means for communicating with the UE in accordance with one of the different beam switching delay times based on transmitting the first downlink message. Additionally, or alternatively, the communications manager1220may support wireless communication at a network entity in accordance with examples as disclosed herein. The capability component1225may be configured as or otherwise support a means for receiving, from a UE and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. The communication component1235may be configured as or otherwise support a means for transmitting, to the UE, the channel state information signal with repetition. The communication component1235may be configured as or otherwise support a means for communicating with the UE in accordance with one of the one or more beam switching delay times based on transmitting the channel state information signal with repetition. FIG.13shows a block diagram1300of a communications manager1320that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The communications manager1320may be an example of aspects of a communications manager1120, a communications manager1220, or both, as described herein. The communications manager1320, or various components thereof, may be an example of means for performing various aspects of dynamic beam switching delay capability as described herein. For example, the communications manager1320may include a capability component1325, a beam switch component1330, a communication component1335, a delay component1340, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses) which may include communications within a protocol layer of a protocol stack, communications associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack, within a device, component, or virtualized component associated with a network entity105, between devices, components, or virtualized components associated with a network entity105), or any combination thereof. The communications manager1320may support wireless communication at a network entity in accordance with examples as disclosed herein. The capability component1325may be configured as or otherwise support a means for receiving, from a UE and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The beam switch component1330may be configured as or otherwise support a means for transmitting, to the UE, a first downlink message that triggers the beam switching event. In some examples, the beam switch component1330may be configured as or otherwise support a means for communicating with the UE in accordance with one of the different beam switching delay times based on transmitting the first downlink message. In some examples, the delay component1340may be configured as or otherwise support a means for determining that the beam switching event is performed in accordance with a first beam switching delay time of the different beam switching delay times, where the beam switching event includes transmitting, at a time that is the first beam switching delay time after transmitting the first downlink message, a second downlink message using the selected reception beam at the UE. In some examples, the first downlink message includes a downlink control information signal including a transmission configuration indicator information, and the second downlink message includes a physical downlink shared channel. In some examples, the first downlink message includes a downlink control information signal and the second downlink message includes an aperiodic channel state information reference signal. In some examples, the beam switch component1330may be configured as or otherwise support a means for receiving, at a time that is the first beam switching delay time after transmitting the first downlink message, an indication of the selected reception beam at the UE, where the first downlink message includes at least one of a downlink reference signal, a synchronization signal block, a channel state information reference signal, or a combination thereof. In some examples, to support receiving the set of multiple UE capability values, the delay component1340may be configured as or otherwise support a means for periodically receiving the set of multiple UE capability values pertaining to support, by the UE, of different beam switching delay times for selection of the reception beam at the UE. In some examples, receiving the set of multiple UE capability values based on a change in one or more parameters at the UE or is in response to an expiry of a timer. In some examples, the delay component1340may be configured as or otherwise support a means for transmitting, to the UE, a request for a predetermined beam switching delay value, where receiving the set of multiple UE capability values is based on transmitting the request for the predetermined beam switching delay value. In some examples, the capability component1325may be configured as or otherwise support a means for transmitting a first capability selection message indicating a first beam switching delay time of the different beam switching delay times. In some examples, the capability component1325may be configured as or otherwise support a means for communicating with the UE in accordance with the first beam switching delay time based on transmitting the first capability selection message. In some examples, the capability component1325may be configured as or otherwise support a means for transmitting a second capability selection message indicating a second beam switching delay time of the different beam switching delay times, where the second beam switching delay time is different from the first beam switching delay time. In some examples, the communication component1335may be configured as or otherwise support a means for communicating with the UE in accordance with the second beam switching delay time based on transmitting the second capability selection message. Additionally, or alternatively, the communications manager1320may support wireless communication at a network entity in accordance with examples as disclosed herein. In some examples, the capability component1325may be configured as or otherwise support a means for receiving, from a UE and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. The communication component1335may be configured as or otherwise support a means for transmitting, to the UE, the channel state information signal with repetition. In some examples, the communication component1335may be configured as or otherwise support a means for communicating with the UE in accordance with one of the one or more beam switching delay times based on transmitting the channel state information signal with repetition. In some examples, the UE capability value is based on a subcarrier spacing, a number of antenna panels at the UE, a periodicity of the channel state information signal, a slot resolution, a symbol resolution, a number of channel state information reference signal resources used in a beam training session, or a combination thereof. FIG.14shows a diagram of a system1400including a device1405that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The device1405may be an example of or include the components of a device1105, a device1205, or a network entity105as described herein. The device1405may communicate with one or more network entities105, one or more UEs115, or any combination thereof, which may include communications over one or more wired interfaces, over one or more wireless interfaces, or any combination thereof. The device1405may include components that support outputting and obtaining communications, such as a communications manager1420, a transceiver1410, an antenna1415, a memory1425, code1430, and a processor1435. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus1440). The transceiver1410may support bi-directional communications via wired links, wireless links, or both as described herein. In some examples, the transceiver1410may include a wired transceiver and may communicate bi-directionally with another wired transceiver. Additionally, or alternatively, in some examples, the transceiver1410may include a wireless transceiver and may communicate bi-directionally with another wireless transceiver. In some examples, the device1405may include one or more antennas1415, which may be capable of transmitting or receiving wireless transmissions (e.g., concurrently). The transceiver1410may also include a modem to modulate signals, to provide the modulated signals for transmission (e.g., by one or more antennas1415, by a wired transmitter), to receive modulated signals (e.g., from one or more antennas1415, from a wired receiver), and to demodulate signals. The transceiver1410, or the transceiver1410and one or more antennas1415or wired interfaces, where applicable, may be an example of a transmitter1115, a transmitter1215, a receiver1110, a receiver1210, or any combination thereof or component thereof, as described herein. In some examples, the transceiver may be operable to support communications via one or more communications links (e.g., a communication link125, a backhaul communication link120, a midhaul communication link162, a fronthaul communication link168). The memory1425may include RAM and ROM. The memory1425may store computer-readable, computer-executable code1430including instructions that, when executed by the processor1435, cause the device1405to perform various functions described herein. The code1430may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code1430may not be directly executable by the processor1435but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the memory1425may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. The processor1435may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA, a microcontroller, a programmable logic device, discrete gate or transistor logic, a discrete hardware component, or any combination thereof). In some cases, the processor1435may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor1435. The processor1435may be configured to execute computer-readable instructions stored in a memory (e.g., the memory1425) to cause the device1405to perform various functions (e.g., functions or tasks supporting dynamic beam switching delay capability). For example, the device1405or a component of the device1405may include a processor1435and memory1425coupled with the processor1435, the processor1435and memory1425configured to perform various functions described herein. The processor1435may be an example of a cloud-computing platform (e.g., one or more physical nodes and supporting software such as operating systems, virtual machines, or container instances) that may host the functions (e.g., by executing code1430) to perform the functions of the device1405. In some examples, a bus1440may support communications of (e.g., within) a protocol layer of a protocol stack. In some examples, a bus1440may support communications associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack), which may include communications performed within a component of the device1405, or between different components of the device1405that may be co-located or located in different locations (e.g., where the device1405may refer to a system in which one or more of the communications manager1420, the transceiver1410, the memory1425, the code1430, and the processor1435may be located in one of the different components or divided between different components). In some examples, the communications manager1420may manage aspects of communications with a core network130(e.g., via one or more wired or wireless backhaul links). For example, the communications manager1420may manage the transfer of data communications for client devices, such as one or more UEs115. In some examples, the communications manager1420may manage communications with other network entities105, and may include a controller or scheduler for controlling communications with UEs115in cooperation with other network entities105. In some examples, the communications manager1420may support an X2 interface within an LTE/LTE-A wireless communications network technology to provide communication between network entities105. The communications manager1420may support wireless communication at a network entity in accordance with examples as disclosed herein. For example, the communications manager1420may be configured as or otherwise support a means for receiving, from a UE and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The communications manager1420may be configured as or otherwise support a means for transmitting, to the UE, a first downlink message that triggers the beam switching event. The communications manager1420may be configured as or otherwise support a means for communicating with the UE in accordance with one of the different beam switching delay times based on transmitting the first downlink message. Additionally, or alternatively, the communications manager1420may support wireless communication at a network entity in accordance with examples as disclosed herein. For example, the communications manager1420may be configured as or otherwise support a means for receiving, from a UE and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. The communications manager1420may be configured as or otherwise support a means for transmitting, to the UE, the channel state information signal with repetition. The communications manager1420may be configured as or otherwise support a means for communicating with the UE in accordance with one of the one or more beam switching delay times based on transmitting the channel state information signal with repetition. By including or configuring the communications manager1420in accordance with examples as described herein, the device1405may support techniques for improved communication reliability, reduced latency, reduced power consumption, improved coordination between devices, longer battery life, or a combination thereof. In some examples, the communications manager1420may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the transceiver1410, the one or more antennas1415(e.g., where applicable), or any combination thereof. Although the communications manager1420is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager1420may be supported by or performed by the processor1435, the memory1425, the code1430, the transceiver1410, or any combination thereof. For example, the code1430may include instructions executable by the processor1435to cause the device1405to perform various aspects of dynamic beam switching delay capability as described herein, or the processor1435and the memory1425may be otherwise configured to perform or support such operations. FIG.15shows a flowchart illustrating a method1500that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The operations of the method1500may be implemented by a UE or its components as described herein. For example, the operations of the method1500may be performed by a UE115as described with reference toFIGS.1through10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally, or alternatively, the UE may perform aspects of the described functions using special-purpose hardware. At1505, the method may include transmitting, to a network entity and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The operations of1505may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1505may be performed by a capability component925as described with reference toFIG.9. At1510, the method may include receiving, from the network entity, a first downlink message that triggers the beam switching event. The operations of1510may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1510may be performed by a beam switch component930as described with reference toFIG.9. At1515, the method may include switching to the reception beam based on receiving the first downlink message. The operations of1515may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1515may be performed by a beam switch component930as described with reference toFIG.9. FIG.16shows a flowchart illustrating a method1600that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The operations of the method1600may be implemented by a UE or its components as described herein. For example, the operations of the method1600may be performed by a UE115as described with reference toFIGS.1through10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally, or alternatively, the UE may perform aspects of the described functions using special-purpose hardware. At1605, the method may include transmitting, to a network entity and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. The operations of1605may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1605may be performed by a capability component925as described with reference toFIG.9. At1610, the method may include receiving, from the network entity, the channel state information signal with repetition. The operations of1610may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1610may be performed by a beam switch component930as described with reference toFIG.9. At1615, the method may include switching to the reception beam based on receiving the channel state information signal with repetition. The operations of1615may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1615may be performed by a beam switch component930as described with reference toFIG.9. FIG.17shows a flowchart illustrating a method1700that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The operations of the method1700may be implemented by a network entity or its components as described herein. For example, the operations of the method1700may be performed by a network entity as described with reference toFIGS.1through6and11through14. In some examples, a network entity may execute a set of instructions to control the functional elements of the network entity to perform the described functions. Additionally, or alternatively, the network entity may perform aspects of the described functions using special-purpose hardware. At1705, the method may include receiving, from a UE and via one or more uplink messages, a set of multiple UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event. The operations of1705may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1705may be performed by a capability component1325as described with reference toFIG.13. At1710, the method may include transmitting, to the UE, a first downlink message that triggers the beam switching event. The operations of1710may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1710may be performed by a beam switch component1330as described with reference toFIG.13. At1715, the method may include communicating with the UE in accordance with one of the different beam switching delay times based on transmitting the first downlink message. The operations of1715may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1715may be performed by a beam switch component1330as described with reference toFIG.13. FIG.18shows a flowchart illustrating a method1800that supports dynamic beam switching delay capability in accordance with one or more aspects of the present disclosure. The operations of the method1800may be implemented by a network entity or its components as described herein. For example, the operations of the method1800may be performed by a network entity as described with reference toFIGS.1through6and11through14. In some examples, a network entity may execute a set of instructions to control the functional elements of the network entity to perform the described functions. Additionally, or alternatively, the network entity may perform aspects of the described functions using special-purpose hardware. At1805, the method may include receiving, from a UE and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition. The operations of1805may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1805may be performed by a capability component1325as described with reference toFIG.13. At1810, the method may include transmitting, to the UE, the channel state information signal with repetition. The operations of1810may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1810may be performed by a communication component1335as described with reference toFIG.13. At1815, the method may include communicating with the UE in accordance with one of the one or more beam switching delay times based on transmitting the channel state information signal with repetition. The operations of1815may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1815may be performed by a communication component1335as described with reference toFIG.13. The following provides an overview of aspects of the present disclosure:Aspect 1: A method for wireless communication at a UE, comprising: transmitting, to a network entity and via one or more uplink messages, a plurality of UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event; receiving, from the network entity, a first downlink message that triggers the beam switching event; and switching to the reception beam based at least in part on receiving the first downlink message.Aspect 2: The method of aspect 1, further comprising: performing the beam switching event in accordance with a first beam switching delay time of the different beam switching delay times, wherein the beam switching event comprises receiving, at a time that is the first beam switching delay time after receiving the first downlink message, a second downlink message using the selected reception beam at the UE.Aspect 3: The method of aspect 2, wherein the first downlink message comprises a downlink control information signal comprising a transmission configuration indicator information, and the second downlink message comprises a physical downlink shared channel.Aspect 4: The method of any of aspects 2 through 3, wherein the first downlink message comprises a downlink control information signal and the second downlink message comprises an aperiodic channel state information reference signal.Aspect 5: The method of any of aspects 1 through 4, further comprising: transmitting, at a time that is the first beam switching delay time after receiving the first downlink message, an indication of the selected reception beam at the UE, wherein the first downlink message comprises at least one of a downlink reference signal, a synchronization signal block, a channel state information reference signal, or a combination thereofAspect 6: The method of any of aspects 1 through 5, wherein transmitting the plurality of UE capability values comprises: periodically transmitting the plurality of UE capability values pertaining to support, by the UE, of different beam switching delay times for selection of the reception beam at the UE.Aspect 7: The method of any of aspects 1 through 6, further comprising: determining a change in one or more parameters at the UE, wherein transmitting the plurality of UE capability values is based at least in part on the change in the one or more parameters at the UE.Aspect 8: The method of any of aspects 1 through 7, further comprising: receiving, from the network entity, a request for a predetermined beam switching delay value, wherein transmitting the plurality of UE capability values is based at least in part on receiving the request for the predetermined beam switching delay value.Aspect 9: The method of any of aspects 1 through 8, further comprising: determining an expiry of a timer, wherein transmitting the plurality of UE capability values is in response to the expiry of the timer.Aspect 10: The method of any of aspects 1 through 9, further comprising: receiving a first capability selection message indicating a first beam switching delay time of the different beam switching delay times; and communicating with the network entity in accordance with the first beam switching delay time based at least in part on receiving the first capability selection message.Aspect 11: The method of aspect 10, further comprising: receiving a second capability selection message indicating a second beam switching delay time of the different beam switching delay times, wherein the second beam switching delay time is different from the first beam switching delay time; and communicating with the network entity in accordance with the second beam switching delay time based at least in part on receiving the second capability selection message.Aspect 12: The method of any of aspects 10 through 11, wherein communicating with the network entity comprises communicating with the network entity a predetermined time after the receiving the first capability selection message.Aspect 13: The method of any of aspects 1 through 12, wherein the plurality of UE capability values indicates a plurality of indices from a pre-configured table.Aspect 14: The method of any of aspects 1 through 13, wherein the one or more uplink messages comprise at least one of a physical uplink shared channel, a physical uplink control channel, a random access channel, a sounding reference signal, or a combination thereofAspect 15: The method of any of aspects 1 through 14, wherein the uplink message comprises at least one of a physical uplink shared channel, a physical uplink control channel, a random access channel, a sounding reference signal, or a combination thereofAspect 16: A method for wireless communication at a UE, comprising: transmitting, to a network entity and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition; receiving, from the network entity, the channel state information signal with repetition; and switching to the reception beam based at least in part on receiving the channel state information signal with repetition.Aspect 17: The method of aspect 16, further comprising: receiving, from the network entity, a delay parameter indicating a time period after the channel state information signal; and assuming an absence of downlink messages during the time period after receiving the channel state information signal based at least in part on the delay parameter.Aspect 18: The method of any of aspects 16 through 17, wherein the UE capability value is based at least in part on a subcarrier spacing, a number of antenna panels at the UE, a periodicity of the channel state information signal, a slot resolution, a symbol resolution, a number of channel state information reference signal resources used in a beam training session, or a combination thereofAspect 19: A method for wireless communication at a network entity, comprising: receiving, from a UE and via one or more uplink messages, a plurality of UE capability values pertaining to UE support of different beam switching delay times for selection of a reception beam at the UE, the different beam switching delay times each associated with a same type of beam switching event; transmitting, to the UE, a first downlink message that triggers the beam switching event; and communicating with the UE in accordance with one of the different beam switching delay times based at least in part on transmitting the first downlink message.Aspect 20: The method of aspect 19, further comprising: determining that the beam switching event is performed in accordance with a first beam switching delay time of the different beam switching delay times, wherein the beam switching event comprises transmitting, at a time that is the first beam switching delay time after transmitting the first downlink message, a second downlink message using the selected reception beam at the UE.Aspect 21: The method of aspect 20, wherein the first downlink message comprises a downlink control information signal comprising a transmission configuration indicator information, and the second downlink message comprises a physical downlink shared channel.Aspect 22: The method of any of aspects 20 through 21, wherein the first downlink message comprises a downlink control information signal and the second downlink message comprises an aperiodic channel state information reference signal.Aspect 23: The method of any of aspects 19 through 22, further comprising: receiving, at a time that is the first beam switching delay time after transmitting the first downlink message, an indication of the selected reception beam at the UE, wherein the first downlink message comprises at least one of a downlink reference signal, a synchronization signal block, a channel state information reference signal, or a combination thereofAspect 24: The method of any of aspects 19 through 23, wherein receiving the plurality of UE capability values comprises: periodically receiving the plurality of UE capability values pertaining to support, by the UE, of different beam switching delay times for selection of the reception beam at the UE.Aspect 25: The method of any of aspects 19 through 24, wherein receiving the plurality of UE capability values based at least in part on a change in one or more parameters at the UE or is in response to an expiry of a timer.Aspect 26: The method of any of aspects 19 through 25, further comprising: transmitting, to the UE, a request for a predetermined beam switching delay value, wherein receiving the plurality of UE capability values is based at least in part on transmitting the request for the predetermined beam switching delay value.Aspect 27: The method of any of aspects 19 through 26, further comprising: transmitting a first capability selection message indicating a first beam switching delay time of the different beam switching delay times; and communicating with the UE in accordance with the first beam switching delay time based at least in part on transmitting the first capability selection message.Aspect 28: The method of aspect 27, further comprising: transmitting a second capability selection message indicating a second beam switching delay time of the different beam switching delay times, wherein the second beam switching delay time is different from the first beam switching delay time; and communicating with the UE in accordance with the second beam switching delay time based at least in part on transmitting the second capability selection message.Aspect 29: A method for wireless communication at a network entity, comprising: receiving, from a UE and via an uplink message, a UE capability value pertaining to UE support of one or more beam switching delay times for selection of a reception beam at the UE for receiving downlink transmission after receiving a channel state information signal with repetition; transmitting, to the UE, the channel state information signal with repetition; and communicating with the UE in accordance with one of the one or more beam switching delay times based at least in part on transmitting the channel state information signal with repetition.Aspect 30: The method of aspect 29, wherein the UE capability value is based at least in part on a subcarrier spacing, a number of antenna panels at the UE, a periodicity of the channel state information signal, a slot resolution, a symbol resolution, a number of channel state information reference signal resources used in a beam training session, or a combination thereofAspect 31: An apparatus for wireless communication at a UE, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 1 through 15.Aspect 32: An apparatus for wireless communication at a UE, comprising at least one means for performing a method of any of aspects 1 through 15.Aspect 33: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code comprising instructions executable by a processor to perform a method of any of aspects 1 through 15.Aspect 34: An apparatus for wireless communication at a UE, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 16 through 18.Aspect 35: An apparatus for wireless communication at a UE, comprising at least one means for performing a method of any of aspects 16 through 18.Aspect 36: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code comprising instructions executable by a processor to perform a method of any of aspects 16 through 18.Aspect 37: An apparatus for wireless communication at a network entity, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 19 through 28.Aspect 38: An apparatus for wireless communication at a network entity, comprising at least one means for performing a method of any of aspects 19 through 28.Aspect 39: A non-transitory computer-readable medium storing code for wireless communication at a network entity, the code comprising instructions executable by a processor to perform a method of any of aspects 19 through 28.Aspect 40: An apparatus for wireless communication at a network entity, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 29 through 30.Aspect 41: An apparatus for wireless communication at a network entity, comprising at least one means for performing a method of any of aspects 29 through 30.Aspect 42: A non-transitory computer-readable medium storing code for wireless communication at a network entity, the code comprising instructions executable by a processor to perform a method of any of aspects 29 through 30. It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined. Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.” The term “determine” or “determining” encompasses a variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” can include receiving (such as receiving information), accessing (such as accessing data in a memory) and the like. Also, “determining” can include resolving, obtaining, selecting, choosing, establishing and other such similar actions. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label. The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples. The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein. | 146,066 |
11943032 | DESCRIPTION OF EMBODIMENTS Embodiments of the present invention are described below with reference to the accompanying drawings. Embodiment 1 The following describes, in detail, a transmission scheme, a transmission device, a reception scheme, and a reception device pertaining to the present embodiment. Before beginning the description proper, an outline of transmission schemes and decoding schemes in a conventional spatial multiplexing MIMO system is provided. FIG.1illustrates the structure of an Nt×Nrspatial multiplexing MIMO system. An information vector z is encoded and interleaved. The encoded bit vector u=(u1, . . . uNt) is obtained as the interleave output. Here, u, =(u1t, . . . u1M) (where M is the number of transmitted bits per symbol). For a transmit vector s=(s1, . . . SNt), a received signal si=map(ui) is found for transmit antenna #i. Normalizing the transmit energy, this is expressible as E{|si|2}=Es/Nt(where Esis the total energy per channel). The receive vector y=(y1, . . . yNr)Tis expressed in formula 1, below. [Math. 1] y=(y1, . . . ,yNr)T=HNtNrs+n(formula 1) Here, HNtNris the channel matrix, n=(n1, . . . nNr) is the noise vector, and the average value of niis zero for independent and identically distributed (i.i.d) complex Gaussian noise of variance σ2. Based on the relationship between transmitted symbols introduced into a receiver and the received symbols, the probability distribution of the received vectors can be expressed as formula 2, below, for a multi-dimensional Gaussian distribution. [Math. 2] p(y❘"\[LeftBracketingBar]"u)=1(2πσ2)Nrexp(-12σ2y-Hs(u)2)(formula2) Here, a receiver performing iterative decoding is considered. Such a receiver is illustrated inFIG.1as being made up of an outer soft-in/soft-out decoder and a MIMO detector. The log-likelihood ratio vector (L-value) forFIG.1is given by formula 3 through formula 5, as follows. [Math. 3] L(u)=(L(u1), . . . ,L(uNt))T(formula 3) [Math. 4] L(ui)=(L(ui1), . . . ,L(uiM)) (formula 4) [Math. 5] L(uij)=lnP(uij=+1)P(uij=-1)(formula5) (Iterative Detection Scheme) The following describes the MIMO signal iterative detection performed by the Nt×Nrspatial multiplexing MIMO system. The log-likelihood ratio of unm, is defined by formula 6. [Math. 6] L(umn❘"\[LeftBracketingBar]"y)=lnP(umn=+1❘"\[LeftBracketingBar]"y)P(umn=-1❘"\[LeftBracketingBar]"y)(formula6) Through application of Bayes' theorem, formula 6 can be expressed as formula 7. [Math. 7] L(umn❘"\[LeftBracketingBar]"y)=lnp(y❘"\[LeftBracketingBar]"umn=+1)P(umn=+1)/p(y)p(y❘"\[LeftBracketingBar]"umn=-1)P(umn=-1)/p(y)lnP(umn=+1)P(umn=-1)+lnp(y❘"\[LeftBracketingBar]"umn=+1)p(y❘"\[LeftBracketingBar]"umn=-1)lnP(umn=+1)P(umn=-1)+ln∑Umn,+1p(y❘"\[LeftBracketingBar]"u)p(u❘"\[LeftBracketingBar]"umn)∑Umn,-1p(y❘"\[LeftBracketingBar]"u)p(u❘"\[LeftBracketingBar]"umn)(formula7) Note that Umn,±1={u|umn=±1}. Through the approximation lnΣaj˜max In aj, formula 7 can be approximated as formula 8. The symbol ˜ is herein used to signify approximation. [Math. 8] L(umn❘"\[LeftBracketingBar]"y)≈lnP(umn=+1)P(umn=+1)+maxUmn+1{lnp(y❘"\[LeftBracketingBar]"u)+P(u❘"\[LeftBracketingBar]"umn)}-maxUmn,-1{lnp(y❘"\[LeftBracketingBar]"u)+P(u❘"\[LeftBracketingBar]"umn)}(formula8) In formula 8, P(u|umn) and In P(u|umn) can be expressed as follows. [Math. 9] P(u❘"\[LeftBracketingBar]"umn)=∏(ij)≠(mn)P(uij)=∏(ij)≠(mn)exp(uijL(uij)2)exp(L(uij)2)+exp(-L(uij)2)(formula9) [Math. 10] lnP(u❘"\[LeftBracketingBar]"umn)=(∑ijlnP(uij))-lnP(umn)(formula10) [Math. 11] lnP(uij)=12uijP(uij)-ln(exp(L(uij)2)+exp(-L(uij)2))≈12uijL(uij)-12❘"\[LeftBracketingBar]"L(uij)❘"\[RightBracketingBar]"for❘"\[LeftBracketingBar]"L(uij)❘"\[RightBracketingBar]">2=|L(uij)2|uijsign(L(uij))-1)(formula1) Note that the log-probability of the formula given in formula 2 can be expressed as formula 12. [Math. 12] lnP(y❘"\[LeftBracketingBar]"u)=-Nr2ln(2πσ2)-12σ2y-Hs(u)2(formula12) Accordingly, given formula 7 and formula 13, the posterior L-value for the MAP or APP (a posteriori probability) can be can be expressed as follows. [Math. 13] L(umn❘"\[LeftBracketingBar]"y)=ln∑Umn,+1exp{-12σ2y-Hs(u)2+∑ijlnP(uij)}∑Umn,+1exp{-12σ2y-Hs(u)2+∑ijlnP(uij)}(formula13) This is hereinafter termed iterative APP decoding. Also, given formula 8 and formula 12, the posterior L-value for the Max-log APP can be can be expressed as follows. [Math. 14] L(umn❘"\[LeftBracketingBar]"y)≈maxUmn,+1{Ψ(u,y,L(u))}-maxUmn,-1{Ψ(u,y,L(U))}(formula14) [Math. 15] Ψ(u,y,L(u))=-12σ2y-Hs(u)2+∑ijlnP(uij)(formula15) This is hereinafter referred to as iterative Max-log APP decoding. As such, the external information required by the iterative decoding system is obtainable by subtracting prior input from formula 13 or from formula 14. (System Model) FIG.23illustrates the basic configuration of a system related to the following explanations. The illustrated system is a 2×2 spatial multiplexing MIMO system having an outer decoder for each of two streams A and B. The two outer decoders perform identical LDPC encoding (Although the present example considers a configuration in which the outer encoders use LDPC codes, the outer encoders are not restricted to the use of LDPC as the error-correcting codes. The example may also be realized using other error-correcting codes, such as turbo codes, convolutional codes, or LDPC convolutional codes. Further, while the outer encoders are presently described as individually configured for each transmit antenna, no limitation is intended in this regard. A single outer encoder may be used for a plurality of transmit antennas, or the number of outer encoders may be greater than the number of transmit antennas. The system also has interleavers (πa, πb) for each of the streams A and B. Here, the modulation scheme is 2h-QAM (i.e., h bits transmitted per symbol). The receiver performs iterative detection (iterative APP (or Max-log APP) decoding) of MIMO signals, as described above. The LDPC codes are decoded using, for example, sum-product decoding. FIG.2illustrates the frame configuration and describes the symbol order after interleaving. Here, (ia,ja) and (ib,jb) can be expressed as follows. [Math. 16] (ia,ja)=πa(Ωia,jaa) (formula 16) [Math. 17] (ib,jb)=πb(Ωib,jba) (formula 17) Here, iaand ibrepresent the symbol order after interleaving, jaand jbrepresent the bit position in the modulation scheme (where ja,jb=1, . . . h), πaand πbrepresent the interleavers of streams A and B, and Ωia,jaaand Ωib,jbbrepresent the data order of streams A and B before interleaving. Note thatFIG.2illustrates a situation where ia=ib. (Iterative Decoding) The following describes, in detail, the sum-product decoding used in decoding the LDPC codes and the MIMO signal iterative detection algorithm, both used by the receiver. Sum-Product Decoding A two-dimensional M×N matrix H={Hmn} is used as the check matrix for LDPC codes subject to decoding. For the set[1,N]={1, 2 . . . N}, the partial sets A(m) and B(n) are defined as follows. [Math. 18] A(m)≡{n:Hmn=1} (formula 18) [Math. 19] B(n)≡{m:Hmn=1} (formula 19) Here, A(m) signifies the set of column indices equal to 1 for row m of check matrix H, while B(n) signifies the set of row indices equal to 1 for row n of check matrix H. The sum-product decoding algorithm is as follows. Step A-1 (Initialization): For all pairs (m,n) satisfying Hmn=1, set the prior log ratio βmn=1. Set the loop variable (number of iterations) lsum=1, and set the maximum number of loops lsum,max. Step A-2 (Processing): For all pairs (m,n) satisfying Hmn=1 in the order m=1, 2, . . . M, update the extrinsic value log ratio αmnusing the following update formula. [Math. 20] αmn=(∏n′∈A(m)∖nsign(λn′+βmn′))×f(∑n′∈A(m)∖nf(λn′+βmn′))(formula20) [Math. 21] sign(x)≡{1x≥0-1x<0(formula21) [Math. 22] f(x)≡lnexp(x)+1exp(x)-1(formula22) where f is the Gallager function. λncan then be computed as follows. Step A-3 (Column Operations): For all pairs (m,n) satisfying Hmn=1 in the order n=1, 2, . . . N, update the extrinsic value log ratio βmnusing the following update formula. [Math. 23] βmn=∑m′∈B(n)∖mαm′n(formula23) Step A-4 (Log-likelihood Ratio Calculation): For n∈[1,N], the log-likelihood ratio Ln is computed as follows. [Math. 24] Ln=∑m′∈B(n)∖mαm′n+λn(formula24) Step A-5 (Iteration Count): If lsum<lsum,max, then lsumis incremented and the process returns to step A-2. Sum-product decoding ends when lsum=lsum,max. The above describes one iteration of sum-product decoding operations. Afterward, MIMO signal iterative detection is performed. The variables m, n, αmn, βmn, λn, and L. used in the above explanation of sum-product decoding operations are expressed as ma, na, αmanaa, βmanaa, λna, and Lnafor stream A and as mb, nb, αmbnbb, βmbnmbb, λnb, and Lnbfor stream B. (MIMO Signal Iterative Detection) The following describes the calculation of λnfor MIMO signal iterative detection. The following formula is derivable from formula 1. [Math. 25] y(t)=(y1(t),y2(t))T=H22(t)s(t)+n(t) (formula 25) Given the frame configuration illustrated inFIG.2, the following functions are derivable from formula 16 and formula 17. [Math. 26] na=Ωia,jaa(formula 26) [Math. 27] nb=Ωib,jbb(formula 27) where na,nb∈[1,N]. For iteration k of MIMO signal iterative detection, the variables λna, Lna, λnb, and Lnbare expressed as λk,na, Lk,na, λk,nb, and Lk,nb. Step B-1 (Initial Detection; k=0) For initial wave detection, λo,naand λo,nbare calculated as follows. For iterative APP decoding: [Math. 28] λ0,nX=ln∑U0,nX+1exp{-12σ2y(iX)-H22(iX)s(u(iX))2}∑U0,nX-1exp{-12σ2y(iX)-H22(iX)s(u(iX))2}(formula28) For iterative Max-log APP decoding: [Math. 29] λ0,nX=maxU0,nX,+1{Ψ(u(iX),y(iX))}-maxU0,nX,-1{Ψ(u(iX),y(iX))}(formula29) [Math. 30] Ψ(u(iX),y(iX))=-12σ2y(iX)-H22(iX)s(u(iX))2(formula30) where X=a,b. Next, the iteration count for the MIMO signal iterative detection is set to lmimo=0, with the maximum iteration count being lmimo,max. Step B-2 (Iterative Detection; Iteration k): When the iteration count is k, formula 11, formula 13) through formula 15), formula 16), and formula 17) can be expressed as formula 31) through formula 34), below. Note that (X,Y)=(a,b)(b,a). For iterative APP decoding: [Math. 31] λk,nX=Lk-1,ΩX,jXX(uΩX,jXX)+ln∑Uk,nX,+1exp{-12σ2y(iX)-H22(iX)s(u(iX))2+ρ(uΩX,jXX)}∑Uk,nX,+1exp{-12σ2y(iX)-H22(iX)s(u(iX))2+ρ(uΩX,jXX)}(formula31) [Math. 32] ρ(uΩX,jXX)=∑γ=1γ≠jXh❘"\[LeftBracketingBar]"Lk-1,ΩiX,γX(uΩiX,γX)2❘"\[RightBracketingBar]"(uΩiX,γXsign(Lk-1,ΩiX,γX(uΩiX,γX))-1)+∑γ=1h❘"\[LeftBracketingBar]"Lk-1,ΩiX,γX(uΩiX,γX)2❘"\[RightBracketingBar]"(uΩiX,γXsign(Lk-1,ΩiX,γX(uΩiX,γX))-1)(formula32) For iterative Max-log APP decoding: [Math. 33] λk,nX=Lk-1,ΩiX,jXX(uΩiX,jXX)+maxUk,nX,+1{Ψ(u(iX),y(iX),ρ(uΩiX,jXX))}-maxUk,nX,-1{Ψ(u(iX),y(iX),ρ(uΩiX,jXX))}(formula33) [Math. 34] Ψ(u(iX),y(iX),ρ(uΩiX,jXX))=-12σ2y(iX)-H22(iX)s(u(iX))2+ρ(uΩiX,jXX)(formula34) Step B-3 (Iteration Count and Codeword Estimation) If lmimo<lmimo,max, then lmimois incremented and the process returns to step B-2. When lmimo=lmimo,max, an estimated codeword is found, as follows. [Math. 35] u^nX={1Llmimo,nX≥0-1Llmimo,nX<0(formula35) where X=a,b. FIG.3shows a sample configuration of a transmission device300pertaining to the present Embodiment. An encoder302A takes information (data)301A and a frame configuration signal313as input (which includes the error-correction scheme, coding rate, block length, and other information used by the encoder302A in error-correction coding of the data, such that the scheme designated by the frame configuration signal313is used. The error-correction scheme may be switched). In accordance with the frame configuration signal313, the encoder302A performs error-correction coding, such as convolutional encoding, LDPC encoding, turbo encoding or similar, and outputs encoded data303A. An interleaver304A takes the encoded data303A and the frame configuration signal313as input, performs interleaving, i.e., rearranges the order thereof, and then outputs interleaved data305A. (Depending on the frame configuration signal313, the interleaving scheme may be switched.) A mapper306A takes the interleaved data305A and the frame configuration signal313as input and performs modulation, such as QPSK (Quadrature Phase Shift Keying), 16-QAM (16-Quadradture Amplitude Modulation), or 64-QAM (64-Quadradture Amplitude Modulation) thereon, then outputs a baseband signal307A. (Depending on the frame configuration signal313, the modulation scheme may be switched.) FIGS.19A and19Billustrate an example of a QPSK modulation mapping scheme for a baseband signal made up of an in-phase component I and a quadrature component Q in the IQ plane. For example, as shown inFIG.19A, when the input data are 00, then the output is I=1.0, Q=1.0. Similarly, when the input data are 01, the output is I=−1.0, Q=1.0, and so on.FIG.19Billustrates an example of a QPSK modulation mapping scheme in the IQ plane differing fromFIG.19Ain that the signal points ofFIG.19Ahave been rotated about the origin to obtain the signal points ofFIG.19B. Non-Patent Literature 9 and Non-Patent Literature 10 describe such a constellation rotation scheme. Alternatively, the Cyclic Q Delay described in Non-Patent Literature 9 and Non-Patent Literature 10 may also be adopted. An alternate example, distinct fromFIGS.19A and19B, is shown inFIGS.20A and20B, which illustrate a signal point layout for 16-QAM in the IQ plane. The example ofFIG.20Acorresponds toFIG.19A, while that ofFIG.20Bcorresponds toFIG.19B. An encoder302B takes information (data)301B and the frame configuration signal313as input (which includes the error-correction scheme, coding rate, block length, and other information used by the encoder302A in error-correction coding of the data, such that the scheme designated by the frame configuration signal313is used. The error-correction scheme may be switched). In accordance with the frame configuration signal313, the encoder302B performs error-correction coding, such as convolutional encoding, LDPC encoding, turbo encoding or similar, and outputs encoded data303B. An interleaver304B takes the encoded data303B and the frame configuration signal313as input, performs interleaving, i.e., rearranges the order thereof, and outputs interleaved data305B. (Depending on the frame configuration signal313, the interleaving scheme may be switched.) A mapper306B takes the interleaved data305B and the frame configuration signal313as input and performs modulation, such as QPSK, 16-QAM, or 64-QAM thereon, then outputs a baseband signal307B. (Depending on the frame configuration signal313, the modulation scheme may be switched.) A signal processing scheme information generator314takes the frame configuration signal313as input and accordingly outputs signal processing scheme information315. The signal processing scheme information315designates the fixed precoding matrix to be used, and includes information on the pattern of phase changes used for changing the phase. A weighting unit308A takes baseband signal307A, baseband signal307B, and the signal processing scheme information315as input and, in accordance with the signal processing scheme information315, performs weighting on the baseband signals307A and307B, then outputs a weighted signal309A. The weighting scheme is described in detail, later. A wireless unit310A takes weighted signal309A as input and performs processing such as quadrature modulation, band limitation, frequency conversion, amplification, and so on, then outputs transmit signal311A. Transmit signal311A is then output as radio waves by an antenna312A. A weighting unit308B takes baseband signal307A, baseband signal307B, and the signal processing scheme information315as input and, in accordance with the signal processing scheme information315, performs weighting on the baseband signals307A and307B, then outputs weighted signal316B. FIG.21illustrates the configuration of the weighting units308A and308B. The area ofFIG.21enclosed in the dashed line represents one of the weighting units. Baseband signal307A is multiplied by w11 to obtain w11·s1(t), and multiplied by w21 to obtain w21·s1(t). Similarly, baseband signal307B is multiplied by w12 to obtain w12·s2(t), and multiplied by w22 to obtain w22·s2(t). Next, z1(t)=w11·s1(t)+w12·s2(t) and z2(t)=w21·s1(t)+w22·s22(t) are obtained. Here, as explained above, s1(t) and s2(t) are baseband signals modulated according to a modulation scheme such as BPSK (Binary Phase Shift Keying), QPSK, 8-PSK (8-Phase Shift Keying), 16-QAM, 32-QAM (32-Quadrature Amplitude Modulation), 64-QAM, 256-QAM 16-APSK (16-Amplitude Phase Shift Keying) and so on. Both weighting units perform weighting using a fixed precoding matrix. The precoding matrix uses, for example, the scheme of formula 36, and satisfies the conditions of formula 37 or formula 38, all found below. However, this is only an example. The value of α is not restricted to formula 37 and formula 38, and may take on other values, e.g., α=1. Here, the precoding matrix is: [Math. 36] (w11w12w21w22)=1α2+1(ej0α×ej0α×ej0ejπ)(formula36) In formula 36, above, a may be given by: [Math. 37] α=2+42+2(formula37) Alternatively, in formula 36, above, a may be given by: [Math. 38] α=2+3+52+3-5(formula38) The precoding matrix is not restricted to that of formula 36, but may also be as indicated by formula 39. [Math. 39] (w11w12w21w22)=(abcd)(formula39) In formula 39, let a=Aejδ11, b=Bejδ12, c=cejδ21, and d=Dejδ22. Further, one of a, b, c, and d may be zero. For example, the following configurations are possible: (1) a may be zero while b, c, and d are non-zero, (2) b may be zero while a, c, and d are non-zero, (3) c may be zero while a, b, and d are non-zero, or (4) d may be zero while a, b, and c are non-zero. When any of the modulation scheme, error-correcting codes, and the coding rate thereof are changed, the precoding matrix may also be set, changed, and fixed for use. A phase changer317B takes weighted signal316B and the signal processing scheme information315as input, then regularly changes the phase of the signal316B for output. This regular change is a change of phase performed according to a predetermined phase changing pattern having a predetermined period (cycle) (e.g., every n symbols (n being an integer, n≥1) or at a predetermined interval). The details of the phase changing pattern are explained below, in Embodiment 4. Wireless unit310B takes post-phase-change signal309B as input and performs processing such as quadrature modulation, band limitation, frequency conversion, amplification, and so on, then outputs transmit signal311B. Transmit signal311B is then output as radio waves by an antenna312B. FIG.4illustrates a sample configuration of a transmission device400that differs from that ofFIG.3. The points of difference ofFIG.4fromFIG.3are described next. An encoder402takes information (data)401and the frame configuration signal313as input, and, in accordance with the frame configuration signal313, performs error-correction coding and outputs encoded data402. A distributor404takes the encoded data403as input, performs distribution thereof, and outputs data405A and data405B. AlthoughFIG.4illustrates only one encoder, the number of encoders is not limited as such. The present invention may also be realized using m encoders (m being an integer, m≥1) such that the distributor divides the encoded data created by each encoder into two groups for distribution. FIG.5illustrates an example of a frame configuration in the time domain for a transmission device according to the present Embodiment. Symbol500_1is for notifying the reception device of the transmission scheme. For example, symbol500_1conveys information such as the error-correction scheme used for transmitting data symbols, the coding rate thereof, and the modulation scheme used for transmitting data symbols. Symbol501_1is for estimating channel fluctuations for modulated signal z1(t) (where t is time) transmitted by the transmission device. Symbol502_1is a data symbol transmitted by modulated signal z1(t) as symbol number u (in the time domain). Symbol503_1is a data symbol transmitted by modulated signal z1(t) as symbol number u+1. Symbol501_2is for estimating channel fluctuations for modulated signal z2(t) (where t is time) transmitted by the transmission device. Symbol502_2is a data symbol transmitted by modulated signal z2(t) as symbol number u (in the time domain). Symbol503_2is a data symbol transmitted by modulated signal z1(t) as symbol number u+1. Here, the symbols of z1(t) and of z2(t) having the same time (identical timing) are transmitted from the transmit antenna using the same (shared/common) frequency. The following describes the relationships between the modulated signals z1(t) and z2(t) transmitted by the transmission device and the received signals r1(t) and r2(t) received by the reception device. InFIG.5,504#1and504#2indicate transmit antennas of the transmission device, while505#1and505#2indicate receive antennas of the reception device. The transmission device transmits modulated signal z1(t) from transmit antenna504#1and transmits modulated signal z2(t) from transmit antenna504#2. Here, the modulated signals z1(t) and z2(t) are assumed to occupy the same (shared/common) frequency (bandwidth). The channel fluctuations in the transmit antennas of the transmission device and the antennas of the reception device are h11(t), h12(t), h21(t), and h22(t), respectively. Assuming that receive antenna505#1of the reception device receives received signal r1(t) and that receive antenna505#2of the reception device receives received signal r2(t), the following relationship holds. [Math. 40] (r1(t)r2(t))=(h11(t)h12(t)h21(t)h22(t))(z1(t)z2(t))(formula40) FIG.6pertains to the weighting scheme (precoding scheme) and the phase changing scheme of the present Embodiment. A weighting unit600is a combined version of the weighting units308A and308B fromFIG.3. As shown, stream s1(t) and stream s2(t) correspond to the baseband signals307A and307B ofFIG.3. That is, the streams s1(t) and s2(t) are baseband signals made up of an in-phase component I and a quadrature component Q conforming to mapping by a modulation scheme such as QPSK, 16-QAM, and 64-QAM. As indicated by the frame configuration ofFIG.6, stream s1(t) is represented as s1(u) at symbol number u, as s1(u+1) at symbol number u+1, and so forth. Similarly, stream s2(t) is represented as s2(u) at symbol number u, as s2(u+1) at symbol number u+1, and so forth. The weighting unit600takes the baseband signals307A (s1(t)) and307B (s2(t)) as well as the signal processing scheme information315fromFIG.3as input, performs weighting in accordance with the signal processing scheme information315, and outputs the weighted signals309A (z1(t)) and316B(z2′(t)) fromFIG.3. The phase changer317B changes the phase of weighted signal316B(z2′(t)) and outputs post-phase-change signal309B(z2(t)). Here, given vector W1=(w11,w12) from the first row of the fixed precoding matrix F, z1(t) is expressible as formula 41, below. [Math. 41] z1(t)=W1×(s1(t),s2(t))T(formula 41) Similarly, given vector W2=(w21,w22) from the second row of the fixed precoding matrix F, and letting the phase changing formula applied by the phase changer by y(t), then z2(t) is expressible as formula 42, below. [Math. 42] z2(t)=y(t)×W2×(s1(t),s2(t))T(formula 42) Here, y(t) is a phase changing formula following a predetermined scheme. For example, given a period (cycle) of four and time u, the phase changing formula is expressible as formula 43, below. [Math. 43] y(u)=ej0(formula 43) Similarly, the phase changing formula for time u+1 may be, for example, as given by formula 44. [Math. 44] y(u+1)=ejπ2(formula44) That is, the phase changing formula for time u+k is expressible as formula 45. [Math. 45] y(u+k)=ejkπ2(formula45) Note that formula 43 through formula 45 are given only as an example of regular phase changing. The regular change of phase is not restricted to a period (cycle) of four. Improved reception capabilities (the error-correction capabilities, to be exact) may potentially be promoted in the reception device by increasing the period (cycle) number (this does not mean that a greater period (cycle) is better, though avoiding small numbers such as two is likely ideal). Furthermore, although formula 43 through formula 45, above, represent a configuration in which a change in phase is carried out through rotation by consecutive predetermined phases (in the above formula, every π/2), the change in phase need not be rotation by a constant amount, but may also be random. For example, in accordance with the predetermined period (cycle) of y(t), the phase may be changed through sequential multiplication as shown in formula 46 and formula 47. The key point of regular phase changing is that the phase of the modulated signal is regularly changed. The degree of phase change is preferably as even as possible, such as from −π radians to π radians. However, given that this describes a distribution, random changes are also possible. [Math. 46] ej0→ejπ5→ej2π5→ej3π5→ej4π5→ejπ→ej6π5→ej7π5→ej8π5→ej9π5(formula46) [Math. 47] ejπ2→ejπ→ej3π2→ej2π→ejπ4→ej34π→ej5π4→ej7π4(formula47) As such, the weighting unit600ofFIG.6performs precoding using fixed, predetermined precoding weights, and the phase changer317B changes the phase of the signal input thereto while regularly varying the phase changing degree. When a specialized precoding matrix is used in a LOS environment, the reception quality is likely to improve tremendously. However, depending on the direct wave conditions, the phase and amplitude components of the direct wave may greatly differ from the specialized precoding matrix, upon reception. The LOS environment has certain rules. Thus, data reception quality is tremendously improved through a regular change applied to a transmit signal that obeys those rules. The present invention offers a signal processing scheme for improvements in the LOS environment. FIG.7illustrates a sample configuration of a reception device700pertaining to the present embodiment. Wireless unit703_X receives, as input, received signal702_X received by antenna701_X, performs processing such as frequency conversion, quadrature demodulation, and the like, and outputs baseband signal704_X. Channel fluctuation estimator705_1for modulated signal z1transmitted by the transmission device takes baseband signal704_X as input, extracts reference symbol501_1for channel estimation fromFIG.5, estimates the value of h11from formula 40, and outputs channel estimation signal706_1. Channel fluctuation estimator705_2for modulated signal z2transmitted by the transmission device takes baseband signal704_X as input, extracts reference symbol501_2for channel estimation fromFIG.5, estimates the value of h12from formula 40, and outputs channel estimation signal706_2. Wireless unit703_Y receives, as input, received signal702_Y received by antenna701_X, performs processing such as frequency conversion, quadrature demodulation, and the like, and outputs baseband signal704_Y. Channel fluctuation estimator707_1for modulated signal z1transmitted by the transmission device takes baseband signal704_Y as input, extracts reference symbol501_1for channel estimation fromFIG.5, estimates the value of h21from formula 40, and outputs channel estimation signal708_1. Channel fluctuation estimator707_2for modulated signal z2transmitted by the transmission device takes baseband signal704_Y as input, extracts reference symbol501_2for channel estimation fromFIG.5, estimates the value of h22from formula 40, and outputs channel estimation signal708_2. A control information decoder709receives baseband signal704_X and baseband signal704_Y as input, detects symbol500_1that indicates the transmission scheme fromFIG.5, and outputs a transmission scheme information signal710for the transmission device. A signal processor711takes the baseband signals704_X and704_Y, the channel estimation signals706_1,706_2,708_1, and708_2, and the transmission scheme information signal710as input, performs detection and decoding, and then outputs received data712_1and7122. Next, the operations of the signal processor711fromFIG.7are described in detail.FIG.8illustrates a sample configuration of the signal processor711pertaining to the present embodiment. As shown, the signal processor711is primarily made up of an inner MIMO detector, soft-in/soft-out decoders, and a coefficient generator. Non-Patent Literature 2 and Non-Patent Literature 3 describe a scheme of iterative decoding using this structure. The MIMO system described in Non-Patent Literature 2 and Non-Patent Literature 3 is a spatial multiplexing MIMO system, while the present Embodiment differs from Non-Patent Literature 2 and Non-Patent Literature 3 in describing a MIMO system that regularly changes the phase over time while using the same precoding matrix. Taking the (channel) matrix H(t) of formula 36, then by letting the precoding weight matrix fromFIG.6be F (here, a fixed precoding matrix remaining unchanged for a given received signal) and letting the phase changing formula used by the phase changer fromFIG.6be Y(t) (here, Y(t) changes over time t), then the receive vector R(t)=(r1(t),r2(t))Tand the stream vector S(t)=(s1(t),s2(t))Tthe following function is derived: [Math. 48] R(t)=H(t)×Y(t)×F×S(t) (formula 48) where Y(t)=(100y(t)) Here, the reception device may use the decoding schemes of Non-Patent Literature 2 and 3 on R(t) by computing H(t)×Y(t)×F. Accordingly, the coefficient generator819fromFIG.8takes a transmission scheme information signal818(corresponding to710fromFIG.7) indicated by the transmission device (information for specifying the fixed precoding matrix in use and the phase changing pattern used when the phase is changed) and outputs a signal processing scheme information signal820. The inner MIMO detector803takes the signal processing scheme information signal as input and performs iterative detection and decoding using the signal and the relationship thereof to formula 48. The operations thereof are described below. The processor illustrated inFIG.8uses a processing scheme, as illustrated byFIG.10, to perform iterative decoding (iterative detection). First, detection of one codeword (or one frame) of modulated signal (stream) s1and of one codeword (or one frame) of modulated signal (stream) s2is performed. As a result, the soft-in/soft-out decoder obtains the log-likelihood ratio of each bit of the codeword (or frame) of modulated signal (stream) s1and of the codeword (or frame) of modulated signal (stream) s2. Next, the log-likelihood ratio is used to perform a second round of detection and decoding. These operations are performed multiple times (these operations are hereinafter referred to as iterative decoding (iterative detection)). The following explanations center on the creation scheme of the log-likelihood ratio of a symbol at a specific time within one frame. InFIG.8, a memory815takes baseband signal801X (corresponding to baseband signal704_X fromFIG.7), channel estimation signal group802X (corresponding to channel estimation signals706_1and706_2fromFIG.7), baseband signal801Y (corresponding to baseband signal704_Y fromFIG.7), and channel estimation signal group802Y (corresponding to channel estimation signals708_1and708_2fromFIG.7) as input, executes (computes) H(t)×Y(t)×F from formula 48 in order to perform iterative decoding (iterative detection) and stores the resulting matrix as a transformed channel signal group. The memory815then outputs the above-described signals as needed, specifically as baseband signal816X, transformed channel estimation signal group817X, baseband signal816Y, and transformed channel estimation signal group817Y. Subsequent operations are described separately for initial detection and for iterative decoding (iterative detection). (Initial Detection) The inner MIMO detector803takes baseband signal801X, channel estimation signal group802X, baseband signal801Y, and channel estimation signal group802Y as input. Here, the modulation scheme for modulated signal (stream) s1and modulated signal (stream) s2is taken to be 16-QAM. The inner MIMO detector803first computes H(t)×Y(t)×F from the channel estimation signal groups802X and802Y, thus calculating a candidate signal point corresponding to baseband signal801X.FIG.11represents such a calculation. InFIG.11, each black dot is a candidate signal point in the IQ plane. Given that the modulation scheme is 16-QAM,256candidate signal points exist. (However,FIG.11is only a representation and does not indicate all 256 candidate signal points.) Letting the four bits transmitted in modulated signal s1be b0, b1, b2, and b3 and the four bits transmitted in modulated signal s2be b4, b5, b6, and b7, candidate signal points corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) are found inFIG.11. The Euclidean squared distance between each candidate signal point and each received signal point1101(corresponding to baseband signal801X) is then computed. The Euclidian squared distance between each point is divided by the noise variance σ2. Accordingly, EX(b0, b1, b2, b3, b4, b5, b6, b7) is calculated. That is, EXis the Euclidian squared distance between a candidate signal point corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) and a received signal point, divided by the noise variance. Here, each of the baseband signals and the modulated signals s1and s2is a complex signal. Similarly, the inner MIMO detector803computes H(t)×Y(t)×F from the channel estimation signal groups802X and802Y, calculates candidate signal points corresponding to baseband signal801Y, computes the Euclidean squared distance between each of the candidate signal points and the received signal points (corresponding to baseband signal801Y), and divides the Euclidean squared distance by the noise variance σ2. Accordingly, EY(b0, b1, b2, b3, b4, b5, b6, b7) is calculated. That is, EYis the Euclidian squared distance between a candidate signal point corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) and a received signal point, divided by the noise variance. Next, EX(b0, b1, b2, b3, b4, b5, b6, b7)+EY(b0, b1, b2, b3, b4, b5, b6, b7)=E(b0, b1, b2, b3, b4, b5, b6, b7) is computed. The inner MIMO detector803outputs E(b0, b1, b2, b3, b4, b5, b6, b7) as a signal804. Log-likelihood calculator805A takes the signal804as input, calculates the log-likelihood of bits b0, b1, b2, and b3, and outputs log-likelihood signal806A. Note that this log-likelihood calculation produces the log-likelihood of a bit being 1 and the log-likelihood of a bit being 0. The calculation scheme is as shown in formula 28, formula 29, and formula 30, and the details are given by Non-Patent Literature 2 and 3. Similarly, log-likelihood calculator805A takes the signal804as input, calculates the log-likelihood of bits b0, b1, b2, and b3, and outputs log-likelihood signal806B. A deinterleaver (807A) takes log-likelihood signal806A as input, performs deinterleaving corresponding to that of the interleaver (the interleaver (304A) fromFIG.3), and outputs deinterleaved log-likelihood signal808A. Similarly, a deinterleaver (807B) takes log-likelihood signal806B as input, performs deinterleaving corresponding to that of the interleaver (the interleaver (304B) fromFIG.3), and outputs deinterleaved log-likelihood signal808B. Log-likelihood ratio calculator809A takes deinterleaved log-likelihood signal808A as input, calculates the log-likelihood ratio of the bits encoded by encoder302A fromFIG.3, and outputs log-likelihood ratio signal810A. Similarly, log-likelihood ratio calculator809B takes deinterleaved log-likelihood signal808B as input, calculates the log-likelihood ratio of the bits encoded by encoder302B fromFIG.3, and outputs log-likelihood ratio signal810B. Soft-in/soft-out decoder811A takes log-likelihood ratio signal810A as input, performs decoding, and outputs decoded log-likelihood ratio812A. Similarly, soft-in/soft-out decoder811B takes log-likelihood ratio signal810B as input, performs decoding, and outputs decoded log-likelihood ratio812B. (Iterative Decoding (Iterative Detection), k Iterations) The interleaver (813A) takes the k-1th decoded log-likelihood ratio812A decoded by the soft-in/soft-out decoder as input, performs interleaving, and outputs interleaved log-likelihood ratio814A. Here, the interleaving pattern used by the interleaver (813A) is identical to that of the interleaver (304A) fromFIG.3. Another interleaver (813B) takes the k-1th decoded log-likelihood ratio812B decoded by the soft-in/soft-out decoder as input, performs interleaving, and outputs interleaved log-likelihood ratio814B. Here, the interleaving pattern used by the other interleaver (813B) is identical to that of another interleaver (304B) fromFIG.3. The inner MIMO detector803takes baseband signal816X, transformed channel estimation signal group817X, baseband signal816Y, transformed channel estimation signal group817Y, interleaved log-likelihood ratio814A, and interleaved log-likelihood ratio814B as input. Here, baseband signal816X, transformed channel estimation signal group817X, baseband signal816Y, and transformed channel estimation signal group817Y are used instead of baseband signal801X, channel estimation signal group802X, baseband signal801Y, and channel estimation signal group802Y because the latter cause delays due to the iterative decoding. The iterative decoding operations of the inner MIMO detector803differ from the initial detection operations thereof in that the interleaved log-likelihood ratios814A and814B are used in signal processing for the former. The inner MIMO detector803first calculates E(b0, b1, b2, b3, b4, b5, b6, b7) in the same manner as for initial detection. In addition, the coefficients corresponding to formula 11 and formula 32 are computed from the interleaved log-likelihood ratios814A and814B. The value of E(b0, b1, b2, b3, b4, b5, b6, b7) is corrected using the coefficients so calculated to obtain E′(b0, b1, b2, b3, b4, b5, b6, b7), which is output as the signal804. Log-likelihood calculator805A takes the signal804as input, calculates the log-likelihood of bits b0, b1, b2, and b3, and outputs the log-likelihood signal806A. Note that this log-likelihood calculation produces the log-likelihood of a bit being 1 and the log-likelihood of a bit being 0. The calculation scheme is as shown in formula 31 through formula 35, and the details are given by Non-Patent Literature 2 and 3. Similarly, log-likelihood calculator805B takes the signal804as input, calculates the log-likelihood of bits b4, b5, b6, and b7, and outputs the log-likelihood signal806A. Operations performed by the deinterleaver onwards are similar to those performed for initial detection. WhileFIG.8illustrates the configuration of the signal processor when performing iterative detection, this structure is not absolutely necessary as good reception improvements are obtainable by iterative detection alone. As long as the components needed for iterative detection are present, the configuration need not include the interleavers813A and813B. In such a case, the inner MIMO detector803does not perform iterative detection. The key point for the present Embodiment is the calculation of H(t)×Y(t)×F. As shown in Non-Patent Literature 5 and the like, QR decomposition may also be used to perform initial detection and iterative detection. Also, as indicated by Non-Patent Literature 11, MMSE (Minimum Mean-Square Error) and ZF (Zero-Forcing) linear operations may be performed based on H(t)×Y(t)×F when performing initial detection. FIG.9illustrates the configuration of a signal processor, unlike that ofFIG.8, that serves as the signal processor for modulated signals transmitted by the transmission device fromFIG.4. The point of difference fromFIG.8is the number of soft-in/soft-out decoders. A soft-in/soft-out decoder901takes the log-likelihood ratio signals810A and810B as input, performs decoding, and outputs a decoded log-likelihood ratio902. A distributor903takes the decoded log-likelihood ratio902as input for distribution. Otherwise, the operations are identical to those explained forFIG.8. As described above, when a transmission device according to the present Embodiment using a MIMO system transmits a plurality of modulated signals from a plurality of antennas, changing the phase over time while multiplying by the precoding matrix so as to regularly change the phase results in improvements to data reception quality for a reception device in a LOS environment where direct waves are dominant, in contrast to a conventional spatial multiplexing MIMO system. In the present Embodiment, and particularly in the configuration of the reception device, the number of antennas is limited and explanations are given accordingly. However, the Embodiment may also be applied to a greater number of antennas. In other words, the number of antennas in the reception device does not affect the operations or advantageous effects of the present Embodiment. Also, although LDPC codes are described as a particular example, the present Embodiment is not limited in this manner. Furthermore, the decoding scheme is not limited to the sum-product decoding example given for the soft-in/soft-out decoder. Other soft-in/soft-out decoding schemes, such as the BCJR algorithm, SOYA, and the Max-Log-Map algorithm may also be used. Details are provided in Non-Patent Literature 6. In addition, although the present Embodiment is described using a single-carrier scheme, no limitation is intended in this regard. The present Embodiment is also applicable to multi-carrier transmission. Accordingly, the present Embodiment may also be realized using, for example, spread-spectrum communications, OFDM (Orthogonal Frequency-Division Multiplexing), SC-FDMA (Single Carrier Frequency-Division Multiple Access), SC-OFDM (Single Carrier Orthogonal Frequency-Division Multiplexing), wavelet OFDM as described in Non-Patent Literature 7, and so on. Furthermore, in the present Embodiment, symbols other than data symbols, such as pilot symbols (preamble, unique word, etc) or symbols transmitting control information, may be arranged within the frame in any manner. The following describes an example in which OFDM is used as a multi-carrier scheme. FIG.12illustrates the configuration of a transmission device using OFDM. InFIG.12, components operating in the manner described forFIG.3use identical reference numbers. OFDM-related processor1201A takes weighted signal309A as input, performs OFDM-related processing thereon, and outputs transmit signal1202A. Similarly, OFDM-related processor1201B takes post-phase-change signal309B as input, performs OFDM-related processing thereon, and outputs transmit signal1202A FIG.13illustrates a sample configuration of the OFDM-related processors1201A and1201B and onward fromFIG.12. Components1301A through1310A belong between1201A and312A fromFIG.12, while components1301B through1310B belong between1201B and312B. Serial-to-parallel converter1302A performs serial-to-parallel conversion on weighted signal1301A (corresponding to weighted signal309A fromFIG.12) and outputs parallel signal1303A. Reorderer1304A takes parallel signal1303A as input, performs reordering thereof, and outputs reordered signal1305A. Reordering is described in detail later. IFFT (Inverse Fast Fourier Transform) unit1306A takes reordered signal1305A as input, applies an IFFT thereto, and outputs post-IFFT signal1307A. Wireless unit1308A takes post-IFFT signal1307A as input, performs processing such as frequency conversion and amplification, thereon, and outputs modulated signal1309A. Modulated signal1309A is then output as radio waves by antenna1310A. Serial-to-parallel converter1302B performs serial-to-parallel conversion on weighted signal1301B (corresponding to post-phase-change signal309B fromFIG.12) and outputs parallel signal1303B. Reorderer1304B takes parallel signal1303B as input, performs reordering thereof, and outputs reordered signal1305B. Reordering is described in detail later. IFFT unit1306B takes reordered signal1305B as input, applies an IFFT thereto, and outputs post-IFFT signal1307B. Wireless unit1308B takes post-IFFT signal1307B as input, performs processing such as frequency conversion and amplification thereon, and outputs modulated signal1309B. Modulated signal1309B is then output as radio waves by antenna1310A. The transmission device fromFIG.3does not use a multi-carrier transmission scheme. Thus, as shown inFIG.6, the change of phase is performed to achieve a period (cycle) of four and the post-phase-change symbols are arranged with respect to the time domain. As shown inFIG.12, when multi-carrier transmission, such as OFDM, is used, then, naturally, precoded post-phase-change symbols may be arranged with respect to the time domain as inFIG.3, and this applies to each (sub-)carrier. However, for multi-carrier transmission, the arrangement may also be in the frequency domain, or in both the frequency domain and the time domain. The following describes these arrangements. FIGS.14A and14Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13. The frequency axes are made up of (sub-)carriers 0 through 9. The modulated signals z1and z2share common time (timing) and use a common frequency band.FIG.14Aillustrates a reordering scheme for the symbols of modulated signal z1, whileFIG.14Billustrates a reordering scheme for the symbols of modulated signal z2. With respect to the symbols of weighted signal1301A input to serial-to-parallel converter1302A, the assigned ordering is #0, #1, #2, #3, and so on. Here, given that the example deals with a period (cycle) of four, #0, #1, #2, and #3 are equivalent to one period (cycle). Similarly, #4n, #4n+1, #4n+2, and #4n+3 (n being a non-zero positive integer) are also equivalent to one period (cycle). As shown inFIG.14A, symbols #0, #1, #2, #3, and so on are arranged in order, beginning at carrier 0. Symbols #0 through #9 are given time $1, followed by symbols #10 through #19 which are given time #2, and so on in a regular arrangement. Note that the modulated signals z1and z2are complex signals. Similarly, with respect to the symbols of weighted signal1301B input to serial-to-parallel converter1302B, the assigned ordering is #0, #1, #2, #3, and so on. Here, given that the example deals with a period (cycle) of four, a different change of phase is applied to each of #0, #1, #2, and #3, which are equivalent to one period (cycle). Similarly, a different change of phase is applied to each of #4n, #4n+1, #4n+2, and #4n+3 (n being a non-zero positive integer), which are also equivalent to one period (cycle) As shown inFIG.14B, symbols #0, #1, #2, #3, and so on are arranged in order, beginning at carrier 0. Symbols #0 through #9 are given time $1, followed by symbols #10 through #19 which are given time #2, and so on in a regular arrangement. The symbol group1402shown inFIG.14Bcorresponds to one period (cycle) of symbols when the phase changing scheme ofFIG.6is used. Symbol #0 is the symbol obtained by using the phase at time u inFIG.6, symbol #1 is the symbol obtained by using the phase at time u+1 inFIG.6, symbol #2 is the symbol obtained by using the phase at time u+2 inFIG.6, and symbol #3 is the symbol obtained by using the phase at time u+3 inFIG.6. Accordingly, for any symbol #x, symbol #x is the symbol obtained by using the phase at time u inFIG.6when x mod 4 equals 0 (i.e., when the remainder of x divided by 4 is 0, mod being the modulo operator), symbol #x is the symbol obtained by using the phase at time u+1 inFIG.6when x mod 4 equals 1, symbol #x is the symbol obtained by using the phase at time u+2 inFIG.6when x mod 4 equals 2, and symbol #x is the symbol obtained by using the phase at time u+3 inFIG.6when x mod 4 equals 3. In the present Embodiment, modulated signal z1shown inFIG.14Ahas not undergone a change of phase. As such, when using a multi-carrier transmission scheme such as OFDM, and unlike single carrier transmission, symbols may be arranged with respect to the frequency domain. Of course, the symbol arrangement scheme is not limited to those illustrated byFIGS.14A and14B. Further examples are shown inFIGS.15A,16A, and16B. FIGS.15A and15Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from that ofFIGS.14A and14B.FIG.15Aillustrates a reordering scheme for the symbols of modulated signal z1, whileFIG.15Billustrates a reordering scheme for the symbols of modulated signal z2.FIGS.15A and15Bdiffer fromFIGS.14A and14Bin that different reordering schemes are applied to the symbols of modulated signal z1and to the symbols of modulated signal z2. InFIG.15B, symbols #0 through #5 are arranged at carriers 4 through 9, symbols #6 though #9 are arranged at carriers 0 through 3, and this arrangement is repeated for symbols #10through #19. Here, as inFIG.14B, symbol group1502shown inFIG.15Bcorresponds to one period (cycle) of symbols when the phase changing scheme ofFIG.6is used. FIGS.16A and16Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from that of FIGS.14A and14B.FIG.16Aillustrates a reordering scheme for the symbols of modulated signal z1, whileFIG.16Billustrates a reordering scheme for the symbols of modulated signal z2.FIGS.16A and16Bdiffer fromFIGS.14A and14Bin that, whileFIGS.14A and14Bshowed symbols arranged at sequential carriers,FIGS.16A and16Bdo not arrange the symbols at sequential carriers. Obviously, forFIGS.16A and16B, different reordering schemes may be applied to the symbols of modulated signal z1and to the symbols of modulated signal z2as inFIGS.15Aand FIGS.17A and17Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from those ofFIGS.14A through16B.FIG.17Aillustrates a reordering scheme for the symbols of modulated signal z1andFIG.17Billustrates a reordering scheme for the symbols of modulated signal z2. WhileFIGS.14A through16Bshow symbols arranged with respect to the frequency axis,FIGS.17A and17Buse the frequency and time axes together in a single arrangement. WhileFIG.6describes an example where a change of phase is performed in a four slot period (cycle), the following example describes an eight slot period (cycle). InFIGS.17A and17B, the symbol group1702is equivalent to one period (cycle) of symbols when the phase changing scheme is used (i.e., to eight symbols) such that symbol #0 is the symbol obtained by using the phase at time u, symbol #1 is the symbol obtained by using the phase at time u+1, symbol #2 is the symbol obtained by using the phase at time u+2, symbol #3 is the symbol obtained by using the phase at time u+3, symbol #4 is the symbol obtained by using the phase at time u+4, symbol #5 is the symbol obtained by using the phase at time u+5, symbol #6 is the symbol obtained by using the phase at time u+6, and symbol #7 is the symbol obtained by using the phase at time u+7. Accordingly, for any symbol #x, symbol #x is the symbol obtained by using the phase at time u when x mod 8 equals 0, symbol #x is the symbol obtained by using the phase at time u+1 when x mod 8 equals 1, symbol #x is the symbol obtained by using the phase at time u+2 when x mod 8 equals 2, symbol #x is the symbol obtained by using the phase at time u+3 when x mod 8 equals 3, symbol #x is the symbol obtained by using the phase at time u+4 when x mod 8 equals 4, symbol #x is the symbol obtained by using the phase at time u+5 when x mod 8 equals 5, symbol #x is the symbol obtained by using the phase at time u+6 when x mod 8 equals 6, and symbol #x is the symbol obtained by using the phase at time u+7 when x mod 8 equals 7. InFIGS.17A and17Bfour slots along the time axis and two slots along the frequency axis are used for a total of 4×2=8 slots, in which one period (cycle) of symbols is arranged. Here, given m×n symbols per period (cycle) (i.e., m×n different phases are available for multiplication), then n slots (carriers) in the frequency domain and m slots in the time domain should be used to arrange the symbols of each period (cycle), such that m>n. This is because the phase of direct waves fluctuates slowly in the time domain relative to the frequency domain. Accordingly, the present Embodiment performs a regular change of phase that reduces the influence of steady direct waves. Thus, the phase changing period (cycle) should preferably reduce direct wave fluctuations. Accordingly, m should be greater than n. Taking the above into consideration, using the time and frequency domains together for reordering, as shown inFIGS.17A and17B, is preferable to using either of the frequency domain or the time domain alone due to the strong probability of the direct waves becoming regular. As a result, the effects of the present invention are more easily obtained. However, reordering in the frequency domain may lead to diversity gain due the fact that frequency-domain fluctuations are abrupt. As such, using the frequency and time domains together for reordering is not always ideal. FIGS.18A and18Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from that ofFIGS.17A and14B.FIG.18Aillustrates a reordering scheme for the symbols of modulated signal z1, whileFIG.18Billustrates a reordering scheme for the symbols of modulated signal z2. Much likeFIGS.17A and17B,FIGS.18A and18Billustrate the use of the time and frequency domains, together. However, in contrast toFIGS.17A and17B, where the frequency domain is prioritized and the time domain is used for secondary symbol arrangement,FIGS.18A and18Bprioritize the time domain and use the frequency domain for secondary symbol arrangement. InFIG.18B, symbol group1802corresponds to one period (cycle) of symbols when the phase changing scheme is used. InFIGS.17A,17B,18A, and18B, the reordering scheme applied to the symbols of modulated signal z1and the symbols of modulated signal z2may be identical or may differ as inFIGS.15A and15B. Both approaches allow good reception quality to be obtained. Also, inFIGS.17A,17B,18A, and18B, the symbols may be arranged non-sequentially as inFIGS.16A and16B. Both approaches allow good reception quality to be obtained. FIG.22indicates frequency on the horizontal axis and time on the vertical axis thereof, and illustrates an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from the above.FIG.22illustrates a regular phase changing scheme using four slots, similar to time u through u+3 fromFIG.6. The characteristic feature ofFIG.22is that, although the symbols are reordered with respect the frequency domain, when read along the time axis, a periodic shift of n (n=1 in the example ofFIG.22) symbols is apparent. The frequency-domain symbol group2210inFIG.22indicates four symbols to which the change of phase is applied at time u through u+3 fromFIG.6. Here, symbol #0 is obtained through a change of phase at time u, symbol #1 is obtained through a change of phase at time u+1, symbol #2 is obtained through a change of phase at time u+2, and symbol #3 is obtained through a change of phase at time u+3. Similarly, for frequency-domain symbol group2220, symbol #4 is obtained through a change of phase at time u, symbol #5 is obtained through a change of phase at time u+1, symbol #6 is obtained through a change of phase at time u+2, and symbol #7 is obtained through a change of phase at time u+3. The above-described change of phase is applied to the symbol at time $1. However, in order to apply periodic shifting in the time domain, the following phase changes are applied to symbol groups2201,2202,2203, and2204. For time-domain symbol group2201, symbol #0 is obtained through a change of phase at time u, symbol #9 is obtained through a change of phase at time u+1, symbol #18is obtained through a change of phase at time u+2, and symbol #27is obtained through a change of phase at time u+3. For time-domain symbol group2202, symbol #28is obtained through a change of phase at time u, symbol #1 is obtained through a change of phase at time u+1, symbol #10is obtained through a change of phase at time u+2, and symbol #19is obtained through a change of phase at time u+3. For time-domain symbol group2203, symbol #20is obtained through a change of phase at time u, symbol #29is obtained through a change of phase at time u+1, symbol #2 is obtained through a change of phase at time u+2, and symbol #11is obtained through a change of phase at time u+3. For time-domain symbol group2204, symbol #12is obtained through a change of phase at time u, symbol #21is obtained through a change of phase at time u+1, symbol #30is obtained through a change of phase at time u+2, and symbol #3 is obtained through a change of phase at time u+3. The characteristic feature ofFIG.22is seen in that, taking symbol #11 as an example, the two neighbouring symbols thereof having the same time in the frequency domain (#10 and #12) are both symbols changed using a different phase than symbol #11, and the two neighbouring symbols thereof having the same carrier in the time domain (#2 and #20) are both symbols changed using a different phase than symbol #11. This holds not only for symbol #11, but also for any symbol having two neighboring symbols in the frequency domain and the time domain. Accordingly, phase changing is effectively carried out. This is highly likely to improve date reception quality as influence from regularizing direct waves is less prone to reception. AlthoughFIG.22illustrates an example in which n=1, the invention is not limited in this manner. The same may be applied to a case in which n=3. Furthermore, althoughFIG.22illustrates the realization of the above-described effects by arranging the symbols in the frequency domain and advancing in the time domain so as to achieve the characteristic effect of imparting a periodic shift to the symbol arrangement order, the symbols may also be randomly (or regularly) arranged to the same effect. Embodiment 2 In Embodiment 1, described above, phase changing is applied to a weighted (precoded with a fixed precoding matrix) signal z(t). The following Embodiments describe various phase changing schemes by which the effects of Embodiment 1 may be obtained. In the above-described Embodiment, as shown inFIGS.3and6, phase changer317B is configured to perform a change of phase on only one of the signals output by the weighting unit600. However, phase changing may also be applied before precoding is performed by the weighting unit600. In addition to the components illustrated inFIG.6, the transmission device may also feature the weighting unit600before the phase changer317B, as shown inFIG.25. In such circumstances, the following configuration is possible. The phase changer317B performs a regular change of phase with respect to baseband signal s2(t), on which mapping has been performed according to a selected modulation scheme, and outputs s2′(t)=s2(t)y(t) (where y(t) varies over time t). The weighting unit600executes precoding on s2′t, outputs z2(t)=W2s2′(t) (see formula 42) and the result is then transmitted. Alternatively, phase changing may be performed on both modulated signals s1(t) and s2(t). As such, the transmission device is configured so as to include a phase changer taking both signals output by the weighting unit600, as shown inFIG.26. Like phase changer317B, phase changer317A performs regular a regular change of phase on the signal input thereto, and as such changes the phase of signal z1′(t) precoded by the weighting unit. Post-phase-change signal z1(t) is then output to a transmitter. However, the phase changing rate applied by the phase changers317A and317B varies simultaneously in order to perform the phase changing shown inFIG.26. (The following describes a non-limiting example of the phase changing scheme.) For time u, phase changer317A fromFIG.26performs the change of phase such that z1(t)=y1(t)z1′(t), while phase changer317B performs the change of phase such that z2(t)=y2(t)z2′(t). For example, as shown inFIG.26, for time u, y1(u)=ej0and y2(u)=e−jπ/2, for time u+1, y1(u+1)=ejπ/4and y2(u+1)=ej3π/4, and for time u+k, y1(u+k)=ejkπ/4and y2(u+k)=ejj(k3π4−π/2). Here, the regular phase changing period (cycle) may be the same for both phase changers317A and317B, or may vary for each. Also, as described above, a change of phase may be performed before precoding is performed by the weighting unit. In such a case, the transmission device should be configured as illustrated inFIG.27. When a change of phase is carried out on both modulated signals, each of the transmit signals is, for example, control information that includes information about the phase changing pattern. By obtaining the control information, the reception device knows the phase changing scheme by which the transmission device regularly varies the change, i.e., the phase changing pattern, and is thus able to demodulate (decode) the signals correctly. Next, variants of the sample configurations shown inFIGS.6and25are described with reference toFIGS.28and29.FIG.28differs fromFIG.6in the inclusion of phase change ON/OFF information2800and in that the change of phase is performed on only one of z1′(t) and z2′(t) (i.e., performed on one of z1′(t) and z2′(t), which have identical time or a common frequency). Accordingly, in order to perform the change of phase on one of z1′(t) and z2′(t), the phase changers317A and317B shown inFIG.28may each be ON, and performing the change of phase, or OFF, and not performing the change of phase. The phase change ON/OFF information2800is control information therefor. The phase change ON/OFF information2800is output by the signal processing scheme information generator314shown inFIG.3. Phase changer317A ofFIG.28changes the phase to produce z1(t)=y1(t)z1′(t), while phase changer317B changes the phase to produce z2(t)=y2(t)z2′(t). Here, a change of phase having a period (cycle) of four is, for example, applied to z1′(t). (Meanwhile, the phase of z2′(t) is not changed.) Accordingly, for time u, y1(u)=ej0and y2(u)=1, for time u+1, y1(u+1)=ejπ/2and y2(u+1)=1, for time u+2, y1(u+2)=ejπ/2and y2(u+2)=1, and for time u+3, y1(u+3)=ej3π/2and y2(u+3)=1. Next, a change of phase having a period (cycle) of four is, for example, applied to z2′(t). (Meanwhile, the phase of z1′(t) is not changed.) Accordingly, for time u+4, y1(u+4)=1 and y2(u+4)=ej0, for time u+5, y1(u+5)=1 and y2(u+5)=ejπ/2, for time u+6, y1(u+6)=1 and y2(u+6)=ejπ, and for time u+7, y1(u+7)=1 and y2(u+7)=ej3π/2. Accordingly, given the above examples.for any time 8 k, y1(8 k)=ej0and y2(8 k)=1,for any time 8 k+1, y1(8 k+1)=ejπ/2and y2(8 k+1)=1,for any time 8 k+2, y1(8 k+2)=ejπand y2(8 k+2)=1,for any time 8 k+3, y1(8 k+3)=ej3π/2and y2(8 k+3)=1,for any time 8 k+4, y1(8 k+4)=1 and y2(8 k+4)=ej0,for any time 8 k+5, y1(8 k+3)=1 and y2(8 k+5)=ejπ/2,for any time 8 k+6, y1(8 k+6)=1 and y2(8 k+6)=ejπ, andfor any time 8 k+7, y1(8 k+7)=1 and y2(8 k+7)=ej3π/2. As described above, there are two intervals, one where the change of phase is performed on z1′(t) only, and one where the change of phase is performed on z2′(t) only. Furthermore, the two intervals form a phase changing period (cycle). While the above explanation describes the interval where the change of phase is performed on z1′(t) only and the interval where the change of phase is performed on z2′(t) only as being equal, no limitation is intended in this manner. The two intervals may also differ. In addition, while the above explanation describes performing a change of phase having a period (cycle) of four on z1′(t) only and then performing a change of phase having a period (cycle) of four on z2′(t) only, no limitation is intended in this manner. The changes of phase may be performed on z1′(t) and on z2′(t) in any order (e.g., the change of phase may alternate between being performed on z1′(t) and on z2′(t), or may be performed in random order). Phase changer317A ofFIG.29changes the phase to produce s1′(t)=y1(t)s1(t), while phase changer317B changes the phase to produce s2′(t)=y2(t)s2(t). Here, a change of phase having a period (cycle) of four is, for example, applied to s1(t). (Meanwhile, s2(t) remains unchanged). Accordingly, for time u, y1(u)=ej0and y2(u)=1, for time u+1, y1(u+1)=ejπ/2and y2(u+1)=1, for time u+2, y1(u+2)=ejπand y2(u+2)=1, and for time u+3, y1(u+3)=ej3π/2and y2(u+3)=1. Next, a change of phase having a period (cycle) of four is, for example, applied to s2(t). (Meanwhile, s1(t) remains unchanged). Accordingly, for time u+4, y1(u+4)=1 and y2(u+4)=ej0, for time u+5, y1(u+5)=1 and y2(u+5)=ejπ/2, for time u+6, y1(u+6)=1 and y2(u+6)=ejπ, and for time u+7, y1(u+7)=1 and y2(u+7)=ej3π/2. Accordingly, given the above examples,for any time 8 k, y1(8 k)=ej0and y2(8 k)=1,for any time 8 k+1, y1(8 k+1)=ejπ/2and y2(8 k+1)=1,for any time 8 k+2, y1(8 k+2)=ejπand y2(8 k+2)=1,for any time 8 k+3, y1(8 k+3)=ej3π/2and y2(8 k+3)=1,for any time 8 k+4, y1(8 k+4)=1 and y2(8 k+4)=ej0,for any time 8 k+5, y1(8 k+5)=1 and y2(8 k+5)=ejπ/2,for any time 8 k+6, y1(8 k+6)=1 and y2(8 k+6)=ejπ, andfor any time 8 k+7, y1(8 k+7)=1 and y2(8 k+7)=ej3π/2. As described above, there are two intervals, one where the change of phase is performed on s1(t) only, and one where the change of phase is performed on s2(t) only. Furthermore, the two intervals form a phase changing period (cycle). Although the above explanation describes the interval where the change of phase is performed on s1(t) only and the interval where the change of phase is performed on s2(t) only as being equal, no limitation is intended in this manner. The two intervals may also differ. In addition, while the above explanation describes performing the change of phase having a period (cycle) of four on s1(t) only and then performing the change of phase having a period (cycle) of four on s2(t) only, no limitation is intended in this manner. The changes of phase may be performed on s1(t) and on s2(t) in any order (e.g., may alternate between being performed on s1(t) and on s2(t), or may be performed in random order). Accordingly, the reception conditions under which the reception device receives each transmit signal z1(t) and z2(t) are equalized. By periodically switching the phase of the symbols in the received signals z1(t) and z2(t), the ability of the error corrected codes to correct errors may be improved, thus ameliorating received signal quality in the LOS environment. Accordingly, Embodiment 2 as described above is able to produce the same results as the previously described Embodiment 1. Although the present Embodiment used a single-carrier scheme, i.e., time domain phase changing, as an example, no limitation is intended in this regard. The same effects are also achievable using multi-carrier transmission. Accordingly, the present Embodiment may also be realized using, for example, spread-spectrum communications, OFDM, SC-FDMA (Single Carrier Frequency-Division Multiple Access), SC-OFDM, wavelet OFDM as described in Non-Patent Literature 7, and so on. As previously described, while the present Embodiment explains the change of phase as changing the phase with respect to the time domain t, the phase may alternatively be changed with respect to the frequency domain as described in Embodiment 1. That is, considering the phase changing scheme in the time domain t described in the present Embodiment and replacing t with f (f being the ((sub-) carrier) frequency) leads to a change of phase applicable to the frequency domain. Also, as explained above for Embodiment 1, the phase changing scheme of the present Embodiment is also applicable to changing the phase with respect both the time domain and the frequency domain. Accordingly, althoughFIGS.6,25,26, and27illustrate changes of phase in the time domain, replacing time t with carrier f in each ofFIGS.6,25,26, and27corresponds to a change of phase in the frequency domain. In other words, replacing (t) with (t, f) where t is time and f is frequency corresponds to performing the change of phase on time-frequency blocks. Furthermore, in the present Embodiment, symbols other than data symbols, such as pilot symbols (preamble, unique word, etc) or symbols transmitting control information, may be arranged within the frame in any manner. Embodiment 3 Embodiments 1 and 2, described above, discuss regular changes of phase. Embodiment 3 describes a scheme of allowing the reception device to obtain good received signal quality for data, regardless of the reception device arrangement, by considering the location of the reception device with respect to the transmission device. Embodiment 3 concerns the symbol arrangement within signals obtained through a change of phase. FIG.31illustrates an example of frame configuration for a portion of the symbols within a signal in the time-frequency domain, given a transmission scheme where a regular change of phase is performed for a multi-carrier scheme such as OFDM. First, an example is explained in which the change of phase is performed one of two baseband signals, precoded as explained in Embodiment 1 (seeFIG.6). (AlthoughFIG.6illustrates a change of phase in the time domain, switching time t with carrier f inFIG.6corresponds to a change of phase in the frequency domain. In other words, replacing (t) with (t, f) where t is time and f is frequency corresponds to performing phase changes on time-frequency blocks.)FIG.31illustrates the frame configuration of modulated signal z2′, which is input to phase changer317B fromFIG.12. Each square represents one symbol (although both signals s1and s2are included for precoding purposes, depending on the precoding matrix, only one of signals s1and s2may be used). Consider symbol3100at carrier 2 and time $2 ofFIG.31. The carrier here described may alternatively be termed a sub-carrier. Within carrier 2, there is a very strong correlation between the channel conditions for symbol3100at carrier 2, time $2 and the channel conditions for the time domain nearest-neighbour symbols to time $2, i.e., symbol3013at time $1 and symbol3101at time $3 within carrier 2. Similarly, for time $2, there is a very strong correlation between the channel conditions for symbol3100at carrier 2, time $2 and the channel conditions for the frequency-domain nearest-neighbour symbols to carrier 2, i.e., symbol3104at carrier 1, time $2 and symbol3104at time $2, carrier 3. As described above, there is a very strong correlation between the channel conditions for symbol3100and the channel conditions for symbols3101,3102,3103, and3104. The present description considers N different phases (N being an integer, N≥2) for multiplication in a transmission scheme where the phase is regularly changed. The symbols illustrated inFIG.31are indicated as e′ °, for example. This signifies that this symbol is signal z2′ fromFIG.6phase-changed through multiplication by ej0. That is, the values indicated inFIG.31for each of the symbols are the values of y(t) from formula 42, which are also the values of z2(t)=y2(t)z2′(t) described in Embodiment 2. The present Embodiment takes advantage of the high correlation in channel conditions existing between neighbouring symbols in the frequency domain and/or neighbouring symbols in the time domain in a symbol arrangement enabling high data reception quality to be obtained by the reception device receiving the phase-changed symbols. In order to achieve this high data reception quality, conditions #1 and #2 are necessary. (Condition #1) As shown inFIG.6, for a transmission scheme involving a regular change of phase performed on precoded baseband signal z2′ using multi-carrier transmission such as OFDM, time X, carrier Y is a symbol for transmitting data (hereinafter, data symbol), neighbouring symbols in the time domain, i.e., at time X−1, carrier Y and at time X+1, carrier Y are also data symbols, and a different change of phase should be performed on precoded baseband signal z2′ corresponding to each of these three data symbols, i.e., on precoded baseband signal z2′ at time X, carrier Y, at time X−1, carrier Y and at time X+1, carrier Y. (Condition #2) As shown inFIG.6, for a transmission scheme involving a regular change of phase performed on precoded baseband signal z2′ using multi-carrier transmission such as OFDM, time X, carrier Y is a data symbol, neighbouring symbols in the frequency domain, i.e., at time X, carrier Y−1 and at time X, carrier Y+1 are also data symbols, and a different change of phase should be performed on precoded baseband signal z2′ corresponding to each of these three data symbols, i.e., on precoded baseband signal z2′ at time X, carrier Y, at time X, carrier Y−1 and at time X, carrier Y+1. Ideally, data symbols satisfying Condition #1 should be present. Similarly, data symbols satisfying Condition #2 should be present. The reasons supporting Conditions #1 and #2 are as follows. A very strong correlation exists between the channel conditions of given symbol of a transmit signal (hereinafter, symbol A) and the channel conditions of the symbols neighbouring symbol A in the time domain, as described above. Accordingly, when three neighbouring symbols in the time domain each have different phases, then despite reception quality degradation in the LOS environment (poor signal quality caused by degradation in conditions due to direct wave phase relationships despite high signal quality in terms of SNR) for symbol A, the two remaining symbols neighbouring symbol A are highly likely to provide good reception quality. As a result, good received signal quality is achievable after error correction and decoding. Similarly, a very strong correlation exists between the channel conditions of given symbol of a transmit signal (hereinafter, symbol A) and the channel conditions of the symbols neighbouring symbol A in the frequency domain, as described above. Accordingly, when three neighbouring symbols in the frequency domain each have different phases, then despite reception quality degradation in the LOS environment (poor signal quality caused by degradation in conditions due to direct wave phase relationships despite high signal quality in terms of SNR) for symbol A, the two remaining symbols neighbouring symbol A are highly likely to provide good reception quality. As a result, good received signal quality is achievable after error correction and decoding. Combining Conditions #1 and #2, ever greater data reception quality is likely achievable for the reception device. Accordingly, the following Condition #3 can be derived. (Condition #3) As shown inFIG.6, for a transmission scheme involving a regular change of phase performed on precoded baseband signal z2′ using multi-carrier transmission such as OFDM, time X, carrier Y is a data symbol, neighbouring symbols in the time domain, i.e., at time X−1, carrier Y and at time X+1, carrier Y are also data symbols, and neighbouring symbols in the frequency domain, i.e., at time X, carrier Y−1 and at time X, carrier Y+1 are also data symbols, and a different change in phase should be performed on precoded baseband signal z2′ corresponding to each of these five data symbols, i.e., on precoded baseband signal z2′ at time X, carrier Y, at time X, carrier Y−1, at time X, carrier Y+1, at a time X−1, carrier Y, and at time X+1, carrier Y. Here, the different changes in phase are as follows. Changes in phase are defined from 0 radians to 2π radians. For example, for time X, carrier Y, a phase change of ejθX,Yis applied to precoded baseband signal z2′ fromFIG.6, for time X−1, carrier Y, a phase change of ejθX−1,Yis applied to precoded baseband signal z2′ fromFIG.6, for time X+1, carrier Y, a phase change of ejθX+1,Yis applied to precoded baseband signal z2′ fromFIG.6, such that 0<θX,Y<2π, 0≤θX−1,Y<2π, and 0≤θX+1,Y<2π, all units being in radians. Accordingly, for Condition #1, it follows that θX,Y≠θX−1,Y, θX,Y≠θX+1,Y, and that θX+1,Y≠θX+1,Y. Similarly, for Condition #2, it follows that θX,Y≠θX,Y−1, θX,Y≠θX,Y+1, and that θX,Y−1≠θX,Y+1. And, for Condition #3, it follows that θX,Y≠θX−1,Y, θX,Y≠θX+1,Y, θX,Y≠θX,Y−1, θX,Y≠θX,Y−1, θX−1,Y≠θX+1,Y, θX−1,Y≠θX,Y−1, θX−1,Y≠θX+1,Y, θX+1,Y≠θX−1,Y, θX+1,Y≠θX,Y+1, and that θX,Y−1≠θX,Y+1. Ideally, a data symbol should satisfy Condition #3. FIG.31illustrates an example of Condition #3 where symbol A corresponds to symbol3100. The symbols are arranged such that the phase by which precoded baseband signal z2′ fromFIG.6is multiplied differs for symbol3100, for both neighbouring symbols thereof in the time domain3101and3102, and for both neighbouring symbols thereof in the frequency domain3102and3104. Accordingly, despite received signal quality degradation of symbol3100for the receiver, good signal quality is highly likely for the neighbouring signals, thus guaranteeing good signal quality after error correction. FIG.32illustrates a symbol arrangement obtained through phase changes under these conditions. As evident fromFIG.32, with respect to any data symbol, a different change in phase is applied to each neighbouring symbol in the time domain and in the frequency domain. As such, the ability of the reception device to correct errors may be improved. In other words, inFIG.32, when all neighbouring symbols in the time domain are data symbols, Condition #1 is satisfied for all Xs and all Ys. Similarly, inFIG.32, when all neighbouring symbols in the frequency domain are data symbols, Condition #2 is satisfied for all Xs and all Ys. Similarly, inFIG.32, when all neighbouring symbols in the frequency domain are data symbols and all neighbouring symbols in the time domain are data symbols, Condition #3 is satisfied for all Xs and all Ys. The following describes an example in which a change of phase is performed on two precoded baseband signals, as explained in Embodiment 2 (seeFIG.26). When a change of phase is performed on precoded baseband signal z1′ and precoded baseband signal z2′ as shown inFIG.26, several phase changing schemes are possible. The details thereof are explained below. Scheme 1 involves a change in phase performed on precoded baseband signal z2′ as described above, to achieve the change in phase illustrated byFIG.32. InFIG.32, a change of phase having a period (cycle) of 10 is applied to precoded baseband signal z2′. However, as described above, in order to satisfy Conditions #1, #2, and #3, the change in phase applied to precoded baseband signal z2′ at each (sub-)carrier varies over time. (Although such changes are applied inFIG.32with a period (cycle) of ten, other phase changing schemes are also possible.) Then, as shown inFIG.33, the change in phase performed on precoded baseband signal z1′ produces a constant value that is one-tenth of that of the change in phase performed on precoded baseband signal z2′. InFIG.33, for a period (cycle) (of change in phase performed on precoded baseband signal z2′) including time $1, the value of the change in phase performed on precoded baseband signal z1′ is ej0. Then, for the next period (cycle) (of change in phase performed on precoded baseband signal z2′) including time $2, the value of the change in phase performed on precoded baseband signal z1′ is ejπ/9, and so on. The symbols illustrated inFIG.33are indicated as el °, for example. This signifies that this symbol is signal z1′ fromFIG.26on which a change in phase as been applied through multiplication by ej0. That is, the values indicated inFIG.33for each of the symbols are the values of z1′(t)=y2(t)z1′(t) described in Embodiment 2 for y1(t). As shown inFIG.33, the change in phase performed on precoded baseband signal z1′ produces a constant value that is one-tenth that of the change in phase performed on precoded baseband signal z2′ such that the phase changing value varies with the number of each period (cycle). (As described above, inFIG.33, the value is ej0for the first period (cycle), ejπ/9for the second period (cycle), and so on.) As described above, the change in phase performed on precoded baseband signal z2′ has a period (cycle) of ten, but the period (cycle) can be effectively made greater than ten by taking the change in phase applied to precoded baseband signal z1′ and to precoded baseband signal z2′ into consideration. Accordingly, data reception quality may be improved for the reception device. Scheme 2 involves a change in phase of precoded baseband signal z2′ as described above, to achieve the change in phase illustrated byFIG.32. InFIG.32, a change of phase having a period (cycle) of ten is applied to precoded baseband signal z2′. However, as described above, in order to satisfy Conditions #1, #2, and #3, the change in phase applied to precoded baseband signal z2′ at each (sub-)carrier varies over time. (Although such changes are applied inFIG.32with a period (cycle) of ten, other phase changing schemes are also possible.) Then, as shown inFIG.30, the change in phase performed on precoded baseband signal z1′ differs from that performed on precoded baseband signal z2′ in having a period (cycle) of three rather than ten. The symbols illustrated inFIG.30are indicated as ej0, for example. This signifies that this symbol is signal z1′ fromFIG.26to which a change in phase has been applied through multiplication by ej0. That is, the values indicated inFIG.30for each of the symbols are the values of z1(t)=y1(t)z1′(t) described in Embodiment 2 for y1(t). As described above, the change in phase performed on precoded baseband signal z2′ has a period (cycle) of ten, but by taking the changes in phase applied to precoded baseband signal z1′ and precoded baseband signal z2′ into consideration, the period (cycle) can be effectively made equivalent to 30 for both precoded baseband signals z1′ and z2′. Accordingly, data reception quality may be improved for the reception device. An effective way of applying scheme 2 is to perform a change in phase on precoded baseband signal z1′ with a period (cycle) of N and perform a change in phase on precoded baseband signal z2′ with a period (cycle) of M such that N and M are coprime. As such, by taking both precoded baseband signals z1′ and z2′ into consideration, a period (cycle) of N×M is easily achievable, effectively making the period (cycle) greater when N and M are coprime. The above describes an example of the phase changing scheme pertaining to Embodiment 3. The present invention is not limited in this manner. As explained for Embodiments 1 and 2, a change in phase may be performed with respect the frequency domain or the time domain, or on time-frequency blocks. Similar improvement to the data reception quality can be obtained for the reception device in all cases. The same also applies to frames having a configuration other than that described above, where pilot symbols (SP (Scattered Pilot) and symbols transmitting control information are inserted among the data symbols. The details of change in phase in such circumstances are as follows. FIGS.47A and47Billustrate the frame configuration of modulated signals (precoded baseband signals) z1or z1′ and z2′ in the time-frequency domain.FIG.47Aillustrates the frame configuration of modulated signal (precoded baseband signals) z1or z1′ whileFIG.47Billustrates the frame configuration of modulated signal (precoded baseband signals) z2′. InFIGS.47A and47B,4701marks pilot symbols while4702marks data symbols. The data symbols4702are symbols on which precoding or precoding and a change in phase have been performed. FIGS.47A and47B, likeFIG.6, indicate the arrangement of symbols when a change in phase is applied to precoded baseband signal z2′ (while no change of phase is performed on precoded baseband signal z1). (AlthoughFIG.6illustrates a change in phase with respect to the time domain, switching time t with carrier f inFIG.6corresponds to a change in phase with respect to the frequency domain. In other words, replacing (t) with (t, f) where t is time and f is frequency corresponds to performing a change of phase on time-frequency blocks.) Accordingly, the numerical values indicated inFIGS.47A and47Bfor each of the symbols are the values of precoded baseband signal z2′ after the change in phase. No values are given for the symbols of precoded baseband signal z1′ (z1) as no change in phase is performed thereon. The key point ofFIGS.47A and47Bis that the change in phase is performed on the data symbols of precoded baseband signal z2′, i.e., on precoded symbols. (The symbols under discussion, being precoded, actually include both symbols s1and s2.) Accordingly, no change of phase is performed on the pilot symbols inserted into z2′. FIGS.48A and48Billustrate the frame configuration of modulated signals (precoded baseband signals) z1or z1′ and z2′ in the time-frequency domain.FIG.48Aillustrates the frame configuration of modulated signal (precoded baseband signals) z1or z1′ whileFIG.47Billustrates the frame configuration of modulated signal (precoded baseband signals) z2′. InFIGS.48A and48B,4701marks pilot symbols while4702marks data symbols. The data symbols4702are symbols on which precoding, or precoding and a change in phase, have been performed. FIGS.48A and48B, likeFIG.26, indicate the arrangement of symbols when a change in phase is applied to precoded baseband signal z1′ and to precoded baseband signal z2′. (AlthoughFIG.26illustrates a change in phase with respect to the time domain, switching time t with carrier f inFIG.26corresponds to a change in phase with respect to the frequency domain. In other words, replacing (t) with (t, f) where t is time and f is frequency corresponds to performing a change of phase on time-frequency blocks.) Accordingly, the numerical values indicated inFIGS.48Aand48B for each of the symbols are the values of precoded baseband signal z1′ and z2′ after the change in phase. The key point ofFIG.47is that a change of phase is performed on the data symbols of precoded baseband signal z1′, that is, on the precoded symbols thereof, and on the data symbols of precoded baseband signal z2′, that is, on the precoded symbols thereof. (The symbols under discussion, being precoded, actually include both symbols s1and s2.) Accordingly, no change of phase is performed on the pilot symbols inserted in z1′, nor on the pilot symbols inserted in z2′. FIGS.49A and49Billustrate the frame configuration of modulated signals (precoded baseband signals) z1or z1′ and z2′ in the time-frequency domain.FIG.49Aillustrates the frame configuration of modulated signal (precoded baseband signals) z1or z1′ whileFIG.49Billustrates the frame configuration of modulated signal (precoded baseband signal) z2′. InFIGS.49A and49B,4701marks pilot symbols,4702marks data symbols, and4901marks null symbols for which the in-phase component of the baseband signal I=0 and the quadrature component Q=0. As such, data symbols4702are symbols on which precoding or precoding and the change in phase have been performed.FIGS.49A and49Bdiffer fromFIGS.47A and47Bin the configuration scheme for symbols other than data symbols. The times and carriers at which pilot symbols are inserted into modulated signal z1′ are null symbols in modulated signal z2′. Conversely, the times and carriers at which pilot symbols are inserted into modulated signal z2′ are null symbols in modulated signal z1 FIGS.49A and49B, likeFIG.6, indicate the arrangement of symbols when a change in phase is applied to precoded baseband signal z2′ (while no change of phase is performed on precoded baseband signal z1). (AlthoughFIG.6illustrates a change of phase with respect to the time domain, switching time t with carrier f inFIG.6corresponds to a change of phase with respect to the frequency domain. In other words, replacing (t) with (t, f) where t is time and f is frequency corresponds to performing a change of phase on time-frequency blocks.) Accordingly, the numerical values indicated inFIGS.49A and49Bfor each of the symbols are the values of precoded baseband signal z2′ after a change of phase is performed. No values are given for the symbols of precoded baseband signal z1′ (z1) as no change of phase is performed thereon. The key point ofFIGS.49A and49Bis that a change of phase is performed on the data symbols of precoded baseband signal z2′, i.e., on precoded symbols. (The symbols under discussion, being precoded, actually include both symbols s1and s2.) Accordingly, no change of phase is performed on the pilot symbols inserted into z2′. FIGS.50A and50Billustrate the frame configuration of modulated signals (precoded baseband signals) z1or z1′ and z2′ in the time-frequency domain. FIG. illustrates the frame configuration of modulated signal (precoded baseband signal) z1or z1′ whileFIG.50Billustrates the frame configuration of modulated signal (precoded baseband signal) z2′. InFIGS.50A and50B,4701marks pilot symbols,4702marks data symbols, and4901marks null symbols for which the in-phase component of the baseband signal I=0 and the quadrature component Q=0. As such, data symbols4702are symbols on which precoding, or precoding and a change of phase, have been performed.FIGS.50A and50Bdiffer fromFIGS.48A and48Bin the configuration scheme for symbols other than data symbols. The times and carriers at which pilot symbols are inserted into modulated signal z1′ are null symbols in modulated signal z2′. Conversely, the times and carriers at which pilot symbols are inserted into modulated signal z2′ are null symbols in modulated signal z1′. FIGS.50A and50B, likeFIG.26, indicate the arrangement of symbols when a change of phase is applied to precoded baseband signal z1′ and to precoded baseband signal z2′. (AlthoughFIG.26illustrates a change of phase with respect to the time domain, switching time t with carrier f inFIG.26corresponds to a change of phase with respect to the frequency domain. In other words, replacing (t) with (t, f) where t is time and f is frequency corresponds to performing a change of phase on time-frequency blocks.) Accordingly, the numerical values indicated inFIGS.50A and50Bfor each of the symbols are the values of precoded baseband signal z1′ and z2′ after a change of phase. The key point ofFIGS.50A and50Bis that a change of phase is performed on the data symbols of precoded baseband signal z1′, that is, on the precoded symbols thereof, and on the data symbols of precoded baseband signal z2′, that is, on the precoded symbols thereof. (The symbols under discussion, being precoded, actually include both symbols s1and s2.) Accordingly, no change of phase is performed on the pilot symbols inserted in z1′, nor on the pilot symbols inserted in z2′. FIG.51illustrates a sample configuration of a transmission device generating and transmitting modulated signal having the frame configuration ofFIGS.47A,47B,49A, and49B. Components thereof performing the same operations as those ofFIG.4use the same reference symbols thereas. InFIG.51, the weighting units308A and308B and phase changer317B only operate at times indicated by the frame configuration signal313as corresponding to data symbols. InFIG.51, a pilot symbol generator5101(that also generates null symbols) outputs baseband signals5102A and5102B for a pilot symbol whenever the frame configuration signal313indicates a pilot symbol (or a null symbol). Although not indicated in the frame configurations fromFIGS.47A through50B, when precoding (or phase rotation) is not performed, such as when transmitting a modulated signal using only one antenna (such that the other antenna transmits no signal) or when using a space-time coding transmission scheme (particularly, space-time block coding) to transmit control information symbols, then the frame configuration signal313takes control information symbols5104and control information5103as input. When the frame configuration signal313indicates a control information symbol, baseband signals5102A and5102B thereof are output. Wireless units310A and310B ofFIG.51take a plurality of baseband signals as input and select a desired baseband signal according to the frame configuration signal313. Wireless units310A and310B then apply OFDM signal processing and output modulated signals311A and311B conforming to the frame configuration. FIG.52illustrates a sample configuration of a transmission device generating and transmitting modulated signal having the frame configuration ofFIGS.48A,48B,50A, and50B. Components thereof performing the same operations as those ofFIGS.4and51use the same reference symbols thereas.FIG.51features an additional phase changer317A that only operates when the frame configuration signal313indicates a data symbol. At all other times, the operations are identical to those explained forFIG.51. FIG.53illustrates a sample configuration of a transmission device that differs from that ofFIG.51. The following describes the points of difference. As shown inFIG.53, phase changer317B takes a plurality of baseband signals as input. Then, when the frame configuration signal313indicates a data symbol, phase changer317B performs a change of phase on precoded baseband signal316B. When frame configuration signal313indicates a pilot symbol (or null symbol) or a control information symbol, phase changer317B pauses phase changing operations, such that the symbols of the baseband signal are output as-is. (This may be interpreted as performing forced rotation corresponding to ej0.) A selector5301takes the plurality of baseband signals as input and selects a baseband signal having a symbol indicated by the frame configuration signal313for output. FIG.54illustrates a sample configuration of a transmission device that differs from that ofFIG.52. The following describes the points of difference. As shown inFIG.54, phase changer317B takes a plurality of baseband signals as input. Then, when the frame configuration signal313indicates a data symbol, phase changer317B performs a change of phase on precoded baseband signal316B. When frame configuration signal313indicates a pilot symbol (or null symbol) or a control information symbol, phase changer317B pauses phase changing operations such that the symbols of the baseband signal are output as-is. (This may be interpreted as performing forced rotation corresponding to ej0.) Similarly, as shown inFIG.54, phase changer5201takes a plurality of baseband signals as input. Then, when the frame configuration signal313indicates a data symbol, phase changer5201performs a change of phase on precoded baseband signal309A. When frame configuration signal313indicates a pilot symbol (or null symbol) or a control information symbol, phase changer5201pauses phase changing operations such that the symbols of the baseband signal are output as-is. (This may be interpreted as performing forced rotation corresponding to ej0,) The above explanations are given using pilot symbols, control symbols, and data symbols as examples. However, the present invention is not limited in this manner. When symbols are transmitted using schemes other than precoding, such as single-antenna transmission or transmission using space-time block coding, not performing a change of phase is important. Conversely, performing a change of phase on symbols that have been precoded is the key point of the present invention. Accordingly, a characteristic feature of the present invention is that the change of phase is not performed on all symbols within the frame configuration in the time-frequency domain, but only performed on signals that have been precoded. Embodiment 4 Embodiments 1 and 2, described above, discuss a regular change of phase. Embodiment 3, however, discloses performing a different change of phase on neighbouring symbols. The present Embodiment describes a phase changing scheme that varies according to the modulation scheme and the coding rate of the error-correcting codes used by the transmission device. Table 1, below, is a list of phase changing scheme settings corresponding to the settings and parameters of the transmission device. TABLE 1No. ofModulatedPhaseTransmissionCodingChangingSignalsModulation SchemeRatePattern2#1: QPSK, #2: QPSK#1: 1/2, #2#1: —, #2: A2/32#1: QPSK, #2: QPSK#1: 1/2, #2:#1: A, #2: B3/42#1: QPSK, #2: QPSK#1: 2/3, #2:#1: A, #2: C3/52#1: QPSK, #2: QPSK#1: 2/3, #2:#1: C,2/3#2: —2#1: QPSK, #2: QPSK#1: 3/3, #2:#1: D, #2: E2/32#1: QPSK, #2: 16-QAM#1: 1/2, #2:#1: B, #2: A2/32#1: QPSK, #2: 16-QAM#1: 1/2, #2:#1: A, #2: C3/42#1: QPSK, #2: 16-QAM#1: 1/2, #2:#1: —,3/5#2: E2#1: QPSK, #2: 16-QAM#1: 2/3, #2:#1: D,3/4#2: —2#1: QPSK, #2: 16-QAM#1: 2/3, #2:#1: D, #2: B5/62#1: 16-QAM, #2:#1: 1/2, #2:#1: —, #2: E16-QAM2/3············ In Table 1, #1 denotes modulated signal s1from Embodiment 1 described above (baseband signal s1modulated with the modulation scheme set by the transmission device) and #2 denotes modulated signal s2(baseband signal s2modulated with the modulation scheme set by the transmission device). The coding rate column of Table 1 indicates the coding rate of the error-correcting codes for modulation schemes #1 and #2. The phase changing pattern column of Table 1 indicates the phase changing scheme applied to precoded baseband signals z1(z1′) and z2(z2′), as explained in Embodiments 1 through 3. Although the phase changing patterns are labeled A, B, C, D, E, and so on, this refers to the phase change degree applied, for example, in a phase changing pattern given by formula 46 and formula 47, above. In the phase changing pattern column of Table 1, the dash signifies that no change of phase is applied. The combinations of modulation scheme and coding rate listed in Table 1 are examples. Other modulation schemes (such as 128-QAM and 256-QAM) and coding rates (such as 7/8) not listed in Table 1 may also be included. Also, as described in Embodiment 1, the error-correcting codes used for s1and s2may differ (Table 1 is given for cases where a single type of error-correcting codes is used, as inFIG.4). Furthermore, the same modulation scheme and coding rate may be used with different phase changing patterns. The transmission device transmits information indicating the phase changing patterns to the reception device. The reception device specifies the phase changing pattern by cross-referencing the information and Table 1, then performs demodulation and decoding. When the modulation scheme and error-correction scheme determine a unique phase changing pattern, then as long as the transmission device transmits the modulation scheme and information regarding the error-correction scheme, the reception device knows the phase changing pattern by obtaining that information. As such, information pertaining to the phase changing pattern is not strictly necessary. In Embodiments 1 through 3, the change of phase is applied to precoded baseband signals. However, the amplitude may also be modified along with the phase in order to apply periodical, regular changes. Accordingly, an amplification modification pattern regularly modifying the amplitude of the modulated signals may also be made to conform to Table 1. In such circumstances, the transmission device should include an amplification modifier that modifies the amplification after weighting unit308A or weighting unit308B fromFIG.3or4. In addition, amplification modification may be performed on only one of or on both of the precoded baseband signals z1(t) and z2(t) (in the former case, the amplification modifier is only needed after one of weighting unit308A and308B). Furthermore, although not indicated in Table 1 above, the mapping scheme may also be regularly modified by the mapper, without a regular change of phase. That is, when the mapping scheme for modulated signal s1(t) is 16-QAM and the mapping scheme for modulated signal s2(t) is also 16-QAM, the mapping scheme applied to modulated signal s2(t) may be regularly changed as follows: from 16-QAM to 16-APSK, to 16-QAM in the IQ plane, to a first mapping scheme producing a signal point layout unlike 16-APSK, to 16-QAM in the IQ plane, to a second mapping scheme producing a signal point layout unlike 16-APSK, and so on. As such, the data reception quality can be improved for the reception device, much like the results obtained by a regular change of phase described above. In addition, the present invention may use any combination of schemes for a regular change of phase, mapping scheme, and amplitude, and the transmit signal may transmit with all of these taken into consideration. The present Embodiment may be realized using single-carrier schemes as well as multi-carrier schemes. Accordingly, the present Embodiment may also be realized using, for example, spread-spectrum communications, OFDM, SC-FDMA, SC-OFDM, wavelet OFDM as described in Non-Patent Literature 7, and so on. As described above, the present Embodiment describes changing the phase, amplitude, and mapping schemes by performing phase, amplitude, and mapping scheme modifications with respect to the time domain t. However, much like Embodiment 1, the same changes may be carried out with respect to the frequency domain. That is, considering the phase, amplitude, and mapping scheme modification in the time domain t described in the present Embodiment and replacing t with f (f being the ((sub-) carrier) frequency) leads to phase, amplitude, and mapping scheme modification applicable to the frequency domain. Also, the phase, amplitude, and mapping scheme modification of the present Embodiment is also applicable to phase, amplitude, and mapping scheme modification in both the time domain and the frequency domain. Furthermore, in the present Embodiment, symbols other than data symbols, such as pilot symbols (preamble, unique word, etc) or symbols transmitting control information, may be arranged within the frame in any manner. Embodiment A1 The present Embodiment describes a scheme for regularly changing the phase when encoding is performed using block codes as described in Non-Patent Literature 12 through 15, such as QC (Quasi-Cyclic) LDPC Codes (not only QC-LDPC but also LDPC codes may be used), concatenated LDPC and BCH (Bose-Chaudhuri-Hocquenghem) codes, Turbo codes or Duo-Binary Turbo Codes using tail-biting, and so on. The following example considers a case where two streams s1and s2are transmitted. However, when encoding has been performed using block codes and control information and the like is not required, the number of bits making up each coded block matches the number of bits making up each block code (control information and so on described below may yet be included). When encoding has been performed using block codes or the like and control information or the like (e.g., CRC (cyclic redundancy check) transmission parameters) is required, then the number of bits making up each coded block is the sum of the number of bits making up the block codes and the number of bits making up the information. FIG.34illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used.FIG.34illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used when, for example, two streams s1and s2are transmitted as indicated by the transmission device fromFIG.4, and the transmission device has only one encoder. (Here, the transmission scheme may be any single-carrier scheme or multi-carrier scheme such as OFDM.) As shown inFIG.34, when block codes are used, there are 6000 bits making up a single coded block. In order to transmit these 6000 bits, the number of required symbols depends on the modulation scheme, being 3000 symbols for QPSK, 1500 symbols for 16-QAM, and 1000 symbols for 64-QAM. Then, given that the transmission device fromFIG.4transmits two streams simultaneously,1500of the aforementioned 3000 symbols needed when the modulation scheme is QPSK are assigned to s1and the other 1500 symbols are assigned to s2. As such, 1500 slots for transmitting the 1500 symbols (hereinafter, slots) are required for each of s1and s2. By the same reasoning, when the modulation scheme is 16-QAM, 750 slots are needed to transmit all of the bits making up a single coded block, and when the modulation scheme is 64-QAM, 500 slots are needed to transmit all of the bits making up a single coded block. The following describes the relationship between the above-defined slots and the phase of multiplication, as pertains to schemes for a regular change of phase. Here, five different phase changing values (or phase changing sets) are assumed as having been prepared for use in the scheme for a regular change of phase. That is, five different phase changing values (or phase changing sets) have been prepared for the phase changer of the transmission device fromFIG.4(equivalent to the period (cycle) from Embodiments 1 through 4) (As inFIG.6, five phase changing values are needed in order to perform a change of phase with a period (cycle) of five on precoded baseband signal z2′ only. Also, as inFIG.26, two phase changing values are needed for each slot in order to perform the change of phase on both precoded baseband signals z1′ and z2′. These two phase changing values are termed a phase changing set. Accordingly, five phase changing sets should ideally be prepared in order to perform the change of phase with a period (cycle) of five in such circumstances). These five phase changing values (or phase changing sets) are expressed as PHASE[0], PHASE[1], PHASE[2], PHASE[3], and PHASE[4]. For the above-described 1500 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is QPSK, PHASE[0] is used on 300 slots, PHASE[1] is used on 300 slots, PHASE[2] is used on 300 slots, PHASE[3] is used on 300 slots, and PHASE[4] is used on 300 slots. This is due to the fact that any bias in phase usage causes great influence to be exerted by the more frequently used phase, and that the reception device is dependent on such influence for data reception quality. Similarly, for the above-described 700 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is 16-QAM, PHASE[0] is used on 150 slots, PHASE[1] is used on 150 slots, PHASE[2] is used on 150 slots, PHASE[3] is used on 150 slots, and PHASE[4] is used on 150 slots. Furthermore, for the above-described 500 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is 64-QAM, PHASE[0] is used on 100 slots, PHASE[1] is used on 100 slots, PHASE[2] is used on 100 slots, PHASE[3] is used on 100 slots, and PHASE[4] is used on 100 slots. As described above, a scheme for a regular change of phase requires the preparation of N phase changing values (or phase changing sets) (where the N different phases are expressed as PHASE[0], PHASE[1], PHASE[2] . . . PHASE[N−2], PHASE[N−1]). As such, in order to transmit all of the bits making up a single coded block, PHASE[0] is used on K0slots, PHASE[1] is used on K1slots, PHASE[i] is used on Kislots (where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1)), and PHASE[N−1] is used on KN−1slots, such that Condition #A01 is met. (Condition #A01) K0=K1. . . =Ki=KN−1. That is, Ka=Kb(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). Then, when a communication system that supports multiple modulation schemes selects one such supported modulation scheme for use, Condition #A01 is preferably satisfied for the supported modulation scheme. However, when multiple modulation schemes are supported, each such modulation scheme typically uses symbols transmitting a different number of bits per symbols (though some may happen to use the same number), Condition #A01 may not be satisfied for some modulation schemes. In such a case, the following condition applies instead of Condition #A01. (Condition #A02) The difference between K a and Kb satisfies 0 or 1. That is, |Ka−Kb| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b) FIG.35illustrates the varying numbers of symbols and slots needed in two coded blocks when block codes are used.FIG.35illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used when, for example, two streams s1and s2are transmitted as indicated by the transmission device fromFIG.3andFIG.12, and the transmission device has two encoders. (Here, the transmission scheme may be any single-carrier scheme or multi-carrier scheme such as OFDM.) As shown inFIG.35, when block codes are used, there are 6000 bits making up a single coded block. In order to transmit these 6000 bits, the number of required symbols depends on the modulation scheme, being 3000 symbols for QPSK, 1500 symbols for 16-QAM, and 1000 symbols for 64-QAM. The transmission device fromFIG.3and the transmission device fromFIG.12each transmit two streams at once, and have two encoders. As such, the two streams each transmit different code blocks. Accordingly, when the modulation scheme is QPSK, two coded blocks drawn from s1and s2are transmitted within the same interval, e.g., a first coded block drawn from s1is transmitted, then a second coded block drawn from s2is transmitted. As such, 3000 slots are needed in order to transmit the first and second coded blocks. By the same reasoning, when the modulation scheme is 16-QAM, 1500 slots are needed to transmit all of the bits making up the two coded blocks, and when the modulation scheme is 64-QAM, 1000 slots are needed to transmit all of the bits making up the two coded blocks. The following describes the relationship between the above-defined slots and the phase of multiplication, as pertains to schemes for a regular change of phase. Here, five different phase changing values (or phase changing sets) are assumed as having been prepared for use in the scheme for a regular change of phase. That is, five different phase changing values (or phase changing sets) have been prepared for the phase changers of the transmission devices fromFIGS.3and12(equivalent to the period (cycle) from Embodiments 1 through 4) (As inFIG.6, five phase changing values are needed in order to perform a change of phase having a period (cycle) of five on precoded baseband signal z2′ only. Also, as inFIG.26, two phase changing values are needed for each slot in order to perform the change of phase on both precoded baseband signals z1′ and z2′. These two phase changing values are termed a phase changing set. Accordingly, five phase changing sets should ideally be prepared in order to perform the change of phase with a period (cycle) of five in such circumstances). These five phase changing values (or phase changing sets) are expressed as PHASE[0], PHASE[1], PHASE[2], PHASE[3], and PHASE [4]. For the above-described 3000 slots needed to transmit the 6000×2 bits making up a single coded block when the modulation scheme is QPSK, PHASE[0] is used on 600 slots, PHASE[1] is used on 600 slots, PHASE[2] is used on 600 slots, PHASE[3] is used on 600 slots, and PHASE[4] is used on 600 slots. This is due to the fact that any bias in phase usage causes great influence to be exerted by the more frequently used phase, and that the reception device is dependent on such influence for data reception quality. Furthermore, in order to transmit the first coded block, PHASE[0] is used on slots 600 times, PHASE[1] is used on slots 600 times, PHASE[2] is used on slots 600 times, PHASE[3] is used on slots 600 times, and PHASE[4] is used on slots 600 times. Furthermore, in order to transmit the second coded block, PHASE[0] is used on slots 600 times, PHASE[1] is used on slots 600 times, PHASE[2] is used on slots 600 times, PHASE[3] is used on slots 600 times, and PHASE[4] is used on slots 600 times. Similarly, for the above-described 1500 slots needed to transmit the 6000×2 bits making up the two coded blocks when the modulation scheme is 16-QAM, PHASE[0] is used on 300 slots, PHASE[1] is used on 300 slots, PHASE[2] is used on 300 slots, PHASE[3] is used on 300 slots, and PHASE[4] is used on 300 slots. Furthermore, in order to transmit the first coded block, PHASE[0] is used on slots 300 times, PHASE[1] is used on slots 300 times, PHASE[2] is used on slots 300 times, PHASE[3] is used on slots 300 times, and PHASE[4] is used on slots 300 times. Furthermore, in order to transmit the second coded block, PHASE[0] is used on slots 300 times, PHASE[1] is used on slots 300 times, PHASE[2] is used on slots 300 times, PHASE[3] is used on slots 300 times, and PHASE[4] is used on slots 300 times. Similarly, for the above-described 1000 slots needed to transmit the 6000×2 bits making up the two coded blocks when the modulation scheme is 64-QAM, PHASE[0] is used on 200 slots, PHASE[1] is used on 200 slots, PHASE[2] is used on 200 slots, PHASE[3] is used on 200 slots, and PHASE[4] is used on 200 slots. Furthermore, in order to transmit the first coded block, PHASE[0] is used on slots 200 times, PHASE[1] is used on slots 200 times, PHASE[2] is used on slots 200 times, PHASE[3] is used on slots 200 times, and PHASE[4] is used on slots 200 times. Furthermore, in order to transmit the second coded block, PHASE[0] is used on slots 200 times, PHASE[1] is used on slots 200 times, PHASE[2] is used on slots 200 times, PHASE[3] is used on slots 200 times, and PHASE[4] is used on slots 200 times. As described above, a scheme for regularly changing the phase requires the preparation of phase changing values (or phase changing sets) expressed as PHASE[0], PHASE[1], PHASE[2] . . . PHASE[N−2], PHASE[N−1]. As such, in order to transmit all of the bits making up two coded blocks, PHASE[0] is used on K0slots, PHASE[1] is used on K1slots, PHASE[i] is used on Kislots (where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1), and PHASE[N−1] is used on KN−1slots, such that Condition #A03 is met. (Condition #A03) K0=K1. . . =Ki=KN−1. That is, Ka=Kb(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). Further, in order to transmit all of the bits making up the first coded block, PHASE[0] is used K0,1times, PHASE[1] is used K1,1times, PHASE[i] is used Ki,1times (where i=0, 1, 2 . . . N−1(i denotes an integer that satisfies 0≤i≤N−1), and PHASE[N−1] is used KN−1,1times, such that Condition #A04 is met. (Condition #A04) K0,1=K1,1=Ki,1=KN−1,1. That is, Ka,1=Kb,1(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). Furthermore, in order to transmit all of the bits making up the second coded block, PHASE[0] is used K0,2times, PHASE[1] is used K1,2times, PHASE[i] is used Ki,2times (where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1), and PHASE[N−1] is used KN−1,2times, such that Condition #A05 is met. (Condition #A05) K0,2=K1,2=Ki,2=KN−1,2. That is, Ka,2=Kb,2(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). Then, when a communication system that supports multiple modulation schemes selects one such supported modulation scheme for use, Condition #A03, #A04, and #A05 should preferably be met for the supported modulation scheme. However, when multiple modulation schemes are supported, each such modulation scheme typically uses symbols transmitting a different number of bits per symbol (though some may happen to use the same number), Conditions #A03, #A04, and #A05 may not be satisfied for some modulation schemes. In such a case, the following conditions apply instead of Condition #A03, #A04, and #A05. (Condition #A06) The difference between Kaand Kbsatisfies 0 or 1. That is, |Ka−Kb| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b) (Condition #A07) The difference between Ka,1and Kb,1satisfies 0 or 1. That is, |Ka,1−Kb,1| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1, (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1) a≠b) (Condition #A08) The difference between Ka,2and Kb,2satisfies 0 or 1. That is, |Ka,2−Kb,2| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b) As described above, bias among the phases being used to transmit the coded blocks is removed by creating a relationship between the coded block and the phase of multiplication. As such, data reception quality can be improved for the reception device. In the present Embodiment N phase changing values (or phase changing sets) are needed in order to perform a change of phase having a period (cycle) of N with the scheme for a regular change of phase. As such, N phase changing values (or phase changing sets) PHASE[0], PHASE[1], PHASE[2] . . . PHASE[N−2], and PHASE[N−1] are prepared. However, schemes exist for reordering the phases in the stated order with respect to the frequency domain. No limitation is intended in this regard. The N phase changing values (or phase changing sets) may also change the phases of blocks in the time domain or in the time-frequency domain to obtain a symbol arrangement as described in Embodiment 1. Although the above examples discuss a phase changing scheme with a period (cycle) of N, the same effects are obtainable using N phase changing values (or phase changing sets) at random. That is, the N phase changing values (or phase changing sets) need not always for a regular period (cycle). As long as the above-described conditions are satisfied, great quality data reception improvements are realizable for the reception device. Furthermore, given the existence of modes for spatial multiplexing MIMO schemes, MIMO schemes using a fixed precoding matrix, space-time block coding schemes, single-stream transmission, and schemes using a regular change of phase (the transmission schemes described in Embodiments 1 through 4), the transmission device (broadcaster, base station) may select any one of these transmission schemes. As described in Non-Patent Literature 3, spatial multiplexing MIMO schemes involve transmitting signals s1and s2, which are mapped using a selected modulation scheme, on each of two different antennas. As described in Embodiments 1 through 4, MIMO schemes using a fixed precoding matrix involve performing precoding only (with no change of phase). Further, space-time block coding schemes are described in Non-Patent Literature 9, 16, and 17. Single-stream transmission schemes involve transmitting signal s1, mapped with a selected modulation scheme, from an antenna after performing predetermined processing. Schemes using multi-carrier transmission such as OFDM involve a first carrier group made up of a plurality of carriers and a second carrier group made up of a plurality of carriers different from the first carrier group, and so on, such that multi-carrier transmission is realized with a plurality of carrier groups. For each carrier group, any of spatial multiplexing MIMO schemes, MIMO schemes using a fixed precoding matrix, space-time block coding schemes, single-stream transmission, and schemes using a regular change of phase may be used. In particular, schemes using a regular change of phase on a selected (sub-)carrier group are preferably used to realize the present Embodiment. When a change of phase is performed, then for example, a phase changing value for PHASE[i] of X radians is performed on only one precoded baseband signal, the phase changers ofFIGS.3,4,5,12,25,29,51, and53multiplies precoded baseband signal z2′ by ejX. Then, for a change of phase by, for example, a phase changing set for PHASE[i] of X radians and Y radians is performed on both precoded baseband signals, the phase changers fromFIGS.26,27,28,52, and54multiplies precoded baseband signal z2′ by ejXand multiplies precoded baseband signal z1′ by ejY. Embodiment B1 The following describes a sample configuration of an application of the transmission schemes and reception schemes discussed in the above embodiments and a system using the application. FIG.36illustrates the configuration of a system that includes devices executing transmission schemes and reception schemes described in the above Embodiments. As shown inFIG.36, the devices executing transmission schemes and reception schemes described in the above Embodiments include various receivers such as a broadcaster, a television3611, a DVD recorder3612, a STB (set-top box)3613, a computer3620, a vehicle-mounted television3641, a mobile phone3630and so on within a digital broadcasting system3600. Specifically, the broadcaster3601uses a transmission scheme discussed in the above-described Embodiments to transmit multiplexed data, in which video, audio, and other data are multiplexed, over a predetermined transmission band. The signals transmitted by the broadcaster3601are received by an antenna (such as antenna3660or3640) embedded within or externally connected to each of the receivers. Each receiver obtains the multiplexed data by using reception schemes discussed in the above-described Embodiments to demodulate the signals received by the antenna. Accordingly, the digital broadcasting system3600is able to realize the effects of the present invention, as discussed in the above-described Embodiments. The video data included in the multiplexed data are coded with a video coding method compliant with a standard such as MPEG-2 (Moving Picture Experts Group), MPEG4-AVC (Advanced Video Coding), VC-1, or the like. The audio data included in the multiplexed data are encoded with an audio coding method compliant with a standard such as Dolby AC-3 (Audio Coding), Dolby Digital Plus, MLP (Meridian Lossless Packing), DTS (Digital Theater Systems), DTS-HD, PCM (Pulse-Code Modulation), or the like. FIG.37illustrates the configuration of a receiver7900that executes a reception scheme described in the above-described Embodiments. The receiver3700corresponds to a receiver included in one of the television3611, the DVD recorder3612, the STB3613, the computer3620, the vehicle-mounted television3641, the mobile phone3630and so on fromFIG.36. The receiver3700includes a tuner3701converting a high-frequency signal received by an antenna3760into a baseband signal, and a demodulator3702demodulating the baseband signal so converted to obtain the multiplexed data. The demodulator3702executes a reception scheme discussed in the above-described Embodiments, and thus achieves the effects of the present invention as explained above. The receiver3700further includes a stream interface3720that demultiplexes the audio and video data in the multiplexed data obtained by the demodulator3702, a signal processor3704that decodes the video data obtained from the demultiplexed video data into a video signal by applying a video decoding method corresponding thereto and decodes the audio data obtained from the demultiplexed audio data into an audio signal by applying an audio decoding method corresponding thereto, an audio output unit3706that outputs the decoded audio signal through a speaker or the like, and a video display unit3707that outputs the decoded video signal on a display or the like. When, for example, a user uses a remote control3750, information for a selected channel (selected (television) program or audio broadcast) is transmitted to an operation input unit3710. Then, the receiver3700performs processing on the received signal received by the antenna3760that includes demodulating the signal corresponding to the selected channel, performing error-correcting decoding, and so on, in order to obtain the received data. At this point, the receiver3700obtains control symbol information that includes information on the transmission scheme (the transmission scheme, modulation scheme, error-correction scheme, and so on from the above-described Embodiments) (as described usingFIGS.5and41) from control symbols included the signal corresponding to the selected channel. As such, the receiver3700is able to correctly set the reception operations, demodulation scheme, error-correction scheme and so on, thus enabling the data included in the data symbols transmitted by the broadcaster (base station) to be obtained. Although the above description is given for an example of the user using the remote control3750, the same operations apply when the user presses a selection key embedded in the receiver3700to select a channel. According to this configuration, the user is able to view programs received by the receiver3700. The receiver3700pertaining to the present Embodiment further includes a drive3708that may be a magnetic disk, an optical disc, a non-volatile semiconductor memory, or a similar recording medium. The receiver3700stores data included in the demultiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding (in some circumstances, the data obtained through demodulation by the demodulator3702may not be subject to error correction. Also, the receiver3700may perform further processing after error correction. The same hereinafter applies to similar statements concerning other components), data corresponding to such data (e.g., data obtained through compression of such data), data obtained through audio and video processing, and so on, on the drive3708. Here, an optical disc is a recording medium, such as DVD (Digital Versatile Disc) or BD (Blu-ray Disc), that is readable and writable with the use of a laser beam. A magnetic disk is a floppy disk, a hard disk, or similar recording medium on which information is storable through the use of magnetic flux to magnetize a magnetic body. A non-volatile semiconductor memory is a recording medium, such as flash memory or ferroelectric random access memory, composed of semiconductor element(s). Specific examples of non-volatile semiconductor memory include an SD card using flash memory and a Flash SSD (Solid State Drive). Naturally, the specific types of recording media mentioned herein are merely examples. Other types of recording mediums may also be used. According to this structure, the user is able to record and store programs received by the receiver3700, and is thereby able to view programs at any given time after broadcasting by reading out the recorded data thereof. Although the above explanations describe the receiver3700storing multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding on the drive3708, a portion of the data included in the multiplexed data may instead be extracted and recorded. For example, when data broadcasting services or similar content is included along with the audio and video data in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding, the audio and video data may be extracted from the multiplexed data demodulated by the demodulator3702and stored as new multiplexed data. Furthermore, the drive3708may store either the audio data or the video data included in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding as new multiplexed data. The aforementioned data broadcasting service content included in the multiplexed data may also be stored on the drive3708. Furthermore, when a television, recording device (e.g., a DVD recorder, BD recorder HDD recorder, SD card, or similar), or mobile phone incorporating the receiver3700of the present invention receives multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding that includes data for correcting bugs in software used to operate the television or recording device, for correcting bugs in software for preventing personal information and recorded data from being leaked, and so on, such software bugs may be corrected by installing the data on the television or recording device. As such, bugs in the receiver3700are corrected through the inclusion of data for correcting bugs in the software of the receiver3700. Accordingly, the television, recording device, or mobile phone incorporating the receiver3700may be made to operate more reliably. Here, the process of extracting a portion of the data included in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding is performed by, for example, the stream interface3703. Specifically, the stream interface3703, demultiplexes the various data included in the multiplexed data demodulated by the demodulator3702, such as audio data, video data, data broadcasting service content, and so on, as instructed by a non-diagrammed controller such as a CPU. The stream interface3703then extracts and multiplexes only the indicated demultiplexed data, thus generating new multiplexed data. The data to be extracted from the demultiplexed data may be determined by the user or may be determined in advance according to the type of recording medium. According to such a structure, the receiver3700is able to extract and record only the data needed in order to view the recorded program. As such, the amount of data to be recorded can be reduced. Although the above explanation describes the drive3708as storing multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding, the video data included in the multiplexed data so obtained may be converted by using a different video coding method than the original video coding method applied thereto, so as to reduce the amount of data or the bit rate thereof. The drive3708may then store the converted video data as new multiplexed data. Here, the video coding method used to generate the new video data may conform to a different standard than that used to generate the original video data. Alternatively, the same video coding method may be used with different parameters. Similarly, the audio data included in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding may be converted by using a different audio coding method than the original audio coding method applied thereto, so as to reduce the amount of data or the bit rate thereof. The drive3708may then store the converted audio data as new multiplexed data. Here, the process by which the audio or video data included in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding is converted so as to reduce the amount of data or the bit rate thereof is performed by, for example, the stream interface3703or the signal processor3704. Specifically, the stream interface3703demultiplexes the various data included in the multiplexed data demodulated by the demodulator3702, such as audio data, video data, data broadcasting service content, and so on, as instructed by an undiagrammed controller such as a CPU. The signal processor3704then performs processing to convert the video data so demultiplexed by using a different video coding method than the original video coding method applied thereto, and performs processing to convert the audio data so demultiplexed by using a different video coding method than the original audio coding method applied thereto. As instructed by the controller, the stream interface3703then multiplexes the converted audio and video data, thus generating new multiplexed data. The signal processor3704may, in accordance with instructions from the controller, performing conversion processing on either the video data or the audio data, alone, or may perform conversion processing on both types of data. In addition, the amounts of video data and audio data or the bit rate thereof to be obtained by conversion may be specified by the user or determined in advance according to the type of recording medium. According to such a structure, the receiver3700is able to modify the amount of data or the bitrate of the audio and video data for storage according to the data storage capacity of the recording medium, or according to the data reading or writing speed of the drive3708. Therefore, programs can be stored on the drive despite the storage capacity of the recording medium being less than the amount of multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding, or the data reading or writing speed of the drive being lower than the bit rate of the demultiplexed data obtained through demodulation by the demodulator3702. As such, the user is able to view programs at any given time after broadcasting by reading out the recorded data. The receiver3700further includes a stream output interface3709that transmits the multiplexed data demultiplexed by the demodulator3702to external devices through a communications medium3730. The stream output interface3709may be, for example, a wireless communication device transmitting modulated multiplexed data to an external device using a wireless transmission scheme conforming to a wireless communication standard such as Wi-Fi™ (IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, and so on), WiGig, WirelessHD, Bluetooth, ZigBee, and so on through a wireless medium (corresponding to the communications medium3730). The stream output interface3709may also be a wired communication device transmitting modulated multiplexed data to an external device using a communication scheme conforming to a wired communication standard such as Ethernet™, USB (Universal Serial Bus), PLC (Power Line Communication), HDMI (High-Definition Multimedia Interface) and so on through a wired transmission path (corresponding to the communications medium3730) connected to the stream output interface3709. According to this configuration, the user is able to use an external device with the multiplexed data received by the receiver3700using the reception scheme described in the above-described Embodiments. The usage of multiplexed data by the user here includes use of the multiplexed data for real-time viewing on an external device, recording of the multiplexed data by a recording unit included in an external device, and transmission of the multiplexed data from an external device to a yet another external device. Although the above explanations describe the receiver3700outputting multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding through the stream output interface3709, a portion of the data included in the multiplexed data may instead be extracted and output. For example, when data broadcasting services or similar content is included along with the audio and video data in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding, the audio and video data may be extracted from the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding, multiplexed and output by the stream output interface3709as new multiplexed data. In addition, the stream output interface3709may store either the audio data or the video data included in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding as new multiplexed data. Here, the process of extracting a portion of the data included in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding is performed by, for example, the stream interface3703. Specifically, the stream interface3703demultiplexes the various data included in the multiplexed data demodulated by the demodulator3702, such as audio data, video data, data broadcasting service content, and so on, as instructed by an undiagrammed controller such as a CPU. The stream interface3703then extracts and multiplexes only the indicated demultiplexed data, thus generating new multiplexed data. The data to be extracted from the demultiplexed data may be determined by the user or may be determined in advance according to the type of stream output interface3709. According to this structure, the receiver3700is able to extract and output only the required data to an external device. As such, fewer multiplexed data are output using less communication bandwidth. Although the above explanation describes the stream output interface3709as outputting multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding, the video data included in the multiplexed data so obtained may be converted by using a different video coding method than the original video coding method applied thereto, so as to reduce the amount of data or the bit rate thereof. The stream output interface3709may then output the converted video data as new multiplexed data. Here, the video coding method used to generate the new video data may conform to a different standard than that used to generate the original video data. Alternatively, the same video coding method may be used with different parameters. Similarly, the audio data included in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding may be converted by using a different audio coding method than the original audio coding method applied thereto, so as to reduce the amount of data or the bit rate thereof. The stream output interface3709may then output the converted audio data as new multiplexed data. Here, the process by which the audio or video data included in the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding is converted so as to reduce the amount of data or the bit rate thereof is performed by, for example, the stream interface3703or the signal processor3704. Specifically, the stream interface3703demultiplexes the various data included in the multiplexed data demodulated by the demodulator3702, such as audio data, video data, data broadcasting service content, and so on, as instructed by an undiagrammed controller. The signal processor3704then performs processing to convert the video data so demultiplexed by using a different video coding method than the original video coding method applied thereto, and performs processing to convert the audio data so demultiplexed by using a different video coding method than the original audio coding method applied thereto. As instructed by the controller, the stream interface3703then multiplexes the converted audio and video data, thus generating new multiplexed data. The signal processor3704may, in accordance with instructions from the controller, performing conversion processing on either the video data or the audio data, alone, or may perform conversion processing on both types of data. In addition, the amounts of video data and audio data or the bit rate thereof to be obtained by conversion may be specified by the user or determined in advance according to the type of stream output interface3709. According to this structure, the receiver3700is able to modify the bit rate of the video and audio data for output according to the speed of communication with the external device. Thus, despite the speed of communication with an external device being slower than the bit rate of the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding, by outputting new multiplexed data from the stream output interface to the external device, the user is able to use the new multiplexed data with other communication devices. The receiver3700further includes an audiovisual output interface3711that outputs audio and video signals decoded by the signal processor3704to the external device through an external communications medium. The audiovisual output interface3711may be, for example, a wireless communication device transmitting modulated audiovisual data to an external device using a wireless transmission scheme conforming to a wireless communication standard such as Wi-Fi™ (IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, and so on), WiGig, WirelessHD, Bluetooth, ZigBee, and so on through a wireless medium. The stream output interface3709may also be a wired communication device transmitting modulated audiovisual data to an external device using a communication scheme conforming to a wired communication standard such as Ethernet™, USB, PLC, HDMI, and so on through a wired transmission path connected to the stream output interface3709. Furthermore, the stream output interface3709may be a terminal for connecting a cable that outputs analogue audio signals and video signals as-is. According to such a structure, the user is able to use the audio signals and video signals decoded by the signal processor3704with an external device. Further, the receiver3700includes an operation input unit3710that receives user operations as input. The receiver3700behaves in accordance with control signals input by the operation input unit3710according to user operations, such as by switching the power supply ON or OFF, changing the channel being received, switching subtitle display ON or OFF, switching between languages, changing the volume output by the audio output unit3706, and various other operations, including modifying the settings for receivable channels and the like. The receiver3700may further include functionality for displaying an antenna level representing the received signal quality while the receiver3700is receiving a signal. The antenna level may be, for example, a index displaying the received signal quality calculated according to the RSSI (Received Signal Strength Indicator), the received signal magnetic field strength, the C/N (carrier-to-noise) ratio, the BER, the packet error rate, the frame error rate, the channel state information, and so on, received by the receiver3700and indicating the level and the quality of a received signal. In such circumstances, the demodulator3702includes a signal quality calibrator that measures the RSSI, the received signal magnetic field strength, the C/N ratio, the BER, the packet error rate, the frame error rate, the channel state information, and so on. In response to user operations, the receiver3700displays the antenna level (signal level, signal quality) in a user-recognizable format on the video display unit3707. The display format for the antenna level (signal level, signal quality) may be a numerical value displayed according to the RSSI, the received signal magnetic field strength, the C/N ratio, the BER, the packet error rate, the frame error rate, the channel state information, and so on, or may be an image display that varies according to the RSSI, the received signal magnetic field strength, the C/N ratio, the BER, the packet error rate, the frame error rate, the channel state information, and so on. The receiver3700may display multiple antenna level (signal level, signal quality) calculated for each stream s1, s2, and so on demultiplexed using the reception scheme discussed in the above-described Embodiments, or may display a single antenna level (signal level, signal quality) calculated for all such streams. When the video data and audio data composing a program are transmitted hierarchically, the signal level (signal quality) may also be displayed for each hierarchical level. According to the above structure, the user is given an understanding of the antenna level (signal level, signal quality) numerically or visually during reception using the reception schemes discussed in the above-described Embodiments. Although the above example describes the receiver3700as including the audio output unit3706, the video display unit3707, the drive3708, the stream output interface3709, and the audiovisual output interface3711, all of these components are not strictly necessary. As long as the receiver3700includes at least one of the above-described components, the user is able to use the multiplexed data obtained through demodulation by the demodulator3702and error-correcting decoding. Any receiver may be freely combined with the above-described components according to the usage scheme. (Multiplexed Data) The following is a detailed description of a sample configuration of multiplexed data. The data configuration typically used in broadcasting is an MPEG-2 transport stream (TS). Therefore the following description describes an example related to MPEG2-TS. However, the data configuration of the multiplexed data transmitted by the transmission and reception schemes discussed in the above-described Embodiments is not limited to MPEG2-TS. The advantageous effects of the above-described Embodiments are also achievable using any other data structure. FIG.38illustrates a sample configuration for multiplexed data. As shown, the multiplexed data are elements making up programmes (or events, being a portion thereof) currently provided by various services. For example, one or more video streams, audio streams, presentation graphics (PG) streams, interactive graphics (IG) streams, and other such element streams are multiplexed to obtain the multiplexed data. When a broadcast program provided by the multiplexed data is a movie, the video streams represent main video and sub video of the movie, the audio streams represent main audio of the movie and sub-audio to be mixed with the main audio, and the presentation graphics streams represent subtitles for the movie. Main video refers to video images normally presented on a screen, whereas sub-video refers to video images (for example, images of text explaining the outline of the movie) to be presented in a small window inserted within the video images. The interactive graphics streams represent an interactive display made up of GUI (Graphical User Interface) components presented on a screen. Each stream included in the multiplexed data is identified by an identifier, termed a PID, uniquely assigned to the stream. For example, PID 0x1011 is assigned to the video stream used for the main video of the movie, PIDs 0x1100 through 0x111F are assigned to the audio streams, PIDs 0x1200 through 0x121F are assigned to the presentation graphics, PIDs 0x1400 through 0x141F are assigned to the interactive graphics, PIDs 0x1B00 through 0x1B1F are assigned to the video streams used for the sub-video of the movie, and PIDs 0x1A00 through 0x1A1F are assigned to the audio streams used as sub-audio to be mixed with the main audio of the movie. FIG.39is a schematic diagram illustrating an example of the multiplexed data being multiplexed. First, a video stream3901, made up of a plurality of frames, and an audio stream3904, made up of a plurality of audio frames, are respectively converted into PES packet sequence3902and3905, then further converted into TS packets3903and3906. Similarly, a presentation graphics stream3911and an interactive graphics stream3914are respectively converted into PES packet sequence3912and3915, then further converted into TS packets3913and3916. The multiplexed data3917is made up of the TS packets3903,3906,3913, and3916multiplexed into a single stream. FIG.40illustrates further details of a PES packet sequence as contained in the video stream. The first tier ofFIG.40shows a video frame sequence in the video stream. The second tier shows a PES packet sequence. Arrows yy1, yy2, yy3, and yy4indicate the plurality of Video Presentation Units, which are I-pictures, B-pictures, and P-pictures, in the video stream as divided and individually stored as the payload of a PES packet. Each PES packet has a PES header. A PES header contains a PTS (Presentation Time Stamp) at which the picture is to be displayed, a DTS (Decoding Time Stamp) at which the picture is to be decoded, and so on. FIG.41illustrates the structure of a TS packet as ultimately written into the multiplexed data. A TS packet is a 188-byte fixed-length packet made up of a 4-byte PID identifying the stream and of a 184-byte TS payload containing the data. The above-described PES packets are divided and individually stored as the TS payload. For a BD-ROM, each TS packet has a 4-byte TP_Extra_Header affixed thereto to build a 192-byte source packet, which is to be written as the multiplexed data. The TP_Extra_Header contains information such as an Arrival Time Stamp (ATS). The ATS indicates a time for starring transfer of the TS packet to the PID filter of a decoder. The multiplexed data are made up of source packets arranged as indicated in the bottom tier ofFIG.41. A SPN (source packet number) is incremented for each packet, beginning at the head of the multiplexed data. In addition to the video streams, audio streams, presentation graphics streams, and the like, the TS packets included in the multiplexed data also include a PAT (Program Association Table), a PMT (Program Map Table), a PCR (Program Clock Reference) and so on. The PAT indicates the PID of a PMT used in the multiplexed data, and the PID of the PAT itself is registered as 0. The PMT includes PIDs identifying the respective streams, such as video, audio and subtitles, contained in the multiplexed data and attribute information (frame rate, aspect ratio, and the like) of the streams identified by the respective PIDs. In addition, the PMT includes various types of descriptors relating to the multiplexed data. One such descriptor may be copy control information indicating whether or not copying of the multiplexed data is permitted. The PCR includes information for synchronizing the ATC (Arrival Time Clock) serving as the chronological axis of the ATS to the STC (System Time Clock) serving as the chronological axis of the PTS and DTS. Each PCR packet includes an STC time corresponding to the ATS at which the packet is to be transferred to the decoder. FIG.42illustrates the detailed data configuration of a PMT. The PMT starts with a PMT header indicating the length of the data contained in the PMT. Following the PMT header, descriptors pertaining to the multiplexed data are arranged. One example of a descriptor included in the PMT is the copy control information described above. Following the descriptors, stream information pertaining to the respective streams included in the multiplexed data is arranged. Each piece of stream information is composed of stream descriptors indicating a stream type identifying a compression codec employed for a corresponding stream, a PID for the stream, and attribute information (frame rate, aspect ratio, and the like) of the stream. The PMT includes the same number of stream descriptors as the number of streams included in the multiplexed data. When recorded onto a recoding medium or the like, the multiplexed data are recorded along with a multiplexed data information file. FIG.43illustrates a sample configuration for the multiplexed data information file. As shown, the multiplexed data information file is management information for the multiplexed data, is provided in one-to-one correspondence with the multiplexed data, and is made up of multiplexed data information, stream attribute information, and an entry map. The multiplexed data information is made up of a system rate, a playback start time, and a playback end time. The system rate indicates the maximum transfer rate of the multiplexed data to the PID filter of a later-described system target decoder. The multiplexed data includes ATS at an interval set so as not to exceed the system rate. The playback start time is set to the time specified by the PTS of the first video frame in the multiplexed data, whereas the playback end time is set to the time calculated by adding the playback duration of one frame to the PTS of the last video frame in the multiplexed data. FIG.44illustrates a sample configuration for the stream attribute information included in the multiplexed data information file. As shown, the stream attribute information is attribute information for each stream included in the multiplexed data, registered for each PID. That is, different pieces of attribute information are provided for different streams, namely for the video streams, the audio streams, the presentation graphics streams, and the interactive graphics streams. The video stream attribute information indicates the compression codec employed to compress the video stream, the resolution of individual pictures constituting the video stream, the aspect ratio, the frame rate, and so on. The audio stream attribute information indicates the compression codec employed to compress the audio stream, the number of channels included in the audio stream, the language of the audio stream, the sampling frequency, and so on. This information is used to initialize the decoder before playback by a player. In the present Embodiment, the stream type included in the PMT is used among the information included in the multiplexed data. When the multiplexed data are recorded on a recording medium, the video stream attribute information included in the multiplexed data information file is used. Specifically, the video coding method and device described in any of the above Embodiments may be modified to additionally include a step or unit of setting a specific piece of information in the stream type included in the PMT or in the video stream attribute information. The specific piece of information is for indicating that the video data are generated by the video coding method and device described in the Embodiment. According to such a structure, video data generated by the video coding method and device described in any of the above Embodiments is distinguishable from video data compliant with other standards. FIG.45illustrates a sample configuration of an audiovisual output device4500that includes a reception device4504receiving a modulated signal that includes audio and video data transmitted by a broadcaster (base station) or data intended for broadcasting. The configuration of the reception device4504corresponds to the reception device3700fromFIG.37. The audiovisual output device4500incorporates, for example, an OS (Operating System), or incorporates a communication device4506for connecting to the Internet (e.g., a communication device intended for a wireless LAN (Local Area Network) or for Ethernet™). As such, a video display unit4501is able to simultaneously display audio and video data, or video in video data for broadcast4502, and hypertext4503(from the World Wide Web) provided over the Internet. By operating a remote control4507(alternatively, a mobile phone or keyboard), either of the video in video data for broadcast4502and the hypertext4503provided over the Internet may be selected to change operations. For example, when the hypertext4503provided over the Internet is selected, the website displayed may be changed by remote control operations. When audio and video data, or video in video data for broadcast4502is selected, information from a selected channel (selected (television) program or audio broadcast) may be transmitted by the remote control4507. As such, an interface4505obtains the information transmitted by the remote control. The reception device4504performs processing such as demodulation and error-correction corresponding to the selected channel, thereby obtaining the received data. At this point, the reception device4504obtains control symbol information that includes information on the transmission scheme (as described usingFIG.5) from control symbols included the signal corresponding to the selected channel. As such, the reception device4504is able to correctly set the reception operations, demodulation scheme, error-correction scheme and so on, thus enabling the data included in the data symbols transmitted by the broadcaster (base station) to be obtained. Although the above description is given for an example of the user using the remote control4507, the same operations apply when the user presses a selection key embedded in the audiovisual output device4500to select a channel. In addition, the audiovisual output device4500may be operated using the Internet. For example, the audiovisual output device4500may be made to record (store) a program through another terminal connected to the Internet. (Accordingly, the audiovisual output device4500should include the drive3708fromFIG.37.) The channel is selected before recording begins. As such, the reception device4504performs processing such as demodulation and error-correction corresponding to the selected channel, thereby obtaining the received data. At this point, the reception device4504obtains control symbol information that includes information on the transmission scheme (the transmission scheme, modulation scheme, error-correction scheme, and so on from the above-described Embodiments) (as described usingFIG.5) from control symbols included the signal corresponding to the selected channel. As such, the reception device4504is able to correctly set the reception operations, demodulation scheme, error-correction scheme and so on, thus enabling the data included in the data symbols transmitted by the broadcaster (base station) to be obtained. (Supplement) The present description considers a communications/broadcasting device such as a broadcaster, a base station, an access point, a terminal, a mobile phone, or the like provided with the transmission device, and a communications device such as a television, radio, terminal, personal computer, mobile phone, access point, base station, or the like provided with the reception device. The transmission device and the reception device pertaining to the present invention are communication devices in a form able to execute applications, such as a television, radio, personal computer, mobile phone, or similar, through connection to some sort of interface (e.g., USB). Furthermore, in the present Embodiment, symbols other than data symbols, such as pilot symbols (namely preamble, unique word, postamble, reference symbols, scattered pilot symbols and so on), symbols intended for control information, and so on may be freely arranged within the frame. Although pilot symbols and symbols intended for control information are presently named, such symbols may be freely named otherwise as the function thereof remains the important consideration. Provided that a pilot symbol, for example, is a known symbol modulated with PSK modulation in the transmitter and receiver (alternatively, the receiver may be synchronized such that the receiver knows the symbols transmitted by the transmitter), the receiver is able to use this symbol for frequency synchronization, time synchronization, channel estimation (CSI (Channel State Information) estimation for each modulated signal), signal detection, and the like. The symbols intended for control information are symbols transmitting information (such as the modulation scheme, error-correcting coding scheme, coding rate of error-correcting codes, and setting information for the top layer used in communications) transmitted to the receiving party in order to execute transmission of non-data (i.e., applications). The present invention is not limited to the Embodiments, but may also be realized in various other ways. For example, while the above Embodiments describe communication devices, the present invention is not limited to such devices and may be implemented as software for the corresponding communications scheme. Although the above-described Embodiments describe phase changing schemes for schemes of transmitting two modulated signals from two antennas, no limitation is intended in this regard. Precoding and a change of phase may be performed on four signals that have been mapped to generate four modulated signals transmitted using four antennas. That is, the present invention is applicable to performing a change of phase on N signals that have been mapped and precoded to generate N modulated signals transmitted using N antennas. Although the above-described Embodiments describe examples of systems where two modulated signals are transmitted from two antennas and received by two respective antennas in a MIMO system, the present invention is not limited in this regard and is also applicable to MISO (Multiple Input Single Output) systems. In a MISO system, the reception device does not include antenna701_Y, wireless unit703_Y, channel fluctuation estimator707_1for modulated signal z1, and channel fluctuation estimator707_2for modulated signal z2fromFIG.7. However, the processing described in Embodiment 1 may still be executed to estimate r1and r2. Technology for receiving and decoding a plurality of signals transmitted simultaneously at a common frequency are received by a single antenna is widely known. The present invention is additional processing supplementing conventional technology for a signal processor reverting a phase changed by the transmitter. Although the present invention describes examples of systems where two modulated signals are transmitted from two antennas and received by two respective antennas in a MIMO communications system, the present invention is not limited in this regard and is also applicable to MISO systems. In a MISO system, the transmission device performs precoding and change of phase such that the points described thus far are applicable. However, the reception device does not include antenna701_Y, wireless unit703_Y, channel fluctuation estimator707_1for modulated signal z1, and channel fluctuation estimator707_2for modulated signal z2fromFIG.7. However, the processing described in the present description may still be executed to estimate the data transmitted by the transmission device. Technology for receiving and decoding a plurality of signals transmitted simultaneously at a common frequency are received by a single antenna is widely known (a single-antenna receiver may apply ML operations (Max-log APP or similar)). The present invention may have the signal processor711fromFIG.7perform demodulation (detection) by taking the precoding and change of phase applied by the transmitter into consideration. The present description uses terms such as precoding, precoding weights, precoding matrix, and so on. The terminology itself may be otherwise (e.g., may be alternatively termed a codebook) as the key point of the present invention is the signal processing itself. Furthermore, although the present description discusses examples mainly using OFDM as the transmission scheme, the invention is not limited in this manner. Multi-carrier schemes other than OFDM and single-carrier schemes may all be used to achieve similar Embodiments. Here, spread-spectrum communications may also be used. When single-carrier schemes are used, a change of phase is performed with respect to the time domain. In addition, although the present description discusses the use of ML operations, APP, Max-log APP, ZF, MMSE and so on by the reception device, these operations may all be generalized as wave detection, demodulation, detection, estimation, and demultiplexing as the soft results (log-likelihood and log-likelihood ratio) and the hard results (zeroes and ones) obtained thereby are the individual bits of data transmitted by the transmission device. Different data may be transmitted by each stream s1(t) and s2(t) (s1(i), s2(i)), or identical data may be transmitted thereby. The two stream baseband signals s1(i) and s2(i) (where i indicates sequence (with respect to time or (carrier) frequency)) undergo precoding and a regular change of phase (the order of operations may be freely reversed) to generate two post-processing baseband signals z1(i) and z2(i). For post-processing baseband signal z1(i), the in-phase component I is I1(i) while the quadrature component is Q1(i), and for post processing baseband signal z2(i), the in-phase component is I1(i) while the quadrature component is Q2(i). The baseband components may be switched, as long as the following holds.Let the in-phase component and the quadrature component of switched baseband signal r1(i) be I1(i) and Q2(i), and the in-phase component and the quadrature component of switched baseband signal r2(i) be I2(i) and Q1(i). The modulated signal corresponding to switched baseband signal r1(i) is transmitted by transmit antenna1and the modulated signal corresponding to switched baseband signal r2(i) is transmitted from transmit antenna2, simultaneously on a common frequency. As such, the modulated signal corresponding to switched baseband signal r1(i) and the modulated signal corresponding to switched baseband signal r2(i) are transmitted from different antennas, simultaneously on a common frequency. Alternatively,For switched baseband signal r1(i), the in-phase component may be I1(i) while the quadrature component may be I2(i), and for switched baseband signal r2(i), the in-phase component may be Q1(i) while the quadrature component may be Q2(i).For switched baseband signal r1(i), the in-phase component may be I2(i) while the quadrature component may be I1(i), and for switched baseband signal r2(i), the in-phase component may be Q1(i) while the quadrature component may be Q2(i).For switched baseband signal r1(i), the in-phase component may be I1(i) while the quadrature component may be I2(i), and for switched baseband signal r2(i), the in-phase component may be Q2(i) while the quadrature component may be Q1(i).For switched baseband signal r1(i), the in-phase component may be I2(i) while the quadrature component may be I1(i), and for switched baseband signal r2(i), the in-phase component may be Q2(i) while the quadrature component may be Q1(i).For switched baseband signal r1(i), the in-phase component may be I1(i) while the quadrature component may be Q2(i), and for switched baseband signal r2(i), the in-phase component may be Q1(i) while the quadrature component may be I2(i).For switched baseband signal r1(i), the in-phase component may be Q2(i) while the quadrature component may be I1(i), and for switched baseband signal r2(i), the in-phase component may be I2(i) while the quadrature component may be Q1(i).For switched baseband signal r1(i), the in-phase component may be Q2(i) while the quadrature component may be I1(i), and for switched baseband signal r2(i), the in-phase component may be Q1(i) while the quadrature component may be I2(i).For switched baseband signal r2(i), the in-phase component may be I1(i) while the quadrature component may be I2(i), and for switched baseband signal r1(i), the in-phase component may be Q1(i) while the quadrature component may be Q2(i).For switched baseband signal r2(i), the in-phase component may be I2(i) while the quadrature component may be I1(i), and for switched baseband signal r1(i), the in-phase component may be Q1(i) while the quadrature component may be Q2(i).For switched baseband signal r2(i), the in-phase component may be I1(i) while the quadrature component may be I2(i), and for switched baseband signal r1(i), the in-phase component may be Q2(i) while the quadrature component may be Q1(i).For switched baseband signal r2(i), the in-phase component may be I2(i) while the quadrature component may be I1(i), and for switched baseband signal r1(i), the in-phase component may be Q2(i) while the quadrature component may be Q1(i).For switched baseband signal r2(i), the in-phase component may be I1(i) while the quadrature component may be Q2(i), and for switched baseband signal r1(i), the in-phase component may be I2(i) while the quadrature component may be Q1(i).For switched baseband signal r2(i), the in-phase component may be I1(i) while the quadrature component may be Q2(i), and for switched baseband signal r1(i), the in-phase component may be Q1(i) while the quadrature component may be I2(i).For switched baseband signal r2(i), the in-phase component may be Q2(i) while the quadrature component may be I1(i), and for switched baseband signal r1(i), the in-phase component may be I2(i) while the quadrature component may be Q1(i).For switched baseband signal r2(i), the in-phase component may be Q2(i) while the quadrature component may be I1(i), and for switched baseband signal r1(i), the in-phase component may be Q1(i) while the quadrature component may be I2(i). Alternatively, although the above description discusses performing two types of signal processing on both stream signals so as to switch the in-phase component and quadrature component of the two signals, the invention is not limited in this manner. The two types of signal processing may be performed on more than two streams, so as to switch the in-phase component and quadrature component thereof. Alternatively, although the above examples describe switching baseband signals having a common time (common (sub-)carrier) frequency), the baseband signals being switched need not necessarily have a common time. For example, any of the following are possible.For switched baseband signal r1(i), the in-phase component may be I1(i+v) while the quadrature component may be Q2(i+w), and for switched baseband signal r2(i), the in-phase component may be I2(i+w) while the quadrature component may be Q1(i+v).For switched baseband signal r1(i), the in-phase component may be I1(i+v) while the quadrature component may be I2(i+w), and for switched baseband signal r2(i), the in-phase component may be Q1(i+v) while the quadrature component may be Q2(i+w).For switched baseband signal r1(i), the in-phase component may be I2(i+w) while the quadrature component may be I1(i+v), and for switched baseband signal r2(i), the in-phase component may be Q1(i+v) while the quadrature component may be Q2(i+w).For switched baseband signal r1(i), the in-phase component may be I1(i+v) while the quadrature component may be I2(i+w), and for switched baseband signal r2(i), the in-phase component may be Q2(i+w) while the quadrature component may be Q1(i+v).For switched baseband signal r1(i), the in-phase component may be I2(i+w) while the quadrature component may be I1(i+v), and for switched baseband signal r2(i), the in-phase component may be Q2(i+w) while the quadrature component may be Q1(i+v).For switched baseband signal r1(i), the in-phase component may be I1(i+v) while the quadrature component may be Q2(i+w), and for switched baseband signal r2(i), the in-phase component may be Q1(i+v) while the quadrature component may be I2(i+w).For switched baseband signal r1(i), the in-phase component may be Q2(i+w) while the quadrature component may be I1(i+v), and for switched baseband signal r2(i), the in-phase component may be I2(i+w) while the quadrature component may be Q1(i+v).For switched baseband signal r1(i), the in-phase component may be Q2(i+w) while the quadrature component may be I1(i+v), and for switched baseband signal r2(i), the in-phase component may be Q1(i+v) while the quadrature component may be I2(i+w).For switched baseband signal r2(i), the in-phase component may be I1(i+v) while the quadrature component may be I2(i+w), and for switched baseband signal r1(i), the in-phase component may be Q1(i+v) while the quadrature component may be Q2(i+w).For switched baseband signal r2(i), the in-phase component may be I2(i+w) while the quadrature component may be I1(i+v), and for switched baseband signal r1(i), the in-phase component may be Q1(i+v) while the quadrature component may be Q2(i+w).For switched baseband signal r2(i), the in-phase component may be I1(i+v) while the quadrature component may be I2(i+w), and for switched baseband signal r1(i), the in-phase component may be Q2(i+w) while the quadrature component may be Q1(i+v).For switched baseband signal r2(i), the in-phase component may be I2(i+w) while the quadrature component may be I1(i+v), and for switched baseband signal r1(i), the in-phase component may be Q2(i+w) while the quadrature component may be Q1(i+v).For switched baseband signal r2(i), the in-phase component may be I1(i+v) while the quadrature component may be Q2(i+w), and for switched baseband signal r1(i), the in-phase component may be I2(i+w) while the quadrature component may be Q1(i+v).For switched baseband signal r2(i), the in-phase component may be I1(i+v) while the quadrature component may be Q2(i+w), and for switched baseband signal r1(i), the in-phase component may be Q1(i+v) while the quadrature component may be I2(i+w).For switched baseband signal r2(i), the in-phase component may be Q2(i+w) while the quadrature component may be I1(i+v), and for switched baseband signal r1(i), the in-phase component may be I2(i+w) while the quadrature component may be Q1(i+v).For switched baseband signal r2(i), the in-phase component may be Q2(i+w) while the quadrature component may be I1(i+v), and for switched baseband signal r1(i), the in-phase component may be Q1(i+v) while the quadrature component may be I2(i+w). FIG.55illustrates a baseband signal switcher5502explaining the above. As shown, of the two processed baseband signals z1(i)5501_1and z2(i)5501_2, processed baseband signal z1(i)5501_1has in-phase component I1(i) and quadrature component Q1(i), while processed baseband signal z2(i)5501_2has in-phase component I2(i) and quadrature component Q2(i). Then, after switching, switched baseband signal r1(i)5503_1has in-phase component Ir1(i) and quadrature component Qr1(i), while switched baseband signal r2(i)5503_2has in-phase component Ir2(i) and quadrature component Qr1(i). The in-phase component Ir1(i) and quadrature component Qr1(i) of switched baseband signal r1(i)5503_1and the in-phase component Ir2(i) and quadrature component Qr1(i) of switched baseband signal r2(i)5503_2may be expressed as any of the above. Although this example describes switching performed on baseband signals having a common time (common ((sub-)carrier) frequency) and having undergone two types of signal processing, the same may be applied to baseband signals having undergone two types of signal processing but having different time (different ((sub-)carrier) frequencies). Each of the transmit antennas of the transmission device and each of the receive antennas of the reception device shown in the figures may be formed by a plurality of antennas. The present description uses the symbol V, which is the universal quantifier, and the symbol ∃, which is the existential quantifier. Furthermore, the present description uses the radian as the unit of phase in the complex plane, e.g., for the argument thereof. When dealing with the complex plane, the coordinates of complex numbers are expressible by way of polar coordinates. For a complex number z=a+jb (where a and b are real numbers and j is the imaginary unit), the corresponding point (a, b) on the complex plane is expressed with the polar coordinates[r, θ], converted as follows: a=r×cos θ b=r×sin θ [Math. 49] r=a2+b2(formula49) where r is the absolute value of z (r=|z|), and θ is the argument thereof. As such, z=a +jb is expressible as re. In the present invention, the baseband signals s1, s2, z1, and z2are described as being complex signals. A complex signal made up of in-phase signal I and quadrature signal Q is also expressible as complex signal I+jQ. Here, either of I and Q may be equal to zero. FIG.46illustrates a sample broadcasting system using the phase changing scheme described in the present description. As shown, a video encoder4601takes video as input, performs video encoding, and outputs encoded video data4602. An audio encoder takes audio as input, performs audio encoding, and outputs encoded audio data4604. A data encoder4605takes data as input, performs data encoding (e.g., data compression), and outputs encoded data4606. Taken as a whole, these components form a source information encoder4600. A transmitter4607takes the encoded video data4602, the encoded audio data4604, and the encoded data4606as input, performs error-correcting coding, modulation, precoding, and phase changing (e.g., the signal processing by the transmission device fromFIG.3) on a subset of or on the entirety of these, and outputs transmit signals4608_1through4608_N. Transmit signals4608_1through4608_N are then transmitted by antennas4609_1through4609_N as radio waves. A receiver4612takes received signals4611_1through4611_M received by antennas4610_1through4610_M as input, performs processing such as frequency conversion, change of phase, decoding of the precoding, log-likelihood ratio calculation, and error-correcting decoding (e.g., the processing by the reception device fromFIG.7), and outputs received data4613,4615, and4617. A source information decoder4619takes the received data4613,4615, and4617as input. A video decoder4614takes received data4613as input, performs video decoding, and outputs a video signal. The video is then displayed on a television display. An audio decoder4616takes received data4615as input. The audio decoder4616performs audio decoding and outputs an audio signal. the audio is then played through speakers. A data decoder4618takes received data4617as input, performs data decoding, and outputs information. In the above-described Embodiments pertaining to the present invention, the number of encoders in the transmission device using a multi-carrier transmission scheme such as OFDM may be any number, as described above. Therefore, as inFIG.4, for example, the transmission device may have only one encoder and apply a scheme for distributing output to the multi-carrier transmission scheme such as OFDM. In such circumstances, the wireless units310A and310B fromFIG.4should replace the OFDM-related processors1301A and1301B fromFIG.12. The description of the OFDM-related processors is as given for Embodiment 1. Although Embodiment 1 gives formula 36 as an example of a precoding matrix, another precoding matrix may also be used, when the following scheme is applied. [Math. 50] (w11w12w21w22)=1α2+1(ej0α×ejπα×ej0ej0)(formula50) In the precoding matrices of formula 36 and formula 50, the value of α is set as given by formula 37 and formula 38. However, no limitation is intended in this manner. A simple precoding matrix is obtainable by setting α=1, which is also a valid value. In Embodiment A1, the phase changers fromFIGS.3,4,6,12,25,29,51, and53are indicated as having a phase changing value of PHASE[i] (where i=0, 1, 2 . . . N−2, N−1 (i denotes an integer that satisfies 0≤i≤N−1)) to achieve a period (cycle) of N (value reached given thatFIGS.3,4,6,12,25,29,51, and53perform a change of phase on only one baseband signal). The present description discusses performing a change of phase on one precoded baseband signal (i.e., inFIGS.3,4,6,12,25,29, and51) namely on precoded baseband signal z2′. Here, PHASE[k] is calculated as follows. [Math. 51] PHASE[k]=2kπNradians(formula51) where k=0, 1, 2 . . . N−2, N−1 (k denotes an integer that satisfies 0≤k≤N−1). When N=5, 7, 9, 11, or 15, the reception device is able to obtain good data reception quality. Although the present description discusses the details of phase changing schemes involving two modulated signals transmitted by a plurality of antennas, no limitation is intended in this regard. Precoding and a change of phase may be performed on three or more baseband signals on which mapping has been performed according to a modulation scheme, followed by predetermined processing on the post-phase-change baseband signals and transmission using a plurality of antennas, to realize the same results. Programs for executing the above transmission scheme may, for example, be stored in advance in ROM (Read-Only Memory) and be read out for operation by a CPU. Furthermore, the programs for executing the above transmission scheme may be stored on a computer-readable recording medium, the programs stored in the recording medium may be loaded in the RAM (Random Access Memory) of the computer, and the computer may be operated in accordance with the programs. The components of the above-described Embodiments may be typically assembled as an LSI (Large Scale Integration), a type of integrated circuit. Individual components may respectively be made into discrete chips, or a subset or entirety of the components may be made into a single chip. Although an LSI is mentioned above, the terms IC (Integrated Circuit), system LSI, super LSI, or ultra LSI may also apply, depending on the degree of integration. Furthermore, the method of integrated circuit assembly is not limited to LSI. A dedicated circuit or a general-purpose processor may be used. After LSI assembly, a FPGA (Field Programmable Gate Array) or reconfigurable processor may be used. Furthermore, should progress in the field of semiconductors or emerging technologies lead to replacement of LSI with other integrated circuit methods, then such technology may of course be used to integrate the functional blocks. Applications to biotechnology are also plausible. Embodiment C1 Embodiment 1 explained that the precoding matrix in use may be switched when transmission parameters change. The present Embodiment describes a detailed example of such a case, where, as described above (in the supplement), the transmission parameters change such that streams s1(t) and s2(t) switch between transmitting different data and transmitting identical data, and the precoding matrix and phase changing scheme being used are switched accordingly. The example of the present Embodiment describes a situation where two modulated signals transmitted from two different transmit antenna alternate between having the modulated signals include identical data and having the modulated signals each include different data. FIG.56illustrates a sample configuration of a transmission device switching between transmission schemes, as described above. InFIG.56, components operating in the manner described forFIG.54use identical reference numbers. As shown,FIG.56differs fromFIG.54in that a distributor404takes the frame configuration signal313as input. The operations of the distributor404are described usingFIG.57. FIG.57illustrates the operations of the distributor404when transmitting identical data and when transmitting different data. As shown, given encoded data x1, x2, x3, x4, x5, x6, and so on, when transmitting identical data, distributed data405is given as x1, x2, x3, x4, x5, x6, and so on, while distributed data405B is similarly given as x1, x2, x3, x4, x5, x6, and so on. On the other hand, when transmitting different data, distributed data405A are given as x1, x3, x5, x7, x9, and so on, while distributed data405B are given as x2, x4, x6, x8, x10, and so on. The distributor404determines, according to the frame configuration signal313taken as input, whether the transmission mode is identical data transmission or different data transmission. An alternative to the above is shown inFIG.58. As shown, when transmitting identical data, the distributor404outputs distributed data405A as x1, x2, x3, x4, x5, x6, and so on, while outputting nothing as distributed data405B. Accordingly, when the frame configuration signal313indicates identical data transmission, the distributor404operates as described above, while interleaver304B and mapper306B fromFIG.56do not operate. Thus, only baseband signal307A output by mapper306A fromFIG.56is valid, and is taken as input by both weighting unit308A and308B. One characteristic feature of the present Embodiment is that, when the transmission mode switches from identical data transmission to different data transmission, the precoding matrix may also be switched. As indicated by formula 36 and formula 39 in Embodiment 1, given a matrix made up of w11, w12, w21, and w22, the precoding matrix used to transmit identical data may be as follows. [Math. 52] (w11w12w21w22)=(a00a)(formula52) where a is a real number (a may also be a complex number, but given that the baseband signal input as a result of precoding undergoes a change of phase, a real number is preferable for considerations of circuit size and complexity reduction). Also, when a is equal to one, the weighting units308A and308B do not perform weighting and output the input signal as-is. Accordingly, when transmitting identical data, the weighted baseband signals309A and316B are identical signals output by the weighting units308A and308B. When the frame configuration signal indicates identical transmission mode, a phase changer5201performs a change of phase on weighted baseband signal309A and outputs post-phase-change baseband signal5202. Similarly, when the frame configuration signal indicates identical transmission mode, phase changer317B performs a change of phase on weighted baseband signal316B and outputs post-phase-change baseband signal309B. The change of phase performed by phase changer5201is of ejA(t)(alternatively, ejA(f)or ejA(t,f)) (where t is time and f is frequency) (accordingly, ejA(t)(alternatively, ejA(f)or ejA(t,f)) is the value by which the input baseband signal is multiplied), and the change of phase performed by phase changer317B is of ejB(t)(alternatively, ejB(f)or el BjB(t,f)) (where t is time and f is frequency) (accordingly, ejB(t)(alternatively, ejB(f)or el BjB(t,f)) is the value by which the input baseband signal is multiplied). As such, the following condition is satisfied. [Math. 53] ejA(t)≠ejB(t)(formula 53) Some time t satisfies(Or, some (carrier) frequency f satisfies ejA(f)≠ejB(f))(Or, some (carrier) frequency f and time t satisfy ejA(t,f)≠ejB(t,f)) As such, the transmit signal is able to reduce multi-path influence and thereby improve data reception quality for the reception device. (However, the change of phase may also be performed by only one of the weighted baseband signals309A and316B.) InFIG.56, when OFDM is used, processing such as IFFT and frequency conversion is performed on post-phase-change baseband signal5202, and the result is transmitted by a transmit antenna. (SeeFIG.13) (Accordingly, post-phase-change baseband signal5202may be considered the same as signal1301A fromFIG.13.) Similarly, when OFDM is used, processing such as IFFT and frequency conversion is performed on post-phase-change baseband signal309B, and the result is transmitted by a transmit antenna. (SeeFIG.13) (Accordingly, post-phase-change baseband signal309B may be considered the same as signal1301B fromFIG.13.) When the selected transmission mode indicates different data transmission, then any of formula 36, formula 39, and formula 50 given in Embodiment 1 may apply. Significantly, the phase changers5201and317B fromFIG.56us a different phase changing scheme than when transmitting identical data. Specifically, as described in Embodiment 1, for example, phase changer5201performs the change of phase while phase changer317B does not, or phase changer317B performs the change of phase while phase changer5201does not. Only one of the two phase changers performs the change of phase. As such, the reception device obtains good data reception quality in the LOS environment as well as the NLOS environment. When the selected transmission mode indicates different data transmission, the precoding matrix may be as given in formula 52, or as given in any of formula 36, formula 50, and formula 39, or may be a precoding matrix unlike that given in formula 52. Thus, the reception device is especially likely to experience improvements to data reception quality in the LOS environment. Furthermore, although the present Embodiment discusses examples using OFDM as the transmission scheme, the invention is not limited in this manner. Multi-carrier schemes other than OFDM and single-carrier schemes may all be used to achieve similar Embodiments. Here, spread-spectrum communications may also be used. When single-carrier schemes are used, the change of phase is performed with respect to the time domain. As explained in Embodiment 3, when the transmission scheme involves different data transmission, the change of phase is performed on the data symbols, only. However, as described in the present Embodiment, when the transmission scheme involves identical data transmission, then the change of phase need not be limited to the data symbols but may also be performed on pilot symbols, control symbols, and other such symbols inserted into the transmission frame of the transmit signal. (The change of phase need not always be performed on symbols such as pilot symbols and control symbols, though doing so is preferable in order to achieve diversity gain.) Embodiment C2 The present Embodiment describes a configuration scheme for a base station corresponding to Embodiment C1. FIG.59illustrates the relationship of a base stations (broadcasters) to terminals. A terminal P (5907) receives transmit signal5903A transmitted by antenna5904A and transmit signal5905A transmitted by antenna5906A of broadcaster A (5902A), then performs predetermined processing thereon to obtained received data. A terminal Q (5908) receives transmit signal5903A transmitted by antenna5904A of base station A (5902A) and transmit signal593B transmitted by antenna5904B of base station B (5902B), then performs predetermined processing thereon to obtained received data. FIGS.60and61illustrate the frequency allocation of base station A (5902A) for transmit signals5903A and5905A transmitted by antennas5904A and5906A, and the frequency allocation of base station B (5902B) for transmit signals5903B and5905B transmitted by antennas5904B and5906B. InFIGS.60and61, frequency is on the horizontal axis and transmission power is on the vertical axis. As shown, transmit signals5903A and5905A transmitted by base station A (5902A) and transmit signals5903B and5905B transmitted by base station B (5902B) use at least frequency band X and frequency band Y. Frequency band X is used to transmit data of a first channel, and frequency band Y is used to transmit data of a second channel. Accordingly, terminal P (5907) receives transmit signal5903A transmitted by antenna5904A and transmit signal5905A transmitted by antenna5906A of base station A (5902A), extracts frequency band X therefrom, performs predetermined processing, and thus obtains the data of the first channel. Terminal Q (5908) receives transmit signal5903A transmitted by antenna5904A of base station A (5902A) and transmit signal5903B transmitted by antenna5904B of base station B (5902B), extracts frequency band Y therefrom, performs predetermined processing, and thus obtains the data of the second channel. The following describes the configuration and operations of base station A (5902A) and base station B (5902B). As described in Embodiment C1, both base station A (5902A) and base station B (5902B) incorporate a transmission device configured as illustrated byFIGS.56and13. When transmitting as illustrated byFIG.60, base station A (5902A) generates two different modulated signals (on which precoding and a change of phase are performed) with respect to frequency band X as described in Embodiment C1. The two modulated signals are respectively transmitted by the antennas5904A and5906A. With respect to frequency band Y, base station A (5902A) operates interleaver304A, mapper306A, weighting unit308A, and phase changer fromFIG.56to generate modulated signal5202. Then, a transmit signal corresponding to modulated signal5202is transmitted by antenna1310A fromFIG.13, i.e., by antenna5904A fromFIG.59. Similarly, base station B (5902B) operates interleaver304A, mapper306A, weighting unit308A, and phase changer5201fromFIG.56to generate modulated signal5202. Then, a transmit signal corresponding to modulated signal5202is transmitted by antenna1310A fromFIG.13, i.e., by antenna5904B fromFIG.59. The creation of encoded data in frequency band Y may involve, as shown inFIG.56, generating encoded data in individual base stations or may involve having one of the base stations generate such encoded data for transmission to other base stations. As an alternative scheme, one of the base stations may generate modulated signals and be configured to pass the modulated signals so generated to other base stations. Also, inFIG.59, signal5901includes information pertaining to the transmission mode (identical data transmission or different data transmission). The base stations obtain this signal and thereby switch between generation schemes for the modulated signals in each frequency band. Here, signal5901is indicated inFIG.59as being input from another device or from a network. However, configurations where, for example, base station A (5902) is a master station passing a signal corresponding to signal5901to base station B (5902B) are also possible. As explained above, when the base station transmits different data, the precoding matrix and phase changing scheme are set according to the transmission scheme to generate modulated signals. On the other hand, to transmit identical data, two base stations respectively generate and transmit modulated signals. In such circumstances, base stations each generating modulated signals for transmission from a common antenna may be considered to be two combined base stations using the precoding matrix given by formula 52. The phase changing scheme is as explained in Embodiment C1, for example, and satisfies the conditions of formula 53. In addition, the transmission scheme of frequency band X and frequency band Y may vary over time. Accordingly, as illustrated inFIG.61, as time passes, the frequency allocation changes from that indicated inFIG.60to that indicated inFIG.61. According to the present Embodiment, not only can the reception device obtain improved data reception quality for identical data transmission as well as different data transmission, but the transmission devices can also share a phase changer. Furthermore, although the present Embodiment discusses examples using OFDM as the transmission scheme, the invention is not limited in this manner. Multi-carrier schemes other than OFDM and single-carrier schemes may all be used to achieve similar Embodiments. Here, spread-spectrum communications may also be use. When single-carrier schemes are used, the change of phase is performed with respect to the time domain. As explained in Embodiment 3, when the transmission scheme involves different data transmission, the change of phase is carried out on the data symbols, only. However, as described in the present Embodiment, when the transmission scheme involves identical data transmission, then the change of phase need not be limited to the data symbols but may also be performed on pilot symbols, control symbols, and other such symbols inserted into the transmission frame of the transmit signal. (The change of phase need not always be performed on symbols such as pilot symbols and control symbols, though doing so is preferable in order to achieve diversity gain.) Embodiment C3 The present Embodiment describes a configuration scheme for a repeater corresponding to Embodiment C1. The repeater may also be termed a repeating station. FIG.62illustrates the relationship of a base stations (broadcasters) to repeaters and terminals. As shown inFIG.63, base station6201at least transmits modulated signals on frequency band X and frequency band Y. Base station6201transmits respective modulated signals on antenna6202A and antenna6202B. The transmission scheme here used is described later, with reference toFIG.63. Repeater A (6203A) performs processing such as demodulation on received signal6205A received by receive antenna6204A and on received signal6207A received by receive antenna6206A, thus obtaining received data. Then, in order to transmit the received data to a terminal, repeater A (6203A) performs transmission processing to generate modulated signals6209A and6211A for transmission on respective antennas6210A and6212A. Similarly, repeater B (6203B) performs processing such as demodulation on received signal6205B received by receive antenna6204B and on received signal6207B received by receive antenna6206B, thus obtaining received data. Then, in order to transmit the received data to a terminal, repeater B (6203B) performs transmission processing to generate modulated signals6209B and6211B for transmission on respective antennas6210B and6212B. Here, repeater B (6203B) is a master repeater that outputs a control signal6208. repeater A (6203A) takes the control signal as input. A master repeater is not strictly necessary. Base station6201may also transmit individual control signals to repeater A (6203A) and to repeater B (6203B). Terminal P (5907) receives modulated signals transmitted by repeater A (6203A), thereby obtaining data. Terminal Q (5908) receives signals transmitted by repeater A (6203A) and by repeater B (6203B), thereby obtaining data. Terminal R (6213) receives modulated signals transmitted by repeater B (6203B), thereby obtaining data. FIG.63illustrates the frequency allocation for a modulated signal transmitted by antenna6202A among transmit signals transmitted by the base station, and the frequency allocation of modulated signals transmitted by antenna6202B. InFIG.63, frequency is on the horizontal axis and transmission power is on the vertical axis. As shown, the modulated signals transmitted by antenna6202A and by antenna6202B use at least frequency band X and frequency band Y. Frequency band X is used to transmit data of a first channel, and frequency band Y is used to transmit data of a second channel. As described in Embodiment C1, the data of the first channel is transmitted using frequency band X in different data transmission mode. Accordingly, as shown inFIG.63, the modulated signals transmitted by antenna6202A and by antenna6202B include components of frequency band X. These components of frequency band X are received by repeater A and by repeater B. Accordingly, as described in Embodiment 1 and in Embodiment C1, modulated signals in frequency band X are signals on which mapping has been performed, and to which precoding (weighting) and the change of phase are applied. As shown inFIG.62, the data of the second channel is transmitted by antenna6202A ofFIG.2and transmits data in components of frequency band Y. These components of frequency band Y are received by repeater A and by repeater B. FIG.64illustrate the frequency allocation for transmit signals transmitted by repeater A and repeater B, specifically for modulated signal6209A transmitted by antenna6210A and modulated signal6211A transmitted by antenna6212A of repeater6210A, and for modulated signal6209B transmitted by antenna6210B and modulated signal6211B transmitted by antenna6212B of repeater B. InFIG.64, frequency is on the horizontal axis and transmission power is on the vertical axis. As shown, modulated signal6209A transmitted by antenna6210A and modulated signal6211A transmitted by antenna6212A use at least frequency band X and frequency band Y. Also, modulated signal6209B transmitted by antenna6210B and modulated signal6211B transmitted by antenna6212B similarly use at least frequency band X and frequency band Y. Frequency band X is used to transmit data of a first channel, and frequency band Y is used to transmit data of a second channel. As described in Embodiment C1, the data of the first channel is transmitted using frequency band X in different data transmission mode. Accordingly, as shown inFIG.64, modulated signal6209A transmitted by antenna6210A and modulated signal6211A transmitted by antenna6212B include components of frequency band X. These components of frequency band X are received by terminal P. Similarly, as shown inFIG.64, modulated signal6209B transmitted by antenna6210B and modulated signal6211B transmitted by antenna6212B include components of frequency band X. These components of frequency band X are received by terminal R. Accordingly, as described in Embodiment 1 and in Embodiment C1, modulated signals in frequency band X are signals on which mapping has been performed, and to which precoding (weighting) and the change of phase are applied. As shown inFIG.64, the data of the second channel is carried by the modulated signals transmitted by antenna6210A of repeater A (6203A) and by antenna6210B of repeater B (6203) fromFIG.62and transmits data in components of frequency band Y. Here, the components of frequency band Y in modulated signal6209A transmitted by antenna6210A of repeater A (6203A) and those in modulated signal6209B transmitted by antenna6210B of repeater B (6203B) are used in a transmission mode that involves identical data transmission, as explained in Embodiment C1. These components of frequency band Y are received by terminal Q. The following describes the configuration of repeater A (6203A) and repeater B (6203B) fromFIG.62, with reference toFIG.65. FIG.65illustrates a sample configuration of a receiver and transmitter in a repeater. Components operating identically to those ofFIG.56use the same reference numbers thereas. Receiver6203X takes received signal6502A received by receive antenna6501A and received signal6502B received by receive antenna6501B as input, performs signal processing (signal demultiplexing or compositing, error-correction decoding, and so on) on the components of frequency band X thereof to obtain data6204X transmitted by the base station using frequency band X, outputs the data to the distributor404and obtains transmission scheme information included in control information (and transmission scheme information when transmitted by a repeater), and outputs the frame configuration signal313. Receiver6203X and onward constitute a processor for generating a modulated signal for transmitting frequency band X. Further, the receiver here described is not only the receiver for frequency band X as shown inFIG.65, but also incorporates receivers for other frequency bands. Each receiver forms a processor for generating modulated signals for transmitting a respective frequency band. The overall operations of the distributor404are identical to those of the distributor in the base station described in Embodiment C2. When transmitting as indicated inFIG.64, repeater A (6203A) and repeater B (6203B) generate two different modulated signals (on which precoding and change of phase are performed) in frequency band X as described in Embodiment C1. The two modulated signals are respectively transmitted by antennas6210A and6212A of repeater A (6203) fromFIG.62and by antennas6210B and6212B of repeater B (6203B) fromFIG.62. As for frequency band Y, repeater A (6203A) operates a processor6500pertaining to frequency band Y and corresponding to the signal processor6500pertaining to frequency band X shown inFIG.65(the signal processor6500is the signal processor pertaining to frequency band X, but given that an identical signal processor is incorporated for frequency band Y, this description uses the same reference numbers), interleaver304A, mapper306A, weighting unit308A, and phase changer5201to generate modulated signal5202. A transmit signal corresponding to modulated signal5202is then transmitted by antenna1301A fromFIG.13, that is, by antenna6210A fromFIG.62. Similarly, repeater B (6203B) operates interleaver304A, mapper306A, weighting unit308A, and phase changer5201fromFIG.62pertaining to frequency band Y to generate modulated signal5202. Then, a transmit signal corresponding to modulated signal5202is transmitted by antenna1310A fromFIG.13, i.e., by antenna6210B fromFIG.62. As shown inFIG.66(FIG.66illustrates the frame configuration of the modulated signal transmitted by the base station, with time on the horizontal axis and frequency on the vertical axis), the base station transmits transmission scheme information6601, repeater-applied phase change information6602, and data symbols6603. The repeater obtains and applies the transmission scheme information6601, the repeater-applied phase change information6602, and the data symbols6603to the transmit signal, thus determining the phase changing scheme. When the repeater-applied phase change information6602fromFIG.66is not included in the signal transmitted by the base station, then as shown inFIG.62, repeater B (6203B) is the master and indicates the phase changing scheme to repeater A (6203A). As explained above, when the repeater transmits different data, the precoding matrix and phase changing scheme are set according to the transmission scheme to generate modulated signals. On the other hand, to transmit identical data, two repeaters respectively generate and transmit modulated signals. In such circumstances, repeaters each generating modulated signals for transmission from a common antenna may be considered to be two combined repeaters using the precoding matrix given by formula 52. The phase changing scheme is as explained in Embodiment C1, for example, and satisfies the conditions of formula 53. Also, as explained in Embodiment C1 for frequency band X, the base station and repeater may each have two antennas that transmit respective modulated signals and two antennas that receive identical data. The operations of such a base station or repeater are as described for Embodiment C1. According to the present Embodiment, not only can the reception device obtain improved data reception quality for identical data transmission as well as different data transmission, but the transmission devices can also share a phase changer. Furthermore, although the present Embodiment discusses examples using OFDM as the transmission scheme, the invention is not limited in this manner. Multi-carrier schemes other than OFDM and single-carrier schemes may all be used to achieve similar Embodiments. Here, spread-spectrum communications may also be used. When single-carrier schemes are used, the change of phase is performed with respect to the time domain. As explained in Embodiment 3, when the transmission scheme involves different data transmission, the change of phase is carried out on the data symbols, only. However, as described in the present Embodiment, when the transmission scheme involves identical data transmission, then the change of phase need not be limited to the data symbols but may also be performed on pilot symbols, control symbols, and other such symbols inserted into the transmission frame of the transmit signal. (The change of phase need not always be performed on symbols such as pilot symbols and control symbols, though doing so is preferable in order to achieve diversity gain.) Embodiment C4 The present Embodiment concerns a phase changing scheme different from the phase changing schemes described in Embodiment 1 and in the Supplement. In Embodiment 1, formula 36 is given as an example of a precoding matrix, and in the Supplement, formula 50 is similarly given as another such example. In Embodiment A1, the phase changers fromFIGS.3,4,6,12,25,29,51, and53are indicated as having a phase changing value of PHASE[i] (where i=0, 1, 2 . . . N−2, N−1 (i denotes an integer that satisfies 0≤i≤N−1)) to achieve a period (cycle) of N (value reached given thatFIGS.3,4,6,12,25,29,51, and53perform the change of phase on only one baseband signal). The present description discusses performing a change of phase on one precoded baseband signal (i.e., inFIGS.3,4,6,12,25,29, and51) namely on precoded baseband signal z2′. Here, PHASE[k] is calculated as follows. [Math. 54] PHASE[k]=kπNradians(formula54) where k=0, 1, 2 . . . N−2, N−1 (k denotes an integer that satisfies 0≤k≤N−1). Accordingly, the reception device is able to achieve improvements in data reception quality in the LOS environment, and especially in a radio wave propagation environment. In the LOS environment, when the change of phase has not been performed, a regular phase relationship holds. However, when the change of phase is performed, the phase relationship is modified, in turn avoiding poor conditions in a burst-like propagation environment. As an alternative to formula 54, PHASE[k] may be calculated as follows. [Math. 55] PHASE[k]=-kπN+Zradians(formula55) where k=0, 1, 2 . . . N−2, N−1 (k denotes an integer that satisfies 0≤k≤N−1). As a further alternative phase changing scheme, PHASE[k] may be calculated as follows. [Math. 56] PHASE[k]=kπN+Zradians(formula56) where k=0, 1, 2 . . . N−2, N−1 (k denotes an integer that satisfies 0≤k≤N−1), and Z is a fixed value. As a further alternative phase changing scheme, PHASE[k] may be calculated as follows. [Math. 57] PHASE[k]=-kπN+Zradians(formula57) where k=0, 1, 2 . . . N−2, N−1 (k denotes an integer that satisfies 0≤k≤N−1), and Z is a fixed value. As such, by performing the change of phase according to the present Embodiment, the reception device is made more likely to obtain good reception quality. The change of phase of the present Embodiment is applicable not only to single-carrier schemes but also to multi-carrier schemes. Accordingly, the present Embodiment may also be realized using, for example, spread-spectrum communications, OFDM, SC-FDMA, SC-OFDM, wavelet OFDM as described in Non-Patent Literature 7, and so on. As previously described, while the present Embodiment explains the change of phase by changing the phase with respect to the time domain t, the phase may alternatively be changed with respect to the frequency domain as described in Embodiment 1. That is, considering the change of phase in the time domain t described in the present Embodiment and replacing t with f (f being the ((sub-) carrier) frequency) leads to a change of phase applicable to the frequency domain. Also, as explained above for Embodiment 1, the phase changing scheme of the present Embodiment is also applicable to a change of phase in both the time domain and the frequency domain. Further, when the phase changing scheme described in the present Embodiment satisfies the conditions indicated in Embodiment A1, the reception device is highly likely to obtain good data quality. Embodiment C5 The present Embodiment concerns a phase changing scheme different from the phase changing schemes described in Embodiment 1, in the Supplement, and in Embodiment C4. In Embodiment 1, formula 36 is given as an example of a precoding matrix, and in the Supplement, formula 50 is similarly given as another such example. In Embodiment A1, the phase changers fromFIGS.3,4,6,12,25,29,51, and53are indicated as having a phase changing value of PHASE[i] (where i=0, 1, 2 . . . N−2, N−1 (i denotes an integer that satisfies 0≤i≤N−1)) to achieve a period (cycle) of N (value reached given thatFIGS.3,4,6,12,25,29,51, and53perform the change of phase on only one baseband signal). The present description discusses performing a change of phase on one precoded baseband signal (i.e., inFIGS.3,4,6,12,25,29,51and53) namely on precoded baseband signal z2′. The characteristic feature of the phase changing scheme pertaining to the present Embodiment is the period (cycle) of N=2n+1. To achieve the period (cycle) of N=2n+1, n+1 different phase changing values are prepared. Among these n+1 different phase changing values, n phase changing values are used twice per period (cycle), and one phase changing value is used only once per period (cycle), thus achieving the period (cycle) of N=2n+1. The following describes these phase changing values in detail. The n+1 different phase changing values required to achieve a phase changing scheme in which the phase changing value is regularly switched in a period (cycle) of N=2n+1 are expressed as PHASE[0], PHASE[1], PHASE[i] PHASE[n−1], PHASE[n] (where i=0, 1, 2 . . . n−2, n−1, n (i denotes an integer that satisfies 0≤i≤n)). Here, the n+1 different phase changing values of PHASE[0], PHASE[1], PHASE[i] PHASE[n−1], PHASE[n] are expressed as follows. [Math. 58] PHASE[k]=2kπ2n+1radians(formula58) where k=0, 1, 2 . . . n−2, n−1, n (k denotes an integer that satisfies 0≤k≤n). The n+1 different phase changing values PHASE[0], PHASE[1] PHASE[i] PHASE[n−1], PHASE[n] are given by formula 58. PHASE[0] is used once, while PHASE[1] through PHASE[n] are each used twice (i.e., PHASE[1] is used twice, PHASE[2] is used twice, and so on, until PHASE[n−1] is used twice and PHASE[n] is used twice). As such, through this phase changing scheme in which the phase changing value is regularly switched in a period (cycle) of N=2n+1, a phase changing scheme is realized in which the phase changing value is regularly switched between fewer phase changing values. Thus, the reception device is able to achieve better data reception quality. As the phase changing values are fewer, the effect thereof on the transmission device and reception device may be reduced. According to the above, the reception device is able to achieve improvements in data reception quality in the LOS environment, and especially in a radio wave propagation environment. In the LOS environment, when the change of phase has not been performed, a regular phase relationship occurs. However, when the change of phase is performed, the phase relationship is modified, in turn avoiding poor conditions in a burst-like propagation environment. As an alternative to formula 54, PHASE[k] may be calculated as follows. [Math. 59] PHASE[k]=-2kπ2n+1radians(formula59) where k=0, 1, 2 . . . n−2, n−1, n (k denotes an integer that satisfies 0≤k≤n). The n+1 different phase changing values PHASE[0], PHASE[1] PHASE[i] PHASE[n-1], PHASE[n] are given by formula 59. PHASE[0] is used once, while PHASE[1] through PHASE[n] are each used twice (i.e., PHASE[1] is used twice, PHASE[2] is used twice, and so on, until PHASE[n-1] is used twice and PHASE[n] is used twice). As such, through this phase changing scheme in which the phase changing value is regularly switched in a period (cycle) of N=2n +1, a phase changing scheme is realized in which the phase changing value is regularly switched between fewer phase changing values. Thus, the reception device is able to achieve better data reception quality. As the phase changing values are fewer, the effect thereof on the transmission device and reception device may be reduced. As a further alternative, PHASE[k] may be calculated as follows. [Math. 60] PHASE[k]=-2kπ2n+1radians(formula60) where k=0, 1, 2 . . . n−2, n−1, n (k denotes an integer that satisfies 0≤k≤n) and Z is a fixed value. The n+1 different phase changing values PHASE[0], PHASE[1] PHASE[i] PHASE[n−1], PHASE[n] are given by formula 60. PHASE[0] is used once, while PHASE[1] through PHASE[n] are each used twice (i.e., PHASE[1] is used twice, PHASE[2] is used twice, and so on, until PHASE[n-1] is used twice and PHASE[n] is used twice). As such, through this phase changing scheme in which the phase changing value is regularly switched in a period (cycle) of N=2n+1, a phase changing scheme is realized in which the phase changing value is regularly switched between fewer phase changing values. Thus, the reception device is able to achieve better data reception quality. As the phase changing values are fewer, the effect thereof on the transmission device and reception device may be reduced. As a further alternative, PHASE[k] may be calculated as follows. [Math. 61] PHASE[k]=-2kπ2n+1+Zradians(formula61) where k=0, 1, 2 . . . n−2, n−1, n(k denotes an integer that satisfies 0≤k≤n) and Z is a fixed value. The n+1 different phase changing values PHASE[0], PHASE[1] PHASE[i] PHASE[n-1], PHASE[n] are given by formula 61. PHASE[0] is used once, while PHASE[1] through PHASE[n] are each used twice (i.e., PHASE[1] is used twice, PHASE[2] is used twice, and so on, until PHASE[n−1] is used twice and PHASE[n] is used twice). As such, through this phase changing scheme in which the phase changing value is regularly switched in a period (cycle) of N=2n+1, a phase changing scheme is realized in which the phase changing value is regularly switched between fewer phase changing values. Thus, the reception device is able to achieve better data reception quality. As the phase changing values are smaller, the effect thereof on the transmission device and reception device may be reduced. As such, by performing the change of phase according to the present Embodiment, the reception device is made more likely to obtain good reception quality. The change of phase of the present Embodiment is applicable not only to single-carrier schemes but also to transmission using multi-carrier schemes. Accordingly, the present Embodiment may also be realized using, for example, spread-spectrum communications, OFDM, SC-FDMA, SC-OFDM, wavelet OFDM as described in Non-Patent Literature 7, and so on. As previously described, while the present Embodiment explains the change of phase as a change of phase with respect to the time domain t, the phase may alternatively be changed with respect to the frequency domain as described in Embodiment 1. That is, considering the change of phase with respect to the time domain t described in the present Embodiment and replacing t with f (f being the ((sub-) carrier) frequency) leads to a change of phase applicable to the frequency domain. Also, as explained above for Embodiment 1, the phase changing scheme of the present Embodiment is also applicable to a change of phase with respect to both the time domain and the frequency domain. Embodiment C6 The present Embodiment describes a scheme for regularly changing the phase, specifically that of Embodiment C5, when encoding is performed using block codes as described in Non-Patent Literature 12 through 15, such as QC LDPC Codes (not only QC-LDPC but also LDPC codes may be used), concatenated LDPC (blocks) and BCH codes, Turbo codes or Duo-Binary Turbo Codes using tail-biting, and so on. The following example considers a case where two streams s1and s2are transmitted. When encoding has been performed using block codes and control information and the like is not necessary, the number of bits making up each coded block matches the number of bits making up each block code (control information and so on described below may yet be included). When encoding has been performed using block codes or the like and control information or the like (e.g., CRC transmission parameters) is required, then the number of bits making up each coded block is the sum of the number of bits making up the block codes and the number of bits making up the information. FIG.34illustrates the varying numbers of symbols and slots needed in two coded blocks when block codes are used.FIG.34illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used when, for example, two streams s1and s2are transmitted as indicated by the transmission device fromFIG.4, and the transmission device has only one encoder. (Here, the transmission scheme may be any single-carrier scheme or multi-carrier scheme such as OFDM.) As shown inFIG.34, when block codes are used, there are 6000 bits making up a single coded block. In order to transmit these 6000 bits, the number of required symbols depends on the modulation scheme, being 3000 symbols for QPSK, 1500 symbols for 16-QAM, and 1000 symbols for 64-QAM. Then, given that the transmission device fromFIG.4transmits two streams simultaneously, 1500 of the aforementioned 3000 symbols needed when the modulation scheme is QPSK are assigned to s1and the other 1500 symbols are assigned to s2. As such, 1500 slots for transmitting the 1500 symbols are required for each of s1and s2. By the same reasoning, when the modulation scheme is 16-QAM, 750 slots are needed to transmit all of the bits making up one coded block, and when the modulation scheme is 64-QAM, 500 slots are needed to transmit all of the bits making up one coded block. The following describes the relationship between the above-defined slots and the phase, as pertains to schemes for a regular change of phase. Here, five different phase changing values (or phase changing sets) are assumed as having been prepared for use in the scheme for a regular change of phase, which has a period (cycle) of five. That is, the phase changer of the transmission device fromFIG.4uses five phase changing values (or phase changing sets) to achieve the period (cycle) of five. However, as described in Embodiment C5, three different phase changing values are present. Accordingly, some of the five phase changing values needed for the period (cycle) of five are identical. (As inFIG.6, five phase changing values are needed in order to perform a change of phase having a period (cycle) of five on precoded baseband signal z2′ only. Also, as inFIG.26, two phase changing values are needed for each slot in order to perform the change of phase on both precoded baseband signals z1‘ and z2’. These two phase changing values are termed a phase changing set. Accordingly, five phase changing sets should ideally be prepared in order to perform a change of phase having a period (cycle) of five in such circumstances). The five phase changing values (or phase changing sets) needed for the period (cycle) of five are expressed as P[0], P[1], P[2], P[3], and P[4]. The following describes the relationship between the above-defined slots and the phase, as pertains to schemes for a regular change of phase. For the above-described 1500 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is QPSK, phase changing value P[0] is used on 300 slots, phase changing value P[1] is used on 300 slots, phase changing value P[2] is used on 300 slots, phase changing value P[3] is used on 300 slots, and phase changing value P[4] is used on 300 slots. This is due to the fact that any bias in phase changing value usage causes great influence to be exerted by the more frequently used phase changing value, and that the reception device is dependent on such influence for data reception quality. Similarly, for the above-described 750 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is 16-QAM, phase changing value P[0] is used on 150 slots, phase changing value P[1] is used on 150 slots, phase changing value P[2] is used on 150 slots, phase changing value P[3] is used on 150 slots, and phase changing value P[4] is used on 150 slots. Furthermore, for the above-described 500 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is 64-QAM, phase changing value P[0] is used on 100 slots, phase changing value P[1] is used on 100 slots, phase changing value P[2] is used on 100 slots, phase changing value P[3] is used on 100 slots, and phase changing value P[4] is used on 100 slots. As described above, a phase changing scheme for a regular change of phase changing value as given in Embodiment C5 requires the preparation of N=2n+1 phase changing values P[0], P[1] . . . P[2n−1], P[2n] (where P[0], P[1] . . . P[2n−1], P[2n] are expressed as PHASE[0], PHASE[1], PHASE[2] PHASE[n−1], PHASE[n] (see Embodiment C5)). As such, in order to transmit all of the bits making up a single coded block, phase changing value P[0] is used on K0slots, phase changing value P[1] is used on K1slots, phase changing value P[i] is used on Kislots (where i=0, 1, 2 . . . 2n−1, 2n (i denotes an integer that satisfies 0≤i≤2n)), and phase changing value P[2n] is used on K2nslots, such that Condition #C01 is met. (Condition #C01) K0=K1. . . =Ki=K2n. That is, Ka=Kb(∀a and ∀b where a, b, =0, 1, 2 . . . 2n−1, 2n (a denotes an integer that satisfies 0≤a≤2n, b denotes an integer that satisfies 0≤b≤2n), a≠b). A phase changing scheme for a regular change of phase changing value as given in Embodiment C5 having a period (cycle) of N=2n+1 requires the preparation of phase changing values PHASE[0], PHASE[1], PHASE[2] PHASE[n−1], PHASE[n]. As such, in order to transmit all of the bits making up a single coded block, phase changing value PHASE[0] is used on G0slots, phase changing value PHASE[1] is used on G1slots, phase changing value PHASE[i] is used on G slots (where i=0, 1, 2 . . . n−1, n (i denotes an integer that satisfies 0≤i≤n), and phase changing value PHASE[n] is used on Gnslots, such that Condition #C01 is met. Condition #C01 may be modified as follows. (Condition #C02) 2×G0=G1. . . =Gi=Gn. That is, 2×G0=Ga(∀a where a=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n)). Then, when a communication system that supports multiple modulation schemes selects one such supported scheme for use, Condition #C01 (or Condition #C02) should preferably be met for the supported modulation scheme. However, when multiple modulation schemes are supported, each such modulation scheme typically uses symbols transmitting a different number of bits per symbols (though some may happen to use the same number), Condition #C01 (or Condition #C02) may not be satisfied for some modulation schemes. In such a case, the following condition applies instead of Condition #C01. (Condition #C03) The difference between Kaand Kbsatisfies 0 or 1. That is, |Ka−Kb| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . 2n−1, 2n (a denotes an integer that satisfies 0≤a≤2n, b denotes an integer that satisfies 0≤b≤2n) a≠b). Alternatively, Condition #C03 may be expressed as follows. (Condition #C04) The difference between Gaand Gbsatisfies 0, 1, or 2. That is, |Ga−Gb| satisfies 0, 1, or 2 (∀a, ∀b, where a, b=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n, b denotes an integer that satisfies 1≤b≤n), a≠b) and The difference between 2×G0and Gasatisfies 0, 1, or 2. That is, |2×G0−Ga| satisfies 0, 1, or 2 (∀a, where a=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n)). FIG.35illustrates the varying numbers of symbols and slots needed in two coded blocks when block codes are used.FIG.35illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used when, for example, two streams s1and s2are transmitted as indicated by the transmission device fromFIG.3andFIG.12, and the transmission device has two encoders. (Here, the transmission scheme may be any single-carrier scheme or multi-carrier scheme such as OFDM.) As shown inFIG.35, when block codes are used, there are 6000 bits making up a single coded block. In order to transmit these 6000 bits, the number of required symbols depends on the modulation scheme, being 3000 for QPSK, 1500 for 16-QAM, and 1000 for 64-QAM. The transmission device fromFIG.3and the transmission device fromFIG.12each transmit two streams at once, and have two encoders. As such, the two streams each transmit different code blocks. Accordingly, when the modulation scheme is QPSK, two coded blocks drawn from s1and s2are transmitted within the same interval, e.g., a first coded block drawn from s1is transmitted, then a second coded block drawn from s2is transmitted. As such, 3000 slots are needed in order to transmit the first and second coded blocks. By the same reasoning, when the modulation scheme is 16-QAM, 1500 slots are needed to transmit all of the bits making up one coded block, and when the modulation scheme is 64-QAM, 1000 slots are needed to transmit all of the bits making up one coded block. The following describes the relationship between the above-defined slots and the phase, as pertains to schemes for a regular change of phase. Here, five different phase changing values (or phase changing sets) are assumed as having been prepared for use in the scheme for a regular change of phase, which has a period (cycle) of five. That is, the phase changer of the transmission device fromFIG.4uses five phase changing values (or phase changing sets) to achieve the period (cycle) of five. However, as described in Embodiment C5, three different phase changing values are present. Accordingly, some of the five phase changing values needed for the period (cycle) of five are identical. (As inFIG.6, five phase changing values are needed in order to perform the change of phase having a period (cycle) of five on precoded baseband signal z2′ only. Also, as inFIG.26, two phase changing values are needed for each slot in order to perform the change of phase on both precoded baseband signals z1′ and z2′. These two phase changing values are termed a phase changing set. Accordingly, five phase changing sets should ideally be prepared in order to perform a change of phase having a period (cycle) of five in such circumstances). The five phase changing values (or phase changing sets) needed for the period (cycle) of five are expressed as P[0], P[1], P[2], P[3], and P[4]. For the above-described 3000 slots needed to transmit the 6000X2 bits making up the pair of coded blocks when the modulation scheme is QPSK, phase changing value P[0] is used on 600 slots, phase changing value P[1] is used on 600 slots, phase changing value P[2] is used on 600 slots, phase changing value P[3] is used on 6100 slots, and phase changing value P[4] is used on 600 slots. This is due to the fact that any bias in phase changing value usage causes great influence to be exerted by the more frequently used phase changing value, and that the reception device is dependent on such influence for data reception quality. Further, in order to transmit the first coded block, phase changing value P[0] is used on slots 600 times, phase changing value P[1] is used on slots 600 times, phase changing value P[2] is used on slots 600 times, phase changing value P[3] is used on slots 600 times, and phase changing value PHASE[4] is used on slots 600 times. Furthermore, in order to transmit the second coded block, phase changing value P[0] is used on slots 600 times, phase changing value P[1] is used on slots 600 times, phase changing value P[2] is used on slots 600 times, phase changing value P[3] is used on slots 600 times, and phase changing value P[4] is used on slots 600 times. Similarly, for the above-described 1500 slots needed to transmit the 6000×2 bits making up the pair of coded blocks when the modulation scheme is 16-QAM, phase changing value P[0] is used on 300 slots, phase changing value P[1] is used on 300 slots, phase changing value P[2] is used on 300 slots, phase changing value P[3] is used on 300 slots, and phase changing value P[4] is used on 300 slots. Furthermore, in order to transmit the first coded block, phase changing value P[0] is used on slots 300 times, phase changing value P[1] is used on slots 300 times, phase changing value P[2] is used on slots 300 times, phase changing value P[3] is used on slots 300 times, and phase changing value P[4] is used on slots 300 times. Furthermore, in order to transmit the second coded block, phase changing value P[0] is used on slots 300 times, phase changing value P[1] is used on slots 300 times, phase changing value P[2] is used on slots 300 times, phase changing value P[3] is used on slots 300 times, and phase changing value P[4] is used on slots 300 times. Furthermore, for the above-described 1000 slots needed to transmit the 6000×2 bits making up the two coded blocks when the modulation scheme is 64-QAM, phase changing value P[0] is used on 200 slots, phase changing value P[1] is used on 200 slots, phase changing value P[2] is used on 200 slots, phase changing value P[3] is used on 200 slots, and phase changing value P[4] is used on 200 slots. Further, in order to transmit the first coded block, phase changing value P[0] is used on slots 200 times, phase changing value P[1] is used on slots 200 times, phase changing value P[2] is used on slots 200 times, phase changing value P[3] is used on slots 200 times, and phase changing value P[4] is used on slots 200 times. Furthermore, in order to transmit the second coded block, phase changing value P[0] is used on slots 200 times, phase changing value P[1] is used on slots 200 times, phase changing value P[2] is used on slots 200 times, phase changing value P[3] is used on slots 200 times, and phase changing value P[4] is used on slots 200 times. As described above, a phase changing scheme for regularly varying the phase changing value as given in Embodiment C5 requires the preparation of N=2n+1 phase changing values P[0], P[1] . . . P[2n−1], P[2n] (where P[0], P[1] . . . P[2n−1], P[2n] are expressed as PHASE[0], PHASE[1], PHASE[2] PHASE[n−1], PHASE[n] (see Embodiment C5)). As such, in order to transmit all of the bits making up the two coded blocks, phase changing value P[0] is used on K0slots, phase changing value P[1] is used on K1slots, phase changing value P[i] is used on Kislots (where i=0, 1, 2 . . . 2n−1, 2n (i denotes an integer that satisfies 0≤i≤2n)), and phase changing value P[2n] is used on K2. slots, such that Condition #C01 is met. (Condition #C05) K0=K1. . . Ki=K2n. That is, Ka=Kb(∀a and ∀b where a, b, =0, 1, 2 . . . 2n−1, 2n (a denotes an integer that satisfies 0≤a≤2n, b denotes an integer that satisfies 0≤b≤2n), a≠b). In order to transmit all of the bits making up the first coded block, phase changing value P[0] is used K0,1times, phase changing value P[1] is used K1,1times, phase changing value P[i] is used Ki,1(where i=0, 1, 2 . . . 2n−1, 2n (i denotes an integer that satisfies 0≤i≤2n)), and phase changing value P[2n] is used K2n,1times. (Condition #C06) K0,1=K1,1. . . =Ki,1=K2n,1. That is, Ka,1=Kb,1(∀a and ∀b where a, b, =0, 1, 2 . . . 2n−1, 2n (a denotes an integer that satisfies 0≤a≤2n, b denotes an integer that satisfies 0≤b≤2n), a≠b). In order to transmit all of the bits making up the second coded block, phase changing value P[0] is used K0,2times, phase changing value P[1] is used K1,2times, phase changing value P[i] is used Ki,2(where i=0, 1, 2 . . . 2n−1, 2n (i denotes an integer that satisfies 0≤i≤2n)), and phase changing value P[2n] is used K2n,2times. (Condition #C07) K0,2=K1,2. . . =Ki,2=K2n,2. That is, Ka,2=Kb,2(∀a and ∀b where a, b, =0, 1, 2 . . . 2n−1, 2n (a denotes an integer that satisfies 0≤a≤2n, b denotes an integer that satisfies 0≤b≤2n), a≠b). A phase changing scheme for regularly varying the phase changing value as given in Embodiment C5 having a period (cycle) of N=2n+1 requires the preparation of phase changing values PHASE[0], PHASE[1], PHASE[2] PHASE[n−1], PHASE[n]. As such, in order to transmit all of the bits making up the two coded blocks, phase changing value PHASE[0] is used on G0slots, phase changing value PHASE[1] is used on G1slots, phase changing value PHASE[i] is used on G slots (where i=0, 1, 2 . . . n−1, n (i denotes an integer that satisfies 0≤i≤n)), and phase changing value PHASE[n] is used on Gnslots, such that Condition #C05 is met. (Condition #C08) 2×G0=G1. . . ==That is, 2×G0=Ga(∀a where a=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n, b denotes an integer that satisfies 1≤b≤n)). In order to transmit all of the bits making up the first coded block, phase changing value PHASE[0] is used G0,1times, phase changing value PHASE[1] is used G1,1times, phase changing value PHASE[i] is used Gi,1(where i=0, 1, 2 . . . n−1, n (i denotes an integer that satisfies 0≤i≤n)), and phase changing value PHASE[n] is used Gn,1times. (Condition #C09) 2×G0,1=G1,1. . . =Gi,1= . . . Gn,1. That is, 2×G0,1=Ga,1(∀a where a=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n)). In order to transmit all of the bits making up the second coded block, phase changing value PHASE[0] is used G0,2times, phase changing value PHASE[1] is used G1,2times, phase changing value PHASE[i] is used Gi,2(where i=0, 1, 2 . . . n−1, n (i denotes an integer that satisfies 0≤i≤n)), and phase changing value PHASE[n] is used Gn,1times. (Condition #C10) 2×G0,2=G1,2. . . =Gi,2=Gn,2. That is, 2×G0,2=Ga,2(∀a where a=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n)). Then, when a communication system that supports multiple modulation schemes selects one such supported scheme for use, Condition #C05, Condition #C06, and Condition #C07 (or Condition #C08, Condition #C09, and Condition #C10) should preferably be met for the supported modulation scheme. However, when multiple modulation schemes are supported, each such modulation scheme typically uses symbols transmitting a different number of bits per symbols (though some may happen to use the same number), Condition #C05, Condition #C06, and Condition #C07 (or Condition #C08, Condition #C09, and Condition #C10) may not be satisfied for some modulation schemes. In such a case, the following conditions apply instead of Condition #C05, Condition #C06, and Condition #C07. (Condition #C11) The difference between K a and Kb satisfies 0 or 1. That is, |Ka−Kb| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . 2n−1, 2n (a denotes an integer that satisfies 0≤a≤2n, b denotes an integer that satisfies 0≤b≤2n), a≠b). (Condition #C12) The difference between Ka,1and Kb,1satisfies 0 or 1. That is, |Ka,1−Kb,1| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . 2n−1, 2n (a denotes an integer that satisfies b denotes an integer that satisfies 0≤b≤2n), a≠b). (Condition #C13) The difference between Ka,2and Kb,2satisfies 0 or 1. That is, |Ka,2−Kb,2| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . 2n−1, 2n (a denotes an integer that satisfies b denotes an integer that satisfies 0≤b≤2n), a≠b). Alternatively, Condition #C11, Condition #C12, and Condition #C13 may be expressed as follows. (Condition #C14) The difference between Gaand Gbsatisfies 0, 1, or 2. That is, |Ga−Gb|satisfies 0, 1, or 2 (∀a, ∀b, where a, b=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n, b denotes an integer that satisfies 1≤b≤n), a≠b) and The difference between 2×G0and Gasatisfies 0, 1, or 2. That is, |2×G0−Ga| satisfies 0, 1, or 2 (∀a, where a=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n)). (Condition #C15) The difference between Ga,1and Gb,1satisfies 0, 1, or 2. That is, |Ga,1−Gb,1| satisfies 0, 1, or 2 (∀a, ∀b, where a, b=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n, b denotes an integer that satisfies 1≤b≤n), a≠b) and The difference between 2×G0,1and Ga,1satisfies 0, 1, or 2. That is, |2×G0,1−Ga,1| satisfies 0, 1, or 2 (∀a, where a=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n)). (Condition #C16) The difference between Ga,2and Gb,2satisfies 0, 1, or 2. That is, |Ga,2−Gb,2| satisfies 0, 1, or 2 (∀a, ∀b, where a, b=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n, b denotes an integer that satisfies 1≤b≤n), a≠b) and The difference between 2×G0,2and Ga,2satisfies 0, 1, or 2. That is, |2×G0,2−Ga,2| satisfies 0, 1, or 2 (∀a, where a=1, 2 . . . n−1, n (a denotes an integer that satisfies 1≤a≤n)). As described above, bias among the phase changing values being used to transmit the coded blocks is removed by creating a relationship between the coded block and the phase changing values. As such, data reception quality can be improved for the reception device. In the present Embodiment, N phase changing values (or phase changing sets) are needed in order to perform the change of phase having a period (cycle) of N with a regular phase changing scheme. As such, N phase changing values (or phase changing sets) P[0], P[1], P[2] . . . P[N−2], and P[N−1] are prepared. However, schemes exist for ordering the phases in the stated order with respect to the frequency domain. No limitation is intended in this regard. The N phase changing values (or phase changing sets) P[0], P[1], P[2] . . . P[N−2], and P[N−1] may also change the phases of blocks in the time domain or in the time-frequency domain to obtain a symbol arrangement as described in Embodiment 1. Although the above examples discuss a phase changing scheme with a period (cycle) of N, the same effects are obtainable using N phase changing values (or phase changing sets) at random. That is, the N phase changing values (or phase changing sets) need not always have regular periodicity. As long as the above-described conditions are satisfied, quality data reception improvements are realizable for the reception device. Furthermore, given the existence of modes for spatial multiplexing MIMO schemes, MIMO schemes using a fixed precoding matrix, space-time block coding schemes, single-stream transmission, and schemes using a regular change of phase, the transmission device (broadcaster, base station) may select any one of these transmission schemes. As described in Non-Patent Literature 3, spatial multiplexing MIMO schemes involve transmitting signals s1and s2, which are mapped using a selected modulation scheme, on each of two different antennas. MIMO schemes using a fixed precoding matrix involve performing precoding only (with no change of phase). Further, space-time block coding schemes are described in Non-Patent Literature 9, 16, and 17. Single-stream transmission schemes involve transmitting signal s1, mapped with a selected modulation scheme, from an antenna after performing predetermined processing. Schemes using multi-carrier transmission such as OFDM involve a first carrier group made up of a plurality of carriers and a second carrier group made up of a plurality of carriers different from the first carrier group, and so on, such that multi-carrier transmission is realized with a plurality of carrier groups. For each carrier group, any of spatial multiplexing MIMO schemes, MIMO schemes using a fixed precoding matrix, space-time block coding schemes, single-stream transmission, and schemes using a regular change of phase may be used. In particular, schemes using a regular change of phase on a selected (sub-)carrier group are preferably used to realize the present Embodiment. When a change of phase by, for example, a phase changing value for P[i] of X radians is performed on only one precoded baseband signal, the phase changers fromFIGS.3,4,6,12,25,29,51, and53multiply precoded baseband signal z2′ by ejX. Then, when a change of phase by, for example, a phase changing set for P[i] of X radians and Y radians is performed on both precoded baseband signals, the phase changers fromFIGS.26,27,28,52, and54multiply precoded baseband signal z2′ by ejXand multiply precoded baseband signal z1′ by ejY. Embodiment C7 The present Embodiment describes a scheme for regularly changing the phase, specifically as done in Embodiment A1 and Embodiment C6, when encoding is performed using block codes as described in Non-Patent Literature 12 through 15, such as QC LDPC Codes (not only QC-LDPC but also LDPC (block) codes may be used), concatenated LDPC and BCH codes, Turbo codes or Duo-Binary Turbo Codes, and so on. The following example considers a case where two streams s1and s2are transmitted. When encoding has been performed using block codes and control information and the like is not necessary, the number of bits making up each coded block matches the number of bits making up each block code (control information and so on described below may yet be included). When encoding has been performed using block codes or the like and control information or the like (e.g., CRC transmission parameters) is required, then the number of bits making up each coded block is the sum of the number of bits making up the block codes and the number of bits making up the information. FIG.34illustrates the varying numbers of symbols and slots needed in one coded block when block codes are used.FIG.34illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used when, for example, two streams s1and s2are transmitted as indicated by the transmission device fromFIG.4, and the transmission device has only one encoder. (Here, the transmission scheme may be any single-carrier scheme or multi-carrier scheme such as OFDM.) As shown inFIG.34, when block codes are used, there are 6000 bits making up a single coded block. In order to transmit these 6000 bits, the number of required symbols depends on the modulation scheme, being 3000 symbols for QPSK, 1500 symbols for 16-QAM, and 1000 symbols for 64-QAM. Then, given that the transmission device fromFIG.4transmits two streams simultaneously,1500of the aforementioned 3000 symbols needed when the modulation scheme is QPSK are assigned to s1and the other 1500 symbols are assigned to s2. As such, 1500 slots for transmitting the 1500 symbols (hereinafter, slots) are required for each of s1and s2. By the same reasoning, when the modulation scheme is 16-QAM, 750 slots are needed to transmit all of the bits making up one coded block, and when the modulation scheme is 64-QAM, 500 slots are needed to transmit all of the bits making up one coded block. The following describes the relationship between the above-defined slots and the phase, as pertains to schemes for a regular change of phase. Here, five different phase changing values (or phase changing sets) are assumed as having been prepared for use in the scheme for a regular change of phase, which has a period (cycle) of five. The phase changing values (or phase changing sets) prepared in order to regularly change the phase with a period (cycle) of five are P[0], P[1], P[2], P[3], and P[4]. However, P[0], P[1], P[2], P[3], and P[4] should include at least two different phase changing values (i.e., P[0], P[1], P[2], P[3], and P[4] may include identical phase changing values). (As inFIG.6, five phase changing values are needed in order to perform a change of phase having a period (cycle) of five on precoded baseband signal z2′ only. Also, as inFIG.26, two phase changing values are needed for each slot in order to perform the change of phase on both precoded baseband signals z1‘ and z2’. These two phase changing values are termed a phase changing set. Accordingly, five phase changing sets should ideally be prepared in order to perform a change of phase having a period (cycle) of five in such circumstances). For the above-described 1500 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is QPSK, phase changing value P[0] is used on 300 slots, phase changing value P[1] is used on 300 slots, phase changing value P[2] is used on 300 slots, phase changing value P[3] is used on 300 slots, and phase changing value P[4] is used on 300 slots. This is due to the fact that any bias in phase changing value usage causes great influence to be exerted by the more frequently used phase changing value, and that the reception device is dependent on such influence for data reception quality. Furthermore, for the above-described 750 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is 16-QAM, phase changing value P[0] is used on 150 slots, phase changing value P[1] is used on 150 slots, phase changing value P[2] is used on 150 slots, phase changing value P[3] is used on 150 slots, and phase changing value P[4] is used on 150 slots. Further, for the above-described 500 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is 64-QAM, phase changing value P[0] is used on 100 slots, phase changing value P[1] is used on 100 slots, phase changing value P[2] is used on 100 slots, phase changing value P[3] is used on 100 slots, and phase changing value P[4] is used on 100 slots. As described above, the phase changing values used in the phase changing scheme regularly switching between phase changing values with a period (cycle) of N are expressed as P[0], P[1] P[N−2], P[N−1]. However, P[0], P[1] . . . P[N−2], P[N−1] should include at least two different phase changing values (i.e., P[0], P[1] . . . P[N−2], P[N−1] may include identical phase changing values). In order to transmit all of the bits making up a single coded block, phase changing value P[0] is used on K0slots, phase changing value P[1] is used on K1slots, phase changing value P[i] is used on Kislots (where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1)), and phase changing value P[N−1] is used on KN−1slots, such that Condition #C17 is met. (Condition #C17) K0=K1. . . =Ki=KN−1. That is, Ka=Kb(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). Then, when a communication system that supports multiple modulation schemes selects one such supported scheme for use, Condition #C17 should preferably be met for the supported modulation scheme. However, when multiple modulation schemes are supported, each such modulation scheme typically uses symbols transmitting a different number of bits per symbols (though some may happen to use the same number), Condition #C17 may not be satisfied for some modulation schemes. In such a case, the following condition applies instead of Condition #C17. (Condition #C18) The difference between K a and Kb satisfies 0 or 1. That is, |Ka−Kb| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). FIG.35illustrates the varying numbers of symbols and slots needed in two coded block when block codes are used.FIG.35illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used when, for example, two streams s1and s2are transmitted as indicated by the transmission device fromFIG.3andFIG.12, and the transmission device has two encoders. (Here, the transmission scheme may be any single-carrier scheme or multi-carrier scheme such as OFDM.) As shown inFIG.35, when block codes are used, there are 6000 bits making up a single coded block. In order to transmit these 6000 bits, the number of required symbols depends on the modulation scheme, being 3000 symbols for QPSK, 1500 symbols for 16-QAM, and 1000 symbols for 64-QAM. The transmission device fromFIG.3and the transmission device fromFIG.12each transmit two streams at once, and have two encoders. As such, the two streams each transmit different code blocks. Accordingly, when the modulation scheme is QPSK, two coded blocks drawn from s1and s2are transmitted within the same interval, e.g., a first coded block drawn from s1is transmitted, then a second coded block drawn from s2is transmitted. As such, 3000 slots are needed in order to transmit the first and second coded blocks. By the same reasoning, when the modulation scheme is 16-QAM, 1500 slots are needed to transmit all of the bits making up one coded block, and when the modulation scheme is 64-QAM, 1000 slots are needed to transmit all of the bits making up one coded block. The following describes the relationship between the above-defined slots and the phase, as pertains to schemes for a regular change of phase. Here, five different phase changing values (or phase changing sets) are assumed as having been prepared for use in the scheme for a regular change of phase, which has a period (cycle) of five. That is, the phase changer of the transmission device fromFIG.4uses five phase changing values (or phase changing sets) P[0], P[1], P[2], P[3], and P[4] to achieve the period (cycle) of five. However, P[0], P[1], P[2], P[3], and P[4] should include at least two different phase changing values (i.e., P[0], P[1], P[2], P[3], and P[4] may include identical phase changing values). (As inFIG.6, five phase changing values are needed in order to perform a change of phase having a period (cycle) of five on precoded baseband signal z2′ only. Also, as inFIG.26, two phase changing values are needed for each slot in order to perform the change of phase on both precoded baseband signals z1′ and z2′. These two phase changing values are termed a phase changing set. Accordingly, five phase changing sets should ideally be prepared in order to perform a change of phase having a period (cycle) of five in such circumstances). The five phase changing values (or phase changing sets) needed for the period (cycle) of five are expressed as P[0], P[1], P[2], P[3], and P[4]. For the above-described 3000 slots needed to transmit the 6000×2 bits making up the pair of coded blocks when the modulation scheme is QPSK, phase changing value P[0] is used on 600 slots, phase changing value P[1] is used on 600 slots, phase changing value P[2] is used on 600 slots, phase changing value P[3] is used on 600 slots, and phase changing value P[4] is used on 600 slots. This is due to the fact that any bias in phase changing value usage causes great influence to be exerted by the more frequently used phase changing value, and that the reception device is dependent on such influence for data reception quality. Further, in order to transmit the first coded block, phase changing value P[0] is used on slots 600 times, phase changing value P[1] is used on slots 600 times, phase changing value P[2] is used on slots 600 times, phase changing value P[3] is used on slots 600 times, and phase changing value P[4] is used on slots 600 times. Furthermore, in order to transmit the second coded block, phase changing value P[0] is used on slots 600 times, phase changing value P[1] is used on slots 600 times, phase changing value P[2] is used on slots 600 times, phase changing value P[3] is used on slots 600 times, and phase changing value P[4] is used on slots 600 times. Similarly, for the above-described 1500 slots needed to transmit the 6000×2 bits making up the pair of coded blocks when the modulation scheme is 16-QAM, phase changing value P[0] is used on 300 slots, phase changing value P[1] is used on 300 slots, phase changing value P[2] is used on 300 slots, phase changing value P[3] is used on 300 slots, and phase changing value P[4] is used on 300 slots. Further, in order to transmit the first coded block, phase changing value P[0] is used on slots 300 times, phase changing value P[1] is used on slots 300 times, phase changing value P[2] is used on slots 300 times, phase changing value P[3] is used on slots 300 times, and phase changing value P[4] is used on slots 300 times. Furthermore, in order to transmit the second coded block, phase changing value P[0] is used on slots 300 times, phase changing value P[1] is used on slots 300 times, phase changing value P[2] is used on slots 300 times, phase changing value P[3] is used on slots 300 times, and phase changing value P[4] is used on slots 300 times. Similarly, for the above-described 1000 slots needed to transmit the 6000×2 bits making up the pair of coded blocks when the modulation scheme is 64-QAM, phase changing value P[0] is used on 200 slots, phase changing value P[1] is used on 200 slots, phase changing value P[2] is used on 200 slots, phase changing value P[3] is used on 200 slots, and phase changing value P[4] is used on 200 slots. Further, in order to transmit the first coded block, phase changing value P[0] is used on slots 200 times, phase changing value P[1] is used on slots 200 times, phase changing value P[2] is used on slots 200 times, phase changing value P[3] is used on slots 200 times, and phase changing value P[4] is used on slots 200 times. Furthermore, in order to transmit the second coded block, phase changing value P[0] is used on slots 200 times, phase changing value P[1] is used on slots 200 times, phase changing value P[2] is used on slots 200 times, phase changing value P[3] is used on slots 200 times, and phase changing value P[4] is used on slots 200 times. As described above, the phase changing values used in the phase changing scheme regularly switching between phase changing values with a period (cycle) of N are expressed as P[0], P[1] . . . P[N−2], P[N−1]. However, P[0], P[1] . . . P[N−2], P[N−1] should include at least two different phase changing values (i.e., P[0], P[1] . . . P[N−2], P[N−1] may include identical phase changing values). In order to transmit all of the bits making up two coded blocks, phase changing value P[0] is used on K0slots, phase changing value P[1] is used on K1slots, phase changing value P[i] is used on Kislots (where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1)), and phase changing value P[N−1] is used on KN−1slots, such that Condition #C19 is met. (Condition #C19) K0=K1. . . =Ki=KN−1. That is, Ka=Kb(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). In order to transmit all of the bits making up the first coded block, phase changing value P[0] is used K0,1times, phase changing value P[1] is used K1,1 times, phase changing value P[i] is used Ki,1(where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1)), and phase changing value P[N−1] is used KN−1,1times. (Condition #C20) K0,1=K1,1= . . . Ki,1= . . . KN−1,1. That is, Ka,1=Kb,1(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). In order to transmit all of the bits making up the second coded block, phase changing value P[0] is used K0,2times, phase changing value P[1] is used K1,2 times, phase changing value P[i] is used Ki,2(where i=0, 1, 2 . . . N−1(i denotes an integer that satisfies 0≤i≤N−1)), and phase changing value P[N−1] is used KN−1,2times. (Condition #C21) K0,2=K1,2= . . . Ki,2= . . . KN−1,2. That is, Ka,2=Kb,2(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). Then, when a communication system that supports multiple modulation schemes selects one such supported scheme for use, Condition #C19, Condition #C20, and Condition #C21 are preferably met for the supported modulation scheme. However, when multiple modulation schemes are supported, each such modulation scheme typically uses symbols transmitting a different number of bits per symbols (though some may happen to use the same number), Condition #C19, Condition #C20, and Condition #C21 may not be satisfied for some modulation schemes. In such a case, the following conditions apply instead of Condition #C19, Condition #C20, and Condition #C21. (Condition #C22) The difference between K a and Kb satisfies 0 or 1. That is, |Ka−Kb| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). (Condition #C23) The difference between Ka,1and Kb,1satisfies 0 or 1. That is, |Ka,1−Kb,1| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). (Condition #C24) The difference between Ka,2and Kb,2satisfies 0 or 1. That is, |Ka,2−Kb,2| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). As described above, bias among the phase changing values being used to transmit the coded blocks is removed by creating a relationship between the coded block and the phase changing values. As such, data reception quality can be improved for the reception device. In the present Embodiment, N phase changing values (or phase changing sets) are needed in order to perform a change of phase having a period (cycle) of N with the scheme for a regular change of phase. As such, N phase changing values (or phase changing sets) P[0], P[1], P[2] . . . P[N−2], and P[N−1] are prepared. However, schemes exist for ordering the phases in the stated order with respect to the frequency domain. No limitation is intended in this regard. The N phase changing values (or phase changing sets) P[0], P[1], P[2] . . . P[N−2], and P[N−1] may also change the phases of blocks in the time domain or in the time-frequency domain to obtain a symbol arrangement as described in Embodiment 1. Although the above examples discuss a phase changing scheme with a period (cycle) of N, the same effects are obtainable using N phase changing values (or phase changing sets) at random. That is, the N phase changing values (or phase changing sets) need not always have regular periodicity. As long as the above-described conditions are satisfied, great quality data reception improvements are realizable for the reception device. Furthermore, given the existence of modes for spatial multiplexing MIMO schemes, MIMO schemes using a fixed precoding matrix, space-time block coding schemes, single-stream transmission, and schemes using a regular change of phase, the transmission device (broadcaster, base station) may select any one of these transmission schemes. As described in Non-Patent Literature 3, spatial multiplexing MIMO schemes involve transmitting signals s1and s2, which are mapped using a selected modulation scheme, on each of two different antennas. MIMO schemes using a fixed precoding matrix involve performing precoding only (with no change of phase). Further, space-time block coding schemes are described in Non-Patent Literature 9, 16, and 17. Single-stream transmission schemes involve transmitting signal s1, mapped with a selected modulation scheme, from an antenna after performing predetermined processing. Schemes using multi-carrier transmission such as OFDM involve a first carrier group made up of a plurality of carriers and a second carrier group made up of a plurality of carriers different from the first carrier group, and so on, such that multi-carrier transmission is realized with a plurality of carrier groups. For each carrier group, any of spatial multiplexing MIMO schemes, MIMO schemes using a fixed precoding matrix, space-time block coding schemes, single-stream transmission, and schemes using a regular change of phase may be used. In particular, schemes using a regular change of phase on a selected (sub-)carrier group are preferably used to realize the present Embodiment. When a change of phase by, for example, a phase changing value for P[i] of X radians is performed on only one precoded baseband signal, the phase changers ofFIGS.3,4,6,12,25,29,51, and53multiply precoded baseband signal z2′ by ejX. Then, when a change of phase by, for example, a phase changing set for P[i] of X radians and Y radians is performed on both precoded baseband signals, the phase changers fromFIGS.26,27,28,52, and54multiply precoded baseband signal z2′ by ejXand multiply precoded baseband signal z1′ by ejY. Embodiment D1 The present Embodiment is first described as a variation of Embodiment 1.FIG.67illustrates a sample transmission device pertaining to the present Embodiment. Components thereof operating identically to those ofFIG.3use the same reference numbers thereas, and the description thereof is omitted for simplicity, below.FIG.67differs fromFIG.3in the insertion of a baseband signal switcher6702directly following the weighting units. Accordingly, the following explanations are primarily centered on the baseband signal switcher6702. FIG.21illustrates the configuration of the weighting units308A and308B. The area ofFIG.21enclosed in the dashed line represents one of the weighting units. Baseband signal307A is multiplied by w11 to obtain w11·s1(t), and multiplied by w21 to obtain w21·s1(t). Similarly, baseband signal307B is multiplied by w12 to obtain w12·s2(t), and multiplied by w22 to obtain w22·s2(t). Next, z1(t)=w11·s1(t)+w12·s2(t) and z2(t)=w21·s1(t)+w22·s22(t) are obtained. Here, as explained in Embodiment 1, s1(t) and s2(t) are baseband signals modulated according to a modulation scheme such as BPSK, QPSK, 8-PSK, 16-QAM, 32-QAM, 64-QAM, 256-QAM, 16-APSK and so on. Both weighting units perform weighting using a fixed precoding matrix. The precoding matrix uses, for example, the scheme of formula 62, and satisfies the conditions of formula 63 or formula 64, all found below. However, this is only an example. The value of α is not limited to formula 63 and formula 64, and may, for example, be 1, or may be 0 (a is preferably a real number greater than or equal to 0, but may be also be an imaginary number). Here, the precoding matrix is [Math. 62] (w11w12w21w22)=1α2+1(ej0α×ej0α×ej0ejπ)(formula62) In formula 62, above, a is given by: [Math. 63] α=2+42+2(formula63) Alternatively, in formula 62, above, a may be given by: [Math. 64] α=2+3+52+3-5(formula64) Alternatively, the precoding matrix is not restricted to that of formula 62, but may also be: [Math. 65] (w11w12w21w22)=(abcd)(formula65) where a=Aejδ11, b=Bejδ12, c=Cejδ21, and d=Dejδ22. Further, one of a, b, c, and d may be equal to zero. For example: (1) a may be zero while b, c, and d are non-zero, (2) b may be zero while a, c, and d are non-zero, (3) c may be zero while a, b, and d are non-zero, or (4) d may be zero while a, b, and c are non-zero. Alternatively, any two of a, b, c, and d may be equal to zero. For example, (1) a and d may be zero while b and c are non-zero, or (2) b and c may be zero while a and d are non-zero. When any of the modulation scheme, error-correcting codes, and the coding rate thereof are changed, the precoding matrix in use may also be set and changed, or the same precoding matrix may be used as-is. Next, the baseband signal switcher6702fromFIG.67is described. The baseband signal switcher6702takes weighted signal309A and weighted signal316B as input, performs baseband signal switching, and outputs switched baseband signal6701A and switched baseband signal6701B. The details of baseband signal switching are as described with reference toFIG.55. The baseband signal switching performed in the present Embodiment differs from that ofFIG.55in terms of the signal used for switching. The following describes the baseband signal switching of the present Embodiment with reference toFIG.68. InFIG.68, weighted signal309A(p1(i)) has an in-phase component I of Ip1(i) and a quadrature component Q of Qp1(i), while weighted signal316B(p2(i)) has an in-phase component I of Ip2(i) and a quadrature component Q of Qp2(i). In contrast, switched baseband signal6701A (q1(i)) has an in-phase component I of Iq1(i) and a quadrature component Q of Qq1(i), while switched baseband signal6701B (q2(i) has an in-phase component I of Iq2(i) and a quadrature component Q of Qq2(i). (Here, i represents (time or (carrier) frequency order). In the example ofFIG.67, i represents time, though i may also represent (carrier) frequency whenFIG.67is applied to an OFDM scheme, as inFIG.12. These points are elaborated upon below.) Here, the baseband components are switched by the baseband signal switcher6702, such that:For switched baseband signal q1(i), the in-phase component I may be Ip1(i) while the quadrature component Q may be Qp2(i), and for switched baseband signal q2(i), the in-phase component I may be Ip2(i) while the quadrature component q may be Qp1(i). The modulated signal corresponding to switched baseband signal q1(i) is transmitted by transmit antenna1and the modulated signal corresponding to switched baseband signal q2(i) is transmitted from transmit antenna2, simultaneously on a common frequency. As such, the modulated signal corresponding to switched baseband signal q1(i) and the modulated signal corresponding to switched baseband signal q2(i) are transmitted from different antennas, simultaneously on a common frequency. Alternatively,For switched baseband signal q1(i), the in-phase component may be Ip1(i) while the quadrature component may be Ip2(i), and for switched baseband signal q2(i), the in-phase component may be Qp1(i) while the quadrature component may be Qp2(i).For switched baseband signal q1(i), the in-phase component may be Ip2(i) while the quadrature component may be Ip1(i), and for switched baseband signal q2(i), the in-phase component may be Qp1(i) while the quadrature component may be Qp2(i).For switched baseband signal q1(i), the in-phase component may be Ip1(i) while the quadrature component may be Ip2(i), and for switched baseband signal q2(i), the in-phase component may be Qp2(i) while the quadrature component may be Qp1(i).For switched baseband signal q1(i), the in-phase component may be Ip2(i) while the quadrature component may be Ip1(i), and for switched baseband signal q2(i), the in-phase component may be Qp2(i) while the quadrature component may be Qp1(i).For switched baseband signal q1(i), the in-phase component may be Ip1(i) while the quadrature component may be Qp2(i), and for switched baseband signal q2(i), the in-phase component may be Qp1(i) while the quadrature component may be Ip2(i).For switched baseband signal q1(i), the in-phase component may be Qp2(i) while the quadrature component may be Ip1(i), and for switched baseband signal q2(i), the in-phase component may be Ip2(i) while the quadrature component may be Qp1(i).For switched baseband signal q1(i), the in-phase component may be Qp2(i) while the quadrature component may be Ip1(i), and for switched baseband signal q2(i), the in-phase component may be Qp1(i) while the quadrature component may be Ip2(i).For switched baseband signal q2(i), the in-phase component may be Ip1(i) while the quadrature component may be Ip2(i), and for switched baseband signal q1(i), the in-phase component may be Qp1(i) while the quadrature component may be Qp2(i).For switched baseband signal q2(i), the in-phase component may be Ip2(i) while the quadrature component may be Ip1(i), and for switched baseband signal q1(i), the in-phase component may be Qp1(i) while the quadrature component may be Qp2(i).For switched baseband signal q2(i), the in-phase component may be Ip1(i) while the quadrature component may be Ip2(i), and for switched baseband signal q1(i), the in-phase component may be Qp2(i) while the quadrature component may be Qp1(i).For switched baseband signal q2(i), the in-phase component may be Ip2(i) while the quadrature component may be Ip1(i), and for switched baseband signal q1(i), the in-phase component may be Qp2(i) while the quadrature component may be Qp1(i).For switched baseband signal q2(i), the in-phase component may be Ip1(i) while the quadrature component may be Qp2(i), and for switched baseband signal q1(i), the in-phase component may be Ip2(i) while the quadrature component may be Qp1(i)For switched baseband signal q2(i), the in-phase component may be Ip1(i) while the quadrature component may be Qp2(i), and for switched baseband signal q1(i), the in-phase component may be Qp1(i) while the quadrature component may be Ip2(i).For switched baseband signal q2(i), the in-phase component may be Qp2(i) while the quadrature component may be Ip1(i), and for switched baseband signal q1(i), the in-phase component may be Ip2(i) while the quadrature component may be Qp1(i).For switched baseband signal q2(i), the in-phase component may be Qp2(i) while the quadrature component may be Ip1(i), and for switched baseband signal q1(i), the in-phase component may be Qp1(i) while the quadrature component may be Ip2(i). Alternatively, the weighted signals309A and316B are not limited to the above-described switching of in-phase component and quadrature component. Switching may be performed on in-phase components and quadrature components greater than those of the two signals. Also, while the above examples describe switching performed on baseband signals having a common time (common (sub-)carrier) frequency), the baseband signals being switched need not necessarily have a common time (common (sub-)carrier) frequency). For example, any of the following are possible.For switched baseband signal q1(i), the in-phase component may be Ip1(i+v) while the quadrature component may be Qp2(i+w), and for switched baseband signal q2(i), the in-phase component may be Ip2(i+w) while the quadrature component may be Qp1(i+v).For switched baseband signal q1(i), the in-phase component may be Ip1(i+v) while the quadrature component may be Ip2(i+w), and for switched baseband signal q2(i), the in-phase component may be Qp1(i+v) while the quadrature component may be Qp2(i+w).For switched baseband signal q1(i), the in-phase component may be Ip2(i+w) while the quadrature component may be Ip1(i+v), and for switched baseband signal q2(i), the in-phase component may be Qp1(i+v) while the quadrature component may be Qp2(i+w).For switched baseband signal q1(i), the in-phase component may be Ip1(i+v) while the quadrature component may be Ip2(i+w), and for switched baseband signal q2(i), the in-phase component may be Qp2(i+w) while the quadrature component may be Qp1(i+v).For switched baseband signal q1(i), the in-phase component may be Ip2(i+w) while the quadrature component may be Ip1(i+v), and for switched baseband signal q2(i), the in-phase component may be Qp2(i+w) while the quadrature component may be Qp1(i+v).For switched baseband signal q1(i), the in-phase component may be Ip1(i+v) while the quadrature component may be Qp2(i+w), and for switched baseband signal q2(i), the in-phase component may be Qp1(i+v) while the quadrature component may be Ip2(i+w).For switched baseband signal q1(i), the in-phase component may be Qp2(i+w) while the quadrature component may be Ip1(i+v), and for switched baseband signal q2(i), the in-phase component may be Ip2(i+w) while the quadrature component may be Qp1(i+v).For switched baseband signal q1(i), the in-phase component may be Qp2(i+w) while the quadrature component may be Ip1(i+v), and for switched baseband signal q2(i), the in-phase component may be Qp1(i+v) while the quadrature component may be Ip2(i+w).For switched baseband signal q2(i), the in-phase component may be Ip1(i+v) while the quadrature component may be Ip2(i+w), and for switched baseband signal q1(i), the in-phase component may be Qp1(i+v) while the quadrature component may be Qp2(i+w).For switched baseband signal q2(i), the in-phase component may be Ip2(i+w) while the quadrature component may be Ip1(i+v), and for switched baseband signal q1(i), the in-phase component may be Qp1(i+v) while the quadrature component may be Qp2(i+w).For switched baseband signal q2(i), the in-phase component may be Ip1(i+v) while the quadrature component may be Ip2(i+w), and for switched baseband signal q1(i), the in-phase component may be Qp2(i+w) while the quadrature component may be Qp1(i+v).For switched baseband signal q2(i), the in-phase component may be Ip2(i+w) while the quadrature component may be Ip1(i+v), and for switched baseband signal q1(i), the in-phase component may be Qp2(i+w) while the quadrature component may be Qp1(i+v).For switched baseband signal q2(i), the in-phase component may be Ip1(i+v) while the quadrature component may be Qp2(i+w), and for switched baseband signal q1(i), the in-phase component may be Ip2(i+w) while the quadrature component may be Qp1(i+v).For switched baseband signal q2(i), the in-phase component may be Ip1(i+v) while the quadrature component may be Qp2(i+w), and for switched baseband signal q1(i), the in-phase component may be Qp1(i+v) while the quadrature component may be Ip2(i+w).For switched baseband signal q2(i), the in-phase component may be Qp2(i+w) while the quadrature component may be Ip1(i+v), and for switched baseband signal q1(i), the in-phase component may be Ip2(i+w) while the quadrature component may be Qp1(i+v).For switched baseband signal q2(i), the in-phase component may be Qp2(i+w) while the quadrature component may be Ip1(i+v), and for switched baseband signal q1(i), the in-phase component may be Qp1(i+v) while the quadrature component may be Ip2(i+w). Here, weighted signal309A(p1(i)) has an in-phase component I of Ip1(i) and a quadrature component Q of Qp1(i), while weighted signal316B(p2(i)) has an in-phase component I of Ip2(i) and a quadrature component Q of Qp2(i). In contrast, switched baseband signal6701A(q1(i)) has an in-phase component I of Iq1(i) and a quadrature component Q of Qq1(i), while switched baseband signal6701B(q2(i)) has an in-phase component Iq2(i) and a quadrature component Q of Qq2(i). InFIG.68, as described above, weighted signal309A(p1(i)) has an in-phase component I of Ip1(i) and a quadrature component Q of Qp1(i), while weighted signal316B(p2(i)) has an in-phase component I of Ip2(i) and a quadrature component Q of Qp2(i). In contrast, switched baseband signal6701A(q1(i)) has an in-phase component I of LAO and a quadrature component Q of Qq1(i), while switched baseband signal6701B(q2(i)) has an in-phase component LAO and a quadrature component Q of Qq2(i). As such, in-phase component I of LAO and quadrature component Q of Qq1(i) of switched baseband signal6701A(q1(i)) and in-phase component Iq2(i) and quadrature component Q of Qq2(i) of baseband signal6701B(q2(i)) are expressible as any of the above. As such, the modulated signal corresponding to switched baseband signal6701A(q1(i)) is transmitted from transmit antenna312A, while the modulated signal corresponding to switched baseband signal6701B(q2(i)) is transmitted from transmit antenna312B, both being transmitted simultaneously on a common frequency. Thus, the modulated signals corresponding to switched baseband signal6701A(q1(i)) and switched baseband signal6701B(q2(i)) are transmitted from different antennas, simultaneously on a common frequency. Phase changer317B takes switched baseband signal6701B and signal processing scheme information315as input and regularly changes the phase of switched baseband signal6701B for output. This regular change is a change of phase performed according to a predetermined phase changing pattern having a predetermined period (cycle) (e.g., every n symbols (n being an integer, n≥1) or at a predetermined interval). The phase changing pattern is described in detail in Embodiment 4. Wireless unit310B takes post-phase-change signal309B as input and performs processing such as quadrature modulation, band limitation, frequency conversion, amplification, and so on, then outputs transmit signal311B. Transmit signal311B is then output as radio waves by an antenna312B. FIG.67, much likeFIG.3, is described as having a plurality of encoders. However,FIG.67may also have an encoder and a distributor likeFIG.4. In such a case, the signals output by the distributor are the respective input signals for the interleaver, while subsequent processing remains as described above forFIG.67, despite the changes required thereby. FIG.5illustrates an example of a frame configuration in the time domain for a transmission device according to the present Embodiment. Symbol500_1is a symbol for notifying the reception device of the transmission scheme. For example, symbol500_1conveys information such as the error-correction scheme used for transmitting data symbols, the coding rate thereof, and the modulation scheme used for transmitting data symbols. Symbol501_2is for estimating channel fluctuations for modulated signal z2(t) (where t is time) transmitted by the transmission device. Symbol502_1is a data symbol transmitted by modulated signal z1(t) as symbol number u (in the time domain). Symbol503_1is a data symbol transmitted by modulated signal z1(t) as symbol number u+1. Symbol501_2is for estimating channel fluctuations for modulated signal z2(t) (where t is time) transmitted by the transmission device. Symbol502_2is a data symbol transmitted by modulated signal z2(t) as symbol number u. Symbol503_2is a data symbol transmitted by modulated signal z1(t) as symbol number u+1. Here, the symbols of z1(t) and of z2(t) having the same time (identical timing) are transmitted from the transmit antenna using the same (shared/common) frequency. The following describes the relationships between the modulated signals z1(t) and z2(t) transmitted by the transmission device and the received signals r1(t) and r2(t) received by the reception device. InFIGS.5,504#1 and504#2 indicate transmit antennas of the transmission device, while505#1and505#2 indicate receive antennas of the reception device. The transmission device transmits modulated signal z1(t) from transmit antenna504#1 and transmits modulated signal z2(t) from transmit antenna504#2. Here, modulated signals z1(t) and z2(t) are assumed to occupy the same (shared/common) frequency (bandwidth). The channel fluctuations in the transmit antennas of the transmission device and the antennas of the reception device are h11(t), h12(t), h21(t), and h22(t), respectively. Assuming that receive antenna505#1 of the reception device receives received signal r1(t) and that receive antenna505#2 of the reception device receives received signal r2(t), the following relationship holds. [Math. 66] (r1(t)r2(t))=(h11(t)h12(t)h21(t)h22(t))(z1(t)z2(t))(formula66) FIG.69pertains to the weighting scheme (precoding scheme), the baseband switching scheme, and the phase changing scheme of the present Embodiment. The weighting unit600is a combined version of the weighting units308A and308B fromFIG.67. As shown, stream s1(t) and stream s2(t) correspond to the baseband signals307A and307B ofFIG.3. That is, the streams s1(t) and s2(t) are baseband signals made up of an in-phase component I and a quadrature component Q conforming to mapping by a modulation scheme such as QPSK, 16-QAM, and 64-QAM. As indicated by the frame configuration ofFIG.69, stream s1(t) is represented as s1(u) at symbol number u, as s1(u+1) at symbol number u+1, and so forth. Similarly, stream s2(t) is represented as s2(u) at symbol number u, as s2(u+1) at symbol number u+1, and so forth. The weighting unit600takes the baseband signals307A (s1(t)) and307B (s2(t)) as well as the signal processing scheme information315fromFIG.67as input, performs weighting in accordance with the signal processing scheme information315, and outputs the weighted signals309A (pi(t)) and316B(p2(t)) fromFIG.67. Here, given vector W1=(w11,w12) from the first row of the fixed precoding matrix F, p1(t) can be expressed as formula 67, below. [Math. 67] p1(t)=W1s1(t) (formula 67) Here, given vector W2=(w21,w22) from the first row of the fixed precoding matrix F, p2(t) can be expressed as formula 68, below. [Math. 68] p2(t)=W2s2(t) (formula 68) Accordingly, precoding matrix F may be expressed as follows. [Math. 69] F=(w11w12w21w22)(formula69) After the baseband signals have been switched, switched baseband signal6701A(q1(i)) has an in-phase component I of Iq1(i) and a quadrature component Q of Qp1(i), and switched baseband signal6701B(q2(i)) has an in-phase component I of Iq2(i) and a quadrature component Q of Qq2(i). The relationships between all of these are as stated above. When the phase changer uses phase changing formula y(t), the post-phase-change baseband signal309B(q′2(i)) is given by formula 70, below. [Math. 70] q2′(t)=y(t)q2(t) (formula 70) Here, y(t) is a phase changing formula obeying a predetermined scheme. For example, given a period (cycle) of four and time u, the phase changing formula may be expressed as formula 71, below. [Math. 71] y(u)=ej0(formula 71) Similarly, the phase changing formula for time u+1 may be, for example, as given by formula 72. [Math. 72] y(u+1)=ejπ2(formula72) That is, the phase changing formula for time u+k generalizes to formula 73. [Math. 73] y(u+k)=ejkπ2(formula73) Note that formula 71 through formula 73 are given only as an example of a regular change of phase. The regular change of phase is not restricted to a period (cycle) of four. Improved reception capabilities (the error-correction capabilities, to be exact) may potentially be promoted in the reception device by increasing the period (cycle) number (this does not mean that a greater period (cycle) is better, though avoiding small numbers such as two is likely ideal.). Furthermore, although formula 71 through formula 73, above, represent a configuration in which a change of phase is carried out through rotation by consecutive predetermined phases (in the above formula, every 7/2), the change of phase need not be rotation by a constant amount but may also be random. For example, in accordance with the predetermined period (cycle) of y(t), the phase may be changed through sequential multiplication as shown in formula 74 and formula The key point of the regular change of phase is that the phase of the modulated signal is regularly changed. The phase changing degree variance rate is preferably as even as possible, such as from −π radians to π radians. However, given that this concerns a distribution, random variance is also possible. [Math. 74] ej0→ejπ5→ej2π5→ej3π5→ej4π5→ejπ→ej6π5→ej7π5→ej8π5→ej9π5(formula74) [Math. 75] ejπ2→ejπ→ej3π2→ej2π→ejπ4→ej34π→ej5π4→ej7π4(formula75) As such, the weighting unit600ofFIG.6performs precoding using fixed, predetermined precoding weights, the baseband signal switcher performs baseband signal switching as described above, and the phase changer changes the phase of the signal input thereto while regularly varying the degree of change. When a specialized precoding matrix is used in the LOS environment, the reception quality is likely to improve tremendously. However, depending on the direct wave conditions, the phase and amplitude components of the direct wave may greatly differ from the specialized precoding matrix, upon reception. The LOS environment has certain rules. Thus, data reception quality is tremendously improved through a regular change of transmit signal phase that obeys those rules. The present invention offers a signal processing scheme for improving the LOS environment. FIG.7illustrates a sample configuration of a reception device700pertaining to the present embodiment. Wireless unit703_X receives, as input, received signal702_X received by antenna701_X, performs processing such as frequency conversion, quadrature demodulation, and the like, and outputs baseband signal704_X. Channel fluctuation estimator705_1for modulated signal z1transmitted by the transmission device takes baseband signal704_X as input, extracts reference symbol501_1for channel estimation fromFIG.5, estimates the value of h11from formula 66, and outputs channel estimation signal706_1. Channel fluctuation estimator705_2for modulated signal z2transmitted by the transmission device takes baseband signal704_X as input, extracts reference symbol501_2for channel estimation fromFIG.5, estimates the value of h12from formula 66, and outputs channel estimation signal706_2. Wireless unit703_Y receives, as input, received signal702_Y received by antenna701_X, performs processing such as frequency conversion, quadrature demodulation, and the like, and outputs baseband signal704_Y. Channel fluctuation estimator707_1for modulated signal z1transmitted by the transmission device takes baseband signal704_Y as input, extracts reference symbol501_1for channel estimation fromFIG.5, estimates the value of h21from formula 66, and outputs channel estimation signal708_1. Channel fluctuation estimator707_2for modulated signal z2transmitted by the transmission device takes baseband signal704_Y as input, extracts reference symbol501_2for channel estimation fromFIG.5, estimates the value of h22from formula 66, and outputs channel estimation signal708_2. A control information decoder709receives baseband signal704_X and baseband signal704_Y as input, detects symbol500_1that indicates the transmission scheme fromFIG.5, and outputs a transmission device transmission scheme information signal710. A signal processor711takes the baseband signals704_X and704_Y, the channel estimation signals706_1,706_2,708_1, and708_2, and the transmission scheme information signal710as input, performs detection and decoding, and then outputs received data712_1and7122. Next, the operations of the signal processor711fromFIG.7are described in detail.FIG.8illustrates a sample configuration of the signal processor711pertaining to the present embodiment. As shown, the signal processor711is primarily made up of an inner MIMO detector, a soft-in/soft-out decoder, and a coefficient generator. Non-Patent Literature 2 and Non-Patent Literature 3 describe the scheme of iterative decoding with this structure. The MIMO system described in Non-Patent Literature 2 and Non-Patent Literature 3 is a spatial multiplexing MIMO system, while the present Embodiment differs from Non-Patent Literature 2 and Non-Patent Literature 3 in describing a MIMO system that regularly changes the phase over time, while using the precoding matrix and performing baseband signal switching. Taking the (channel) matrix H(t) of formula 66, then by letting the precoding weight matrix fromFIG.69be F (here, a fixed precoding matrix remaining unchanged for a given received signal) and letting the phase changing formula used by the phase changer fromFIG.69be Y(t) (here, Y(t) changes over time t), then given the baseband signal switching, the receive vector R(t)=(r1(t),r2(t))Tand the stream vector S(t)=(s1(t),s2(t))Tlead to the decoding method of Non-Patent Literature 2 and Non-Patent Literature 3, thus enabling MIMO detection. Accordingly, the coefficient generator819fromFIG.8takes a transmission scheme information signal818(corresponding to710fromFIG.7) indicated by the transmission device (information for specifying the fixed precoding matrix in use and the phase changing pattern used when the phase is changed) and outputs a signal processing scheme information signal820. The inner MIMO detector803takes the signal processing scheme information signal820as input and performs iterative detection and decoding using the signal. The operations are described below. The processor illustrated inFIG.8uses a processing scheme, as is illustrated inFIG.10, to perform iterative decoding (iterative detection). First, detection of one codeword (or one frame) of modulated signal (stream) s1and of one codeword (or one frame) of modulated signal (stream) s2are performed. As a result, the log-likelihood ratio of each bit of the codeword (or frame) of modulated signal (stream) s1and of the codeword (or frame) of modulated signal (stream) s2are obtained from the soft-in/soft-out decoder. Next, the log-likelihood ratio is used to perform a second round of detection and decoding. These operations (referred to as iterative decoding (iterative detection)) are performed multiple times. The following explanations center on the creation of the log-likelihood ratio of a symbol at a specific time within one frame. InFIG.8, a memory815takes baseband signal801X (corresponding to baseband signal704_X fromFIG.7), channel estimation signal group802X (corresponding to channel estimation signals706_1and706_2fromFIG.7), baseband signal801Y (corresponding to baseband signal704_Y fromFIG.7), and channel estimation signal group802Y (corresponding to channel estimation signals708_1and708_2fromFIG.7) as input, performs iterative decoding (iterative detection), and stores the resulting matrix as a transformed channel signal group. The memory815then outputs the above-described signals as needed, specifically as baseband signal816X, transformed channel estimation signal group817X, baseband signal816Y, and transformed channel estimation signal group817Y. Subsequent operations are described separately for initial detection and for iterative decoding (iterative detection). (Initial Detection) The inner MIMO detector803takes baseband signal801X, channel estimation signal group802X, baseband signal801Y, and channel estimation signal group802Y as input. Here, the modulation scheme for modulated signal (stream) s1and modulated signal (stream) s2is described as 16-QAM. The inner MIMO detector803first computes a candidate signal point corresponding to baseband signal801X from the channel estimation signal groups802X and802Y.FIG.11represents such a calculation. InFIG.11, each black dot is a candidate signal point in the IQ plane. Given that the modulation scheme is 16-QAM,256candidate signal points exist. (However,FIG.11is only a representation and does not indicate all 256 candidate signal points.) Letting the four bits transmitted in modulated signal s1be b0, b1, b2, and b3 and the four bits transmitted in modulated signal s2be b4, b5, b6, and b7, candidate signal points corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) are found inFIG.11. The Euclidean squared distance between each candidate signal point and each received signal point1101(corresponding to baseband signal801X) is then computed. The Euclidian squared distance between each point is divided by the noise variance σ2. Accordingly, EX(b0, b1, b2, b3, b4, b5, b6, b7) is calculated. That is, the Euclidian squared distance between a candidate signal point corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) and a received signal point is divided by the noise variance. Here, each of the baseband signals and the modulated signals s1and s2is a complex signal. Similarly, the inner MIMO detector803calculates candidate signal points corresponding to baseband signal801Y from channel estimation signal group802X and channel estimation signal group802Y, computes the Euclidean squared distance between each of the candidate signal points and the received signal points (corresponding to baseband signal801Y), and divides the Euclidean squared distance by the noise variance σ2. Accordingly, EY(b0, b1, b2, b3, b4, b5, b6, b7) is calculated. That is, EYis the Euclidian squared distance between a candidate signal point corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) and a received signal point, divided by the noise variance. Next, EX(b0, b1, b2, b3, b4, b5, b6, b7)+EY(b0, b1, b2, b3, b4, b5, b6, b7)=E(b0, b1, b2, b3, b4, b5, b6, b7) is computed. The inner MIMO detector803outputs E(b0, b1, b2, b3, b4, b5, b6, b7) as the signal804. The log-likelihood calculator805A takes the signal804as input, calculates the log-likelihood of bits b0, b1, b2, and b3, and outputs the log-likelihood signal806A. Note that this log-likelihood calculation produces the log-likelihood of a bit being 1 and the log-likelihood of a bit being 0. The calculation is as shown in formula 28, formula 29, and formula 30, and the details thereof are given by Non-Patent Literature 2 and 3. Similarly, log-likelihood calculator805B takes the signal804as input, calculates the log-likelihood of bits b4, b5, b6, and b7, and outputs log-likelihood signal806A. A deinterleaver (807A) takes log-likelihood signal806A as input, performs deinterleaving corresponding to that of the interleaver (the interleaver (304A) fromFIG.67), and outputs deinterleaved log-likelihood signal808A. Similarly, a deinterleaver (807B) takes log-likelihood signal806B as input, performs deinterleaving corresponding to that of the interleaver (the interleaver (304B) fromFIG.67), and outputs deinterleaved log-likelihood signal808B. Log-likelihood ratio calculator809A takes deinterleaved log-likelihood signal808A as input, calculates the log-likelihood ratio of the bits encoded by encoder302A fromFIG.67, and outputs log-likelihood ratio signal810A. Similarly, log-likelihood ratio calculator809B takes deinterleaved log-likelihood signal808B as input, calculates the log-likelihood ratio of the bits encoded by encoder302B fromFIG.67, and outputs log-likelihood ratio signal810B. Soft-in/soft-out decoder811A takes log-likelihood ratio signal810A as input, performs decoding, and outputs a decoded log-likelihood ratio812A. Similarly, soft-in/soft-out decoder811B takes log-likelihood ratio signal810B as input, performs decoding, and outputs decoded log-likelihood ratio812B. (Iterative Decoding (Iterative Detection), k Iterations) The interleaver (813A) takes the k−1th decoded log-likelihood ratio812A decoded by the soft-in/soft-out decoder as input, performs interleaving, and outputs an interleaved log-likelihood ratio814A. Here, the interleaving pattern used by the interleaver (813A) is identical to that of the interleaver (304A) fromFIG.67. Another interleaver (813B) takes the k−1th decoded log-likelihood ratio812B decoded by the soft-in/soft-out decoder as input, performs interleaving, and outputs interleaved log-likelihood ratio814B. Here, the interleaving pattern used by the interleaver (813B) is identical to that of the other interleaver (304B) fromFIG.67. The inner MIMO detector803takes baseband signal816X, transformed channel estimation signal group817X, baseband signal816Y, transformed channel estimation signal group817Y, interleaved log-likelihood ratio814A, and interleaved log-likelihood ratio814B as input. Here, baseband signal816X, transformed channel estimation signal group817X, baseband signal816Y, and transformed channel estimation signal group817Y are used instead of baseband signal801X, channel estimation signal group802X, baseband signal801Y, and channel estimation signal group802Y because the latter cause delays due to the iterative decoding. The iterative decoding operations of the inner MIMO detector803differ from the initial detection operations thereof in that the interleaved log-likelihood ratios814A and814B are used in signal processing for the former. The inner MIMO detector803first calculates E(b0, b1, b2, b3, b4, b5, b6, b7) in the same manner as for initial detection. In addition, the coefficients corresponding to formula 11 and formula 32 are computed from the interleaved log-likelihood ratios814A and914B. The value of E(b0, b1, b2, b3, b4, b5, b6, b7) is corrected using the coefficients so calculated to obtain E′(b0, b1, b2, b3, b4, b5, b6, b7), which is output as the signal804. Log-likelihood calculator805A takes the signal804as input, calculates the log-likelihood of bits b0, b1, b2, and b3, and outputs a log-likelihood signal806A. Note that this log-likelihood calculation produces the log-likelihood of a bit being 1 and the log-likelihood of a bit being 0. The calculation is as shown in formula 31 through formula 35, and the details are given by Non-Patent Literature 2 and 3. Similarly, log-likelihood calculator805B takes the signal804as input, calculates the log-likelihood of bits b4, b5, b6, and b7, and outputs log-likelihood signal806B. Operations performed by the deinterleaver onwards are similar to those performed for initial detection. WhileFIG.8illustrates the configuration of the signal processor when performing iterative detection, this structure is not absolutely necessary as good reception improvements are obtainable by iterative detection alone. As long as the components needed for iterative detection are present, the configuration need not include the interleavers813A and813B. In such a case, the inner MIMO detector803does not perform iterative detection. As shown in Non-Patent Literature 5 and the like, QR decomposition may also be used to perform initial detection and iterative detection. Also, as indicated by Non-Patent Literature 11, MMSE and ZF linear operations may be performed when performing initial detection. FIG.9illustrates the configuration of a signal processor unlike that ofFIG.8, that serves as the signal processor for modulated signals transmitted by the transmission device fromFIG.4as used inFIG.67. The point of difference fromFIG.8is the number of soft-in/soft-out decoders. A soft-in/soft-out decoder901takes the log-likelihood ratio signals810A and810B as input, performs decoding, and outputs a decoded log-likelihood ratio902. A distributor903takes the decoded log-likelihood ratio902as input for distribution. Otherwise, the operations are identical to those explained forFIG.8. As described above, when a transmission device according to the present Embodiment using a MIMO system transmits a plurality of modulated signals from a plurality of antennas, changing the phase over time while multiplying by the precoding matrix so as to regularly change the phase results in improvements to data reception quality for a reception device in a LOS environment, where direct waves are dominant, compared to a conventional spatial multiplexing MIMO system. In the present Embodiment, and particularly in the configuration of the reception device, the number of antennas is limited and explanations are given accordingly. However, the Embodiment may also be applied to a greater number of antennas. In other words, the number of antennas in the reception device does not affect the operations or advantageous effects of the present Embodiment. Further, in the present Embodiments, the encoding is not particularly limited to LDPC codes. Similarly, the decoding scheme is not limited to implementation by a soft-in/soft-out decoder using sum-product decoding. The decoding scheme used by the soft-in/soft-out decoder may also be, for example, the BCJR algorithm, SOYA, and the Max-Log-Map algorithm. Details are provided in Non-Patent Literature 6. In addition, although the present Embodiment is described using a single-carrier scheme, no limitation is intended in this regard. The present Embodiment is also applicable to multi-carrier transmission. Accordingly, the present Embodiment may also be realized using, for example, spread-spectrum communications, OFDM, SC-FDMA, SC-OFDM, wavelet OFDM as described in Non-Patent Literature 7, and so on. Furthermore, in the present Embodiment, symbols other than data symbols, such as pilot symbols (preamble, unique word, and so on) or symbols transmitting control information, may be arranged within the frame in any manner. The following describes an example in which OFDM is used as a multi-carrier scheme. FIG.70illustrates the configuration of a transmission device using OFDM. InFIG.70, components operating in the manner described forFIGS.3,12, and67use identical reference numbers. An OFDM-related processor1201A takes weighted signal309A as input, performs OFDM-related processing thereon, and outputs transmit signal1202A. Similarly, OFDM-related processor1201B takes post-phase-change signal309B as input, performs OFDM-related processing thereon, and outputs transmit signal1202BFIG.13illustrates a sample configuration of the OFDM-related processors7001A and1201B and onward fromFIG.70. Components1301A through1310A belong between1201A and312A fromFIG.70, while components1301B through1310B belong between1201B and312B. Serial-to-parallel converter1302A performs serial-to-parallel conversion on switched baseband signal1301A (corresponding to switched baseband signal6701A fromFIG.70) and outputs parallel signal1303A. Reorderer1304A takes parallel signal1303A as input, performs reordering thereof, and outputs reordered signal1305A. Reordering is described in detail later. IFFT unit1306A takes reordered signal1305A as input, applies an IFFT thereto, and outputs post-IFFT signal1307A. Wireless unit1308A takes post-IFFT signal1307A as input, performs processing such as frequency conversion and amplification, thereon, and outputs modulated signal1309A. Modulated signal1309A is then output as radio waves by antenna1310A. Serial-to-parallel converter1302B performs serial-to-parallel conversion on post-phase-change signal1301B (corresponding to post-phase-change signal309B fromFIG.12) and outputs parallel signal1303B. Reorderer1304B takes parallel signal1303B as input, performs reordering thereof, and outputs reordered signal1305B. Reordering is described in detail later. IFFT unit1306B takes reordered signal1305B as input, applies an IFFT thereto, and outputs post-IFFT signal1307B. Wireless unit1308B takes post-IFFT signal1307B as input, performs processing such as frequency conversion and amplification thereon, and outputs modulated signal1309B. Modulated signal1309B is then output as radio waves by antenna1310A. The transmission device fromFIG.67does not use a multi-carrier transmission scheme. Thus, as shown inFIG.69, a change of phase is performed to achieve a period (cycle) of four and the post-phase-change symbols are arranged in the time domain. As shown inFIG.70, when multi-carrier transmission, such as OFDM, is used, then, naturally, symbols in precoded baseband signals having undergone switching and phase changing may be arranged in the time domain as inFIG.67, and this may be applied to each (sub-)carrier. However, for multi-carrier transmission, the arrangement may also be in the frequency domain, or in both the frequency domain and the time domain. The following describes these arrangements. FIGS.14A and14Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13. The frequency axes are made up of (sub-)carriers 0 through 9. The modulated signals z1and z2share common time (timing) and use a common frequency band.FIG.14Aillustrates a reordering scheme for the symbols of modulated signal z1, whileFIG.14Billustrates a reordering scheme for the symbols of modulated signal z2. With respect to the symbols of switched baseband signal1301A input to serial-to-parallel converter1302A, the ordering is #0, #1, #2, #3, and so on. Here, given that the example deals with a period (cycle) of four, #0, #1, #2, and #3 are equivalent to one period (cycle). Similarly, #4n, #4n+1, #4n+2, and #4n+3 (n being a non-zero positive integer) are also equivalent to one period (cycle). As shown inFIG.14A, symbols #0, #1, #2, #3, and so on are arranged in order, beginning at carrier 0. Symbols #0 through #9 are given time $1, followed by symbols #10 through #19 which are given time #2, and so on in a regular arrangement. Here, modulated signals z1and z2are complex signals. Similarly, with respect to the symbols of weighted signal1301B input to serial-to-parallel converter1302B, the assigned ordering is #0, #1, #2, #3, and so on. Here, given that the example deals with a period (cycle) of four, a different change in phase is applied to each of #0, #1, #2, and #3, which are equivalent to one period (cycle). Similarly, a different change in phase is applied to each of #4n, #4n+1, #4n+2, and #4n+3 (n being a non-zero positive integer), which are also equivalent to one period (cycle) As shown inFIG.14B, symbols #0, #1, #2, #3, and so on are arranged in order, beginning at carrier 0. Symbols #0 through #9 are given time $1, followed by symbols #10 through #19 which are given time #2, and so on in a regular arrangement. The symbol group1402shown inFIG.14Bcorresponds to one period (cycle) of symbols when the phase changing scheme ofFIG.69is used. Symbol #0 is the symbol obtained by using the phase at time u inFIG.69, symbol #1 is the symbol obtained by using the phase at time u+1 inFIG.69, symbol #2 is the symbol obtained by using the phase at time u+2 inFIG.69, and symbol #3 is the symbol obtained by using the phase at time u+3 inFIG.69. Accordingly, for any symbol #x, symbol #x is the symbol obtained by using the phase at time u inFIG.69when x mod 4 equals 0 (i.e., when the remainder of x divided by 4 is 0, mod being the modulo operator), symbol #x is the symbol obtained by using the phase at time x+1 inFIG.69when x mod 4 equals 1, symbol #x is the symbol obtained by using the phase at time x+2 inFIG.69when x mod 4 equals 2, and symbol #x is the symbol obtained by using the phase at time x+3 inFIG.69when x mod 4 equals 3. In the present Embodiment, modulated signal z1shown inFIG.14Ahas not undergone a change of phase. As such, when using a multi-carrier transmission scheme such as OFDM, and unlike single carrier transmission, symbols can be arranged in the frequency domain. Of course, the symbol arrangement scheme is not limited to those illustrated byFIGS.14A and14B. Further examples are shown inFIGS.15A,15B,16A, and16B. FIGS.15A and15Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from that ofFIGS.14A and14B.FIG.15Aillustrates a reordering scheme for the symbols of modulated signal z1, whileFIG.15Billustrates a reordering scheme for the symbols of modulated signal z2.FIGS.15A and15Bdiffer fromFIGS.14A and14Bin the reordering scheme applied to the symbols of modulated signal z1and the symbols of modulated signal z2. InFIG.15B, symbols #0 through #5 are arranged at carriers 4 through 9, symbols #6 though #9 are arranged at carriers 0 through 3, and this arrangement is repeated for symbols #10 through #19. Here, as inFIG.14B, symbol group1502shown inFIG.15Bcorresponds to one period (cycle) of symbols when the phase changing scheme ofFIG.6is used. FIGS.16A and16Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from that ofFIGS.14A and14B.FIG.16Aillustrates a reordering scheme for the symbols of modulated signal z1, whileFIG.16Billustrates a reordering scheme for the symbols of modulated signal z2.FIGS.16A and16Bdiffer fromFIGS.14A and14Bin that, whileFIGS.14A and14Bshowed symbols arranged at sequential carriers,FIGS.16A and16Bdo not arrange the symbols at sequential carriers. Obviously, forFIGS.16A and16B, different reordering schemes may be applied to the symbols of modulated signal z1and to the symbols of modulated signal z2as inFIGS.15A and15B. FIGS.17A and17Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from those ofFIGS.14A through16B.FIG.17Aillustrates a reordering scheme for the symbols of modulated signal z1whileFIG.17Billustrates a reordering scheme for the symbols of modulated signal z2. WhileFIGS.14A through16Bshow symbols arranged with respect to the frequency axis,FIGS.17A and17Buse the frequency and time axes together in a single arrangement. WhileFIG.69describes an example where the change of phase is performed in a four slot period (cycle), the following example describes an eight slot period (cycle). InFIGS.17A and17B, the symbol group1702is equivalent to one period (cycle) of symbols when the phase changing scheme is used (i.e., on eight symbols) such that symbol #0 is the symbol obtained by using the phase at time u, symbol #1 is the symbol obtained by using the phase at time u+1, symbol #2 is the symbol obtained by using the phase at time u+2, symbol #3 is the symbol obtained by using the phase at time u+3, symbol #4 is the symbol obtained by using the phase at time u+4, symbol #5 is the symbol obtained by using the phase at time u+5, symbol #6 is the symbol obtained by using the phase at time u+6, and symbol #7 is the symbol obtained by using the phase at time u+7. Accordingly, for any symbol #x, symbol #x is the symbol obtained by using the phase at time u when x mod 8 equals 0, symbol #x is the symbol obtained by using the phase at time u+1 when x mod 8 equals 1, symbol #x is the symbol obtained by using the phase at time u+2 when x mod 8 equals 2, symbol #x is the symbol obtained by using the phase at time u+3 when x mod 8 equals 3, symbol #x is the symbol obtained by using the phase at time u+4 when x mod 8 equals 4, symbol #x is the symbol obtained by using the phase at time u+5 when x mod 8 equals 5, symbol #x is the symbol obtained by using the phase at time u+6 when x mod 8 equals 6, and symbol #x is the symbol obtained by using the phase at time u+7 when x mod 8 equals 7. InFIGS.17A and17Bfour slots along the time axis and two slots along the frequency axis are used for a total of 4×2=8 slots, in which one period (cycle) of symbols is arranged. Here, given m×n symbols per period (cycle) (i.e., m×n different phases are available for multiplication), then n slots (carriers) in the frequency domain and m slots in the time domain should be used to arrange the symbols of each period (cycle), such that m >n. This is because the phase of direct waves fluctuates slowly in the time domain relative to the frequency domain. Accordingly, the present Embodiment performs a regular change of phase that reduces the influence of steady direct waves. Thus, the phase changing period (cycle) should preferably reduce direct wave fluctuations. Accordingly, m should be greater than n. Taking the above into consideration, using the time and frequency domains together for reordering, as shown inFIGS.17A and17B, is preferable to using either of the frequency domain or the time domain alone due to the strong probability of the direct waves becoming regular. As a result, the effects of the present invention are more easily obtained. However, reordering in the frequency domain may lead to diversity gain due the fact that frequency-domain fluctuations are abrupt. As such, using the frequency and time domains together for reordering is not always ideal. FIGS.18A and18Bindicate frequency on the horizontal axes and time on the vertical axes thereof, and illustrate an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from that ofFIGS.17A and17B.FIG.18Aillustrates a reordering scheme for the symbols of modulated signal z1, whileFIG.18Billustrates a reordering scheme for the symbols of modulated signal z2. Much likeFIGS.17A and17B,FIGS.18A and18Billustrate the use of the time and frequency axes, together. However, in contrast toFIGS.17A and17B, where the frequency axis is prioritized and the time axis is used for secondary symbol arrangement,FIGS.18A and18Bprioritize the rime axis and use the frequency axis for secondary symbol arrangement. InFIG.18B, symbol group1802corresponds to one period (cycle) of symbols when the phase changing scheme is used. InFIGS.17A,17B,18A, and18B, the reordering scheme applied to the symbols of modulated signal z1and the symbols of modulated signal z2may be identical or may differ as like inFIGS.15A and15B. Either approach allows good reception quality to be obtained. Also, inFIGS.17A,17B,18A, and18B, the symbols may be arranged non-sequentially as inFIGS.16A and16B. Either approach allows good reception quality to be obtained. FIG.22indicates frequency on the horizontal axis and time on the vertical axis thereof, and illustrates an example of a symbol reordering scheme used by the reorderers1301A and1301B fromFIG.13that differs from the above.FIG.22illustrates a regular phase changing scheme using four slots, similar to time u through u+3 fromFIG.69. The characteristic feature ofFIG.22is that, although the symbols are reordered with respect to the frequency domain, when read along the time axis, a periodic shift of n (n=1 in the example ofFIG.22) symbols is apparent. The frequency-domain symbol group2210inFIG.22indicates four symbols to which are applied the changes of phase at time u through u+3 fromFIG.6. Here, symbol #0 is obtained using the change of phase at time u, symbol #1 is obtained using the change of phase at time u+1, symbol #2 is obtained using the change of phase at time u+2, and symbol #3 is obtained using the change of phase at time u+3. Similarly, for frequency-domain symbol group2220, symbol #4 is obtained using the change of phase at time u, symbol #5 is obtained using the change of phase at time u+1, symbol #6 is obtained using the change of phase at time u+2, and symbol #7 is obtained using the change of phase at time u+3. The above-described change of phase is applied to the symbol at time $1. However, in order to apply periodic shifting with respect to the time domain, the following change of phases are applied to symbol groups2201,2202,2203, and2204. For time-domain symbol group2201, symbol #0 is obtained using the change of phase at time u, symbol #9 is obtained using the change of phase at time u+1, symbol #18 is obtained using the change of phase at time u+2, and symbol #27 is obtained using the change of phase at time u+3. For time-domain symbol group2202, symbol #28 is obtained using the change of phase at time u, symbol #1 is obtained using the change of phase at time u+1, symbol #10 is obtained using the change of phase at time u+2, and symbol #19 is obtained using the change of phase at time u+3. For time-domain symbol group2203, symbol #20 is obtained using the change of phase at time u, symbol #29 is obtained using the change of phase at time u+1, symbol #2 is obtained using the change of phase at time u+2, and symbol #11 is obtained using the change of phase at time u+3. For time-domain symbol group2204, symbol #12 is obtained using the change of phase at time u, symbol #21 is obtained using the change of phase at time u+1, symbol #30 is obtained using the change of phase at time u+2, and symbol #3 is obtained using the change of phase at time u+3. The characteristic feature ofFIG.22is seen in that, taking symbol #11 as an example, the two neighbouring symbols thereof along the frequency axis (#10 and #12) are both symbols change using a different phase than symbol #11, and the two neighbouring symbols thereof having the same carrier in the time domain (#2 and #20) are both symbols changed using a different phase than symbol #11. This holds not only for symbol #11, but also for any symbol having two neighboring symbols in the frequency domain and the time domain. Accordingly, the change of phase is effectively carried out. This is highly likely to improve data reception quality as influence from regularizing direct waves is less prone to reception. AlthoughFIG.22illustrates an example in which n=1, the invention is not limited in this manner. The same may be applied to a case in which n=3. Furthermore, althoughFIG.22illustrates the realization of the above-described effects by arranging the symbols in the frequency domain and advancing in the time domain so as to achieve the characteristic effect of imparting a periodic shift to the symbol arrangement order, the symbols may also be randomly (or regularly) arranged to the same effect. Although the present Embodiment describes a variation of Embodiment 1 in which a baseband signal switcher is inserted before the change of phase, the present Embodiment may also be realized as a combination with Embodiment 2, such that the baseband signal switcher is inserted before the change of phase inFIGS.26and28. Accordingly, inFIG.26, phase changer317A takes switched baseband signal6701A(q1(i)) as input, and phase changer317B takes switched baseband signal6701B(q2(i)) as input. The same applies to the phase changers317A and317B fromFIG.28. The following describes a scheme for allowing the reception device to obtain good received signal quality for data, regardless of the reception device arrangement, by considering the location of the reception device with respect to the transmission device. FIG.31illustrates an example of frame configuration for a portion of the symbols within a signal in the time-frequency domains, given a transmission scheme where a regular change of phase is performed for a multi-carrier scheme such as OFDM. FIG.31illustrates the frame configuration of modulated signal z2′ corresponding to the switched baseband signal input to phase changer317B fromFIG.67. Each square represents one symbol (although both signals s1and s2are included for precoding purposes, depending on the precoding matrix, only one of signals s1and s2may be used). Consider symbol3100at carrier 2 and time $2 ofFIG.31. The carrier here described may alternatively be termed a sub-carrier. Within carrier 2, there is a very strong correlation between the channel conditions for symbol610A at carrier 2, time $2 and the channel conditions for the time domain nearest-neighbour symbols to time $2, i.e., symbol3013at time $1 and symbol3101at time $3 within carrier 2. Similarly, for time $2, there is a very strong correlation between the channel conditions for symbol3100at carrier 2, time $2 and the channel conditions for the frequency-domain nearest-neighbour symbols to carrier 2, i.e., symbol3104at carrier 1, time $2 and symbol3104at time $2, carrier 3. As described above, there is a very strong correlation between the channel conditions for symbol3100and the channel conditions for each symbol3101,3102,3103, and3104. The present description considers N different phases (N being an integer, N≥2) for multiplication in a transmission scheme where the phase is regularly changed. The symbols illustrated inFIG.31are indicated as el °, for example. This signifies that this symbol is signal z2′ fromFIG.6having undergone a change in phase through multiplication by ej0. That is, the values given for the symbols inFIG.31are the value of y(t) as given by formula 70. The present Embodiment takes advantage of the high correlation in channel conditions existing between neighbouring symbols in the frequency domain and/or neighbouring symbols in the time domain in a symbol arrangement enabling high data reception quality to be obtained by the reception device receiving the post-phase-change symbols. In order to achieve this high data reception quality, conditions #D1-1 and #D1-2 should preferably be met. (Condition #D1-1) As shown inFIG.69, for a transmission scheme involving a regular change of phase performed on switched baseband signal q2using a multi-carrier scheme such as OFDM, time X, carrier Y is a symbol for transmitting data (hereinafter, data symbol), neighbouring symbols in the time domain, i.e., at time X−1, carrier Y and at time X+1, carrier Y are also data symbols, and a different change of phase should be performed on switched baseband signal q2corresponding to each of these three data symbols, i.e., on switched baseband signal q2at time X, carrier Y, at time X−1, carrier Y and at time X+1, carrier Y. (Condition #D1-2) As shown inFIG.69, for a transmission scheme involving a regular change of phase performed on switched baseband signal q2using a multi-carrier scheme such as OFDM, time X, carrier Y is a symbol for transmitting data (hereinafter, data symbol), neighbouring symbols in the time domain, i.e., at time X, carrier Y+1 and at time X, carrier Y−1 are also data symbols, and a different change of phase should be performed on switched baseband signal q2corresponding to each of these three data symbols, i.e., on switched baseband signal q2at time X, carrier Y, at time X, carrier Y−1 and at time X, carrier Y+1. Ideally, a data symbol should satisfy Condition #D1-1. Similarly, the data symbols should satisfy Condition #D1-2. The reasons supporting Conditions #D1-1 and #D1-2 are as follows. A very strong correlation exists between the channel conditions of given symbol of a transmit signal (hereinafter, symbol A) and the channel conditions of the symbols neighbouring symbol A in the time domain, as described above. Accordingly, when three neighbouring symbols in the time domain each have different phases, then despite reception quality degradation in the LOS environment (poor signal quality caused by degradation in conditions due to phase relations despite high signal quality in terms of SNR) for symbol A, the two remaining symbols neighbouring symbol A are highly likely to provide good reception quality. As a result, good received signal quality is achievable after error correction and decoding. Similarly, a very strong correlation exists between the channel conditions of given symbol of a transmit signal (symbol A) and the channel conditions of the symbols neighbouring symbol A in the frequency domain, as described above. Accordingly, when three neighbouring symbols in the frequency domain each have different phases, then despite reception quality degradation in the LOS environment (poor signal quality caused by degradation in conditions due to direct wave phase relationships despite high signal quality in terms of SNR) for symbol A, the two remaining symbols neighbouring symbol A are highly likely to provide good reception quality. As a result, good received signal quality is achievable after error correction and decoding. Combining Conditions #D1-1 and #D1-2, ever greater data reception quality is likely achievable for the reception device. Accordingly, the following Condition #D1-3 can be derived. (Condition #D1-3) As shown inFIG.69, for a transmission scheme involving a regular change of phase performed on switched baseband signal q2using a multi-carrier scheme such as OFDM, time X, carrier Y is a symbol for transmitting data (data symbol), neighbouring symbols in the time domain, i.e., at time X−1, carrier Y and at time X+1, carrier Y are also data symbols, and neighbouring symbols in the frequency domain, i.e., at time X, carrier Y−1 and at time X, carrier Y+1 are also data symbols, such that a different change of phase should be performed on switched baseband signal q2corresponding to each of these five data symbols, i.e., on switched baseband signal q2at time X, carrier Y, at time X, carrier Y−1, at time X, carrier Y+1, at time X−1, carrier Y and at time X+1, carrier Y. Here, the different changes in phase are as follows. Phase changes are defined from 0 radians to 2π radians. For example, for time X, carrier Y, a phase change of ejθX,Yis applied to precoded baseband signal q2fromFIG.69, for time X−1, carrier Y, a phase change of ejθX−1,Yis applied to precoded baseband signal q2fromFIG.69, for time X+1, carrier Y, a phase change of ejθX+1,Yis applied to precoded baseband signal q2fromFIG.69, such that 0≤θX,Y<2π, 0<θX−1,Y<2π, and 0≤θX+1,Y<2π, □□ all units being in radians. And, for Condition #D1-1, it follows that θX,Y≠θX−1,Y, θX,Y≠θX+1,Y, and that θX,Y−1≠θX,Y+1. Similarly, for Condition #D1-2, it follows that θX,Y≠θX,Y−1, θX,Y≠θX,Y+1, and that θX,Y−1≠θX,Y+1. And, for Condition #D1-3, it follows that θX,Y≠θX−1,Y, θX,Y≠θX+1,Y, θX,Y≠θX,Y−1, θX,Y≠θX,Y+1, θX−1,Y≠θX+1,Y, θX−1,Y≠θX,Y−1, θX−1,Y≠θX,Y+1, θX+1,Y≠θX,Y−1, θX+1,Y≠θX,Y+1, and that θX,Y−1≠θX,Y+1. Ideally, a data symbol should satisfy Condition #D1-1. FIG.31illustrates an example of Condition #D1-3, where symbol A corresponds to symbol3100. The symbols are arranged such that the phase by which switched baseband signal q2fromFIG.69is multiplied differs for symbol3100, for both neighbouring symbols thereof in the time domain3101and3102, and for both neighbouring symbols thereof in the frequency domain3102and3104. Accordingly, despite received signal quality degradation of symbol3100for the receiver, good signal quality is highly likely for the neighbouring signals, thus guaranteeing good signal quality after error correction. FIG.32illustrates a symbol arrangement obtained through phase changes under these conditions. As evident fromFIG.32, with respect to any data symbol, a different change in phase is applied to each neighbouring symbol in the time domain and in the frequency domain. As such, the ability of the reception device to correct errors may be improved. In other words, inFIG.32, when all neighbouring symbols in the time domain are data symbols, Condition #D1-1 is satisfied for all Xs and all Ys. Similarly, inFIG.32, when all neighbouring symbols in the frequency domain are data symbols, Condition #D1-2 is satisfied for all Xs and all Ys. Similarly, inFIG.32, when all neighbouring symbols in the frequency domain are data symbols and all neighbouring symbols in the time domain are data symbols, Condition #D1-3 is satisfied for all Xs and all Ys. The following discusses the above-described example for a case where the change of phase is performed on two switched baseband signals q1and q2(seeFIG.68). Several phase changing schemes are applicable to performing a change of phase on two switched baseband signals q1and q2. The details thereof are explained below. Scheme 1 involves a change of phase of switched baseband signal q2as described above, to achieve the change of phase illustrated byFIG.32. InFIG.32, a change of phase having a period (cycle) of ten is applied to switched baseband signal q2. However, as described above, in order to satisfy Conditions #D1-1, #D1-2, and #D1-3, the change in phase applied to switched baseband signal q2at each (sub-)carrier changes over time. (Although such changes are applied inFIG.32with a period (cycle) of ten, other phase changing schemes are also applicable.) Then, as shown inFIG.33, the phase change degree performed on switched baseband signal q2produce a constant value that is one-tenth that of the change in phase performed on switched baseband signal q2. InFIG.33, for a period (cycle) (of phase change performed on switched baseband signal q2) including time $1, the value of the change in phase performed on switched baseband signal q1is ej0. Then, for the next period (cycle) (of change in phase performed on switched baseband signal q2) including time $2, the value of the phase changing degree performed on precoded baseband signal q1is ejπ/9, and so on. The symbols illustrated inFIG.33are indicated as ej0, for example. This signifies that this symbol is signal q1fromFIG.26having undergone a change of phase through multiplication by ej0. As shown inFIG.33, the change in phase applied to switched baseband signal q1produces a constant value that is one-tenth that of the change in phase performed on precoded, switched baseband signal q2such that the phase changing value varies with the number of each period (cycle). (As described above, inFIG.33, the value is ej0for the first period (cycle), ejπ/9for the second period (cycle), and so on.) As described above, the change in phase performed on switched baseband signal q2has a period (cycle) of ten, but the period (cycle) can be effectively made greater than ten by taking the degree of phase change applied to switched baseband signal q1and to switched baseband signal q2into consideration. Accordingly, data reception quality may be improved for the reception device. Scheme 2 involves a change in phase of switched baseband signal q2as described above, to achieve the change in phase illustrated byFIG.32. InFIG.32, a change of phase having a period (cycle) of ten is applied to switched baseband signal q2. However, as described above, in order to satisfy Conditions #D1-1, #D1-2, and #D1-3, the change in phase applied to switched baseband signal q2at each (sub-)carrier changes over time. (Although such changes are applied inFIG.32with a period (cycle) of ten, other phase changing schemes are also applicable.) Then, as shown inFIG.33, the change in phase performed on switched baseband signal q2produces a constant value that is one-tenth of that performed on switched baseband signal q2. The symbols illustrated inFIG.30are indicated as ej0, for example. This signifies that this symbol is switched baseband signal q1having undergone a change of phase through multiplication by ej0. As described above, the change in phase performed on switched baseband signal q2has a period (cycle) of ten, but the period (cycle) can be effectively made greater than ten by taking the changes in phase applied to switched baseband signal q1and to switched baseband signal q2into consideration. Accordingly, data reception quality may be improved for the reception device. An effective way of applying scheme 2 is to perform a change in phase on switched baseband signal q1with a period (cycle) of N and perform a change in phase on precoded baseband signal q2with a period (cycle) of M such that N and M are coprime. As such, by taking both switched baseband signals q1and q2into consideration, a period (cycle) of N×M is easily achievable, effectively making the period (cycle) greater when N and M are coprime. While the above discusses an example of the above-described phase changing scheme, the present invention is not limited in this manner. The change in phase may be performed with respect to the frequency domain, the time domain, or on time-frequency blocks. Similar improvement to the data reception quality can be obtained for the reception device in all cases. The same also applies to frames having a configuration other than that described above, where pilot symbols (SP symbols) and symbols transmitting control information are inserted among the data symbols. The details of the change in phase in such circumstances are as follows. FIGS.47A and47Billustrate the frame configuration of modulated signals (switched baseband signals q1and q2) z1or z1′ and z2′ in the time-frequency domain.FIG.47Aillustrates the frame configuration of modulated signal (switched baseband signal q1) z1or z1′ whileFIG.47Billustrates the frame configuration of modulated signal (switched baseband signal q2) z2′. InFIGS.47A and47B,4701marks pilot symbols while4702marks data symbols. The data symbols4702are symbols on which switching or switching and change in phase have been performed. FIGS.47A and47B, likeFIG.69, indicate the arrangement of symbols when a change in phase is applied to switched baseband signal q2(while no change in phase is performed on switched baseband signal q1). (AlthoughFIG.69illustrates a change in phase with respect to the time domain, switching time t with carrier f inFIG.69corresponds to a change in phase with respect to the frequency domain. In other words, replacing (t) with (t, f) where t is time and f is frequency corresponds to performing a change of phase on time-frequency blocks.) Accordingly, the numerical values indicated inFIGS.47A and47Bfor each of the symbols are the values of switched baseband signal q2after the change in phase. No values are given for the symbols of switched baseband signal q1(z1) fromFIGS.47A and47Bas no change in phase is performed thereon. The important point ofFIGS.47A and47Bis that the change in phase performed on the data symbols of switched baseband signal q2, i.e., on symbols having undergone precoding or precoding and switching. (The symbols under discussion, being precoded, actually include both symbols s1and s2.) Accordingly, no change in phase is performed on the pilot symbols inserted in z2′. FIGS.48A and48Billustrate the frame configuration of modulated signals (switched baseband signals q1and q2) z1or z1′ and z2′ in the time-frequency domain.FIG.48Aillustrates the frame configuration of modulated signal (switched baseband signal q1) z1or z1′ whileFIG.48Billustrates the frame configuration of modulated signal (switched baseband signal q2) z2′. InFIGS.48A and48B,4701marks pilot symbols while4702marks data symbols. The data symbols4702are symbols on which precoding or precoding and a change in phase have been performed. FIGS.48A and48Bindicate the arrangement of symbols when a change in phase is applied to switched baseband signal q1and to switched baseband signal q2. Accordingly, the numerical values indicated inFIGS.48A and48Bfor each of the symbols are the values of switched baseband signals q1and q2after the change in phase. The important point ofFIGS.48A and48Bis that the change in phase is performed on the data symbols of switched baseband signal q1, that is, on the precoded or precoded and switched symbols thereof, and on the data symbols of switched baseband signal q2, that is, on the precoded or precoded and switched symbols thereof. (The symbols under discussion, being precoded, actually include both symbols s1and s2.) Accordingly, no change in phase is performed on the pilot symbols inserted in z1′, nor on the pilot symbols inserted in z2′. FIGS.49A and49Billustrate the frame configuration of modulated signals (switched baseband signals q1and q2) z1or z1′ and z2′ in the time-frequency domain.FIG.49Aillustrates the frame configuration of modulated signal (switched baseband signal q1) z1or z1′ whileFIG.49Billustrates the frame configuration of modulated signal (switched baseband signal q2) z2′. InFIGS.49A and49B,4701marks pilot symbols,4702marks data symbols, and4901marks null symbols for which the in-phase component of the baseband signal I=0 and the quadrature component Q=0. As such, data symbols4702are symbols on which precoding or precoding and a change in phase have been performed.FIGS.49A and49Bdiffer fromFIGS.47A and47Bin the configuration scheme for symbols other than data symbols. The times and carriers at which pilot symbols are inserted into modulated signal z1′ are null symbols in modulated signal z2′. Conversely, the times and carriers at which pilot symbols are inserted into modulated signal z2′ are null symbols in modulated signal z1′. FIGS.49A and49B, likeFIG.69, indicate the arrangement of symbols when a change in phase is applied to switched baseband signal q2(while no change in phase is performed on switched baseband signal q1). (AlthoughFIG.69illustrates a change in phase with respect to the time domain, switching time t with carrier f inFIG.6corresponds to a change in phase with respect to the frequency domain. In other words, replacing (t) with (t, f) where t is time and f is frequency corresponds to performing the change of phase on time-frequency blocks.) Accordingly, the numerical values indicated inFIGS.49A and49Bfor each of the symbols are the values of switched baseband signal q2after the change in phase. No values are given for the symbols of switched baseband signal q1fromFIGS.49A and49Bas no change in phase is performed thereon. The important point ofFIGS.49A and49Bis that the change in phase performed on the data symbols of switched baseband signal q2, i.e., on symbols having undergone precoding or precoding and switching. (The symbols under discussion, being precoded, actually include both symbols s1and s2.) Accordingly, no change in phase is performed on the pilot symbols inserted in z2′. FIGS.50A and50Billustrate the frame configuration of modulated signals (switched baseband signals q1and q2) z1or z1′ and z2′ in the time-frequency domain.FIG.50Aillustrates the frame configuration of modulated signal (switched baseband signal q1) z1or z1′ whileFIG.50Billustrates the frame configuration of modulated signal (switched baseband signal q2) z2′. InFIGS.50A and50B,4701marks pilot symbols,4702marks data symbols, and4901marks null symbols for which the in-phase component of the baseband signal I=0 and the quadrature component Q=0. As such, data symbols4702are symbols on which precoding or precoding and a change in phase have been performed.FIGS.50A and50Bdiffer fromFIGS.48A and48Bin the configuration scheme for symbols other than data symbols. The times and carriers at which pilot symbols are inserted into modulated signal z1′ are null symbols in modulated signal z2′. Conversely, the times and carriers at which pilot symbols are inserted into modulated signal z2′ are null symbols in modulated signal z1′. FIGS.50A and50Bindicate the arrangement of symbols when a change in phase is applied to switched baseband signal q1and to switched baseband signal q2. Accordingly, the numerical values indicated inFIGS.50A and50Bfor each of the symbols are the values of switched baseband signals q1and q2after a change in phase. The important point ofFIGS.50A and50Bis that a change in phase is performed on the data symbols of switched baseband signal q1, that is, on the precoded or precoded and switched symbols thereof, and on the data symbols of switched baseband signal q2, that is, on the precoded or precoded and switched symbols thereof. (The symbols under discussion, being precoded, actually include both symbols s1and s2.) Accordingly, no change in phase is performed on the pilot symbols inserted in z1′, nor on the pilot symbols inserted in z2′. FIG.51illustrates a sample configuration of a transmission device generating and transmitting modulated signal having the frame configuration ofFIGS.47A,47B,49A, and49B. Components thereof performing the same operations as those ofFIG.4use the same reference symbols thereas.FIG.51does not include a baseband signal switcher as illustrated inFIGS.67and70. However,FIG.51may also include a baseband signal switcher between the weighting units and phase changers, much likeFIGS.67and70. InFIG.51, the weighting units308A and308B, phase changer317B, and baseband signal switcher only operate at times indicated by the frame configuration signal313as corresponding to data symbols. InFIG.51, a pilot symbol generator5101(that also generates null symbols) outputs baseband signals5102A and5102B for a pilot symbol whenever the frame configuration signal313indicates a pilot symbol (and a null symbol). Although not indicated in the frame configurations fromFIGS.47A through50B, when precoding (and phase rotation) is not performed, such as when transmitting a modulated signal using only one antenna (such that the other antenna transmits no signal) or when using a space-time coding transmission scheme (particularly, space-time block coding) to transmit control information symbols, then the frame configuration signal313takes control information symbols5104and control information5103as input. When the frame configuration signal313indicates a control information symbol, baseband signals5102A and5102B thereof are output. The wireless units310A and310B ofFIG.51take a plurality of baseband signals as input and select a desired baseband signal according to the frame configuration signal313. The wireless units310A and310B then apply OFDM signal processing and output modulated signals311A and311B conforming to the frame configuration. FIG.52illustrates a sample configuration of a transmission device generating and transmitting modulated signal having the frame configuration ofFIGS.48A,48B,50A, and50B. Components thereof performing the same operations as those ofFIGS.4and51use the same reference symbols thereas.FIG.52features an additional phase changer317A that only operates when the frame configuration signal313indicates a data symbol. At all other times, the operations are identical to those explained forFIG.51.FIG.52does not include a baseband signal switcher as illustrated inFIGS.67and70. However,FIG.52may also include a baseband signal switcher between the weighting unit and phase changer, much likeFIGS.67and70. FIG.53illustrates a sample configuration of a transmission device that differs from that ofFIG.51.FIG.53does not include a baseband signal switcher as illustrated inFIGS.67and70. However,FIG.53may also include a baseband signal switcher between the weighting unit and phase changer, much likeFIGS.67and70. The following describes the points of difference. As shown inFIG.53, phase changer317B takes a plurality of baseband signals as input. Then, when the frame configuration signal313indicates a data symbol, phase changer317B performs the change in phase on precoded baseband signal316B. When frame configuration signal313indicates a pilot symbol (or null symbol) or a control information symbol, phase changer317B pauses phase changing operations such that the symbols of the baseband signal are output as-is. (This may be interpreted as performing forced rotation corresponding to ej0.) A selector5301takes the plurality of baseband signals as input and selects a baseband signal having a symbol indicated by the frame configuration signal313for output. FIG.54illustrates a sample configuration of a transmission device that differs from that ofFIG.52.FIG.54does not include a baseband signal switcher as illustrated inFIGS.67and70. However,FIG.54may also include a baseband signal switcher between the weighting unit and phase changer, much likeFIGS.67and70. The following describes the points of difference. As shown inFIG.54, phase changer317B takes a plurality of baseband signals as input. Then, when the frame configuration signal313indicates a data symbol, phase changer317B performs the change in phase on precoded baseband signal316B. When frame configuration signal313indicates a pilot symbol (or null symbol) or a control information symbol, phase changer317B pauses phase changing operations such that the symbols of the baseband signal are output as-is. (This may be interpreted as performing forced rotation corresponding to el °.) Similarly, as shown inFIG.54, phase changer5201takes a plurality of baseband signals as input. Then, when the frame configuration signal313indicates a data symbol, phase changer5201performs the change in phase on precoded baseband signal309A. When frame configuration signal313indicates a pilot symbol (or null symbol) or a control information symbol, phase changer5201pauses phase changing operations such that the symbols of the baseband signal are output as-is. (This may be interpreted as performing forced rotation corresponding to The above explanations are given using pilot symbols, control symbols, and data symbols as examples. However, the present invention is not limited in this manner. When symbols are transmitted using schemes other than precoding, such as single-antenna transmission or transmission using space-time block codes, the absence of change in phase is important. Conversely, performing the change of phase on symbols that have been precoded is the key point of the present invention. Accordingly, a characteristic feature of the present invention is that the change in phase is not performed on all symbols within the frame configuration in the time-frequency domain, but only performed on baseband signals that have been precoded and have undergone switching. The following describes a scheme for regularly changing the phase when encoding is performed using block codes as described in Non-Patent Literature 12 through 15, such as QC LDPC Codes (not only QC-LDPC but also LDPC codes may be used), concatenated LDPC and BCH codes, Turbo codes or Duo-Binary Turbo Codes using tail-biting, and so on. The following example considers a case where two streams s1and s2are transmitted. When encoding has been performed using block codes and control information and the like is not necessary, the number of bits making up each coded block matches the number of bits making up each block code (control information and so on described below may yet be included). When encoding has been performed using block codes or the like and control information or the like (e.g., CRC transmission parameters) is necessary, then the number of bits making up each coded block is the sum of the number of bits making up the block codes and the number of bits making up the information. FIG.34illustrates the varying numbers of symbols and slots needed in two coded blocks when block codes are used. UnlikeFIGS.69and70, for example,FIG.34illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used when, for example, two streams s1and s2are transmitted as indicated inFIG.4, with an encoder and distributor. (Here, the transmission scheme may be any single-carrier scheme or multi-carrier scheme such as OFDM.) As shown inFIG.34, when block codes are used, there are 6000 bits making up a single coded block. In order to transmit these 6000 bits, the number of required symbols depends on the modulation scheme, being 3000 for QPSK,1500for 16-QAM, and1000for 64-QAM. Then, given that the above-described transmission device transmits two streams simultaneously,1500of the aforementioned 3000 symbols needed when the modulation scheme is QPSK are assigned to s1and the other 1500 symbols are assigned to s2. As such, 1500 slots for transmitting the 1500 symbols (hereinafter, slots) are required for each of s1and s2. By the same reasoning, when the modulation scheme is 16-QAM, 750 slots are needed to transmit all of the bits making up one coded block, and when the modulation scheme is 64-QAM, 500 slots are needed to transmit all of the bits making up one coded block. The following describes the relationship between the above-defined slots and the phase of multiplication, as pertains to schemes for a regular change of phase. Here, five different phase changing values (or phase changing sets) are assumed as having been prepared for use in the scheme for a regular change of phase. That is, the phase changer of the above-described transmission device uses five phase changing values (or phase changing sets) to achieve the period (cycle) of five. (As inFIG.69, five phase changing values are needed in order to perform a change of phase having a period (cycle) of five on switched baseband signal q2only. Similarly, in order to perform the change in phase on both switched baseband signals q1and q2, two phase changing values are needed for each slot. These two phase changing values are termed a phase changing set. Accordingly, here, in order to perform a change of phase having a period (cycle) of five, five such phase changing sets should be prepared). The five phase changing values (or phase changing sets) are expressed as PHASE[0], PHASE[1], PHASE[2], PHASE[3], and PHASE[4]. For the above-described 1500 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is QPSK, PHASE[0] is used on 300 slots, PHASE[1] is used on 300 slots, PHASE[2] is used on 300 slots, PHASE[3] is used on 300 slots, and PHASE[4] is used on 300 slots. This is due to the fact that any bias in phase usage causes great influence to be exerted by the more frequently used phase, and that the reception device is dependent on such influence for data reception quality. Furthermore, for the above-described 750 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is 16-QAM, PHASE[0] is used on 150 slots, PHASE[1] is used on 150 slots, PHASE[2] is used on 150 slots, PHASE[3] is used on 150 slots, and PHASE[4] is used on 150 slots. Further still, for the above-described 500 slots needed to transmit the 6000 bits making up a single coded block when the modulation scheme is 64-QAM, PHASE[0] is used on 150 slots, PHASE[1] is used on 100 slots, PHASE[2] is used on 100 slots, PHASE[3] is used on 100 slots, and PHASE[4] is used on 100 slots. As described above, a scheme for a regular change of phase requires the preparation of N phase changing values (or phase changing sets) (where the N different phases are expressed as PHASE[0], PHASE[1], PHASE[2] . . . PHASE[N−2], PHASE[N−1]). As such, in order to transmit all of the bits making up a single coded block, PHASE[0] is used on K0slots, PHASE[1] is used on K1slots, PHASE[i] is used on Kislots (where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1)), and PHASE[N−1] is used on KN−1slots, such that Condition #D1-4 is met. (Condition #D1-4) K0=K1. . . =Ki= . . . KN−1. That is, Ka=Kb(for ∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). Then, when a communication system that supports multiple modulation schemes selects one such supported scheme for use, Condition #D1-4 is preferably satisfied for the supported modulation scheme. However, when multiple modulation schemes are supported, each such modulation scheme typically uses symbols transmitting a different number of bits per symbols (though some may happen to use the same number), Condition #D1-4 may not be satisfied for some modulation schemes. In such a case, the following condition applies instead of Condition #D1-4. (Condition #D1-5) The difference between K a and Kb satisfies 0 or 1. That is, |Ka−Kb| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b) FIG.35illustrates the varying numbers of symbols and slots needed in two coded block when block codes are used.FIG.35illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used when, for example, two streams s1and s2are transmitted as indicated by the transmission device fromFIG.67andFIG.70, and the transmission device has two encoders. (Here, the transmission scheme may be any single-carrier scheme or multi-carrier scheme such as OFDM.) As shown inFIG.35, when block codes are used, there are 6000 bits making up a single coded block. In order to transmit these 6000 bits, the number of required symbols depends on the modulation scheme, being 3000 for QPSK, 1500 for 16-QAM, and 1000 for 64-QAM. The transmission device fromFIG.67and the transmission device fromFIG.70each transmit two streams at once, and have two encoders. As such, the two streams each transmit different code blocks. Accordingly, when the modulation scheme is QPSK, two coded blocks drawn from s1and s2are transmitted within the same interval, e.g., a first coded block drawn from s1is transmitted, then a second coded block drawn from s2is transmitted. As such, 3000 slots are needed in order to transmit the first and second coded blocks. By the same reasoning, when the modulation scheme is 16-QAM, 1500 slots are needed to transmit all of the bits making up the two coded blocks, and when the modulation scheme is 64-QAM, 1000 slots are needed to transmit all of the bits making up the two coded blocks. The following describes the relationship between the above-defined slots and the phase of multiplication, as pertains to schemes for a regular change of phase. Here, five different phase changing values (or phase changing sets) are assumed as having been prepared for use in the scheme for a regular change of phase. That is, the phase changer of the transmission device fromFIG.67andFIG.67uses five phase changing values (or phase changing sets) to achieve the period (cycle) of five. (As inFIG.69, five phase changing values are needed in order to perform a change of phase having a period (cycle) of five on switched baseband signal q2only. Similarly, in order to perform the change in phase on both switched baseband signals q1and q2, two phase changing values are needed for each slot. These two phase changing values are termed a phase changing set. Accordingly, here, in order to perform a change of phase having a period (cycle) of five, five such phase changing sets should be prepared). The five phase changing values (or phase changing sets) are expressed as PHASE[0], PHASE[1], PHASE[2], PHASE[3], and PHASE [4]. For the above-described 3000 slots needed to transmit the 6000×2 bits making up the two coded blocks when the modulation scheme is QPSK, PHASE[0] is used on 600 slots, PHASE[1] is used on 600 slots, PHASE[2] is used on 600 slots, PHASE[3] is used on 600 slots, and PHASE[4] is used on 600 slots. This is due to the fact that any bias in phase usage causes great influence to be exerted by the more frequently used phase, and that the reception device is dependent on such influence for data reception quality. Further, in order to transmit the first coded block, PHASE[0] is used on slots 600 times, PHASE[1] is used on slots 600 times, PHASE[2] is used on slots 600 times, PHASE[3] is used on slots 600 times, and PHASE[4] is used on slots 600 times. Furthermore, in order to transmit the second coded block, PHASE[0] is used on slots 600 times, PHASE[1] is used on slots 600 times, PHASE[2] is used on slots 600 times, PHASE[3] is used on slots 600 times, and PHASE[4] is used on slots 600 times. Similarly, for the above-described 1500 slots needed to transmit the 6000×2 bits making up the two coded blocks when the modulation scheme is 16-QAM, PHASE[0] is used on 300 slots, PHASE[1] is used on 300 slots, PHASE[2] is used on 300 slots, PHASE[3] is used on 300 slots, and PHASE[4] is used on 300 slots. Further, in order to transmit the first coded block, PHASE[0] is used on slots 300 times, PHASE[1] is used on slots 300 times, PHASE[2] is used on slots 300 times, PHASE[3] is used on slots 300 times, and PHASE[4] is used on slots 300 times. Furthermore, in order to transmit the second coded block, PHASE[0] is used on slots 300 times, PHASE[1] is used on slots 300 times, PHASE[2] is used on slots 300 times, PHASE[3] is used on slots 300 times, and PHASE[4] is used on slots 300 times. Similarly, for the above-described 1000 slots needed to transmit the 6000×2 bits making up the two coded blocks when the modulation scheme is 64-QAM, PHASE[0] is used on 200 slots, PHASE[1] is used on 200 slots, PHASE[2] is used on 200 slots, PHASE[3] is used on 200 slots, and PHASE[4] is used on 200 slots. Further, in order to transmit the first coded block, PHASE[0] is used on slots 200 times, PHASE[1] is used on slots 200 times, PHASE[2] is used on slots 200 times, PHASE[3] is used on slots 200 times, and PHASE[4] is used on slots 200 times. Furthermore, in order to transmit the second coded block, PHASE[0] is used on slots 200 times, PHASE[1] is used on slots 200 times, PHASE[2] is used on slots 200 times, PHASE[3] is used on slots 200 times, and PHASE[4] is used on slots 200 times. As described above, a scheme for a regular change of phase requires the preparation of N phase changing values (or phase changing sets) (where the N different phases are expressed as PHASE[0], PHASE[1], PHASE[2] . . . PHASE[N−2], PHASE[N−1]). As such, in order to transmit all of the bits making up a single coded block, PHASE[0] is used on K0slots, PHASE[1] is used on K1slots, PHASE[i] is used on Kislots (where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1)), and PHASE[N−1] is used on KN−1slots, such that Condition #D1-6 is met. (Condition #D1-6) K0=K1. . . =Ki= . . . KN−1. That is, K a=Kb (for ∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies a b). Further, in order to transmit all of the bits making up the first coded block, PHASE[0] is used K0,1times, PHASE[1] is used K1,1times, PHASE[i] is used times (where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1)), and PHASE[N−1] is used KN−1,1times, such that Condition #D1-7 is met. (Condition #D1-7) K0,1=K1,1=Ki,1=KN−1,1. That is, Ka,1=Kb,1(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b). Furthermore, in order to transmit all of the bits making up the second coded block, PHASE[0] is used K0,2times, PHASE[1] is used K1,2times, PHASE[i] is used Ki,2times (where i=0, 1, 2 . . . N−1 (i denotes an integer that satisfies 0≤i≤N−1)), and PHASE[N−1] is used KN−1,2times, such that Condition #D1-8 is met. (Condition #D1-8) K0,2=K1,2= . . . ki,2= . . . KN−1,2. That is, Ka,2=Kb,2(∀a and ∀b where a, b, =0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that Then, when a communication system that supports multiple modulation schemes selects one such supported scheme for use, Condition #D1-6 Condition #D1-7, and Condition #D1-8 are preferably satisfied for the supported modulation scheme. However, when multiple modulation schemes are supported, each such modulation scheme typically uses symbols transmitting a different number of bits per symbols (though some may happen to use the same number), Condition #D1-6 Condition #D1-7, and Condition #D1-8 may not be satisfied for some modulation schemes. In such a case, the following conditions apply instead of Condition #D1-6 Condition #D1-7, and Condition #D1-8. (Condition #D1-9) The difference between K a and Kb satisfies 0 or 1. That is, |Ka−Kb| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b) (Condition #D1-10) The difference between Ka,1and Kb,1satisfies 0 or 1. That is, |Ka,1−Kb,1| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b) (Condition #D1-11) The difference between Ka,2and Kb,2satisfies 0 or 1. That is, |Ka,2−Kb,2| satisfies 0 or 1 (∀a, ∀b, where a, b=0, 1, 2 . . . N−1 (a denotes an integer that satisfies 0≤a≤N−1, b denotes an integer that satisfies 0≤b≤N−1), a≠b) As described above, bias among the phases being used to transmit the coded blocks is removed by creating a relationship between the coded block and the phase of multiplication. As such, data reception quality may be improved for the reception device. As described above, N phase changing values (or phase changing sets) are needed in order to perform a change of phase having a period (cycle) of N with the scheme for the regular change of phase. As such, N phase changing values (or phase changing sets) PHASE[0], PHASE[1], PHASE[2] . . . PHASE[N−2], and PHASE[N−1] are prepared. However, schemes exist for ordering the phases in the stated order with respect to the frequency domain. No limitation is intended in this regard. The N phase changing values (or phase changing sets) PHASE[0], PHASE[1], PHASE[2] . . . PHASE[N−2], and PHASE[N−1] may also change the phases of blocks in the time domain or in the time-frequency domain to obtain a symbol arrangement. Although the above examples discuss a phase changing scheme with a period (cycle) of N, the same effects are obtainable using N phase changing values (or phase changing sets) at random. That is, the N phase changing values (or phase changing sets) need not always have regular periodicity. As long as the above-described conditions are satisfied, great quality data reception improvements are realizable for the reception device. Furthermore, given the existence of modes for spatial multiplexing MIMO schemes, MIMO schemes using a fixed precoding matrix, space-time block coding schemes, single-stream transmission, and schemes using a regular change of phase, the transmission device (broadcaster, base station) may select any one of these transmission schemes. As described in Non-Patent Literature 3, spatial multiplexing MIMO schemes involve transmitting signals s1and s2, which are mapped using a selected modulation scheme, on each of two different antennas. MIMO schemes using a fixed precoding matrix involve performing precoding only (with no change in phase). Further, space-time block coding schemes are described in Non-Patent Literature 9, 16, and 17. Single-stream transmission schemes involve transmitting signal s1, mapped with a selected modulation scheme, from an antenna after performing predetermined processing. Schemes using multi-carrier transmission such as OFDM involve a first carrier group made up of a plurality of carriers and a second carrier group made up of a plurality of carriers different from the first carrier group, and so on, such that multi-carrier transmission is realized with a plurality of carrier groups. For each carrier group, any of spatial multiplexing MIMO schemes, MIMO schemes using a fixed precoding matrix, space-time block coding schemes, single-stream transmission, and schemes using a regular change of phase may be used. In particular, schemes using a regular change of phase on a selected (sub-)carrier group are preferably used to realize the above. Although the present description describes the present Embodiment as a transmission device applying precoding, baseband switching, and change in phase, all of these may be variously combined. In particular, the phase changer discussed for the present Embodiment may be freely combined with the change in phase discussed in all other Embodiments. Embodiment D2 The present Embodiment describes a phase change initialization scheme for the regular change of phase described throughout the present description. This initialization scheme is applicable to the transmission device fromFIG.4when using a multi-carrier scheme such as OFDM, and to the transmission devices ofFIGS.67and70when using a single encoder and distributor, similar toFIG.4. The following is also applicable to a scheme for regularly changing the phase when encoding is performed using block codes as described in Non-Patent Literature 12 through 15, such as QC LDPC Codes (not only QC-LDPC but also LDPC codes may be used), concatenated LDPC and BCH codes, Turbo codes or Duo-Binary Turbo Codes using tail-biting, and so on. The following example considers a case where two streams s1and s2are transmitted. When encoding has been performed using block codes and control information and the like is not necessary, the number of bits making up each coded block matches the number of bits making up each block code (control information and so on described below may yet be included). When encoding has been performed using block codes or the like and control information or the like (e.g., CRC transmission parameters) is required, then the number of bits making up each coded block is the sum of the number of bits making up the block codes and the number of bits making up the information. FIG.34illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used.FIG.34illustrates the varying numbers of symbols and slots needed in each coded block when block codes are used when, for example, two streams s1and s2are transmitted as indicated by the above-described transmission device, and the transmission device has only one encoder. (Here, the transmission scheme may be any single-carrier scheme or multi-carrier scheme such as OFDM.) As shown inFIG.34, when block codes are used, there are 6000 bits making up a single coded block. In order to transmit these 6000 bits, the number of required symbols depends on the modulation scheme, being 3000 for QPSK, 1500 for 16-QAM, and 1000 for 64-QAM. Then, given that the above-described transmission device transmits two streams simultaneously, 1500 of the aforementioned 3000 symbols needed when the modulation scheme is QPSK are assigned to s1and the other 1500 symbols are assigned to s2. As such, 1500 slots for transmitting the 1500 symbols (hereinafter, slots) are required for each of s1and s2. By the same reasoning, when the modulation scheme is 16-QAM, 750 slots are needed to transmit all of the bits making up each coded block, and when the modulation scheme is 64-QAM, 500 slots are needed to transmit all of the bits making up each coded block. The following describes a transmission device transmitting modulated signals having a frame configuration illustrated byFIGS.71A and71B.FIG.71Aillustrates a frame configuration for modulated signal z1′ or z1(transmitted by antenna312A) in the time and frequency domains. Similarly,FIG.71Billustrates a frame configuration for modulated signal z2(transmitted by antenna312B) in the time and frequency domains. Here, the frequency (band) used by modulated signal z1′ or z1and the frequency (band) used for modulated signal z2are identical, carrying modulated signals z1′ or z1and z2at the same time. As shown inFIG.71A, the transmission device transmits a preamble (control symbol) during interval A. The preamble is a symbol transmitting control information for another party. In particular, this preamble includes information on the modulation scheme used to transmit a first and a second coded block. The transmission device transmits the first coded block during interval B. The transmission device then transmits the second coded block during interval C. Further, the transmission device transmits a preamble (control symbol) during interval D. The preamble is a symbol transmitting control information for another party. In particular, this preamble includes information on the modulation scheme used to transmit a third or fourth coded block and so on. The transmission device transmits the third coded block during interval E. The transmission device then transmits the fourth coded block during interval D. Also, as shown inFIG.71B, the transmission device transmits a preamble (control symbol) during interval A. The preamble is a symbol transmitting control information for another party. In particular, this preamble includes information on the modulation scheme used to transmit a first and a second coded block. The transmission device transmits the first coded block during interval B. The transmission device then transmits the second coded block during interval C. Further, the transmission device transmits a preamble (control symbol) during interval D. The preamble is a symbol transmitting control information for another party. In particular, this preamble includes information on the modulation scheme used to transmit a third or fourth coded block and so on. The transmission device transmits the third coded block during interval E. The transmission device then transmits the fourth coded block during interval D. FIG.72indicates the number of slots used when transmitting the coded blocks fromFIG.34, specifically using 16-QAM as the modulation scheme for the first coded block. Here, 750 slots are needed to transmit the first coded block. Similarly,FIG.72also indicates the number of slots used to transmit the second coded block, using QPSK as the modulation scheme therefor. Here, 1500 slots are needed to transmit the second coded block. FIG.73indicates the slots used when transmitting the coded blocks fromFIG.34, specifically using QPSK as the modulation scheme for the third coded block. Here, 1500 slots are needed to transmit the coded block. As explained throughout this description, modulated signal z1, i.e., the modulated signal transmitted by antenna312A, does not undergo a change in phase, while modulated signal z2, i.e., the modulated signal transmitted by antenna312B, does undergo a change in phase. The following phase changing scheme is used forFIGS.72and73. Before the change in phase can occur, seven different phase changing values is prepared. The seven phase changing values are labeled #0, #1, #2, #3, #4, #5, #6, and #7. The change in phase is regular and periodic. In other words, the phase changing values are applied regularly and periodically, such that the order is #0, #1, #2, #3, #4, #5, #6, #0, #1, #2, #3, #4, #5, #6, #0, #1, #2, #3, #4, #5, #6 and so on. As shown inFIG.72, given that 750 slots are needed for the first coded block, phase changing value #0 is used initially, such that #0, #1, #2, #3, #4, #5, #6, #0, #1, #2 . . . #3, #4, #5, #6 are used in succession, with the 750th slot using #0 at the final position. The change in phase is then applied to each slot for the second coded block. The present description assumes multi-cast transmission and broadcasting applications. As such, a receiving terminal may have no need for the first coded block and extract only the second coded block. In such circumstances, given that the final slot used for the first coded block uses phase changing value #0, the initial phase changing value used for the second coded block is #1. As such, the following schemes are conceivable:(a): The aforementioned terminal monitors the transmission of the first coded block, i.e., monitors the pattern of the phase changing values through the final slot used to transmit the first coded block, and then estimates the phase changing value used for the initial slot of the second coded block;(b): (a) does not occur, and the transmission device transmits information on the phase changing values in use at the initial slot of the second coded block. Scheme (a) leads to greater energy consumption by the terminal due to the need to monitor the transmission of the first coded block. However, scheme (b) leads to reduced data transmission efficiency. Accordingly, there is a need to improve the phase changing value allocation described above. Consider a scheme in which the phase changing value used to transmit the initial slot of each coded block is fixed. Thus, as indicated inFIG.72, the phase changing value used to transmit the initial slot of the second coded block and the phase changing value used to transmit the initial slot of the first coded block are identical, being #0. Similarly, as indicated inFIG.73, the phase changing value used to transmit the initial slot of the third coded block is not #3, but is instead identical to the phase changing value used to transmit the initial slot of the first and second coded blocks, being #0. As such, the problems accompanying both schemes (a) and (b) described above can be constrained while retaining the effects thereof. In the present Embodiment, the scheme used to initialize the phase changing value for each coded block, i.e., the phase changing value used for the initial slot of each coded block, is fixed so as to be #0. However, other schemes may also be used for single-frame units. For example, the phase changing value used for the initial slot of a symbol transmitting information after the preamble or control symbol has been transmitted may be fixed at #0. Embodiment D3 The above-described Embodiments discuss a weighting unit using a precoding matrix expressed in complex numbers for precoding. However, the precoding matrix may also be expressed in real numbers. That is, suppose that two baseband signals s1(i) and s2(i) (where i is time or frequency) have been mapped (using a modulation scheme), and precoded to obtained precoded baseband signals z1(i) and z2(i). As such, mapped baseband signal s1(i) has an in-phase component of Is1(i) and a quadrature component of Qs1(i), and mapped baseband signal s2(i) has an in-phase component of Is2(i) and a quadrature component of Qs2(i), while precoded baseband signal z1(i) has an in-phase component of Iz1(i) and a quadrature component of Qz1(i), and precoded baseband signal z2(i) has an in-phase component of Iz2(i) and a quadrature component of Qz2(i), which gives the following precoding matrix H r when all values are real numbers. [Math. 76] (Iz1(i)Qz1(i)Iz2(i)Qz2(i))=Hr(Is1(i)Qs1(i)Is2(i)Qs2(i))(formula76) Precoding matrix Hrmay also be expressed as follows, where all values are real numbers. [Math. 77] Hr=(a11a12a13a14a21a22a23a24a31a32a33a34a41a42a43a44)(formula77) where a11, a12, a13, a14, a21, a22, a23, a24, a31, a32, a33, a34, a41, a42, a43, and a44are real numbers. However, none of the following may hold: {a11=0, a12=0, a 13=0, and a14=0}, {a21=0, a22=0, a23=0, and a24=0}, a32=0, {a33=0, and a34=0}, and {a41=0, a42=0, a43=0, and a44=0}. Also, none of the following may hold: {a41=0, a21=0, a31=0, and a41=0}, {a22=0, a32=0, and a42=0}, {a23=0, a33=0, and a43=0}, and {a14=0, a24=0, a34=0, and a44=0}. Embodiment E1 The present embodiment describes a scheme of initializing phase change in a case where (i) the transmission device inFIG.4is used, (ii) the transmission device inFIG.4is compatible with the multi-carrier scheme such as the OFDM scheme, and (iii) one encoder and a distributor is adopted in the transmission device inFIG.67and the transmission device inFIG.70as shown inFIG.4, when the phase change scheme for regularly performing phase change described in this description is used. The following describes the scheme for regularly changing the phase when using a Quasi-Cyclic Low-Density Parity-Check (QC-LDPC) code (or an LDPC code other than a QC-LDPC code), a concatenated code consisting of an LDPC code and a Bose-Chaudhuri-Hocquenghem (BCH) code, and a block code such as a turbo code or a duo-binary turbo code using tail-biting. These codes are described in Non-Patent Literatures 12 through 15. The following describes a case of transmitting two streams s1and s2as an example. Note that, when the control information and the like are not required to perform encoding using the block code, the number of bits constituting the coding (encoded) block is the same as the number of bits constituting the block code (however, the control information and the like described below may be included). When the control information and the like (e.g. CRC (cyclic redundancy check), a transmission parameter) are required to perform encoding using the block code, the number of bits constituting the coding (encoded) block can be a sum of the number of bits constituting the block code and the number of bits of the control information and the like. FIG.34shows a change in the number of symbols and slots required for one coding (encoded) block when the block code is used.FIG.34shows a change in the number of symbols and slots required for one coding (encoded) block when the block code is used in a case where the two streams s1and s2are transmitted and the transmission device has a single encoder, as shown in the transmission device described above (note that, in this case, either the single carrier transmission or the multi-carrier transmission such as the OFDM may be used as a transmission system). As shown inFIG.34, let the number of bits constituting one coding (encoded) block in the block code be 6000 bits. In order to transmit the 6000 bits, 3000 symbols, 1500 symbols and 1000 symbols are necessary when the modulation scheme is QPSK, 16QAM and 64QAM, respectively. Since two streams are to be simultaneously transmitted in the transmission device above, when the modulation scheme is QPSK, 1500 symbols are allocated to s1and remaining 1500 symbols are allocated to s2out of the above-mentioned 3000 symbols. Therefore, 1500 slots (referred to as slots) are necessary to transmit 1500 symbols by s1and transmit 1500 symbols by s2. Making the same considerations, 750 slots are necessary to transmit all the bits constituting one coding (encoded) block when the modulation scheme is 16QAM, and 500 slots are necessary to transmit all the bits constituting one block when the modulation scheme is 64QAM. Next, a case where the transmission device transmits modulated signals each having a frame structure shown inFIGS.71A and71Bis considered.FIG.71Ashows a frame structure in the time and frequency domain for a modulated signal z′l or z1(transmitted by the antenna312A).FIG.71Bshows a frame structure in the time and frequency domain for a modulated signal z2(transmitted by the antenna312B). In this case, the modulated signal z′l or z1and the modulated signal z2are assumed to occupy the same frequency (bandwidth), and the modulated signal z′l or z1and the modulated signal z2are assumed to exist at the same time. As shown inFIG.71A, the transmission device transmits a preamble (control symbol) in an interval A. The preamble is a symbol for transmitting control information to the communication partner and is assumed to include information on the modulation scheme for transmitting the first coding (encoded) block and the second coding (encoded) block. The transmission device is to transmit the first coding (encoded) block in an interval B. The transmission device is to transmit the second coding (encoded) block in an interval C. The transmission device transmits the preamble (control symbol) in an interval D. The preamble is a symbol for transmitting control information to the communication partner and is assumed to include information on the modulation scheme for transmitting the third coding (encoded) block, the fourth coding (encoded) block and so on. The transmission device is to transmit the third coding (encoded) block in an interval E. The transmission device is to transmit the fourth coding (encoded) block in an interval F. As shown inFIG.71B, the transmission device transmits a preamble (control symbol) in the interval A. The preamble is a symbol for transmitting control information to the communication partner and is assumed to include information on the modulation scheme for transmitting the first coding (encoded) block and the second coding (encoded) block. The transmission device is to transmit the first coding (encoded) block in the interval B. The transmission device is to transmit the second coding (encoded) block in the interval C. The transmission device transmits the preamble (control symbol) in the interval D. The preamble is a symbol for transmitting control information to the communication partner and is assumed to include information on the modulation scheme for transmitting the third coding (encoded) block, the fourth coding (encoded) block and so on. The transmission device is to transmit the third coding (encoded) block in the interval E. The transmission device is to transmit the fourth coding (encoded) block in the interval F. FIG.72shows the number of slots used when the coding (encoded) blocks are transmitted as shown inFIG.34, and, in particular, when 16QAM is used as the modulation scheme in the first coding (encoded) block. In order to transmit first coding (encoded) block, 750 slots are necessary. Similarly,FIG.100shows the number of slots used when QPSK is used as the modulation scheme in the second coding (encoded) block. In order to transmit second coding (encoded) block, 1500 slots are necessary. FIG.73shows the number of slots used when the coding (encoded) block is transmitted as shown inFIG.34, and, in particular, when QPSK is used as the modulation scheme in the third coding (encoded) block. In order to transmit third coding (encoded) block, 1500 slots are necessary. As described in this description, a case where phase change is not performed for the modulated signal z1, i.e. the modulated signal transmitted by the antenna312A, and is performed for the modulated signal z2, i.e. the modulated signal transmitted by the antenna312B, is considered. In this case,FIGS.72and73show the scheme of performing phase change. First, assume that seven different phase changing values are prepared to perform phase change, and are referred to as #0, #1, #2, #3, #4, #5 and #6. The phase changing values are to be regularly and cyclically used. That is to say, the phase changing values are to be regularly and cyclically changed in the order such as #0, #1, #2, #3, #4, #5, #6, #0, #1, #2, #3, #4, #5, #6, #0, #1, #2, #3, #4, #5, #6, . . . . First, as shown inFIG.72, 750 slots exist in the first coding (encoded) block. Therefore, starting from #0, the phase changing values are arranged in the order #0, #1, #2, #3, #4, #5, #6, #0, #1, #2, . . . , #4, #5, #6, #0, and end using #0 for the 750thslot. Next, the phase changing values are to be applied to each slot in the second coding (encoded) block. Since this description is on the assumption that the phase changing values are applied to the multicast communication and broadcast, one possibility is that a reception terminal does not need the first coding (encoded) block and extracts only the second coding (encoded) block. In such a case, even when phase changing value #0 is used to transmit the last slot in the first coding (encoded) block, the phase changing value #1 is used first to transmit the second coding (encoded) block. In this case, the following two schemes are considered:(a) The above-mentioned terminal monitors how the first coding (encoded) block is transmitted, i.e. the terminal monitors a pattern of the phase changing value used to transmit the last slot in the first coding (encoded) block, and estimates the phase changing value to be used to transmit the first slot in the second coding (encoded) block; and(b) The transmission device transmits information on the phase changing value used to transmit the first slot in the second coding (encoded) block without performing (a). In the case of (a), since the terminal has to monitor transmission of the first coding (encoded) block, power consumption increases. In the case of (b), transmission efficiency of data is reduced. Therefore, there is room for improvement in allocation of precoding matrices as described above. In order to address the above-mentioned problems, a scheme of fixing the phase changing value used to transmit the first slot in each coding (encoded) block is proposed. Therefore, as shown inFIG.72, the phase changing value used to transmit the first slot in the second coding (encoded) block is set to #0 as with the phase changing value used to transmit the first slot in the first coding (encoded) block. Similarly, as shown inFIG.73, the phase changing value used to transmit the first slot in the third coding (encoded) block is set not to #3 but to #0 as with the phase changing value used to transmit the first slot in the first coding (encoded) block and in the second coding (encoded) block. With the above-mentioned scheme, an effect of suppressing the problems occurring in (a) and (b) is obtained. Note that, in the present embodiment, the scheme of initializing the phase changing values in each coding (encoded) block, i.e. the scheme in which the phase changing value used to transmit the first slot in each coding (encoded) block is fixed to #0, is described. As a different scheme, however, the phase changing values may be initialized in units of frames. For example, in the symbol for transmitting the preamble and information after transmission of the control symbol, the phase changing value used in the first slot may be fixed to #0. For example, inFIG.71, a frame is interpreted as starting from the preamble, the first coding (encoded) block in the first frame is first coding (encoded) block, and the first coding (encoded) block in the second frame is the third coding (encoded) block. This exemplifies a case where “the phase changing value used in the first slot may be fixed (to #0) in units of frames” as described above usingFIGS.72and73. The following describes a case where the above-mentioned scheme is applied to a broadcasting system that uses the DVB-T2 standard. First, the frame structure for a broadcast system according to the DVB-T2 standard is described. FIG.74is an overview of the frame structure of a signal a signal transmitted by a broadcast station according to the DVB-T2 standard. According to the DVB-T2 standard, an OFDM scheme is employed. Thus, frames are structured in the time and frequency domains.FIG.74shows the frame structure in the time and frequency domains. The frame is composed of P1 Signalling data (7401), L1 Pre-Signalling data (7402), L1 Post-Signalling data (7403), Common PLP (7404), and PLPs #1 to #N (7405_1to7405_N) (PLP: Physical Layer Pipe). (Here, L1 Pre-Signalling data (7402) and L1 Post-Signalling data (7403) are referred to as P2 symbols.) As above, the frame composed of P1 Signalling data (7401), L1 Pre-Signalling data (7402), L1 Post-Signalling data (7403), Common PLP (7404), and PLPs #1 to #N (7405_1to7405_N) is referred to as a T2 frame, which is a unit of frame structure. The P1 Signalling data (7401) is a symbol for use by a reception device for signal detection and frequency synchronization (including frequency offset estimation). Also, the P1 Signalling data (7401) transmits information including information indicating the FFT (Fast Fourier Transform) size, and information indicating which of SISO (Single-Input Single-Output) and MISO (Multiple-Input Single-Output) is employed to transmit a modulated signal. (The SISO scheme is for transmitting one modulated signal, whereas the MISO scheme is for transmitting a plurality of modulated signals using space-time block codes shown in Non-Patent Literatures 9, 16 and 17.) The L1 Pre-Signalling data (7402) transmits information including: information about the guard interval used in transmitted frames; information about the signal processing method for reducing PAPR (Peak to Average Power Ratio); information about the modulation scheme, error correction scheme (FEC: Forward Error Correction), and coding rate of the error correction scheme all used in transmitting L1 Post-Signalling data; information about the size of L1 Post-Signalling data and the information size; information about the pilot pattern; information about the cell (frequency region) unique number; and information indicating which of the normal mode and extended mode (the respective modes differs in the number of subcarriers used in data transmission) is used. The L1 Post-Signalling data (7403) transmits information including: information about the number of PLPs; information about the frequency region used; information about the unique number of each PLP; information about the modulation scheme, error correction scheme, coding rate of the error correction scheme all used in transmitting the PLPs; and information about the number of blocks transmitted in each PLP. The Common PLP (7404) and PLPs #1 to #N (7405_1to7405_N) are fields used for transmitting data. In the frame structure shown inFIG.74, the P1 Signalling data (7401), L1 Pre-Signalling data (7402), L1 Post-Signalling data (7403), Common PLP (7404), and PLPs #1 to #N (7405_1to7405_N) are illustrated as being transmitted by time-sharing. In practice, however, two or more of the signals are concurrently present.FIG.75shows such an example. As shown inFIG.75, L1 Pre-Signalling data, L1 Post-Signalling data, and Common PLP may be present at the same time, and PLP #1 and PLP #2 may be present at the same time. That is, the signals constitute a frame using both time-sharing and frequency-sharing. FIG.76shows an example of the structure of a transmission device obtained by applying the phase change schemes of performing phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals) to a transmission device compliant with the DVB-T2 standard (i.e., to a transmission device of a broadcast station). A PLP signal generator7602receives PLP transmission data (transmission data for a plurality of PLPs)7601and a control signal7609as input, performs mapping of each PLP according to the error correction scheme and modulation scheme indicated for the PLP by the information included in the control signal7609, and outputs a (quadrature) baseband signal7603carrying a plurality of PLPs. A P2 symbol signal generator7605receives P2 symbol transmission data7604and the control signal7609as input, performs mapping according to the error correction scheme and modulation scheme indicated for each P2 symbol by the information included in the control signal7609, and outputs a (quadrature) baseband signal7606carrying the P2 symbols. A control signal generator7608receives P1 symbol transmission data7607and P2 symbol transmission data7604as input, and then outputs, as the control signal7609, information about the transmission scheme (the error correction scheme, coding rate of the error correction, modulation scheme, block length, frame structure, selected transmission schemes including a transmission scheme that regularly hops between precoding matrices, pilot symbol insertion scheme, IFFT (Inverse Fast Fourier Transform)/FFT, method of reducing PAPR, and guard interval insertion scheme) of each symbol group shown inFIG.74(P1 Signalling data (7401), L1 Pre-Signalling data (7402), L1 Post-Signalling data (7403), Common PLP (7404), PLPs #1 to #N (7405_1to7405_N)). A frame configurator7610receives, as input, the baseband signal7603carrying PLPs, the baseband signal7606carrying P2 symbols, and the control signal7609. On receipt of the input, the frame configurator7610changes the order of input data in frequency domain and time domain based on the information about frame structure included in the control signal, and outputs a (quadrature) baseband signal7611_1corresponding to stream 1 (a signal after the mapping, that is, a baseband signal based on a modulation scheme to be used) and a (quadrature) baseband signal7611_2corresponding to stream 2 (a signal after the mapping, that is, a baseband signal based on a modulation scheme to be used) both in accordance with the frame structure. A signal processor7612receives, as input, the baseband signal7611_1corresponding to stream 1, the baseband signal7611_2corresponding to stream 2, and the control signal7609and outputs a modulated signal1(7613_1) and a modulated signal2(7613_2) each obtained as a result of signal processing based on the transmission scheme indicated by information included in the control signal7609. The characteristic feature noted here lies in the following. That is, when a transmission scheme that performs phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals) is selected, the signal processor performs phase change on signals after performing precoding (or after performing precoding, and switching the baseband signals) in a manner similar toFIGS.6,25,26,27,28,29and69. Thus, processed signals so obtained are the modulated signal1(7613_1) and modulated signal2(7613_2) obtained as a result of the signal processing. A pilot inserter7614_1receives, as input, the modulated signal1(7613_1) obtained as a result of the signal processing and the control signal7609, inserts pilot symbols into the received modulated signal1(7613_1), and outputs a modulated signal7615_1obtained as a result of the pilot signal insertion. Note that the pilot symbol insertion is carried out based on information indicating the pilot symbol insertion scheme included the control signal7609. A pilot inserter7614_2receives, as input, the modulated signal2(7613_2) obtained as a result of the signal processing and the control signal7609, inserts pilot symbols into the received modulated signal2(7613_2), and outputs a modulated signal7615_2obtained as a result of the pilot symbol insertion. Note that the pilot symbol insertion is carried out based on information indicating the pilot symbol insertion scheme included the control signal7609. An IFFT (Inverse Fast Fourier Transform) unit7616_1receives, as input, the modulated signal7615_1obtained as a result of the pilot symbol insertion and the control signal7609, and applies IFFT based on the information about the IFFT method included in the control signal7609, and outputs a signal7617_1obtained as a result of the IFFT. An IFFT unit76162receives, as input, the modulated signal7615_2obtained as a result of the pilot symbol insertion and the control signal7609, and applies IFFT based on the information about the IFFT method included in the control signal7609, and outputs a signal7617_2obtained as a result of the IFFT. A PAPR reducer7618_1receives, as input, the signal7617_1obtained as a result of the IFFT and the control signal7609, performs processing to reduce PAPR on the received signal7617_1, and outputs a signal7619_1obtained as a result of the PAPR reduction processing. Note that the PAPR reduction processing is performed based on the information about the PAPR reduction included in the control signal7609. A PAPR reducer7618_2receives, as input, the signal7617_2obtained as a result of the IFFT and the control signal7609, performs processing to reduce PAPR on the received signal7617_2, and outputs a signal7619_2obtained as a result of the PAPR reduction processing. Note that the PAPR reduction processing is carried out based on the information about the PAPR reduction included in the control signal7609. A guard interval inserter7620_1receives, as input, the signal7619_1obtained as a result of the PAPR reduction processing and the control signal7609, inserts guard intervals into the received signal7619_1, and outputs a signal7621_1obtained as a result of the guard interval insertion. Note that the guard interval insertion is carried out based on the information about the guard interval insertion scheme included in the control signal7609. A guard interval inserter7620_2receives, as input, the signal7619_2obtained as a result of the PAPR reduction processing and the control signal7609, inserts guard intervals into the received signal7619_2, and outputs a signal7621_2obtained as a result of the guard interval insertion. Note that the guard interval insertion is carried out based on the information about the guard interval insertion scheme included in the control signal7609. A P1 symbol inserter7622receives, as input, the signal7621_1obtained as a result of the guard interval insertion, the signal7621_2obtained as a result of the guard interval insertion, and the P1 symbol transmission data7607, generates a P1 symbol signal from the P1 symbol transmission data7607, adds the P1 symbol to the signal7621_1obtained as a result of the guard interval insertion, and adds the P1 symbol to the signal7621_2obtained as a result of the guard interval insertion. Then, the P1 symbol inserter7622outputs a signal7623_1as a result of the addition of the P1 symbol and a signal7623_2as a result of the addition of the P1 symbol. Note that a P1 symbol signal may be added to both the signals7623_1and7623_2or to one of the signals7623_1and7623_2. In the case where the P1 symbol signal is added to one of the signals7623_1and7623_2, the following is noted. For purposes of description, an interval of the signal to which a P1 symbol is added is referred to as a P1 symbol interval. Then, the signal to which a P1 signal is not added includes, as a baseband signal, a zero signal in an interval corresponding to the P1 symbol interval of the other signal. A wireless processor7624_1receives the signal7623_1obtained as a result of the processing related to P1 symbol and the control signal7609, performs processing such as frequency conversion, amplification, and the like, and outputs a transmission signal7625_1. The transmission signal7625_1is then output as a radio wave from an antenna7626_1. A wireless processor7624_2receives the signal7623_2obtained as a result of the processing related to P1 symbol and the control signal7609, performs processing such as frequency conversion, amplification, and the like, and outputs a transmission signal76252. The transmission signal76252is then output as a radio wave from an antenna76262. As described above, by the P1 symbol, P2 symbol and control symbol group, information on transmission scheme of each PLP (for example, a transmission scheme of transmitting a single modulated signal, a transmission scheme of performing phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals)) and a modulation scheme being used is transmitted to a terminal. In this case, if the terminal extracts only PLP that is necessary as information to perform demodulation (including separation of signals and signal detection) and error correction decoding, power consumption of the terminal is reduced. Therefore, as described usingFIGS.71through73, the scheme in which the phase changing value used in the first slot in the PLP transmitted using, as the transmission scheme, the transmission scheme for regularly performing phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals) is fixed (to #0) is proposed. Note that the PLP transmission scheme is not limited to those described above. For example, a transmission scheme using space-time block codes disclosed in Non-Patent Literatures 9, 16 and 17 or another transmission scheme may be adopted. For example, assume that the broadcast station transmits each symbol having the frame structure as shown inFIG.74. In this case, as an example,FIG.77shows a frame structure in frequency-time domain when the broadcast station transmits PLP $1 (to avoid confusion, #1 is replaced by $1) and PLP $K using the transmission scheme of performing phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals). Note that, in the following description, as an example, assume that seven phase changing values are prepared in the transmission scheme of performing phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals), and are referred to as #0, #1, #2, #3, #4, #5 and #6. The phase changing values are to be regularly and cyclically used. That is to say, the phase changing values are to be regularly and cyclically changed in the order such as #0, #1, #2, #3, #4, #5, #6, #0, #1, #2, #3, #4, #5, #6, #0, #1, #2, #3, #4, #5, #6, . . . . As shown inFIG.77, the slot (symbol) in PLP $1 starts with a time T and a carrier 3 (7701inFIG.77) and ends with a time T+4 and a carrier 4 (7702inFIG.77) (seeFIG.77). This is to say, in PLP $1, the first slot is the time T and the carrier 3, the second slot is the time T and the carrier 4, the third slot is the time T and a carrier 5, . . . , the seventh slot is a time T+1 and a carrier 1, the eighth slot is the time T+1 and a carrier 2, the ninth slot is the time T+1 and the carrier 3, . . . , the fourteenth slot is the time T+1 and a carrier 8, the fifteenth slot is a time T+2 and a carrier 0, . . . . The slot (symbol) in PLP $K starts with a time S and a carrier 4 (7703inFIG.77) and ends with a time S+8 and the carrier 4 (7704inFIG.77) (seeFIG.77). This is to say, in PLP $K, the first slot is the time S and the carrier 4, the second slot is the time S and a carrier 5, the third slot is the time S and a carrier 6, . . . , the fifth slot is the time S and a carrier 8, the ninth slot is a time S+1 and a carrier 1, the tenth slot is the time S+1 and a carrier 2 . . . , the sixteenth slot is the time S+1 and the carrier 8, the seventeenth slot is a time S+2 and a carrier 0, . . . . Note that information on slot that includes information on the first slot (symbol) and the last slot (symbol) in each PLP and is used by each PLP is transmitted by the control symbol including the P1 symbol, the P2 symbol and the control symbol group. In this case, as described usingFIGS.71through73, the first slot in PLP $1, which is the time T and the carrier 3 (7701inFIG.77), is subject to phase change using the phase changing value #0. Similarly, the first slot in PLP $K, which is the time S and the carrier 4 (7703inFIG.77), is subject tophase change using the phase changing value #0 regardless of the number of the phase changing values used in the last slot in PLP $K −1, which is the time S and the carrier 3 (7705inFIG.77). (However, as described above, it is assumed that precoding (or switching the precoding matrices and baseband signals) has been performed before the phase change is performed). Also, the first slot in another PLP transmitted using a transmission scheme that performs phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals) is precoded using the precoding matrix #0. With the above-mentioned scheme, an effect of suppressing the problems described in Embodiment D2 above, occurring in (a) and (b) is obtained. Naturally, the reception device extracts necessary PLP from the information on slot that is included in the control symbol including the P1 symbol, the P2 symbol and the control symbol group and is used by each PLP to perform demodulation (including separation of signals and signal detection) and error correction decoding. The reception device learns a phase change rule of regularly performing phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals) in advance (when there are a plurality of rules, the transmission device transmits information on the rule to be used, and the reception device learns the rule being used by obtaining the transmitted information). By synchronizing a timing of rules of switching the phase changing values based on the number of the first slot in each PLP, the reception device can perform demodulation of information symbols (including separation of signals and signal detection). Next, a case where the broadcast station (base station) transmits a modulated signal having a frame structure shown inFIG.78is considered (the frame composed of symbol groups shown inFIG.78is referred to as a main frame). InFIG.78, elements that operate in a similar way toFIG.74bear the same reference signs. The characteristic feature is that the main frame is separated into a subframe for transmitting a single modulated signal and a subframe for transmitting a plurality of modulated signals so that gain control of received signals can easily be performed. Note that the expression “transmitting a single modulated signal” also indicates that a plurality of modulated signals that are the same as the single modulated signal transmitted from a single antenna are generated, and the generated signals are transmitted from respective antennas. InFIG.78, PLP #1 (7405_1) through PLP #N (7405_N) constitute a subframe7800for transmitting a single modulated signal. The subframe7800is composed only of PLPs, and does not include PLP for transmitting a plurality of modulated signals. Also, PLP $1 (7802_1) through PLP $M (7802_M) constitute a subframe7801for transmitting a plurality of modulated signals. The subframe7801is composed only of PLPs, and does not include PLP for transmitting a single modulated signal. In this case, as described above, when the above-mentioned transmission scheme for regularly performing phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals) is used in the subframe7801, the first slot in PLP (PLP $1 (7802_1) through PLP $M (7802_M)) is assumed to be precoded using the precoding matrix #0 (referred to as initialization of the precoding matrices). The above-mentioned initialization of precoding matrices, however, is irrelevant to a PLP in which another transmission scheme, for example, one of the transmission scheme not performing phase change, the transmission scheme using the space-time block codes and the transmission scheme using a spatial multiplexing MIMO system (seeFIG.23) is used in PLP $1 (7802_1) through PLP $M (7802_M). As shown inFIG.79, PLP $1 is assumed to be the first PLP in the subframe for transmitting a plurality of modulated signals in the Xth main frame. Also, PLP $1′ is assumed to be the first PLP in the subframe for transmitting a plurality of modulated signals in the Yth main frame (Y is not X). Both PLP $1 and PLP $1′ are assumed to use the transmission scheme for regularly performing phase change on the signal after performing precoding (or after performing precoding, and switching the baseband signals). InFIG.79, elements that operate in a similar way toFIG.77bear the same reference signs. In this case, the first slot (7701inFIG.79(time T and carrier 3)) in PLP $1, which is the first PLP in the subframe for transmitting a plurality of modulated signals in the Xth main frame, is assumed to be subject to phase change using the phase changing value #0. Similarly, the first slot (7901inFIG.79(time T′ and carrier 7)) in PLP $1′, which is the first PLP in the subframe for transmitting a plurality of modulated signals in the Yth main frame, is assumed to be subject to phase change using the phase changing value #0. As described above, in each main frame, the first slot in the first PLP in the subframe for transmitting a plurality of modulated signals is characterized by being subject to phase change using the phase changing value #0. This is also important to suppress the problems described in Embodiment D2 occurring in (a) and (b). Note that since the first slot (7701inFIG.79(time T and carrier 3)) in PLP $1 is assumed to be subject to phase change using the phase changing value #0, when the phase changing value is updated in the time-frequency domain, the slot at time T, carrier 4 is subject to phase change using the phase changing value #1, the slot at time T, carrier 5 is subject to phase change using the phase changing value #2, the slot at time T, carrier 6 is subject to phase change using the phase changing value #3, and so on. Similarly, note that since the first slot (7901inFIG.79(time T′ and carrier 7)) in PLP $1 is assumed to be subject to phase change using the phase changing value #0, when the phase changing value is updated in the time-frequency domain, the slot at time T′, carrier 8 is subject to phase change using the phase changing value #1, the slot at time T′+1, carrier 1 is subject to phase change using the phase changing value #2, the slot at time T′+2, carrier 1 is subject to phase change using the phase changing value #3, the slot at time T′+3, carrier 1 is subject to phase change using the phase changing value #4, and so on. Note that, in the present embodiment, cases where (i) the transmission device inFIG.4is used, (ii) the transmission device inFIG.4is compatible with the multi-carrier scheme such as the OFDM scheme, and (iii) one encoder and a distributor is adopted in the transmission device inFIG.67and the transmission device inFIG.70as shown inFIG.4are taken as examples. The initialization of phase changing values described in the present embodiment, however, is also applicable to a case where the two streams s1and s2are transmitted and the transmission device has two single encoders as shown in the transmission device inFIG.3, the transmission device inFIG.12, the transmission device inFIG.67and the transmission device inFIG.70. The transmission devices pertaining to the present invention, as illustrated byFIGS.3,4,12,13,51,52,67,70,76, and so on transmit two modulated signals, namely modulated signal #1 and modulated signal #2, on two different transmit antennas. The average transmission power of the modulated signals #1 and #2 may be set freely. For example, when the two modulated signals each have a different average transmission power, conventional transmission power control technology used in wireless transmission systems may be applied thereto. Therefore, the average transmission power of modulated signals #1 and #2 may differ. In such circumstances, transmission power control may be applied to the baseband signals (e.g., when mapping is performed using the modulation scheme), or may be performed by a power amplifier immediately before the antenna. Embodiment F1 The schemes for regularly performing phase change on the modulated signal after precoding described in Embodiments 1 through 4, Embodiment A1, Embodiments C1 through C7, Embodiments D1 through D3 and Embodiment E1 are applicable to any baseband signals s1and s2mapped in the IQ plane. Therefore, in Embodiments 1 through 4, Embodiment A1, Embodiments C1 through C7, Embodiments D1 through D3 and Embodiment E1, the baseband signals s1and s2have not been described in detail. On the other hand, when the scheme for regularly performing phase change on the modulated signal after precoding is applied to the baseband signals s1and s2generated from the error correction coded data, excellent reception quality can be achieved by controlling average power (average value) of the baseband signals s1and s2. In the present embodiment, the following describes a scheme of setting the average power of s1and s2when the scheme for regularly performing phase change on the modulated signal after precoding is applied to the baseband signals s1and s2generated from the error correction coded data. As an example, the modulation schemes for the baseband signal s1and the baseband signal s2are described as QPSK and 16QAM, respectively. Since the modulation scheme for s1is QPSK, s1transmits two bits per symbol. Let the two bits to be transmitted be referred to as b0 and b1. On the other hand, since the modulation scheme for s2is 16QAM, s2transmits four bits per symbol. Let the four bits to be transmitted be referred to as b2, b3, b4 and b5. The transmission device transmits one slot composed of one symbol for s1and one symbol for s2, i.e. six bits b0, b1, b2, b3, b4 and b5 per slot. For example, inFIG.80as an example of signal point layout in the IQ plane for 16QAM, (b2, b3, b4, b5)=(0, 0, 0, 0) is mapped onto (I, Q)=(3×g, 3×g), (b2, b3, b4, b5)=(0, 0, 0, 1) is mapped onto (I, Q)=(3×g, 1×g), (b2, b3, b4, b5)=(0, 1, 0) is mapped onto (I, Q)=(1×g, 3×g), (b2, b3, b4, b5)=(0, 0, 1, 1) is mapped onto (I, Q)=(1×g, 1×g), (b2, b3, b4, b5)=(0, 1, 0, 0) is mapped onto (I, Q)=(3×g, −3×g), (b2, b3, b4, b5)=(1, 1, 1, 0) is mapped onto (I, Q)=(−1×g, −3×g), and (b2, b3, b4, b5)=(1, 1, 1, 1) is mapped onto (I, Q)=(−1×g, −1×g). Note that b2 through b5 shown on the top right ofFIG.80shows the bits and the arrangement of the numbers shown on the IQ plane. Also, inFIG.81as an example of signal point layout in the IQ plane for QPSK, (b0, b1)=(0, 0) is mapped onto (I, Q)=(1×h, 1×h), (b0, b1)=(0, 1) is mapped onto (I, Q)=(1×h, −1×h), (b0, b1)=(1, 0) is mapped onto (I, Q)=(−1×h, 1×h), and (b0, b1)=(1, 1) is mapped onto (I, Q)=(−1×h, −1×h). Note that b0 and b1 shown on the top right ofFIG.81shows the bits and the arrangement of the numbers shown on the IQ plane. Here, assume that the average power of s1is equal to the average power of s2, i.e. h shown inFIG.81is represented by formula 78 and g shown inFIG.80is represented by formula 79. [Math. 78] h=z2(formula78) [Math. 79] g=z10(Formula79) FIG.82shows the log-likelihood ratio obtained by the reception device in this case.FIG.82schematically shows absolute values of the log-likelihood ratio for b0 through b5 described above when the reception device obtains the log-likelihood ratio. InFIG.82,8200is the absolute value of the log-likelihood ratio for b0,8201is the absolute value of the log-likelihood ratio for b1,8202is the absolute value of the log-likelihood ratio for b2,8203is the absolute value of the log-likelihood ratio for b3,8204is the absolute value of the log-likelihood ratio for b4, and8205is the absolute value of the log-likelihood ratio for b5. In this case, as shown inFIG.82, when the absolute values of the log-likelihood ratio for b0 and b1 transmitted in QPSK are compared with the absolute values of the log-likelihood ratio for b2 through b5 transmitted in 16QAM, the absolute values of the log-likelihood ratio for b0 and b1 are higher than the absolute values of the log-likelihood ratio for b2 through b5. That is, reliability of b0 and b1 in the reception device is higher than the reliability of b2 through b5 in the reception device. This is because of the following reason. When h is represented by formula 79 inFIG.80, a minimum Euclidian distance between signal points in the IQ plane for QPSK is as follows. [Math. 80] 2z(formula80) On the other hand, when h is represented by formula 78 inFIG.78, a minimum Euclidian distance between signal points in the IQ plane for 16QAM is as follows. [Math. 81] 210z(Formula81) If the reception device performs error correction decoding (e.g. belief propagation decoding such as a sum-product decoding in a case where the communication system uses LDPC codes) under this situation, due to a difference in reliability that “the absolute values of the log-likelihood ratio for b0 and b1 are higher than the absolute values of the log-likelihood ratio for b2 through b5”, a problem that the data reception quality degrades in the reception device by being affected by the absolute values of the log-likelihood ratio for b2 through b5 arises. In order to overcome the problem, the difference between the absolute values of the log-likelihood ratio for b0 and b1 and the absolute values of the log-likelihood ratio for b2 through b5 should be reduced compared withFIG.82, as shown inFIG.83. Therefore, it is considered that the average power (average value) of s1is made to be different from the average power (average value) of s2.FIGS.84and85each show an example of the structure of the signal processor relating to a power changer (although being referred to as the power changer here, the power changer may be referred to as an amplitude changer or a weight unit) and the weighting (precoding) unit. InFIG.84, elements that operate in a similar way toFIG.3andFIG.6bear the same reference signs. Also, inFIG.85, elements that operate in a similar way toFIG.3,FIG.6andFIG.84bear the same reference signs. The following explains some examples of operations of the power changer. Example 1 First, an example of the operation is described usingFIG.84. Let s1(t) be the (mapped) baseband signal for the modulation scheme QPSK. The mapping scheme for s1(t) is as shown inFIG.81, and h is as represented by formula 78. Also, let s2(t) be the (mapped) baseband signal for the modulation scheme 16QAM. The mapping scheme for s2(t) is as shown inFIG.80, and g is as represented by formula 79. Note that t is time. In the present embodiment, description is made taking the time domain as an example. The power changer (8401B) receives a (mapped) baseband signal307B for the modulation scheme 16QAM and a control signal (8400) as input. Letting a value for power change set based on the control signal (8400) be u, the power changer outputs a signal (8402B) obtained by multiplying the (mapped) baseband signal307B for the modulation scheme 16QAM by u. Let u be a real number, and u>1.0. Letting the precoding matrix used in the scheme for regularly performing phase change on the modulated signal after precoding be F and the phase changing value used for regularly performing phase change be y(t) (y(t) may be imaginary number having the absolute value of 1, i.e. ej−θ(t), the following formula is satisfied. [Math. 82] (z1(t)z2(t))=(100y(t))F(ej000uej0)(s1(t)s2(t))=(100y(t))F(100u)(s1(t)s2(t))(formula82) Therefore, a ratio of the average power for QPSK to the average power for 16QAM is set to 1:u2. With this structure, the reception device is in a reception condition in which the absolute value of the log-likelihood ratio shown inFIG.83is obtained. Therefore, data reception quality is improved in the reception device. The following describes a case where u in the ratio of the average power for QPSK to the average power for 16QAM 1:u2is set as shown in the following formula. [Math. 83] u=5(formula83) In this case, the minimum Euclidian distance between signal points in the IQ plane for QPSK and the minimum Euclidian distance between signal points in the IQ plane for 16QAM can be the same. Therefore, excellent reception quality can be achieved. The condition that the minimum Euclidian distances between signal points in the IQ plane for two different modulation schemes are equalized, however, is a mere example of the scheme of setting the ratio of the average power for QPSK to the average power for 16QAM. For example, according to other conditions such as a code length and a coding rate of an error correction code used for error correction codes, excellent reception quality may be achieved when the value u for power change is set to a value (higher value or lower value) different from the value at which the minimum Euclidian distances between signal points in the IQ plane for two different modulation schemes are equalized. In order to increase the minimum distance between candidate signal points obtained at the time of reception, a scheme of setting the value u as shown in the following formula is considered, for example. [Math. 84] u=2(formula84) The value, however, is set appropriately according to conditions required as a system. This will be described later in detail. In the conventional technology, transmission power control is generally performed based on feedback information from a communication partner. The present invention is characterized in that the transmission power is controlled regardless of the feedback information from the communication partner in the present embodiment. Detailed description is made on this point. The above describes that the value u for power change is set based on the control signal (8400). The following describes setting of the value u for power change based on the control signal (8400) in order to improve data reception quality in the reception device in detail. Example 1-1 The following describes a scheme of setting the average power (average values) of s1and s2according to a block length (the number of bits constituting one coding (encoded) block, and is also referred to as the code length) for the error correction coding used to generate s1and s2when the transmission device supports a plurality of block lengths for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of block lengths are supported. Encoded data for which error correction codes whose block length is selected from among the plurality of supported block lengths has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected block length for the error correction codes described above. The power changer (8401B) sets the value u for power change according to the control signal (8400). The example 1-1 is characterized in that the power changer (8401B) sets the value u for power change according to the selected block length indicated by the control signal (8400). Here, a value for power change set according to a block length X is referred to as uLX For example, when 1000 is selected as the block length, the power changer (8401B) sets a value for power change to uL1000. When 1500 is selected as the block length, the power changer (8401B) sets a value for power change to uL1500. When 3000 is selected as the block length, the power changer (8401B) sets a value for power change to uL3000. In this case, for example, by setting uL1000, uL1500and uL3000so as to be different from one another, a high error correction capability can be achieved for each code length. Depending on the set code length, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the code length is changed, it is unnecessary to change the value for power change (for example, uL1000=uL1500may be satisfied. What is important is that two or more values exist in uL1000, uL1500and uL3000). Although the case of three code lengths is taken as an example in the above description, the present invention is not limited to this. The important point is that two or more values for power change exist when there are two or more code lengths that can be set, and the transmission device selects any of the values for power change from among the two or more values for power change when the code length is set, and performs power change. Example 1-2 The following describes a scheme of setting the average power (average values) of s1and s2according to a coding rate for the error correction codes used to generate s1and s2when the transmission device supports a plurality of coding rates for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of coding rates are supported. Encoded data for which error correction codes whose coding rate is selected from among the plurality of supported coding rates has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected coding rate for the error correction codes described above. The power changer (8401B) sets the value u for power change according to the control signal (8400). The example 1-2 is characterized in that the power changer (8401B) sets the value u for power change according to the selected coding rate indicated by the control signal (8400). Here, a value for power change set according to a coding rate rx is referred to as urX. For example, when r1is selected as the coding rate, the power changer (8401B) sets a value for power change to ur1. When r2is selected as the coding rate, the power changer (8401B) sets a value for power change to ur2. When r3is selected as the coding rate, the power changer (8401B) sets a value for power change to ur3. In this case, for example, by setting ur1, ur2and ur3so as to be different from one another, a high error correction capability can be achieved for each coding rate. Depending on the set coding rate, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the coding rate is changed, it is unnecessary to change the value for power change (for example, ur1=ur2may be satisfied. What is important is that two or more values exist in ur1, ur2and ur3). Note that, as examples of r1, r2and r3described above, coding rates 1/2, 2/3 and 3/4 are considered when the error correction code is the LDPC code. Although the case of three coding rates is taken as an example in the above description, the present invention is not limited to this. The important point is that two or more values for power change exist when there are two or more coding rates that can be set, and the transmission device selects any of the values for power change from among the two or more values for power change when the coding rate is set, and performs power change. Example 1-3 In order for the reception device to achieve excellent data reception quality, it is important to implement the following. The following describes a scheme of setting the average power (average values) of s1and s2according to a modulation scheme used to generate s1and s2when the transmission device supports a plurality of modulation schemes. Here, as an example, a case where the modulation scheme for s1is fixed to QPSK and the modulation scheme for s2is changed from 16QAM to 64QAM by the control signal (or can be set to either 16QAM or 64QAM) is considered. Note that, in a case where the modulation scheme for s2(t) is 64QAM, the mapping scheme for s2(t) is as shown inFIG.86. InFIG.86, k is represented by the following formula. [Math. 85] k=z42(formula85) By performing mapping in this way, the average power obtained when h inFIG.81for QPSK is represented by formula 78 becomes equal to the average power obtained when g inFIG.80for 16QAM is represented by formula 79. In the mapping in 64QAM, the values I and Q are determined from an input of six bits. In this regard, the mapping 64QAM may be performed similarly to the mapping in QPSK and 16QAM. That is to say, inFIG.86as an example of signal point layout in the IQ plane for 64QAM, (b0, b1, b2, b3, b4, b5)=(0, 0, 0, 0, 0, 0) is mapped onto (I, Q)=(7×k, 7×k), (b0, b1, b2, b3, b4, b5)=(0, 0, 0, 0, 0, 1) is mapped onto (I, Q)=(7×k, 5×k), (b0, b1, b2, b3, b4, b5)=(0, 0, 0, 0, 1, 0) is mapped onto (I, Q)=(5×k, 7×k), (b0, b1, b2, b3, b4, b5)=(0, 0, 0, 0, 1, 1) is mapped onto (I, Q)=(5×k, 5×k), (b0, b1, b2, b3, b4, b5)=(0, 0, 0, 1, 0, 0) is mapped onto (I, Q)=(7×k, 1×k), (b0, b1, b2, b3, b4, b5)=(1, 1, 1, 1, 1, 0) is mapped onto (I, Q)=(−3×k, −1×k), and (b0, b1, b2, b3, b4, b5)=(1, 1, 1, 1, 1, 1) is mapped onto (I, Q)=(−3×k, −3×k). Note that b0 through b5 shown on the top right ofFIG.86shows the bits and the arrangement of the numbers shown on the IQ plane. InFIG.84, the power changer8401B sets such that u=u16when the modulation scheme for s2is 16QAM, and sets such that u=u64when the modulation scheme for s2is 64QAM. In this case, due to the relationship between minimum Euclidian distances, by setting such that u16<u64, excellent data reception quality is obtained in the reception device when the modulation scheme for s2is either 16QAM or 64QAM. Note that, in the above description, the “modulation scheme for s1is fixed to QPSK”. It is also considered that the modulation scheme for s2is fixed to QPSK. In this case, power change is assumed to be not performed for the fixed modulation scheme (here, QPSK), and to be performed for a plurality of modulation schemes that can be set (here, 16QAM and 64QAM). That is to say, in this case, the transmission device does not have the structure shown inFIG.84, but has a structure in which the power changer8401B is eliminated from the structure inFIG.84and a power changer is provided to a s1(t)-side. When the fixed modulation scheme (here, QPSK) is set to s2, the following formula 86 is satisfied. [Math. 86] (z1(t)z2(t))=(100y(t))F(uej000ej0)(s1(t)s2(t))=(100y(t))F(u001)(s1(t)s2(t))(formula86) When the modulation scheme for s2is fixed to QPSK and the modulation scheme for s1is changed from 16QAM to 64QAM (is set to either 16QAM or 64QAM), the relationship u16<u64should be satisfied (note that a multiplied value for power change in 16QAM is u16, a multiplied value for power change in 64QAM is u64, and power change is not performed in QPSK). Also, when a set of the modulation scheme for s1and the modulation scheme for s2can be set to any one of a set of QPSK and 16QAM, a set of 16QAM and QPSK, a set of QPSK and 64QAM and a set of 64QAM and QPSK, the relationship u16<u64should be satisfied. The following describes a case where the above-mentioned description is generalized. Let the modulation scheme for s1be fixed to a modulation scheme C in which the number of signal points in the IQ plane is c. Also, let the modulation scheme for s2be set to either a modulation scheme A in which the number of signal points in the IQ plane is a or a modulation scheme B in which the number of signal points in the IQ plane is b (a>b>c) (however, let the average power (average value) for s2in the modulation scheme A be equal to the average power (average value) for s2in the modulation scheme B). In this case, a value for power change set when the modulation scheme A is set to the modulation scheme for s2is ua. Also, a value for power change set when the modulation scheme B is set to the modulation scheme for s2is ub. In this case, when the relationship ub<uais satisfied, excellent data reception quality is obtained in the reception device. Power change is assumed to be not performed for the fixed modulation scheme (here, modulation scheme C), and to be performed for a plurality of modulation schemes that can be set (here, modulation schemes A and B). When the modulation scheme for s2is fixed to the modulation scheme C and the modulation scheme for s1is changed from the modulation scheme A to the modulation scheme B (is set to either the modulation schemes A or B), the relationship ub<uashould be satisfied. Also, when a set of the modulation scheme for s1and the modulation scheme for s2can be set to any one of a set of the modulation scheme C and the modulation scheme A, a set of the modulation scheme A and the modulation scheme C, a set of the modulation scheme C and the modulation scheme B and a set of the modulation scheme B and the modulation scheme C, the relationship ub<uashould be satisfied. Example 2 The following describes an example of the operation different from that described in Example 1, usingFIG.84. Let s1(t) be the (mapped) baseband signal for the modulation scheme 64QAM. The mapping scheme for s1(t) is as shown inFIG.86, and k is as represented by formula 85. Also, let s2(t) be the (mapped) baseband signal for the modulation scheme 16QAM. The mapping scheme for s2(t) is as shown inFIG.80, and g is as represented by formula 79. Note that t is time. In the present embodiment, description is made taking the time domain as an example. The power changer (8401B) receives a (mapped) baseband signal307B for the modulation scheme 16QAM and a control signal (8400) as input. Letting a value for power change set based on the control signal (8400) be u, the power changer outputs a signal (8402B) obtained by multiplying the (mapped) baseband signal307B for the modulation scheme 16QAM by u. Let u be a real number, and u<1.0. Letting the precoding matrix used in the scheme for regularly performing phase change on the modulated signal after precoding be F and the phase changing value used for regularly performing phase change be y(t) (y(t) may be imaginary number having the absolute value of 1, i.e. ejθ(t), formula 82 is satisfied. Therefore, a ratio of the average power for 64QAM to the average power for 16QAM is set to 1:u2. With this structure, the reception device is in a reception condition as shown inFIG.83. Therefore, data reception quality is improved in the reception device. In the conventional technology, transmission power control is generally performed based on feedback information from a communication partner. The present invention is characterized in that the transmission power is controlled regardless of the feedback information from the communication partner in the present embodiment. Detailed description is made on this point. The above describes that the value u for power change is set based on the control signal (8400). The following describes setting of the value u for power change based on the control signal (8400) in order to improve data reception quality in the reception device in detail. Example 2-1 The following describes a scheme of setting the average power (average values) of s1and s2according to a block length (the number of bits constituting one coding (encoded) block, and is also referred to as the code length) for the error correction codes used to generate s1and s2when the transmission device supports a plurality of block lengths for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of block lengths are supported. Encoded data for which error correction codes whose block length is selected from among the plurality of supported block lengths has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected block length for the error correction codes described above. The power changer (8401B) sets the value u for power change according to the control signal (8400). The example 1-1 is characterized in that the power changer (8401B) sets the value u for power change according to the selected block length indicated by the control signal (8400). Here, a value for power change set according to a block length X is referred to as uLX For example, when 1000 is selected as the block length, the power changer (8401B) sets a value for power change to uL1000. When 1500 is selected as the block length, the power changer (8401B) sets a value for power change to uL1500. When 3000 is selected as the block length, the power changer (8401B) sets a value for power change to uL3000. In this case, for example, by setting uL1000, uL1500and uL3000so as to be different from one another, a high error correction capability can be achieved for each code length. Depending on the set code length, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the code length is changed, it is unnecessary to change the value for power change (for example, uL1000=uL1500may be satisfied. What is important is that two or more values exist in uL1000, uL1500and uL3000). Although the case of three code lengths is taken as an example in the above description, the present invention is not limited to this. The important point is that two or more values for power change exist when there are two or more code lengths that can be set, and the transmission device selects any of the values for power change from among the two or more values for power change when the code length is set, and performs power change. Example 2-2 The following describes a scheme of setting the average power (average values) of s1and s2according to a coding rate for the error correction codes used to generate s1and s2when the transmission device supports a plurality of coding rates for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of coding rates are supported. Encoded data for which error correction codes whose coding rate is selected from among the plurality of supported coding rates has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected coding rate for the error correction codes described above. The power changer (8401B) sets the value u for power change according to the control signal (8400). The example 1-2 is characterized in that the power changer (8401B) sets the value u for power change according to the selected coding rate indicated by the control signal (8400). Here, a value for power change set according to a coding rate rx is referred to as urx. For example, when r1is selected as the coding rate, the power changer (8401B) sets a value for power change to ur1. When r2is selected as the coding rate, the power changer (8401B) sets a value for power change to ur2. When r3is selected as the coding rate, the power changer (8401B) sets a value for power change to ur3. In this case, for example, by setting ur1, ur2and ur3so as to be different from one another, a high error correction capability can be achieved for each coding rate. Depending on the set coding rate, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the coding rate is changed, it is unnecessary to change the value for power change (for example, ur1=ur2may be satisfied. What is important is that two or more values exist in ur1, ur2and ur3). Note that, as examples of r1, r2and r3described above, coding rates 1/2, 2/3 and 3/4 are considered when the error correction code is the LDPC code. Although the case of three coding rates is taken as an example in the above description, the present invention is not limited to this. The important point is that two or more values for power change exist when there are two or more coding rates that can be set, and the transmission device selects any of the values for power change from among the two or more values for power change when the coding rate is set, and performs power change. Example 2-3 In order for the reception device to achieve excellent data reception quality, it is important to implement the following. The following describes a scheme of setting the average power (average values) of s1and s2according to a modulation scheme used to generate s1and s2when the transmission device supports a plurality of modulation schemes. Here, as an example, a case where the modulation scheme for s1is fixed to 64QAM and the modulation scheme for s2is changed from 16QAM to QPSK by the control signal (or can be set to either 16QAM or QPSK) is considered. In a case where the modulation scheme for s1is 64QAM, the mapping scheme for s1(t) is as shown inFIG.86, and k is represented by formula 85 inFIG.86. In a case where the modulation scheme for s2is 16QAM, the mapping scheme for s2(t) is as shown inFIG.80, and g is represented by formula 79 inFIG.80. Also, in a case where the modulation scheme for s2(t) is QPSK, the mapping scheme for s2(t) is as shown inFIG.81, and h is represented by formula 78 inFIG.81. By performing mapping in this way, the average power in 16QAM becomes equal to the average power (average value) in QPSK. InFIG.84, the power changer8401B sets such that u=u16when the modulation scheme for s2is 16QAM, and sets such that u=u4when the modulation scheme for s2is QPSK. In this case, due to the relationship between minimum Euclidian distances, by setting such that u4<u16, excellent data reception quality is obtained in the reception device when the modulation scheme for s2is either 16QAM or QPSK. Note that, in the above description, the modulation scheme for s1is fixed to 64QAM. When the modulation scheme for s2is fixed to 64QAM and the modulation scheme for s1is changed from 16QAM to QPSK (is set to either 16QAM or QPSK), the relationship u 4<u16should be satisfied (the same considerations should be made as the example 1-3) (note that a multiplied value for power change in 16QAM is u16, a multiplied value for power change in QPSK is u4, and power change is not performed in 64QAM). Also, when a set of the modulation scheme for s1and the modulation scheme for s2can be set to any one of a set of 64QAM and 16QAM, a set of 16QAM and 64QAM, a set of 64QAM and QPSK and a set of QPSK and 64QAM, the relationship u4<u16should be satisfied. The following describes a case where the above-mentioned description is generalized. Let the modulation scheme for s1be fixed to a modulation scheme C in which the number of signal points in the IQ plane is c. Also, let the modulation scheme for s2be set to either a modulation scheme A in which the number of signal points in the IQ plane is a or a modulation scheme B in which the number of signal points in the IQ plane is b (c>b>a) (however, let the average power (average value) for s2in the modulation scheme A be equal to the average power (average value) for s2in the modulation scheme B). In this case, a value for power change set when the modulation scheme A is set to the modulation scheme for s2is ua. Also, a value for power change set when the modulation scheme B is set to the modulation scheme for s2is ub. In this case, when the relationship ua<ubis satisfied, excellent data reception quality is obtained in the reception device. Power change is assumed to be not performed for the fixed modulation scheme (here, modulation scheme C), and to be performed for a plurality of modulation schemes that can be set (here, modulation schemes A and B). When the modulation scheme for s2is fixed to the modulation scheme C and the modulation scheme for s1is changed from the modulation scheme A to the modulation scheme B (is set to either the modulation schemes A or B), the relationship ua<ubshould be satisfied. Also, when a set of the modulation scheme for s1and the modulation scheme for s2can be set to any one of a set of the modulation scheme C and the modulation scheme A, a set of the modulation scheme A and the modulation scheme C, a set of the modulation scheme C and the modulation scheme B and a set of the modulation scheme B and the modulation scheme C, the relationship ua<ubshould be satisfied. Example 3 The following describes an example of the operation different from that described in Example 1, usingFIG.84. Let s1(t) be the (mapped) baseband signal for the modulation scheme 16QAM. The mapping scheme for s1(t) is as shown inFIG.80, and g is as represented by formula 79. Let s2(t) be the (mapped) baseband signal for the modulation scheme 64QAM. The mapping scheme for s2(t) is as shown inFIG.86, and k is as represented by formula 85. Note that t is time. In the present embodiment, description is made taking the time domain as an example. The power changer (8401B) receives a (mapped) baseband signal307B for the modulation scheme 64QAM and a control signal (8400) as input. Letting a value for power change set based on the control signal (8400) be u, the power changer outputs a signal (8402B) obtained by multiplying the (mapped) baseband signal307B for the modulation scheme 64QAM by u. Let u be a real number, and u>1.0. Letting the precoding matrix used in the scheme for regularly performing phase change on the modulated signal after precoding be F and the phase changing value used for regularly performing phase change be y(t) (y(t) may be imaginary number having the absolute value of 1, i.e. ejθ(t), formula 82 is satisfied. Therefore, a ratio of the average power for 16QAM to the average power for 64QAM is set to 1:u2. With this structure, the reception device is in a reception condition as shown inFIG.83. Therefore, data reception quality is improved in the reception device. In the conventional technology, transmission power control is generally performed based on feedback information from a communication partner. The present invention is characterized in that the transmission power is controlled regardless of the feedback information from the communication partner in the present embodiment. Detailed description is made on this point. The above describes that the value u for power change is set based on the control signal (8400). The following describes setting of the value u for power change based on the control signal (8400) in order to improve data reception quality in the reception device in detail. Example 3-1 The following describes a scheme of setting the average power (average values) of s1and s2according to a block length (the number of bits constituting one coding (encoded) block, and is also referred to as the code length) for the error correction codes used to generate s1and s2when the transmission device supports a plurality of block lengths for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of block lengths are supported. Encoded data for which error correction codes whose block length is selected from among the plurality of supported block lengths has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected block length for the error correction codes described above. The power changer (8401B) sets the value u for power change according to the control signal (8400). The example 1-1 is characterized in that the power changer (8401B) sets the value u for power change according to the selected block length indicated by the control signal (8400). Here, a value for power change set according to a block length X is referred to as uLX For example, when 1000 is selected as the block length, the power changer (8401B) sets a value for power change to uL1000. When 1500 is selected as the block length, the power changer (8401B) sets a value for power change to uL1500. When 3000 is selected as the block length, the power changer (8401B) sets a value for power change to uL3000. In this case, for example, by setting uL1000, uL1500and uL3000so as to be different from one another, a high error correction capability can be achieved for each code length. Depending on the set code length, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the code length is changed, it is unnecessary to change the value for power change (for example, uL1000=uL1500may be satisfied. What is important is that two or more values exist in uL1000, uL1500and uL1000). Although the case of three code lengths is taken as an example in the above description, the present invention is not limited to this. The important point is that two or more values for power change exist when there are two or more code lengths that can be set, and the transmission device selects any of the values for power change from among the two or more values for power change when the code length is set, and performs power change. Example 3-2 The following describes a scheme of setting the average power (average values) of s1and s2according to a coding rate for the error correction codes used to generate s1and s2when the transmission device supports a plurality of coding rates for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of coding rates are supported. Encoded data for which error correction codes whose coding rate is selected from among the plurality of supported coding rates has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected coding rate for the error correction codes described above. The power changer (8401B) sets the value u for power change according to the control signal (8400). The example 1-2 is characterized in that the power changer (8401B) sets the value u for power change according to the selected coding rate indicated by the control signal (8400). Here, a value for power change set according to a coding rate rx is referred to as urx. For example, when r1is selected as the coding rate, the power changer (8401B) sets a value for power change to ur1. When r2is selected as the coding rate, the power changer (8401B) sets a value for power change to ur2. When r3is selected as the coding rate, the power changer (8401B) sets a value for power change to ur3. In this case, for example, by setting ur1, ur2and ur3so as to be different from one another, a high error correction capability can be achieved for each coding rate. Depending on the set coding rate, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the coding rate is changed, it is unnecessary to change the value for power change (for example, ur1=ur2may be satisfied. What is important is that two or more values exist in ur1, ur2and ur3). Note that, as examples of r1, r2and r3described above, coding rates 1/2, 2/3 and 3/4 are considered when the error correction code is the LDPC code. Although the case of three coding rates is taken as an example in the above description, the present invention is not limited to this. The important point is that two or more values for power change exist when there are two or more coding rates that can be set, and the transmission device selects any of the values for power change from among the two or more values for power change when the coding rate is set, and performs power change. Example 3-3 In order for the reception device to achieve excellent data reception quality, it is important to implement the following. The following describes a scheme of setting the average power (average values) of s1and s2according to a modulation scheme used to generate s1and s2when the transmission device supports a plurality of modulation schemes. Here, as an example, a case where the modulation scheme for s1is fixed to 16QAM and the modulation scheme for s2is changed from 64QAM to QPSK by the control signal (or can be set to either 64QAM or QPSK) is considered. In a case where the modulation scheme for s1is 16QAM, the mapping scheme for s2(t) is as shown inFIG.80, and g is represented by formula 79 inFIG.80. In a case where the modulation scheme for s2is 64QAM, the mapping scheme for s1(t) is as shown inFIG.86, and k is represented by formula 85 inFIG.86. Also, in a case where the modulation scheme for s2(t) is QPSK, the mapping scheme for s2(t) is as shown inFIG.81, and his represented by formula 78 inFIG.81. By performing mapping in this way, the average power in 16QAM becomes equal to the average power in QPSK. InFIG.84, the power changer8401B sets such that u=u64when the modulation scheme for s2is 64QAM, and sets such that u=u4when the modulation scheme for s2is QPSK. In this case, due to the relationship between minimum Euclidian distances, by setting such that u4<u64, excellent data reception quality is obtained in the reception device when the modulation scheme for s2is either 16QAM or 64QAM. Note that, in the above description, the modulation scheme for s1is fixed to 16QAM. When the modulation scheme for s2is fixed to 16QAM and the modulation scheme for s1is changed from 64QAM to QPSK (is set to either 64QAM or QPSK), the relationship u 4<u64should be satisfied (the same considerations should be made as the example 1-3) (note that a multiplied value for power change in 64QAM is u64, a multiplied value for power change in QPSK is u4, and power change is not performed in 16QAM). Also, when a set of the modulation scheme for s1and the modulation scheme for s2can be set to any one of a set of 16QAM and 64QAM, a set of 64QAM and 16QAM, a set of 16QAM and QPSK and a set of QPSK and 16QAM, the relationship u 4<u64should be satisfied. The following describes a case where the above-mentioned description is generalized. Let the modulation scheme for s1be fixed to a modulation scheme C in which the number of signal points in the IQ plane is c. Also, let the modulation scheme for s2be set to either a modulation scheme A in which the number of signal points in the IQ plane is a or a modulation scheme B in which the number of signal points in the IQ plane is b (c>b>a) (however, let the average power (average value) for s2in the modulation scheme A be equal to the average power (average value) for s2in the modulation scheme B). In this case, a value for power change set when the modulation scheme A is set to the modulation scheme for s2is ua. Also, a value for power change set when the modulation scheme B is set to the modulation scheme for s2is ub. In this case, when the relationship ua<ubis satisfied, excellent data reception quality is obtained in the reception device. Power change is assumed to be not performed for the fixed modulation scheme (here, modulation scheme C), and to be performed for a plurality of modulation schemes that can be set (here, modulation schemes A and B). When the modulation scheme for s2is fixed to the modulation scheme C and the modulation scheme for s1is changed from the modulation scheme A to the modulation scheme B (is set to either the modulation schemes A or B), the relationship ua<ubshould be satisfied. Also, when a set of the modulation scheme for s1and the modulation scheme for s2can be set to any one of a set of the modulation scheme C and the modulation scheme A, a set of the modulation scheme A and the modulation scheme C, a set of the modulation scheme C and the modulation scheme B and a set of the modulation scheme B and the modulation scheme C, the relationship ua<ubshould be satisfied. Example 4 The case where power change is performed for one of the modulation schemes for s1and s2has been described above. The following describes a case where power change is performed for both of the modulation schemes for s1and s2. An example of the operation is described usingFIG.85. Let s1(t) be the (mapped) baseband signal for the modulation scheme QPSK. The mapping scheme for s1(t) is as shown inFIG.81, and h is as represented by formula 78. Also, let s2(t) be the (mapped) baseband signal for the modulation scheme 16QAM. The mapping scheme for s2(t) is as shown inFIG.80, and g is as represented by formula 79. Note that t is time. In the present embodiment, description is made taking the time domain as an example. The power changer (8401A) receives a (mapped) baseband signal307A for the modulation scheme QPSK and the control signal (8400) as input. Letting a value for power change set based on the control signal (8400) be v, the power changer outputs a signal (8402A) obtained by multiplying the (mapped) baseband signal307A for the modulation scheme QPSK by v. The power changer (8401B) receives a (mapped) baseband signal307B for the modulation scheme 16QAM and a control signal (8400) as input. Letting a value for power change set based on the control signal (8400) be u, the power changer outputs a signal (8402B) obtained by multiplying the (mapped) baseband signal307B for the modulation scheme 16QAM by u. Then, let u=v x w (w >1.0). Letting the precoding matrix used in the scheme for regularly performing phase change on the modulated signal after precoding be F and the phase changing value used for regularly performing phase change be y(t) (y(t) may be imaginary number having the absolute value of 1, i.e. ejθ(t), formula 87 shown next is satisfied. [Math. 87] (z1(t)z2(t))=(100y(t))F(vej000uej0)(s1(t)s2(t))=(100y(t))F(v00u)(s1(t)s2(t))=(100y(t))F(v00v×w)(s1(t)s2(t))(formula87) Therefore, a ratio of the average power for QPSK to the average power for 16QAM is set to v2:u 2=v2:v2×w2=1:w2. With this structure, the reception device is in a reception condition as shown inFIG.83. Therefore, data reception quality is improved in the reception device. Note that, in view of formula 83 and formula 84, effective examples of the ratio of the average power for QPSK to the average power for 16QAM are considered to be v2:u2=v2:v2×w2=1:w2=1:5 or v2:u2=v2:v2×w2=1:w2=1:2. The ratio, however, is set appropriately according to conditions required as a system. In the conventional technology, transmission power control is generally performed based on feedback information from a communication partner. The present invention is characterized in that the transmission power is controlled regardless of the feedback information from the communication partner in the present embodiment. Detailed description is made on this point. The above describes that the values v and u for power change are set based on the control signal (8400). The following describes setting of the values v and u for power change based on the control signal (8400) in order to improve data reception quality in the reception device in detail. Example 4-1 The following describes a scheme of setting the average power (average values) of s1and s2according to a block length (the number of bits constituting one coding (encoded) block, and is also referred to as the code length) for the error correction codes used to generate s1and s2when the transmission device supports a plurality of block lengths for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of block lengths are supported. Encoded data for which error correction codes whose block length is selected from among the plurality of supported block lengths has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected block length for the error correction codes described above. The power changer (8401B) sets the value v for power change according to the control signal (8400). Similarly, the power changer (8401B) sets the value u for power change according to the control signal (8400). The present invention is characterized in that the power changers (8401A and8401B) respectively set the values v and u for power change according to the selected block length indicated by the control signal (8400). Here, values for power change set according to the block length X are referred to as vLXand uLX. For example, when 1000 is selected as the block length, the power changer (8401A) sets a value for power change to vL1000. When 1500 is selected as the block length, the power changer (8401A) sets a value for power change to vL1500. When 3000 is selected as the block length, the power changer (8401A) sets a value for power change to vL3000. On the other hand, when 1000 is selected as the block length, the power changer (8401B) sets a value for power change to uL1000. When 1500 is selected as the block length, the power changer (8401B) sets a value for power change to uL1500. When 3000 is selected as the block length, the power changer (8401B) sets a value for power change to uL3000. In this case, for example, by setting vL1000, vL1500and vL3000so as to be different from one another, a high error correction capability can be achieved for each code length. Similarly, by setting uL1000, uL1500and uL3000so as to be different from one another, a high error correction capability can be achieved for each code length. Depending on the set code length, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the code length is changed, it is unnecessary to change the value for power change (for example, uL1000=uL1500may be satisfied, and vL1000=vL1500may be satisfied. What is important is that two or more values exist in a set of vL1000, vL1500and vL3000, and that two or more values exist in a set of uL1000, uL1500and uL1000). Note that, as described above, vLXand uLXare set so as to satisfy the ratio of the average power 1:w2. Although the case of three code lengths is taken as an example in the above description, the present invention is not limited to this. One important point is that two or more values uLXfor power change exist when there are two or more code lengths that can be set, and the transmission device selects any of the values for power change from among the two or more values uLXfor power change when the code length is set, and performs power change. Another important point is that two or more values vLXfor power change exist when there are two or more code lengths that can be set, and the transmission device selects any of the values for power change from among the two or more values vLXfor power change when the code length is set, and performs power change. Example 4-2 The following describes a scheme of setting the average power (average values) of s1and s2according to a coding rate for the error correction codes used to generate s1and s2when the transmission device supports a plurality of coding rates for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of coding rates are supported. Encoded data for which error correction codes whose coding rate is selected from among the plurality of supported coding rates has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected coding rate for the error correction codes described above. The power changer (8401A) sets the value v for power change according to the control signal (8400). Similarly, the power changer (8401B) sets the value u for power change according to the control signal (8400). The present invention is characterized in that the power changers (8401A and8401B) respectively set the values v and u for power change according to the selected coding rate indicated by the control signal (8400). Here, values for power change set according to the coding rate rx are referred to as vrxand urx. For example, when r1is selected as the coding rate, the power changer (8401A) sets a value for power change to vr1. When r2is selected as the coding rate, the power changer (8401A) sets a value for power change to vr2. When r3is selected as the coding rate, the power changer (8401A) sets a value for power change to vr3. Also, when r1is selected as the coding rate, the power changer (8401B) sets a value for power change to ur1. When r2is selected as the coding rate, the power changer (8401B) sets a value for power change to ur2. When r3is selected as the coding rate, the power changer (8401B) sets a value for power change to ur3In this case, for example, by setting vr1, vr2and vr3so as to be different from one another, a high error correction capability can be achieved for each code length. Similarly, by setting ur1, ur2and ur3so as to be different from one another, a high error correction capability can be achieved for each coding rate. Depending on the set coding rate, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the coding rate is changed, it is unnecessary to change the value for power change (for example, vr1=vr2may be satisfied, and ur1=ur2may be satisfied. What is important is that two or more values exist in a set of vr1, vr2and vr3, and that two or more values exist in a set of ur1, ur2and ur3). Note that, as described above, vrxand urxare set so as to satisfy the ratio of the average power 1:w2. Also, note that, as examples of r1, r2and r3described above, coding rates 1/2, 2/3 and 3/4 are considered when the error correction code is the LDPC code. Although the case of three coding rates is taken as an example in the above description, the present invention is not limited to this. One important point is that two or more values up, for power change exist when there are two or more coding rates that can be set, and the transmission device selects any of the values for power change from among the two or more values up, for power change when the coding rate is set, and performs power change. Another important point is that two or more values vrxfor power change exist when there are two or more coding rates that can be set, and the transmission device selects any of the values for power change from among the two or more values vrxfor power change when the coding rate is set, and performs power change. Example 4-3 In order for the reception device to achieve excellent data reception quality, it is important to implement the following. The following describes a scheme of setting the average power (average values) of s1and s2according to a modulation scheme used to generate s1and s2when the transmission device supports a plurality of modulation schemes. Here, as an example, a case where the modulation scheme for s1is fixed to QPSK and the modulation scheme for s2is changed from 16QAM to 64QAM by the control signal (or can be set to either 16QAM or 64QAM) is considered. In a case where the modulation scheme for s1is QPSK, the mapping scheme for s1(t) is as shown inFIG.81, and h is represented by formula 78 inFIG.81. In a case where the modulation scheme for s2is 16QAM, the mapping scheme for s2(t) is as shown inFIG.80, and g is represented by formula 79 inFIG.80. Also, in a case where the modulation scheme for s2(t) is 64QAM, the mapping scheme for s2(t) is as shown inFIG.86, and k is represented by formula 85 inFIG.86. InFIG.85, when the modulation scheme for s1is QPSK and the modulation scheme for s2is 16QAM, assume that v=α and u=α×w16. In this case, the ratio between the average power of QPSK and the average power of 16QAM is v2:u2=α2:α2×w162=1:w162. InFIG.85, when the modulation scheme for s1is QPSK and the modulation scheme for s2is 64QAM, assume that v=β and u=β×w64. In this case, the ratio between the average power of QPSK and the average power of 64QAM is v:u=β2:β2×w642=1:w642. In this case, according to the minimum Euclidean distance relationship, the reception device achieves high data reception quality when 1.0<w16<w64, regardless of whether the modulation scheme for s2is 16QAM or 64QAM. Note that although “the modulation scheme for s1is fixed to QPSK” in the description above, it is possible that “the modulation scheme for s2is fixed to QPSK”. In this case, power change is assumed to be not performed for the fixed modulation scheme (here, QPSK), and to be performed for a plurality of modulation schemes that can be set (here, 16QAM and 64QAM). When the fixed modulation scheme (here, QPSK) is set to s2, the following formula 88 is satisfied. [Math. 88] (z1(t)z2(t))=(100y(t))F(uej000vej0)(s1(t)s2(t))=(100y(t))F(u00v)(s1(t)s2(t))=(100y(t))F(v×w00v)(s1(t)s2(t))(formula88) Given that, even when “the modulation scheme for s2is fixed to QPSK and the modulation scheme for s1is changed from 16QAM to 64QAM (set to either 16QAM or 64QAM)”, 1.0<w16<w64should be fulfilled. (Note that the value used for the multiplication for the power change in the case of 16QAM is u=α×w16, the value used for the multiplication for the power change in the case of 64QAM is u=β×w64, the value used for the power change in the case of QPSK is v=α when the selectable modulation scheme is 16QAM and v=β when the selectable modulation scheme is 64QAM.) Also, when the set of (the modulation scheme for s1, the modulation scheme for s2) is selectable from the sets of (QPSK, 16QAM), (16QAM, QPSK), (QPSK, 64QAM) and (64QAM, QPSK), 1.0<w16<w64should be fulfilled. The following describes a case where the above-mentioned description is generalized. For generalization, assume that the modulation scheme for s1is fixed to a modulation scheme C with which the number of signal points in the IQ plane is c. Also assume that the modulation scheme for s2is selectable from a modulation scheme A with which the number of signal points in the IQ plane is a and a modulation scheme B with which the number of signal points in the IQ plane is b (a>b>c). In this case, when the modulation scheme for s2is set to the modulation scheme A, assume that ratio between the average power of the modulation scheme for s1, which is the modulation scheme C, and the average power of the modulation scheme for s2, which is the modulation scheme A, is 1:wa2. Also, when the modulation scheme for s2is set to the modulation scheme B, assume that ratio between the average power of the modulation scheme for s1, which is the modulation scheme C, and the average power of the modulation scheme for s2, which is the modulation scheme B, is 1:wb2. If this is the case, the reception device achieves a high data reception quality when wb<wais fulfilled. Note that although “the modulation scheme for s1is fixed to C” in the description above, even when “the modulation scheme for s2is fixed to the modulation scheme C and the modulation scheme for s1is changed from the modulation scheme A to the modulation scheme B (set to either the modulation scheme A or the modulation scheme B), the average powers should fulfill wb<wa. (If this is the case, as with the description above, when the average power of the modulation scheme C is 1, the average power of the modulation scheme A is wa2, and the average power of the modulation scheme B is wb2.) Also, when the set of (the modulation scheme for s1, the modulation scheme for s2) is selectable from the sets of (the modulation scheme C, the modulation scheme A), (the modulation scheme A, the modulation scheme C), (the modulation scheme C, the modulation scheme B) and (the modulation scheme B, the modulation scheme C), the average powers should fulfill wb<wa. Example 5 The following describes an example of the operation different from that described in Example 4, usingFIG.85. Let s1(t) be the (mapped) baseband signal for the modulation scheme 64QAM. The mapping scheme for s1(t) is as shown in FIG.86, and k is as represented by formula 85. Also, let s2(t) be the (mapped) baseband signal for the modulation scheme 16QAM. The mapping scheme for s2(t) is as shown inFIG.80, and g is as represented by formula 79. Note that t is time. In the present embodiment, description is made taking the time domain as an example. The power changer (8401A) receives a (mapped) baseband signal307A for the modulation scheme 64QAM and the control signal (8400) as input. Letting a value for power change set based on the control signal (8400) be v, the power changer outputs a signal (8402A) obtained by multiplying the (mapped) baseband signal307A for the modulation scheme 64QAM by v. The power changer (8401B) receives a (mapped) baseband signal307B for the modulation scheme 16QAM and a control signal (8400) as input. Letting a value for power change set based on the control signal (8400) be u, the power changer outputs a signal (8402B) obtained by multiplying the (mapped) baseband signal307B for the modulation scheme 16QAM by u. Then, let u=v×w (w<1.0). Letting the precoding matrix used in the scheme for regularly performing phase change on the modulated signal after precoding be F and the phase changing value used for regularly performing phase change be y(t) (y(t) may be imaginary number having the absolute value of 1, i.e. ejθ(t), formula 87 shown above is satisfied. Therefore, a ratio of the average power for 64QAM to the average power for 16QAM is set to v2:u 2=v2:v2×w2=1:w2. With this structure, the reception device is in a reception condition as shown inFIG.83. Therefore, data reception quality is improved in the reception device. In the conventional technology, transmission power control is generally performed based on feedback information from a communication partner. The present invention is characterized in that the transmission power is controlled regardless of the feedback information from the communication partner in the present embodiment. Detailed description is made on this point. The above describes that the values v and u for power change are set based on the control signal (8400). The following describes setting of the values v and u for power change based on the control signal (8400) in order to improve data reception quality in the reception device in detail. Example 5-1 The following describes a scheme of setting the average power (average values) of s1and s2according to a block length (the number of bits constituting one coding (encoded) block, and is also referred to as the code length) for the error correction codes used to generate s1and s2when the transmission device supports a plurality of block lengths for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of block lengths are supported. Encoded data for which error correction codes whose block length is selected from among the plurality of supported block lengths has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected block length for the error correction codes described above. The power changer (8401B) sets the value v for power change according to the control signal (8400). Similarly, the power changer (8401B) sets the value u for power change according to the control signal (8400). The present invention is characterized in that the power changers (8401A and8401B) respectively set the values v and u for power change according to the selected block length indicated by the control signal (8400). Here, values for power change set according to the block length X are referred to as vLXand uLX. For example, when 1000 is selected as the block length, the power changer (8401A) sets a value for power change to vL1000. When 1500 is selected as the block length, the power changer (8401A) sets a value for power change to vL1500. When 3000 is selected as the block length, the power changer (8401A) sets a value for power change to vL3000. On the other hand, when 1000 is selected as the block length, the power changer (8401B) sets a value for power change to uL1000. When 1500 is selected as the block length, the power changer (8401B) sets a value for power change to uL1500. When 3000 is selected as the block length, the power changer (8401B) sets a value for power change to uL3000. In this case, for example, by setting vL1000, vL1500and vL3000so as to be different from one another, a high error correction capability can be achieved for each code length. Similarly, by setting uL1000, uL1500and uL1000so as to be different from one another, a high error correction capability can be achieved for each code length. Depending on the set code length, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the code length is changed, it is unnecessary to change the value for power change (for example, uL1000=uL1500may be satisfied, and vL1000=vL1500may be satisfied. What is important is that two or more values exist in a set of vL1000, vL1500and vL3000, and that two or more values exist in a set of uL1000, uL1500and uL1000). Note that, as described above, vLXand up(are set so as to satisfy the ratio of the average power 1:w2. Although the case of three code lengths is taken as an example in the above description, the present invention is not limited to this. One important point is that two or more values uLXfor power change exist when there are two or more code lengths that can be set, and the transmission device selects any of the values for power change from among the two or more values uLXfor power change when the code length is set, and performs power change. Another important point is that two or more values vLXfor power change exist when there are two or more code lengths that can be set, and the transmission device selects any of the values for power change from among the two or more values vLXfor power change when the code length is set, and performs power change. Example 5-2 The following describes a scheme of setting the average power (average values) of s1and s2according to a coding rate for the error correction codes used to generate s1and s2when the transmission device supports a plurality of coding rates for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of coding rates are supported. Encoded data for which error correction codes whose coding rate is selected from among the plurality of supported coding rates has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected coding rate for the error correction codes described above. The power changer (8401A) sets the value v for power change according to the control signal (8400). Similarly, the power changer (8401B) sets the value u for power change according to the control signal (8400). The present invention is characterized in that the power changers (8401A and8401B) respectively set the values v and u for power change according to the selected coding rate indicated by the control signal (8400). Here, values for power change set according to the coding rate rx are referred to as vrxand urx. For example, when r1is selected as the coding rate, the power changer (8401A) sets a value for power change to vr1. When r2is selected as the coding rate, the power changer (8401A) sets a value for power change to vr2. When r3is selected as the coding rate, the power changer (8401A) sets a value for power change to vr3. Also, when r1is selected as the coding rate, the power changer (8401B) sets a value for power change to ur1. When r2is selected as the coding rate, the power changer (8401B) sets a value for power change to ur2. When r3is selected as the coding rate, the power changer (8401B) sets a value for power change to ur3. In this case, for example, by setting vr1, vr2and vr3so as to be different from one another, a high error correction capability can be achieved for each code length. Similarly, by setting ur1, ur2and ur3so as to be different from one another, a high error correction capability can be achieved for each coding rate. Depending on the set coding rate, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the coding rate is changed, it is unnecessary to change the value for power change (for example, vr1=vr2may be satisfied, and ur1=ur2may be satisfied. What is important is that two or more values exist in a set of vr1, vr2and vr3, and that two or more values exist in a set of Url, ur2and ur3). Note that, as described above, vrxand urxare set so as to satisfy the ratio of the average power 1:w2. Also, note that, as examples of r1, r2and r3described above, coding rates 1/2, 2/3 and 3/4 are considered when the error correction code is the LDPC code. Although the case of three coding rates is taken as an example in the above description, the present invention is not limited to this. One important point is that two or more values up, for power change exist when there are two or more coding rates that can be set, and the transmission device selects any of the values for power change from among the two or more values up, for power change when the coding rate is set, and performs power change. Another important point is that two or more values vrxfor power change exist when there are two or more coding rates that can be set, and the transmission device selects any of the values for power change from among the two or more values vrxfor power change when the coding rate is set, and performs power change. Example 5-3 In order for the reception device to achieve excellent data reception quality, it is important to implement the following. The following describes a scheme of setting the average power (average values) of s1and s2according to a modulation scheme used to generate s1and s2when the transmission device supports a plurality of modulation schemes. Here, as an example, a case where the modulation scheme for s1is fixed to 64QAM and the modulation scheme for s2is changed from 16QAM to QPSK by the control signal (or can be set to either 16QAM or QPSK) is considered. In a case where the modulation scheme for s1is 64QAM, the mapping scheme for s1(t) is as shown inFIG.86, and k is represented by formula 85 inFIG.86. In a case where the modulation scheme for s2is 16QAM, the mapping scheme for s2(t) is as shown inFIG.80, and g is represented by formula 79 inFIG.80. Also, in a case where the modulation scheme for s2(t) is QPSK, the mapping scheme for s2(t) is as shown inFIG.81, and his represented by formula 78 inFIG.81. InFIG.85, when the modulation scheme for s1is 64QAM and the modulation scheme for s2is 16QAM, assume that v=a and u=α×w16. In this case, the ratio between the average power of 64QAM and the average power of 16QAM is v2:u2=α2:α2×w162=1:w162. InFIG.85, when the modulation scheme for s1is 64QAM and the modulation scheme for s2is QPSK, assume that v=β and u=β×w4. In this case, the ratio between the average power of 64QAM and the average power of QPSK is v2:u2=β2:β2×w42=1:w42. In this case, according to the minimum Euclidean distance relationship, the reception device achieves a high data reception quality when w4<w16<1.0, regardless of whether the modulation scheme for s2is 16QAM or QPSK. Note that although “the modulation scheme for s1is fixed to 64QAM” in the description above, it is possible that “the modulation scheme for s2is fixed to 64QAM and the modulation scheme for s1is changed from 16QAM to QPSK (set to either 16QAM or QPSK)”, w4<w16<1.0 should be fulfilled. (The same as described in Example 4-3.). (Note that the value used for the multiplication for the power change in the case of 16QAM is u=α×w16, the value used for the multiplication for the power change in the case of QPSK is u=β×w4, the value used for the power change in the case of 64QAM is v=a when the selectable modulation scheme is 16QAM and v=β when the selectable modulation scheme is QPSK.). Also, when the set of (the modulation scheme for s1, the modulation scheme for s2) is selectable from the sets of (64QAM, 16QAM), (16QAM, 64QAM), (64QAM, QPSK) and (QPSK, 64QAM), w4<w16<1.0 should be fulfilled. The following describes a case where the above-mentioned description is generalized. For generalization, assume that the modulation scheme for s1is fixed to a modulation scheme C with which the number of signal points in the IQ plane is c. Also assume that the modulation scheme for s2is selectable from a modulation scheme A with which the number of signal points in the IQ plane is a and a modulation scheme B with which the number of signal points in the IQ plane is b (c>b>a). In this case, when the modulation scheme for s2is set to the modulation scheme A, assume that ratio between the average power of the modulation scheme for s1, which is the modulation scheme C, and the average power of the modulation scheme for s2, which is the modulation scheme A, is 1:wa2. Also, when the modulation scheme for s2is set to the modulation scheme B, assume that ratio between the average power of the modulation scheme for s1, which is the modulation scheme C, and the average power of the modulation scheme for s2, which is the modulation scheme B, is 1:wb2. If this is the case, the reception device achieves a high data reception quality when wa<wbis fulfilled. Note that although “the modulation scheme for s1is fixed to C” in the description above, even when “the modulation scheme for s2is fixed to the modulation scheme C and the modulation scheme for s1is changed from the modulation scheme A to the modulation scheme B (set to either the modulation scheme A or the modulation scheme B), the average powers should fulfill wa<wb. (If this is the case, as with the description above, when the average power of the modulation scheme is C, the average power of the modulation scheme A is wa2, and the average power of the modulation scheme B is wb2.) Also, when the set of (the modulation scheme for s1, the modulation scheme for s2) is selectable from the sets of (the modulation scheme C, the modulation scheme A), (the modulation scheme A, the modulation scheme C), (the modulation scheme C, the modulation scheme B) and (the modulation scheme B, the modulation scheme C), the average powers should fulfill wa<wb. Example 6 The following describes an example of the operation different from that described in Example 4, usingFIG.85. Let s1(t) be the (mapped) baseband signal for the modulation scheme 16QAM. The mapping scheme for s1(t) is as shown inFIG.86, and g is as represented by formula 79. Let s2(t) be the (mapped) baseband signal for the modulation scheme 64QAM. The mapping scheme for s2(t) is as shown inFIG.86, and k is as represented by formula 85. Note that t is time. In the present embodiment, description is made taking the time domain as an example. The power changer (8401A) receives a (mapped) baseband signal307A for the modulation scheme 16QAM and the control signal (8400) as input. Letting a value for power change set based on the control signal (8400) be v, the power changer outputs a signal (8402A) obtained by multiplying the (mapped) baseband signal307A for the modulation scheme 16QAM by v. The power changer (8401B) receives a (mapped) baseband signal307B for the modulation scheme 64QAM and a control signal (8400) as input. Letting a value for power change set based on the control signal (8400) be u, the power changer outputs a signal (8402B) obtained by multiplying the (mapped) baseband signal307B for the modulation scheme 64QAM by u. Then, let u=v×w (w<1.0). Letting the precoding matrix used in the scheme for regularly performing phase change on the modulated signal after precoding be F and the phase changing value used for regularly performing phase change be y(t) (y(t) may be imaginary number having the absolute value of 1, i.e. ejθ(t), formula 87 shown above is satisfied. Therefore, a ratio of the average power for 64QAM to the average power for 16QAM is set to v2:u2=v2:v2×w2=1:w2. With this structure, the reception device is in a reception condition as shown inFIG.83. Therefore, data reception quality is improved in the reception device. In the conventional technology, transmission power control is generally performed based on feedback information from a communication partner. The present invention is characterized in that the transmission power is controlled regardless of the feedback information from the communication partner in the present embodiment. Detailed description is made on this point. The above describes that the values v and u for power change are set based on the control signal (8400). The following describes setting of the values v and u for power change based on the control signal (8400) in order to improve data reception quality in the reception device in detail. Example 6-1 The following describes a scheme of setting the average power (average values) of s1and s2according to a block length (the number of bits constituting one coding (encoded) block, and is also referred to as the code length) for the error correction codes used to generate s1and s2when the transmission device supports a plurality of block lengths for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of block lengths are supported. Encoded data for which error correction codes whose block length is selected from among the plurality of supported block lengths has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected block length for the error correction codes described above. The power changer (8401B) sets the value v for power change according to the control signal (8400). Similarly, the power changer (8401B) sets the value u for power change according to the control signal (8400). The present invention is characterized in that the power changers (8401A and8401B) respectively set the values v and u for power change according to the selected block length indicated by the control signal (8400). Here, values for power change set according to the block length X are referred to as vLXand uLX. For example, when 1000 is selected as the block length, the power changer (8401A) sets a value for power change to vL1000. When 1500 is selected as the block length, the power changer (8401A) sets a value for power change to vL1500. When 3000 is selected as the block length, the power changer (8401A) sets a value for power change to vL3000. On the other hand, when 1000 is selected as the block length, the power changer (8401B) sets a value for power change to uL1000. When 1500 is selected as the block length, the power changer (8401B) sets a value for power change to uL1500. When 3000 is selected as the block length, the power changer (8401B) sets a value for power change to uL3000. In this case, for example, by setting vL1000, vL1500and vL3000so as to be different from one another, a high error correction capability can be achieved for each code length. Similarly, by setting uL1000, uL1500and uL1000so as to be different from one another, a high error correction capability can be achieved for each code length. Depending on the set code length, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the code length is changed, it is unnecessary to change the value for power change (for example, uL1000=uL1500may be satisfied, and vL1000=vL1500may be satisfied. What is important is that two or more values exist in a set of vL1000, vL1500and vL3000, and that two or more values exist in a set of uL1000, uL1500and uL1000). Note that, as described above, vLXand uLXare set so as to satisfy the ratio of the average power 1:w2. Although the case of three code lengths is taken as an example in the above description, the present invention is not limited to this. One important point is that two or more values uLXfor power change exist when there are two or more code lengths that can be set, and the transmission device selects any of the values for power change from among the two or more values uLXfor power change when the code length is set, and performs power change. Another important point is that two or more values vLXfor power change exist when there are two or more code lengths that can be set, and the transmission device selects any of the values for power change from among the two or more values vLXfor power change when the code length is set, and performs power change. Example 6-2 The following describes a scheme of setting the average power of s1and s2according to a coding rate for the error correction codes used to generate s1and s2when the transmission device supports a plurality of coding rates for the error correction codes. Examples of the error correction codes include block codes such as turbo codes or duo-binary turbo codes using tail-biting, LDPC codes, or the like. In many communication systems and broadcasting systems, a plurality of coding rates are supported. Encoded data for which error correction codes whose coding rate is selected from among the plurality of supported coding rates has been performed is distributed to two systems. The encoded data having been distributed to the two systems is modulated in the modulation scheme for s1and in the modulation scheme for s2to generate the (mapped) baseband signals s1(t) and s2(t). The control signal (8400) is a signal indicating the selected coding rate for the error correction codes described above. The power changer (8401A) sets the value v for power change according to the control signal (8400). Similarly, the power changer (8401B) sets the value u for power change according to the control signal (8400). The present invention is characterized in that the power changers (8401A and8401B) respectively set the values v and u for power change according to the selected coding rate indicated by the control signal (8400). Here, values for power change set according to the coding rate rx are referred to as vrxand urx. For example, when r1is selected as the coding rate, the power changer (8401A) sets a value for power change to vr1. When r2is selected as the coding rate, the power changer (8401A) sets a value for power change to vr2. When r3is selected as the coding rate, the power changer (8401A) sets a value for power change to vr3. Also, when r1is selected as the coding rate, the power changer (8401B) sets a value for power change to ur1. When r2is selected as the coding rate, the power changer (8401B) sets a value for power change to ur2. When r3is selected as the coding rate, the power changer (8401B) sets a value for power change to ur3. In this case, for example, by setting vr1, vr2and vr3so as to be different from one another, a high error correction capability can be achieved for each code length. Similarly, by setting ur1, ur2and ur3so as to be different from one another, a high error correction capability can be achieved for each coding rate. Depending on the set coding rate, however, the effect might not be obtained even if the value for power change is changed. In such a case, even when the coding rate is changed, it is unnecessary to change the value for power change (for example, vr1=vr2may be satisfied, and ur1=ur2may be satisfied. What is important is that two or more values exist in a set of vr1, vr2and vr3, and that two or more values exist in a set of ur1, ur2and ur3). Note that, as described above, vrxand urxare set so as to satisfy the ratio of the average power 1:w2. Also, note that, as examples of r1, r2and r3described above, coding rates 1/2, 2/3 and 3/4 are considered when the error correction code is the LDPC code. Although the case of three coding rates is taken as an example in the above description, the present invention is not limited to this. One important point is that two or more values up, for power change exist when there are two or more coding rates that can be set, and the transmission device selects any of the values for power change from among the two or more values up, for power change when the coding rate is set, and performs power change. Another important point is that two or more values vrxfor power change exist when there are two or more coding rates that can be set, and the transmission device selects any of the values for power change from among the two or more values vrxfor power change when the coding rate is set, and performs power change. Example 6-3 In order for the reception device to achieve excellent data reception quality, it is important to implement the following. The following describes a scheme of setting the average power (average values) of s1and s2according to a modulation scheme used to generate s1and s2when the transmission device supports a plurality of modulation schemes. Here, as an example, a case where the modulation scheme for s1is fixed to 16QAM and the modulation scheme for s2is changed from 64QAM to QPSK by the control signal (or can be set to either 16QAM or QPSK) is considered. In a case where the modulation scheme for s1is 16QAM, the mapping scheme for s1(t) is as shown inFIG.80, and g is represented by formula 79 inFIG.80. In a case where the modulation scheme for s2is 64QAM, the mapping scheme for s2(t) is as shown inFIG.86, and k is represented by formula 85 inFIG.86. Also, in a case where the modulation scheme for s2(t) is QPSK, the mapping scheme for s2(t) is as shown inFIG.81, and his represented by formula 78 inFIG.81. InFIG.85, when the modulation scheme for s1is 16QAM and the modulation scheme for s2is 64QAM, assume that v=α and u=α×w64. In this case, the ratio between the average power of 64QAM and the average power of 16QAM is v2:u2=α2:α2×w642=1:w642. InFIG.85, when the modulation scheme for s1is 16QAM and the modulation scheme for s2is QPSK, assume that v=β and u=β×w4. In this case, the ratio between the average power of 64QAM and the average power of QPSK is v2:u2=β2:β2×w42=1:w42. In this case, according to the minimum Euclidean distance relationship, the reception device achieves a high data reception quality when w4<w64, regardless of whether the modulation scheme for s2is 64QAM or QPSK. Note that although “the modulation scheme for s1is fixed to 16QAM” in the description above, it is possible that “the modulation scheme for s2is fixed to 16QAM and the modulation scheme for s1is changed from 64QAM to QPSK (set to either 16QAM or QPSK)”, w4<w64should be fulfilled. (The same as described in Example 4-3.). (Note that the value used for the multiplication for the power change in the case of 16QAM is u=α×w16, the value used for the multiplication for the power change in the case of QPSK is u=β×w4, the value used for the power change in the case of 64QAM is v=a when the selectable modulation scheme is 16QAM and v=β when the selectable modulation scheme is QPSK.). Also, when the set of (the modulation scheme for s1, the modulation scheme for s2) is selectable from the sets of (16QAM, 64QAM), (64QAM, 16QAM), (16QAM, QPSK) and (QPSK, 16QAM), w4<w64should be fulfilled. The following describes a case where the above-mentioned description is generalized. For generalization, assume that the modulation scheme for s1is fixed to a modulation scheme C with which the number of signal points in the IQ plane is c. Also assume that the modulation scheme for s2is selectable from a modulation scheme A with which the number of signal points in the IQ plane is a and a modulation scheme B with which the number of signal points in the IQ plane is b (c>b>a). In this case, when the modulation scheme for s2is set to the modulation scheme A, assume that ratio between the average power of the modulation scheme for s1, which is the modulation scheme C, and the average power of the modulation scheme for s2, which is the modulation scheme A, is 1:wa2. Also, when the modulation scheme for s2is set to the modulation scheme B, assume that ratio between the average power of the modulation scheme for s1, which is the modulation scheme C, and the average power of the modulation scheme for s2, which is the modulation scheme B, is 1:wb2. If this is the case, the reception device achieves a high data reception quality when wa<wbis fulfilled. Note that although “the modulation scheme for s1is fixed to C” in the description above, even when “the modulation scheme for s2is fixed to the modulation scheme C and the modulation scheme for s1is changed from the modulation scheme A to the modulation scheme B (set to either the modulation scheme A or the modulation scheme B), the average powers should fulfill wa<wb. (If this is the case, as with the description above, when the average power of the modulation scheme is C, the average power of the modulation scheme A is wa2, and the average power of the modulation scheme B is wb2.) Also, when the set of (the modulation scheme for s1and the modulation scheme for s2) is selectable from the sets of (the modulation scheme C and the modulation scheme A), (the modulation scheme A and the modulation scheme C), (the modulation scheme C and the modulation scheme B) and (the modulation scheme B and the modulation scheme C), the average powers should fulfill wa<wb. In the present description including “Embodiment 1”, and so on, the power consumption by the transmission device can be reduced by setting α=1 in the formula 36 representing the precoding matrices used for the scheme for regularly changing the phase. This is because the average power of z1and the average power of z2are the same even when “the average power (average value) of s1and the average power (average value) of s2are set to be different when the modulation scheme for s1and the modulation scheme for s2are different”, and setting a=1 does not result in increasing the PAPR (Peak-to-Average Power Ratio) of the transmission power amplifier provided in the transmission device. However, even when ail, there are some precoding matrices that can be used with the scheme that regularly changes the phase and have limited influence to PAPR. For example, when the precoding matrices represented by formula 36 in Embodiment 1 are used to achieve the scheme for regularly changing the phase, the precoding matrices have limited influence to PAPR even when a1. Operations of the Reception Device Subsequently, explanation is provided of the operations of the reception device. Explanation of the reception device has already been provided in Embodiment 1 and so on, and the structure of the reception device is illustrated inFIGS.7,8and9, for instance According to the relation illustrated inFIG.5, when the transmission device transmits modulated signals as introduced inFIGS.84and85, one relation among the two relations denoted by the two formulas below is satisfied. Note that in the two formulas below, r1(t) and r2(t) indicate reception signals, and h11(t), h12(t), h21(t), and h22(t) indicate channel fluctuation values. In the case of Example 1, Example 2 and Example 3, the following relationship shown in formula 89 is derived fromFIG.5. [Math. 89] (r1(t)r2(t))=(h11(t)h12(t)h21(t)h22(t))(z1(t)z2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(ej000uej0)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(100u)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(s1(t)us2(t))(formula89) Also, as explained in Example 1, Example 2, and Example 3, the relationship may be as shown in formula 90 below: [Math. 90] (r1(t)r2(t))=(h11(t)h12(t)h21(t)h22(t))(z1(t)z2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(uej000ej0)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(u001)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(us1(t)s2(t))(formula90) The reception device performs demodulation (detection) (i.e. estimates the bits transmitted by the transmission device) by using the relationships described above (in the same manner as described in Embodiment 1 and so on). In the case of Example 4, Example 5 and Example 6, the following relationship shown in formula 91 is derived fromFIG.5. [Math. 91] (r1(t)r2(t))=(h11(t)h12(t)h21(t)h22(t))(z1(t)z2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(vej000uej0)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(v00v×w)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(vs1(t)us2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(vs1(t)v×w×s2(t))(formula91) Also, as explained in Example 3, Example 4, and Example 5, the relationship may be as shown in formula 92 below: [Math. 92] (r1(t)r2(t))=(h11(t)h12(t)h21(t)h22(t))(z1(t)z2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(uej000vej0)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(v×w00v)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(us1(t)vs2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(v×ws1(t)vs2(t))(formula92) The reception device performs demodulation (detection) (i.e. estimates the bits transmitted by the transmission device) by using the relationships described above (in the same manner as described in Embodiment 1 and so on). Note that although Examples 1 through 6 show the case where the power changer is added to the transmission device, the power change may be performed at the stage of mapping. As described in Example 1, Example 2, and Example 3, and as particularly shown in formula 89, the mapper306B inFIG.3andFIG.4may output u×s2(t), and the power changer may be omitted in such cases. If this is the case, it can be said that the scheme for regularly changing the phase is applied to the signal s1(t) after the mapping and the signal u×s2(t) after the mapping, the modulated signal after precoding. As described in Example 1, Example 2, and Example 3, and as particularly shown in formula 90, the mapper306A inFIG.3andFIG.4may output u×s1(t), and the power changer may be omitted in such cases. If this is the case, it can be said that the scheme for regularly changing the phase is applied to the signal s2(t) after the mapping and the signal u×s1(t) after the mapping, the modulated signal after precoding. In Example 4, Example 5, and Example 6, as particularly shown in formula 91, the mapper306A inFIG.3andFIG.4may output v×s1(t), and the mapper306B may output u×s2(t), and the power changer may be omitted in such cases. If this is the case, it can be said that the scheme for regularly changing the phase is applied to the signal v×s1(t) after the mapping and the signal u×s2(t) after the mapping, the modulated signals after precoding. In Example 4, Example 5, and Example 6, as particularly shown in formula 92, the mapper306A inFIG.3andFIG.4may output u×s1(t), and the mapper306B may output v×s2(t), and the power changer may be omitted in such cases. If this is the case, it can be said that the scheme for regularly changing the phase is applied to the signal u×s1(t) after the mapping and the signal v×s2(t) after the mapping, the modulated signals after precoding. Note that F shown in formulas 89 through 92 denotes precoding matrices used at time t, and y(t) denotes phase changing values. The reception device performs demodulation (detection) by using the relationships between r1(t), r2(t) and s1(t), s2(t) described above (in the same manner as described in Embodiment 1 and so on). However, distortion components, such as noise components, frequency offset, channel estimation error, and the likes are not considered in the formulas described above. Hence, demodulation (detection) is performed with them. Regarding the values u and v that the transmission device uses for performing the power change, the transmission device transmits information about these values, or transmits information of the transmission mode (such as the transmission scheme, the modulation scheme and the error correction scheme) to be used. The reception device detects the values used by the transmission device by acquiring the information, obtains the relationships described above, and performs the demodulation (detection). In the present embodiment, the switching between the phase changing values is performed on the modulated signal after precoding in the time domain. However, when a multi-carrier transmission scheme such as an OFDM scheme is used, the present invention is applicable to the case where the switching between the phase changing values is performed on the modulated signal after precoding in the frequency domain, as described in other embodiments. If this is the case, t used in the present embodiment is to be replaced with f (frequency ((sub) carrier)). Accordingly, in the case of performing the switching between the phase changing values on the modulated signal after precoding in the time domain, z1(t) and z2(t) at the same time point is transmitted from different antennas by using the same frequency. On the other hand, in the case of performing the switching between the phase changing values on the modulated signal after precoding in the frequency domain, z1(f) and z2(f) at the same frequency is transmitted from different antennas at the same time point. Also, even in the case of performing switching between the phase changing values on the modulated signal after precoding in the time and frequency domains, the present invention is applicable as described in other embodiments. The scheme pertaining to the present embodiment, which switches between the phase changing values on the modulated signal after precoding, is not limited the scheme which switches between the phase changing values on the modulated signal after precoding as described in the present Description. Also, assume that processed baseband signals z1(i), z2(i) (where i represents the order in terms of time or frequency (carrier)) are generated by regular phase change and precoding (it does not matter which is performed first) on baseband signals s1(i) and s2(i) for two streams. Let the in-phase component I and the quadrature component Q of the processed baseband signal z1(i) be I1(i) and Q1(i) respectively, and let the in-phase component I and the quadrature component Q of the processed baseband signal z2(i) be I2(i) and Q2(i) respectively. In this case, the baseband components may be switched, and modulated signals corresponding to the switched baseband signal r1(i) and the switched baseband signal r2(i) may be transmitted from different antennas at the same time and over the same frequency by transmitting a modulated signal corresponding to the switched baseband signal r1(i) from transmit antenna1and a modulated signal corresponding to the switched baseband signal r2(i) from transmit antenna2at the same time and over the same frequency. Baseband components may be switched as follows.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I1(i) and Q2(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be I2(i) and Q1(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I1(i) and I2(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q1(i) and Q2(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i) and I1(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q1(i) and Q2(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I1(i) and I2(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q2(i) and Q1(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i) and I1(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q2(i) and Q1(i) respectively. Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I1(i) and Q2(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q1(i) and I2(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q2(i) and I1(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be I2(i) and Q1(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q2(i) and I1(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q1(i) and I2(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i) and I2(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q1(i) and Q2(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I2(i) and I1(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q1(i) and Q2(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i) and I2(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q2(i) and Q1(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I2(i) and I1(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q2(i) and Q1(i) respectively. Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i) and Q2(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i) and Q1(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i) and Q2(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q1(i) and I2(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q2(i) and I1(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i) and Q1(i) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q2(i) and I1(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q1(i) and I2(i) respectively. In the above description, signals in two streams are processed and in-phase components and quadrature components of the processed signals are switched, but the present invention is not limited in this way. Signals in more than two streams may be processed, and the in-phase components and quadrature components of the processed signals may be switched. In addition, the signals may be switched in the following manner. For example,Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i) and Q2(i) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i) and Q1(i) respectively. Such switching can be achieved by the structure shown inFIG.55. In the above-mentioned example, switching between baseband signals at the same time (at the same frequency ((sub)carrier)) has been described, but the present invention is not limited to the switching between baseband signals at the same time. As an example, the following description can be made.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I1(i+v) and Q2(i+w) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be I2(i+w) and Q1(i+v) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I1(i+v) and I2(i+w) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q1(i+v) and Q2(i+w) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i+w) and I1(i+v) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q1(i+v) and Q2(i+w) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I1(i+v) and I2(i+w) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q2(i+w) and Q1(i+v) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i+w) and I1(i+v) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q2(i+w) and Q1(i+v) respectively. Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I1(i+v) and Q2(i+w) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q1(i+v) and I2(i+w) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q2(i+w) and I1(i+v) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be I2(i+w) and Q1(i+v) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q2(i+w) and I1(i+v) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q1(i+v) and I2(i+w) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i+v) and I2(i+w) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q1(i+v) and Q2(i+w) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I2(i+w) and I1(i+v) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q1(i+v) and Q2(i+w) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i+v) and I2(i+w) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q2(i+w) and Q1(i+v) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I2(i+w) and I1(i+v) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q2(i+w) and Q1(i+v) respectively. Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i+v) and Q2(i+w) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i+w) and Q1(i+v) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i+v) and Q2(i+w) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q1(i+v) and I2(i+w) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q2(i+w) and I1(i+v) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i+w) and Q1(i+v) respectively.Let the in-phase component and the quadrature component of the switched baseband signal r2(i) be Q2(i+w) and I1(i+v) respectively, and the in-phase component and the quadrature component of the switched baseband signal r1(i) be Q1(i+v) and I2(i+w) respectively. In addition, the signals may be switched in the following manner. For example,Let the in-phase component and the quadrature component of the switched baseband signal r1(i) be I2(i+w) and Q2(i+w) respectively, and the in-phase component and the quadrature component of the switched baseband signal r2(i) be I1(i+v) and Q1(i+w) respectively. This can also be achieved by the structure shown inFIG.55. FIG.55illustrates a baseband signal switcher5502explaining the above. As shown, of the two processed baseband signals z1(i)5501_1and z2(i)5501_2, processed baseband signal z1(i)5501_1has in-phase component I1(i) and quadrature component Q1(i), while processed baseband signal z2(i)5501_2has in-phase component I2(i) and quadrature component Q2(i). Then, after switching, switched baseband signal r1(i)5503_1has in-phase component Ir1(i) and quadrature component Qr1(i), while switched baseband signal r2(i)5503_2has in-phase component Ir2(i) and quadrature component Qr1(i). The in-phase component Ir1(i) and quadrature component Qr1(i) of switched baseband signal r1(i)5503_1and the in-phase component Ir2(i) and quadrature component Qr1(i) of switched baseband signal r2(i)5503_2may be expressed as any of the above. Although this example describes switching performed on baseband signals having a common time (common ((sub-)carrier) frequency) and having undergone two types of signal processing, the same may be applied to baseband signals having undergone two types of signal processing but having different time (different ((sub-)carrier) frequencies). The switching may be performed while regularly changing switching methods. For example,At time 0, for switched baseband signal r1(0), the in-phase component may be I1(0) while the quadrature component may be Q1(0), and for switched baseband signal r2(0), the in-phase component may be I2(0) while the quadrature component may be Q2(0);At time 1, for switched baseband signal r1(1), the in-phase component may be I2(1) while the quadrature component may be Q2(1), and for switched baseband signal r2(1), the in-phase component may be I1(1) while the quadrature component may be Q1(1), and so on. In other words,When time is 2k (k is an integer), for switched baseband signal r1(2k), the in-phase component may be I1(2k) while the quadrature component may be Q1(2k), and for switched baseband signal r2(2k), the in-phase component may be I2(2k) while the quadrature component may be Q2(2k).When time is 2k+1 (k is an integer), for switched baseband signal r1(2k+1), the in-phase component may be I2(2k+1) while the quadrature component may be Q2(2k+1), and for switched baseband signal r2(2k+1), the in-phase component may be I1(2k+1) while the quadrature component may be Q1(2k+1).When time is 2k (k is an integer), for switched baseband signal r1(2k), the in-phase component may be I2(2k) while the quadrature component may be Q2(2k), and for switched baseband signal r2(2k), the in-phase component may be I1(2k) while the quadrature component may be Q1(2k).When time is 2k+1 (k is an integer), for switched baseband signal r1(2k+1), the in-phase component may be I1(2k+1) while the quadrature component may be Q1(2k+1), and for switched baseband signal r2(2k+1), the in-phase component may be I2(2k+1) while the quadrature component may be Q2(2k+1). Similarly, the switching may be performed in the frequency domain. In other words,When frequency ((sub) carrier) is 2k (k is an integer), for switched baseband signal r1(2k), the in-phase component may be I1(2k) while the quadrature component may be Q1(2k), and for switched baseband signal r2(2k), the in-phase component may be I2(2k) while the quadrature component may be Q2(2k).When frequency ((sub) carrier) is 2k+1 (k is an integer), for switched baseband signal r1(2k+1), the in-phase component may be I2(2k+1) while the quadrature component may be Q2(2k+1), and for switched baseband signal r2(2k+1), the in-phase component may be I1(2k+1) while the quadrature component may be Q1(2k+1).When frequency ((sub) carrier) is 2k (k is an integer), for switched baseband signal r1(2k), the in-phase component may be I2(2k) while the quadrature component may be Q2(2k), and for switched baseband signal r2(2k), the in-phase component may be I1(2k) while the quadrature component may be Q1(2k). When frequency ((sub) carrier) is 2k+1 (k is an integer), for switched baseband signal r1(2k+1), the in-phase component may be I1(2k+1) while the quadrature component may be Q1(2k+1), and for switched baseband signal r2(2k+1), the in-phase component may be I2(2k+1) while the quadrature component may be Q2(2k+1). Embodiment G1 The present embodiment describes a scheme that is used when the modulated signal subject to the QPSK mapping and the modulated signal subject to the 16QAM mapping are transmitted, for example, and is used for setting the average power of the modulated signal subject to the QPSK mapping and the average power of the modulated signal subject to the 16QAM mapping such that the average powers will be different from each other. This scheme is different from Embodiment F1. As explained in Embodiment F1, when the modulation scheme for the modulated signal of s1is QPSK and the modulation scheme for the modulated signal of s2is 16QAM (or the modulation scheme for the modulated signal s1is 16QAM and the modulation scheme for the modulated signal s2is QPSK), if the average power of the modulated signal subject to the QPSK mapping and the average power of the modulated signal subject to the 16QAM mapping are set to be different from each other, the PAPR (Peak-to-Average Power Ratio) of the transmission power amplifier provided in the transmission device may increase, depending on the precoding matrix used by the transmission device. The increase of the PAPR may lead to the increase in power consumption by the transmission device. In the present embodiment, description is provided on the scheme for regularly performing phase change after performing the precoding described in “Embodiment 1” and so on, where, even when α≠1 in the formula 36 of the precoding matrix to be used in the scheme for regularly changing the phase, the influence to the PAPR is suppressed to a minimal extent. In the present embodiment, description is provided taking as an example a case where the modulation scheme applied to the streams s1and s2is either QPSK or 16QAM. Firstly, explanation is provided of the mapping scheme for QPSK modulation and the mapping scheme for 16QAM modulation. Note that, in the present embodiment, the symbols s1and s2refer to signals which are either in accordance with the mapping for QPSK modulation or the mapping for 16QAM modulation. First of all, description is provided concerning mapping for 16QAM with reference to the accompanyingFIG.80.FIG.80illustrates an example of a signal point layout in the I-Q plane (I: in-phase component; Q: quadrature component) for 16QAM. Concerning the signal point9400inFIG.94, when the bits transferred (input bits) are b0—b3, that is, when the bits transferred are indicated by (b0, b1, b2, b3)=(1, 0, 0, 0) (this value being illustrated inFIG.94), the coordinates in the I-Q plane (I: in-phase component; Q: quadrature component) corresponding thereto is denoted as (I, Q)=(−3×g, 3×g). The values of coordinates I and Q in this set of coordinates indicates the mapped signals. Note that, when the bits transferred (b0, b1, b2, b3) take other values than in the above, the set of values I and Q is determined according to the values of the bits transferred (b0, b1, b2, b3) and according toFIG.80. Further, similar as in the above, the values of coordinates I and Q in this set indicates the mapped signals (s1and s2). Subsequently, description is provided concerning mapping for QPSK modulation with reference to the accompanyingFIG.81.FIG.81illustrates an example of a signal point layout in the I-Q plane (I: in-phase component; Q: quadrature component) for QPSK. Concerning the signal point8100inFIG.81, when the bits transferred (input bits) are b0 and b1, that is, when the bits transferred are indicated by (b0, b1)=(1, 0) (this value being illustrated inFIG.81), the coordinates in the I-Q plane (I: in-phase component; Q: quadrature component) corresponding thereto is denoted as (I, Q)=(−1×h, 1×h). Further, the values of coordinates I and Q in this set of coordinates indicates the mapped signals. Note that, when the bits transferred (b0, b1) take other values than in the above, the set of coordinates (I, Q) is determined according to the values of the bits transferred (b0, b1) and according toFIG.81. Further, similar as in the above, the values of coordinates I and Q in this set indicates the mapped signals (s1and s2). Further, when the modulation scheme applied to s1and s2is either QPSK or 16QAM, in order to equalize the values of the average power, h is as represented by formula 78, and g is as represented by formula 79. FIGS.87and88illustrate an example of the scheme of changing the modulation scheme, the power changing value, and the precoding matrix in the time domain (or in the frequency domain, or in the time domain and the frequency domain) when using a precoding-related signal processor illustrated inFIG.85. InFIG.87, a chart is provided indicating the modulation scheme, the power changing value (u, v), and the phase changing value (y[t]) to be set at each of times t=0 through t=11. Note that, concerning the modulated signals z1(t) and z2(t), the modulated signals z1(t) and z2(t) at the same time point are to be simultaneously transmitted from different transmit antennas at the same frequency. (Although the chart inFIG.87is based on the time domain, when using a multi-carrier transmission scheme as the OFDM scheme, switching between schemes (modulation scheme, power changing value, phase changing value) may be performed according to the frequency (subcarrier) domain, rather than according to the time domain. In such a case, replacement should be made of t=0 with f=f0, t=1 with f=f1, . . . , as is shown inFIG.87. (Note that here, f denotes frequencies (subcarriers), and thus, f0, f1, . . . , indicate different frequencies (subcarriers) to be used.) Further, note that concerning the modulated signals z1(f) and z2(f) in such a case, the modulated signals z1(f) and z2(f) having the same frequency are to be simultaneously transmitted from different transmit antennas. As illustrated inFIG.87, when the modulation scheme applied is QPSK, the power changer (although referred to as the power changer herein, may also be referred to as an amplification changer or a weight unit) multiplies a (a being a real number) with respect to a signal modulated in accordance with QPSK. Similarly, when the modulation scheme applied is 16QAM, the power changer (although referred to as the power changer herein, may also be referred to as the amplification changer or the weight unit) multiplies b (b being a real number) with respect to a signal modulated in accordance with 16QAM. In the example illustrated inFIG.87, three phase changing values, namely y[0], y[1], and y[2] are prepared as phase changing values used in the scheme for regularly performing phase change after precoding. Additionally, the period (cycle) for the scheme for regularly performing phase change after precoding is 3 (thus, each of t0−t2, t3−t5, . . . composes one period (cycle)). Note, in this embodiment, since the phase change is performed on one of the signals after precoding as shown in the example inFIG.85, y[i] is an imaginary number having the absolute value of 1 (i.e. y[i]=ejθ). However, as described in this Description, the phase change may be performed after performing the precoding on a plurality of signals. If this is the case, a phase changing value exists for each of the plurality of signals after precoding. The modulation scheme applied to s1(t) is QPSK in period (cycle) t0−t2, 16QAM in period (cycle) t3−t5 and so on, whereas the modulation scheme applied to s2(t) is 16QAM in period (cycle) t0−t2, QPSK in period (cycle) t3−t5 and so on. Thus, the set of (modulation scheme of s1(t), modulation scheme of s2(t)) is either (QPSK, 16QAM) or (16QAM, QPSK). Here, it is important that: when performing phase change according to y[0], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of s1(t), modulation scheme of s2(t)), when performing phase change according to y[1], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of s1(t), modulation scheme of s2(t)), and similarly, when performing phase change according to y[2], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of s1(t), modulation scheme of s2(t)). In addition, when the modulation scheme applied to s1(t) is QPSK, the power changer (8501A) multiples s1(t) with a and thereby outputs a x s1(t). On the other hand, when the modulation scheme applied to s1(t) is 16QAM, the power changer (8501A) multiples s1(t) with b and thereby outputs b×s1(t). Further, when the modulation scheme applied to s2(t) is QPSK, the power changer (8501B) multiples s2(t) with a and thereby outputs a×s2(t). On the other hand, when the modulation scheme applied to s2(t) is 16QAM, the power changer (8501B) multiples s2(t) with b and thereby outputs b×s2(t). Note that, regarding the scheme for differently setting the average power of signals in accordance with mapping for QPSK modulation and the average power of signals in accordance with mapping for 16QAM modulation, description has already been made in Embodiment F1. Thus, when taking the set of (modulation scheme of s1(t), modulation scheme of s2(t)) into consideration, the period (cycle) for the phase change and the switching between modulation schemes is 6=3×2 (where 3: the number of phase changing values prepared as phase changing values used in the scheme for regularly performing phase change after precoding, and 2: both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of s1(t), modulation scheme of s2(t)) for each of the phase changing values), as shown inFIG.87. As description has been made in the above, by making an arrangement such that both (QPSK, 16QAM) and (16QAM, QPSK) exist as the set of (modulation scheme of s1(t), modulation scheme of s2(t)), and such that both (QPSK, 16QAM) and (16QAM, QPSK) exist as the set of (modulation scheme of s1(t), modulation scheme of s2(t)) with respect to each of the phase changing values prepared as phase changing values used in the scheme for regularly performing phase change, the following advantageous effects are to be yielded. That is, even when differently setting the average power of signals in accordance with mapping for QPSK modulation and the average power of signals in accordance with mapping for 16QAM modulation, the influence with respect to the PAPR of the transmission power amplifier included in the transmission device is suppressed to a minimal extent, and thus the influence with respect to the power consumption of the transmission device is suppressed to a minimal extent, while the reception quality of data received by the reception device in the LOS environment is improved, as explanation has already been provided in the present description. Note that, although description has been provided in the above, taking as an example a case where the set of (modulation scheme of s1(t), modulation scheme of s2(t)) is (QPSK, 16QAM) and (16QAM, QPSK), the possible sets of (modulation scheme of s1(t), modulation scheme of s2(t)) are not limited to this. More specifically, the set of (modulation scheme of s1(t), modulation scheme of s2(t)) may be one of: (QPSK, 64QAM), (64QAM, QPSK); (16QAM, 64QAM), (64QAM, 16QAM); (128QAM, 64QAM), (64QAM, 128QAM); (256QAM, 64QAM), (64QAM, 256QAM), and the like. That is, the present invention is to be similarly implemented provided that two different modulation schemes are prepared, and a different one of the modulation schemes is applied to each of s1(t) and s2(t). InFIG.88, a chart is provided indicating the modulation scheme, the power changing value, and the phase changing value to be set at each of times t=0 through t=11. Note that, concerning the modulated signals z1(t) and z2(t), the modulated signals z1(t) and z2(t) at the same time point are to be simultaneously transmitted from different transmit antennas at the same frequency. (Although the chart inFIG.88is based on the time domain, when using a multi-carrier transmission scheme as the OFDM scheme, switching between schemes may be performed according to the frequency (subcarrier) domain, rather than according to the time domain. In such a case, replacement should be made of t=0 with f=f0, t=1 with f=f1, . . . , as is shown inFIG.88. (Note that here, f denotes frequencies (subcarriers), and thus, f0, f1, . . . , indicate different frequencies (subcarriers) to be used.) Further, note that concerning the modulated signals z1(f) and z2(f) in such a case, the modulated signals z1(f) and z2(f) having the same frequency are to be simultaneously transmitted from different transmit antennas. Note that the example illustrated inFIG.88is an example that differs from the example illustrated inFIG.87, but satisfies the requirements explained with reference toFIG.87. As illustrated inFIG.88, when the modulation scheme applied is QPSK, the power changer (although referred to as the power changer herein, may also be referred to as an amplification changer or a weight unit) multiplies a (a being a real number) with respect to a signal modulated in accordance with QPSK. Similarly, when the modulation scheme applied is 16QAM, the power changer (although referred to as the power changer herein, may also be referred to as the amplification changer or the weight unit) multiplies b (b being a real number) with respect to a signal modulated in accordance with 16QAM. In the example illustrated inFIG.88, three phase changing values, namely y[0], y[1], and y[2] are prepared as phase changing values used in the scheme for regularly performing phase change after precoding. Additionally, the period (cycle) for the scheme for regularly performing phase change after precoding is 3 (thus, each of t0−t2, t3−t5, composes one period (cycle)). Further, QPSK and 16QAM are alternately set as the modulation scheme applied to s1(t) in the time domain, and the same applies to the modulation scheme set to s2(t). The set of (modulation scheme of s1(t), modulation scheme of s2(t)) is either (QPSK, 16QAM) or (16QAM, QPSK). Here, it is important that: when performing phase change according to y[0], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of s1(t), modulation scheme of s2(t)), when performing phase change according to y[1], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of s1(t), modulation scheme of s2(t)), and similarly, when performing phase change according to y[2], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of s1(t), modulation scheme of s2(t)). In addition, when the modulation scheme applied to s1(t) is QPSK, the power changer (8501A) multiples s1(t) with a and thereby outputs a x s1(t). On the other hand, when the modulation scheme applied to s1(t) is 16QAM, the power changer (8501A) multiples s1(t) with b and thereby outputs b×s1(t). Further, when the modulation scheme applied to s2(t) is QPSK, the power changer (8501B) multiples s2(t) with a and thereby outputs a x s2(t). On the other hand, when the modulation scheme applied to s2(t) is 16QAM, the power changer (8501B) multiples s2(t) with b and thereby outputs b×s2(t). Thus, when taking the set of (modulation scheme of s1(t), modulation scheme of s2(t)) into consideration, the period (cycle) for the phase change and the switching between modulation schemes is 6=3×2 (where 3: the number of phase changing values prepared as phase changing values used in the scheme for regularly performing phase change after precoding, and 2: both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of s1(t), modulation scheme of s2(t)) for each of the phase changing values), as shown inFIG.88. As description has been made in the above, by making an arrangement such that both (QPSK, 16QAM) and (16QAM, QPSK) exist as the set of (modulation scheme of s1(t), modulation scheme of s2(t)), and such that both (QPSK, 16QAM) and (16QAM, QPSK) exist as the set of (modulation scheme of s1(t), modulation scheme of s2(t)) with respect to each of the phase changing values prepared as phase changing values used in the scheme for regularly performing phase change, the following advantageous effects are to be yielded. That is, even when differently setting the average power of signals in accordance with mapping for QPSK modulation and the average power of signals in accordance with mapping for 16QAM modulation, the influence with respect to the PAPR of the transmission power amplifier included in the transmission device is suppressed to a minimal extent, and thus the influence with respect to the power consumption of the transmission device is suppressed to a minimal extent, while the reception quality of data received by the reception device in the LOS environment is improved, as explanation has already been provided in the present description. Note that, although description has been provided in the above, taking as an example a case where the set of (modulation scheme of s1(t), modulation scheme of s2(t)) is (QPSK, 16QAM) and (16QAM, QPSK), the possible sets of (modulation scheme of s1(t), modulation scheme of s2(t)) are not limited to this. More specifically, the set of (modulation scheme of s1(t), modulation scheme of s2(t)) may be one of: (QPSK, 64QAM), (64QAM, QPSK); (16QAM, 64QAM), (64QAM, 16QAM); (128QAM, 64QAM), (64QAM, 128QAM); (256QAM, 64QAM), (64QAM, 256QAM), and the like. That is, the present invention is to be similarly implemented provided that two different modulation schemes are prepared, and a different one of the modulation schemes is applied to each of s1(t) and s2(t). Additionally, the relation between the modulation scheme, the power changing value, and the phase changing value set at each of times (or for each of frequencies) is not limited to those described in the above with reference toFIGS.87and88. To summarize the explanation provided in the above, the following points are essential. Arrangements are to be made such that the set of (modulation scheme of s1(t), modulation scheme of s2(t)) can be either (modulation scheme A, modulation scheme B) or (modulation scheme B, modulation scheme A), and such that the average power of signals in accordance with mapping for QPSK modulation and the average power of signals in accordance with mapping for 16QAM modulation are differently set. Further, when the modulation scheme applied to s1(t) is modulation scheme A, the power changer (8501A) multiples s1(t) with a and thereby outputs a x s1(t). Further, when the modulation scheme applied to s1(t) is modulation scheme B, the power changer (8501A) multiples s1(t) with a and thereby outputs b×s1(t). Similarly, when the modulation scheme applied to s2(t) is modulation scheme A, the power changer (8501B) multiples s2(t) with a and thereby outputs a x s2(t). On the other hand, when the modulation scheme applied to s2(t) is modulation scheme B, the power changer (8501A) multiples s2(t) with b and thereby outputs b×s2(t). Further, an arrangement is to be made such that phase changing values y[0], y[1], y[n −2], and y[n −1] (or y[k], where k satisfies 0≤k≤n−1) exist as phase changing values prepared for use in the scheme for regularly performing phase change after precoding. Further, an arrangement is to be made such that both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of s1(t), modulation scheme of s2(t)) for y[k]. (Here, the arrangement may be made such that both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of s1(t), modulation scheme of s2(t)) for y[k] for all values of k, or such that a value k exists where both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of s1(t), modulation scheme of s2(t)) for y[k].) As description has been made in the above, by making an arrangement such that both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of s1(t), modulation scheme of s2(t)), and such that both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of s1(t), modulation scheme of s2(t)) with respect to each of the phase changing values prepared as phase changing values used in the scheme for regularly performing phase change, the following advantageous effects are to be yielded. That is, even when differently setting the average power of signals for modulation scheme A and the average power of signals for modulation scheme B, the influence with respect to the PAPR of the transmission power amplifier included in the transmission device is suppressed to a minimal extent, and thus the influence with respect to the power consumption of the transmission device is suppressed to a minimal extent, while the reception quality of data received by the reception device in the LOS environment is improved, as explanation has already been provided in the present description. In connection with the above, explanation is provided of a scheme for generating baseband signals s1(t) and s2(t) in the following. As illustrated inFIGS.3and4, the baseband signal s1(t) is generated by the mapper306A and the baseband signal s2(t) is generated by the mapper306B. As such, in the examples provided in the above with reference toFIGS.87and88, the mapper306A and306B switch between mapping according to QPSK and mapping according to 16QAM by referring to the charts illustrated inFIGS.87and88. Here, note that, although separate mappers for generating each of the baseband signal s1(t) and the baseband signal s2(t) are provided in the illustrations inFIGS.3and4, the present invention is not limited to this. For instance, the mapper (8902) may receive input of digital data (8901), generate s1(t) and s2(t) according toFIGS.87and88, and respectively output s1(t) as the mapped signal307A and s2(t) as the mapped signal307B. FIG.90illustrates one structural example of the periphery of the weighting unit (precoding unit), which differs from the structures illustrated inFIGS.85and89. InFIG.90, elements that operate in a similar way toFIG.3andFIG.85bear the same reference signs. InFIG.91, a chart is provided indicating the modulation scheme, the power changing value, and the phase changing value to be set at each of times t=0 through t=11 with respect to the structural example illustrated inFIG.90. Note that, concerning the modulated signals z1(t) and z2(t), the modulated signals z1(t) and z2(t) at the same time point are to be simultaneously transmitted from different transmit antennas at the same frequency. (Although the chart inFIG.91is based on the time domain, when using a multi-carrier transmission scheme as the OFDM scheme, switching between schemes may be performed according to the frequency (subcarrier) domain, rather than according to the time domain. In such a case, replacement should be made of t=0 with f=f0, t=1 with f=f1, . . . , as is shown inFIG.91. (Note that here, f denotes frequencies (subcarriers), and thus, f0, f1, . . . , indicate different frequencies (subcarriers) to be used.) Further, note that concerning the modulated signals z1(f) and z2(f) in such a case, the modulated signals z1(f) and z2(f) having the same frequency are to be simultaneously transmitted from different transmit antennas. As illustrated inFIG.91, when the modulation scheme applied is QPSK, the power changer (although referred to as the power changer herein, may also be referred to as an amplification changer or a weight unit) multiplies a (a being a real number) with respect to a signal modulated in accordance with QPSK. Similarly, when the modulation scheme applied is 16QAM, the power changer (although referred to as the power changer herein, may also be referred to as the amplification changer or the weight unit) multiplies b (b being a real number) with respect to a signal modulated in accordance with 16QAM. In the example illustrated inFIG.91, three phase changing values, namely y[0], y[1], and y[2] are prepared as phase changing values used in the scheme for regularly performing phase change after precoding. Additionally, the period (cycle) for the scheme for regularly performing phase change after precoding is 3 (thus, each of t0−t2, t3−t5, . . . composes one period (cycle)). Further, the modulation scheme applied to s1(t) is fixed to QPSK, and the modulation scheme to be applied to s2(t) is fixed to 16QAM. Additionally, the signal switcher (9001) illustrated inFIG.90receives the mapped signals307A and307B and the control signal (8500) as input thereto. The signal switcher (9001) performs switching with respect to the mapped signals307A and307B according to the control signal (8500) (there are also cases where the switching is not performed), and outputs switched signals (9002A: Ω1(t), and9002B: Ω2(0). Here, it is important that:When performing phase change according to y[0], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(0), when performing phase change according to y[1], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of Q1(t), modulation scheme of Ω2(t)), and similarly, when performing phase change according to y[2], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)). Further, when the modulation scheme applied to Ω1(t) is QPSK, the power changer (8501A) multiples Ω1(t) with a and thereby outputs a×Ω1(t). On the other hand, when the modulation scheme applied to Ω1(t) is 16QAM, the power changer (8501A) multiples Ω1(t) with b and thereby outputs b×Ω1(t). Further, when the modulation scheme applied to Ω2(t) is QPSK, the power changer (8501B) multiples Ω2(t) with a and thereby outputs a×Ω2(t). On the other hand, when the modulation scheme applied to Ω2(t) is 16QAM, the power changer (8501B) multiples Ω2(t) with b and thereby outputs b×Ω2(t). Note that, regarding the scheme for differently setting the average power of signals in accordance with mapping for QPSK modulation and the average power of signals in accordance with mapping for 16QAM modulation, description has already been made in Embodiment F1. Thus, when taking the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) into consideration, the period (cycle) for the phase change and the switching between modulation schemes is 6=3×2 (where 3: the number of phase changing values prepared as phase changing values used in the scheme for regularly performing phase change after precoding, and 2: both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) for each of the phase changing values), as shown inFIG.91. As description has been made in the above, by making an arrangement such that both (QPSK, 16QAM) and (16QAM, QPSK) exist as the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)), and such that both (QPSK, 16QAM) and (16QAM, QPSK) exist as the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) with respect to each of the phase changing values prepared as phase changing values used in the scheme for regularly performing phase change, the following advantageous effects are to be yielded. That is, even when differently setting the average power of signals in accordance with mapping for QPSK modulation and the average power of signals in accordance with mapping for 16QAM modulation, the influence with respect to the PAPR of the transmission power amplifier included in the transmission device is suppressed to a minimal extent, and thus the influence with respect to the power consumption of the transmission device is suppressed to a minimal extent, while the reception quality of data received by the reception device in the LOS environment is improved, as explanation has already been provided in the present description. Note that, although description has been provided in the above, taking as an example a case where the set of (modulation scheme of Q1(t), modulation scheme of Ω2(t)) is (QPSK, 16QAM) and (16QAM, QPSK), the possible sets of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) are not limited to this. More specifically, the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) may be one of: (QPSK, 64QAM), (64QAM, QPSK); (16QAM, 64QAM), (64QAM, 16QAM); (128QAM, 64QAM), (64QAM, 128QAM); (256QAM, 64QAM), (64QAM, 256QAM), and the like. That is, the present invention is to be similarly implemented provided that two different modulation schemes are prepared, and a different one of the modulation schemes is applied to each of Ω1(t) and Ω2(t). InFIG.92, a chart is provided indicating the modulation scheme, the power changing value, and the phase changing value to be set at each of times t=0 through t=11 with respect to the structural example illustrated inFIG.90. Note that the chart inFIG.92differs from the chart inFIG.91. Note that, concerning the modulated signals z1(t) and z2(t), the modulated signals z1(t) and z2(t) at the same time point are to be simultaneously transmitted from different transmit antennas at the same frequency. (Although the chart inFIG.92is based on the time domain, when using a multi-carrier transmission scheme as the OFDM scheme, switching between schemes may be performed according to the frequency (subcarrier) domain, rather than according to the time domain. In such a case, replacement should be made of t=0 with f=f0, t=1 with f=f1, . . . , as is shown inFIG.92. (Note that here, f denotes frequencies (subcarriers), and thus, f0, f1, . . . , indicate different frequencies (subcarriers) to be used.) Further, note that concerning the modulated signals z1(f) and z2(f) in such a case, the modulated signals z1(f) and z2(f) having the same frequency are to be simultaneously transmitted from different transmit antennas. As illustrated inFIG.92, when the modulation scheme applied is QPSK, the power changer (although referred to as the power changer herein, may also be referred to as an amplification changer or a weight unit) multiplies a (a being a real number) with respect to a signal modulated in accordance with QPSK. Similarly, when the modulation scheme applied is 16QAM, the power changer (although referred to as the power changer herein, may also be referred to as the amplification changer or the weight unit) multiplies b (b being a real number) with respect to a signal modulated in accordance with 16QAM. In the example illustrated inFIG.92, three phase changing values, namely y[0], y[1], and y[2] are prepared as phase changing values used in the scheme for regularly performing phase change after precoding. Additionally, the period (cycle) for the scheme for regularly performing phase change after precoding is 3 (thus, each of t0−t2, t3−t5, . . . composes one period (cycle)). Further, the modulation scheme applied to s1(t) is fixed to QPSK, and the modulation scheme to be applied to s2(t) is fixed to 16QAM. Additionally, the signal switcher (9001) illustrated inFIG.90receives the mapped signals307A and307B and the control signal (8500) as input thereto. The signal switcher (9001) performs switching with respect to the mapped signals307A and307B according to the control signal (8500) (there are also cases where the switching is not performed), and outputs switched signals (9002A: Ω1(t), and9002B: Ω2(t)). Here, it is important that:When performing phase change according to y[0], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)), when performing phase change according to y[1], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)), and similarly, when performing phase change according to y[2], both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)). Further, when the modulation scheme applied to Ω1(t) is QPSK, the power changer (8501A) multiples Ω1(t) with a and thereby outputs a x Ω1(t). On the other hand, when the modulation scheme applied to Ω1(t) is 16QAM, the power changer (8501A) multiples Ω1(t) with b and thereby outputs b×Ω1(t). Further, when the modulation scheme applied to Ω2(t) is QPSK, the power changer (8501B) multiples Ω2(t) with a and thereby outputs a x Ω2(t). On the other hand, when the modulation scheme applied to Ω2(t) is 16QAM, the power changer (8501B) multiples Ω2(t) with b and thereby outputs b×Ω2(t). Note that, regarding the scheme for differently setting the average power of signals in accordance with mapping for QPSK modulation and the average power of signals in accordance with mapping for 16QAM modulation, description has already been made in Embodiment F1. Thus, when taking the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) into consideration, the period (cycle) for the phase change and the switching between modulation schemes is 6=3×2 (where 3: the number of phase changing values prepared as phase changing values used in the scheme for regularly performing phase change after precoding, and 2: both (QPSK, 16QAM) and (16QAM, QPSK) can be the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) for each of the phase changing values), as shown inFIG.92. As description has been made in the above, by making an arrangement such that both (QPSK, 16QAM) and (16QAM, QPSK) exist as the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)), and such that both (QPSK, 16QAM) and (16QAM, QPSK) exist as the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) with respect to each of the phase changing values prepared as phase changing values used in the scheme for regularly performing phase change, the following advantageous effects are to be yielded. That is, even when differently setting the average power of signals in accordance with mapping for QPSK modulation and the average power of signals in accordance with mapping for 16QAM modulation, the influence with respect to the PAPR of the transmission power amplifier included in the transmission device is suppressed to a minimal extent, and thus the influence with respect to the power consumption of the transmission device is suppressed to a minimal extent, while the reception quality of data received by the reception device in the LOS environment is improved, as explanation has already been provided in the present description. Note that, although description has been provided in the above, taking as an example a case where the set of (modulation scheme of Q1(t), modulation scheme of Ω2(t)) is (QPSK, 16QAM) and (16QAM, QPSK), the possible sets of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) are not limited to this. More specifically, the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) may be one of: (QPSK, 64QAM), (64QAM, QPSK); (16QAM, 64QAM), (64QAM, 16QAM); (128QAM, 64QAM), (64QAM, 128QAM); (256QAM, 64QAM), (64QAM, 256QAM), and the like. That is, the present invention is to be similarly implemented provided that two different modulation schemes are prepared, and a different one of the modulation schemes is applied to each of Ω1(t) and Ω2(t). Additionally, the relation between the modulation scheme, the power changing value, and the phase changing value set at each of times (or for each of frequencies) is not limited to those described in the above with reference toFIGS.91and92. To summarize the explanation provided in the above, the following points are essential. Arrangements are to be made such that the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) can be either (modulation scheme A, modulation scheme B) or (modulation scheme B, modulation scheme A), and such that the average power for the modulation scheme A and the average power for the modulation scheme B are differently set. Further, when the modulation scheme applied to Ω1(t) is modulation scheme A, the power changer (8501A) multiples Ω1(t) with a and thereby outputs a x Ω1(t). On the other hand, when the modulation scheme applied to Ω1(t) is modulation scheme B, the power changer (8501A) multiples Ω1(t) with b and thereby outputs b×Ω1(t). Further, when the modulation scheme applied to Ω2(t) is modulation scheme A, the power changer (8501B) multiples Ω2(t) with a and thereby outputs a×Ω2(t). On the other hand, when the modulation scheme applied to Ω2(t) is modulation scheme B, the power changer (8501B) multiples Ω2(t) with b and thereby outputs b×Ω2(t). Further, an arrangement is to be made such that phase changing values y[0], y[1], . . . , y[n−2], and y[n−1] (or y[k], where k satisfies 0≤k≤n−1) exist as phase changing values prepared for use in the scheme for regularly performing phase change after precoding. Further, an arrangement is to be made such that both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) for y[k]. (Here, the arrangement may be made such that both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) for y[k] for all values of k, or such that a value k exists where both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) for y[k].) As description has been made in the above, by making an arrangement such that both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)), and such that both (modulation scheme A, modulation scheme B) and (modulation scheme B, modulation scheme A) exist as the set of (modulation scheme of Ω1(t), modulation scheme of Ω2(t)) with respect to each of the phase changing values prepared as phase changing values used in the scheme for regularly performing phase change, the following advantageous effects are to be yielded. That is, even when differently setting the average power of signals for modulation scheme A and the average power of signals for modulation scheme B, the influence with respect to the PAPR of the transmission power amplifier included in the transmission device is suppressed to a minimal extent, and thus the influence with respect to the power consumption of the transmission device is suppressed to a minimal extent, while the reception quality of data received by the reception device in the LOS environment is improved, as explanation has already been provided in the present description. Subsequently, explanation is provided of the operations of the reception device. Explanation of the reception device has already been provided in Embodiment 1 and so on, and the structure of the reception device is illustrated inFIGS.7,8and9, for instance. According to the relation illustrated inFIG.5, when the transmission device transmits modulated signals as introduced inFIGS.87,88,91and92, one relation among the two relations denoted by the two formulas below is satisfied. Note that in the two formulas below, r1(t) and r2(t) indicate reception signals, and h11(t), h12(t), h21(t), and h22(t) indicate channel fluctuation values. [Math. 93] (r1(t)r2(t))=(h11(t)h12(t)h21(t)h22(t))(z1(t)z2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(vej000uej0)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(v00u)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(a00b)(s1(t)s2(t))(formulaG1) [Math. 94] (r1(t)r2(t))=(h11(t)h12(t)h21(t)h22(t))(z1(t)z2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(vej000uej0)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(v00u)(s1(t)s2(t))=(h11(t)h12(t)h21(t)h22(t))(100y(t))F(b00a)(s1(t)s2(t))(formulaG2) Note that F shown in formulas G1 and G2 denotes precoding matrices used at time t, and y(t) denotes phase changing values. The reception device performs demodulation (detection) of signals by utilizing the relation defined in the two formulas above (that is, demodulation is to be performed in the same manner as explanation has been provided in Embodiment 1). However, the two formulas above do not take into consideration such distortion components as noise components, frequency offsets, and channel estimation errors, and thus, the demodulation (detection) is performed with such distortion components included in the signals. Regarding the values u and v that the transmission device uses for performing the power change, the transmission device transmits information about these values, or transmits information of the transmission mode (such as the transmission scheme, the modulation scheme and the error correction scheme) to be used. The reception device detects the values used by the transmission device by acquiring the information, obtains the two formulas described above, and performs the demodulation (detection). Although description is provided in the present invention taking as an example a case where switching between phase changing values is performed in the time domain, the present invention may be similarly embodied when using a multi-carrier transmission scheme such as OFDM or the like and when switching between phase changing values in the frequency domain, as description has been made in other embodiments. If this is the case, t used in the present embodiment is to be replaced with f (frequency ((sub) carrier)). Further, the present invention may be similarly embodied in a case where switching between phase changing values is performed in the time-frequency domain. In addition, in the present embodiment, the scheme for regularly performing phase change after precoding is not limited to the scheme for regularly performing phase change after precoding, explanation of which has been provided in the other sections of the present description. Further in addition, the same effect of minimalizing the influence with respect to the PAPR is to be obtained when applying the present embodiment with respect to a precoding scheme where phase change is not performed. Embodiment G2 In the present embodiment, description is provided on the scheme for regularly performing phase change, the application of which realizes an advantageous effect of reducing circuit size when the broadcast (or communications) system supports both of a case where the modulation scheme applied to s1is QPSK and the modulation scheme applied to s2is 16QAM, and a case where the modulation scheme applied to s1is 16QAM and the modulation scheme applied to s2is 16QAM. Firstly, explanation is made of the scheme for regularly performing phase change in a case where the modulation scheme applied to s1is 16QAM and the modulation scheme applied to s2is 16QAM. Examples of the precoding matrices used in the scheme for regularly performing phase change in a case where the modulation scheme applied to s1is 16QAM and the modulation scheme applied to s2is 16QAM are shown in Embodiment 1. The precoding matrices [F] are represented as follows. [Math. 95] F=1α2+1(ej0α×ej0α×ej0ejπ)(formulaG3) In the following, description is provided on an example where the formula G3 is used as the precoding matrices for the scheme for regularly performing phrase change after precoding in a case where 16QAM is applied as the modulation scheme to both s1and s2. FIG.93illustrates a structural example of the periphery of the weighting unit (precoding unit) which supports both of a case where the modulation scheme applied to s1is QPSK and the modulation scheme applied to s2is 16QAM, and a case where the modulation scheme applied to s1is 16QAM and the modulation scheme applied to s2is 16QAM. InFIG.93, elements that operate in a similar way toFIG.3,FIG.6andFIG.85bear the same reference signs, and explanations thereof are omitted. InFIG.93, the baseband signal switcher9301receives the precoded signal309A(z1(t)), the precoded and phase-changed signal309B(z2(t)), and the control signal8500as input. When the control signal8500indicates “do not perform switching of signals”, the precoded signal309A(z1(t)) is output as the signal9302A(z1′(t)), and the precoded and phase-changed signal309B(z2(t)) is output as the signal9302B(z2′(t)). In contrast, when the control signal8500indicates “perform switching of signals”, the baseband signal switcher8501performs the following:When time is 2k (k is an integer), outputs the precoded signal309A(z1(2k)) as the signal9302A(r1(2k)), and outputs the precoded signal309B(z2(2k)) as the precoded and phase-changed signal9302B(r2(2k)),When time is 2k+1 (k is an integer), outputs the precoded and phase-changed signal309B(z2(2k+1)) as the signal9302A(r1(2k+1)), and outputs the precoded signal309A(z1(2k+1)) as the signal9302B(r2(2k+1)), and further,When time is 2k (k is an integer), outputs the precoded signal309B(z2(2k)) as the signal9302A(r1(2k)), and outputs the precoded signal309A(z1(2k)) as the precoded and phase-changed signal9302B(r2(2k)),When time is 2k+1 (k is an integer), outputs the precoded signal309A(z1(2k+1)) as the signal9302A(r1(2k+1)), and outputs the precoded and phase-changed signal309B(z2(2k+1)) as the signal9302B(r2(2k+1)). (Although the above description provides an example of the switching between signals, the switching between signals is not limited to this. It is to be noted that importance lies in that switching between signals is performed when the control signal indicates “perform switching of signals”.) As explained inFIG.3,FIG.4,FIG.5,FIG.12,FIG.13and so on, the signal9302A(r1(t)) is transmitted from an antenna instead of z1(t) (Note that predetermined processing is performed as shown inFIG.3,FIG.4,FIG.5,FIG.12,FIG.13and so on). Also, the signal9302B(r2(t)) is transmitted from an antenna instead of z2(t) (Note that predetermined processing is performed as shown inFIG.3,FIG.4,FIG.5,FIG.12,FIG.13and so on.) Note that the signal9302A(r1(t)) and the signal9302B(r2(t)) are transmitted from different antenna. Here, it should be noted that the switching of signals as described in the above is performed with respect to only precoded symbols. That is, the switching of signals is not performed with respect to other inserted symbols such as pilot symbols and symbols for transmitting information that is not to be procoded (e.g. control information symbols), for example. Further, although the description is provided in the above of a case where the scheme for regularly performing phase change after precoding is applied in the time domain, the present invention is not limited to this. The present embodiment may be similarly applied also in cases where the scheme for regularly performing phase change after precoding is applied in the frequency domain and in the time-frequency domain. Similarly, the switching of signals may be performed in the frequency domain or the time-frequency domain, even though description is provided in the above where switching of signals is performed in the time domain. Subsequently, explanation is provided concerning the operation of each of the units inFIG.93in a case where 16QAM is applied as the modulation scheme for both s1and s2. Since s1(t) and s2(t) are baseband signals (mapped signals) mapped with the modulation scheme 16QAM, the mapping scheme applied thereto is as illustrated inFIG.80, and g is represented by formula 79. The power changer (8501A) receives a (mapped) baseband signal307A for the modulation scheme 16QAM and the control signal (8500) as input. Letting a value for power change set based on the control signal (8500) be v, the power changer outputs a signal (power-changed signal:8502A) obtained by multiplying the (mapped) baseband signal307A for the modulation scheme 16QAM by v. The power changer (8501B) receives a (mapped) baseband signal307B for the modulation scheme 16QAM and a control signal (8500) as input. Letting a value for power change set based on the control signal (8500) be u, the power changer outputs a signal (power-changed signal:8502B) obtained by multiplying the (mapped) baseband signal307B for the modulation scheme 16QAM by u. Here, the factors v and u satisfy: v=u=Q, v2:u2=1:1. By making such an arrangement, data is received at an excellent reception quality by the reception device. The weighting unit600receives the power-changed signal8502A (the signal obtained by multiplying the baseband signal (mapped signal)307A mapped with the modulation scheme 16QAM by the factor v), the power-changed signal8502B (the signal obtained by multiplying the baseband signal (mapped signal)307B mapped with the modulation scheme 16QAM by the factor u) and the information315regarding the weighting scheme as input. Further, the weighting unit600determines the precoding matrix based on the information315regarding the weighting scheme, and outputs the precoded signal309A(z1(0) and the precoded signal316B(z2′(t)). The phase changer317B performs phase change on the precoded signal316B(z2′(t)), based on the information315regarding the information processing scheme, and outputs the precoded and phase-changed signal309B(z2(t)). Here, when F represents a precoding matrix used in the scheme for regularly performing phase change after precoding and y(t) represents the phase changing values, the following formula holds. [Math. 96] (r1(t)r2(t))=(100y(t))F(vej000uej0)(s1(t)s2(t))=(100y(t))F(v00u)(s1(t)s2(t))=(100y(t))F(Ω00Ω)(s1(t)s2(t))(formulaG4) Note that y(t) is an imaginary number having the absolute value of 1 (i.e. y[i]=ejθ). When the precoding matrix F, which is a precoding matrix used in the scheme for regularly performing phase change after precoding, is represented by formula G3 and when 16QAM is applied as the modulation scheme of both s1and s2, formula 37 is suitable as the value of a, as is described in Embodiment 1. When a is represented by formula 37, z1(t) and z2(t) each are baseband signals corresponding to one of the 256 signal points in the IQ plane, as illustrated inFIG.94. Note thatFIG.94illustrates an example of the layout of the 256 signal points, and the layout may be a phase-rotated layout of the 256 signal components. Here, since the modulation scheme applied to s1is 16QAM and the modulation scheme applied to s2is also 16QAM, the weighted and phase-changed signals z1(t) and z2(t) are each transmitted as 4 bits according to 16QAM. Therefore a total of 8 bits are transferred as is indicated by the 256 signals points illustrated inFIG.94. In such a case, since the minimum Euclidian distance between the signal points is comparatively large, the reception quality of data received by the reception unit is improved. The baseband signal switcher9301receives the precoded signal309A(z1(t)), the precoded and phase-changed signal309B(z2(t)), and the control signal8500as input. Since 16QAM is applied as the modulation scheme of both s1and s2, the control signal8500indicates “do not perform switching of signals”. Thus, the precoded signal309A(z1(t)) is output as the signal9302A(r1(0) and the precoded and phase-changed signal309B(z2(t)) is output as the signal9302B(r2(t)). Subsequently, explanation is provided concerning the operation of each of the units inFIG.116in a case where QPSK is applied as the modulation scheme for s1and 16QAM is applied as the modulation scheme for s2. Let s1(t) be the (mapped) baseband signal for the modulation scheme QPSK. The mapping scheme for s1(t) is as shown inFIG.81, and h is as represented by formula 78. Since s2(t) is the (mapped) baseband signal for the modulation scheme 16QAM, the mapping scheme for s2(t) is as shown inFIG.80, and g is as represented by formula 79. The power changer (8501A) receives the baseband signal (mapped signal)307A mapped according to the modulation scheme QPSK, and the control signal (8500) as input. Further, the power changer (8501A) multiplies the baseband signal (mapped signal)307A mapped according to the modulation scheme QPSK by a factor v, and outputs the signal obtained as a result of the multiplication (the power-changed signal:8502A). The factor v is a value for performing power change and is set according to the control signal (8500). The power changer (8501B) receives a (mapped) baseband signal307B for the modulation scheme 16QAM and a control signal (8500) as input. Letting a value for power change set based on the control signal (8500) be u, the power changer outputs a signal (power-changed signal:8502B) obtained by multiplying the (mapped) baseband signal307B for the modulation scheme 16QAM by u. In Embodiment F1, description is provided that one exemplary example is where “the ratio between the average power of QPSK and the average power of 16QAM is set so as to satisfy the formula v2:u2=1:5”. (By making such an arrangement, data is received at an excellent reception quality by the reception device.) In the following, explanation is provided of the scheme for regularly performing phase change after precoding when such an arrangement is made. The weighting unit600receives the power-changed signal8502A (the signal obtained by multiplying the baseband signal (mapped signal)307A mapped with the modulation scheme QPSK by the factor v), the power-changed signal8502B (the signal obtained by multiplying the baseband signal (mapped signal)307B mapped with the modulation scheme 16QAM by the factor u) and the information315regarding the signal processing scheme as input. Further, the weighting unit600performs precoding according to the information315regarding the signal processing scheme, and outputs the precoded signal309A(z1(t)) and the precoded signal316B(z2′(t)). Here, when F represents a precoding matrix used in the scheme for regularly performing phase change after precoding and y(t) represents the phase change values, the following formula holds. [Math. 97] (z1(t)z2(t))=(100y(t))F(vej000uej0)(s1(t)s2(t))=(100y(t))F(v00u)(s1(t)s2(t))=(100y(t))F(v005v)(s1(t)s2(t))(formulaG5) Note that y(t) is an imaginary number having the absolute value of 1 (i.e. y[i]=ejθ). When the precoding matrix F, which is a precoding matrix according to the precoding scheme for regularly performing phase change after precoding, is represented by formula G3 and when 16QAM is applied as the modulation scheme of both s1and s2, formula 37 is suitable as the value of a, as is described. The reason for this is explained in the following. FIG.95illustrates the relationship between the 16 signal points of 16QAM and the 4 signal points of QPSK on the IQ plane when the transmission state is as described in the above. InFIG.95, each ∘ indicates a signal point of 16QAM, and each • indicates a signal point of QPSK. As can be seen inFIG.95, four signal points among the 16 signal points of the 16QAM coincide with the 4 signal points of the QPSK. Under such circumstances, when the precoding matrix F, which is a precoding matrix used in the scheme for regularly performing phase change after precoding, is represented by formula G3 and when formula 37 is the value of a, each of z1(t) and z2(t) is a baseband signal corresponding to 64 signal points extracted from the 256 signal points illustrated inFIG.94of a case where the modulation scheme applied to s1is 16QAM and the modulation scheme applied to s2is 16QAM. Note thatFIG.94illustrates an example of the layout of the 256 signal points, and the layout may be a phase-rotated layout of the 256 signal components. Since QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2, the weighted and phase-changed signals z1(t) and z2(t) are respectively transmitted as 2 bits according to QPSK, and 4 bits according to 16QAM. Therefore a total of 6 bits are transferred as is indicated by the 64 signals points. Since the minimum Euclidian distance between the 64 signal points as described in the above is comparatively large, the reception quality of the data received by the reception device is improved. The baseband signal switcher9301receives the precoded signal309A(z1(t)), the precoded and phase-changed signal309B(z2(t)), and the control signal8500as input. Since QPSK is the modulation scheme for s1and 16QAM is the modulation scheme for s2and thus, the control signal8500indicates “perform switching of signals”, the baseband signal switcher9301performs, for instance, the following:When time is 2k (k is an integer), outputs the precoded signal309A(z1(2k)) as the signal9302A(r1(2k)), and outputs the precoded signal309B(z2(2k)) as the precoded and phase-changed signal9302B(r2(2k)),When time is 2k+1 (k is an integer), outputs the precoded and phase-changed signal309B(z2(2k+1)) as the signal9302A(r1(2k+1)), and outputs the precoded signal309A(z1(2k+1)) as the signal9302B(r2(2k+1)), and further,When time is 2k (k is an integer), outputs the precoded signal309B(z2(2k)) as the signal9302A(r1(2k)), and outputs the precoded signal309A(z1(2k)) as the precoded and phase-changed signal9302B(r2(2k)),When time is 2k+1 (k is an integer), outputs the precoded signal309A(z1(2k+1)) as the signal9302A(r1(2k+1)), and outputs the precoded and phase-changed signal309B(z2(2k+1)) as the signal9302B(r2(2k+1)). Note that, in the above, description is made that switching of signals is performed when QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2. By making such an arrangement, the reduction of PAPR is realized and further, the electric consumption by the transmission unit is suppressed, as description has been provided in Embodiment F1. However, when the electric consumption by the transmission device need not be taken into account, an arrangement may be made such that switching of signals is not performed similar to the case where 16QAM is applied as the modulation scheme for both s1and s2. Additionally, description has been provided in the above on a case where QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2, and further, the condition v2:u2=1:5 is satisfied, since such a case is considered to be exemplary. However, there exists a case where excellent reception quality is realized when (i) the scheme for regularly performing phase change after precoding when QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2and (ii) the scheme for regularly performing phase change after precoding when 16QAM is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2are considered as being identical under the condition v2<u2. Thus, the condition to be satisfied by values v and u is not limited to v2:u2=1:5. By considering (i) the scheme for regularly performing phase change after precoding when QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2and (ii) the scheme for regularly performing phase change after precoding when 16QAM is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2to be identical as explained in the above, the reduction of circuit size is realized. Further, in such a case, the reception device performs demodulation according to formulas G4 and G5, and to the scheme of switching between signals, and since signal points coincide as explained in the above, the sharing of a single arithmetic unit computing reception candidate signal points is possible, and thus, the circuit size of the reception device can be realized to a further extent. Note that, although description has been provided in the present embodiment taking the formula G3 as an example of the scheme for regularly performing phase change after precoding, the scheme for regularly performing phase change after precoding is not limited to this. The essential points of the present invention are as described in the following:When both the case where QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2and the case where 16QAM is the modulation scheme applied for both s1and s2are supported, the same scheme for regularly performing phase change after precoding is applied in both cases.The condition v2=u2holds when 16QAM is the modulation scheme applied for both s1and s2, and the condition v2<u2holds when QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2 Further, examples where excellent reception quality of the reception device is realized are described in the following. Example 1 (the following two conditions are to be satisfied): The condition v2=u2holds when 16QAM is the modulation scheme applied for both s1and s2, and the condition v2:u2=1:5 holds when QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2, andThe same scheme for regularly performing phase change after precoding is applied in both of cases where 16QAM is the modulation scheme applied for both s1and s2and QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2. Example 2 (the following two conditions are to be satisfied):The condition v2=u2holds when 16QAM is the modulation scheme applied for both s1and s2, and the condition v2<u2holds when QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2, andWhen both the case where QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2and the case where 16QAM is the modulation scheme applied for both s1and s2are supported, the same scheme for regularly performing phase change after the precoding is applied in both cases, and the precoding matrices are represented by formula G3. Example 3 (the following two conditions are to be satisfied):The condition v2=u2holds when 16QAM is the modulation scheme applied for both s1and s2, and the condition v2<u2holds when QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2, andWhen both the case where QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2and the case where 16QAM is the modulation scheme applied for both s1and s2are supported, the same scheme for regularly performing phase change after the precoding is applied in both cases, and the precoding matrices are represented by formula G3, and a is represented by formula 37. Example 4 (the following two conditions are to be satisfied):The condition v2=u2holds when 16QAM is the modulation scheme applied for both s1and s2, and the condition v2:u2=1:5 holds when QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2.When both the case where QPSK is the modulation scheme applied to s1and 16QAM is the modulation scheme applied to s2and the case where 16QAM is the modulation scheme applied for both s1and s2are supported, the same scheme for regularly performing phase change after the precoding is applied in both cases, and the precoding matrices are represented by formula G3, and a is represented by formula 37. Note that, although the present embodiment has been described with an example where the modulation schemes are QPSK and 16QAM, the present embodiment is not limited to this example. The scope of the present embodiment may be expanded as described below. Consider a modulation scheme A and a modulation scheme B. Let a be the number of a signal point on the IQ plane of the modulation scheme A, and let b be the number of signal points on the IQ plane of the modulation scheme B, where a<b. Then, the essential points of the present invention are described as follows. The following two conditions are to be satisfied.If the case where the modulation scheme of s1is the modulation scheme A and the modulation scheme of s2is the modulation scheme B, and the case where the modulation scheme of s1is the modulation scheme B and the modulation scheme of s2is the modulation scheme B are both supported, the same scheme is used in common in both the cases for regularly performing phase change after precoding.When the modulation scheme of s1is the modulation scheme B and the modulation scheme of s2is the modulation scheme B, the condition v2=u2is satisfied, and when the modulation scheme of s1is the modulation scheme A and the modulation scheme of s2is the modulation scheme B, the condition v2<u2is satisfied. Here, the baseband signal switching as described with reference toFIG.93may be optionally executed. However, when the modulation scheme of s1is the modulation scheme A and the modulation scheme of s2is the modulation scheme B, it is preferable to perform the above-described baseband signal switching with the influence of the PAPR taken into account. Alternatively, the following two conditions are to be satisfied.If the case where the modulation scheme of s1is the modulation scheme A and the modulation scheme of s2is the modulation scheme B, and the case where the modulation scheme of s1is the modulation scheme B and the modulation scheme of s2is the modulation scheme B are both supported, the same scheme is used in common in both the cases for regularly performing phase change after precoding, and the precoding matrices are presented by formula G3. When the modulation scheme of s1is the modulation scheme B and the modulation scheme of s2is the modulation scheme B, the condition v2=u2is satisfied, and when the modulation scheme of s1is the modulation scheme A and the modulation scheme of s2is the modulation scheme B, the condition v2<u2is satisfied. Here, the baseband signal switching as described with reference toFIG.93may be optionally executed. However, when the modulation scheme of s1is the modulation scheme A and the modulation scheme of s2is the modulation scheme B, it is preferable to perform the above-described baseband signal switching with the influence of the PAPR taken into account. As an exemplary set of the modulation scheme A and the modulation scheme B, (modulation scheme A, modulation scheme B) is one of (QPSK, 16QAM), (16QAM, 64QAM), (64QAM, 128QAM), and (64QAM, 256QAM). Although the above explanation is given for an example where phase change is performed on one of the signals after precoding, the present invention is not limited to this. As described in this Description, even when phase change is performed on a plurality of precoded signals, the present embodiment is applicable. If this is the case, the relationship between the modulated signal set and the precoding matrices (the essential points of the present invention). Further, although the present embodiment has been described on the assumption that the precoding matrices F are represented by formula G3, the present invention is not limited to this. For example, any one of the following may be used: [Math. 98] F=1α2+1(α×ej0ejπej0α×ej0)(formulaG6) [Math. 99] F=1α2+1(ej0α×ejπα×ej0ej0)(formulaG7) [Math. 100] F=1α2+1(α×ej0ej0ej0α×ejπ)(formulaG8) [Math. 101] F=1α2+1(ejθ11α×ej(θ11+λ)α×ejθ21ej(θ21+λ+π))(formulaG9) [Math. 102] F=1α2+1(α×ejθ11ej(θ11+λ+π)ejθ21α×ej(θ21+λ))(formulaG10) Note that θ11, θ21and λ in formulas G9 and G10 are fixed values (radians). Although description is provided in the present invention taking as an example a case where switching between phase change values is performed in the time domain, the present invention may be similarly embodied when using a multi-carrier transmission scheme such as OFDM or the like and when switching between phase change values in the frequency domain, as description has been made in other embodiments. If this is the case, t used in the present embodiment is to be replaced with f (frequency ((sub) carrier)). Further, the present invention may be similarly embodied in a case where switching between phase change values is performed in the time-frequency domain. Note that, in the present embodiment, the scheme for regularly performing phase change after precoding is not limited to the scheme for regularly performing phase change after precoding as described in this Description. Furthermore, in any one of the two patterns of setting the modulation scheme according to the present embodiment, the reception device performs demodulation and detection using the reception scheme described in Embodiment F1. INDUSTRIAL APPLICABILITY The present invention is widely applicable to wireless systems that transmit different modulated signals from a plurality of antennas, such as an OFDM-MIMO system. Furthermore, in a wired communication system with a plurality of transmission locations (such as a Power Line Communication (PLC) system, optical communication system, or Digital Subscriber Line (DSL) system), the present invention may be adapted to MIMO, in which case a plurality of transmission locations are used to transmit a plurality of modulated signals as described by the present invention. A modulated signal may also be transmitted from a plurality of transmission locations. REFERENCE SIGNS LIST 302A,302B Encoders304A,304B Interleavers306A,306B Mappers314Signal processing scheme information generator308A,308B Weighting units310A,310B Wireless units312A,312B Antennas317A,317B Phase changers402Encoder404Distributor504#1,504#2Transmit antennas505#1,505#2Receive antennas600Weighting unit701_X,701_Y Antennas703_X,703_Y Wireless units705_1Channel fluctuation estimator705_2Channel fluctuation estimator707_1Channel fluctuation estimator707_2Channel fluctuation estimator709Control information decoder711Signal processor803Inner MIMO detector805A,805B Log-likelihood calculators807A,807B Deinterleavers809A,809B Log-likelihood ratio calculators811A,811B Soft-in/soft-out decoders813A,813B Interleavers815Memory819Coefficient generator901Soft-in/soft-out decoder903Distributor1201A,1201B OFDM-related processors1302A,1302A Serial-to-parallel converters1304A,1304B Reorderers1306A,1306B IFFT units1308A,1308B Wireless units | 596,469 |
11943033 | DETAILED DESCRIPTION The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. While aspects and implementations are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Aspects described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, implementations and/or uses may come about via integrated chip implementations and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, artificial intelligence (AI)-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described aspects may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described aspects. In some practical settings, devices incorporating described aspects and features may also include additional components and features for implementation and practice of claimed and described aspect. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor(s), interleaver, adders/summers, etc.). It is intended that aspects described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc. of varying sizes, shapes, and constitution. FIG.1is a diagram illustrating an example of a wireless communications system and an access network100. The wireless communications system (also referred to as a wireless wide area network (WWAN)) illustrates base stations102or180, UEs104, an Evolved Packet Core (EPC)160, and another core network190(e.g., a 5G Core (5GC)). A UE104and/or a base station102or180may communicate in a full-duplex mode in which uplink communication and downlink communication is exchanged in a same frequency band at overlapping times. The UE and the base station may exchange communication using one or more directional beams. For example, beamforming182may be used between a base station180and a UE104to compensate for the path loss and short range in millimeter wave (mmW) communication. The base station180and the UE104may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming. The base station180may transmit a beamformed signal to the UE104in one or more transmit directions182′. The UE104may receive the beamformed signal from the base station180in one or more receive directions182″. The UE104may also transmit a beamformed signal to the base station180in one or more transmit directions. The base station180may receive the beamformed signal from the UE104in one or more receive directions. A beam between the UE104and the base station180may become blocked, which may lead to downlink and/or uplink beam degradation leading to a beam failure. A UE104or a base station102or180operating in a full-duplex mode may experience self-interference for a beam that leads to a beam failure for downlink communication. The base station180/UE104may perform beam training to determine the best receive and transmit directions for each of the base station180/UE104. The transmit and receive directions for the base station180may or may not be the same. The transmit and receive directions for the UE104may or may not be the same. Aspects presented herein enable latency reduction (i.e., it is possible to receive DL signal in UL only slots), improved spectrum efficiency, and improved resource utilization by providing full-duplex communication with the ability to reselect a full-duplex beam pair using a beam management report. For example, a UE104may include a determination/application component198configured to transmit a beam management report that reports a set of one or more candidate full-duplex beam pairs to the base station and applies a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after transmitting the beam management report to the base station. In some examples, the component198may also be configured to determine when to apply a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after transmitting the beam management report to the base station. A base station102or180may include a determination/application component199configured to receive a beam management report that reports a set of one or more candidate full-duplex beam pairs to the base station and configured to apply a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after receiving the beam management report. The component199may also be configured to determine when to apply a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after receiving the beam management report from the UE. Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies. The base stations102may include macrocells (high power cellular base station) and/or small cells (low power cellular base station). The macrocells include base stations. The small cells include femtocells, picocells, and microcells. The base stations102configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC160through first backhaul links132(e.g., S1 interface). The base stations102configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network190through second backhaul links184. In addition to other functions, the base stations102may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations102may communicate directly or indirectly (e.g., through the EPC160or core network190) with each other over third backhaul links134(e.g., X2 interface). The first backhaul links132, the second backhaul links184, and the third backhaul links134may be wired or wireless. The base stations102may wirelessly communicate with the UEs104. Each of the base stations102may provide communication coverage for a respective geographic coverage area110. There may be overlapping geographic coverage areas110. For example, the small cell102′ may have a coverage area110′ that overlaps the coverage area110of one or more macro base stations102. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links120between the base stations102and the UEs104may include uplink (UL) (also referred to as reverse link) transmissions from a UE104to a base station102and/or downlink (DL) (also referred to as forward link) transmissions from a base station102to a UE104. The communication links120may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations102/UEs104may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). Some UEs104may communicate with each other using device-to-device (D2D) communication link158. The D2D communication link158may use the DL/UL WWAN spectrum. The D2D communication link158may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR. The wireless communications system may further include a Wi-Fi access point (AP)150in communication with Wi-Fi stations (STAs)152via communication links154, e.g., in a 5 GHz unlicensed frequency spectrum or the like. When communicating in an unlicensed frequency spectrum, the STAs152/AP150may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. The small cell102′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell102′ may employ NR and use the same unlicensed frequency spectrum (e.g., 5 GHz, or the like) as used by the Wi-Fi AP150. The small cell102′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz). Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz), and FR5 (114.25 GHz-300 GHz). Each of these higher frequency bands falls within the EHF band. With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, or may be within the EHF band. A base station102, whether a small cell102′ or a large cell (e.g., macro base station), may include and/or be referred to as an eNB, gNodeB (gNB), or another type of base station. Some base stations180, such as a gNB may operate in a traditional sub 6 GHz spectrum, in millimeter wave frequencies, and/or near millimeter wave frequencies in communication with the UE104. When the gNB (e.g., the base station180) operates in millimeter wave or near millimeter wave frequencies, the gNB may be referred to as a millimeter wave base station. The millimeter wave base station (e.g., the base station180) may utilize beamforming182with the UE104to compensate for the path loss and short range. The base station180and the UE104may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming. The EPC160may include a Mobility Management Entity (MME)162, other MMEs164, a Serving Gateway166, a Multimedia Broadcast Multicast Service (MBMS) Gateway168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway172. The MME162may be in communication with a Home Subscriber Server (HSS)174. The MME162is the control node that processes the signaling between the UEs104and the EPC160. Generally, the MME162provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway166, which itself is connected to the PDN Gateway172. The PDN Gateway172provides UE IP address allocation as well as other functions. The PDN Gateway172and the BM-SC170are connected to the IP Services176. The IP Services176may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BM-SC170may provide functions for MBMS user service provisioning and delivery. The BM-SC170may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway168may be used to distribute MBMS traffic to the base stations102belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. The core network190may include a Access and Mobility Management Function (AMF)192, other AMFs193, a Session Management Function (SMF)194, and a User Plane Function (UPF)195. The AMF192may be in communication with a Unified Data Management (UDM)196. The AMF192is the control node that processes the signaling between the UEs104and the core network190. Generally, the AMF192provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF195. The UPF195provides UE IP address allocation as well as other functions. The UPF195is connected to the IP Services197. The IP Services197may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switch (PS) Streaming (PSS) Service, and/or other IP services. The base station may include and/or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. The base station102provides an access point to the EPC160or core network190for a UE104. Examples of UEs104include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs104may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE104may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. In some scenarios, the term UE may also apply to one or more companion devices such as in a device constellation arrangement. One or more of these devices may collectively access the network and/or individually access the network. FIG.2Ais a diagram200illustrating an example of a first subframe within a 5G NR frame structure.FIG.2Bis a diagram230illustrating an example of DL channels within a 5G NR subframe.FIG.2Cis a diagram250illustrating an example of a second subframe within a 5G NR frame structure.FIG.2Dis a diagram280illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided byFIGS.2A,2C, the 5G NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL), where D is DL, U is UL, and F is flexible for use between DL/UL, and subframe 3 being configured with slot format 1 (with all UL). While subframes 3, 4 are shown with slot formats 1, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI), or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI). Note that the description infra applies also to a 5G NR frame structure that is TDD. FIGS.2A-2Dillustrate a frame structure, and the aspects of the present disclosure may be applicable to other wireless communication technologies, which may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For normal CP, each slot may include 14 symbols, and for extended CP, each slot may include 12 symbols. The symbols on DL may be CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission). The number of slots within a subframe is based on the CP and the numerology. The numerology defines the subcarrier spacing (SCS) and, effectively, the symbol length/duration, which is equal to 1/SCS. SCSμΔf = 2μ· 15 [kHz]Cyclic prefix015Normal130Normal260Normal, Extended3120Normal4240Normal For normal CP (14 symbols/slot), different numerologies μ 0 to 4 allow for 1, 2, 4, 8, and 16 slots, respectively, per subframe. For extended CP, the numerology 2 allows for 4 slots per subframe. Accordingly, for normal CP and numerology μ, there are 14 symbols/slot and 2μslots/subframe. The subcarrier spacing may be equal to 2μ*15 kHz, where μ is the numerology 0 to 4. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=4 has a subcarrier spacing of 240 kHz. The symbol length/duration is inversely related to the subcarrier spacing.FIGS.2A-2Dprovide an example of normal CP with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (seeFIG.2B) that are frequency division multiplexed. Each BWP may have a particular numerology and CP (normal or extended). A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme. As illustrated inFIG.2A, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulation RS (DM-RS) (indicated as R for one particular configuration, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and phase tracking RS (PT-RS). FIG.2Billustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within one BWP may be referred to as a control resource set (CORESET). A UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., common search space, UE-specific search space) during PDCCH monitoring occasions on the CORESET, where the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE104to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the DM-RS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block (also referred to as SS block (SSB)). The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages. As illustrated inFIG.2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS). The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL. FIG.2Dillustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgment (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACK and/or negative ACK (NACK)). The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI. FIG.3is a block diagram of a base station310in communication with a UE350in an access network. In the DL, IP packets from the EPC160may be provided to a controller/processor375. The controller/processor375implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor375provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. The transmit (TX) processor316and the receive (RX) processor370implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor316handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator374may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE350. Each spatial stream may then be provided to a different antenna320via a separate transmitter318TX. Each transmitter318TX may modulate an RF carrier with a respective spatial stream for transmission. At the UE350, each receiver354RX receives a signal through its respective antenna352. Each receiver354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor356. The TX processor368and the RX processor356implement layer 1 functionality associated with various signal processing functions. The RX processor356may perform spatial processing on the information to recover any spatial streams destined for the UE350. If multiple spatial streams are destined for the UE350, they may be combined by the RX processor356into a single OFDM symbol stream. The RX processor356then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station310. These soft decisions may be based on channel estimates computed by the channel estimator358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station310on the physical channel. The data and control signals are then provided to the controller/processor359, which implements layer 3 and layer 2 functionality. The controller/processor359can be associated with a memory360that stores program codes and data. The memory360may be referred to as a computer-readable medium. In the UL, the controller/processor359provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC160. The controller/processor359is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. Similar to the functionality described in connection with the DL transmission by the base station310, the controller/processor359provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. Channel estimates derived by a channel estimator358from a reference signal or feedback transmitted by the base station310may be used by the TX processor368to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor368may be provided to different antenna352via separate transmitters354TX. Each transmitter354TX may modulate an RF carrier with a respective spatial stream for transmission. The UL transmission is processed at the base station310in a manner similar to that described in connection with the receiver function at the UE350. Each receiver318RX receives a signal through its respective antenna320. Each receiver318RX recovers information modulated onto an RF carrier and provides the information to a RX processor370. The controller/processor375can be associated with a memory376that stores program codes and data. The memory376may be referred to as a computer-readable medium. In the UL, the controller/processor375provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE350. IP packets from the controller/processor375may be provided to the EPC160. The controller/processor375is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. At least one of the TX processor368, the RX processor356, and the controller/processor359may be configured to perform aspects in connection with the determination/application component198ofFIG.1. At least one of the TX processor316, the RX processor370, and the controller/processor375may be configured to perform aspects in connection with the determination/application component199ofFIG.1. Wireless communication systems may be configured to share available system resources and provide various telecommunication services (e.g., telephony, video, data, messaging, broadcasts, etc.) based on multiple-access technologies that support communication with multiple users. Full-duplex operation in which a wireless device exchanges uplink and downlink communication that overlaps in time may enable more efficient use of the wireless spectrum. Full-duplex operation may include simultaneous transmission and reception in a same frequency range. In some examples, the frequency range may be a mmW frequency range, e.g., frequency range 2 (FR2). In some examples, the frequency range may be a sub-6 GHz frequency range, e.g., frequency range 1 (FR1). Full-duplex capability may be supported at a base station and/or a UE. For example, a UE may transmit uplink communication from one antenna panel and may receive downlink communication with another antenna panel. In some examples, the full-duplex communication may be conditional on beam separation or other conditions. Full-duplex communication may reduce latency. For example, full-duplex operation may enable a UE to receive a downlink signal in an uplink only slot, which can reduce the latency for the downlink communication. Full-duplex communication may improve spectrum efficiency, e.g., spectrum efficiency per cell or per UE. Full-duplex communication may enable more efficient use of wireless resources. FIGS.4A-4Cillustrate various modes of full-duplex communication. Full-duplex communication supports transmission and reception of information over a same frequency band in manner that overlap in time. In this manner, spectral efficiency may be improved with respect to the spectral efficiency of half-duplex communication, which supports transmission or reception of information in one direction at a time without overlapping uplink and downlink communication. Due to the simultaneous Tx/Rx nature of full-duplex communication, a UE or a base station may experience self-interference caused by signal leakage from its local transmitter to its local receiver. In addition, the UE or base station may also experience interference from other devices, such as transmissions from a second UE or a second base station. Such interference (e.g., self-interference or interference caused by other devices) may impact the quality of the communication, or even lead to a loss of information. FIG.4Ashows a first example of full-duplex communication400in which a first base station402ais in full-duplex communication with a first UE404aand a second UE406a. The first UE404aand the second UE406amay be configured for half-duplex communication or full-duplex communication.FIG.4Aillustrates the first UE404aperforming downlink reception, and the second UE406aperforming uplink transmission. The second UE406amay transmit a first uplink signal to the first base station402aas well as to other base stations, such as a second base station408ain proximity to the second UE406a. The first base station402atransmits a downlink signal to the first UE404aconcurrently (e.g., overlapping at least partially in time) with receiving the uplink signal from the second UE406a. The base station402amay experience self-interference at its receiving antenna that is receiving the uplink signal from UE406a, the self-interference being due to reception of at least part of the downlink signal transmitted to the UE404a. The base station402amay experience additional interference due to signals from the second base station408a. Interference may also occur at the first UE404abased on signals from the second base station408aas well as from uplink signals from the second UE406a. FIG.4Bshows a second example of full-duplex communication410in which a first base station402bis in full-duplex communication with a first UE404b. In this example, the UE404bis also operating in a full-duplex mode. The first base station402band the UE404breceive and transmit communication that overlaps in time and is in a same frequency band. The base station and the UE may each experience self-interference, due to a transmitted signal from the device leaking to (e.g., being received by) a receiver at the same device. The first UE404bmay experience additional interference based on one or more signals emitted from a second UE406band/or a second base station408bin proximity to the first UE404b. FIG.4Cshows a third example of full-duplex communication420in which a first UE404ctransmits and receives full-duplex communication with a first base station402cand a second base station408c. The first base station402cand the second base station408cmay serve as multiple transmission and reception points (multi-TRPs) for UL and DL communication with the UE404c. The second base station408cmay also exchange communication with a second UE406c. InFIG.4C, the first UE404cmay transmit an uplink signal to the first base station402cthat overlaps in time with receiving a downlink signal from the second base station408c. The first UE404cmay experience self-interference as a result of receiving at least a portion of the first signal when receiving the second signal, e.g., the UE's uplink signal to the base station402cmay leak to (e.g., be received by) the UE's receiver when the UE is attempting to receive the signal from the other base station408c. The first UE404cmay experience additional interference from the second UE406c. Full-duplex communication may be in a same frequency band. The uplink and downlink communication may be in different frequency subbands, in the same frequency subband, or in partially overlapping frequency subbands.FIG.5illustrates a first example500and a second example510of in-band full-duplex (IBFD) resources and a third example520of sub-band full-duplex resources. In IBFD, signals may be transmitted and received in overlapping times and overlapping in frequency. As shown in the first example500, a time and a frequency allocation of transmission resources502may fully overlap with a time and a frequency allocation of reception resources504. In the second example510, a time and a frequency allocation of transmission resources512may partially overlap with a time and a frequency of allocation of reception resources514. IBFD is in contrast to sub-band FDD, where transmission and reception resources may overlap in time using different frequencies, as shown in the third example520. In the third example520, the UL, the transmission resources522are separated from the reception resources524by a guard band526. The guard band may be frequency resources, or a gap in frequency resources, provided between the transmission resources522and the reception resources524. Separating the transmission frequency resources and the reception frequency resources with a guard band may help to reduce self-interference. Transmission resources and a reception resources that are immediately adjacent to each other may be considered as having a guard band width of 0. As an output signal from a wireless device may extend outside the transmission resources, the guard band may reduce interference experienced by the wireless device. Sub-band FDD may also be referred to as “flexible duplex”. If the full-duplex operation is for a UE or a device implementing UE functionality, the transmission resources502,512, and522may correspond to uplink resources, and the reception resources504,514, and524may correspond to downlink resources. Alternatively, if the full-duplex operation is for a base station or a device implementing base station functionality, the transmission resources502,512, and522may correspond to downlink resources, and the reception resources504,514, and524may correspond to uplink resources. As described in connection withFIG.1, a UE104and a base station102or180may use beamforming182to exchange downlink and uplink communication using directional beams. After determination of a beam for communication, conditions may change and may cause a beam to fail. For example, a UE may experience a beam failure if a user moves to a location that blocks the beam to the base station. For example, the UE may move to a different orientation or may move around a corner, or may move to a location in which a building or other structure blocks the beam. In other examples, the surrounding environment may change, e.g., a vehicle may move to a position that blocks the beam between the UE and the base station. If the current beam used by the UE becomes unreliable, the UE may switch to a new beam. The UE may monitor the quality of the beam and may perform radio link monitoring (RLM) in order to detect a reduction in the beam quality. For example, a UE may monitor a quality of a signal received via reception beam(s). Measurements for RLM, e.g., of downlink signals, may be performed by a physical (PHY) layer of the UE based on one or more RLM reference signals. The PHY layer may pass the RLM measurements to a medium access control (MAC) layer and radio resource control (RRC) layer. The RRC layer may be responsible for detecting a radio link failure (RLF), and the MAC layer may be responsible for detecting beam failures. For monitoring active link performances, a UE may perform measurements of at least one signal, e.g., reference signals, for beam failure detection. The measurements may include deriving a metric similar to a Signal to Interference plus Noise Ratio (SINR) for the signal, or RSRP strength or block error rate (BLER) of a reference control channel chosen by base station and/or implicitly derived by UE based on the existing RRC configuration. The reference signal may comprise any of CSI-RS, Physical Broadcast Channel (PBCH), a synchronization signal, or other reference signals for time and/or frequency tracking, etc. In some cases, the UE may determine a configured metric such as block error rate (BLER) for a reference signal. The measurement(s) may indicate the UE's ability to transmit an uplink transmission to the base station using the beam. FIG.6illustrates an example communication flow600between a UE602and a base station604that may reselect a full-duplex beam pair using a beam management report based on RLM measurements of a reference signal in accordance with some aspects of the disclosure. The UE602may correspond to UE104inFIG.1, UE350inFIG.3, UE404a,404b,404c,406a,406b, or406cinFIG.4A,4B, or4C. The base station604may correspond to base station102,180,310,402a,402b,402c,408a,408b, or408c. InFIG.6, the UE602and the base station604may use beamforming with at least one active downlink and uplink beam pair for full-duplex communication606. As beam conditions may change, the UE may continue to perform measurements, e.g., Layer 1 beam management. For full-duplex communication, the UE may perform measurements for one or more beam pairs, e.g., a pair of an uplink beam for transmitting uplink communication and a downlink beam for receiving downlink communication in a full-duplex manner. The UE602may perform measurements based on one or more DL and UL reference signals for each beam, e.g., CSI-RS or SSB for a downlink beam and a self-interference measurement based on SRS transmitting from the uplink beam. The base station604may configure channel measurement resources (CMRs) and interference measurement resources (IMRs) to perform the SINR measurements. The CMRs measure the downlink channel quality and the IMRs measure the self-interference from the uplink beam to its own downlink beam at the UE. With the CMRs and the IMRs, the UE measures the SINR values per uplink and downlink beam pair. The UE may perform measurements for each possible combination of beams, e.g., each candidate beam pair. The UE may report measurements to the base station for a set of one or more candidate beam pair combinations for full-duplex communication having the best SINR values based on the channel and self-interference measurements. For example, the UE may report the top N best full-duplex candidate beam pairs that have the highest SINR values, N being an integer number. N may be configured by the base station or may be a defined number. The report may be referred to as a beam management report. The UE602may transmit to the base station604and the base station604may receive from the UE602, a beam management report that reports a set of one or more candidate full-duplex beam pairs, at608. As presented herein, the UE may apply a rule, condition, or configuration to determine when to apply a candidate beam pair from the beam management report. In some examples, the UE may determine the rule from a set of multiple rules/options for applying a new full-duplex beam pair following a beam management report. The UE602may determine, at610, when to apply one of the full-duplex beam pairs from the set of one or more candidate full-duplex beam pairs after transmitting the beam management report to the base station604. For example, the UE may apply the beam pair having the highest SINR measurement value among the reported beam pair candidates. The base station604may also determine, at620, when to apply the full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after receiving the beam management report from the UE602. The UE and the base station may determine to apply the new candidate beam pair based on the same timing so that the base station and UE transmit/receive communication using the new beam pair in coordination. Aspects presented herein enable the UE and the base station to apply the new beam pair in a manner that may reduce latency and save signaling overhead. For example, in some options for application of the new beam pair, the UE may apply the new full-duplex beam pair without an explicit indication from a base station. In other examples, the UE may determine to wait for an indication from the base station before applying the new beam pair combination after providing the beam management report. The UE602may then apply the new full-duplex beam pair at a first determined time, at612, after transmitting the beam management report608and based on the time determined at610. The base station604may similarly apply the full-duplex beam pair in the beam management report at a similarly determined time. The UE602and the base station604may select between multiple different options for the timing to apply the new full-duplex beam pair after reporting a beam management report for a set of N best beam pair candidates for full-duplex communication. In a first option, the UE602may wait for the base station604to provide an indication613, such as a final new beam pair indication, via a MAC-CE or DCI to reset the full-duplex beam pair after the UE602sends the beam management report608. In some aspects, the new beam pair indication613may indicate to the UE602the beam pair from the set of candidate beam pairs that the base station selects for full-duplex communication. The first option may enable the base station to control the selection of the new beam pair and the timing of the use of the new beam pair. In a second option, after the UE602reports the top N candidate beam pairs in the beam management report, the UE may directly reset the full-duplex beam pair and apply the new full-duplex beam pair (e.g. reset to the top beam pair with a highest SINR value among the selected top N candidate beam pairs) without waiting for an indication from the base station604. For example, the UE602may reset to the new beam pair after a period of time, such as x slots or x symbols (e.g. 28 symbols or 2 slots), following the transmission of the beam management report608. The UE may save signaling and reduce the latency for the full-duplex beam pair reset. In the timing, x may be an integer number of slots/symbols, which may be defined in the standard spec, or may be signaled to the UE602by the base station via RRC, MAC-CE, and/or DCI. In this example, the UE and the base station may change beams in response to the transmission and reception of the beam management report, respectively. In a third option, the UE602may apply the new beam pair based on an ACK for the beam management report. For example, after the UE602reports the top N candidate beam pairs, the base station604may send an ACK/NACK in DCI for the report. The report608may be sent via PUSCH or PUCCH. In this example, the UE does not wait for a new beam indication from the base station (e.g., at613), and may instead reset and apply the new full-duplex beam pair based on the ACK611that informs the UE602that the base station604successfully received the beam management report608. For example, the UE may reset to the top beam pair with a highest SINR value among the selected top N candidate beam pairs a period of time, such as after x slots or symbols (e.g. 28 symbols or 2 slots), following the base station's ACK611for the beam management report608. The UE may save signaling and reduce the latency for the full-duplex beam pair reset. In the timing, x may be an integer number of slots/symbols, which may be defined or may be signaled to the UE602by the base station via RRC, MAC-CE, and/or DCI. In some examples, the base station604may configure/signal to the UE602which rule among a plurality of potential rules to use to determine the timing for applying the new beam pair following the beam management report. For example, the base station may include a flag, or other indication, in the RRC message605that informs the UE about a timing option for application of a full-duplex beam pair after transmission of a beam management report. In some examples, a flag=0 may indicate to the UE to apply a first option (e.g., to wait for a new beam pair indication from the base station); a flag=1 may indicate to the UE apply a second option (e.g., to apply the new beam pair a period of time after sending the beam management report); and a flag=2 may indicate to the UE to apply a third option (e.g., to apply the new beam pair a period of time after receiving an ACK for the beam management report). In such examples, the flag may be based on multiple bits of the RRC message. In some examples, a flag=0 may indicate for the UE to apply a first option (e.g., to wait for a new beam pair indication from the base station); and a flag=1 may indicate for the UE to select between multiple options (e.g., between the second and third option described above). The flag may be based on a single bit in the RRC message. In some examples, the timing option that the UE and base station determine to apply, at610and612, may be based on a defined rule that indicates an option for the UE to use, e.g., based on conditions. After applying the new beam pair, at612and622, the UE602and base station604may exchange full-duplex communication624using the new beam pair. For example, the UE may transmit uplink transmissions to the base station using a first beam of the full-duplex beam pair and may receive downlink transmissions from the base station using a second beam of the full-duplex beam pair. The UE602may use the beam pair to exchange communication with the base station in a full-duplex manner, e.g., such as described in connection withFIGS.4A-CorFIG.5. Similarly, the base station may use a first beam of the full-duplex beam pair to receive uplink transmissions from the UE and may transmit downlink transmissions to the UE using a second beam of the full-duplex beam pair. FIG.7Ais a flowchart700of a method of wireless communication using full-duplex communication in accordance with one aspect of the present disclosure. The method may be performed by a UE (e.g., the UE104,350,404a-c,602; the apparatus802). The method ofFIG.7Aenables the UE to reselect a full-duplex beam pair using a beam management report. At702, the UE transmits a beam management report that reports a set of one or more candidate full-duplex beam pairs to a base station. In one example,702may be performed by a beam management report component846via the transmission component834and/or cellular RF transceiver822of the apparatus802inFIG.8.FIG.6illustrates an example of the transmission of the beam management report, at608. At706, the UE applies the full-duplex beam pair from the set of one or more candidate full-duplex beam pairs at a determined time after transmitting the beam management report to the base station. Various examples of timing for the application of the FD beam, at612, are described in connection withFIG.6. In one example,706may be performed by an application component842inFIG.8. In some aspects, the base station may configure CMRs and IMRs for the UE to use to perform the SINR measurements. The UE may use the CMRs to measure the downlink channel quality and the IMRs to measure the self-interference from the uplink beam to its own downlink beam at the UE. With the CMRs and the IMRs, the UE measures the SINR values per uplink and downlink beam pair, e.g., as described in connection withFIG.6. The UE may then report the top N best full-duplex candidate beam pairs that have the highest SINR values. In some aspects, the UE may receive a configuration from the base station that indicates timing for the UE to apply the full-duplex beam pair.FIG.7Billustrates a method of wireless communication750that may include702and704fromFIG.7A. As illustrated at701, the UE may receive a configuration from the base station that indicates the timing for the UE to apply the full-duplex beam pair. The reception may be performed, e.g., by a configuration component844via the reception component830and/or the cellular RF transceiver822of the apparatus802inFIG.8. The configuration may indicate a rule for application of the full-duplex beam pair from among a set of rules. In another aspect, the UE may receive the configuration in RRC signaling from the base station. In another aspect, the UE determines when to apply the full-duplex beam pair based on a defined rule. At704, in some examples, the UE may determine when to apply a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after transmitting the beam management report to the base station. For example, the UE may determine between different timing options for applying the full-duplex beam pair after reporting the beam management report. In one example,704may be performed by a determination component840inFIG.8. Further,FIG.6illustrates an example of the determination of when to apply the FD beam pair, at610. The determined time may be based one of: reception of a beam pair indication from the base station; transmission of the beam management report; or reception of an ACK from the base station for the beam management report. For example, the determined time to apply the full-duplex beam pair may be based on a defined rule, as illustrated at710. In some aspects, the determined time may be based on reception of a beam pair indication from the base station, as illustrated at712. For example, the UE may receive a beam pair indication, from the base station, indicating the full-duplex beam pair, and the determined time may be based on the reception of the beam pair indication from the base station. The determined time may be a period of time, e.g., a number of slots or symbols, following transmission of the beam management report. In some aspects, the determined time may be based on reception of an ACK from the base station acknowledging receipt of the beam management report, as illustrated at718. For example, the UE may receive an ACK from the base station for the beam management report, where the determined time is based on reception of the ACK from the base station. The determined time may be a period of time, e.g., a number of slots or symbols, following the reception of the ACK from the base station. In one example,708may be performed by a determination component840inFIG.8. At712, the UE may apply the full-duplex beam pair after a period of time following the transmission of the beam management report. In one aspect, the full-duplex beam pair has a highest measurement quality metric among the set of one or more candidate full-duplex beam pairs reported in the beam management report. In another aspect, the measurement quality metric comprises a SINR. In one example,712may be performed by an application component842inFIG.8. At701, the UE may receive a configuration of the period of time in at least one of RRC signaling, a MAC-CE, or DCI. In one example, the reception of the configuration, at702, may be performed by the configuration component844via the reception component830of the apparatus802inFIG.8. The period of time may be based on a number of slots following the transmission of the beam management report; or a number of symbols following the transmission of the beam management report. At718, the UE may apply the full-duplex beam pair after a period of time following the reception of the ACK from the base station. In one aspect, the full-duplex beam pair has a highest measurement quality metric among the set of one or more candidate full-duplex beam pairs reported in the beam management report. In another aspect, the measurement quality metric comprises a SINR. As illustrated at701, the UE may receive a configuration of the period of time in at least one of RRC signaling, a MAC-CE, or DCI. In one example,701may be performed by a reception component830inFIG.8. The period of time may be based on a number of slots following the transmission of the beam management report; or a number of symbols following the transmission of the beam management report. In other aspects, the UE may define the period of time as a defined period of time for application of the full-duplex beam pair. As illustrated at708, the UE may use the full-duplex beam pair to transmit and receive communication with the base station, e.g., in a full-duplex mode after the application of the full-duplex beam pair, at706. The transmission and reception may be performed, e.g., by the transmission component834and the reception component830of the apparatus802inFIG.8. FIG.8is a diagram800illustrating an example of a hardware implementation for an apparatus802. The apparatus802may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the apparatus802includes a cellular baseband processor804(also referred to as a modem) coupled to a cellular RF transceiver822and one or more subscriber identity modules (SIM) cards820, an application processor806coupled to a secure digital (SD) card808and a screen810, a Bluetooth module812, a wireless local area network (WLAN) module814, a Global Positioning System (GPS) module816, and a power supply818. The cellular baseband processor804communicates through the cellular RF transceiver822with the UE104and/or BS102/180. The cellular baseband processor804may include a computer-readable medium/memory. The computer-readable medium/memory may be non-transitory. The cellular baseband processor804is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the cellular baseband processor804, causes the cellular baseband processor804to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the cellular baseband processor804when executing software. The cellular baseband processor804further includes a reception component830, a communication manager832, and a transmission component834. The communication manager832includes the one or more illustrated components. The components within the communication manager832may be stored in the computer-readable medium/memory and/or configured as hardware within the cellular baseband processor804. The cellular baseband processor804may be a component of the UE350and may include the memory360and/or at least one of the TX processor368, the RX processor356, and the controller/processor359. In one configuration, the apparatus802may be a modem chip and include just the cellular baseband processor804, and in another configuration, the apparatus802may be the entire UE (e.g., see350ofFIG.3) and include the additional modules of the apparatus802. The communication manager832includes a beam management report component846configured to transmit a beam management report that reports a set of one or more candidate full-duplex beam pairs to the base station, e.g., as described in connection with702inFIG.7A or7B. The communication manager832may include a determination component840that is configured to determine when to apply a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after transmitting the beam management report to the base station, e.g., as described in connection with704inFIG.7B. The determination component840may also determine between a time based on one of after receiving a beam pair indication from the base station; after a period of time following the transmission of the beam management report; or after receiving an ACK from the base station for the beam management report. The determined time may be based on a period of time as a number of slots following the transmission of the beam management report; or a number of symbols following the transmission of the beam management report. The communication manager832also includes an application component842that is configured to apply the full-duplex beam pair at a determined time, e.g., as described in connection with706,710,712, and/or718inFIG.7A or7B. In one aspect, the UE may apply the full-duplex beam pair based on receiving the beam pair indication from the base station. In another aspect, the UE may apply the full-duplex beam pair after a period of time following the transmission of the beam management report. In yet another aspect, the UE may apply the full-duplex beam pair after a period of time following the reception of the ACK from the base station. The apparatus802may further include a configuration component844that is configured to receive a configuration of the timing for application of the FD beam pair and/or the period of time in at least one of RRC signaling, a MAC-CE, or DCI, e.g., as described in connection with701inFIG.7B. The apparatus802may include additional components that perform each of the blocks of the algorithm in the flowcharts ofFIG.7A,7B, and/or the aspects performed by the UE inFIG.6. As such, each block in the flowcharts ofFIGS.7A,7B, and/or the aspects performed by the UE inFIG.6may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. As shown, the apparatus802may include a variety of components configured for various functions. In one configuration, the apparatus802, and in particular the cellular baseband processor804, may include: means for transmitting a beam management report that reports a set of one or more candidate full-duplex beam pairs to a base station; means for determining when to apply a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after transmitting the beam management report to the base station; and means for applying the full-duplex beam pair at a determined time. The means may be one or more of the components of the apparatus802configured to perform the functions recited by the means. As described supra, the apparatus802may include the TX Processor368, the RX Processor356, and the controller/processor359. As such, in one configuration, the means may be the TX Processor368, the RX Processor356, and the controller/processor359configured to perform the functions recited by the means. FIG.9Ais a flowchart900of a method of wireless communication using full-duplex communication in accordance with one aspect of the present disclosure. The method may be performed by a base station (e.g., the base station102/180,310,402a-c,408a-c,604; the apparatus1002). The method enables the base station to reselect a full-duplex beam pair based on a beam management report. At902, the base station receives, from the UE, a beam management report that reports a set of one or more candidate full-duplex beam pairs for the UE. In one example,902may be performed by a beam management report component1046via a reception component1030inFIG.10. Further,FIG.6illustrates an example of the reception of the beam management report by the base station, at608. At906, the base station may apply the full-duplex beam pair from the set of one or more candidate full-duplex beam pairs at a determined time after receiving the beam management report from the UE. Various examples of timing for the application of the FD beam, at622, are described in connection withFIG.6. In one example,906may be performed by an application component1042inFIG.10. FIG.9Billustrates a method of wireless communication950that may include902and904fromFIG.9A. In some aspects, the base station may configure CMRs and IMRs for the UE to use to perform the SINR measurements. The CMRs may be for measurement of the downlink channel quality and the IMRs may be for measurement of the self-interference from an uplink beam to reception on a downlink beam at the UE. With the CMRs and the IMRs, the UE measures the SINR values per uplink and downlink beam pair. The report received at the base station may report the top N best full-duplex candidate beam pairs that have the highest SINR values. In one aspect, the base station may transmit, e.g., as illustrated at901, a configuration to the UE that indicates timing for the UE to apply the full-duplex beam pair. The configuration may indicate a rule for application of the full-duplex beam pair from among a set of rules. In another aspect, the base station may transmit the configuration in RRC signaling to the UE. In another aspect, the UE determines when to apply the full-duplex beam pair based on a defined rule. The configuration may be performed by the configuration component1044of the apparatus1002inFIG.10. At904, in some examples, the base station may determine when to apply a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after receiving the beam management report from the UE. For example, the base station may determine a timing option from among different timing options for the application of the full-duplex beam pair. In one example,904may be performed by a determination component1040inFIG.10. Further,FIG.6illustrates an example of the determination of when to apply the FD beam pair, at620. The determined time may be based one of: reception of a beam pair indication from the base station; transmission of the beam management report; or reception of an ACK from the base station for the beam management report. For example, the determined time to apply the full-duplex beam pair may be based on a defined rule, as illustrated at910. In some aspects, the determined time may be based on transmission of a beam pair indication from the base station, as illustrated at912. For example, the base station may transmit a beam pair indication to the UE indicating the full-duplex beam pair, and the determined time may be based on the transmission of the beam pair indication from the base station. The determined time may be a period of time, e.g., a number of slots or symbols, following transmission of the beam management report. In some aspects, the determined time may be based on transmission of an ACK from the base station acknowledging receipt of the beam management report, as illustrated at918. For example, the base station may transmit an ACK for the beam management report, where the determined time is based on transmission of the ACK. The determined time may be a period of time, e.g., a number of slots or symbols, following the ACK. At910, the base station may apply the full-duplex beam pair based on the beam pair indication sent to the UE. In one example,910may be performed by an application component1042inFIG.10. At912, the base station may apply the full-duplex beam pair after a period of time following the reception of the beam management report from the UE. In one aspect, the full-duplex beam pair has a highest measurement quality metric among the set of one or more candidate full-duplex beam pairs reported in the beam management report. In another aspect, the measurement quality metric comprises a SINR. In one example,912may be performed by an application component1042inFIG.10. At901, the base station may transmit a configuration of the period of time in at least one of RRC signaling, a MAC-CE, or DCI. In one example,901may be performed by a configuration component1044inFIG.10. The period of time may be based on a number of slots following the reception of the beam management report; or a number of symbols following the reception of the beam management report. At918, the base station may apply the full-duplex beam pair after a period of time following the transmission of the ACK of the beam management report to the UE. In one aspect, the full-duplex beam pair has a highest measurement quality metric among the set of one or more candidate full-duplex beam pairs reported in the beam management report. In another aspect, the measurement quality metric includes a SINR. In one example,918may be performed by an application component1042inFIG.10. At901, the base station may transmit to the UE a configuration of the period of time in at least one of RRC signaling, a MAC-CE, or DCI. In one example,920may be performed by a configuration component1044inFIG.10. The period of time may be based on a number of slots following the reception of the beam management report; or a number of symbols following the reception of the beam management report. In other aspects, the base station may define the period of time as a defined period of time for application of the full-duplex beam pair. As illustrated at908, the base station may use the full-duplex beam pair to transmit and receive communication with the UE, e.g., in a full-duplex mode after the application of the full-duplex beam pair, at906. The transmission and reception may be performed, e.g., by the transmission component1034and the reception component1030of the apparatus1002inFIG.10. FIG.10is a diagram1000illustrating an example of a hardware implementation for an apparatus1002. The apparatus1002may be a base station, a component of a base station, or may implement base station functionality. In some aspects, the apparatus may include a baseband unit1004. The baseband unit1004may communicate through a cellular RF transceiver with the UE104. The baseband unit1004may include a computer-readable medium/memory. The baseband unit1004is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the baseband unit1004, causes the baseband unit1004to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the baseband unit1004when executing software. The baseband unit1004further includes a reception component1030, a communication manager1032, and a transmission component1034. The communication manager1032includes the one or more illustrated components. The components within the communication manager1032may be stored in the computer-readable medium/memory and/or configured as hardware within the baseband unit1004. The baseband unit1004may be a component of the base station310and may include the memory376and/or at least one of the TX processor316, the RX processor370, and the controller/processor375. The communication manager1032may include a beam management report component1046that is configured to receive a beam management report that reports a set of one or more candidate full-duplex beam pairs to the base station, e.g., as described in connection with902inFIG.9A or9B. The communication manager1032may include a determination component1040that is configured to determine when to apply a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after receiving the beam management report from the UE, e.g., as described in connection with904inFIG.9B. The determined time may be based on one or after transmitting a beam pair indication to the UE; after a period of time following the reception of the beam management report; or after transmitting an ACK to the UE for the beam management report. The period of time may be based on a number of slots following the reception of the beam management report; or a number of symbols following the reception of the beam management report. The communication manager1032also includes an application component1042that is configured to apply the full-duplex beam pair at a determined time, e.g., as described in connection with906,910,912, and/or918inFIG.9A or9B. In one aspect, the base station may apply the full-duplex beam pair based on the beam pair indication sent to the UE. In another aspect, the base station may apply the full-duplex beam pair after a period of time following the reception of the beam management report. In yet another aspect, the base station may apply the full-duplex beam pair after a period of time following the transmission of the ACK to the UE for the beam management report. The communication manager1032may include a configuration component1044that is configured to transmit a configuration of the timing for application of the full-duplex beam pair or a period of time in at least one of RRC signaling, a MAC-CE, or DCI, e.g., as described in connection with901inFIG.9B. The apparatus may include additional components that perform each of the blocks of the algorithm in the flowcharts ofFIGS.9A,9B, and/or the aspects performed by the base station inFIG.6. As such, each block in the flowcharts ofFIGS.9A,9B, and/or the aspects performed by the base station inFIG.6may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. As shown, the apparatus1002may include a variety of components configured for various functions. In one configuration, the apparatus1002, and in particular the baseband unit1004, may include: means for receiving, from a user equipment (UE), a beam management report that reports a set of one or more candidate full-duplex beam pairs for the UE; means for determining when to apply a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after receiving the beam management report from the UE and means for applying the full-duplex beam pair at a determined time. The means may be one or more of the components of the apparatus1002configured to perform the functions recited by the means. As described supra, the apparatus1002may include the TX Processor316, the RX Processor370, and the controller/processor375. As such, in one configuration, the means may be the TX Processor316, the RX Processor370, and the controller/processor375configured to perform the functions recited by the means. It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented. The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Terms such as “if,” “when,” and “while” should be interpreted to mean “under the condition that” rather than imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when,” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module,” “mechanism,” “element,” “device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.” The following aspects are illustrative only and may be combined with other aspects or teachings described herein, without limitation. Aspect 1 is a method of wireless communication at a UE, comprising: transmitting a beam management report that reports a set of one or more candidate full-duplex beam pairs to a base station; and applying a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs at a determined time after transmitting the beam management report to the base station. In aspect 2, the method of aspect 1 further includes receiving a beam pair indication, from the base station, indicating the full-duplex beam pair, wherein the UE applies the full-duplex beam pair at the determined time based on receiving the beam pair indication. In aspect 3, the method of aspect 1 further includes that the UE applies the full-duplex beam pair after a period of time following transmission of the beam management report. In aspect 4, the method of any of aspects 1-3 further includes that the full-duplex beam pair has a highest measurement quality metric among the set of one or more candidate full-duplex beam pairs reported in the beam management report. In aspect 5, the method of aspect 4 further includes that the highest measurement quality metric comprises an SINR. In aspect 6, the method of any of aspects 1 or 3-5 further includes that the period of time comprises a number of slots following the transmission of the beam management report. In aspect 7, the method of any of aspects 1 or 3-5 further includes that the period of time comprises a number of symbols following the transmission of the beam management report. In aspect 8, the method of any of aspects 1 or 3-7 further includes that receiving a configuration of the period of time in at least one of RRC signaling, a MAC-CE, or DCI. In aspect 9, the method of any of aspects 1 or 3-7 further includes that the period of time comprises a defined period of time for application of the full-duplex beam pair. In aspect 10, the method of aspect 1 further includes receiving an ACK from the base station for the beam management report, wherein the determined time is based on reception of the ACK from the base station. In aspect 11, the method of aspect 10 further includes that the UE applies the full-duplex beam pair after a period of time following reception of the ACK from the base station. In aspect 12, the method of aspect 11 further includes that the full-duplex beam pair has a highest measurement quality metric among the set of the one or more candidate full-duplex beam pairs reports in the beam management report. In aspect 13, the method of aspect 12 further includes that the measurement quality metric comprises a signal to interference and noise ratio (SINR). In aspect 14, the method of any of aspects 10-13 further includes that the period of time comprises a number of slots following the reception of the ACK. In aspect 15, the method of any of aspects 10-13 further includes that the period of time comprises a number of symbols following the reception of the ACK. In aspect 16, the method of any of aspects 10-15 further includes receiving a configuration of the period of time in at least one of RRC signaling, a MAC-CE, or DCI. In aspect 17, the method of any of aspects 10-15 further includes that the period of time comprises a defined period of time for application of the full-duplex beam pair. In aspect 18, the method of any of aspects 1-17 further includes determining when to apply the full-duplex beam pair from the set of the one or more candidate full-duplex beam pairs after transmitting the beam management report to the base station. In aspect 19, the method of any of aspects 1-18 further includes receiving a configuration from the base station that indicates timing for the UE to apply the full-duplex beam pair. In aspect 20, the method of aspect 19 further includes that the configuration indicates a rule for application of the full-duplex beam pair from among a set of rules. In aspect 21, the method of aspect 19 or aspect 20 further includes that the configuration is received in RRC signaling from the base station. In aspect 22, the method of any of aspects 1-18 further includes that the determined time to apply the full-duplex beam pair is based on a defined rule. Aspect 23 is an apparatus for wireless communication at a UE, comprising means to perform the method of any of aspects 1-22. In aspect 24, the apparatus of aspect 23 further includes at least one antenna and a transceiver coupled to the at least one antenna. Aspect 25 is an apparatus for wireless communication at a UE, comprising: memory; and at least one processor coupled to the memory, the memory and at least one processor being configured to perform the method of any of aspects 1-22. In aspect 26, the apparatus of aspect 25 further includes at least one antenna and a transceiver coupled to the at least one antenna and the at least one processor. Aspect 27 is a non-transitory computer-readable medium storing computer executable code for wireless communication at a UE, the code when executed by a processor cause the processor to perform the method of any of aspects 1-22. Aspect 28 is a method of wireless communication at a base station, comprising: receiving, from a UE, a beam management report that reports a set of one or more candidate full-duplex beam pairs for the UE; and applying a full-duplex beam pair from the set of one or more candidate full-duplex beam pairs at a determined time after receiving the beam management report from the UE. In aspect 29, the method of aspect 28 further includes transmitting a beam pair indication, to the UE, indicating the full-duplex beam pair, wherein the determined time for application of the full-duplex beam pair is based on sending the beam pair indication. In aspect 30, the method of aspect 28 further includes that the base station applies the full-duplex beam pair after a period of time following reception of the beam management report. In aspect 31, the method of aspect 30 further includes the full-duplex beam pair has a highest measurement quality metric among the set of one or more candidate full-duplex beam pairs reported in the beam management report. In aspect 32, the method of aspect 30 further includes that the highest measurement quality metric comprises a signal to interference and noise ratio (SINR). In aspect 33, the method of any of aspects 30-32 further includes that the period of time comprises a number of slots following the reception of the beam management report. In aspect 34, the method of any of aspects 30-32 further includes that the period of time comprises a number of symbols following the reception of the beam management report. In aspect 35, the method of any of aspects 30-34 further includes transmitting, to the UE, a configuration of the period of time in at least one of RRC signaling, a MAC-CE, or DCI. In aspect 36, the method of any of aspects 30-34 further includes that the period of time comprises a defined period of time for application of the full-duplex beam pair. In aspect 37, the method of aspect 28 further includes that the base station applies the full-duplex beam pair after an ACK of the beam management report, the method further comprising: transmitting, to the UE, an ACK for the beam management report. In aspect 38, the method of aspect 37 further includes that the base station applies the full-duplex beam pair after a period of time following transmission of the ACK from the base station. In aspect 39, the method of any of aspects 28-38 further includes that the full-duplex beam pair has a highest measurement quality metric among the set of one or more candidate full-duplex beam pairs reported in the beam management report. In aspect 40, the method of aspect 39 further includes that the measurement quality metric comprises a SINR. In aspect 41, the method of any of aspects 38-40 further includes that the period of time comprises a number of slots following the transmission of the ACK. In aspect 42, the method of any of aspects 38-40 further includes that the period of time comprises a number of symbols following the transmission of the ACK. In aspect 43, the method of any of aspects 38-42 further includes that transmitting, to the UE, a configuration of the period of time in at least one of RRC signaling, a MAC-CE, or DCI. In aspect 44, the method of any of aspects 38-42 further includes that the period of time comprises a defined period of time for application of the full-duplex beam pair. In aspect 45, the method of any of aspects 28-44 further includes transmitting, to the UE, a configuration that indicates timing for the UE to apply the full-duplex beam pair. In aspect 46, the method of aspect 45 further includes that the configuration indicates a rule for application of the full-duplex beam pair from among a set of rules. In aspect 47, the method of aspect 45 or 46 further includes that the configuration is transmitted in RRC signaling. In aspect 48, the method of any of aspects 28-47 further includes determining when to apply the full-duplex beam pair from the set of one or more candidate full-duplex beam pairs after receiving the beam management report from the UE. In aspect 49, the method of any of aspects 28-48 further includes that the base station determines when to apply the full-duplex beam pair based on a defined rule. Aspect 50 is an apparatus for wireless communication at a base station, comprising means to perform the method of any of aspects 28-49. In aspect 51, the apparatus of aspect 50 further includes at least one antenna and a transceiver coupled to the at least one antenna. Aspect 52 is an apparatus for wireless communication at a base station, comprising: memory; and at least one processor coupled to the memory, the memory and at least one processor being configured to perform the method of any of aspects 28-49. In aspect 53, the apparatus of aspect 52 further includes at least one antenna and a transceiver coupled to the at least one antenna and the at least one processor. Aspect 54 is a non-transitory computer-readable medium storing computer executable code for wireless communication at a base station, the code when executed by a processor cause the processor to perform the method of any of aspects 28-49. | 94,178 |
11943034 | DETAILED DESCRIPTION The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional. FIG.3is a schematic diagram illustrating a communications network100where embodiments presented herein can be applied. The communications network100could be a third generation (3G) telecommunications network, a fourth generation (4G) telecommunications network, or a fifth (5G) telecommunications network and support any 3GPP telecommunications standard, where applicable. The communications network100comprises a network node200configured to provide network access to at least one terminal device300ain a radio access network110. The radio access network110is operatively connected to a core network120. The core network120is in turn operatively connected to a service network130, such as the Internet. The terminal device300ais thereby, via the network node200, enabled to access services of, and exchange data with, the service network130. Examples of network nodes200are radio access network nodes, radio base stations, base transceiver stations, Node Bs, evolved Node Bs, g Node Bs, access points, and access nodes, and backhaul nodes. Examples of terminal devices300aare wireless devices, mobile stations, mobile phones, handsets, wireless local loop phones, user equipment (UE), smartphones, laptop computers, tablet computers, network equipped sensors, network equipped vehicles, and so-called Internet of Things devices. The network node200is configured to communicate with the terminal device300ain beams, one of which is illustrated at reference numeral140b-c, and the terminal device300ais configured to communicate with the network node200in beams, one of which is illustrated at reference numeral150a. Further, the network node200and the terminal device300acould be configured to communicate with each other using a variety of beams having different shapes and widths, herein generally referred to as having different beam patterns. As disclosed above, beam management is performed in order for the network node200and the terminal devices300a-300fto know what beams to use for communication with each other. Issues with traditional beam management procedures have been disclosed above. An object of embodiments herein is therefore to provide an efficient beam management procedure that does not suffer from the issues noted above, or at least where the above issues are mitigated or reduced. The embodiments disclosed herein thus relate to mechanisms for beam management and participating in a beam management procedure. In order to obtain such mechanisms there is provided a network node200, a method performed by the network node200, a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the network node200, causes the network node200to perform the method. In order to obtain such mechanisms there is further provided a terminal device300a, a method performed by the terminal device300a, and a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the terminal device300a, causes the terminal device300ato perform the method. Reference is now made toFIG.4illustrating a method for beam management as performed by the network node200according to an embodiment. It is assumed that a beam management procedure is to be performed. Hence, the network node200is configured to perform step S104: S104: The network node200performs a beam management procedure for terminal devices300a-300fserved by the network node200. Performing the beam management procedure comprises steps S106, S108, and S110. The beam management procedure comprises a first part. Particularly, the network node200is configured to perform step S106: S106: The network node200transmits, during a first part of the beam management procedure, a reference signal so as to enable each of the terminal devices (300a-300f) participating in the beam management procedure to identify in which beam in a first set of beams140a,140b,140c, in which the reference signal is transmitted from the network node200, the reference signal is received with highest received power. The first set of beams140a,140b,140cis thus used by the network node200for transmitting the reference signal. The beam management procedure comprises a second part. Particularly, the network node200is configured to perform step S108: S108: The network node200transmits, during a second part of the beam management procedure, the reference signal so as to enable each of the terminal devices300a-300f(participating in the beam management procedure) to identify in which beam in a second set of beams150a,150b,150c, in which the reference signal is received from the network node200by the terminal devices300a-300f(participating in the beam management procedure), the reference signal is received with highest received power. The second set of beams150a,150b,150cis thus used by the terminal devices300a-300ffor receiving the reference signal. The beam management procedure comprises a third part. Particularly, the network node200is configured to perform step S110: S110: The network node transmits, during a third part of the beam management procedure, the reference signal so as to enable each of the terminal devices300a-300fparticipating in the beam management procedure to identify for which beam in a third set of beams140b-a,140b-b,140b-c, in which the reference signal is transmitted from the network node200, the reference signal is received with highest received power. The third set of beams140b-a,140b-b,140b-cis thus used by the network node200for transmitting the reference signal. There is one respective third set of beams140b-a,140b-b,140b-cfor each respective beam140bin the first set of beams140a,140b,140c. The third part of the beam management procedure is performed for each respective third set of beams140b-a,140b-b,140b-c. The second part is performed before the third part at least for one of the respective third set of beams140b-a,140b-b,140b-c. Thereby, after the terminal devices300a-300fhave reported the best beam from first part of the beam management procedure, a shared second part of the beam management procedure can be performed for all terminal devices having reported the same best beam. Further, this also allows the third part of the beam management procedure to be shared for these terminal devices. Embodiments relating to further details of beam management as performed by the network node200will now be disclosed. In some aspects the network node200provides information to the terminal devices300a-300fabout the beam management procedure. Particularly, according to an embodiment the network node200is configured to perform (optional) step S102: S102: The network node200provides, to the terminal devices300a-300f, information regarding the beam management procedure before performing the beam management procedure. The information might define a point in time at which the beam management procedure is to be performed, the order in which the first, second, and third part of the beam management procedure are to be performed, etc. There could be different types of reference signals that the network node200transmits. Examples include, but are not limited to, channel state information reference signals (CSI-RS), and synchronization signal block (SSB). Aspects of the first part of the beam management procedure will now be disclosed. The first part of the beam management procedure might involve the network node200to transmit the reference signal in each beam in the first set of beams140a,140b,140c. Particularly, according to an embodiment the network node200is configured to perform (optional) step S106a: S106a: The network node200transmits, towards terminal devices300a-300fserved by the network node200, one occurrence of the reference signal in each beam in the first set of beams140a,140b,140c. Step S106ais in some aspects part of step S106. The first part of the beam management procedure might involve the terminal devices300a-300fparticipating in the beam management procedure to measure received power on the reference signal as transmitted in the beams in the first set of beams140a,140b,140cand then to report this to the network node200. Particularly, according to an embodiment the network node200is configured to perform (optional) step S106b: S106b: The network node200receives, from each of the terminal devices300a-300f(participating in the beam management procedure), a respective first report. The first report for a particular terminal device300a-300fidentifies at least that beam in the first set of beams140a,140b,140chaving been received with highest received power at that particular terminal device300a-300f. In some aspects the first part of the beam management procedure is part of the above-mentioned P-1 procedure. Aspects of the second part of the beam management procedure will now be disclosed. The second part of the beam management procedure might involve the network node200to transmit the reference signal in those beams in the first set of beams140a,140b,140cfor which at least one first report has been received. In this respect, one occurrence of the second part of the beam management procedure might thus be performed for each of those beams in the first set of beams140a,140b,140cfor which at least one first report has been received. Particularly, according to an embodiment the network node200is configured to perform (optional) step S108afor each occurrence of the second part of the beam management procedure: S108a: The network node200transmits a configured number of occurrences of the reference signal in one of those beams in the first set of beams140a,140b,140cfor which at least one first report has been received. Step S108amight thus be repeated for each of those beams in the first set of beams140a,140b,140cfor which at least one first report has been received. Step S108ais in some aspects part of step S108. Each occurrence of the second part of the beam management procedure might be shared by a respective group of terminal devices. Particularly, according to an embodiment one occurrence of the second part of the beam management procedure is performed per beam in the first set of beams140a,140b,140cfor which at least one first report has been received. Each occurrence of the second part of the beam management procedure is performed for all those of the terminal devices300a-300ffor which the same beam in the first set of beams140a,140b,140cwas received with highest received power. In the illustrative example of below referencedFIG.6, terminal devices300b,300c,300dall report beam140bas strongest and thus form a group of terminal devices that share one occurrence of the second part of the beam management procedure. There might be different ways to determine the configured number of occurrences of the reference signal. In some aspects the reference signal is transmitted as many times as there are number of narrow beams at the terminal devices300a-300f. Particularly, according to an embodiment the configured number of occurrences is defined by number of beams in the second set of beams150a,150b,150c. In the illustrative example of below referencedFIG.6, terminal devices300b,300c,300dall have three narrow beams150a,150b,150cand thus the reference signal might be transmitted three times in beam140bduring this occurrence of the second part of the beam management procedure. If there are terminal devices300b,300c,300dwith different number of narrow beams150a,150b,150cthen the reference signal might be transmitted as many times as the highest number of narrow beams during this occurrence of the second part of the beam management procedure. It might be so that different terminal devices, or groups thereof, report different best beams in the first set of beams140a,140b,140c. In the illustrative example of below referencedFIG.6, terminal device300ais likely to report beam140aas best beam, whereas terminal devices300b,300c,300dare likely to report beam140bas best beam. There might be different ways to determine for which beam in the first set of beams140a,140b,140cto perform the second part of the beam management procedure first. In some aspects the order is determined by the number of terminal devices300a-300freporting that a certain beam140a,140b,140cis best. Particularly, according to an embodiment, in which order to perform the second part of the beam management procedure for, with respect to the beams in the first set of beams140a,140b,140c, depends on how many of the terminal devices300a-300fhave identified each of the beams in the first set of beams140a,140b,140cas received with highest received power. Other criteria might depend on the type of service provided to the terminal devices300a-300f, such that the second part of the beam management procedure is first performed for a beam in the first set of beams140a,140b,140cserving a group of terminal devices300a-300fwith a relative high level of service, or high level of service demand, etc. In some aspects the second part of the beam management procedure is part of the above-mentioned P-3 procedure. Aspects of the third part of the beam management procedure will now be disclosed. The third part of the beam management procedure might involve the network node200to transmit the reference signal in those beams140b-a,140b-b,140b-ccovered by those beams in the first set of beams140a,140b,140cbeing identified in the first reports. In this respect, one occurrence of the third part of the beam management procedure might thus be performed for each of those beams in the first set of beams140a,140b,140cfor which at least one first report has been received. Particularly, according to an embodiment the network node200is configured to perform (optional) step S110afor each occurrence of the third part of the beam management procedure: S110a: The network node200transmits one occurrence of the reference signal in each beam in that respective third set of beams140b-a,140b-b,140b-ccovered by one of those beams in the first set of beams140a,140b,140cbeing identified in the respective first reports. Step S110amight thus be repeated for each set of third beams as covered by those beams in the first set of beams140a,140b,140cfor which at least one first report has been received. Step S110ais in some aspects part of step S110. The third part of the beam management procedure might involve the terminal devices300a-300freceiving the reference signal in step S110ato measure received power on the reference signal as transmitted in the beams in the third set of beams140b-a,140b-b,140b-cand then to report this to the network node200. Particularly, according to an embodiment the network node200is configured to perform (optional) step S110b: S110b: The network node200receives, from each of the terminal devices300a-300fhaving received the reference signal in at least one of the beams in the third set of beams140b-a,140b-b,140b-c, a respective second report. The second report for a particular terminal device300a-300fidentifies at least that beam in the third set of beams140b-a,140b-b,140b-chaving been received with highest received power at that particular terminal device300a-300f. Step S110bis in some aspects part of step S110. Each occurrence of the third part of the beam management procedure might be shared by a respective group of terminal devices. Particularly, according to an embodiment one occurrence of the third part of the beam management procedure is performed per third set of beams140b-a,140b-b,140b-c. Each occurrence of the third part of the beam management procedure is performed for all those of the terminal devices300a-300ffor which same the beam in the first set of beams140a,140b,140cwas received with highest received power. In the illustrative example of below referencedFIG.6, terminal devices300b,300c,300dall report beam140bas strongest and thus form a group of terminal devices that share one occurrence of the third part of the beam management procedure. One occurrence of the third part of the beam management procedure might be shared by the same group of terminal devices having shared one occurrence of the second part of the beam management procedure. In some aspects the third part of the beam management procedure is part of the above-mentioned P-2 procedure. Aspects of the order in which the second part and the third part of the beam management procedure are performed will now be disclosed. According to a first example the beam management procedure is performed according to a first configuration such that all occurrences of the second part of the beam management procedure are performed before any occurrence of the third part of the beam management procedure are performed. In some aspects all occurrences of the P-3 procedure are thus performed before all occurrences of the P-2 procedure. According to a second example the beam management procedure is performed according to a second configuration such that each occurrence of the second part of the beam management procedure is followed by one occurrence of the third part of the beam management procedure. In some aspects one occurrences of the P-2 procedure follows after each occurrence of the P-3 procedure. There could be different ways to determine which configuration to use. In some aspects the order is determined according to a specification. Hence, according to an embodiment, whether to perform the beam management procedure according to the first configuration or the second configuration is determined according to a specification. Reference is now made toFIG.5illustrating a method for participating in a beam management procedure as performed by the terminal device300aaccording to an embodiment. As disclosed above, it is assumed that a beam management procedure is to be performed. Thus the terminal device300a-300fis configured to perform step S204: S204: The terminal device300a-300fparticipates in a beam management procedure with the network node200serving the terminal device300a-300f. Participating in the beam management procedure comprises steps S206, S208, and S210. As disclosed above, the beam management procedure comprises a first part. Particularly, the terminal device300a-300fis configured to perform step S206: S206: The terminal device300a-300fidentifies, during a first part of the beam management procedure, which beam in a first set of beams140a,140b,140c, in which a reference signal is transmitted from the network node200, is received with highest received power. As disclosed above, the beam management procedure comprises a second part. Particularly, the terminal device300a-300fis configured to perform step S208: S208: The terminal device300a-300fidentifies, during a second part of the beam management procedure, in which beam in a second set of beams150a,150b,150c, in which the reference signal is received from the network node200, is received with highest received power. As disclosed above, the beam management procedure comprises a third part. Particularly, the terminal device300a-300fis configured to perform step S210: S210: The terminal device300a-300fidentifies, during a third part of the beam management procedure, which beam in a third set of beams140b-a,140b-b,140b-c, in which the reference signal is transmitted from the network node200, that the reference signal with highest received power. The reference signal is received using the beam identified during the second part of the beam management procedure. Embodiments relating to further details of participating in a beam management procedure as performed by the terminal device300awill now be disclosed. As disclosed above, in some aspects the network node200provides information to the terminal devices300a-300fabout the beam management procedure. Particularly, according to an embodiment the terminal device300a-300fis configured to perform (optional) step S202: S202: the terminal device300a-300fobtains, from the network node200, information regarding the beam management procedure before participating in the beam management procedure. Examples of different types of reference signals that the network node200might transmit (and thus the terminal device300a-300fmight received) have been disclosed above. Aspects of participating in the first part of the beam management procedure will now be disclosed. As disclosed above, the first part of the beam management procedure might involve the network node200to transmit the reference signal in each beam in the first set of beams140a,140b,140c. Particularly, according to an embodiment the terminal device300a-300fis configured to perform (optional) step S206a: S206a: The terminal device300a-300freceives, from the network node200, one occurrence of the reference signal in at least one of the beams in the first set of beams140a,140b,140c. Step S206ais in some aspects part of step S206. The terminal device300a-300fmight then measure received power of the reference signal in the transmitted beams as received by the terminal device300a-300fand report this to the network node200. Particularly, according to an embodiment the terminal device300a-300fis configured to perform (optional) step S206b: S206b: The terminal device300a-300ftransmits to the network node200, a first report identifying at least that beam in the first set of beams140a,140b,140chaving been received with highest received power at the terminal device300a-300f. Step S206bis in some aspects part of step S206. Aspects of participating in the second part of the beam management procedure will now be disclosed. As disclosed above, the second part of the beam management procedure might involve the network node200to transmit the reference signal in those beams in the first set of beams140a,140b,140cfor which at least one first report has been received. Particularly, according to an embodiment the terminal device300a-300fis configured to perform (optional) step S208a: S208a: The terminal device300a-300freceives a configured number of occurrences of the reference signal as transmitted by the network node200in those beams in the first set of beams140a,140b,140cidentified in the first report. One respective occurrence is by the terminal device300a-300freceived in one respective beam in the second set of beams150a,150b,150c. Step S208ais in some aspects part of step S208. The terminal device300a-300fmight then measure received power of the reference signal as received by the terminal device300a-300fin each of the beams in the second set of beams150a,150b,150c. Aspects of participating in the third part of the beam management procedure will now be disclosed. As disclosed above, the third part of the beam management procedure might involve the network node200to transmit the reference signal in those beams140b-a,140b-b,140b-ccovered by those beams in the first set of beams140a,140b,140cbeing identified in the first reports. Particularly, according to an embodiment the terminal device300a-300fis configured to perform (optional) step S210a: S210a: The terminal device300a-300freceives, from the network node200, one occurrence of the reference signal in at least one of the beams in that respective third set of beams140b-a,140b-b,140b-ccovered by one of those beams in the first set of beams140a,140b,140cbeing identified in the first report. Step S210ais in some aspects part of step S210. The terminal device300a-300fmight then measure received power of the reference signal in the transmitted beams as received by the terminal device300a-300fand report this to the network node200. Particularly, according to an embodiment the terminal device300a-300fis configured to perform (optional) step S210b: S210b: The terminal device300a-300ftransmits, to the network node200, a second report identifying at least that beam in the third set of beams140b-a,140b-b,140b-chaving been received with highest received power at the terminal device300a-300f. The thus selected beam in the second set of beams and the thus selected beam in the third set of beams can then be used for communication between the network node200and the terminal device300a-300f. Reference is now made toFIG.6, illustrating one example of a beam management process according to the herein disclosed embodiments. In the first part a P-1 procedure common for all terminal devices300a-300fis performed by the network node200transmitting a reference signal in wide beams140a,140b,140c. The terminal devices300a-300fare expected to use as wide receive beam150as possible in order to capture all possible propagation paths. Each terminal device300a-300freports back at least the best beam of the wide beam140a,140b,140cto the network node200. In the illustrative example ofFIG.6, terminal device300areports wide beam140a, terminal devices300b-300dreport wide beam140b, and terminal devices300e,300freport back wide beam140c. Since terminal devices300b-300dall report the same wide beam140bthey are grouped together in one group and since terminal devices300e,300fboth report the same wide beam140cthey are grouped together in another group. In the second part a shared P-3 procedure is performed for terminal devices300b-300d. During the shared P-3 procedure the reference signals are transmitted repeatedly by the network node200in wide beam140bin order to let the terminal devices300b-300ddetermine a suitable narrow receive beam from a set of beams150a,150b,150c. In the illustrative example ofFIG.6it is assumed that terminal device300bfinds narrow beam150bto be best, that terminal device300cfinds narrow beam150bto be best, and that terminal device300dfinds narrow beam150ato be best. A shared P-3 procedure is also performed for terminal devices300e,300fwhere the network node200uses wide beam140c, and another P-3 procedure is performed just for terminal device300awhere the network node200uses wide beam140a. In the third part a shared P-2 procedure is performed for terminal devices300b-300din order to refine the transmit beam at the network node200. During the shared P-2 procedure the reference signal is transmitted in narrow beams140b-a,140b-b,140b-c, covered by the angular span of the wide beam140breported as best by the terminal devices300b-300d. It is here noted that for illustrative purposes the narrow beams140b-a,140b-b,140b-cinFIG.6have a wide angular span than the wide beam140b. Each terminal device300b-300dreports back at least the best beam of the narrow beams140b-a,140b-b,140b-cto the network node200. A shared P-2 procedure is also performed for terminal devices300e,300fwhere the network node200uses narrow beams covered by wide beam140c, and another P-2 procedure is performed just for terminal device300awhere the network node200uses narrow beams covered by wide beam140a. Since both the P-2 procedure and the P-3 procedure are shared between all terminal devices in each group the overhead needed for reference signal transmission has been minimized. If, instead the P-2 procedure was performed before the P-3 procedure, it would not be possible to share the P-3 procedure between groups of terminal devices because the different terminal devices300a-300fwill likely have different best narrow transmission beams at the network node200, and then one P-3 procedure has to be performed for each narrow transmit beam separately, as illustrated inFIG.1. One particular embodiment of a beam management procedure, and for participating in the same, based on at least some of the above disclosed embodiments will now be disclosed in detail with reference to the signalling diagram ofFIG.7aandFIG.7b. Parallel reference is continued toFIG.6. S301: The network node200configures the P-1, P-2 and P-3 procedures (such as which resources to use and settings for the reports to be sent by the terminal devices participating in the beam management procedure) and signals, using higher layer signaling, a notification thereof to the terminal device300b. One way to implement step S301is to perform step S102and step S202. S302: The network node200triggers the P-1 procedure by signaling a P-1 trigger command to the terminal device300b. S303: The network node200transmits CSI-RSs in wide beams140a,140b,140cand the terminal device300breceives the CSI-RSs in a wide beam150and performs RSRP measurements on the CSI-RSs. One way to implement step S303is to perform steps S104, S106, S106aand steps S204, S206, S206a. S304: The terminal device300bsignals a first beam report to the network node200, providing information about the best wide beam and the corresponding RSRP value. One way to implement step S304is to perform steps S104, S106, S106band steps S204, S206, S206b. S305: The network node200groups the terminal devices such that terminal devices reporting the same best wide beam belong to the same group. S306: The network node200triggers a shared P-3 procedure for each group in the best wide beam reported for that group, i.e. one P-3 procedure per group where all the terminal devices within one group share the same P-3 procedure. S307: The network node200performs the P-3 procedure per group by transmitting the CSI-RS for the respective P-3 procedures using the wide beam as was reported per group. One way to implement step S307is to perform steps S104, S108, S108aand step S204, S208, S208a. S308: The terminal device300bmeasures the RSRP for the CSI-RSs while sweeping its narrow beams150a,150b,150cand selects the narrow beam150bwith highest RSRP value. S309: The network node200triggers a shared P-2 procedure for each group, i.e. one P-2 procedure per group where all terminal devices within one group share the same P-2 procedure. S310: The network node200transmits the CSI-RS for the respective P-2 procedure per group in narrow beams140b-a,140b-b,140b-c, where all narrow beams140b-a,140b-b,140b-c, are confined within the reported best wide beam140bper group. One way to implement step S310is to perform steps S104, S111, S110aand step S204, S210, S210a. S311: The terminal device300buses its selected narrow beam150bto measure the RSRP for the different CSI-RSs and report the best narrow beam140b-bto the network node200. One way to implement step S311is to perform steps S104, S110, S110band step S204, S210, S210b. S312: The network node200and the terminal device300binitiate data communication using the beam pair link defined by the narrow beam140b-bat the network node200and the narrow beam150bat the terminal device300b. FIG.8schematically illustrates, in terms of a number of functional units, the components of a network node200according to an embodiment. Processing circuitry210is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product1210a(as inFIG.12), e.g. in the form of a storage medium230. The processing circuitry210may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA). Particularly, the processing circuitry210is configured to cause the network node200to perform a set of operations, or steps, as disclosed above. For example, the storage medium230may store the set of operations, and the processing circuitry210may be configured to retrieve the set of operations from the storage medium230to cause the network node200to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry210is thereby arranged to execute methods as herein disclosed. The storage medium230may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory. The network node200may further comprise a communications interface220for communications with other entities, functions, nodes, and devices of the communications network100. As such the communications interface220may comprise one or more transmitters and receivers, comprising analogue and digital components. The processing circuitry210controls the general operation of the network node200e.g. by sending data and control signals to the communications interface220and the storage medium230, by receiving data and reports from the communications interface220, and by retrieving data and instructions from the storage medium230. Other components, as well as the related functionality, of the network node200are omitted in order not to obscure the concepts presented herein. FIG.9schematically illustrates, in terms of a number of functional modules, the components of a network node200according to an embodiment. The network node200ofFIG.9comprises a number of functional modules; a beam management module210bconfigured to perform step S104, a transmit module210cconfigured to perform step S106, a transmit module210fconfigured to perform step S108, and a transmit module210hconfigured to perform step S110. The network node200ofFIG.9may further comprise a number of optional functional modules, such as any of a notify module210aconfigured to perform step S102, a transmit module210dconfigured to perform step S106a, a receive module210econfigured to perform step S106b, a transmit module210gconfigured to perform step S108a, a transmit module210iconfigured to perform step S110a, a receive module210jconfigured to perform step S110b. In general terms, each functional module210a-210jmay be implemented in hardware or in software. Preferably, one or more or all functional modules210a-210jmay be implemented by the processing circuitry210, possibly in cooperation with the communications interface220and/or the storage medium230. The processing circuitry210may thus be arranged to form the storage medium230fetch instructions as provided by a functional module210a-210jand to execute these instructions, thereby performing any steps of the network node200as disclosed herein. The network node200may be provided as a standalone device or as a part of at least one further device. For example, the network node200may be provided in a node of the radio access network110or in a node of the core network120. Alternatively, functionality of the network node200may be distributed between at least two devices, or nodes. These at least two nodes, or devices, may either be part of the same network part (such as the radio access network110or the core network120) or may be spread between at least two such network parts. In general terms, instructions that are required to be performed in real time may be performed in a device, or node, operatively closer to the radio access network110than instructions that are not required to be performed in real time. Thus, a first portion of the instructions performed by the network node200may be executed in a first device, and a second portion of the instructions performed by the network node200may be executed in a second device; the herein disclosed embodiments are not limited to any particular number of devices on which the instructions performed by the network node200may be executed. Hence, the methods according to the herein disclosed embodiments are suitable to be performed by a network node200residing in a cloud computational environment. Therefore, although a single processing circuitry210is illustrated inFIG.8the processing circuitry210may be distributed among a plurality of devices, or nodes. The same applies to the functional modules210a-210jofFIG.9and the computer program1220aofFIG.12. FIG.10schematically illustrates, in terms of a number of functional units, the components of a terminal device300aaccording to an embodiment. Processing circuitry310is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product1210b(as inFIG.12), e.g. in the form of a storage medium330. The processing circuitry310may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA). Particularly, the processing circuitry310is configured to cause the terminal device300ato perform a set of operations, or steps, as disclosed above. For example, the storage medium330may store the set of operations, and the processing circuitry310may be configured to retrieve the set of operations from the storage medium330to cause the terminal device300ato perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry310is thereby arranged to execute methods as herein disclosed. The storage medium330may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory. The terminal device300amay further comprise a communications interface320for communications with entities, functions, nodes, and devices of the communications network100. As such the communications interface320may comprise one or more transmitters and receivers, comprising analogue and digital components. The processing circuitry310controls the general operation of the terminal device300ae.g. by sending data and control signals to the communications interface320and the storage medium330, by receiving data and reports from the communications interface320, and by retrieving data and instructions from the storage medium330. Other components, as well as the related functionality, of the terminal device300aare omitted in order not to obscure the concepts presented herein. FIG.11schematically illustrates, in terms of a number of functional modules, the components of a terminal device300aaccording to an embodiment. The terminal device300aofFIG.11comprises a number of functional modules; a beam management module310bconfigured to perform step S204, an identify module310cconfigured to perform step S206, an identify module310fconfigured to perform step S208, and an identify module310hconfigured to perform step S210. The terminal device300aofFIG.11may further comprise a number of optional functional modules, such as any of an obtain module310aconfigured to perform step S202, a receive module310dconfigured to perform step S206a, a transmit module310econfigured to perform step S206b, a receive module310gconfigured to perform step S208, a receive module310iconfigured to perform step S210a, a transmit module310jconfigured to perform step S210b. In general terms, each functional module310a-310jmay be implemented in hardware or in software. Preferably, one or more or all functional modules310a-310jmay be implemented by the processing circuitry310, possibly in cooperation with the communications interface320and/or the storage medium330. The processing circuitry310may thus be arranged to form the storage medium330fetch instructions as provided by a functional module310a-310jand to execute these instructions, thereby performing any steps of the terminal device300aas disclosed herein. FIG.12shows one example of a computer program product1210a,1210bcomprising computer readable means1230. On this computer readable means1230, a computer program1220acan be stored, which computer program1220acan cause the processing circuitry210and thereto operatively coupled entities and devices, such as the communications interface220and the storage medium230, to execute methods according to embodiments described herein. The computer program1220aand/or computer program product1210amay thus provide means for performing any steps of the network node200as herein disclosed. On this computer readable means1230, a computer program1220bcan be stored, which computer program1220bcan cause the processing circuitry310and thereto operatively coupled entities and devices, such as the communications interface320and the storage medium330, to execute methods according to embodiments described herein. The computer program1220band/or computer program product1210bmay thus provide means for performing any steps of the terminal device300aas herein disclosed. In the example ofFIG.12, the computer program product1210a,1210bis illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product1210a,1210bcould also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program1220a,1220bis here schematically shown as a track on the depicted optical disk, the computer program1220a,1220bcan be stored in any way which is suitable for the computer program product1210a,1210b. The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims. | 42,152 |
11943035 | DETAILED DESCRIPTION As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may generally all be referred to herein as a “circuit”, “module” or “system”. Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine-readable code, computer readable code, and/or program code, referred to hereafter as “code”. The storage devices may be tangible, non-transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code. Certain functional units described in this specification may be labeled as “modules”, in order to more particularly emphasize their independent implementation. For example, a module may be implemented as a hardware circuit comprising custom very-large-scale integration (“VLSI”) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. Modules may also be implemented in code and/or software for execution by various types of processors. An identified module of code may, for instance, include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may include disparate instructions stored in different locations which, when joined logically together, include the module and achieve the stated purpose for the module. Indeed, a module of code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. This operational data may be collected as a single data set, or may be distributed over different locations including over different computer readable storage devices. Where a module or portions of a module are implemented in software, the software portions are stored on one or more computer readable storage devices. Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but need not necessarily be, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, random access memory (“RAM”), read-only memory (“ROM”), erasable programmable read-only memory (“EPROM” or “Flash Memory”), portable compact disc read-only memory (“CD-ROM”), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. Code for carrying out operations for embodiments may be any number of lines and may be written in any combination of one or more programming languages including an object-oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the “C” programming language, or the like, and/or machine languages such as assembly languages. The code may be executed entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the very last scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (“LAN”) or a wide area network (“WAN”), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). Reference throughout this specification to “one embodiment”, “an embodiment”, or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including”, “comprising”, “having”, and variations thereof mean “including but are not limited to”, unless otherwise expressly specified. An enumerated listing of items does not imply that any or all of the items are mutually exclusive, otherwise unless expressly specified. The terms “a”, “an”, and “the” also refer to “one or more” unless otherwise expressly specified. Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid any obscuring of aspects of an embodiment. Aspects of the embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by code. This code may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which are executed via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the schematic flowchart diagrams and/or schematic block diagrams for the block or blocks. The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices, to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function/act specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks. The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices, to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code executed on the computer or other programmable apparatus provides processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. The schematic flowchart diagrams and/or schematic block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods and program products according to various embodiments. In this regard, each block in the schematic flowchart diagrams and/or schematic block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may substantially be executed concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, to the illustrated Figures. Although various arrow types and line types may be employed in the flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and code. The description of elements in each figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements. The description of elements in each figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements. FIG.1depicts an embodiment of a wireless communication system100for recovering from beam failure. In one embodiment, the wireless communication system100includes remote units102and base units104. Even though a specific number of remote units102and base units104are depicted inFIG.1, one skilled in the art will recognize that any number of remote units102and base units104may be included in the wireless communication system100. In one embodiment, the remote units102may include computing devices, such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, modems), or the like. In some embodiments, the remote units102include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. The remote units102may be referred to as subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, UE, user terminals, a device, or by other terminology used in the art. The remote units102may communicate directly with one or more of the base units104via UL communication signals. A remote unit may connect to the base unit with one or more cells. In the condition of CA (Carrier Aggregation), a remote unit is connected with a base unit via a Pcell (Primary cell) and at least one Scell (Secondary cell). The Pcell and the Scell may come from the same base unit or from different base units. As shown inFIG.1, a remote unit102may connect with the same base unit104via cells103-1and103-2. Alternatively, the remote unit102may connect with different base units104via cells103-2and103-3. The base units104may be distributed over a geographic region. In certain embodiments, a base unit104may also be referred to as an access point, an access terminal, a base, a base station, a Node-B, an eNB, a gNB, a Home Node-B, a relay node, a device, or by any other terminology used in the art. The base units104are generally part of a radio access network that includes one or more controllers communicably coupled to one or more corresponding base units104. The radio access network is generally communicably coupled to one or more core networks, which may be coupled to other networks, like the Internet and public switched telephone networks, among other networks. These and other elements of radio access and core networks are not illustrated but are well known generally by those having ordinary skill in the art. In one implementation, the wireless communication system100is compliant with NR (5G). More generally, however, the wireless communication system100may implement some other open or proprietary communication protocol. The base units104may serve a number of remote units102within a serving area, for example, a cell (or a cell sector) or more cells via a wireless communication link. The base units104transmit DL communication signals to serve the remote units102in the time, frequency, and/or spatial domain. FIG.2depicts one embodiment of an apparatus200that may be used for recovering from beam failure. The apparatus200includes one embodiment of the remote unit102. Furthermore, the remote unit102may include a processor202, a memory204, an input device206, a display208, a transmitter210, and a receiver212. In some embodiments, the input device206and the display208are combined into a single device, such as a touchscreen. In certain embodiments, the remote unit102may not include any input device206and/or display208. In various embodiments, the remote unit102may include at least one of the processor202, the memory204, the transmitter210and the receiver212, and may not include the input device206and/or the display208. The processor202, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor202may be a microcontroller, a microprocessor, a central processing unit (“CPU”), a graphics processing unit (“GPU”), an auxiliary processing unit, a field programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, the processor202executes instructions stored in the memory204to perform the methods and routines described herein. The processor202is communicatively coupled to the memory204, the input device206, the display208, the transmitter210, and the receiver212. The memory204, in one embodiment, is a computer readable storage medium. In some embodiments, the memory204includes volatile computer storage media. For example, the memory204may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory204includes non-volatile computer storage media. For example, the memory204may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory204includes both volatile and non-volatile computer storage media. In some embodiments, the memory204stores data relating to system parameters. In some embodiments, the memory204also stores program code and related data, such as an operating system or other controller algorithms operating on the remote unit102. The input device206, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device206may be integrated with the display208, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, the input device206includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device206includes two or more different devices, such as a keyboard and a touch panel. The display208, in one embodiment, may include any known electronically controllable display or display device. The display208may be designed to output visual, audible, and/or haptic signals. In some embodiments, the display208includes an electronic display capable of outputting visual data to a user. For example, the display208may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting example, the display208may include a wearable display such as a smart watch, smart glasses, a heads-up display, or the like. Further, the display208may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like. In certain embodiments, the display208includes one or more speakers for producing sound. For example, the display208may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the display208includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all or portions of the display208may be integrated with the input device206. For example, the input device206and display208may form a touchscreen or similar touch-sensitive display. In other embodiments, the display208may be located near the input device206. The transmitter210is used to provide UL communication signals to the base unit104and the receiver212is used to receive DL communication signals from the base unit104. In various embodiments, the transmitter210and the receiver212may transmit and receive resources via different cells. Although only one transmitter210and one receiver212are illustrated, the remote unit102may have any suitable number of transmitters210and receivers212. The transmitter210and the receiver212may be any suitable type of transmitters and receivers. In one embodiment, the transmitter210and the receiver212may be part of a transceiver. FIG.3depicts one embodiment of an apparatus300that may be used for recovering from beam failure. The apparatus300includes one embodiment of the base unit104. Furthermore, the base unit104may include at least one of a processor302, a memory304, an input device306, a display308, a transmitter310and a receiver312. As may be appreciated, the processor302, the memory304, the input device306, the display308, the transmitter310, and the receiver312may be substantially similar to the processor202, the memory204, the input device206, the display208, the transmitter210, and the receiver212of the remote unit102, respectively. Although only one transmitter310and one receiver312are illustrated, the base unit104may have any suitable number of transmitters310and receivers312. The transmitter310and the receiver312may be any suitable type of transmitters and receivers. In one embodiment, the transmitter310and the receiver312may be part of a transceiver. In various embodiments, a base unit104, which is a physical entity, may be referred to as a Pcell or a Scell, which is a logical entity. In CA (carrier aggregation) scenario, a remote unit may be connected with a base unit (or more base units) via a Pcell and a Scell. The connection via the Pcell and the connection via the Scell may be a connection to the same base unit, or to different base units. Therefore, a Pcell (or a Scell) may be regarded as a logical entity that can be communicated via X2 interface. That is to say, “a remote unit transmits a message via a Pcell to a base unit” may be expressed as “a remote unit transmits a message to a Pcell” in which the Pcell used herein refers to a logical entity representing the physical entity (i.e. the base unit to which is connected via the Pcell). Similarly, “a remote unit transmits a message via a Scell to a base unit” may be expressed as “a remote unit transmits a message to a Scell” in which the Scell used herein refers to a logical entity representing the physical entity (i.e. the base unit to which is connected via the Scell). Physically, the base unit to which is connected via the Pcell and the base unit to which is connected via the Scell may be the same base unit, or different base units. The Pcell and the Scell, when they represent logical entities, are different logical entities, and may be regarded as two logical entities that can communication via X2 interface. On the other hand, the Pcell and the Scell may correspond to the same base unit, or to different base units, depending on the detailed implementation of the carrier aggregation. FIG.4is a schematic flow chart diagram illustrating a process of determining beam failure. In step402, the remote unit periodically monitors the CSI-RS (Channel Status Indicator Reference Signal) quasi co-located with the TCI (Transmission Configuration Indication) of the configured PDCCH. In step404, the remote unit calculates the hypothetical BLER (Block Error Rate) of the PDCCH and reports the same to its MAC layer. In step406, it is judged whether the BLER of the last serving beam is below a threshold consecutively for a predefined number of times. If the judge result is No, the process will return to the step402. If the judge result is Yes, the remote unit knows that all of the beams fail. The process proceeds to step408, in which the MAC layer will instruct the PHY layer to initiate the beam recovery process. FIG.5is a schematic flow chart diagram illustrating a beam failure recovery process using RACH. In step502, the remote unit is configured with a set of contention-free RACH resources, wherein each resource corresponds to a candidate beam that may be chosen in the condition of beam failure recovery. In step504, the remote unit transmits, via a RACH resource, a contention-free RACH signal containing an indicator corresponding to the chosen candidate beam. The contention-free RACH transmission may also be supplemented with contention-based RACH transmission. That is to say, if the remote unit does not receive any response after a certain time, it will switch to contention-based RACH transmission. In step506, the base unit receives the indicator corresponding to the chosen candidate beam (for contention-free beam recovery process) or the Message 3 including the UE ID and the indicator corresponding to the chosen candidate beam (for contention-based beam recovery process). The base unit learns that the remote unit wants to recover from beam failure with the chosen candidate beam. In step508, the chosen candidate beam is configured as a new serving beam for the remote unit. As can be seen from the above process shown inFIG.5, both contention-free and contention-based beam recovery processes depend on RACH process. However, in NR R15, RACH resource can be defined only for PCell. Scell cannot be assigned with its own RACH resources. This prevents a remote unit from initiating the beam failure recovery process to a Scell using the beam failure recovery process shown inFIG.5. In the CA scenario, a remote unit is connected with a Pcell and a Scell. Methods of recovering from beam failure of Pcell and/or Scell will be described. A first embodiment is related to a condition in. Which all of the beams from Scell fail but at least one beam from Pcell is still working. In this condition, the UE may use the working beam(s) of the Pcell to send information regarding beam failure recovery for the Scell and information regarding new candidate beam to the base unit.FIG.6is a schematic flow chart diagram illustrating a beam failure recovery process of the first embodiment. In step602, in the condition that the remote unit determines that beam failure occurs for the Scell and at least one beam of the Pcell is still working (i.e. beam failure occurs for the Scell but does not occur for the Pcell), the remote unit sends, to Pcell, a beam failure recovery request message containing both information regarding beam failure recovery and information regarding new candidate beam via working beam(s) of the Pcell. The information regarding beam failure recovery may be “Scell ID” of the Scell for which the beam failure occurs. The information regarding new candidate beam may be CSI-RS resource ID or SSB_index of a candidate beam qnew, which is configured by the base unit through RRC for Scell beam link monitoring in Candidate-Beam-RS-List. The message may be transmitted in the way of MAC CE in the form of “Scell ID+CSI-RS resource ID or Scell ID+SSB_index”. The MAC CE may be scheduled in priority over other UL transmissions. After sending the beam failure recovery request message to the Pcell, the remote unit monitors (step608) for PDCCH with CRC scrambled with its C-RNTI in Beam-failure-Recovery-Response-CORESET. The monitor starts from the time the remote unit sends the beam failure recovery request message till the time configured by the higher layer parameter Beam-failure-recovery-request-window-2. In particular, with TX/RX beam correspondence and QCL information, the remote unit uses the RX spatial filter corresponding to the candidate beam qnewto monitor the PDCCH from the Scell. In step604, upon receiving the beam failure recovery request message from the remote unit, the Pcell passes the message to the Scell. As described above, the Pcell and the Scell may correspond to the same base unit, or to different base units. In the condition that the Pcell and the Scell correspond to the same base unit, the step604may be regarded as the beam failure recovery request message only logically sending from the Pcell to the Scell. In the condition that the Pcell and the Scell correspond to different base units, the step604may be regarded as the beam failure recovery request message being sent from one base unit (the base unit connected via the Pcell) to another base unit (the base unit connected via the Scell). In step606, upon receiving the beam failure recovery request message passed from the Pcell, the Scell knows, by the information regarding beam failure recovery (i.e. Scell ID), that the beam failure occurs for the Scell, and therefore sends, in PDCCH via the new candidate beam indicated by the information regarding new candidate beam (i.e. CSI-RS resource ID or SSB_index), a CORSET resource preconfigured for beam recovery by higher layer parameter Beam-failure-Recovery-Response-CORESET. As the remote unit is monitoring in a predefined CORSET with the new candidate beam for the PDCCH, the remote unit is able to receive the CORSET resource sent via the new candidate beam. Therefore, the beam is recovered for the Scell. After the remote unit receives CORSET resource via the PUCCH, it may further receive in the scheduled PUSCH regarding new beam and new TCI state information (for TCI-States and/or TCI-StatesPDCCH). In the step602, the remote unit may send the message via PUCCH or PUSCH of the Pcell. In addition to the PUCCH or PUSCH of the Pcell, the remote unit may also choose to send the message via PUCCH of the Scell. As discussed previously, the beam failure of the Scell is defined by the BLER (of the last serving beam) falling below a threshold consecutively for a predefined number of times, in which the BLER is calculated by the remote unit. Since the remote unit only calculates the BLER of the downlink beam(s), the beam failure only means that the downlink beam(s) fail. On the other hand, the uplink beam(s) may NOT fail. Therefore, it is possible to send the message via PUCCH of the Scell, even if the downlink beam(s) of Scell fail. Because all the downlink beams from the Scell have failed, the uplink beam(s) to Scell may also have degraded. So the PUCCH of the Scell has lower reliability. It means that the Scell may not successfully receive the message sent in PUCCH of the Scell. Therefore, it is preferable that the message is sent via the PUCCH of the Scell before it is also sent via the PUCCH or PUSCH of the Pcell. In addition, since the transmission via the PUCCH of the Scell is not reliable, the transmission of the message via the PUCCH or PUSCH of the Pcell is preferably made before a response to the transmission via the PUCCH of the Scell is received. In other words, the transmission of the message via the PUCCH or PUSCH of the Pcell shall be made within a predetermined period from the transmission of the message via the PUCCH of the Scell, in the condition that no response to the transmission of the message via the PUCCH of the Scell is received. As described above, the remote unit may send the message via the PUCCH of the Scell, the PUCCH of the Pcell, or the PUSCH of the Pcell. The priority of using these channels has several alternatives. Alternative 1: The priority may follow RRC configuration signal from the base unit. Alternative 2: The priority may be fixed in a standard. A few options are (from high to low priority): Pcell PUSCH→Pcell PUCCH→Scell PUCCH Pcell PUSCH→Pcell PUCCH→Scell PUCCH Scell PUCCH→Pcell PUSCH→Pcell PUCCH Scell PUCCH→Pcell PUSCH→Pcell PUCCH Alternative 3: Use the earliest instance of Pcell PUSCH, Pcell PUCCH, Scell PUCCH. Alternative 4: This can be decided by the remote unit. The first embodiment is related to a condition in which all of the beams from Scell fail but at least one beam from Pcell is still working. The second embodiment is related to a condition in which all of the beams from Pcell fail but at least one beam from. Scell is still working. The beam failure recovery of the Pcell can be performed by the process shown inFIG.5, because RACH resources can be defined for the PCell. On the other hand, the beam failure recovery of the Pcell can be alternatively performed by the process shown inFIG.6. In particular, in the condition that all of the beams to Pcell fail but at least one beam to Scell is still working, the remote unit may send the beam failure recovery request message to Scell via the working beam(s) of the Scell. In this ease, the roles of Pcell and Scell are reversed. The beam failure recovery request message of the second embodiment may include information regarding beam failure recovery, which may be “Pcell ID” of the Pcell for which the beam failure occurs, and information regarding new candidate beam. The transmission of the beam failure recovery request message in the second embodiment may be via PUCCH of the Pcell (which may not be reliable), PUCCH of the Scell, or PUSCH of the Scell, in the similar way to the first embodiment. The detailed implementation of the second embodiment is substantially the same as the first embodiment as shown inFIG.6. FIG.7is a schematic flow chart diagram illustrating a beam failure recovery process from the point of view of a remote unit for both the first and the second embodiments. In step702(which corresponds to the step602ofFIG.6), the remote unit sends a beam failure recovery request message including information regarding beam failure recovery and information regarding a new candidate beam via a working beam of a first cell. In the first embodiment, the first cell is Pcell; while in the second embodiment, the first cell is Scell. In step704(which correspond to the step608ofFIG.6), the remote unit monitors a response via the new candidate beam of a second cell. In the first embodiment, the second cell is Scell; while in the second embodiment, the second cell is Pcell. The response is monitored via the same beam as the new candidate beam from sending the beam failure recovery request message (step702or step602) for a predetermined time period (till the time configured by the higher layer parameter Beam-failure-recovery-request-window-2). The response would be a CORSET resource preconfigured for beam recovery sent via PDCCH. In step706, the remote unit receives the response via the new candidate beam from the second cell. Therefore, the beam is recovered. FIG.8is a schematic flow chart diagram illustrating a beam failure recovery process from the point of view of a base unit for both the first and the second embodiments. In step802, the base unit receives a beam failure recovery request message including information regarding beam failure recovery and information regarding a new candidate beam. In the first embodiment, the base unit receives the message via Pcell; while in the second embodiment, the base unit receives the message via Scell. In the condition that the connection via the Pcell and the connection via the Scell are a connection to different base units, the beam failure recovery request message is received from another base unit (Pcell for the first embodiment, or Scell for the second embodiment) (corresponding to the step604ofFIG.6). In step804, the base unit sends a response via the new candidate beam. In particular, the response is CORSET resource preconfigured for beam recovery sent via PDCCH. In the first and second embodiment, the beam failure occurs only for Scell or only for Pcell. A third embodiment is related to a condition in which the beam failure occurs for both Pcell and Scell. That is, all of the beams from Scell fail, and all of the beams from Pcell also fail. In the condition that last downlink serving beams to the Pcell and Scell are lost at the same time, the remote unit should recover the beam to Pcell first using the process shown inFIG.5. Afterwards, the remote unit may recover the beam to Scell using the process shown inFIG.6. Before using the process shown inFIG.5to recover beam to Pcell, the remote unit may send beam failure recovery request message via PUCCHs of both Pcell and Scell. As discussed earlier, the beam failure technically only means that the downlink beam(s) fail, but the uplink beam(s) may NOT fail. Therefore, the remote unit may try to notify the Pcell and/or the Scell of the beam failure recovery via PUCCH of Pcell and/or PUCCH of Scell. Needless to say, the transmissions via PUCCHs of both Pcell and Scell are not reliable in the condition that beam failure occurs. The process shown inFIG.5for recovering from beam failure of Pcell may be made before a response to the transmission via the PUCCHs of both Pcell and Scell is received. A fourth embodiment is related to a condition in which Pcell and Scell are quasi co-located. If Pcell and Scell are transmitted from the same TRP (Transmission Receiving Point), their frequencies are relatively close from each other. Therefore, in the condition that Pcell and Scell are quasi co-located, the beam failure tends to occur to the Pcell and the Scell at the same time. Since the Pcell may be recovered from the beam failure using the process shown inFIG.5, in which the RACH resources are used, the Scell, which is quasi co-located with the Pcell, may use the recovered beam of the Pcell as its own recovered beam. In particular, the QCL (quasi co-location) relationship may be defined between CSI-RS resources of the Pcell and Scell. For example, with intra-band CA, the TX/RX configuration and the channel spatial properties are similar in the carriers between Pcell and Scell, and TX and RX spatial filters of the CSI-RS or SSB of the Pcell can be reused for Scell if QCL relationship is defined between Pcell and Scell. This allows the base unit and the remote unit to manage the beams of the Scell through the beams of the Pcell without extra overhead in the Scell. The base unit may also configure the TCI-state for PDSCH or TCI-statePDCCH for PDCCH using the CSI-RS or SSB of the Pcell In order to use, in Scell, a CSI-RS resource or SSB index defined in Pcell, a carrier index needs to be included together with the CSI-RS resource ID or SSB index when TCI states are configured by RRC. For across carrier beam management in CA, CSI-RS resource in another carrier (Pcell) can be identified as (carrier index, CRI), and SSB as (carrier index, SSB index) in the Scell. The TCI-states for PDSCH or TCI-statePDCCH in the Scell may also be configured in the Pcell through RRC. When the remote unit receives the RRC configuration for TCI-states, the remote unit understands from the carrier index that the spatial RX filter for the corresponding CSI-RS resource or the SSB in the Pcell should be reused in the Scell. When the TCI-states and TCI-statesPDCCH configured for the Scell have been configured, the remote unit can operate with the configured beams in the Scell. FIG.9is a schematic flow chart diagram illustrating a beam failure recovery process from the point of view of a remote unit according to the fourth embodiment. In step902, the remote unit receives a beam management message including a carrier index and a reference signal. The reference signal may be CSI-RS resource ID or SSB index. In step904, in the condition of a beam failure, the remote unit sends a RACH signal via RACH resource to a first cell. The first cell is a Pcell that may be assigned with RACH resources. In step906, the working beam of the first cell is configured, so that the beam is recovered for the first cell. In step908, the working beam of the first cell is configured as the working beam of a second cell, so that the beam is recovered for the second cell. The second cell is a Scell that cannot be assigned with RACH resources. After the beams for the first cell and for the second cell are recovered, the remote unit may further receive a RRC configuration for TCI-states for PDSCH and PDCCH for the first cell and for the second cell. Various solutions for recovering from beam failure in the condition of carrier aggregation are disclosed. In all of the above embodiments, the remote unit is described as being connected with base unit(s) via one Pcell and one Scell in the condition of carrier aggregation. However, in carrier aggregation, the remote unit may be connected with base unit(s) via one Pcell and a plurality of (up to four) Scells. Among the Scells, the primary Scell is a Primary-Secondary Cell (PScell). Unlike other Scells, the PScell may be assigned with its RACH resources. That is to say, in connection to the assignment of RACH resources, the PScell is similar to the Pcell. Therefore, the Pcell in all of the above embodiments may be replaced by the PScell. Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects to be only illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | 39,195 |
11943036 | BEST MODE Hereinafter, embodiments according to the present disclosure will be described in detail by referring to accompanying drawings. Detailed description to be disclosed with accompanying drawings is to describe exemplary embodiments of the present disclosure and is not to represent the only embodiment that the present disclosure may be implemented. The following detailed description includes specific details to provide complete understanding of the present disclosure. However, those skilled in the pertinent art knows that the present disclosure may be implemented without such specific details. In some cases, known structures and devices may be omitted or may be shown in a form of a block diagram based on a core function of each structure and device in order to prevent a concept of the present disclosure from being ambiguous. In the present disclosure, when an element is referred to as being “connected”, “combined” or “linked” to another element, it may include an indirect connection relation that yet another element presents therebetween as well as a direct connection relation. In addition, in the present disclosure, a term, “include” or “have”, specifies the presence of a mentioned feature, step, operation, component and/or element, but it does not exclude the presence or addition of one or more other features, stages, operations, components, elements and/or their groups. In the present disclosure, a term such as “first”, “second”, etc. is used only to distinguish one element from other element and is not used to limit elements, and unless otherwise specified, it does not limit an order or importance, etc. between elements. Accordingly, within a scope of the present disclosure, a first element in an embodiment may be referred to as a second element in another embodiment and likewise, a second element in an embodiment may be referred to as a first element in another embodiment. A term used in the present disclosure is to describe a specific embodiment, and is not to limit a claim. As used in a described and attached claim of an embodiment, a singular form is intended to include a plural form, unless the context clearly indicates otherwise. A term used in the present disclosure, “and/or”, may refer to one of related enumerated items or it means that it refers to and includes any and all possible combinations of two or more of them. In addition, “/” between words in the present disclosure has the same meaning as “and/or”, unless otherwise described. The present disclosure describes a wireless communication network or a wireless communication system, and an operation performed in a wireless communication network may be performed in a process in which a device (e.g., a base station) controlling a corresponding wireless communication network controls a network and transmits or receives a signal, or may be performed in a process in which a terminal associated to a corresponding wireless network transmits or receives a signal with a network or between terminals. In the present disclosure, transmitting or receiving a channel includes a meaning of transmitting or receiving information or a signal through a corresponding channel. For example, transmitting a control channel means that control information or a control signal is transmitted through a control channel. Similarly, transmitting a data channel means that data information or a data signal is transmitted through a data channel. Hereinafter, a downlink (DL) means a communication from a base station to a terminal and an uplink (UL) means a communication from a terminal to a base station. In a downlink, a transmitter may be part of a base station and a receiver may be part of a terminal. In an uplink, a transmitter may be part of a terminal and a receiver may be part of a base station. A base station may be expressed as a first communication device and a terminal may be expressed as a second communication device. A base station (BS) may be substituted with a term such as a fixed station, a Node B, an eNB (evolved-NodeB), a gNB (Next Generation NodeB), a BTS (base transceiver system), an Access Point (AP), a Network (5G network), an AI (Artificial Intelligence) system/module, an RSU (road side unit), a robot, a drone (UAV: Unmanned Aerial Vehicle), an AR (Augmented Reality) device, a VR (Virtual Reality) device, etc. In addition, a terminal may be fixed or mobile, and may be substituted with a term such as a UE (User Equipment), an MS (Mobile Station), a UT (user terminal), an MSS (Mobile Subscriber Station), an SS (Subscriber Station), an AMS (Advanced Mobile Station), a WT (Wireless terminal), an MTC (Machine-Type Communication) device, an M2M (Machine-to-Machine) device, a D2D (Device-to-Device) device, a vehicle, an RSU (road side unit), a robot, an AI (Artificial Intelligence) module, a drone (UAV: Unmanned Aerial Vehicle), an AR (Augmented Reality) device, a VR (Virtual Reality) device, etc. The following description may be used for a variety of radio access systems such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may be implemented by a wireless technology such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA may be implemented by a radio technology such as GSM (Global System for Mobile communications)/GPRS (General Packet Radio Service)/EDGE (Enhanced Data Rates for GSM Evolution). OFDMA may be implemented by a radio technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (Evolved UTRA), etc. UTRA is a part of a UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is a part of an E-UMTS (Evolved UMTS) using E-UTRA and LTE-A (Advanced)/LTE-A pro is an advanced version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an advanced version of 3GPP LTE/LTE-A/LTE-A pro. To clarify description, it is described based on a 3GPP communication system (e.g., LTE-A, NR), but a technical idea of the present disclosure is not limited thereto. LTE means a technology after 3GPP TS (Technical Specification) 36.xxx Release 8. In detail, an LTE technology in or after 3GPP TS 36.xxx Release 10 is referred to as LTE-A and an LTE technology in or after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro. 3GPP NR means a technology in or after TS 38.xxx Release 15. LTE/NR may be referred to as a 3GPP system. “xxx” means a detailed number for a standard document. LTE/NR may be commonly referred to as a 3GPP system. For a background art, a term, an abbreviation, etc. used to describe the present disclosure, matters described in a standard document disclosed before the present disclosure may be referred to. For example, the following document may be referred to. For 3GPP LTE, TS 36.211 (physical channels and modulation), TS 36.212 (multiplexing and channel coding), TS 36.213 (physical layer procedures), TS 36.300 (overall description), TS 36.331 (radio resource control) may be referred to. For 3GPP NR, TS 38.211 (physical channels and modulation), TS 38.212 (multiplexing and channel coding), TS 38.213 (physical layer procedures for control), TS 38.214 (physical layer procedures for data), TS 38.300 (NR and NG-RAN (New Generation-Radio Access Network) overall description), TS 38.331 (radio resource control protocol specification) may be referred to. Abbreviations of terms which may be used in the present disclosure is defined as follows.BM: beam managementCQI: Channel Quality IndicatorCRI: channel state information—reference signal resource indicatorCSI: channel state informationCSI-IM: channel state information—interference measurementCSI-RS: channel state information—reference signalDMRS: demodulation reference signalFDM: frequency division multiplexingFFT: fast Fourier transformIFDMA: interleaved frequency division multiple accessIFFT: inverse fast Fourier transformL1-RSRP: Layer 1 reference signal received powerL1-RSRQ: Layer 1 reference signal received qualityMAC: medium access controlNZP: non-zero powerOFDM: orthogonal frequency division multiplexingPDCCH: physical downlink control channelPDSCH: physical downlink shared channelPMI: precoding matrix indicatorRE: resource elementRI: Rank indicatorRRC: radio resource controlRSSI: received signal strength indicatorRx: ReceptionQCL: quasi co-locationSINR: signal to interference and noise ratioSSB (or SS/PBCH block): Synchronization signal block (including PSS (primary synchronization signal), SSS (secondary synchronization signal) and PBCH (physical broadcast channel))TDM: time division multiplexingTRP: transmission and reception pointTRS: tracking reference signalTx: transmissionUE: user equipmentZP: zero power Overall System As more communication devices have required a higher capacity, a need for an improved mobile broadband communication compared to the existing radio access technology (RAT) has emerged. In addition, massive MTC (Machine Type Communications) providing a variety of services anytime and anywhere by connecting a plurality of devices and things is also one of main issues which will be considered in a next-generation communication. Furthermore, a communication system design considering a service/a terminal sensitive to reliability and latency is also discussed. As such, introduction of a next-generation RAT considering eMBB (enhanced mobile broadband communication), mMTC (massive MTC), URLLC (Ultra-Reliable and Low Latency Communication), etc. is discussed and, for convenience, a corresponding technology is referred to as NR in the present disclosure. NR is an expression which represents an example of a 5G RAT. A new RAT system including NR uses an OFDM transmission method or a transmission method similar to it. A new RAT system may follow OFDM parameters different from OFDM parameters of LTE. Alternatively, a new RAT system follows a numerology of the existing LTE/LTE-A as it is, but may support a wider system bandwidth (e.g., 100 MHz). Alternatively, one cell may support a plurality of numerologies. In other words, terminals which operate in accordance with different numerologies may coexist in one cell. A numerology corresponds to one subcarrier spacing in a frequency domain. As a reference subcarrier spacing is scaled by an integer N, a different numerology may be defined. FIG.1illustrates a structure of a wireless communication system to which the present disclosure may be applied. In reference toFIG.1, NG-RAN is configured with gNBs which provide a control plane (RRC) protocol end for a NG-RA (NG-Radio Access) user plane (i.e., a new AS (access stratum) sublayer/PDCP (Packet Data Convergence Protocol)/RLC (Radio Link Control)/MAC/PHY) and UE. The gNBs are interconnected through a Xn interface. The gNB, in addition, is connected to an NGC (New Generation Core) through an NG interface. In more detail, the gNB is connected to an AMF (Access and Mobility Management Function) through an N2 interface, and is connected to a UPF (User Plane Function) through an N3 interface. FIG.2illustrates a frame structure in a wireless communication system to which the present disclosure may be applied. A NR system may support a plurality of numerologies. Here, a numerology may be defined by a subcarrier spacing and a cyclic prefix (CP) overhead. Here, a plurality of subcarrier spacings may be derived by scaling a basic (reference) subcarrier spacing by an integer N (or, p). In addition, although it is assumed that a very low subcarrier spacing is not used in a very high carrier frequency, a used numerology may be selected independently from a frequency band. In addition, a variety of frame structures according to a plurality of numerologies may be supported in a NR system. Hereinafter, an OFDM numerology and frame structure which may be considered in a NR system will be described. A plurality of OFDM numerologies supported in a NR system may be defined as in the following Table 1. TABLE 1Δf = 2μ· 15μ[kHz]CP015Normal130Normal260Normal,Extended3120Normal4240Normal NR supports a plurality of numerologies (or subcarrier spacings (SCS)) for supporting a variety of 5G services. For example, when a SCS is 15 kHz, a wide area in traditional cellular bands is supported, and when a SCS is 30 kHz/60 kHz, dense-urban, lower latency and a wider carrier bandwidth are supported, and when a SCS is 60 kHz or higher, a bandwidth wider than 24.25 GHz is supported to overcome a phase noise. An NR frequency band is defined as a frequency range in two types (FR1, FR2). FR1, FR2 may be configured as in the following Table 2. In addition, FR2 may mean a millimeter wave (mmW). TABLE 2FrequencyRangeCorrespondingSubcarrierdesignationfrequency rangeSpacingFR1410 MHz-7125 MHz15, 30, 60 kHzFR224250 MHz-52600 MHz60, 120, 240 kHz Regarding a frame structure in an NR system, a size of a variety of fields in a time domain is expresses as a multiple of a time unit of Tc=1/(Δfmax−Nf). Here, Δfmaxis 480-103 Hz and Nfis 4096. Downlink and uplink transmission is configured (organized) with a radio frame having a duration of Tf=1/(ΔfmaxNf/100)·Tc=10 ms. Here, a radio frame is configured with 10 subframes having a duration of Tsf=(ΔfmaxNf/1000)·Tc=1 ms, respectively. In this case, there may be one set of frames for an uplink and one set of frames for a downlink. In addition, transmission in an uplink frame No. i from a terminal should start earlier by TTA=(NTA+NTA,offset)Tcthan a corresponding downlink frame in a corresponding terminal starts. For a subcarrier spacing configuration μ, slots are numbered in an increasing order of naμ∈{0, . . . , Nslotsubframe,μ−1} in a subframe and are numbered in an increasing order of ns,fμ∈{0, . . . , Nslotframe,μ−1} in a radio frame. One slot is configured with Nsymbslotconsecutive OFDM symbols and Nsymbslotis determined according to CP. A start of a slot nsμin a subframe is temporally arranged with a start of an OFDM symbol nsμNsymbslotin the same subframe. All terminals may not perform transmission and reception at the same time, which means that all OFDM symbols of a downlink slot or an uplink slot may not be used. Table 3 represents the number of OFDM symbols per slot (Nsymbslot), the number of slots per radio frame (Nslotframe,μ) and the number of slots per subframe (Nslotsubframe,μ) in a normal CP and Table 4 represents the number of OFDM symbols per slot, the number of slots per radio frame and the number of slots per subframe in an extended CP. TABLE 3μNsymbslotNslotframe, μNslotsubframe,μ01410111420221440431480841416016 TABLE 4NsymbslotNslotframe,μNslotsubframe,μμ12404 FIG.2is an example on μ=2 (SCS is 60 kHz), 1 subframe may include 4 slots referring to Table 3. 1 subframe={1,2,4} slot shown inFIG.2is an example, the number of slots which may be included in 1 subframe is defined as in Table 3 or Table 4. In addition, a mini-slot may include 2, 4 or 7 symbols or more or less symbols. Regarding a physical resource in a NR system, an antenna port, a resource grid, a resource element, a resource block, a carrier part, etc. may be considered. Hereinafter, the physical resources which may be considered in an NR system will be described in detail. First, in relation to an antenna port, an antenna port is defined so that a channel where a symbol in an antenna port is carried can be inferred from a channel where other symbol in the same antenna port is carried. When a large-scale property of a channel where a symbol in one antenna port is carried may be inferred from a channel where a symbol in other antenna port is carried, it may be said that 2 antenna ports are in a QC/QCL (quasi co-located or quasi co-location) relationship. In this case, the large-scale property includes at least one of delay spread, doppler spread, frequency shift, average received power, received timing. FIG.3illustrates a resource grid in a wireless communication system to which the present disclosure may be applied. In reference toFIG.3, it is illustratively described that a resource grid is configured with NRBμNscRBsubcarriers in a frequency domain and one subframe is configured with 14·2μOFDM symbols, but it is not limited thereto. In an NR system, a transmitted signal is described by OFDM symbols of 2μNsymb(μ)and one or more resource grids configured with NRBμNscRBsubcarriers. Here, NRBμ≤NRBmax,μ. The NRBmax,μrepresents a maximum transmission bandwidth, which may be different between an uplink and a downlink as well as between numerologies. In this case, one resource grid may be configured per p and antenna port p. Each element of a resource grid for p and an antenna port p is referred to as a resource element and is uniquely identified by an index pair (k,l′). Here, k=0, . . . , NRBμNscRB−1 is an index in a frequency domain and l′=0, . . . , 2μNsymb(μ)−1 refers to a position of a symbol in a subframe. When referring to a resource element in a slot, an index pair (k,l) is used. Here, l=0, . . . , Nsymbμ−1. A resource element (k,l′) for p and an antenna port p corresponds to a complex value, ak,l′(p,μ). When there is no risk of confusion or when a specific antenna port or numerology is not specified, indexes p and μ may be dropped, whereupon a complex value may be ak,l′(p)or ak,l′. In addition, a resource block (RB) is defined as NscRB=12 consecutive subcarriers in a frequency domain. Point A plays a role as a common reference point of a resource block grid and is obtained as follows.offsetToPointA for a primary cell (PCell) downlink represents a frequency offset between point A and the lowest subcarrier of the lowest resource block overlapped with a SS/PBCH block which is used by a terminal for an initial cell selection. It is expressed in resource block units assuming a 15 kHz subcarrier spacing for FR1 and a 60 kHz subcarrier spacing for FR2.absoluteFrequencyPointA represents a frequency-position of point A expressed as in ARFCN (absolute radio-frequency channel number). Common resource blocks are numbered from 0 to the top in a frequency domain for a subcarrier spacing configuration μ. The center of subcarrier 0 of common resource block 0 for a subcarrier spacing configuration μ is identical to ‘point A’. A relationship between a common resource block number nCRBμand a resource element (k,l) for a subcarrier spacing configuration μ in a frequency domain is given as in the following Equation 1. nCRBμ=⌊kNscRB⌋[Equation1] In Equation 1, k is defined relatively to point A so that k=0 corresponds to a subcarrier centering in point A. Physical resource blocks are numbered from 0 to NBWP,isize,μ−1 in a bandwidth part (BWP) and i is a number of a BWP. A relationship between a physical resource block nPRBand a common resource block nCRBin BWP i is given by the following Equation 2. nCRBμ=nPRBμ+NBWP,istart,μ[Equation 2] NBWP,istart,μis a common resource block that a BWP starts relatively to common resource block 0. FIG.4illustrates a physical resource block in a wireless communication system to which the present disclosure may be applied. And,FIG.5illustrates a slot structure in a wireless communication system to which the present disclosure may be applied. In reference toFIG.4andFIG.5, a slot includes a plurality of symbols in a time domain. For example, for a normal CP, one slot includes 7 symbols, but for an extended CP, one slot includes 6 symbols. A carrier includes a plurality of subcarriers in a frequency domain. An RB (Resource Block) is defined as a plurality of (e.g., 12) consecutive subcarriers in a frequency domain. A BWP (Bandwidth Part) is defined as a plurality of consecutive (physical) resource blocks in a frequency domain and may correspond to one numerology (e.g., an SCS, a CP length, etc.). A carrier may include a maximum N (e.g., 5) BWPs. A data communication may be performed through an activated BWP and only one BWP may be activated for one terminal. In a resource grid, each element is referred to as a resource element (RE) and one complex symbol may be mapped. In an NR system, up to 400 MHz may be supported per component carrier (CC). If a terminal operating in such a wideband CC always operates turning on a radio frequency (FR) chip for the whole CC, terminal battery consumption may increase. Alternatively, when several application cases operating in one wideband CC (e.g., eMBB, URLLC, Mmtc, V2X, etc.) are considered, a different numerology (e.g., a subcarrier spacing, etc.) may be supported per frequency band in a corresponding CC. Alternatively, each terminal may have a different capability for the maximum bandwidth. By considering it, a base station may indicate a terminal to operate only in a partial bandwidth, not in a full bandwidth of a wideband CC, and a corresponding partial bandwidth is defined as a bandwidth part (BWP) for convenience. A BWP may be configured with consecutive RBs on a frequency axis and may correspond to one numerology (e.g., a subcarrier spacing, a CP length, a slot/a mini-slot duration). Meanwhile, a base station may configure a plurality of BWPs even in one CC configured to a terminal. For example, a BWP occupying a relatively small frequency domain may be configured in a PDCCH monitoring slot, and a PDSCH indicated by a PDCCH may be scheduled in a greater BWP. Alternatively, when UEs are congested in a specific BWP, some terminals may be configured with other BWP for load balancing. Alternatively, considering frequency domain inter-cell interference cancellation between neighboring cells, etc., some middle spectrums of a full bandwidth may be excluded and BWPs on both edges may be configured in the same slot. In other words, a base station may configure at least one DL/UL BWP to a terminal associated with a wideband CC. A base station may activate at least one DL/UL BWP of configured DL/UL BWP(s) at a specific time (by L1 signaling or MAC CE (Control Element) or RRC signaling, etc.). In addition, a base station may indicate switching to other configured DL/UL BWP (by L1 signaling or MAC CE or RRC signaling, etc.). Alternatively, based on a timer, when a timer value is expired, it may be switched to a determined DL/UL BWP. Here, an activated DL/UL BWP is defined as an active DL/UL BWP. But, a configuration on a DL/UL BWP may not be received when a terminal performs an initial access procedure or before a RRC connection is set up, so a DL/UL BWP which is assumed by a terminal under these situations is defined as an initial active DL/UL BWP. FIG.6illustrates physical channels used in a wireless communication system to which the present disclosure may be applied and a general signal transmission and reception method using them. In a wireless communication system, a terminal receives information through a downlink from a base station and transmits information through an uplink to a base station. Information transmitted and received by a base station and a terminal includes data and a variety of control information and a variety of physical channels exist according to a type/a usage of information transmitted and received by them. When a terminal is turned on or newly enters a cell, it performs an initial cell search including synchronization with a base station or the like (S601). For the initial cell search, a terminal may synchronize with a base station by receiving a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from a base station and obtain information such as a cell identifier (ID), etc. After that, a terminal may obtain broadcasting information in a cell by receiving a physical broadcast channel (PBCH) from a base station. Meanwhile, a terminal may check out a downlink channel state by receiving a downlink reference signal (DL RS) at an initial cell search stage. A terminal which completed an initial cell search may obtain more detailed system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information carried in the PDCCH (S602). Meanwhile, when a terminal accesses to a base station for the first time or does not have a radio resource for signal transmission, it may perform a random access (RACH) procedure to a base station (S603to S606). For the random access procedure, a terminal may transmit a specific sequence as a preamble through a physical random access channel (PRACH) (S603and S605) and may receive a response message for a preamble through a PDCCH and a corresponding PDSCH (S604and S606). A contention based RACH may additionally perform a contention resolution procedure. A terminal which performed the above-described procedure subsequently may perform PDCCH/PDSCH reception (S607) and PUSCH (Physical Uplink Shared Channel)/PUCCH (physical uplink control channel) transmission (S608) as a general uplink/downlink signal transmission procedure. In particular, a terminal receives downlink control information (DCI) through a PDCCH. Here, DCI includes control information such as resource allocation information for a terminal and a format varies depending on its purpose of use. Meanwhile, control information which is transmitted by a terminal to a base station through an uplink or is received by a terminal from a base station includes a downlink/uplink ACK/NACK (Acknowledgement/Non-Acknowledgement) signal, a CQI (Channel Quality Indicator), a PMI (Precoding Matrix Indicator), a RI (Rank Indicator), etc. For a 3GPP LTE system, a terminal may transmit control information of the above-described CQI/PMI/RI, etc. through a PUSCH and/or a PUCCH. Table 5 represents an example of a DCI format in an NR system. TABLE 5DCIFormatUse0_0Scheduling of a PUSCH in one cell0_1Scheduling of one or multiplePUSCHs in one cell, or indicationof cell group downlink feedbackinformation to a UE0_2Scheduling of a PUSCH in one cell1_0Scheduling of a PDSCH in one DL cell1_1Scheduling of a PDSCH in one cell1_2Scheduling of a PDSCH in one cell In reference to Table 5, DCI formats 0_0, 0_1 and 0_2 may include resource information (e.g., UL/SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), information related to a transport block (TB) (e.g., MCS (Modulation Coding and Scheme), a NDI (New Data Indicator), a RV (Redundancy Version), etc.), information related to a HARQ (Hybrid—Automatic Repeat and request) (e.g., a process number, a DAI (Downlink Assignment Index), PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., DMRS sequence initialization information, an antenna port, a CSI request, etc.), power control information (e.g., PUSCH power control, etc.) related to scheduling of a PUSCH and control information included in each DCI format may be pre-defined. DCI format 0_0 is used for scheduling of a PUSCH in one cell. Information included in DCI format 0_0 is CRC (cyclic redundancy check) scrambled by a C-RNTI (Cell Radio Network Temporary Identifier) or a CS-RNTI (Configured Scheduling RNTI) or a MCS-C-RNTI (Modulation Coding Scheme Cell RNTI) and transmitted. DCI format 0_1 is used to indicate scheduling of one or more PUSCHs or configure grant (CG) downlink feedback information to a terminal in one cell. Information included in DCI format 0_1 is CRC scrambled by a C-RNTI or a CS-RNTI or a SP-CSI-RNTI (Semi-Persistent CSI RNTI) or a MCS-C-RNTI and transmitted. DCI format 0_2 is used for scheduling of a PUSCH in one cell. Information included in DCI format 0_2 is CRC scrambled by a C-RNTI or a CS-RNTI or a SP-CSI-RNTI or a MCS-C-RNTI and transmitted. Next, DCI formats 1_0, 1_1 and 1_2 may include resource information (e.g., frequency resource allocation, time resource allocation, VRB (virtual resource block)-PRB (physical resource block) mapping, etc.), information related to a transport block (TB) (e.g., MCS, NDI, RV, etc.), information related to a HARQ (e.g., a process number, DAI, PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., an antenna port, a TCI (transmission configuration indicator), a SRS (sounding reference signal) request, etc.), information related to a PUCCH (e.g., PUCCH power control, a PUCCH resource indicator, etc.) related to scheduling of a PDSCH and control information included in each DCI format may be pre-defined. DCI format 1_0 is used for scheduling of a PDSCH in one DL cell. Information included in DCI format 1_0 is CRC scrambled by a C-RNTI or a CS-RNTI or a MCS-C-RNTI and transmitted. DCI format 1_1 is used for scheduling of a PDSCH in one cell. Information included in DCI format 1_1 is CRC scrambled by a C-RNTI or a CS-RNTI or a MCS-C-RNTI and transmitted. DCI format 1_2 is used for scheduling of a PDSCH in one cell. Information included in DCI format 1_2 is CRC scrambled by a C-RNTI or a CS-RNTI or a MCS-C-RNTI and transmitted. Beam Management (BM) A BM procedure is L1 (layer 1)/L2 (layer 2) procedures to obtain and maintain a set of beams of a base station (e.g., a gNB, a TRP, etc.) and/or terminal (e.g., a UE) beams which may be used for downlink (DL) and uplink (UL) transmission/reception, it may include the following procedures and terms.Beam measurement: An operation that a base station or a UE measures a property of a received beamformed signalBeam determination: An operation that a base station or a UE selects its Tx beam/Rx beamBeam sweeping: An operation that a spatial region is covered by using a Tx and/or Rx beam for a certain time interval in a pre-determined methodBeam report: An operation that a UE reports information of a beamformed signal based on beam measurement A BM procedure may be classified into (1) a DL BM procedure using a SS (synchronization signal)/PBCH (physical broadcast channel) Block or a CSI-RS and (2) an UL BM procedure using an SRS (sounding reference signal). In addition, each BM procedure may include Tx beam sweeping for determining a Tx Beam and Rx beam sweeping for determining a Rx beam. Hereinafter, a DL BM procedure will be described. A DL BM procedure may include (1) transmission of beamformed DL RSs (reference signals) of a base station (e.g., a CSI-RS or a SS Block (SSB)) and (2) beam reporting of a terminal. Here, beam reporting may include preferred DL RS ID (identifier) (s) and corresponding L1-RSRP (Reference Signal Received Power). The DL RS ID may be a SSBRI (SSB Resource Indicator) or a CRI (CSI-RS Resource Indicator). Hereinafter, a DL BM procedure using an SSB will be described. FIG.7is a diagram which illustrates a downlink beam management operation in a wireless communication system to which the present disclosure may be applied. In reference toFIG.7, an SSB beam and a CSI-RS beam may be used for beam measurement. A measurement metric is L1-RSRP per resource/block. An SSB may be used for coarse beam measurement and a CSI-RS may be used for fine beam measurement. An SSB may be used for both of Tx beam sweeping and Rx beam sweeping. Rx beam sweeping using an SSB may be performed while an UE changes an Rx beam for the same SSBRI across a plurality of SSB bursts. In this case, one SS burst includes one or more SSBs and one SS burst set includes one or more SSB bursts. FIG.8is a diagram which illustrates a downlink beam management procedure using SSB in a wireless communication system to which the present disclosure may be applied. A configuration on a beam report using an SSB is performed in a CSI/beam configuration in a RRC connected state (or a RRC connected mode). In reference toFIG.8, a terminal receives CSI-ResourceConfig IE including CSI-SSB-ResourceSetList including SSB resources used for BM from a base station (S410). Table 6 represents an example of CSI-ResourceConfig IE and as in Table 6, a BM configuration using an SSB configures an SSB like a CSI-RS resource without being separately defined. TABLE 6ASN1STARTTAG-CSI-RESOURCECONFIG-STARTCSI-ResourceConfig ::=SEQUENCE {csi-ResourceConfigIdCSI-ResourceConfigId,csi-RS-ResourceSetListCHOICE {nzp-CSI-RS-SSBSEQUENCE {nzp-CSI-RS-ResourceSetListSEQUENCE(SIZE(1..maxNrofNZP-CSI-RS-ResourceSetsPerConfig))OFNZP-CSI-RS-ResourceSetId OPTIONAL,csi-SSB-ResourceSetListSEQUENCE(SIZE(1..maxNrofCSI-SSB-ResourceSetsPerConfig))OFCSI-SSB-ResourceSetId OPTIONAL},csi-IM-ResourceSetListSEQUENCE(SIZE(1..maxNrofCSI-IM-ResourceSetsPerConfig))OFCSI-IM-ResourceSetId},bwp-IdBWP-Id,resourceTypeENUMERATED{aperiodic,semiPersistent, periodic },. . .}TAG-CSI-RESOURCECONFIGTOADDMOD-STOP-- ASN1STOP In Table 6, a csi-SSB-ResourceSetList parameter represents a list of SSB resources used for beam management and reporting in one resource set. Here, an SSB resource set may be configured as {SSBx1, SSBx2, SSBx3, SSBx4, . . . }. An SSB index may be defined from 0 to 63. A terminal receives an SSB resource from the base station based on the CSI-SSB-ResourceSetList (S420). When CSI-RS reportConfig related to a report on a SSBRI and L1-RSRP is configured, the terminal performs (beam) reporting of the best SSBRI and corresponding L1-RSRP to a base station (S430). Hereinafter, a DL BM procedure using a CSI-RS will be described. Describing a usage of a CSI-RS, i) a repetition parameter is configured for a specific CSI-RS resource set and when TRS_info is not configured, a CSI-RS is used for beam management. ii) when a repetition parameter is not configured and TRS_info is configured, a CSI-RS is used for a TRS (tracking reference signal). iii) when a repetition parameter is not configured and TRS_info is not configured, a CSI-RS is used for CSI acquisition. Such a repetition parameter may be configured only for CSI-RS resource sets associated with CSI-ReportConfig having a report of L1 RSRP or ‘No Report (or None)’. If a terminal is configured with CSI-ReportConfig in which reportQuantity is configured as ‘cri-RSRP’ or ‘none’ and CSI-ResourceConfig for channel measurement (a higher layer parameter resourcesForChannelMeasurement) does not include a higher layer parameter ‘trs-Info’ and includes NZP-CSI-RS-ResourceSet in which a higher layer parameter ‘repetition’ is configured, the terminal may be configured only with a same number of port (1-port or 2-port) having a higher layer parameter ‘nrofPorts’ for all CSI-RS resources in NZP-CSI-RS-ResourceSet. When (a higher layer parameter) repetition is configured as ‘ON’, it is related to a Rx beam sweeping procedure of a terminal. In this case, when a terminal is configured with NZP-CSI-RS-ResourceSet, the terminal may assume that at least one CSI-RS resource in NZP-CSI-RS-ResourceSet is transmitted with the same downlink spatial domain transmission filter. In other words, at least one CSI-RS resource in NZP-CSI-RS-ResourceSet is transmitted through the same Tx beam. Here, at least one CSI-RS resource in NZP-CSI-RS-ResourceSet may be transmitted in a different OFDM symbol. In addition, a terminal does not expect to receive a different periodicity in periodicityAndOffset in all CSI-RS resources in NZP-CSI-RS-Resourceset. Meanwhile, when repetition is configured as ‘OFF’, it is related to a Tx beam sweeping procedure of a base station. In this case, when repetition is configured as ‘OFF’, a terminal does not assume that at least one CSI-RS resource in NZP-CSI-RS-ResourceSet is transmitted in the same downlink spatial domain transmission filter. In other words, at least one CSI-RS resource in NZP-CSI-RS-ResourceSet is transmitted through a different Tx beam. In other words, when reportQuantity of the CSI-RS reportConfig IE is configured as ‘ssb-Index-RSRP’, a terminal reports the best SSBRI and corresponding L1-RSRP to a base station. In addition, when a CSI-RS resource may be configured in the same OFDM symbol(s) as an SSB (SS/PBCH Block) and ‘QCL-TypeD’ is applicable, the terminal may assume that a CSI-RS and an SSB are quasi co-located with regard to ‘QCL-TypeD’. Here, the QCL TypeD may mean that antenna ports are quasi-colocated with regard to a spatial Rx parameter. When a terminal receives a plurality of DL antenna ports in a QCL Type D relationship, it is allowed to apply the same Rx beam. In addition, a terminal does not expect that a CSI-RS will be configured in a RE overlapped with a RE of an SSB. FIG.9is a diagram which illustrates a downlink beam management operation using CSI-RS in a wireless communication system to which the present disclosure may be applied. FIG.9(a)represents a Rx beam determination (or refinement) procedure of a terminal andFIG.9(b)represents a Tx beam sweeping procedure of a base station. In addition,FIG.9(a)is a case when a repetition parameter is configured as ‘ON’ andFIG.9(b)is a case when a repetition parameter is configured as ‘OFF’. FIG.10is a diagram which illustrates an Rx beam determination process of a terminal in a wireless communication system to which the present disclosure may be applied. In reference toFIG.9(a)andFIG.10, an Rx beam determination process of a terminal is described. A terminal receives NZP CSI-RS resource set IE including a higher layer parameter repetition through RRC signaling from a base station (S610). Here, the repetition parameter is configured as ‘ON’. A terminal repetitively receives resources in a CSI-RS resource set configured as repetition ‘ON’ through the same Tx beam (or DL spatial domain transmission filter) of a base station in a different OFDM symbol (S620). A terminal determines its Rx beam (S630). A terminal omits a CSI report (S640). In this case, reportQuantity of a CSI report configuration may be configured as ‘No report (or None)’. In other words, the terminal may omit a CSI report when it is configured as repetition ‘ON’. FIG.11is a diagram which illustrates a Tx beam determination process of a base station in a wireless communication system to which the present disclosure may be applied. In reference toFIG.9(b)andFIG.11, a Tx beam determination process of a base station is described. A terminal receives NZP CSI-RS resource set IE including a higher layer parameter repetition through RRC signaling from a base station (S710). Here, the repetition parameter is configured as ‘OFF’ and it is related to a Tx beam sweeping procedure of a base station. A terminal receives resources in a CSI-RS resource set configured as repetition ‘OFF’ through a different Tx beam (or DL spatial domain transmission filter) of a base station (S720). A terminal selects (or determines) the best beam (S740). A terminal reports an ID and related quality information (e.g., L1-RSRP) of a selected beam to a base station (S740). In this case, reportQuantity of a CSI report configuration may be configured as ‘CRI+L1-RSRP’. In other words, when a CSI-RS is transmitted for BM, the terminal reports a CRI and a related L1-RSRP. FIG.12is a diagram which illustrates resource allocation in a time and frequency domain related to a downlink beam management operation in a wireless communication system to which the present disclosure may be applied. In reference toFIG.12, it is shown that when repetition ‘ON’ is configured in a CSI-RS resource set, a plurality of CSI-RS resources are repetitively used by applying the same Tx beam and when repetition ‘OFF’ is configured in a CSI-RS resource set, different CSI-RS resources are transmitted in a different Tx beam. Hereinafter, a beam indication method related to downlink BM will be described. A terminal may be configured by RRC with a list of a maximum M candidate transmission configuration indication (TCI) states at least for a purpose of a QCL (Quasi Co-location) indication. Here, M may be 64. Each TCI state may be configured as one RS set. Each ID of a DL RS at least for a spatial QCL purpose (QCL Type D) in a RS set may refer to one of DL RS types such as an SSB, a P(periodic)-CSI RS, an SP(semi-persistent)-CSI RS, an A(aperiodic)-CSI RS, etc. An ID of DL RS(s) in a RS set used at least for a purpose of a spatial QCL may be initialized/updated at least by explicit signaling. Table 7 illustrates a TCI-State information element (IE). A TCI-State IE is associated with a quasi co-location (QCL) type corresponding to one or two DL reference signals (RS). TABLE 7ASN1STARTTAG-TCI-STATE-STARTTCI-State ::=SEQUENCE {tci-StateIdTCI-StateId,qcl-Type1QCL-Info,qcl-Type2QCL-InfoOPTIONAL,-- Need R. . .}QCL-Info ::=SEQUENCE {cellServCellIndexOPTIONAL,-- Need Rbwp-IdBWP-IdOPTIONAL, -- Cond CSI-RS-IndicatedreferenceSignalCHOICE {csi-rsNZP-CSI-RS-ResourceId,ssbSSB-Index},qcl-TypeENUMERATED {typeA, typeB, typeC,typeD},. . .}TAG-TCI-STATE-STOP-- ASN1STOP In Table 7, a bwp-Id parameter represents a DL BWP (bandwidth part) where an RS is located, a cell parameter represents a carrier where a RS is located and a referencesignal parameter represents reference antenna port(s) which is a source of a quasi co-location for corresponding target antenna port(s) or a reference signal including it. The target antenna port(s) may be a CSI-RS, a PDCCH DMRS, or a PDSCH DMRS. In an example, a corresponding TCI state ID (identifier) may be indicated in NZP CSI-RS resource configuration information to indicate QCL reference RS information for a NZP (non-zero power) CSI-RS. In another example, a TCI state ID may be indicated to each CORESET configuration to indicate QCL reference information for PDCCH DMRS antenna port(s). In another example, a TCI state ID may be indicated through DCI to indicate QCL reference information for PDSCH DMRS antenna port(s). Hereinafter, uplink beam management will be described. For UL BM, beam reciprocity (or beam correspondence) between a Tx beam and a Rx beam may be valid or may not be valid according to terminal implementation. If reciprocity between a Tx beam and a Rx beam is valid both in a base station and a terminal, a UL beam pair may be matched by a DL beam pair. But, when reciprocity between a Tx beam and a Rx beam is not valid in any one of a base station and a terminal, a process for determining a UL beam pair is required separately from a DL beam pair determination. In addition, although both of a base station and a terminal maintain beam correspondence, a base station may use a UL BM procedure for determining a DL Tx beam without requesting a terminal to report a preferred beam. UL BM may be performed through beamformed UL SRS transmission and whether UL BM of an SRS resource set is applied may be configured by a (higher layer parameter) usage. When a usage is configured as ‘BeamManagement (BM)’, only one SRS resource may be transmitted in each of a plurality of SRS resource sets in a given time instant. A terminal may be configured with one or more SRS(Sounding Reference Symbol) resource sets configured by (a higher layer parameter) SRS-ResourceSet (through higher layer signaling, RRC signaling, etc.) For each SRS resource set, a UE may be configured with K≥1 SRS resources (a higher layer parameter SRS-resource). Here, K is a natural number and the maximum number of K is indicated by SRS_capability. Like DL BM, an UL BM procedure may be also classified into Tx beam sweeping of a terminal and Rx beam sweeping of a base station. FIG.13is a diagram which illustrates an uplink beam management operation using SRS in a wireless communication system to which the present disclosure may be applied. FIG.13(a)illustrates a Rx beam determination operation of a base station andFIG.13(b)illustrates a Tx beam sweeping operation of a terminal. FIG.14is a diagram which illustrates an uplink beam management procedure in a wireless communication system to which the present disclosure may be applied. A terminal receives RRC signaling (e.g., an SRS-Config IE) including a (higher layer parameter) usage parameter configured as ‘beam management’ from a base station (S1010). Table 8 represents an example of an SRS-Config IE (Information Element) and an SRS-Config IE is used for SRS transmission configuration. An SRS-Config IE includes a list of SRS-Resources and a list of SRS-ResourceSets. Each SRS resource set means a set of SRS-resources. A network may trigger transmission of an SRS resource set by using configured aperiodicSRS-ResourceTrigger (L1 DCI). TABLE 8ASN1STARTTAG-MAC-CELL-GROUP-CONFIG-STARTSRS-Config ::=SEQUENCE {srs-ResourceSetToReleaseListSEQUENCE(SIZE (1..maxNrofSRS-ResourceSets)) OF SRS-ResourceSetIdOPTIONAL, -- Need Nsrs-ResourceSetToAddModListSEQUENCE(SIZE (1..maxNrofSRS-ResourceSets)) OF SRS-ResourceSetOPTIONAL, -- Need Nsrs-ResourceToReleaseListSEQUENCE(SIZE (1..maxNrofSRS-Resources)) OF SRS-ResourceIdOPTIONAL, Need Nsrs-ResourceToAddModListSEQUENCE(SIZE (1..maxNrofSRS-Resources)) OF SRS-ResourceOPTIONAL, -- Need Ntpc-AccumulationENUMERATED {disabled}. . .OPTIONAL, -- Need S}SRS-ResourceSet ::=SEQUENCE {srs-ResourceSetIdSRS-ResourceSetId,srs-ResourceIdListSEQUENCE(SIZE (1..maxNrofSRS-ResourcesPerSet)) OF SRS-ResourceIdOPTIONAL, -- Cond SetupresourceTypeCHOICE {aperiodicSEQUENCE {aperiodicSRS-ResourceTriggerINTEGER (1..maxNrofSRS-TriggerStates-1),csi-RSNZP-CSI-RS-ResourceIdOPTIONAL,-- Cond NonCodebookslotOffsetINTEGER (1..32)OPTIONAL,-- Need S. . .},semi-persistentSEQUENCE {associatedCSI-RSNZP-CSI-RS-ResourceIdOPTIONAL,-- Cond NonCodebook. . .},periodicSEQUENCE {associatedCSI-RSNZP-CSI-RS-ResourceIdOPTIONAL,-- Cond NonCodebook. . .}},usageENUMERATED { beamManagement,codebook, nonCodebook, antennaSwitching},alphaAlphaOPTIONAL, -- Need Sp0INTEGER (−202..24)OPTIONAL, -- Cond SetuppathlossReferenceRSCHOICE {ssb-IndexSSB-Index,csi-RS-IndexNZP-CSI-RS-ResourceIdSRS-SpatialRelationInfo ::=SEQUENCE {servingCellIdServCellIndexOPTIONAL, -- Need SreferenceSignalCHOICE {ssb-IndexSSB-Index,csi-RS-IndexNZP-CSI-RS-ResourceId,srsSEQUENCE {resourceIdSRS-ResourceId,uplinkBWPBWP-Id}}}SRS-ResourceId ::=INTEGER(0..maxNrofSRS-Resources-1) In Table 8, usage represents a higher layer parameter which indicates whether an SRS resource set is used for beam management or is used for codebook-based or non-codebook-based transmission. A usage parameter corresponds to a L1 parameter ‘SRS-SetUse’. ‘spatialRelationInfo’ is a parameter which represents a configuration of a spatial relation between a reference RS and a target SRS. Here, a reference RS may be a SSB, a CSI-RS or a SRS corresponding to a L1 parameter ‘SRS-SpatialRelationInfo’. The usage is configured per SRS resource set. A terminal determines a Tx beam for an SRS resource which will be transmitted based on SRS-SpatialRelation Info included in the SRS-Config IE (S1020). Here, SRS-SpatialRelation Info is configured per SRS resource and represents whether the same beam as a beam used in a SSB, a CSI-RS or a SRS will be applied per SRS resource. In addition, SRS-SpatialRelationInfo may be configured or may not be configured for each SRS resource. If SRS-SpatialRelationInfo is configured for an SRS resource, the same beam as a beam used in a SSB, a CSI-RS or a SRS is applied and transmitted. But, if SRS-SpatialRelationInfo is not configured for an SRS resource, the terminal randomly determines a Tx beam and transmits an SRS through the determined Tx beam (S1030). In more detail, for a P-SRS that ‘SRS-ResourceConfigType’ is configured as ‘periodic’:i) when SRS-SpatialRelationInfo is configured as ‘SSB/PBCH’, a UE transmits a corresponding SRS resource by applying the same spatial domain transmission filter (or generated by a corresponding filter) as a spatial domain Rx filter used for SSB/PBCH reception; orii) when SRS-SpatialRelationInfo is configured as ‘CSI-RS’, a UE transmits a SRS resource by applying the same spatial domain transmission filter used for periodic CSI-RS or SP (semi-persistent) CSI-RS reception; oriii) when SRS-SpatialRelationInfo is configured as ‘SRS’, a UE transmits a corresponding SRS resource by applying the same spatial domain transmission filter used for periodic SRS transmission. Although ‘SRS-ResourceConfigType’ is configured as ‘SP (semi-persistent)-SRS’ or ‘AP (aperiodic)-SRS’, a beam determination and transmission operation may be applied in a way similar to the above. Additionally, a terminal may receive or may not receive a feedback on an SRS from a base station as in the following three cases (S1040).i) when Spatial_Relation_Info is configured for all SRS resources in a SRS resource set, a terminal transmits an SRS with a beam indicated by a base station. For example, when Spatial_Relation_Info indicates all the same SSB, CRI or SRI, a terminal repetitively transmits an SRS with the same beam. This case corresponds toFIG.13(a)as a usage for a base station to select an Rx beam.ii) Spatial_Relation_Info may not be configured for all SRS resources in an SRS resource set. In this case, a terminal may transmit with freely changing SRS beams. In other words, this case corresponds toFIG.13(b)as a usage for a terminal to sweep Tx beams.iii) Spatial_Relation_Info may be configured only for a part of SRS resources in an SRS resource set. In this case, for a configured SRS resource, an SRS may be transmitted with an indicated beam, and for a SRS resource that Spatial_Relation_Info is not configured an SRS may be transmitted by randomly applying a Tx beam by a terminal. CSI-Related Operation In an NR (New Radio) system, a CSI-RS (channel state information-reference signal) is used for time and/or frequency tracking, CSI computation, L1 (layer 1)-RSRP (reference signal received power) computation and mobility. Here, CSI computation is related to CSI acquisition and L1-RSRP computation is related to beam management (BM). CSI (channel state information) collectively refers to information which may represent quality of a radio channel (or also referred to as a link) formed between a terminal and an antenna port.To perform one of the usages of a CSI-RS, a terminal (e.g., user equipment, UE) receives configuration information related to CSI from a base station (e.g., general Node B, gNB) through RRC (radio resource control) signaling. The configuration information related to CSI may include at least one of information related to a CSI-IM (interference management) resource, information related to CSI measurement configuration, information related to CSI resource configuration, information related to a CSI-RS resource or information related to CSI report configuration.i) Information related to a CSI-IM resource may include CSI-IM resource information, CSI-IM resource set information, etc. A CSI-IM resource set is identified by a CSI-IM resource set ID (identifier) and one resource set includes at least one CSI-IM resource. Each CSI-IM resource is identified by a CSI-IM resource ID.ii) Information related to CSI resource configuration may be expressed as CSI-ResourceConfig IE. Information related to a CSI resource configuration defines a group which includes at least one of an NZP (non zero power) CSI-RS resource set, a CSI-IM resource set or a CSI-SSB resource set. In other words, the information related to a CSI resource configuration may include a CSI-RS resource set list and the CSI-RS resource set list may include at least one of a NZP CSI-RS resource set list, a CSI-IM resource set list or a CSI-SSB resource set list. A CSI-RS resource set is identified by a CSI-RS resource set ID and one resource set includes at least one CSI-RS resource. Each CSI-RS resource is identified by a CSI-RS resource ID. Parameters representing a usage of a CSI-RS (e.g., a ‘repetition’ parameter related to BM, a ‘trs-Info’ parameter related to tracking) may be configured per NZP CSI-RS resource set.iii) Information related to a CSI report configuration includes a report configuration type (reportConfigType) parameter representing a time domain behavior and a report quantity (reportQuantity) parameter representing CSI-related quantity for a report. The time domain behavior may be periodic, aperiodic or semi-persistent.A terminal measures CSI based on the configuration information related to CSI. The CSI measurement may include (1) a process in which a terminal receives a CSI-RS and (2) a process in which CSI is computed through a received CSI-RS and detailed description thereon is described after. For a CSI-RS, RE (resource element) mapping of a CSI-RS resource in a time and frequency domain is configured by higher layer parameter CSI-RS-ResourceMapping.A terminal reports the measured CSI to a base station. Here, when quantity of CSI-ReportConfig is configured as ‘none (or No report)’, the terminal may omit the report. But, although the quantity is configured as ‘none (or No report)’, the terminal may perform a report to a base station. When the quantity is configured as ‘none’, an aperiodic TRS is triggered or repetition is configured. In this case, only when repetition is configured as ‘ON’, a report of the terminal may be omitted. CSI Measurement An NR system supports more flexible and dynamic CSI measurement and reporting. Here, the CSI measurement may include a procedure of receiving a CSI-RS and acquiring CSI by computing a received CSI-RS. As a time domain behavior of CSI measurement and reporting, aperiodic/semi-persistent/periodic CM (channel measurement) and IM (interference measurement) are supported. 4-port NZP CSI-RS RE pattern is used for CSI-IM configuration. CSI-IM based IMR of NR has a design similar to CSI-IM of LTE and is configured independently from ZP CSI-RS resources for PDSCH rate matching. In addition, each port emulates an interference layer having (a desirable channel and) a precoded NZP CSI-RS in NZP CSI-RS-based IMR. As it is about intra-cell interference measurement for a multi-user case, MU interference is mainly targeted. A base station transmits a precoded NZP CSI-RS to a terminal in each port of configured NZP CSI-RS based IMR. A terminal assumes a channel/interference layer and measures interference for each port in a resource set. When there is no PMI and RI feedback for a channel, a plurality of resources are configured in a set and a base station or a network indicates a subset of NZP CSI-RS resources through DCI for channel/interference measurement. A resource setting and a resource setting configuration are described in more detail. Resource Setting Each CSI resource setting ‘CSI-ResourceConfig’ includes a configuration for a S≥1 CSI resource set (given by a higher layer parameter csi-RS-ResourceSetList). A CSI resource setting corresponds to CSI-RS-resourcesetlist. Here, S represents the number of configured CSI-RS resource sets. Here, a configuration for a S≥1 CSI resource set includes each CSI resource set including CSI-RS resources (configured with a NZP CSI-RS or CSI-IM) and a SS/PBCH block (SSB) resource used for L1-RSRP computation. Each CSI resource setting is positioned at a DL BWP (bandwidth part) identified by a higher layer parameter bwp-id. In addition, all CSI resource settings linked to a CSI reporting setting have the same DL BWP. A time domain behavior of a CSI-RS resource in a CSI resource setting included in a CSI-ResourceConfig IE may be indicated by a higher layer parameter resourceType and may be configured to be aperiodic, periodic or semi-persistent. For a periodic and semi-persistent CSI resource setting, the number (S) of configured CSI-RS resource sets is limited to ‘1’. For a periodic and semi-persistent CSI resource setting, configured periodicity and a slot offset are given by a numerology of an associated DL BWP as given by bwp-id. When UE is configured with a plurality of CSI-ResourceConfigs including the same NZP CSI-RS resource ID, the same time domain behavior is configured for CSI-ResourceConfig. When UE is configured with a plurality of CSI-ResourceConfigs including the same CSI-IM resource ID, the same time domain behavior is configured for CSI-ResourceConfig. One or more CSI resource settings for channel measurement (CM) and interference measurement (IM) are configured through higher layer signaling as follows.CSI-IM resource for interference measurementNZP CSI-RS resource for interference measurement NZP CSI-RS resource for channel measurement In other words, a CMR (channel measurement resource) may be a NZP CSI-RS for CSI acquisition and an IMR (Interference measurement resource) may be a NZP CSI-RS for CSI-IM and IM. In this case, CSI-IM (or a ZP CSI-RS for IM) is mainly used for inter-cell interference measurement. In addition, an NZP CSI-RS for IM is mainly used for intra-cell interference measurement from multi-users. UE may assume that CSI-RS resource(s) for channel measurement and CSI-IM/NZP CSI-RS resource(s) for interference measurement configured for one CSI reporting are ‘QCL-TypeD’ per resource. Resource Setting Configuration As described, a resource setting may mean a resource set list. For aperiodic CSI, each trigger state configured by using a higher layer parameter CSI-AperiodicTriggerState is associated with one or a plurality of CSI-ReportConfigs that each CSI-ReportConfig is linked to a periodic, semi-persistent or aperiodic resource setting. One reporting setting may be connected to up to 3 resource settings.When one resource setting is configured, a resource setting (given by a higher layer parameter resourcesForChannelMeasurement) is about channel measurement for L1-RSRP computation.When two resource settings are configured, a first resource setting (given by a higher layer parameter resourcesForChannelMeasurement) is for channel measurement and a second resource setting (given by csi-IM-ResourcesForInterference or nzp-CSI-RS-ResourcesForInterference) is for interference measurement performed in CSI-IM or a NZP CSI-RS. When three resource settings are configured, a first resource setting (given by resourcesForChannelMeasurement) is for channel measurement, a second resource setting (given by csi-IM-ResourcesForInterference) is for CSI-IM based interference measurement and a third resource setting (given by nzp-CSI-RS-ResourcesForInterference) is for NZP CSI-RS based interference measurement. For semi-persistent or periodic CSI, each CSI-ReportConfig is linked to a periodic or semi-persistent resource setting.When one resource setting (given by resourcesForChannelMeasurement) is configured, the resource setting is about channel measurement for L1-RSRP computation.When two resource settings are configured, a first resource setting (given by resourcesForChannelMeasurement) is for channel measurement and a second resource setting (given by a higher layer parameter csi-IM-ResourcesForInterference) is used for interference measurement performed in CSI-IM. CSI Computation When interference measurement is performed in CSI-IM, each CSI-RS resource for channel measurement is associated with a CSI-IM resource per resource in an order of CSI-RS resources and CSI-IM resources in a corresponding resource set. The number of CSI-RS resources for channel measurement is the same as the number of CSI-IM resources. In addition, when interference measurement is performed in an NZP CSI-RS, UE does not expect to be configured with one or more NZP CSI-RS resources in an associated resource set in a resource setting for channel measurement. A terminal configured with a higher layer parameter nzp-CSI-RS-ResourcesForInterference does not expect that 18 or more NZP CSI-RS ports will be configured in a NZP CSI-RS resource set. For CSI measurement, a terminal assumes the followings.Each NZP CSI-RS port configured for interference measurement corresponds to an interference transmission layer.All interference transmission layers of an NZP CSI-RS port for interference measurement consider EPRE (energy per resource element) ratio.A different interference signal in RE(s) of an NZP CSI-RS resource for channel measurement, an NZP CSI-RS resource for interference measurement or a CSI-IM resource for interference measurement CSI Reporting For CSI reporting, a time and frequency resource which may be used by UE are controlled by a base station. CSI (channel state information) may include at least one of a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), a SS/PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI) or L1-RSRP. For CQI, PMI, CRI, SSBRI, LI, RI, L1-RSRP, a terminal is configured by a higher layer with N≥1 CSI-ReportConfig reporting setting, M≥1 CSI-ResourceConfig resource setting and a list of one or two trigger states (provided by aperiodicTriggerStateList and semiPersistentOnPUSCH-TriggerStateList). Each trigger state in the aperiodicTriggerStateList includes a associated CSI-ReportConfigs list which indicates a channel and optional resource set IDs for interference. In semiPersistentOnPUSCH-TriggerStateList, one associated CSI-ReportConfig is included in each trigger state. In addition, a time domain behavior of CSI reporting supports periodic, semi-persistent, aperiodic.i) Periodic CSI reporting is performed in a short PUCCH, a long PUCCH. Periodicity and a slot offset of periodic CSI reporting may be configured by RRC and refers to a CSI-ReportConfig IE.ii) SP (semi-periodic) CSI reporting is performed in a short PUCCH, a long PUCCH, or a PUSCH. For SP CSI in a short/long PUCCH, periodicity and a slot offset are configured by RRC and a CSI report is activated/deactivated by separate MAC CE/DCI. For SP CSI in a PUSCH, periodicity of SP CSI reporting is configured by RRC, but a slot offset is not configured by RRC and SP CSI reporting is activated/deactivated by DCI (format 0_1). For SP CSI reporting in a PUSCH, a separated RNTI (SP-CSI C-RNTI) is used. An initial CSI report timing follows a PUSCH time domain allocation value indicated by DCI and a subsequent CSI report timing follows a periodicity configured by RRC. DCI format 0_1 may include a CSI request field and activate/deactivate a specific configured SP-CSI trigger state. SP CSI reporting has activation/deactivation equal or similar to a mechanism having data transmission in a SPS PUSCH.iii) Aperiodic CSI reporting is performed in a PUSCH and is triggered by DCI. In this case, information related to trigger of aperiodic CSI reporting may be delivered/indicated/configured through MAC-CE. For AP CSI having an AP CSI-RS, AP CSI-RS timing is configured by RRC and timing for AP CSI reporting is dynamically controlled by DCI. In NR, a method of dividing and reporting CSI in a plurality of reporting instances applied to a PUCCH based CSI report in LTE (e.g., transmitted in an order of RI, WB PMI/CQI, SB PMI/CQI) is not applied. Instead, in NR, there is a limit that a specific CSI report is not configured in a short/long PUCCH and a CSI omission rule is defined. In addition, regarding AP CSI reporting timing, a PUSCH symbol/slot location is dynamically indicated by DCI. In addition, candidate slot offsets are configured by RRC. For CSI reporting, a slot offset (Y) is configured per reporting setting. For UL-SCH, a slot offset K2is separately configured. 2 CSI latency classes (low latency class, high latency class) are defined with regard to CSI computation complexity. Low latency CSI is WB CSI which includes up to 4 ports Type-I codebooks or up to 4 ports non-PMI feedback CSI. High latency CSI refers to CSI other than low latency CSI. For a normal terminal, (Z, Z′) is defined in a unit of OFDM symbols. Here, Z represents the minimum CSI processing time until a CSI report is performed after receiving aperiodic CSI triggering DCI. In addition, Z′ refers to the minimum CSI processing time until a CSI report is performed after receiving a CSI-RS for a channel/interference. Additionally, a terminal reports the number of CSI which may be calculated at the same time. Quasi-co Location (QCL) An antenna port is defined so that a channel where a symbol in an antenna port is transmitted can be inferred from a channel where other symbol in the same antenna port is transmitted. When a property of a channel where a symbol in one antenna port is carried may be inferred from a channel where a symbol in other antenna port is carried, it may be said that 2 antenna ports are in a QC/QCL (quasi co-located or quasi co-location) relationship. Here, the channel property includes at least one of delay spread, doppler spread, frequency/doppler shift, average received power, received timing/average delay, or a spatial RX parameter. Here, a spatial Rx parameter means a spatial (Rx) channel property parameter such as an angle of arrival. A terminal may be configured at list of up to M TCI-State configurations in a higher layer parameter PDSCH-Config to decode a PDSCH according to a detected PDCCH having intended DCI for a corresponding terminal and a given serving cell. The M depends on UE capability. Each TCI-State includes a parameter for configuring a quasi co-location relationship between ports of one or two DL reference signals and a DM-RS (demodulation reference signal) of a PDSCH. A quasi co-location relationship is configured by a higher layer parameter qcl-Type1 for a first DL RS and qcl-Type2 for a second DL RS (if configured). For two DL RSs, a QCL type is not the same regardless of whether a reference is a same DL RS or a different DL RS. A QCL type corresponding to each DL RS is given by a higher layer parameter qcl-Type of QCL-Info and may take one of the following values.‘QCL-TypeA’: {Doppler shift, Doppler spread, average delay, delay spread}‘QCL-TypeB’: {Doppler shift, Doppler spread}‘QCL-TypeC’: {Doppler shift, average delay}‘QCL-TypeD’: {Spatial Rx parameter} For example, when a target antenna port is a specific NZP CSI-RS, it may be indicated/configured that a corresponding NZP CSI-RS antenna port is quasi-colocated with a specific TRS with regard to QCL-Type A and is quasi-colocated with a specific SSB with regard to QCL-Type D. A terminal received such indication/configuration may receive a corresponding NZP CSI-RS by using a doppler, delay value measured in a QCL-TypeA TRS and apply a Rx beam used for receiving QCL-TypeD SSB to reception of a corresponding NZP CSI-RS. UE may receive an activation command by MAC CE signaling used to map up to 8 TCI states to a codepoint of a DCI field ‘Transmission Configuration Indication’. When HARQ-ACK corresponding to a PDSCH carrying an activation command is transmitted in a slot n, mapping indicated between a TCI state and a codepoint of a DCI field ‘Transmission Configuration Indication’ may be applied by starting from a slot n+3Nslotsubframe,μ+1. After UE receives an initial higher layer configuration for TCI states before receiving an activation command, UE may assume for QCL-TypeA, and if applicable, for QCL-TypeD that a DMRS port of a PDSCH of a serving cell is quasi-colocated with a SS/PBCH block determined in an initial access process. When a higher layer parameter (e.g., tci-PresentInDCI) indicating whether there is a TCI field in DCI configured for UE is set to be enabled for a CORESET scheduling a PDSCH, UE may assume that there is a TCI field in DCI format 1_1 of a PDCCH transmitted in a corresponding CORESET. When tci-PresentInDCI is not configured for a CORESET scheduling a PDSCH or when a PDSCH is scheduled by DCI format 1_0 and a time offset between reception of DL DCI and a corresponding PDSCH is equal to or greater than a predetermined threshold (e.g., timeDurationForQCL), in order to determine a PDSCH antenna port QCL, UE may assume that a TCI state or a QCL assumption for a PDSCH is the same as a TCI state or a QCL assumption applied to a CORESET used for PDCCH transmission. Here, the predetermined threshold may be based on reported UE capability. When a parameter tci-PresentInDCI is set to be enabled, a TCI field in DCI in a scheduling CC (component carrier) may indicate an activated TCI state of a scheduled CC or a DL BWP. When a PDSCH is scheduled by DCI format 1_1, UE may use a TCI-state according to a value of a ‘Transmission Configuration Indication’ field of a detected PDCCH having DCI to determine a PDSCH antenna port QCL. When a time offset between reception of DL DCI and a corresponding PDSCH is equal to or greater than a predetermined threshold (e.g., timeDurationForQCL), UE may assume that a DMRS port of a PDSCH of a serving cell is quasi-colocated with RS(s) in a TCI state for QCL type parameter(s) given by an indicated TCI state. When a single slot PDSCH is configured for UE, an indicated TCI state may be based on an activated TCI state of a slot having a scheduled PDSCH. When multiple-slot PDSCHs are configured for UE, an indicated TCI state may be based on an activated TCI state of a first slot having a scheduled PDSCH and UE may expect that activated TCI states across slots having a scheduled PDSCH are the same. When a CORESET associated with a search space set for cross-carrier scheduling is configured for UE, UE may expect that a tci-PresentInDCI parameter is set to be enabled for a corresponding CORESET. When one or more TCI states are configured for a serving cell scheduled by a search space set including QCL-TypeD, UE may expect that a time offset between reception of a PDCCH detected in the search space set and a corresponding PDSCH is equal to or greater than a predetermined threshold (e.g., timeDurationForQCL). For both of a case in which a parameter tci-PresentInDCI is set to be enabled and a case in which tci-PresentInDCI is not configured in a RRC connected mode, when a time offset between reception of DL DCI and a corresponding PDSCH is less than a predetermined threshold (e.g., timeDurationForQCL), UE may assume that a DMRS port of a PDSCH of a serving cell is quasi-colocated with RS(s) for QCL parameter(s) used for PDCCH QCL indication of a CORESET associated with a monitored search space having the lowest CORESET-ID in the latest slot where one or more CORESETs in an activated BWP of a serving cell is monitored by UE. In this case, when QCL-TypeD of a PDSCH DMRS is different from QCL-TypeD of a PDCCH DMRS and they are overlapped in at least one symbol, UE may expect that reception of a PDCCH associated with a corresponding CORESET will be prioritized. It may be also applied to intra-band CA (carrier aggregation) (when a PDSCH and a CORESET exist in a different CC). When any of configured TCI states does not include QCL-TypeD, a different QCL assumption may be obtained from TCI states indicated for a scheduled PDSCH, regardless of a time offset between reception of DL DCI and a corresponding PDSCH. For a periodic CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, UE may expect a TCI state to indicate one of the following QCL type(s).QCL-TypeC with a SS/PBCH block, and if applicable, QCL-TypeD with the same SS/PBCH block, orQCL-TypeC with a SS/PBCH block, and if applicable, QCL-TypeD with a CSI-RS resource in configured NZP-CSI-RS-ResourceSet including a higher layer parameter repetition For an aperiodic CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, UE may expect a TCI state to indicate QCL-TypeA with a periodic CSI-RS resource of NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with the same periodic CSI-RS resource. For a CSI-RS resource of NZP-CSI-RS-ResourceSet configured without a higher layer parameter trs-Info and without a higher layer parameter repetition, UE may expect a TCI state to indicate one of the following QCL type(s).QCL-TypeA with a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with the same CSI-RS resource, orQCL-TypeA with a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with a SS/PBCH block, orQCL-TypeA with a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with a CSI-RS resource in configured NZP-CSI-RS-ResourceSet including a higher layer parameter repetition, orwhen QCL-TypeD is not applicable, QCL-TypeB with a CSI-RS resource in configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info For a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter repetition, UE may expect a TCI state to indicate one of the following QCL type(s).QCL-TypeA with a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with the same CSI-RS resource, orQCL-TypeA with a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with a CSI-RS resource in configured NZP-CSI-RS-ResourceSet including a higher layer parameter repetition, orQCL-TypeC with a SS/PBCH block, and if applicable, QCL-TypeD with the same SS/PBCH block. For a DMRS of a PDCCH, UE may expect a TCI state to indicate one of the following QCL type(s).QCL-TypeA with a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with the same CSI-RS resource, orQCL-TypeA with a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with a CSI-RS resource in configured NZP-CSI-RS-ResourceSet including a higher layer parameter repetition, orQCL-TypeA with a CSI-RS resource of NZP-CSI-RS-ResourceSet configured without a higher layer parameter trs-Info and without a higher layer parameter repetition, and if applicable, QCL-TypeD with the same CSI-RS resource. For a DMRS of a PDSCH, UE may expect a TCI state to indicate one of the following QCL type(s).QCL-TypeA with a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with the same CSI-RS resource, orQCL-TypeA with a CSI-RS resource of configured NZP-CSI-RS-ResourceSet including a higher layer parameter trs-Info, and if applicable, QCL-TypeD with a CSI-RS resource in configured NZP-CSI-RS-ResourceSet including a higher layer parameter repetition, orQCL-TypeA with a CSI-RS resource of NZP-CSI-RS-ResourceSet configured without a higher layer parameter trs-Info and without a higher layer parameter repetition, and if applicable, QCL-TypeD with the same CSI-RS resource. Spatial Parameter Based Uplink/Downlink Signal Transmission and Reception Hereinafter, various examples of the present disclosure about a spatial parameter set or candidates of a spatial parameter set configured based on a predetermined threshold and beam switching timing of a terminal are described. In addition, hereinafter, various examples of the present disclosure that a terminal performs downlink signal reception or uplink signal transmission are described by using a spatial parameter set based on a predetermined threshold and beam switching timing of a terminal. In a NR system, when a terminal performs reception beamforming, it may report time required for beam change (or beam switching) to a base station (e.g., gNB, eNB, etc.). For example, time required by a terminal from an occasion of receiving DCI including triggering information on an aperiodic (AP) CSI-RS until an occasion of receiving an AP CSI-RS triggered by the DCI may be reported by a terminal to a base station as a parameter, beamSwitchTiming (BST). For example, BST may be reported to a base station by being selected among {14, 28, 48, 224, 336} symbols. In addition, a time domain length of one symbol is different according to SCS, so BST may need a different value per SCS supported by a terminal. Accordingly, a different BST value may be reported for FR and/or SCS and for example, a BST value may be reported for SCS=60 kHz and SCS=120 kHz corresponding to FR2, respectively. A BST value is necessary because a terminal may not know which CSI-RS resource is indicated by DCI until completing interpretation of DCI. In more detail, it is because certain time for processing of a terminal is required to apply a beam optimized for reception of a CSI-RS indicated by DCI. In addition, an additional reason why BST is required is that when a terminal is equipped with a plurality of reception panels, it takes time to activate other deactivated panel or switch a panel in order to perform reception of a corresponding CSI-RS after DCI reception and a subsequent operation of CSI-RS reception (e.g., CSI reporting, beam management, time/frequency tracking, etc.). For example, large values like BST={224, 336} may be deemed corresponding to a value that a terminal may report by considering such panel activation/switching delay. Accordingly, a BST value may be configured with the sum of time required for DCI reception and processing and time required for beam switching (e.g., panel activation/switching). For example, a terminal reporting a value of one of BST={14, 28, 48} may be deemed to have no time required for panel activation/switching or ignore it. A spatial parameter which will be applied by a terminal to downlink reception or uplink transmission may be different based on BST and a predetermined threshold (hereinafter, for convenience of a description, referred to as a BAR value). For example, when an AP CSI-RS is transmitted before BAR, a terminal may receive a corresponding AP CSI-RS based on a QCL reference RS of other DL RS/channel (e.g., a default CORESET which is a standard for performing buffering or other DL signal/channel transmitted in the same symbol as a corresponding AP CSI-RS), not a QCL reference RS configured for a corresponding AP CSI-RS. Alternatively, when an AP CSI-RS is transmitted after BAR, a corresponding AP CSI-RS may be received based on a QCL reference RS configured for a corresponding AP CSI-RS. Here, the BAR value may mean a threshold related to an occasion or timing that a CSI/BM related reference signal (e.g., an AP CSI-RS, etc.) is transmitted/received. For example, the BAR value may be a threshold related to a scheduling offset between a last symbol of a PDCCH carrying triggering DCI and a first symbol of an aperiodic CSI-RS resource. A reference signal for a space related (e.g., QCL related) assumption for a CSI/BM related reference signal may be determined/configured based on such a BAR value. A term of a BAR value in the present disclosure may be understood/interpreted according to technical contents described in examples of the present disclosure and does not limit a scope of the present disclosure. For example, BAR may be configured as a different value according to BST. For example, for one of BST={14, 28, 48}, BAR may be BST and for one of BST={224, 336}, BAR may be 48. Here, a reference threshold may correspond to 48. In other words, for a BST value equal to or less than a reference threshold, a BAR value may be configured to be the same as BST and for a BST value exceeding a reference threshold, a BAR value may be configured to be the same as a reference threshold. For example, when a terminal which reported a value of one of BST={224, 336} receives a CSI-RS within 48 symbols, a reference threshold, from a DCI reception occasion, based on a default beam which performed buffering (without panel switching), or based on a reception beam corresponding to a TCI state configured for other DL channel/RS overlapped with a corresponding symbol, it may receive a corresponding CSI-RS. When a terminal which reported a value of one of BST={224, 336} receives a CSI-RS within a BST value and after 48 symbols, a reference threshold, from a DCI reception occasion, it may receive an AP CSI-RS according to QCL reference RS information of an indicated CSI-RS (based on a reception beam in a panel which received DCI without panel switching). When a terminal which reported a value of one of BST={224, 336} receives a CSI-RS after a BST value (and after a reference threshold), it may receive an AP CSI-RS according to QCL reference RS information of an indicated CSI-RS (based on a reception beam of a panel which received DCI and other panel). In reference to the after-described example ofFIG.16, when a first reference threshold is configured as 48 symbols, a first spatial parameter set (e.g., a default beam or other overlapped DL channel/RS) may be applied when downlink reception/uplink transmission triggered/scheduled by DCI is performed within a first threshold smaller than 48 symbols and a second spatial parameter set (e.g., a QCL reference RS configured for a corresponding downlink reception/uplink transmission signal/channel) may be applied when downlink reception/uplink transmission triggered/scheduled by DCI is performed after a first reference threshold, 48 symbols. For example, a spatial parameter set applied to aperiodic CSI-RS reception is described in more detail as follows. For each aperiodic CSI-RS resource of a CSI-RS resource set associated with each CSI triggering state, through higher layer signaling qcl-info including a list of references for a TCI state for an aperiodic CSI-RS resource associated with a CSI triggering state, UE may receive an indication on a QCL configuration for QCL RS source(s) and QCL type(s). When a state included in the list is configured as a reference for a RS associated with QCL-TypeD, a corresponding RS may be a SS/PBCH block positioned at the same or different CC/DL BWP, or may be a periodically or semi-persistently configured CSI-RS resource positioned at the same or different CC/DL BWP. Here, when a scheduling offset between a last symbol of a PDCCH carrying triggering DCI and a first symbol of an aperiodic CSI-RS resource of NZP-CSI-RS-ResourceSet configured without a higher layer parameter trs-info is smaller than a predetermined threshold (e.g., beamSwitchTiming) related to beam switching time reported by a UE when the reported value of the threshold is one of {14, 28, 48}, or when the scheduling offset is smaller than 48 when the reported value is one of {224, 336}, an operation may be performed as follows. If there is other DL signal having a TCI state indicated in the same symbol as a CSI-RS, UE may apply a QCL assumption of the other DL signal even when receiving an aperiodic CSI-RS. The other DL signal may correspond to a PDSCH scheduled with an offset equal to or greater than a timeDurationForQCL threshold, an aperiodic CSI-RS scheduled with an offset equal to or greater than that when a value of a beamSwitchTiming threshold reported by UE is one of {14, 28, 48}, an aperiodic CSI-RS scheduled with an offset equal to or greater than that when a value of a beamSwitchTiming threshold reported by UE is one of {224, 336}, a periodic CSI-RS, a semi-persistent CSI-RS. If there is no other DL signal having a TCI state indicated in the same symbol as a CSI-RS, when receiving an aperiodic CSI-RS, UE may apply a QCL assumption used for a CORESET associated with a monitored search space having the lowest controlResourceSetId in the latest slot that one or more CORESETs in an activated BWP of a serving cell are monitored. When a scheduling offset between a last symbol of a PDCCH carrying triggering DCI and a first symbol of an aperiodic CSI-RS resource is equal to or greater than a predetermined threshold (e.g., beamSwitchTiming) related to beam switching time reported by UE when a reported value of the threshold is one of {14, 28, 48}, or when the scheduling offset is equal to or greater than 48 when the reported value is one of {224, 336}, UE may expect to apply a QCL assumption of an indicated TCI state to an aperiodic CSI-RS resource of a CSI triggering state indicated by a CSI trigger field of DCI. If only one reference threshold (e.g., 48 symbols) is applied to a terminal, a problem may occur that it is hard to apply a valid spatial parameter set according to terminal capability. For example, in a wireless communication system under study to support a frequency band higher than FR1 and FR2 in Table 2 (e.g., FR3 or FR4), it may be required to support SCS higher than 120 kHz. A symbol duration in high SCS (e.g., exceeding 120 kHz) is shorter than a symbol duration in SCS of 120 kHz. When a terminal supporting such a short symbol duration has capability of BST longer than a reference threshold, 48 symbols, (e.g., 224 or 336 symbols), even when downlink reception or uplink transmission is performed at an occasion after a reference threshold (e.g., 48 symbols) from a DCI detection/reception occasion, a problem may occur that it is difficult to apply a spatial parameter set configured/indicated for corresponding downlink reception/uplink transmission. In other words, despite a length of the same 48 symbols, as SCS gets larger, an absolute time length gets shorter, so a problem may occur that a terminal does not have enough time to receive and process DCI and perform beam switching. To solve such a problem, the present disclosure describes various examples defining or configuring an additional reference threshold. FIG.15is a flow chart for describing a beam switching operation of a terminal according to the present disclosure. In S1510, a terminal may report beam switching time related information to a base station. Beam switching time related information may be pre-transmitted by a terminal to a base station as terminal capability information. As described later, beam switching time may include time required for processing of a terminal from an occasion that a terminal receives DCI until performing downlink signal reception or uplink signal transmission scheduled or triggered by the DCI. Here, time required for processing of a terminal may include time that a terminal processes DCI and prepares downlink signal reception or uplink signal transmission. In S1520, a terminal may receive downlink control information (DCI) from a base station. DCI may include triggering information or scheduling information on a downlink signal (or channel) to be received by a terminal. Alternatively, DCI may include triggering information or scheduling information on an uplink signal (or channel) to be transmitted by a terminal. For example, DCI may include triggering/scheduling related information on a downlink signal/channel such as aperiodic CSI-RS triggering, PDSCH scheduling, etc. and may include triggering/scheduling related information on an uplink signal/channel such as aperiodic SRS transmission, PUSCH scheduling, etc. In S1530, a terminal may perform downlink signal/channel reception or uplink signal/channel transmission corresponding to the DCI by using a spatial parameter set based on a predetermined threshold and beam switching time. A downlink or uplink signal/channel corresponding to DCI may include a downlink or uplink signal/channel triggered/scheduled by DCI. Based on a predetermined threshold and beam switching time, a spatial parameter set used for downlink or uplink signal/channel transmission and reception may be determined among spatial parameter set candidates. Spatial parameter set candidates may include a first spatial parameter set applied when a downlink reception/uplink transmission occasion is equal to or less then (or below) a predetermined threshold and a second spatial parameter set applied when a downlink reception/uplink transmission occasion exceeds (or is equal to or greater than) a predetermined threshold. Here, a predetermined threshold may correspond to one threshold among a plurality of threshold candidates. A plurality of threshold candidates may be preconfigured as a different value based on one or more of terminal capability, SCS (Subcarrier Spacing), a FR (Frequency Range) (or a frequency position, or a center frequency position), a CP (Cyclic Prefix) related configuration (e.g., a CP length/type) or may be predetermined between a terminal and a base station without separate signaling. FIG.16is a diagram for describing beam switching timing of a terminal according to an embodiment of the present disclosure. An example ofFIG.16is just to describe a relative relationship of terminal operation timing related to examples of the present disclosure, and it does not limit an absolute position or size in a time domain. In an example ofFIG.16, it is described by assuming that a plurality of spatial parameter set candidates include a first and second spatial parameter set, but a scope of the present disclosure is not limited thereto, and even for 3 or more spatial parameter set candidates, examples of the present disclosure may be applied. In addition, in an example ofFIG.16, it is described by assuming that a plurality of threshold candidates include a first and second threshold, but a scope of the present disclosure is not limited thereto, and even for 3 or more threshold candidates, examples of the present disclosure may be applied. An example ofFIG.16represents cases that an occasion when a terminal detects/receives DCI and timing of downlink reception or uplink transmission performed based on corresponding DCI are included in Duration A, B, or C. In an example ofFIG.16, a first threshold and a second threshold may be defined as a difference (or offset) value with a DCI detection/reception occasion. Duration A may be distinguished as a duration which is equal to or less than (or below) a first threshold from a DCI reception occasion, Duration B may be distinguished as a duration which exceeds (or is equal to or greater than) a first threshold and is equal to or less than (or below) a second threshold and Duration C may be distinguished as a duration which exceeds (or is equal to or greater than) a second threshold. In addition, a first threshold or a second threshold may be configured based on BST reported by a terminal to a base station in relation toFIG.15. For example, when a BST value is equal to or less than a first or second reference threshold, a first or second threshold is configured to be the same as a BST value and when a BST value exceeds a first or second reference threshold, a first or second reference threshold is applied as a first or second threshold as it is. When a first threshold is applied to a terminal, a first spatial parameter set may be applied when downlink reception/uplink transmission triggered/scheduled by DCI belongs to Duration A and a second spatial parameter set may be applied when downlink reception/uplink transmission triggered/scheduled by DCI belongs to Duration B or C. In more detail, in Duration B or C, when downlink reception/uplink transmission is performed within BST, a second spatial parameter set may be applied without beam switching and when downlink reception/uplink transmission is performed after BST, a second spatial parameter set may be applied with beam switching. When a second threshold is applied to a terminal, a first spatial parameter set may be applied when downlink reception/uplink transmission triggered/scheduled by DCI belongs to Duration A or B and a second spatial parameter set may be applied when downlink reception/uplink transmission triggered/scheduled by DCI belongs to Duration C. In more detail, in Duration C, when downlink reception/uplink transmission is performed within BST, a second spatial parameter set may be applied without beam switching and when downlink reception/uplink transmission is performed after BST, a second spatial parameter set may be applied with beam switching. Here, a first spatial parameter set may correspond to a default spatial parameter set or a spatial parameter set related to reception of DCI. For example, when a terminal receives DCI and performs downlink reception or uplink transmission triggered/scheduled by corresponding DCI within a first or second threshold, a first spatial parameter set may be applied. Alternatively, a second spatial parameter set may correspond to a spatial parameter set configured for downlink reception or uplink transmission triggered/scheduled by DCI. For example, when a terminal receives DCI and performs downlink reception or uplink transmission triggered/scheduled by corresponding DCI after a first or second threshold, a second spatial parameter set may be applied. Here, a spatial parameter set may include QCL information (or a QCL reference RS). For example, for a downlink, a TCI state and for an uplink, spatial relation RS information may be included in a spatial parameter set. Embodiment 1 This embodiment is about a method of determining or configuring a reference threshold based on a threshold for SCS (e.g., a SCS threshold) and a threshold for BST (e.g., a BST threshold). For example, when SCS is below (or equal to or less than) a SCS threshold or BST is below (or equal to or less than) a BST threshold, a first threshold may be configured based on a first reference threshold. Alternatively, when SCS is equal to or greater than (or exceeds) a SCS threshold and BST is equal to or greater than (or exceeds) a BST threshold, a second threshold may be configured based on a second reference threshold. Here, a second reference threshold may be greater than a first reference threshold. For example, a first threshold may be applied based on a first reference threshold (e.g., 48) for a terminal supporting SCS equal to or less than 120 kHz, a SCS threshold (regardless of BST). For example, when BST reported by a terminal is equal to or less than 48, a first reference threshold, a first threshold (or first BAR) may be applied in the same way as BST and when BST reported by a terminal exceeds 48, a first reference threshold, a first threshold (or first BAR) may be applied in the same way as 48, a first reference threshold. For example, a first threshold may be applied based on a first reference threshold (e.g., 48) for a terminal supporting BST equal to or less than 48, a BST threshold (regardless of SCS). For example, when BST reported by a terminal is equal to or less than 48, a first reference threshold, a first threshold (or first BAR) may be applied in the same way as BST. For example, a second threshold may be applied based on a second reference threshold (e.g., 96) for a terminal supporting SCS exceeding 120 kHz, a SCS threshold and supporting BST exceeding 48, a BST threshold. For example, when BST reported by a terminal is equal to or less than 96, a second reference threshold, a second threshold (or second BAR) may be applied in the same way as BST and when BST reported by a terminal exceeds 96, a second reference threshold, a second threshold (or second BAR) may be applied in the same way as 96, a second reference threshold. For example, for a terminal which reported BST equal to or greater than a specific value for new SCS (>120 kHz) (e.g., one of BST={224, 336}), a BAR value higher than 48 may be stipulated. For example, a BAR value applied to a terminal which reported one of BST={224, 336} may be changed according to corresponding SCS. For example, for a terminal which reported BST={224,336}, it may be defined/configured as BAR=48 symbols for SCS={60,120} kHz and it may be defined/configured as BAR=96 symbols for SCS={240, 480} kHz. As such, a BAR value (e.g., a BAR value, a threshold which is a standard for determining a spatial parameter set applied to AP CSI-RS reception) may be configured/defined based on (or by considering) SCS and BST. 224 or 336 as a BST value in the above-described example is just an example, and it does not limit a scope of the present disclosure. In addition, as new SCS is supported in the present disclosure, new BST candidate values (e.g., 96, 448, etc.) may be additionally defined and in this case, a BST threshold may be defined as a value larger than 48 without being limited to 48. In addition, a second threshold according to a second reference threshold may be applied to all or part of BST candidate value(s) larger than a second reference threshold (e.g., a BAR value defined to support new SCS (e.g., 96, a second reference threshold)). Embodiment 2 This embodiment is about a method that one or more of a reference threshold candidate, a BST candidate value, or a BST set is defined/configured based on SCS and/or terminal capability. According to embodiment 1, a first or second reference threshold which will be applied to a terminal reporting a BST value equal to or greater than a BST threshold may by defined as a specific value (or a fixed value) according to SCS. But, time required until DCI decoding is completed (without performing beam/channel switching) may be different per terminal. For example, despite BST=336 in SCS=480 kHz, some terminals may complete DCI decoding in the same beam/panel as DCI reception beam/panel within 48 symbols, while other terminals may complete it within 96 symbols. In this case, a terminal that a higher threshold (or BAR value) is required is generally UE having low performance (or low end) and may select and report one of higher BST values and a terminal that a lower threshold (or BAR value) is required is generally UE having high performance (or high end or advanced) and may select and report one of lower BST values. Considering it, a reference threshold may be configured/defined based on capability of a terminal and/or SCS supported by a terminal. For example, a threshold (or a BAR value) applied to specific SCS according to a terminal may be configured/defined differently. Additionally or alternatively, a configuration/a scope of BST candidate values may be differently configured/defined according to a threshold (or a BAR value). Additionally or alternatively, a plurality of BST sets with a different scope or configuration of BST candidate values may be configured/defined for specific SCS. Additionally or alternatively, a threshold (or a BAR value) may be differently configured/defined per BST set. A threshold (or a BAR value) applied according to a terminal may be configured/defined as a different value based on one or more of capability, a type or a category of a terminal or a configuration/an indication of a base station. For example, a plurality of BST sets may be configured/defined as a different combination of BST candidates. For example, a different BST set may have a different scope of BST candidates, may have different granularity of BST candidates, may have the same or different number of BST candidates and some BST candidate(s) may be overlapped. For example, a first BST set may be {14, 28, 48, 224, 336} and a second BST set may be {28, 56, 96, 336, 448}. For example, a corresponding threshold (or BAR value) may be differently configured/defined per BST set. For example, a reference threshold for a first BST set may be 48 symbols and a reference threshold for a second BST set may be 96 symbols. A terminal may report to a base station information on which set of a plurality of BST sets will be selected/applied and information on which BST value in a corresponding set will be selected/applied. As an additional example, according to a type/a category of a terminal, which threshold (or BAR value) and/or BST set will be applied may be configured/defined. For example, a BST set and/or a BAR value which will be applied to MTC, IoT, a vehicle terminal may be configured/defined differently from a BST set and/or BAR value which will be applied to an eMBB terminal like a handset. Embodiment 3 This embodiment is about a method of differently configuring/defining a threshold (or a BAR value) based on a CP related configuration. For example, based on whether to apply an extended CP (ECP) and/or a CP length, a threshold (or a BAR value) may be configured/defined. As an interval between samples gets shorter when new SCS (e.g., SCS larger than the existing SCS) is applied, a normal CP length may not cover the maximum delay spread according to a communication environment, so an ECP based waveform generation method may be applied. As a symbol duration is different according to a CP type/length, a threshold (or a BAR value) which is related to DCI processing and beam switching of a terminal and is a standard for applying a spatial parameter set may be applied based on a CP type/length. When a threshold (or a BAR value) is configured/defined by considering or based on a CP type or length, a threshold (or a BAR value) applied to a CP with a first type/length may be the same as or different from a threshold (or a BAR value) applied to a CP with a second type/length. In a different case, a threshold (or a BAR value) applied to a CP with a first type/length may be greater than a threshold (or a BAR value) applied to a CP with a second type/length. For example, an ECP supports a symbol duration longer than a normal CP, so a threshold (or a BAR value) applied to an ECP may be configured/defined as a value which is smaller/lower than a threshold (or a BAR value) applied to a normal CP. The above-described embodiments may be applied independently or may be entirely or partially combined and applied. In addition, the above-described embodiments described a reference threshold (or BAR value) which determines a QCL reference RS when receiving an AP CSI-RS as a main example, but a scope of the present disclosure is not limited thereto. For example, examples of the present disclosure may be also applied to a threshold which determines a spatial parameter set which will be applied to downlink transmission and/or uplink transmission related to time required for beam switching of a terminal. For example, in applying a different QCL assumption for a PDSCH/a DMRS by comparing time from DCI reception to a PDSCH reception occasion with a predetermined threshold (e.g., a value of timeDurationForQCL), a reference threshold for the predetermined threshold may be applied as one of a plurality of candidate values. For example, when a capability value reported by a terminal exceeds a reference threshold, the reference threshold may be applied as the predetermined threshold. Alternatively, when a capability value reported by a terminal is equal to or less than a reference threshold, the capability value may be applied as the predetermined threshold. Candidates of the reference threshold may be configured/defined differently based on one or more of SCS, a FR (or a frequency position, or a center frequency position), terminal capability, or a CP related configuration (e.g., a CP length/type). As an additional example, in determining a spatial relation RS which will be applied to AP SRS transmission, or in determining a spatial relation RS which will be applied to PUSCH transmission, a different spatial relation RS may be applied based on a predetermined threshold and here, a reference threshold for the predetermined threshold may be applied as one of a plurality of candidate values. For example, when a capability value reported by a terminal exceeds a reference threshold, the reference threshold may be applied as the predetermined threshold. Alternatively, when a capability value reported by a terminal is equal to or less than a reference threshold, the capability value may be applied as the predetermined threshold. Candidates of the reference threshold may be configured/defined differently based on one or more of SCS, a FR (or a frequency position, or a center frequency position), capital capability, or a CP related configuration (e.g., a CP length/type). FIG.17is a diagram for describing a signaling process according to an embodiment of the present disclosure. An example of a signaling operation of a base station and a terminal for the above-described embodiments may be as inFIG.17. Here, a terminal/a base station is just an example, and may be applied by being substituted with a variety of devices as described inFIG.18. AsFIG.17is for convenience of a description, it does not limit a scope of the present disclosure. In addition, some of steps described inFIG.17may be merged or omitted. In addition, a CSI related operation or a beam management operation is assumed in performing procedures described below, but a scope of the present disclosure is not limited thereto, and it may be applied to a variety of downlink reception or uplink transmission operations. A terminal may transmit capability information to a base station S105. In other words, a base station may receive capability information from UE. For example, the capability information may include beam management/CSI related information, information on a terminal (e.g., a terminal category, etc.), etc. For example, as in the above-described embodiments, the capability information may include time information (e.g., BST, etc.) related to beam activation/change which may be supported by a terminal. In an example, as in embodiment 2, when a plurality of sets of BST candidate values are configured, indication/selection information on a set supported by a terminal among the plurality of sets may be included in the capability information. The operation in S105may be omitted in some cases. For example, the above-described operation in S105that a terminal (100/200inFIG.18) transmits the capability information to a base station (200/100inFIG.18) may be implemented by a device inFIG.18which will be described below. For example, in reference toFIG.18, one or more processors102may control one or more transceivers106and/or one or more memories104, etc. to transmit the capability information and one or more transceivers106may transmit capability information to a base station. A terminal may receive configuration information from a base station S110. In other words, a base station may transmit a configuration to UE. The configuration may include one or more of system information (SI), scheduling information, a BM (Beam management) related configuration (e.g., DL BM related CSI-ResourceConfig IE, NZP CSI-RS resource set IE, etc.), a CSI related configuration. For example, the configuration may include beam configuration information (e.g., spatial relation assumption information) of a reference signal for CSI/BM. In an example, the beam configuration information may include reference signal related information for a QCL relationship. The configuration may be transmitted through higher layer (e.g., RRC or MAC CE) signaling. In addition, when the configuration information is predefined or preconfigured, a corresponding step may be omitted. For example, the above-described operation in S110that a terminal (100/200inFIG.18) receives the configuration from a base station (200/100inFIG.18) may be implemented by a device inFIG.18which will be described below. For example, in reference toFIG.18, one or more processors102may control one or more transceivers106and/or one or more memories104, etc. to receive the configuration and one or more transceivers106may receive the configuration from a base station. A terminal may receive control information from a base station S115. In other words, a base station may transmit control information to UE. For example, the control information may be DCI and may be received through a PDCCH. For example, the control information may include information triggering aperiodic CSI reporting (e.g., including beam related reporting). In some cases, S115may be omitted. For example, the above-described operation in S115that a terminal (100/200inFIG.18) receives the control information from a base station (200/100inFIG.18) may be implemented by a device inFIG.18which will be described below. For example, in reference toFIG.18, one or more processors102may control one or more transceivers106and/or one or more memories104, etc. to receive the control information and one or more transceivers106may receive the control information from a base station. A terminal may receive a reference signal (e.g., a CSI-RS) from a base station S120. The reference signal may be related to channel state reporting/beam reporting. For example, the reference signal may be received based on the beam configuration information. For example, the reference signal may be received by applying a spatial relation assumption (e.g., a QCL relationship) based on the above-described embodiments. For example, the spatial relation assumption may be differently applied based on the above-described information triggering aperiodic CSI reporting and a timing offset that the reference signal is received. With this regard, a specific threshold (e.g., a BAR value in the above-described embodiments) may be configured/defined based on the above-described embodiments. For example, a specific threshold (or a BAR value) may be configured/defined based on BST transmitted through SCS and capability information. For example, a specific threshold (or a BAR value) may be configured/defined differently according to a terminal (e.g., a type/a category of a terminal). For example, a specific threshold (or a BAR value) may be configured/defined differently per set of BST candidate values. For example, a specific threshold (or a BAR value) may be configured/defined based on (or by considering) a CP length. For example, when the time offset is within the specific threshold, the reference signal may be received by applying a spatial relation assumption (e.g., a QCL relationship) of other RS or CORESET. For example, when the timing offset is equal to or greater than (or exceeds) the specific threshold value, the reference signal may be received by applying a spatial relation assumption (e.g., a QCL relationship) configured for a corresponding reference signal. For example, the specific threshold value may be configured/defined as one of a plurality of candidate values. For example, a plurality of candidates of the specific threshold value may include a first threshold value (e.g., a value equal to or less than 48) and a second threshold value (e.g., a value larger than 48). For example, the above-described operation in S120that a terminal (100/200inFIG.18) receives the reference signal from a base station (200/100inFIG.18) may be implemented by a device inFIG.18which will be described below. For example, in reference toFIG.18, one or more processors102may control one or more transceivers106and/or one or more memories104, etc. to receive the reference signal and one or more transceivers106may receive the reference signal from a base station. A terminal may perform CSI measurement/beam related measurement based on a received reference signal and perform CSI reporting/beam reporting to a base station S125. For example, the above-described beam management operation/CIS related operation may be applied to perform CSI reporting/beam reporting. For example, the above-described operation in S125that a terminal (100/200inFIG.18) performs the CSI reporting/beam reporting to a base station (200/100inFIG.18) may be implemented by a device inFIG.18which will be described below. For example, in reference toFIG.18, one or more processors102may control one or more transceivers106and/or one or more memories104, etc. to perform the CSI reporting/beam reporting and one or more transceivers106may perform the CSI reporting/beam reporting to a base station. As described above, the above-described base station/terminal operation (e.g., embodiment 1, 2, 3, an example ofFIG.15,FIG.16, toFIG.17, etc.) may be implemented by a device (e.g.,100/200inFIG.18) which will be described below. For example, a terminal may correspond to a first wireless device and a base station may correspond to a second wireless device and in some cases, the opposite may be considered. For example, the above-described base station/terminal operation (e.g., embodiment 1, 2, 3, an example ofFIG.15,FIG.16, toFIG.17, etc.) may be processed by one or more processors inFIG.18(e.g.,102,202) and the above-described base station/terminal operation (e.g., embodiment 1, 2, 3, an example ofFIG.15,FIG.16, toFIG.17) may be stored in a memory (e.g., one or more memories inFIG.18(104,204)) in a form of a command/a program (e.g., an instruction, an executable code) for driving at least one processor inFIG.18(e.g.,102,202). General Device to which the Present Disclosure May be Applied FIG.18is a diagram which illustrates a block diagram of a wireless communication system according to an embodiment of the present disclosure. In reference toFIG.18, a first device/wireless device100and a second device/wireless device200may transmit and receive a wireless signal through a variety of radio access technologies (e.g., LTE, NR). A first wireless device100may include one or more processors102and one or more memories104and may additionally include one or more transceivers106and/or one or more antennas108. A processor102may control a memory104and/or a transceiver106and may be configured to implement description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure. For example, a processor102may transmit a wireless signal including first information/signal through a transceiver106after generating first information/signal by processing information in a memory104. In addition, a processor102may receive a wireless signal including second information/signal through a transceiver106and then store information obtained by signal processing of second information/signal in a memory104. A memory104may be connected to a processor102and may store a variety of information related to an operation of a processor102. For example, a memory104may store a software code including commands for performing all or part of processes controlled by a processor102or for performing description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure. Here, a processor102and a memory104may be part of a communication modem/circuit/chip designed to implement a wireless communication technology (e.g., LTE, NR). A transceiver106may be connected to a processor102and may transmit and/or receive a wireless signal through one or more antennas108. A transceiver106may include a transmitter and/or a receiver. A transceiver106may be used together with a RF (Radio Frequency) unit. In the present disclosure, a wireless device may mean a communication modem/circuit/chip. A second wireless device200may include one or more processors202and one or more memories204and may additionally include one or more transceivers206and/or one or more antennas208. A processor202may control a memory204and/or a transceiver206and may be configured to implement description, functions, procedures, proposals, methods and/or operation flows charts included in the present disclosure. For example, a processor202may generate third information/signal by processing information in a memory204, and then transmit a wireless signal including third information/signal through a transceiver206. In addition, a processor202may receive a wireless signal including fourth information/signal through a transceiver206, and then store information obtained by signal processing of fourth information/signal in a memory204. A memory204may be connected to a processor202and may store a variety of information related to an operation of a processor202. For example, a memory204may store a software code including commands for performing all or part of processes controlled by a processor202or for performing description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure. Here, a processor202and a memory204may be part of a communication modem/circuit/chip designed to implement a wireless communication technology (e.g., LTE, NR). A transceiver206may be connected to a processor202and may transmit and/or receive a wireless signal through one or more antennas208. A transceiver206may include a transmitter and/or a receiver. A transceiver206may be used together with a RF unit. In the present disclosure, a wireless device may mean a communication modem/circuit/chip. Hereinafter, a hardware element of a wireless device100,200will be described in more detail. It is not limited thereto, but one or more protocol layers may be implemented by one or more processors102,202. For example, one or more processors102,202may implement one or more layers (e.g., a functional layer such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors102,202may generate one or more PDUs (Protocol Data Unit) and/or one or more SDUs (Service Data Unit) according to description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure. One or more processors102,202may generate a message, control information, data or information according to description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure. One or more processors102,202may generate a signal (e.g., a baseband signal) including a PDU, a SDU, a message, control information, data or information according to functions, procedures, proposals and/or methods disclosed in the present disclosure to provide it to one or more transceivers106,206. One or more processors102,202may receive a signal (e.g., a baseband signal) from one or more transceivers106,206and obtain a PDU, a SDU, a message, control information, data or information according to description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure. One or more processors102,202may be referred to as a controller, a micro controller, a micro processor or a micro computer. One or more processors102,202may be implemented by a hardware, a firmware, a software, or their combination. In an example, one or more ASICs (Application Specific Integrated Circuit), one or more DSPs (Digital Signal Processor), one or more DSPDs (Digital Signal Processing Device), one or more PLDs (Programmable Logic Device) or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors102,202. Description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure may be implemented by using a firmware or a software and a firmware or a software may be implemented to include a module, a procedure, a function, etc. A firmware or a software configured to perform description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure may be included in one or more processors102,202or may be stored in one or more memories104,204and driven by one or more processors102,202. Description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure may be implemented by using a firmware or a software in a form of a code, a command and/or a set of commands. One or more memories104,204may be connected to one or more processors102,202and may store data, a signal, a message, information, a program, a code, an instruction and/or a command in various forms. One or more memories104,204may be configured with ROM, RAM, EPROM, a flash memory, a hard drive, a register, a cash memory, a computer readable storage medium and/or their combination. One or more memories104,204may be positioned inside and/or outside one or more processors102,202. In addition, one or more memories104,204may be connected to one or more processors102,202through a variety of technologies such as a wire or wireless connection. One or more transceivers106,206may transmit user data, control information, a wireless signal/channel, etc. mentioned in methods and/or operation flow charts, etc. of the present disclosure to one or more other devices. One or more transceivers106,206may receiver user data, control information, a wireless signal/channel, etc. mentioned in description, functions, procedures, proposals, methods and/or operation flow charts, etc. included in the present disclosure from one or more other devices. For example, one or more transceivers106,206may be connected to one or more processors102,202and may transmit and receive a wireless signal. For example, one or more processors102,202may control one or more transceivers106,206to transmit user data, control information or a wireless signal to one or more other devices. In addition, one or more processors102,202may control one or more transceivers106,206to receive user data, control information or a wireless signal from one or more other devices. In addition, one or more transceivers106,206may be connected to one or more antennas108,208and one or more transceivers106,206may be configured to transmit and receive user data, control information, a wireless signal/channel, etc. mentioned in description, functions, procedures, proposals, methods and/or operation flow charts, etc. included in the present disclosure through one or more antennas108,208. In the present disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., an antenna port). One or more transceivers106,206may convert a received wireless signal/channel, etc. into a baseband signal from a RF band signal to process received user data, control information, wireless signal/channel, etc. by using one or more processors102,202. One or more transceivers106,206may convert user data, control information, a wireless signal/channel, etc. which are processed by using one or more processors102,202from a baseband signal to a RF band signal. Therefor, one or more transceivers106,206may include an (analogue) oscillator and/or a filter. Embodiments described above are that elements and features of the present disclosure are combined in a predetermined form. Each element or feature should be considered to be optional unless otherwise explicitly mentioned. Each element or feature may be implemented in a form that it is not combined with other element or feature. In addition, an embodiment of the present disclosure may include combining a part of elements and/or features. An order of operations described in embodiments of the present disclosure may be changed. Some elements or features of one embodiment may be included in other embodiment or may be substituted with a corresponding element or a feature of other embodiment. It is clear that an embodiment may include combining claims without an explicit dependency relationship in claims or may be included as a new claim by amendment after application. It is clear to a person skilled in the pertinent art that the present disclosure may be implemented in other specific form in a scope not going beyond an essential feature of the present disclosure. Accordingly, the above-described detailed description should not be restrictively construed in every aspect and should be considered to be illustrative. A scope of the present disclosure should be determined by reasonable construction of an attached claim and all changes within an equivalent scope of the present disclosure are included in a scope of the present disclosure. A scope of the present disclosure includes software or machine-executable commands (e.g., an operating system, an application, a firmware, a program, etc.) which execute an operation according to a method of various embodiments in a device or a computer and a non-transitory computer-readable medium that such a software or a command, etc. are stored and are executable in a device or a computer. A command which may be used to program a processing system performing a feature described in the present disclosure may be stored in a storage medium or a computer-readable storage medium and a feature described in the present disclosure may be implemented by using a computer program product including such a storage medium. A storage medium may include a high-speed random-access memory such as DRAM, SRAM, DDR RAM or other random-access solid state memory device, but it is not limited thereto, and it may include a nonvolatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices or other nonvolatile solid state storage devices. A memory optionally includes one or more storage devices positioned remotely from processor(s). A memory or alternatively, nonvolatile memory device(s) in a memory include a non-transitory computer-readable storage medium. A feature described in the present disclosure may be stored in any one of machine-readable mediums to control a hardware of a processing system and may be integrated into a software and/or a firmware which allows a processing system to interact with other mechanism utilizing a result from an embodiment of the present disclosure. Such a software or a firmware may include an application code, a device driver, an operating system and an execution environment/container, but it is not limited thereto. Here, a wireless communication technology implemented in a wireless device100,200of the present disclosure may include Narrowband Internet of Things for a low-power communication as well as LTE, NR and 6G. Here, for example, an NB-IoT technology may be an example of a LPWAN (Low Power Wide Area Network) technology, may be implemented in a standard of LTE Cat NB1 and/or LTE Cat NB2, etc. and is not limited to the above-described name. Additionally or alternatively, a wireless communication technology implemented in a wireless device100,200of the present disclosure may perform a communication based on a LTE-M technology. Here, in an example, a LTE-M technology may be an example of a LPWAN technology and may be referred to a variety of names such as an eMTC (enhanced Machine Type Communication), etc. For example, an LTE-M technology may be implemented in at least any one of various standards including 1) LTE CAT 0, 2) LTE Cat S1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M and so on and it is not limited to the above-described name. Additionally or alternatively, a wireless communication technology implemented in a wireless device100,200of the present disclosure may include at least any one of a ZigBee, a Bluetooth and a low power wide area network (LPWAN) considering a low-power communication and it is not limited to the above-described name. In an example, a ZigBee technology may generate PAN (personal area networks) related to a small/low-power digital communication based on a variety of standards such as IEEE 802.15.4, etc. and may be referred to as a variety of names. INDUSTRIAL APPLICABILITY A method proposed by the present disclosure is mainly described based on an example applied to 3GPP LTE/LTE-A, 5G system, but may be applied to various wireless communication systems other than the 3GPP LTE/LTE-A, 5G system. | 126,545 |
11943037 | DETAILED DESCRIPTION FIG.1throughFIG.24, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device. The following documents are hereby incorporated by reference into the present disclosure as if fully set forth herein: 3GPP TS 38.211 v16.1.0, “NR; Physical channels and modulation”; 3GPP TS 38.212 v16.1.0, “NR; Multiplexing and Channel coding”; 3GPP TS 38.213 v16.1.0, “NR; Physical Layer Procedures for Control”; 3GPP TS 38.214 v16.1.0, “NR; Physical Layer Procedures for Data”; 3GPP TS 38.321 v16.1.0, “NR; Medium Access Control (MAC) protocol specification”; and 3GPP TS 38.331 v16.1.0, “NR; Radio Resource Control (RRC) Protocol Specification.” FIGS.1-3below describe various embodiments implemented in wireless communications systems and with the use of orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) communication techniques. The descriptions ofFIGS.1-3are not meant to imply physical or architectural limitations to the manner in which different embodiments may be implemented. Different embodiments of the present disclosure may be implemented in any suitably-arranged communications system. FIG.1illustrates an example wireless network according to embodiments of the present disclosure. The embodiment of the wireless network shown inFIG.1is for illustration only. Other embodiments of the wireless network100could be used without departing from the scope of this disclosure. As shown inFIG.1, the wireless network includes a gNB101(e.g., base station, BS), a gNB102, and a gNB103. The gNB101communicates with the gNB102and the gNB103. The gNB101also communicates with at least one network130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network. The gNB102provides wireless broadband access to the network130for a first plurality of UEs within a coverage area120of the gNB102. The first plurality of UEs includes a UE111, which may be located in a small business; a UE112, which may be located in an enterprise (E); a UE113, which may be located in a WiFi hotspot (HS); a UE114, which may be located in a first residence (R); a UE115, which may be located in a second residence (R); and a UE116, which may be a mobile device (M), such as a cell phone, a wireless laptop, a wireless PDA, or the like. The gNB103provides wireless broadband access to the network130for a second plurality of UEs within a coverage area125of the gNB103. The second plurality of UEs includes the UE115and the UE116. In some embodiments, one or more of the gNBs101-103may communicate with each other and with the UEs111-116using 5G/NR, long term evolution (LTE), long term evolution-advanced (LTE-A), WiMAX, WiFi, or other wireless communication techniques. Depending on the network type, the term “base station” or “BS” can refer to any component (or collection of components) configured to provide wireless access to a network, such as transmit point (TP), TRP, an enhanced base station (eNodeB or eNB), a 5G/NR base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wirelessly enabled devices. Base stations may provide wireless access in accordance with one or more wireless communication protocols, e.g., 5G/NR 3GPP NR, long term evolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA), Wi-Fi 802.11a/b/g/n/ac, etc. For the sake of convenience, the terms “BS” and “TRP” are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, the term “user equipment” or “UE” can refer to any component such as “mobile station,” “subscriber station,” “remote terminal,” “wireless terminal,” “receive point,” or “user device.” For the sake of convenience, the terms “user equipment” and “UE” are used in this patent document to refer to remote wireless equipment that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a stationary device (such as a desktop computer or vending machine). Dotted lines show the approximate extents of the coverage areas120and125, which are shown as approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with gNBs, such as the coverage areas120and125, may have other shapes, including irregular shapes, depending upon the configuration of the gNBs and variations in the radio environment associated with natural and man-made obstructions. As described in more detail below, one or more of the UEs111-116include circuitry, programing, or a combination thereof, for handling beam failure recovery operations. In certain embodiments, and one or more of the gNBs101-103includes circuitry, programing, or a combination thereof, for handling beam failure recovery operations. AlthoughFIG.1illustrates one example of a wireless network, various changes may be made toFIG.1. For example, the wireless network could include any number of gNBs and any number of UEs in any suitable arrangement. Also, the gNB101could communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network130. Similarly, each gNB102-103could communicate directly with the network130and provide UEs with direct wireless broadband access to the network130. Further, the gNBs101,102, and/or103could provide access to other or additional external networks, such as external telephone networks or other types of data networks. FIG.2illustrates an example gNB102according to embodiments of the present disclosure. The embodiment of the gNB102illustrated inFIG.2is for illustration only, and the gNBs101and103ofFIG.1could have the same or similar configuration. However, gNBs come in a wide variety of configurations, andFIG.2does not limit the scope of this disclosure to any particular implementation of a gNB. As shown inFIG.2, the gNB102includes multiple antennas205a-205n, multiple RF transceivers210a-210n, transmit (TX) processing circuitry215, and receive (RX) processing circuitry220. The gNB102also includes a controller/processor225, a memory230, and a backhaul or network interface235. The RF transceivers210a-210nreceive, from the antennas205a-205n, incoming RF signals, such as signals transmitted by UEs in the network100. The RF transceivers210a-210ndown-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are sent to the RX processing circuitry220, which generates processed baseband signals by filtering, decoding, and/or digitizing the baseband or IF signals. The RX processing circuitry220transmits the processed baseband signals to the controller/processor225for further processing. The TX processing circuitry215receives analog or digital data (such as voice data, web data, e-mail, or interactive video game data) from the controller/processor225. The TX processing circuitry215encodes, multiplexes, and/or digitizes the outgoing baseband data to generate processed baseband or IF signals. The RF transceivers210a-210nreceive the outgoing processed baseband or IF signals from the TX processing circuitry215and up-converts the baseband or IF signals to RF signals that are transmitted via the antennas205a-205n. The controller/processor225can include one or more processors or other processing devices that control the overall operation of the gNB102. For example, the controller/processor225could control the reception of UL channel signals and the transmission of DL channel signals by the RF transceivers210a-210n, the RX processing circuitry220, and the TX processing circuitry215in accordance with well-known principles. The controller/processor225could support additional functions as well, such as more advanced wireless communication functions. For instance, the controller/processor225could support beam forming or directional routing operations in which outgoing/incoming signals from/to multiple antennas205a-205nare weighted differently to effectively steer the outgoing signals in a desired direction. Any of a wide variety of other functions could be supported in the gNB102by the controller/processor225. The controller/processor225is also capable of executing programs and other processes resident in the memory230, such as an OS. The controller/processor225can move data into or out of the memory230as required by an executing process. The controller/processor225is also coupled to the backhaul or network interface235. The backhaul or network interface235allows the gNB102to communicate with other devices or systems over a backhaul connection or over a network. The interface235could support communications over any suitable wired or wireless connection(s). For example, when the gNB102is implemented as part of a cellular communication system (such as one supporting 5G/NR, LTE, or LTE-A), the interface235could allow the gNB102to communicate with other gNBs over a wired or wireless backhaul connection. When the gNB102is implemented as an access point, the interface235could allow the gNB102to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The interface235includes any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or RF transceiver. The memory230is coupled to the controller/processor225. Part of the memory230could include a RAM, and another part of the memory230could include a Flash memory or other ROM. AlthoughFIG.2illustrates one example of gNB102, various changes may be made toFIG.2. For example, the gNB102could include any number of each component shown inFIG.2. As a particular example, an access point could include a number of interfaces235, and the controller/processor225could support routing functions to route data between different network addresses. As another particular example, while shown as including a single instance of TX processing circuitry215and a single instance of RX processing circuitry220, the gNB102could include multiple instances of each (such as one per RF transceiver). Also, various components inFIG.2could be combined, further subdivided, or omitted and additional components could be added according to particular needs. FIG.3illustrates an example UE116according to embodiments of the present disclosure. The embodiment of the UE116illustrated inFIG.3is for illustration only, and the UEs111-115ofFIG.1could have the same or similar configuration. However, UEs come in a wide variety of configurations, andFIG.3does not limit the scope of this disclosure to any particular implementation of a UE. As shown inFIG.3, the UE116includes an antenna305, a radio frequency (RF) transceiver310, TX processing circuitry315, a microphone320, and receive (RX) processing circuitry325. The UE116also includes a speaker330, a processor340, an input/output (I/O) interface (IF)345, a touchscreen350, a display355, and a memory360. The memory360includes an operating system (OS)361and one or more applications362. The RF transceiver310receives, from the antenna305, an incoming RF signal transmitted by a gNB of the network100. The RF transceiver310down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to the RX processing circuitry325, which generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal. The RX processing circuitry325transmits the processed baseband signal to the speaker330(such as for voice data) or to the processor340for further processing (such as for web browsing data). The TX processing circuitry315receives analog or digital voice data from the microphone320or other outgoing baseband data (such as web data, e-mail, or interactive video game data) from the processor340. The TX processing circuitry315encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver310receives the outgoing processed baseband or IF signal from the TX processing circuitry315and up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna305. The processor340can include one or more processors or other processing devices and execute the OS361stored in the memory360in order to control the overall operation of the UE116. For example, the processor340could control the reception of uplink channel signals and the transmission of downlink channel signals by the RF transceiver310, the RX processing circuitry325, and the TX processing circuitry315in accordance with well-known principles. In some embodiments, the processor340includes at least one microprocessor or microcontroller. The processor340is also capable of executing other processes and programs resident in the memory360, such as processes for beam failure recovery operation. The processor340can move data into or out of the memory360as required by an executing process. In some embodiments, the processor340is configured to execute the applications362based on the OS361or in response to signals received from gNBs or an operator. The processor340is also coupled to the I/O interface345, which provides the UE116with the ability to connect to other devices, such as laptop computers and handheld computers. The I/O interface345is the communication path between these accessories and the processor340. The processor340is also coupled to the touchscreen350and the display355. The operator of the UE116can use the touchscreen350to enter data into the UE116. The display355may be a liquid crystal display, light emitting diode display, or other display capable of rendering text and/or at least limited graphics, such as from web sites. The memory360is coupled to the processor340. Part of the memory360could include a random access memory (RAM), and another part of the memory360could include a Flash memory or other read-only memory (ROM). AlthoughFIG.3illustrates one example of UE116, various changes may be made toFIG.3. For example, various components inFIG.3could be combined, further subdivided, or omitted and additional components could be added according to particular needs. As a particular example, the processor340could be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Also, whileFIG.3illustrates the UE116configured as a mobile telephone or smartphone, UEs could be configured to operate as other types of mobile or stationary devices. To meet the demand for wireless data traffic having increased since deployment of 4G communication systems and to enable various vertical applications, 5G/NR communication systems have been developed and are currently being deployed. The 5G/NR communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 28 GHz or 60 GHz bands, so as to accomplish higher data rates or in lower frequency bands, such as 6 GHz, to enable robust coverage and mobility support. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G/NR communication systems. In addition, in 5G/NR communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation and the like. The discussion of 5G systems and frequency bands associated therewith is for reference as certain embodiments of the present disclosure may be implemented in 5G systems. However, the present disclosure is not limited to 5G systems or the frequency bands associated therewith, and embodiments of the present disclosure may be utilized in connection with any frequency band. For example, aspects of the present disclosure may also be applied to deployment of 5G communication systems, 6G or even later releases which may use terahertz (THz) bands. A communication system includes a downlink (DL) that refers to transmissions from a base station or one or more transmission points to UEs and an uplink (UL) that refers to transmissions from UEs to a base station or to one or more reception points. A time unit for DL signaling or for UL signaling on a cell is referred to as a slot and can include one or more symbols. A symbol can also serve as an additional time unit. A frequency (or bandwidth (BW)) unit is referred to as a resource block (RB). One RB includes a number of sub-carriers (SCs). For example, a slot can have duration of 0.5 milliseconds or 1 millisecond, include 14 symbols and an RB can include 12 SCs with inter-SC spacing of 30 KHz or 15 KHz, and so on. DL signals include data signals conveying information content, control signals conveying DL control information (DCI), and reference signals (RS) that are also known as pilot signals. A gNB transmits data information or DCI through respective physical DL shared channels (PDSCHs) or physical DL control channels (PDCCHs). A PDSCH or a PDCCH can be transmitted over a variable number of slot symbols including one slot symbol. For brevity, a DCI format scheduling a PDSCH reception by a UE is referred to as a DL DCI format and a DCI format scheduling a physical uplink shared channel (PUSCH) transmission from a UE is referred to as an UL DCI format. A gNB transmits one or more of multiple types of RS including channel state information RS (CSI-RS) and demodulation RS (DMRS). A CSI-RS is primarily intended for UEs to perform measurements and provide CSI to a gNB. For channel measurement, non-zero power CSI-RS (NZP CSI-RS) resources are used. For interference measurement reports (IMRs), CSI interference measurement (CSI-IM) resources associated with a zero power CSI-RS (ZP CSI-RS) configuration are used. A CSI process includes NZP CSI-RS and CSI-IM resources. A UE can determine CSI-RS transmission parameters through DL control signaling or higher layer signaling, such as radio resource control (RRC) signaling, from a gNB. Transmission instances of a CSI-RS can be indicated by DL control signaling or be configured by higher layer signaling. A DM-RS is transmitted only in the BW of a respective PDCCH or PDSCH and a UE can use the DMRS to demodulate data or control information. FIG.4andFIG.5illustrate example wireless transmit and receive paths according to this disclosure. In the following description, a transmit path400may be described as being implemented in a gNB (such as the gNB102), while a receive path500may be described as being implemented in a UE (such as a UE116). However, it may be understood that the receive path500can be implemented in a gNB and that the transmit path400can be implemented in a UE. In some embodiments, the receive path500is configured to support the beam indication channel in a multi-beam system as described in embodiments of the present disclosure. The transmit path400as illustrated inFIG.4includes a channel coding and modulation block405, a serial-to-parallel (S-to-P) block410, a size N inverse fast Fourier transform (IFFT) block415, a parallel-to-serial (P-to-S) block420, an add cyclic prefix block425, and an up-converter (UC)430. The receive path500as illustrated inFIG.5includes a down-converter (DC)555, a remove cyclic prefix block560, a serial-to-parallel (S-to-P) block565, a size N fast Fourier transform (FFT) block570, a parallel-to-serial (P-to-S) block575, and a channel decoding and demodulation block580. As illustrated inFIG.4, the channel coding and modulation block405receives a set of information bits, applies coding (such as a low-density parity check (LDPC) coding), and modulates the input bits (such as with quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a sequence of frequency-domain modulation symbols. The serial-to-parallel block410converts (such as de-multiplexes) the serial modulated symbols to parallel data in order to generate N parallel symbol streams, where N is the IFFT/FFT size used in the gNB102and the UE116. The size N IFFT block415performs an IFFT operation on the N parallel symbol streams to generate time-domain output signals. The parallel-to-serial block420converts (such as multiplexes) the parallel time-domain output symbols from the size N IFFT block415in order to generate a serial time-domain signal. The add cyclic prefix block425inserts a cyclic prefix to the time-domain signal. The up-converter430modulates (such as up-converts) the output of the add cyclic prefix block425to an RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before conversion to the RF frequency. A transmitted RF signal from the gNB102arrives at the UE116after passing through the wireless channel, and reverse operations to those at the gNB102are performed at the UE116. As illustrated inFIG.5, the down-converter555down-converts the received signal to a baseband frequency, and the remove cyclic prefix block560removes the cyclic prefix to generate a serial time-domain baseband signal. The serial-to-parallel block565converts the time-domain baseband signal to parallel time domain signals. The size N FFT block570performs an FFT algorithm to generate N parallel frequency-domain signals. The parallel-to-serial block575converts the parallel frequency-domain signals to a sequence of modulated data symbols. The channel decoding and demodulation block580demodulates and decodes the modulated symbols to recover the original input data stream. Each of the gNBs101-103may implement a transmit path400as illustrated inFIG.4that is analogous to transmitting in the downlink to UEs111-116and may implement a receive path500as illustrated inFIG.5that is analogous to receiving in the uplink from UEs111-116. Similarly, each of UEs111-116may implement the transmit path400for transmitting in the uplink to the gNBs101-103and may implement the receive path500for receiving in the downlink from the gNBs101-103. Each of the components inFIG.4andFIG.5can be implemented using only hardware or using a combination of hardware and software/firmware. As a particular example, at least some of the components inFIG.4andFIG.5may be implemented in software, while other components may be implemented by configurable hardware or a mixture of software and configurable hardware. For instance, the FFT block570and the IFFT block415may be implemented as configurable software algorithms, where the value of size N may be modified according to the implementation. Furthermore, although described as using FFT and IFFT, this is by way of illustration only and may not be construed to limit the scope of this disclosure. Other types of transforms, such as discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) functions, can be used. It may be appreciated that the value of the variable N may be any integer number (such as 1, 2, 3, 4, or the like) for DFT and IDFT functions, while the value of the variable N may be any integer number that is a power of two (such as 1, 2, 4, 8, 16, or the like) for FFT and IFFT functions. AlthoughFIG.4andFIG.5illustrate examples of wireless transmit and receive paths, various changes may be made toFIG.4andFIG.5. For example, various components inFIG.4andFIG.5can be combined, further subdivided, or omitted and additional components can be added according to particular needs. Also,FIG.4andFIG.5are meant to illustrate examples of the types of transmit and receive paths that can be used in a wireless network. Any other suitable architectures can be used to support wireless communications in a wireless network. In a wireless communications system, a radio link failure (RLF) could occur if a significant/sudden link quality drop is observed at the UE side. If a RLF occurs, fast RLF recovery mechanisms, therefore, become essential to promptly re-establish the communication link(s) and avoid severe service interruption. At higher frequencies, e.g., millimeter-wave (mmWave) frequencies or FR2 in the 3GPP NR, both the transmitter and receiver could use directional (analog) beams to transmit and receive various RSs/channels such as SSBs, CSI-RSs, PDCCHs or PDSCHs. Hence, prior to declaring a full RLF, the UE could first detect and recover a potential beam failure if the signal qualities/strengths of certain beam pair links (BPLs) are below a certain threshold for a certain period of time. FIG.6Aillustrates an example of a beam failure event600according to embodiments of the present disclosure. An embodiment of the beam failure event600shown inFIG.6Ais for illustration only. FIG.6Billustrates an example of a beam failure recovery procedure650according to embodiments of the present disclosure. An embodiment of the beam failure recovery procedure650shown inFIG.6Bis for illustration only. The 3GPP Rel. 15 beam failure recovery (BFR) procedure mainly targets for a primary cell (PCell or PSCell) under the carrier aggregation (CA) framework as shown inFIG.6A. The BFR procedure in the 3GPP Rel. 15 comprises the following key components, which are also depicted inFIG.6B: (1) beam failure detection (BFD); (2) new beam identification (NBI); (3) BFR request (BFRQ); and (4) BFRQ response (BFRR). As can be seen fromFIG.6B, the UE is first configured by the gNB a set of BFD RS resources to monitor the link qualities between the gNB and the UE. One BFD RS resource could correspond to one (periodic) CSI-RS/SSB RS resource, which could be a quasi-co-located (QCL) source RS with typed in a TCI state for a CORESET. If the received signal qualities of all the BFD RS resources are below a given threshold (implying that the hypothetical BLERs of the corresponding CORESETs/PDCCHs are above a given threshold), the UE could declare a beam failure instance (BFI). Further, if the UE has declared N_BFI consecutive BFIs within a given time period, the UE would declare a beam failure. After declaring/detecting the beam failure, the UE would transmit the BFRQ to the gNB via a contention-free (CF) PRACH (CF BFR-PRACH) resource, whose index is associated with a new beam identified by the UE. Specifically, to determine a potential new beam, the UE could be first configured by the network a set of SSB and/or CSI-RS resources (NBI RS resources) via a higher layer parameter candidateBeamRSList. The UE would then measure the NBI RSs and calculate their L1-RSRPs. If at least one of the measured L1-RSRPs of the NBI RSs is beyond a given threshold, the UE would select the beam that corresponds to the NBI RS with the highest L1-RSRP as the new beam. To determine a CF BFR-PRACH resource to convey the BFRQ, the UE could be first configured by the network a set of PRACH resources, each associated with a NBI RS resource. The UE could then select the PRACH resource that has the one-to-one correspondence to the selected NBI RS resource (the new beam) to send the BFRQ to the gNB. From the index of the selected CF PRACH resource, the gNB could also know which beam is selected by the UE as the new beam. Four slots after the UE has transmitted the BFRQ, the UE could start to monitor a dedicated CORESET/search space for BFRQ response. The dedicated CORESET is addressed to the UE-specific C-RNTI and would be transmitted by the gNB using the newly identified beam. If the UE detects a valid UE-specific DCI in the dedicated CORESET for BFRR, the UE assumes that the beam failure recovery request has been successfully received by the network, and the UE would complete the BFR process. Otherwise, if the UE does not receive the BFRR within a configured time window, the UE would initiate a contention-based (CB) random access (RA) process to reconnect to the network. FIG.7Aillustrates another example of a beam failure event700according to embodiments of the present disclosure. An embodiment of the beam failure event700shown inFIG.7Ais for illustration only. FIG.7Billustrates another example of a beam failure recovery procedure750according to embodiments of the present disclosure. An embodiment of the beam failure recovery procedure750shown inFIG.7Bis for illustration only. In the 3GPP Rel. 16, the BFR procedures were customized for the secondary cell (SCell) under the CA framework, in which the BPL(s) between the PCell and the UE is assumed to be always working. An illustrative example of the SCell beam failure is given inFIG.7A. InFIG.7B, the key components of the Rel. 16 SCell BFR are presented. It is evident fromFIG.7Bthat prior to sending the BFRQ, the Rel. 15 and Rel. 16 BFR procedures have similar BFD designs. After declaring/detecting the beam failure for the SCell, the UE would transmit the BFRQ in form of a scheduling request (SR) over a PUCCH for the working PCell. Furthermore, the UE could only transmit the BFRQ at this stage without indicating any new beam index, failed SCell index or other information to the network. This is different from the Rel. 15 PCell/PSCell procedure, in which the UE would indicate both the BFRQ and the identified new beam index to the network at the same time. Allowing the gNB to quickly know the beam failure status of the SCell without waiting for the UE to identify a new beam could be beneficial. For instance, the gNB could deactivate the failed SCell and allocate the resources to other working SCells. The UE could be indicated by the network an uplink grant in response to the BFRQ SR, which would allocate necessary resources for the MAC CE to carry new beam index (if identified), failed SCell index and etc. over the PUSCH for the working PCell. After transmitting the MAC CE for BFR to the working PCell, the UE would start to monitor the BFRR. The BFRR could be a TCI state indication for a CORESET for the corresponding SCell. The BFRR to the MAC CE for BFR could also be a normal uplink grant for scheduling a new transmission for the same HARQ process as the PUSCH carrying the MAC CE for BFR. If the UE could not receive the BFRR within a configured time window, the UE could transmit BFR-PUCCH again, or fall back to contention-based random access (CBRA) process. In a multi-TRP system, in which different TRPs could be geographically non-co-located, one or more BFLs between the UE and the TRP(s) could fail. In this disclosure, a TRP can represent a collection of measurement antenna ports, measurement RS resources and/or control resource sets (CORESETs). For example, a TRP could be associated with one or more of: a plurality of CSI-RS resources, a plurality of CRIs (CSI-RS resource indices/indicators), a measurement RS resource set, for example, a CSI-RS resource set along with its indicator, a plurality of CORESETs associated with a CORESETPoolIndex, and a plurality of CORESETs associated with a TRP-specific index/indicator/identity. Furthermore, different TRPs could broadcast/be associated with different physical cell identities (PCIs) and one or more TRPs in the system could broadcast/be associated with different PCIs from that of serving cell/TRP. FIG.8illustrates an example of a beam failure event in a multi-TRP system800according to embodiments of the present disclosure. An embodiment of the beam failure event in a multi-TRP system800shown inFIG.8is for illustration only. InFIG.8, a conceptual example of BPL failure in a multi-TRP system is presented. As can be seen fromFIG.8, two TRPs, TRP-1 and TRP-2, could simultaneously transmit to the UE various RSs/channels in either a coherent or a non-coherent manner. As the two TRPs are not physically co-located, their channel conditions between the UE could be largely different from each other. For instance, the BPL between one coordinating TRP (TRP-2 inFIG.8) and the UE could fail due to blockage, while the BPL between the other coordinating TRP (TRP-1 inFIG.8) and the UE could still work. According to the BFR procedures defined in the 3GPP Rel. 15 and Rel. 16, the UE would trigger or initiate the BFR only when all the BFD RSs, and therefore, the corresponding BPLs are failed. Hence, there is a need to customize the BFR procedures for the multi-TRP system (TRP-specific BFR and/or partial BFR) such that the UE could initiate or trigger the BFR when the BFD RS(s) for at least one TRP, and therefore, the corresponding BPL(s) are failed, while the BPL(s) between the other TRP(s) in the multi-TRP system and UE are still working. FIG.9illustrates another example of a beam failure event in a multi-TRP system900according to embodiments of the present disclosure. An embodiment of the beam failure event in a multi-TRP system900shown inFIG.9is for illustration only. InFIG.9, another example of BPL failure in a multi-TRP system is presented. Different from the example shown inFIG.8, the failed BFD RSs, and therefore, the corresponding failed BPLs could be associated with more than one TRPs, and there are still working BPLs between the two TRPs and the UE. Based on the Rel. 15 and Rel. 16 BFR firing/triggering conditions, the UE would not trigger or initiate a BFR for the example shown inFIG.9because not all the BFD RSs are failed. To avoid a potential RLF, the UE could still initiate or trigger the BFR even though only a subset of the BFD RSs are failed, resulting in the so-called partial BFR design. Detailed partial BFR mechanisms and signaling support need to be specified for a multi-TRP system, which are not characterized in the prior arts. It is evident fromFIG.8andFIG.9that the TRP-specific BFR could be a special case of the partial BFR. This disclosure considers various design aspects for the TRP-specific BFR or the partial BFR in a multi-TRP system. Both multi-DCI and single-DCI based multi-TRP operations are considered, wherein the higher layer signaling index CORESETPoolIndex is configured in the multi-DCI based multi-TRP system. In the present disclosure, various TRP-specific or per TRP BFR designs are first presented for the multi-DCI based multi-TRP system, followed by various TRP-specific or per TRP BFR designs for the single-DCI based multi-TRP system. Various partial BFR strategies are also discussed in this disclosure for either the single-DCI based or the multi-DCI based multi-TRP operation. The UE could be indicated by the network that the UE could perform/conduct the TRP-specific BFR or per TRP BFR or multi-TRP BFR when other necessary conditions are met/satisfied; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. For example, a higher layer parameter, denoted by enableMtrpBfr, could be defined/used to turn on/off the TRP-specific BFR or per TRP BFR or multi-TRP BFR. The higher layer parameter enableMtrpBfr could be included/indicated in a transmission configuration indication (TCI) state (e.g., via the higher layer parameter TCI-State) or CSI resource setting (e.g., via the higher layer parameter CSI-ResourceConfig) or CSI reporting setting (e.g., via the higher layer parameter CSI-ReportConfig) or aperiodic CSI trigger/trigger state. For instance, if the UE is configured with the higher layer parameter enableMtrpBfr set to ‘enabled’, the UE could perform the TRP-specific BFR or per TRP BFR or multi-TRP BFR discussed below in the present disclosure when other necessary BFR conditions are met/satisfied. In one embodiment, TRP-specific/per TRP BFR for multi-PDCCH or multi-DCI based multi-TRP is provided. FIG.10illustrates an example TRP-specific or per TRP or partial beam failure in a multi-PDCCH or multi-DCI based multi-TRP system1000according to embodiments of the present disclosure. An embodiment of the TRP-specific or per TRP or partial beam failure in a multi-PDCCH or multi-DCI based multi-TRP system1000shown inFIG.10is for illustration only. In a multi-DCI or multi-PDCCH based multi-TRP system, the UE could receive from the network one or more PDCCHs/DCIs associated with different TRP-specific index/ID values such as CORESETPoolIndex values, PCI values and etc. Furthermore, at least two (M≥2) BFD RS (beam) sets each associated with a different TRP-specific index/ID value such as CORESETPoolIndex value or PCI could be configured. For the example shown inFIG.10, the BFD RS beam set denoted by q0-1 could be associated with TRP-1 (e.g., CORESETPoolIndex value ‘0’), and another BFD RS beam set denoted by q0-2 could be associated with TRP-2 (e.g., CORESETPoolIndex value ‘1’). Each configured BFD RS beam set could contain/comprise N≥1 BFD RS resources/beams. The UE could implicitly determine/configure the BFD RS beam sets (and therefore, the corresponding BFD RS resources/beams configured therein). Specifically, the BFD RS resource(s)/beam(s) configured in a BFD RS beam set, e.g., q0-1 or q0-2 inFIG.10, shall be configured as the QCL-typeD source RS(s) in one or more active TCI states for one or more PDCCHs transmitted from one or more CORESETs associated with a CORESETPoolIndex value—the BFD RS beam set is therefore said to be associated with the CORESETPoolIndex value. Furthermore, different BFD RS beam sets could be associated with different CORESETPoolIndex values. For the above discussed implicit configuration of the BFD RS beam sets (and therefore, the corresponding BFD RS resources/beams configured therein), various means of associating the configured BFD RS beam sets and the TRPs, e.g., via the higher layer signaling index values such as CORESETPoolIndex values are presented as follows. For example, the first BFD RS beam set in the list/pool of configured M=2 BFD RS beam sets is associated with/corresponds to CORESETPoolIndex value ‘0’, and the second BFD RS beam set in the list/pool of configured M=2 BFD RS beam sets is associated with/corresponds to CORESETPoolIndex value ‘1’. Or equivalently, the BFD RS beam set m or the m-th BFD RS beam set in the list/pool of configured M=2 BFD RS beam sets shall be associated with/correspond to CORESETPoolIndex value m, where m=1,2. That is, the BFD RS resource(s)/beam(s) configured in the BFD RS beam set m or the m-th BFD RS beam set in the list/pool of configured M=2 BFD RS beam sets shall be configured as the QCL-typeD source RS(s) in one or more active TCI states for one or more PDCCHs transmitted from one or more CORESETs associated with the CORESETPoolIndex value m−1, where m=1,2. For another example, the BFD RS beam set with the lowest BFD RS beam set index/ID value in the list/pool of configured M=2 BFD RS beam sets is associated with/corresponds to CORESETPoolIndex value ‘0’, and the BFD RS beam set with the highest BFD RS beam set index/ID value in the list/pool of configured M=2 BFD RS beam sets is associated with/corresponds to CORESETPoolIndex value ‘1’. That is, the BFD RS resource(s)/beam(s) configured in the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of configured M=2 BFD RS beam sets shall be configured as the QCL-typeD source RS(s) in one or more active TCI states for one or more PDCCHs transmitted from one or more CORESETs associated with the CORESETPoolIndex value m−1, where m=1,2. Yet for another example, the UE could be explicitly indicated by the network the exact mapping between the M=2 BFD RS beam sets and the CORESPETPoolIndex values ‘0’ and ‘1’; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. The above discussed design examples can be extended to M>2, wherein more than two BFD RS beam sets and more than two higher layer signaling index values such as CORESETPoolIndex values can be configured. For example, the BFD RS beam set m or the m-th BFD RS beam set m the list/pool of configured M>2 BFD RS beam sets shall be associated with/correspond to the higher layer signaling index value m (such as CORESETPoolIndex value m−1), where m=1, 2, . . . , M. That is, the BFD RS resource(s)/beam(s) configured in the BFD RS beam set m or the m-th BFD RS beam set in the list/pool of configured M>2 BFD RS beam sets shall be configured as the QCL-typeD source RS(s) in one or more active TCI states for one or more PDCCHs transmitted from one or more CORESETs associated with the higher layer signaling index value m (such as CORESETPoolIndex value m−1), where m=1, 2, . . . , M. For another example, the BFD RS beam set with the lowest BFD RS beam set index/ID value in the list/pool of configured M>2 BFD RS beam sets is associated with/corresponds to the higher layer signaling index value ‘0’ (such as CORESETPoolIndex value ‘0’), the BFD RS beam set with the second lowest BFD RS beam set index/ID value in the list/pool of configured M>2 BFD RS beam sets is associated with/corresponds to the higher layer signaling index value ‘1’ (such as CORESETPoolIndex value ‘1’), and so on, and the BFD RS beam set with the highest BFD RS beam set index/ID value in the list/pool of configured M>2 BFD RS beam sets is associated with/corresponds to the higher layer signaling index value ‘M−1’ (such as CORESETPoolIndex value ‘M−1’). That is, the BFD RS resource(s)/beam(s) configured in the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of configured M>2 BFD RS beam sets shall be configured as the QCL-typeD source RS(s) in one or more active TCI states for one or more PDCCHs transmitted from one or more CORESETs associated with the higher layer signaling index value m (such as CORESETPoolIndex value m−1), where m=1,2. Yet for another example, the UE could be explicitly indicated by the network the exact mapping between the M>2 BFD RS beam sets and the M>2 higher layer signaling index values such as CORESPETPoolIndex values; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. Alternatively, the UE could be explicitly indicated by the network the M≥2 BFD RS beam sets (and therefore, the BFD RS resource(s)/beam(s) configured therein); this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. For the above discussed explicit configuration of the BFD RS beam sets (and therefore, the corresponding BFD RS resources/beams configured therein), various means of associating the network configured BFD RS beam sets and the TRPs, e.g., via the TRP-specific index/ID values such as CORESETPoolIndex values or PCIs are presented as follows. For example, the first BFD RS beam set or the BFD RS beam set with the lowest BFD RS beam set index/ID value in the list/pool of network configured M≥2 BFD RS beam sets is associated with/corresponds to the first TRP-specific index/ID value in a list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, the second BFD RS beam set or the BFD RS beam set with the second lowest BFD RS beam set index/ID value in the list/pool of network configured M≥2 BFD RS beam sets is associated with/corresponds to the second TRP-specific index/ID value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, and so on, and the last (M-th) BFD RS beam set or the BFD RS beam set with the highest BFD RS beam set index/ID value in the list/pool of higher layer configured M≥2 BFD RS beam sets is associated with/corresponds to the last TRP-specific index/ID value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values. That is, the BFD RS beam set m or the m-th BFD RS beam set or the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of configured M>2 BFD RS beam sets shall be associated with/correspond to the m-th entry/TRP-specific index/ID value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, where m=1, 2, . . . , M. For another example, the first BFD RS beam set or the BFD RS beam set with the lowest BFD RS beam set index/ID value in the list/pool of network configured M≥2 BFD RS beam sets is associated with/corresponds to the lowest TRP-specific index/ID value such as the lowest CORESETPoolIndex value or PCI value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, the second BFD RS beam set or the BFD RS beam set with the second lowest BFD RS beam set index/ID value in the list/pool of higher layer configured M≥2 BFD RS beam sets is associated with/corresponds to the second lowest TRP-specific index/ID value such as the second lowest CORESETPoolIndex value or PCI value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, and so on, and the last (M-th) BFD RS beam set or the BFD RS beam set with the highest BFD RS beam set index/ID value in the list/pool of higher layer configured M≥2 BFD RS beam sets is associated with/corresponds to the highest TRP-specific index/ID value such as the highest CORESETPoolIndex value or PCI value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values. That is, the BFD RS beam set m or the m-th BFD RS beam set or the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of configured M≥2 BFD RS beam sets shall be associated with/correspond to the m-th lowest (or highest) TRP-specific index/ID value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, where m=1, 2, . . . , M. Yet for another example, the UE could be explicitly indicated by the network the exact mapping between the M≥2 BFD RS beam sets and the TRP-specific index/ID values such as CORESETPoolIndex values or PCI values; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. Optionally, the UE could be first higher layer configured by the network (e.g., via higher layer RRC signaling) a list/pool of M_tot≥2 candidate BFD RS beam sets each containing/comprising at least one candidate BFD RS resource/beam. The UE could then receive from the network at least one MAC CE activation command/bitmap to activate M≥2 BFD RS beam sets from the higher layer configured list/pool of M_tot≥2 candidate BFD RS beam sets. In one example, the UE could receive from the network a single MAC CE activation command/bitmap to activate M≥2 BFD RS beam sets from the higher layer configured list/pool of M_tot≥2 candidate BFD RS beam sets. For instance, the bitmap could contain/comprise M_tot entries/bit positions with each entry/bit position in the bitmap corresponding to an entry in the RRC configured list/pool of M_tot candidate BFD RS beam sets. If an entry/bit position in the bitmap is enabled, e.g., set to ‘1’, the corresponding entry in the RRC configured list/pool of M_tot candidate BFD RS beam sets is activated as a BFD RS beam set. The bitmap could have M≥2 entries/bit positions set to ‘1’s, hence activating a list/pool of M≥2 BFD RS beam sets from the RRC configured list/pool of M_tot candidate BFD RS beam sets. In another example, the UE could receive from the network M≥2 MAC CE activation commands/bitmaps. Each MAC CE activation command/bitmap could activate at least one BFD RS beam set from the RRC configured list/pool of M_tot candidate BFD RS beam sets. For instance, the UE could receive from the network M≥2 bitmaps. Each of the M≥2 bitmaps could contain/comprise M_tot entries/bit positions with each entry/bit position in the bitmap corresponding to an entry in the RRC configured list/pool of M_tot candidate BFD RS beam sets. If an entry/bit position in a bitmap is enabled, e.g., set to ‘1’, the corresponding entry in the RRC configured list/pool of M_tot candidate BFD RS beam sets is activated as a BFD RS beam set. Each bitmap could contain/comprise at least one entry/bit position set to ‘1’. Hence, the M≥2 MAC CE activation commands/bitmaps could contain/comprise M≥2 entries/bit positions set to ‘1’s, activating a list/pool of M≥2 BFD RS beam sets from the RRC configured list/pool of M_tot candidate BFD RS beam sets. In yet another example, the UE could receive from the network M≥2 MAC CE activation commands/bitmaps. Each MAC CE activation command/bitmap could activate at least one BFD RS beam set from the RRC configured list/pool of M_tot candidate BFD RS beam sets. Furthermore, each MAC CE activation command/bitmap could contain/comprise/indicate at least one TRP-specific index/ID value such as CORESETPoolIndex value or PCI. Alternatively, each MAC CE activation command/bitmap could contain/comprise index of at least one TRP-specific index/ID value such as CORESETPoolIndex value or PCI in the higher layer configured list/set/pool of TRP-specific index/ID values such as CORESETPoolIndex values or PCIs. TABLE 1MAC CE activation command/bitmap for BFD RS beam setsEntity index/ID value#1#2. . .#M A conceptual example of such a MAC CE activation command/bitmap is presented in TABLE 1. As illustrated in TABLE 1, the entity index/ID value could correspond to the TRP-specific index/ID value such as CORESETPoolIndex value or PCI, or the index of at least one TRP-specific index/ID value such as CORESETPoolIndex value or PCI in the higher layer configured list/set/pool of TRP-specific index/ID values such as CORESETPoolIndex values or PCIs. For instance, the UE could receive from the network M≥2 bitmaps each containing/comprising/indicating a TRP-specific index/ID value such as CORESETPoolIndex value or PCI. In addition, each of the M≥2 bitmaps could contain/comprise M_tot entries/bit positions with each entry/bit position in the bitmap corresponding to an entry in the RRC configured list/pool of M_tot candidate BFD RS beam sets. If an entry/bit position in a bitmap is enabled, e.g., set to ‘1’, the corresponding entry in the RRC configured list/pool of M_tot candidate BFD RS beam sets is activated as a BFD RS beam set. Each bitmap could contain/comprise at least one entry/bit position set to ‘1’. Hence, the M≥2 MAC CE activation commands/bitmaps could contain/comprise M≥2 entries/bit positions set to ‘1’ s, activating a list/pool of M≥2 BFD RS beam sets from the RRC configured list/pool of M_tot candidate BFD RS beam sets. For the above discussed explicit configuration/activation of the BFD RS beam sets (and therefore, the corresponding BFD RS resources/beams configured therein), various means of associating the RRC configured and MAC CE(s)/bitmap(s) activated BFD RS beam sets and the TRPs, e.g., via the TRP-specific index/ID values such as CORESETPoolIndex values or PCIs are presented as follows. For example, the first BFD RS beam set or the BFD RS beam set with the lowest BFD RS beam set index/ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 BFD RS beam sets is associated with/corresponds to the first TRP-specific index/ID value in a list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, the second BFD RS beam set or the BFD RS beam set with the second lowest BFD RS beam set index/ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 BFD RS beam sets is associated with/corresponds to the second TRP-specific index/ID value in a list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, and so on, and the last (M-th) BFD RS beam set or the BFD RS beam set with the highest BFD RS beam set index/ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 BFD RS beam sets is associated with/corresponds to the last TRP-specific index/ID value in a list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values. That is, the BFD RS beam set m or the m-th BFD RS beam set or the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 BFD RS beam sets shall be associated with/correspond to the m-th entry/TRP-specific index/ID value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, where m=1, 2, . . . , M. For instance, for M=2, the BFD RS beam set m or the m-th BFD RS beam set or the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M=2 BFD RS beam sets shall be associated with/correspond to CORESETPoolIndex value m−1, where m=1,2. For another example, the first BFD RS beam set or the BFD RS beam set with the lowest BFD RS beam set index/ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 BFD RS beam sets is associated with/corresponds to the lowest TRP-specific index/ID value such as the lowest CORESETPoolIndex value or PCI value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, the second BFD RS beam set or the BFD RS beam set with the second lowest BFD RS beam set index/ID value in the list/pool of network configured and MAC CE(s)/bitmap(s) activated M≥2 BFD RS beam sets is associated with/corresponds to the second lowest TRP-specific index/ID value such as the second lowest CORESETPoolIndex value or PCI value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, and so on, and the last (M-th) BFD RS beam set or the BFD RS beam set with the highest BFD RS beam set index/ID value in the list/pool of network configured and MAC CE(s)/bitmap(s) activated M≥2 BFD RS beam sets is associated with/corresponds to the highest TRP-specific index/ID value such as the highest CORESETPoolIndex value or PCI value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values. That is, the BFD RS beam set m or the m-th BFD RS beam set or the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 BFD RS beam sets shall be associated with/correspond to the m-th lowest (or highest) TRP-specific index/ID value in the list/set/pool of higher layer configured TRP-specific index/ID values such as CORESETPoolIndex values or PCI values, where m=1, 2, . . . , M. For instance, for M=2, the BFD RS beam set m or the m-th BFD RS beam set or the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M=2 BFD RS beam sets shall be associated with/correspond to CORESETPoolIndex value m−1, where m=1,2. Yet for another example, the UE could be explicitly indicated by the network the exact mapping between the M≥2 network configured and MAC CE(s)/bitmap(s) activated BFD RS beam sets and the TRP-specific index/ID values such as CORESETPoolIndex values or PCI values; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. Yet for another example, if the MAC CE activation command/bitmap contains/comprises/indicates a TRP-specific index/ID value such as CORESETPoolIndex value or PCI (as illustrated inFIG.8A), the BFD RS beam set activated by the MAC CE activation command/bitmap shall be associated with/correspond to the TRP-specific index/ID value such as CORESETPoolIndex value or PCI. For instance, for M=2, if the MAC CE activation command/bitmap contains/comprises/indicates CORESETPoolIndex value ‘0’, the corresponding activated BFD RS beam set (and therefore, the BFD RS resources/beams configured therein) is associated with CORETPoolIndex value ‘0’, and if the MAC CE activation command/bitmap contains/comprises/indicates CORESETPoolIndex value ‘1’, the corresponding activated BFD RS beam set (and therefore, the BFD RS resources/beams configured therein) is associated with CORETPoolIndex value ‘1’. If the received signal qualities of the BFD RSs in a (TRP-specific) BFD RS beam set are below a configured threshold for a given period of time, indicating that the hypothetical BLERs of the corresponding PDCCHs could be beyond an out-of-sync BLER threshold, the UE could perform/conduct the TRP-specific BFR or per TRP BFR or multi-TRP BFR. To evaluate the received signal qualities of the BFD RS resources/beams from a configured (TRP-specific) BFD RS beam set, the UE could be indicated/configured by the network M≥2 beam failure detection (BFD) thresholds; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. For the example shown inFIG.10, the UE could be configured by the network M=2 BFD thresholds Qout-1 and Qout-2 for comparing with the received signal qualities of the BFD RSs from the BFD RS beam sets q0-1 and q0-2, respectively. Note that Qout-1 could be the same as Qout-2. The UE could measure L1 beam metrics of the BFD RSs in q0-1 every X_1 ms, where X_1=max{minimal periodicity of the BFD RS resources/beams configured in q0-1, 2 ms}, and the BFD RSs in q0-2 every X_2 ms, where X_2=max{minimal periodicity of the BFD RS resources/beams configured in q0-2, 2 ms}. The L1 beam metric could be L1-RSRP, L1-RSRQ or L1-SINR. The UE could then compare the L1 measurements with the configured BFD thresholds. For instance, the UE could compare the measured L1-RSRPs of one or more BFD RS resources/beams in q0-1 with Qout-1, and the measured L1-RSRPs of one or more BFD RS resources/beams in q0-2 with Qout-2. The UE could also maintain M≥2 separate BFI counters, each corresponding to a configured BFD RS beam set (e.g., q0-1 or q0-2 inFIG.10). For example, if the measured L1-RSRPs of one or more BFD RSs in q0-1 are below Qout-1, the UE would increment the BFI count for the BFD RS beam set q0-1. Similarly, if the measured L1-RSRPs of one or more BFD RS resources/beams in q0-2 are below Qout-2, the UE would increment the BFI count for the BFD RS beam set q0-2. The UE could also be indicated/configured by the network M≥2 (TRP-specific) maximum numbers of BFI count each corresponding to a configured BFD RS beam set, and M≥2 (TRP-specific) BFD timers each corresponding to a configured BFD RS beam set. For the example shown inFIG.10, denote the M=2 maximum numbers of BFI count for the BFD RS beam sets q0-1 (TRP-1) and q0-2 (TRP-2) by maxBFIcount-1 and maxBFIcount-2, and the M=2 BFD timers for the BFD RS beam sets q0-1 (TRP-1) and q0-2 (TRP-2) by BFDtimer-1 and BFDtimer-2. The UE could declare a beam failure for the BFD RS beam set q0-2 (and therefore TRP-2) and indicate to the higher layers the BFD RS beam set index of q0-2, if the BFI count for the BFD RS beam set q0-2 (TRP-2) reaches maxBFIcount-2 before the expiration of BFDtimer-2. Otherwise, if BFDtimer-2 expires before the BFI count for the BFD RS beam set q0-2 satisfies maxBFIcount-2, the UE would not declare any beam failure for the BFD-RS beam set q0-2 (and therefore, TRP-2), and reset the BFI count for the BFD RS beam set q0-2. The aforementioned beam failure detection criteria for the BFD RS beam set m (m=1, 2, . . . , M) can be summarized as follows: the physical layer in the UE could assess the radio link quality of the BFD RS beam set m and indicates the BFD RS beam set index m to the higher layers in the UE every X_m ms, if the hypothetical PDCCH BLER of all the BFD RS resources/beams in the BFD RS beam set m is higher than a threshold, where X_m is max{minimal periodicity of the BFD RS resources/beams in the BFD RS beam set m, 2 ms}. If the UE has detected/declared beam failure for at least one BFD RS beam set in the list/pool of M≥2 BFD RS beam sets (i.e., the above discussed beam failure detection criteria for at least one BFD RS beam set in the list/pool of M≥2 BFD RS beam sets is achieved/met/satisfied), the UE could initiate/trigger the TRP-specific BFR or partial BFR or multi-TRP BFR by transmitting to the network a beam failure recovery request (BFRQ) along with any other necessary indications. For example, after the UE has detected beam failure for a BFD RS beam set, e.g., the BFD RS beam set q0-2 (TRP-2) inFIG.10, the UE could transmit a beam failure recovery indication (BFRI) to the working TRP, e.g., TRP-1 inFIG.10, through dedicated uplink resource(s) associated with the working TRP. The BFRI indicates the working TRP that the beam failure has been detected for at least one configured BFD RS beam set other than the BFD RS beam set associated with the working TRP. Along with the BFRI, the UE could also transmit to the working TRP the failed TRP ID, e.g., in form of the failed BFD RS beam set index/ID value or CORESETPoolIndex value, and other necessary indications/measurements. FIGS.11A and11Billustrate an example TRP-specific or per TRP or partial beam failure recovery procedure1100and1150in a multi-TRP system according to embodiments of the present disclosure.FIG.11Bis an example that is continued fromFIG.11A. Embodiments of the TRP-specific or per TRP or partial beam failure recovery procedure1100and1150shown inFIGS.11A and11Bare for illustration only. In the example shown inFIGS.11A and11B, the UE could multiplex the BFRI, failed TRP ID and other necessary information with the CSI report, HARQ/ACK, and/or other UCIs on the PUCCH(s) associated with the working TRP-1. The UE could also transmit the BFRI, failed TRP ID and other necessary information through one or more MAC CEs on the PUSCH(s) to the working TRP-1 assuming that there are available scheduled PUSCH resources. As discussed above, the UE could also transmit to the network the BFRQ for the failed BFD RS beam set(s), or equivalently the failed TRP(s) (e.g., TRP-2 inFIG.10). The transmission of BFRI to the working TRP(s) is an independent process to that of BFRQ/new beam information. Furthermore, the UE could transmit the BFRQ/new beam information to either the working TRP(s) or the failed TRP(s) through the dedicated uplink resource(s) associated with the working TRP(s) or the failed TRP(s) respectively. To detect one or more new beams for the failed TRP/BFD RS beam set, the UE could be indicated by the network M≥2 NBI RS beam sets each containing/comprising at least one NBI RS resource/beam; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. Furthermore, the NBI RS resource(s)/beam(s) in a NBI RS beam set could be a set of SSB and/or CSI-RS resource(s)/beam(s). The M≥2 NBI RS beam sets could have one-to-one correspondence to the M≥2 BFD RS beam sets or the M≥2 TRPs in the multi-TRP system. For the example shown inFIG.10, the NBI RS beam set denoted by q1-1 could be associated with TRP-1 (or the BFD RS beam set q0-1), and another NBI RS beam set denoted by q1-2 could be associated with TRP-2 (or the BFD RS beam set q0-2). Various means of associating the network configured NBI RS beam sets and the BFD RS beam sets are presented as follows. For example, the first NBI RS beam set or the NBI RS beam set with the lowest NBI RS beam set index/ID value in the list/pool of network configured M≥2 NBI RS beam sets is associated with/corresponds to the first BFD RS beam set or the BFD RS beam set with the lowest BFD RS beam set index/ID value in the list/pool of network configured M≥2 BFD RS beam sets, the second NBI RS beam set or the NBI RS beam set with the second lowest NBI RS beam set index/ID value in the list/pool of network configured M≥2 NBI RS beam sets is associated with/corresponds to the second BFD RS beam set or the BFD RS beam set with the second lowest BFD RS beam set index/ID value in the list/pool of network configured M≥2 BFD RS beam sets, and so on, and the last (M-th) NBI RS beam set or the NBI RS beam set with the highest NBI RS beam set index/ID value in the list/pool of higher layer configured M≥2 NBI RS beam sets is associated with/corresponds to the last (M-th) BFD RS beam set or the BFD RS beam set with the highest BFD RS beam set index/ID value in the list/pool of network configured M≥2 BFD RS beam sets. That is, the NBI RS beam set m or the m-th NBI RS beam set or the NBI RS beam set with the m-th lowest (or highest) NBI RS beam set ID value in the list/pool of configured M≥2 NBI RS beam sets shall be associated with/correspond to the BFD RS beam set m or the m-th BFD RS beam set or the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of configured M≥2 BFD RS beam sets, where m=1, 2, . . . , M. For another example, the UE could be explicitly indicated by the network the exact mapping between the M≥2 NBI RS beam sets and the M≥2 BFD RS beam sets; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. Optionally, the UE could be first higher layer configured by the network (e.g., via higher layer RRC signaling) a list/pool of M_tot≥2 candidate NBI RS beam sets each containing/comprising at least one candidate NBI RS resource/beam. The UE could then receive from the network at least one MAC CE activation command/bitmap to activate M≥2 NBI RS beam sets from the higher layer configured list/pool of M_tot≥2 candidate NBI RS beam sets. This MAC CE activation command/bitmap could be the same as that (as shown in TABLE 1) used for activating the M≥2 BFD RS beam sets from the higher layer configured list/pool of M_tot≥2 candidate BFD RS beam sets. In one example, the UE could receive from the network a single MAC CE activation command/bitmap to activate M≥2 NBI RS beam sets from the higher layer configured list/pool of M_tot≥2 candidate NBI RS beam sets. For instance, the bitmap could contain/comprise M_tot entries/bit positions with each entry/bit position in the bitmap corresponding to an entry in the RRC configured list/pool of M_tot candidate NBI RS beam sets. If an entry/bit position in the bitmap is enabled, e.g., set to ‘1’, the corresponding entry in the RRC configured list/pool of M_tot candidate NBI RS beam sets is activated as a NBI RS beam set. The bitmap could have M≥2 entries/bit positions set to ‘1’s, hence activating a list/pool of M≥2 NBI RS beam sets from the RRC configured list/pool of M_tot candidate NBI RS beam sets. In another example, the UE could receive from the network M≥2 MAC CE activation commands/bitmaps. Each MAC CE activation command/bitmap could activate at least one NBI RS beam set from the RRC configured list/pool of M_tot candidate NBI RS beam sets. For instance, the UE could receive from the network M≥2 bitmaps. Each of the M≥2 bitmaps could contain/comprise M_tot entries/bit positions with each entry/bit position in the bitmap corresponding to an entry in the RRC configured list/pool of M_tot candidate NBI RS beam sets. If an entry/bit position in a bitmap is enabled, e.g., set to ‘1’, the corresponding entry in the RRC configured list/pool of M_tot candidate NBI RS beam sets is activated as a NBI RS beam set. Each bitmap could contain/comprise at least one entry/bit position set to ‘1’. Hence, the M≥2 MAC CE activation commands/bitmaps could contain/comprise M≥2 entries/bit positions set to ‘1’s, activating a list/pool of M≥2 NBI RS beam sets from the RRC configured list/pool of M_tot candidate NBI RS beam sets. In yet another example, the UE could receive from the network M≥2 MAC CE activation commands/bitmaps. Each MAC CE activation command/bitmap could activate at least one NBI RS beam set from the RRC configured list/pool of M_tot candidate NBI RS beam sets. Furthermore, each MAC CE activation command/bitmap could contain/comprise/indicate at least one TRP-specific index/ID value such as CORESETPoolIndex value or PCI. Alternatively, each MAC CE activation command/bitmap could contain/comprise index of at least one TRP-specific index/ID value such as CORESETPoolIndex value or PCI in the higher layer configured list/set/pool of TRP-specific index/ID values such as CORESETPoolIndex values or PCIs. Optionally, each MAC CE activation command/bitmap could also contain/comprise at least one BFD RS beam set index/ID value. As discussed above, the format of the MAC CE activation command/bitmap could be the same as that presented in TABLE 1. Here, the entity index/ID value shown in TABLE 1 could correspond to the TRP-specific index/ID value such as CORESETPoolIndex value or PCI, the index of at least one TRP-specific index/ID value such as CORESETPoolIndex value or PCI in the higher layer configured list/set/pool of TRP-specific index/ID values such as CORESETPoolIndex values or PCIs, or the BFD RS beam set index/ID value. For instance, the UE could receive from the network M≥2 bitmaps each containing/comprising/indicating a BFD RS beam set index/ID value. In addition, each of the M≥2 bitmaps could contain/comprise M_tot entries/bit positions with each entry/bit position in the bitmap corresponding to an entry in the RRC configured list/pool of M_tot candidate NBI RS beam sets. If an entry/bit position in a bitmap is enabled, e.g., set to ‘1’, the corresponding entry in the RRC configured list/pool of M_tot candidate NBI RS beam sets is activated as a NBI RS beam set. Each bitmap could contain/comprise at least one entry/bit position set to ‘1’. Hence, the M≥2 MAC CE activation commands/bitmaps could contain/comprise M≥2 entries/bit positions set to ‘1’s, activating a list/pool of M≥2 NBI RS beam sets from the RRC configured list/pool of M_tot candidate NBI RS beam sets. For the above discussed explicit configuration/activation of the NBI RS beam sets (and therefore, the corresponding NBI RS resources/beams configured therein), various means of associating the RRC configured and MAC CE(s)/bitmap(s) activated NBI RS beam sets and the BFD RS beam sets are presented as follows. For example, the first NBI RS beam set or the NBI RS beam set with the lowest NBI RS beam set index/ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 NBI RS beam sets is associated with/corresponds to the first BFD RS beam set or the BFD RS beam set with the lowest BFD RS beam set index/ID value in the list/pool of M≥2 BFD RS beam sets, the second NBI RS beam set or the NBI RS beam set with the second lowest NBI RS beam set index/ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 NBI RS beam sets is associated with/corresponds to the second BFD RS beam set or the BFD RS beam set with the second lowest BFD RS beam set index/ID value in the list/pool of M≥2 BFD RS beam sets, and so on, and the last (M-th) NBI RS beam set or the NBI RS beam set with the highest NBI RS beam set index/ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 NBI RS beam sets is associated with/corresponds to the last (M-th) BFD RS beam set or the BFD RS beam set with the highest BFD RS beam set index/ID value in the list/pool of M≥2 BFD RS beam sets. That is, the NBI RS beam set m or the m-th NBI RS beam set or the NBI RS beam set with the m-th lowest (or highest) NBI RS beam set ID value in the list/pool of RRC configured and MAC CE(s)/bitmap(s) activated M≥2 NBI RS beam sets shall be associated with/correspond to the BFD RS beam set m or the m-th BFD RS beam set or the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the M≥2 BFD RS beam sets, where m=1, 2, . . . , M. For another example, the UE could be explicitly indicated by the network the exact mapping between the M≥2 network configured and MAC CE(s)/bitmap(s) activated NBI RS beam sets and the M≥2 BFD RS beam sets; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. Yet for another example, if the MAC CE activation command/bitmap contains/comprises/indicates a BFD RS beam set index/ID value, the NBI RS beam set activated by the MAC CE activation command/bitmap shall be associated with/correspond to the BFD RS beam set with the indicated BFD RS beam set index/ID value. To facilitate the detection of the new beam(s), the UE could also be indicated by the network M≥2 (TRP-specific) beam failure recovery (BFR) thresholds. For the example shown inFIG.10, the UE could be configured by the network M=2 BFR thresholds Qin-1 and Qin-2 for detecting potential new beam(s) for TRP-1 and/or TRP-2 (or the BFD RS beam sets q0-1 and/or q0-2), respectively. The UE could measure L1 beam metrics of the NBI RSs configured in q1-1 or q1-2 or both, depending on the failed TRP(s)/BFD RS beam set(s). The L1 beam metric could be L1-RSRP, L1-RSRQ or L1-SINR. The UE could then compare the L1 measurements of one or more of the NBI RSs with the configured BFR threshold(s). For the example shown inFIG.10(the BFD RS beam set q0-2 or TRP-2 is failed), the UE could compare the measured L1-RSRPs of one or more NBI RSs in q1-2 with Qin-2. If the measured L1-RSRP of a NBI RS in q1-2 is beyond Qin-2, and is the largest among all the measured L1-RSRPs of the one or more NBI RSs in q1-2, the UE could identify/determine the resource/beam associated with the NBI RS as the new beam for the failed BFD RS beam set q0-2. Various means of computing/calculating the index of the selected NBI RS/beam are presented as follows. In one example N.1, the (resource) index of the selected NBI RS or the new beam is determined based on/according to all the NBI RS resources/beams configured in the corresponding NBI RS beam set, from which the NBI RS or the new beam is selected. For instance, if the selected NBI RS or the new beam corresponds to the k-th entry/RS resource in NBI RS beam set m (m∈{1, 2, . . . , M}) comprising a total of K(m) entries/RS resources, the (resource) index of the selected NBI RS or the new beam could then be computed/calculated as k∈{1, . . . , K(m)}. In another example N.2, the (resource) index of the selected NBI RS or the new beam is determined based on/according to all the NBI RS resources/beams configured in all M≥2 NBI RS beam sets. For instance, if the selected NBI RS or the new beam corresponds to the k-th entry/RS resource in NBI RS beam set m (m∈{1, 2, . . . , M}) comprising a total of K(m) entries/resources, the (resource) index of the selected NBI RS or the new beam could then be computed/calculated as Σi=1m-1K(i)+k with k∈{1, . . . , K(m)}. The use of example N.1 or example N.2 to compute/calculate/determine the index of the selected NBI RS/beam could be: (1) fixed in the system specifications, e.g., using example N.1, (2) indicated/configured by the network, or (3) autonomously determined by the UE. After identifying the new beam for the failed TRP/BFD RS beam set, the UE could transmit to the network the BFRQ or the new beam information for the failed TRP/BFD RS beam set. As illustrated inFIG.11, the UE could transmit to the failed TRP-2 the BFRQ through a CF PRACH resource, whose resource index is associated with the newly identified beam. In addition, the UE could also indicate the working TRP-1 that “a new beam has been identified for the failed TRP-2/BFD RS beam set q0-2” through UCI multiplexing on the PUCCH and/or MAC CE on the PUSCH associated with TRP-1. Four slots after the UE has transmitted the BFRQ to TRP-2, the UE could start to monitor a dedicated CORESET/search space transmitted from the failed TRP-2 for BFRQ response (BFRR). The dedicated CORESET is addressed to the UE-specific C-RNTI, and is transmitted with the newly identified beam. If the UE could detect a valid UE-specific DCI in the dedicated CORESET for BFRR, the UE would assume that the beam failure recovery request has been successfully received by the failed TRP, and the UE would complete the BFR process for TRP-2. The UE could also be indicated by the network M≥2 (TRP-specific) BFR timers. For the example shown inFIG.10, denote BFRtimer-1 and BFRtimer-2 as the M=2 BFR timers for TRP-1/BFD RS beam set q0-1 and TRP-2/BFD RS beam set q0-2, respectively. If the UE could not receive the BFRR or successfully identify a new beam before BFRtimer-2 expires, the UE would initiate a contention based (CB) random access (RA) process to reconnect to the network. As shown inFIG.11, the UE could also indicate the working TRP-1 whether the UE has completed the BFR process with the failed TRP-2. Alternatively, the UE could transmit the BFRQ to the network in form of a scheduling request (SR) over the PUCCH associated with either the working TRP(s) or the failed TRP(s). The UE could be indicated by the network an uplink grant in response to the BFRQ SR, which would allocate necessary resources for at least one MAC CE for BFR. The BFR MAC CE(s) from the UE could include/contain/comprise at least one of the following. The new beam information/index for the failed TRP(s)/BFD RS beam set(s) (if identified); for instance, if identified, the new beam index could be the index of the selected NBI RS resource/beam in the NBI RS beam set associated with the failed BFD RS beam set; the index of the selected NBI RS resource/beam could be computed/calculated/determined according to the aforementioned design example N.1 or example N.2; furthermore, the index of the selected NBI RS resource/beam could be a resource indicator such as a SSBRI or a CRI depending on the resource type(s) in the NBI RS beam set associated with the failed BFD RS beam set. The failed TRP ID; for instance, the failed TRP ID could be in form of the corresponding BFD RS beam set index/ID value; alternatively, the failed TRP ID could be the corresponding CORESETPoolIndex or PCI value. An indicator to indicate whether at least a new beam has been identified for the failed TRP(s)/BFD RS beam set(s); for instance, a one-bit indicator could be used with ‘1’ indicating that at least one new beam has been identified for the failed TRP(s)/BFD RS beam set(s) and ‘0’ indicating otherwise. If the index of the selected NBI RS resource/beam is computed/calculated/determined according to the aforementioned design example N.2, the BFR MAC CE(s) from the UE could also include/contain/comprise the index/ID value of the NBI RS beam set, from which the NBI RS resource or the new beam is selected. For instance, if the NBI RS or the new beam is selected from NBI RS beam set m∈{1, 2, . . . , M}, the NBI RS beam set index/ID m is reported in the BFR MAC CE(s). If the index of the selected NBI RS resource/beam is computed/calculated/determined according to the aforementioned design example N.2 and the index/ID value of the NBI RS beam set, from which the NBI RS or the new beam is selected, is not reported or absent in the BFR MAC CE(s), the UE could indicate to the network the association/mapping between the reported indices of the selected NBI RS(s)/new beam(s) and the reported failed TRP IDs (e.g., in form of failed BFD RS beam set indices or CORESETPoolIndex values). Furthermore, if the number of reported indices of the selected NBI RS(s)/new beams and the number of reported failed TRP IDs (e.g., in form of failed BFD RS beam set indices or CORESETPoolIndex values) are not equal, the UE could also indicate to the network the association/mapping between the reported indices of the selected NBI RS(s)/new beam(s) and the reported failed TRP IDs (e.g., in form of failed BFD RS beam set indices or CORESETPoolIndex values). Optionally, the UE could be configured by the network more than one MAC CEs for BFR (e.g., M≥2 BFR MAC CEs). Various means of associating the M≥2 BFD RS beam sets and the M≥2 BFR MAC CEs are presented as follows. Each BFR MAC CE could contain/include/comprise an entity ID. In one example, the first configured BFR MAC CE or the BFR MAC CE with the lowest entity ID value could correspond to the first BFD RS beam set in the list/pool of M≥2 BFD RS beam sets, the second configured BFR MAC CE or the BFR MAC CE with the second lowest entity ID value could correspond to the second BFD RS beam set in the list/pool of M≥2 BFD RS beam sets, and so on, and the last (M-th) configured BFR MAC CE or the BFR MAC CE with the highest entity ID value could correspond to the last (M-th) BFD RS beam set in the list/pool of M≥2 BFD RS beam sets. That is, the m-th configured MAC CE for BFR, or the BFR MAC CE with the m-th lowest (or highest) entity ID value could correspond to the m-th BFD RS beam set or BFD RS beam set m in the list/pool of M≥2 BFD RS beam sets. In another example, the first configured BFR MAC CE or the BFR MAC CE with the lowest entity ID value could correspond to the BFD RS beam set with the lowest BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets, the second configured BFR MAC CE or the BFR MAC CE with the second lowest entity ID value could correspond to the BFD RS beam set with the second lowest BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets, and so on, and the last (M-th) configured BFR MAC CE or the BFR MAC CE with the highest entity ID value could correspond to the BFD RS beam set with the highest BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets. That is, the m-th BFR MAC CE, or the BFR MAC CE with the m-th lowest (or highest) entity ID value could correspond to the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets. In yet another example, the UE could be explicitly indicated by the network the exact mapping between the M≥2 BFD RS beam sets and the M≥2 BFR MAC CEs; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. In yet another example, the entity ID contained/comprised in a BFR MAC CE could correspond to a TRP-specific index/ID value such as CORESETPoolIndex value or PCI. Alternatively, the entity ID contained/comprised in a BFR MAC CE could correspond to a BFD RS beam set index/ID value. That is, a BFR MAC CE is associated with a BFD RS beam set if they are associated with the same TRP-specific index/ID value such as CORESETPoolIndex value or PCI or the same BFD RS beam set index/ID value. In addition, the UE could also indicate to the working TRP(s)—e.g., via MAC CE over one or more PUSCHs scheduled for the working TRP(s)—at least one of the following: the new beam information/index for the failed TRP/BFD RS beam set, the failed TRP ID in form of the failed BFD RS beam set index/ID value or other necessary information. After transmitting the MAC CE for BFR to the network, the UE could start to monitor the BFRR. The BFRR could be a TCI state indication for a PDCCH transmitted from a CORESET associated with the failed BFD RS beam set. As discussed above, a CORESET and a BFD RS beam set could be associated via the CORESETPoolIndex value. The BFRR to the MAC CE for BFR could also be a normal uplink grant for scheduling a new transmission for the same HARQ process as the PUSCH carrying the MAC CE for BFR. As discussed above, the UE could send to the network multiple (more than one) BFR MAC CEs each corresponding to a failed BFD RS beam set. In addition, for the multi-TRP BFR, the UE could also indicate to the network multiple (more than one) new beam indices or multiple (more than one) failed BFD RS beam set indices/IDs. Hence, the UE could receive from the network a single BFRR for all the (failed) BFD RS beam sets. For example, the BFRR could be a dedicated CORESET/search space addressed to the UE-specific C-RNTI, and transmitted using the newly identified beam. For another example, the BFRR could be a TCI state indication for a PDCCH transmitted from a CORESET associated with a failed BFD RS beam set. For another example, the BFRR could be an uplink grant for scheduling a new transmission for the same HARQ process (e.g., with the same HARQ process ID) as the PUSCH carrying the MAC CE for the multi-TRP BFR. Alternatively, the UE could receive from the network multiple (more than one) BFRRs each for a (failed) BFD RS beam set. For example, the BFRR for the (failed) BFD RS beam set m could be a dedicated CORESET/search space associated with the BFD RS beam set m (e.g., via the association between the CORESETPoolIndex values and the BFD RS beam sets discussed above) addressed to the UE-specific C-RNTI, and transmitted using the newly identified beam, where m∈{1, 2, . . . , M}. For another example, the BFRR for the (failed) BFD RS beam set m could be a TCI state indication for a PDCCH transmitted from a CORESET associated with the BFD RS beam set m (e.g., via the association between the CORESETPoolIndex values and the BFD RS beam sets discussed above), where m∈{1, 2, . . . , M}. Yet for another example, the BFRR for the (failed) BFD RS beam set m could be an uplink grant for scheduling a new transmission for the same HARQ process (e.g., with the same HARQ process ID) as the PUSCH associated with the BFD RS beam set m carrying the MAC CE for the BFD RS beam set m, where m∈{1, 2, . . . , M}. The association between a PUSCH and a BFD RS beam set could be via the association between the CORESET/PDCCH scheduling the PUSCH and the BFD RS beam set (e.g., via the association between the CORESETPoolIndex values and the BFD RS beam sets discussed above). The use of a single BFRR for all the (failed) BFD RS beam sets or multiple (more than one) BFRRs each for a (failed) BFD RS beam set could be: (1) fixed in the system specifications, e.g., using a single BFRR for all the (failed) BFD RS beam sets, (2) indicated/configured by the network, or (3) autonomously determined by the UE. If the UE could receive the BFRR(s) before BFR timer expires, the UE could consider the BFR procedure for the failed TRP(s) is successfully completed. Otherwise, if the UE could not receive the BFRR(s) before the corresponding BFR timer expires, the UE could transmit the BFRQ again via the PUCCH associated with either the failed TRP(s) or the working TRP(s), or fall back to the CBRA process. In addition to not receiving the BFRR(s) before the corresponding BFR timer expires, the CBRA could also be triggered according to at least one of the following. In one example, the CBRA is triggered/initiated if at least two BFD RS beam sets are failed within a time window, i.e., the maximum number of BFI count is achieved for each of the at least two BFD RS beam sets within a time window. The time window could be: (1) fixed in the system specifications, (2) configured/indicated by the network, or (3) autonomously determined by the UE. In another example, the CBRA is triggered/initiated if at least one BFD RS beam set is failed, i.e., the maximum number of BFI count is achieved for the at least one BFD RS beam set, and the UE is not configured by the network any SR-PUCCH for/to transmit the BFRQ for the failed BFD RS beam set. In yet another example, the CBRA is triggered/initiated if at least one BFD RS beam set is failed, i.e., the maximum number of BFI count is achieved for the at least one BFD RS beam set, and the UE does not receive from the network any uplink grant to the SR-PUCCH for BFRQ before the corresponding BFR timer associated with the failed BFD RS beam set expires. In yet another example, the CBRA is triggered/initiated if at least one specific/predefined BFD RS beam set is failed, i.e., the maximum number of BFI count is achieved for the at least one specific/predefined BFD RS beam set. For example, the specified/predefined BFD RS beam set(s) or the index(s)/ID(s) of the specific/predefined BFD RS beam set(s) is fixed in the system specifications. E.g., the index/ID of the specific/predefined BFD RS beam set shall be 1. For another example, the specified/predefined BFD RS beam set(s) or the index(s)/ID(s) of the specific/predefined BFD RS beam set(s) shall be indicated by the network; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. Yet for another example, the UE could autonomously determine the specified/predefined BFD RS beam set(s) or the index(s)/ID(s) of the specific/predefined BFD RS beam set(s). The UE could be indicated by the network a list/set/pool of M≥2 BFR parameters, with the m-th entry/BFR parameter in the list/set/pool of BFR parameters denoted as BFR parameter-m with m=1, 2, . . . , M. In the present disclosure, the BFR parameter-m could correspond to Qout-m (BFD threshold), BFDtimer-m (BFD timer), Qin-m (BFR threshold), BFRtimer-m (BFR timer), maxBFIcount-m (maximum number of BFI count) or NBI RS beam set m. There could be various means to associate the M≥2 BFD RS beam sets and the M≥2 BFR parameters parameter-m's, and the M≥2 BFD RS beam sets and the M≥2 BFR parameters could have one-to-one correspondence. Here, the M≥2 BFD RS beam sets could be configured by RRC or configured by RRC and activated by MAC CE(s)/bitmap(s). In one example, the first entry/BFR parameter or the BFR parameter with the lowest BFR parameter index/ID value in the list/set/pool of BFR parameters could correspond to the first BFD RS beam set in the list/pool of M≥2 BFD RS beam sets, the second entry/BFR parameter or the BFR parameter with the second lowest BFR parameter index/ID value in the list/set/pool of BFR parameters could correspond to the second BFD RS beam set in the list/pool of M≥2 BFD RS beam sets, and so on, and the last (M-th) entry/BFR parameter or the BFR parameter with the highest BFR parameter index/ID value in the list/set/pool of BFR parameters could correspond to the last (M-th) BFD RS beam set in the list/pool of M≥2 BFD RS beam sets. That is, the m-th entry/BFR parameter, i.e., BFR parameter-m, or the BFR parameter with the m-th lowest (or highest) BFR parameter index/ID value in the list/set/pool of M≥2 BFR parameters could correspond to the m-th BFD RS beam set or BFD RS beam set m in the list/pool of M≥2 BFD RS beam sets. In another example, the first entry/BFR parameter or the BFR parameter with the lowest BFR parameter index/ID value in the list/set/pool of BFR parameters could correspond to the BFD RS beam set with the lowest BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets, the second entry/BFR parameter or the BFR parameter with the second lowest BFR parameter index/ID value in the list/set/pool of BFR parameters could correspond to the BFD RS beam set with the second lowest BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets, and so on, and the last (M-th) entry/BFR parameter or the BFR parameter with the highest BFR parameter index/ID value in the list/set/pool of BFR parameters could correspond to the BFD RS beam set with the highest BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets. That is, the m-th entry/BFR parameter, i.e., BFR parameter-m, or the BFR parameter with the m-th lowest (or highest) BFR parameter index/ID value in the list/set/pool of M≥2 BFR parameters could correspond to the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets. In yet another example, the UE could be explicitly indicated by the network the exact mapping between the M≥2 BFD RS beam sets and the M≥2 BFR parameters; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. Alternatively, the UE could be first configured by the network (e.g., via higher layer RRC signaling) a list/set/pool of M_tot candidate BFR parameters. The UE could then receive from the network at least one MAC CE activation command/bitmap to activate M≥2 BFR parameters from the higher layer configured list/pool of M_tot≥2 candidate BFR parameters. In one example, the UE could receive from the network a single MAC CE activation command/bitmap to activate M≥2 BFR parameters from the higher layer configured list/pool of M_tot≥2 candidate BFR parameters. For instance, the bitmap could contain/comprise M_tot entries/bit positions with each entry/bit position in the bitmap corresponding to an entry in the RRC configured list/pool of M_tot candidate BFR parameters. If an entry/bit position in the bitmap is enabled, e.g., set to ‘1’, the corresponding entry in the RRC configured list/pool of M_tot candidate BFR parameters is activated as a BFR parameter. The bitmap could have M≥2 entries/bit positions set to ‘1’s, hence activating a list/pool of M≥2 BFR parameters from the RRC configured list/pool of M_tot candidate BFR parameters. In another example, the UE could receive from the network M≥2 MAC CE activation commands/bitmaps. Each MAC CE activation command/bitmap could activate at least one BFR parameter from the RRC configured list/pool of M_tot candidate BFR parameters. For instance, the UE could receive from the network M≥2 bitmaps. Each of the M≥2 bitmaps could contain/comprise M_tot entries/bit positions with each entry/bit position in the bitmap corresponding to an entry in the RRC configured list/pool of M_tot candidate BFR parameters. If an entry/bit position in a bitmap is enabled, e.g., set to ‘1’, the corresponding entry in the RRC configured list/pool of M_tot candidate BFR parameters is activated as a BFR parameter. Each bitmap could contain/comprise at least one entry/bit position set to ‘1’. Hence, the M≥2 MAC CE activation commands/bitmaps could contain/comprise M≥2 entries/bit positions set to ‘1’s, activating a list/pool of M≥2 BFR parameters from the RRC configured list/pool of M_tot candidate BFR parameters. In yet another example, the UE could receive from the network M≥2 MAC CE activation commands/bitmaps. Each MAC CE activation command/bitmap could activate at least one BFR parameter from the RRC configured list/pool of M_tot candidate BFR parameters. Furthermore, each MAC CE activation command/bitmap could contain/comprise/indicate at least one TRP-specific index/ID value such as CORESETPoolIndex value or PCI. Alternatively, each MAC CE activation command/bitmap could contain/comprise index of at least one TRP-specific index/ID value such as CORESETPoolIndex value or PCI in the higher layer configured list/set/pool of TRP-specific index/ID values such as CORESETPoolIndex values or PCIs. Optionally, each MAC CE activation command/bitmap could contain/comprise a BFD RS beam set index/ID value. A conceptual example of such a MAC CE activation command/bitmap is presented in TABLE 1. As illustrated in TABLE 1, the entity index/ID value could correspond to the TRP-specific index/ID value such as CORESETPoolIndex value or PCI, the index of at least one TRP-specific index/ID value such as CORESETPoolIndex value or PCI in the higher layer configured list/set/pool of TRP-specific index/ID values such as CORESETPoolIndex values or PCIs, or the BFD RS beam set index/ID value. There could be various means to associate the M≥2 BFD RS beam sets and the M≥2 RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters parameter-m's, and the M≥2 BFD RS beam sets and the M≥2 RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters have one-to-one correspondence. Here, the M≥2 BFD RS beam sets could be configured by RRC or configured by RRC and activated by MAC CE(s)/bitmap(s). In one example, the first entry/BFR parameter or the BFR parameter with the lowest BFR parameter index/ID value in the list/set/pool of RRC configured and MAC CE(s)/bitmap(s) activated BRF parameters could correspond to the first BFD RS beam set in the list/pool of M≥2 BFD RS beam sets, the second entry/BFR parameter or the BFR parameter with the second lowest parameter index/ID value in the list/set/pool of RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters could correspond to the second BFD RS beam set in the list/pool of M≥2 BFD RS beam sets, and so on, and the last (M-th) entry/BFR parameter or the BFR parameter with the highest BFR parameter index/ID value in the list/set/pool of RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters could correspond to the last (M-th) BFD RS beam set in the list/pool of M≥2 BFD RS beam sets. That is, the m-th entry/BFR parameter, i.e., BFR parameter-m, or the BFR parameter with the m-th lowest (or highest) parameter index/ID value in the list/set/pool of M≥2 RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters could correspond to the m-th BFD RS beam set or BFD RS beam set m in the list/pool of M≥2 BFD RS beam sets. In another example, the first entry/BFR parameter or the BFR parameter with the lowest BFR parameter index/ID value in the list/set/pool of RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters could correspond to the BFD RS beam set with the lowest BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets, the second entry/BFR parameter or the BFR parameter with the second lowest BFR parameter index/ID value in the list/set/pool of RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters could correspond to the BFD RS beam set with the second lowest BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets, and so on, and the last (M-th) entry/BFR parameter or the BFR parameter with the highest BFR parameter index/ID value in the list/set/pool of RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters could correspond to the BFD RS beam set with the highest BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets. That is, the m-th entry/BFR parameter, i.e., BFR parameter-m, or the BFR parameter with the m-th lowest (or highest) BFR parameter index/ID value in the list/set/pool of M≥2 RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters could correspond to the BFD RS beam set with the m-th lowest (or highest) BFD RS beam set ID value in the list/pool of M≥2 BFD RS beam sets. In yet another example, the UE could be explicitly indicated by the network the exact mapping between the M≥2 BFD RS beam sets and the M≥2 RRC configured and MAC CE(s)/bitmap(s) activated BFR parameters; this indication could be via higher layer (RRC) or/and MAC CE or/and DCI based signaling or/and any combination of at least two of RRC, MAC CE and DCI based signaling; this indication could be via a separate (dedicated) parameter or joint with another parameter. FIG.12illustrates another example TRP-specific or per TRP or partial beam failure in a multi-PDCCH or multi-DCI based multi-TRP system1200according to embodiments of the present disclosure. An embodiment of the TRP-specific or per TRP or partial beam failure in a multi-PDCCH or multi-DCI based multi-TRP system1200shown inFIG.12is for illustration only. InFIG.12, an illustrative example of a multi-DCI/PDCCH based multi-TRP system is presented under a carrier aggregation (CA) framework. As can be seen fromFIG.12, both PCell and SCell are deployed at TRP-1, and the UE could declare beam failure for TRP-1 SCell. Different from the examples shown inFIG.10andFIG.11, the UE inFIG.12could still communicate with TRP-1 through its PCell, and initiate/complete the BFR procedure for TRP-1 SCell. Furthermore, as shown inFIG.12, the UE could still communicate with TRP-2, and indicate TRP-2 necessary beam failure recovery status/information of TRP-1 SCell. Similar to those provided inFIG.10, the TRP-specific configurations are also given inFIG.12for both TRP-1 and TRP-2. Different from those given inFIG.10, TRP-1 inFIG.12has two sets of TRP-specific configurations. One corresponds to TRP-1 PCell and the other corresponds to TRP-1 SCell. FIGS.13A and13Billustrate an example TRP-specific or per TRP or partial beam failure recovery procedure1300and1350in a multi-TRP system according to embodiments of the present disclosure.FIG.13Bis an example that is continued fromFIG.13A. An embodiment of the TRP-specific or per TRP or partial beam failure recovery procedure1300and1350shown inFIGS.13A and13Bare for illustration only. InFIGS.13A and13B, the BFR procedure for TRP-1 SCell in the multi-DCI/PDCCH based multi-TRP system inFIG.12is illustrated. Similar to the BFR procedure illustrated inFIGS.11A and11B, the UE inFIGS.13A and13Bcould also indicate to the working TRP, i.e., TRP-2 in this example, the necessary BFR status/information of the failed TRP-1 SCell so that the working TRP-1 could adjust its DL transmissions to the UE accordingly. In contrast to the BFR procedure for the failed TRP shown inFIGS.13A and13B, the UE inFIGS.11A and11Bwould use different signaling mediums to initiate and complete a different BFR procedure for the failed TRP SCell through the same TRP PCell. As can be seen fromFIGS.13A and13B, after declaring/detecting the beam failure for the TRP-1 SCell, the UE would transmit the BFRQ as a SR over the PUCCH associated with the working TRP-1 PCell. At this stage, the UE would only transmit the BFRQ without incorporating any new beam information and/or failed SCell index. This is different from the design example shown inFIGS.11A and11B, in which the UE would send both the BFRQ and the new beam information to the failed TRP through the CF BFR-PRACH. The UE could be indicated by TRP-1 PCell an uplink grant in response to the BFRQ SR, which would allocate necessary resources for the MAC CE to carry the new beam index for the failed TRP-1 SCell (if identified), failed SCell index (or index of the component carrier (CC) that contains the failed TRP/BFD RS beam set) and other necessary information. To identify one or more new beams for the failed TRP-1 SCell, the UE would compare the L1-RSRPs of all the NBI RSs in q1-1s with Qin-1s. If the L1-RSRP of a particular NBI RS in q1-1s is beyond Qin-1s and is the largest among those of all the NBI RSs in q1-1s, the UE would identify the beam associated with the particular NBI RS as the new beam for the failed TRP-1 SCell. The UE could then indicate to TRP-1 PCell about the newly identified beam, the failed SCell index and other necessary information through the MAC CE signaling over the scheduled PUSCH for TRP-1 PCell. After transmitting the MAC CE for BFR to TRP-1 PCell, the UE would start to monitor the BFRR. The BFRR could be a TCI state indication for a CORESET for TRP-1 SCell. The BFRR to the MAC CE for BFR could also be a normal uplink grant for scheduling a new transmission for the same HARQ process as the PUSCH carrying the MAC CE for BFR. If the UE could receive the BFRR before BFRtimer-1s expires, the UE would consider the BFR procedure for the failed TRP-1 SCell is successfully completed. Otherwise, if the UE could not receive the BFRR before the timer BFRtimer-1s expires, the UE could transmit the BFRQ again via the PUCCH for TRP-1 PCell or fall back to the CBRA process. During the entire BFR procedure for the failed TRP-1 SCell, the UE could also indicate to the working TRP-2 the status and/or configurations of the BFR for the failed TRP-1 SCell. As can be seen fromFIGS.13A and13B, the UE could indicate to the working TRP-2 (via the BFRI) that the UE has declared beam failure for the TRP-1 SCell. The UE could also send the failed TRP ID in form of the failed BFD RS beam set index/ID value and failed TRP SCell index in form of the index of the CC containing the failed TRP SCell to the working TRP through its associated PUCCH and/or PUSCH. Further, the UE could also indicate to the working TRP-2 whether the UE has identified a new beam for the failed TRP-1 SCell and/or whether the UE has successfully completed the BFR procedure for the failed TRP-1 SCell. According to the above information, the working TRP-2 could adjust/optimize the resource allocations for the UE to compensate for the gain loss during their BFR procedure for the failed TRP-1 SCell. Note that the UE could send additional indications to those described in FIGURE S13A and13B to the working TRP-2 through its associated PUCCH and/or PUSCH if necessary. Various other beam failure events for the multi-DCI/PDCCH based multi-TRP system than those exhibited inFIG.10,FIGS.11A and11B,FIG.12, andFIGS.13A and13Bare also possible. In the following, four additional beam failure events for the multi-DCI/PDCCH based multi-TRP system are discussed. In one example of non-CA framework (the same TRPs setting as that inFIG.10), it may be assumed that the UE has declared beam failure for both TRP-1 and TRP-2, the UE would independently perform the BFR procedures for both TRP-1 and TRP-2 following the BFR procedure for TRP-2 inFIGS.11A and11B, different fromFIGS.11A and11B, the UE would not share the BFR status for one coordinating TRP, e.g., TRP-1, with the other coordinating TRP, e.g., TRP-2, because now both of them are failed TRPs. In one example of CA framework (the same TRPs setting as that inFIG.10), it may be assumed that the UE has declared beam failure for both TRP-1 SCell and TRP-2, the UE would perform the same BFR procedure for TRP-1 SCell as that for TRP-1 SCell inFIGS.13A and13B; the UE would perform the same BFR procedure for TRP-2 as that for TRP-2 inFIGS.11A and11B; in addition, the UE could also indicate to TRP-1 PCell about the BFR status for TRP-2 such as whether the UE has identified a new beam for TRP-2 and etc.; different fromFIGS.13A and13B, the UE would not indicate to TRP-2 about the BFR status for TRP-1 SCell because now, TRP-2 is also a failed TRP. In one example of CA framework (the same TRPs setting as that inFIG.12), it may be assumed that the UE has declared beam failure for both TRP-1 PCell and TRP-2; the UE would independently perform the BFR procedures for both TRP-1 PCell and TRP-2 following the BFR procedure for TRP-2 inFIGS.11A and11B; different fromFIGS.11A and11B, the UE would not share the BFR status for one coordinating TRP, e.g., TRP-1 PCell, with the other coordinating TRP, e.g., TRP-2, because now both of them are failed TRPs. In one example of CA framework (the same TRPs setting as that inFIG.12), it may be assumed that the UE has declared beam failure for TRP-1 PCell; the UE would perform the same BFR procedure for TRP-1 PCell as that for TRP-2 inFIG.9; further, the UE could indicate to the working TRP-2 about the BFR status for TRP-1 PCell such as whether the UE has identified a new beam for TRP-1 PCell and etc. It is noted that the provided design approaches in this disclosure could be applied to many other deployment scenarios with moderate modifications. If ideal backhaul or close-to-ideal backhaul is assumed between the coordinating TRPs in the multi-DCI/PDCCH based multi-TRP system, the UE could initiate and complete the BFR procedure for the failed TRP with the working TRP. This is different from the design examples shown inFIGS.11A and11B, andFIGS.13A and13B(assuming non-ideal backhaul), in which the UE could only transmit certain limited BFR status/condition information for the failed TRP to the working TRP; the UE would still need to initiate and complete the BFR procedure with the failed TRP. FIG.14illustrates yet an example TRP-specific or per TRP or partial beam failure recovery procedure1400in a multi-TRP system according to embodiments of the present disclosure. An embodiment of the TRP-specific or per TRP or partial beam failure recovery procedure1400shown inFIG.14is for illustration only. InFIG.14, an example of the BFR procedure design for the failed TRP-2 inFIG.10is provided assuming that TRP-1 is still working, and TRP-1 and TRP-2 are connected via ideal or close-to-ideal backhaul. The procedures presented inFIG.14are after the UE has declared/detected beam failure for TRP-2. It can be observed fromFIG.14that the working TRP-1 would act like a PCell and the failed TRP-2 would act like an SCell in the BFR procedure shown inFIGS.13A and13B. Further, the working TRP-1 could send the BFRQ, new beam index and other information received from the UE to the failed TRP-2 through backhaul. The failed TRP-2 could also indicate to the working TRP-1 through backhaul about whether the UL grant for MAC CE for BFR and/or BFRR may be transmitted to the UE. In the example shownFIG.14, the UE would receive the BFRR from the working TRP-1. Another alternative could be that the UE would receive the BFRR from the failed TRP-2 transmitted using the newly identified beam. Further, along with the transmission of the BFRQ, new beam index and other information, the UE could also indicate to the receiving TRP whether the BFRQ, new beam index and other information are for this TRP or a different (coordinating) TRP by explicitly incorporating the failed TRP ID and/or implicitly sending a one-bit indicator (0—for this TRP, 1—for the other TRP). This design principle could be applied to all the embodiments/examples described in this disclosure. As depicted inFIGS.11A and11B, the UE could initiate the BFR for the failed TRP after the UE has identified a new beam for the failed TRP. That is, the UE could transmit the BFRQ along with the new beam information to the failed TRP via CF PRACH such that the CF PRACH resource index is associated with the newly identified beam. Similarly, the UE could initiate the BFR procedure for the failed TRP with the working TRP after the UE has identified a new beam for the failed TRP. The UE could transmit the BFRQ along with the new beam information to the working TRP over various UL channels/signaling mediums, and the working TRP could pass along the received BFRQ and the new beam information to the failed TRP through backhaul. FIG.15illustrates yet an example TRP-specific or per TRP or partial beam failure recovery procedure1500in a multi-TRP system according to embodiments of the present disclosure. An embodiment of the TRP-specific or per TRP or partial beam failure recovery procedure1500shown inFIG.15is for illustration only. Even after the UE has identified the new beam for the failed TRP, the UE could still initiate the BFR procedure for the failed TRP with the working TRP rather than the failed TRP due to various reasons: (1) the working TRP has the most recent UL channels/resources to carry the BFRQ and the new beam information, (2) the working TRP has the most available UL channels/resources to carry the BFRQ and the new beam information, and (3) the propagation delay between the working TRP and the UE is smaller than that between the failed TRP and the UE. Note that inFIG.15, the BFR procedure is illustrated after the UE has identified a new beam for the failed TRP-2. Further, inFIG.15, the UE would receive the BFRR from the working TRP-1. Another alternative could be that the UE would receive the BFRR from the failed TRP-2 transmitted using the newly identified beam. FIGS.16A and16Billustrate yet an example TRP-specific or per TRP or partial beam failure recovery procedure1600and1650in a multi-TRP system according to embodiments of the present disclosure.FIG.16Bis an example that is continued fromFIG.16A. Embodiments of the TRP-specific or per TRP or partial beam failure recovery procedure1600and1650shown inFIGS.16A and16Bare for illustration only. InFIGS.16A and16B, an example of the BFR procedure design for the failed TRP-1 SCell inFIG.10is provided assuming that TRP-1 PCell and TRP-2 are still working, and TRP-1 and TRP-2 are connected via ideal or close-to-ideal backhaul. The design procedures shown inFIGS.16A and16Bare after the UE has declared/detected beam failure for TRP-1 SCell. As can be seen fromFIGS.16A and16Bthat as both TRP-1 PCell and TRP-2 are working and ideal backhaul is assumed between TRP-1 and TRP-2, the UE could independently initiate the BFR procedure for the failed TRP-1 SCell with both TRP-1 PCell and TRP-2. For instance, the UE could transmit two BFRQs for the failed TRP-1 SCell, one to TRP-1 PCell as a SR through its associated PUCCH (BFRQ_1), and the other to TRP-2 as a SR through its associated PUCCH (BFRQ_2). TRP-2 could then pass BFRQ_2 for TRP-1 SCell to TRP-1 PCell through backhaul. For another example, after the UE has identified a new beam for TRP-1 SCell, the UE could transmit the new beam information to TRP-1 PCell via MAC CE_1 on TRP-1 PCell's scheduled PUSCH, and the UE could also transmit the new beam information to TRP-2 via MAC CE_2 on TRP-2's scheduled PUSCH. TRP-2 could pass MAC CE_2 to TRP-1 PCell through backhaul. Duplicating the same BFR message/signaling such as BFRQ and new beam index across different geographically non-co-located TRPs could improve the reliability of the BFR procedure. For instance, if TRP-1 PCell could not correctly receive BFRQ_1, it could still know that the beam failure between TRP-1 SCell and the UE has occurred and send the UL grant for MAC CE_1 to the UE because TRP-1 PCell could have received BFRQ_2 from TRP-2 through backhaul. Duplicating/repeating the same BFR message/signaling across different coordinating TRPs, however, could be a source of signaling and resource overhead. Hence, one or more duplicates/repetitions of the same BFR message/signaling, e.g., BFRQ_2 inFIGS.16A and16B, could be omitted in the BFR procedure. Further, to facilitate the BFR procedure shown inFIGS.16A and16B, the UE could be configured by the network with a BFR process ID through high layer signaling. The UE could indicate the BFR process ID to the coordinating TRPs along with the transmission of the BFRQs, new beam information and etc. so that the network could handle the duplicates/repetitions of the same BFR message/signaling without ambiguity. In one embodiment, TRP-specific/per TRP BFR for single-DCI based multi-TRP is provided. In a single-DCI/PDCCH based multi-TRP system, the UE could only receive the PDCCHs from one of the coordinating TRP, referred to as the primary TRP in this disclosure. The UE could receive the PDSCHs from all the coordinating TRPs scheduled by the PDCCHs transmitted from the primary TRP. Further, it is assumed that the coordinating TRPs in a single-PDCCH based framework are connected with each other via ideal backhaul with zero latency. FIG.17illustrates an example TRP-specific or per TRP or partial beam failure in a single-PDCCH or single-DCI based multi-TRP system1700according to embodiments of the present disclosure. An embodiment of the TRP-specific or per TRP or partial beam failure in a single-PDCCH or single-DCI based multi-TRP system1700shown inFIG.17is for illustration only. InFIG.17, an illustrative example of a single-PDCCH based multi-TRP system is presented. As can be seen from the example shown inFIG.17, TRP-1 is the primary TRP transmitting the PDCCH to the UE. Further, for a single-PDCCH based multi-TRP system, the UE could only declare beam failure and perform BFR for the primary TRP. As shown inFIG.17, due to the blockage, the UE could declare beam failure for TRP-1 because the received signal qualities of the BFD RSs from TRP-1 could fall below the predetermined threshold for a given period of time. The BPL(s) between the non-primary/secondary TRP-2 and the UE, however, could still work. As indicated inFIG.17, the UE could be configured by the network with a BFD RS beam set q0, a NBI RS beam set q1, a maximum number of BFI count maxBFIcount, a BFD timer BFDtimer, a BFR timer BFRtimer, a BFD threshold Qout, and a BFR threshold Qin for the primary TRP-1. Different from the design examples shown inFIG.14,FIG.15,FIGS.16A and16B, andFIG.17, TRP-2 does not have its own PDCCH. In this disclosure, it is assumed that the non-primary TRP could still have its own UL channels such as PUCCH/PUSCH, which are separately configured from those for the primary TRP. In contrast to the multi-PDCCH based design examples shown inFIG.14,FIG.15,FIGS.16A and16B, andFIG.17, the UL resources such as PUCCH/PUSCH configured/scheduled for the non-primary TRP in the single-PDCCH based framework could be very limited and only used for transmitting essential UL information. Based on these system assumptions, several BFR procedures for the failed primary TRP in the single-PDCCH based multi-TRP system are developed and described as follows. FIGS.18A and18Billustrate an example TRP-specific or per TRP or partial beam failure recovery procedure1800and1850in a multi-TRP system according to embodiments of the present disclosure.FIG.18Bis an example that is continued fromFIG.18A. Embodiments of the TRP-specific or per TRP or partial beam failure recovery procedure1800and1850shown inFIGS.18A and18Bare for illustration only. InFIGS.18A and18B, an example of BFR procedure design for the failed primary TRP in the single-PDCCH based multi-TRP system is presented. The UE could only receive the BFD RSs transmitted from the primary TRP, i.e., TRP-1 in this example, in the BFD RS beam set q0. The UE would measure the L1-RSRPs of the BFD RSs in q0, and if all of them fall below Qout, the UE would increment the BFI count. The UE would declare beam failure for TRP-1 if maxBFIcount is achieved before the timer BFDtimer expires. As shown inFIGS.18A and18B, after declaring/detecting the beam failure for the primary TRP-1, the UE would transmit the BFRQ for TRP-1 to TRP-2. The UE could multiplex the BFRQ with the CSI report, HARQ/ACK, and/or other UCIs on the PUCCH associated with the working TRP-2. Alternatively, the UE could also transmit the BFRQ for TRP-1 through the MAC CE on the PUSCH associated with the working TRP-2 assuming that there are available scheduled PUSCH resources. TRP-2 could then indicate the BFRQ for TRP-1 to TRP-1 through the ideal backhaul. Upon receiving the BFRQ, the primary TRP-1 could know that the beam failure between the primary TRP-1 and the UE has occurred, and the UE would transmit the new beam index and other information through the CF PRACH resource in a later phase. With such prior knowledge, TRP-1 could well prepare to detect/decode the corresponding CF PRACH resource(s) and/or take other necessary actions to ensure that the BFR procedure could succeed. After the UE has identified a new beam for TRP-1, the UE would transmit the BFRQ, the new beam index and other necessary information to TRP-1 through the configured CF PRACH resource(s) for TRP-1. The UE could receive the BFRR to the BFRQ from TRP-1 from a dedicated BFR-CORESET. These procedures are similar to those presented inFIGS.11A and11B. For the single-PDCCH based multi-TRP system, leveraging the available UL resources of the non-primary TRP to transmit the BFR messages/signaling for the failed primary TRP could be more beneficial under the CA framework, in which both PCell and SCell(s) could be deployed at the primary TRP. FIG.19illustrates another example TRP-specific or per TRP or partial beam failure in a single-PDCCH or single-DCI based multi-TRP system1900according to embodiments of the present disclosure. An embodiment of the TRP-specific or per TRP or partial beam failure in a single-PDCCH or single-DCI based multi-TRP system1900shown inFIG.19is for illustration only. FIGS.20A and20Billustrate an example TRP-specific or per TRP or partial beam failure recovery procedure2000and2050in a multi-TRP system according to embodiments of the present disclosure.FIG.20Bis an example that is continued fromFIG.20A. Embodiments of the TRP-specific or per TRP or partial beam failure recovery procedure2000and2050shown inFIGS.20A and20Bare for illustration only. InFIGS.20A and20B, an example of the BFR procedure designed for the multi-TRP setting inFIG.19is presented. As can be seen fromFIGS.20A and20B, the UE would transmit the BFRQ for TRP-1 SCell to TRP-2 as a SR like signaling through TRP-2's PUCCH. TRP-2 would then pass the BFRQ for TRP-1 SCell to TRP-1 PCell through the ideal backhaul. In this example, the SR would request TRP-1 PCell's PUSCH resources to carry the potential new beam information identified by the UE. InFIGS.20A and20B, transmitting the BFRQ for the failed TRP-1 SCell to TRP-2 rather than to TRP-1 PCell could be due to various reasons such that the PUCCH resources for TRP-2 would come first, and/or the propagation delay between TRP-2 and the UE is smaller than that between TRP-1 and the UE. In the example shown inFIGS.20A and20B, after the UE has identified a new beam for the failed TRP-1 SCell, the UE would transmit the new beam index and other necessary information to TRP-1 PCell through MAC CE on the scheduled PUSCH resources for TRP-1 PCell. Note that other design options such as transmitting the new beam index and other necessary information to TRP-2 through its PUSCH, transmitting both the BFRQ and the new beam information to TRP-2 through its PUCCH and PUSCH, repeating the transmissions of the BFRQ and the new beam information across both TRP-1 PCell and TRP-2 (similar to FIGS.16A and16B) and etc. are also possible, depending on the availability of the UL resources for TRP-1 PCell and TRP-2 and whether the SR is to request the PUSCH resources for TRP-1 PCell or TRP-2 or both. The basic design principles discussed in this disclosure would apply to these design options as well. In one embodiment, partial BFR for multi-TRP is provided. As shown inFIGS.11A and11B,FIGS.13A and13B,FIG.14,FIG.15, andFIGS.16A and16B, the BFR procedures are developed on a per TRP basis for the multi-PDCCH based multi-TRP system. That is, both the BFD RS beam set and the NBI RS beam set are defined per TRP, and the UE could initiate the TRP-specific BFR process if a given TRP's BFD RSs are failed, and the UE could identify one or more new beams for the given TRP. The TRP-specific BFR could be seen as one type, or a special case of partial BFR for the multi-PDCCH based multi-TRP system, if a full BFR is defined as: all the BFD RSs from all the coordinating TRPs are failed. In addition to the TRP-specific BFR, another type of partial BFR could be defined such that the BFD RSs (NBI RSs) in a (virtual) BFD RS beam set ((virtual) NBI RS beam set) are from different coordinating TRPs. Further, different from the TRP-specific BFR, in which the UE would identify one or more new beams for the failed TRP, the UE in the partial BFR design could identify one or more new beams for each of the coordinating TRPs. FIG.21Aillustrates an example configuration of BFD RSs for TRP-specific or per TRP or partial beam failure recovery2100according to embodiments of the present disclosure. An embodiment of the configuration of BFD RSs for TRP-specific or per TRP or partial beam failure recovery2100shown inFIG.21Ais for illustration only. InFIG.21A, conceptual examples of BFD RSs configurations for both TRP-specific BFR and partial BFR are presented. In the TRP-specific BFR design, the BFD RS beam set for TRP-1 (q0_1) contains two BFD RSs, i.e., BFD-RS-1-1 and BFD-RS-1-2, and the BFD RS beam set for TRP-2 (q0_1) contains two BFD RSs, i.e., BFD-RS-2-1 and BFD-RS-2-2. As shown on the RHS inFIG.21, virtual BFD RS beams sets are defined for the partial BFR design such that a first virtual BFD RS beam set (q′0-1) could contain BFD-RS-1-1 from TRP-1 (q0-1) and BFD-RS-2-2 from TRP-2 (q0-2), and a second virtual BFD RS beam set (q′0-2) could contain BFD-RS-1-2 from TRP-1 (q0-1) and BFD-RS-2-1 from TRP-2 (q0-2). FIG.21Billustrates an example configuration of NBI RSs for TRP-specific or per TRP or partial beam failure recovery2150according to embodiments of the present disclosure. An embodiment of the configuration of NBI RSs for TRP-specific or per TRP or partial beam failure recovery2150shown inFIG.21Bis for illustration only. Similar design principles could be applied to the configurations of the NBI RSs for the partial BFR as well. As can be seen from the examples shown inFIG.22, a first virtual NBI RS beam set (q′1-1) for partial BFR could contain NBI-RS-1-1 from TRP-1 (q1-1) and NBI-RS-2-2 from TRP-2 (q1-2), and a second NBI RS beam set (q′1-2) for partial BFR could contain NBI-RS-1-2 from TRP-1 (q1-1) and NBI-RS-2-1 from TRP-2 (q1-2). Further, as can be seen from TABLE 2, the BFD threshold/timer, the BFR threshold/timer and the maximum number of BFI count could all be defined on the basis of virtual BFD RS beam set/NBI RS beam set. For example, BFDtimer′-1 is defined for the virtual BFD RS beam set q′0-1, and BFDtimer′-2 is defined for the virtual BFD RS beam set q′0-2. That is, BFD-RS-1-1 and BFD-RS-1-2 could correspond to two different BFD RS timers, though they are transmitted from the same TRP-1. The UE could be configured by the network with the parameters shown in TABLE 2 via higher layer signaling such as RRC signaling. For instance, the UE could be configured/indicated by the network about the rules of constructing the virtual BFD/RS beam sets and how they would be mapped to the coordinating TRPs. TABLE 2BFR parameters for partial BFRq′0-1, q′1-1q′0-2, q′1-2Maximum numbermaxBFIcount′-1maxBFIcount′-2of BFI countBFD timerBFDtimer′-1BFDtimer′-2BFR timerBFRtimer′-1BFRtimer′-2BFD thresholdsQout′-1Qout′-2BFR thresholdsQin′-1Qin′-2 FIGS.22A and22Billustrate an example TRP-specific or per TRP or partial beam failure recovery procedure2200and2250in a multi-TRP system according to embodiments of the present disclosure.FIG.22Bis an example that is continued fromFIG.22A. Embodiments of the TRP-specific or per TRP or partial beam failure recovery procedure2200and2250shown inFIGS.22A and22Bare for illustration only. InFIGS.22A and22B, a design example of the partial BFR procedure for the multi-PDCCH based multi-TRP system under the non-CA setting is presented. As can be seen fromFIGS.22A and22B, the UE would measure the L1-RSRPs of all the BFD RSs in the virtual BFD RS beam sets. If the L1-RSRPs of the BFD RSs in a virtual BFD RS beam set (e.g., q′0_1 inFIGS.22A and22B) fall below the configured threshold (Qout′-1 inFIGS.22A and22B) before the BFD timer (BFDtimer′-1 inFIGS.22A and22B) expires, the UE would declare beam failure for the virtual BFD RS beam set. The UE would then measure the L1-RSRPs of the NBI RSs in the corresponding virtual NBI RS beam set (q′1-1 inFIG.22) and determine two NBI RSs, and therefore, two new beams one for each coordinating TRP, whose L1-RSRPs are beyond Qin′-1. After identifying the new beams, the UE would send two BFRQs for partial BFR to both TRP-1 and TRP-2 through the configured CF PRACH resources for the two TRPs, though the beam failure event is only for a single virtual BFD RS beam set. Along with the transmission of the BFRQs, the UE would also indicate to the coordinating TRPs the newly selected beams for them, which are associated with the indices of the CF PRACH resources. For instance, the UE would transmit the BFRQ for partial BFR and the new beam information for TRP-1 through the corresponding CF PRACH resource for TRP-1, and the BFRQ for partial BFR and the new beam information for TRP-2 through the corresponding CF PRACH resource for TRP-2. After sending the BFRQs to the coordinating TRPs, the UE would start to monitor a dedicated CORESET/search space for BFRR from each of the coordinating TRPs. Each coordinating TRP would transmit a dedicated BFR-CORESET (addressed to the UE-specific C-RNTI) to the UE through the new beam. As shown inFIGS.22A and23B, if the UE could detect valid UE-specific DCIs in the dedicated CORESETs for BFRR from both TRP-1 and TRP-2, the UE would assume that the BFRQs have been successfully received by both of the coordinating TRPs, and the UE would complete the partial BFR process. Otherwise, if the UE could not receive the BFRR from either of the coordinating TRPs (e.g., from TRP-1) before the corresponding BFR timer expires (e.g., BFRtimer′-1), the UE would initiate a CBRA process to the corresponding TRP (e.g., to TRP-1). If the UE could not receive the BFRR from any of the coordinating TRPs before the BFR timer expires, the UE would initiate the CBRA processes to reconnect to both TRPs. The partial BFR procedure depicted inFIGS.22A and22Bcan be extended to other system settings and/or deployment scenarios such as full BFR for the multi-PDCCH based multi-TRP system, partial BFR for the single-PDCCH based multi-TRP system, partial BFR for the multi-PDCCH based multi-TRP system under the CA setting. For instance, to support the full BFR for the multi-PDCCH based multi-TRP system, the UE could be configured by the network with only one virtual BFD (NBI) RS beam set containing all BFD (NBI) RSs from all the coordinating TRPs. In one embodiment, UE-initiated BFR for multi-TRP is provided. Rather than configured/indicated by the network, the UE could proactively select an appropriate BFR type from various potential BFR types such as TRP-specific/per TRP BFR, partial BFR or full BFR for the multi-TRP system. The UE could determine the appropriate BFR type based on various factors such as the UE's prediction/assessment of the channel conditions, UE's moving speed, UE's orientation change and etc. InFIG.24, an example of the UE-initiated BFR type selection for the multi-TRP system is presented. FIG.23illustrates a flowchart of a method2300for UE-initiated BFR type selection for TRP-specific or per TRP or partial beam failure recovery in a multi-TRP system according to embodiments of the present disclosure. The method2300as may be performed by a UE (e.g.,111-116as illustrated inFIG.1). An embodiment of the method2300shown inFIG.23is for illustration only. One or more of the components illustrated inFIG.23can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions. As illustrated inFIG.23, in2301, the UE could be configured by the network with various configurations of BFD RSs/(virtual) BFD RS beam sets, NBI RSs/(virtual) NBI RS beam sets, maximum number of BFI counts, BFD thresholds/timers, BFR thresholds/timers, and etc. For instance, the UE could be explicitly indicated by the network about the mapping relationships between the BFD/NBI RSs and the coordinating TRPs. For another example, the UE could also be indicated by the network about the rules of constructing the virtual BFD/NBI RS beam sets for potential partial BFR procedure triggering/firing. In2302, the UE could determine an appropriate BFR type from various potential BFR types such as TRP-specific/per TRP BFR, partial BFR and full BFR for the multi-TRP system. As described before, the selection of the appropriate BFR type could be based on the configurations in2301and/or UE's assessment/prediction of the channel condition, UE's moving speed, UE's orientation change and etc. For example, the UE could first measure the L1-RSRPs of all the BFD RSs from all the coordinating TRPs. The UE could hypothetically evaluate/assess the measured L1-RSRPs for both the TRP-specific BFR (given the mapping relationship between the BFD RSs and the coordinating TRPs) and the partial BFR (given the rules of constructing the virtual BFD RS beam sets). Based on the evaluation/assessment, the UE could determine one BFR type and indicate to the network about the selected BFR type (in step2303) along with the transmission of other BFR messages/signaling. Similar to the determination of the BFR type, the UE could also determine an appropriate BFR procedure from various BFR procedures such as those developed inFIGS.11A and11B,FIGS.13A and13B,FIG.14,FIG.15,FIGS.16A and16B,FIGS.18A and18B,FIGS.20A and20B, andFIGS.22A and22Bfor the multi-TRP system. FIG.24illustrates a flowchart of a method2400for UE-initiated BFR procedure determination for TRP-specific or per TRP or partial beam failure recovery procedure in a multi-TRP system according to embodiments of the present disclosure. The method2400as may be performed by a UE (e.g.,111-116as illustrated inFIG.1). An embodiment of the method2400shown inFIG.24is for illustration only. One or more of the components illustrated inFIG.24can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions. InFIG.24, an example of the UE-initiated BFR procedure determination for the multi-TRP system is provided. As illustrated inFIG.24, in2401, the UE could have already determined the BFR type for the multi-TRP system. The BFR type could correspond to TRP-specific/per TRP BFR, partial BFR or full BFR, and the determination procedures could follow those described inFIG.23. In2402, the UE could be configured by the network with various system settings and/or deployment scenarios such as whether the UE would operate under the multi-PDCCH or the single-PDCCH based multi-TRP system and/or whether carrier aggregation is assumed for one or more coordinating TRPs. The UE could also be indicated by the network about certain network status/condition such as the backhaul condition (ideal backhaul or non-ideal backhaul) between the coordinating TRPs. In2403, the UE would determine an appropriate BFR procedure from various potential BFR procedures based on the configurations and/or indications in2402. The potential BFR procedures could correspond to those presented inFIGS.11A and11B,FIGS.13A and13B,FIG.14,FIG.15,FIGS.16A and16B,FIGS.18A and18B,FIGS.20A and20B, andFIGS.22A and22Bin the present disclosure. For instance, if the UE operates under the multi-PDCCH based framework with ideal backhaul and CA setting, the UE could select the procedure presented inFIGS.16A and16Bas the candidate BFR procedure. For another example, if the UE operates under the single-PDCCH based framework with ideal backhaul and non-CA setting, the UE could determine the procedure developed inFIGS.18A and18Bas the candidate BFR procedure. As illustrated inFIG.25, in2504, the UE could indicate to the network about the selected BFR procedure along with the transmission of other BFR messages/signaling. For illustrative purposes the steps of this algorithm are described serially, however, some of these steps may be performed in parallel to each other. The above operation diagrams illustrate example methods that can be implemented in accordance with the principles of the present disclosure and various changes could be made to the methods illustrated in the flowcharts herein. For example, while shown as a series of steps, various steps in each figure could overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, steps may be omitted or replaced by other steps. Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. None of the description in this application should be read as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of patented subject matter is defined by the claims. | 137,626 |
11943038 | It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the sequence of operations as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes of various illustrated components, will be determined in part by the particular intended application and use environment. Certain features of the illustrated embodiments have been enlarged or distorted relative to others to facilitate visualization and clear understanding. In particular, thin features may be thickened, for example, for clarity or illustration. DETAILED DESCRIPTION The following description and drawings merely illustrate the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its scope. Furthermore, all examples recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Additionally, the term, “or,” as used herein, refers to a non-exclusive or, unless otherwise indicated (e.g., “or else” or “or in the alternative”). Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The numerous innovative teachings of the present application will be described with particular reference to the presently preferred exemplary embodiments. However, it should be understood that this class of embodiments provides only a few examples of the many advantageous uses of the innovative teachings herein. In general, statements made in the specification of the present application do not necessarily limit any of the various claimed inventions. Moreover, some statements may apply to some inventive features but not to others. Those skilled in the art and informed by the teachings herein will realize that the invention is also applicable to various other technical areas or embodiments. The various embodiments provide a relay-assisted beamforming approach for mmWave communications in an urban scenario, and a resource efficient relay selection scheme designed to optimally enhance QoS in 2-hop Amplify-and-Forward (AF) cooperative networks. By exploiting the correlation structure of the channel induced by shadowing, a phenomenon prominent in mmWave communications, the inventors devise mechanisms to reduce both latency and CSI estimation overhead. AF is adopted herein as it is the simplest forwarding scheme, and of minimal implementation complexity. Other, possibly more involved forwarding schemes may also be utilized within the context of the various embodiments. FIG.1graphically depicts a simplified network deployment example useful in understanding the various embodiments. Specifically,FIG.1depicts a plurality of city blocks defined by streets and buildings in the normal manner, wherein clusters C of relays R form respective communications nodes which are deployed across certain street segments and configured to beamform a signal received from a source node S toward a destination node D. A dashed line depicts all mmWave signal propagation paths from the source S to the destination D, passing through a relay cluster C3. It is noted that relay cluster C3is depicted as receiving the signal from the source node S and having a currently selected relay Rs which has been configured for beamforming/forwarding the signal toward the destination node D. Each of the nodes (i.e., each cluster C of relays R) is associated with a respective location that may be defined using street addresses such as from city/area mapping data, global positioning system (GPS) coordinates, or other location defining means. For simplicity of this discussion it is assumed that each cluster C contains R evenly spaced relays. However, the various embodiments discussed herein are suitable for use with any spatial relay distribution and/or relay quantity within any cluster. At each time instance, only one relay from every cluster, namely, the cluster representative, is active. The relays are connected via the fiber-optic link or other back channel to computational resources such as at a central node, where information may be exchanged in accordance with the various embodiments. In various embodiments, a propagation path between the source or destination and any of the cluster representatives, as well as the corresponding line-of-sight (LoS) and non-line-of-sight (NLoS) portions of the path, may be configured/operational in the manner described herein with respect to the various relay clusters. The various embodiments utilize a relay-assisted beamforming for mmWave communications in an urban scenario, which exploits the shadowing-induced correlation structure of the channel to reduce both latency and CSI estimation overhead. In particular, one relay from each cluster is optimally selected at each time slot to participate in optimal beamforming at the next time slot. This relay selection is implemented in a predictive and distributed manner, by exploiting channel correlations and by using past and present measurements of magnitude CSI. As a result, at each time slot, optimal beamforming based on relays selected in the previous slot and optimal predictive relay selection for the next time slot are implemented completely in parallel. This parallelization eliminates delays induced by sequential execution of relay selection and beamforming, and substantially reduces CSI estimation overhead. Simulations confirm that the proposed relay selection scheme outperforms any randomized selection policy, while, at the same time, achieves comparable performance to an ideal selection scheme that relies on perfect CSI estimates for all candidate relays. The system100ofFIG.1, as well as the various embodiments discussed herein, will be described as a 2-hop Amplify-and-Forward (AF) cooperative network. AF is the least resource-demanding forwarding scheme, and it offers a closed form solution. However, various embodiments may also be implemented using Decode-and-Forward (DF). By exploiting the correlation structure of the channel, induced by a phenomenon that is prominent in mmWave communications, caused by large objects in the path of the propagating signal (i.e., shadowing) the various embodiments operate to predict CSI magnitude in time and space, and thus reduce both latency and CSI estimation overhead. The various embodiments provide joint optimal relay selection and distributed cooperative beamforming that maximizes the expected Signal-to-Interference plus Noise Ratio (SINR) at the destination, and under power constraints. In particular, assuming a time-slotted system operation, one relay from each cluster is optimally selected at each time slot to participate in optimal beamforming at the next time slot. An execution method suitable for use at each cluster is described in more detail below with respect toFIG.5. Assuming a time slotted system operation, various embodiments optimize QoS in a 2-stage fashion, where, in every time slot, and simultaneously with AF beamforming to the destination, each cluster predictively selects a cluster representative (1st stage) to optimally enhance AF beamforming at the subsequent time slot (2nd stage). As a result, at each time slot, optimal beamforming based on relays selected in the previous slot and optimal predictive relay selection for the next time slot are implemented completely in parallel. Predictive relay selection is achieved by exploiting channel correlations with current and past networkwide magnitude-only CSI (also known as Received Signal Strength (RSS)) which is invariant to relay cluster size and is measured sequentially during the operation of the system. This combination of cooperative beamforming and relay selection, which together comprise the proposed 2-stage problem formulation, presents distinct operational advantages over the trivial ideal scheme, stemming directly from the predictive nature of the approach. This parallelization eliminates delays induced by sequential execution of relay selection and beamforming, and substantially reduces CSI estimation overhead. Simulations confirm that the proposed relay selection scheme outperforms any randomized selection policy, while, at the same time, achieves comparable performance to an ideal selection scheme that relies on perfect CSI estimates for all candidate relays. FIG.2depicts a high-level block diagram of a computing device configured for implementing a controller function according to one embodiment and suitable for use in performing the various functions as described herein. It will be appreciated that the controller function described herein may be located within the network100ofFIG.1, proximate a particular element within the network100and so on. As depicted inFIG.2, computing device200includes a processor element210(e.g., a central processing unit (CPU) or other suitable processor(s)), a memory220(e.g., random access memory (RAM), read only memory (ROM), and the like), a communications interface230(e.g., one or more interfaces enabling communications via a wireless communication network such as a 3G/4G/LTE/5G wireless network, an optical fiber link and the like), and an optional input/output interface240(e.g., GUI delivery mechanism, user input reception mechanism, web portal interacting with remote workstations and so on). It will be appreciated that computing device200depicted inFIG.2provides a general architecture and functionality suitable for implementing functional elements described herein or portions of the functional elements described herein. It will be appreciated that the functions depicted and described herein may be implemented in hardware or in a combination of software and hardware, e.g., using a general purpose computer, one or more application specific integrated circuits (ASIC), or any other hardware equivalents. In one embodiment, computer instructions are loaded into memory220and executed by processor210to implement the functions as discussed herein. The various functions, elements and/or modules described herein, or portions thereof, may be implemented as a computer program product wherein computer instructions, when processed by a computing device, adapt the operation of the computing device such that the methods or techniques described herein are invoked or otherwise provided. Instructions for invoking the inventive methods may be stored in tangible and non-transitory computer readable medium such as fixed or removable media or memory, or stored within a memory within a computing device operating according to the instructions. The communications interface230facilitates communications with various elements within or related to the network100ofFIG.1, such as various clusters C of relays R, channel sounders S and other devices (not shown) that may be implemented within the context of a mmWave network such as described herein. In various embodiments, the communications interface230facilitates high-speed communications with the various millimeter wave network elements to enable the controller200to provide rapid management of these elements. The memory220is depicted as storing computer instructions executable by the processor210to implement various functions associated with the network100ofFIG.1, such a configuration manager220-CM, a session manager220-SM, a relay selection and beamforming module220-RSBM, and (optionally) a cluster timing/phase control module220-CTPCM. The configuration manager220-CM is used to manage the various elements of the network100ofFIG.1as needed. Such elements may comprise base stations, eNodeBs, relays, relay clusters, nodes, sounders and so on. The session manager220-SM is configured to manage network services sessions supported by the network100ofFIG.1as needed. Such sessions may be associated with voice, video, data, and/or other types of network services. The relay selection and beamforming module220-RSBM operates to select appropriate relays within the various relay clusters for use in forwarding a signal, as well as determining the beamforming characteristics to be used in forwarding that signal. The various functions associated with the relay selection and beamforming module220-RSBM will be described in more detail below with respect to the various embodiments. The cluster timing/phase control module220-CTPCM supports cluster timing and/or phase control mechanisms suitable for use in enabling the various clusters C within the network100to modify local timing/phase parameters (e.g., of a local oscillator) such that the various clusters C (and relays R therein) operate in a synchronized manner. In various embodiments this module generates timing signals suitable for use by the clusters and/or relays to adapt local oscillator operation such that local timing errors may be reduced or eliminated. Such timing signals may be propagated via a communications interface130, such as by using timestamps, reference signals and so on. Different mechanisms are contemplated by the inventors. As depicted above with respect toFIG.1, a system model according to various embodiments comprises static relays deployed in clusters across streets. Each cluster is defined within an area over which the channel exhibits similar statistical characteristics. This is typical in mmWave networks, which are primarily designed for relatively short distance point-to-point communications. Assuming a time-slotted system operation, the proposed scheme optimizes QoS in a 2-stage fashion, where, in every time slot, and simultaneously with AF beamforming to the destination, each cluster predictively selects a representative relay (1st stage) to optimally enhance AF beamforming at the subsequent time slot (2nd stage). Predictive relay selection is achieved by exploiting channel correlations with current and past networkwide magnitude-only CSI (also known as Received Signal Strength (RSS)) which is invariant to relay cluster size, and is measured sequentially during the operation of the system. This combination of cooperative beamforming and relay selection, which together comprise the proposed 2-stage problem formulation, presents distinct operational advantages over the trivial ideal scheme, stemming directly from the predictive nature of the approach. As discussed herein, network QoS is quantified by the expected Signal-to-Interference+Noise Ratio (SINR) at the destination, which is a standard performance metric. One of the communications goals is to maximize that expected SINR, subject to a shared power constraint among all relay clusters. Therefore, in various embodiments the optimal beamforming weights need to be computed centrally for all clusters. Nevertheless, the proposed relay selection procedure is conducted in a completely distributed manner; each cluster independently decides its successor representative for the subsequent time slot by solving a simple local stochastic optimization problem, without the need for inter-cluster information exchange. It is noted that the diversity resulting from the reflective nature of the mmWave signal propagation, as well as the possibly street-wise varying channel parameters, induce significant differences as far as both problem description and development of corresponding efficient implementation techniques are concerned. Various embodiments provide distributed cooperative beamforming for expected SINR maximization in mmWave networks. The disclosed beamforming formulation allows for efficient exploitation of the spatial diversity induced by dominant mmWave propagation paths, which is a consequence of the spatial propagation patterns of the mmWave medium. The CSI induced by the mmWave propagation paths is optimally combined constructively at the destination, resulting in superior network QoS, without the disadvantages of multi-hop relaying. Although distributed beamforming is a well established technique for exploitation of spatial diversity in free-space communications, the various embodiments described herein utilize beamforming within the context of urban mmWave networks, which are inherently topologically distinct as compared to the free-space setting. Indeed, the spatial structure of the mmWave medium is explicitly reflected in the adopted mmWave channel model, as well as in the form of the optimal beamforming weights and achieved network SINR. In particular, the channel model extends the state of the art by introducing a new channel correlation kernel for effectively modeling the statistical dependencies among the involved source-relay and relay-destination channels; such dependencies do not appear in free-space channel modeling. As briefly mentioned above, within each time slot, the implementation of the proposed relay selection scheme is completely decoupled from that of optimal beamforming. This is due to the predictive nature of the proposed scheme, which determines the best cluster representative before the start of each time slot. Consequently, in a given slot, optimal beamforming and optimal predictive relay selection for the next slot can be performed in parallel, as one does not depend on the other. This parallelism results in improved time slot utilization. Additionally, as predictive selection is implemented solely based on past channel measurements, significant reduction of CSI estimation overhead per time slot is achieved as compared to the respective ideal scheme, with the reduction being more pronounced as the relay density per cluster increases. This is particularly important in mmWave networks, where dense infrastructure is essential for achieving satisfactory performance. Generally speaking, the various embodiments provide a novel, practical and computationally efficient technique for implementing the disclosed relay selection scheme. Specifically, the local stochastic problem each cluster is responsible for is replaced by a surrogate based on Sample Average Approximation (SAA), which relies on predictive Monte Carlo sampling of the channel uncertainty involved. Heavily appealing to the statistical structure of the adopted mmWave channel model, the proposed technique efficiently exploits spatiotemporal correlations of the mmWave medium, and results in easily computable, near-optimal relay selection policies. This is achieved via, illustratively, a well-designed, non-trivial combination of Kalman filtering and Gaussian process regression. mmWave Urban Channel Model As previously noted, the various embodiments find particular utility within the context of urban setting. It is noted that the various embodiments may also be used within the context of non-urban settings. This section is dedicated to the development of a sufficiently detailed illustrative urban mmWave channel model. This channel model may be applied to any city topology such as one comprising a densely built area with high-rise buildings, separated by non-curved street canyons. Consider simplified city topologies such as that ofFIG.1, which shows a top view schematic of a particular urban area including road intersections, streets and the like. Due to blockage caused by high-rise buildings, the only way a mmWave signal starting from a source located atS(e.g., S) can reach its destination atD(e.g., D) is by traversing street segments. More specifically, the transmitted signal is spatially diversified through all sets of consecutive, non-repeating segments from the source to the destination. Then, a (dominant) propagation path is defined as every such set of traversed street segments whose aggregate length is equal to the minimum1-distance from the source to the destination. The following conventions used herein: where the Line-of-Sight (LoS) portion of every path is the segment between the transmitting node and the nearest intersection, while the remaining segments comprise the Non-Line-of-Sight (NLoS) portion of the path. All considered paths have common LoS portion, while their NLoS portions differ. As previously noted, to overcome severe signal attenuation, various embodiments deploy clusters of relays across certain street segments, which will beamform the signal to its destination. For simplicity in exposition, assume that each cluster contains evenly spaced relays. It is noted that the approach works for any spatial relay distribution within each cluster. At each time instance, only one relay from every cluster, namely, the cluster representative, is active. The relays are connected via optical fiber to a central node via which they can exchange information. A propagation path between the source or destination and any of the cluster representatives, as well as the corresponding LoS and NLoS portions of the path are all defined in exactly the same fashion as in the previous paragraph. Let Ncbe the number of available relay clusters C in the network. Also, let Lrbe the number of all possible signal paths fromS(e.g., S) to relay cluster r=1, . . . , Nc. The channel betweenSand a relay in cluster r (e.g., Rs) located atis experienced as a combination of all channels across all possible paths betweenSand. In particular, under the flat fading assumption, the complex channel gain fromSto point p along path i can be decomposed as follows: fri(p,t)=ΔfriPL(p)︸path-lossfriSH(p,t)︸shadowingfriMF(p,t)︸multi-path,(1) where friPL() is the path-loss component, friSH(, t) the large-scale fading component (shadowing), and friMF(, t) the small-scale fading component (multi-path). A similar decomposition holds for the channel gri(, t) fromtop, along path i=1, . . . , Kr, where Kris the number of respective signal paths from cluster r to the destination. In the mmWave setting, the channel path-loss does not depend on the Euclidean distance betweenSand, but rather on their absolute locations (e.g., such as by the “Manhattan distance” or distance between two points measured along axes at right angles), and is therefore parametrized separately for each segment. As previously noted, each of the nodes/clustersis associated with a respective location that may be defined using street addresses such as from city/area mapping data, global positioning system (GPS) coordinates, or other location defining means. Let the set of all individually traversed street segments τ of path i to cluster r be denoted byrif, which includes the segment τSwhere the source is located, but does not include segment τrwhere cluster r is located. Similarly, the set of traversed segments of path i from cluster r to the destination, including the segment τDthe destination is located but excluding segment τr, isrig. In the following, consider only the source-relay channels fri, for every path i associated with cluster r. The discussion for grifollows in a completely analog manner, and is omitted for brevity. It is also assume an additional loss Δ occurring at every intersection, i.e., every propagation path exhibits a total intersection loss ΔNrf, where Nrfare the number of traversed intersections fromSto. Therefore, the overall path-loss component of channel friis expressed as friPL(p)=10-ΔNrf2·10dτS-αL2(dτrf(p))-αN2∏τ∈𝒮rif\{τS}dτ-αN2,(2) where dτs, denotes the length of the LoS segment τs, dτrf() is the distance between the intersection of segment τrassociated with friand locationin τr(that is, the intersection of τrwhich is1-closest to the source), and dτdenotes the length of the τ-th street segment. Assume that a relay cannot be located exactly on an intersection, so dτrf≠0. Likewise, the shadowing and multi-path components of the channel experienced across each path may be decomposed on a per-segment basis as friSH(p,t)=sτrf(p,t)∏τ∈𝒮rifsτ(t)and(3)friMF(p,t)=qτrf(p,t)∏τ∈𝒮rifqτ(t),(4) where sτand qτare the shadowing and multi-path terms experienced across segment τ. Consequently, by expressing the magnitude of (1) in logarithmic scale (dB), then obtain the additive model Fri(p,t)=Δ10log10(❘"\[LeftBracketingBar]"friPL(p)·friSH(p,t)·friMF(p,t)❘"\[RightBracketingBar]"2)=Δarif(p)+brif(p,t)+crif(p,t)(5)where-arif(p)=ΔαL10log10dτS+αN∑τ∈𝒮rif10log10dτ+aN10log10dτrf(p)+ΔNrf,(6)brif(p,t)=Δ∑τ∈𝒮rif10log10❘"\[LeftBracketingBar]"sτ(t)❘"\[RightBracketingBar]"2+10log10❘"\[LeftBracketingBar]"sτrf(p,t)❘"\[RightBracketingBar]"2=Δ∑τ∈𝒮rifβτ(t)+βτrf(p,t)(7)andcrif(p,t)=Δ∑τ∈𝒮rif10log10❘"\[LeftBracketingBar]"qτ(t)❘"\[RightBracketingBar]"2+10log10❘"\[LeftBracketingBar]"qτrf(p,t)❘"\[RightBracketingBar]"2=Δ∑τ∈𝒮rifξτ(t)+ξτrf(p,t).(8) It should be noted that in the above equations, the combined shadowing components pertaining to segments without relays have been separated from the respective term referring to the segment containing the relay cluster. Those terms exhibit distinct statistical behavior, and will be considered separately. In addition to the above, for every time slot t, assume a phase term ej2πϕτ(t)for each distinct segment τ∈rif, r=1, . . . , Nc, i=1, . . . , Lr, where each ϕτ(t) is uniformly distributed in [0,1]. Modeling the phase as a uniformly distributed process and independent of the respective channel magnitude is a standard assumption in the literature, which heuristically follows from the statistical structure of the well-known Rayleigh fading model. Additionally, as phase varies rapidly both in time and space, phase correlations are difficult to capture, therefore model, let alone exploit in statistical prediction. This fact consequently justifies the phase whiteness assumption, in both time and space. Note that phase whiteness is a standard assumption in the literature, and in various contexts. Similarly, for every time slot t and every location, assume another phase term ϕτrf(, t), also uniformly distributed in [0,1]. Across all time slots, all segments, and all locations, all phase components are mutually independent, and also independent of the respective channel magnitudes, as well. Then, the channel fri(, t) can be reconstructed as fri(p,t)=eln(10)Fri(p,t)20ej2πΦrif(p,t),whereΦrif(p,t)=Δ∑τ∈𝒮rifϕτ(t)+ϕτrf(p,t).(9) For all segments, assume a log-normal distribution for modeling shadowing and multi-path fading. The channel paths fri, i=1, . . . , Lr, are statistically dependent, as they might traverse common segments. Still, it is reasonable to model all shadowing and multi-path components as being mutually independent across different segments, since each segment will exhibit distinct spatial features. However, within each segment τ∈rif, βτ(t) is assumed to be zero mean and jointly Gaussian in time, with correlation between two time slots k and l given by 𝔼[βτ(k)βτ(l)]=Δη2e-|k-l|/γ,(10) where η2is the shadowing power and γ the correlation time. Further assuming that the multi-path component qτ(t) is white in time with variance σξ2, the combined log-magnitude terms zτ(t)βτ(t)+ξτ(t), t=1, . . . , NTare jointly Gaussian with mean zero and covariance ∑τ=Δη2[1…e-(NT-1)/γ⋮⋱⋮e-(NT-1)/γ…1]+σξ2INT=Δη2T+σξ2INT∈ℝNT×NT.(11) Likewise, the term βτrf(, t), corresponding to the segment where cluster r is located, is assumed to be jointly Gaussian, both in space and time. Specifically, assume that the individual relays of cluster r can be located at a discrete set of δ positions across the segment τr. At two such positions, saymandn, and between any two time slots k and l, the spatiotemporal correlation of βτr(, t) is defined as: 𝔼[βτrf(pn,k)βτrf(pm,l)]=ΔKFF(pn,pm)e-|k-l|/γ,(12) where the spatial kernel KFFis given by KFF(pn,pm)=Δη2e-||pn-pm||2/β.(13) We further assume that the “incoming” and “outgoing” shadowing terms βτrf(, t) and βτrg(, t) at positionsm, andnand between time slots k and l are themselves correlated as 𝔼[βτrf(pn,k)βτrg(pm,l)]=ΔKFG(pn,pm)e-|k-l|/γ,(14) where the cross-correlation kernel KFGis defined as KFG(pn,pm)=Δη2e(ϵ||pn-pm||2-dmax)/β,(15) with ϵ=1 for dτrf(m)+dτfg(n)≥dfulland ϵ=−1 otherwise, and where dfullis the length of segment τr, and dmaxis the furthest possible distance between two discrete relay positions of a cluster. This kernel describes the correlation between the incoming and outgoing channels at each cluster, at different locations and at different time slots. Intuitively, correlation should be proportional to the size of the part of the segment which is traversed by both channels, if such a part exists (as shown inFIG.3(c)). Otherwise, as the distance between the locations where the two channels are respectively experienced increases, their correlation should be decreasing (as shown inFIG.3(b)). The proposed kernel captures precisely the behavior outlined above, while resulting in a valid cross-covariance structure for βτrfand βτrg. FIG.3graphically depicts a cross-correlation structure of incoming and outgoing channel terms useful in understanding the various embodiments. Specifically,FIG.3graphically depicts a cross-correlation structure of the incoming and outgoing channel terms βτrf(n, t), βτrg(m, t) when (FIG.3(a)) dτrf(m)+dτrg(n)=dfull; (FIG.3(b)) dτrf(m)+dτrg(n)<dfull; and (FIG.3(c)) dτrf(m)+dτrg(n)>dfull; for cluster r with δ=3 relay positions, at a common time slot t. As discussed above, assuming that qτrf(, t) and qτrg(, t) are both white in both space and time, as well as mutually independent, the collection of combined terms [zτrf(pi,t)zτrg(pi,t)]=Δ[βτrf(pi,t)+ξτrf(pi,t)βτrg(pi,t)+ξτrg(pi,t)],(16) for i=1, . . . , δ and t=1, . . . , NT, are Gaussian with mean zero and covariance Στr∈2ϵNT×2δNTgiven by ∑τr=ΔT⊗K+σξ2I2δNT,(17) where ⊗ indicates Kronecker product, and the per-slot cross-covariance matrix K∈2δ×2δis defined as K=Δ[KFFKFGKFGKGG],(18) where, overloading notation, KFF, KGGand KFGare correlation matrices corresponding to the kernels (13) and (15), respectively, each evaluated on all δ2pairs of possible positions across segment Tr, according to some common order. Joint Beamforming and Relay Selection The various embodiments assume that the network configuration and/or topologies associated with the clusters change at a low rate, and may focus on the time period over which the clusters have been optimally determined and are fixed. During that time, the statistical model of the channel stays the same; however, the channel itself changes. Therefore, assignment of new clusters is necessary only when “coarse-grained” features of the communication system change, such as the locations of the source and destination, the ergodic properties of the communication channel, and other similar statistics. Then, cluster assignment should be performed at a coarser time scale than the change of the individual relay channel realizations. For the duration of a communication task, the aforementioned features typically do not change rapidly, and therefore the cluster does not need to change, justifying the need for a relay selection scheme that operates at a per time-slot basis. In every time slot, the proposed system jointly performs beaforming and relay selection, by addressing a 2-stage stochastic problem. Before going into the details (and the advantages) of each stage separately, it is noted that although the 2-stage problem refers to the necessary actions needed to be taken during a single time slot, in practice these actions refer to two consecutive time slots, due to the availability of the required CSI. More specifically, during time slot t, both current beamforming weights of the cluster representative are calculated (corresponding, as discussed below, to the 2nd stage problem at time slot t), and the relays from all clusters to be selected at the next time slot are determined (which corresponds to the 1st stage problem at time slot t+1). Both tasks (beamforming and relay selection) are based on current CSI, as well as past CSI of cluster representatives selected up to time slot t. We assume that 2-hop relaying is used to assist the communication betweenSandD. The whole network is assumed to operate for NTtime slots. In each time slot t=1, . . . , NT, the source atStransmits the signal √{square root over (PS)}s(t), where s(t) is an information symbol with E[|s(t)|2]=1, and PS>0 the source transmission power. The signal received at the representative relay of each cluster r, located atr(t) is, Rr(t)=∑Lri=1PSfri(t)s(t)+nr(t),(19) where nr(t)˜(0, σ2) is the reception noise at cluster r. Working in an AF fashion, each cluster representative modulates its received signal Rr(t) by a complex weight wr(t) and re-transmits it. Note that a mmWave signal arriving atDdirectly from the source and without the help of a relay has negligible power, and can be ignored. Therefore, the aggregate signal received at the destination from all relay representatives is yD(t)=∑r=1Nc∑k=1Krwr(t)grk(t)Rr(t)+nD(t)=PS∑r=1Ncwr(t)∑k=1Kr∑Lri=1grk(t)fri(t)s(t)︸signal+∑r=1Ncwr(t)∑k=1Krgrk(t)nr(t)+nD(t)︸interference+destinationnoise,(20) where nD(t)˜(0, σD2) is the reception noise atD. Optimal Beamforming for 2-Hop Relaying The various embodiments may be used to extend known distributed relay beamforming schemes to the significantly more complex setting of urban mmWave relay networks. Here, distributed beamforming is considered for enforcing relay cluster cooperation, such that all individual signal paths forwarded from all relay clusters are combined constructively at the destination. Although the solution of the beamforming stage for the mmWave communication setting studied herein is a straightforward manipulation of the expressions found in the literature pertaining to the free-space communication scenario, the result is interesting because it shows the explicit dependence of the optimal beamforming weights and achievable SINR on the aggregate mmWave channels from all propagation paths. At every time slot t, the goal is to obtain the respective beamforming weights to be used by each cluster, w(t)[w*1(t), . . . w*Nc(t)]T∈NC×1such that the SINR atDis maximized, subject to a total transmission power budget PC>0 over all relay clusters. Define the vectors fr(p,t)=△[fr1(p,t),…,frLr(p,t)]T∈ℂLr×1,(21)gr(p,t)=△[gr1(p,t),…,grKr(p,t)]T∈ℂKr×1,(22) r=1, . . . , Nc. Then, after dropping dependence on (t) and (r(t), t) for brevity, the SINR is maximized by solving the following: maximizewwHRwwHQw+σD2subjecttowHDw≤PC,where(23)R=△PShhH,h=△[1Tg11Tf1,…,1TgNc1TfNc]T,(24)D=△PSdiag(1Tf12,…,1TfNc2)+σ21Ncand(25)Q=△σ2diag(1Tg12,…,1TgNc2)(26) and 1 is the all-ones vector. A crucial technical property of problem (23) is that its optimal can be explicitly expressed as: V(t)=∑r=1NcPCPS1Tfr21Tgr2PSσD21Tfr2+PCσ21Tgr2+σ2σD2=∑r=1NcVI(Sr(pr(t),t)),(27) where Sr(r(t), t) is a vector of all random variables referring to the shadowing, multi-path, and phase terms of all unique segments traversed for all paths fromStoD, which also pass through each cluster representative, located atr(t). Specifically, V(t) depends on the relay positions at time slot t. Thus, by optimally positioning the relays, V(t) can be further maximized. This problem is explored in the next subsection. It is noted that the optimal beamforming vectors enjoys an explicit form similar to that used in the free-space scenario: wopt(t)=PCD-12vmaxvmax2,(28) where the alignment vector vmax∈Nc×1is defined as vmax=△[PS1Tg1*1Tf1*PSσD21Tf12+PCσ21Tg12+σ2σD2⋮PS1TgNC*1TfNC*PSσD21TfNC2+PCσ21TgNC2+σ2σD2],(29) and where |1Tfr|2and |1Tgr|2are the incoming and outgoing aggregate channels atr, respectively. In other words, each cluster representative atrdoes not need to estimate the individual channels from every propagation path, but rather only the aggregate channel from all propagation paths. In practice, this can be computed by the selected relay via the exchange of pilots. One may also observe that, while the i-th element of vmaxcan be estimated by the i-th relay only, the vector norm in (28) involves the source and destination channels of all cluster representatives who will beamform at the current time. Therefore, that scalar will have to be computed centrally and then distributed to all clusters. This may be implemented using module220-CTPCM ofFIG.2and a high-speed, optical fiber based backhaul network that connects all relay clusters, as well as all relays within a cluster, with each other. For the source and destination which are, e.g. moving vehicles, no wired connection to the backhaul exists. The beamforming stage requires(Nc) operations. It is noted that during the beamforming step, phase synchronization is required to take care of local oscillator phase offsets. Thus, in various embodiments, phase synchronization between relay clusters is performed via the backhaul network (e.g., via controller200) or via a master relay cluster (e.g., cluster C3of the network100ofFIG.1) to which all other relay clusters synchronize, or by some other means. Optimal Relay Selection for 2-Hop Relaying At every time slot, each cluster must decide which is the appropriate relay to be used for beamforming. Typically, this would first require estimating the respective channel of every relay in the cluster, and then deciding upon the strongest one. Clearly, this decision making procedure not only wastes power and bandwidth during CSI estimation, but also induces extra delay before optimized communication can take place within each time slot. This delay is significant, especially if the number of relays per cluster is large. In this subsection, a new scheme for adaptive relay selection which completely avoids this overhead is proposed, thus resulting in much better time slot utilization. More specifically, the proposed relay selection scheme is based on transferring the implementation of the relay selection procedure from the current time slot, to the previous time slot. In other words, relay selection would be implemented predictively by efficiently exploiting the statistical model of the mmWave channel, before the respective time slot starts. As a result, at each time slot, optimal beamforming is implemented by utilizing the cluster representatives which were optimally selected during the previous slot. This immediately results in the complete elimination of the “waiting delay” discussed above; indeed, if predictive relay selection is sufficiently accurate, then the cluster representatives at each time slot can be predetermined, before the slot starts. This means that relay selection and beamforming can be completely decoupled within each time slot, and thus can be parallelized; indeed, at each time slot, optimal beamforming can be implemented simultaneously with optimal predictive relay selection affecting the next time slot. In addition to eliminating the “waiting delay”, the proposed scheme also enables a substantial reduction of the CSI estimation overhead required for relay selection, as well as significant power savings. We now describe the proposed relay selection scheme in detail. As described above, at time slot t, the interest is in deciding on the best relay representatives from all clusters to participate in beamforming at time slot t+1, such that the networkwide SINR, V(t+1), is maximized. However, at the current time slot t, future CSI needed for evaluating V(t+1) is not yet available. Nevertheless, a reasonable causal criterion for optimal relay selection is to maximize a projection of V(t+1) on information available at time slot t. Following this path, it is proposed to maximize an WSE predictor of V(t+1) relative to the collectionr(t) of all magnitude CSI, or RSS, from the segments of all propagation paths associated with all previously selected representatives of cluster r, as well as the positions of the representatives themselves, up until and including t. Then, due to the additive structure of (27), each cluster r can independently solve maximizep𝔼[VISr(p,t+1))❘𝒞r(t)]subjecttop∈𝒞r(t)(30) wherer(⋅) constitutes the set of candidate relays within the cluster which can potentially be selected. This set can either be unconstrained, including any relay within the cluster, or constrained to only a subset of relays within the cluster. As can be seen by (30), the approach exploits spatial and temporal dependencies of channel shadowing, an otherwise negative effect imposed by the communication medium, in order to actually benefit network QoS by predicting future, one-step-ahead SINR. Next, define the setsrf=∪i=1Lrrifandrg=∪i=1Krrig. Then, at every feasible location∈r(t), the objective of (30) may be expressed as 𝔼[VISr(p,t+1))❘𝒞r(t)]=∫VI(p,s)pSr(p,t+1)❘𝒞r(t)(s)ds,(31) where, dropping dependence on (, t+1), VImay be reexpressed in a more integration-friendly form as VI(·,𝒵rf,φrf,𝒵rg,φrg)=PCPSF(𝒵rf,φrf,)G(𝒵rg,φrg)PSσD2F(𝒵rf,φrf,)+PCσ2G(𝒵rg,φrg)+σ2σD2,(32) with F being a function of the setsrf={zτrf,}, and φrf={ϕτrf,}, corresponding to the combined shadowing plus multi-path, and phase terms of the unique segments traversed in all paths between the source and cluster r, and respectively for G,rgand φrg. By a slightly tedious but straightforward procedure, it may be shown that the joint conditional density of all random variables contained in vector Sr(, t+1) relative tor(t) can be expressed as (by overloading notation) pSr(p,t+1)❘𝒞r(t)(𝒵rf,φrf,𝒵rg,φrg)=𝒩([zτrfzτrg];μτrt+1|t(p),∑τrt+1|t(p))×𝒰(ϕτrf;0,1)𝒰(ϕτrg;0,1)×∏τ∈𝒮rf⋃𝒮rg𝒩(zτ;μτt+1|t,(στt+1|t)2)𝒰(ϕτ;0,1),(33) where(⋅; 0,1) denotes the uniform density on [0,1], and where μτrt+1|t(), Στrt+1|t(), μτt+1|tand (στt+1|t)2constitute the corresponding posterior statistics, each relative to local CSI at the corresponding segment, respectively. This readily follows by mutual independence of the corresponding CSI processes across segments. Note that, although phase information at time slot t+1 is present in (32), the objective (31) is independent of phase information at past time slots. This is because of the standard assumption that, for each segment, the phase component of the channel is white in time and space, and mutually independent of the respective phase component of all other segments. Indeed, one may readily observe that, in (33), all distributions associated with channel phases are uniform in [0,1], which is precisely the prior distribution of all phase components, for all segments taking part in the communication. From the discussion above, it follows that tractably evaluating (31) is a challenging task. Of course, as expected, the first step towards evaluation of (31) is the efficient determination of the aforementioned predictors. This is the subject of the next two subsections. Channel Prediction for Cluster-Free Segments The shadowing component of the channel for a cluster-free segment τ, βτ, is a Gaussian process evolving in time, which may also be represented as a stable autoregression of order 1. Indeed, it may be easily shown that, at every segment τ∈∪r=1Nc(rf∪rg), βτcan be represented via the stochastic difference equation: βτ(t)=κβτ(t-1)+wτ(t),t=1,…,NT,(34) where κe−1/γ, βτ(0)˜(0, η2), with the latter being independent of wτ(t)(0, (1−κ2)η2), t=1, . . . , NT. At the same time, across time slots, the shadowing process βτ(t) cannot be measured directly. Instead, it may be considered as corrupted by unpredictable noise, due to the presence of the multi-path component ξτ(t); indeed, at each time slot t and segment τ, the term zτ(t)=βτ(t)+ξτ(t) is observed. Now, for every segment τ∈∪r=1Nc(rf∪rg), define the vector mτ1:t=Δ[zτ(1),…,zτ(t)]T∈ℝt×1,(35) which contains all observable zero-mean CSI magnitudes associated with that segment, up to time t. Then, exploiting the autoregressive representation of (34), it follows that the posterior distribution of zτ(t+1) relative to mτ1:tis Gaussian with conditional mean and variance given by μτt+1|t=κβτt|tand(36)(στt+1|t)2=κ2ρβτt|t+(1-κ2)η2+σξ2,(37) respectively, where, by definition, βτt|t=△𝔼[βτ(t)|mτ1:t]and(38)ρβτt❘t=△𝔼[(βτ(t)-𝔼[βτ(t)|mτ1:t])2|mτ1:t](39) are the conditional mean and variance of βτ(t) relative to mτ1:t, respectively. Therefore, determination of μτt+1|tand (στt+1|t)2is equivalent to that of βτt|tand ρβτt|t, respectively, for all t=1, . . . , NT. Again due to the autoregressive structure of (34), the latter pair of conditional estimates may be evaluated recursively via a Kalman filter, achieving constant computational complexity per time slot. Specifically, for every t=1, . . . , NT, both βτt|tand ρβτt|tmay be evaluated recursively via the updates βτt|t=κβτt-1|t-1+Kt(zτ(t)-κβτt-1❘t-1),(40)ρβτt|t=Ktσξ2and(41)Kt=κ2ρβτt-1|t-1+(1-κ2)η2κ2ρβτt-1|t-1+(1-κ2)η2+σξ2,(42) initialized by setting βτ0|0=0 and ρβτ0|=η2, stemming from the statistics of the initial condition βτ(0). By direct comparison of (36) and (37) to the Kalman filter equations (40), (41) and (42), it is easy to derive an algorithm for the direct recursive evaluation of μτt+1|tand ττt+1|t)2, comprised, for t=1, . . . , NT, by the dynamic equations μτt+1|t=κ(1-Kt)μτt|t-1+κKtzτ(t),(43)(στt+1|t)2=(1+κ2Kt)σξ2+(1-κ2)η2and(44)Kt=(στt|t-1)2-σξ2(στt|t-1)2,(45) initialized by setting μτ1|0=0 and (στ1|0)2=η2+σξ2. For each cluster-free segment τ∈∪r=1Nc(rf∪rg), the corresponding Kalman filter may be implemented either centrally within each cluster, or in a completely distributed fashion, where each cluster-free segment is responsible for tracking its own channel, and then for distributing its estimate to the associated cluster, responsible for the actual relay selection. Due to its recursive nature, each Kalman filter required an order of(1) operations for each cluster-free segment. Channel Prediction for Segments Containing Clusters Next, consider the segment τr, containing cluster r. Then, if define zτrf,g[zτrfzτrg]Tand store all CSI measurements of every previously selected representative of cluster r in mτr1:t=[zτrf,g(pr(1),1),…,zτrf,g(pr(t),t)]T∈ℝ2t×1,(46) then, for each location∈r(t), the mean vector and covariance matrix of the Gaussian random vector zτrf,g(, t+1) conditioned on mτr1:tare μτrt+1❘t(p)=(σ_τr1:t(p))T(∑_τr1:t)-1mτr1:t∈ℝ2×1(47)∑τrt+1❘t(p)=K_-(σ_τr1:t(p))T(∑_τr1:t)-1σ_τr1:t(p)∈ℝ2×2,(48) respectively, where K_=[η2+σξ2η2e-dmax/βη2e-dmax/βη2+σξ2],(49) andΣτr1:t∈2t×2t,στr1:t∈2t×2are sampled for every time slot until t from Στr∈2δNT×2δNTat the positions that correspond to the distance between the candidate locationand the respective locations where the incoming and outgoing channels of segment τrhave been experienced so far. It is noted that unlike before, (47) and (48) cannot be estimated using a Kalman filter, but rather, using full-blown Gaussian process regression. The dominant operation of (47) and (48) is the inversion of the covariance matrixΣτr1:t. The computational complexity of this inversion is of the order of(t3) operations, and grows with time due to conditioning on past CSI. Nevertheless, the complexity can be reduced to(t2), via a classical application of the matrix inversion lemma. Reduced-Complexity Sample Average Approximation Having determined the necessary posterior statistics involved in (33), the next step is evaluate the objective of (30) or, equivalently, the multi-dimensional integral (31). However, since a closed-form representation of (31) is substantially impossible to derive, a near-optimal approach is used. In particular, the SAA method is relied upon, and replace (30) by an easily computable surrogate, constructed via unconditional Monte Carlo sampling. To define the proposed surrogate to (30), fix∈r(t) and t=1, . . . , NT, and consider the change of variables (again, overloading notation) vτ=(στt+1|t)-1(zτ-μτt+1|t),∀τ∈rf⋃rgand(50)vτrf,g=(∑τrr+1|t(p))-1/2(zτrf,g-μτrt+1|t(p)),(51) to the integral of (31). Additionally, also define the collectionsrf{vτrf,g, {τ}τ∈rf} andrg{vτrf,g, {τ}τ∈rg}. Then, (31) may be equivalently represented as 𝔼[VI(Sr(p,t+1))❘𝒞r(t)]=∫V_It+1|t(p,s)pS_(s)ds,(52)whereV_It+1|t(p,𝒱rf,ϕrf,𝒱rg,ϕrg)=PCPSFt+1❘t(p,𝒱rf,φrf)Gt+1❘t(p,𝒱rg,φrg)PSσD2Ft+1|t(p,𝒱rf,φrf)+PCσ2Gt+1❘t(p,𝒱rg,φrg)+σ2σD2(53) with the functions Ft+1|tand Gt+1|tbeing defined as follows (where if x is a vector, then x|idenotes its i-th entry): Ft+1|t(p,𝒱rf,φrf)=ΔF(p,(∑τrt+1|t(p))vτrf,g1/2+μτrt+1|t(p)1{vτστt+1|t+μτt+1|t}τ∈𝒮rf,φrf)(54)andGt+1|t(p,𝒱rg,φrg)=ΔG(p,(∑τrt+1|t(p))vτrf,g1/2+μτrt+1|t(p)2,{vτστt+1|t+μτt+1|t}τ∈𝒮rg,φrg),(55) and whereSfollows the distribution induced by the density pS_(𝒱rf,φrf,𝒱rg,φrg)=𝒩(vτrf,g;0,I2)𝒰(ϕτrf;0,1)𝒰(ϕτrg;0,1)×∏τ∈𝒮rf⋃𝒮rg𝒩(zτ;0,1)𝒰(ϕτ;0,1).(56) The representation (52) exhibits an important and rather practically appealing property: The density pSis completely independent of bothandr(t), and all such dependence has been transferred toVIt+1|t. Advantageously, sampling from pSis greatly facilitated for the SAA-based scheme, such as described with respect to the Joint Beamforming and relay Selection Scheme ofFIG.4, which is also presented below: for t = 1: NTdoBeamforming (2nd stage of time slot t)Inputs: Channel aggregates |1Tfr|2and |1Tgr|2Compute optimal wopt(t) from (28)Relay selection (1st stage of time slot t + 1)for every cluster r doInputs: a) RSSuntil tb) RSS zτrf(t) and zτrg(t) until tGenerateSfrom (56)for each p ∈r(t) doCompute {circumflex over (V)}I(p, t + 1) from (57)end forChoose pr(t + 1) ∈{circumflex over (V)}I(p, t + 1)end forend for For each relay cluster r and at every time slot t, the SAA method works by randomly generating a total of NSscenarios, drawn from the distribution induced by pS. Clearly, due to the special form of pS, this is straightforward to implement. Then, each scenarioS(i), i=1, . . . , NSis used to evaluateVIt+1|t, at every possible relay position within the set of feasible locations,r(t). Finally, leveraging (52), the SAA of (31) is formulated by replacing the expectation in its objective with an empirical mean as maximizepV^I(p,t+1)=Δ1Ns∑i=1NsV_It+1|t(p,S_(i))subjecttop∈𝒞r(t),(57) The above may be solved by enumeration. The optimal solution of (57) corresponds to the selected relay at t+1. In some embodiments, the same set of scenarios may be used by all relays, in all clusters, and even at all time slots. This, of course, keeps the sampling requirements at a bare minimum, networkwide. In regard to the per cluster computational complexity of the proposed SAA-based scheme, at each time slot t, the conditional statistics of the term zτrf,g(⋅, t+1) relative to mτr1:tneed to be evaluated, for all r=1, . . . , Nc. As explained above, for a single relay of a specific cluster, this requires an order of(t2) operations at time slot t, but since this needs to be done for all relays of the cluster, then end up with an order of(δt2) operations. Additionally, for each of the |Srf∪Srg| segments (not containing a cluster) associated with cluster r,(1) complexity is required due to the recursive form of the Kalman filter. Therefore, the total computational complexity of the SAA-scheme for cluster r, in time slot t, is at most of the order of O(δt2+|Srf∪Srg|); in fact, in most cases, this complexity is often much smaller, since each of the segments contained in Srf∪Srgmay also be associated with clusters other than r, as well. 2-Stage Joint Beamforming/Relay Selection FIG.4depicts a pseudocode representation of a 2-stage joint beamforming and relay selection method or scheme according to an embodiment. Specifically, at time t, beamforming towards the destination is performed, which corresponds to the 2nd stage problem of time slot t. In this stage, the RSS and phases of the channel aggregates at every cluster representative need to be centrally collected, in order to compute the optimal beamforming weights. Within the same time slot t, and in parallel to beamforming, the 1st stage problem of time slot t+1 is solved, i.e., every cluster individually selects the relay to be used for beamforming in the subsequent time slot. In this stage, in addition to the CSI of the cluster representative atr, the relay selection process also requires the CSI of the unique segments that comprise the propagation paths to that cluster. This information can be easily acquired via low cost devices, e.g., channel sounders, placed on every street segment, and then sent through the backhaul network to the respective cluster. In various embodiments, it is deemed to be sufficient to condition on a window of past time slots rather than to the entire observed RSS history. Such an approximation works well even for a relatively small window size, due to the exponentially decaying structure of the temporal correlation component of the channel model. Moreover, depending on the mmWave channel coherence time, some embodiments are adapted to follow a two-timescale design, where the beamforming weights are computed in every time slot but relay selection would be executed over a longer time interval (e.g., 2, 3, 4 or more time-slots). That is, in some embodiments the steps of beamforming and relay selection are performed during a first time slot and each subsequent time slot. Whereas in other embodiments, the step of beamforming is performed during each time slot, but the step of relay selection is performed during a first time slot and then every Nth subsequent time slot, where N is an integer greater than 0 (e.g., 1, 2, 3, 4, 10, 50 etc.). Operational Phases of the Time Slot This section provides a discussion of relay selection and beamforming operations. In every time slot of the ideal scheme, relay selection is always implemented before optimal beamforming; this is simply due to the fact that acquisition of the current RSS has to inevitably be performed in the same time slot as beamforming. On the other hand, in the proposed scheme, relay selection at the current time slot is implemented predictively during the previous time slot, by efficiently exploiting past RSS observations. As a result, the overhead caused by the relay selection process can be effectively bypassed, and optimal beamforming at the current time slot may be implemented completely in parallel with the predictive relay selection affecting the next time slot. Next, looking at the CSI estimation requirement of each selection scheme into more detail. In the ideal scheme, the incoming and outgoing channels of every relay for all clusters are initially estimated. This requires estimating Nideal=2δNcdistinct channels. Channel estimation is initiated by a pilot symbol broadcaster from the source, with every relay of all clusters measuring their RSS. A similar procedure is done for estimating the respective channels towards the destination. On the contrary, the proposed scheme requires estimating the CSI of only the cluster representative, as well as the CSI of every associated segment τ∈rf∪rg, for every cluster r=1, . . . , Nc. Therefore, Nproposed=2Nc+|∪r=1Ncrf∪rg| channels have to be estimated, where |⋅| denotes the cardinality of a set. In other words, when δ>1+|∪r=1Ncrf∪rg|/2Nc, the proposed scheme will always require less number of channel estimations. FIG.5depicts a flow diagram of a method according to an embodiment and suitable for use as an execution method at each of a plurality of relay cluster C, such as described above with respect to the simplified deployment example ofFIG.1. Specifically, the method500ofFIG.5tracks the method400discussed above with respect toFIG.4, as well as the various teachings disclosed herein. In various embodiments, it is contemplated that the method500ofFIG.5is executed at each cluster operative to forward a signal such as from the source node S to the destination node D, as posited above. That is, the method500provides for relay selection at each of a plurality of cooperating nodes within a millimeter wave network, wherein each node is configured to forward a received signal toward a destination node, wherein at least some of the nodes comprise a cluster of relays configured for beamforming in a link between the respective node and the destination node. The method may be implemented at the controller200as described above with respect toFIG.2. At step510, during an initial portion of a current first or Nth time slot t (which may occur during each time slot t, after the occurrence of some number of time slots t, or periodically) the method estimates Channel State Information (CSI) associated with a currently selected relay and CSI associated with network segments traversed by the received signal. Each cluster may receive this information from respective clusters, such as initially provided by one or proximately located sounders. At step520(which may occur after or contemporaneously with step530), during the current time slot t, the method performs/causes beamforming at the currently selected relay using beamforming weights determined in accordance with a corresponding contribution to Signal-to-Interference+Noise Ratio (SINR), given by V(t), at the destination node. At step530(which may occur before, after, or contemporaneously with step520), during the current time slot t, the method selects a relay for a next time slot t+1 in accordance with CSI estimations associated with a maximized minimum mean square error (MNISE) predictor of a next time slot V(t+1) at the destination node. In particular, the method500selects the most suitable relay to participate in beamforming of the subsequent time slot, wherein the selected relay may comprise the relay that maximizes the prediction of the average SINR at the destination. Specifically, step530may be implemented as follows: At step531, using the obtained estimates and/or the accumulated CSI from some or all previous time slots (step510), generate from the distribution of equation (56) NSsamples of vectorS. At step532, for each relay of the cluster, (1) compute the optimal SINR (equation (53)) using the generated NSsamples; and then (2) evaluate the empirical mean of the NSvalues (equation (57)). At step533, choose the relay that yields the largest value from the evaluation at step532. It is noted that steps520and530may be performed in parallel. Generally speaking, for an initial portion of at least some of the time slots t, the method500comprises estimating N channels. If N<2R, then the various embodiments require estimating fewer channels than the respective initial time slot portions of conventional relaying. It is noted that the decision-making method of a subsequent portion of the time slots t may be performed using local or centralized computational resources, such as a local (e.g. proximate one or several clusters or communications nodes) or remote (e.g., remote to the various clusters or communications nodes, such as at a network operations center, network management system or the like) controller configured in relevant part as discussed above with respect toFIG.2, Compared to the ideal, the proposed relay selection scheme is particularly advantageous in dense network topologies, where, to account for high channel variability, each cluster needs to include a large number of relays, and the number of relays per cluster is relatively larger than the number of segments taking part in the communication. Actually, a dense network is required even if the shadowing variance is low, since this implies weaker channel correlation, due to the now dominant multi-path fading. It is then clear that the proposed scheme requires significantly fewer channels to be estimated than the ideal scheme, which in turn leads to reduced channel estimation overhead. It is noted that the various embodiments incur a computational burden associated with the relay selection process, due to the execution of the method400ofFIG.4or the method500ofFIG.5. However, the parallelization of relay selection and optimal beamforming in each time slot not only compensates for that burden, but also naturally leads to more consistent ergodic performance, as long as the accuracy of predictive relay selection is adequate. It is noted that the various embodiments described above contemplate the use of a specific mmWave communication model. However, the various embodiments are applicable to any other mmWave communication models where the respective channel model conforms to a segmented structure as defined above. Further, it is noted that various embodiments may be implemented in a model-free or model-agnostic manner, such as by using reinforcement learning and similar methodologies. In these embodiments, the above-described methods are modified to correspond to the channel model used, the specific reinforcement learning methodology used and so on (e.g., steps in the relay prediction phase are modified to correspond to a specific reinforcement learning algorithm). Although various embodiments which incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings. Thus, while the foregoing is directed to various embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. | 61,879 |
11943039 | DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.1Ais a diagram of an example communications system100in which one or more disclosed embodiments may be implemented. The communications system100may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system100may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems100may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiplexing, orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), and the like. As shown inFIG.1A, the communications system100may include wireless transmit/receive units (WTRUs)102a,102b,102c,102d, a radio access network (RAN)104, a core network106, a public switched telephone network (PSTN)108, the Internet110, and other networks112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs102a,102b,102c,102dmay be any type of device configured to operate and/or communicate in a wireless environment. By way of example, the WTRUs102a,102b,102c,102dmay be configured to transmit and/or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, consumer electronics, and the like. The communications systems100may also include a base station114aand a base station114b. Each of the base stations114a,114bmay be any type of device configured to wirelessly interface with at least one of the WTRUs102a,102b,102c,102dto facilitate access to one or more communication networks, such as the core network106, the Internet110, and/or the other networks112. By way of example, the base stations114a,114bmay be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a site controller, an access point (AP), a wireless router, and the like. While the base stations114a,114bare each depicted as a single element, it will be appreciated that the base stations114a,114bmay include any number of interconnected base stations and/or network elements. The base station114amay be part of the RAN104, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station114aand/or the base station114bmay be configured to transmit and/or receive wireless signals within a particular geographic region, which may be referred to as a cell (not shown). The cell may further be divided into cell sectors. For example, the cell associated with the base station114amay be divided into three sectors. Thus, in one embodiment, the base station114amay include three transceivers, i.e., one for each sector of the cell. In another embodiment, the base station114amay employ multiple-input multiple-output (MIMO) technology and, therefore, may utilize multiple transceivers for each sector of the cell. The base stations114a,114bmay communicate with one or more of the WTRUs102a,102b,102c,102dover an air interface116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface116may be established using any suitable radio access technology (RAT). More specifically, as noted above, the communications system100may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDM, OFDMA, SC-FDMA, and the like. For example, the base station114ain the RAN104and the WTRUs102a,102b,102cmay implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface116using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA). In another embodiment, the base station114aand the WTRUs102a,102b,102cmay implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface116using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A). In other embodiments, the base station114aand the WTRUs102a,102b,102cmay implement radio technologies such as IEEE 802.11 (WLAN), 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like. The base station114binFIG.1Amay be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, and the like. In one embodiment, the base station114band the WTRUs102c,102dmay implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In another embodiment, the base station114band the WTRUs102c,102dmay implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station114band the WTRUs102c,102dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish a picocell or femtocell. As shown inFIG.1A, the base station114bmay have a direct connection to the Internet110. Thus, the base station114bmay not be required to access the Internet110via the core network106. The RAN104may be in communication with the core network106, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs102a,102b,102c,102d. For example, the core network106may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication. Although not shown inFIG.1A, it will be appreciated that the RAN104and/or the core network106may be in direct or indirect communication with other RANs that employ the same RAT as the RAN104or a different RAT. For example, in addition to being connected to the RAN104, which may be utilizing an E-UTRA radio technology, the core network106may also be in communication with another RAN (not shown) employing a GSM radio technology. The core network106may also serve as a gateway for the WTRUs102a,102b,102c,102dto access the PSTN108, the Internet110, and/or other networks112. The PSTN108may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet110may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and the internet protocol (IP) in the TCP/IP internet protocol suite. The networks112may include wired or wireless communications networks owned and/or operated by other service providers. For example, the networks112may include another core network connected to one or more RANs, which may employ the same RAT as the RAN104or a different RAT. Some or all of the WTRUs102a,102b,102c,102din the communications system100may include multi-mode capabilities, i.e., the WTRUs102a,102b,102c,102dmay include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU102cshown inFIG.1Amay be configured to communicate with the base station114a, which may employ a cellular-based radio technology, and with the base station114b, which may employ an IEEE 802 radio technology. FIG.1Bis a system diagram of an example WTRU102. As shown inFIG.1B, the WTRU102may include a processor118, a transceiver120, a transmit/receive element122, a speaker/microphone124, a keypad126, a display/touchpad128, non-removable memory130, removable memory132, a power source134, a global positioning system (GPS) chipset136, and other peripherals138. It will be appreciated that the WTRU102may include any sub-combination of the foregoing elements while remaining consistent with an embodiment. The processor118may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor118may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU102to operate in a wireless environment. The processor118may be coupled to the transceiver120, which may be coupled to the transmit/receive element122. WhileFIG.1Bdepicts the processor118and the transceiver120as separate components, it will be appreciated that the processor118and the transceiver120may be integrated together in an electronic package or chip. The transmit/receive element122may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station114a) over the air interface116. For example, in one embodiment, the transmit/receive element122may be an antenna configured to transmit and/or receive RF signals. In another embodiment, the transmit/receive element122may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit/receive element122may be configured to transmit and receive both RF and light signals. It will be appreciated that the transmit/receive element122may be configured to transmit and/or receive any combination of wireless signals. In addition, although the transmit/receive element122is depicted inFIG.1Bas a single element, the WTRU102may include any number of transmit/receive elements122. More specifically, the WTRU102may employ MIMO technology. Thus, in one embodiment, the WTRU102may include two or more transmit/receive elements122(e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface116. The transceiver120may be configured to modulate the signals that are to be transmitted by the transmit/receive element122and to demodulate the signals that are received by the transmit/receive element122. As noted above, the WTRU102may have multi-mode capabilities. Thus, the transceiver120may include multiple transceivers for enabling the WTRU102to communicate via multiple RATs, such as UTRA and IEEE 802.11, for example. The processor118of the WTRU102may be coupled to, and may receive user input data from, the speaker/microphone124, the keypad126, and/or the display/touchpad128(e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor118may also output user data to the speaker/microphone124, the keypad126, and/or the display/touchpad128. In addition, the processor118may access information from, and store data in, any type of suitable memory, such as the non-removable memory130and/or the removable memory132. The non-removable memory130may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory132may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor118may access information from, and store data in, memory that is not physically located on the WTRU102, such as on a server or a home computer (not shown). The processor118may receive power from the power source134, and may be configured to distribute and/or control the power to the other components in the WTRU102. The power source134may be any suitable device for powering the WTRU102. For example, the power source134may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like. The processor118may also be coupled to the GPS chipset136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU102. In addition to, or in lieu of, the information from the GPS chipset136, the WTRU102may receive location information over the air interface116from a base station (e.g., base stations114a,114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU102may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment. The processor118may further be coupled to other peripherals138, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals138may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, and the like. FIG.1Cis a system diagram of the RAN104and the core network106according to an embodiment. As noted above, the RAN104may employ an E-UTRA radio technology to communicate with the WTRUs102a,102b,102cover the air interface116. The RAN104may also be in communication with the core network106. The RAN104may include eNode-Bs140a,140b,140c, though it will be appreciated that the RAN104may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs140a,140b,140cmay each include one or more transceivers for communicating with the WTRUs102a,102b,102cover the air interface116. In one embodiment, the eNode-Bs140a,140b,140cmay implement MIMO technology. Thus, the eNode-B140a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU102a. Each of the eNode-Bs140a,140b,140cmay be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and/or downlink, and the like. As shown inFIG.1C, the eNode-Bs140a,140b,140cmay communicate with one another over an X2 interface. The core network106shown inFIG.1Cmay include a mobility management gateway (MME)142, a serving gateway144, and a packet data network (PDN) gateway146. While each of the foregoing elements are depicted as part of the core network106, it will be appreciated that any one of these elements may be owned and/or operated by an entity other than the core network operator. The MME142may be connected to each of the eNode-Bs142a,142b,142cin the RAN104via an S1 interface and may serve as a control node. For example, the MME142may be responsible for authenticating users of the WTRUs102a,102b,102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs102a,102b,102c, and the like. The MME142may also provide a control plane function for switching between the RAN104and other RANs (not shown) that employ other radio technologies, such as GSM or WCDMA. The serving gateway144may be connected to each of the eNode Bs140a,140b,140cin the RAN104via the S1 interface. The serving gateway144may generally route and forward user data packets to/from the WTRUs102a,102b,102c. The serving gateway144may also perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when downlink data is available for the WTRUs102a,102b,102c, managing and storing contexts of the WTRUs102a,102b,102c, and the like. The serving gateway144may also be connected to the PDN gateway146, which may provide the WTRUs102a,102b,102cwith access to packet-switched networks, such as the Internet110, to facilitate communications between the WTRUs102a,102b,102cand IP-enabled devices. An access router (AR)150of a wireless local area network (WLAN)155may be in communication with the Internet110. The AR150may facilitate communications between APs160a,160b, and160c. The APs160a,160b, and160cmay be in communication with STAs170a,170b, and170c. The core network106may facilitate communications with other networks. For example, the core network106may provide the WTRUs102a,102b,102cwith access to circuit-switched networks, such as the PSTN108, to facilitate communications between the WTRUs102a,102b,102cand traditional land-line communications devices. For example, the core network106may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the core network106and the PSTN108. In addition, the core network106may provide the WTRUs102a,102b,102cwith access to the networks112, which may include other wired or wireless networks that are owned and/or operated by other service providers. To serve STAs with poor wireless link conditions more efficiently with respect to the power budget, relay functionality was introduced. A relay node allows range extension and supports packet/frame forwarding between source and destination nodes. A relay node is a device that may include two logical entities: a relay STA (R-STA) and a relay AP (R-AP). The R-STA associates with a parent node or AP. The R-AP allows STAs to associate and obtain connectivity to the parent node/AP via the R-STA. A simple bidirectional two-hop relay function has been proposed using one relay node. Two-hop relaying uses a bidirectional relay function, reduces power consumption on the STA with battery constraints, has a limited modulation and coding set (MCS) range, shares one transmit opportunity (TXOP) to reduce the number of contentions for channel access, uses address buffer overflow at the relay node with a flow control mechanism, uses a probe request for relay node discovery, and includes information on the AP-STA link budget (if available) to reduce the number of responses. FIG.2is a signal diagram of a downlink relay procedure200from an AP (source) to a STA (destination) through a relay node. The procedure200is performed between an AP202, a relay node204, and a STA206. The AP202sends a downlink data frame210with the early ACK indication bits set to “00” to the relay node204(step230). After a short interframe space (SIFS) interval212, the relay node204sends an ACK214to the AP202and sets the early ACK indication bits for the next outgoing frame to “11” (step232). After receiving the ACK214, the AP202removes the data frame210from its transmission buffer and defers for a period of time equal to: MAX_PPDU+ACK+(2×SIFS) before the next event (step234). After a second SIFS interval216, the relay node204sends a data frame218to the STA206(step236). The relay node204sends the data frame218with a different MCS than was used for the data frame210and sets the early ACK indication bits to “00.” The relay node204buffers the data frame218until successful delivery to the STA206or until a retry limit is reached. If the STA206successfully receives the data frame218, after a third SIFS interval220, the STA206sends an ACK222to the relay node204, with the early ACK indication bits set to “10” (step238). FIG.3is a signal diagram of an uplink relay method300from a STA (source) to an AP (destination) through a relay node. The method300is performed between an AP302, a relay node304, and a STA306. The STA306sends an uplink data frame310with the early ACK indication bits set to “00” to the relay node304(step330). After a SIFS interval312, the relay node304sends an ACK314to the STA306and sets the early ACK indication bits for the next outgoing frame to “11” (step332). After receiving the ACK314, the STA306removes the data frame310from its transmission buffer and defers for a period of time equal to: MAX_PPDU+ACK+(2×SIFS) before the next event (step334). After a second SIFS interval316, the relay node304sends a data frame318to the AP302(step336). The relay node304sends the data frame318with a different MCS than was used for the data frame310and sets the early ACK indication bits to “00.” The relay node304buffers the data frame318until successful delivery to the AP302or until a retry limit is reached. If the AP302successfully receives the data frame318, after a third SIFS interval320, the AP302sends an ACK322to the relay node304, with the early ACK indication bits set to “10” (step338). A Relay Element is defined for using in connection with the relay operation and may be used with any of the embodiments described herein. A STA with dot11RelaySTACapable set to true includes the Relay Element in an association request or a probe request, for example. The Relay Element contains parameters to support the relay operation.FIG.4shows a Relay Element format400, including an element ID field402, a length field404, a Relay Control field406, and a root AP BSSID field408. The element ID field402includes an identified for the Relay Element400. The length field404includes a length of the Relay Element400. The Relay Control field406indicates whether the AP is a root AP or whether it relays an SSID, as specified in Table 1. TABLE 1Relay ControlMeaning0Root AP1Relayed SSID2-255Reserved The rootAP BSSID field408indicates the BSSID of the root AP. A STA paged via a traffic indication map (TIM) is implicitly assigned a restricted access window (RAW) slot. The AP allocates an equal-length time slot for the STA to send a PS-Poll frame and to retrieve the downlink (DL) data. RAW slot indexf(x)=(x+Noffset)modNRAWEquation (1) NRAW=TRAW/TS, where TRAWis the entire RAW duration, TSis the duration of one RAW slot, and x is the position index of a paged STA or association identifier (AID). With relay being used, the end-STA (the destination STA in a relay procedure) takes more time to send the PS-Poll and retrieve the DL data, causing time slot misalignment for all STAs (relay or non-relay), and the current implicit time slot allocation method does not work. For a system that uses relay functions, there are two issues: the assigned RAW slot of a regular STA may collide with the beacon/TIM transmitted by a R-AP, and the assigned RAW slot of the end-STA may collide with the RAW slot of other STAs because when the end-STA receives the RAW slot information it is delayed by the relay. Therefore, methods to resolve the collision of the RAW slot are required to ensure proper DL data retrieval, and a procedure for the end-STA using relay to retrieve DL data via TIM that can keep the current procedures for non-relay STA intact is desired. FIG.5is a signal diagram of downlink data retrieval method500for relay using a two-step traffic indication map (TIM)-based DL data retrieval. The method500is performed between an AP502, a relay node n504, a STA m506, a first end-STA p508, and a second end-STA q510. The method500includes two stages: stage 1520is a TIM-based DL data retrieval between the root AP and STAs (including relay nodes) associated to the root AP, and stage 2522is a TIM-based DL data retrieval between the relay node and end-STAs associated to the relay node. In stage 1520, the relay node retrieves the DL data from the AP on behalf of the end-STA using the TIM. The AP502broadcasts a TIM530with a positive indication of DL data buffered at the AP for STAs506,508,510. The positive indication in the TIM530may be set using one of the following approaches. A positive indication in the TIM530is reflected on the AID of each end-STA508,510that is associated through the relay node504. Alternately, a positive indication in the TIM530is reflected on the AID of the relay node504if at least one end-STA that is associated through the relay node504has DL data buffered at the AP502, then the AP502sets a positive indication for the relay node504in the TIM530. Alternately, a positive indication in the TIM530is indicated by using a broadcast side channel from the AP502, which may be specific to a group of STAs associated through the relay node504. Upon receiving a positive indication in the TIM530for its own AID, or at least one positive indication for the AID of end-STAs associated with it, the relay node504(the R-STA entity within it) sends a PS-Poll frame532, or similar management frame, in the UL to retrieve the DL data from the AP502on behalf of the end-STA(s). In the case where the relay node504receives more than one positive indication for the AID of end-STAs associated with it, the relay node504may choose to implement one or more of the following procedures. The relay node504sends a PS-Poll frame532for each end-STA associated with the relay node with a positive indication in a one-by-one manner. The AID/Duration field in the PS-Poll frame532is set to the AID of the end-STA, which is different than the transmitter address (TA) in the PS-Poll frame. Alternately, the relay node504sends a PS-Poll frame532for all end-STAs associated with the relay node with a positive indication. The AID/Duration field in the PS-Poll frame532is set to a special value which represents “all end-STAs.” Alternately, the relay node504sends a PS-Poll frame532for each subset of all end-STAs associated with the relay node with a positive indication in a subset-by-subset manner. The AID/Duration field in the PS-Poll frame532may be reused to signal the subset of associated end-STAs. Upon receiving the PS-Poll frame532from the relay node504retrieving DL data for one or several end-STAs, the AP502sends the DL data534as a medium access control (MAC) protocol data unit (MPDU) for one end-STA or as an aggregate MPDU (A-MPDU) for several end-STAs to the relay node504. If the relay node504receives the DL data534for the end-STA from the AP correctly, it sends an ACK536and sets the ACK indication bits. As an example, the relay node504may set the ACK indication bits to “10” for the next outgoing frame. This may be interpreted by the AP502that the relay node504will not forward the DL data536to the corresponding end-STA immediately because it may be in a sleep/doze mode. If the TIM530contains a positive indication for the STA m506, the STA m506sends a PS-Poll frame538to the AP502. Upon receiving the PS-Poll frame538, the AP502sends a data frame540to the STA m506, with the ACK indication bits set to “00.” Upon receiving the data frame540, the STA m506sends an ACK542and sets the ACK indication bits to “10.” Any non-relay STA associated to the root AP retrieves its DL data as presently known. In stage 2522, the end-STA retrieves the DL data from the relay node using the TIM. The relay node n504broadcasts a TIM550, with only positive indications of end-STAs that are associated with the relay node n504. Upon receiving a positive indication in the TIM550, the end-STA p508sends a PS-Poll frame552in the UL to retrieve the DL data from the relay node n504. Upon receiving the PS-Poll frame552from the end-STA p508, the relay node n504sends the DL data554using a three-address format to the end-STA p508with the ACK indication bits set to “00.” If the end-STA p508receives the DL data554correctly from the relay node n504, it sends an ACK556and sets the ACK indication bits to “10” for the next outgoing frame. Similarly, upon receiving a positive indication in the TIM550, the end-STA q510sends a PS-Poll frame558in the UL to retrieve the DL data from the relay node n504. Upon receiving the PS-Poll frame558from the end-STA q510, the relay node n504sends the DL data560using a three-address format to the end-STA q510with the ACK indication bits set to “00.” If the end-STA q510receives the DL data560correctly from the relay node n504, it sends an ACK562and sets the ACK indication bits to “10” for the next outgoing frame. In this way, there is no impact on non-relay STAs, and they do not need to be aware of one or more relay nodes being used, because the time slot allocated to the relay node is the same as the time slot for the non-relay STA. FIG.6is a signal diagram of downlink data retrieval method600for relay using a relay node-initiated retrieval. The method600is performed between an AP602, a relay node n604, a STA m606, a first end-STA p608, and a second end-STA q610. The method600includes two stages: stage 1620is a relay node-initiated DL data retrieval, and stage 2622is an end-STA initiated DL data retrieval. In stage 1620, during a channel access period630(a time period during which a device is allowed to access the channel), the relay node n604sends a PS-Poll frame632in the UL to the AP602at any time on behalf of a set of particular end-STAs associated with the relay node n604(in this capacity, the relay node n604functions as a R-AP). The set of the particular end-STAs may be a specific set of end-STAs associated with the R-AP entity within the relay node n604. The AID/Duration field in the PS-Poll frame632is set to the AID of the end-STA, which is different than the TA address in the PS-Poll frame. Alternately, the set of the particular end-STAs may be all end-STAs associated with the R-AP entity within the relay node n604. The AID/Duration field in the PS-Poll frame632is set to a special value which represents “all end-STAs.” Alternately, the set of the particular end-STAs may be a subset of all end-STAs associated with the R-AP entity within the relay node n604. The AID/Duration field in the PS-Poll frame632may be reused to signal the subset of associated end-STAs. Upon receiving the PS-Poll frame632from the relay node n604, the AP602sends the DL data634(as a MPDU for one end-STA or as an A-MPDU for several end-STAs) to the relay node n604. Alternatively, the AP602may reply to the PS-Poll frame632with an ACK frame that contains a one-bit field with a “1” indicating that traffic is buffered (as indicated in the TIM) and that the end-STA should stay awake (i.e., a service period starts) or a “0” indicating that no traffic is buffered, so the end-STA should go back to sleep. The AP starts transmitting the DL data634to the relay node n604after an interframe space (IFS) time (for example, a SIFS following the ACK frame. If the relay node n604receives the DL data634for the end-STA from the AP602correctly, it sends an ACK frame636and sets the ACK indication bits to “10” for the next outgoing frame, which means that the relay node n604will not forward the DL data634to the corresponding end-STA immediately, because it may be in a sleep/doze mode. The ACK frame636may be designed specifically for this purpose; for example, a short ACK frame may be used. Alternately, the STA m606sends a PS-Poll frame638to the AP602. Upon receiving the PS-Poll frame638, the AP602sends a data frame640to the STA m606, with the ACK indication bits set to “00.” Upon receiving the data frame640, the STA m606sends an ACK frame642and sets the ACK indication bits to “10.” The ACK frame642may be designed specifically for this purpose; for example, a short ACK frame may be used. Any non-relay STA associated to the root AP retrieves its DL data as presently known. In stage 2622, the end-STA wakes up at any time to send a PS-Poll frame in the UL to its associated relay node (i.e., the R-AP entity within the relay node) to retrieve the DL data from the relay node. During a channel access period650, the end-STA p608sends a PS-Poll frame652to the relay node n604. Upon receiving the PS-Poll frame652, the relay node n604sends the DL data654using the three-address format to the end-STA p608with the ACK indication bits set to “00.” Alternatively, the relay node n604may reply to the PS-Poll frame652with an ACK frame that contains a one-bit field, with a “1” indicating that traffic is buffered (as indicated in the TIM) and the end-STA should stay awake (i.e., a service period starts), and a “0” indicating that no traffic is buffered and the end-STA should go back to sleep. The relay node n604starts transmitting the DL data654to the end-STA p608after an IFS time (for example, a SIFS) following the ACK frame. If the end-STA p608receives the DL data654correctly from the relay node n604, it sends an ACK frame656and sets the ACK indication bits to “10” for the next outgoing frame. Similarly, during the channel access period650, the end-STA q610sends a PS-Poll frame658to the relay node n604. Upon receiving the PS-Poll frame658, the relay node n604sends the DL data660using the three-address format to the end-STA q610with the ACK indication bits set to “00.” Alternatively, the relay node n604may reply to the PS-Poll frame658with an ACK frame that contains a one-bit field, with a “1” indicating that traffic is buffered (as indicated in the TIM) and the end-STA should stay awake (i.e., a service period starts), and a “0” indicating that no traffic is buffered and the end-STA should go back to sleep. The relay node n604starts transmitting the DL data660to the end-STA q610after an IFS time (for example, a SIFS) following the ACK frame. If the end-STA q610receives the DL data660correctly from the relay node n604, it sends an ACK frame662and sets the ACK indication bits to “10” for the next outgoing frame. A third method for DL data retrieval may be used (not shown in the Figures), which is a hybrid method using stage 1520of the method500(the relay node retrieves the DL data from the AP on behalf of the end-STA using the TIM) and stage 2622of the method600(the end-STA initiates DL data retrieval from the relay node). A fourth method for DL data retrieval may be used (not shown in the Figures), which is a hybrid method using stage 1620of the method600(relay initiated DL data retrieval from the AP) and stage 2522of the method500(the end-STA retrieves the DL data from the relay node using the TIM). Relay functionality may be used to serve STAs with poor link budgets. When a R-AP receives the UL data from an end-STA, it replies with an ACK. When the AP receives the relayed UL data from the R-STA, it replies with an ACK to the R-STA. However, the path through the relay node may not always be reliable and may have temporary outages or flow/buffer management issues, where some data/frames will be thrown out. To accommodate this, there is a need to introduce a properly designed ACK and efficient flow control for receiving and transmitting frames at the relay node. In addition, the network allocation vector (NAV) setting along the relay path needs to be carried out efficiently. STAs that are at the edge of a BSS coverage area typically suffer poor link quality. In addition, such STAs may also suffer from hidden node issues and overlapping BSS (OBSS) interference. These STAs may be served efficiently with respect to power budget by using a relay. A relay node is typically capable of supporting a four-address frame (i.e., transmitter, receiver, source address, and destination address) and forwarding the frame from a source node to the destination node. Typically, the relay node is aware that a frame from the source node is to be forwarded to a destination node by the destination node address included in the frame when it is transmitted by the source node to the relay node. The channel conditions from the relay node to the destination node may sometimes deteriorate. The source node is not aware of this channel condition and may therefore keep sending frames to the relay node, which may cause congestion and buffer overflow at the relay node, leading to packet or frame loss. An efficient flow control mechanism is required where the relay node needs to stop accepting new frames when its frame/packet buffer is full and try to transmit the currently buffered frames before accepting new frames. To do this, the relay node should be able to signal to the source node to stop sending frames. This may be achieved by signaling using the “10” value for the early ACK indication bits in the SIG field of the PHY preamble/header and using the associated protocol and procedures described below. When a relay node sends an ACK, BA, or any other frame to the source node (AP/STA) with a “10” value for the early ACK indication bits in response to a frame from the source node to be forwarded to the destination node, the source node may follow one or more of the following relay flow control procedures. (1) The source node stops sending more frames to the relay node or does not attempt to send more frames to the relay node. (2) The source node does not attempt to send more data until after a specified time. (3) The source node does not attempt to send more data until the relay node explicitly signals that it may do so. (4) The source node attempts to resend the current data frame. (5) The source node attempts to resend the current data frame after a specified time. (6) The source node attempts to resend the current data frame only after the relay node explicitly signals that it may do so. (7) The source node may truncate the TXOP if needed, for example, with a CF-End frame. In relay flow control in the DL (AP to STA) for a typical data/ACK sequence, the source node (AP) sends frames (e.g., data frames) to the relay node to be forwarded to the destination node. In normal relay operation, the relay node sets a “11” value for the early ACK indication as long as the relay node can or will forward data frames to the destination node. So the relay node will set the early ACK indication to “11” regardless of whether the data frame has the “more data” field set to “1” (indicating that the source node has more data frames to send after the current data frame) or the data frame has the “more data” field set to “0” (indicating that the source node has no more data frames to send after the current data frame). If the relay node cannot receive more frames or equivalently cannot forward more frames, it sends a response frame, e.g., an ACK frame with a “10” value for the early ACK indication. Upon receiving an ACK frame from the relay node with a “10” value for the early ACK indication, in response to a frame from the source node that should be forwarded to the destination node, the source node (AP) may stop sending frames to the relay node for forwarding and follow the relay flow control procedures. FIG.7is a signal diagram of relay flow control method700in the DL (AP to STA) for a data/ACK frame sequence. The method700is performed between an AP702, a relay node704, and a STA706. The AP702sends a DL data frame710to the relay node704with the early ACK indication bits set to “00” (step730). Upon successful receipt of the DL data frame710and after a SIFS interval712, the relay node704sends an ACK frame714to the AP702. The relay node704sets the early ACK indication bits in the ACK frame714to “10” to signal that the AP702should stop sending frames (step732). After receiving the ACK frame714, the AP702stops sending frames to the relay node704and follows the relay flow control procedures (step734). The relay node704may access the medium to send a buffered data frame716to the STA706with the early ACK indication bits set to “00” (step736). Upon successful receipt of the data frame716and after a SIFS interval718, the STA706sends an ACK frame720to the relay node704with the early ACK indication bits set to “10” (step738). In one embodiment of the method700, a short ACK may be used in place of the ACK. In relay flow control in the UL (STA to AP) for a typical data/ACK sequence, the source node (STA) sends frames (e.g., data frames) to the relay node to be forwarded to the destination node. Similar to normal relay operation for the DL, in normal relay operation in the UL, the relay node sets a “11” value for the early ACK indication as long as the relay node can or will forward data frames to the destination node. So the relay node will set the early ACK indication to “11” regardless of whether the data frame has the “more data” field set to “1” (indicating that the source node has more data frames to send after the current data frame) or the data frame has the “more data” field set to “0” (indicating that the source node has no more data frames to send after the current data frame). If the relay node cannot receive more frames or equivalently cannot forward more frames, it sends a response frame, e.g., an ACK frame with a “10” value for the early ACK indication. Upon receiving an ACK frame from the relay node with a “10” value for the early ACK indication, in response to a frame from the source node that should be forwarded to the destination node, the source node (STA) may stop sending frames to the relay node for forwarding and follow the relay flow control procedures. FIG.8is a signal diagram of relay flow control method800in the UL (STA to AP) for a data/ACK frame sequence. The method800is performed between an AP802, a relay node804, and a STA806. The STA806sends an UL data frame810to the relay node804with the early ACK indication bits set to “00” (step830). Upon successful receipt of the data frame810and after a SIFS interval812, the relay node804sends an ACK frame814to the STA806. The relay node804sets the early ACK indication bits in the ACK frame814to “10” to signal that the STA806should stop sending frames (step832). After receiving the ACK frame814, the STA806stops sending frames to the relay node804and follows the relay flow control procedures (step834). The relay node804may access the medium to send a buffered data frame816to the AP802with the early ACK indication bits set to “00” (step836). Upon successful receipt of the data frame816and after a SIFS interval818, the AP802sends an ACK frame820to the relay node804with the early ACK indication bits set to “10” (step838). In one embodiment of the method800, a short ACK may be used in place of the ACK. When A-MPDUs are forwarded on a relay path, it may improve the efficiency of frame transmission on the relay path because the A-MPDU carries aggregated MPDUs. So the relay path is now accessed for the aggregated transmission of MPDUs rather than individually for each MPDU/frame transmission. For this case, in the methods700and800, the data frame is replaced by an A-MPDU and the ACK frame is replaced by a BA frame. The A-MPDU from the source node carries a “01” value in the early ACK indication field to signal a BA response. In the relay flow control for the A-MPDU/BA sequence, the BA from the relay node carries a “10” value for the early ACK indication field to signal to the source node to stop sending frames and to follow the relay flow control procedures. In relay flow control for the DL (AP to STA) for a typical A-MPDU/BA sequence, if the relay node cannot receive more frames or equivalently cannot forward more frames, it sends a response frame (e.g., a BA frame) with a “10” value for the early ACK indication. Upon receiving a BA frame from the relay node with a “10” value for the early ACK indication, in response to a frame from the source node that should be forwarded to the destination node, the source node (AP) may stop sending frames to the relay node for forwarding and follow the relay flow control procedures. FIG.9is a signal diagram of relay flow control method900in the DL for an A-MPDU/BA frame sequence. The method900is performed between an AP902, a relay node904, and a STA906. The AP902sends a DL A-MPDU frame910to the relay node904with the early ACK indication bits set to “01” (step930). Upon successful receipt of the A-MPDU frame910and after a SIFS interval912, the relay node904sends a BA frame914to the AP902. The relay node904sets the early ACK indication bits in the BA frame914to “10” to signal that the AP902should stop sending frames (step932). After receiving the BA frame914, the AP902stops sending frames to the relay node904and follows the relay flow control procedures (step934). The relay node904may access the medium to send a buffered A-MPDU frame916to the STA906with the early ACK indication bits set to “01” (step936). Upon successful receipt of the A-MPDU frame916and after a SIFS interval918, the STA906sends a BA frame920to the relay node904with the early ACK indication bits set to “10” (step938). In one embodiment of the method900, a short BA may be used in place of the BA. In relay flow control for the UL (STA to AP) for a typical A-MPDU/BA sequence, if the relay node cannot receive more frames or equivalently cannot forward more frames, it sends a response frame (e.g., a BA frame) with a “10” value for the early ACK indication. Upon receiving a BA frame from the relay node with a “10” value for the early ACK indication, in response to a frame from the source node that should be forwarded to the destination node, the source node (STA) may stop sending frames to the relay node for forwarding and follow the relay flow control procedures. FIG.10is a signal diagram of relay flow control method1000in the UL for an A-MPDU/BA frame sequence. The method1000is performed between an AP1002, a relay node1004, and a STA1006. The STA1006sends an UL A-MPDU frame1010to the relay node1004with the early ACK indication bits set to “01” (step1030). Upon successful receipt of the A-MPDU frame1010and after a SIFS interval1012, the relay node1004sends a BA frame1014to the STA1006. The relay node1004sets the early ACK indication bits in the BA frame1014to “10” to signal that the STA1006should stop sending frames (step1032). After receiving the BA frame1014, the STA1006stops sending frames to the relay node1004and follows the relay flow control procedures (step1034). The relay node1004may access the medium to send a buffered A-MPDU frame1016to the AP1002with the early ACK indication bits set to “01” (step1036). Upon successful receipt of the A-MPDU frame1016and after a SIFS interval1018, the AP1002sends a BA frame1020to the relay node1004with the early ACK indication bits set to “10” (step1038). In one embodiment of the method1000, a short BA may be used in place of the BA. In one embodiment, which may be used with any other embodiment described herein, a new short/null data packet (NDP) frame may be defined specifically for a relay node to send to the source node to signal to the source node to stop sending frames. Such a short/NDP frame is referred to herein as a short/NDP relay stop frame. A short/NDP relay stop frame, sent from the relay node to the source node, may have one or more of the following characteristics. (1) The short/NDP relay stop frame may be sent by itself (i.e., not as a response frame) to prevent the source node from sending frames for forwarding. (2) The short/NDP relay stop frame may be sent as a response to any frame sent from the source node for forwarding to the relay node. In this scenario, the source node behaves as described previously for the case when it receives a frame from the relay node with a “10” value for the early ACK indication, in response to a frame from the source node that should be forwarded to the destination node. (3) The short/NDP relay stop frame may indicate that the last frame sent by the source node earlier was not forwarded and has to be resent. (4) The short/NDP relay stop frame may include information indicating that one or more frames sent by the source node earlier were not forwarded and have to be resent. (5) The short/NDP relay stop frame may include information on a specific time duration after which the source node may attempt to send frames for forwarding (i.e., a time out duration). (6) The short/NDP relay stop frame may include any or all the above information in the SIG field of the PHY preamble of the frame. FIG.11is a diagram of a format of a short/NDP relay stop frame1100. The short/NDP relay stop frame1100includes a short training field (STF)1102, a long training field (LTF)1104, and a signal (SIG) field1106. The SIG field1106contains short/NDP relay stop information, including any one or more of: a time out duration for the source node or identifiers for any frames that were not forwarded to the destination node. In another embodiment, a new frame that is a regular frame and not a short/NDP frame may be used in place of the short/NDP relay stop frame with the same functionality and characteristics of the short/NDP relay stop frame. In one embodiment, which may be used with any other embodiment described herein, a new short/NDP frame may be defined specifically for a relay node to signal to the source node that it may attempt to start sending frames to the relay node or that it is able to receive more frames from the source node. Such a short/NDP frame is referred to herein as a short/NDP relay start frame. A short/NDP relay start frame, sent from the relay node to the source node, may have one or more of the following characteristics. (1) The short/NDP relay start frame may be sent by itself (i.e., not as a response frame) to signal to the source node to attempt to send frames for forwarding. (2) The short/NDP relay start frame may be sent as a response to a frame sent from the source node requesting the frame forwarding or relay service from the relay node. (3) The short/NDP relay start frame may indicate that the last frame sent by the source node earlier was not forwarded and has to be resent. (4) The short/NDP relay start frame may include information indicating that one or more frames sent by the source node earlier were not forwarded and have to be resent. (5) The short/NDP relay start frame may include information on a specific time duration after which the source node may attempt to send frames for forwarding (i.e., a time out duration). (6) The short/NDP relay start frame may include one or more of the following: the remaining buffer size at the relay node, a number of frames that may be sent by the source node, or a size of the frames that may be sent by the source node. (7) The short/NDP relay start frame may include any or all the above information in the SIG field of the PHY preamble of the frame. FIG.12is a diagram of a format of a short/NDP relay start frame1200. The short/NDP relay start frame1200includes a STF1202, a LTF1204, and a SIG field1206. The SIG field1206contains short/NDP relay start information, including any one or more of: a time out duration for the source node, identifiers for any frames that were not forwarded to the destination node, the remaining buffer size at the relay node, a number of frames that may be sent by the source node, or a size of the frames that may be sent by the source node. In another embodiment, a new frame that is a regular frame and not a short/NDP frame may be used in place of the short/NDP relay start frame with the same functionality and characteristics of the short/NDP relay start frame. One transmit opportunity (TXOP) is shared with the relay node to reduce channel access contention, but this creates the following issues. If a TXOP is reserved from the source node to the relay node and from the relay node to the destination node and includes a SIFS and an ACK time, but the relay link is bad, then one part of the entire TXOP will be wasted. The current mechanism to reserve the TXOP is primarily one-hop, and may not be directly applicable to a two-hop relay. Therefore, a mechanism to reserve the TXOP from the source node to the relay node and from the relay node to the destination node is needed, and a method to truncate the relay-shared TXOP when the relay link goes bad is desired. To facilitate the ready to send (RTS)/clear to send (CTS) based TXOP reservation for a two-hop based relay, a frame format for a relay-RTS (R-RTS) frame is described. The R-RTS frame may reuse the frame format of the existing RTS frame including the modifications described herein. R-RTS format 1: The R-RTS frame includes a PLOP header and a MAC header which contains Frame Control, Duration, TA, receiver address (RA), and frame check sequence (FCS) fields. A one-bit field in the SIG field of the PLOP header is reused to indicate whether the R-RTS frame is used to reserve the TXOP for relay or the time duration by which if the PHY_RXSTART.indication primitive is not received, then a STA that used information from an RTS/R-RTS frame as the most recent basis to update its NAV is permitted to reset its NAV to be larger than the normal RTS/CTS case. R-RTS format 2: The R-RTS frame includes a PLOP header and a MAC header which contains Frame Control, Duration, TA, RA, and FCS fields. Additionally, the MAC header contains a new one-bit indication which signals whether the R-RTS frame is used to reserve the TXOP for relay or the time duration by which if the PHY-RXSTART.indication primitive is not detected, then a STA that used information from an RTS/R-RTS frame as the most recent basis to update its NAV setting is permitted to reset its NAV is larger than the normal RTS/CTS case. In both formats 1 and 2, if the one-bit indication (in the SIG field or in the MAC header) is set to “1”, it implies the same information. A STA that used information from an RTS/R-RTS frame as the most recent basis to update its NAV setting is permitted to reset its NAV if no PHY-RXSTART.indication primitive is detected from the PHY during a period with a duration of: (4×aSIFSTime)+(2×CTS_Time)+(R-RTS_Time)+aPHY-RX-START-Delay+(4×aSlotTime) Equation (2) This period starts at the PHY-RXEND.indication primitive corresponding to the detection of the RTS/R-RTS frame if the relay node transmits a R-RTS frame in the two-hop relay TXOP reservation procedure (described below) is implemented. Alternatively, if the relay node transmits a CTS frame in the two-hop relay TXOP reservation procedure (described below) is implemented, the effective period is: (5×aSIFSTime)+(3×CTS_Time)+(R-RTS_Time)+aPHY-RX-START-Delay+(5×aSlotTime) Equation (3) If the one-bit indication is set to “0,” it implies that a STA that used information from an RTS/R-RTS frame as the most recent basis to update its NAV setting is permitted to reset its NAV if no PHY-RXSTART.indication primitive is detected from the PHY during a period with a duration of: (2×aSIFSTime)+(CTS_Time)+aPHY-RX-START-Delay+(2×aSlotTime) Equation (4) This period starts at the PHY-RXEND.indication primitive corresponding to the detection of the RTS/R-RTS frame. FIG.13is a signal diagram of a network allocation vector (NAV) setting method1300for relay in a case of a successful data transmission. The method1300is performed between a source node1302, a relay node1304, a destination node1306, and other STAs1308. The source node1302initiates the TXOP reservation procedures for the entire duration of the relay frame exchanges, and the duration to transmit the data frame from the relay node to the destination node is assumed to be the worst case or calculated conservatively. The source node1302sends a R-RTS frame1310with the one-bit indication set to “1” to the relay node1304. The duration field in the R-RTS frame1310depends on the detailed signaling procedures. If the relay node1304sends a R-RTS frame (described below), the duration is: 7×aSIFStime+2×CTS_Time+R-RTS_Time+2×ACK_time+Data_Time (source node to relay node)+Data_Time (relay node to destination node) Equation (5) If the relay node1304sends a CTS frame (described below), the duration is: 8×aSIFStime+3×CTS_Time+R-RTS_Time+2×ACK_time+Data_Time (source node to relay node)+Data_Time (relay node to destination node) Equation (6) The Data_Time value (source node to relay node) in Equations (5) and (6) is calculated using the length of the data frame and data rate used for the transmission. The Data_Time value (relay node to destination node) in Equations (5) and (6) is calculated using the length of the data frame and the assumption that the lowest data rate is used for the transmission between the relay node and the destination node. If the source node has knowledge of link between the relay node and the destination node through channel feedback or other means, it calculates the Data_Time value (relay node to destination node) conservatively using the length of the data frame and a lower bound of the data rate to be used for the transmission between the relay node and the destination node. Any of the other STAs1308that receive the R-RTS frame1310set their NAV based on the duration field value of the R-RTS frame1310(step1350). There are two possible procedures for a relay node1304that receives the R-RTS frame1310. In one procedure, the relay node1304transmits a R-RTS frame1312with the one-bit indication set to “0” to the destination node1306after a SIFS interval1314if the NAV at the relay node1304indicates that the medium is idle. The duration field of the R-RTS frame1312is the value obtained from the duration field of the R-RTS frame1310received from the source node1302, minus the time in microseconds required to transmit the R-RTS frame1310and the SIFS interval1314. The RA field is set as the MAC address of the destination node1306, and the TA field is set as the MAC address of the relay node1304. The R-RTS frame1312may also serve as an implicit CTS to the R-RTS frame1310from the source node1302. Upon receiving/detecting the R-RTS frame1312from the relay node1304, the source node1302may determine whether its R-RTS frame1310transmission succeeds or not by one of the following. (1) The source node1302checks whether the TA field of the R-RTS frame1312matches the RA field of the R-RTS frame1310transmitted by the source node1302. (2) If the source node1302knows the MAC address of the destination node1306, it checks whether the RA field of the R-RTS frame1312matches the MAC address of the destination node1306. (3) If the source node1302knows the MAC address of the destination node1306, it checks whether the TA field of the R-RTS frame1312matches the RA field of the R-RTS frame1310transmitted by the source node1302and whether the RA field of the R-RTS frame1312matches the MAC address of the destination node1306. The same rule of CTS reception within the CTSTimeout interval for the source node (as described in connection with the second procedure below) applies to the implicit CTS (i.e., the R-RTS from the relay node1304) as well. In a second procedure (not shown inFIG.13), the relay node1304that is addressed by the R-RTS frame1310transmits an explicit CTS frame to the source node1302after the SIFS interval1314if the NAV at the relay node1304indicates that the medium is idle. The RA field of the CTS frame is copied from the TA field of the R-RTS frame1310. The duration field of the CTS field is the value obtained from the duration field of the R-RTS frame1310, minus the time in microseconds required to transmit the CTS frame and the SIFS interval1314. If the source node1302does not receive such an explicit CTS frame from the relay node1304within a CTSTimeout interval, with a value of aSIFSTime+aSlotTime+aPHY-RX-START-Delay, starting at the PHY-TXEND.confirm primitive, then the source node1302concludes that the transmission of the R-RTS frame1310has failed and invokes its backoff procedure upon expiration of the CTSTimeout interval. If such an explicit CTS frame from the relay node1304is received during the CTSTimeout interval, the source node1302concludes that the transmission of the R-RTS frame1310succeeded, but holds its data transmission. Then, the relay node1304sends the R-RTS frame1312with the one-bit indication set to “0” to the destination node1306after a SIFS interval after sending the CTS. The duration field of the R-RTS frame1312is the value obtained from the duration field of the CTS frame from the relay node1304to the source node1302, minus the time in microseconds required to transmit the R-RTS frame1310and its SIFS interval1314. The RA field is set as the MAC address of the destination node1306, and the TA field is set as the MAC address of the relay node1304. Any of the other STAs1308that receive the R-RTS frame1312set their NAV based on the duration field value of the R-RTS frame1312(step1352). The destination node1306that is addressed by the R-RTS frame1312from the relay node1304transmits a CTS frame1316to the relay node1304after a SIFS interval1318if the NAV at the destination node1306indicates that the medium is idle. The field setting of the CTS frame1316in reference to the R-RTS frame1312and the rule of handling the CTSTimeout is the same as currently implemented. Any of the other STAs1308that receive the CTS frame1316set their NAV based on the duration field value of the CTS frame1316(step1354). Upon receiving the CTS frame1316from the destination node1306within the CTSTimeout interval, the relay node1304transmits a CTS frame1320addressed to the source node1302to indicate whether the TXOP reservation for the two-hop relay succeeds. Different than conventional CTS transmission, at this step the relay node1304does need to check if the NAV at the relay node indicates that the medium is idle, because the previous steps have guaranteed that the medium is idle. The RA field of the CTS frame1320is set to the MAC address of the source node1302. The duration field of the CTS frame1320is the value obtained from the duration field of the CTS frame1316, minus the time in microseconds required to transmit the CTS frame1316and its SIFS interval1322. Any of the other STAs1308that receive the CTS frame1320set their NAV based on the duration field value of the CTS frame1320(step1356). Upon receiving the CTS frame1320from the relay node1304, the source node1302knows that the TXOP reservation for the two-hop relay succeeds. The source node1302starts transmitting a data frame1324after a SIFS interval1326following the CTS frame1320received from the relay node1304. The relay node1304processes the received data frame1324. If the received data frame1324is decoded correctly, the relay node1304sends an ACK frame1328after a SIFS interval1330without changing the duration of reserved TXOP. If the received data frame1324is not decoded correctly, the source node1302will not receive an ACK by the time aSIFS time+ACK_Time after sending the data frame1324. The source node1302will release the TXOP by sending a CF-End frame1332. The relay node1304sends a CF-End frame1334and the destination node1306sends a CF-End frame1336upon receipt of the CF-End frame1332. If the relay node1304successfully receives the data frame1324, the relay node1304transmits the data frame as data frame1338to the destination node1306after a SIFS interval1340. The destination node1306processes the received data frame1338from the relay node1304. If received data frame1338is decoded correctly, the destination node1306sends an ACK frame1342after a SIFS interval1344. The destination node1306may use a method at this step to release the TXOP and reset the NAV for the other STAs1308near the destination node1306. For example, the destination node1306may set the ACK indication to be “10” in the outgoing frame. Upon receiving the ACK frame1342from the destination node1306and if the current TXOP has not yet expired, the relay node1304sends the CF-End frame1334after a SIFS interval1346to truncate/release the TXOP. If the relay node1304does not receive the ACK frame1342within aSIFS time+ACK_Time after sending the data frame1338and the remaining TXOP allows it to retransmit the data frame1338, it may retransmit the data frame1338to the destination node1306. Upon receiving the CF-End frame1334from the relay node1304before the current TXOP expires, the source node1302sends the CF-End frame1332after a SIFS interval1348. Upon receiving the CF-End frame1334from the relay node1304before the current TXOP expires, the destination node1306sends the CF-End frame1336. This step is only necessary if the method to release TXOP and reset the NAV has not been previously applied. There is no need to implement both steps. When the TXOP is released, the NAV at the other STAs1308is reset (step1358). FIG.14is a signal diagram of a second NAV setting method1400for relay in a case of a successful data transmission. The method1400is performed between a source node1402, a relay node1404, a destination node1406, and other STAs1408. The source node1402initiates the TXOP reservation procedures for the entire duration of the relay frame exchanges, and the duration to transmit the data frame from the relay node to the destination node is assumed to be the worst case or calculated conservatively. The source node1402sends a R-RTS frame1410with the one-bit indication set to “1” to the relay node1404. The duration field in the R-RTS frame1410depends on the detailed signaling procedures. If the relay node1404sends a R-RTS frame (described below), the duration is: 7×aSIFStime+2×CTS_Time+R-RTS_Time+2×ACK_time+Data_Time (source node to relay node)+Data_Time (relay node to destination node) Equation (7) If the relay node1404sends a CTS frame (described below), the duration is: 8×aSIFStime+3×CTS_Time+R-RTS_Time+2×ACK_time+Data_Time (source node to relay node)+Data_Time (relay node to destination node) Equation (8) The Data_Time value (source node to relay node) in Equations (7) and (8) is calculated using the length of the data frame and data rate used for the transmission. The Data_Time value (relay node to destination node) in Equations (7) and (8) is calculated using the length of the data frame and the assumption that the lowest data rate is used for the transmission between the relay node and the destination node. If the source node has knowledge of link between the relay node and the destination node through channel feedback or other means, it calculates the Data_Time value (relay node to destination node) conservatively using the length of the data frame and a lower bound of the data rate to be used for the transmission between the relay node and the destination node. Any of the other STAs1408that receive the R-RTS frame1410set their NAV based on the duration field value of the R-RTS frame1410(step1450). There are two possible procedures for a relay node1404that receives the R-RTS frame1410. In one procedure, the relay node1404transmits a R-RTS frame1412with the one-bit indication set to “0” to the destination node1406after a SIFS interval1414if the NAV at the relay node1404indicates that the medium is idle. The duration field of the R-RTS frame1412is the value obtained from the duration field of the R-RTS frame1410received from the source node1402, minus the time in microseconds required to transmit the R-RTS frame1410and the SIFS interval1414. The RA field is set as the MAC address of the destination node1406, and the TA field is set as the MAC address of the relay node1404. The R-RTS frame1412may also serve as an implicit CTS to the R-RTS frame1410from the source node1402. Upon receiving/detecting the R-RTS frame1412from the relay node1404, the source node1402may determine whether its R-RTS frame1410transmission succeeds or not by one of the following. (1) The source node1402checks whether the TA field of the R-RTS frame1412matches the RA field of the R-RTS frame1410transmitted by the source node1402. (2) If the source node1402knows the MAC address of the destination node1406, it checks whether the RA field of the R-RTS frame1412matches the MAC address of the destination node1406. (3) If the source node1402knows the MAC address of the destination node1406, it checks whether the TA field of the R-RTS frame1412matches the RA field of the R-RTS frame1410transmitted by the source node1402and whether the RA field of the R-RTS frame1412matches the MAC address of the destination node1406. The same rule of CTS reception within the CTSTimeout interval for the source node (as described in connection with the second procedure below) applies to the implicit CTS (i.e., the R-RTS from the relay node1404) as well. In a second procedure (not shown inFIG.14), the relay node1404that is addressed by the R-RTS frame1410transmits an explicit CTS frame to the source node1402after the SIFS interval1414if the NAV at the relay node1404indicates that the medium is idle. The RA field of the CTS frame is copied from the TA field of the R-RTS frame1410. The duration field of the CTS field is the value obtained from the duration field of the R-RTS frame1410, minus the time in microseconds required to transmit the CTS frame and the SIFS interval1414. If the source node1402does not receive such an explicit CTS frame from the relay node1404within a CTSTimeout interval, with a value of aSIFSTime+aSlotTime+aPHY-RX-START-Delay, starting at the PHY-TXEND.confirm primitive, then the source node1402concludes that the transmission of the R-RTS frame1410has failed and invokes its backoff procedure upon expiration of the CTSTimeout interval. If such an explicit CTS frame from the relay node1404is received during the CTSTimeout interval, the source node1402concludes that the transmission of the R-RTS frame1410succeeded, but holds its data transmission. Then, the relay node1404sends the R-RTS frame1412with the one-bit indication set to “0” to the destination node1406after a SIFS interval after sending the CTS. The duration field of the R-RTS frame1412is the value obtained from the duration field of the CTS frame from the relay node1404to the source node1402, minus the time in microseconds required to transmit the R-RTS frame1410and its SIFS interval1414. The RA field is set as the MAC address of the destination node1406, and the TA field is set as the MAC address of the relay node1404. Any of the other STAs1408that receive the R-RTS frame1412set their NAV based on the duration field value of the R-RTS frame1412(step1452). The destination node1406that is addressed by the R-RTS frame1412from the relay node1404transmits a CTS frame1416to the relay node1404after a SIFS interval1418if the NAV at the destination node1406indicates that the medium is idle. The field setting of the CTS frame1416in reference to the R-RTS frame1412and the rule of handling the CTSTimeout is the same as currently implemented. Any of the other STAs1408that receive the CTS frame1416set their NAV based on the duration field value of the CTS frame1416(step1454). Upon receiving the CTS frame1416from the destination node1406within the CTSTimeout interval, the relay node1404transmits a CTS frame1420addressed to the source node1402to indicate whether the TXOP reservation for the two-hop relay succeeds. Different than conventional CTS transmission, at this step the relay node1404does need to check if the NAV at the relay node indicates that the medium is idle, because the previous steps have guaranteed that the medium is idle. The RA field of the CTS frame1420is set to the MAC address of the source node1402. The duration field of the CTS frame1420is the value obtained from the duration field of the CTS frame1416, minus the time in microseconds required to transmit the CTS frame1416and its SIFS interval1422. Any of the other STAs1408that receive the CTS frame1420set their NAV based on the duration field value of the CTS frame1420(step1456). Upon receiving the CTS frame1420from the relay node1404, the source node1402knows that the TXOP reservation for the two-hop relay succeeds. The source node1402starts transmitting a data frame1424after a SIFS interval1426following the CTS frame1420received from the relay node1404. The relay node1404processes the received data frame1424. If the received data frame1424is decoded correctly, the relay node1404sends an ACK frame1428after a SIFS interval1430, with the ACK indication bits set to “11.” At this point, the relay node1404has a good knowledge of the duration to transmit the data frame to the destination node1406. The duration of the remaining TXOP is set to be: 2×aSIFStime+Data_Time (relay node to destination node)+ACK_time Equation (9) The Data_Time value (relay node to destination node) is calculated using the length of the data frame and the data rate used for the transmission from the relay node1404to the destination node1406. Any of the other STAs1408that receive the ACK frame1428set their NAV based on the duration field value of the ACK frame1428(step1458). If the received data frame1424is not decoded correctly, the source node1402will not receive an ACK by the time aSIFS time+ACK_Time after sending the data frame1424. The source node1402releases the TXOP by sending a CF-End frame1432or retransmits the data frame1424to the relay node1404. If the source node1402releases the TXOP, then the relay node1404sends a CF-End frame (not shown inFIG.14) and the destination node1406sends a CF-End frame (not shown inFIG.14) upon receipt of the CF-End frame1432. If the relay node1404successfully receives the data frame1424, the relay node1404transmit the data frame as data frame1434to the destination node1406after a SIFS interval1436. The destination node1406processes the received data frame1434from the relay node1404. If the received data frame1434is decoded correctly, the destination node1406sends an ACK frame1438after a SIFS interval1440. The destination node1406may use a method at this step to release the TXOP and reset the NAV for the other STAs1408near the destination node1406. For example, the destination node1406may set the ACK indication bits to “10” in the outgoing frame. After a SIFS interval1442by the end of TXOP set by the ACK frame1428from the relay node1404, the source node1402sends the CF-End frame1432. When the TXOP is released, the NAV at the other STAs1408is reset (step1460). Alternatively, a “Data+CF-ACK” frame may be used to carry both the data frame from the relay node to the destination node and the ACK for the data transmitted from the source node to the relay node. Such a frame may be a new defined frame or a reused existing Data+CF-ACK frame. The implicit ACK method may be considered a special case of using only one frame to carry both the data frame from the relay node to the destination node and the ACK for the data frame transmitted from the source node to the relay node. When one frame transmitted by the relay node carries both the data frame from the relay node to the destination node and the ACK for the data transmitted from the source node to the relay node, the timing of the procedures in both methods1300and1400are reduced by the ACK_Time and a SIFS time, as shown in connection with a method1500shown inFIG.15and described below. For example, the duration of the R-RTS frame from the source node to the relay node includes: 6×aSIFStime+2×CTS_Time+R-RTS_Time+ACK_time+Data_Time (source node to relay node)+Data_Time (relay node to destination node) Equation (10) FIG.15is a signal diagram of a third NAV setting method1500for relay in a case of a successful data transmission. The method1500is performed between a source node1502, a relay node1504, a destination node1506, and other STAs1508. The source node1502initiates the TXOP reservation procedures for the entire duration of the relay frame exchanges, and the duration to transmit the data frame from the relay node to the destination node is assumed to be the worst case or calculated conservatively. The source node1502sends a R-RTS frame1510with the one-bit indication set to “1” to the relay node1504. The duration field in the R-RTS frame1510depends on the detailed signaling procedures. If the relay node1504sends a R-RTS frame (described below), the duration is: 7×aSIFStime+2×CTS_Time+R-RTS_Time+2×ACK_time+Data_Time (source node to relay node)+Data_Time (relay node to destination node) Equation (11) If the relay node1504sends a CTS frame (described below), the duration is: 8×aSIFStime+3×CTS_Time+R-RTS_Time+2×ACK_time+Data_Time (source node to relay node)+Data_Time (relay node to destination node) Equation (12) The Data_Time value (source node to relay node) in Equations (11) and (12) is calculated using the length of the data frame and data rate used for the transmission. The Data_Time value (relay node to destination node) in Equations (11) and (12) is calculated using the length of the data frame and the assumption that the lowest data rate is used for the transmission between the relay node and the destination node. If the source node has knowledge of link between the relay node and the destination node through channel feedback or other means, it calculates the Data_Time value (relay node to destination node) conservatively using the length of the data frame and a lower bound of the data rate to be used for the transmission between the relay node and the destination node. Any of the other STAs1508that receive the R-RTS frame1510set their NAV based on the duration field value of the R-RTS frame1510(step1550). There are two possible procedures for a relay node1504that receives the R-RTS frame1510. In one procedure, the relay node1504transmits a R-RTS frame1512with the one-bit indication set to “0” to the destination node1506after a SIFS interval1514if the NAV at the relay node1504indicates that the medium is idle. The duration field of the R-RTS frame1512is the value obtained from the duration field of the R-RTS frame1510received from the source node1502, minus the time in microseconds required to transmit the R-RTS frame1510and the SIFS interval1514. The RA field is set as the MAC address of the destination node1506, and the TA field is set as the MAC address of the relay node1504. The R-RTS frame1512may also serve as an implicit CTS to the R-RTS frame1510from the source node1502. Upon receiving/detecting the R-RTS frame1512from the relay node1504, the source node1502may determine whether its R-RTS frame1510transmission succeeds or not by one of the following. (1) The source node1502checks whether the TA field of the R-RTS frame1512matches the RA field of the R-RTS frame1510transmitted by the source node1502. (2) If the source node1502knows the MAC address of the destination node1506, it checks whether the RA field of the R-RTS frame1512matches the MAC address of the destination node1506. (3) If the source node1502knows the MAC address of the destination node1506, it checks whether the TA field of the R-RTS frame1512matches the RA field of the R-RTS frame1510transmitted by the source node1502and whether the RA field of the R-RTS frame1512matches the MAC address of the destination node1506. The same rule of CTS reception within the CTSTimeout interval for the source node (as described in connection with the second procedure below) applies to the implicit CTS (i.e., the R-RTS from the relay node1504) as well. In a second procedure (not shown inFIG.15), the relay node1504that is addressed by the R-RTS frame1510transmits an explicit CTS frame to the source node1502after the SIFS interval1514if the NAV at the relay node1504indicates that the medium is idle. The RA field of the CTS frame is copied from the TA field of the R-RTS frame1510. The duration field of the CTS field is the value obtained from the duration field of the R-RTS frame1510, minus the time in microseconds required to transmit the CTS frame and the SIFS interval1514. If the source node1502does not receive such an explicit CTS frame from the relay node1504within a CTSTimeout interval, with a value of aSIFSTime+aSlotTime+aPHY-RX-START-Delay, starting at the PHY-TXEND.confirm primitive, then the source node1502concludes that the transmission of the R-RTS frame1510has failed and invokes its backoff procedure upon expiration of the CTSTimeout interval. If such an explicit CTS frame from the relay node1504is received during the CTSTimeout interval, the source node1502concludes that the transmission of the R-RTS frame1510succeeded, but holds its data transmission. Then, the relay node1504sends the R-RTS frame1512with the one-bit indication set to “0” to the destination node1506after a SIFS interval after sending the CTS. The duration field of the R-RTS frame1512is the value obtained from the duration field of the CTS frame from the relay node1504to the source node1502, minus the time in microseconds required to transmit the R-RTS frame1510and its SIFS interval1514. The RA field is set as the MAC address of the destination node1506, and the TA field is set as the MAC address of the relay node1504. Any of the other STAs1508that receive the R-RTS frame1512set their NAV based on the duration field value of the R-RTS frame1512(step1552). The destination node1506that is addressed by the R-RTS frame1512from the relay node1504transmits a CTS frame1516to the relay node1504after a SIFS interval1518if the NAV at the destination node1506indicates that the medium is idle. The field setting of the CTS frame1516in reference to the R-RTS frame1512and the rule of handling the CTSTimeout is the same as currently implemented. Any of the other STAs1508that receive the CTS frame1516set their NAV based on the duration field value of the CTS frame1516(step1554). Upon receiving the CTS frame1516from the destination node1506within the CTSTimeout interval, the relay node1504transmits a CTS frame1520addressed to the source node1502to indicate whether the TXOP reservation for the two-hop relay succeeds. Different than conventional CTS transmission, at this step the relay node1504does need to check if the NAV at the relay node indicates that the medium is idle, because the previous steps have guaranteed that the medium is idle. The RA field of the CTS frame1520is set to the MAC address of the source node1502. The duration field of the CTS frame1520is the value obtained from the duration field of the CTS frame1516, minus the time in microseconds required to transmit the CTS frame1516and its SIFS interval1522. Any of the other STAs1508that receive the CTS frame1520set their NAV based on the duration field value of the CTS frame1520(step1556). Upon receiving the CTS frame1520from the relay node1504, the source node1502knows that the TXOP reservation for the two-hop relay succeeds. The source node1502starts transmitting a data frame1524after a SIFS interval1526following the CTS frame1520received from the relay node1504. The relay node1504processes the received data frame1524. If the received data frame1524is decoded correctly, the relay node1504forwards the data frame to the destination node1506by sending a Data+CF-ACK frame1528after a SIFS interval1530, with a NAV setting in its MAC header whose duration is calculated using the length of the data frame and the data rate used for the transmission. If the received data frame1524is not decoded correctly, the source node1502will not receive an ACK by the time aSIFS time+ACK_Time after sending the data frame1524. The source node1502releases the TXOP by sending a CF-End frame1532. If the source node1502releases the TXOP, then the relay node1504sends a CF-End frame (not shown inFIG.15) and the destination node1506sends a CF-End frame (not shown inFIG.15) upon receipt of the CF-End frame1532. The destination node1506processes the received data frame (from the received Data+CF-ACK frame1528) from the relay node1504. If the received data frame is decoded correctly, the destination node1506sends an ACK frame1534after a SIFS interval1536. The destination node1506may use a method at this step to release the TXOP and reset the NAV for the other STAs1508near the destination node1506. For example, the destination node1506may set the ACK indication bits to “10” in the outgoing frame. Upon receiving the Data+CF-ACK frame1528from the relay node1504before the current TXOP expires, the source node1502sends the CF-End frame1532after a SIFS interval1538following the duration signaled in the NAV setting in the received Data+CF-ACK frame1528. FIG.16is a signal diagram of a fourth NAV setting method1600for relay in a case of a successful data transmission. The method1600is performed between a source node1602, a relay node1604, a destination node1606, and other STAs1608. The source node1602reserves the TXOP for the duration of the frame exchanges between the source node1602and the relay node1604. The source node sends an RTS frame1610to the relay node1604. The duration in the RTS frame1610includes: 3×aSIFStime+CTS_Time+ACK_time+Data_Time (source node to relay node) Equation (13) The Data_Time value (source node to relay node) in Equation (13) is calculated using the length of the data frame and the data rate used for the transmission. Any of the other STAs1608that receive the RTS frame1610set their NAV based on the duration field value of the RTS frame1610(step1640). After receiving the RTS frame1610, the relay node1604waits for a SIFS interval1612and transmits a CTS frame1614to the source node1602. Any of the other STAs1608that receive the CTS frame1614set their NAV based on the duration field value of the CTS frame1614(step1642). Upon receipt of the CTS frame1614, the source node1602transmits a data frame1616after a SIFS interval1618. The relay node1604processes the received data frame1616. If the received data frame1616is decoded correctly, the relay node1604sends an ACK frame1620after a SIFS interval1622, and sets the ACK indication bits to “11” in the next outgoing frame. The duration field in the ACK frame1620is set to the value of: 3×aSIFSTime+CTS-to-self_Time (at destination node)+ACK_time+Data_Time (relay node to destination node) Equation (14) or 4×aSIFSTime+CTS-to-self_Time (at source node)+CTS-to-self_Time (at destination node)+ACK_time+Data_Time (relay node to destination node) Equation (15) The choice between using Equation (14) or Equation (15) to determine the duration field depends on whether the optional CTS-to-self frame at the source node1602is implemented or not, as will be described below. If the source node implements the optional CTS-to-self frame, then Equation (15) is used to determine the duration field. The Data_Time value (relay node to destination node) in Equations (14) and (15) is calculated using the length of the data frame and the data rate used for the transmission from the relay node1604to the destination node1606. Any of the other STAs1608that receive the ACK frame1620set their NAV based on the duration field value of the ACK frame1620(step1644). If the received data frame1616is not decoded correctly, the source node1602will not receive an ACK by the time aSIFS time+ACK_Time after sending the data frame1616. The TXOP then ends. Upon receiving the ACK frame1620from the relay node1604, the destination node1606sends a CTS-to-self frame1624after a SIFS interval1626, with the end of the TXOP aligned with the end of the TXOP set above by the relay node, if the NAV at the destination node1606indicates that the medium is idle. Any of the other STAs1608that receive the CTS-to-self frame1624set their NAV based on the duration field value of the CTS-to-self frame1624(step1646). Optionally, the source node1602may send a CTS-to-self frame1628after a SIFS interval1630, with the end of TXOP aligned with the end of the TXOP set above by the relay node. Any of the other STAs1608that receive the CTS-to-self frame1628set their NAV based on the duration field value of the CTS-to-self frame1628(step1648). After the SIFS interval1630following the CTS-to-self frame1624from the destination node1606or a SIFS interval1632if the optional CTS-to-self frame1628from the source node1602, the relay node1604transmits the data frame as a data frame1634to the destination node1606. The destination node1606processes the received data frame1634. If the received data frame1634is decoded correctly, the destination node1606sends an ACK frame1636to the relay node1604after a SIFS interval1638. The destination node1606may set the ACK indication bits to “10” in the outgoing frame. After the ACK frame1636is sent, this indicates the end of the frame exchange sequence. The other STAs1608wait for an interframe space1650, which may be a SIFS, a point coordination function interframe space (PIFS), or a distributed coordination function interframe space (DIFS) before entering a back-off window1652. The current UL frame delivery procedure allows the AP to assign a channel access slot to the STA to contend using a management frame when requested by the STA. When using relay functions, the R-AP does not have full knowledge of the usage of all channel access slots as the AP does when requested by an end-STA. Without appropriate coordination between the AP and the R-AP and consideration of the limited range of meters and sensors operating on lower power, either an overload or an under-utilization of some channel access slots may happen. Currently, the TIM is carried on a beacon. The relay node may broadcast its beacon with the full TIM, the same as broadcast by the root AP. However, this is inefficient when using relay because only a small number of end-STAs are actually associated with the relay node. Therefore, methods to reduce the overhead for the TIM broadcast by the relay node are desirable. The TIM indication and data retrieval procedures for end-STAs that are associated with R-APs are as follows. For a R-AP, when it becomes a relay node for a root STA, it may be assigned two AIDs. One AID is for the R-STA, which may represent the STA itself, in case the STA itself may also transmit and receive data traffic. A second AID is for the R-AP, which may represent the group of end-STAs that are associated with the R-AP. Alternatively, the group of end-STAs that are associated with the R-AP may also be identified by a group identifier. When one or more end-STAs choose to associate with a R-AP instead of the root AP, the R-AP may report the new association to the root AP using an end-STA Report Information Element (IE), for example, as shown inFIG.17. The end-STA Report IE may be used in connection with any of the embodiments described herein. The end-STA Report IE1700includes an element ID field1702, a length field1704, a number of fields indication1706, and a plurality of information fields1708a-1708n. The element ID field1702includes an identifier indicating that it is an end-STA Report IE. The length field1704indicates the length of the end-STA Report IE1700. The number of fields indication1706includes the number of end-STAs reported in the IE1700. Each information field1708a-1708ncontains the information of one end-STA, including an ID subfield1710, a previous association subfield1712, and a previous AID subfield1714. The ID subfield1710includes the ID of the end-STA, which may be implemented as a MAC address, an AID, or any other type of IDs that the STAs and the AP have agreed upon. The previous association subfield1712indicates the previous association of the end-STA and may be implemented as the MAC address of the previous AP, R-AP, or root AP that the end-STA was associated with. The previous AID subfield1714includes the AID of the root AP that the end-STA was previously associated with, if any. The end-STA Report IE1700or any subset of the fields or subfields thereof may be implemented as a field, a subfield, or subsets of subfields of any existing or new IE; as a part of any control, management, or other type of frame; or in MAC/PLCP headers. The R-AP may assign another AID value to the end-STA that is associated with the R-AP. The TIM indications for the end-STAs in beacons from the R-AP may follow this new AID assignment. When the root AP receives the end-STA Report IE1700, it associates the MAC address/ID of the end-STA with the AID or MAC address of the R-AP and acknowledges receipt of the end-STA Report IE1700using an ACK, a BA, or other type of frame. The AP may assign two separate UL time slots of different length (following the same TIM beacon or TIM short beacon, or following two different TIM beacons or TIM short beacons) for the two different AIDs in the same or different RAW, one associated with the R-STA and one associated with the R-AP. If frames arrive that are destined to the R-STA itself, the AP may indicate a positive TIM for the AID associated with the AID for the R-STA and assign a shorter UL time slot that is sufficient for the R-STA to send a PS-Poll frame to retrieve its own DL data. If frames arrive that are destined for the group of end-STAs associated with the R-AP, the AP may indicate a positive TIM for the AID associated with the AID for the R-AP and assign a longer UL time slot that may be sufficient for the R-STA to retrieve all frames buffered for all end-STAs associated with it. In a first alternative, the UL time slot may be sufficient for the R-STA to retrieve all frames buffered for all end-STAs associated with it and then send out a beacon for the relay BSS indicating a positive TIM for the end-STAs using the R-AP AIDs. In a second alternative, the UL time slot may be sufficient for the R-STA to retrieve all frames buffered for all end-STAs associated with it and then send out a beacon for the relay BSS indicating a positive TIM for the end-STAs using the R-AP assigned AIDs, and for all the end-STAs to send PS-Poll frames to retrieve the frames buffered for them at the R-AP. If there is only one frame buffered for a particular end-STA that is associated with a R-AP at the time of the TIM indication, when the R-STA transmits a PS-Poll frame to the AP to retrieve the DL data frame for its end-STAs, the AP may send the buffered frame using a four-address MAC frame with the immediate receiver being the R-STA. The R-AP may then forward the frame to the end-STA using the normal MAC frame format. If there are multiple frames buffered for end-STAs that are associated with a R-AP at the time of the TIM indication, when the R-STA transmits a PS-Poll frame to the AP to retrieve the DL data frames for its end-STAs, the AP may send the buffered frames using a multi-user A-MPDU containing all frames that are destined for the R-AP's end-STAs. The R-AP may then forward the frames to the end-STA using an aggregate MAC service data unit (A-MSDU), an A-MPDU, or through the normal positive TIM and data retrieval process. Several solutions to address the various problems/aspects of the ACK mechanism and/or procedures for range extension/relay are described. The ACK mechanism for A-MSDU transmission depends on the direction (to the distribution system (DS) or from the DS) and relay node's transmission scheme of data frame to destination node. In the scenario where the AP sends an A-MSDU containing data for several STAs to the relay node, one way to reduce the receiver power consumption in the destination node is for the relay node to break up the A-MSDU into individual data frames for each recipient and send them to each intended recipient/STA one by one. In this scenario, the relay node sets the partial AID (PAID) subfield in the SIG field of each data frame to the PAID of the destination node. When the source node detects a data frame with a PAID that matches one of PAIDs of the A-MSDU (according to the mapping between the AID and the MAC address of the destination node), it knows that the transmission from the source node to the relay node succeeded. Hence, the PAID serves as an implicit ACK to the source node/AP. FIG.18is a signal diagram for an implicit ACK method1800for an A-MSDU from the DS. The method1800is performed between an AP1802, a relay node1804, a STA i1806and a STA j1808. The AP1802sends a DL A-MSDU frame1810with the ACK indication bits set to “11,” so that other STAs can expect that another data frame will follow. After a SIFS interval1812, the AP1802receives a PHY SIG field with the ACK indication bits set to “00” and checks the PAID subfield in the SIG field. The relay node1804sends a data frame1814for the STA i1806with the ACK indication bits set to “00” and with a MCS no greater than the MCS used between the AP1802and the relay node1804and sets the address fields appropriately. If the STA i1806successfully receives the data frame1814, then after a SIFS interval1816, the STA i1806sends an ACK frame1818to the relay node1804with the ACK indication bits set to “10.” After a SIFS interval1820, the relay node1804sends a data frame1822for the STA j1808with the ACK indication bits set to “00” and with a MCS no greater than the MCS used between the AP1802and the relay node1804and sets the address fields appropriately. If the STA j1808successfully receives the data frame1822, then after a SIFS interval1824, the STA j1808sends an ACK frame1826to the relay node1804with the ACK indication bits set to “10.” In another scenario, the AP sends an A-MSDU containing data for several STAs to the relay node. One way to reduce the signaling overhead and channel access contention is that the relay node forwards the A-MSDU to all the destination STAs. To facilitate the implicit ACK to the source node, a group ID may be used to indicate the group of STAs that are included in the A-MSDU. Usually, the group IDs are maintained and announced by the root AP. With the relay system, each relay node may also maintain and announce its own group ID. In this way, more groups may be formed within one BSS. The relay node sets the PAID subfield in the SIG field of an A-MSDU frame to the destination node to the corresponding group ID. When the source node detects a data frame whose PAID subfield in the SIG field matches the group of the A-MSDU frame that it transmitted to the relay node, it knows that the transmission from the source node to the relay node succeeded. Hence, the PAID serves as an implicit ACK to the source node/AP. FIG.19is a signal diagram for an alternate implicit ACK method1900for an A-MSDU from the DS. The method1900is performed between an AP1902, a relay node1904, a STA i1906and a STA j1908. The AP1902sends a DL A-MSDU frame1910with the ACK indication bits set to “11,” so that other STAs can expect that another data frame will follow. After a SIFS interval1912, the AP1902receives a PHY SIG field with the ACK indication bits set to “00” and checks the PAID subfield in the SIG field. The relay node1904sends an A-MSDU frame1914for the group of STAs (STA i1906and STA j1908) with the ACK indication bits set to “00” and with a MCS no greater than the MCS used between the AP1902and the relay node1904and sets the PAID subfield in the SIG field to be corresponding group ID. If the STA i1906successfully receives the A-MSDU frame1914, then after a SIFS interval1916, the STA i1906sends an ACK frame1918to the relay node1904with the ACK indication bits set to “10.” If the STA j1908successfully receives the A-MSDU frame1914, then after a SIFS interval1920, the STA j1908sends an ACK frame1922to the relay node1904with the ACK indication bits set to “10.” To save signaling overhead and latency for data transmission in a 1 MHz mode relay (where there is no PAID subfield in the SIG field), implicitly signaling the ACK from the relay node to the source node is proposed. The source node has the knowledge of the destination node's MAC address and AID or BSSID at the time of association/re-association. The source node sends the DL data frame with the ACK indication bits set to 11, so that other STAs can expect that another data frame will follow. The relay node sends the data frame to the destination node with a MCS no greater than the MCS used between the source node and the relay node. In other words, the MAC used between the relay node and the destination node is more robust than that used between the source node and the relay node. The relay node sets the RA field to the MAC address of the destination node in the MAC header of the data frame. Within a SIFS time, the source node receives a PHY SIG field with the ACK indication bits set to 00, and checks the RA subfield in the MAC header. If the RA subfield in the MAC header matches the destination node's MAC address, it knows that the transmission from the source node to the relay node succeeded. Hence, the PAID serves as an implicit ACK to the source node/AP. FIG.20is a signal diagram for an implicit ACK method2000for a 1 MHz mode relay. The method2000is performed between a source node2002, a relay node2004, and a destination node2006. The source node2002sends a data frame2010to the relay node2004, with the ACK indication bits set to “11,” so that other STAs can expect that another data frame will follow. After a SIFS interval2012, the source node2002receives a PHY SIG field with the ACK indication bits set to “00” and checks the RA subfield in the MAC header. The relay node2004sends the data frame as a data frame2014for the destination node2006with the ACK indication bits set to “00” and with a MCS no greater than the MCS used between the source node2002and the relay node2004and sets the RA subfield in the MAC header to the MAC address of the destination node2006. If the destination node2006successfully receives the data frame2014, then after a SIFS interval2016, the destination node2006sends an ACK frame2018to the relay node2004with the ACK indication bits set to “10.” Alternatively, a direction indication bit is added to the SIG field of the PLOP header, which may be used as the implicit ACK. The source node sends the DL data frame with the ACK indication bits set to 11, so that other STAs can expect that another data frame will follow. The relay node sends/forwards the data frame to the destination node using a direction indication bit set to the same direction (to the DS or from the DS) as the direction of the transmission from the source node to the relay node. Within a SIFS time, if the source node receives a PHY SIG field with the ACK indication bits set to 00 and the direction indication bit set to the same direction as the direction of the transmission from the source node to the relay node, it knows that the transmission from the source node to the relay node succeeded. Hence, the direction indication bit in the SIG field serves as an implicit ACK to the source node. FIG.21is a signal diagram for an alternate implicit ACK method2100for a 1 MHz mode relay. The method2100is performed between a source node2102, a relay node2104, and a destination node2106. The source node2102sends a data frame2110to the relay node2104, with the ACK indication bits set to “11,” so that other STAs can expect that another data frame will follow. After a SIFS interval2112, the source node2102receives a PHY SIG field with the ACK indication bits set to “00” and the direction indication bit set to the same direction as the direction of the transmission from the source node2102to the relay node2104. The relay node2104sends the data frame as a data frame2114for the destination node2106with the ACK indication bits set to “00” and the direction indication bit set to the same direction as the direction of the transmission from the source node2102to the relay node2104. If the destination node2106successfully receives the data frame2114, then after a SIFS interval2116, the destination node2106sends an ACK frame2118to the relay node2104with the ACK indication bits set to “10.” Certain STA types or applications may require that the source node knows that the data frame is delivered to the destination node successfully before it can flush its transmitter data buffer and go back to sleep. For those STAs or applications, the relay nodes will not send an ACK frame to the source node until it receives an ACK frame from the destination node. The source node sends the data frame with the ACK indication bits set to “11,” so that other STAs can expect that another data frame will follow. If the relay node receives the data frame successfully, it sends the data frame to the destination node using an appropriate MCS. If the destination node receives the data frame successfully, it sends an ACK frame back to the relay node. Upon receiving the ACK frame from the destination node, the relay node sends an ACK frame back to the source node. FIG.22is a signal diagram of an ACK forwarding method2200. The method2200is performed between a source node2202, a relay node2204, and a destination node2206. The source node2202sends a data frame2210to the relay node2204, with the ACK indication bits set to “11,” so that other STAs can expect that another data frame will follow. After a SIFS interval2212, the relay node2204sends the data frame as a data frame2214for the destination node2206with the ACK indication bits set to “00.” When the relay node2204sends the data frame2214, the source node2202determines a new ACK timing2216. There is no signaling for the source node2202to receive the new ACK timing2216; the source node2202knows that if relay is used, the ACK timing2216will be different (or longer) than non-relay data transmission. If the destination node2206successfully receives the data frame2214, then after a SIFS interval2218, the destination node2206sends an ACK frame2220to the relay node2204. Upon receiving the ACK frame2220from the destination node2206, after a SIFS interval2222, the relay node2204sends an ACK frame2224to the source node2202. In one scenario, several STAs send data frames to a relay node. Those data frames may be transmitted to the relay node in sequential order in the time domain or in a frequency, code, or spatial orthogonal manner. When one of the STAs sends a control frame requesting a block ACK to the relay node, the relay node either sends back a block ACK frame before it forwards the data frames to the AP or the relay node assembles those data frames into an A-MSDU frame and sends the A-MSDU frame to the destination node (or AP). This block ACK may be a multiuser ACK. If the relay node sends the assembled data frames in an A-MSDU frame, a group ID may be used to indicate the group of STAs that are included in the A-MSDU frame. The relay node sets the PAID subfield in the SIG field of the A-MSDU frame to the destination node to the corresponding group ID. When the source node detects a data frame whose PAID subfield in the SIG field matches the group that it belongs to, it knows that the transmission from the source node to the relay node succeeded. Hence, the PAID serves as an implicit block ACK to the source nodes. An end-to-end block ACK scheme for a STA using range extension or relay may be used. The source node first performs end-to-end add traffic stream (addTS)/add block ACK (addBA) operations with the destination node through the relay node. The source node sends packets using a delayed BA mechanism, and sets the ACK indication in the PLOP header to “11” or “10.” Upon successful receipt of data frames from the source node, the relay node does not send an ACK, but sends data frames to the destination node. When the source node finishes the transmission, it may enter a sleep mode if it is a non-AP STA. When the source node awakes from sleep, it may send a four-address format block ACK request (BAR) frame to the relay node. The four-address BAR frame is a new frame format. The relay node forwards the BAR frame to the destination node. The destination node sends a four-address BA frame, which is also a new frame format. FIG.23is a signal diagram of an end-to-end block ACK method2300. The method2300is performed between a source node2302, a relay node2304, and a destination node2306. The source node2302sends several data frames2310, with the ACK indication bits of each data frame set to “11,” so that other STAs can expect that another data frame will follow or to “10,” meaning that no ACK is required. After sending the data frames2310, the source node2302may enter a sleep mode is it is a non-AP STA (step2312). Upon receiving the data frames2310, the relay node2304sends the data frames as data frames2314for the destination node2306. If the source node2302is a non-AP STA and exits the sleep mode, it sends a block ACK request (BAR) frame2316to the relay node2304. If the source node2302is an AP, then the source node2302can estimate the timing for the relay node2304to finish the data block transmission and after this estimated time, sends the BAR frame2316to the relay node2304. Upon receiving the BAR frame2316, the source node2302sends a BAR frame2318to the destination node2306. The destination node2306response with a BA frame2320. The relay node2304then sends a BA frame2322to the source node2302. The following methods may be used to facilitate the Speed Frame Exchange for relay operation. In a first method, a relay frame field is used to control the Speed Frame Exchange procedures for relay. Upon receiving a data frame from the source node with a More Data field set to “1,” the relay node may choose to continue the Speed Frame Exchange between the source node and the relay node, and forward the received data frame(s) to the destination node later. The relay node transmits an ACK frame (to acknowledge the received data frame) with the Relayed Frame field set to “0.” A source node that receives the ACK frame that matches its MAC address with the Relayed Frame field set to “0” may continue its data frame transmission within the current TXOP if it has more data to transmit. Upon receiving the ACK frame that matches its address with the Relayed Frame field set to “0,” the source node transmits a data frame a SIFS interval after the received ACK frame. Two examples are described below. In a first example, the relay node sets the Relayed Frame field to “1” after receiving the second data frame from the source node with the More Data field equal to “0”. The relay node forwards the received data frames to the destination node on a one-by-one basis. FIG.24is a signal diagram of the first example of a speed frame exchange method2400for relay. The method2400is performed between a source node2402, a relay node2404, and a destination node2406. The source node2402sends a first data frame2410to the relay node2404, with the More Data field set to “1,” to indicate to the relay node2404that the source node2402has more data frames to transmit. After a SIFS interval2412, the relay node2404sends an ACK frame2414to the source node2402, with the More Data field set to “0” and the Relayed Frame field set to “0.” After a SIFS interval2416, the source node2402sends a second data frame2418to the relay node2404, with the More Data field set to “0,” to indicate that the source node2402does not have any more data frames to transmit. After a SIFS interval2420, the relay node2404sends an ACK frame2422to the source node2402, with the More Data field set to “0” and the Relayed Frame field set to “1.” After a SIFS interval2424, the relay node2404sends the first data frame as data frame2426to the destination node2406, with the Relayed Frame field set to “1.” After a SIFS interval2428, the destination node sends an ACK frame2430to the relay node2404. After receiving the ACK frame2430, the relay node2404waits for a SIFS interval (not shown inFIG.24) before sending the second data frame as data frame2432. Similarly, in a second example, the relay node sets the Relayed Frame field to “1” after receiving the second data frame from the source node with the More Data field equal to “0”. The relay node aggregates the received data frames into one A-MSDU and forwards the A-MSDU to the destination node. FIG.25is a signal diagram of the second example of a speed frame exchange method2500for relay. The method2500is performed between a source node2502, a relay node2504, and a destination node2506. The source node2502sends a first data frame2510to the relay node2504, with the More Data field set to “1,” to indicate to the relay node2504that the source node2502has more data frames to transmit. After a SIFS interval2512, the relay node2504sends an ACK frame2514to the source node2502, with the More Data field set to “0” and the Relayed Frame field set to “0.” After a SIFS interval2516, the source node2502sends a second data frame2518to the relay node2504, with the More Data field set to “0,” to indicate that the source node2502does not have any more data frames to transmit. After a SIFS interval2520, the relay node2504sends an ACK frame2522to the source node2502, with the More Data field set to “0” and the Relayed Frame field set to “1.” After a SIFS interval2524, the relay node2504sends the first data frame and the second data frame as an A-MSDU frame2526to the destination node2506, with the Relayed Frame field set to “1.” After a SIFS interval2528, the destination node sends an ACK frame2530to the relay node2504. Alternately, upon receiving a data frame from the source node with a More Data field set to “1,” the relay node may choose not to continue the Speed Frame Exchange between the source node and the relay node, and immediately forward the received data frame to the destination node. The relay node transmits an ACK frame (to acknowledge the received data frame) with the Relayed Frame field set to “1.” A source node that receives the ACK frame that matches its address with the Relayed Frame field set to “1” does not initiate any further frame transmission within the current TXOP. In a second method to facilitate the Speed Frame Exchange for relay operation, a new one-bit field called “Speed Frame Exchange Continue” (SFEC) may be defined in the ACK frame to control the Speed Frame Exchange procedures for relay. In this method, the source node and the relay node follow the procedures below. Upon receiving a data frame from the source node with the More Data field set to “1,” the relay node may choose to continue the Speed Frame Exchange between the source node and the relay node, and forward the received data frame(s) to the destination node later. The relay node transmits an ACK frame (to acknowledge the received data frame) with the SFEC field set to “1.” A source node that receives the ACK frame that matches its MAC address with SFEC field set to “1” may continue its data frame transmission within the current TXOP if it has more data to transmit. Upon receiving the ACK frame that matches its address with SFEC field set to “1,” the source node transmits a data frame a SIFS time after the received ACK frame. Two examples are described below. In the first example, the relay node sets the SFEC field to “0” after receiving the second data frame from the source node with the More Data field set to “0.” The relay node forwards the received data frames to the destination node on a one-by-one basis. FIG.26is a signal diagram of the first example of a speed frame exchange method2600for relay using the SFEC field. The method2600is performed between a source node2602, a relay node2604, and a destination node2606. The source node2602sends a first data frame2610to the relay node2604, with the More Data field set to “1,” to indicate to the relay node2604that the source node2602has more data frames to transmit. After a SIFS interval2612, the relay node2604sends an ACK frame2614to the source node2602, with the More Data field set to “0” and the SFEC field set to “1.” After a SIFS interval2616, the source node2602sends a second data frame2618to the relay node2604, with the More Data field set to “0,” to indicate that the source node2602does not have any more data frames to transmit. After a SIFS interval2620, the relay node2604sends an ACK frame2622to the source node2602, with the More Data field set to “0” and the SFEC field set to “0.” After a SIFS interval2624, the relay node2604sends the first data frame as data frame2626to the destination node2606, with the Relayed Frame field set to “1.” After a SIFS interval2628, the destination node sends an ACK frame2630to the relay node2604. After receiving the ACK frame2630, the relay node2604waits for a SIFS interval (not shown inFIG.26) before sending the second data frame as data frame2632. Similarly, in a second example, the relay node sets the SFEC field to “0” after receiving the second data frame from the source node with the More Data field set to “0.” The relay node aggregates the received data frames into one A-MSDU and forwards the A-MSDU to the destination node. FIG.27is a signal diagram of the second example of a speed frame exchange method2700for relay using the SFEC field. The method2700is performed between a source node2702, a relay node2704, and a destination node2706. The source node2702sends a first data frame2710to the relay node2704, with the More Data field set to “1,” to indicate to the relay node2704that the source node2702has more data frames to transmit. After a SIFS interval2712, the relay node2704sends an ACK frame2714to the source node2702, with the More Data field set to “0” and the SFEC field set to “1.” After a SIFS interval2716, the source node2702sends a second data frame2718to the relay node2704, with the More Data field set to “0,” to indicate that the source node2702does not have any more data frames to transmit. After a SIFS interval2720, the relay node2704sends an ACK frame2722to the source node2702, with the More Data field set to “0” and the SFEC field set to “0.” After a SIFS interval2724, the relay node2704sends the first data frame and the second data frame as an A-MSDU frame2726to the destination node2706, with the Relayed Frame field set to “1.” After a SIFS interval2728, the destination node sends an ACK frame2730to the relay node2704. Alternately, upon receiving a data frame from the source node with the More Data field set to “1,” the relay node may choose not to continue the Speed Frame Exchange between the source node and the relay node and forward the received data frame to the destination immediately. The relay node transmits an ACK frame with the SFEC field set to “0.” A source node that receives the ACK frame that matches its MAC address with the SFEC field set to “0” does not initiate any further frame transmission within the current TXOP. In the methods2600and2700, the Relayed Frame field may be included in the ACK frame. The relay node may set the Relayed Frame field to “1,” and the source node interprets this as an indication that the current TXOP is shared with the R-STA using an explicit ACK procedure. The source node relies on the SFEC field to determine whether to continue the Speed Frame Exchange procedures or not. The methods2400,2500,2600, and2700may be applicable to the Speed Frame Exchange between the relay node and the destination node as well. In the methods2400,2500,2600, and2700, the source node may be a non-AP STA or an AP. The NDP ACK frame may be used in the methods2400,2500,2600, and2700instead of the regular ACK. In the case where the NDP ACK is used, the transmitter/source node calculates the ACK ID using the same formula as the receiver/responder/relay node (i.e., using the partial FCS and the information from the scrambling seed in the SERVICE field of the frame being acknowledged), and check whether the ACK ID in the received NDP ACK frame matches the ACK ID calculated at the transmitter/source node. If it matches, the received NDP ACK frame is considered as a matched ACK (equivalent to the RA field of the regular ACK frame matching the transmitter's address). In the case where the NDP block ACK frame is used, the transmitter compares the block ACK ID in the received NDP block ACK frame with the N least significant bits (LSBs) of the PLCP data scrambler of the PSDU that carries the soliciting A-MPDU or the BAR. If they match, then the received NDP block ACK frame is considered to be a matched block ACK frame. In the case where the NDP modified ACK frame is used to respond to a NDP PS-Poll frame, the transmitter of the NDP PS-Poll frame calculates the ACK ID using the same formula as the receiver/responder (using the RA, TA, and CRC fields of received NDP PS-Poll frame), and compares it with the ACK ID in the received NDP modified ACK frame. If they match, then the received NDP modified ACK frame is considered to be a matched NDP modified ACK frame. The NDP ACK, NDP block ACK, and NDP modified ACK matching conditions and procedures are not limited to relay operation, and may be applicable to all STAs (AP and non-AP) that use NDP ACK, NDP block ACK, and NDP modified ACK frames. Currently, a R-AP that is associated with a root AP may accept associations from end-STAs. However, a root AP has no means to control the association behavior of the R-APs that are associated with it, and the association behavior for the R-APs may have an impact on system performance. Therefore, methods to control the association behavior of the R-APs are desirable. A root AP, or any other controlling entity such as a centralized control AP, may provide control and constraints for the association behavior of the R-APs that are associated with it, to provide better control of system performance. An end-STA may also provide requirements on the R-AP. A root AP, or any other controlling entity, may use a Relay Control IE to control and constrain the behavior, such as the association behavior, of R-APs that are associated with it. An end-STA may also use a Relay Control IE to specify its requirements for a R-AP. A R-AP may also use the Relay Control IE to specify its own operation, constraints, etc. The Relay Control IE may be used in connection with any of the embodiments described herein. FIG.28is a diagram of a Relay Control IE format2800. The Relay Control IE2800includes an element ID field2802, a length field2804, a number of relays field2806, a number of current relays field2808, a relay capabilities field2810, a number of end-STAs field2812, an end-STA types field2814, an end-STA capabilities field2816, an end-STA traffic specification (spec) field2818, and a relay gains field2820. The element ID field2802identifies the Relay Control IE2800as a Relay Control IE. The length field2804indicates the length of the Relay Control IE2800. The number of relays field2806includes the total number of allowable R-APs that are allowed to associate with the current root AP or the transmitting STA. The number of current relays field2808includes the number of R-APs that are currently associated with the root AP or the transmitting STA. In one implementation (not shown inFIG.28), the number of relays field2806and the number of current relays field2808may be combined into one field called (for example) Allowed Additional Relays, which indicates the maximum additional number of R-APs that are allowed to associate with the root AP or the transmitting STAs. The relay capabilities field2810specifies the capabilities that a R-AP may support or is required to support. The relay capabilities field2810may be implemented as a bitmap with a positive “1” indicating the support or the need to support a certain capability associated with the bit. Such capabilities may include: sectorized operation, Type 0 or Type 1 sectorization, transmit power control, coordination, synchronization for end-STA, RAW, Periodic RAW (PRAW), target wake time (TWT), Subchannel Selective Transmission (SST), etc. The number of end-STAs field2812specifies the maximum number of end-STAs that a R-AP is allowed to provide association to. The end-STA types field2814specifies the type(s) of end-STAs that the R-AP is allowed to provide association to. The end-STA types specified may include: sensors, event-driven sensors, energy-limited STA, 1 MHz STAs, 2 MHz and above STAs, SST STAs, STAs using sectorized operations, HEW STAs, legacy STAs, or all types of STAs. The end-STA capabilities field2816specifies the capabilities that an end-STA must support to be associated with the R-AP. The end-STA capabilities field2816may be implemented as a bitmap with a positive “1” indicating the support or the need to support a certain capability associated with the bit. Such capabilities may include: sectorized operation, Type 0 or Type 1 sectorization, transmit power control, coordination, synchronization for end-STA, RAW, PRAW, TWT, Subchannel Selective Transmission (SST), mandatory set of MCS, etc. The end-STA traffic specification field2818specifies the type of traffic that an end-STA generates to be able to be allowed to associate with the R-AP. Such a traffic specification may include traffic access categories (ACs) and traffic load. The traffic ACs subfield may specify the type of ACs traffic that a STA generates to be associated with the R-AP. For example, the root AP may specify that only STAs generating event report traffic, such as a fire alarm or intruder detection, may be supported by one or more R-APs. In another example, a root AP may specify that only STAs generating AC_VI and AC_VO traffic may be supported by one or more R-APs. The traffic load subfield may specify the traffic load that an end-STA may generate to be associated with the R-AP. For example, the root AP may specify that an end-STA may not generate more than 500 kbps on average to be associated with one or more R-APs. In addition, the traffic load may be specified per AC or using another type of specification. The relay gains field2820specifies the threshold for gains when having traffic forwarded through a relay node that a STA should obtain to be associated with the R-AP. This field may include a relay gain categories subfield and a relay gain threshold subfield. The relay gain categories subfield may include: energy, medium occupation time, aggregation gain, range, etc. The relay gains field2820may include multiple relay gain categories subfields. The relay gain threshold subfield specifies the minimal gain that an end-STA should obtain when sending packets through the R-AP instead of sending packets to the root AP directly. The exact implementation may depend on the relay gain categories. For energy, the relay gain threshold may be specified by integers that specify the energy saving when transmitting through the R-AP instead of directly transmitting to the root AP. Each integer may be associated with a certain unit of energy, such as mJ. The energy usage may be estimated using a packet of a pre-defined size or may be the energy consumed to transmit some unit of data. In another example, the relay gain threshold may be specified by integers that specify the saving of medium occupation time when transmitting through the R-AP instead of directly transmitting to the root AP. Each integer may be associated with a certain unit of time, such as a nanosecond or a microsecond. The reduction of medium occupation time may be estimated using a packet of a pre-defined size or per some units of data. Any subset of the subfields of the Relay Control IE2800may be implemented as a subfield or subsets of subfields of any existing or new IE, for example, the Relay Element, Relay Operation Element, the S1G/VHT/HEW/VHSE Operation Element, the S1GNHT/HEW/VHSE Capability Element, or as a part of any action frames, action without ACK frames, control, management, or extension frames, such as beacon, short beacon, probe request, probe response, association request, association response, reassociation request, reassociation response, S1G action frames, HEW action frames, or in MAC/PLCP headers. For example, the inclusion of some of the fields or subfields in the Relay Element may be indicated by a value in the Relay Control field in the Relay Element. A root AP, R-AP, or end-STA may include the Relay Control IE in its beacon, short beacon, probe request, probe response, association request, association response, reassociation request, reassociation response, or any other type of control, management, or extension frames at time of association, reassociation, or at other times. A root AP may include a Relay Control IE to specify its requirements for the relay nodes that want to associate with it. For example, the root AP may specify the capabilities that a STA must satisfy to be associated as a R-AP, such as a minimal number of supported end-STAs or sectorized operations, SST, etc. The root AP may also indicate how many slots of R-AP that it has. A root AP may include a Relay Control IE to control the behavior of the R-AP. For example, the root AP may specify the number of end-STAs that the R-AP is allowed to provide association with, and/or the type of the end-STAs, the end-STAs with certain capabilities, and/or the type and/or load of the traffic that an end-STA generates, so that the R-AP may provide association to the appropriate end-STAs. In addition to or alternatively, the root AP may specify the gain threshold that a STA must obtain when it transmits through the R-AP instead of transmitting directly to the AP to be able to associate with the R-AP. A STA that is capable of relaying may include the Relay Control IE in its probe request, association request, reassociation request, or any other type of control, management, or extension frames to indicate to an AP, which may be a root AP, of its own relaying capabilities. When a root AP receives a probe request including the Relay Control IE from a relaying STA, it may choose not to reply to the request because its own capabilities do not match those required by the relaying STA, the capabilities supported by the relaying STA do not match its own requirements for R-APs, or the root AP determined that there is not enough gain by associating with the relaying STA as a R-AP. When a root AP receives an association request or a reassociation request including the Relay Control IE from a relaying STA, it may choose to reject the request because its own capabilities do not match those required by the relaying STA as a root AP, the capabilities supported by the relaying STA do not match its own requirements for R-APs, or the root AP determined that there is not enough gain by associating with the relaying STA as a R-AP. A R-AP that is associated with a root AP may include the Relay Control IE in its beacon, short beacon, probe response, association response, reassociation response, or any other type of control, management, or extension frames to indicate its relay capabilities and constraints or operations to STAs, including end-STAs. An end-STA may include a Relay Control IE in its probe request, association request, reassociation request, or any other control, management, or extension frames to indicate its requirements for a R-AP. For example, the end-STA may specify that a R-AP must have sectorized operation capabilities, SST, etc. In another example, an end-STA may also specify that a R-AP should support Sensor Only. When a R-AP receives a probe request including the Relay Control IE from an end-STA, it may choose not to reply to the request because its own capabilities do not match those required by the end-STA, the capabilities supported by the end-STA do not match its own requirements for end-STAs, or the end-STA would not achieve sufficient gain by transmitting through the R-AP. When a R-AP receives an association request or a reassociation request including the Relay Control IE from an end-STA, it may choose to reject the request because its own capabilities do not match those required by the end-STA, the capabilities supported by the end-STA do not match its own requirements for end-STAs, or the end-STA would not achieve sufficient gain by transmitting through the R-AP. The exiting design of the Relay Element is not flexible. The root AP BSSID subfield is always included, causing extra overhead when there is no need to signal the root AP BSSID. Additionally, the design of the relay element does not allow the transmitter to identify itself as a non-AP R-STA. Therefore, it is desirable to develop an efficient design to allow the use of the relay element in various management frames for relay (such as beacon, association, and probe request/response frames) to sufficiently support the relay operation. The Relay Element format may be modified as described below to allow efficient signaling of different cases where the Relay Element is transmitted and for efficient signaling of the RootAP BSSID subfield. The Reply Element format shown and described above in connection withFIG.4is modified in that the root AP BSSID field is made optional. In addition to the two values of the Relay Control subfield already defined in Table 1 above (representing cases 0 and 1), additional values of the Relay Control field may be designed to represent one or several of the following cases/scenarios. A Relay Control value of “2” may be used to indicate a root AP without a RootAP BSSID field in the Relay Element. For example, this may be used in the case where the Relay Element is included in the management frames (such as beacon, probe response, association response, or reassociation response frames) transmitted by the root AP. In those cases, there is no need to signal the RootAP BSSID. A Relay Control value of “3” may be used to indicate a relayed SSID without the RootAP BSSID field in the Relay Element. For example, this may be used in the case where the Relay Element is included in the association response or reassociation response frames (transmitted by the non-root AP R-AP) where there is no need to signal the RootAP BSSID. A Relay Control value of “4” may be used to indicate a non-AP STA capable of relay operation with the RootAP BSSID field in the Relay Element. For example, this may be used in the case where the Relay Element is included in the reassociation request frame where the current associated RootAP BSSID is available. A Relay Control value of “5” may be used to indicate a non-AP STA capable of relay operation without the RootAP BSSID field in the Relay Element. For example, this may be used in an association request or a probe request frame. An example of the values for the Relay Control field is shown in Table 2. The actual design of the method may use any order of the Relay Control field values to represent the cases/scenarios or a subset of cases/scenarios. TABLE 2Relay ControlMeaning0Root AP1Relayed SSID2Root AP without RootAP BSSID subfield inRelay Element3Relayed SSID without RootAP BSSIDsubfield in Relay Element4Non-AP STA5Non-AP STA without RootAP BSSID subfield6-255Reserved The embodiments described above relate to procedures for support of a relay node, but a relay node may also be considered as a STA which performs the procedures described herein to support the functions or requirements of a relay node. Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element may be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and non-transitory computer-readable storage media. Examples of non-transitory computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer. | 136,003 |
11943040 | DESCRIPTION OF THE PREFERRED EMBODIMENTS While this invention is illustrated and described in a preferred embodiment, the invention may be produced in many different configurations. There is depicted in the drawings, and will herein be described in detail, a preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and the associated functional specifications for its construction and is not intended to limit the invention to the embodiment illustrated. Those skilled in the art will envision many other possible variations within the scope of the present invention. Note that in this description, references to “one embodiment” or “an embodiment” mean that the feature being referred to is included in at least one embodiment of the invention. Further, separate references to “one embodiment” in this description do not necessarily refer to the same embodiment; however, neither are such embodiments mutually exclusive, unless so stated and except as will be readily apparent to those of ordinary skill in the art. Thus, the present invention can include any variety of combinations and/or integrations of the embodiments described herein. An electronic device (e.g., a router, switch, hardware platform, controller, base station etc.) stores and transmits (internally and/or with other electronic devices over a network) code (composed of software instructions) and data using machine-readable media, such as non-transitory machine-readable media (e.g., machine-readable storage media such as magnetic disks; optical disks; read only memory; flash memory devices; phase change memory) and transitory machine-readable transmission media (e.g., electrical, optical, acoustical or other form of propagated signals—such as carrier waves, infrared signals). In addition, such electronic devices include hardware, such as a set of one or more processors coupled to one or more other components—e.g., one or more non-transitory machine-readable storage media (to store code and/or data) and network connections (to transmit code and/or data using propagating signals), as well as user input/output devices (e.g., a keyboard, a touchscreen, and/or a display) in some cases. The coupling of the set of processors and other components is typically through one or more interconnects within the electronic devices (e.g., busses and possibly bridges). Thus, a non-transitory machine-readable medium of a given electronic device typically stores instructions for execution on one or more processors of that electronic device. One or more parts of an embodiment of the invention may be implemented using different combinations of software, firmware, and/or hardware. As used herein, a network device such as a switch, router, base station, controller, or virtual machine is a piece of networking component, including hardware and software that communicatively interconnects with other equipment of the network (e.g., other network devices, and end systems). Base stations provide radio connectivity to user equipment such as cell phones. The base station houses antennas that receive and transmit signals of the cellular network to customer phones and other cellular devices. The base station is connected to a mobile operator's switch/router that connects the cellular calls to the public switched telephone network or the cellular IP data traffic to the Internet. Any physical device in the network is generally identified by its type, ID/name, Medium Access Control (MAC) address, and Internet Protocol (IP) address. A virtual function runs on a physical platform that can be the switch or a server attached to the switch. There may be several instances of the same virtual function or different types of virtual functions on the same physical platform. The SDN controller can run on a single server or may be distributed on several servers. At any point in time, one controller may be the master while others are slaves. Alternatively, the plurality of controllers may be in a peer mode. Note that while the illustrated examples in the specification discuss mainly NFV (as ETSI defines) relying on SDN (as Internet Engineering Task Force [IETF] and Open Networking Forum [ONF] define), embodiments of the invention may also be applicable in other kinds of distributed virtualized network function architectures and programmable network architectures, not necessarily tied to NFV and SDN. FIG.1illustrates a block diagram of Drone Base Station (DBS) components according to invention. DBS Controller120is an onboard controller that controls the DBS configuration, communicates with other sub-components of DBS as well as DroneRAN Controller. Drone104is simply an unmanned small aircraft component of the DBS that can be controlled locally and from a remote drone control center. Base Station105is a typical low-power small base station with an antenna array for transmitting and receiving radio signals from cellular User Equipment (UE). It covers an area called drone-cell, which has a limited diameter coverage area and number of UEs supported. At higher altitudes, free-space propagation is an important effect that leads to a completely different radio environment. Macro base stations are often placed in elevated positions, such as on cell towers or on top of buildings to eliminate obstruction of Line of Sight (LoS) from other tall objects such as trees and buildings. If the base station moves to a higher altitude, as in the case of a DBS, the likelihood of objects obstructing the LoS path becomes much smaller. Since the signal propagation in the sky is close to free-space propagation, the signal strength becomes stronger due to the highly reduced path loss. Although the strong signal strength from the serving base station is highly desirable, the DBS may have LoS paths crossing many other DBSs' in Drone RAN. If the cells share the same radio resources, this phenomenon increases the radio frequency interference for the DBS. Thus, handling the interference becomes a key issue in DRAN design. Partitioning the radio frequency bands between adjacent DBSs is one way to reduce the interference. Other important configuration parameters to reduce interference and hence improve the signal strength to UEs are inter-DBS distance, antenna height, and antenna down-tilt angles. Dedicated radio resources can be easily reserved to serve specific groups of UEs completely free of any interference from other terrestrial UEs. DBS may optionally include Core Network103that has typical data plane and control plane virtualized network functions (VNFs) that allow the DBS to perform packet routing without needing to send packets to the operator's terrestrial core network. The DBS may not necessarily have an onboard core network; instead, it may use other DBS's core network. If DBS is employed as part of a DRAN, it connects to other DBSs via radio links through backhaul UE119subcomponent. It can be visualized as a flying UE used simply to attach to base station component of an adjacent DBS to establish a direct radio link in the sky. FIG.2illustrates a DRAN comprised of DBS102(positioned in above ground) attached to fixed (ground-based) base station (cellular or WiMax) or satellite101with backhaul radio connection118. DroneRAN Controller100controls DBS102. DBS102has onboard DBS Controller120, Drone104, Core Network103, Base Station105and UE119as illustrated inFIG.1. Base Station105serves a group of terrestrial UEs shown as UE group122(in the drone-cell). Similarly, Base Station101serves a group of terrestrial UEs shown as UE group121(in the macro-cell). Several control channels are also illustrated. Drone Control Channel114carries control messages for onboard control of Drone104, Core Network103, Base Station105and UE119. D2C control channel is between DroneRAN Controller100and DBS Controller120and comprises concatenated tunnels of110and111, as well as the internal control channel112. UE119attaches to base station101to form a backhaul radio data connection118between DBS102and BS101. Control channel is a tunneled connection on data connection118carrying only control messages between DroneRAN and DBS controllers. FIG.3illustrates a DRAN comprised of DBS102aand DBS102b(both positioned above ground) and attached to fixed (ground-based) base station101with backhaul radio connection118a. DroneRAN Controller100controls both DBS102aas well as102b. DBS102ahas onboard DBS Controller120a, Drone104a, Core Network103a, Base Station105aand UE119a, wherein UE119ais attached to base station101to form the backhaul radio connection. DBS102bhas onboard DBS Controller120b, Drone104b, Core Network103b, Base Station105band UE119b, wherein UE119bis attached to base station105ato form D2D data connection. Base Station105aserves a group of terrestrial UEs shown as UE group122a(in the drone-cell). Similarly, Base Station105bserves a group of terrestrial UEs shown as UE group122b(in the drone-cell). Base Station101serves a group of terrestrial UEs shown as UE group121(in the macro-cell). Several control channels are illustrated. The control channel between DroneRAN Controller and DBS120ais comprised of concatenated connections110,111aand112a. The control channel between DroneRAN Controller and DBS120bis comprised of concatenated connections110,111a,111band112b. Furthermore, between DBS120aand120b, there is D2D control channel119. Note that both D2D control channel119and D2C control channel111bshare the same data connection118bformed between UE119band Base Station105a. These control channels are, for example, GTP or GRE tunnels, both known in prior art. Connection118ais the backhaul connection since it attaches the DroneRAN comprised of two DBSs to the fixed base station101. FIG.4illustrates a similar topology toFIG.3without a fixed base station connection. In practice, this kind of topology occurs when the D2C link is not feasible to establish due to a physical reason, or for any special use-cases requiring only peer-to-peer communications wherein outside communications are not required or prohibited. When there is no fixed base station connection, the UEs of122aand122bcannot access to internet, but they can still communicate with each other through on-board core networks103aand103b. The routing between two networks is simply operated by control interactions between103aand103b. The communication between the DBSs is achieved through the D2D control channel112a,112band112ctraversing the D2D data connection established through backhaul EU119. If the fixed base station disconnects for a short period, drones may continue to stay either in their previous positions and act according to the last control actions they received from the DroneRAN Controller. If the disconnection to fixed base station is for a longer period, the DBS controllers are capable of flight functions such as obstacle avoidance, minor local topology updates, and for return to base when their power is low. FIG.5illustrates a DRAN network diagram showing a plurality of DBSs,201a,201b,201cand201d(all positioned above ground), and a fixed (ground-based) base station207with backhaul radio connection220. DroneRAN Controller200controls all DBSs in this DRAN. Each of data connections220,221,222and223is established through onboard UE's connection to an adjacent node's base station. For example, data connection220is established by UE271connecting to fixed base station207, while data connection222is established by UE281connecting to base station of DBS201b, and so on. The control channels are illustrated on the figure as202,217a,217b,217cand217d, forming a tree graph. Note that each DBS is reachable by the DroneRAN controller using this tree. The DroneRAN controller may change locations of data connections220,221,222and223from time to time and the corresponding tree topology of control channels to mitigate interference or to optimize data packet routing path. Meaning, the connection topology of the control and data networks DRAN is always dynamic, and optimized according to the performance and load of the network. FIG.6illustrates a high-level method of the system of the present invention. Each DBS controller in DRAN obtains UE Key Performance Indicators (KPIs) such as the number of active UEs, UE signal strength, connection and handover rates, each terrestrial UE's 2D coordinates, etc., and feeds this information that describes the load and performance of DRAN to DroneRAN controller in step300. First, DroneRAN Controller makes a determination if the DRAN topology and graph are optimal in step301. If so, it checks to determine if the RF distribution is optimal in step302. If so, it checks to determine if UE Load Balancing is optimal in step303. If so, time is incremented in step339, and the method returns to step300to obtain new network measurements. If step301requires an update on topology and/or graph, the new DRAN 3D topology is determined in step311, and the graph topology (connections) is determined in step319. If step302requires an update, the new RF distribution is determined in step312. If step303requires an update, the new UE load balancing is determined in step313. If there are any changes according to any combination of steps described above, in step304, the control messages pertaining to changes to each DBS are determined in step314, and sent to each respective DBS in step317. Step309checks to determine if all DBSs successfully received the control messages. If so, the method goes back to step339. Otherwise, a failure is reported to DRAN controller. A simplified diagram of a DBS is illustrated inFIG.7showing each sub-component within a dashed-line block inFIG.7. Drone sub-component has typical UAV componentry including Flight Controller429that is the brain of the aircraft. It is basically a circuit board with sensors, which detects orientation changes of the drone, receives control commands, and controls the motors in order to keep the drone in the air. The drone has Electronic Speed Controller (ESC)427that regulates the drone speed by controlling an electric DC motor, stops the drone at a specified location and stabilizes the drone at a determined coordinate. Additionally, drone has power428, camera426, Global Position System (GPS)425, and other sensors. Drone transmits and receives signals to DroneRAN Controller that has an integrated Drone Control Center through UE450. This configuration achieves a completely integrated control of both drone and radio network components of DBS. The base station subcomponent is comprised of Antenna Arrays435as an integral component of Remote Radio Unit (RRU)426wherein the tilt of antennas can be controlled. It also has Distributed Unit (DU), Central Unit (CU) User Plane (UP)438as well as CU Control Plane (CP)439using to the terminology of 5G standards. These components may all be implemented as an integrated function in one embodiment. However, in another embodiment, only one of the DBSs in the DRAN may have a CU-UP and CU-CP (brain of the base station), while all other DBSs may only have integrated DU and RRU controlled by the CU-UP and CU-CP. Many different configurations as such become feasible with componentization of the base station, and assumed covered by this invention. The core network subcomponent can be visualized as a mini flying core network of a mobile operator comprised of almost all necessary VNFs to run the data and control planes. IP addresses assigned to UEs and routing database446sits in the core network. Each core network shares the IP addresses of its directly attached UEs with the core networks of the adjacent nodes to enable formation of a routing table. DBS Controller subcomponent is the brain of the DBS (a) having all local control functions, and (b) capability receiving control actions from the centralized DroneRAN Controller and executing these control actions. All events and performance data related to DBS's drone-cell is kept and updated in database447. TCF401controls the 3D location of the drone and communicates with Flight Controller429. The 3D drone topology is stored in database402. LBF403and IAF404control the base station's CU-CP component by sending instructions on radio resource partitioning, scheduler tables and antenna tilt angles. It also sends Black List406to change configuration of inter-DBS connection or to force UE groups towards other DBSs. Local DBS Graph409contains the information on all data connections and control channels (including IP addresses of tunnel end points) of the DBS. GCF408controls the data connections and control channels of the DBS.FIG.8illustrates the DroneRAN Controller that has all the functions of DBS Controller shown inFIG.7, but for every DBS in the DRAN. DroneRAN Controller has an integrated Drone Control Center671that controls the drones. The control actions are translated into control messages in Control Messaging Interface672and sent towards each DBS. This interface receives other configuration control actions from LBF and IAF, and sends them to each DBS. The above-described features and applications can be implemented as software processes that are specified as a set of instructions recorded on a computer readable storage medium (also referred to as computer readable medium). When these instructions are executed by one or more processing unit(s) (e.g., one or more processors, cores of processors, or other processing units), they cause the processing unit(s) to perform the actions indicated in the instructions. Embodiments within the scope of the present disclosure may also include tangible and/or non-transitory computer-readable storage media for carrying or having computer-executable instructions or data structures stored thereon. Such non-transitory computer-readable storage media can be any available media that can be accessed by a general purpose or special purpose computer, including the functional design of any special purpose processor. By way of example, and not limitation, such non-transitory computer-readable media can include flash memory, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code means in the form of computer-executable instructions, data structures, or processor chip design. The computer readable media does not include carrier waves and electronic signals passing wirelessly or over wired connections. Computer-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Computer-executable instructions also include program modules that are executed by computers in stand-alone or network environments. Generally, program modules include routines, programs, components, data structures, objects, and the functions inherent in the design of special-purpose processors, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of the program code means for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps. Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for performing or executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a Global Positioning System (GPS) receiver, or a portable storage device (e.g., a universal serial bus (USB) flash drive), to name just a few. In this specification, the term “software” is meant to include firmware residing in read-only memory or applications stored in magnetic storage or flash storage, for example, a solid-state drive, which can be read into memory for processing by a processor. Also, in some implementations, multiple software technologies can be implemented as sub-parts of a larger program while remaining distinct software technologies. In some implementations, multiple software technologies can also be implemented as separate programs. Finally, any combination of separate programs that together implement a software technology described here is within the scope of the subject technology. In some implementations, the software programs, when installed to operate on one or more electronic systems, define one or more specific machine implementations that execute and perform the operations of the software programs. A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network. These functions described above can be implemented in digital electronic circuitry, in computer software, firmware or hardware. The techniques can be implemented using one or more computer program products. Programmable processors and computers can be included in or packaged as mobile devices. The processes and logic flows can be performed by one or more programmable processors and by one or more programmable logic circuitry. General and special purpose computing devices and storage devices can be interconnected through communication networks. Some implementations include electronic components, for example microprocessors, storage and memory that store computer program instructions in a machine-readable or computer-readable medium (alternatively referred to as computer-readable storage media, machine-readable media, or machine-readable storage media). Some examples of such computer-readable media include RAM, ROM, read-only compact discs (CD-ROM), recordable compact discs (CD-R), rewritable compact discs (CD-RW), read-only digital versatile discs (e.g., DVD-ROM, dual-layer DVD-ROM), a variety of recordable/rewritable DVDs (e.g., DVD-RAM, DVD-RW, DVD+RW, etc.), flash memory (e.g., SD cards, mini-SD cards, micro-SD cards, etc.), magnetic or solid state hard drives, read-only and recordable BluRay® discs, ultra density optical discs, any other optical or magnetic media, and floppy disks. The computer-readable media can store a computer program that is executable by at least one processing unit and includes sets of instructions for performing various operations. Examples of computer programs or computer code include machine code, for example is produced by a compiler, and files including higher-level code that are executed by a computer, an electronic component, or a microprocessor using an interpreter. While the above discussion primarily refers to microprocessor or multi-core processors that execute software, some implementations are performed by one or more integrated circuits, for example application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). In some implementations, such integrated circuits execute instructions that are stored on the circuit itself. As used in this specification and any claims of this application, the terms “computer”, “server”, “processor”, and “memory” all refer to electronic or other technological devices. These terms exclude people or groups of people. For the purposes of the specification, the terms display or displaying means displaying on an electronic device. As used in this specification and any claims of this application, the terms “computer readable medium” and “computer readable media” are entirely restricted to tangible, physical objects that store information in a form that is readable by a computer. These terms exclude any wireless signals, wired download signals, and any other ephemeral signals. To provide for interaction with a user, implementations of the subject matter described in this specification can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. In addition, a computer can interact with a user by sending documents to and receiving documents from a device that is used by the user; for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser. The subject matter described in this specification can be implemented in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the subject matter described in this specification, or any combination of one or more such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), an inter-network (e.g., the Internet), and peer-to-peer networks (e.g., ad hoc peer-to-peer networks). Those of skill in the art will appreciate that other embodiments of the disclosure may be practiced in network computing environments with many types of computer system configurations, including personal computers, hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. Embodiments may also be practiced in distributed computing environments where tasks are performed by local and remote processing devices that are linked (either by hardwired links, wireless links, or by a combination thereof) through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices. The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. In some aspects to of the disclosed subject matter, a server transmits data (e.g., an HTML page) to a client device (e.g., for purposes of displaying data to and receiving user input from a user interacting with the client device). Data generated at the client device (e.g., a result of the user interaction) can be received from the client device at the server. It is understood that any specific order or hierarchy of steps in the processes disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged, or that all illustrated steps be performed. Some of the steps may be performed simultaneously. For example, in certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components illustrated above should not be understood as requiring such separation, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Various modifications to these aspects will be readily apparent, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, where reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the subject technology. A phrase, for example, an “aspect” does not imply that the aspect is essential to the subject technology or that the aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. A phrase, for example, an aspect may refer to one or more aspects and vice versa. A phrase, for example, a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A phrase, for example, a configuration may refer to one or more configurations and vice versa. The various embodiments described above are provided by way of illustration only and should not be construed to limit the scope of the disclosure. Those skilled in the art will readily recognize various modifications and changes that may be made to the principles described herein without following the example embodiments and applications illustrated and described herein, and without departing from the spirit and scope of the disclosure. While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. As noted above, particular embodiments of the subject matter have been described, but other embodiments are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous. CONCLUSION A system and method have been shown in the above embodiments for the effective implementation of a system and method for implementing a DroneRAN controller. While various preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, it is intended to cover all modifications falling within the spirit and scope of the invention, as defined in the appended claims. | 34,151 |
11943041 | Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures, where showings therein are for purposes of illustrating embodiments of the present disclosure and not for purposes of limiting the same. DETAILED DESCRIPTION The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology can be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and may be practiced using one or more embodiments. In one or more instances, structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. One or more embodiments of the subject disclosure are illustrated by and/or described in connection with one or more figures and are set forth in the claims. Using various embodiments, dynamic shielding of cellular signals for of an unmanned aerial vehicle (UAV) may be performed by utilizing an antenna and a specialized antenna shielding unit of a UAV that may selectively connect to access points of a cellular network during travel of the UAV along set flight paths. The antenna of the UAV may communicate with the access points through a cellular technology signal, such as those signals communicated by base stations (e.g., access points) of the cellular network and the antenna of the UAV. Traditionally, cellular networks are optimized for devices connecting at a ground level, such as two meters off the ground where typical cellular devices (e.g., mobile phones) may generally operate. In such cases, ground level objects (e.g., buildings and other manmade objects, trees and other natural obstacles, etc.) and geographic conditions (e.g., landforms including hills, mountains, etc. that may affect signal transmissions) may cause signal interference, reception problems, and issues in network coverage. In other embodiments, signal interference and/or loss may occur from other ground level occurrences, including loss due to bodies (e.g., people) and in-vehicle loss from transportation vehicles utilized by people during use of UEs. In order to compensate for ground level issues in network coverage, cellular base stations are optimized to transmit wireless network signals to account these ground level factors. However, UAVs travelling at altitude may instead encounter little to no ground level interference from ground level factors and/or may encounter different signal interferences on the cellular network, such as multiple base station signals interfering at altitude. In order to provide network connectivity to an antenna of a UAV operating at altitude similar to user endpoints (UEs, which may include user devices, such as mobile phones, as well as UAVs) at ground level, the antenna of the UAV may be shielded using one or more radio frequency (RF) signal absorbing or reflecting materials that may be used to mimic RF signal reception at a ground level corresponding to the UAVs current position and altitude. For example, a UAV may be instructed to travel one or more flight paths at one or more altitudes, including preprogrammed routes and real-time instruction and operation of the UAV. The UAV may correspond to any device operated or to be operated at flight altitude. While operating the UAV on a flight path, a controller of the UAV may adjust and shield the antenna using the RF signal absorbing/reflecting material(s) or “shield(s).” This/these shield(s) may prevent RF signal reception by the antenna of the UAV from one or more incident directions. In this regard, the shield(s) may go up, down, or otherwise rotate or configure around the antenna to block incoming RF radiation from one or more selected directions by the controller. The controller may also add more or additional shields to a direction to provide additional shielding of RF signals incident from that direction. In order to determine a placement or orientation of the shield(s) around the antenna, information necessary to imitate or mimic ground level interferences and network issues may be utilized. Additionally, as the UAV travels along a flight path, the current location of the UAV may be determined (e.g., at least a two-dimensional (2D) position of a latitude and longitude, however, certain embodiments may further use a three-dimensional (3D) position having latitude, longitude, and altitude). The 2D or 3D positions may be measured from a ground level or may be relative to the location and position of the base stations used to facilitate network connectivity and communication with the aerial-based devices at flight altitudes through a cellular technology signal. The location of the UAV may be used to extrapolate interference or loss of RF signals from base towers of the cellular network by determining interference cause by ground based objects at a ground level position matching or corresponding to the 2D or 3D position of the UAV (e.g., having the same or similar latitude and/or longitude). Once ground based interferences and losses are determined, placement or orientation of the shield(s) may be determined based on the ground based interferences/loss so that the shield(s) mimic or imitate such interferences/loss at altitude. This placement/orientation of the shield(s) may be determined using the information of the cellular network performance, a cellular network map of ground based performance, losses, and/or interferences, or other information that determines what RF signals should be received at particular positions based on the ground level interferences and/or losses of signals for the cellular network from the base stations of the cellular network. In certain embodiments, the controller may select placement of the shields instead or additionally using detected RF signals, for example, where the antenna may detect RF signals from a specific direction or from a base station in a certain direction. In other embodiment, the arrangement and/or placement of the shield(s) may be predetermined based on the route of the UAV so that the present location of the UAV does not need to be determined and the shield(s) are adjusted/orientated according to time and/or the controller of the UAV may access the location-based shielding placements/orientations based on the location of the UAV without needing to determine the placements/orientations during flight on the path. Once shielded, the antenna of the UAV may be used to communicate on the cellular network with a base tower using the cellular technology signal (e.g., 3G, 4G, 4G LTE, 5G, etc.) for the cellular network. The shield(s) of the antenna may further be adjusted during travel on the flight path, which may correspond to new locations. For example, once within range of another base station based on the ground level interference from ground level object, the shield(s) may be adjusted so that the antenna may connect with the new base station and shield the antenna from RF signals from the previously connected base station. In this way, the shields may imitate terrain clutter and signal loss occurring from ground In one or more embodiments, a device includes an antenna and a shielding unit for the antenna and comprising at least one radio signal shielding component that is movable around the antenna, wherein the at least one radio signal shielding component prevents reception of radio signals by the antenna from at least one direction associated with placement of the at least one radio signal around the antenna. The device further includes a non-transitory memory storing antenna shielding data for the at least one radio signal shielding component around the antenna during operation of an unmanned aerial vehicle, as well as one or more hardware processors configured to execute instructions to cause the device to perform operations comprising determining a location of the unmanned aerial vehicle during operation of the unmanned aerial vehicle and determining a first placement of the at least one radio signal shielding component using the antenna shielding data and the location. The operations also include instructing the at least one radio signal to shield the antenna according to the first placement and communicating, using the antenna, on a network during operation of the unmanned aerial vehicle based on shielding the antenna using the first placement. In one or more embodiments, a method for a dynamically shielding cellular signals for an antenna of an unmanned aerial vehicle includes receiving a navigation route for an unmanned aerial vehicle to execute during flight of the unmanned aerial vehicle and determining an orientation of a radio signal shield for an antenna of the unmanned aerial vehicle using ground level signal propagation information of radio signals for a network and the navigation route, wherein the radio signal shield prevents the radio signals from being received by the antenna from directions based on the orientation. The method further includes adjusting the radio signal shield using the orientation and communicating with a cellular base station of the network using the antenna. In one or more embodiments, a system comprises an unmanned aerial vehicle, an antenna mounted to the unmanned aerial vehicle, and a plurality of radio frequency shields that prevent radio frequency reception of the antenna from one or more directions based on one or more positions of the plurality of radio frequency shields, wherein the plurality of radio frequency shields are rotatable around the antenna. The system further includes a non-transitory memory storing geographic information for transmission of radio signals of a network at a ground level, wherein the geographic information comprises ground level objects affecting the radio signals of the network at the ground level, and one or more hardware processors configured to execute instructions to cause the device to perform operations comprising receiving a flight path of the unmanned aerial vehicle. The operations further include determining shielding positions of the plurality of radio frequency shields during flight of the unmanned aerial vehicle on the flight path using the geographic information, wherein the shielding positions are selected to simulate the ground level objects affecting radio signals of the network during flight of the unmanned aerial vehicle on the flight path. The operations then adjust the plurality of radio frequency shields according to the shielding positions during flight of the unmanned aerial vehicle on the flight path and communicate, using the antenna signal, on the network with one or more base stations during flight of the unmanned aerial vehicle on the flight path based on the shield positions. The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly. Various techniques are provided for a dynamic shield system of cellular signals for an antenna of an unmanned aerial vehicle. One or more unmanned aerial vehicles (UAVs), also referred to herein as unmanned aerial systems (UASs) or drones, may operate at a flight altitude corresponding to one or more locations along a flight path or route within a three-dimensional (3D) space having a latitude, longitude, and altitude. These UAVs may travel at one or more altitudes according to a flight plan or route and communicate on a cellular network using the antenna. A location or travel route of the UAV may have a 3D position (or a 3D path/route within a 3D space) while travelling on the flight route, which may correspond to a ground level location or position, for example, through the same or similar latitude and/or longitude (e.g., two-dimensional (2D) coordinates). In other embodiments, the location or route of a UAV in 3D space (e.g., at altitude) may otherwise correspond to ground level positions, for example, through matching or creating similarities of the UAV at altitude to locations of ground level UE within coverage for a wireless network. The altitude coordinate may be a distance (e.g., height) from a reference sea level. In some cases, rather than the longitude, latitude, and/or altitude coordinates, other coordinate systems by which to define the position of the UAV relative to the access point/base station or other selected landmark. The cellular network may be provided by a cellular network carrier or provider to facilitate communications between devices over the cellular network. Cellular network carriers generally design the wireless network to account for ground level disruptions in RF signal transmissions, ground level interference from terrain clutter and other geographic objects or considerations, and other types of losses caused at the ground level to ground level UEs. Base stations of a cellular network are generally those base stations utilized with user endpoints (UEs, which may include cellular devices as well as the UAVs discussed herein) at ground level or near ground level, such as vehicles (e.g., cars) and mobile phones operated at or near ground level. For example, position and orientation (e.g., tilt) of antennas of the base stations may be configured to provide higher signal strength for devices below these antennas. In this regard, the base stations may be designed with a main antenna pattern that primarily encompasses a ground region. Furthermore, at lower altitudes, obstructions such as buildings and trees may help prevent signals from multiple base stations from reaching the vehicles and devices at or near ground level with signal strengths that cause significant interference. Additionally, body and vehicle loss may be accounted for when designing and optimizing a wireless cellular network at ground level. In some aspects, although the UAVs are not communicating with base stations dedicated to aerial communication, the UAVs may be configured to (e.g., programmed to) send and receive radio signals on the cellular network to accommodate (e.g., communicate with) the base stations without disrupting service to UEs at ground level. In an aspect, the base stations may accommodate cellular communication with the UAVs with minimal or no changes to structural features, such as the housing, antennas, and/or other components, such that the use of the base stations with the UEs at ground level are not affected by the accommodation of UAVs through providing a dynamic shield system of cellular signals for an antenna of a UAV. In this regard, the dynamic shield system may be utilized to mimic or imitate ground level interference, loss, or other RF signal issues and losses encountered by ground level UEs while the UAV travels at altitude in an environment that is not designed for network signal coverage and lacking a dominate base station or other RF signal transceiver, which has instead been optimized for ground level UEs. When radio modules, such as 3G, 4G, 4G Long Term Evolution (LTE), 5G, other 3rdGeneration Partnership Project (3GPP)-based radio modules, and/or other radio modules, are placed at flight altitude, such as 400 feet or 500 feet, the line of sight propagation of signals from multiple base stations may be received by the radio modules and cause interference. The different antenna patterns (e.g., different vertical antenna patterns) of the base stations at different radio frequencies (e.g., in different frequency bands) and/or at different altitudes may cause degradation of communicated signals, including signals associated with application data and command/control functions. In addition, higher altitudes generally have fewer obstructions than at ground level, and thus more signals may reach the devices/vehicles at higher altitudes and cause interference relative to devices/vehicles at ground level. The aerial devices/vehicles (e.g., UAVs) may include antennas to receive radio signals from one or more base stations, such as a closest base station and/or a base station associated with highest signal strength. The UAV may be equipped with cellular technology (e.g., using LTE or other cellular technology communication signal) antenna that receives RF signals on the cellular network. However, at altitude, the aforementioned issues become apparent to radio signals received by the antennas of the UAVs. In order to compensate for these issues, the UAVs may be equipped with one or more wireless signal shields and a shielding unit or component, which may dynamically adjust to mirror or imitate ground level interference and loss of UEs at a ground level associated with the current position of the UAVs. The dynamic shielding unit may include one or more shielding components or materials, which may absorb and/or reflect wireless signals incoming from an incident direction (e.g., when interposed between the direction of the incoming wireless signal and an antenna of the UAV). Thus, when one or more of the shielding components or materials (or one or more shields) are placed between the antenna of the UAV and the incoming direction of a wireless signal, the shield(s) may prevent the antenna from detecting, absorbing and/or receiving the wireless signal, as well as transmitting wireless signals from the antenna to other receivers or transceivers in that direction. The shield(s) may completely absorb or reflect the signal, or partially absorb or reflect the signal. Thus, more than one shield may be required in certain aspects to provide a more complete signal shielding from a direction. The shield(s) may prevent radio frequency (RF) signals on the cellular network in the RF range used by the cellular network that are provided from base stations of the cellular network carrier within coverage areas of the RF signals from those base stations. In other embodiments, the shield may further or instead absorb or reflect wireless signals for other types of wireless networks, for example, to accommodate other types of wireless communication signals (e.g., satellite systems, short range wireless communication signals, etc.). However, in certain embodiments, the material used for the shields may be selected to only block RF signals on the cellular network to allow other types of wireless communications selectively used for the UAV (e.g., line of sight communications to control the UAV). The shielding unit may therefore include one or more shields used to selectively block wireless signal from specific directions determined by the UAV or other control unit. In order to provide selecting blocking, the shield(s) of the shielding unit may be arranged, rotatable, or otherwise movable around an antenna of the UAV used to communicate on the cellular network. A controller and one or more physical movement components may be used to move, arrange, and place the shield(s) around the antenna as determined by the controller or other processing component of the UAV. The physical movement components may include mechanical attachments, motors, or other features to arrange the shield(s), as well as reposition the shields during flight of the UAV. The controller and/or a processor of the UAV may determine placement, arrangement, and/or repositioning of the shield(s) during flight, for example, based on input data necessary to determine placement of the shield(s) in order to have the shield(s) mimic or imitate ground based loss and interference while the UAV travels at altitude. Thus, the shield(s) may have the capability to rotate and move as necessary around the antenna using the shielding unit and one or more processors to determine correct shield placement during flight. In order to determine correct shield placement of the shield(s) during flight, a location of the UAV may be required. As previously discussed, a position or location of the UAV may be determined, for example, a GPS coordinate of the UAV. Thus, the UAV may include a GPS component, which may interface with one or more remote GPS processors to determine a location of the UAV. Other types of location determining systems may also be used. Additionally, the location of the UAV may be determined through the flight route of the UAV, which may be plotted prior to travel on the flight path, and thus, the location of the UAV may be determined as a factor of time (e.g., where the UAV is on the flight path over time). The UAVs may be equipped with additional devices and sensors necessary for autonomous flying, which may also be used to determine a location of the UAV, for example, where the UAV diverges from a flight path. The location of the UAV may correspond to a 3D position (e.g. longitude, latitude, and altitude), which may be used to determine a similar ground level location, for example, in 2D space (e.g., the ground level longitude and/or latitude). The location of the UAV may therefore be matched or associated with a ground level location so that similar ground level losses that may occur for ground based UEs having the ground level location may be determined. Using the location of the UAV, the controller or other processor for the UAV may determine similar ground level loss and/or interference experienced at ground level for ground level propagation of RF signals to ground level UEs when utilizing the cellular network at a ground level location similar to the location of the UAV. For example, at altitude, the UAV may not experience loss due to geographic clutter, terrain, and other ground level issues. However, the UAV may experience other coverage and interference issues due to interfering base stations (e.g., where a dominate RF base station does not exist due to the lack of ground level loss), the obstacle information around the UAV, weather information around the UAV and/or generally any other static and dynamic information associated with flight of the UAV. Thus, the antenna of the UAV may be shielded in specific directions to mimic or imitate the ground level losses experienced by ground level propagation of RF signals from one or more base stations of the cellular network to UEs having a similar location to the current location of the UAV when travelling at altitude. The information on ground level interference and loss and may be used to determine which RF signal base station may be used by a ground level device at a ground level location similar to the at altitude location of the UAV. Thus, information of cellular network coverage, terrain and geographic objects and considerations, base station RF signal propagation, and/or other information or mapping that determines what loss/interference ground level UEs experience at various positions may be used with the position of the UAV. Such information may be determined by the cellular network carrier or a third party determining and/or mapping cellular network coverage, base station usage, and/or RF signal propagation. Thus, the controller and/or processor of the UAV may select shield placements based on the location and this information in order to mirror the ground level interference and/or loss. The shielding of the antenna may also be affected by the altitude, for example, by requiring additional shielding for higher altitudes having more competing RF base stations and/or loss obstruction by geographic conditions. In other embodiments, the ground level location matching or associated with the flight location of the UAV may not be required, and instead the flight location of the UAV may be used to determine shield placement or orientation through a 3D map of signal coverage of the cellular network and at altitude (e.g., altitude based) interferences or other information. For example, a map of cellular coverage may include interferences in cellular network signaling, network connectivity issues in the cellular network signals, messaging errors on the cellular network, and/or other signal diagnostics for cellular network signals on the cellular network. The map may include 3D positions of such network issues, and may be used by the controller or processor to determine shield placement based on the network coverage issues. Once the ground level interference and/or loss is determined for the current location of the UAV, the shield controller and/or processor of the UAV may determine the shield placement. As discussed herein, a shield placement may correspond to shielding of the antenna using the one or more shields in order to mimic or imitate ground level interference and loss experienced by ground level UEs at a similar location to the UAV. Thus, the shield placement or orientation may be used to selectively shield the antenna of the UAV in order to receive RF signals for a selected direction and avoid interference of RF signals on the cellular network caused by operating the UAV at one or more altitudes. In this regard, the shield placement may be used to select RF signals for a specific base station, thereby creating a dominate RF server for communication with the UAV. In certain embodiments, the UAV may not determine shield placement or orientation using the location of the UAV and the necessary information on ground level loss and/or geographic conditions, and instead a remote processing entity, such as the cellular network carrier, may determine the shield placement and preload the shield placement or feed the shield placement in real-time to the UAV. Once the position of the shield(s) is determined, the shield(s) may be moved, rotated, or otherwise arranged around the antenna based on the positioning of the shield(s) to mimic the ground level loss experienced at ground level for RF signals on the cellular network. The shield(s) may therefore be used to select specific RF signals to be blocked and other signaling to be received by the antenna of the UAV. During flight, as the location of the UAV changes, the ground level loss/interference for the changing positions may be determined, and the shield(s) may be adjusted and repositioned as necessary. Once the shields are positioned, the UAV may utilize the antenna to communicate on the cellular network through communicating with one or more base stations of the cellular network carrier. The network may include a wide area network (WAN), such as a cellular-based WAN. In the case of a cellular network, the cellular network information may be provided for the cellular-based WAN. In an aspect, communications on the cellular network may be provided as part a broadcast message to and from the UAV. For example, the information may be communicated in a master information block (MIB) message, system information block (SIB) message, Multimedia Broadcast Multicast Services (MBMS)-based message, Evolved MBMS (eMBMS)-based message, and/or generally any message that can be transmitted (e.g., broadcasted) to and from the base stations of the cellular network and UAVs within receiving range of radio signals from the base stations. Although the description of the present disclosure is made with respect to UAVs and cellular networks, the techniques described herein may be applied to any wireless network and any devices/vehicles capable of establishing connectivity in such wireless networks. By way of non-limiting example, the devices/vehicles may include, or may be included in, devices or vehicles at or near ground level (e.g., mobile devices, cars), naval-based devices (e.g., watercraft), and devices at higher altitudes (e.g., UAVs, any device at higher altitudes). In this regard, the techniques described herein may be utilized for devices located at higher altitudes, including as mobile phones and/or other devices/vehicles operated at higher floors of a building. FIG.1illustrates an example network environment100in which a dynamic shield system of cellular signals for an antenna of an unmanned aerial vehicle may be implemented in accordance with one or more embodiments. Not all of the depicted components may be required, however, and one or more embodiments may include additional components shown in the figure. Variations in the arrangement and type of the components may be made without departing from the spirit or scope of the claims as set forth herein. Additional components, different components, and/or fewer components may be provided. It is noted that sizes of various components and distances between these components are not drawn to scale inFIG.1. In an embodiment, the network environment100is implemented to form part of a cellular network, such as a 3G, 4G, 5G, and/or other 3GPP-based cellular network, and/or a cellular network based on other cellular standards. In this regard, as an example, the description ofFIG.1is made herein with respect to the network environment100providing a cellular network. However, in some examples, the network environment100may be additionally or alternatively implemented to form part of a satellite communication network, microwave radio network, and/or other wireless networks. The network environment100includes a UAV110, a cellular network carrier120, base stations122a-c, and a user device130. UAV110, cellular network carrier120, base stations122a-c, and user device130may be in communication directly or indirectly with each other. As used herein, the phrases “in communication,” “communicatively connected,” and variances thereof, encompass direct communication and/or indirect communication through one or more intermediary components and does not require direct physical (e.g., wired and/or wireless) communication and/or constant communication, but rather additionally includes selective communication at periodic or aperiodic intervals, as well as one-time events. UAV110may include, may be a component of, and/or may be referred to as, a user endpoint or UE. UAV110may include a flight control unit, communication unit, and payload unit. The flight control unit or other operation module of UAV110that may be configured to facilitate navigation of UAV110, e.g., take off, landing, and flight of UAV110. Such an operation module may include any appropriate avionics, control actuators, and/or other equipment, along with associated logic, circuitry, interfaces, memory, and/or code. Additionally, the flight control unit or other operation module may include a controller that receives flight route information from one or more sources, including a memory and/or external controller (e.g., set instructions from a service provider and/or inflight navigation/instructions from an operator) that operates UAV110. The flight control unit may further include one or more components to determine a location or position of UAV110, including a 3D position (e.g., longitude, latitude, and altitude) of UAV110when operating along a flight path. The location determination component may correspond to a global positioning system (GPS) component, or other component used to determine a location of UAV110. The GPS component provides a current position of UAV110(e.g., using three coordinates). The position information from the GPS, together with position information of devices in communication with UAV110, may allow UAV110to execute a flight route as well as provide positioning information associated with determination of antenna shielding, as discussed herein. Thus, the components of the flight control unit may facilitate implementation of various features supported by UAV110. The communication unit may include one or more radio transceivers (e.g., that include antennas) along with associated logic, circuitry, interfaces, memory, and/or code that enable communications, e.g. with one or more of base stations122a-c, and/or directly with cellular network carrier120, via wireless interfaces and using the radio transceivers. InFIG.1, the radio transceivers of UAV110may be included in an antenna housing112, which may be omnidirectional or directional. Antenna housing112may be utilized to radiate and/or receive power uniformly in all directions, or one or more desired directions to allow increased performance (e.g., higher signal strength) in the desired direction, such as through higher gain and directivity and reduced interference due to signals from sources deviating from the desired direction. In this regard, signal strength of command/control links and/or application data channels may be improved, and/or interference of signals from different base stations may be reduced through the use of a directional antenna. Antenna housing112may be contained within a housing of UAV110(e.g., embedded within the housing and/or circuitry of UAV110), or disposed (e.g., mounted) outside a housing of UAV110as an attachable and/or removable module. Antenna housing112may further include one or more antenna shields for the antenna/radio transceivers in antenna housing112, which may be used to directionally block radio signals on a cellular network from one or more of base stations112a-c, thereby further directionally receiving radio signals from other sources (e.g., base stations112a-c). In some cases, the shields and/or antenna of antenna housing112may be movable along and/or rotatable about one, two, or three axes. In other cases, the shields and/or antenna of antenna housing112may be fixed (e.g., not movable and not rotatable). Antenna housing112may include an antenna using a cellular technology (e.g., using LTE or other cellular technology communication signal). One or more radio transceivers of antenna housing112may be used to communication on a cellular network using cellular tower signals from base stations122a-c. In this the shield(s) of antenna housing112may be used to mimic ground based loss and interference of ground based RF signal propagation from base stations122a-c. The shield(s) may include one or more components having RF absorption and/or reflection capabilities, such as material that may reflect or absorb RF signals from base stations122a-cwhen interposed between RF signals from base stations122a-cto the antenna of antenna housing112. Antenna housing112may have a number of shields based on an altitude that UAV110may travel at while on a flight path or route, for example, where additional shields may be required at higher altitudes due to increased interference of RF signals from base stations122a-cdue to lack of ground based terrain and clutter. Additional shields may therefore provide additional absorption and/or reflection/rejection of RF signals from reaching the antenna within antenna housing112. Placement of the shields may be selected based on a controller of antenna housing112and/or a processor of UAV110, which may utilize location information from the flight control unit and information of ground based loss/interference for signal propagation of RF signals from base stations122a-c. In various embodiments, placement of the shield(s) may be chosen so that the shields may cover an opposite direction from the direction of travel of UAV110, thereby eliminating interference of RF signals from a base station that UAV110is travelling away from. However, other placements may also be used, for example, based on signal strength and/or when approaching one of base stations122a-cthat UAV110would like to communicate with during approach and flight. The signal strength may be, or may be based on, measurements such as received signal strength indicator (RSSI), reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), and/or other measurements. Such measurements of signal strength may be detected and/or computed by UAV110. In an aspect, signal strength may be referred to as signal quality, signal level, or signal power. Higher signal strength is generally associated with better reception. Thus, an antenna of antenna housing112may be used to message with one or more of base stations122a-c. In various embodiments, the communication unit of UAV110may further include suitable logic, circuitry, interfaces, memory, and/or code that enable wired communications, e.g. with one or more of base stations122a-c, and/or cellular network carrier120directly. In this regard, UAV110may be configured to interface with a wired network, such as via an Ethernet interface, power-line modem, Digital Subscriber Line (DSL) modem, Public Switched Telephone Network (PSTN) modem, cable modem, and/or other appropriate components for wired communication. A wired link may be implemented with a power-line cable, coaxial cable, fiber-optic cable, or other cable or wires that support corresponding wired network technologies. For example, UAV110may utilize wired connections when at or near ground level, such as a wired connection between UAV110and one or more ground level devices or cellular network carrier120for facilitating testing and/or calibration/setup of UAV110. In other embodiments, the communication unit may send and/or receive information, including flight paths and cellular network information, over a cellular technology signal/network (e.g., 3G, 4G, 5G, and/or other 3GPP-based cellular network) to one or more of base stations122a-c. Thus, UAV110may wirelessly communicate with other devices using wireless standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, Bluetooth® standard, ZigBee® standard, and/or other wireless standards; cellular standards, such as 3G, 4G, 4G LTE, 5G, and/or other cellular standards; infrared-based communication; optical-based communications; and/or other appropriate communication standards and/or protocols. In some cases, UAV110may be configured to communicate with another device using a proprietary wireless communication protocol and interface. The payload unit may be configured to implement features supported by UAV110and facilitate implementation of such features. The payload unit may include any equipment and associated logic, circuitry, interfaces, memory, and/or code. Depending on an application(s) of UAV110, the payload unit may include one or more onboard sensors, which may be contained within a housing of UAV110or mounted outside the housing of UAV110. By way of non-limiting example, sensors may include environmental sensors, such as temperature sensors, rain sensors, pressure sensors, humidity sensors, fog sensors, gas sensors, etc., or combination thereof; object/obstacle detection sensors, such as radar sensors, proximity sensors, motion detectors, etc., or combination thereof; imaging sensors (e.g., cameras); acoustic sensors, and/or other types of sensors, or combination thereof. Such sensors may be utilized to prevent collisions, and may include other necessary processing features for a collision avoidance system. Alternatively or in addition, the payload unit may include tools, actuators, robotic manipulators, etc., capable of performing an action, such as touching, grasping, delivering, and/or measuring objects. For delivery applications, the payload unit may include the object to be delivered, e.g. the object may be secured within a housing of UAV110. Payload unit may also contain necessary rechargeable power sources, including a rechargeable solar battery and associated solar charging panel or photovoltaic charging source. User device130may be, and/or may include, a mobile phone, a personal digital assistant (PDA), a tablet device, a computer, or generally any device that is operable to communicate wirelessly (e.g., via cellular standards using antennas) with UAV110, cellular network carrier120, and/or one or more of base stations122a-c. In an aspect, user device130may be a device at ground level that utilizes the wireless network provided by cellular network carrier120. In this regard, user device130may receive radio signals from one or more of base stations122a-c, which may be configured to provide the wireless network to user device130based on ground objects126. Thus, the wireless network provided by one or more of base stations122a-cmay be specifically calibrated and/or configured for communication with user device130based on ground objects126. In some cases, UAV110and/or user device130may be configured to interface with a wired network, such as via an Ethernet interface, power-line modem, DSL modem, PSTN modem, cable modem, and/or other appropriate components for wired communication. Alternatively or in addition, UAV110and/or user device130may support proprietary wired communication protocols and interfaces. UAV110and user device130may be configured to communicate over a wired link (e.g., through a network router, switch, hub, or other network device) for purposes of wired communication, e.g. such as during testing, setup, and/or calibration stages of UAV110and/or during use of user device130. UAV110may be at or near ground level to receive a wired connection. Although a single UAV and user device (e.g., UAV110and user device130) is shown inFIG.1, multiple UAVs and user devices (e.g., multiple UAVs and/or user devices) may be utilized and function similarly. One or more of base stations122a-cmay include, may be a component of, and/or may be referred to as, a cell, a Node B (NB), an Evolved Node B (eNodeB or eNB), or a Home eNB (HeNB). One or more of base stations122a-cinclude suitable logic, circuitry, interfaces, memory, and/or code that enable communications, e.g. with user device130, one of the other base stations122a-c, and/or cellular network carrier120, via wireless interfaces and utilizing one or more radio transceivers (e.g., RF signal antennas). In an aspect, base stations122a-cmay transmit (e.g., broadcast) messages that, if received by UAV110, facilitate directing and/or placement of one or more shields within antenna housing112of UAV110in order to provide shielding of one or more antennas of UAV110, as well as navigation of UAV110. In some cases, the messages transmitted by base stations122a-cmay be based on information base stations122a-creceive from cellular network carrier120. In some cases, one or more of base stations122a-cmay be mobile (e.g., mobile base stations at ground level, mobile base stations at flight altitudes, mobile naval-based base stations, etc.), in which case its position information is dynamic. Base stations122a-cmay be macrocell base stations, microcell base stations, picocell base stations, femtocell base stations, and/or other cell sizes. For example, the macrocell base station may provide a coverage area over a radial range up to the tens or hundreds of kilometers, the picocell base station may provide coverage over a radial range in the hundreds of meters, and the femtocell base station may provide coverage over a radial range in the tens of meters. InFIG.1, base stations122a,122b, and122chave nominal coverage area124a,124b, and124c, respectively, at ground level or near ground level. The coverage area of a base station may be different in different environments, at different altitudes, and at different frequency bands. For example, a base station may have a smaller coverage area on a rainy day than the same base station on a sunny day, e.g. due to attenuation of signals by rain. When altitudes are taken into consideration, the coverage area provided by base stations122a-cmay more appropriately be referred to as a coverage volume, with different coverage areas at different altitudes. In an aspect, a coverage area of a base station may be larger at flight altitudes (e.g., 400 feet) than at lower altitudes such as ground level, due to fewer obstructions at flight altitudes for example. Due to the change in coverage area at altitude, UAV110may encounter interference and other signal issues during flight at altitude due to the lack of ground based loss, thereby not having a dominant RF signaling station from base stations122a-cto utilize. As used herein, the coverage area and coverage volume may be referred to more generally as a coverage region, where the region may be two-dimensional (e.g., coverage area) or three-dimensional (e.g., coverage volume). Cellular network carrier120may be, may include, and/or may be a component of, a core network for processing information from UAVs (e.g., UAV110), user devices (e.g., user device130), and/or base stations (e.g., base stations122a-c) and managing connections of the UAVs and/or user devices to the base stations. For example, cellular network carrier120may be, may include, and/or may be in communication with, a mobile telephone switching office (MTSO). Cellular network carrier120and base stations122a-cmay be provided by a cellular network carrier or provider. Cellular network carrier120includes suitable logic, circuitry, interfaces, memory, and/or code that enable communications, e.g. with one or more of base stations122a-cand/or one or more UEs (e.g., UAV110and user device130), via wireless interfaces and utilize one or more radio transceivers. In this regard, cellular network carrier120may be dedicated to facilitate connectivity of UAVs (or other vehicles/devices at flight altitude) with base stations122a-c(and/or other base stations), or may be utilized to facilitate connectivity of UAVs and ground-based devices with base stations122a-c(and/or other base stations). In an aspect, cellular network carrier120may be, may include, or may be a part of, a server (e.g., a centralized server) that can generate and distribute information to base stations122a-c, as well as receive information from base stations122a-c. Base stations122a-cmay then relay the information from cellular network carrier120to UAV110and/or user device130. In some cases, when UAV110is in range of cellular network carrier120, cellular network carrier120may transmit information directly to UAV110(e.g., through a wired or wireless signal). In an aspect, cellular network carrier120may provide each of base stations122a-cwith respective flight and/or travel route/path information (e.g., position, altitude, route, obstacle, weather, and other necessary information to navigate UAV110) to be transmitted (e.g., broadcasted) to UAV110. In other embodiments, cellular network carrier120may directly provide the information to UAV110. Cellular network carrier120may also provide UAV110with information necessary to determine positioning and/or orientation of shields of antenna housing112 Base stations122a-cmay be in communication with cellular network carrier120through a backhaul network. Cellular network carrier120may be in direct communication with one or more of base stations122a-cor in communication with one or more of base stations122a-cthrough one or more intermediary base stations. For example, inFIG.1, cellular network carrier120is in direct communication with base stations122a-c. In other cases, a base station may be in communication with cellular network carrier120via one or more intervening base stations. In an embodiment, cellular network carrier120may determine and/or have access to signal strength statistics at different positions (e.g., altitudes) and/or different frequency bands, e.g. based on the measurement reports generated by the UEs, including UAV110and/or user device130. In some cases, cellular network carrier120may determine preferred frequency bands to be utilized at various altitudes based on the signal strength statistics. Additionally, cellular network carrier120may determine ground level interference and loss due to geographic conditions, terrain, and additional clutter (e.g., human made objects, persons, vehicles, etc.), which may be mapped or otherwise associated with ground level locations. The information may be used to determine a dominant or selected base station at a ground level location, as well as other RF signal propagation at ground level. In information may also be used to select positioning and orientation of the shields of antenna housing112during flight of UAV110to mimic the ground level loss. The flight path140may be a portion of a flight path along which UAV110is moving or intends to move in going from a starting point to a destination point. The flight path140may be defined by a set of positions, including positions142a-dshown inFIG.1, at which UAV110is located, has been located, or is expected to be located. The positions142a-dmay each be associated with a set of three-dimensional coordinates (e.g., longitude, latitude, altitude). For example, during a flight route, the starting point may be a warehouse or takeoff point at which UAV110is provided with the travel route for execution. At the position142a, UAV110may be within coverage area124afor base station122a. Different base stations may provide better signal strength at the different positions142a-dalong flight path140. For example, among base stations122a-c, the base station122amay be generally associated with the highest signal strength at the position142a, whereas the base station122bmay have higher signal strength of position142band base station122cmay be generally associated with higher signal strength at the positions142cand142d. As shown inFIG.1, the coverage areas124a-cof base stations122a-cmay overlap. The coverage areas124a-cmay represent the coverage areas of base stations122a-cat ground level. UAV110may be within range of two or more of base stations122a-c, thereby causing interference or other signal issues and/or degradation. For example, UAV110may be within range of the base stations122aand122bin an overlap region150. Based on a specific position of UAV110, signal strength between UAV110and the base station122amay be different from (e.g., stronger than, weaker than) signal strength between UAV110and the base station122b. In some cases, the overlap in the coverage regions may be more pronounced at flight altitudes than at ground level, such as due to fewer obstructions. Thus, overlap region150may correspond to interference areas or potential issues in coverage at altitude of base stations122aand122bwhen providing coverage areas124aand124b. During flight path140, UAV110may therefore enter into RF signal range of base stations122a-chaving coverage areas124a-c. In an aspect, the flight path140may be a preprogrammed flight path, e.g. preloaded by cellular network carrier120to UAV. For example, UAV110may communicate (e.g., directly or indirectly) with cellular network carrier120and provide a starting point (e.g., a current position of UAV110) and a destination point. In response, cellular network carrier120may generate and provide to UAV110one or more potential flight paths. An operator of UAV110and/or user device130may select and/or confirm the flight path to be utilized. In further embodiments, during flight of UAV110, UAV110may autonomously make adjustments to the flight path140, or may be instructed of the flight path and/or adjustments to the flight path. The adjustments may be based on onboard sensors (e.g., for sensing obstacles, weather, etc.) and/or based on information received from one or more of base stations122a-c(e.g., obstacle, weather, traffic emergency information). In an aspect, UAV110may be operated to maintain a minimum distance separation between UAV110and other UAVs, and/or between UAV110and obstacles, e.g. such as minimum distance separation requirements or recommendations from the Federal Aviation Administration (FAA). In some cases, a flight path of UAV110may have a fixed altitude level (e.g., UAV110has to fly somewhere between a fixed minimum altitude level and a fixed maximum altitude level) and/or an operating frequency of UAV110may be within a fixed frequency band (e.g., fixed frequency range). Such parameters on the flight path of UAV110may be set by cellular network carrier120and/or flight regulations. Thus, the flight path and/or connectivity between UAV110and the cellular network via base stations122a-c(and/or other base stations) may be further facilitated through additional information such as obstacle, weather, traffic management information (e.g., air traffic management information), emergency broadcast information, and/or generally any other information that may be static or dynamic in the airspace that can be communicated to facilitate communication of UAV110with use of the cellular network. The obstacle information and weather information may identify obstacles (e.g., trees, buildings) and weather (e.g., rain, fog, hail) within coverage regions of the base stations122a-122c, or portion thereof. For example, the base station122amay provide position information (e.g., latitude, longitude, height) encompassed by the obstacles. The traffic management information may provide information indicative of signal strengths at different frequency bands and/or at different positions (e.g., altitudes, longitudes, and/or latitudes). In some cases, the traffic management information may provide preferred frequency bands at different altitudes. The emergency broadcast information may identify traffic incidences and/or no-fly zones (e.g., temporary no-fly zones due to these traffic incidences). Such information may allow UAV110to select the base station to connect with during flight, adjust a frequency band utilized for communication, and/or adjust a flight path (e.g., an altitude of various points along the flight path). During or after execution of flight path140by UAV110, antenna housing112may adjust one or more internal shields to shield an internal antenna of antenna housing112used by UAV110to communicate on the wireless network provided by base stations122a-c. Location information of UAV110during flight may be used with the information on ground based loss and interference of RF signals from base stations122a-cin coverage areas124a-cto determine placement of the internal shields, as discussed herein. For example, the internal shield(s) may be placed or oriented to mimic ground level loss/interference and select one of base stations122a-cfor communication with on the cellular network by blocking RF signals from the other ones of base stations122a-c. The location information may include a longitude, latitude, and altitude of UAV110, and/or information indicative of the longitude, latitude, and altitude (e.g., information from which cellular network carrier120may derive the longitude, latitude, and altitude). In some cases, rather than the longitude, latitude, and/or altitude coordinates, other coordinate systems by which to define the position of base stations122a-cmay be utilized. As previously discussed, cellular network carrier120and/or another third party entity providing network coverage diagnostics and analysis may determine the information of RF signal propagation, ground level loss/interference, and/or other information of RF signal transmission and reception of RF signals from base stations122a-chaving coverage areas124a-cand ground level UEs, such as user device110. The information may further include altitude based interferences of coverage areas124a-cin a 3D space, which may display propagation of signals from base stations122a-chaving coverage areas124a-c. Thus, the information may be used to select a base station for transmission of signals at specific locations in 3D (e.g., for a specific latitude, longitude, and altitude). In certain embodiments, selection of the antenna shielding placement/orientation may be based on measurements of relative signal strengths of signals from different base stations and interferences of similar signaling. The base station that is selected may differ at different altitudes and/or at different frequency bands used for communication. To facilitate connectivity between base stations122a-cand UAVs (e.g., UAV110) during flight of the UAVs, information for ground level interference/loss may be used for base stations122a-c. Using this information with the location information, antenna housing112may configure one or more internal shields to mimic ground level loss/interference, and connect with one or more of base stations122a-cin coverage areas124a-cduring a flight route. UAV110may maintain a wireless communication link between UAV110and one of base stations122a-cin order to send and/or receive information at an acceptable signal strength during at least a portion of a flight path of UAV110through the shielding provided by antenna housing112. Received information by UAV110may correspond to a flight path or route information, and/or any changes or deviations to the selected route. In certain embodiments, the antenna of antenna housing112may also receive information for arrangement and/or orientation of the shields over the wireless communication link. Thus, antenna shielding arrangement and orientation may be selected and rearranged during flight path140based on the location information and the information of ground based loss. The shields of antenna housing112may therefore be used to receive RF signals from another base station when the signal strength and/or signal strength statistics associated with signals from the selected one of base stations122a-cfalls below a threshold value or otherwise would be different at a ground level location associated with UAV110's present location. In an embodiment, UAV110may receive information (e.g., geographic clutter and/or information) from non-network devices (also referred to as non-network nodes). In this regard, base stations122a-cand cellular network carrier120may be referred to as network devices or network nodes of the cellular network. In some cases, a non-network device may provide one-way communication from the non-network device to UAV110. A non-network device may be placed at locations at or near an obstacle for example, and broadcast (e.g., using its antenna(s)) its position information and/or other geographic information to help prevent collision of UAV110and/or other UEs/UAVs with the obstacle. As an example, the non-network device may be placed at or near a tall tree. As another example, the non-network device may be placed at a location designated as a no-fly zone and utilized as a no-fly zone beacon. For instance, a traffic accident (e.g., whether between two cars at ground level, two UAVs, a car and a building, and so forth) may cause emergency helicopters and/or other aircrafts to deployed in and/or around the no-fly zone. UAV110may impede emergency response if flown in or around the no-fly zone. AlthoughFIG.1is described with respect to UAV110, the UE may generally be any device, e.g. at ground level or at higher altitudes, that can collect cellular network information using an antenna housing112. Although UAV110is depicted as including a single antenna, in some cases UAV110may have more and/or different antennas than those shown inFIG.1. For example, in an aspect, UAV110does not include an omnidirectional antenna, and/or UAV110includes multiple directional antennas. In addition,FIG.1illustrates one example of a network configuration. Other network configurations may be utilized to allow communication between UAV110, cellular network carrier120, base stations122a-c, and user device130. The network environment100may include a different number of UAVs, user devices, base stations, and/or network management systems than that shown inFIG.1. FIG.2illustrates an example of base station transmitting a cellular network signal that is affected by ground level objects causing interference and loss, according to an embodiment. Environment200ofFIG.2includes UAV110having antenna housing112discussed in reference to network environment100ofFIG.1. Additionally, a base tower122having coverage area124corresponds generally to one of base stations122a-chaving coverage areas124a-c, respectively, in network environment100ofFIG.1. Moreover, ground objects126a-c, and user devices130a-bcorresponds generally to ground objects126and user device130, respectively, in network environment100ofFIG.1. In various embodiments, environment200ofFIG.2demonstrates signal differences between UEs located at ground level (e.g., user devices130a-b) and UEs at altitude (e.g., UAV110). As shown inFIG.2, environment200includes base station122broadcasting RF signals within coverage area124for communication with UEs. The radio signals may correspond to a cellular network, or other network used for wireless communications. In general, base station122is optimized for transmission of radio signals in coverage area124at a ground level, such as two meters or similar off the ground where many ground based wireless devices operate (e.g., user devices130a-b). Thus, base station122and coverage area124are optimized to take into account ground objects126a-c, such as office buildings, homes, and/or trees. Other geographic conditions, terrain, and/or ground based objects may be considered, includes human bodies, vehicles, geographic affects, and the like. Additional human made or nature geographical objects and conditions may similarly affect radio signals from base station122in coverage area124. Ground objects126a-cmay therefore cause signal interference and/or loss due to additional unwanted signal, interruption, RF signal absorption or reflection, or other causes of signal interference or loss. Thus, base station122may be configured to transmit within coverage area124based on such interference/loss and be the dominant RF signal carrier for coverage area124. Users utilizing user device130a-bmay receive optimized radio signal coverage area124for the wireless network from base station122based on such considerations by a cellular network operator or carrier at a ground level. A similar nearby base station may further transmit within a coverage area based on ground based geographic terrain and clutter, where such a base station is the dominant RF signal carrier for the region when user devices130a-bare within that region. However, UAV110may be flying at an altitude where ground objects126a-cdo not impede radio signal transmissions from base station122within coverage area124. Instead, other interference may occur at altitude, for example, from another base station having an overlapping signal coverage area at altitude due to the lack of ground based geographic conditions impeding signal propagation and causing ground level interference or loss. At the altitude, other factors may influence signal transmissions, interferences, and/or messaging on the cellular network provided by base station122. In order to communicate on the cellular network provided by these base towers, UAV110may utilize an antenna with a specialized dynamic shield component in antenna housing112to the antenna to selectively block RF signals from specific directions of incidence. For example, while within the ground level coverage area124of base station122at altitude (e.g., determined from the coverage area along a 2D coordinate system or the coverage volume in a 3D coordinate system), antenna housing112may adjust one or more shields to the RF signal antenna of UAV110to allow RF signals in coverage area124from base station122, while absorbing or reflecting other RF signals. Positioning and orientation of the shields may be determined based on the location of UAV110, coverage area124, and/or ground objects126a-ccausing the ground level interference/loss. Thus, antenna housing112may adjust the shields to mimic the ground level interference/loss within coverage area124at altitude for the antenna of UAV110. FIG.3illustrates a block diagram of an exemplary UAV having a dynamic shielding unit that imitates ground level interference and loss at altitude, according to an embodiment. System300includes unmanned aerial vehicle (UAV)110and antenna housing112discussed in reference to network environment100ofFIG.1. In this regard, UAV110and/or a controller of antenna housing112may control one or more moveable shields of antenna housing112to provide RF signal shielding (e.g., absorbing or reflecting) from RF signals from unwanted directions during flight of UAV110in order to mimic ground level RF communications of UEs while UAV110travels at altitude. UAV110includes one or more processors, memories, and other appropriate components for executing instructions such as program code and/or data stored on one or more computer readable mediums to implement the various applications, data, and steps described herein. For example, such instructions may be stored in one or more computer readable media such as memories or data storage devices internal and/or external to various components of system300, and/or accessible over network160. UAV110may be implemented as a UAV, UAS, drone, or other aerial vehicle that may utilize appropriate hardware and software configured for wired and/or wireless communication with cellular network carrier120. Although only one UAV is shown, a plurality of UAVs may function similarly. UAV110ofFIG.1contains a processor111and antenna housing112. Processor111may utilize executable processes, procedures, and/or applications with associated hardware to operate UAV110, such as a flight controller and/or navigation component or unit. Processor111may also be utilized to determine shielding orientations for antenna housing112and/or provide data required by a controller of antenna housing112for determination of the shielding orientations. In other embodiments, UAV110may include additional or different modules having specialized hardware and/or software as required. Processor111may correspond to one or more processing units of UAV110to operate and navigate UAV110, for example, to travel one or more flight paths in order to collect cellular network information. In this regard, processor111may be configured to facilitate navigation of UAV110, e.g., take off, landing, and flight of UAV110, which may include execution of the flight path(s) or route(s). Processor111may include any appropriate avionics, control actuators, and/or other equipment, along with associated logic, circuitry, interfaces, memory, and/or code. Additionally, processor111may include a controller that receives flight route information from one or more sources, including memory115and/or external controller (e.g., set instructions from cellular network carrier120and/or inflight navigation/instructions from an operator) that operates UAV110. Thus, processor111may be fed flight controls, paths, and/or routes from one or more of memory115and/or communication component114. Processor111may determine a location of UAV110, which may be utilized with antenna housing112for shielding of one or more antennas. Additionally, processor111may be utilized to determine shielding requirements for antenna housing112, or may provide information to another controller of antenna housing112for determination of the shielding requirements. The provided information may include the location of UAV110, as well as ground based interference/loss information for ground based UEs or cellular network mapping, as appropriate. Processor111may also be utilized to communicate on a cellular network utilizing an antenna within antenna housing112(e.g., a 3G, 4G, 5G, and/or other 3GPP-based cellular network). Antenna housing112may be utilized to detect cellular network information, for example, by receiving power (e.g., radio signals) from one or more base stations or other cellular network signal propagation source. Antenna housing112includes a housing shell112a, an antenna113, and shielding components114a-c. Housing shell112amay be contained within a housing of UAV110(e.g., embedded within the housing and/or circuitry of UAV110), or disposed (e.g., mounted) outside a housing of UAV110as an attachable and/or removable module. Housing shell112amay enclose the necessary components to provide a dynamic shield system of cellular signals for antenna113of UAV110. Thus, housing shell112amay include additional, less, and/or different components to those shown in system300, including necessary mechanical components, motors, powers sources, etc., for the placement, orientations, and rearrangement of shielding components114a-c. Antenna113may sense the radio signals, and be used to record the radio signals along with associated information (e.g., position information) to memory115for storage and use. In some cases, the antenna housing112may be movable along and/or rotatable about one, two, or three axes. In other cases, the antenna housing112may be fixed (e.g., not movable and not rotatable). Antenna113may correspond to a cellular technology (e.g., using LTE or other cellular technology communication signal) antenna. Antenna113may be used to measure signal strength, signal diagnostics, and/or interferences of cellular tower signals for a cellular network. The signal strength may be, or may be based on, measures such as received signal strength indicator (RSSI), reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), and/or other measures. Additionally, antenna113may be used to message and/or communicate with one or more base stations. Shielding components114a-cmay include wireless signal shielding materials and necessary mechanical components to be movable and/or rotatable around antenna113. Shielding components114a-cmay block RF signals from a direction of incidence to antenna113by moving to interpose one or more of shielding components114a-cbetween the direction of incidence and antenna113. The material for shielding components114a-cmay absorb and/or reflect wireless signals incoming from the incident direction (e.g., when interposed between the direction of the incoming wireless signal and antenna113). Thus, when one or more of shielding components114a-care placed between antenna and the incoming direction of the wireless signal, the one or more of shielding components114a-cmay prevent antenna113from detecting, absorbing and/or receiving the wireless signal, as well as transmitting wireless signals from antenna113to other receivers or transceivers in that direction. One or more of shielding components114a-cmay completely absorb or reflect the signal, or partially absorb or reflect the signal. Thus, more than one of shielding components114a-cmay be required in certain aspects to provide complete signal shielding from a direction. Shielding components114a-cmay block signals on the cellular network in the RF range used by the cellular network that are provided from base stations of the cellular network carrier within coverage areas of the RF signals from those base stations. In other embodiments, shielding components114a-cmay further or instead absorb or reflect wireless signals for other types of wireless networks, for example, to accommodate other types of wireless communication signals (e.g., satellite systems, short range wireless communication signals, etc.). However, in certain embodiments, the material used for shielding components114a-cmay be selected to only block RF signals on the cellular network to allow other types of wireless communications selectively used for the UAV (e.g., line of sight communications to control the UAV). FIG.4illustrates a block diagram of an exemplary UAV controlling a dynamic shield system of cellular signals for an antenna of the UAV, according to an embodiment. Not all of the depicted components may be required, however, and one or more embodiments may include additional components shown in the additional Figures described herein. Variations in the arrangement and type of the components may be made without departing from the spirit or scope of the claims as set forth herein. Additional components, different components, and/or fewer components may be provided. For explanatory purposes, processor111and an antenna shielding controller116of UAV110is described herein with reference to network environment100ofFIG.1and system300ofFIG.3; however, antenna shielding controller116is not limited to network environment100ofFIG.1and/or and system300ofFIG.3. UAV110may include processor111, a memory115, and antenna shielding controller116. Processor111may implement any control and feedback operations appropriate for interacting with the avionics, control actuators, and/or other equipment included in the flight control unit to fly UAV110, including, but not limited to, taking off, landing, and/or setting/adjusting direction, velocity, and/or acceleration of UAV110. In some cases, processor111may receive commands from user devices, base stations, and/or a cellular network carrier to, for example, configure and execute a flight plan (e.g., program a flight path), adjust a programmed flight path, deploy UAV110, land UAV110, navigate UAV110, and/or other commands that facilitate navigating UAV110and utilizing UAV110to perform an action. In some cases, processor111may receive commands to move and/or rotate UAV110and/or a component thereof (e.g., an antenna). Processor111may further be utilized to control placement, movement, and/or orientation of one or more shielding components of antenna for UAV110using antenna shielding controller116, for example, by providing information to antenna shielding controller116for placement/orientation of the shielding components to selectively block RF signals in order to mimic ground level interference/loss while UAV110travels at altitude. Memory115may include flight paths and routes2000that may be output to memory115from processor111at step2300during transfer of current location and shielding information between memory115and processor111. Flight paths and routes2000may include information for flight routes2001and a current location2002during operation of UAV110. Additionally, flight paths and routes2000includes ground-based location similarity2003, which may be determined based on current location2002in order for processor111and/or antenna shielding controller116to determine a shield configuration to mimic ground level interference/loss. Thus, processor111may further be utilized to monitor (e.g., autonomously monitor) a current position of UAV110. Processor111may include, or may be in communication with, a GPS that provides the position of UAV110. In some cases, processor111may implement location determination techniques. For example, processor111may determine a positional difference between UAV110and a base station based on the position information of UAV110and the base station. Processor111may then execute flight paths and routes accordingly to navigate UAV110. Based on ground-based location similarity in data for flight paths and routes2000, processor111may further retrieve antenna shielding data2100. Antenna shielding data2100includes ground-based geographic objects2101, network signal propagation2102, base station locations2103, and altitude-based signal factors2104, each of which may be utilized to determine shielding orientation and/or placement of one or more RF signal shields for an antenna of UAV110. Processor111may determine an antenna shield configuration, and output the antenna shield configuration to antenna shielding controller116. Thus, antenna shielding controller116may utilize present antenna shield configuration2304to move, orient, or place one or more RF shields surrounding an antenna in order to receive select RF signals as would a UE at ground-based location similarity2003. In other embodiments, data for flight paths and routes2000and antenna shielding data2100may instead be transmitted to antenna shielding controller116. While an example manner of implementing UAV110is illustrated inFIG.4, one or more of the components (e.g., elements, processes, and/or devices) illustrated inFIG.4may be combined, divided, re-arranged, omitted, eliminated, and/or implemented in any other way. Further, the components of UAV110inFIG.4may be implemented by hardware, software, firmware, and/or any combination of hardware, software, and/or firmware. Thus, for example, any of the components of UAV110may be implemented by one or more analog and/or digital circuits, logic circuits, programmable processors, application specific integrated circuits (ASICs), programmable logic devices (PLDs), and/or field programmable logic devices (FPLDs). In this regard, when implemented using circuitry, the components of UAV110may be referred to as UAV processing circuit, communication transceiver circuit, mobility controller circuit, and autonomous positioner circuit, respectively. When reading any claims as set forth herein to cover purely software and/or firmware implementations, at least one of the components of UAV110is hereby expressly defined to include a tangible computer readable storage device or storage disk such as a memory, digital versatile disk (DVD), compact disk (CD), a Blu-ray Disc™, and/or other storage device/disk storing the software and/or firmware. FIG.5illustrates a flow diagram for a dynamic shield system of cellular signals for an antenna of a UAV, according to an embodiment. Note that one or more steps, processes, and methods described herein in flowchart500may be omitted, performed in a different sequence, or combined as desired or appropriate. At step502, a navigation route for an unmanned aerial vehicle to execute during flight of the unmanned aerial vehicle is received. At step504, an orientation of a radio signal shield for an antenna of the unmanned aerial vehicle is determined using ground level signal propagation information of radio signals for a network and the navigation route, wherein the radio signal shield prevents or attenuates the radio signals from being received by the antenna from directions based on the orientation. The radio signal shield may include one or more components or materials that prevent or attenuate reception of radio frequency signals by the antenna from an opposite direction of travel of the unmanned aerial vehicle on the travel route, wherein the component(s) rotates to prevent or attenuate the reception of the radio frequency signals by the antenna from directions that the antenna does not require the radio frequency signals. In order to prevent or attenuate radio frequency signals, the component(s) may comprise at least one of a radio frequency absorbing material or a radio frequency reflecting material of radio frequency signals. The orientation of the component(s) may be dependent on travel route direction of travel of the unmanned aerial vehicle along a flight path, such as the navigation route, as well as an altitude of the UAV. Additionally, a number of component(s) used to shield the antenna may be dependent on the altitude of the unmanned aerial vehicle during operation. Where there are multiple components, the orientation may comprise an arrangement of the plurality of components around the antenna. The ground level signal propagation information or other antenna shielding data may specific for a geographic region of travel by the unmanned aerial vehicle, wherein the unmanned aerial vehicle operates by flying a route within the geographic region. The information or other data may be determined using radio signal coverage areas at a ground level for base stations of a cellular network carrier providing the network. Additionally, the information or other data may comprise placement information for the component(s) used to send and receive the radio signals with a selected base station of the base stations using the antenna, wherein the selected base station is further selected by a similar user endpoint at the ground level corresponding to a current position of the unmanned aerial vehicle during operation. Thus, the placement information for the component(s) may mimic geographic conditions at the ground level for the antenna. At step506, the radio signal shield is adjusted using the orientation. And at step508, the unmanned aerial vehicle communicates with a cellular base station of the network using the antenna. Communicating on the network comprises sending and receiving the radio signals by the antenna with a base station selected based on the placement or orientation of the component(s). The network may comprise one of a 3G, a 4G, a 4G Long Term Evolution (LTE), or a 5G network for communication with user endpoints including the unmanned aerial vehicle. In various embodiments, during further operation of the unmanned aerial vehicle, a change in a route travelled by the unmanned aerial vehicle is received. Thus, a second placement or orientation is determined of the component(s) using the signal propagation and/or antenna shielding data and the change in the route, and the components are arranged or moved based on the second placement or orientation before further communications or during those communications on the network FIG.6illustrates a block diagram of an example of an electronic system with which one or more embodiments of the present disclosure may be implemented, according to an embodiment. In various embodiments, computer system600ofFIG.6may comprise a personal computing device (e.g., smart phone, a computing tablet, a personal computer, laptop, a wearable computing device such as glasses or a watch, Bluetooth device, key FOB, badge, etc.) capable of communicating with the network. In other embodiments, a cellular network carrier or provider may utilize a network computing device (e.g., a network server) capable of communicating with the network similar to computer system600. Moreover, one or more of the systems of a UAV may include and/or function similarly to computer system600. It should be appreciated that each of the devices utilized by users and/or service providers (e.g., cellular network carriers) may be implemented as computer system600in a manner as follows. Computer system600includes a bus602or other communication mechanism for communicating information data, signals, and information between various components of computer system600. Components include an input/output (I/O) component604that processes a user action, such as selecting keys from a keypad/keyboard, selecting one or more buttons, image, or links, and/or moving one or more images, etc., and sends a corresponding signal to bus602. I/O component604may also include an output component, such as a display611and a cursor control613(such as a keyboard, keypad, mouse, etc.). An optional audio input/output component605may also be included to allow a user to use voice for inputting information by converting audio signals. Audio I/O component605may allow the user to hear audio. A transceiver or network interface606transmits and receives signals between computer system600and other devices, such as another communication device, service device, or a service provider server via network160. Network160may be implemented as a single network or a combination of multiple networks. For example, in various embodiments, network160may include the Internet or one or more intranets, landline networks, wireless networks, and/or other appropriate types of networks. Thus, network160may correspond to small scale communication networks, such as a private or local area network, or a larger scale network, such as a wide area network or the Internet, accessible by the various components described herein. In various embodiments, the transmission is wireless, although other transmission mediums and methods may also be suitable. One or more processors612, which can be a micro-controller, digital signal processor (DSP), or other processing component, processes these various signals, such as for display on computer system600or transmission to other devices via a communication link618. Processor(s)612may also control transmission of information, such as cookies or IP addresses, to other devices. Components of computer system600also include a system memory component614(e.g., RAM), a static storage component616(e.g., ROM), and/or a disk drive617. Computer system600performs specific operations by processor(s)612and other components by executing one or more sequences of instructions contained in system memory component614. Logic may be encoded in a computer readable medium, which may refer to any medium that participates in providing instructions to processor(s)612for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. In various embodiments, non-volatile media includes optical or magnetic disks, volatile media includes dynamic memory, such as system memory component614, and transmission media includes coaxial cables, copper wire, and fiber optics, including wires that comprise bus602. In various embodiments, the logic is encoded in non-transitory computer readable medium. In one example, transmission media may take the form of acoustic or light waves, such as those generated during radio wave, optical, and infrared data communications. Some common forms of computer readable media includes, for example, floppy disk, flexible disk, hard disk, magnetic tape, any other magnetic medium, CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, RAM, PROM, EEPROM, FLASH-EEPROM, any other memory chip or cartridge, or any other medium from which a computer is adapted to read. In various embodiments of the present disclosure, execution of instruction sequences to practice the present disclosure may be performed by computer system600. In various other embodiments of the present disclosure, a plurality of computer systems600coupled by communication link618to the network (e.g., such as a LAN, WLAN, PTSN, and/or various other wired or wireless networks, including telecommunications, mobile, and cellular phone networks) may perform instruction sequences to practice the present disclosure in coordination with one another. Where applicable, various embodiments provided by the present disclosure may be implemented using hardware, software, or combinations of hardware and software. Also, where applicable, the various hardware components and/or software components set forth herein may be combined into composite components comprising software, hardware, and/or both without departing from the spirit of the present disclosure. Where applicable, the various hardware components and/or software components set forth herein may be separated into sub-components comprising software, hardware, or both without departing from the scope of the present disclosure. In addition, where applicable, it is contemplated that software components may be implemented as hardware components and vice-versa. Software, in accordance with the present disclosure, such as program code and/or data, may be stored on one or more computer readable mediums. It is also contemplated that software identified herein may be implemented using one or more general purpose or specific purpose computers and/or computer systems, networked and/or otherwise. Where applicable, the ordering of various steps described herein may be changed, combined into composite steps, and/or separated into sub-steps to provide features described herein. The foregoing disclosure is not intended to limit the present disclosure to the precise forms or particular fields of use disclosed. As such, it is contemplated that various alternate embodiments and/or modifications to the present disclosure, whether explicitly described or implied herein, are possible in light of the disclosure. Having thus described embodiments of the present disclosure, persons of ordinary skill in the art will recognize that changes may be made in form and detail without departing from the scope of the present disclosure. Thus, the present disclosure is limited only by the claims. | 88,336 |
11943042 | DETAILED DESCRIPTION Systems are currently being deployed to provide high-bandwidth, low-latency network communication via constellations of satellites in low Earth orbit (LEO).FIG.1is a not-to-scale schematic diagram that illustrates a simple example of communication in such a system100. An endpoint terminal102is installed at a house, a business, a vehicle, or another location where it is desired to obtain communication access via a network of satellites. A communication path is established between the endpoint terminal102and a first satellite104. In the illustrated embodiment, the first satellite104, in turn, establishes a communication path with a gateway terminal106. In another embodiment, the first satellite104may establish a communication path with another satellite prior to communication with a gateway terminal106. The gateway terminal106is physically connected via fiber optic, Ethernet, or another physical connection to a ground network108. The ground network108may be any type of network, including the Internet. Latency of communication between the endpoint terminal102and the ground network108is determined at least in part by the distance between the endpoint terminal102and the satellite104, and the distance between the satellite104and the gateway terminal106. For previous satellite communication systems that used satellites in geosynchronous or geostationary Earth orbit (GEO), the large distances involved created high amounts of latency. Therefore, it is desirable to use constellations of satellites in non-GEO orbit, for example, low Earth orbit (LEO), for communication systems. Embodiments of the present disclosure are directed to configurations for endpoint terminals102(or user terminals) to optimize network communications to and from satellite constellations. In particular, the exemplary embodiments disclosed herein relate to systems and methods for positioning endpoint terminals102based on obstructions that may prevent signals from being transmitted between the endpoint terminals102and satellites within satellite constellations. An Earth-based endpoint terminal102may be a terminal connected to Earth or as a non-orbiting body positioned in the Earth's atmosphere, such as a non-mobile atmospheric platform. For example, an Earth-based endpoint terminal102may be in Earth's troposphere, such as within about 10 kilometers (about 6.2 miles) of the Earth's surface, and/or within the Earth's stratosphere, such as within about 50 kilometers (about 31 miles) of the Earth's surface, for example on a stationary object, such as a balloon. While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described herein in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives consistent with the present disclosure and the appended claims. References in the specification to “one embodiment,” “an embodiment,” “an illustrative embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may or may not necessarily include that particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. In the drawings, some structural or method features may be shown in specific arrangements and/or orderings. However, it should be appreciated that such specific arrangements and/or orderings may not be required. Rather, in some embodiments, such features may be arranged in a different manner and/or order than shown in the illustrative figures. Additionally, the inclusion of a structural or method feature in a particular figure is not meant to imply that such feature is required in all embodiments and, in some embodiments, it may not be included or may be combined with other features. Many embodiments of the technology described herein may take the form of computer- or controller-executable instructions, including routines executed by a programmable computer or controller. Those skilled in the relevant art will appreciate that the technology can be practiced on computer/controller systems other than those shown and described above. The technology can be embodied in a special-purpose computer, controller or data processor that is specifically programmed, configured or constructed to perform one or more of the computer-executable instructions described above. Accordingly, the terms “computer” and “controller” as generally used herein refer to any data processor and can include Internet appliances and hand-held devices (including palm-top computers, wearable computers, cellular or mobile phones, multi-processor systems, processor-based or programmable consumer electronics, network computers, mini computers and the like). Information handled by these computers can be presented at any suitable display medium, including a CRT display or LCD. Satellite Constellations The satellite constellations of the present disclosure are in non-geostationary orbits. A satellite in a geostationary orbit is at an altitude of approximately 35,786 km above mean sea level. Satellite constellations of the present disclosure are at lower altitudes. In one embodiment of the present disclosure, the satellite constellation of the present disclosure is at an altitude of less than 10,000 km. In another embodiment, the satellite constellation of the present disclosure is in a low Earth orbit at an altitude of less than 2000 km. In another embodiment, the satellite constellation of the present disclosure is in a very low Earth orbit at an altitude of less than 500 km. User or endpoint terminals102of the present systems100are designed and configured in accordance with embodiments of the present disclosure to work in conjunction with LEO satellite constellations. Because LEO satellite constellations, unlike GEO satellite constellations, do not remain stationary relative to a specific location on Earth, such changes are accommodated in the design of the satellite constellation and the user terminals102. The drifting nature of LEO satellite constellations is described in greater detail below. Unsynchronized (Drifting) Orbital Planes Referring toFIG.2A, a constellation of satellites is provided. The constellation shows four satellite orbits in four different orbital planes, including satellites strings A, B, C, and D. For simplification in the illustrated embodiment, the satellite strings include one satellite. However, in accordance with embodiments of the present disclosure, each satellite string includes a plurality of satellites following each other in the path of the orbital plane. Satellite strings A, B, C, D are at similar altitudes, but at different inclinations, inclinations angle A and inclination angle B. For example, string A is at an inclination α of about 55 degrees relative to the equator E and string B is at an inclination β of about 32 degrees relative to the equator E. Satellite strings C and D mirror satellite strings A and B. The altitudes of the satellite strings are not exactly the same to avoid collision of satellites in different systems, but they are within close range of each other, such that altitude is a minimal factor in the different operating characteristics of the first and second satellite strings A and B. For example, satellite string A and satellite string B may be in an altitude range of a few kilometers, less than 200 km. Referring toFIG.2B, the two satellite strings A and B ofFIG.2Ahave different westward drift rates in view of their different inclinations A and B. Therefore, after a period of time, as the Earth rotates in the eastward direction as indicated by arrow γ inFIG.2B, both satellite strings A and B have drifted westward. However, the second string of satellites B has drifted more westward than the first string of satellites A, as shown by drift differential Δd. The drift differential Δd between the first and second satellite strings A and B can be undesirable because it adds uncertainty to the meshing between the two areas of coverage by the two satellite strings A and B. Meshing or interleaving between satellite strings can be desirable in communication systems that depend on a known satellite constellation for predictable satellite coverage. Referring toFIG.2C, in a frame that rotates with the Earth, satellites in the first and second satellite strings X1and Y1are in discrete orbits, each defining an orbital path and each satellite string X1and Y1having a different inclination, similar to the satellite constellation. The satellite system may be designed with the required number of loops to be repeating ground track systems or may have a drifting pattern relative to the Earth's rotation rate. Meshing or interleaving between satellite strings is desirable in communication systems that depend on a known satellite constellation for predictable satellite coverage. As seen in the three-dimensional satellite travel paths ofFIG.2C, the orbital track of satellites traveling at a certain inclination angle and the geometry of the Earth create a higher density of satellites near the northern-most and southern-most planes of latitude as compared to near the equator. Assuming each satellite string X1or Y1inFIG.2Chas a known number of equally spaced or substantially equally spaced satellites traveling in a planar orbit circling the Earth, the orbital pattern of a satellite constellation at a specific inclination angle (compare the orbital patterns of X1and Y1at different inclination angles) and the geometry of the Earth create a swarm of satellites at or near the upper and lower limiting latitudes of the orbital path. For a prograde orbit, the upper and lower limiting latitudes of the orbital path (indicated as P and Q for satellite string X1inFIG.2Cor R and S for satellite string Y1inFIG.2C) typically correspond to the angle of inclination of the satellite. For example, a satellite string X1having an angle of inclination of 42 degrees has upper and lower limiting latitudes P and Q of 42 degrees north of the equator and 42 degrees south of the equator. For a retrograde orbit, the upper and lower limiting latitudes of the orbital path correspond to 180 degrees minus the inclination angle. For example, a satellite having an angle of inclination of 138 degrees also has and upper and lower limiting latitude of 42 degrees Likewise, a satellite string Y1having an angle of inclination of 53 degrees has upper and lower limiting latitudes R and S of 53 degrees north of the equator and 53 degrees south of the equator. User Terminal Having a Steerable Beam and a Limited Field of Regard In accordance with one embodiment of the present disclosure, a user terminal is configured for communication with a LEO satellite constellation consisting of satellites which emit or receive radio frequency (RF signals). An antenna (e.g., a dipole antenna, parabolic antenna, or patch antenna) typically generates or receives radiation in a pattern that has a preferred direction, known as the main beam. Signal quality (e.g., signal to noise ratio or SNR), whether in transmitting or receiving scenarios, can be improved by aligning, or steering, the main beam of the antenna with a direction of the target or source of signal. In electronically steered antenna systems, a plurality of individual antenna elements are employed together to reorient, or steer, the main beam relative to those physically fixed antenna elements. In mechanically steered antenna systems, a single or multiple antenna elements are physically moved to reorient the main beam. Because LEO satellite constellations, unlike GEO satellite constellations, do not remain stationary relative to a specific location on Earth, the user terminal of the present embodiment is configured with an antenna system having an antenna aperture with at least one degree of freedom to orient this preferred direction of transmitting or receiving electromagnetic radiation. This steering may be accomplished either electronic or mechanical means, or a combination thereof. In accordance with the embodiments of the present disclosure, the user terminal is incapable of steering its main beam to address the entire hemisphere of the sky as defined by the local horizon of the location of the user terminal on the Earth. This steering limitation is the result of mechanical, regulatory, or electrical limitations of the beam steering technology used in the user terminal. The area in which this antenna is capable of steering to for communication is referred to as the field of regard, or interchangeably the communication zone. An antenna which is incapable of steering its beam to address any arbitrary location within its local hemisphere of sky is referred hereafter as a limited field of regard antenna. User Terminal Having a Phased Array Antenna In accordance with one illustrative embodiment of the present disclosure, a user terminal may be configured with a phased array antenna that electronically steers in one or two directions. The phased array antenna includes array antenna aperture defined by a lattice of a plurality of antenna elements configured to transmit and/or receive signals in a preferred direction (i.e., the antenna's beamforming ability) without physically repositioning or reorienting the system. FIG.3shows am exemplary schematic layout or lattice150of individual antenna elements152iof a phased array antenna. The illustrated phased array antenna lattice150included antenna elements152ithat are arranged in a 2D array of M columns by N rows. For example, the phased array antenna lattice150has a generally circular or polygonal arrangement of the antenna elements152i. In other embodiments, the phased array antenna may have another arrangement of antenna elements, for example, a square arrangement or other polygonal arrangement of the antenna elements. The antenna elements152iin the antenna lattice150can be phase offset such that the phased array antenna emits a waveform in a preferred direction. When the phase offsets to individual antenna elements are properly applied, the combined wave front has a desired directivity of the main lobe. Referring to the exemplary embodiment inFIG.8, a phased array antenna aperture154can generate a communication zone176having a boresight vector (illustrated as the central longitudinal axis178of the communication zone176) and field of regard160. The shape of the communication zone176may be defined by the shape of the antenna aperture154. In a non-limiting example where the antenna aperture154is circular, the communication zone176may be generally conically shaped. In a non-limiting example where the antenna aperture154is square, the communication zone176may be generally pyramidal. The field of regard160is a function of the angle the phased array antenna can steer from its boresight vector178. In the case of an electrically steering phased array antenna, the field of regard is a limited field of regard which is less than the total sky view of a particular use at a specific location. Field of Regard for a Phased Array Antenna Referring toFIG.4, an upward sky view is provided for exemplary user terminal in Los Angeles, California, United States, illustrating a field of regard160for an exemplary two-dimensional phased array antenna. Because the user terminal is looking upward at the sky, East and West direction indicators are transposed. Referring toFIG.5, in another location using the same two-dimensional phased array antenna, an upward sky view is provided for a user terminal in Seattle, Washington, United States, illustrating a similar field of regard260. In the illustrated fields of regard160and260ofFIGS.4and5, upward sky views of visible satellites166(FIG.4) and266(FIG.5) in the satellite constellation (for example, one of the exemplary constellations ofFIG.2C) are shown. The visible satellites166and266in the respective fields of regard160(FIG.4) and260(FIG.5) are available for communication. The exemplary fields of regard160and260in the respective illustrated embodiments ofFIGS.4and5are designed to be generally circular in configuration, inscribing the largest angle to which the antenna system is capable of (or configured to) steer as measured from the boresight vector of the antenna system. However, depending on the design and configuration of the phased array antenna and the antenna aperture in the user terminal, the field of regard may have other shapes (for example, a square shape, a polygonal shape, or another suitable shape). Design of the User Terminal Referring now toFIGS.7A,7B, and7C, an exemplary user terminal180is designed and configured to allow for tilt-ability of the housing182for a phased array antenna aperture154(seeFIG.3) relative to its mount, such as by a mounting leg184. Such tilt-ability of the phased array antenna aperture154allows for not only rain and snow removal and heat dissipation, but also for orientation of the field of regard160awith the sky for enhanced radio frequency communication with one or more satellites depending on the geolocation of the phased array antenna aperture154and the orbit of the satellite constellation. FIGS.7A,7B, and7Cillustrate exemplary limits of tilt-ability of an exemplary phased array antenna system having an exemplary mounting system of the illustrated embodiment, withFIG.7Ashowing an antenna aperture154tilted to full vertical tilt relative to a mounting leg184,FIG.7Cshowing the antenna aperture154tilted to near horizontal relative to the mounting leg184, and withFIG.7Bshowing a middle tilt position. However, other tilting positions and tilting configurations are within the scope of the present disclosure. The user terminal180ofFIGS.7A-7Cis merely an exemplary illustration of a user terminal180having a tilt-able antenna aperture154. For example, in other non-limiting embodiments, the user terminal may have other tilt-ability mechanisms or the housing may remain fixed and the antenna aperture may be tilt-able. Geobelt Still referring toFIGS.4and5, the shaded areas170and270in the sky views illustrate the GEO-belt of satellites in geosynchronous equatorial orbit (GEO). See alsoFIG.6for an illustration of the GEO-belt of satellites172. A GEO orbit is a circular orbit 35,786 km (22,236 mi) above Earth's equator and following the direction of Earth's rotation. An object in GEO orbit has an orbital period equal to the Earth's rotational period. Therefore, to ground observers, the satellite appears motionless at a fixed position in the sky. Many satellites co-exist in the GEO-belt. For example, communications satellites are often placed in a GEO orbit so that Earth based satellite antennas can be pointed permanently at the position in the sky where the satellites are located and do not need to be rotated for tracking. Further, weather satellites in GEO orbit for real time monitoring and data collection, and navigation satellites in GEO orbit to provide a known calibration point to enhance GPS accuracy. Within the GEO-belt, weather or earth observation satellites might not interfere with GEO-belt communication satellites. However, broadcast or communication satellites are typically spaced to avoid frequency interference or overlap. In addition to proper spacing between satellites within the GEO-belt, communication satellites in other orbits, such as LEO and MEO orbits, can be designed and configured to avoid interference with already existing GEO communication satellites. Referring toFIG.6, a not-to-scale simplified illustration of Earth and its satellites is provided, which shows the line formed by the GEO-belt172of satellites. Returning toFIGS.4and5, the respective shaded areas170and270show what the potential interference zone for the GEO-belt172of satellites in geosynchronous equatorial orbit (GEO) look like in the fields of regard (e.g.,160inFIGS.4and260inFIG.5) of a user terminal having a phased array antenna. Depending on the latitude of the user terminal, the view of the GEO belt interference zone170or270with respect to the field of regard160or260may change. For example,FIG.4illustrates a sky view for a user terminal in Los Angeles, California, at a latitude of 34.0522° N (see L1inFIG.5). In contrast,FIG.4illustrates a sky view for a user terminal in Seattle, Washington, at a latitude of 47.6062° N (see L2inFIG.5). Although, the GEO-belt172seen inFIG.6is generally comprised of a band of satellites located in space at a certain altitude above Earth's equator and following the direction of Earth's rotation, the GEO-belt interference zone170or270is a larger range of communication interference based on the performance of an antenna system to avoid interference with the GEO belt. For example, in accordance with embodiments of the present application, the GEO-belt interference zone may be in a range of +/−5 to 30 degrees of the GEO-belt. In the illustrated embodiment of the present application, the GEO-belt interference zone170or270is defined as +/−18 degrees of the GEO-belt172. Therefore, the shaded areas170and270representing the GEO-belt interference zones170and270in respectiveFIGS.4and5are sized to represent the communication interference zone of +/−18 degrees of the GEO-belt172. As seen in the illustrated examples ofFIGS.4and5, the GEO-belt interference zone170or270is more centered in the sky view of user terminals positioned closer to the equator. Because Los Angeles L1is closer to the equator E than Seattle L2(seeFIG.2C), the GEO-belt interference zone170has a greater degree of overlap with the field of regard160for an antenna system having a substantially vertical central vector (see central boresight vector178inFIG.8for field of regard160) in Los Angeles inFIG.4than in the field of regard260for an antenna system having a substantially vertical central vector in Seattle inFIG.5. Therefore, a greater tilt angle for the user terminal is generally used if the user terminal is positioned closer to the equator within the upper and lower limits of the satellite string orbital path (seeFIG.2C) to reduce the amount of overlap between the field of regard and the GEO-belt interference zone. As a non-limiting example,FIG.9shows the user terminal as being tilted in a range of −10 to 43 degrees in the northern hemisphere, depending on the latitudinal positioning of the user terminal and the angle of inclination of the orbital path of the satellite string (for example, 42 degrees as seen for orbital path X1inFIG.2C). For example, the user terminal may be tilted 22 degrees in Seattle and 27 degrees in Los Angeles, and more than 30 degrees in south Florida. Tilting Depending on Latitude Returning toFIGS.4and5, the tilt of the phased array antenna aperture154of the user terminal can be selected based on the latitude of the user terminal, for example, see L1for Los Angeles and L2for Seattle inFIG.2C. Referring toFIG.4, the field of regard can be adjusted from a non-tilted field of regard160to a first exemplary tilted field of regard162at a first northward tilt angle away from the Earth's equator or a second exemplary tilted field of regard164at a second northward tilt angle away from the Earth's equator. Compare also inFIG.8, a non-tilted field of regard160with a tilted field of regard162. In accordance with embodiments of the present disclosure, an antenna system is an antenna having an antenna aperture with a defined limited field of regard. In some embodiments described herein, an antenna system (such as a phased array antenna aperture) may be capable of electronic steering to steer its beam in a selected non-vertical direction. Such beam steering is to be distinguished from physical tilting of the antenna aperture and the field of regard it generates (as illustrated inFIG.8). In accordance with embodiments of the present disclosure, a non-tilted antenna is an antenna having a limited field of regard which has a central vector (or boresight vector) located in a substantially vertical orientation. The central vector is defined as the vector between the antenna aperture location and the geometric centroid of the antenna system's field of regard projected onto the hemisphere of the sky defined by the local horizon surrounding the antenna aperture location. A substantially vertical orientation is designed to be substantially perpendicular to a tangent plane to the Earth's mean surface (not accounting for geological features such as mountainous inclines or valley declines, which depending on altitude may further affect prescribed tilt angle). In a non-limiting example of a planar phased array, a non-tilted flat phased array antenna system may include an antenna aperture surface oriented substantially parallel to a tangent plane to the Earth's mean surface (not accounting for geological features such as mountainous inclines or valley declines, which depending on altitude may further affect prescribed tilt angle). However, in other non-planar antenna systems, such as conformal phased array systems, a non-tilted antenna may not be oriented in a substantially horizontal orientation but still may have a substantially vertically oriented boresight vector. Other exemplary tilted fields of regard may also be determined depending on the mesh of the satellite constellation in the field of regard160,162, and/or164of the user terminal. In the illustrated embodiment, the first and second tilted fields of regard162and164show reduced overlap with the GEO-belt interference zone170and an increased number of satellites visible within that field of regard, with the second tilted field of regard164having no overlap with the GEO-belt interference zone170and an increased number of satellites visible within that field of regard. Likewise, referring toFIG.5, the field of regard can be adjusted from a first non-tilted field of regard260to a first exemplary tilted field of regard262at a first northward tilt angle away from the Earth's equator or a second exemplary tilted field of regard264at a second northward tilt angle way from the Earth's equator. The first and second tilted fields of regard262and264show reduced overlap with the GEO-belt interference zone270and an increased number of satellites visible within that field of regard, with the second tilted field of regard264having less overlap than the first tilted field of regard262and an increased number of satellites visible within that field of regard. In the illustrated embodiments ofFIGS.4and5for tilting of the field of regard, the tilting for the illustrated latitudes may be in the northward direction away from the Earth's equator. For other locations, such as equivalent latitudes toFIGS.4and4in the southern hemisphere, the tilting of the field of regard may be southward away from the Earth's equator. For still other locations in the northern hemisphere, the tilting may be in the southward direction to optimize for the same parameters. Likewise, there may be locations in the southern hemisphere where tilting in the northward direction may be preferable to optimize for the same parameters. For example, as described above, the upper and lower limiting latitudes of the orbital path typically correspond to the angle of inclination of the satellite. For example, as seen inFIG.2C, the orbital path of a satellite string X1having an angle of inclination of 42 degrees has upper and lower limiting latitudes P and Q of 42 degrees north of the equator and 42 degrees south of the equator. Likewise, the orbital path of a satellite string Y2having an angle of inclination of 53 degrees has upper and lower limiting latitudes of 53 degrees north of the equator and 53 degrees south of the equator. Above or below the upper and lower limiting latitudes of a satellite orbital path, the tilting may be in the opposite direction to tilt toward the swarm of satellites at or near the upper and lower limiting latitudes of the orbital path. See, for example,FIG.9. Accordingly, a method of orienting a user or endpoint terminal at an Earth-based location includes determining a latitude location of the Earth-based location for a limited field of regard antenna for communication with a non-GEO satellite constellation. Based on a first latitude location of the user or endpoint terminal, the user or automated system may select a first tilt angle to adjust the field of regard from a non-tilted field or regard to a first tilted field of regard for a first tilted antenna aperture. Based on a second latitude location of the user or endpoint terminal, the user or automated system may select a second tilt angle to adjust the field of regard from non-tilted field of regard to a second tilted field of regard for a second tilted antenna aperture, and so on. After the tilt angle is selected, the user or an automated system may tilt the user or endpoint terminal to the appropriate tilt angle. Such tilt reduces the interference of the field of regard with the GEO-belt interference zone and increases the number of satellites visible within that field of regard (as seen inFIG.2C). Referring toFIG.8, a series of adjacently located homes in the Earth's northern hemisphere, each having an endpoint terminal102are illustrated. In the illustrated embodiment ofFIG.8, the northward direction is toward the right of the page. The antenna systems of the user terminals102have fields of regard176which are shaped in a predetermined fashion (e.g., corresponding to the shape of the aperture of the antenna systems, etc.) resulting from the maximum angle that the user terminal may steer from the boresight vector178to the field of regard176. In addition, the antenna systems of the user terminals102are oriented to have a boresight vector substantially vertical (or substantially perpendicular to a tangent to the Earth's mean surface). Shown in phantom inFIG.8, the user terminals102can be tilted northward to generate tilted fields of regard each generating a tilted cone-shaped communication zone186having a tilted boresight vector and a tilted field of regard162. As can be seen inFIG.8, the tilted fields of regard162of at least a subset of user terminals in a given geographical area (or cell) on Earth will communicate with the same satellite for reliability of communication if the users tilt their antenna systems at the same or similar tilt angles. For example, if every user terminal in a geographical cell, such as a 30 km diameter cell, points their antenna system in the same direction at the same tilt angle, the fields of regard of their antenna systems will overlap at a LEO distance, for example, a distance of 500 km from the Earth. If the users tilt their antenna system in arbitrary different directions, there may not be enough overlap between communication zones to serve all users in a subset or geographical region using the same satellite, and communication reliability may decrease for a given geographical area on Earth. In some cases, there may be multiple satellites available for communication with a certain geographical cell. In this case, a first subset of user terminals within the geographical cell may tilt at a first tilt angle to communicate with a first satellite, and a second subset of user terminals within the geographical cell may tilt at a second tilt angle to communicate with a second satellite, and so on. There may be additional prescribed tilt angles within the geographical cell depending on the satellite availability within the satellite constellation. Of note, for tilted communication, the distance the communications signals must travel is longer as compared to direct overhead communication. Even though the travel distance for communication between tilted user terminals and satellites is increased, the advantageous effects tilting away from the GEO-belt and tilting toward the swarm of satellites near the upper and lower limiting latitudes of the satellite string orbital path may provide enhanced communication performance. Referring toFIG.9, a method of orienting a user or endpoint terminal at an Earth-based location further includes determining the upper and lower limiting latitudes of an orbital path for a satellite string as defined by the angle of inclination of the satellite string. For example, for an orbital path Y1inFIG.2Chaving an angle of inclination of 53 degrees, a user terminal may be properly orientated to have no tilt at the upper limiting latitude for the orbital path at 53 degrees latitude or at corresponding lower limiting latitude for the orbital path −53 degrees latitude. In accordance with embodiments of the present disclosure,FIG.9illustrates a series of user terminals located at various latitudes and showing adjusted north and south tilt angles based on latitude and the upper limiting latitude of the orbital path for the satellite string. At the equator, the tilt angle is the greatest at 43 degrees northward. As the user terminals are positioned more northward on the Earth's surface, the tilting angle remains in the northward direction by progressively decreases to 35 degree at 15°N, to 27 degrees at 32°N, to 22 degrees at 42°N, then back to 27 degrees at 48N. At 53°N, the user terminal is tilted 10 degrees southward to tilt toward the swarm of satellites at the upper limiting latitude of the orbital path for the satellite string. Tilting Depending on Geographical Features In addition to north or south tilting for tilting away from the GEO-belt and tilting to increase the number of visible satellites within the field of regard, the user terminal may also be tilted in north or south and east or west directions for load balancing of satellites in the satellite constellation based on user terminal population density or geographical features. For example, if a certain geographic area does not include a dense set of user terminals, an adjacent geographic area may be able to take advantage of the satellite coverage available in the first geographic area. As a non-limiting example, if a geographic cell of user terminals is located eastward of a large body of water, such as the Pacific Ocean, some or all of the user terminals in the geographic cell may be tilted westward to take advantage of a second nearby satellite that is further in distance from the user terminal than a first satellite, but the second nearby satellite having reduced communication load. Likewise, a cell of user terminals located westward of the Atlantic Ocean may be tilted eastward to take advantage of a second nearby satellite that is further in distance from the user terminal than a first satellite, but the second nearby satellite having reduced communication load. Referring toFIG.10, three satellites SAT1, SAT2, and SAT3 are shown, each defining a geographic coverage cell C1, C2, or C3for communication coverage. Within each cell are a plurality of user terminals UT1-UT5. In the illustrated embodiment, UT1 and UT2 are configured for communication with SAT1, both being within SAT1's coverage cell C1. However, UT2 is also within SAT2's coverage cell C2and can be electronically steered to communicate with either satellite SAT1 or SAT2. In SAT2's coverage cell are three other user terminals UT3, UT4, and UT5. For load balancing, UT4 and/or UT5 may be tilted eastward to communicate with SAT3, which is currently located over the Atlantic Ocean and has no user terminals within its coverage cell C3. As discussed above, for tilted communication, the distance the communications signals must travel is longer as compared to direct overhead communication. Even though the travel distance for communication between UT4 or UT5 and SAT3 as compared to the travel distance for communication to SAT2 is increased, the advantageous effects of load balancing may provide enhanced communication performance. In another non-limiting example, geographic area may not be a body of water, but may be sparsely inhabited, or may be a country that does not subscribe to the service provided by the satellite constellation. The tilting configuration for a cell of user terminals or a portion of the cell of user terminal may include a combination of north or south and east or west tilting. In addition the factors discussed above, other factors that may affect tilt angle of a user terminal include the latitude location for the endpoint terminal, a longitude location of the endpoint terminal, obstructions, geological features, population density, an altitude of the end point terminal, a load balancing analysis of the satellite constellation, one or more angles of inclination of the satellite constellation, a geographical cell to which the end point terminal belongs, and combinations thereof. Selecting Location for User Terminal Based on Geographical Features Referring toFIGS.11A-11C, a method of configuring a user terminal at an Earth-based location may also include an assessment the landscape surrounding the endpoint terminal102, such as trees, buildings, and other obstructions that might affect the communication between a given user terminal and the constellation of satellites166with which it is communicating. In the illustrated embodiment ofFIGS.11A-11C, the northward direction is toward the right of the page. Therefore, a method of configuring an endpoint terminal102may include assessing interfering obstructions close to one or more tilted communication zones of the endpoint terminal102, and determining if an endpoint terminal102can, in fact, be located in a specific location, or if a new location needs to be determined for that endpoint terminal102. Such obstructions may be determined by land owner surveys or by Global Navigation Satellite System (GNSS) and geospatial data. In addition, such obstructions may be determined by analyzing image data corresponding to a field of regard of the endpoint terminal102. For example, obstructions may be determined using computer vision techniques, object recognition techniques, among other techniques. Referring toFIG.12, a block diagram of an example device1200that facilitates configuring the endpoint terminal102for communication with a satellite constellation is provided. In a non-limiting example, the device1200may correspond to a mobile device (e.g., a smart phone, a tablet, a laptop, etc.). The mobile device may be owned and/or operated by a user who wishes to configure the endpoint terminal102. In another non-limiting example, the device1200may be part of and/or implemented by the endpoint terminal102. As shown, the device1200may include one or more engines, including a field of regard engine1202, a scene engine1204, an obstruction engine1206, and a display engine1208. In a non-limiting example, the engines of the device1200may be part of and/or implemented by an application running on the device1200. For instance, a user of the device1200may download and install the application on the device1200in order to facilitate configuring the endpoint terminal102for communication with a satellite constellation. In a non-limiting example, the application may be referred to as a “field of view checker” or a “field of regard checker.” As shown, device1200may also include a display1214that displays graphics and/or images (e.g., for viewing by a user of the device1200). The device1200may include one or more additional components not illustrated inFIG.12, such as an accelerometer, a gyroscope, a magnetometer, an inertial measurement unit (IMU), a camera device, an image sensor, a radar sensor, a light detection and ranging (LIDAR) sensor, a Global Positioning System (GPS), a graphics processing unit (GPU)114, a digital signal processor (DSP), an image signal processor (ISP), among other components. In one example, the field of regard engine1202may determine a field of regard of the endpoint terminal102corresponding to the location of the device1200. For instance, if the endpoint terminal102has been installed at a location, the field of regard engine1202may determine the field of regard of the endpoint terminal102while the device1200is located nearby (e.g., within several feet, within several inches, etc.) of the endpoint terminal102. Reducing or minimizing the distance between the device1200and the endpoint terminal102may result in a more accurate determination of the field of regard (and therefore a more accurate determination of obstructions within the field of regard). In another example, if the endpoint terminal102has not yet been installed at a location, the field of regard engine1202may determine the field of regard available to the endpoint terminal102as if the endpoint terminal102is located at the current location of the device1200(regardless of whether the endpoint terminal102is actually located at the current location of the device1200). For example, the field of regard engine1202can evaluate a potential (rather than actual or current) field of regard of the endpoint terminal102. Referring toFIG.13, an example field of regard1302determined by the field of regard engine1202is provided. In this example, the field of regard1302is illustrated as a cone whose apex corresponds to the current location of the device1200. The field of regard1302may extend from the current location of the device1200towards a predetermined direction. In non-limiting examples where the device1200is located in the Northern hemisphere, the field of regard1302may extend towards true North. In non-limiting examples where the device1200is located in the Southern hemisphere, the field of regard1302may extend towards true South. In some cases, the cone may be of a predetermined width (e.g., angle). In a non-limiting example, the width of the cone may be 50 degrees. In another non-limiting example, the width of the cone may be 60 degrees. In some cases, the field of regard1302may be tilted at an angle corresponding to the tilt of the endpoint terminal102. In one non-limiting example, the tilt of an antenna system of the endpoint terminal102may be selected based on factors such as the geographic coordinates of the endpoint terminal102. In another non-limiting example, the tilt of an antenna system of the endpoint terminal102may be selected based on factors such as the latitude of the endpoint terminal102. Based on the geographic coordinates and/or the latitude of the endpoint terminal102(e.g., obtained using a GPS or other positioning system), the field of regard engine1202may determine an appropriate tilt angle for the field of regard1302. In one example, the field of regard engine1202may determine the appropriate tilt angle for the field of regard1302using a look-up table that maps geographic locations (e.g., latitudes) to predetermined tilt angles. It should be noted that while the field of regard1302can be defined as a cone whose apex corresponds to the current location of the antenna system of the endpoint terminal102, the shape of the field of regard1302can be modified based on additional and/or alternative factors. For example, in addition to using the tilt of the antenna system of the endpoint terminal102, the field of regard engine1202may apply additional constraints to refine or otherwise modify the shape of the field of regard1302. The modified field of regard generated by applying these additional and/or alternative factors may be presented to the user by the display engine1208, as described herein. In an embodiment, the field of regard engine1202may determine a minimum elevation angle for the antenna system of the endpoint terminal102. The minimum elevation angle may be defined as a limitation on the scan angle of the antenna system of the endpoint terminal102, whereby the antenna system may be prohibited from performing any scans below the minimum elevation angle towards the horizon. The minimum elevation angle may be defined based on regional, local, country, or other location-based regulation. Thus, based on the geographic coordinates and/or the latitude of the endpoint terminal102, the field of regard engine1202may determine the minimum elevation angle for the antenna system of the endpoint terminal102. The field of regard engine1202may revise or otherwise modify the field of regard1302for the antenna system of the endpoint terminal102to remove any areas of the original field of regard that the antenna system is prohibited from scanning based on the determined minimum elevation angle. Thus, the modified field of regard may omit the areas from the original field of regard that the antenna system is prohibited from scanning based on the determined minimum elevation angle. In an embodiment, the field of regard engine1202can determine the GEO-belt interference zone to be applied to modify the field of regard1302for the antenna system of the endpoint terminal102. As noted above, the GEO-belt interference zone is a larger range of communication interference based on the performance of an antenna system to avoid interference with the GEO belt. For example, in accordance with embodiments of the present application, the GEO-belt interference zone may be in a range of +/−5 to 30 degrees of the GEO-belt. The GEO-belt interference zone may, thus, differ based on the geographic coordinates and/or the latitude of the endpoint terminal102. For example, in the embodiment illustrated inFIGS.4and5of the present application, the GEO-belt interference zone170or270is defined as +/−18 degrees of the GEO-belt172. Therefore, the shaded areas170and270representing the GEO-belt interference zones170and270in respectiveFIGS.4and5are sized to represent the communication interference zone of +/−18 degrees of the GEO-belt172. The field of regard engine1202may use the GEO-belt interference zone at the geographic coordinates and/or latitude of the endpoint terminal102to further refine or otherwise modify the field of regard1302for the antenna system of the endpoint terminal102, resulting in a modified field of regard. For example, if a portion of the GEO-belt interference zone overlaps a portion of the original field of regard of the antenna system, the field of regard engine1202may revise or otherwise modify the shape of the original field of regard to omit the portion that overlaps with the GEO-belt interference zone, resulting in a modified field of regard. The resulting shape of the modified field of regard may correspond to the shape of the original field of regard minus any portions that overlap with the GEO-belt interference zone. In an embodiment, the field of regard engine1202can further utilize the range of positions for the satellites in the satellite constellation that may be visible to the antenna system of the endpoint terminal102to generate a modified field of regard. For instance, the field of regard engine1202may utilize the geographic coordinates and/or the latitude of the endpoint terminal102, as well as the known configuration of the satellite constellation, to determine the actual communication range for the visible satellites of the satellite constellation at the geographic location of the endpoint terminal102. The resulting communication range, in some instances, may not completely overlap the original field of regard1302of the antenna system of the endpoint terminal102. As such, the field of regard engine1202may revise or otherwise modify the shape of the original field of regard1302for the antenna system of the endpoint terminal102to omit the portion of the original field of regard1302that does not overlap with the communication range of the visible satellites of the satellite constellation, as these non-overlapping regions may correspond to regions where satellites of the satellite constellation do not traverse. Thus, the shape of the modified field of regard may correspond to regions of the original field of regard that are associated with the communication range of the visible satellites of the satellite constellation. In an embodiment, the field of regard engine1202can further refine or otherwise modify the shape of the field of regard1302to accommodate load balancing requirements for the satellite constellation. As noted above, different endpoint terminals may be electronically steered to communicate with different satellites of a satellite constellation based on load balancing requirements. For example, as illustrated inFIG.10, an endpoint terminal within two or more satellite coverage cells can be electronically steered to communicate with any of the satellites corresponding to the two or more satellite coverage cells. For load balancing, this endpoint terminal may be electronically steered such that it is tilted to communicate with a particular satellite for load balancing purposes. In an embodiment, the field of regard engine1202can determine which satellites of the satellite constellation the endpoint terminal102is assigned to communicate with for load balancing purposes and determine the portions of the different satellite coverage cells that overlap with the maximum scan angle of the antenna system of the endpoint terminal102. The field of regard engine1202may use this overlap to modify the shape of the field of regard1302for the antenna system of the endpoint terminal102to generate a modified field of regard. The shape of the modified field of regard may thus correspond to regions of the original field of regard1302that are associated with the satellite coverage cells of the satellites assigned to communicate with the endpoint terminal102for load balancing purposes. In some examples, rather than using an antenna aperture shape whose apex corresponds to the current location and tilt angle of the antenna system of the endpoint terminal102as the original field of regard1302for the antenna system, the field of regard engine1202generates a mask that is mapped on to a hemisphere or other spherical section corresponding to the full sky view to the horizon. The mask may represent a modified field of regard for the antenna system of the endpoint terminal102. In an embodiment, the field of regard engine1202uses the various factors (e.g., tilt angle, scan angle of the antenna system, physical constellation configuration and positioning, regulatory constraints, etc.) to calculate the shape of the mask that is to be mapped onto the hemisphere or other spherical section in place of the original field of regard1302. It should be noted that the modified field of regard may represent an enveloping or exemplary shape that provides a general understanding of a zone of communication between the endpoint terminal102and the visible satellites of the satellite constellation. For instance, the resulting modified field of regard may omit certain regions in which the visible satellites of the satellite constellation actually transmit as a result of regulatory or other constraints (e.g., minimum elevation angle for the antenna system of the endpoint terminal102, the GEO-belt interference zone, etc.). In some embodiments, the shape of the modified field of regard may be expanded to incorporate a buffer region to provide additional tolerance in the event that the device1200is miscalibrated or other configuration issues, while still providing an encompassing representation of a possible zone of communication between the endpoint terminal102and the visible satellites of the satellite constellation. In some examples, the scene engine1204may receive one or more image frames (e.g., an image frame1216) captured by the device1200. The image frame1216may include image data corresponding to a scene surrounding the device1200. In particular, the image frame1216may include image data corresponding to an upward view of the sky. As such, the image frame1216may include at least a portion of the field of regard of the endpoint terminal102. The scene engine1204may determine which portion (if any) of the image frame1216overlaps with the field of regard. For example, the scene engine1204may determine the attitude (e.g., angle and/or orientation) of the device1200when the image frame1216was captured. The scene engine1204may determine the attitude of the device1200using one or more sensors or devices integrated into the device1200, such as a gyroscope, an accelerometer, and/or a magnetometer. In one example, the scene engine1204may access the data obtained by these devices via one or more sensor application program interfaces (APIs) of the device1200. Based on the attitude of the device1200, the scene engine1204may determine which portion (if any) of the scene corresponding to the image frame1216overlaps with the field of regard. In some cases, the obstruction engine1206may determine whether any obstructions are visible and/or present within the portion of the field of regard determined by the scene engine1204. As described above, an obstruction may include any physical object or neighboring field of regard that might affect the communication between the endpoint terminal102and the constellation of satellites with which it is communicating. The obstruction engine1206may detect obstructions in various ways. In one example, the obstruction engine1206may detect obstructions based on historical data indicating the ability of various Earth-based locations to receive and/or transmit signals to and from the constellation of satellites166. For example, one or more endpoint terminals, gateways, and/or satellites may periodically (e.g., hourly or daily) assess the strength of signals transmitted between the satellites and the various Earth-based locations. Earth-based locations associated with low signal strengths (e.g., signal strengths below a threshold strength) may correspond to obstructions. Thus, the obstruction engine1206may have previous knowledge of the location of obstructions. Based on the current location of the device1200, the obstruction engine1206may determine whether any known obstructions are present and/or visible within the portion of the field of regard included within the image frame1216. Additionally or alternatively, the obstruction engine1206may detect obstructions based on an analysis of the image frame1216. For example, the obstruction engine1206may include and/or be in communication with a computer vision system. The computer vision system may be configured and/or trained to identify various types of obstructions, such as trees, buildings, hills, etc. In a non-limiting example, the computer vision system may be configured and/or trained to detect regions of the image frame1216that do not correspond to a clear, unobstructed view of the sky. The computer vision system may enable the obstruction engine1206to detect previously unknown obstructions in real-time. In further examples, the obstruction engine126may determine obstructions based at least in part on background signal noise within the endpoint terminal102. For instance, the obstruction engine126may measure the amount of noise (e.g., the signal-to-noise ratio) within signals received by the endpoint terminal102. A high level of noise may indicate an obstruction is at least partially preventing signals from being transmitted between the endpoint terminal102and the satellite constellation. The display engine1208may output an indication of the portion of the field of regard included within the image frame1216. For example, the display engine1208may direct the display1214to overlay a field of regard outline1210on the image frame1216. Referring toFIG.14A, an example field of regard outline1214is provided. In this example, the display engine1208may visually indicate the portion of the field of regard included within the image frame1216by darkening portions of the image frame1216not included within the field of regard. The display engine1208may indicate and/or emphasize the portion of the field of regard included within the image frame1216in any suitable manner. In some cases, the field of regard outline1214may be implemented as a 3-dimensional (3D) scene rendered on top of a live view of a camera of the device1200. For example, display engine1208may render a 3D scene from the perspective of inside the tip of a cone that corresponds to the field of regard. In some cases, the display engine1208may output an instruction1212to the user within the display1214. For example, the display engine1208may generate an instruction1212that facilitates finding a suitable location for the endpoint terminal102. Referring toFIG.14A, the instruction1212may include directing the user to move the device1200(e.g., the user's phone). Moving the device1200may enable the scene engine1204to obtain and analyze image data corresponding to different portions of the field of regard. For instance, as shown inFIG.14A, the field of regard of the endpoint terminal102may be larger than the field of view of the device1200. Thus, the image frame1216may not include the entirety of the field of regard of the endpoint terminal102. The display engine1208may direct the user to move the device1200to facilitate detecting obstructions within the entirety of the field of regard. As the device1200moves, the display engine1208may update the field of regard outline1210to account for changes in the scene currently visible within the field of view of the device1200. For example, the field of regard is stationary, but the scene visible within the field of view of the device1200may change. As such, the display engine1208may synchronize moving and/or adjusting the field of regard outline1210with movement of the device1200. In a non-limiting example, the display engine1208can update the field of regard outline1210in response to each image frame captured by the device1200. In another non-limiting example, the display engine1208can update the field of regard outline1210after a predetermined number of image frames (e.g., five image frames) are captured, or in response to detecting at least a threshold amount of movement between consecutive frames. FIGS.14B and14Cprovide additional examples of the field of regard outline1210and/or the instruction1212. In particular,FIG.14Billustrates an image frame1216that includes a relatively small portion of the field of regard. In this example, the display engine1208may display an instruction1212that directs the user to tilt the device1200upwards in order to capture a larger portion of the field or regard. Referring toFIG.14C, an additional instruction1212directing the user to move the device1200is provided.FIG.14Calso illustrates a graphical rendering of an example field of regard. In some examples, the display engine1208may visually indicate any obstructions that are visible within the field of regard. For instance, the display engine1208may highlight, outline, or otherwise indicate the trees and/or the telephone pole shown inFIG.14A. Further, the display engine1208may display one or more satellites and/or orbital paths within the display1214. Displaying satellites and/or orbital paths within the display1214may indicate and/or emphasize the importance of selecting a location that provides an unobstructed field of regard for the endpoint terminal. The display engine1208may display simulated satellites, or the actual trajectories of satellites within the constellation of satellites166. The field of regard for an antenna system of a user terminal102can be represented using a mask mapped onto a hemisphere or other spherical section representing the full sky view to the horizon. The mask may be shaped based on one or more factors (e.g., tilt angle of the antenna system, scan angle of the antenna system, physical constellation configuration and positioning, regulatory constraints, etc.). Thus, rather than a field of regard corresponding to the aperture of the antenna system, as illustrated inFIGS.13and14A-14C, a modified field of regard for the antenna system of the endpoint terminal102may be generated using a mask mapped onto the hemisphere or other spherical section representing the full sky view to the horizon and having a shape defined by the field of regard engine1202based on the various factors selected for defining the field of regard for the antenna system. As noted above, the scene engine1204may receive one or more image frames (e.g., an image frame1216) captured by the device1200, whereby the image frame1216may include image data corresponding to a scene surrounding the device1200. The image frame1216may thus include at least a portion of the modified field of regard of the endpoint terminal102. The scene engine1204may determine which portion (if any) of the image frame1216overlaps with the mask mapped onto the hemisphere or other spherical section representing the full sky view and representing the modified field of regard for the antenna system of the endpoint terminal102. In an embodiment, the obstruction engine1206may determine whether any obstructions are visible and/or present within the portion of the modified field of regard determined by the scene engine1204. The obstruction engine1206may detect obstructions according to the methods described above. For instance, the obstruction engine1206may detect obstructions based on historical data indicating the ability of various Earth-based locations to receive and/or transmit signals to and from the constellation of satellites166. Thus, the obstruction engine1206may have previous knowledge of the location of obstructions. Based on the current location of the device1200and the modified field of regard, the obstruction engine1206may determine whether any known obstructions are present and/or visible within the portion of the modified field of regard included within the image frame1216. In an embodiment, the field of regard engine1202can utilize obstructions as an additional factor in determining a modified field of regard for the antenna system of the endpoint terminal102. For instance, the field of regard engine1202may utilize historical data indicating the ability of various Earth-based locations to receive and/or transmit signals to and from the constellation of satellites166to identify any known obstructions that may interfere or otherwise prevent signals from being transmitted between the user terminal and the satellite constellation. In some instances, based on the geographic coordinates and/or the latitude of the endpoint terminal102(e.g., obtained using a GPS or other positioning system) and historical data, the field of regard engine1202may identify any known obstructions within the vicinity of the endpoint terminal102. These known obstructions may be applied to the original field of regard for the antenna system of the endpoint terminal102, whereby the field of regard engine1202may revise or otherwise modify the original field of regard to remove any areas of the original field of regard corresponding to these known obstructions. Thus, the modified field of regard may omit the areas from the original field of regard that include known obstructions that at least partially prevent signals from being transmitted between the endpoint terminal102and the satellite constellation. Referring toFIGS.15A-15C, an example modified field of regard outline1502corresponding to a field of regard mapped onto a hemisphere or other spherical section representing the full sky view is provided. In this example, the modified field of regard outline1502may have a different shape compared to that of the field of regard outline1210illustrated inFIGS.14A-14C. The modified field of regard outline1502illustrated inFIGS.15A-15Cmay be generated by the field of regard engine1202based on one or more factors selected for definition of the field of regard for an antenna system of the endpoint terminal102. To generate the modified field of regard1502for the antenna system of the endpoint terminal102, the field of regard engine1202may initially define the hemisphere or other spherical section representing the full sky view. For instance, based on the geographic coordinates and/or the latitude of the endpoint terminal102(e.g., obtained using a GPS or other positioning system), the field of regard engine1202may determine the coordinate and/or latitudinal range of the hemisphere or other spherical section from which the field of regard is to be derived. Additionally, based on the geographic coordinates and/or the latitude of the endpoint terminal102(e.g., obtained using a GPS or other positioning system), the field of regard engine1202may determine an appropriate tilt angle for the field of regard. In one example, the field of regard engine1202may determine the appropriate tilt angle for the field of regard using a look-up table that maps geographic locations (e.g., latitudes) to predetermined tilt angles. The field of regard engine1202may further apply one or more other factors or constraints to the initial or original field of regard to further modify the shape of the field of regard for the antenna system of the endpoint terminal102, resulting in a modified field of regard1502. As noted above, the field of regard engine1202may apply a minimum elevation angle for the antenna system of the endpoint terminal102, the GEO-belt interference zone, the actual communication range of satellites in the satellite constellation that traverse a portion of the hemispherical or sectional region of the sky corresponding to the geographic and/or latitudinal location of the antenna system of the endpoint terminal102, load balancing requirements, and the like to refine the shape of the field of regard. The resulting shape of the field of regard may be applied as a mask to the hemisphere or other spherical section representing the full sky view. The field of regard engine1202may provide data corresponding to shape and position of the modified field of regard relative to the hemisphere or other spherical section representing the full sky view at the geographic and/or latitudinal location of the antenna system to the display engine1208. This may cause the display engine1208to direct the display1214to overlay an outline corresponding to the shape of the modified field of regard on to an image frame. For instance, as the user moves the device1200, the display1214may be updated to graphically represent a portion of the modified field of regard in accordance with the orientation and location of the device1200. As illustrated inFIGS.15A-C, the resulting shape of the field of regard may differ from the field of regard represented inFIGS.14A-C, as the resulting shape may be determined based on the aforementioned factors. Additionally, the shape of the field of regard may be dynamically updated in real-time based on any obstructions detected by the obstruction engine1206based on one or more image frames (e.g., an image frame1216) captured by the device1200, as noted above. Referring toFIG.15A, an example modified field of regard outline1502is provided. In this example, the display engine1208may visually indicate the portion of the modified field of regard included within the image frame1216by darkening portions of the image frame1216not included within the field of regard. The display engine1208may indicate and/or emphasize the portion of the modified field of regard included within the image frame1216in any suitable manner. In some cases, the modified field of regard outline1502may be implemented as a 3D scene rendered on top of a live view of a camera of the device1200. Similar to the examples described above in connection withFIGS.14A-14C, the display engine1208may output an instruction1212to the user within the display1214. For example, the display engine1208may generate an instruction1212that facilitates finding a suitable location for the endpoint terminal102. Referring toFIG.15A, the instruction1212may include directing the user to install the endpoint terminal102in a location corresponding to the modified field of regard. Moving the device1200may enable the scene engine1204to obtain and analyze image data corresponding to different portions of the modified field of regard. For instance, as shown inFIG.15A, the modified field of regard of the endpoint terminal102may be larger than the field of view of the device1200. Thus, the image frame1216may not include the entirety of the modified field of regard of the endpoint terminal102. As the device1200moves, the display engine1208may update the modified field of regard outline1502to account for changes in the scene currently visible within the field of view of the device1200. As such, the display engine1208may synchronize moving and/or adjusting the modified field of regard outline1502with movement of the device1200. FIGS.15B and15Cprovide additional examples of the modified field of regard outline1502and/or the instruction1212. In particular,FIG.15Billustrates an image frame1216that includes a different portion of the modified field of regard. Referring toFIG.15Calso illustrates a graphical rendering of an example modified field of regard with a corresponding instruction1212for installing the endpoint terminal102. As noted above, the modified field of regard may represent an enveloping or exemplary shape that provides a general understanding of a zone of communication between the endpoint terminal102and the visible satellites of the satellite constellation. Thus, the modified field of regard outline1502that may be presented via the image frame1216of the device1200may provide this enveloping or exemplary shape corresponding to the modified field of regard. The modified field of regard outline1502may omit regions of in which the visible satellites of the satellite constellation may actually transmit. These regions may be omitted as a result of regulatory or other constraints (e.g., minimum elevation angle for the antenna system of the endpoint terminal102, the GEO-belt interference zone, etc.). In some embodiments, the modified field of regard outline1502may incorporate one or more buffer regions to provide additional tolerance in the event that the device1200is miscalibrated or as a result of other configuration issues that may introduce inaccuracies in the determination of a definitive field of regard. This may provide for an encompassing representation of a possible zone of communication between the endpoint terminal102and the visible satellites of the satellite constellation. Referring toFIGS.11A-11C, examples of evaluating the level of communication facilitated by various locations of the endpoint terminal102are provided. The level of communication between an endpoint terminal102and the constellation of satellites166may include a zone corresponding to the field of regard of the endpoint terminal102and/or the level of intensity of signals between the endpoint terminal102and the constellation of satellites166subject to the presence of any obstructions. In particular,FIG.11Aillustrates a potential location1of the endpoint terminal102and a corresponding communication zone186ahaving a boresight vector (illustrated as the central longitudinal axis188aof the communication zone186a) and field of regard162a. In a non-limiting example, the communication zone186amay be conically shaped. As shown, the communication zone186ais tilted (e.g., based on the latitude of the endpoint terminal102). At location1, the field of regard162aincludes multiple obstructions. Specifically, as illustrated by the sky-facing view from the communication zone186ainFIG.11B, a tree T and a building B are visible within the field of regard162a. Based on detecting the tree T and/or the building B within the field of regard162a, the device1200may determine that location1is unsuitable for installation of the endpoint terminal102. For example, the device1200may determine that the obstructions will prevent a sufficient level of communication between the endpoint terminal102and the constellation of satellites166. Thus, the device1200may provide a visual indication and/or output an instruction to the user directing the user to move the device1200to a new (e.g., different) location. FIG.11Aillustrates a potential location2of the endpoint terminal102and a corresponding communication zone186bhaving a boresight vector (illustrated as the central longitudinal axis188bof the communication zone186b) and field of regard162b. In a non-limiting example, the communication zone186bmay be conically shaped. Alternatively, the communication zone186bmay be pyramidal shaped if the antenna aperture is square shaped. Thus, the shape of the communication zone186bmay be determined based on the shape of the antenna aperture. As shown, the communication zone186bis tilted (e.g., at the same tilt angle as the communication zone186a). For reference, an un-tilted communication zone176having a boresight vector (illustrated as the central longitudinal axis178of the communication zone176) and field of regard160are illustrated inFIG.11A. At location2, the field of regard162bincludes a relatively small obstruction (e.g., in comparison with the obstructions included within the field of regard162a). Specifically, as illustrated by the sky-facing view from the communication zone186binFIG.11C, only a portion of the tree T is included within the field of regard162b. In some examples, the device1200may determine that the portion of the tree T included within the field of regard162bdoes not substantially prevent communication between the endpoint terminal102and the constellation of satellites166. Thus, the device1200may provide a visual indication and/or output an instruction to the user directing the user to install (e.g., secure or mount) the endpoint terminal102at location2. Referring toFIGS.16A and16B, additional examples of field of regard outlines and/or user instructions are provided. Specifically,FIGS.16A and16Billustrate example obstructions (e.g., trees) visible within a portion of a field of regard.FIGS.16A and16Balso illustrate instructions directing the user to move their phone in order to obtain image data associated with different portions of the field of regard. In one example, the scene illustrated inFIG.16Amay correspond to a first portion of the field of regard and the scene illustrated inFIG.16Bmay correspond to a second portion of the field of regard. Image data for the first and second portions of the field of regard may be obtained by rotating the device1200to change the field of view of the device1200(while the device1200is otherwise stationary). The device1200may evaluate the suitability of the location based on obstructions detected in the entirety of the field of regard. For example, the device1200may combine analyses of obstructions detected in each portion of the field of regard. In one example, the device1200may compile (e.g., stitch together) image data associated with multiple portions of the field of regard to generate a representation of the entire field of regard. The representation of the entire field of regard may indicate obstructions within one or more portions of the field of regard. In some cases, the device1200may store and/or transmit the representation of the entire field of regard. In a non-limiting example, the device1200may transmit the representation to a backend server (e.g., a customer support server) for use in detecting or troubleshooting connectivity problems of the endpoint terminal102. Further, the device1200and/or the backend server may continue to update the representation of the entire field of regard in response to detecting new or removed obstructions. For instance, the device1200and/or the backend server may, dynamically and in real-time, update the shape of the field of regard to omit regions corresponding to detected obstructions. This may result in a new shape of the field of regard. The device1200may update the display1214to present a new outline corresponding to the new shape of the field of regard. In some examples, the device1200may evaluate the suitability of a location by generating a signal-to-noise ratio (SNR) plot that describes the strength of signals transmitted between an endpoint terminal and a satellite constellation at various points within a field of regard. Referring toFIG.17, an example SNR plot1702is provided. In this example, the areas1704of the SNR plot1702correspond to points with low signal strength (e.g., due to obstructions). Specifically, the SNR plot1702illustrates the impact that various trees may have on the strength of signals transmitted and/or received by the endpoint terminal102. In some examples, the device1200may determine whether the level of communication associated with a field of regard (as indicated by an SNR plot1702) exceeds a threshold level of communication. A location corresponding to a field of regard whose level of communication exceeds the threshold level may be a suitable location for the endpoint terminal102, while a location corresponding to a field of regard whose level of communication is below the threshold level may be an unsuitable location. The methods for configuring and/or locating endpoint terminals described herein may be implemented in various use-case scenarios. In a first use-case scenario, the endpoint terminal102has not been previously installed at a location. In this scenario, an initial suitable location for the endpoint terminal102can be determined. Once the suitable location is determined, the endpoint terminal102can be installed and/or configured for communication with a constellation of satellites. In a second use-case scenario, the endpoint terminal102has been previously installed at a location. In this scenario, it may be determined that an obstruction (a new or existing obstruction) is degrading the quality of communication between the endpoint terminal102and a constellation of satellites. For example, the endpoint terminal102(or another device, such as a satellite or gateway) may determine that the strength of signals transmitted and/or received by the endpoint terminal102has dropped (e.g., below a threshold level). In response, the endpoint terminal102may output an indication (e.g., to the device1200) of the drop in signal strength. If the endpoint terminal102(or another device, such as a backend server) detects an obstruction that is likely causing the drop in signal strength, the endpoint terminal102may output an indication of the obstruction. Further, the endpoint terminal102may direct the user to determine a new (e.g., more suitable) location for the endpoint terminal102. Referring toFIG.18, an example of an instruction provided to the user after the endpoint terminal102has been installed is provided. In this example, the device1200may display an instruction directing the user to position their phone where the endpoint terminal102is located in order to detect obstructions (or confirm no obstructions are currently visible within the field of regard of the endpoint terminal102). Referring toFIGS.19A-19C, additional examples of a field of regard and user instructions displayed on a device1200for scanning the field of regard to dynamically identify obstructed and unobstructed regions are provided. As noted above, a scene engine1204may receive one or more image frames (e.g., an image frame1216) captured by the device1200. The scene engine1204may determine which portion (if any) of the image frame1216overlaps with the field of regard by determining the attitude (e.g., angle and/or orientation) of the device1200when the image frame1216was captured. Further, the scene engine1204may determine the attitude of the device1200using one or more sensors or devices integrated into the device1200, such as a gyroscope, an accelerometer, and/or a magnetometer. In one example, the scene engine1204may access the data obtained by these devices via one or more sensor APIs of the device1200. Based on the attitude of the device1200, the scene engine1204may determine which portion (if any) of the scene corresponding to the image frame1216overlaps with the field of regard. Additionally, the display engine1208may visually indicate the portion of the field of regard included within the image frame1216by darkening portions of the image frame1216not included within the field of regard. As illustrated inFIG.19A, no portion of the field of regard is included within the image frame captured by the device1200. Accordingly, the display engine1208may darken the entire image frame to visually represent that the device1200is positioned away from the field of regard. In an embodiment, the scene engine1204may use the attitude of the device1200, as well as the location of the field of regard, to determine a vector direction for movement of the device1200to capture the field of regard. For instance, if the scene engine1204determines that no portion of the field of regard is included within the image frame captured by the device1200, the scene engine1204may calculate the shortest vector between the current device attitude and an edge of the field of regard. The scene engine1204may provide this shortest vector to the display engine1208, which may generate an instruction1212that directs the user to move the device1200towards the field of regard. For example, as illustrated inFIG.19A, the display engine1208may display an instruction1212to “Look Up” along with an arrow or other graphical representation of an element that provides the user with a direction in which to move the device1200. Moving the device1200may enable the scene engine1204to obtain and analyze new image data to determine whether the attitude of the device1200coincides with any portion of the field of regard. In an embodiment, if the scene engine1204determines, based on the new image data, that the attitude of the device1200coincides with a portion of the field of regard, the scene engine1204may transmit an indication to the display engine1208that at least a portion of the field of regard is visible within the image frame1216. This may cause the display engine1208to update the instruction1212to indicate that the user may begin using the device1200to scan the field of regard. For example, as illustrated inFIG.19B, the display engine1208may update the instruction1212to instruct the user to use the device1200to scan the entire sky coincident with the field of regard of the endpoint terminal102. As noted above, as the device1200moves within the field of regard, the display engine1208may update the field of regard outline1210to account for changes in the scene currently visible within the field of view of the device1200. For example, the field of regard is stationary, but the scene visible within the field of view of the device1200may change. As such, the display engine1208may synchronize moving and/or adjusting the field of regard outline1210with movement of the device1200. In an embodiment, the display engine1208may dynamically and visually indicate the regions of the field of regard that need to be scanned in order to identify any obstructed and unobstructed regions of the field of regard. For instance, as illustrated inFIG.19B, the display engine1208may generate and display, within the field of regard, a set of dots1902indicating regions of the field of regard for which image data is required. Further, the display engine1208may update the instruction1212to indicate what percentage or amount of the field of regard has been scanned for determining the obstructed and unobstructed regions of the field of regard. For instance, the display engine1208may capture, using an image sensor of the device1200, one or more image frames that include image data that may be processed by the scene engine1204. The one or more image frames may be captured along with the attitude of the device1200. In an embodiment, the display engine1208may use the captured one or more image frames and the data corresponding to the attitude of the device1200when these image frames were captured to determine which regions of the field of regard the captured image frames correspond to. Based on this determination, the display engine1204may dynamically, and in real-time, update the display of the device1200to indicate the remaining regions of the field of regard that remain to be scanned. As illustrated inFIG.19B, as the user utilizes the device1200to scan the field of regard, the display engine1208may dynamically update the display to remove one or more dots from the regions of the field of regard that have been scanned and for which image data has been obtained. This may provide the user with a real time illustration of any regions of the field of regard that remain to be scanned, thereby instructing the user to move the device1200to scan the regions of the field of regard for which a set of dots1902are displayed. This, along with the dynamic updates to the instruction1212to indicate the percentage or amount of the field of regard that has been scanned, a user of the device1200may discern what regions of the field of regard the user needs to scan in order to complete the evaluation of the field of regard. It should be noted that while dots are used extensively throughout the present disclosure for the purpose of illustration, other methods may be used to denote regions of the field of display that need to be scanned in order to complete the evaluation of the field of regard. For instance, the display engine1208may utilize, additionally or alternatively, different colors to denote regions for which image data has been obtained and regions for which image data is still required. As an example, the regions for which image data has been obtained may be denoted using a color with a positive association (e.g., green, blue, etc.) while regions for which image data is still required may be denoted using a color with a negative association (e.g., red, orange, etc.). In some instances, the regions for which image data has been obtained may be devoid of any indicators (e.g., alternative color, dots, etc.) such that the user of the device1200may readily determine that these regions have been successfully scanned. In an embodiment, if the display engine1208determines that image data corresponding to the entire field of regard has been obtained, the display engine1208may update the instruction1212to indicate that scanning of the field of regard has been completed. For example, referring toFIG.19C, once the user has completed scanning the field of regard and the display engine1208determines that corresponding image data has been stored for evaluation, the display engine1208may update the instruction1212to allow the user to view the results of the scan. Accordingly, the user may select the instruction1212displayed on the device1200to view the results of its scan of the field of regard. The display engine1208may also provide the obtained image data to the scene engine1204, which may use the image data to identify the obstructed and unobstructed regions of the field of regard. If the user of the device1200selects the instruction1212, the display engine1208may update the display of the device1200to provide the user with an indication corresponding to the processing of the image data being performed to estimate the obstructions within the field of regard. Referring toFIG.20, the display engine1208may, in real time, indicate the progress made by the scene engine1204in processing the image data obtained from the stored images captured through scanning of the field of regard using the device1200. For example, as illustrated inFIG.20, the display engine1208may indicate what percentage or amount of the image data has been processed by the scene engine1204for determining the estimated obstructions within the field of regard. In an embodiment, the scene engine1204processes the stored images captured through scanning of the field of regard using a machine learning algorithm or artificial intelligence to segment the image data into obstructed and unobstructed regions of the field of regard. For instance, the scene engine1204may use a combination of computer vision (e.g., object classification and/or detection) and existing data corresponding to known obstructions at the geographic location of the user terminal102to calculate the portions of the field of regard that are obstructed. Additionally, the scene engine1204may calculate the length of time and/or how often these portions of the field of regard will remain obstructed. In an embodiment, the scene engine1204uses a convolutional neural network (CNN) to segment the image data into obstructed and unobstructed regions of the field of regard. The CNN may perform binary segmentation of the stored images, whereby for each pixel in a stored image, the CNN may predict whether that pixel represents an obstructed or unobstructed region of the stored image and/or field of regard represented in the stored image. The CNN may be trained using sample images and segmentation masks from open-source and/or proprietary datasets. Further, in some instances, as new image data is obtained from different users for corresponding devices, the scene engine1204may store this new image data, along with the classification of regions of the fields of regard corresponding to the new image data, to supplement the datasets used to train the CNN. Prior to training the CNN used to segment the image data into obstructed and unobstructed regions of the field of regard, the CNN weights may be initialized to a set of pre-trained weights obtained from training the CNN using a sample dataset (e.g., open-source or proprietary). In some instances, as new image data and corresponding classifications are obtained, the datasets used to train the CNN may be changed. For example, as the dataset including the new image data obtained from users and corresponding classifications grows over time, the open-source and/or proprietary datasets used in addition to this dataset may be removed from the training pool. This may reduce the reliance on datasets constructed without using image data corresponding to deployed devices or otherwise from users of these devices. In an embodiment, the scene engine1204, in addition to using a CNN to segment the image data into obstructed and unobstructed regions of the field of regard, can use a separate machine learning algorithm or artificial intelligence for semantic classification of the image data. For instance, the separate machine learning algorithm or artificial intelligence may be utilized by the scene engine1204to determine where new image data corresponds to images captured indoors or outdoors. This classification of image data may be used to better identify obstructions, instruct users to capture different image data (e.g., instruct a user capturing images indoors to capture additional images outdoors, etc.) that may be used to more accurately identify obstructed and unobstructed regions of the field of regard, and the like. In an embodiment, the scene engine1204may weigh the different regions of the field of regard according to the frequency at which satellites of the satellite constellation pass through these regions. For example, the scene engine1204may obtain satellite constellation data corresponding to other users within the geographic region of the user terminal102or within other geographic regions for which there may be a similar distribution or frequency in which satellites of the constellation pass through the geographic regions. The scene engine1204may use this weighing of the different regions of the field of regard to further refine the segmentation of the image data such that, in addition to identifying obstructed and unobstructed regions of the field of regard, the scene engine1204may generate sub-segments corresponding to the frequency in which satellites pass through the unobstructed regions of the field of regard, as well as providing insight into the impact of obstructions within the field of regard to communications to and from the satellites of the satellite constellation. In an embodiment, as the scene engine1204processes the image data obtained via scanning of the field of regard using the device1200, the scene engine1204may provide, in real time to the display engine1208, a status regarding the processing of the image data. For example, as illustrated inFIG.20, the display engine1208may indicate the amount or percentage of processing performed by the scene engine1204to identify the estimated obstructions within the field of regard, as well as any additional data that may be used to determine the estimated performance of the user terminal102in communicating with the satellite constellation at its present location. Once the scene engine1204has completed processing the image data using the machine learning algorithm or artificial intelligence, the scene engine1204may provide to the display engine1208obstruction data that may be used to generate an obstruction map visualization that illustrates the obstructed and unobstructed regions of the field of regard. Referring toFIG.21, the display engine1208may use the obstruction data to generate the obstruction map visualization, which may be presented to the user via the display of the device1200. The obstruction data may include coordinates corresponding to different regions of the field of regard that are either obstructed or unobstructed. Accordingly, the display engine1208may use the provided coordinates and the obstruction data for these coordinates to create a visualization of the obstruction map for the field of regard. The obstruction map may provide a visual representation of obstructed and unobstructed regions of the field of regard. For example, as illustrated inFIG.21, the display engine1208may display on the device1200a graphical representation of the user terminal102and of the field of regard of the user terminal102. Within the graphical representation of the field of regard, the display engine1208may divide the field of regard into obstructed and unobstructed regions based on the obtained obstruction data. The display engine1208may further distinguish the obstructed and unobstructed regions using one or more techniques to allow the user of the device1200to readily discern between these regions. For example, as illustrated inFIG.21, the display engine1208may use a blue color to graphically denote unobstructed regions of the field of regard and a red color to graphically denote obstructed regions of the field of regard. It should be noted that while different colors are used to distinguish between obstructed and unobstructed regions of the field of regard, other techniques may be used to distinguish between these regions. For example, the display engine1208may indicate, via the display, only the unobstructed regions of the field of regard, combining the obstructed regions of the field of regard with other portions of the hemisphere around the user terminal102that are not part of the field of regard. In addition to graphically displaying the obstructed and unobstructed regions of the field of regard, the display engine1208may further provide data corresponding to how often and/or for how long portions of the field of regard may be obstructed. For example, as illustrated inFIG.21, the display engine1208may indicate the frequency at which the user terminal102may encounter communication interruptions with the satellites of the satellite constellation. This frequency may be determined by the scene engine1204based on the calculation of obstructed and unobstructed regions using the provided image data and data corresponding to the frequency at which satellites of the satellite constellation pass through these regions of the field of regard. In an embodiment, based on this data, the scene engine1204can generate a recommendation for changing the location of the user terminal102to ideally reduce the size of the obstruction regions in the field of regard and, thus, reduce the amount of expected communication interruptions. This recommendation may be provided to the user by the display engine1208via the display of the device1200. In an embodiment, rather than providing a simulation of the field of regard and of the corresponding obstructed and unobstructed regions (as illustrated inFIG.21), the display engine1208may overlay the obstructed and unobstructed regions of the field of regard on to the image data captured using the device1200. For example, the display engine1208may dynamically overlay the obstructed and unobstructed regions onto the field of regard displayed on the device1200such that as the user moves the device1200, the portions of the obstructed and unobstructed regions corresponding to the portion of the field of regard visible through the device1200are presented. This may allow the user to identify, from the image data, the various obstructions that comprise the obstruction regions estimated by the scene engine1204. Referring toFIGS.19B-C, the portions of the house within the field of regard may be highlighted to denote that these portions of the house represent an obstruction region of the field of regard. For example, the display engine1208may highlight these areas using the same methodology as that illustrated inFIG.21, whereby the obstruction regions may be represented using the color red. Thus, the user may use the device1200to view the obstructed and unobstructed regions of the field of regard through the image data in real time. In some instances, rather than overlaying the obstructed and unobstructed regions of the field of regard onto the image data in real-time, the display engine1208may generate a virtual reality (VR) or panoramic visualization of the captured image data. The display engine1208may overlay the obstructed and unobstructed regions of the field of regard onto the VR or panoramic visualization of the captured image data such that the user may discern these regions from the processed image data. This may reduce the processing requirements of the device1200in performing real time update of the display to provide the portions of the estimated obstruction map corresponding to the portion of the field of regard corresponding to the present attitude of the device1200. In an embodiment, the display engine1208can provide the user with an option to add the captured image data to the training dataset that is used to continuously update the CNN and other machine learning algorithms and/or artificial intelligence to identify obstructed and unobstructed regions of different fields of regard and to provide different classifications for obtained image data (e.g., indoor or outdoor images captured, etc.). If the user selects this option, the display engine1208may add the captured image data, as well as any classifications generated from the image data (e.g., obstructed and unobstructed regions, indoor or outdoor images, etc.), to the dataset utilized to train the CNN and other machine learning algorithms and/or artificial intelligence. However, if the user opts to not include their image data to the dataset, the display engine1208may forego adding this image data to the dataset utilized to train the CNN and other machine learning algorithms. Methods for Locating a User Terminal FIG.22illustrates components in a block diagram of a non-limiting exemplary embodiment of an endpoint terminal102according to various aspects of the present disclosure. In some embodiments, the endpoint terminal102is a device that is installed at an end-user premises in order to provide access to the communication network to the end-user premises. As shown, the endpoint terminal102includes an endpoint communication interface2202. The endpoint communication interface2202allows the endpoint terminal102to communicate with a satellite, such as the first satellite104(seeFIG.1). In some embodiments, the endpoint communication interface2202may include a phased array antenna configured to communicate with the first satellite104, for example, via the Ku band. In some embodiments, the endpoint terminal102may also include a local communication interface, such as an Ethernet interface, a Wi-Fi interface, or other interface that allows other devices at the endpoint premises to connect to the network via the endpoint terminal102. The endpoint terminal102further includes an antenna system location determination engine2200. The location determination engine2200may receive information regarding the latitude location for the endpoint terminal, a longitude location of the endpoint terminal, obstructions, geological features, population density, an altitude of the end point terminal, a load balancing analysis of the satellite constellation, one or more angles of inclination of the satellite constellation, a geographical cell to which the end point terminal belongs, and combinations thereof. Actual embodiments of the illustrated devices will have more components included therein which are known to one of ordinary skill in the art. For example, each of the illustrated devices will have a power source, one or more processors, computer-readable media for storing computer-executable instructions, and so on. These additional components are not illustrated herein for the sake of clarity. FIG.23is a flowchart that illustrates a non-limiting example embodiment of a procedure2300for determining a location for a user terminal according to various aspects of the present disclosure. The procedure2300is an example of a procedure suitable for use with the endpoint terminal102shown inFIG.22for configuring an endpoint terminal for communicating with a non-GEO satellite constellation. In some embodiments, the procedure2300is executed recursively to adjust for changes in the satellite constellation, satellite communication loads, the endpoint terminal102, or the endpoint terminal cell. In block2301, the procedure includes determining the factors of communication for the endpoint terminal selected from the group consisting of the latitude location for the endpoint terminal, a longitude location of the endpoint terminal, obstructions, geological features, population density, an altitude of the end point terminal, a load balancing analysis of the satellite constellation, one or more angles of inclination of the satellite constellation, a geographical cell to which the end point terminal belongs, and combinations thereof. In block2302, based on the factors of communication for the endpoint terminal, selecting a location for the antenna system to adjust the field of regard to avoid obstructions. In block2303, installing the endpoint terminal to the selected location. While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the disclosure. In some examples, the procedures described herein (e.g., procedure2300or other procedures described herein) may be performed by a computing device or apparatus, such as a computing device having the computing device architecture2400shown inFIG.24. In one example, the procedure2300can be performed by a computing device with the computing device architecture2400. The computing device can include any suitable device, such as a mobile device (e.g., a mobile phone), a desktop computing device, a tablet computing device, a wearable device, a server (e.g., in a software as a service (SaaS) system or other server-based system), and/or any other computing device with the resource capabilities to perform the processes described herein, including procedure2300. In some cases, the computing device or apparatus may include various components, such as one or more input devices, one or more output devices, one or more processors, one or more microprocessors, one or more microcomputers, and/or other component that is configured to carry out the steps of processes described herein. In some examples, the computing device may include a display (as an example of the output device or in addition to the output device), a network interface configured to communicate and/or receive the data, any combination thereof, and/or other component(s). The network interface may be configured to communicate and/or receive Internet Protocol (IP) based data or other type of data. The components of the computing device can be implemented in circuitry. For example, the components can include and/or can be implemented using electronic circuits or other electronic hardware, which can include one or more programmable electronic circuits (e.g., microprocessors, graphics processing units (GPUs), digital signal processors (DSPs), central processing units (CPUs), and/or other suitable electronic circuits), and/or can include and/or be implemented using computer software, firmware, or any combination thereof, to perform the various operations described herein. Procedure2300is illustrated as a logical flow diagram, the operation of which represent a sequence of operations that can be implemented in hardware, computer instructions, or a combination thereof. In the context of computer instructions, the operations represent computer-executable instructions stored on one or more computer-readable storage media that, when executed by one or more processors, perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, components, data structures, and the like that perform particular functions or implement particular data types. The order in which the operations are described is not intended to be construed as a limitation, and any number of the described operations can be combined in any order and/or in parallel to implement the processes. Additionally, the processes described herein may be performed under the control of one or more computer systems configured with executable instructions and may be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications) executing collectively on one or more processors, by hardware, or combinations thereof. As noted above, the code may be stored on a computer-readable or machine-readable storage medium, for example, in the form of a computer program comprising a plurality of instructions executable by one or more processors. The computer-readable or machine-readable storage medium may be non-transitory. FIG.24illustrates an example computing device architecture2400of an example computing device which can implement the various techniques described herein. For example, the computing device architecture2400can implement the question answering system300shown inFIG.3. The components of computing device architecture2400are shown in electrical communication with each other using connection2405, such as a bus. The example computing device architecture2400includes a processing unit (CPU or processor)2410and computing device connection2405that couples various computing device components including computing device memory2415, such as read only memory (ROM)2420and random access memory (RAM)2425, to processor2410. Computing device architecture2400can include a cache of high-speed memory connected directly with, in close proximity to, or integrated as part of processor2410. Computing device architecture2400can copy data from memory2415and/or the storage device2430to cache2412for quick access by processor2410. In this way, the cache can provide a performance boost that avoids processor2410delays while waiting for data. These and other modules can control or be configured to control processor2410to perform various actions. Other computing device memory2415may be available for use as well. Memory2415can include multiple different types of memory with different performance characteristics. Processor2410can include any general purpose processor and a hardware or software service, such as service 12432, service 22434, and service 32436stored in storage device2430, configured to control processor2410as well as a special-purpose processor where software instructions are incorporated into the processor design. Processor2410may be a self-contained system, containing multiple cores or processors, a bus, memory controller, cache, etc. A multi-core processor may be symmetric or asymmetric. To enable user interaction with the computing device architecture2400, input device2445can represent any number of input mechanisms, such as a microphone for speech, a touch-sensitive screen for gesture or graphical input, keyboard, mouse, motion input, speech and so forth. Output device2435can also be one or more of a number of output mechanisms known to those of skill in the art, such as a display, projector, television, speaker device, etc. In some instances, multimodal computing devices can enable a user to provide multiple types of input to communicate with computing device architecture2400. Communication interface2440can generally govern and manage the user input and computing device output. There is no restriction on operating on any particular hardware arrangement and therefore the basic features here may easily be substituted for improved hardware or firmware arrangements as they are developed. Storage device2430is a non-volatile memory and can be a hard disk or other types of computer readable media which can store data that are accessible by a computer, such as magnetic cassettes, flash memory cards, solid state memory devices, digital versatile disks, cartridges, random access memories (RAMS)2425, read only memory (ROM)2420, and hybrids thereof. Storage device2430can include services2432,2434,2436for controlling processor2410. Other hardware or software modules are contemplated. Storage device2430can be connected to the computing device connection2405. In one aspect, a hardware module that performs a particular function can include the software component stored in a computer-readable medium in connection with the necessary hardware components, such as processor2410, connection2405, output device2435, and so forth, to carry out the function. The term “computer-readable medium” includes, but is not limited to, portable or non-portable storage devices, optical storage devices, and various other mediums capable of storing, containing, or carrying instruction(s) and/or data. A computer-readable medium may include a non-transitory medium in which data can be stored and that does not include carrier waves and/or transitory electronic signals propagating wirelessly or over wired connections. Examples of a non-transitory medium may include, but are not limited to, a magnetic disk or tape, optical storage media such as compact disk (CD) or digital versatile disk (DVD), flash memory, memory or memory devices. A computer-readable medium may have stored thereon code and/or machine-executable instructions that may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, or the like. In some embodiments the computer-readable storage devices, mediums, and memories can include a cable or wireless signal containing a bit stream and the like. However, when mentioned, non-transitory computer-readable storage media expressly exclude media such as energy, carrier signals, electromagnetic waves, and signals per se. Specific details are provided in the description above to provide a thorough understanding of the embodiments and examples provided herein. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For clarity of explanation, in some instances the present technology may be presented as including individual functional blocks including functional blocks comprising devices, device components, steps or routines in a method embodied in software, or combinations of hardware and software. Additional components may be used other than those shown in the figures and/or described herein. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. Individual embodiments may be described above as a process or method which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in a figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination can correspond to a return of the function to the calling function or the main function. Processes and methods according to the above-described examples can be implemented using computer-executable instructions that are stored or otherwise available from computer-readable media. Such instructions can include, for example, instructions and data which cause or otherwise configure a general purpose computer, special purpose computer, or a processing device to perform a certain function or group of functions. Portions of computer resources used can be accessible over a network. The computer executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, firmware, source code, etc. Examples of computer-readable media that may be used to store instructions, information used, and/or information created during methods according to described examples include magnetic or optical disks, flash memory, USB devices provided with non-volatile memory, networked storage devices, and so on. Devices implementing processes and methods according to these disclosures can include hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof, and can take any of a variety of form factors. When implemented in software, firmware, middleware, or microcode, the program code or code segments to perform the necessary tasks (e.g., a computer-program product) may be stored in a computer-readable or machine-readable medium. A processor(s) may perform the necessary tasks. Typical examples of form factors include laptops, smart phones, mobile phones, tablet devices or other small form factor personal computers, personal digital assistants, rackmount devices, standalone devices, and so on. Functionality described herein also can be embodied in peripherals or add-in cards. Such functionality can also be implemented on a circuit board among different chips or different processes executing in a single device, by way of further example. The instructions, media for conveying such instructions, computing resources for executing them, and other structures for supporting such computing resources are example means for providing the functions described in the disclosure. In the foregoing description, aspects of the application are described with reference to specific embodiments thereof, but those skilled in the art will recognize that the application is not limited thereto. Thus, while illustrative embodiments of the application have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art. Various features and aspects of the above-described application may be used individually or jointly. Further, embodiments can be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. The specification and drawings are, accordingly, to be regarded as illustrative rather than restrictive. For the purposes of illustration, methods were described in a particular order. It should be appreciated that in alternate embodiments, the methods may be performed in a different order than that described. One of ordinary skill will appreciate that the less than (“<”) and greater than (“>”) symbols or terminology used herein can be replaced with less than or equal to (“≤”) and greater than or equal to (“≥”) symbols, respectively, without departing from the scope of this description. Where components are described as being “configured to” perform certain operations, such configuration can be accomplished, for example, by designing electronic circuits or other hardware to perform the operation, by programming programmable electronic circuits (e.g., microprocessors, or other suitable electronic circuits) to perform the operation, or any combination thereof. The phrase “coupled to” refers to any component that is physically connected to another component either directly or indirectly, and/or any component that is in communication with another component (e.g., connected to the other component over a wired or wireless connection, and/or other suitable communication interface) either directly or indirectly. Claim language or other language reciting “at least one of” a set and/or “one or more” of a set indicates that one member of the set or multiple members of the set (in any combination) satisfy the claim. For example, claim language reciting “at least one of A and B” means A, B, or A and B. In another example, claim language reciting “at least one of A, B, and C” means A, B, C, or A and B, or A and C, or B and C, or A and B and C. The language “at least one of” a set and/or “one or more” of a set does not limit the set to the items listed in the set. For example, claim language reciting “at least one of A and B” can mean A, B, or A and B, and can additionally include items not listed in the set of A and B. The various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, firmware, or combinations thereof. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application. The techniques described herein may also be implemented in electronic hardware, computer software, firmware, or any combination thereof. Such techniques may be implemented in any of a variety of devices such as general purposes computers, wireless communication device handsets, or integrated circuit devices having multiple uses including application in wireless communication device handsets and other devices. Any features described as modules or components may be implemented together in an integrated logic device or separately as discrete but interoperable logic devices. If implemented in software, the techniques may be realized at least in part by a computer-readable data storage medium comprising program code including instructions that, when executed, performs one or more of the methods described above. The computer-readable data storage medium may form part of a computer program product, which may include packaging materials. The computer-readable medium may comprise memory or data storage media, such as random access memory (RAM) such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), FLASH memory, magnetic or optical data storage media, and the like. The techniques additionally, or alternatively, may be realized at least in part by a computer-readable communication medium that carries or communicates program code in the form of instructions or data structures and that can be accessed, read, and/or executed by a computer, such as propagated signals or waves. The program code may be executed by a processor, which may include one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, an application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Such a processor may be configured to perform any of the techniques described in this disclosure. A general purpose processor may be a microprocessor; but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Accordingly, the term “processor,” as used herein may refer to any of the foregoing structure, any combination of the foregoing structure, or any other structure or apparatus suitable for implementation of the techniques described herein. | 122,592 |
11943043 | DETAILED DESCRIPTION Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein, one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim. Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, or the like (collectively referred to as “elements”). These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. It should be noted that while aspects may be described herein using terminology commonly associated with a 5G or NR radio access technology (RAT), aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G). FIG.1is a diagram illustrating an example of a wireless network100, in accordance with the present disclosure. The wireless network100may be or may include elements of a 5G (NR) network and/or an LTE network, among other examples. The wireless network100may include a number of base stations110(shown as BS110a, BS110b, BS110c, and relay station110d) and other network entities. A base station (BS) is an entity that communicates with user equipment (UEs) and may also be referred to as an NR BS, a Node B, a gNB, a 5G node B (NB), an access point, a transmit receive point (TRP), or the like. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS and/or a BS subsystem serving this coverage area, depending on the context in which the term is used. In some aspects, a BS may be implemented on a satellite. In such a case, the geographic area of the cell provided by the BS may move with the BS. A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG)). ABS for a macro cell may be referred to as a macro BS. ABS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown inFIG.1, a BS110amay be a macro BS for a macro cell102a, a BS110bmay be a pico BS for a pico cell102b, and a BS110cmay be a femto BS for a femto cell102c. A BS may support one or multiple (e.g., three) cells. The terms “eNB”, “base station”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” may be used interchangeably herein. In some aspects, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some aspects, the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in the wireless network100through various types of backhaul interfaces, such as a direct physical connection or a virtual network, using any suitable transport network. Wireless network100may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. In the example shown inFIG.1, a relay station110dmay communicate with macro BS110aand a UE120din order to facilitate communication between BS110aand UE120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, or the like. In some aspects, as shown, a satellite may act as a relay station110dand may be referred to as a transparent satellite. In such an implementation, BS110amay be referred to as or part of a gateway or an earth station. For example, the BS110amay include a gateway (that is, the base station and gateway may be co-located or implemented in one device). Wireless network100may be a heterogeneous network that includes BSs of different types, such as macro BSs, pico BSs, femto BSs, relay BSs, or the like. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network100. For example, macro BSs may have a high transmit power level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts). A network controller130may couple to a set of BSs and may provide coordination and control for these BSs. Network controller130may communicate with the BSs via a backhaul. The BSs may also communicate with one another, directly or indirectly, via a wireless or wireline backhaul. UEs120(e.g.,120a,120b,120c) may be dispersed throughout wireless network100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, or the like. A UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium. Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, and/or location tags, that may communicate with a base station, another device (e.g., remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE). UE120may be included inside a housing that houses components of UE120, such as processor components and/or memory components. In some aspects, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, and/or electrically coupled. In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, or the like. A frequency may also be referred to as a carrier, a frequency channel, or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed. In some aspects, two or more UEs120(e.g., shown as UE120aand UE120e) may communicate directly using one or more sidelink channels (e.g., without using a base station110as an intermediary to communicate with one another). For example, the UEs120may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol or a vehicle-to-infrastructure (V2I) protocol), and/or a mesh network. In this case, the UE120may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station110. Devices of wireless network100may communicate using the electromagnetic spectrum, which may be subdivided based on frequency or wavelength into various classes, bands, channels, or the like. For example, devices of wireless network100may communicate using an operating band having a first frequency range (FR1), which may span from 410 MHz to 7.125 GHz, and/or may communicate using an operating band having a second frequency range (FR2), which may span from 24.25 GHz to 52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 is often referred to as a “millimeter wave” band despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. Thus, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies less than 6 GHz, frequencies within FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz). Similarly, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies within the EHF band, frequencies within FR2, and/or mid-band frequencies (e.g., less than 24.25 GHz). It is contemplated that the frequencies included in FR1 and FR2 may be modified, and techniques described herein are applicable to those modified frequency ranges. As indicated above,FIG.1is provided as an example. Other examples may differ from what is described with regard toFIG.1. FIG.2is a diagram illustrating an example200of a base station110in communication with a UE120in a wireless network100, in accordance with the present disclosure. Base station110may be equipped with T antennas234athrough234t, and UE120may be equipped with R antennas252athrough252r, where in general T≥1 and R≥1. At base station110, a transmit processor220may receive data from a data source212for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS(s) selected for the UE, and provide data symbols for all UEs. Transmit processor220may also process system information (e.g., for semi-static resource partitioning information (SRPI)) and control information (e.g., CQI requests, grants, and/or upper layer signaling) and provide overhead symbols and control symbols. Transmit processor220may also generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS) or a demodulation reference signal (DMRS)) and synchronization signals (e.g., a primary synchronization signal (PSS) or a secondary synchronization signal (SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor230may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs)232athrough232t. Each modulator232may process a respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modulator232may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators232athrough232tmay be transmitted via T antennas234athrough234t, respectively. At UE120, antennas252athrough252rmay receive the downlink signals from base station110and/or other base stations and may provide received signals to demodulators (DEMODs)254athrough254r, respectively. Each demodulator254may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator254may further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector256may obtain received symbols from all R demodulators254athrough254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor258may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE120to a data sink260, and provide decoded control information and system information to a controller/processor280. The term “controller/processor” may refer to one or more controllers, one or more processors, or a combination thereof. A channel processor may determine a reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, and/or a channel quality indicator (CQI) parameter, among other examples. In some aspects, one or more components of UE120may be included in a housing284. Network controller130may include communication unit294, controller/processor290, and memory292. Network controller130may include, for example, one or more devices in a core network. Network controller130may communicate with base station110via communication unit294. Antennas (e.g., antennas234athrough234tand/or antennas252athrough252r) may include, or may be included within, one or more antenna panels, antenna groups, sets of antenna elements, and/or antenna arrays, among other examples. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include one or more antenna elements. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include a set of coplanar antenna elements and/or a set of non-coplanar antenna elements. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include antenna elements within a single housing and/or antenna elements within multiple housings. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include one or more antenna elements coupled to one or more transmission and/or reception components, such as one or more components ofFIG.2. On the uplink, at UE120, a transmit processor264may receive and process data from a data source262and control information (e.g., for reports that include RSRP, RSSI, RSRQ, and/or CQI) from controller/processor280. Transmit processor264may also generate reference symbols for one or more reference signals. The symbols from transmit processor264may be precoded by a TX MIMO processor266if applicable, further processed by modulators254athrough254r(e.g., for DFT-s-OFDM or CP-OFDM), and transmitted to base station110. In some aspects, a modulator and a demodulator (e.g., MOD/DEMOD254) of the UE120may be included in a modem of the UE120. In some aspects, the UE120includes a transceiver. The transceiver may include any combination of antenna(s)252, modulators and/or demodulators254, MIMO detector256, receive processor258, transmit processor264, and/or TX MIMO processor266. The transceiver may be used by a processor (e.g., controller/processor280) and memory282to perform aspects of any of the methods described herein (for example, as described with reference toFIGS.3-5). At base station110, the uplink signals from UE120and other UEs may be received by antennas234, processed by demodulators232, detected by a MIMO detector236if applicable, and further processed by a receive processor238to obtain decoded data and control information sent by UE120. Receive processor238may provide the decoded data to a data sink239and the decoded control information to controller/processor240. Base station110may include communication unit244and communicate to network controller130via communication unit244. Base station110may include a scheduler246to schedule UEs120for downlink and/or uplink communications. In some aspects, a modulator and a demodulator (e.g., MOD/DEMOD232) of the base station110may be included in a modem of the base station110. In some aspects, the base station110includes a transceiver. The transceiver may include any combination of antenna(s)234, modulators and/or demodulators232, MIMO detector236, receive processor238, transmit processor220, and/or TX MIMO processor230. The transceiver may be used by a processor (e.g., controller/processor240) and memory242to perform aspects of any of the methods described herein (for example, as described with reference toFIGS.3-5). Controller/processor240of base station110, controller/processor280of UE120, and/or any other component(s) ofFIG.2may perform one or more techniques associated with an uplink frequency target for a non-terrestrial network, as described in more detail elsewhere herein. For example, controller/processor240of base station110, controller/processor280of UE120, and/or any other component(s) ofFIG.2may perform or direct operations of, for example, process600ofFIG.6and/or other processes as described herein. Memories242and282may store data and program codes for base station110and UE120, respectively. In some aspects, memory242and/or memory282may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the base station110and/or the UE120, may cause the one or more processors, the UE120, and/or the base station110to perform or direct operations of, for example, process600ofFIG.6and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples. In some aspects, UE120may include means for determining a transmission frequency for an uplink transmission based at least in part on a reference point for the uplink transmission, means for transmitting the uplink transmission based at least in part on the transmission frequency, means for receiving information indicating a location of the gateway or a Doppler drift value associated with a feeder link between the gateway and the satellite based at least in part on the gateway being the reference point, means for receiving information indicating whether the reference point is the satellite or the gateway, means for receiving information indicating whether a target uplink frequency used to determine the transmission frequency is controlled by a received downlink frequency of the user equipment or is independent of the received downlink frequency of the user equipment, means for determining whether a target uplink frequency used to determine the transmission frequency is controlled by a received downlink frequency of the user equipment or is independent of the received downlink frequency of the user equipment based at least in part on a capability of the user equipment, and/or the like. In some aspects, such means may include one or more components of UE120described in connection withFIG.2, such as controller/processor280, transmit processor264, TX MIMO processor266, MOD254, antenna252, DEMOD254, MIMO detector256, receive processor258, and/or the like. While blocks inFIG.2are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor264, the receive processor258, and/or the TX MIMO processor266may be performed by or under the control of controller/processor280. As indicated above,FIG.2is provided as an example. Other examples may differ from what is described with regard toFIG.2. FIG.3is a diagram illustrating an example300of a regenerative satellite deployment and an example310of a transparent satellite deployment in a non-terrestrial network. Example300shows a regenerative satellite deployment. In example300, a UE120is served by a satellite320via a service link330. For example, the satellite320may include a BS110(e.g., BS110a, relay station110d) and/or the like. More specifically, the satellite320may include a gNB or a distributed unit of a gNB. In some aspects, the satellite320may be referred to as a non-terrestrial base station, a regenerative repeater, an on-board processing repeater, and/or the like. In some aspects, the satellite320may demodulate an uplink radio frequency signal, and may modulate a baseband signal derived from the uplink radio signal to produce a downlink radio frequency transmission. For example, the satellite320may perform digital processing of a received signal to generate the downlink radio frequency transmission. The satellite320may transmit the downlink radio frequency signal on the service link330. The satellite320may provide a cell that covers the UE120. For example, the UE120may connect to the cell provided by the satellite320. The service link330is a radio link between the satellite320and the UE120. Example310shows a transparent satellite deployment, which may also be referred to as a bent-pipe satellite deployment. In example310, a UE120is served by a satellite340via the service link330. The satellite340may be a transparent satellite. The satellite340may relay a signal received from gateway350via a feeder link360. Gateway350may include a BS110(such as a gNB), an earth station, a router interfacing to a control network, or the like. For example, the satellite may receive an uplink radio frequency transmission, and may transmit a downlink radio frequency transmission without demodulating the uplink radio frequency transmission. In some aspects, the satellite may frequency convert the uplink radio frequency transmission received on the service link330to a frequency of the uplink radio frequency transmission on the feeder link360, and may amplify and/or filter the uplink radio frequency transmission. In some aspects, the UEs120shown in example300and example310may be associated with a Global Navigation Satellite System (GNSS) capability, a Global Positioning System (GPS) capability, and/or the like, though not all UEs have such capabilities. The satellite340may provide a cell that covers the UE120. For example, the UE120may connect to the cell provided by the satellite340. The service link330may include a link between the satellite340and the UE120, and may include one or more of an uplink or a downlink. The feeder link360may include a link between the satellite340and the gateway350, and may include one or more of an uplink (e.g., from the UE to the gateway) or a downlink (e.g., from the gateway to the UE). An uplink of the service link330may be shown by reference number330-U in subsequent Figures and a downlink of the service link330may be shown by reference number330-D in subsequent Figures. Similarly, an uplink of the feeder link360may be shown by reference number360-U in subsequent Figures and a downlink of the feeder link360may be shown by reference number360-D in subsequent Figures. The feeder link360and the service link330may each experience Doppler effects due to the movement of the satellites320and340, and potentially movement of a UE120. These Doppler effects may be significantly larger than in a terrestrial network due to the larger relative speed of the satellites320and340relative to the UE in an NTN. The Doppler effect on the feeder link360may be compensated for to some degree, but may still be associated with some amount of uncompensated frequency error. Furthermore, the gateway350may be associated with a residual frequency error, and/or the satellite320/340may be associated with an on-board frequency error (that is, frequency errors associated with components of the gateway350and/or the satellite320/340, as compared to frequency errors caused by Doppler effects). These sources of frequency error may cause a received downlink frequency at the UE120to drift from a target downlink frequency. As indicated above,FIG.3is provided as an example. Other examples may differ from what is described with regard toFIG.3. A UE may perform an uplink transmission in accordance with a transmission frequency for the uplink transmission. The transmission frequency is the actual frequency measured at the UE's output. In terrestrial mobile communications, an uplink transmission frequency may be synchronized with a received downlink frequency. For example, the received downlink frequency may not exactly match an assigned downlink frequency based at least in part on, for example, network-side oscillator errors. The UE may synchronize with a base station in accordance with an observed downlink frequency. Once the UE has synchronized to the received downlink signal, the uplink signal may use the received downlink signal as a reference frequency. As one example, in a time division duplexing (TDD) configuration, the target uplink frequency may be the same frequency as the received downlink signal. As another example, in a frequency division duplexing (FDD) configuration, the target uplink frequency may be equal to the received downlink frequency multiplied by a ratio of an assigned uplink frequency and the received downlink frequency. Thus, the UE may align the UE's uplink frequency with an observed downlink frequency in order to facilitate communication with the base station in view of error in the received downlink frequency. In a non-terrestrial network, there are multiple sources of frequency error. For example, a gateway may have a residual frequency error due to, for example, one or more components of the gateway. The gateway may transmit a signal to the satellite (which may be subject to the residual frequency error). The satellite may perform a frequency translation and forward the signal to the UE. The satellite may also be associated with some degree of uncompensated Doppler drift relative to the gateway due to a location and/or speed of the satellite relative to the gateway. Furthermore, the satellite may be associated with an onboard frequency error (due to one or more components of the satellite), and a service link between the satellite and the UE may be associated with a Doppler drift separate from a feeder link between the satellite and the gateway due to a location and/or speed of the satellite relative to the UE. Different points of reference for determination of a transmission frequency used to perform an uplink transmission may lead to different determinations of the transmission frequency, since there are multiple sources of frequency errors in non-terrestrial networks (NTNs), and Doppler drifts can be large and/or unknown. For example, if the transmission frequency is determined with reference to a target uplink frequency measured at a satellite, then the transmission frequency to be transmitted by the UE may be different than if the target uplink frequency is measured with reference to a gateway associated with a transparent satellite (due to different Doppler drifts and/or different frequency errors associated with the satellite and/or the gateway). Furthermore, some UEs may have a GNSS capability or a similar capability from which a frequency can be determined, while other UEs may not have a GNSS capability or a similar capability. A UE that has a GNSS capability may be capable of deriving a more accurate frequency estimate from the GNSS capability than from some methods used in terrestrial networks, such as referring to a received downlink frequency. However, a UE that does not have a GNSS capability may not be capable of deriving a frequency estimate from the GNSS capability. Techniques and apparatuses described herein define a target uplink frequency based at least in part on a reference point where the target uplink frequency is to be measured (either the satellite or the gateway). The reference point is a point at which, if frequency adjustment is performed properly, a signal is received at a target uplink frequency. By specifying the reference point, different UEs can determine appropriate frequency compensation in a uniform fashion, thereby improving frequency accuracy of uplink transmissions and reducing interference. The target uplink frequency may be independent from the received downlink frequency, or may be controlled by the received downlink frequency. If the target uplink frequency is controlled by the received downlink frequency, then the UE may perform Doppler compensation based at least in part on the received downlink frequency, which may be beneficial for low-capability UEs and/or the like. If the target uplink frequency is independent from the received downlink frequency, then the UE may determine the target uplink frequency based at least in part on a positioning system (e.g., GPS, GNSS, and/or the like), which may provide improved accuracy relative to downlink signal based determination of the target uplink frequency. When the uncompensated feeder link doppler and gateway and satellite on-board frequency errors are small, uplink transmissions with frequency based at least in part on received downlink frequency and with frequency independent of the received downlink frequency can coexist without significant interference. FIG.4is a diagram illustrating an example400of frequency adjustment based at least in part on a reference point at a satellite, in accordance with the present disclosure. As shown, example400includes a UE120and a satellite320/340. As described elsewhere herein, the satellite320/340may be a regenerative satellite or a transparent satellite. The gateway (e.g., gateway350) associated with the satellite340is omitted inFIG.4. As shown by reference number410, the reference point for a target uplink frequency may be the satellite320/340. Therefore, as shown by reference number420, the UE120may determine a transmission frequency based at least in part on a reference point at the satellite. For example, the UE120may adjust a frequency based at least in part on an expected frequency drifts on both the downlink and uplink of the service link330so that the satellite320/340receives a signal at the target uplink frequency or within an acceptable range of the target uplink frequency. In some aspects, as shown by reference number430, the UE120may determine the transmission frequency independent of a received downlink frequency. For example, the UE120may determine the target uplink frequency as an assigned uplink frequency for the uplink transmission. In such a case, the UE120may determine the transmission frequency based at least in part on a GNSS capability, a GPS capability, and/or the like. For example, the UE120may determine a frequency source to control a clock function of the UE120using the GNSS capability or the GPS capability, and may determine the transmission frequency using the clock function as a clock source for the uplink transmission. As another example, the UE120may use position information, speed information, velocity information, and/or the like to estimate a Doppler drift associated with the service link330, and may adjust the transmission frequency to compensate for the Doppler drift at the reference point. The position information, speed information, or velocity information can be for the UE120(such as determined using the GNSS capability or the GPS capability) and/or for the satellite320/340. For example, the satellite320/340may transmit, to the UE120, position information and speed information (such as in a system information block). In some aspects, the transmitted information may identify an ephemeris (e.g., a position and/or velocity over time) of the satellite320/340. In some aspects, the UE120may determine the uplink transmission using the frequency source of the GPS/GNSS capability and may adjust the uplink transmission based at least in part on the position information, speed information, velocity information, and/or the like. Determining the transmission frequency independent of the received downlink frequency may be beneficial for UEs that have GPS/GNSS capabilities, since determining the transmission frequency using the GPS/GNSS capability may be more accurate and/or reliable than determining the transmission frequency as controlled by the received downlink frequency. As an example of determining the transmission frequency independent of the received downlink frequency when the satellite320/340is the reference point, the transmission frequency (e.g., an ideal transmit frequency) may be equal to ft=ful_assigned−Doppler_service such that the carrier frequency measured by the satellite320/340is f=ful_assigned, where ft is the transmission frequency, ful_assigned is an assigned uplink frequency for the uplink transmission, and Doppler_service is a Doppler drift on the service link330. As shown by reference number440, in some aspects, the UE120may determine the transmission frequency as controlled by a received downlink frequency. For example, the UE120may use a received downlink signal as a frequency source to control a clock function of the UE120, and the clock function may be used as a clock source for the uplink transmission. Thus, the UE120may adjust the transmission frequency based at least in part on Doppler drift on the service link330and/or an on-board frequency error at the satellite320/340. Determining the transmission frequency as controlled by a received downlink frequency may be less resource intensive than determining the transmission frequency using a GPS/GNSS capability, and may be useful for UEs that do not have GPS/GNSS capabilities. As an example, if the transmission frequency is coupled with the received downlink frequency, a UE120's transmission frequency (e.g., an ideal transmit frequency, ft) should ensure that the uplink carrier frequency measured by the satellite320/340(e.g., the target uplink frequency) is equal to f=fdl*ful_assigned/fdl_assigned, where fdl_assigned is an assigned downlink frequency of the communication and fdl=fdl_transmit_satellite−fdl_compensated is a determined downlink frequency with fdl_compensated being a pre-compensated downlink frequency (e.g., a frequency adjustment applied by the satellite320/340to compensate for Doppler drift on the service link330), and fdl_transmit_satellite being an actual transmitted downlink frequency after pre-compensation is applied. If downlink pre-compensation is applied, the pre-compensated value (e.g., fdl_compensated) may be signaled in a system information block (SIB), for example, per beam or per satellite320/340. Thus, the UE120may use fdl_compensated to account for a Doppler drift value on the service link330in order to determine the transmitted downlink frequency fdl_transmit_satellite relative to fdl. In some aspects, the UE120may be capable of determining the transmission frequency independently of the received downlink frequency and as controlled by the received downlink frequency. In such a case, the UE120may receive signaling indicating whether to determine the transmission frequency independently of the received downlink frequency or as controlled by the received downlink frequency. In some aspects, a wireless communication specification may specify whether the UE120is to determine the transmission frequency independently of the received downlink frequency or as controlled by the received downlink frequency. In some aspects, the UE120may select whether to determine the transmission frequency independently of the received downlink frequency or as controlled by the received downlink frequency, for example, based at least in part on a capability of the UE120(e.g., whether the UE120is associated with a GNSS/GPS capability), a state of the UE120(e.g., whether the UE120is associated with an active GNSS/GPS unit), an interference condition, and/or the like. As shown by reference number450, the UE120may transmit the uplink transmission using the transmission frequency. By determining the transmission frequency using the satellite320/340as the reference point, the determination of the transmission frequency may be simplified, since the UE120does not need to handle feeder link Doppler drift (e.g., since feeder link Doppler drift is common to all UEs covered by a satellite320/340and thus does not cause inter-carrier interference). Furthermore, a gateway can typically compensate feeder link Doppler effects more effectively than a UE120, since the gateway may have more accurate location information regarding the satellite320/240than the UE120. FIG.5is a diagram illustrating an example500of frequency adjustment based at least in part on a reference point510at a gateway350, in accordance with the present disclosure. As shown inFIG.5, example500includes a satellite340and a gateway350, as well as a UE120. As shown by reference number520, the satellite340may signal, to the UE120, information indicating one or more of a feeder link Doppler drift (e.g., a Doppler drift associated with the feeder link360, which may be expressed as a Doppler value and a rate of change associated with the Doppler value) or location information associated with the gateway350(such as a position of the gateway350and/or a speed of the gateway350). For example, when the reference point510is at the gateway350, the UE120may compensate Doppler drift associated with the feeder link360as well as Doppler drift associated with the service link330. As shown by reference number530, the UE120may determine a transmission frequency based at least in part on the reference point at the gateway350. For example, the UE120may determine the transmission frequency so that an uplink transmission by the UE120is received at the gateway350at a target uplink frequency, taking into account Doppler drifts on the service link330and the feeder link360, as well as residual frequency error at the gateway350and on-board frequency error at the satellite340. The UE120may determine the Doppler drift on the feeder link360based at least in part on the signaling shown by reference number520. For example, the UE120may use the feeder link Doppler drift value, or may determine a feeder link Doppler drift value based at least in part on a relative position and/or velocity of the gateway350relative to the UE120and/or the satellite340. The information shown by reference number520may be signaled, for example, using a SIB and/or the like. As shown by reference number540, in some aspects, the UE120may determine the transmission frequency independent of a received downlink frequency. Determining the transmission frequency independent of a received downlink frequency is described in more detail in connection withFIG.4. As shown by reference number550, in other aspects, the UE120may determine the transmission frequency as controlled by the received downlink frequency, which is also described in more detail in connection withFIG.4. As shown by reference number560, the UE120may transmit the uplink transmission at the transmission frequency. Thus, the gateway350may receive the uplink transmission at approximately the target uplink frequency, since the transmission frequency compensates for Doppler drifts on links330and360, as well as on-board frequency error of the satellite340and residual frequency error of the gateway350. In some aspects, the UE120may receive signaling indicating whether the reference point is to be at the satellite340or the gateway350in a transparent deployment, which may provide increased flexibility for configuration of the reference point. For example, the signaling may include a SIB and/or the like. In some aspects, the reference point may be specified, for example, by a wireless communication specification, which may conserve signaling resources. As indicated above,FIG.5is provided as an example. Other examples may differ from what is described with regard toFIG.5. FIG.6is a diagram illustrating an example process600performed, for example, by a UE, in accordance with the present disclosure. Example process600is an example where the UE (e.g., UE120and/or the like) performs operations associated with an uplink frequency target for a non-terrestrial network. As shown inFIG.6, in some aspects, process600may include determining a transmission frequency for an uplink transmission based at least in part on a reference point for the uplink transmission, the reference point being associated with one of: a satellite that provides a cell covering the user equipment, the satellite being associated with a non-terrestrial network, or a gateway associated with the satellite (block610). For example, the UE (e.g., using antenna252, DEMOD254, MIMO detector256, receive processor258, controller/processor280, and/or the like) may determine a transmission frequency for an uplink transmission based at least in part on a reference point for the uplink transmission. The reference point may be associated with one of a satellite that provides a cell covering the user equipment, the satellite being associated with a non-terrestrial network, or a gateway associated with the satellite, as described above. As further shown inFIG.6, in some aspects, process600may include transmitting the uplink transmission based at least in part on the transmission frequency (block620). For example, the UE (e.g., using controller/processor280, transmit processor264, TX MIMO processor266, MOD254, antenna252, and/or the like) may transmit the uplink transmission based at least in part on the transmission frequency, as described above. Process600may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. With respect to process600, in a first aspect, process600includes receiving information indicating a location of the gateway or a Doppler drift value associated with a feeder link between the gateway and the satellite based at least in part on the gateway being the reference point. With respect to process600, in a second aspect, alone or in combination with the first aspect, the information is received in a system information block. With respect to process600, in a third aspect, alone or in combination with one or more of the first and second aspects, process600includes receiving information indicating whether the reference point is the satellite or the gateway. With respect to process600, in a fourth aspect, alone or in combination with one or more of the first through third aspects, the information is received in a system information block. With respect to process600, in a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the reference point is defined in a wireless communication specification. With respect to process600, in a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the transmission frequency is determined based at least in part on a target uplink frequency, and the target uplink frequency is an assigned uplink frequency for the uplink transmission measured at the reference point. With respect to process600, in a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the transmission frequency is independent of a received downlink frequency of the user equipment. With respect to process600, in an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the transmission frequency is controlled by a received downlink frequency of the user equipment. With respect to process600, in a ninth aspect, alone or in combination with one or more of the first through eighth aspects, process600includes receiving information indicating whether a target uplink frequency used to determine the transmission frequency is controlled by a received downlink frequency of the user equipment or is independent of the received downlink frequency of the user equipment. With respect to process600, in a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the information is received in a system information block. With respect to process600, in an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, process600includes determining whether a target uplink frequency used to determine the transmission frequency is controlled by a received downlink frequency of the user equipment or is independent of the received downlink frequency of the user equipment based at least in part on a capability of the user equipment. With respect to process600, in a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the capability is a Global Navigation Satellite System (GNSS) capability. With respect to process600, in a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, a wireless communication specification specifies whether a target uplink frequency used to determine the transmission frequency is controlled by a received downlink frequency of the user equipment or is independent of the received downlink frequency of the user equipment. With respect to process600, in a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the satellite is the reference point, a target uplink frequency used to determine the transmission frequency is independent of a downlink frequency of the user equipment, and the transmission frequency is based at least in part on an assigned uplink frequency and a Doppler drift value associated with a link between the user equipment and the satellite. With respect to process600, in a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the satellite is the reference point, a target uplink frequency used to determine the transmission frequency is independent of a downlink frequency of the user equipment, and the transmission frequency is equal to an assigned uplink frequency minus a Doppler drift value associated with a link between the user equipment and the satellite. With respect to process600, in a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, the satellite is the reference point, a target uplink frequency used to determine the transmission frequency is based at least in part on a received downlink frequency of the user equipment, and the transmission frequency is based at least in part on a pre-compensated downlink frequency. With respect to process600, in a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the transmission frequency is based at least in part on an assigned uplink frequency and a ratio of a determined downlink frequency and an assigned downlink frequency, and the determined downlink frequency is determined based at least in part on the pre-compensated downlink frequency and a transmitted downlink frequency transmitted by the satellite. With respect to process600, in an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, the transmission frequency is equal to an assigned uplink frequency multiplied by a ratio of a determined downlink frequency and an assigned downlink frequency, and the determined downlink frequency is determined by subtracting the pre-compensated downlink frequency from a transmitted downlink frequency transmitted by the satellite. With respect to process600, in a nineteenth aspect, alone or in combination with one or more of the first through eighteenth aspects, the pre-compensated downlink frequency is signaled to the user equipment in a system information block. AlthoughFIG.6shows example blocks of process600, in some aspects, process600may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted inFIG.6. Additionally, or alternatively, two or more of the blocks of process600may be performed in parallel. The following provides an overview of some Aspects of the present disclosure:Aspect 1: A method of wireless communication performed by a user equipment, comprising: determining a transmission frequency for an uplink transmission based at least in part on a reference point for the uplink transmission, the reference point being associated with one of: a satellite that provides a cell covering the user equipment, the satellite being associated with a non-terrestrial network, or a gateway associated with the satellite; and transmitting the uplink transmission based at least in part on the transmission frequency.Aspect 2: The method of Aspect 1, comprising: receiving information indicating a location of the gateway or a Doppler drift value associated with a feeder link between the gateway and the satellite based at least in part on the gateway being the reference point.Aspect 3: The method of Aspect 2, wherein the information is received in a system information block.Aspect 4: The method of Aspect 1, comprising: receiving information indicating whether the reference point is the satellite or the gateway.Aspect 5: The method of Aspect 4, wherein the information is received in a system information block.Aspect 6: The method of any of Aspects 1-5, wherein the reference point is defined in a wireless communication specification.Aspect 7: The method of any of Aspects 1-6, wherein the transmission frequency is determined based at least in part on a target uplink frequency, and wherein the target uplink frequency is an assigned uplink frequency for the uplink transmission measured at the reference point.Aspect 7: The method of Aspect 6, wherein the transmission frequency is independent of a received downlink frequency of the user equipment.Aspect 8: The method of any of Aspects 1-7, wherein the transmission frequency is controlled by a received downlink frequency of the user equipment.Aspect 9: The method of any of Aspects 1-8, comprising: receiving information indicating whether a target uplink frequency used to determine the transmission frequency is controlled by a received downlink frequency of the user equipment or is independent of the received downlink frequency of the user equipment.Aspect 10: The method of Aspect 9, wherein the information is received in a system information block.Aspect 11: The method of any of Aspects 1-10, comprising: determining whether a target uplink frequency used to determine the transmission frequency is controlled by a received downlink frequency of the user equipment or is independent of the received downlink frequency of the user equipment based at least in part on whether the user equipment has a capability.Aspect 12: The method of Aspect 11, wherein the capability is being able to use a Global Navigation Satellite System (GNSS) as a frequency source. Aspect 13: The method of any of Aspects 1-12, wherein a wireless communication specification specifies whether a target uplink frequency used to determine the transmission frequency is controlled by a received downlink frequency of the user equipment or is independent of the received downlink frequency of the user equipment.Aspect 14: The method of any of Aspects 1-13, wherein the satellite is the reference point, wherein a target uplink frequency used to determine the transmission frequency is independent of a downlink frequency of the user equipment, and wherein the transmission frequency is based at least in part on an assigned uplink frequency and a Doppler drift value associated with a link between the user equipment and the satellite.Aspect 15: The method of Aspect 14, comprising: estimating the Doppler drift value based at least in part on location information or speed information.Aspect 16: The method of any of Aspects 1-15, wherein the satellite is the reference point, wherein a target uplink frequency used to determine the transmission frequency is independent of a downlink frequency of the user equipment, and wherein the transmission frequency is equal to an assigned uplink frequency minus a Doppler drift value associated with a link between the user equipment and the satellite.Aspect 17: The method of any of Aspects 1-16, wherein the satellite is the reference point, wherein a target uplink frequency used to determine the transmission frequency is based at least in part on a received downlink frequency of the user equipment, and wherein the transmission frequency is based at least in part on a pre-compensated downlink frequency.Aspect 18: The method of Aspect 17, wherein the transmission frequency is based at least in part on an assigned uplink frequency and a ratio of a determined downlink frequency and an assigned downlink frequency, wherein the determined downlink frequency is determined based at least in part on the pre-compensated downlink frequency and a transmitted downlink frequency transmitted by the satellite.Aspect 19: The method of Aspect 17, wherein the transmission frequency is equal to an assigned uplink frequency multiplied by a ratio of a determined downlink frequency and an assigned downlink frequency, wherein the determined downlink frequency is determined by subtracting the pre-compensated downlink frequency from a transmitted downlink frequency transmitted by the satellite.Aspect 20: The method of Aspect 17, wherein the pre-compensated downlink frequency is signaled to the user equipment in a system information block.Aspect 21: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more Aspects of Aspects 1-20.Aspect 22: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the memory and the one or more processors configured to perform the method of one or more Aspects of Aspects 1-20.Aspect 23: An apparatus for wireless communication, comprising at least one means for performing the method of one or more Aspects of Aspects 1-20.Aspect 24: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more Aspects of Aspects 1-20.Aspect 25: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more Aspects of Aspects 1-20. The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects. As used herein, the term “component” is intended to be broadly construed as hardware and/or a combination of hardware and software. “Software” shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and/or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. As used herein, a processor is implemented in hardware and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code—it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein. As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like. Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c). No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more.” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more.” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, or a combination of related and unrelated items), and may be used interchangeably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has,” “have,” “having,” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or,” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of”). | 60,782 |
11943044 | DETAILED DESCRIPTION In describing the preferred embodiments of the present invention illustrated in the drawings, specific terminology is resorted to for the sake of clarity. However, the present invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. Turning to the drawing,FIG.1shows the paired satellite system10in accordance with a non-limiting illustrative example embodiment of the invention. The system10has at least one paired satellite assembly, and here is illustrated with a first paired satellite assembly100and a second paired satellite assembly150, though any suitable number of paired satellite assemblies can be provided. In addition, while each assembly100,150is shown here to have two satellites, each assembly100,150can have any suitable number of satellites, including more than two. The first and second assemblies150each have a first satellite102,152, a second satellite104,154, and a connection or link106,156. The first and second satellites102,152,104,154are separate and discrete complete satellites, and can be any suitable satellite, such as for example a CubSat. Thus, each satellite includes its own antenna103,105,153,155and processing device108,109,158,159, such as a processor or controller that controls operation of the satellite including, for example, flight control, pointing and operating the antenna103,105,153,155, flight thrusters, and communications including the receiving and transmitting of signals with a ground station. It should be noted, however, that when the satellites are coupled together, certain functions and features can be shared or performed by one satellite and not the other. For example, only one satellite can have a processing device and that processing device of the one satellite can control the operations of both satellites. In one embodiment of the invention, the first satellites102,152and second satellites104,154of each pair100,150are identical to each other, though in other embodiments the satellites102,152, and104,154can be different types of satellites or have different size, shape, structure and/or operation. Thus, each pair can have identical satellites or different types of satellites. In addition, the paired satellite assemblies100,150can be in any suitable orbit, such as for example Low Earth Orbit (LEO) or any non-geostationary orbit. The first paired assembly100can be traveling in a different orbit/path as the second paired assembly150, or they can be in the same or substantially the same orbit/path. The satellites102,152,104,154communicate with one or more antennas202,204,252,254of one or more ground stations200,254by beams formed at the satellite and/or at the antennas. The connection or link106,156connects the first satellite102,152with the second satellite104,154, respectively as shown. The connection106,156can be electrical, so that the first satellite102,152are in wired or wireless communication with the second satellite104,154, respectively. In one embodiment, the connection106,156can be an electrical cable, a wireless connection, or other communication link. The connection106,156provides a high-speed link. In addition to having linked communications, the connection106,156can physically or mechanically couple the first satellite102,152to the second satellite104,154, so that the first satellites102,152are physically linked and travel together in space with the second satellites104,154, respectively. In one embodiment, the connection106,156can be a rigid rod or bar having a first end and a second end. The first end can include a first pivot mechanism or device that pivotally or rotationally connects to the first satellite102,152. The second end can be opposite the first end and include a second pivot mechanism or device that pivotally or rotationally connects to the second satellite104,154, so that the satellites102,152,104,154, respectively, can pivot or rotate in all directions and especially 360 degrees parallel to one another, as well as angularly inward and outward from each other. Thus, as shown, the connection106,156can have a predetermined length to maintain a predetermined fixed distance between the first satellite102,152and the second satellite104,154. That distance can be as close as possible to each other but sufficiently apart from one another so that the satellites do not inadvertently come into contact or otherwise get damaged. And, the first satellite102,152can pivot or rotate with respect to the second satellite104,154, respectively. Thus, though the first and second satellites102,152, and104,154are co-located and form a constellation, each satellite102,152,104,154can form or communicate with a different ground station and/or beam. Still in other embodiments of the invention, the physical connection106,156can be wireless. For example, the satellites102,152,104,154can have electromagnetics that physically maintain the first satellites102,152at or within a predetermined distance to the second satellites104,154, respectively. Or, the satellites102,152,104,154can have thrusters that are controlled by avionics, such as a controller, to maintain the first satellite102,152at or within a predetermined distance to the second satellites104,154, respectively. FIG.1also shows the satellite pairs100,150during handover with a first ground station assembly200and a second ground station assembly250. The first ground station assembly200has a first antenna202and a second antenna204, and the second ground station assembly250has a first antenna252and a second antenna254. In one example embodiment, the first ground station assembly200can be, for example, a user, and the second ground station assembly250can be, for example, a gateway. In one example embodiment shown, the first and second paired satellite assemblies100are travelling to the right (in the FIGURE). Accordingly, the second paired assembly150is leaving the first communication area/zone or field of view (e.g., line of sight) of the first ground station assembly200(i.e., descending) and entering the second communication area of the second ground station assembly250, and the first paired assembly150is entering the first communication area or field of view (i.e., ascending). As shown inFIG.1, the system10enables seamless communication handover at the first ground station200(and the second ground station250, though only the first ground station200is discussed in this example) as the satellite assemblies100,150travel in orbit. That is, the first ground station200will establish communication with the first paired satellites100before it loses communication with the second paired satellites150. Beginning at an initial time TO, the satellites152,154of the second pair150communicate with one or both of the first and second antenna202,204of the first ground station200. At a first time period T1, the first pair100is entering the first communication zone. Accordingly, the first pair100comes within range of the first communication zone, and the first and/or second satellite102,104establish communication with the first or second antennas202,204. That is, the first and/or second antennas252,254of the first ground station acquire one or both of the satellites102,104of the ascending satellite pair100, and track those satellites. This happens before the second pair150completely descends and leaves the first communication zone and stops communicating with the first ground station200. Thus, at least one or both of the satellites102,104initiate communication with the first ground station200before the second pair150initiates communication with the second ground station250, or after one of the satellites152,154of the second pair150initiates communication with one of the antenna252,254of the second ground station250. That is, at least one or both of the satellites102,104start communicating with the first ground station200while the first ground station is still communicating with at least one of the satellites152,154of the second pair, i.e., before the first ground station200loses all communication with the second pair150. At a second time period T2, the second pair150continues to leave the first communication zone. Accordingly, the satellites152,154of the second pair150come within range of the second communication zone of the second ground station250. The second satellite154redirects from the first ground station200to the second ground station250, so it stops communicating with the second antenna204of the first ground station200and starts communicating with the first antenna254of the second ground station250. And at a third time period T3, the second paired satellites150completely leave the first communication zone, whereby both of the satellites152,154communicate with the second ground station250and not with the first ground station200—or the second satellite154has redirected to a third ground station (not shown) and the first satellite152communicates with the second ground station250. Prior to time T3, the first pair100has established communication with the first ground station200, so that the first ground station200has a seamless handover from the second satellite pair250to the first satellite pair200. Thus, the first ground station200has seamless and continuous communication because it has established communication with the first pair200before the second pair250leaves the first communication zone. The satellites100,150can be non-geostationary and can be in low-earth orbit (LEO), but any suitable orbit can be utilized. At a fourth time period T4, the first ground station200will establish communication with another paired satellite (not shown), before the first paired satellites100leaves the first communication zone and initiates communication with the second ground station250(or a different ground station). The first satellites102,152and the second satellites152,154communicate with one another via the communication link106,156, respectively, to cooperate during operation, such as during the handover or hand-off procedure. The satellites102,152,104,154communicate to control which satellite102,152,104,154within each pair100,150, respectively, communicates with which antenna of which ground station200,250. For example, the first satellite102,152can respectively control operation of the second satellite104,154; the second satellite104,154can respectively control operation of the first satellite102,152; or the satellites102,152,104,154can jointly decide how each satellite102,104operate (e.g., frequency, beam, direction, and which antenna202,204,252,254to communicate with). In one embodiment, the satellites102,152,104,154can include a processing device to perform various functions and operations in accordance with the invention. The processing device can be, for instance, a processor, application specific integrated circuits (ASIC), or controller. All or parts of the system, processes, and/or data utilized in the invention can be stored on or read from a storage device. The storage device can have stored thereon machine executable instructions for performing the processes of the invention. The processing device can execute software that can be stored on the storage device. Unless indicated otherwise, the process is preferably implemented in automatically by the processor substantially in real time without delay. The storage device can be a memory or non-transitory computer readable medium, such as any tangible medium that can store, encode or carry non-transitory instructions for execution by the computer and cause the computer to perform any one or more of the operations of the invention described herein, or that is capable of storing, encoding, or carrying data structures utilized by or associated with instructions. In one embodiment, the ground antennas202,204,252,254are 4.5 Mts terminals, with a 1.2 Mts user and a 0.7 Mts user, though any suitable size and parameters can be provided. It is further noted that while the invention has been described for use to pair satellites in the illustrated embodiment, it is noted that it can be utilized with other suitable devices. For example, the satellite can be any element, object or device that can be placed into space. The satellite can be a satellite module or satellite component, including for example any one or more of a processor304, receiver(s)/transmitter(s), and/or antenna. For example, one or both of the satellites or satellite modules can be an antenna, a portion of an antenna, or any other element, object, device or component that is placed into space, typically to support, for example, communication with other satellites, ground station, and/or end user device. And, the invention can include more than two satellites or satellite modules. The invention includes the satellite pair100,150and its operation, such as to conduct handover. Still further, the invention includes the ground station system and operation. The ground station communicates with the first and second satellite pairs100,150. For example, during handover, the ground stations configurate (e.g., positioning, tracking) the first and second antenna202,204to communicate with the first and second satellites102,152,104,154in accordance with the configuration described above, to provide seamless handover from a descending satellite pair to an ascending satellite pair. For example, the first ground station200(e.g., the first antenna202) acquires a signal from the ascending first satellite pair100(e.g., the second satellite104) before the first ground station (e.g., the second antenna204) loses communication with the descending second satellite pair150(e.g., the first satellite152). The first ground station200can then communicate with both satellites of the first satellite pair100. As the first satellite pair descends, it (e.g., the second satellite104) can communicate with a new ground station and the first ground station (e.g., the first antenna202) can continue to communicate with the first satellite pair (e.g., the first satellite102). The ground stations200,250can each have a processing device206,256such as a processor or controller, which controls the operation of the antennas102,152,104,154. The description and drawings of the present invention provided in the paper should be considered as illustrative only of the principles of the invention. The invention may be configured in a variety of ways and is not intended to be limited by the preferred embodiment. Numerous applications of the invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | 14,975 |
11943045 | DETAILED DESCRIPTION In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures and components have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present concepts. A number of descriptive terms and phrases are used in describing the various embodiments of this disclosure. These descriptive terms and phrases are used to convey a generally agreed upon meaning to those skilled in the art unless a different definition is given in this specification. Some descriptive terms and phrases are presented in the following paragraphs for clarity. A Baseband Unit (BBU) is a portion of a base station of a radio access network (RAN) that implements most, or all, of the OSI layer2functionality of the RAN and may include functionality of higher OSI network layers. The BBU may also be referred to as a virtual radio access network (vRAN) and the terms may be used interchangeably. In some embodiments, the BBU may include portions of the OSI layer1functionality of the RAN and a data connection to a remote radio unit (RRU). A Remote Radio Unit (RRU), which can also be referred to as a remote radio head (RRH), is a portion of a base station of a RAN that includes a connection to couple to an antenna and transmitter and/or receiver circuitry, but does not include full OSI layer2functionality of the RAN, such as medium access control (MAC) functionality. A RRU also includes some or all of the OSI layer1functionality of the RAN and a data connection to a baseband unit (BBU). A Fronthaul Link, or fronthaul connection, is the data connection used by a BBU and RRU to communicate with each other. Any sort of data communication mechanism can be used, depending on the embodiment, but in at least some embodiments, a network is used that is compatible with a standard published or maintained by The Institute of Electrical and Electronic Engineers (IEEE®) 802® working groups, such as a version of the IEEE 802.3 standard (i.e. Ethernet), a version of the IEEE 802.11 standard (i.e. WiFi®), or a version of IEEE 802.16 (i.e. WiMAX®). If a network having a non-deterministic protocol is used, an adaptive link protocol can be used by the BBU and RRU for communication over that link. In other embodiments, the fronthaul link may be a dedicated fiber-grade link using common public radio interface (CPRI) or other deterministic protocol. A Cluster of RRUs is a set of RRUs that are managed by a single BBU at a given point in time. The RRUs of a given cluster may be selected from a group of RRUs that the BBU can communicate with. A reference to “the group/cluster of RRUs” can mean one or more RRUs that are included in the group/cluster of RRUs and does not necessarily mean that every one of the RRUs in the group/cluster of RRUs are being referred to by each reference. A reference to the group/cluster can refer to a single RRU of that group/cluster, two RRUs of that group/cluster, or any combination of the RRUs of that group/cluster, up to and including all of the RRUs of that group/cluster. User Equipment (UE) refers to a device in wireless communication with the base station of the RAN. It may also be referred to as a mobile terminal, mobile device, wireless terminal, or a wireless device and the terms may be used interchangeably, even though some UE may not be mobile or may not be completely wireless (e.g. may have a wired power connection). Examples of UE include smartphones, tablets, mobile WiFi hotspots, remote data collection units (e.g. weather stations), and connected automobiles. An unmanned aircraft system (UAS) can also be known as a drone, an unmanned aerial vehicle (UAV), or an unmanned aircraft, and the terms may be used interchangeably herein. A UAS can be remotely piloted or can be autonomously piloted based on parameters provided to the UAS, such as a predetermined flight path, a hover position including latitude, longitude, and altitude, a position relative to a fixed or moving ground-based target, or other parameters. A virtual machine (VM), as the term is commonly used in the industry, is an emulation of a computer system that runs on a physical computer host, such as a server. A VM looks and acts like it is a stand-alone computer to the computer programs that run within the VM, with its own operating system (OS) and memory and I/O resources available to the program to use. A single host computer may have any number of VMs running on it and a single VM can then have one or more programs that run on it. As an example, a BBU can be embodied as a program running within a VM on a server. As used herein, however, the term virtual machine (VM) can also include an operating system environment natively running on the computer hardware, which may be a different use of the term than one of ordinary skill in the art would typically use. The term may be used in some instances, however, where it will be clear to one of ordinary skill that an OS running natively on the computer hardware would not be included in that particular instance. Turning now to a description of the technology disclosed herein, a distributed radio access network (RAN) uses one or more baseband units (BBUs) coupled to one or more remote radio units (RRUs) over a fronthaul link. This system may be referred to as using Radio-as-a-Service™ (RaaS) technology or a RaaS system. The BBUs can be based on proprietary hardware or can be implemented using software on a computer server, although dedicated hardware acceleration added to the server may be used in some embodiments. The RRUs are typically built using custom hardware and include, or are coupled to, a radio frequency (RF) receiver, transmitter, or transceiver. RaaS technology enables easy deployment and maintenance of RAN systems, including 4G networks, and clears the path to 5G networks. RRUs are simple and relatively inexpensive plug-and-play devices that allow RAN connectivity to be positioned wherever it is needed, and BBUs can be instantiated on commodity servers to implement the RAN software stack without any dedicated hardware in many cases. With such a virtual implementation of the radio stack, network updates and upgrades can be handled as software patches using well-established techniques for updating software. Thus, a RaaS architecture makes it straightforward to adopt advanced features such as LTE-U (LTE in unlicensed spectrum) or even 5G. A BBU may run in the cloud, along with an orchestration layer, using an adaptive fronthaul protocol over a standard IP-based network to communicate with one or more RRUs. The adaptive fronthaul protocol may be referred to as RaaS Fronthaul over IP (RaaS-FIP). RaaS-FIP may be used for the exchange of datagrams between a BBU and a RRU. Many different RAN architectures can be supported by a RaaS architecture including, but not limited to, LTE and LTE-A. The BBU implements at least some portion of the networking stack of the RAN, including layer2and in some cases portions of layer1. Higher level layers, may also be included in some embodiments of the BBU. RaaS can virtualize the RAN stack by replacing dedicated, expensive, and bulky base stations with software running on general purpose x86 or ARM CPUs communicating with small, easily deployed RRUs. BBUs can be deployed in many different ways. In some cases a BBU can be a dedicated hardware unit, which may be based on commodity hardware, or as software installed on a standard computer, such as a rack-mounted server. A BBU may be positioned in traditional central office type installations. In such situations, an IP-based fronthaul link using RaaS-FIP may be used for communication between the BBU and RRU, but in some cases a non-IP-based fronthaul link, such as a fiber-grade communications link with a deterministic protocol like CPRI, may be used with dedicated hardware for the communications link included in the dedicated BBU hardware unit. In some cases, BBUs may be mobile, such as using BBUs instantiated on racks of commodity server mounted in a truck. But in many cases, BBUs are instantiated on servers based in data centers, and a standard IP-based network used for communications with the RRUs. The data centers and servers may be owned by the carrier, or they may be owned by a third party that leases the computers to the carrier. In some cases, BBUs can be instantiated using a public computing cloud service such as those offered by Google Compute Engine™ (GCE) compute services or Amazon Web Services™ (AWS) compute services. Positioning RRUs where they are needed allows a carrier to respond to changing customer demands. In a traditional RAN architecture, significant planning and manual configuration needs to take place to deploy a new set of base stations which are bulky and expensive. In a RaaS system, RRUs can be easily positioned where they are need and BBUs dynamically instantiated in a remote data center to support the RRUs as they are positioned. In fact, the RRUs can even be mobile, located on ground-based or aerial vehicles, and the RaaS system can dynamically respond to, or even control, the movement of the mobile RRUs to meet the ever-changing requirements of the mobile terminals in use. BBUs can also be mobile and dynamically associated with RRUs automatically. This can be useful in situations where mobile device usage may peak, such as at concerts and sporting events, events occurring in areas will little to no permanent RAN coverage, and emergency situations, such as responding to a natural disaster, where much of the existing infrastructure may be non-operational. The RaaS system provides the benefits of virtualization, including resource pooling and dynamic allocation of resources when and where it is needed. In addition, all of this can be done with little to no advance planning due to the automatic dynamic allocation of the requested resources. Embodiments of a RaaS architecture can employ an orchestration function. The orchestration function may be integrated into BBUs or may be instantiated separately from a BBU, depending on the embodiment. If there are multiple orchestration modules, such as if multiple BBUs have integrated orchestration modules, the various orchestration modules coordinate with each other. The orchestration module may be implemented as software running on a standard computer, such as a rack-mounted server, or may be implemented using at least some special-purpose hardware. In some embodiments, the orchestration module may be implemented as electronic circuitry, either dedicated or as circuitry employing a processor that executes instructions. The orchestration module can communicate with the BBUs and/or RRUs, depending on the embodiment, and can perform several functions for the RaaS system. In some embodiments, a centralized orchestration module takes care of coordinating existing and incoming RRUs, BBU instances, and virtual machines. In such embodiments, the centralized orchestration module may run in its own virtual machine, or it may share a virtual machine with a BBU. In some cases, especially in larger systems, there may be more than one centralized orchestration module, and the multiple centralized orchestration modules can coordinate among themselves to manage a portion of the RAN. In other embodiments, each BBU includes an orchestration function that manages RRUs for that BBU and coordinates with the orchestration function of other BBUs. In some embodiments, some BBUs may have an integrated orchestration function while other BBUs may not, and are supported by a centralized orchestration function. In such cases, the centralized orchestration function coordinates with the orchestration functions integrated into BBUs to manage the RaaS system. RaaS virtualization decouples RRUs and corresponding controlling BBU instances. RRUs may have multiple controlling BBU instances over time, and BBU instances may control multiple RRUs. The mapping of a RRUs to a cluster of RRUs may be dynamically changed. In some embodiments, a BBU may be instantiated to directly run on an operating system (OS) running natively on the server. In other cases a BBU may be instantiated in a virtual machine running on the server. In some embodiments, a virtual machine provisioned for a RaaS deployment in a data center continuously runs a BBU instance, which is associated with a cluster of RRUs that may include zero, one, or more RRUs. In some embodiments, a BBU instance may start automatically when a virtual machine instance is created. In other embodiments, BBU instances can be dynamically created and destroyed on the virtual machines. Multiple BBU instances may be running on a single virtual machine. Virtual machines may be provisioned with different computational resource, storage space, network capabilities, interfaces, and the like, depending on the details of the particular BBU that will run on that virtual machine. BBU instances with different capabilities, such as a number of RRUs controlled, bandwidth provided to mobile terminals, and the like, may be instantiated on virtual machines according to the resources of the available virtual machines. Tools such as those from the OpenStack® project, the OpenNebula™ project, OpenQRM, and the like, may be used for provisioning, management, and other tasks of the data center devoted to RaaS operations. Virtual machines may be instantiated, destroyed, migrated, and otherwise managed, according to data center capacity, provisioning, network deployment size and load, costs, and other factors. In some embodiments, each physical computer may host a single virtual machine, while in other embodiments, a single physical computer may host multiple virtual machines. A virtual machine may run one or more instances of a BBU, depending on the embodiment. In yet another embodiment, BBU instances may run in an OS running natively on a physical computer. But as the term is used herein, a BBU is running on a virtual machine in each of the examples above. Reference now is made in detail to the examples illustrated in the accompanying drawings and discussed below. FIG.2is a block diagram of an embodiment of a distributed radio access network (RAN)200using RaaS technology. The RAN200represents a radio frequency communication system to facilitate communication between a wireless terminal and a core network299. The RAN200can be any type of RAN, but in at least some embodiments, the RAN200is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and the core network299includes an Evolved Packet Core (EPC). While an E-UTRAN system is used as an example in this document, the principles, systems, apparatus, and methods disclosed herein can be applied by one of ordinary skill to different radio access networks, including legacy networks such as Universal Mobile Telecommunications System (UMTS), other contemporary networks such as Worldwide Interoperability for Microwave Access (WiMAX), and future networks. The RAN200includes a first remote radio unit (RRU)230A coupled to an antenna231A to communicate with a wireless terminal210A. Depending on the system, any number of RRUs can be included, such a second RRU230B coupled to a second antenna231B, and a third RRU230C coupled to third antenna231C. The multiple RRUs230A-C can be geographically distributed and/or there can be multiple RRUs230A-C in a single location. A single RRU230A can be coupled to any number of antennas, although many installations couple two antennas to each RRU230A-C. A RRU230A includes electronic circuitry to perform at least a first portion of a first-level protocol of the RAN200for communicating between the wireless terminal210A and the core network299. The RAN200also includes a first baseband unit (BBU)260A coupled to the core network299. The first BBU260A may be implemented using software running on a computer server204A. The server204A may be one of multiple servers, including server204B, situated in a data center202to provide power, cooling, network connectivity, and management, to the servers204A-B. In some cases the data center202and its servers204A-B may be owned by a carrier that operates the RAN200, but in other cases, the data center202and its servers may be owned by a third party provider that leases specific equipment or resources, such as a virtual machine206B, to the operator of the RAN200. The computer server204A includes a processor to execute code that includes instructions of one or more modules of the BBU260A. The server204A also includes one or more memory devices, coupled to the processor, to store the code, and interface circuitry coupled between the processor and a fronthaul link245. The first BBU260A is coupled to a core network299and is used in a distributed RAN200with a cluster of remote radio units (RRUs), including RRU230A. The first BBU260A includes an orchestration module262A that includes instructions to run on a processor of the server204A. The instructions of the orchestration module262A assign one or more RRUs, including first RRU230A, selected from a group of RRUs230A-C communicably coupled to the fronthaul link245, to the cluster of RRUs based on one or more parameters. The first BBU260A also includes a networking module264A that includes instructions to run on a processor of the server204A. The instructions of the networking module264A perform at least a second-level protocol of the RAN200and communicate over the fronthaul link245with the cluster of RRUs, including RRU230A. In some embodiments, the instructions of the networking module264A also perform a portion of a first-level protocol of the RAN200and/or communicate over the fronthaul link245with the cluster of RRUs using an adaptive fronthaul protocol. In at least some embodiments, the first-level protocol of the RAN200comprises an Evolved Universal Terrestrial Radio Access (E-UTRA) physical-layer (PHY) protocol, and the second-level protocol comprises an E-UTRA medium access control (MAC) protocol. Depending on the system, any number of BBUs can be included, such as a second BBU260B with a second orchestration module262B and a second networking module264B, and a third BBU260C with a third orchestration module262C and third networking module264C. A BBU can run directly in an OS running natively on a server, such as the first BBU260A running on the first server204A, or a BBU can run in a virtual machine, such as the second BBU260B running on virtual machine206B, which is hosted by the second server204B. The BBUs of the RAN200can be geographically distributed and/or there can be multiple BBUs in a single location, such as the BBUs260B-C shown in the data center202. The BBUs260A-C are coupled to the core network299using a backhaul link290. The backhaul link290can be any sort of communication link, such as a S1 interface in an E-UTRAN, or an internet protocol (IP) packet-based network, depending on the embodiment. The backhaul link290may include the internet or a dedicated IP/Multiprotocol Label Switching (MPLS) network in some embodiments. Furthermore, some of additional BBUs may be remotely located in the “cloud”, that is, data and control transport channels may be established between a remote BBU and a RRU, and those channels may be routed over multiple different physical media, and may be processed by multiple intermediate network nodes, such as routers, switches, and the like. The RAN200also includes a fronthaul link245coupled to the BBUs260A-C and the group of RRUs230A-C and utilizing an adaptive fronthaul protocol for communication between the BBUs260A-C and the group of RRUs230A-C. In some embodiments, the fronthaul link245includes a non-deterministic communication link, where at a latency, an arbitration, a bandwidth, a jitter, a packet order, a packet delivery, or some other characteristic of the communication link, cannot be determined with certainty in advance. In some embodiments, the fronthaul link245has a variable roundtrip latency with a maximum that is greater than a response time requirement for a message type sent by the wireless terminal and processed by the second-level protocol of the RAN200. In at least one embodiment, the fronthaul link245exhibits jitter in excess of a maximum jitter requirement of the RAN200, and in some embodiments, the fronthaul link245has a variable throughput with a minimum throughput less than a maximum throughput of the wireless terminal210A. Many embodiments utilize a fronthaul link245that includes an Ethernet network. In some embodiments, the adaptive fronthaul protocol comprises a packet-based protocol with non-guaranteed in-order packet delivery and/or non-guaranteed packet delivery, and may utilize an internet protocol (IP). The fronthaul link245may include multiple networks and/or communication links coupled together with active network devices, such as bridges, routers, switches, and the like. In some installations, the fronthaul link245may include a link, such as a synchronous optical networking (SONET) link, from one or more BBUs to a remote active network device, which then provides dedicated local links to one or more RRUs, such as 1000Base-T Ethernet links. In this configuration, the link from the active network device to the BBU is shared by multiple RRUs. Additional network nodes required by the RAN200to operate properly, such as blocks belonging to the EPC network, the mobility management unit (MME), the home subscriber server (HSS), and the like, may also be remotely located and accessible via transport channels conveyed over the core network299or may be co-located on a server204A-B in the data center202. The various fronthaul and backhaul connections at different levels may have different characteristics in terms of throughput, latency, reliability, quality of service, and the like. For example, a fronthaul connecting RRUs to nearby BBUs may be based on dedicated fiber-grade connections, whereas the fronthaul connecting BBUs to more distant RRUs may be conveyed over a shared medium using internet protocol (IP). The backhaul connecting the BBUs to the core network may be yet a different network connection. Embodiments described herein may utilize an adaptive fronthaul protocol for communication between the RRU and the BBU. An adaptive fronthaul protocol provides mechanisms for the BBU and/or RRU to react to changes in the environment, such as the changes in the fronthaul, the radio signal, the loads of the mobile terminals coupled to the RRUs, or other characteristics of the system, to provide a graceful adaptation to the changes instead of losing the connection between the BBU and RRU if the new conditions cannot support the previous parameters of the connection. Thus, the adaptive fronthaul protocol has provisions for adapting to conditions of the fronthaul link and radio network by changing the way data is communicated over the fronthaul link. Characteristics of an adaptive fronthaul protocol may include, but are not limited to, adapting a compression of the fronthaul uplink information and/or fronthaul downlink information, adapting an amount of loss of data caused by the compression, changing a parameter of the RAN based on characteristics of the fronthaul link, bypassing a function of a second-layer protocol of the RAN based on characteristics of the fronthaul link, using information from a second-layer protocol to change parameters in the a first-layer protocol, or other adaptations in how the fronthaul link is used. Such an adaptive fronthaul protocol allows a much more cost effective link, such as a packet-switching network, to be used in the fronthaul link. In some cases, this may allow for deployments without any special provisioning of the fronthaul link by allowing the fronthaul information to be transmitted over standard internet connections. The orchestration module262A of the first BBU260A receives information from the group of RRUs231A-C and from other orchestration modules, such as the second orchestration module262B of the second BBU260B. The information received, along with settings in the first BBU260A, can be used as the one or more parameters to determine how to assign a RRU from the group of RRUs230A-C to a particular cluster of RRUs. The information can change over time, and the assignments of the RRUs to the clusters can be changed by the orchestration module262B in response, to assign the one or more RRUs to the cluster of RRUs dynamically. In some cases, the BBU260A and/or the group of RRUs230A-C are mobile. In one non-limiting example, the one or more parameters include a geographic service area of the BBU260A. The orchestration module262A can dynamically assign the one or more RRUs to the cluster of RRUs based on current locations of the group of RRUs230A-C and the geographic service area of the first BBU260A. One particular case of a mobile RRU is having RRUs of the group of RRUs230A-C mounted on ground-based vehicles or on unmanned aircraft systems (UAS). As the vehicle or UAS moves the RRUC, the orchestration module262A can dynamically assign the RRU to an appropriate cluster of RRUs, based on its current position, or other parameters. In some embodiments, the orchestration module262A can send commands to the UAS to dynamically position the group of RRUs230A-C based on the one or more parameters. In one example, locations of the first mobile terminal210A, the second mobile terminal210B, and the third mobile terminal210C are determined using location information from the GPS receivers in the mobile terminals210A-C that is provided to the group of RRUs231A-C and then to the first BBU260A. Additionally or alternatively, signal strengths reported by the mobile terminals210A-C and/or the group of RRUs231A-C may be used to estimate positions of the mobile terminals210A-C. The locations of the mobile terminals210A-C are then used to determine positions for the group of RRUs231A-C and the first orchestration module262A sends flight path information to the UASs carrying the RRUs231A-C to move them to their determined positions. The one or more parameters that are used to assign RRUs to the cluster of RRUs can include a wide variety of parameters. Examples of such parameters include, but are not limited to, numbers of mobile terminals210A-C in active communication with the group of RRUs230A-C, radio measurements performed by the group of RRUs230A-C, radio measurements performed by the mobile terminals210A-C, synchronization states of the group of RRUs230A-C, a fronthaul link quality parameter, geographic locations of the group of RRUs230A-C, geographic locations of mobile terminals210A-C in active communication with the group of RRUs230A-C, or any combination thereof. The fronthaul link quality parameter may be determined based on information received from the group of RRUs230A-C over the fronthaul link, such as, but not limited to, RRU buffer status information, RRU buffer overrun indications, RRU buffer underrun indications, information about a received radio frequency signal, or any combination thereof. In some cases, the fronthaul link quality parameter is determined by the BBU260A based on data gathered in the BBU260A, such as, but not limited to a latency of the fronthaul link, a bandwidth of the fronthaul link, errors on the fronthaul link, undelivered packets on the fronthaul link, out-of-order packets on the fronthaul link, buffer overruns, buffer underruns, or any combination thereof. The one or more parameters are then used to assign the RRUs to various clusters of RRUs, such as assigning one or more RRUs of the group of RRUs230A-C to a first cluster of RRUs that are associated with the first BBU260A, and in some embodiments, assigning one or more other RRUs of the group of RRUs230A-C to a second cluster of RRUs that are associated with the second BBU260B. As one non-limiting example, the one or more parameters include geographic locations of the group of RRUs230A-C, which includes a building floor. The orchestration module262A may assign the one or more RRUs to the cluster of RRUs based on the one or more RRUs having a common building floor location. So for example, if the first RRU230A and the second RRU230B were to be located on the first floor of a first building, and the third RRU230C were to be located on the second floor of the first building, the orchestration module262A could assign the first RRU230A and the second RRU230B to be in the first cluster of RRUs that is associated with the first BBU260A, while that third RRU230C is assigned to the second cluster of RRUs that is associated with the second BBU260B. Once the RRUs are assigned to clusters, the one or more parameters can be used to configure the cluster of RRUs associated with the first BBU260A. In some cases, the orchestration module includes instructions to set a transmission power of the cluster of RRUs based on the one or more parameters, and/or set a radio frequency used by the cluster of RRUs to communicate with mobile terminals based on the one or more parameters. In some embodiments, the orchestration module262A configures the cluster of RRUs to appear as a single base station to a mobile terminal210A. In some cases, however, the orchestration module262A configures the cluster of RRUs so that a first RRU230A of the cluster of RRUs transmits data that is different than data transmitted by a second RRU230B of the cluster of RRUs during at least some time periods. As a non-limiting example, this may be done to allow the first RRU230A to communicate with the first mobile terminal210A simultaneously with the second RRU230B communicating with the second mobile terminal210B, using the same frequency, where the two RRUs are at a great enough distance from each other that they do not interfere with each other, or by using beam shaping to direct the signal from each RRU so that they don't cause interference. Thus, the orchestration module262A may configure a first RRU230A of the cluster of RRUs to communicate with a first mobile terminal210A and configure a second RRU230B of the cluster of RRUs to communicate with a second mobile terminal210B based on geographic locations of the first RRU230A, the second RRU230B, the first mobile terminal210A, and the second mobile terminal210B. The geographic location may be an actual geographic position (e.g. a latitude and longitude) or it may be a signal strength between a RRU and a mobile terminal, which can give an approximation of distance between the two. So the first orchestration module262A may configure a first RRU230A of the cluster of RRUs to communicate with a first mobile terminal210A and configure a second RRU230B of the cluster of RRUs to communicate with a second mobile terminal210B based on radio measurements performed by the cluster of RRUs, the first mobile terminal210A, or the second mobile terminal210B. As another non-limiting example the orchestration module262A may configure a first RRU230A of the cluster of RRUs to only transmit to a mobile terminal210A, and configure a second RRU230B of the cluster of RRUs to only receive from the mobile terminal210A. The first BBU260A may determine that the first RRU230A of the cluster of RRUs has failed. This may be accomplished by the networking module264A determining that the failure based on communication parameters, by the orchestration module262A based on parameters received from the first RRU230A, or by other means. Upon determining that the first RRU230A has failed, the BBU260A may hand over a mobile terminal210A associated with the first RRU230A to a second RRU230B of the cluster of RRUs. In some embodiments, the orchestration module262A may determine that a predetermined capacity threshold of the BBU260A has been exceeded. The orchestration module262A may then change a parameter in the cluster of RRUs or a mobile device in communication with the cluster of RRUs in response to the determination that the predetermined capacity threshold of the BBU has been exceeded. By changing a parameter, along with other actions in some cases, one or more of the following may be performed:a handover of a mobile terminal to another BBU;a reduction in a throughput for the mobile terminal;a reduction in a resource block allocation;a change in a modulation and coding scheme for the cluster of RRUs;a suspension of unicast uplink scheduling in the cluster of RRUs for one or more scheduling intervals; ora suspension of unicast downlink scheduling in the cluster of RRUs for one or more scheduling intervals. The first orchestration module262A of the BBU260A may coordinate with the second BBU260B that includes a second orchestration module262B and a second networking module264B. This may include the first orchestration module262A further coordinating RAN parameters with the second BBU260B. In another non-limiting example, if the orchestration module262A determines that a first RRU230A of the cluster of RRUs has failed, the orchestration module262A may move a mobile terminal210A associated with the first RRU230A to a second RRU230B, where the second RRU230B is associated with a second cluster of RRUs that is associated with the second BBU260B. In another example of coordination with a second BBU260B, the first orchestration module262A may move the first RRU230A from the cluster of RRUs to a second cluster of RRUs associated with the second BBU260B. This may be done in response to a physical movement of the first RRU230A, a loading condition of the first BBU260A, a number of mobile terminals210A-C in communication with the first RRU230, or for other reasons. To accomplish moving the first RRU230A from the first cluster of RRUs to the second cluster of RRUs, the first orchestration module may perform any combination of the following tasks:hand over a mobile terminal associated with the selected RRU to another RRU of the cluster of RRUs;change a parameter associated with the mobile terminal in the BBU;send a command to the mobile terminal;send a deactivation command to the selected RRU;inform the selected RRU that it is associated with the second BBU; orset synchronization parameters in the selected RRU that are compatible with the second BBU. In some embodiments, the first orchestration module262A may determine that the loading of the first BBU260A is too high and through coordination with the second orchestration module262B, that the loading on the second BBU260B is such that it is unable to accept any additional load. The orchestration module262A may then determine to instantiate a third BBU260C to handle some of the load. In some embodiments, a new virtual machine206C may be created on a server204B already assigned to the RAN200, on a newly assigned server, or through a public cloud computing server. Once the new virtual machine206C is created, the software that implements the third BBU260C can be started, including its third orchestration module262C and third networking module264C. The first orchestration module262A can then coordinate with the third orchestration module262C to migrate some of the load from the first BBU260A to the newly instantiated third BBU260C. This migration may include moving one or more RRUs, such as the third RRU230C from the first cluster of RRUs associated with the first BBU260A, to a third cluster of RRUs associated with the third BBU260C. It also may include transferring communication with one or more mobile terminals, such as the third mobile terminal210C from the first RRU230A to the third RRU230C which is now associated with the third BBU260C. The ability to dynamically manage the number of BBUs allows for easy and automatic RAN configuration. The ready availability of computing resources through public cloud services, such as Amazon AWS, means that the RAN can be created with minimal capital investment, as the RRUs are relatively inexpensive and the existing interne infrastructure can be used for both the fronthaul and backhaul, which also reduces the capital expenditure required to deploy a RAN. InFIG.2andFIG.3, as well as other figures of this disclosure, arrows connecting different building blocks may represent physical media (e.g., an optical fiber or twisted pair copper wires) or logical data and/or control pipes (e.g., based on the internet protocol). Such logical connections may be conveyed over a shared or dedicated physical medium. In addition, blocks required for correct network functionality (e.g., routers, switches, gateways, and the like) may be present, although they are not explicitly represented in the figures of the present disclosure. FIG.3is a block diagram of an alternative embodiment of a distributed RAN300. The RAN300utilizes an adaptive fronthaul link protocol to allow communication between a BBU and a RRU to occur through a network such as the network345. This adaptive fronthaul link protocol is described in more detail in published international patent application WO 2016/145371 A2, entitled DISTRIBUTED RADIO ACCESS NETWORK WITH ADAPTIVE FRONTHAUL and published on Sep. 15, 2016. The RAN300includes multiple BBUs360A-B in a data center310that are coupled to multiple RRUs330A-B,336,338through the network345. The network345may include any configuration of networks, including portions that traverse the internet, although in some embodiments, local networks may be formed between certain BBUs and certain RRUs. Each RRU330A-B,336,338is coupled to an antenna331A-C to communicate with wireless terminals, or user equipment (UE),310A-E. The BBUs360A-B in the data center310may be coupled to a core network399, such as an EPC of an E-UTRAN through the network345or through a private network. In some embodiments, the distributed RAN300may sometimes be referred to as a Cloud-RAN300. The RAN300is a radio frequency communication system to facilitate communication between a plurality of mobile terminals310A-E and a core network399. The RAN300includes a group of remote radio units (RRUs)330A-B,336,338, each RRU of the group of RRUs coupled to an antenna331A-C to communicate with at least some of the plurality of mobile terminals310A-E and including electronic circuitry to perform at least a first portion of a first-level protocol of a radio access network (RAN)300and communicate over a fronthaul link, which in this embodiment includes the network345. The RAN300also includes a baseband unit (BBU), such as BBU361, coupled to the core network399and the fronthaul link. In the embodiment shown, the network345provides the coupling to the core network399and the fronthaul link for the BBU361. The BBU361is communicably coupled to the group of RRUs330A-B,336,338over the fronthaul link, at least in part in this example, through an internet protocol (IP) based network used for internet communication. In some embodiments, the fronthaul link includes a network compatible with an IEEE 802 standard, such as a wireless network compliant with an IEEE 802.11 standard or an IEEE 802.16 standard. The BBU361includes electronic circuitry to assign one or more RRUs selected from the group of RRUs330A-B,336,338, to a cluster of RRUs based on one or more parameters, and to perform at least a second-level protocol of the RAN300. The BBU361may include custom hardware, such as application-specific integrated circuits to implement various aspects of BBU functionality, such as a second portion of the first-level protocol of the RAN300. In some embodiments, the electronic circuitry of the BBU361includes a processor with memory to store executable code, with at least some of the functionality of the BBU361implemented as instructions of a computer program. The electronic circuitry of the BBU361and/or the orchestration module350may perform a variety of functions, including, but not limited to, assigning the one or more RRUs330A-B,336,338to the cluster of RRUs dynamically, assigning one or more other RRUs330A-B,336,338of the group of RRUs to a second cluster of RRUs, set a transmission power of the cluster of RRUs based on the one or more parameters, or set a radio frequency used by the cluster of RRUs to communicate with mobile terminals310A-E based on the one or more parameters. The one or more parameters can include synchronization states of the group of RRUs330A-B,336,338, a fronthaul link quality parameter, geographic locations of the group of RRUs330A-B,336,338, geographic locations of mobile terminals310A-E in active communication with the group of RRUs330A-B,336,338, geographic service areas of BBUs360A-B,361, or other parameters. In at least one embodiment, the geographic locations of the group of RRUs330A-B,336,338include a building floor and the orchestration module350or the electronic circuitry of the BBU361may assign the one or more RRUs330A-B,336,338to the cluster of RRUs based on the one or more RRUs330A-B,336,338having a common building floor location. In some embodiments, the group of RRUs330A-B,336,338are mobile and the orchestration module350or the electronic circuitry of the BBU361dynamically assign the one or more RRUs330A-B,336,338to the cluster of RRUs based on current locations of the group of RRUs330A-B,336,338and the geographic service area of the BBU361. The RAN300may also include multiple other components, including a data center310housing additional BBUs360A-B and an orchestration unit350. The additional BBUs360A-B and orchestration unit350may be instantiated on one or more servers and may include software running on a processor of one or more servers. A server380is also coupled to the network and may be used to instantiate additional BBUs. A virtual machine may be provisioned on the server380and a software program to implement a BBU may then be started within that virtual machine. A client computer381may be used for a management console. The client computer381may run a RAN management program that couples to the various components of the RAN300through the network345and allows a RAN administrator to manage various aspects of the RAN300. Any number of mobile terminals310A-E may be in active communication with one or more RRUs330A-B,336,338to access the core network399, through one or more BBUs360A-B,361. The RAN300also includes a compound RRU335that includes a single interface circuit coupled to the fronthaul link, a first logical RRU336coupled to the single interface circuit, and a second logical RRU338coupled to the single interface circuit. The first logical RRU336and the second logical RRU338are both included as RRUs in the group of RRUs. A BBU may not be able to tell that a logical RRU is not a stand-alone RRU and can treat the stand-alone RRU330A and the logical RRU336as equivalent devices. The logical RRUs336,338within the compound RRU335, while co-located, can be treated as independent RRUs and set up with different parameters and assigned to the same or different clusters. So as an example, in addition to the cluster of RRUs associated with the BBU361, a second cluster of RRUs may be assigned from the group of RRUs330A-B,336,338and associated with the BBU360A which is also coupled to the fronthaul link. Each RRU of the second cluster of RRUs is included in the group of RRUs330A-B,336,338and is coupled to the fronthaul link. In this example, the first logical RRU336may be included in the cluster of RRUs associated with the BBU361and the second logical RRU338may be included in the second cluster of RRUs associated with the BBU360A. The two different BBUs361,360A may manage their respective logical RRU336,338separately. In fact, the two BBUs361,360A may be operated by two different carriers using different carrier frequencies and different RAN parameters. As was mentioned above, the electronic circuitry of the BBU361can assign one or more RRUs to a cluster or RRUs that is associated with the BBU361. In some embodiments, however, the orchestration module350may do the assigning of RRUs to clusters of RRUs instead of the assigning being done directly by the BBU361. But independent of which element performed the initial assignment, in an example, the first logical RRU336is assigned to a cluster of RRUs associated with the BBU361, along with several other RRUs that are not shown, and the first RRU330A and second logical RRU338are assigned to a second cluster of RRUs associated with the BBU360A. The electronic circuitry of the BBU361may configure its cluster of RRUs, including the first logical RRU336, to appear as a single base station to a mobile terminal310E. The electronic circuitry of the BBU360A may configure the first RRU330A to transmit data that is different than data transmitted by the second logical RRU338of the second cluster of RRUs during at least some time periods. The electronic circuitry of the BBU360A may also configure the first RRU330A of the second cluster of RRUs to communicate with a second mobile terminal310B and configure the second logical RRU338of the second cluster of RRUs to communicate with a third mobile terminal310C based on geographic locations of the first RRU330A, the second logical RRU338, the second mobile terminal310B, and the third mobile terminal310C. The electronic circuitry of the BBU360A may alternatively configure the first RRU330A of the second cluster of RRUs to communicate with a second mobile terminal310B and configure the second logical RRU338of the second cluster of RRUs to communicate with a third mobile terminal310C based on radio measurements performed by the second cluster of RRUs, the second mobile terminal310B, and the third mobile terminal310C. In some embodiments, the electronic circuitry of the BBU361may configure a second RRU330B of the cluster of RRUs to only transmit to a fourth mobile terminal310D, and configure another RRU of the cluster of RRUs to only receive from the fourth mobile terminal310D. The electronic circuitry of the BBU360A may determine that a first RRU330A of the cluster of RRUs has failed, and hand over the second mobile terminal310B associated with the first RRU330A to the second logical RRU338of the second cluster of RRUs. Alternatively the BBU360A could, in response to determining that the first RRU330A has failed, move the second mobile terminal310B associated with the first RRU330A to a second RRU330B, the second RRU330B associated with a third cluster of RRUs associated with the BBU360B. The electronic circuitry of the BBU361, or the orchestration module350, may coordinate RAN parameters between the BBU361and the second BBU360A. The electronic circuitry of the BBU361, or the orchestration module350, may also coordinate moving a selected RRU, from the first cluster of RRUs to the second cluster of RRUs. As a part of this coordination, the electronic circuitry of the BBU361, or the orchestration module350, may perform any combination of:hand over a mobile terminal310B associated with the selected RRU to another RRU of the cluster of RRUs;change a parameter associated with the mobile terminal in the BBU;send a command to the mobile terminal;send a deactivation command to the selected RRU;inform the selected RRU that it is associated with the second BBU360A; orset synchronization parameters in the selected RRU that are compatible with the second BBU360A. The orchestration module350, or the electronic circuitry of the BBU361, may determine that a predetermined capacity threshold of the BBU361has been exceeded and change a parameter in the cluster of RRUs, or a mobile device310E in communication with the cluster of RRUs, in response to the determination that the predetermined capacity threshold of the BBU361has been exceeded. As a part of the change of the parameter, the BBU may perform one or more of:a handover of the mobile terminal310E to another BBU;a reduction in a throughput for the mobile terminal310E;a reduction in a resource block allocation;a change in a modulation and coding scheme for the cluster of RRUs;a suspension of unicast uplink scheduling in the cluster of RRUs for one or more scheduling intervals; ora suspension of unicast downlink scheduling in the cluster of RRUs for one or more scheduling intervals. If a centralized orchestration module350is used, when a new RRU becomes available for use, it connects and advertises itself to the orchestration module350. A negotiation process is carried out between the new RRU and the orchestration module350. The negotiation may include any combination of information about new RRU location and capabilities, radio measurements, synchronization information and command, network listening commands and results, logs and status of the new RRU, logs and status of the orchestration module350, logs and status of one or more BBU instances, or other parameters. After completion of the negotiation, also known as handshake, the orchestration module350may redirect the new RRU to either an existing BBU, or a newly created BBU instance. This redirection, or assignment, may be performed by sending an identifier of the BBU instance, such as an IP address, to the new RRU along with a special redirection command. The redirection command may include additional commands and information, such as synchronization and measurements commands. The receiving BBU instance may also be informed about the incoming RRU. Alternatively, rather than being redirected to a BBU instance, the new RRU may be rejected. The new RRU may then sleep for a predefined amount of time, or for an amount of time decided by the orchestration module350, or until a certain event occurs, before trying to reconnect to the orchestration module350. The orchestration module350also may at any time (e.g. when a new RRU connects to the system) decide to migrate an existing RRU from a first BBU instance to a second BBU instance (existing, or to be created on the fly). The decision on which BBU instance to redirect the new RRU, or whether to reject the new RRU, may be based on any combination of a number of RRUs associated to each running BBU instance, system load and memory usage of each running BBU instance, available resources (e.g. computational capacity, volatile memory, storage, network, and the like) of each virtual machine, a network load of each running BBU instance, a fronthaul state, characteristics of running BBU instances, synchronization information, radio measurements reported by the new RRU, or other parameters. If known, information on the topology of the fronthaul network connecting BBUs and RRUs may be used to make decisions on what BBUs to associate to what RRUs. In some embodiments, variations of the fronthaul topology (or estimates thereof) may be tracked over time based on information provided by RaaS-FIP or other fronthaul transport protocols. BBU instances may report information to the orchestration module350, or exchange information with other BBU instances. Such information may be time-driven information (e.g. periodically-reported information) or event-driven information. Events that may trigger such information to be reported may include system overloading (in terms of computational resources, memory, radio throughput, fronthaul throughput, number of RRUs, number of users, and the like), synchronization events, RRU faults, or other events. Information may include a system load (in terms of computational resources, memory, radio throughput, fronthaul throughput, number of RRUs, number of users, and the like), fronthaul state and statistics, radio measurements, or the like. Occasionally a mobile terminal may have to be handed over from a first cluster of RRUs (associated to a first BBU instance) to a second cluster of RRUs (associated to a second BBU instance). The decision on whether to perform a handover may be taken by the first BBU instance and may be assisted by the orchestration module350. In some embodiments, the orchestration module350may use information from the first BBU instance and at least one other active BBU instance to decide whether to perform the handover, and to decide the identity of the second BBU instance. RRUs may be dynamically configured by their controlling BBU instance, with the possible assistance of the BBU stack or a separate orchestration module, by sending special configuration commands to the RRUs over fronthaul link using the RaaS-FIP protocol. The configuration commands may include, but are not limited to, a synchronization command, a power control command, a network listening command, a poweroff command, a frequency retuning command, or other RaaS-RIP commands. In one non-limiting example that may be referred to as “cell breathing,” the controlling BBU may send a poweroff command to a RRU when a certain condition is detected. For example, in low RAN traffic conditions, the controlling BBU may decide to save resources by turning off one RRU. In another example of “cell breathing,” the controlling BBU may send a “reduce transmit power” command to a RRU located in the proximity of another RRU that recently turned on, or increased its transmit power. In another example of “cell breathing,” the controlling BBU may send an “increase transmit power” command to a RRU located in the proximity another RRU that recently turned off, or decreased its transmit power. A logical communication channel (e.g., a network connection) may be established between the orchestration module350and running BBU instances, as well as among BBU instances. That communication channel may be used for coordination among BBU instances and between the orchestration module350and the BBU instances. Information transferred over the control channel may include BBU instance status and logs, error codes, system load, and the like. A BBU instance may dynamically command an associated RRU to perform a frequency retuning, transmit power adaptation, temporary shutoff of one or more of the available transceivers, a network listening, a geographical location evaluation, an entry or exit of a power-saving “sleep” mode of operation, or the like. The command may be delivered via a control plane of the RaaS-FIP protocol, and reception of the command may be acknowledged by the RRU. Decisions on whether to send the command may be taken by the BBU in cooperation with other BBU instances, the orchestration module350, or a combination thereof. In another embodiment, all the orchestration features described so far can be performed in a distributed way among the running BBU instances. In such embodiments, a centralized orchestration module350may be absent, and orchestration modules may be present in one or more of the running BBU instances as shown inFIG.2. In such embodiments, a RRU boots up and connects to a BBU instance to perform an handshake. The BBU instance may be chosen at random, or according to history, radio measurements, geographical location, or other parameters. The choice of the BBU instance may be performed independently by the RRU or by a specialized module that provides identifiers (e.g., IP addresses) of one or more active BBU instances. During or after the handshake process, the RRU may be assigned by the BBU instance to its cluster or RRUs, or may be migrated to a different BBU instance, either an existing BBU instance or a new BBU instantiated on-the-fly. The migration may be coordinated by the first BBU instance. In another embodiment, if the RRU is rejected by the first BBU instance, the RRU may try a connection to a second BBU instance, and may sequentially try all known BBU instances until it is added to a cluster of RRUs by a BBU instance or until all the known BBU instances have been visited. In the latter case, the RRU may refrain from reconnecting for a predefined amount of time, or until a certain event occurs. The list of identifiers (e.g., IP addresses) of the BBU instances may be provided to the RRU via a name server, a suitable software module devoted to this purpose, or may be hardcoded into the RRU firmware. A RRU may be handed over from a first BBU instance to a second BBU instance for various reasons. The migration may involve any combination of the following actions:handing over some of the mobile terminals associated to the cell corresponding to the first BBU instance to different cells;changing parameters associated to a the mobile terminal associated to the cell corresponding to the first BBU instance;sending commands (e.g., power control, carrier activation/deactivation, and the like) the mobile terminal in active communication with a cluster of RRUs associated with the first BBU instance;sending a deactivation command to the RRU;informing the RRU of the new BBU instance to associate to; andinforming the RRU of the synchronization parameters for the next BBU instance to associate to. Occasionally a RRU may be turned off by the network. A similar combination of steps as described above may take place in this case, except that the RRU may not reconnect to a second BBU instance right away, but may sleep for a pre-defined amount of time, or until a certain event occurs. Multiple orchestration modules may be running concurrently on different nodes. In embodiments, the tasks performed by the orchestration module may be spread among the modules (for load balancing). In case of a fault in one of the BBU instances causing the BBU to stop working properly, the orchestration module350or orchestration modules of other BBUs may recognize the problem and may migrate the RRUs associated with the failed BBU instance to different BBU instances. In case of a RRU failure, the BBU instance controlling the RRU may recognize the failure and may instruct the mobile terminals associated to the RRU to perform a handover, carrier activation/deactivation, power control, random access, RRC connection reestablishment or reconfiguration, or the like. In some cases, a single RRU may be in communication with multiple BBUs. This may be referred to as multi-homing. In one embodiment, a primary BBU instance may be configured to control the RRU, and at least another BBU instance may interact with the RRU for other interaction, such as for retrieving information (e.g. radio measurements, synchronization information, and the like). The other BBU instance may not have full control of the RaaS-FIP data plane for communicating with the RRU. In another embodiment, the two BBU instances may not be coordinated and the RRU may be independently controlled by multiple BBU instances. In another embodiment, the two BBU instances may have some form of slow-scale coordination (either via direct connections, or through a centralized operator-agnostic controller) allowing them to effectively hand the RRU back and forth between the two BBUs. In another implementation, a single carrier frequency may be controlled by multiple BBU instances. The RRU may multiplex/demultiplex data transmission and reception according to the RaaS-FIP protocol links open toward each of the BBU instances. FIG.4is a detailed block diagram of an embodiment of a distributed RAN400. The RAN400includes a remote radio unit (RRU)430coupled to an antenna411, and a baseband unit (BBU)460coupled to the core network499. A fronthaul link445is coupled to the BBU460, through interface circuitry464,466, and the RRU430. The fronthaul link445utilizes an adaptive fronthaul protocol for communication between the BBU460and the RRU430. The RRU430includes electronic circuitry410to perform at least a first portion of a first-level protocol of a radio access network (RAN)400for communicating between the wireless terminal401and the core network499. The BBU460includes a networking module that includes electronic circuitry to perform at least a second-level protocol of the RAN400in the lower level protocol processing block470. The RAN400provides the wireless terminal401with access to the core network499through an RF signal sent between the antenna402of the wireless terminal401and the antenna411of the RRU430. The BBU460may be coupled to the core network499through a computing system that provides higher level protocol processing480, or in some cases, the higher level protocol processing480may be included in the BBU460. In embodiments, the electronic circuitry410of the RRU430includes receiver circuitry, shown as transceiver circuitry412, to receive a radio frequency signal from the antenna411and convert the received radio frequency signal to digital baseband samples. The transceiver circuitry412may include sub-circuits, such as conversion circuitry and/or RF circuitry. The electronic circuitry410also includes adaptive compression circuitry426to adaptively compress the digital baseband samples into fronthaul uplink information based on information received from the BBU460over the fronthaul link445, and interface circuitry436to send the fronthaul uplink information to the BBU460over the fronthaul link445using the adaptive fronthaul protocol. In some systems the adaptive compression performed by the adaptive compression circuitry426is lossy. The BBU460may include an uplink adaptive decompression block446as a part of the networking module to decompress the uplink data received from the RRU430. The BBU460may be configured to send frequency-domain information over the fronthaul link445to the RRU430. The frequency-domain information may include a tonemap descriptor describing a set of tones to be used by the RRU430to generate a radio frequency signal for transmission to the wireless terminal401, and data identifying modulation symbols for tones of the set of tones, and times associated with the modulation symbols. This representation of the frequency-domain information is a form of adaptive compression performed by the downlink adaptive compression block444, which is also a part of the networking module in this embodiment. In systems, the RRU430receives data from the BBU460over the fronthaul link445using the interface circuitry434. The electronic circuitry410of the RRU430may include downlink adaptive decompression circuitry424that has expansion circuitry to generate complex frequency-domain samples based on the data identifying the modulation symbols for the tones, and inverse Fourier transform circuitry to create complex time-domain baseband samples from the complex frequency-domain samples. The electronic circuitry410may also include transmitter circuitry, shown as transceiver circuitry412, to convert the complex time-domain baseband samples into a radio frequency signal to send to the wireless terminal through the antenna411at the times associated with the modulation symbols. In various embodiments, the RRU430may include a buffer433to hold irregularly received downlink data from the fronthaul link445to enable a constant stream of information to be provided for a radio frequency signal sent to the wireless terminal401. A size of the buffer433may be adapted based on a fronthaul quality indicator or information received from the BBU460. The RRU430may include a buffer437to hold irregularly sent uplink data for the fronthaul link445to enable a constant stream of information to be received from a radio frequency signal sent by the wireless terminal. A size of the buffer437may be adapted based on a fronthaul quality indicator or information received from the BBU460. The BBU460may also include an uplink buffer467and/or a downlink buffer463. In some systems, the BBU460can determine an indicator of fronthaul link quality, and dynamically change one or more parameters of the RAN400based on the indicator. The indicator of fronthaul link quality may be determined based, at least in part, on information received by the BBU460from the RRU430. The information received by the BBU460from the RRU430may include RRU buffer status information, RRU buffer overrun indications, RRU buffer underrun indications, information about a received radio frequency signal, or any combination thereof. In some systems the indicator of fronthaul link quality is determined based, at least in part, on a latency of the fronthaul link445, a bandwidth of the fronthaul link445, errors on the fronthaul link445, undelivered packets on the fronthaul link445, out-of-order packets on the fronthaul link445, BBU buffer overruns, BBU buffer underruns, or any combination thereof. The one or more parameters of the RAN400may include frequency-domain allocation size, modulation and coding schemes, number of users, number of grants, pattern of usable subframe, anticipation of scheduling with respect to a time index it refers to, or any combination thereof. In at least one embodiment, the indicator of fronthaul link quality includes a latency of the fronthaul link, and the one or more parameters of the RAN include a ra-ResponseWindowSize parameter in a MAC protocol of an E-UTRA network. The BBU460also may include an orchestration module450, although in some embodiments, the orchestration module is separate from the BBU460. The orchestration module may include any combination of electronic circuitry and computer instructions to be executed by the electronic circuitry. In some embodiments, the orchestration module may be built using application-specific integrated circuits to provide most, if not all, of the functionality of the orchestration module450. In other embodiments, the orchestration module450may be a software program running on a standard computer. Other embodiments may have a mix of special-purpose circuitry and software running on a processor. The orchestration module450may assign RRUs to clusters. The RRUs belonging to a single cluster of RRUs are controlled by the same BBU, thus allowing for tighter coordination. So as an example, the RRU430may be included with other RRUs in a cluster that is controlled by the BBU460. Examples of how a cluster of RRUs can be coordinated include, but are not limited to, a joint scheduling, beamforming, joint reception and/or decoding, interference coordination and management via resource partitioning. In some cases, RRUs belonging to the same cluster may be seen by the mobile terminal as a single base station, thus eliminating the need for handovers when the terminal crosses RRU boundaries. The orchestration module450may also assign a RRU to a cluster of RRUs based on geographical metrics (e.g., RRUs in the same floor of a building), or radio metrics (e.g., RRUs whose transmit signal interfere on each other). Moving RRUs in or out of a cluster may be done dynamically, based on measurements that detect changes in the relevant metrics (geographical, or radio, or the like). In some embodiments, the orchestration module450is aware of the position, or the approximate position, of the mobile terminal401and may decide to cluster together RRUs that are close to the mobile terminal401, where close may be in terms of geographical metrics, radio metrics, or other parameters. The cluster selections may be updated in reaction to a mobile terminal moving from one location to another. The orchestration module450may also coordinate RRUs belonging to different clusters, but the type of coordination (e.g., its time scale) may be different than coordination among RRUs of the same cluster. For example, slow-scale resource partitioning may be deployed across different clusters as a form of interference management. The partitioning of the available RRUs into clusters also may be based on, but not limited to, a number of active mobile terminals, fronthaul quality (e.g., measured or estimated throughput and latency between the BBU and each RRU), radio measurements performed by the RRUs, radio measurements performed by the mobile terminals and reported to the network, synchronization state (e.g., whether a certain RRU is time/frequency/phase synchronized with the remaining RRUs, and to which extent). The partitioning may dynamically change based on new RRUs entering the network, RRUs going offline, mobile terminals moving within the coverage area of the RaaS deployment, changes in fronthaul quality, and the like. The orchestration module450may also set a variety of parameters in the cluster of RRUs. For example, transmission power of a RRU may be decided by the associated BBU based on the same set of parameters used to determine clusters. In some cases a RRU may be turned off to save fronthaul and computational resources based on the same set of parameters used to determine clusters. Different RRUs may all work on the same carrier frequency, or may be assigned different carrier frequencies by the BBU, based on the same set of parameters used to determine clusters. Frequencies may belong to licensed or unlicensed spectrum. In the latter case, RRUs may be instructed by the BBU to perform measurements and sensing such as the listen-before-talk. In a heterogeneous network deployment, where RRUs have lower power signals and an existing macro network of higher-power cells is available, RRUs may use the same frequency as the underlying macro cell or different frequencies. In either case the RRUs may be time and/or phase and/or frequency synchronized with the underlying macro network, and may perform coordination techniques with the underlying macro network under control of the BBU. In one implementation, the RRUs may be configured in a carrier-aggregation system with the underlying macro network. The orchestration module450may perform scheduling for a portion of the RAN400. Uplink (UL) scheduling, performed at the BBU460, may include, but is not limited to, one or more of the selection of mobile terminals, resource block (RB) allocations, modulation coding scheme (MCS), RRUs to include in the cluster of RRUs (e.g. reception points), compression scheme, and resources assigned to the RRUs, such as time-frequency resources, receive antennas, and quantization level. The UL scheduling is performed on a specific time interval known as transmission time interval (TTI). Besides the traditional metrics used to perform the scheduling (e.g., pending data for each terminal, channel qualities, and the like), scheduling in a distributed RAN may be also be based on a fronthaul quality (e.g., measured or estimated fronthaul throughput and latency) for each candidate RRU, a fronthaul state (e.g., size of the fronthaul queues at either the BBU side or RRU side), a synchronization state (e.g., whether the RRU is frequency/phase/time synchronized, and to which extent), a BBU load (e.g., in terms of queued workers, jobs, threads, and the like), or other parameters. Demodulation of uplink signals for a co-scheduled user can be performed by multiple RRUs, by requiring the one or more RRUs to report waveforms, receive signals, or perform other tasks corresponding to the uplink signals. Selection of which RRUs to use as reception points of a certain uplink signal may be based on knowledge of the position, or the approximate position, of the mobile terminal that transmits that signal. In one implementation, the position of a mobile terminal may be estimated and tracked over time. As an example, the BBU may detect whether or not a RRU is close to a certain mobile terminal based on the quality of the reception of the signal transmitted by the mobile terminal, where quality may be signal power, signal-to-noise ratio, or other radio measurement. Similarly, downlink signal metrics may be used for position estimation and tracking. At least one RRU of the cluster of RRUs may use different compression schemes, set of resources, subset of antennas, or be otherwise configured, than another RRU of the cluster of RRUs. The configuration of the RRUs may depend on the required channel quality, target decoding performance, radio measurements, fronthaul qualities and states, and the like. If multiple mobile terminals are scheduled with at least partially overlapping resources, a joint or iterative demodulation or decoding scheme may be used. Periodicity and other parameters (e.g., resources, codes, etc.) related to control signals such as PUCCH, SRS, or the like, may be based at least in part on a fronthaul quality (e.g., measured or estimated fronthaul throughput and latency) for each candidate reception point, fronthaul state, synchronization state, or the like. The orchestration module450may also be used for downlink (DL) scheduling. Downlink scheduling may include the selection of mobile terminals, RB allocations, MCS, RRUs to include in the cluster of RRUs (e.g. transmission points), compression scheme, beamforming, and resources assigned to the RRUs, such as time-frequency resources, and transmission antennas. The DL scheduling is performed on the TTI. Different RRUs may be instructed to transmit the same signal. This may be accomplished using a broadcast or multicast signaling method over the fronthaul (e.g. an Ethernet broadcast packet) to convey the same signal to the at least two RRUs. In another implementation, different RRUs may be instructed to transmit different signals. The transmitted signals may convey different data streams, the same data streams but with different beamforming, a different but partially overlapping set of data streams, or a combination thereof. Selection of which RRUs to use for transmission of a certain downlink signal may be based on knowledge of the position, or the approximate position, of the mobile terminal that receives that signal. In one implementation, the position of a mobile terminal may be estimated and tracked over time. Selection of users to serve, MCS, resources, beams, RRUs, transmission powers, and the like, may be based on a quality of synchronization of the connected RRUs, fronthaul quality a RRU, fronthaul state for a RRU, synchronization state of a RRU, load of a BBU (e.g., in terms of queued workers, jobs, threads, and the like), or the like. In one non-limiting example, a RRU might not be used for transmission while it is experiencing a higher fronthaul latency, or a lower fronthaul throughput, than other RRUs. Different DL signal categories may be transmitted by different RRUs. In example implementation, a set of RRUs within a cluster or RRUs may be used to transmit broadcast signals, such as the primary synchronization sequence (PSS), and a different set of RRUs within the cluster of RRUs may be used to transmit unicast signals, such as a PDSCH for a specific mobile terminal. This partitioning and assignment of signals and signal categories to RRUs may be based at least in part on a fronthaul quality. Different DL signal categories for the same TTI may be scheduled by the BBU at different times. As a non-limiting example, a broadcast signal may be scheduled in advance compared to another unicast signal. This advance period may be selected and possibly disabled based at least in part on a fronthaul quality. In some embodiments, the orchestration module450may utilize a single RRU for UL only or for DL only. In some embodiments, a particular RRU may be designed as a reception point only, and may not include transmission circuitry, or transmission circuitry may be present but not used. In some embodiments, a compound RRU may be formed from a RRU by allowing separate configuration of its DL and UL sections so that one logical RRU is DL only and one logical RRU is UL only. An UL only RRU can be recognized by the orchestration module450which will then use it only as a reception point. In some embodiments, a particular RRUs may be designed as a transmission point only, and may not include reception circuitry, or the reception circuitry may be present but not used or used to receive different signals, such as synchronization signals. In some embodiments, a compound RRU may be formed with the transmission circuitry being used for a transmission only logical RRU. Such DL RRUs can be recognized by the orchestration module450which will then use them only as transmission points. Transmission may occur on the same carrier frequency for all RRUs in a cluster of RRUs, or different RRUs of the cluster of RRUs may use different frequencies. Transmission may occur on the same carrier frequency as the underlying macro network, or on a different one, depending on the embodiment. The carrier frequency may be in unlicensed spectrum. Carrier aggregation may be used to aggregate carrier frequencies from different RRUs, and/or from a macro cell and a RRU. In some embodiments, one or more RRUs may be used as broadcast devices. This means that they may be time, frequency, and/or phase synchronized, and they may be instructed by the BBU to transmit the same data stream. This may be used for certain functionality defined by the LTE-Broadcast standard. RRUs involved in a broadcast transmission may be selected according to their location, radio measurements, synchronization state, or other parameters. The orchestration module450may also coordinate multiple BBUs. The BBUs being coordinated may be deployed on the same server or virtual machine, on different servers, on different virtual machines on the same server, or on different virtual machines on different servers. BBUs may be adaptively moved among different virtual machines with different resources based on a status of the BBUs, such as throughput, number of users, number of jobs and processes, and the like. BBUs allocated to the same virtual machine may share a software module (denoted as worker pool) that distributes and load balances workers, jobs, tasks, threads, or the like, among the BBUs, based on a BBU's load, length of queues, fronthaul latencies, fronthaul throughput, number of active users, and the like. If the worker pool gets overloaded, scheduling of the BBUs using the worker pool may be adapted accordingly, such as by performing a throughput reduction, a resource block (RB) allocation reduction, a modulation and coding scheme (MCS) reduction, and the like. In another embodiment, unicast scheduling (UL, DL, or both) may be suspended for one or more scheduling intervals in order to reduce the loading of the worker pool, whereas scheduling of broadcast signals may continue. Coordination in a cluster of RRUs, such as coordinated multi-point, joint scheduling, soft handovers, frequency selection, or the like, may be performed either by a centralized orchestration unit, an orchestration unit integrated into the BBU that controls the cluster of RRUs, or via direct coordination among the cluster of RRUs. In the latter case, a special RRU-to-RRU fronthaul protocol may take care of exchanging control and data information needed for coordination across the cluster of RRUs. The information may include waveform samples (possibly in compressed format) in time-domain, frequency-domain or other representation, radio measures, synchronization parameters, and the like. An orchestration layer running in the cloud, or one or more orchestration modules450integrated into a BBU460, or a combination thereof, may be responsible for deciding handovers, that is, changing the RRU servicing a mobile terminal. The decision on whether to perform a handover, and which RRU to hand the mobile terminal to, may be based on a fronthaul quality, a fronthaul state, synchronization state, load of the BBU460, or the like. System, network, and radio parameters such as number of carriers, bandwidth of each carrier, value of timers, periodicity of signals (such as reporting of radio measurements), thresholds, services offered, and the like, may be optimized and/or dynamically adapted by the orchestration module450. FIG.5is a block diagram of an embodiment of unmanned aircraft system (UAS)500carrying a remote radio unit (RRU)530. While a quadcopter UAS500is shown, other types of UASs can be used, including aircraft with hover capability and aircraft that must sustain forward motion to maintain altitude, such as many fixed-wing aircraft. The UAS500includes a wireless control link510to receive flight instructions from a ground-based system. The control link510can be any type of wireless communication channel, including, but not limited to, communication in an unlicensed spectrum band such as an industrial, scientific, and medical (ISM) radio band, communication in a licensed spectrum owned by the carrier deploying the UAS500, communication in an RF band designated by the FCC for radio control activities, communication in the L-band or C-band, communication using a proprietary protocol, communication using a protocol approved by the RTCA (formerly the Radio Technical Commission for Aeronautics), or communication over a wireless network compliant with a version of IEEE 802.11 or a version of IEEE 802.16. In some embodiments, the control link510may be implemented as a wireless terminal of the RAN with the flight instructions sent as data over the RAN to the control link. The UAS500also includes a control system520, coupled to the wireless control link510, to control the UAS500based on the flight instructions received through the wireless control link510. In some embodiments, the wireless control link510receives flight instructions providing real-time control instructions to the control system520from a ground-based system to control the flight of the UAS500. But in some embodiments, the flight instructions describe a hover position and the control system520autonomously navigates the UAS500to the hover position and autonomously maintains the UAS500in the hover position. In some embodiments, the flight instructions describe a flight path and the control system510autonomously navigates the UAS500to follow the flight path. The UAS500also includes a propulsion system, coupled to and under control of the control system520, to keep UAS500airborne and provide movement with at least three degrees of freedom. In the embodiment shown, the propulsion system includes the battery and motor506, and rotors504. Any type of propulsion system may be used, including propulsion systems using a battery, a solar cell, a chemical-based fuel, an electric motor, an internal combustion engine, a jet engine, a turbine, a propeller, a rotor, a wing, or a lighter-than-air component. Movement in up to six degrees of freedom, such as latitude, longitude, altitude, yaw, pitch and roll may be provided, although some systems may provide for movement in as few as three of those degrees of freedom. In other embodiments, three degrees of freedom may be defined for the movement, such as X, Y, and Z, or elevation, azimuth, and distance from origin. The UAS500includes a wireless fronthaul link545to communicate with a baseband unit (BBU) of a radio access network (RAN). The fronthaul link545may be any type of wireless communication channel, including, but not limited to, communication in an unlicensed spectrum band such as an industrial, scientific, and medical (ISM) radio band, communication in a licensed spectrum owned by the carrier deploying the UAS500, communication in the L-band or C-band, communication using a proprietary protocol, or communication over a wireless network compliant with a version of IEEE 802.11 or a version of IEEE 802.16. In some embodiments, the wireless control link510and the wireless fronthaul link545co-exist on a single wireless network, and in some cases the wireless control link510is embedded within the wireless fronthaul link545. The single wireless network used may be a wireless network compliant with a version of IEEE 802.11 or a version of IEEE 802.16. In some embodiments, a BBU includes the ground-based system which generates the flight instructions. A remote radio unit (RRU) is included in the UAS500and is coupled to the fronthaul link545. The RRU includes electronic circuitry to perform at least a first portion of a first-level protocol of a radio access network (RAN) and generate a radio frequency signal for communicating with a mobile terminal compatible with the RAN. The RRU facilitates communication between a BBU of the RAN and the mobile terminal. An antenna511is also included in the UAS500. The antenna511is coupled to the wireless control link, the wireless fronthaul link, and the electronic circuitry of the RRU530. In some embodiments, an antenna511is shared by the three wireless transceivers, but in other embodiments, multiple antennas511are used due to the different wireless transceivers using different radio frequencies. The UAS500may be included as a RRU in the RAN system shown inFIG.2,3or4, where the RRU530is a RRU of a cluster of RRUs. The electronic circuitry of the BBU of the RAN may send commands to the UAS500to dynamically position the cluster of RRUs based on the one or more parameters. In some embodiments, the RRU530may be a compound RRU as shown inFIG.6, with two or more logical RRUs that share the fronthaul link545. The UAS500with a compound RRU may communicate with multiple BBUs of the RAN. A compound RRU may be associated with multiple BBU instances that are associated with multiple carriers. The various logical RRUs of the compound RRU may have independent transceivers that can be tuned on different frequencies. The transceivers of the logical RRUs may be partitioned into groups, and each group may be controlled by a different BBU instance. Each BBU instance may have full control of the group, including sending configuration commands to carriers in the group, data transfers in both directions, and the like. The compound RRU may be a neutral-host device shared among multiple mobile network operators, with each mobile network operator able to control, via a BBU instance, a group of carriers within the RRU. FIG.6is a block diagram of compound RRU (CRRU)600. The CRRU600may be used with a plurality of baseband units (BBUs) in a distributed radio access network (RAN), although in some cases, more than one logical RRU of the CRRU600may be assigned to a single BBU. The CRRU600includes a single interface circuit640coupled to a fronthaul link645and adapted to communicate over the fronthaul link645using an adaptive fronthaul protocol. The fronthaul link645may be any sort of communication link, depending on the embodiment, but in at least some embodiments, the fronthaul link645is a network compatible with an IEEE 802 standard and the single interface circuit640includes only a single media access controller (MAC) address for use on the fronthaul link645. The CRRU600also includes radio frequency (RF) circuitry612A/B coupled to an antenna611A/B. A first logical RRU630A and a second logical RRU630B are also included in the CRRU600. A CRRU600may have any number of logical RRUs, depending on the embodiment. The first logical RRU630A is coupled to the single interface circuit640and the radio frequency circuitry612A/B. The first logical RRU630A includes first control registers to control operation of the first logical RRU630A. The second logical RRU630B is also coupled to the single interface circuit640and the radio frequency circuitry612A/B. The second logical RRU630B includes second control registers to control operation of the second logical RRU630B. The first logical RRU630A and the second logical RRU630B appear as independent RRUs to BBUs that communicate with them over the fronthaul link645. In some embodiments, the RF circuitry612A/B can be shared between the two logical RRUs630A,630B. In other embodiments, the RF circuitry612A/B includes a first RF circuit612A coupled to the first logical RRU630A and a first antenna611A, and a second RF circuit612B coupled to the second logical RRU630B and a second antenna611B. The first logical RRU630A includes first conversion circuitry637A and first transformation circuitry coupled to the first control registers, and the second logical RRU630B includes second conversion circuitry637B and second transformation circuitry coupled to the second control registers. The first and second logical RRUs630A/B may include identical elements as shown inFIG.6, or may each have different designs. A logical RRU may be implemented using a variety of circuitry, including application specific integrated circuits (ASICs), discrete logic, various memories, digital signal processors (DSPs) and/or general purpose processors (CPUs). While a design using a DSP and a CPU is shown inFIG.6, other designs are envisioned. Because the two logical RRUs630A/B are shown with the same logical blocks, they will be discussed together and any reference number that leaves off the letter suffix can be interpreted as referring to that block in either the first logical RRU630A or the second logical RRU630B. The transformation circuitry of a logical RRU630as shown inFIG.6includes a processing subsystem that may include a CPU631coupled a tangible computer memory632. The tangible computer memory632holds instructions633executable by CPU631, to perform action associated with the transformation circuitry. The CPU631may also execute instructions633to perform actions associated with the single fronthaul interface circuit640, and other action to control the RRU630. In some embodiments, the processing subsystem may include a DSP634for some of the tasks of the transformation circuitry. The DSP may be coupled to a tangible computer memory635. The tangible computer memory635holds instructions636executable by DSP634, to perform actions associated with the transformation circuitry, such as performing fast Fourier transform (FFT) and/or inverse fast Fourier transform (IFFT) operations. In other embodiments, the processing subsystem may include the DSP634and may not include the CPU631. In such embodiments, the DSP634may be able to provide control functionality or the control functionality may be provided by other circuitry. In other embodiments, the processing subsystem may include the CPU631and not include the DSP634. In such embodiments, the CPU631may be able to perform signal processing functions such as one or more of a FFT, IFFT, selection, quantization, adaptive compression, expansion, formatting, and the like. In some embodiments, dedicated circuitry may be provided for some of the signal processing functions so the CPU631can provide the overall control functionality. Other embodiments may have any number of processors of any type, depending on the embodiment. The first and second control registers may be respectively implemented in the first logical RRU630A and second logical RRU630B in many different ways, depending on the embodiment. In at least one embodiment, the first and second control registers may be implemented as separate hardware registers within the circuitry, or as registers or memory locations within the CPU631or DSP634. In other embodiments, the first and second control registers may be defined as particular memory locations within the memory632of the CPU631and/or particular memory locations within the memory635of the DSP634. The first logical RRU630A includes a first timebase synchronization circuit638A to synchronize the first logical RRU630A with a first timebase of the RAN, and the second logical RRU630B includes a second timebase synchronization circuit638B to synchronize the second logical RRU630B with a second timebase of the RAN, where the second timebase is not necessarily synchronized with the first timebase. The first timebase may be associated with a first BBU and the second timebase may be associated with a second BBU. The timebase synchronization circuit638may be controlled by respective control registers in the logical RRU630. So in some embodiments of the compound RRU600, adaptive compression circuitry is included for use by the adaptive fronthaul protocol for communication over the fronthaul link645. Such adaptive compression circuitry may also be included in a stand-alone RRU. The adaptive compression circuitry may utilize instructions636stored in the memory635, executable by the DSP634, to perform a Fourier transform to convert the digital baseband samples into frequency-domain information for a set of received tones, and a compression of the frequency-domain information by discarding information related to a tone of the set of received tones in the frequency-domain information to generate the fronthaul uplink information under control of the control circuitry. Control circuitry, which may include the DSP634, the CPU631, and/or other circuitry, is configured to identify the one tone based on the information received from the BBU and provide the tone to the DSP634. In some embodiments, the instructions636are executable by the DSP634to perform a Fourier transform to convert the digital baseband samples into frequency-domain information and generate the fronthaul uplink information based on the frequency-domain information at a quantization level that is dynamically controlled by the control circuitry. The control circuitry is configured to determine the quantization level based, at least in part, on the information received from the BBU, and dynamically provide the quantization level to the DSP634. Aspects of various embodiments are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus, systems, and computer program products according to various embodiments disclosed herein. It will be understood that various blocks of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. The flowchart and/or block diagrams in the figures help to illustrate the architecture, functionality, and operation of possible embodiments of systems, devices, methods, and computer program products of various embodiments. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems or circuitry that perform the specified functions or acts, or combinations of special purpose hardware, circuitry, and computer instructions. These computer program instructions, such as those used to implement any method described herein, may also be stored in a non-transitory computer-readable medium, such as a tangible computer memory, or tangible memory, that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. FIG.7shows a flowchart700for an embodiment of a method of facilitating communication701between a core network and a cluster of RRUs by a baseband unit (BBU) in a distributed RAN. The method includes assigning702one or more RRUs, selected from a group of RRUs communicably coupled to the BBU by a fronthaul link, to the cluster of RRUs based on one or more parameters. The method may further include assigning the one or more RRUs to the cluster of RRUs dynamically, based on the changing of the parameters. The one or more parameters can include a large number of measurements, settings, or other information related to the RAN system. In some embodiments, the one or more parameters include numbers of mobile terminals in active communication with the group of RRUs, radio measurements performed by the group of RRUs, radio measurements performed by the mobile terminals, geographic locations of the group of RRUs, geographic locations of mobile terminals in active communication with the group of RRUs, or any combination thereof. In some embodiments, the one or more parameters include synchronization states of the group of RRUs. And in some embodiments, the one or more parameters include a fronthaul link quality parameter. The fronthaul link quality parameter may be determined in various ways, including determining the fronthaul link quality parameter based on information received from the group of RRUs over the fronthaul link, where the information received from the group of RRUs may include RRU buffer status information, RRU buffer overrun indications, RRU buffer underrun indications, information about a received radio frequency signal, or any combination thereof. In some embodiments, the fronthaul link quality parameter is determined based on a latency of the fronthaul link, a bandwidth of the fronthaul link, errors on the fronthaul link, undelivered packets on the fronthaul link, out-of-order packets on the fronthaul link, buffer overruns, buffer underruns, or any combination thereof. The method may continue in some embodiments by assigning703one or more other RRUs of the group of RRUs to a second cluster of RRUs. This assignment may also be performed dynamically. The BBU may also configure704the cluster of RRUs. The configuration can include sending many different settings to the cluster of RRUs. In some embodiments, the configuring includes setting a transmission power of the cluster of RRUs based on the one or more parameters or setting a radio frequency used by the cluster of RRUs to communicate with mobile terminals based on the one or more parameters. The BBU may configure the cluster of RRUs to appear as a single base station to a mobile terminal or it may configure a first RRU of the cluster of RRUs to transmit data that is different than data transmitted by a second RRU of the cluster of RRUs during at least some time periods. As a part of the configuring, the BBU may configure a first RRU of the cluster of RRUs to communicate with a first mobile terminal and configure a second RRU of the cluster of RRUs to communicate with a second mobile terminal based on geographic locations of, or radio measurements performed by, the first RRU, the second RRU, the first mobile terminal, and the second mobile terminal. Embodiments may also configure a first RRU of the cluster of RRUs to only transmit to a mobile terminal, and configure a second RRU of the cluster of RRUs to only receive from the mobile terminal. As a part of dynamic configuring, the BBU may also determine that a first RRU of the cluster of RRUs has failed, and hand over a mobile terminal associated with the first RRU to a second RRU of the cluster of RRUs. In some embodiments, a BBU may determine that a predetermined capacity threshold of the BBU has been exceeded, and use this information in the configuration of the clusters of RRUs. In response to this determination, the BBU may change a parameter in the cluster of RRUs or a mobile device in communication with the cluster of RRUs. The changing of the parameter may be a part of one or more of the following:handing over of the mobile terminal to another BBU;reducing a throughput for the mobile terminal;reducing a resource block allocation;changing a modulation and coding scheme for the cluster of RRUs;suspending unicast uplink scheduling in the cluster of RRUs for one or more scheduling intervals; orsuspending unicast downlink scheduling in the cluster of RRUs for one or more scheduling intervals. The method may also include coordinating705with a second BBU. The coordination with the second BBU may take many forms. In one non-limiting example, the BBU may determine that a first RRU of the cluster of RRUs has failed, and the coordinating with the second BBU includes moving a mobile terminal associated with the first RRU to a second RRU. The second RRU in this case is associated with a second cluster of RRUs that is associated with the second BBU. In another non-limiting example, the BBU may coordinate with the second BBU by coordinating RAN parameters with the second BBU. In addition, the BBU may move a selected RRU from the cluster of RRUs to a second cluster of RRUs associated with the second BBU. Moving the selected RRU may include any combination of:handing over a mobile terminal associated with the selected RRU to another RRU of the cluster of RRUs;changing a parameter associated with the mobile terminal in the BBU;sending a command to the mobile terminal;sending a deactivation command to the selected RRU;informing the selected RRU that it is associated with the second BBU; orsetting synchronization parameters in the selected RRU that are compatible with the second BBU. Some systems where this method can be used may include a compound RRU as shown inFIG.6. The compound RRU can include a first logical RRU and a second logical RRU that share a fronthaul link interface. The first logical RRU acts as a first RRU and the second logical RRU acts as a second RRU. In such systems the method may include assigning the first RRU of the group of RRUs to the cluster of RRUs and not assigning the second RRU of the group of RRUs to the cluster of RRUs based on the one or more parameters, where the first RRU and the second RRU are both logical RRUs of the compound RRU. The method also includes performing706, by the BBU, at least a second-level protocol of the RAN. In some embodiments, the BBU may also perform a portion of a first-level protocol of the RAN. Various RAN architectures and protocols may be used, but in at least one embodiment, the RAN protocol utilizes an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), the core network includes an Evolved Packet Core (EPC), the first-level protocol includes an Evolved Universal Terrestrial Radio Access (E-UTRA) physical-layer (PHY) protocol, and the second-level protocol comprises an E-UTRA medium access control (MAC) protocol The method continues with communicating707over the fronthaul link with the cluster of RRUs. In some embodiments, the communicating over the fronthaul link with the cluster of RRUs is done using an adaptive fronthaul protocol. In some embodiments the RRUs are dynamically managed708based on location. In embodiments, the one or more parameters may include geographic locations of the group of RRUs or geographic locations of mobile terminals in active communication with the group of RRUs. The geographic locations may be directly reported using information derived from a global positioning system (GPS) circuit or other location finding mechanism, or may be estimated based on radio measurements from one or more RRUs and/or mobile terminals. In some embodiments the geographic locations of the group of RRUs include a building floor, and the assigning of the one or more RRUs is based on the one or more RRUs having a common building floor location. In some embodiments, the group of RRUs are mobile and the one or more parameters further include a geographic service area of the BBU. In such embodiments the assigning of the one or more RRUs may include dynamically assigning the one or more RRUs to the cluster of RRUs based on current locations of the group of RRUs and the geographic service area of the BBU. In some embodiments the group of RRUs are located on unmanned aircraft systems (UASs), and the method includes sending commands to the UAS to dynamically position the group of RRUs based on the one or more parameters. The dynamic positioning may be calculated to provide the widest possible coverage for the cluster of RRUs associated with the BBU, to manage a load of the BBU, to provide at least a predetermined minimum service level to the largest number of mobile terminals, or any other target. The dynamic positioning may include sending a hover location to a particular RRU of the cluster of RRUs, or a flight path to the particular RRU of the cluster of RRUs. The dynamic positioning may include sending a flight path to an unassigned RRU that is not in the cluster of RRUs and then adding the RRU to the cluster of RRUs. It may also include coordinating with a second BBU to transfer a second RRU from the second cluster to the cluster of RRUs associated with the BBU and then sending a flight path to the second RRU to position it within the cluster of RRUs. In some embodiments, various RRUs of the group of RRUs may be located on a ground-based or water-based vehicle. The method may continue709and may repeat any of the mentioned activities, depending on the embodiment. FIG.8shows a flowchart800for an embodiment of a method for managing801a distributed RAN. The method includes receiving information802from a remote radio unit (RRU) or baseband unit (BBU) and determining803, based on the information and one or more parameters, that the RRU should be assigned to a particular cluster of RRUs. The method also includes informing804a baseband unit (BBU) associated with the particular cluster of RRUs that the RRU has been assigned to the particular cluster of RRUs. This method may also be used when the one or more parameters indicate that a RRU assigned to the first BBU should be moved to a second BBU to migrate the RRU from the first BBU to the second BBU. In such a method, it may be decided, based on the information received from the first BBU, that the first BBU is not functioning properly. Based on that decision, a cluster of RRUs assigned to the first BBU may be migrated to other BBUs. The migration of the RRU from the first BBU to the second BBU may include any combination of:handing over a mobile terminal associated with the RRU to another RRU associated with the first BBU;changing a parameter associated with the mobile terminal in the first BBU;sending a command to the mobile terminal;sending a deactivation command to the RRU;informing the RRU that is it associated with the second BBU; orsetting synchronization parameters in the RRU compatible with the second BBU. In some embodiments, the determining that the RRU should be migrated includes deciding, based on the information received from the first BBU and information received from another existing BBU, whether to assign the RRU to the other existing BBU, using the other existing BBU as the second BBU in response to the decision, and migrating the RRU to the other existing BBU. In some embodiments, the information received from the first BBU and information received from the other existing BBUs indicates that the RRU has physically moved to an into a service area of the other existing BBU. In the method of the flowchart800, the one or more parameters used to determine that a RRU should be assigned to a particular cluster of RRUs may include numbers of mobile terminals in active communication with the RRU or the first or second BBU, radio measurements performed by the RRU or the first or second BBU, radio measurements performed by the mobile terminals, or any combination thereof. In some embodiments, the one or more parameters include synchronization states831of the RRU or the particular cluster of RRUs or the first or second BBU. The one or more parameters may, in some embodiments, include geographic locations832of the cluster of RRUs or geographic locations of mobile terminals in active communication with the cluster of RRUs. The one or more parameters may also include geographic service areas for the first BBU or the second BBU, and the information from the first BBU may include a geographic location of the RRU. In such embodiments, the method may also include dynamically assigning the RRU to the second BBU based on a movement of the RRU into the geographic service area of the second BBU. The geographic locations of the cluster of RRUs may include a building floor, and the method may further include assigning the RRU to the particular cluster of RRUs based on the RRU and the particular cluster of RRUs having a common building floor location. In some embodiments, a group of RRUs comprising the RRU and the particular cluster of RRUs are mobile and the method may further include dynamically assigning the RRU to the particular cluster of RRUs based on current locations of the RRU and the particular cluster of RRUs. In some embodiments, the one or more parameters include a fronthaul link quality parameter833for a fronthaul link associated with the RRU, the particular cluster of RRUs, or the first or second BBU. The fronthaul link quality parameter may be determined based on information received from the cluster of RRUs over the fronthaul link, such as buffer status information for the first BBU or the RRU, buffer overrun indications for the first BBU or RRU, buffer underrun indications for the first BBU or the RRU, information about a received radio frequency signal, a geographic location of the for the first BBU or the RRU, or any combination thereof. In some embodiments, the fronthaul link quality parameter is determined based on a latency of the fronthaul link, a bandwidth of the fronthaul link, errors on the fronthaul link, undelivered packets on the fronthaul link, out-of-order packets on the fronthaul link, buffer overruns, buffer underruns, or any combination thereof. Different actions may be taken depending on the current situation of the group of RRUs. In some cases the method may determine that the information received from the RRU indicates that the RRU is not currently assigned, and based on the one or more parameters, determine that the RRU should be assigned to an existing cluster of RRUs, where the existing cluster of RRUs is the particular cluster of RRUs. In other cases the method may determine that the information received from the RRU indicates that the RRU is not currently assigned, and based on the one or more parameters, determine that the RRU should be assigned to a new cluster of RRUs. To do this, the method may decide, based on the information received from the RRU and information received from an existing BBU, to assign the new cluster of RRUs to the existing BBU. Alternatively, the method may decide, based on the information received from the RRU and information received from one or more existing BBUs, to assign the new cluster of RRUs to a new BBU. To create a new BBU, the method may instantiate a new BBU on a virtual machine and assign the new BBU to be the BBU associated with the particular cluster of RRUs in response to the decision. In some cases, the method may instantiate the virtual machine as a new virtual machine in a data center before instantiating the new BBU on the virtual machine. In some cases the data center may be managed by a public cloud service, such as Amazon AWS, Google Compute Engine, or the like. In some embodiments, the method may also include determining that the information received from the RRU indicates that the RRU is currently assigned to a first BBU that is no longer appropriate, and deciding, based on the information received from the RRU and information received from an existing BBU, to assign the RRU to a cluster of RRUs currently associated with the existing BBU, and assigning the RRU to the cluster of RRUs associated with the existing BBU. Alternatively, the method may decide, based on the information received from the RRU and information received from an existing BBU, to assign the RRU to a cluster of RRUs associated with a new BBU. The new BBU may be instantiated on an existing virtual machine or a new virtual machine may be instantiated in a data center and the new BBU instantiated on the new virtual machine. In some cases the information received from the RRU indicates that the RRU has physically moved, which indicates that the first BBU is not appropriate for the RRU. This may be because the RRU has moved outside of a geographical service area for the first BBU or that the RRU is no longer able to communicate with the first BBU over the fronthaul link. If the RRU has moved into the service area of an existing BBU, the RRU may be moved to a cluster of RRUs associated with the existing BBU. If the RRU has moved outside of the service area of the existing BBUs, a new BBU may be instantiated. The method shown in the flowchart800may continue in some embodiments by using the information received from a baseband unit (BBU) to determine that a predetermined capacity threshold of the BBU has been exceeded805, which may also be referred to as determining that the BBU is overloaded. The method may then continue by changing a parameter in a cluster of RRUs806associated with the BBU or a mobile device in communication with the cluster of RRUs in response to the determination that the predetermined capacity threshold of the BBU has been exceeded. The changing of the parameter may be a part of performing one or more of:handing over of the mobile terminal to another BBU;reducing a throughput for the mobile terminal;reducing a resource block allocation;changing a modulation and coding scheme for the cluster of RRUs;suspending unicast uplink scheduling in the cluster of RRUs for one or more scheduling intervals; orsuspending unicast downlink scheduling in the cluster of RRUs for one or more scheduling intervals. The method may continue809by repeating one or more of the elements shown in the flowchart800. FIG.9shows a flowchart900for an embodiment of a method of using901a compound RRU (CRRU) in a distributed RAN. A compound RRU, such as that shown inFIG.6, is an apparatus that includes a single interface circuit coupled to a fronthaul link and adapted to communicate over the fronthaul link using an adaptive fronthaul protocol, and a radio frequency (RF) circuitry coupled to an antenna. The compound RRU also includes a first logical RRU and a second logical RRU, both of which are coupled to the single interface circuit and the radio frequency circuitry. The first logical RRU includes first control registers to control operation of the first logical RRU, and the second logical RRU includes second control registers to control operation of the second logical RRU. The method includes receiving a first command902from a first baseband unit (BBU) over a fronthaul link through the single interface circuit of the compound RRU, and continues with using information from the first command to set a first RAN parameter903to a first value in the first logical RRU of the compound RRU. The method also includes receiving a second command904from a second baseband unit (BBU) over the fronthaul link through the single interface circuit of the compound RRU and using information from the second command905to set the first RAN parameter to a second value in the second logical RRU of the compound RRU. The first RAN parameter can be any parameter that impacts a functionality of the RAN, but in at least one embodiment, the first RAN parameter is a carrier frequency to be used by the logical RRU. The method continues with facilitating communication906between the first BBU and a first mobile terminal through the first logical RRU, and facilitating communication907between the second BBU and a second mobile terminal through the second logical RRU. In some embodiments the method also includes synchronizing the first logical RRU to a first timebase of the RAN, and synchronizing the second logical RRU with a second timebase of the RAN, where the second timebase is not necissarily synchronized with the first timebase. The first timebase may be associated with a first cluster of RRUs, associated with a first BBU, that are configured to act as if they are a part of a first base station, and the second timebase may be associated with a second cluster of RRUs, associated with a second BBU, that are configured to act as if they are a part of a second base station. The method may continue909and may repeat any of the mentioned activities, depending on the embodiment. Going back to a general discussion of the disclosed technology, in some embodiments opportunities for monetization of the various elements of the RaaS may exist. A RaaS BBU may be deployed on a private data center, either on-premise or remote, or on a public cloud service such as the Amazon Web Services (AWS), Google Compute Engine, or the like. When deployed on a public cloud service, a virtual machine may be used to run the BBU software, or a new service may be offered by the cloud vendor specifically for running RaaS BBU instances. When deployed on a data center, virtual machine, or the like, not owned by the customer (e.g., a public cloud), billing for the customer may be based on:a flat daily, weekly, monthly, or yearly rate, based on a number of active BBUs, a number of active RRUs, features enabled, a standard version, bandwidth, throughput, or other performance metric, or the like;an actual usage of the BBU, e.g., in terms of number of BBUs and activity level, such as a processing resource usage, number of terminals, terminal activities (e.g., throughput) and time of activity, number and activity (time, load, power) of connected RRUs, features enabled, standard version, bandwidth, throughput, or other performance metric, or the like; A RaaS can be used as a means for testing mobile terminals or the evolved packet core (EPC) of an LTE or LTE-A RAN. The testing could be a conformance test, standard compliancy assessment, performance evaluation, and the like. In such as testing architecture, a RaaS BBU may be implemented in the cloud, and the RaaS-FIP protocol may be used to connect the BBU with a RRU at the customer's premise. In an alternative embodiment, the customer may be directly using the RaaS-FIP protocol interfaced with customer's own software, without the need for a dedicated hardware RRU. In another alternative embodiment for the testing of the EPC or one of the standardized interfaces, such as a S1AP interface, X2AP interface, or the like, at least one of those protocols may be used to connect the BBU in the cloud with the customer's premise. Billing of the customer may be based on an actual usage of the BBU, a number of BBUs, features enabled, standard version, bandwidth, throughput, or other performance metric, or the like. In some embodiments, billing may a flat amount, such as on a daily, monthly, or yearly basis. As will be appreciated by those of ordinary skill in the art, aspects of the various embodiments may be embodied as a system, device, method, or computer program product apparatus. Accordingly, elements of the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, or the like) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “server,” “circuit,” “module,” “client,” “computer,” “logic,” or “system.” Furthermore, aspects of the various embodiments may take the form of a computer program product embodied in one or more computer-readable medium(s) having computer program code stored thereon. Any combination of one or more computer-readable storage medium(s) may be utilized. A computer-readable storage medium may be embodied as, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or other like storage devices known to those of ordinary skill in the art, or any suitable combination of computer-readable storage mediums described herein. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain, or store a program and/or data for use by or in connection with an instruction execution system, apparatus, or device. Even if the data in the computer-readable storage medium requires action to maintain the storage of data, such as in a traditional semiconductor-based dynamic random access memory, the data storage in a computer-readable storage medium can be said to be non-transitory. A computer data transmission medium, such as a transmission line, a coaxial cable, a radio-frequency carrier, and the like, may also be said to store data, although any data storage in a data transmission medium can be said to be transitory. Nonetheless, a computer-readable storage medium, as the term is used herein, does not include a computer data transmission medium. Computer program code for carrying out operations for aspects of various embodiments may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer program code if loaded onto a computer, or other programmable apparatus, produces a computer implemented method. The instructions which execute on the computer or other programmable apparatus may provide the mechanism for implementing some or all of the functions/acts specified in the flowchart and/or block diagram block or blocks. In accordance with various implementations, the program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). The computer program code stored in/on (i.e. embodied therewith) the non-transitory computer-readable medium produces an article of manufacture. The computer program code, if executed by a processor causes physical changes in the electronic devices of the processor which change the physical flow of electrons through the devices. This alters the connections between devices which changes the functionality of the circuit. For example, if two transistors in a processor are wired to perform a multiplexing operation under control of the computer program code, if a first computer instruction is executed, electrons from a first source flow through the first transistor to a destination, but if a different computer instruction is executed, electrons from the first source are blocked from reaching the destination, but electrons from a second source are allowed to flow through the second transistor to the destination. So a processor programmed to perform a task is transformed from what the processor was before being programmed to perform that task, much like a physical plumbing system with different valves can be controlled to change the physical flow of a fluid. Examples of various embodiments are described below: An example radio frequency communication system to facilitate communication between a plurality of mobile terminals and a core network includes a group of remote radio units (RRUs), each RRU of the group of RRUs coupled to an antenna to communicate with at least some of the plurality of mobile terminals and comprising electronic circuitry to perform at least a first portion of a first-level protocol of a radio access network (RAN) and communicate over a fronthaul link, and a baseband unit (BBU) coupled to the core network and the fronthaul link and communicably coupled to the group of RRUs over the fronthaul link, the BBU comprising electronic circuitry to assign one or more RRUs selected from the group of RRUs, to a cluster of RRUs based on one or more parameters, and to perform at least a second-level protocol of the RAN. In the example system, the fronthaul link utilizing an adaptive fronthaul protocol for communication between the BBU and the cluster of RRUs. In some example systems the BBU further configured to perform a second portion of the first-level protocol. In some example systems the RAN protocol comprises an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), the core network comprising an Evolved Packet Core (EPC), the first-level protocol comprises an Evolved Universal Terrestrial Radio Access (E-UTRA) physical-layer (PHY) protocol, andthe second-level protocol comprises an E-UTRA medium access control (MAC) protocol. In some example systems the fronthaul link comprises an internet protocol (IP) based network. In some example systems the fronthaul link comprises a network compatible with an IEEE 802 standard. In some example systems the fronthaul link comprises a wireless network compliant with an IEEE 802.11 or an IEEE 802.16 standard. In some example systems the electronic circuitry of the BBU further assigns the one or more RRUs to the cluster of RRUs dynamically. In some example systems the electronic circuitry of the BBU further assigns one or more other RRUs of the group of RRUs to a second cluster of RRUs. In some example systems the electronic circuitry of the BBU to further set a transmission power of the cluster of RRUs based on the one or more parameters. In some example systems the electronic circuitry of the BBU to further set a radio frequency used by the cluster of RRUs to communicate with a mobile terminal of the plurality of mobile terminals based on the one or more parameters. In some example systems the electronic circuitry of the BBU further configures the cluster of RRUs to appear as a single base station to a mobile terminal of the plurality of mobile terminals. In some example systems a first RRU of the cluster of RRUs transmits data that is different than data transmitted by a second RRU of the cluster of RRUs during at least some time periods. In some example systems the electronic circuitry of the BBU further configures a first RRU of the cluster of RRUs to communicate with a first mobile terminal of the plurality of mobile terminals and configure a second RRU of the cluster of RRUs to communicate with a second mobile terminal of the plurality of mobile terminals based on geographic locations of the first RRU, the second RRU, the first mobile terminal, and the second mobile terminal. In some example systems the electronic circuitry of the BBU further configures a first RRU of the cluster of RRUs to communicate with a first mobile terminal of the plurality of mobile terminals and configure a second RRU of the cluster of RRUs to communicate with a second mobile terminal of the plurality of mobile terminals based on radio measurements performed by the cluster of RRUs, the first mobile terminal, or the second mobile terminal. In some example systems the electronic circuitry of the BBU further configures a first RRU of the cluster of RRUs to only transmit to a first mobile terminal of the plurality of mobile terminals, and configure a second RRU of the cluster of RRUs to only receive from the first mobile terminal. In some example systems, the electronic circuitry of the BBU further determines that a first RRU of the cluster of RRUs has failed, and hands over a mobile terminal of the plurality of mobile terminals associated with the first RRU to a second RRU of the cluster of RRUs. Some example systems also include a second cluster of RRUs, each RRU of the second cluster of RRUs coupled to the fronthaul link, and a second BBU, associated with the second cluster of RRUs and coupled to the fronthaul link, the second BBU comprising electronic circuitry to perform at least the second-level protocol of the RAN. In some example systems the electronic circuitry of the first BBU further coordinate a with the electronic circuitry of the second BBU. In some example systems the electronic circuitry of the BBU further determines that a first RRU of the cluster of RRUs has failed, and moves a mobile terminal of the plurality of mobile terminals associated with the first RRU to a second RRU, the second RRU associated with the second cluster of RRUs. In some example systems the electronic circuitry of the BBU further coordinates moving a selected RRU from the cluster of RRUs to the second cluster of RRUs. In some example systems the electronic circuitry of the BBU further performs any combination of handing over a mobile terminal of the plurality of mobile terminals associated with the selected RRU to another RRU of the cluster of RRUs, changing a parameter associated with the mobile terminal in the BBU, sending a command to the mobile terminal, sending a deactivation command to the selected RRU, informing the selected RRU that it is associated with the second BBU, or setting synchronization parameters in the selected RRU that are compatible with the second BBU. In some example systems the electronic circuitry of the BBU further coordinates RAN parameters with the second BBU. In some example systems the electronic circuitry of the BBU further determines that a predetermined capacity threshold of the BBU has been exceeded, and changes a parameter in the cluster of RRUs or a mobile device in communication with the cluster of RRUs in response to the determination that the predetermined capacity threshold of the BBU has been exceeded. In some example systems the electronic circuitry of the BBU further performs, at least in part by the change of the parameter, at least one of a handover of a mobile terminal of the plurality of mobile terminals to another BBU, a reduction in a throughput for the mobile terminal, a reduction in a resource block allocation, a change in a modulation and coding scheme for the cluster of RRUs, a suspension of unicast uplink scheduling in the cluster of RRUs for one or more scheduling intervals, or a suspension of unicast downlink scheduling in the cluster of RRUs for one or more scheduling intervals. Some example systems also include a compound RRU comprising a single interface circuit coupled to the fronthaul link, a first logical RRU coupled to the single interface circuit, and a second logical RRU coupled to the single interface circuit, the first logical RRU and the second logical RRU both included as RRUs in the group of RRUs. Some example systems also include a second cluster of RRUs, each RRU of the second cluster of RRUs included in the group of RRUs and coupled to the fronthaul link, and a second BBU, associated with the second cluster of RRUs and coupled to the fronthaul link, wherein the first logical RRU is included in the cluster of RRUs and the second logical RRU is included in the second cluster of RRUs. In some example systems the one or more parameters comprise synchronization states of the group of RRUs. In some example systems the one or more parameters comprise a fronthaul link quality parameter. In some example systems the one or more parameters comprise geographic locations of the group of RRUs or geographic locations of at least some of the mobile terminals of the plurality mobile terminals which are in active communication with the group of RRUs. In some example systems the geographic locations of the group of RRUs include a building floor. In some example systems the electronic circuitry of the BBU further assigns the one or more RRUs to the cluster of RRUs based on the one or more RRUs having a common building floor location with another RRU of the cluster of RRUs. In some example systems the group of RRUs are mobile and the one or more parameters further comprise a geographic service area of the BBU. In some example systems the electronic circuitry of the BBU to further dynamically assign the one or more RRUs to the cluster of RRUs based on current locations of the group of RRUs and the geographic service area of the BBU. Some example systems also include one or more unmanned aircraft systems (UAS) coupled to a RRU of the cluster of RRUs. In some example systems the electronic circuitry of the BBU further sends commands to the UAS to dynamically position the cluster of RRUs based on the one or more parameters. Any combination of elements described in this paragraph may be used in a particular embodiment. An example baseband unit (BBU) is coupled to a core network. The example BBU is for use with a cluster of remote radio units (RRUs) in a distributed radio access network (RAN). The example BBU includes a processor to execute code comprising instructions of one or more modules, one or more memory devices, coupled to the processor, to store the code, interface circuitry coupled between the processor and a fronthaul link, an orchestration module comprising instructions to assign one or more RRUs, selected from a group of RRUs communicably coupled to the fronthaul link, to the cluster of RRUs based on one or more parameters, and a networking module comprising instructions to perform at least a second-level protocol of the RAN and communicate over the fronthaul link with the cluster of RRUs. In some example BBUs the networking module further includes instructions to communicate over the fronthaul link with the cluster of RRUs using an adaptive fronthaul protocol. In some example BBUs the networking module further includes instructions to perform a portion of a first-level protocol of the RAN. In some example BBUs the RAN protocol uses an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), the core network includes an Evolved Packet Core (EPC), the first-level protocol comprises an Evolved Universal Terrestrial Radio Access (E-UTRA) physical-layer (PHY) protocol, and the second-level protocol comprises an E-UTRA medium access control (MAC) protocol. In some example BBUs the orchestration module further includes instructions to assign the one or more RRUs to the cluster of RRUs dynamically. In some example BBUs the orchestration module further includes instructions to assign one or more other RRUs of the group of RRUs to a second cluster of RRUs. In some example BBUs the orchestration module further includes instructions to set a transmission power of the cluster of RRUs based on the one or more parameters. In some example BBUs the orchestration module further includes instructions to set a radio frequency used by the cluster of RRUs to communicate with a mobile terminal based on the one or more parameters. In some example BBUs the orchestration module further includes instructions to configure the cluster of RRUs to appear as a single base station to a mobile terminal. In some example BBUs a first RRU of the cluster of RRUs transmits data that is different than data transmitted by a second RRU of the cluster of RRUs during at least some time periods. In some example BBUs the orchestration module further includes instructions to configure a first RRU of the cluster of RRUs to communicate with a first mobile terminal and configure a second RRU of the cluster of RRUs to communicate with a second mobile terminal based on geographic locations of the first RRU, the second RRU, the first mobile terminal, and the second mobile terminal. In some example BBUs the orchestration module further includes instructions to configure a first RRU of the cluster of RRUs to communicate with a first mobile terminal and configure a second RRU of the cluster of RRUs to communicate with a second mobile terminal based on radio measurements performed by the cluster of RRUs, the first mobile terminal, or the second mobile terminal. In some example BBUs the orchestration module further includes instructions to configure a first RRU of the cluster of RRUs to only transmit to a mobile terminal, and configure a second RRU of the cluster of RRUs to only receive from the mobile terminal. Some example BBUs further include determining that a first RRU of the cluster of RRUs has failed, and handing over a mobile terminal associated with the first RRU to a second RRU of the cluster of RRUs. In some example BBUs the orchestration module further includes instructions to coordinate with a second BBU includes a second orchestration module and a second networking module. In some example BBUs the orchestration module further includes instructions to determine that a first RRU of the cluster of RRUs has failed, and move a mobile terminal associated with the first RRU to a second RRU, the second RRU associated with a second cluster of RRUs that is associated with the second BBU. In some example BBUs the orchestration module further includes instructions to coordinate moving a selected RRU from the cluster of RRUs to a second cluster of RRUs associated with the second BBU. In some example BBUs the orchestration module further includes instructions to perform any combination of handing over a mobile terminal associated with the selected RRU to another RRU of the cluster of RRUs, changing a parameter associated with the mobile terminal in the BBU, sending a command to the mobile terminal, sending a deactivation command to the selected RRU, informing the selected RRU that it is associated with the second BBU, or setting synchronization parameters in the selected RRU that are compatible with the second BBU. In some example BBUs the orchestration module further includes instructions to coordinate RAN parameters with the second BBU. In some example BBUs the orchestration module further includes instructions to determine that a predetermined capacity threshold of the BBU has been exceeded, and change a parameter in the cluster of RRUs or a mobile device in communication with the cluster of RRUs in response to the determination that the predetermined capacity threshold of the BBU has been exceeded. In some example BBUs the orchestration module further includes instructions to perform, at least in part by the change of the parameter, at least one of a handover of a mobile terminal to another BBU, a reduction in a throughput for the mobile terminal, a reduction in a resource block allocation, a change in a modulation and coding scheme for the cluster of RRUs, a suspension of unicast uplink scheduling in the cluster of RRUs for one or more scheduling intervals, or a suspension of unicast downlink scheduling in the cluster of RRUs for one or more scheduling intervals. In some example BBUs the one or more parameters comprise numbers of mobile terminals in active communication with the group of RRUs, radio measurements performed by the group of RRUs, radio measurements performed by the mobile terminals, or any combination thereof. In some example BBUs the one or more parameters comprise synchronization states of the group of RRUs. In some example BBUs the one or more parameters comprise a fronthaul link quality parameter. In some example BBUs the fronthaul link quality parameter is determined based on information received from the group of RRUs over the fronthaul link. In some example BBUs the information received from the group of RRUs comprises RRU buffer status information, RRU buffer overrun indications, RRU buffer underrun indications, information about a received radio frequency signal, or any combination thereof. In some example BBUs the fronthaul link quality parameter is determined based on a latency of the fronthaul link, a bandwidth of the fronthaul link, errors on the fronthaul link, undelivered packets on the fronthaul link, out-of-order packets on the fronthaul link, buffer overruns, buffer underruns, or any combination thereof. In some example BBUs the one or more parameters comprise geographic locations of the group of RRUs or geographic locations of mobile terminals in active communication with the group of RRUs. In some example BBUs the geographic locations of the group of RRUs include a building floor, the orchestration module further includes instructions to assign the one or more RRUs to the cluster of RRUs based on the one or more RRUs having a common building floor location. In some example BBUs the group of RRUs are mobile and the one or more parameters further comprise a geographic service area of the BBU. In some example BBUs the orchestration module further includes instructions to dynamically assign the one or more RRUs to the cluster of RRUs based on current locations of the group of RRUs and the geographic service area of the BBU. In some example BBUs the group of RRUs are located on unmanned aircraft systems (UAS). In some example BBUs the orchestration module further includes instructions to send commands to the UAS to dynamically position the group of RRUs based on the one or more parameters. Any combination of elements described in this paragraph may be used in a particular embodiment. An example unmanned aircraft system (UAS) includes a wireless control link to receive flight instructions from a ground-based system, a control system, coupled to the wireless control link, to control the UAS based on the flight instructions received through the wireless control link, a propulsion system, coupled to and under control of the control system, to keep UAS airborne and provide movement with at least three degrees of freedom, a wireless fronthaul link to communicate with a baseband unit (BBU) of a radio access network (RAN), a remote radio unit (RRU) coupled to the fronthaul link, the RRU comprising electronic circuitry to perform at least a first portion of a first-level protocol of a radio access network (RAN) and generate a radio frequency signal for communicating with a mobile terminal compatible with the RAN, and an antenna, coupled to the wireless control link, the wireless fronthaul link, and the electronic circuitry of the RRU. In some example UASs the wireless control link and the wireless fronthaul link co-exist on a single wireless network. In some example UASs the single wireless network comprises a wireless network compliant with a version of IEEE 802.11 or a version of IEEE 802.16. In some example UASs the wireless control link is embedded within the wireless fronthaul link, and a BBU comprises the ground-based system which generates the flight instructions. In some example UASs the flight instructions describe a hover position, and the control system autonomously navigates the UAS to the hover position and autonomously maintains the UAS in the hover position. In some example UASs the flight instructions describe a flight path and the control system autonomously navigates the UAS to follow the flight path. Any combination of elements described in this paragraph may be used in a particular embodiment. An example method, performed by a baseband unit (BBU), facilitates communication between a core network and a cluster of remote radio units (RRUs) in a distributed radio access network (RAN) The example method includes assigning one or more RRUs, selected from a group of RRUs communicably coupled to the BBU by a fronthaul link, to the cluster of RRUs based on one or more parameters, performing at least a second-level protocol of the RAN, and communicating over the fronthaul link with the cluster of RRUs. In some example methods the communicating over the fronthaul link with the cluster of RRUs is done using an adaptive fronthaul protocol. Some example methods also include performing a portion of a first-level protocol of the RAN. In some example methods the RAN protocol comprises an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and the core network comprises an Evolved Packet Core (EPC), the first-level protocol comprises an Evolved Universal Terrestrial Radio Access (E-UTRA) physical-layer (PHY) protocol, and the second-level protocol comprises an E-UTRA medium access control (MAC) protocol. Some example methods also include assigning the one or more RRUs to the cluster of RRUs dynamically. Some example methods also include assigning another RRU of the group of RRUs to a second cluster of RRUs. Some example methods also include setting a transmission power of the cluster of RRUs based on the one or more parameters. Some example methods also include setting a radio frequency used by the cluster of RRUs to communicate with a mobile terminal based on the one or more parameters. Some example methods also include configuring the cluster of RRUs to appear as a single base station to a mobile terminal. Some example methods also include configuring a first RRU of the cluster of RRUs to transmit data that is different than data transmitted by a second RRU of the cluster of RRUs during at least some time periods. Some example methods also include configuring a first RRU of the cluster of RRUs to communicate with a first mobile terminal and configuring a second RRU of the cluster of RRUs to communicate with a second mobile terminal based on geographic locations of the first RRU, the second RRU, the first mobile terminal, and the second mobile terminal. Some example methods also include configuring a first RRU of the cluster of RRUs to communicate with a first mobile terminal and configuring a second RRU of the cluster of RRUs to communicate with a second mobile terminal based on radio measurements performed by the cluster of RRUs, the first mobile terminal, or the second mobile terminal. Some example methods also include configuring a first RRU of the cluster of RRUs to only transmit to a mobile terminal, and configuring a second RRU of the cluster of RRUs to only receive from the mobile terminal. Some example methods also include determining that a first RRU of the cluster of RRUs has failed, and handing over a mobile terminal associated with the first RRU to a second RRU of the cluster of RRUs. Some example methods also include coordinating with a second BBU. Some example methods also include determining that a first RRU of the cluster of RRUs has failed. In some example methods the coordinating with the second BBU comprises moving a mobile terminal associated with the first RRU to a second RRU, the second RRU associated with a second cluster of RRUs that is associated with the second BBU. In some example methods the coordinating with the second BBU comprises moving a selected RRU from the cluster of RRUs to a second cluster of RRUs associated with the second BBU. In some example methods the moving the selected RRU comprises any combination of handing over a mobile terminal associated with the selected RRU to another RRU of the cluster of RRUs, changing a parameter associated with the mobile terminal in the BBU, sending a command to the mobile terminal, sending a deactivation command to the selected RRU, informing the selected RRU that it is associated with the second BBU, or setting synchronization parameters in the selected RRU that are compatible with the second BBU. In some example methods the coordinating with the second BBU comprises coordinating RAN parameters with the second BBU. Some example methods also include determining that a predetermined capacity threshold of the BBU has been exceeded, and changing a parameter in the cluster of RRUs or a mobile device in communication with the cluster of RRUs in response to the determination that the predetermined capacity threshold of the BBU has been exceeded. Some example methods also include performing, at least in part by the changing of the parameter, at least one of handing over of a mobile terminal to another BBU, reducing a throughput for the mobile terminal, reducing a resource block allocation, changing a modulation and coding scheme for the cluster of RRUs, suspending unicast uplink scheduling in the cluster of RRUs for one or more scheduling intervals, or suspending unicast downlink scheduling in the cluster of RRUs for one or more scheduling intervals. In some example methods the one or more parameters comprise numbers of mobile terminals in active communication with the group of RRUs, radio measurements performed by the group of RRUs, radio measurements performed by the mobile terminals, or any combination thereof. In some example methods the one or more parameters comprise synchronization states of the group of RRUs. In some example methods the one or more parameters comprise a fronthaul link quality parameter. Some example methods also include determining the fronthaul link quality parameter based on information received from the group of RRUs over the fronthaul link. In some example methods the information received from the group of RRUs comprises RRU buffer status information, RRU buffer overrun indications, RRU buffer underrun indications, information about a received radio frequency signal, or any combination thereof. Some example methods also include determining the fronthaul link quality parameter based on a latency of the fronthaul link, a bandwidth of the fronthaul link, errors on the fronthaul link, undelivered packets on the fronthaul link, out-of-order packets on the fronthaul link, buffer overruns, buffer underruns, or any combination thereof. Some example methods also include assigning a first RRU of the group of RRUs to the cluster of RRUs and not assigning a second RRU of the group of RRUs to the cluster of RRUs based on the one or more parameters, wherein the first RRU and the second RRU are both logical RRUs of a compound RRU. In some example methods the one or more parameters comprise geographic locations of the group of RRUs or geographic locations of mobile terminals in active communication with the group of RRUs. In some example methods geographic locations of the group of RRUs include a building floor, and the assigning of the one or more RRUs is based on the one or more RRUs having a common building floor location with another RRU of the cluster of RRUs. In some example methods the group of RRUs are mobile and the one or more parameters further comprise a geographic service area of the BBU, and the assigning of the one or more RRUs further comprises dynamically assigning the one or more RRUs to the cluster of RRUs based on current locations of the group of RRUs and the geographic service area of the BBU. In some example methods the group of RRUs are located on unmanned aircraft systems (UAS). Some example methods also include sending commands to the UAS to dynamically position the group of RRUs based on the one or more parameters. Any combination of elements described in this paragraph may be used in a particular embodiment. An example tangible machine readable medium includes one or more instructions that in response to being executed on a computing device cause the computing device to carry out any method described in the previous paragraph. An example method manages a distributed radio access network (RAN). The example method includes receiving information from a remote radio unit (RRU), determining, based on the information and one or more parameters, that the RRU should be assigned to a particular cluster of RRUs, and informing a baseband unit (BBU) associated with the particular cluster of RRUs that the RRU has been assigned to the particular cluster of RRUs. In some example methods the one or more parameters comprise numbers of mobile terminals in active communication with the RRU or the particular cluster of RRUs, radio measurements performed by the RRU or the particular cluster of RRUs, radio measurements performed by the mobile terminals, or any combination thereof. In some example methods the one or more parameters comprise synchronization states of the RRU or the particular cluster of RRUs. In some example methods the one or more parameters comprise a fronthaul link quality parameter for a fronthaul link associated with the RRU or the particular cluster of RRUs. Some example methods also include determining the fronthaul link quality parameter based on information received from the cluster of RRUs over the fronthaul link. In some example methods the one or more parameters comprise geographic locations of the cluster of RRUs or geographic locations of mobile terminals in active communication with the cluster of RRUs. In some example methods the geographic locations of the cluster of RRUs include a building floor. Some example methods also include assigning the RRU to the particular cluster of RRUs based on the RRU and the particular cluster of RRUs having a common building floor location. In some example methods a group of RRUs comprising the RRU and the particular cluster of RRUs are mobile. Some example methods also include dynamically assigning the RRU to the particular cluster of RRUs based on current locations of the RRU and the particular cluster of RRUs. Some example methods also include determining that the information received from the RRU indicates that the RRU is not currently assigned, and determining, based on the one or more parameters, that the RRU should be assigned to an existing cluster of RRUs, wherein the existing cluster of RRUs is the particular cluster of RRUs. Some example methods also include determining that the information received from the RRU indicates that the RRU is not currently assigned, and determining, based on the one or more parameters, that the RRU should be assigned to a new cluster of RRUs, wherein the new cluster of RRUs is the particular cluster of RRUs. Some example methods also include deciding, based on the information received from the RRU and information received from an existing BBU, whether to assign the new cluster of RRUs to the existing BBU, and assigning the existing BBU to be the BBU associated with the particular cluster of RRUs in response to the decision. Some example methods also include deciding, based on the information received from the RRU and information received from one or more existing BBUs, whether to assign the new cluster of RRUs to a new BBU, instantiating a new BBU on a virtual machine, and assigning the new BBU to be the BBU associated with the particular cluster of RRUs in response to the decision. Some example methods also include instantiating the virtual machine as a new virtual machine in a data center. In some example methods the data center comprises a public cloud service. Some example methods also include determining that the information received from the RRU indicates that the RRU is currently assigned to a first BBU that is no longer appropriate, deciding, based on the information received from the RRU and information received from an existing BBU, whether to assign the RRU to a cluster of RRUs currently associated with the existing BBU, and defining the particular cluster of RRUs to be the cluster of RRUs currently associated with the existing BBU in response to the decision defining the particular cluster of RRUs the information received from the RRU indicates that the RRU has physically moved. Some example methods also include determining that the information received from the RRU indicates that the RRU is currently assigned to a first BBU that is no longer appropriate, deciding, based on the information received from the RRU and information received from one or more existing BBUs, whether to assign the RRU to a cluster of RRUs associated with a new BBU, and instantiating the new BBU on a virtual machine, the new BBU associated with the particular cluster of RRUs, in response to the decision. Some example methods also include instantiating the virtual machine as a new virtual machine in a data center. In some example methods the data center comprises a public cloud service. In some example methods the information received from the RRU indicates that the RRU has physically moved. Any combination of elements described in this paragraph may be used in a particular embodiment. An example tangible machine readable medium includes one or more instructions that in response to being executed on a computing device cause the computing device to carry out any method described in the previous paragraph. An example method manages a distributed radio access network (RAN). The example method includes receiving information from a baseband unit (BBU), determining that a predetermined capacity threshold of the BBU has been exceeded, and changing a parameter in a cluster of RRUs associated with the BBU or a mobile device in communication with the cluster of RRUs in response to the determination that the predetermined capacity threshold of the BBU has been exceeded. Some example methods also include performing, at least in part by the changing of the parameter, at least one of handing over of a mobile terminal to another BBU, reducing a throughput for the mobile terminal, reducing a resource block allocation, changing a modulation and coding scheme for the cluster of RRUs, suspending unicast uplink scheduling in the cluster of RRUs for one or more scheduling intervals, or suspending unicast downlink scheduling in the cluster of RRUs for one or more scheduling intervals. Any combination of elements described in this paragraph may be used in a particular embodiment. An example tangible machine readable medium includes one or more instructions that in response to being executed on a computing device cause the computing device to carry out any method described in the previous paragraph. An example method manages a distributed radio access network (RAN). The example method includes receiving information from a first baseband unit (BBU), determining, based the information received and one or more parameters, that a remote radio unit (RRU) assigned to the first BBU should be moved to a second BBU, and migrating the RRU from the first BBU to the second BBU. Some example methods also include deciding, based on the information received from the first BBU, that the first BBU is not functioning properly, and migrating a cluster of RRUs assigned to the first BBU to other BBUs. In some example methods the one or more parameters comprise numbers of mobile terminals in active communication with the RRU or the first or second BBU, radio measurements performed by the RRU or the first or second BBU, radio measurements performed by the mobile terminals, or any combination thereof. In some example methods the one or more parameters comprise synchronization states of the RRU or the first or second BBU. In some example methods the one or more parameters comprise a fronthaul link quality parameter for a fronthaul link associated with the first or second BBU. Some example methods also include determining the fronthaul link quality parameter based on information received from the first or second BBU. In some example methods the information received from the first BBU comprises buffer status information for the first BBU or the RRU, buffer overrun indications for the first BBU or RRU, buffer underrun indications for the first BBU or the RRU, information about a received radio frequency signal, a geographic location of the for the first BBU or the RRU, or any combination thereof. Some example methods also include determining the fronthaul link quality parameter based on a latency of the fronthaul link, a bandwidth of the fronthaul link, errors on the fronthaul link, undelivered packets on the fronthaul link, out-of-order packets on the fronthaul link, buffer overruns, buffer underruns, or any combination thereof. In some example methods the one or more parameters comprise geographic service areas for the first BBU or the second BBU, and the information from the first BBU includes a geographic location of the RRU. Some example methods also include dynamically assigning the RRU to the second BBU based on a movement of the RRU into the geographic service area of the second BBU. In some example methods the migrating the RRU from the first BBU to the second BBU comprising any combination of handing over a mobile terminal associated with the RRU to another RRU associated with the first BBU, change a parameter associated with the mobile terminal in the first BBU, send a command to the mobile terminal, send a deactivation command to the RRU, inform the RRU that is it associated with the second BBU, or set synchronization parameters in the RRU compatible with the second BBU. In some example methods the determining includes deciding, based on the information received from the first BBU and information received from another existing BBU, whether to assign the RRU to the other existing BBU, and using the other existing BBU as the second BBU in response to the decision. In some example methods the information received from the first BBU and information received from the other existing BBUs indicates that the RRU has physically moved into a service area of the other existing BBU. Some example methods also include deciding, based on the information received from the first BBU and information received from one or more other existing BBUs, whether to assign the RRU to a new BBU, instantiating the new BBU on a virtual machine, and using the new BBU as the second BBU in response to the decision. Some example methods also include instantiating the virtual machine as a new virtual machine in a data center. In some example methods the data center comprises a public cloud service. In some example methods the information received from the first BBU and information received from one or more other existing BBUs indicates that the RRU has physically moved to an area outside of a service area of the first BBU and the one or more other existing BBUs. Any combination of elements described in this paragraph may be used in a particular embodiment. An example tangible machine readable medium includes one or more instructions that in response to being executed on a computing device cause the computing device to carry out any method described in the previous paragraph. An example compound remote radio unit (RRU) can be used with a plurality of baseband units (BBUs) in a distributed radio access network (RAN). The example compound RRU includes a single interface circuit coupled to a fronthaul link and adapted to communicate over the fronthaul link using an adaptive fronthaul protocol, radio frequency (RF) circuitry coupled to an antenna, a first logical RRU coupled to the single interface circuit and the radio frequency circuitry, the first logical RRU comprising first control registers to control operation of the first logical RRU, and a second logical RRU coupled to the single interface circuit and the radio frequency circuitry, the second logical RRU comprising second control registers to control operation of the second logical RRU. In some example compound RRUs the RF circuitry comprising a first RF circuit coupled to the first logical RRU and a first antenna, and a second RF circuit coupled to the second logical RRU and a second antenna, the first logical RRU comprising first conversion circuitry and first transformation circuitry coupled to the first control registers, and the second logical RRU comprising second conversion circuitry and second transformation circuitry coupled to the second control registers. In some example compound RRUs the single interface circuit comprising a single media access controller (MAC) address and an interface to a network compatible with an IEEE 802 standard. In some example compound RRUs the first logical RRU comprising a first timebase synchronization circuit to synchronize the first logical RRU with a first timebase of the RAN, and the second logical RRU comprising a second timebase synchronization circuit to synchronize the second logical RRU with a second timebase of the RAN, wherein the second timebase is not synchronized with the first timebase. Any combination of elements described in this paragraph may be used in a particular embodiment. An example method of using a compound remote radio unit (RRU) in a distributed radio access network (RAN) includes receiving a first command from a first baseband unit (BBU) over a fronthaul link through a single interface circuit of the compound RRU, using information from the first command to set a first RAN parameter to a first value in a first logical RRU of the compound RRU, receiving a second command from a second baseband unit (BBU) over the fronthaul link through the single interface circuit of the compound RRU, using information from the second command to set the first RAN parameter to a second value in a second logical RRU of the compound RRU. In some example methods the first RAN parameter is a carrier frequency. Some example methods also include synchronizing the first logical RRU to a first timebase of the RAN, and synchronizing the second logical RRU with a second timebase of the RAN, wherein the second timebase is not synchronized with the first timebase. Some example methods also include facilitating communication between the first BBU and a first mobile terminal through the first logical RRU, and facilitating communication between the second BBU and a second mobile terminal through the first logical RRU. Any combination of elements described in this paragraph may be used in a particular embodiment. An example tangible machine readable medium includes one or more instructions that in response to being executed on a computing device cause the computing device to carry out any method described in the previous paragraph. As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to an element described as “a processor” may refer to a single processor, two processors, or any other number of processors but a reference to “a single processor” refers to only one processor. As used in this specification and the appended claims, the term “or” is generally employed in its sense including both a union operator (OR) and an intersection operator (AND), which may also be referred to as an “inclusive OR” or an “and/or” unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “coupled” includes direct and indirect connections. Moreover, where first and second devices are coupled, intervening devices, including active devices, may be located there between. As used in this specification and the appended claims, the phrase “based on” should be interpreted as being open ended, equivalent to “based, at least in part, on” and allow for the action to be based on other elements in addition to the elements specified. Unless otherwise indicated, all numbers expressing quantities of elements, percentages, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Interpretation of the term “about” is context specific, but in the absence of other indications, should generally be interpreted as ±10% of the modified quantity, measurement, or distance. The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g. 1 to 5 includes 1, 2.78, 3.33, and 5). Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specified function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. § 112(f). The description of the various embodiments provided above is illustrative in nature and is not intended to limit this disclosure, its application, or uses. Thus, different variations beyond those described herein are intended to be within the scope of embodiments. Such variations are not to be regarded as a departure from the intended scope of this disclosure. As such, the breadth and scope of the present disclosure should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and equivalents thereof. | 168,456 |
11943046 | DETAILED DESCRIPTION Exemplary Embodiments In the following a method to configure real-time communications in a real-time distributed system using scheduled and rate-constrained communication flows according to the invention is described based on an example which is not limiting the scope of protection of the invention. The method comprises the computation of a final network configuration, including routing and scheduling configurations, whereby the computed network configuration is subject to a formal analysis and fulfills, fully or partially, a defined set of constraints. An overview of the workflow of the method is depicted inFIG.1. The inputs100of the method comprise a description of the network, includinga network topology, comprising network components like nodes and starcouplers, for example bridges or switches, and1aset of communication flows, comprising scheduled time-triggered flows, TT flows, and rate constraint flows, RC flows, anda set of constraints, comprisingcommunication constraints like scheduling, real-time, routing, resource constraints, andoptionally optimization constraints. The method computes a final configuration300, the output of the method, based on said inputs, wherein the computation of said final configuration is based on three modules, namely, routing110, scheduling130, and formal analysis150modules. The routing module110computes routes based on the network topology subject to constraints, particularly, the routing constraints. The output120of the routing module130is provided as input to the scheduling module. The scheduling module130schedules the TT flows based on the network topology and the routes of said TT flows, as computed by the routing module, subject to constraints, in particular the scheduling constraints. The output140of the scheduling module120is provided as input to the analysis module150. The formal analysis module150checks whether the computed configuration, comprising the routing of TT and RC flows and the TT schedule, fulfills constraints, in particular the real-time and resource constraints, and optionally optimization constraints, and outputs the final configuration300. In an ideal scenario, in a first step, the routing module110computes routes for the set of flows, including TT and RC flows, considering a subset of the constraints related to the routes, and outputs results120to the scheduling module. Following, the scheduling module130schedules the subset of TT flows, based on the computed routes, considering a subset of the constraints affecting scheduling, and output results140to the formal analysis module150. Lastly, the formal analysis module150checks the fulfillment of the set of constraints and outputs a final configuration300. In a realistic scenario it is unlikely to satisfy all constraints on the first execution of each module. In particular due to the sequential approach of the method according to the invention, wherein in a first step routes are computed, and, in a second step, a schedule is computed based on the computed routes, the solution space when performing the second step is subject to the results determined by a first step, so that a different result provided in the first step may conduct to a different, potentially larger, overall solution space. Therefore, the method comprises two, optionally three, feedback loops driving the iterative execution of the method, in order to refine the configuration until all constraints are fulfilled, or a defined termination condition is met. In case that the scheduling module cannot find a schedule for the subset of TT flows, a first feedback loop200provides information to the routing module to find an alternative route for one, or more, of the TT flow(s). Said information comprises the one, or more, TT flow(s) identified as having the highest impact on the schedulability of the set of TT flows. In case that the formal analysis determines that not all constraints are fulfilled, a second feedback loop210provides information to the scheduling module to find an alternative schedule for one, or more, of the TT flow(s). Said information comprises the one, or more, TT flow(s) identified as having the highest impact on the constraints, in particular, on the constraints affecting RC flows. As an alternative to the second feedback loop, in case that the formal analysis determines that not all constraints are fulfilled, or, in the case that finding a new schedule is not possible with the current routes of the set of communication flows, an optional third feedback loop230provides information to the routing module to find an alternative route for one, or more, of the communication flow(s). The iterative execution of the three modules produces multiple configurations, namely, one configuration for every execution of the analysis module. A configuration is considered a final configuration when all constraints are fulfilled, including all optimization constraints being maximally optimized. Among all other configurations different than the final configuration, referred to as partial configurations, a best partial configuration is selected on each iteration, wherein said best partial configuration is the partial configuration maximizing defined criteria. In the case that a final configuration is not found before the defined time limit is reached, or a maximum defined number of iterations of any one, or the sum of, the modules and/or feedback loops, the method outputs the best partial configuration instead. Alternatively, the method may also terminate, providing the best partial configuration as output, if optimization constraints are provided and these have been optimized to a defined threshold with respect to the optimal value. For example, if the defined optimization threshold is 10, the method will terminate once the set of values for the provided optimization constrains are within a 10of the optimal value. As mentioned, the method according to the invention comprises said routing, scheduling, and analysis modules, and said first, second, and optionally third, feedback loops, which may be implemented in a computer system, each as an independent software component, or combined in one, or multiple, software components, or be part of one, or multiple, software libraries. The execution flow of the method, detailed inFIG.1, may be implemented as an algorithm, preferably a software algorithm, executing each said module and feedback loops, according to the depicted workflow, whereby said execution of said modules and said feedback loops by said algorithm may be performed via the execution of one, or multiple, software components, or via the execution of software calls to said one or multiple software libraries, implementing said modules and said feedback loops. Predefined Parameters The computation of said network configuration comprises the search of a valid solution within a solution space of possible solutions, wherein said solution space can be very extensive in networks comprising large topologies and/or large number of communication flows. Said search of a valid solution is driven iteratively by the computation of different routes and/or different schedules, performed by said routing and scheduling modules, and respectively said first, second, and optionally third feedback loops. It is possible that the search falls in areas of the solution space representing “local optima”, wherein the method may perform successive improvements of the solution by performing small adjustments in either routes or schedules of one, or a set, of selected flow(s), despite rerouting, or rescheduling, a different flow, or set of flows, could lead to an existing better solution in the search space. However, the method may exhaust the defined available time doing rerouting, or rescheduling, iterations over the same selection of flow(s), hence resulting in a termination before exploring the remaining solution space or causing a much larger runtime to reach certain areas of the solution space. To avoid falling in local optima, and spreading the search within the solution space, the method may limit the workflow by the definition of optional parameters, namely by:a predefined maximum number of schedules per route of TT flows, whereby the scheduling module will limit the computation of new, different, schedules for a TT flow with one computed route to said maximum number, and/or bya predefined maximum number of routes per flow, whereby the routing module will limit the number of new, different, routes for each communication flow to said maximum number. An implementation of the method may use said predefined maximum number of schedules to determine that a new schedule for the set of TT flows cannot be computed after said predefined maximum number of schedules is reached without successfully finding a final configuration. The practical effects of said limit is to reduce the runtime of the computation, by forcing the method to reroute after so many rescheduling steps are tried, hence avoiding spending time on variations the schedule based on the same routes instead of trying to reroute, potentially causing a larger impact on the configuration, and consequently exploring a different area of the solution space. In addition or alternatively the method may use said predefined maximum number of routes per flow to determine that a new route for a flow cannot be computed after said predefined maximum number of routes is reached without successfully finding a final configuration. The practical effects of said limit is to reduce the runtime of the computation, by avoiding an exhaustive exploration of all possible route combinations of one flow before selecting a different one, potentially causing a larger impact on the configuration, and consequently exploring a different area of the solution space. Constraints The method computes a final configuration subject to a set of constraints, wherein said set of constraints comprises one or more communication constraints, preferablyscheduling constraints, includinga start or end time of transmission, relative to the period for one, more, or all, of said TT flows of the set of communication flows, and/ora start instant or an end instant of reception, relative to the period, for one, more, or all, of said TT flows in the set of communication flows, and/ora minimum or maximum gap between two or more of said TT flows in the set of communication flows, and/orreal-time constraints, includingthe maximum or minimum allowed end-to-end communication latency for one, more, or all, of said set of communication flows, and/orthe maximum allowed relative jitter in the reception of any of the periodic iterations for one, more, or all, of said set of communication flows, and/orrouting constraints, includinga set of preferred components to route one, more, or all, of said set of communication flows, for example to prefer faster components, and/ora set of forbidden components to route one, more, or all, of said set of communication flows, for example to avoid components without time-triggered communication capabilities for TT flows, and/orresource constraints,the maximum memory size available for network packet buffering for one, more, or all, of said network components,the maximum time span a network packet may be buffered before transmission in one, more, or all, of said network components, in particular switch or bridge components,and,said set of constraints may include one or more optional optimization constraints, preferablyminimize the end-to-end communication latency of one, more, or all, of said set of flows, and/orminimize the maximum reception/transmission jitter of one, more, or all, of said set of communication flows, and/orminimize the maximum memory required to temporary store network packets in transit of one, more, or all, of said network components, and/orminimize the worst-case end-to-end communication latency for one, more, or all, of said set of communication flows, and/ormaximize/minimize the length of intervals in which no TT flows are scheduled for one, more, or all, of said network components, and/orminimize/maximize the intervals in which continuous TT flows are scheduled for one, more, or all, of said network components. Modules The routing module comprises a routing algorithm, preferably implemented in a computer system, wherein said algorithm computes network routes for a defined set of communication flows. The algorithm takes as inputsthe network topology, comprising network components, like endpoints, or nodes, and starcouplers, like bridges or switches, and a set of links between said components, andthe set of communication flows, each defining a source node and one or more destination nodes from said topology, and optionallythe set of routing constraints. An implementation of a routing algorithm can be based on graph theory, for example by determining the shortest path, for example implementing the Dijkstra shortest path algorithm, between pairs of vertexes, representing nodes, connected in the graph by directional edges, representing links. If a set of optional routing constraints is provided, the routing algorithm shall be tailored to satisfy those constraints, for example, removing vertexes from the graph if a routing constraint requires the respective component to be avoided. A particularity of the routing algorithm is the capability to reroute communication flows on request via an alternative, different, route than any of the previous computed routes for said flow. For example, by computing on a first step all possible routes for a communication flow on a list of routes and delivering the next one on the list upon each successive request. The scheduling module comprises a scheduling algorithm, preferably implemented in a computer system, wherein said algorithm computes time-triggered schedules for a defined set of communication flows. The algorithm takes as inputsthe network topology, comprising network components, like endpoints, or nodes, and starcouplers, like bridges or switches, and a set of links between said components, andthe set of TT flows, andthe set of routes, one for each of the TT flows, comprising a succession of network components and links, and optionallythe set of scheduling constraints. An implementation of a scheduling algorithm can be based on optimal methods, like SMT or MIP solvers, whereby the term optimal method means that if there is a solution it will be found, even though it may take a very long time, due to the exhaustive search of the entire solution space, which grows exponentially with respect to the size of the inputs. In an implementation using said optimal methods a set of time-triggered constraints may be formulated as mathematical equations determining the time of transmission of each network packet of a TT flow transmitted along the computed route, said constraints comprisingthe sequential timeliness of communication, beginning at the source node and following along the links in the route to the receiver node(s), andthe contention-free configuration of transmissions, whereby no two scheduled frames shall be scheduled at time instants creating contention, or collisions, on egress, andthe cyclic nature of communication, resulting from combining the periods of all TT flows in a hyper-period, or hypercycle, typically computes as the least common multiple of all said periods, anddefined latencies of communication operations, like hardware delays and packet processing latency, as well as defined link propagation latencies, anddefined bounds for the time synchronization of network components, typically as a result of a time-synchronization protocol, like IEEE 802.1AS or SAE AS6802. If a set of optional scheduling constraints is provided, the scheduling algorithm shall be tailored to satisfy those constraints, for example, adding explicit mathematical equations representing the maximum time distance between transmission of the first network packet and the reception of the last network packet of a scheduled flow if a scheduling constraint requires a maximum end-to-end latency to be fulfilled. A different implementation of a scheduling algorithm can be based on suboptimal methods, like heuristic methods, for example Tabu search or Simulated Annealing, whereby the term suboptimal method means that the algorithm will not search the complete solution space, and therefore it may miss a solution fulfilling all constraints. However, suboptimal methods, like those based on heuristics, are typically tailored to perform near-to-optimal solutions with a much lower average runtime than that of optimal methods. A particularity of the scheduling algorithm is the capability to reschedule TT flow(s) on request, to an alternative, different, time-triggered schedule. For example, by adding explicit constraints to forbid the values in a computed schedule, comprising the transmission time instants of network packets comprised by said TT flow, upon each successive request, hence forcing the computation of a new schedule to differ from any previous computed schedule for said TT flow(s). The analysis module comprises a formal analysis algorithm, preferably implemented in a computer system, wherein said algorithm analyzes a configuration and determines whether a defined set of constraints are fulfilled. The algorithm takes as inputsthe network topology, comprising network components, like endpoints, or nodes, and starcouplers, like bridges or switches, and a set of links between said components, andthe set of communication flows, comprising TT and RC flows, andthe set of routes, one for each of the communication flows, and the set of schedules, one for each of the TT flows in the set of communication flows, andthe set of real-time constraints and/or resource constraints, and optionally, additional constraints. An implementation of a formal analysis algorithm can be based on network analysis methods, like Network Calculus, whereby the service curves at each network component, in particular, at each link of each network component, is computed, by means of (min,+) Algebra, to determine the worst-case queuing of network packets conforming said communication flows, and thereby obtaining upper bounds for real-time and resource constrained metrics, like the end-to-end latency and/or maximum jitter of RC flows, as well as the peak queue size required by network components. A particularity of the formal analysis algorithm is the capability to account for scheduled flows, wherein the computation of service and demand curves incorporates the transmission of TT flows. A simple approach may disregard the fact that TT flows are scheduled and consider TT flows as if they were RC flows, hence obtaining a pessimistic upper bound based on an arbitrary service time for TT flows. A more precise approach may take into consideration the exact transmission time of network packets comprised in scheduled TT flows and compute a curve in which TT traffic is serviced according to said schedule. Long-Term Memory An implementation of the three modules may use historic information, preferably in the form of data stored in a computer system, to perform their computations. In particular, the iterative execution of modules110,130,150and feedback loops200,210,220may be based on long-term memory, persistent during the complete execution of the method, storinga set of explored network routes, wherein each network route comprises one route for each of the communication flows—said set of explored network routes is updated after a new route is computed by the routing module, hence resulting in a different combination of routes. An implementation of the method may use the set of explored network routes toavoid repeating combinations of routes which have been already computed, and/ordetermine whether new, different, routes than those already computed, exist;and/or storingthe set of initial routes for each flow, as computed in the first iteration of the first module—said set of initial routes is updated upon the first execution of the routing module. An implementation of the method may use the set of explored network routes torevert the route of a flow to its default, initial route, when no more routes for said flow can be computed and no schedule for said flow could be computed with any of the computed routes, and therefore, a new, different, flow is selected for rerouting,and/or storing:the best partial configuration found so far, comprising the set of routes and schedules computed by the first and second modules, whereby the largest number of constraints in the set of constraints are fulfilled, preferably beingthe first partial configuration if no other partial configuration has been computed, orthe partial configuration fulfilling the communication constraints for the largest subset of communication flows, among all other partial configurations, orif all constraints are fulfilled by the new and the previous configurations and optional optimization constraints are provided, the new configuration optimizes, fully, or partially, said optimization constraints to a larger degree, for exampleevaluating the values of said new configuration against a set of pareto fronts, orif the values of said new configuration are closer to the optimal value than the values of the previous configuration for a larger subset of constraints, orevaluating the values of said new configuration against a set of weighted optimal values for each optimization constraints.Said best partial configuration may be updated upon each execution of the analysis module, if the analysis performed by said analysis module shows that the current configuration is better than any previous configuration. An implementation of the method may use said best partial configuration to output a final, or partial, configuration when the conditions to terminate are met. Medium-Term Memory The iterative execution of modules110,130,150and feedback loops200,210,220may be based on medium-term memory, persistent during successive executions of a module, storingthe set of computed routes in consecutive executions of the first feedback loop:Said set of computed routes in consecutive executions of the first feedback loop is updated after each successive iteration of the first feedback loop and cleared upon the execution of either the second or third feedback loops. An implementation of the method may use said set of computed routes in the first feedback loop to determine whether a defined maximum number of routes have been explored via the first feedback loop.and/or storingthe set of computed routes in consecutive executions of the third feedback loop:Said set of computed routes in consecutive executions of the third feedback loop is updated after each successive iteration of the third feedback loop and cleared upon the execution of either the first or second feedback loops. An implementation of the method may use said set of computed routes in the third feedback loop to determine whether a defined maximum number of routes have been explored via the third feedback loop.and/or storinga set of computed schedules in consecutive executions of the second feedback loop:Said set of computed schedules in consecutive executions of the second feedback loop is updated after each successive iteration of the third feedback loop and cleared upon the execution of either the first or second feedback loops. An implementation of the method may use said set of computed schedules in the third feedback loop to determine whether a defined maximum number of schedules have been explored via the third feedback loop.and/or storingthe last successful schedule, including the set routes for the set of scheduled TT flows, if any:Said last successful schedule is updated after each successive execution of the scheduling module. An implementation of the method may use said last successful schedule to revert to the last successful schedule and routes for the set of TT flows before performing the rescheduling of a selection of one, or multiple, TT flows, thereby increasing the chances of successfully scheduling the selection of TT flow(s) and reducing the required computation runtime. Method Workflow In an implementation of the method including the optional third feedback loop, if the analysis module determines that not all constraints are fulfilled, the method may iterate either over the first feedback loop, or the third feedback loop, wherein the decision for one or the other directs the search of a solution towards different regions of the solution space. Different choices are possible, namelyAn implementation may base the decision on a pure random choice.A different implementation may base the decision on a defined maximum number of iterations of the same feedback loop. For example, said implementation may choose on a first iteration the second feedback loop, hence forcing the rescheduling of a selected flow, and, in subsequent iterations, repeat the choice of the second feedback loop, as long as the second module is able to compute a new, different, schedule, up to a maximum defined number of iterations, whereby after said maximum defined number of iterations the third feedback loop is chosen.A different implementation may base the decision on the average computation time, measured during execution, or estimated at design time, of the respective routing and scheduling modules. For example, said implementation may estimate that the routing module takes on average a portion of the computation time of the scheduling module, and therefore choose the second, or third, feedback loops in a proportional manner, to balance the accrued computation time spent on either first and second modules.A different implementation may base the decision on an estimated effect of either rescheduling or rerouting a selected flow, wherein said estimation may simulate rescheduling and/or rerouting said selected flow, without performing the computation of new routes and/or new schedules, and determine which of the two modules would have a larger impact on a subsequent analysis performed by the analysis module. Flow Selection in the First Feedback Loop In the case that the scheduling module cannot compute a time-triggered schedule or if the computed time-triggered schedule is not able to fulfill all of the scheduling constraints, the first feedback loop may select one, or multiple, of the TT flows in the set of communication flows to be rerouted by the routing module. An implementation of the first feedback loop may choose said TT flow(s) to be rerouted based on a sorted list of all TT flows, wherein the order in the list is determined by the length of the period, and/or the data size of said TT flows, for example, by selecting the first TT flow(s) in said sorted list of all TT flows. A different implementation of the first feedback loop may choose said TT flow(s) to be rerouted based on a different sorted list of all TT flows, wherein the order in said list is determined by the number of scheduling constraints affecting said TT flows, for example, by selecting the first TT flow(s) in said sorted list of all TT flows. Yet a different implementation of the first feedback loop may choose said TT flow(s) to be rerouted based on a different sorted list of all TT flows, wherein the order in said list is determined by an estimation of the complexity of scheduling said TT flow(s), wherein said complexity of scheduling may be, for example, determined by the amount of network packets comprising said TT flows and the availability of unscheduled time intervals on the links comprised in the routes of said TT flow(s). Another implementation of the first feedback loop may choose said TT flow(s) based on a predefined order among all TT flows, or based on a random selection. Flow Selection in the Second Feedback Loop In the case that the analysis module determines that not all constraints are fulfilled, the second feedback loop may select one, or multiple, of the TT flows in the set of communication flows to be rescheduled by the scheduling module. An implementation of the second feedback loop may choose said TT flow(s) to be rescheduled based on a sorted list of all TT flows, wherein the order in the list is determined by the length of the period, and/or the data size of said TT flows, for example, by selecting the first TT flow(s) in said sorted list of all TT flows. A different implementation of the first feedback loop may choose said TT flow(s) to be rerouted based on a different sorted list of all TT flows, wherein the order in said list is determined by the required bandwidth utilization to transmit said TT flow(s), or the density of the already scheduled transmissions, for example measured as the number of scheduled flows per time unit or measured as the portion of time occupied by the transmission of scheduled flows per defined time unit, on the links comprised in the routes of said TT flow(s), wherein a high bandwidth utilization or high density of scheduled transmissions restrict the transmission opportunities for RC flows, and therefore affect the fulfillment of constraints. Another implementation of the second feedback loop may choose said TT flow(s) based on a predefined order among all TT flows, or based on a random selection. Flow Selection in the Third Feedback Loop In the case that the analysis module determines that not all constraints are fulfilled, or the routing module cannot compute a new route for one or multiple selected flow(s), the second feedback loop may select one, or multiple, of the communication flows in the set of communication flows to be rerouted by the routing module. An implementation of the third feedback loop may choose said communication flow(s) to be rerouted based on a sorted list of all communication flows, wherein the order in the list is determined by the length of the period, and/or the data size of said TT flows, for example, by selecting the first TT flow(s) in said sorted list of all TT flows. A different implementation of the third feedback loop may choose said communication flow(s) to be rerouted based on a different sorted list of all communication flows, wherein the order in said list is determined by the number of constraints affecting said communication flows, for example, by selecting the first communication flow(s) in said sorted list of all communication flows. Yet a different implementation of the third feedback loop may choose said communication flow(s) to be rerouted based on a different sorted list of all communication flows, wherein the order in said list is determined by an estimation of the effect on the fulfillment of constraints determined by the formal analysis, wherein said estimation may be, for example, determined by simulating the removal of said (set of) communication flow(s) and performing the formal analysis without said (set of) communication flow(s). Another implementation of the third feedback loop may choose said communication flow(s) based on a predefined order among all communication flows, or based on a random selection. EXAMPLE A simple example is shown inFIG.2, which depicts a network, wherein the network topology of said network comprises five components, namely two nodes400,430and three starcouplers410,420,440, and a set of communication flows, in particular two TT flows, f1with source node400and destination node430, wherein f1is characterized by a period of 20 ms and a data size of 1500 kbyte, and TT flow f2with source node400and destination node430, f2characterized by a period of 10 ms and a data size of 500 kbytes. Furthermore, f1and f2are constrained with scheduling constraint c1and c2, wherein c1constrains the transmission time of f1to be 1 ms relative to the beginning of its 20 ms period and c2constrains the transmission time of f2to be 1 ms relative to the beginning of its 10 ms period. On a first step of the method, the routing module computes routes for f1, and f2, determining for both the same route, comprising the network components, from source to destination, node400—starcoupler410—starcoupler420—node430. On a second step of the method, the scheduling module computes schedules for f1satisfying constraints c1, and concludes that a schedule for f2satisfying constraints c2cannot be computed, in particular, due to both constraints c1and c2, requiring network packets of f1and f2being scheduled in the same link at the same time. A representation of the schedule upon said second step is depicted inFIG.3, with packet500of flow f1and packets510,520of flow f2, wherein the second packet520of f2, with a period of 10 ms, can be scheduled in the link from node400—to node410(instant t2), but the network packet500of f1and the first network packet510of f2are scheduled in at the same instant t1relative to the beginning of their periods. On a third step of the method, the first feedback loop selects f2based on the shortest communication period to be rerouted by the routing module. On a fourth step of the method, the routing module computes a new route for f2, determining the route comprising the network components, from source to destination, node400—starcoupler440—node450. On a fifth step of the method, the scheduling module computes a new schedule for f2satisfying constraints c2. A representation of the schedule upon said fifth step is depicted inFIG.4, wherein the packet500of f1is scheduled at instant t1for transmission in the link from node400to starcoupler410and the packets510,520of2are scheduled at instants t1and t2for transmission in the link from node400to starcoupler440, hence allowing both constraints c1, and c2to be fulfilled. On a sixth step of the method, the analysis module determines that all constraints are fulfilled, and terminates providing the final configuration comprising the routes and schedule for f1and f2. | 33,972 |
11943047 | DETAILED DESCRIPTION Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains may easily carry out the exemplary embodiments. The present invention may be embodied in many different forms and is not limited to the exemplary embodiments described herein. Portions unrelated to the description may be omitted in order to more clearly describe the present invention, and the same or similar components may be denoted by the same reference numerals throughout the present specification. In addition, unless explicitly described to the contrary, the word “comprise”, and variations, such as “comprises” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. Hereinafter, a CRPA neutralization device for an illegal unmanned aerial vehicle (UAV) according to an exemplary embodiment of the present invention will be described with reference toFIGS.1to3. FIG.1is a view illustrating an apparatus of controlled reception pattern antenna (CRPA) neutralization for an illegal unmanned aerial vehicle (UAV) according to an exemplary embodiment of the present invention.FIG.2is a view illustrating a passive propagation mirror according to an exemplary embodiment of the present invention.FIG.3is a view illustrating a reflected wave generating region and an effective gain of a passive propagation mirror according to an exemplary embodiment of the present invention. Referring toFIGS.1to3, an illegal UAV (e.g., a drone) may be equipped with a controlled reception pattern antenna (CRPA)20, which is a satellite navigation device based on multiple elements. In other words, the illegal UAV may be an unauthorized threat target aero vehicle equipped with a satellite navigation device to which the CRPA20based on an operable N-element array antenna is applied. In order to neutralize the CRPA20of such an illegal UAV, the apparatus of CRPA neutralization for an illegal UAV according to an exemplary embodiment of the present invention may include an interference signal generator110and a passive propagation mirror210. The interference signal generator110may transmit a direct wave DW toward the CRPA20of the illegal UAV through a first transmission antenna TX1, and transmit a reflected wave inducing signal GRW toward the passive propagation mirror210through a second transmission antenna TX2. The interference signal generator110may adjust a propagation direction of the direct wave DW and a propagation direction of the reflected wave inducing signal GRW by mechanically moving the first transmission antenna TX1and the second transmission antenna TX2. That is, the interference signal generator110may adjust the propagation direction of the direct wave DW and the propagation direction of the reflected wave inducing signal GRW by mechanical beam steering. Alternatively, each of the first transmission antenna TX1and the second transmission antenna TX2may be an array antenna including a plurality of antenna elements, and the interference signal generator110may adjust the propagation direction of the direct wave DW and the propagation direction of the reflected wave inducing signal GRW by adjusting signals input to the plurality of antenna elements. That is, the interference signal generator110may adjust the propagation direction of the direct wave DW and the propagation direction of the reflected wave inducing signal GRW through electrical beam steering or beamforming. The passive propagation mirror210may reflect the reflected wave inducing signal GRW propagated from the interference signal generator110toward the CRPA20of the illegal UAV, so that the reflected wave RW directly propagates toward the CRPA20of the illegal UAV. The passive propagation mirror210may be configured to rotate a reflector in an azimuth direction with respect to a first axis Ax1and tilt the reflector in an elevation direction with respect to a second axis Ax2in a non-powered manner so that the reflected wave RW may be reflected/propagate in a desired direction. A direction in which the passive propagation mirror210reflects/propagates the reflected wave RW may be fixed according to a positional relationship with the interference signal generator110. Alternatively, according to an exemplary embodiment, the passive propagation mirror210may rotate or tilt the reflector according to remote control of the interference signal generator110or a central control center (not shown) to change a reflected/propagated direction of the reflected wave RW. The interference signal generator110and the passive propagation mirror210may be located in different regions or at a long distance on a line of sight (LOS). Accordingly, the direct wave DW and the reflected wave RW may be incident on the CRPA20of the illegal UAV in different directions. The direct wave DW and the reflected wave RW are interference signals that are incident in different directions and neutralize the CRPA20of the illegal UAV. In order to neutralize a navigation device for an illegal UAV equipped with a CRPA, interference signal generating equipment of high power ranging from tens of kilowatts to hundreds of kilowatts is required, depending on the performance of the CRPA. In addition, an illegal UAV attack may be handled only when the number of interference signal generating equipment proportional to the number of installed CRPA array elements is spatially distributed and arranged. However, it may be difficult to respond to illegal UAVs in a situation in which the interference signal generating equipment should be operated in a mountainous terrain where it is not easy to operate the interference signal generating equipment or in an area in which it is impossible to operate a high-capacity generator. In this case, by installing the passive propagation mirror210according to an exemplary embodiment of the present invention in a mountainous terrain or an area in which it is impossible to operate a high-capacity generator, the number of interference signals for neutralizing the CRPA20of an illegal UAV may be easily increased. FIG.1illustrates the passive propagation mirror210in which a reflector has a rectangular shape. An effective area of the passive propagation mirror210in which the reflector has a rectangular shape may be a width and height of the reflector. According to an exemplary embodiment, as shown inFIG.2, a passive propagation mirror210′ having a circular reflector may be used to adjust a beam width or the like for a radiation pattern. An effective area of the passive propagation mirror210′ having a circular reflector may be an area of a circle. Hereinafter, the passive propagation mirror210having a rectangular reflector will be described as an example. The reflected wave RW reflected by the passive propagation mirror210and propagated to the CRPA20may be reflected in a beam pattern design of the passive propagation mirror210required for an operational area in which the CRPA20is to be neutralized in consideration of a 3 dB bandwidth HBW and a dB bandwidth TBW from a radiation pattern indicated in the effective gain of the passive propagation mirror illustrated inFIG.3. Equation 1 is a relational equation for calculating a gain of an ideal case for the effective gain of the passive propagation mirror, and in practice, the performance may be predicted by applying an effective reflection gain considering reflection efficiency expressed in Equation 2 expressed in decibels. GP=4πAλ2(Equation1)GP′[dBi]=20log(4πAeλ2)+20logη(Equation2) Here, Gp is a normal gain, G′p is a gain converted to decibels, and η is efficiency. In calculating a reflection gain for a GPS L1 signal using the relational expressions of Equations 1 and 2, when a square type reflector with a frequency f=1.6 G, a wavelength of about 0.2 m, and a reflector aperture of 8×6 m2is applied, Gp is about 93.56 dB. In addition, based on these analysis values, expected performance required when designing a reflector of the passive propagation mirror210may be derived additionally in consideration of reflection efficiency and the like. Hereinafter, an apparatus of CRPA neutralization for an illegal UAV according to another exemplary embodiment of the present invention will be described with reference toFIG.4. Compared with the exemplary embodiment ofFIGS.1to3, differences will be mainly described. FIG.4is a view illustrating an apparatus of CRPA neutralization for an illegal UAV according to another exemplary embodiment of the present invention. Referring toFIG.4, an apparatus of CRPA neutralization for an illegal UAV may include an interference signal generator110, a first passive propagation mirror210, and a second passive propagation mirror220located in different areas. That is, the apparatus of CRPA neutralization for an illegal UAV may include a plurality of passive propagation mirrors210and220. The interference signal generator110may transmit a direct wave DW toward the CRPA20of the illegal UAV through the first transmission antenna TX1and transmit a first reflected wave inducing signal GRW toward the first passive propagation mirror210through the second transmission antenna TX2so that the first reflected wave RW propagates toward the CRPA20of the illegal UAV. In addition, the interference signal generator110may transmit a second reflected wave inducing signal GRW′ toward the second passive propagation mirror220through the third transmission antenna TX3. The second reflected wave RW′ may be reflected by the second passive propagation mirror220and propagate toward the CRPA20of the illegal UAV. In other words, the interference signal generator110may transmit the direct wave DW toward the CRPA20of the illegal UAV and propagate a plurality of reflected waves RW and RW′ toward the CRPA20of the illegal UAV using the plurality of passive propagation mirrors210and220. The direct wave DW and the plurality of reflected waves RW and RW′ may be incident on the CRPA20of the illegal UAV in different directions to neutralize the CRPA20. The interference signal generator110may transmit the first reflected wave inducing signal GRW and the second reflected wave inducing signal GRW′ to the first passive propagation mirror210and the second passive propagation mirror220only at a necessary time and position for the moving illegal UAV. That is, the first passive propagation mirror210and the second passive propagation mirror220may be arranged to propagate the reflected waves RW and RW′ toward different points in an expected movement path of the illegal UAV, and the interference signal generator110may selectively transmit the first reflected wave inducing signal GRW and the second reflected wave inducing signal GRW′ in response to the moving position of the illegal UAV. According to an exemplary embodiment, the interference signal generator110may simultaneously transmit the first reflected wave inducing signal GRW and the second reflected wave inducing signal GRW′, or sequentially transmit the first reflected wave inducing signal GRW and the second reflected wave inducting signal GRW′ according to a pre-programmed sequence. The characteristics of the second transmission antenna TX2and the first passive propagation mirror210described above in the exemplary embodiments ofFIGS.1to3may be equally applied to the characteristics of the third transmission antenna TX3and the second passive propagation mirror220. Hereinafter, an apparatus of CRPA neutralization for an illegal UAV according to another exemplary embodiment of the present invention will be described with reference toFIG.5. Compared to the exemplary embodiment ofFIGS.1to3, differences will be mainly described. FIG.5is a view illustrating an apparatus of CRPA neutralization for an illegal UAV according to another exemplary embodiment of the present invention. Referring toFIG.5, the apparatus of CRPA neutralization for an illegal UAV may include an interference signal generator110, a first passive propagation mirror210, and a second passive propagation mirror220located in different areas, and after receiving a GNSS (Global Navigation Satellite System) signal (satellite signal), the interference signal generator110may perform rebroadcast jamming (or meaconing) of re-radiating. The interference signal generator110may transmit a direct wave DW toward the CRPA20of the illegal UAV through the first transmission antenna TX1and transmit the first reflected wave inducing signal GRW toward the first passive propagation mirror210through the second transmission antenna TX2so that the first reflected wave RW propagates toward the CRPA20of the illegal UAV. In addition, the interference signal generator110may receive a GNSS signal through a reception antenna RX, amplify the received GNSS signal by an amplifier Amp to generate a GNSS re-radiation signal GNSS′, and then transmit the GNSS re-radiation signal GNSS′ toward the second passive propagation mirror220through the third transmission antenna TX3. The GNSS reradiation signal GNSS′ may be reflected by the second passive propagation mirror220and propagate toward the CRPA20of the illegal UAV. The GNSS re-radiation signal GNSS′ propagating by including a reflection path by the second passive propagation mirror220may further extend a pseudorange extension for the GNSS signal, thereby increasing a pseudorange error for the CRPA20. rebroadcast jamming (or meaconing) technique of a GNSS signal (satellite signal) may cause jamming and positional error for a satellite navigation device to which the CRPA20is applied. The characteristics of the second transmission antenna TX2and the first passive propagation mirror210described above in the exemplary embodiments ofFIGS.1to3may be equally applied to the characteristics of the third transmission antenna TX3and the second passive propagation mirror220. Hereinafter, an apparatus of CRPA neutralization for an illegal UAV according to another exemplary embodiment of the present invention will be described with reference toFIG.6. Compared to the exemplary embodiment ofFIGS.1to3, differences will be mainly described. FIG.6is a view illustrating an apparatus of CRPA neutralization for an illegal UAV according to another exemplary embodiment of the present invention. Referring toFIG.6, the apparatus of CRPA neutralization for an illegal UAV may include the interference signal generator110and the passive propagation mirror210located in different areas, and the interference signal generator110may receive a GNSS signal (a satellite signal) and then perform rebroadcast jamming (or meaconing) of re-radiating. The interference signal generator110may transmit the direct wave DW toward the CRPA20of the illegal UAV through the first transmission antenna TX1and transmit the reflected wave inducing signal GRW toward the passive propagation mirror210through the second transmission antenna TX2so that the reflected wave RW propagates toward the CRPA20of the illegal UAV. In addition, the interference signal generator110may receive a GNSS signal through a reception antenna RX, amplify the received GNSS signal with the amplifier Amp to generate a GNSS re-radiation signal GNSS′, and then transmit the GNSS re-radiation signal GNSS′ toward the passive propagation mirror210through the third transmission antenna TX3. The GNSS reradiation signal GNSS′ may be reflected by the passive propagation mirror210and propagate toward the CRPA20of the illegal UAV. The propagated GNSS re-radiation signal GNSS′ including the reflection path by the passive propagation mirror210may further extend a pseudorange extension for the GNSS signal, thereby extending a pseudorange error for the CRPA20. In other words, the interference signal generator110may transmit the reflected wave inducing signal GRW and the GNSS re-radiation signal GNSS′ toward one passive propagation mirror210so that the reflected wave RW reflected by the passive propagation mirror210and the GNSS re-radiation signal GNSS′ may propagate toward the CRPA20of the illegal UAV. The characteristics of the second transmission antenna TX2described above in the exemplary embodiments ofFIGS.1to3may be equally applied to the characteristics of the third transmission antenna TX3. Hereinafter, a method of CRPA neutralization for an illegal UAV according to an exemplary embodiment of the present invention will be described with reference toFIG.7. FIG.7is a view illustrating a method of CRPA neutralization for an illegal UAV according to an exemplary embodiment of the present invention. Referring toFIG.7, the method of Method of CRPA neutralization for an illegal UAV according to an exemplary embodiment of the present invention is a method of overcoming a satellite navigation device to which the CRPA20based on an N-element array antenna that may be mounted and operated on a small illegal UAV known as a fatal threat expected worldwide is applied by applying the concept of passive propagation mirrors210and220. This may have a very efficient advantage in terms of operability differentiated from the existing method that may neutralize the CRPA20of an illegal UAV, which is a threat target, by minimizing the number of physical RF interference signal transmitters in operation. It is assumed that an illegal UAV is equipped with a 4-element CRPA20. The first interference signal generator110is installed in a first area, the first passive propagation mirror210is installed in a second area, the second interference signal generator120is installed in a third area, and the second passive propagation mirror220is installed in a fourth area. The first area and the third area may be areas, such as a city center equipped with infrastructure, such as accessibility for equipment operators and large-capacity power supply, and may be areas in which GNSS high-power jammer operation is easy in reality. Meanwhile, the second area and the fourth area may be mountainous regions in which it is not easy to operate high-power RF equipment or areas in which it is difficult to install, operate, and permit an L-band radio wave transmission device for GNSS. Since the first passive propagation mirror210and the second passive propagation mirror220may be installed in the second and fourth areas in which it is impossible to directly install and operate high-power jammer equipment, the penetration of illegal UAVs may be effectively prevented even in these areas. The first interference signal generator110may transmit a direct wave DW toward the CRPA20of the illegal UAV through the first transmission antenna TX1in the manner described above with reference toFIG.6, and transmit a reflected wave inducing signal GRW toward the first passive propagation mirror210through the second transmission antenna TX2, so that the reflected wave RW propagates toward the CRPA20of the illegal UAV. Also, the first interference signal generator110may receive a GNSS signal through the reception antenna RX, amplify the received GNSS signal with the amplifier Amp to generate a GNSS re-radiation signal GNSS′, and then transmits the GNSS re-radiation signal GNSS′ toward the first passive propagation mirror210through the third transmission antenna TX3. The GNSS re-radiation signal GNSS′ may be reflected by the first passive propagation mirror210and propagate toward the CRPA20of the illegal UAV. The second interference signal generator120may transmit the direct wave (DW′) toward the CRPA20of the illegal UAV through the first transmission antenna TX1′ and transmit the reflected wave inducing signal GRW′ toward the second passive propagation mirror220through the second transmission antenna TX2′ in the similar manner as that described above with reference toFIG.6, so that the reflected wave RW′ may propagate toward the CRPA20of the illegal UAV. In addition, the second interference signal generator120may receive the GNSS signal through the reception antenna RX′, amplify the received GNSS signal with the amplifier Amp to generate a GNSS re-radiation signal GNSS″, and then transmit the GNSS re-radiation signal GNSS″ toward the second passive propagation mirror220through a third transmission antenna TX3′. The GNSS reradiation signal GNSS″ may be reflected by the second passive propagation mirror220and propagate toward the CRPA20of the illegal UAV. AlthoughFIG.7illustrates a method of neutralizing the CRPA20of an illegal UAV using the apparatus of CRPA neutralization for the illegal UAV ofFIG.6, at least one of the exemplary embodiment ofFIG.1, the exemplary embodiment ofFIG.4, the exemplary embodiment ofFIG.5, and the exemplary embodiment ofFIG.6may be installed/used in a complex manner to neutralize the CRPA20of an illegal UAV. The direct waves DW and DW′ and the reflected waves RW and RW′ incident in four different directions may exceed the degree of freedom (DOF) condition of the four-element CRPA20of the illegal UAV to neutralize the CRPA20. In addition, the GNSS re-radiation signals GNSS′ and GNSS″ may further extend a pseudorange extension for the GNSS signal, thereby extending a pseudorange error for the CRPA20. The method of CRPA neutralization for an illegal UAV according to an exemplary embodiment of the present invention may neutralize the CRPA20of an illegal UAV by operating physical high-power RF interference signal sources, that is, the interference signal generators110and120, which are fewer than N−1 interference signal sources, which are DOF conditions of an array antenna adaptive signal processing technology known as the number of simultaneously responding interference sources, so that the an illegal UAV equipped with a miniaturized CRPA20may be neutralized. That is, the method of CRPA neutralization for an illegal UAV is a CRPA20countermeasure technique using the minimum number of interference signal generators110and120using non-power passive propagation mirrors210and220. The method of CRPA neutralization for an illegal UAV according to an exemplary embodiment of the present invention uses a theoretical limit based on the constraint of a null steering or beam steering algorithm that transforms and applies array signal processing based on an N-element antenna to GPS CRPA, and uses a theoretical limit of a technical response to the number of jammers in different directions in the general nulling CRPA algorithm. This theory is explained using mathematical axioms as follows. The degree of freedom (DOF) in an array antenna refers to the number of sets of weights capable of synthesizing beams (or nulls) in a desired direction, which is equal to the number N of array antenna elements. Also, if the weight set w=[0 0]T, which is a general trivial solution, is excluded, the number of available sets becomes N−1 according to a mathematical axiom in which one constraint is reduced. A gain of the array antenna under these conditions may be expressed as Equation 3, which is a function of a direction of an input signal and the weight w. A gain function of an array antenna is a combination of an input signal direction and a weight. f(θ,ϕ,ω)={tilde over (ω)}1+{tilde over (ω)}2e−jϕ2(θ,ϕ,ω)+ . . . +−(Equation 3) Here, θ denotes an elevation angle, ϕ denotes an azimuth angle, ω denotes an angular frequency, anddenotes a direction component on which an Nth signal is incident. In general, a power minimization algorithm applied to the CRPA20operates to fix a reference antenna weight to unit gain “1” and remove L GNSS interference signals at the same time, and thus, it may be expressed as a determinant such as Equation 4. [1e-jϕ2(θ1,ϕ1,ω1)…e-jϕN(θ1,ϕ1,ω1)1e-jϕ2(θ2,ϕ2,ω2)…e-jϕN(θ2,ϕ2,ω2)⋮⋮⋱⋮1e-jϕ2(θL,ϕL,ωL)…e-jϕN(θL,ϕL,ωL)][1w~2⋮w~N]=[00⋮0](Equation4) Here, N is the number of antenna elements and L is the number of interference signals. Also, there should be a weight W that satisfies the right side of Equation 4. In order to calculate a solution that satisfies these conditions, in the relationship between the number of equations L and the number of unknowns N−1 in Equation 4, the unknowns may be solved for a case in which L≤N−1 is satisfied, and thus, the number of interference signals (jammers) that may be processed by the signal processing technique in the CRPA20may be induced to be limited to a maximum of N−1. A weight vector solution that may be calculated through Equations 3 and 4 may be expressed in the form of an optimal solution as shown in Equation 5 below. Woptimal=R−1×δ (Equation 5) Here, woptimalis an optimal weight vector, and R is a covariance matrix of an array antenna or a correlation matrix for an input sample and may be expressed as@@@, including constraints on a reference antenna. For the CRPA20, a null steering or beam steering algorithm operates for an external signal received above a noise level of a receiver. Using this principle, the CRPA20may be neutralized using the passive propagation mirrors210and220capable of reflecting signals higher than the noise level in consideration of spatial loss for radio waves. For example, in the case of the basic 4-element CRPA20, the CRPA20may be neutralized using two interference signal generators110and120corresponding to N−2 high-power RF interference sources and two passive radio propagation mirrors210and220. If the CRPA20is an extended type with 8 elements, an electronic attack scenario exceeding N−1 degree of freedom condition may be developed by operating 4 levels of N−4 RF interference signal sources (jammers) and 4 passive propagation mirrors. As an example of specific application, areas (the first area and the third area) in which the interference signal generators110and120(interference signal sources) may be operated and areas (the second area and the fourth area) in which the interference signal generators110and120cannot be operated may be distinguished from each other by recognizing an expected attack path of an illegal UAV equipped with the CRPA20for major facilities or targets and considering the number of GNSS interference sources that may be actually operated. For an operation of an interference signal source to cope with an actual illegal UAV, an area in which a physical high-power RF interference signal source is to be operated and the passive propagation mirrors210and220for inducting a reflected signal may be disposed such that visibility of the reflected wave inducing signals GRW and GWR′ and the passive propagation mirrors210and220are secured in an expected flight path section by predicting an expected appearance and departure point of the illegal UAV according to the size of the equipment and the requirements for operation (altitude, directionality, power supply, influence of surrounding radio interference, etc.). In general, a 4-element CRPA20is applied to small aero vehicles, such as drones. Based on this, the two interference signal generators110and120, which are high-power RF generators, are placed in the optimal positions analyzed by the operator, and the corresponding passive propagation mirrors210and220may be installed in the corresponding section and operate. In addition, a preemptive defense area for an expected flight trace of an illegal UAV may be established, and may be set and operated as a drone safety dome area. If an illegal UAV (drone) appears in the drone safety dome area, it may be detected and precisely tracked by a smart drone detection system, such as low-altitude radar or EO/IR, and in the case of a detour flight to an area outside the drone safety dome area, a protection area or section may be artificially changed by adjusting the azimuth and elevation angles of an additional passive propagation mirror or an existing reflector. In the method of CRPA neutralization for an illegal UAV according to an exemplary embodiment of the present invention, regardless of the number N of array elements of CRPA20, an illegal UAV may be neutralized by extending a response area to remote areas including mountainous areas by a relatively small number of RF transmitters (jammers) based on the N−1 reference of the degree of freedom condition, which is a basic measure of CRPA performance. The drawings referred to and the detailed descriptions of the present invention are merely illustrative and have been used to describe the present invention but not intended to limit the scope of the present invention described in claims. Therefore, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the disclosure as disclosed in the accompanying claims. Therefore, the technical scope of the present invention should be defined by the technical spirit and scope of the accompanying claims. | 28,845 |
11943048 | DESCRIPTION OF EMBODIMENTS The following clearly describes the technical solutions in the embodiments of this disclosure with reference to the accompanying drawings in the embodiments of this disclosure. Apparently, the described embodiments are merely some rather than all of the embodiments of this disclosure. All other embodiments that a person of ordinary skill in the art obtains based on the embodiments of this disclosure shall fall within the protection scope of this disclosure. In the specification and claims of this application, the terms “including”, and any other variants mean to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a list of steps or units is not necessarily limited to those steps or units, but may include other steps or units not expressly listed or inherent to such a process, method, product, or device. In addition, in the specification and claims, the use of “and/or” represents presence of at least one of the connected objects, for example, “A and/or B” indicates that the following three cases: only A, only B, or both A and B. In some embodiments of this disclosure, the word such as “exemplary” or “for example” is used to represent giving an example, an instance, or an illustration. Any embodiment or design scheme described as “an example” or “for example” in some embodiments of this disclosure should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the terms such as “an example” or “for example” are used to present related concepts in a specific manner. The following describes the embodiments of this disclosure with reference to the accompanying drawings. An Ethernet frame transmission method and a communications device provided in some embodiments of this disclosure can be applied to a wireless communications system. The wireless communications system may be a 5G system, an evolved long term evolution (eLTE) system, an LTE system, or a later evolved communications system. FIG.1is a schematic diagram of an architecture of a wireless communications system to which some embodiments of this disclosure may be applied. In this architecture, a terminal (for example, UE) and a wireless communications network constitute a bridge, as shown by a dashed-line box. The bridge is a virtual bridge. The bridge includes the terminal (for example, UE), a new radio-radio access network (NG-RAN), an access and mobility management function (AMF), a session management function (SMF), a policy control function (PCF), and a user plane function (UPF). For downlink data, the UE is an egress device of the bridge (Bridge), and the UPF is an ingress device of the bridge. For uplink data, the UE is an ingress device of the bridge, and the UPF is an egress device of the bridge. In addition, the UE may establish a connection with a first external device, and the UPF may establish a connection with a second external device. It should be noted that in some embodiments of this disclosure, the external device is not limited, and may be any device that can establish a connection with the UE or the UPF. It should be noted that in some embodiments of this disclosure, the terminal may be user equipment (UE) or other terminal-side devices, for example, a mobile phone, a tablet personal computer (Tablet Personal Computer), a laptop computer (Laptop Computer), a personal digital assistant (PDA for short), a mobile Internet device (MID), or a wearable device (Wearable Device). It should be noted that the terminal is not limited to any specific type in some embodiments of this disclosure. In some embodiments of this disclosure, a core-network element (CN network element) may include, but is not limited to, at least one of the following: a core network device, a core network node, a core network function, a core-network element, a mobility management entity (MME), an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a serving gateway (serving GW, SGW), a PDN gateway (PDN Gate Way), a policy control function (PCF), a policy and charging rules function (PCRF), a serving GPRS support node (SGSN), a gateway GPRS support node (GGSN), and a radio access network device. In some embodiments of this disclosure, a RAN network element may include, but is not limited to, at least one of the following: a radio access network device, a radio access network node, a radio access network function, a radio access network unit, a 3GPP radio access network, a non-3GPP radio access network, a centralized unit (CU), a distributed unit (DU), a base station, an evolved NodeB (evolved Node B, eNB), a 5G base station (gNB), a radio network controller (RNC), a NodeB (NodeB), a non-3GPP interworking function (N3IWF), an access controller (AC) node, an access point (AP) device, or a wireless local area network (WLAN) node. In addition, some embodiments of this disclosure are not limited to the network architecture inFIG.1, and may be applied to, for example, a communications system architecture without a bridge. FIG.2is a flowchart of an Ethernet frame transmission method according to some embodiments of this disclosure. The method is applied to a first device, and includes the following steps, as shown inFIG.2. Step201: Remove a specified field from an Ethernet frame. The specified field may be a specified field corresponding to a format of the Ethernet frame (which may also be referred to as a frame format). For example, corresponding specified fields may be configured in advance for different formats. Certainly, this is not limited. For example, the specified field may be specified by a protocol to be, for example, a preamble field or a start frame delimiter field. Alternatively, the specified field may be configured by a network or the like. The Ethernet frame may be an uplink Ethernet frame or a downlink Ethernet frame. Step202: Transmit the Ethernet frame with the specified field removed to a second device. With the foregoing step, the Ethernet frame can be compressed for transmission, thereby reducing resource overheads required for transmitting the Ethernet frame. It should be noted that in some embodiments of this disclosure, the first device may be an ingress device of a bridge, and the second device may be an egress device of the bridge. For example, the first device may be an ingress device in the network architecture inFIG.1orFIG.2or in a 5G system, and the second device may be an egress device in the network architecture inFIG.1orFIG.2or in the 5G system. Certainly, this is not limited. For example, in some embodiments of this disclosure, when applied to a network architecture other than the network architectures inFIG.1andFIG.2, the first device may be a terminal, a core-network element (for example, an UPF), or the like in the network architecture, and the second device may be a core-network element or a terminal. In an optional embodiment, the specified field includes at least one of the following: a preamble (preamble) field, a start frame delimiter (SFD) field, a frame check sequence (FCS) field, a length (length) field, a padding field, and an extension field. The preamble field may be an N-byte preamble field at the start of the Ethernet frame, for example, a 7-byte preamble field at the start of the Ethernet frame. The start frame delimiter field may be a 1-byte start frame delimiter field immediately following the preamble field in the Ethernet frame. The length field may be an M-byte (for example, 2-byte) length field preceding a data field in the Ethernet frame, and may be used to indicate a length of the data field. The frame check sequence field may be a K-byte (for example, 4-byte) frame check sequence field following the data field or the padding field in the Ethernet frame. The padding field may be a padding (padding) field following the data field in the Ethernet frame. The extension field (or referred to as an extension bit field) may be an extension (extension) field at the end of the Ethernet frame. It should be noted that in practical application, some Ethernet frames may include different fields. For example, some Ethernet frames include a length field, a frame check sequence field, a padding field, and an extension field. However, some other Ethernet frames may exclude at least one of the length field, the frame check sequence field, the padding field, and the extension field. In this case, the specified field also excludes these fields. However, it should be noted that when the Ethernet frame includes all of the plurality of fields, it does not mean that the specified field includes the plurality of fields. The specified field may include only some of the plurality of fields. This may be set based on an actual situation. In this embodiment, at least one of the preamble field, the start frame delimiter field, the frame check sequence field, the length field, the padding field, and the extension field can be removed, thereby reducing resource overheads required for transmitting the Ethernet frame. Certainly, the removed field must be a field in the Ethernet frame. For example, if the Ethernet frame includes the frame check sequence field, the frame check sequence field is removed from the Ethernet frame; if the Ethernet frame includes the length field, the length field is removed from the Ethernet frame; if the Ethernet frame includes the padding field, the padding field is removed from the Ethernet frame; and if the Ethernet frame includes the extension field, the extension field is removed from the Ethernet frame. It should be noted that in some embodiments of this disclosure, neither the format or type of the Ethernet frame nor locations of the plurality of fields are limited. Optionally, the removing a specified field from an Ethernet frame includes at least one of the following: removing the frame check sequence field if it is determined, based on a first Ethernet frame size and a second Ethernet frame size, that the Ethernet frame includes the frame check sequence field or if it is determined, based on a format of the Ethernet frame, that the Ethernet frame includes the frame check sequence field, where the first Ethernet frame size is an actually received Ethernet frame size of the Ethernet frame, and the second Ethernet frame size is an Ethernet frame size determined by parsing the format of the Ethernet frame; removing the padding field if it is determined, based on an actual data field length of the Ethernet frame and a protocol-prescribed minimum data field length corresponding to a format of the Ethernet frame, that the Ethernet frame includes the padding field or if it is determined, based on a type field in the Ethernet frame, that the Ethernet frame includes the padding field, where the actual data field length is a length indicated by the length field, or the actual data field length is a data field length of the Ethernet frame determined based on the type field in the Ethernet frame; and removing the extension field if it is determined, based on an Ethernet slot time and a minimum frame size supported by a format of the Ethernet frame, that the Ethernet frame includes the extension field. The including at least one of the following may be understood as including any one or more of the three items. An Ethernet frame size determined by parsing the format of the Ethernet frame excludes the frame check sequence field. The determining, based on a first Ethernet frame size and a second Ethernet frame size, that the Ethernet frame includes the frame check sequence field may be determining that the Ethernet frame includes the frame check sequence field if the first Ethernet frame size is different from the second Ethernet frame size; otherwise, determining that the Ethernet frame excludes the frame check sequence field. In addition, for some Ethernet frame formats, the frame check sequence field is constantly included or excluded. Therefore, it can be determined, based on the format of the Ethernet frame, whether the Ethernet frame includes the frame check sequence field. In this embodiment, whether the frame check sequence field is included can be accurately determined, and if the frame check sequence field is included, the frame check sequence field is removed, thereby reducing transmission resource overheads. The determining, based on an actual data field length of the Ethernet frame and a protocol-prescribed minimum data field length corresponding to a format of the Ethernet frame, that the Ethernet frame includes the padding field may be determining that the padding field is included if the actual data field length is less than the minimum data field length; otherwise, determining that the padding field is excluded. Optionally, a length of the padding field is a difference between the minimum data field length and the actual data field length. The determining, based on a type field in the Ethernet frame, that the Ethernet frame includes the padding field may be determining, based on the type field in the Ethernet frame, that the data field of the Ethernet frame carries an IP, address resolution protocol (ARP), or reverse address resolution protocol (RARP) data packet, so as to determine whether the Ethernet frame carries the padding field and the number of bytes occupied by the padding field. For example, if it is determined, based on the type field, that the data field of the Ethernet frame carries an ARP data packet, it can be determined, based on a fact that an ARP data packet constantly occupies 28 bytes, that the Ethernet frame carries the padding field, and then the number of bytes occupied by the padding field can be determined based on the minimum data field length. In this embodiment, whether the padding field is included can be accurately determined, and if the padding field is included, the padding field is removed, thereby reducing transmission resource overheads. The determining, based on an Ethernet slot time and a minimum frame size supported by a format of the Ethernet frame, that the Ethernet frame includes the extension field may be determining that the Ethernet frame includes the extension field if the minimum frame size is less than the slot time; otherwise, determining that the Ethernet frame excludes the extension field. Optionally, a length of the extension field is a difference between the slot time and the Ethernet frame size determined by parsing the format of the Ethernet frame, where the Ethernet frame size herein excludes the extension field. The Ethernet slot time information may be obtained through interaction between 5GS and Ethernet devices before data transmission is established. In this embodiment, whether the extension field is included can be accurately determined, and if the extension field is included, the extension field is removed, thereby reducing transmission resource overheads. Optionally, the method further includes at least one of the following: transmitting a first indication to the second device in a case that the frame check sequence field is removed, where the first indication is used to indicate that the frame check sequence field in the Ethernet frame is removed; and transmitting a second indication to the second device in a case that the extension field is removed, where the second indication is used to indicate that the extension field in the Ethernet frame is removed. It should be noted that the at least one may mean one or more of the two items. To be specific, in a cast that the frame check sequence field and the extension field are removed, the first indication and the second indication may be transmitted, or only the first indication or the second indication may be transmitted. For example, because it may be determined, based on the format of the Ethernet frame, whether the Ethernet frame includes the frame check sequence field, in this case, the first indication may not be transmitted. The first indication and the second indication may be transmitted in a same message or different messages, and certainly, may be transmitted in the Ethernet frame. For example, the first indication is indicated by one bit, and the second indication is indicated by another bit. In this embodiment, the first indication and/or second indication may be transmitted to accurately notify the second device of a field removal status of the Ethernet frame, so that the second device can correctly perform decompression. In an optional embodiment, the removing a specified field from an Ethernet frame includes: removing the specified field from the Ethernet frame if the received Ethernet frame is a valid Ethernet frame. In this embodiment, the specified field can be removed in the case of a valid Ethernet frame, thereby avoiding invalid operations so as to reduce power consumption. Optionally, the method further includes: discarding the Ethernet frame if the received Ethernet frame is an invalid Ethernet frame. Whether the Ethernet frame is an invalid Ethernet frame may be determined after the format of the received Ethernet frame is determined. The Ethernet frame may be determined to be a valid Ethernet frame if it is not an invalid Ethernet frame. For example, an invalid Ethernet frame is determined in the following manners: if a length of the Ethernet frame is not an integer number of bytes, the Ethernet frame is an invalid Ethernet frame; or if a value indicated by the length field of the Ethernet frame does not match a data field length of the Ethernet frame, the Ethernet frame is an invalid Ethernet frame; or if a frame check code calculated by the first device by using a frame check code algorithm does not match a value indicated by the frame check sequence field in the Ethernet frame, the Ethernet frame is an invalid Ethernet frame. The Ethernet frame may be determined to be a valid Ethernet frame if it is not an invalid Ethernet frame. That a value indicated by the length field of the Ethernet frame does not match a data field length of the Ethernet frame may be that the value indicated by the length field of the Ethernet frame is not consistent with the data field length of the Ethernet frame. The frame check code algorithm may be an algorithm prescribed by a protocol or configured by a network. That a frame check code calculated by the first device by using a frame check code algorithm does not match a value indicated by the frame check sequence field in the Ethernet frame may be that the frame check code calculated by the first device by using a frame check code algorithm is not consistent with the value indicated by the frame check sequence field in the Ethernet frame. In this embodiment, the invalid Ethernet frame can be discarded, thereby saving transmission resources and reducing power consumption. In an optional embodiment, the transmitting the Ethernet frame with the specified field removed to a second device may include: transmitting the Ethernet frame with the specified field removed to the second device through a RAN. The Ethernet frame may be an uplink Ethernet frame or a downlink Ethernet frame. Optionally, an Ethernet frame header of the Ethernet frame is a compressed Ethernet frame header, thereby further reducing the transmission overheads. For example, the compression may be removing the Ethernet frame header in the specified Ethernet frame field. The specified Ethernet frame field may include but is not limited to at least one of the following: a media access control MAC source address field, a MAC destination address field, a type field, a service tag (S-TAG) field, a priority code point (PCP) field, a drop eligibility indicator (DEI) field, and a VLAN identifier (VID) field. The Ethernet frame header may be compressed by the first device, such as a core-network element (for example, a UPF) or a terminal, and then transmitted to the RAN. In addition, if the Ethernet frame header is compressed by a core-network element, the network element may transmit relationship information including a value of the specified Ethernet frame field to a terminal and/or a RAN network element. Further, the relationship information may further include length information of the compressed Ethernet frame header, facilitating decompression by the terminal. Alternatively, the compression may be performed by a RAN network element. No limitation is imposed in this sense. For example, in a 5G system, if the 5G system makes configuration such that Ethernet frame header compression is performed between a terminal and a core network, the terminal and the core-network element are used as anchor points for Ethernet frame header compression and decompression, and a compressed Ethernet frame is transmitted to an egress device of the 5G system through a RAN. For another example, if the 5G system makes configuration such that Ethernet frame header compression is performed between a terminal and a RAN, the terminal and a RAN network element are used as anchor points for Ethernet frame header compression and decompression. In some embodiments of this disclosure, the specified field is removed from the Ethernet frame; and the Ethernet frame with the specified field removed is transmitted to the second device. Since the specified field is removed from the Ethernet frame, resource overheads required for transmitting the Ethernet frame can be reduced. FIG.3is another flowchart of an Ethernet frame transmission method according to some embodiments of this disclosure. The method is applied to a second device, and includes the following steps, as shown inFIG.3. Step301: Receive, from a first device, an Ethernet frame with a specified field removed. For the first device, the second device, the specified field, and the like, reference may be made to the corresponding description in the embodiment inFIG.2. Details are not repeated herein. Step302: Add the specified field to the Ethernet frame. The adding the specified field to the Ethernet frame may be understood as a decompression process: adding the specified field not transmitted in (that is, removed from) the Ethernet frame. Specifically, a value of the specified field is added. The foregoing method can implement transmission of the compressed Ethernet frame, thereby reducing resource overheads required for transmitting the Ethernet frame. In an optional embodiment, the specified field includes at least one of the following: a preamble field, a start frame delimiter field, a frame check sequence field, a length field, a padding field, and an extension field. For the specified field, reference may be made to the corresponding description in the embodiment inFIG.2. Details are not repeated herein. Optionally, a value of the length field corresponds to a data field length of the Ethernet frame. In this embodiment, it may be that if a corresponding Ethernet frame format of the Ethernet frame carries a length field, the length field is added to a specified location (that is, a location of the length field) in the Ethernet frame, and a value of the field is set to an actual data field length of the Ethernet frame. The preamble field may be set to a protocol-prescribed value at a preamble field location. For example, a 7-byte preamble field is added at a start location of the Ethernet frame, and a value of the field is set to a protocol-prescribed value. The start frame delimiter field may be set to a protocol-prescribed value at a start frame delimiter field location. For example, a 1-byte SFD field is added immediately following the preamble field, and a value of the field is set to a protocol-prescribed value. It should be noted that a location of each of the foregoing fields may be defined in a protocol, pre-configured, or the like. This is not limited. Optionally, the method further includes at least one of the following: receiving a first indication from the first device in a case that the frame check sequence field in the Ethernet frame is removed, where the first indication is used to indicate that the frame check sequence field in the Ethernet frame is removed; and receiving a second indication from the first device in a case that the extension field in the Ethernet frame is removed, where the second indication is used to indicate that the extension field in the Ethernet frame is removed. It should be noted that because whether the Ethernet frame includes the frame check sequence field may be determined based on a format of the Ethernet frame, the first indication may not be received in a case that the frame check sequence field is removed from the Ethernet frame, and whether the Ethernet frame includes the frame check sequence field is determined based on the format of the Ethernet frame. For the first indication and the second indication, reference may be made to the corresponding description in the embodiment inFIG.2. Details are not repeated herein. Optionally, the adding the specified field to the Ethernet frame includes at least one of the following: adding the frame check sequence field to the Ethernet frame if the first indication is received, where the frame check sequence field is calculated by using a frame check code algorithm; adding the extension field to the Ethernet frame if the second indication is received, where a length of the extension field is a difference between an Ethernet slot time and an actually received length of the Ethernet frame; and adding the padding field to the Ethernet frame if an actual data field length of the Ethernet frame is less than a protocol-prescribed minimum data field length corresponding to a format of the Ethernet frame, where a length of the padding field is a difference between the minimum data field length and the actual data field length. Values of the padding field and the extension field may be protocol-prescribed values. For this embodiment, reference may be made to the corresponding description in the embodiment inFIG.2. Details are not repeated herein. Same beneficial effects can be achieved. Optionally, the first device is an ingress device of a bridge, and the second device is an egress device of the bridge. For this embodiment, reference may be made to the corresponding description in the embodiment inFIG.2. Details are not repeated herein. Same beneficial effects can be achieved. Optionally, after the adding the specified field to the Ethernet frame, the method further includes: transmitting the Ethernet frame with the specified field added to an external device of the bridge. In this embodiment, a complete Ethernet frame can be transmitted to the external device to improve transmission performance. Optionally, the receiving, from a first device, an Ethernet frame with a specified field removed includes: receiving, from the first device through a RAN, the Ethernet frame with the specified field removed. For this embodiment, reference may be made to the corresponding description in the embodiment inFIG.2. Details are not repeated herein. Same beneficial effects can be achieved. Optionally, an Ethernet frame header of the Ethernet frame is a compressed Ethernet frame header, and after the receiving, from the first device through a RAN, the Ethernet frame with the specified field removed, the method further includes: decompressing the Ethernet frame header. The decompressing the Ethernet frame header may be adding the specified Ethernet frame field removed, for example, at least one of the following: a MAC source address field, a MAC destination address field, a type field, a service tag (S-TAG) field, a priority code point (PCP) field, a drop eligibility indicator (DEI) field, and a VLAN identifier (VID) field. A value of the specified Ethernet frame field may be obtained based on an uncompressed Ethernet frame header. To be specific, an Ethernet frame including an uncompressed Ethernet frame header may be transmitted first, and after it is successfully received, the Ethernet frame including the compressed Ethernet frame header may be transmitted. Alternatively, a value of the specified Ethernet frame field is configured based on relationship information, so that the Ethernet frame including the compressed Ethernet frame header can be directly transmitted. In this embodiment, the Ethernet frame with the specified field added or with the decompressed Ethernet frame header may be transmitted to the external device of the bridge. In this embodiment, the transmission overheads can be further reduced. In this embodiment, the resource overheads required for transmitting the Ethernet frame can be reduced. An example is used below for description. In the example, the first device is an ingress device (for example, UE or a UPF) of a 5G system, and the second device is an output device (for example, a UPF or UE) of the 5G system. Step 1: The ingress device of the 5G system receives an Ethernet frame from an external device (for example, an Ethernet transmit terminal device, a bridge, or an Ethernet switch), and processes the received Ethernet frame in any one of the following manners after parsing each field in the Ethernet frame and determining a specific format of the Ethernet frame: determining that the Ethernet frame is an invalid frame and discarding the Ethernet frame if a length of the received Ethernet frame is not an integer number of bytes; determining that the Ethernet frame is an invalid Ethernet frame and discarding the Ethernet frame if a value indicated by a length field in the Ethernet frame does not match a data field length of the Ethernet frame; determining that the Ethernet frame is an invalid Ethernet frame and discarding the Ethernet frame if a frame check code calculated by the ingress device by using an algorithm prescribed by a protocol or configured by a network does not match a value indicated by a frame check code field in the Ethernet frame; and determining that the received Ethernet frame is a valid Ethernet frame and processing a field in the Ethernet frame, if the ingress device of the 5G system does not discard the received Ethernet frame based on the foregoing determining conditions, where the processing is one or a combination of the following: removing a preamble field from the Ethernet frame, for example, a 7-byte preamble field at the start of the Ethernet frame; removing a start frame delimiter field from the Ethernet frame, for example, a 1-byte SFD (start frame delimiter) field immediately following the preamble field in the Ethernet frame; removing a frame check sequence field from the Ethernet frame if the Ethernet frame includes the frame check sequence field, for example, a 4-byte FCS (frame check sequence) field following a data field or a padding field; removing a length field from the Ethernet frame if the Ethernet frame includes the length field, for example, a 2-byte length field preceding the data field; removing the padding field from the Ethernet frame if the Ethernet frame includes the padding field, for example, a padding field following the data field; and removing an extension bit field from the Ethernet frame if the Ethernet frame includes the extension bit field, for example, an extension field at the end of the Ethernet frame. Removing the frame check sequence field (FCS) is specifically as follows: determining whether an actually received Ethernet frame size and an Ethernet frame size determined by parsing the Ethernet frame (excluding the frame check sequence field) are consistent, and if consistent, determining that the frame check sequence field is not carried, or if inconsistent, determining that the frame check sequence field is carried; removing four bytes following the data field or the padding field (if any) if it is determined that the Ethernet frame carries the frame check sequence field; and indicating, to the egress device, that the frame check sequence field is removed if the frame check sequence field has been removed. Removing the padding field (padding) is specifically as follows: determining whether the padding field is carried by comparing the value indicated by the length field with a minimum data field length prescribed by a corresponding protocol and determined based on an Ethernet frame format, for example, if the value is less than the minimum data field length prescribed by the protocol, determining that the padding field is carried; otherwise, determining that the padding field is not carried (applicable to Ethernet 802.3); or determining, based on a type field in the Ethernet frame, whether the padding field is carried (applicable to Ethernet II); and removing a byte following the data field in the Ethernet frame if it is determined that the Ethernet frame carries the padding field, where the specific number of bytes removed is equal to a difference between the minimum data field length supported by the protocol and an actual data field length. Removing the extension (extension) field is specifically as follows: determining whether the extension field is carried by comparing an Ethernet slot time (for example, a 1000-Mbps slot time (slotTime) is 512 bytes) with a minimum frame size supported by a corresponding Ethernet frame format, where for example, for a 10-Mbps or 100-Mbps Ethernet, if a slot time is fixedly 64 bytes, and a protocol-prescribed minimum Ethernet frame size is 64 bytes, in this scenario, a transmitted Ethernet frame does not carry the extension field; removing the extension field at the end of the Ethernet frame if it is determined that the Ethernet frame carries the extension field, where the specific number of bytes removed is equal to a difference of the Ethernet slot time and the Ethernet frame size (excluding the extension field) determined by parsing the Ethernet frame; and indicating, to the egress device of the 5G system, that the extension field is removed if the extension field has been removed. Step 2: The ingress device of the 5G system transmits the valid Ethernet frame processed in step 1 to a packet filter to obtain a quality of service flow (QoS flow), and transmits the QoS flow to the egress device of the 5G system through a RAN. In addition, if the 5G system configures that Ethernet frame header compression is performed between a terminal and a core network, the terminal and a core-network element are used as anchor points to perform Ethernet frame header compression and decompression, and the compressed Ethernet frame is transmitted to the egress device of the 5G system through the RAN; and if the 5G system configures that Ethernet frame header compression is performed between a terminal and a RAN, the terminal and a RAN network element are used as anchor points to perform Ethernet frame header compression and decompression. Step 3: Before transmitting the decompressed Ethernet frame, the egress device of the 5G system performs corresponding processing on the decompressed Ethernet frame according to a related instruction and/or an operation prescribed by a protocol, where the processing is one or a combination of the following: adding the preamble field to the Ethernet frame, for example, adding a 7-byte preamble field at a start location of the Ethernet frame, and setting a value of the field to a protocol-prescribed value; adding the start frame delimiter field to the Ethernet frame, for example, adding a 1-byte SFD field immediately following the preamble field, and setting a value of the field to a protocol-prescribed value; if a corresponding Ethernet frame format carries the length field, adding the length field to a specified location in the Ethernet frame and setting a value of the field to an actual data field length of the Ethernet frame; if the actual data field length of the Ethernet frame is less than a minimum data field length supported by the corresponding Ethernet frame format, adding the padding field following the data field of the Ethernet frame, and setting a value of the field to a protocol-prescribed value, where a length of the padding field is a difference between the minimum data field length supported by the Ethernet frame format and the actual data field length of the Ethernet; if an indication that the ingress device of the 5G system has removed the frame check sequence field is received, adding the frame check sequence field at a specified location in the Ethernet frame, and setting a value of the field to a frame check code value calculated by using an algorithm prescribed by a protocol or configured by a network; and if an indication that the ingress device of the 5G system has removed the extension bit field is received, adding the extension field at the end of the Ethernet frame, and setting a value of the field to a protocol-prescribed value, where a length of the extension field is a difference between an Ethernet slot time field and an actual Ethernet frame size corresponding to a restored Ethernet frame not transmitted in the 5GS. Step 4: The egress device of the 5G system transmits the Ethernet frame processed in step 3 to an external device (for example, an Ethernet receive terminal, a bridge, or an Ethernet switch). With the methods provided in some embodiments of this disclosure, specific processing can be performed on a field carried in an Ethernet frame while ensuring that the Ethernet frames can be transmitted in a wireless mobile communications system, thereby reducing resource overheads required for transmitting the Ethernet frame in a 5G system. FIG.4is a structural diagram of a communications device according to an embodiment of this disclosure. The communications device is a first device. As shown inFIG.4, the communications device400includes: a removing module401, configured to remove a specified field from an Ethernet frame; and a first transmission module402, configured to transmit the Ethernet frame with the specified field removed to a second device. Optionally, the specified field includes at least one of the following: a preamble field, a start frame delimiter field, a frame check sequence field, a length field, a padding field, and an extension field. Optionally, the removing module401is configured to perform at least one of the following: removing the frame check sequence field if it is determined, based on a first Ethernet frame size and a second Ethernet frame size, that the Ethernet frame includes the frame check sequence field or if it is determined, based on a format of the Ethernet frame, that the Ethernet frame includes the frame check sequence field, where the first Ethernet frame size is an actually received Ethernet frame size of the Ethernet frame, and the second Ethernet frame size is an Ethernet frame size determined by parsing the format of the Ethernet frame; removing the padding field if it is determined, based on an actual data field length of the Ethernet frame and a protocol-prescribed minimum data field length corresponding to a format of the Ethernet frame, that the Ethernet frame includes the padding field or if it is determined, based on a type field in the Ethernet frame, that the Ethernet frame includes the padding field, where the actual data field length is a length indicated by the length field; and removing the extension field if it is determined, based on an Ethernet slot time and a minimum frame size supported by a format of the Ethernet frame, that the Ethernet frame includes the extension field. Optionally, as shown inFIG.5, the communications device400further includes at least one of the following: a second transmission module403, configured to transmit a first indication to the second device in a case that the frame check sequence field is removed, where the first indication is used to indicate that the frame check sequence field in the Ethernet frame is removed; and a third transmission module404, configured to transmit a second indication to the second device in a case that the extension field is removed, where the second indication is used to indicate that the extension field in the Ethernet frame is removed. Optionally, a length of the padding field is a difference between the minimum data field length and the actual data field length; and/or a length of the extension field is a difference between the slot time and the Ethernet frame size determined by parsing the format of the Ethernet frame. Optionally, the removing a specified field from an Ethernet frame includes: removing the specified field from the Ethernet frame if the received Ethernet frame is a valid Ethernet frame. Optionally, as shown inFIG.6, the communications device400further includes: a discarding module405, configured to discard the Ethernet frame if the received Ethernet frame is an invalid Ethernet frame. Optionally, if a length of the Ethernet frame is not an integer number of bytes, the Ethernet frame is an invalid Ethernet frame; or if a value indicated by the length field of the Ethernet frame does not match a data field length of the Ethernet frame, the Ethernet frame is an invalid Ethernet frame; or if a frame check code calculated by the first device by using a frame check code algorithm does not match a value indicated by the frame check sequence field in the Ethernet frame, the Ethernet frame is an invalid Ethernet frame. Optionally, the first device is an ingress device of a bridge, and the second device is an egress device of the bridge. Optionally, the first transmission module402is configured to transmit the Ethernet frame with the specified field removed to the second device through a RAN. Optionally, an Ethernet frame header of the Ethernet frame is a compressed Ethernet frame header. The communications device400can implement the processes implemented by the first device in the method embodiment of this disclosure, with the same beneficial effects achieved. To avoid repetition, details are not described herein again. FIG.7is another structural diagram of a communications device according to some embodiments of this disclosure. The communications device is a second device. As shown inFIG.7, the communications device700includes: a first receiving module701, configured to receive, from a first device, an Ethernet frame with a specified field removed; and an adding module702, configured to add the specified field to the Ethernet frame. Optionally, the specified field includes at least one of the following: a preamble field, a start frame delimiter field, a frame check sequence field, a length field, a padding field, and an extension field. Optionally, as shown inFIG.8, the communications device700further includes at least one of the following: a second receiving module703, configured to receive a first indication from the first device in a case that the frame check sequence field in the Ethernet frame is removed, where the first indication is used to indicate that the frame check sequence field in the Ethernet frame is removed; and a third receiving module704, configured to receive a second indication from the first device in a case that the extension field in the Ethernet frame is removed, where the second indication is used to indicate that the extension field in the Ethernet frame is removed. Optionally, a value of the length field corresponds to a data field length of the Ethernet frame. Optionally, the adding module702is configured to perform at least one of the following: adding the frame check sequence field to the Ethernet frame if the first indication is received, where the frame check sequence field is calculated by using a frame check code algorithm; adding the extension field to the Ethernet frame if the second indication is received, where a length of the extension field is a difference between an Ethernet slot time and an Ethernet frame size (excluding the extension field) determined by parsing a format of the Ethernet frame; and adding the padding field to the Ethernet frame if an actual data field length of the Ethernet frame is less than a protocol-prescribed minimum data field length corresponding to a format of the Ethernet frame, where a length of the padding field is a difference between the minimum data field length and the actual data field length. Optionally, the first device is an ingress device of a bridge, and the second device is an egress device of the bridge. Optionally, as shown inFIG.9, the communications device700further includes: a transmission module705, configured to transmit the Ethernet frame with the specified field added to an external device of the bridge. Optionally, the first receiving module701is configured to receive, from the first device through a RAN, the Ethernet frame with the specified field removed. Optionally, an Ethernet frame header of the Ethernet frame is a compressed Ethernet frame header. As shown inFIG.10, the communications device700further includes: a decompressing module706, configured to decompress the Ethernet frame header. The communications device700can implement the processes implemented by the second device in the method embodiment of this disclosure, with the same beneficial effects achieved. To avoid repetition, details are not described herein again. FIG.11is another structural diagram of a communications device according to some embodiments of this disclosure. As shown inFIG.11, the communications device1100includes a memory1101, a processor1102, and a computer program11011stored in the memory1101and capable of running on the processor1102. When the communications device1100acts as the first device in the foregoing method embodiment, the following steps are implemented when the computer program11011is executed by the processor1102: removing a specified field from an Ethernet frame; and transmitting the Ethernet frame with the specified field removed to a second device. Optionally, the specified field includes at least one of the following: a preamble field, a start frame delimiter field, a frame check sequence field, a length field, a padding field, and an extension field. Optionally, the removing a specified field from an Ethernet frame includes at least one of the following: removing the frame check sequence field if it is determined, based on a first Ethernet frame size and a second Ethernet frame size, that the Ethernet frame includes the frame check sequence field or if it is determined, based on a format of the Ethernet frame, that the Ethernet frame includes the frame check sequence field, where the first Ethernet frame size is an actually received Ethernet frame size of the Ethernet frame, and the second Ethernet frame size is an Ethernet frame size determined by parsing the format of the Ethernet frame; removing the padding field if it is determined, based on an actual data field length of the Ethernet frame and a protocol-prescribed minimum data field length corresponding to a format of the Ethernet frame, that the Ethernet frame includes the padding field or if it is determined, based on a type field in the Ethernet frame, that the Ethernet frame includes the padding field, where the actual data field length is a length indicated by the length field; and removing the extension field if it is determined, based on an Ethernet slot time and a minimum frame size supported by a format of the Ethernet frame, that the Ethernet frame includes the extension field. Optionally, the processor1102is further configured to perform at least one of the following: transmitting a first indication to the second device in a case that the frame check sequence field is removed, where the first indication is used to indicate that the frame check sequence field in the Ethernet frame is removed; and transmitting a second indication to the second device in a case that the extension field is removed, where the second indication is used to indicate that the extension field in the Ethernet frame is removed. Optionally, a length of the padding field is a difference between the minimum data field length and the actual data field length; and/or a length of the extension field is a difference between the slot time and the Ethernet frame size determined by parsing the format of the Ethernet frame. Optionally, the removing a specified field from an Ethernet frame performed by the processor1102includes: removing the specified field from the Ethernet frame if the received Ethernet frame is a valid Ethernet frame. Optionally, the processor1102is further configured to perform the following: discarding the Ethernet frame if the received Ethernet frame is an invalid Ethernet frame. Optionally, if a length of the Ethernet frame is not an integer number of bytes, the Ethernet frame is an invalid Ethernet frame; or if a value indicated by the length field of the Ethernet frame does not match a data field length of the Ethernet frame, the Ethernet frame is an invalid Ethernet frame; or if a frame check code calculated by the first device by using a frame check code algorithm does not match a value indicated by the frame check sequence field in the Ethernet frame, the Ethernet frame is an invalid Ethernet frame. Optionally, the first device is an ingress device of a bridge, and the second device is an egress device of the bridge. Optionally, the transmitting the Ethernet frame with the specified field removed to a second device performed by the processor1102includes: transmitting the Ethernet frame with the specified field removed to the second device through a RAN. Optionally, an Ethernet frame header of the Ethernet frame is a compressed Ethernet frame header. When the communications device1100acts as the second device in the foregoing method embodiment, the following steps are implemented when the computer program11011is executed by the processor1102: receiving, from a first device, an Ethernet frame with a specified field removed; and adding the specified field to the Ethernet frame. Optionally, the specified field includes at least one of the following: a preamble field, a start frame delimiter field, a frame check sequence field, a length field, a padding field, and an extension field. Optionally, the processor1102is further configured to perform at least one of the following: receiving a first indication from the first device in a case that the frame check sequence field in the Ethernet frame is removed, where the first indication is used to indicate that the frame check sequence field in the Ethernet frame is removed; and receiving a second indication from the first device in a case that the extension field in the Ethernet frame is removed, where the second indication is used to indicate that the extension field in the Ethernet frame is removed. Optionally, a value of the length field corresponds to a data field length of the Ethernet frame. Optionally, the adding the specified field to the Ethernet frame includes at least one of the following: adding the frame check sequence field to the Ethernet frame if the first indication is received, where the frame check sequence field is calculated by using a frame check code algorithm; adding the extension field to the Ethernet frame if the second indication is received, where a length of the extension field is a difference between an Ethernet slot time and an Ethernet frame size determined by parsing a format of the Ethernet frame; and adding the padding field to the Ethernet frame if an actual data field length of the Ethernet frame is less than a protocol-prescribed minimum data field length corresponding to a format of the Ethernet frame, where a length of the padding field is a difference between the minimum data field length and the actual data field length. Optionally, the first device is an ingress device of a bridge, and the second device is an egress device of the bridge. Optionally, after adding the specified field to the Ethernet frame, the processor1102is further configured to: transmit the Ethernet frame with the specified field added to an external device of the bridge. Optionally, the receiving, from a first device, an Ethernet frame with a specified field removed performed by the processor1102includes: receiving, from the first device through a RAN, the Ethernet frame with the specified field removed. Optionally, an Ethernet frame header of the Ethernet frame is a compressed Ethernet frame header, and after receiving, from the first device through the RAN, the Ethernet frame with the specified field removed, the processor1102is further configured to: decompress the Ethernet frame header. The communications device1100can implement the processes implemented by the communications device in the foregoing method embodiments. To avoid repetition, details are not described herein again. Some embodiments of this disclosure further provide a computer-readable storage medium, where the computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processes of any foregoing Ethernet frame transmission method embodiment can be implemented, with the same technical effects achieved. To avoid repetition, details are not described herein again. For example, the computer-readable storage medium is a read-only memory (ROM for short), a random access memory (RAM for short), a magnetic disk, an optical disc, or the like. It should be noted that in this specification, the terms “include” and “comprise”, or any of their variants are intended to cover a non-exclusive inclusion, such that a process, a method, an article, or an apparatus that includes a list of elements not only includes those elements but also includes other elements that are not expressly listed, or further includes elements inherent to such a process, method, article, or apparatus. In absence of more constraints, an element preceded by “includes a . . . ” does not preclude the existence of other identical elements in the process, method, article, or apparatus that includes the element. According to the foregoing description of the embodiments, a person skilled in the art may clearly understand that the methods in the foregoing embodiments may be implemented by using software in combination with a necessary common hardware platform, and certainly may alternatively be implemented by using hardware. However, in most cases, the former is an example. Based on such an understanding, the technical solutions of this disclosure essentially, or a part contributing to the prior art may be implemented in a form of a software product. The computer software product is stored in a storage medium (for example, a ROM/RAM, a magnetic disc, or an optical disc), and includes several instructions for instructing a terminal (which may be a mobile phone, a computer, a server, an air conditioner, a network device, or the like) to perform the methods described in the embodiments of this disclosure. A person of ordinary skill in the art may be aware that the units and algorithm steps in the examples described with reference to the embodiments disclosed in this specification can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by hardware or software depends on particular applications and design constraints of the technical solutions. A person skilled in the art may use a different method to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of this disclosure. It may be clearly understood by a person skilled in the art that, for the purpose of convenient and brief description, for a detailed working process of the foregoing system, apparatus, and unit, reference may be made to a corresponding process in the foregoing method embodiments, and details are not described herein again. In the embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the described apparatus embodiment is merely an example. For example, the unit division is merely logical function division and may be other division in actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or may not be performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be indirect couplings or communication connections through some interfaces, apparatuses or units, and may be implemented in electrical, mechanical, or other forms. The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, and may be located in one position or distributed on a plurality of network elements. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions of the embodiments. In addition, functional units in the embodiments of this disclosure may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units are integrated into one unit. When the functions are implemented in a form of a software functional unit and sold or used as a separate product, the functions may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of this disclosure essentially, or the part contributing to the prior art, or some of the technical solutions may be implemented in a form of a software product. The software product is stored in a storage medium, and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform all or some of the steps of the method described in the embodiments of this disclosure. The foregoing storage medium includes: any medium that can store program code, such as a USB flash drive, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disc. In addition, it should be noted that in the apparatus and method of this disclosure, apparently, the components or steps may be decomposed and/or recombined. The decomposition and/or recombination should be considered as an equivalent solution of this disclosure. In addition, steps for performing the foregoing series of processing may be naturally performed in a sequence of description and in a time sequence, but do not need to be performed necessarily in the time sequence, and some steps may be performed in parallel or independently. A person of ordinary skill in the art can understand that all or any steps or components of the method and apparatus in this disclosure may be implemented by hardware, firmware, software, or a combination thereof in any computing apparatus (including a processor, a storage medium, and the like) or a network of computing apparatuses. This can be implemented as long as a person of ordinary skill in the art applies basic programming skill after reading the specification of this disclosure. It can be understood that the embodiments described in the embodiments of this disclosure may be implemented by hardware, software, firmware, middleware, microcode, or a combination thereof. In case of implementation by hardware, a processing unit may be implemented in one or more application-specific integrated circuits (ASIC), digital signal processors (DSP), digital signal processing devices (DSP Device, DSPD), programmable logic devices (PLD), field programmable gate arrays (FPGA), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units used to implement the functions described in this disclosure, or a combination thereof. For software implementation, the techniques described in the embodiments of this disclosure may be implemented by modules (for example, procedures or functions) that perform the functions described in the embodiments of this disclosure. Software code may be stored in the memory and executed by the processor. The memory may be implemented in or outside the processor. Therefore, an objective of this disclosure may also be achieved by running a program or a group of programs on any computing apparatus. The computing apparatus may be a well-known general apparatus. Therefore, the objective of this disclosure may also be achieved by merely providing a program product including program code for implementing the method or apparatus. To be specific, the program product also constitutes this disclosure, and a storage medium storing the program product also constitutes this disclosure. Apparently, the storage medium may be any well-known storage medium or any storage medium that will be developed in the future. It should also be noted that in the apparatus and method of this disclosure, apparently, the components or steps may be decomposed and/or recombined. The decomposition and/or recombination should be considered as an equivalent solution of this disclosure. In addition, steps for performing the foregoing series of processing may be naturally performed in a sequence of description and in a time sequence, but are not necessarily performed in the time sequence. Some steps may be performed in parallel or independently. The embodiments of this disclosure are described above with reference to the accompanying drawings, but this disclosure is not limited to these embodiments. These embodiments are only illustrative rather than restrictive. Inspired by this disclosure, a person of ordinary skill in the art can still derive a plurality of variations without departing from the essence of this disclosure and the protection scope of the claims. All these variations shall fall within the protection of this disclosure. | 62,029 |
11943049 | DETAILED DESCRIPTION The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that may be accessed by a computer. By way of example, and not limitation, such computer-readable media may comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that may be used to store computer executable code in the form of instructions or data structures that may be accessed by a computer. In an implementation, during a connected mode of communication with a BS, a UE of a network may transition from an active communication phase to a discontinuous reception (DRX) phase, which may include a connected mode DRX or CDRX. In the active communication phase, the UE may be participating in a video conferencing, playing an online game, or streaming a video, etc. As a result, the UE may continuously or frequently monitor the downlink resource for data transmission from the BS. After an end of the active communication phase (e.g., end of video conferencing, finish downloading video, etc.), but while a connection is still maintained (e.g., in connected mode), the UE may transition to the DRX phase. In the DRX phase, the UE may sporadically but routinely or periodically monitor the downlink resource for data transmission. The UE and the BS may synchronize to an agreed time and/or period to monitor the downlink resource. The UE may transition to the DRX phase to conserve electrical energy. During the DRX phase, the communication channels between the UE and the BS may experience increasing frequency errors. Once the frequency errors increase above a threshold, the transmissions exchanged (DL or UL) between the UE and the BS may become non-coherent and hence the communication channel may be referred to as a non-coherent channel or the communications may be referred to as non-coherent communications or non-coherent waveforms. For example, when the BS transmits DL data over the non-coherent channel, the UE may attempt to decode the DL data before the communication channel restores back to a coherent state. In some instances, the UE may be able to decode all the DL data before the communication channel restores back to being a coherent channel. As a result, the UE may be able to transition to the DRX phase to conserve electrical energy. In some aspects, receiving data over a non-coherent channel may reduce latency since data may be received during a transition period from non-coherent to coherent waveforms, e.g. from a non-coherent PDCCH to a coherent PDSCH. In other aspects, the UE may use less power since “on” time of the connected mode DRX phase will be shortened. Further, for example for small amounts of data (e.g., such as data that can fit into a slot duration or less), the BS may transmit physical downlink control channel (PDCCH) control signaling and physical downlink shared channel (PDSCH) data non-coherently and quickly go back to sleep without needing to fully converge frequency tracking loops/time tracking loops (FTL/TTL), e.g., to establish a coherent communication. In certain implementations, non-coherent PDCCH may be used during an “on” duration of the CDRX to allow for lower power and more relaxed FTL/TTL. For instance, when the UE is allocated DL data, the BS may use non-coherent PDSCH to transmit the data since tracking loops have not yet fully converged. Similarly, UL signals can also use non-coherent waveforms during the transition phase from a non-coherent communication channel to a coherent communication channel (e.g., a non-coherent physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), and/or random access channel (RACH)). In the case of small amounts of data, the UE does not need to transition to coherent waveform since it will finish the data transfer in a short period and thus save the power typically used for converging the FTL/TTL loops to obtain a coherent channel. FIG.1is a diagram illustrating an example of a wireless communications system and an access network100. The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes at least one BS105, UEs110, an Evolved Packet Core (EPC)160, and a 5G Core (5GC)190. The BS105may include macro cells (high power cellular base station) and/or small cells (low power cellular base station). The macro cells include base stations. The small cells include femtocells, picocells, and microcells. In one implementation, the UE110may include a communication component222and a decoding component224. The communication component222and/or the modem220of the UE110may be configured to communicate with the BS105via a cellular network, a Wi-Fi network, or other wireless and wired networks. The decoding component224may decode data received by the UE110, and/or decode data transmitted over coherent and/or non-coherent channels. In some implementations, the BS105may include a communication component322configured to communicate with the UE110and/or transmit data over coherent and/or non-coherent channels. A BS105configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC160through backhaul links interfaces132(e.g., S1, X2, Internet Protocol (IP), or flex interfaces). A BS105configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with 5GC190through backhaul links interfaces134(e.g., S1, X2, Internet Protocol (IP), or flex interface). In addition to other functions, the BS105may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The BS105may communicate directly or indirectly (e.g., through the EPC160or 5GC190) with each other over the backhaul links interfaces134. The backhaul links134may be wired or wireless. The BS105may wirelessly communicate with the UEs110. Each of the BS105may provide communication coverage for a respective geographic coverage area130. There may be overlapping geographic coverage areas130. For example, the small cell105′ may have a coverage area130′ that overlaps the coverage area130of one or more macro BS105. A network that includes both small cell and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links120between the BS105and the UEs110may include uplink (UL) (also referred to as reverse link) transmissions from a UE110to a BS105and/or downlink (DL) (also referred to as forward link) transmissions from a BS105to a UE110. The communication links120may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The BS105/UEs110may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of YxMHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). Certain UEs110may communicate with each other using device-to-device (D2D) communication link158. The D2D communication link158may use the DL/UL WWAN spectrum. The D2D communication link158may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR. The wireless communications system may further include a Wi-Fi access point (AP)150in communication with Wi-Fi stations (STAs)152via communication links154in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs152/AP150may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. The small cell105′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell105′ may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP150. The small cell105′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. A BS105, whether a small cell105′ or a large cell (e.g., macro base station), may include an eNB, gNodeB (gNB), or other type of base station. Some base stations, such as gNB180may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, and/or near mmW frequencies in communication with the UE110. When the gNB180operates in mmW or near mmW frequencies, the gNB180may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the radio frequency (RF) in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band has extremely high path loss and a short range. The mmW base station180may utilize beamforming182with the UE110to compensate for the path loss and short range. The EPC160may include a Mobility Management Entity (MME)162, other MMEs164, a Serving Gateway166, a Multimedia Broadcast Multicast Service (MBMS) Gateway168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway172. The MME162may be in communication with a Home Subscriber Server (HSS)174. The MME162is the control node that processes the signaling between the UEs110and the EPC160. Generally, the MME162provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway166, which itself is connected to the PDN Gateway172. The PDN Gateway172provides UE IP address allocation as well as other functions. The PDN Gateway172and the BM-SC170are connected to the IP Services176. The IP Services176may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BM-SC170may provide functions for MBMS user service provisioning and delivery. The BM-SC170may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway168may be used to distribute MBMS traffic to the BS105belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. The 5GC190may include a Access and Mobility Management Function (AMF)192, other AMFs193, a Session Management Function (SMF)194, and a User Plane Function (UPF)195. The AMF192may be in communication with a Unified Data Management (UDM)196. The AMF192is the control node that processes the signaling between the UEs110and the 5GC190. Generally, the AMF192provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF195. The UPF195provides UE IP address allocation as well as other functions. The UPF195is connected to the IP Services197. The IP Services197may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BS105may also be referred to as a gNB, Node B, evolved Node B (eNB), an access point, a base transceiver station, a radio base station, an access point, an access node, a radio transceiver, a NodeB, eNodeB (eNB), gNB, Home NodeB, a Home eNodeB, a relay, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. The BS105provides an access point to the EPC160or 5GC190for a UE110. Examples of UEs110include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs110may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE110may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. Referring toFIG.2, one example of an implementation of the UE110may include a modem220having a communication component222and a decoding component224. The communication component222and/or the modem220of the UE110may be configured to communicate with the BS105via a cellular network, a Wi-Fi network, or other wireless and wired networks. The decoding component224may decode data received by the UE110. The decoding component224may be configured to decode coherent and/or non-coherent transmissions. In some implementations, the UE110may include a variety of components, including components such as one or more processors212and memory216and transceiver202in communication via one or more buses244, which may operate in conjunction with the modem220, the communication component222and the decoding component224to enable one or more of the functions described herein related to communicating with the BS105. Further, the one or more processors212, modem220, memory216, transceiver202, RF front end288and one or more antennas265, may be configured to support voice and/or data calls (simultaneously or non-simultaneously) in one or more radio access technologies. The one or more antennas265may include one or more antennas, antenna elements and/or antenna arrays. In an aspect, the one or more processors212may include the modem220that uses one or more modem processors. The various functions related to the communication component222and the decoding component224may be included in the modem220and/or processors212and, in an aspect, may be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors212may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiving device processor, or a transceiver processor associated with transceiver202. Additionally, the modem220may configure the UE110along with the decoding component224and the processors212. In other aspects, some of the features of the one or more processors212and/or the modem220associated with the communication component222may be performed by transceiver202. Also, memory216may be configured to store data used herein and/or local versions of applications275or the communication component222and/or one or more subcomponents of the communication component222being executed by at least one processor212. Memory216may include any type of computer-readable medium usable by a computer or at least one processor212, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, memory216may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining the communication component222and/or one or more of its subcomponents, and/or data associated therewith, when UE110is operating at least one processor212to execute the communication component222and the decoding component224and/or one or more of their subcomponents. Transceiver202may include at least one receiver206and at least one transmitter208. Receiver206may include hardware, firmware, and/or software code executable by a processor for receiving data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). Receiver206may be, for example, a RF receiving device. In an aspect, the receiver206may receive signals transmitted by at least one BS105. Transmitter208may include hardware, firmware, and/or software code executable by a processor for transmitting data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). A suitable example of transmitter208may including, but is not limited to, an RF transmitter. Moreover, in an aspect, UE110may include RF front end288, which may operate in communication with one or more antennas265and transceiver202for receiving and transmitting radio transmissions, for example, wireless communications transmitted by at least one BS105or wireless transmissions transmitted by UE110. RF front end288may be coupled with one or more antennas265and may include one or more low-noise amplifiers (LNAs)290, one or more switches292, one or more power amplifiers (PAs)298, and one or more filters296for transmitting and receiving RF signals. In an aspect, LNA290may amplify a received signal at a desired output level. In an aspect, each LNA290may have a specified minimum and maximum gain values. In an aspect, RF front end288may use one or more switches292to select a particular LNA290and the specified gain value based on a desired gain value for a particular application. Further, for example, one or more PA(s)298may be used by RF front end288to amplify a signal for an RF output at a desired output power level. In an aspect, each PA298may have specified minimum and maximum gain values. In an aspect, RF front end288may use one or more switches292to select a particular PA298and the specified gain value based on a desired gain value for a particular application. Also, for example, one or more filters296may be used by RF front end288to filter a received signal to obtain an input RF signal. Similarly, in an aspect, for example, a respective filter296may be used to filter an output from a respective PA298to produce an output signal for transmission. In an aspect, each filter296may be coupled with a specific LNA290and/or PA298. In an aspect, RF front end288may use one or more switches292to select a transmit or receive path using a specified filter296, LNA290, and/or PA298, based on a configuration as specified by transceiver202and/or processor212. As such, transceiver202may be configured to transmit and receive wireless signals through one or more antennas265via RF front end288. In an aspect, transceiver may be tuned to operate at specified frequencies such that UE110may communicate with, for example, one or more BS105or one or more cells associated with one or more BS105. In an aspect, for example, the modem220may configure transceiver202to operate at a specified frequency and power level based on the UE configuration of the UE110and the communication protocol used by the modem220. In an aspect, the modem220may be a multiband-multimode modem, which may process digital data and communicate with transceiver202such that the digital data is sent and received using transceiver202. In an aspect, the modem220may be multiband and be configured to support multiple frequency bands for a specific communications protocol. In an aspect, the modem220may be multimode and be configured to support multiple operating networks and communications protocols. In an aspect, the modem220may control one or more components of UE110(e.g., RF front end288, transceiver202) to enable transmission and/or reception of signals from the network based on a specified modem configuration. In an aspect, the modem configuration may be based on the mode of the modem and the frequency band in use. In another aspect, the modem configuration may be based on UE configuration information associated with UE110as provided by the network. Referring toFIG.3, one example of an implementation of the BS105may include a modem320with a communication component322configured to transmit data over coherent and/or non-coherent channels. The communication component322and/or the modem320the BS105may be configured to communicate with the UE110via a cellular network, a Wi-Fi network, or other wireless and wired networks. In some implementations, the BS105may include a variety of components, including components such as one or more processors312and memory316and transceiver302in communication via one or more buses344, which may operate in conjunction with the modem320and the communication component322to enable one or more of the functions described herein related to communicating with the UE110. Further, the one or more processors312, modem320, memory316, transceiver302, RF front end388and one or more antennas365, may be configured to support voice and/or data calls (simultaneously or non-simultaneously) in one or more radio access technologies. In an aspect, the one or more processors312may include the modem320that uses one or more modem processors. The various functions related to the communication component322may be included in the modem320and/or processors312and, in an aspect, may be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors312may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiving device processor, or a transceiver processor associated with transceiver302. Additionally, the modem320may configure the BS105and processors312. In other aspects, some of the features of the one or more processors312and/or the modem320associated with the communication component322may be performed by transceiver302. Also, memory316may be configured to store data used herein and/or local versions of applications375or the communication component322and/or one or more subcomponents of the communication component322being executed by at least one processor312. Memory316may include any type of computer-readable medium usable by a computer or at least one processor312, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, memory316may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining the communication component322and/or one or more of its subcomponents, and/or data associated therewith, when the BS105is operating at least one processor312to execute the communication component322and/or one or more of the subcomponents. Transceiver302may include at least one receiving device306and at least one transmitter308. The at least one receiving device306may include hardware, firmware, and/or software code executable by a processor for receiving data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). Receiving device306may be, for example, a RF receiving device. In an aspect, receiving device306may receive signals transmitted by the UE110. Transmitter308may include hardware, firmware, and/or software code executable by a processor for transmitting data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). A suitable example of transmitter308may including, but is not limited to, an RF transmitter. Moreover, in an aspect, the BS105may include RF front end388, which may operate in communication with one or more antennas365and transceiver302for receiving and transmitting radio transmissions, for example, wireless communications transmitted by other BS105or wireless transmissions transmitted by UE110. RF front end388may be coupled with one or more antennas365and may include one or more low-noise amplifiers (LNAs)390, one or more switches392, one or more power amplifiers (PAs)398, and one or more filters396for transmitting and receiving RF signals. In an aspect, LNA390may amplify a received signal at a desired output level. In an aspect, each LNA390may have a specified minimum and maximum gain values. In an aspect, RF front end388may use one or more switches392to select a particular LNA390and the specified gain value based on a desired gain value for a particular application. Further, for example, one or more PA(s)398may be used by RF front end388to amplify a signal for an RF output at a desired output power level. In an aspect, each PA398may have specified minimum and maximum gain values. In an aspect, RF front end388may use one or more switches392to select a particular PA398and the specified gain value based on a desired gain value for a particular application. Also, for example, one or more filters396may be used by RF front end388to filter a received signal to obtain an input RF signal. Similarly, in an aspect, for example, a respective filter396may be used to filter an output from a respective PA398to produce an output signal for transmission. In an aspect, each filter396may be coupled with a specific LNA390and/or PA398. In an aspect, RF front end388may use one or more switches392to select a transmit or receive path using a specified filter396, LNA390, and/or PA398, based on a configuration as specified by transceiver302and/or processor312. As such, transceiver302may be configured to transmit and receive wireless signals through one or more antennas365via RF front end388. In an aspect, transceiver may be tuned to operate at specified frequencies such that BS105may communicate with, for example, the UE110or one or more cells associated with one or more BS105. In an aspect, for example, the modem320may configure transceiver302to operate at a specified frequency and power level based on the base station configuration of the BS105and the communication protocol used by the modem320. In an aspect, the modem320may be a multiband-multimode modem, which may process digital data and communicate with transceiver302such that the digital data is sent and received using transceiver302. In an aspect, the modem320may be multiband and be configured to support multiple frequency bands for a specific communications protocol. In an aspect, the modem320may be multimode and be configured to support multiple operating networks and communications protocols. In an aspect, the modem320may control one or more components of the BS105(e.g., RF front end388, transceiver302) to enable transmission and/or reception of signals from the network based on a specified modem configuration. In an aspect, the modem configuration may be based on the mode of the modem and the frequency band in use. In another aspect, the modem configuration may be based on base station configuration associated with the BS105. Referring now toFIG.4, in an example of non-coherent downlink data communication400, the UE110may be in a DRX phase402of a connected mode discontinuous reception (CDRX) cycle. During the DRX phase402, the UE110may not be actively communicating with the BS105. Instead, the UE110may periodically monitor one or more downlink channels/waveforms420for downlink data during certain “on” durations. The UE110may use less electrical energy when operating in the DRX phase402than an active communication phase. Upon receiving non-coherent downlink data, the UE110may begin exchanging non-coherent data (uplink and downlink) with the BS105via the one or more downlink channels/waveforms420and/or one or more uplink channel/waveforms422. Subsequently, the UE110may transition to an active communication phase404, e.g., based on receiving control signaling and/or data signaling during an “on” period of the DRX phase402that indicates resources for scheduled data transmissions. During the active communication phase404, the UE110may exchange non-coherent data with the BS105until the one or more downlink channels/waveforms420and/or one or more uplink channel/waveforms422transition from non-coherent channels to coherent channels. After the one or more downlink channels/waveforms420and/or one or more uplink channel/waveforms422transition from non-coherent channels to coherent channels, the UE110may exchange coherent data with the BS105. In some aspects of the present disclosure, the UE110may operate in the DRX phase402, during which a frequency error410of the one or more downlink channels/waveforms420(e.g., mismatch in beamforming characteristics of the one or more antennas365of the BS105and the one or more antennas265of the UE110) between the BS105and the UE110may increase with time. The frequency error410may increase above a threshold412. In other words, when the frequency error410is below the threshold412, the one or more downlink/uplink channels/waveforms420/422may be one or more coherent channels. In contrast, when the frequency error410is above the threshold412, the one or more downlink/uplink channels/waveforms420/422may be one or more non-coherent channels. The threshold412may be a value predetermined by the BS105. In some aspects, the frequency error410may be increased due to changes (e.g., operating frequency, electrical power, electrical interference) in the electronics/devices in the UE110and/or BS105, interference (e.g., atmospheric, obstructions), or other factors. Alternatively or in addition, for example, the frequency error410may be increased due to a lack of channel estimation, channel correction, antenna calibration, and/or reference signals transmission/reception during the DRX phase402. In an aspect of the present disclosure, the UE110may periodically monitor the one or more downlink channels/waveforms420during the DRX phase402during one or more periodic “on” durations every DRX cycle440. The DRX cycle440may be 1 millisecond (ms), 2 ms, 5 ms, 10 ms, 20 ms, 50 ms, 100 ms, 200 ms, 500 ms, 1 second (s) or other durations. The DRX cycle440may depend on the applications executed by the UE110, available resources allocated by the BS105, battery mode of the UE110, battery life of the UE110, or other factors. For example, the UE110may monitor the one or more downlink channels/waveforms420during a first on-duration430. During the first on-duration430, the UE110may activate the one or more antennas265of the UE110and/or the modem220to “listen” for downlink control signaling and/or data transmitted by the BS105. At the end of the first on-duration430, the UE110may deactivate the one or more antennas265and/or the modem220to conserve electrical energy when the UE110does not detect any downlink data. The hatching portion of the first on-duration430may indicate an example of control signaling, guard band, and/or cyclic prefixes. Further, for example, the UE110may monitor the one or more downlink channels/waveforms420during a second on-duration432, e.g., at an amount of time from the first on-duration430based on a configured periodicity. During the second on-duration432, the UE110may activate the one or more antennas265of the UE110and/or the modem220to “listen” for downlink control signaling and/or data transmitted by the BS105. At the end of the second on-duration432, the UE110may deactivate the one or more antennas265and/or the modem220to conserve electrical energy when the UE110does not detect any downlink data. The hatching portion of the second on-duration432may indicate an example of control signaling, guard band, and/or cyclic prefixes. In some instances, the BS105may transmit downlink control or data to the UE110, and such data may arrive at the UE110at or after a time406. When the UE110detects the downlink control or data or based on received control signaling indicating scheduled data transmissions, the UE110may transition into the active communication phase404of the CDRX cycle. The UE110may receive downlink data (e.g., boxed labeled “DL” in the figure) and/or transmit uplink data (e.g., boxes labeled “UL” in the figure) as non-coherent data450during a non-coherent communication state451because the one or more downlink channels/waveforms420and/or one or more uplink channel/waveforms422are non-coherent channels in the non-coherent communication state451. Due to the non-coherent connections between the UE110and the BS105, the UE110may decode the received downlink data of the non-coherent data450without some or all of channel state information. The BS105may decode the transmitted uplink data of the non-coherent data450without some or all of channel state information. The channel state information may be used to perform channel estimation. The BS105may indicate the transmission and/or reception of the non-coherent data450to and/or from the UE110in the radio resource control (RRC) configuration, the downlink control information (DCI), or other data structures. The hatched portion of the non-coherent data450may indicate an example of control signaling, guard band, and/or cyclic prefixes. In some implementations, the UE110and/or the BS105may begin to perform a channel estimation process after the time406. The channel estimation process may include the BS105sending reference signals and the UE110estimating the quality of the channel based any changes to the amplitude (i.e., attenuation), phase (i.e., phase-shift), frequency (i.e., frequency-shift), and/or added noise to the reference signals. The quality of the channel may be the channel state information. The channel estimation process may include modifying the beams of the one or more antennas265of the UE110and/or the beams of the one or more antennas365of the BS105to compensate for the quality of the channel. In certain implementations, the channel estimation process may decrease the frequency error410below the threshold412. After the frequency error410decreases below the threshold412, the communication state may transition to a coherent communication state453and the UE110may receive downlink data (e.g., boxes labeled “DL” in the figure) and/or transmit uplink data (e.g., boxes labeled “UL” in the figure) as coherent data452because the one or more downlink channels/waveforms420and/or one or more uplink channel/waveforms422are coherent channels after the channel estimation process. The hatched portion of the coherent data452may indicate an example of control signaling, guard band, and/or cyclic prefixes. In an instance, the UE110may decode the DL data transmitted by the BS105before the one or more downlink channels/waveforms420and/or one or more uplink channel/waveforms422become coherent channels in the coherent communication state453. In such cases, the UE110and/or the BS105may suspend or terminate the channel estimation process. Further, the UE110may transition from the active communication phase404back to the DRX phase402. As such, the early transition of the UE110to the DRX phase402may conserve additional electrical energy. Referring toFIG.5A, an example of a method500for receiving non-coherent data may be performed by the UE110in the wireless communication network100. At block505, the method500may monitor a non-coherent downlink waveform during a discontinuous reception phase. For example, the communication component222, the modem220, and/or the processor212of the UE110may monitor the one or more downlink channels/waveforms420during the DRX phase402, such as described above with regard toFIG.4. In certain implementations, the processor212, the modem220, the communication component222, the transceiver202, the receiver206, the transmitter208, the RF front end288, and/or the subcomponents of the RF front end288may be configured to and/or may define means for monitoring a non-coherent downlink waveform during a discontinuous reception phase. At block510, the method500may receive first data on the non-coherent downlink waveform. For example, the communication component222, the modem220, and/or the processor212of the UE110may receive the DL data on the one or more downlink channels/waveforms420during the active communication phase404, such as described above with regard toFIG.4. The one or more antennas265may receive electro-magnetic signals from one or more antennas265of the UE110. The RF front end288may filter, amplify, and/or extract electrical signals carried by the electro-magnetic signals. The transceiver202or the receiver206may digitize and convert the electrical signal into the data, such as the DL data, and send to the communication component222. In certain implementations, the processor212, the modem220, the communication component222, the transceiver202, the receiver206, the transmitter208, the RF front end288, and/or the subcomponents of the RF front end288may be configured to and/or may define means for receiving first data on the non-coherent downlink waveform. At block515, the method500may decode the downlink data without channel state information of the non-coherent downlink waveform. For example, the decoding component224, the modem220, and/or the processor212of the UE110may decode the downlink data without channel state information of the one or more downlink channels/waveforms420, such as described above with regard toFIG.4. In certain implementations, the processor212, the modem220, and/or the decoding component224may be configured to and/or may define means for decoding the downlink data without channel state information of the non-coherent downlink waveform. Turning now toFIG.5B, the method500of receiving non-coherent data after the DRX phase402may be performed by the UE110. Alternatively or additionally, at block555, the method500may further include transmitting uplink data on a non-coherent uplink channel. For example, the communication component222, the modem220, and/or the processor212of the UE110may transmit the UL data on the one or more uplink channels/waveforms422during the active communication phase404, such as described above with regard toFIG.4. The communication component222may send the UL data to the transceiver202or the transmitter208. The transceiver202or the transmitter208may convert the UL data to electrical signals and send to the RF front end288. The RF front end288may filter and/or amplify the electrical signals. The RF front end288may send the electrical signals as electro-magnetic signals via the one or more antennas265. Alternatively or additionally, the method500may further include any of the methods above, wherein the uplink channel is a physical uplink control channel, a physical uplink shared channel, or a physical random access channel. Alternatively or additionally, at block560, the method500may further include performing, after receiving the downlink data, a channel estimation process to convert the non-coherent downlink channel to a coherent downlink channel. For example, the communication component222, the modem220, and/or the processor212of the UE110may perform the channel estimation by receiving reference signals and transmitting responses to the BS105as described above. Alternatively or additionally, at block565, the method500may further include receiving, after performing the channel estimation process, additional downlink data on the coherent downlink channel. For example, the communication component222, the modem220, and/or the processor212of the UE110may receive additional downlink data as described above. Alternatively or additionally, at block570, the method500may further include suspending the channel estimation process before completion and monitoring, after decoding the downlink data, the non-coherent downlink channel during a second discontinuous reception phase. Alternatively or additionally, at block575, the method500may further include monitoring, after decoding the downlink data, the non-coherent downlink waveform during a second discontinuous reception phase. For example, the communication component222, the modem220, and/or the processor212of the UE110may monitor the non-coherent downlink waveform during a second discontinuous reception phase. Alternatively or additionally, the method500may further include any of the methods above, wherein the downlink waveform is transmitted in a physical downlink control channel, a physical downlink shared channel, a physical broadcast channel, or a physical random access channel. Referring toFIG.6, a method600of transmitting control/data signals in one or more non-coherent channels may be performed by the BS105. At block605, the method600may transmit downlink data on a non-coherent downlink channel. For example, the communication component322of the BS105may transmit the non-coherent data450to the UE110. At block610, the method600may perform a channel estimation process to allow a decoding of a coherent downlink waveform. For example, the communication component322may perform a channel estimation process by transmitting reference signals and receiving channel feedback based on the reference signals. At block615, the method600may transmit additional downlink control/data signals in one or more coherent channels. For example, the communication component322may transmit the coherent data452to the UE110. In certain implementations, the processor312, the modem320, the communication component322, the transceiver302, the receiver306, the transmitter308, the RF front end388, and/or the subcomponents of the RF front end388may be configured to and/or may define means for transmitting downlink data on a non-coherent downlink channel. Additional Implementations In an aspect, a method includes monitoring a non-coherent downlink waveform during a discontinuous reception phase, receiving downlink data on the non-coherent downlink waveform, and decoding the downlink data without channel state information of the non-coherent downlink waveform. Any of the methods above, further comprising transmitting uplink data on a non-coherent uplink waveform. Any of the methods above, wherein the uplink waveform is transmitted in a physical uplink control channel, a physical uplink shared channel, or a physical random access channel. Any of the methods above, further comprising performing, after receiving the downlink data, a channel estimation process to allow a decoding of a coherent downlink waveform. Any of the methods above, further comprising receiving, after performing the channel estimation process, additional downlink data using the coherent downlink waveform. Any of the methods above, further comprising suspending completion transition to the coherent downlink waveform and monitoring, after decoding the downlink data, the non-coherent downlink waveform during a second discontinuous reception phase. Any of the methods above, wherein the downlink waveform is transmitted in a physical downlink control channel, a physical downlink shared channel, a physical broadcast channel, or a physical random access channel. Any of the methods above, further comprising monitoring, after decoding the downlink data, the non-coherent downlink waveform during a second discontinuous reception phase. A user equipment comprising a memory, a transceiver, and one or more processors operatively coupled with the memory and the transceiver, the one or more processors configured to execute instructions in the memory to monitor a non-coherent downlink waveform during a discontinuous reception phase, receive, via the transceiver, downlink data on the non-coherent downlink waveform, and decode the downlink data without channel state information of the non-coherent downlink waveform. Any of the UE above, wherein the one or more processors are further configured to execute the instructions to transmit uplink data on a non-coherent uplink waveform. Any of the UE above, wherein the uplink waveform is transmitted in a physical uplink control channel, a physical uplink shared channel, or a physical random access channel. Any of the UE above, wherein the one or more processors are further configured to execute the instructions to perform, after receiving the downlink data, a channel estimation process to allow a decoding of a coherent downlink waveform. Any of the UE above, wherein the one or more processors are further configured to execute the instructions to receive, after performing the channel estimation process, additional downlink data using the coherent waveform. Any of the UE above, wherein the one or more processors are further configured to execute the instructions to suspend a transition to the downlink coherent waveform and monitor, after decoding the downlink data, the non-coherent downlink waveform during a second discontinuous reception phase. Any of the UE above, wherein the downlink waveform is transmitted in a physical downlink control channel, a physical downlink shared channel, a physical broadcast channel, or a physical random access channel. A non-transitory computer readable medium having instructions stored therein that, when executed by one or more processors of a user equipment (UE), cause the one or more processors to monitor a non-coherent downlink waveform during a discontinuous reception phase, receive downlink data on the non-coherent downlink waveform, and decode the downlink data without channel state information of the non-coherent downlink waveform. Any of the transitory computer readable medium above, further comprising instructions that, when executed by the one or more processors, cause the one or more processors to transmit uplink data on a non-coherent uplink waveform. Any of the transitory computer readable medium above, wherein the uplink waveform is transmitted in a physical uplink control channel, a physical uplink shared channel, or a physical random access channel. Any of the transitory computer readable medium above, further comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform, after receiving the downlink data, a channel estimation process to allow decoding of a coherent downlink waveform. Any of the transitory computer readable medium above, further comprises instructions that, when executed by the one or more processors, cause the one or more processors to receive, after performing the channel estimation process, additional downlink data using the coherent waveform. Any of the transitory computer readable medium above, further comprises instructions that, when executed by the one or more processors, cause the one or more processors to suspend a transition to coherent waveform and monitor, after decoding the downlink data, the non-coherent downlink waveform during a second discontinuous reception phase. Any of the transitory computer readable medium above, wherein the downlink waveform is transmitted in a physical downlink control channel, a physical downlink shared channel, a physical broadcast channel, or a physical random access channel. A user equipment, comprising means for monitoring a non-coherent downlink waveform during a discontinuous reception phase, means for receiving downlink data on the non-coherent downlink waveform, and means for decoding the downlink data without channel state information of the non-coherent downlink waveform. Any of the UE above, further comprising means for transmitting uplink data on a non-coherent uplink waveform. Any of the UE above, wherein the uplink waveform is transmitted in a physical uplink control channel, a physical uplink shared channel, or a physical random access channel. Any of the UE above, further comprising performing, after receiving the downlink data, a channel estimation process to allow a decoding of a coherent downlink waveform. Any of the UE above, further comprising means for receiving, after performing the channel estimation process, additional downlink data using the coherent downlink waveform. Any of the UE above, further comprising means for suspending a transition to the coherent downlink waveform and means for monitoring, after decoding the downlink data, the non-coherent downlink waveform during a second discontinuous reception phase. Any of the UE above, wherein the downlink waveform is transmitted in a physical downlink control channel, a physical downlink shared channel, a physical broadcast channel, or a physical random access channel. The above detailed description set forth above in connection with the appended drawings describes examples and does not represent the only examples that may be implemented or that are within the scope of the claims. The term “example,” when used in this description, means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. For example, changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Also, various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in other examples. In some instances, well-known structures and apparatuses are shown in block diagram form in order to avoid obscuring the concepts of the described examples. It should be noted that the techniques described herein may be used for various wireless communication networks such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms “system” and “network” are often used interchangeably. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and A are commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM™, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS). 3GPP LTE and LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies, including cellular (e.g., LTE) communications over a shared radio frequency spectrum band. The description herein, however, describes an LTE/LTE-A system or 5G system for purposes of example, and LTE terminology is used in much of the description below, although the techniques may be applicable other next generation communication systems. Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, computer-executable code or instructions stored on a computer-readable medium, or any combination thereof. The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a specially-programmed device, such as but not limited to a processor, a digital signal processor (DSP), an ASIC, a FPGA or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination thereof designed to perform the functions described herein. A specially-programmed processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A specially-programmed processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a non-transitory computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above may be implemented using software executed by a specially programmed processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that may be accessed by a general purpose or special purpose computer. By way of example, and not limitation, computer-readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media. The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the common principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Furthermore, although elements of the described aspects may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect may be utilized with all or a portion of any other aspect, unless stated otherwise. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | 60,975 |
11943050 | DETAILED DESCRIPTION I. Introduction This disclosure introduces an advancement to the error indication message to provide detailed information about errors in configurations that are arriving from the Layer 2 to the Layer 1. Specifically, this disclosure describes an Advancement in the Error Indication Messages for a LTE based system which would relay the information from Layer 1 to Layer 2 about the configurations which have encountered an error and also providing details of the area of code in which the issue was found in Layer 1. The Layer 2 can utilize this information to avoid such configurations to be sent down to Layer 1 and to instead send the next best known configuration and to avoid any crash scenarios. These details can also provide a detailed level of debugging on the Layer 1 level reducing the debugging time allowing more efficiency by detecting and pinpointing issues or bugs. This detailed information can also be utilized to prevent Layer 2 to send such configurations to Layer 1, and to provide help and support for troubleshooting problems with such configurations. A database coupled to the Layer 2 module may log such wrong configurations with timestamps, which can be useful for debugging purpose by pinpointing exactly at which location in the Layer 1 the issues are found. As disclosed below, the error indication message can be modified to provide better and more detailed information about the errors being reported, which can help developers and testers to locate issues more quickly or in real time, rather than forcing them to capture and analyze the logs. This will provide a benefit in the debugging process by reducing the overall time. The paper only discuss one of the many different possible ways this error indication message can be modified to provide improved functionality, and can be modified henceforth other Layer 1 specific designs. The paper is spilt into various sections. An introduction to LTE based FAPI message exchange and the details are covered in Sections II. Section III introduces the benefits of advanced Error Protection Messaging. Section IV provides details on the Advancement of the Error Protection Message about the structure and how it will relay the information to Layer 2. Section V provides a detailed example of the overall Error Protection Messaging. II. Introduction to FAPI for LTE 4G Systems The LTE FAPI developed by the Femto Forum describes the FAPI standard by dividing it into two sections: (1) Providing a description of typical procedures which will occur between the L1 and L2/L3 software; and (2) Providing the definition of the L1 API messages. In this section a brief description of the two sections is covered. L1 & L2/L3 Procedures This section gives an overview of the procedures which use the L1 API. These procedures are split into two groups, namely, configuration procedures and sub-frame procedures. Configuration procedures handle the management of the PHY layer and are expected to occur infrequently. Sub-frame procedures determine the structure of each 1 ms sub-frame and operate with a 1 ms periodicity. The configuration procedures supported by the L1 API are: Initialization; Termination; Restart; Reset; and Error notification. These procedures will move the Layer 1 through the IDLE, CONFIGURED and RUNNING states, as shown inFIG.1. FIG.1is a schematic diagram of physical layer 1 (PHY) logical states, in accordance with some embodiments. State101is an IDLE state of a PHY layer. State102is a CONFIGURED state of a PHY layer. State103is a RUNNING state of a PHY layer. The PHY layer remains in IDLE state101until it receives a CONFIG.request, which causes a state change to the CONFIGURED state102. (If a PARAM.request is sent to a PHY in an IDLE state101, the request is handled and the PHY remains in IDLE state101.) The PHY layer enters the CONFIGURED state102, and may be further configured, as shown by the state change arrow for CONFIG.request from CONFIGURED state102to itself. Once the PHY layer is fully configured, the PHY layer may receive a START.request to cause the PHY to enter into a RUNNING state103. The PHY may accept CONFIG.requests in the RUNNING state, to be reconfigured on the fly. The PHY may also receive STOP.requests, to return to CONFIGURED state102and to stop transmitting or receiving, as appropriate. A list of the L1 API configuration messages which are valid in each state is given a Table 1. TABLE 1L1 API configuration messagesIdle StateConfigured StateRunning StatePARAM.requestPARAM.requestCONFIG.requestCONFIG.requestCONFIG.requestSTART.requestSTOP.request L1 API Messages The general message format of the L1 API is shown in Table 3, where it can be seen that each L1 API message consists of a header followed by a message body. The generic header consists of a message type ID, a message body length and a vendor-specific body length. The current list of message types is given in Table 2. The L1 API messages follow a standard naming convention where: all request messages are sent from the L2/L3 software to the PHY; all response messages are sent from the PHY to the L2/L3 software. These are sent in response to a request; and all indication messages are sent from the PHY to the L2/L3 software. These are sent asynchronously. III. Benefits of Advanced Error Indication Messages The current FAPI error indication message provides certain details to Layer 2 at various levels. However, it has been observed during the development stages that the details provided to the Layer 2 in the error indication message is not sufficient to pinpoint the precise issue, which results in a great amount of round trip time debugging. A modification to the error indication message is proposed to ease this issue. The details of the modification are provided in section IV. Wrong configurations or misconfigurations can occur due to various reasons (i.e. Layer 2 sending wrong parameters, corruption on memory on Layer 1 etc.), and may result in serious impacts on the overall system. For instance, in a scenario when a wrong configuration arrives at the Layer 1 the Layer 1 may not be in a position to process the data received. This may result in drop in throughput, further causing CRC failure and retransmission. Or as another example, misconfigurations at L1 (from L2) can cause the system to crash, leading to rebooting of the node and re-attaching of UEs to the node, which can affect overall system and network performance. Or as another example, in a case when multiple CRC failures occur and the system has reached its maximum retries, the User Equipment (UE) may move into the link loss state. The UE going into link loss would require a re-network entry in order for it to attach back onto the network. This may result in wasted resources and may reduce the efficiency of the network system. Unlike the current error reporting mechanism from PHY layer, which typically provides only general information to the MAC layer, the disclosed design can give more accurate information regarding which parameter went wrong. For example, in ulconfig, if a modulation coding scheme (MCS) value with, for example, correct values of 2, 4, 6, becomes corrupted due to any reason, then the data is not decoded. If this happens without this disclosed method, it may be difficult to catch the issue. If the disclosed method is used it will send the unique error code to MAC. For example. for ulconfig the 32 error code bit field can be designed as follows: error code=(ERROR|FATAL|LTE|PUSCH|PUSCH_PARSE|ERROR_MCS). Similarly, for example, in dlconfig, if a number of layers does not match a supported number of antennas, then the DL data may partially decode or not decode at all. This kind of issue is sometimes very tricky to resolve. And based on experience these errors are due to improper configuration. For example, an exemplary error code for dlconfig could be designed as follows: (ERROR|FATAL|LTE|PDSCH|PDSCH_PARSE|ERROR_NUM_LAYER). Many issues may thus be solved more quickly If we have accurate information at right time, avoiding spending a great deal of effort to resolve the wrong configuration issues. Further information about these exemplary error codes appears below. IV. Details of Advanced Error Indication Messages In some embodiments, an Advanced Error Indication message can provide additional information which can help to pinpoint the location at which the issue was found in the Layer 1. The Advance Error Indication message can also be extended to a further use by providing a support over Layer 2, where such issue faced at Layer 1 can be recorded onto a database. This database can be useful to the Layer 2 scheduler where the future configurations can be compared with the configurations in database before being applied. If such a configuration is found then the next best configuration could be applied to avoid any further issues on the Layer 1. The Error Indication msg have two stage of reporting, first is error code and other is sbl_error_msg_body. The error code is able to send limited information. Where our design upgrades the error reporting mechanism, it is exploited and adds a new hierarchy in sbl_error_msg_body as comp error, shown below in Table 2 and Table 3. The added changes in the error indication message provide space to include a new error code design described below. In some embodiments, the advanced error indication message can be divided into 5 levels of error protection: Error level-1: It covers all parameters coming via FAPI. In this level we have boundary checks of all the parameters coming within a FAPI message (Only DL and UL FAPI parameters), the Cell config parameters returns Invalid message this range checking is not part of error level-1. Error level-2: It covers the checks on total number of downlink (DL) and uplink (UL) packet data units (PDUs) supported by L1. Error level-3: It covers the scheduling limitations/tradeoffs that exist in L1 based on the computation capacity or design. For example, L1 cannot process the Random Access Channel (RACH) and Sounding Reference Signal (SRS) together in a single subframe (SF), so accordingly a check may be placed such that when higher layers try to schedule RACH and SRS together then L1 will report appropriate error. Error level-4: It covers the error that exists at component level limitation which can be pointer violation or memory alignment issues. Error level-5: It covers the error that exists at component level limitation check. It may be due to calculated parameters based on the FAPI parsing parameters or scheduling related problem in L1 component. In some embodiments, the ERROR.indication message is reported back by the L1 to the MAC in each subframe procedure using applicable limited error code for each messages. If the L2/L3 software receives an ERROR.indication message for DL_CONFIG.request, UL_CONFIG.request, HI_DCI0.request or TX.request, it should assume that the UE did not receive data and control sent in this subframe. In some embodiments, the L1 API message formats for the ERROR.indication Message are shown below in Table 2. TABLE 2Error Indication Message BodyFieldTypeDescriptionmsgStatusFAPI_MESSAGE_STATUS_TIndicate the message statusmessage_idUINT8Indicate which message received by the PHY has an error.padding[3]UINT8To make error code aligned to 32-bitserror codeUINT32The error codesbl_error_msg_bodyunionError code dependent values. The format of these bytes isdependent on the error code. See Below Tables for details An exemplary message body is shown below in Table 3. TABLE 3sbl_error_msg_body Message BodyFieldSub-FieldTypeDescriptionsfn_errorreceived_sfn_sfUINT8Received subframe numberexpected_sfn_sfUINT8Expected subframe numberpdu_errorsub_error_CodeUINT8Configuration or component level error codedirectionUINT8Indicates if this error was in a DL subframe configuration oran UL subframe configuration.rntiUINT16The RNTI in the received PDU.pdu_typeUINT8The PDU Type parameter specified in both DL subframeconfiguration and UL subframe configuration.padding[1]UINT8Padding byteshi_errorsub_error_codeUINT8Configuration or component level error codephich_lowest_ul_rb_indexUINT8PHICH lowest UL RB indextx_errorsub_error_codeUINT8Configuration or component level error codepdu_indexUINT8PDU indexcomp_errorsub_error_codeUINT32Component level error code for protection level 4 and 5 In some embodiments, the sub error message body has passed second level of error code. But it has limited information passed to L2, its more generic code. To remedy this, the sub error code can provide an extra level of information about what sub error has been hit out of 4 classified errors (sfn_error, pdu_error, hi_error or tx_error). So to improve the error protection mechanism, providing more and accurate error indication is helpful so the MAC can take the decision more effectively. Apart from the boundary checks, error checking can send board-specific limitations to MAC so it will avoid combinations which the PHY is unable to support. For example, if a number of requested packet data units (PDUs; like BCH PDUs, PDSCH PDUs etc.) is wrong in an incoming configuration message, this can be reported back to MAC in a subframe (SF). All DL and UL config parameters can be boundary checked in this way and may have unique error codes passed back, so MAC can configure correct one or take necessary action to avoid it. FIG.2is a schematic diagram of bit fields for error codes in accordance with some embodiments. An error message, in some embodiments, is a bit vector including sections201through208. At section201, the most-significant bit (MSB) is set to 1 for all errors (Bit31). At section202, the next two bits are used to indicate a type of the error (Bit30and29), with the following permitted values: Information (01): This error code type are Informative only, which is not Introducing any major error but useful to convoy it to L2 for scheduling the parameter next time. This error code can be overwritten by both the Non-Fatal and Fatal error type. Non-Fatal (10): These error code types are not breaking the system, but violation of the parameter for the current SF. This error code can be overwritten by the Fatal error type. Fatal (11): These error code types are able to break the L1-SW, this error code is highest priority. If this error type is generated, the system may need to return immediately, and no further processing will be done. At section203, the next three bits for what technology the error code is generating (Bit26to28). At section204, the next five bits is used for identifying the component. These are unique values for each module (Bit21to25). At section205, the next three bits for the sub module representation, which can be used manager/kernel levels (Bits18to20). Below Modules is using those 3 bits to declare its sub modules. At section206, the next nine bits are reserved. At section207, the 8th bit is used as flag for next 2 byte error code. It is set as ‘1’. At section208, for the last 8 bits from LSB, these bits are used for error code, allowing for 256 unique error codes which, in some embodiments, may belong to each PHY error-checking submodule. In some embodiments, there are two software subsystems used to generate the error codes for the new API: an encoder (Error code generator on Layer 1) and a decoder (Error code decoder on Layer 2). The job of Encoder is to fill the 32-bit field of the Error Code. Layer 1 is broken down into various modules and sub-modules. Each module and sub-modules has a respective bit field in the 32-bit field of the Error Code. Each module and sub-module performs a error checks and when an error occurs the Encoder is called where the respective error bit field for that module or sub-module is populated. The Decoder's job at the Layer 2 would be to process this error code received. It would have the knowledge of the respective bit fields of each module. The Implementation at the Layer1 will be very lightweight. It is assumed not to take more than 4-5K of core cycles. Currently error Indication is sent by PHY for each subframe If an error gets hit and travel to MAC Layer. The error logs currently don't get sent to the core network or logging server. However this is not such limitations not to send these error logs, if there is a requirement it can be done. V. Error Protection Message Example Error Level 4 Example: if ( (spm_tdp_dynamic == NULL) || (spm_tdp_static == NULL)){error = (ERROR | FATAL | SPM_PRACH | SPM_PRACH_TDP | ERROR_NULL_POINTER);return error;}IF4_samp_ant0 = spm_tdp_dynamic−>IF4_samples_ant0;if ( ( IS_ALIGNED_SPLIB(IF4_samp_ant0, ALIGNED_8_BYTES) == 0) ){error = (ERROR | NON_FATAL |SPM_PRACH|SPM_PRACH_TDP| ERR_4_PRACH_TDP_NOT_ALIGN);} Error level 2 Example: in some embodiments, for example, if L1 cannot process the RACH and SRS together in a single SF, accordingly a check is placed such that when higher layers try to schedule RACH and SRS together then L1 will report an appropriate error. FIG.3is a flowchart of a method, in accordance with some embodiments. At step301, the method may receive a L1 configuration message from a higher layer. The PHY may be in an IDLE, or CONFIGURED, or RUNNING state. Depending on which state the PHY is in, different error checking steps may be performed. If no error is detected processing continues to step302. In some embodiments, if an error is detected, or if an error is detected that is serious enough to stop execution (e.g., a fatal error), execution may stop and may proceed to step308. Certain lines are shown inFIG.3as dotted lines to indicate that they are optional, as in some embodiments, it may be possible to avoid stopping execution. At step302, the method may perform boundary range error checking for all parameters requested by the configuration message. This does not require coordination with other parameters already configured. If no error is detected processing continues to step303. In some embodiments, if an error is detected, or if an error is detected that is serious enough to stop execution, execution may stop and may proceed to step308. At step303, the method may check number of requested PDUs for UL and DL against the capabilities of the PHY, e.g., to make sure that the number of requested PDUs does not exceed what is capable by the PHY. If no error is detected processing continues to step304. In some embodiments, if an error is detected, or if an error is detected that is serious enough to stop execution, execution may stop and may proceed to step308. At step304, the method may check scheduling configuration against computation capacity. For example, the PHY may be unable to perform all of the configuration steps, such as the example where the L1 is requested to process both RACH and SRS together in one subframe. If no error is detected processing continues to step305. In some embodiments, if an error is detected, or if an error is detected that is serious enough to stop execution, execution may stop and may proceed to step308. At step305, the method may identify pointer violation or memory alignment issues based on component-level limitations or constraints. If no error is detected processing continues to step306. In some embodiments, if an error is detected, or if an error is detected that is serious enough to stop execution, execution may stop and may proceed to step308. At step306, the method may component level limitation check, including checks based on calculated parameters. This can include comparing new configuration parameters with currently-active configuration parameters. If no error is detected processing continues to step307. At step307, if no errors have been detected, the method may set and apply the error-checked configuration. However, if at this stage any of the error conditions have been triggered, at step308, the method may generate and send one or more specific error codes to the higher layer, e.g., the L2 or MAC layer, including in some embodiments a union of all error conditions detected in prior steps. It is possible to include any combination of steps301-306for error checking, and to incorporate any combination of errors generated by steps301-306, including errors from every step, errors from no steps (i.e., successful execution), or a single error from a single step. Use of multiple error checking steps can be understood to be progressive error checking, as the multiple error checking steps progressively create the error code. In some embodiments, these can be performed in any order. The error code may be constructed and sent in one bit vector to the MAC layer. VI. Exemplary Hardware FIG.4is a schematic diagram of an enhanced eNodeB, in accordance with some embodiments. Enhanced eNodeB400may include processor402, processor memory404in communication with the processor, baseband processor406, and baseband processor memory408in communication with the baseband processor. Enhanced eNodeB400may also include first radio transceiver410and second radio transceiver412, internal universal serial bus (USB) port416, and subscriber information module card (SIM card)418coupled to USB port414. In some embodiments, the second radio transceiver412itself may be coupled to USB port416, and communications from the baseband processor may be passed through USB port416. A self-organizing network (SON) module430may also be included, which may include a database (not shown), in some embodiments, or which may be in communication with a coordination server (not shown), in some embodiments, or both, in some embodiments. Processor402and baseband processor406are in communication with one another. Processor402may perform routing functions, and may determine if/when a switch in network configuration is needed. Baseband processor406may generate and receive radio signals for both radio transceivers410and412, based on instructions from processor402. In some embodiments, processors402and406may be on the same physical logic board. In other embodiments, they may be on separate logic boards. The first radio transceiver410may be a radio transceiver capable of providing LTE eNodeB functionality, and may be capable of higher power and multi-channel OFDMA. The second radio transceiver412may be a radio transceiver capable of providing LTE UE functionality. Both transceivers410and412are capable of receiving and transmitting on one or more LTE bands. In some embodiments, either or both of transceivers410and412may be capable of providing both LTE eNodeB and LTE UE functionality. Transceiver410may be coupled to processor402via a Peripheral Component Interconnect-Express (PCI-E) bus, and/or via a daughtercard. Transceiver410may have its L1 (PHY), L2 (MAC), and other layers implemented using software modules that are configured to run on processor402, as described herein. Transceiver412may be for providing LTE UE functionality, in effect emulating a user equipment, it may be connected via the same or different PCI-E bus, or by a USB bus, and may also be coupled to SIM card418. SIM card418may provide information required for authenticating the simulated UE to the evolved packet core (EPC). When no access to an operator EPC is available, a local EPC on the enhanced eNodeB itself (not shown) may be used, or another local EPC on the network may be used. This information may be stored within the SIM card, and may include one or more of an international mobile equipment identity (IMEI), international mobile subscriber identity (IMSI), or other parameter needed to identify a UE. Special parameters may also be stored in the SIM card or provided by the processor during processing to identify to a target eNodeB that device400is not an ordinary UE but instead is a special UE for providing backhaul to device400. Alternatively, transceiver412may be another radio access technology (RAT) radio, such as a 2G, 3G, 4G, 5G, or Wi-Fi radio. Transceivers410and412may have different RATs or the same RAT. As each RAT and as each radio has its own PHY, the concepts and methods described herein could be used for 2G, 3G, 4G, 5G, or Wi-Fi PHY and MAC layer error messaging, or a combination of multiple RAT layer error messaging modules. Wired backhaul or wireless backhaul may be used. Wired backhaul may be an Ethernet-based backhaul (including Gigabit Ethernet), or a fiber-optic backhaul connection, or a cable-based backhaul connection, in some embodiments. Additionally, wireless backhaul may be provided in addition to wireless transceivers410and412, which may be Wi-Fi 802.11a/b/g/n/ac/ad/ah, Bluetooth, ZigBee, microwave (including line-of-sight microwave), or another wireless backhaul connection. Any of the wired and wireless connections may be used for either access or backhaul, according to identified network conditions and needs, and may be under the control of processor402for reconfiguration. Other elements and/or modules may also be included, such as a home eNodeB, a local gateway (LGW), or another module. Additional radio amplifiers, radio transceivers and/or wired network connections may also be included. Processor402may identify the appropriate network configuration, and may perform routing of packets from one network interface to another accordingly. Processor402may use memory404, in particular to store a routing table to be used for routing packets. Baseband processor406may perform operations to generate the radio frequency signals for transmission or retransmission by both transceivers410and412. Baseband processor406may also perform operations to decode signals received by transceivers410and412. Baseband processor406may use memory408to perform these tasks. In some embodiments, the radio transceivers described herein may be base stations compatible with a Long Term Evolution (LTE) radio transmission protocol or air interface. The LTE-compatible base stations may be eNodeBs. In addition to supporting the LTE protocol, the base stations may also support other air interfaces, such as UMTS/HSPA, CDMA/CDMA2000, GSM/EDGE, GPRS, EVDO, other 3G/2G, legacy TDD, or other air interfaces used for mobile telephony. In some embodiments, the base stations described herein may support Wi-Fi air interfaces, which may include one or more of IEEE 802.11a/b/g/n/ac. In some embodiments, the base stations described herein may support IEEE 802.16 (WiMAX), to LTE transmissions in unlicensed frequency bands (e.g., LTE-U, Licensed Access or LA-LTE), to LTE transmissions using dynamic spectrum access (DSA), to radio transceivers for ZigBee, Bluetooth, or other radio frequency protocols, or other air interfaces. In some embodiments, the base stations described herein may use programmable frequency filters. In some embodiments, the base stations described herein may provide access to land mobile radio (LMR)-associated radio frequency bands. In some embodiments, the base stations described herein may also support more than one of the above radio frequency protocols, and may also support transmit power adjustments for some or all of the radio frequency protocols supported. The embodiments disclosed herein can be used with a variety of protocols so long as there are contiguous frequency bands/channels. Although the methods described assume a single-in, single-output (SISO) system, the techniques described can also be extended to multiple-in, multiple-out (MIMO) systems. In some embodiments, the methods described can be used with 2G, 3G, 4G, 5G, Wi-Fi, or multi-RAT base stations or access points. In some embodiments, the methods described could be used in a UE as well as femto, nodeB, eNodeB, metro, or macro, as long as an API is used for communication between the PHY and the MAC layers. Those skilled in the art will recognize that multiple hardware and software configurations could be used depending upon the access protocol, backhaul protocol, duplexing scheme, or operating frequency band by adding or replacing daughtercards to the dynamic multi-RAT node. Presently, there are radio cards that can be used for the varying radio parameters. Accordingly, the multi-RAT nodes of the present invention could be designed to contain as many radio cards as desired given the radio parameters of heterogeneous mesh networks within which the multi-RAT node is likely to operate. Those of skill in the art will recognize that, to the extent an off-the shelf radio card is not available to accomplish transmission/reception in a particular radio parameter, a radio card capable of performing, e.g., in white space frequencies, would not be difficult to design. Those of skill in the art will also recognize that hardware may embody software, software may be stored in hardware as firmware, and various modules and/or functions may be performed or provided either as hardware or software depending on the specific needs of a particular embodiment. In the present disclosure, the words location and position may be used in various instances to have the same meaning, as is common in the relevant art. In any of the scenarios described herein, where processing may be performed at the cell, the processing may also be performed in coordination with a cloud coordination server. The eNodeB may be in communication with the cloud coordination server via an X2 protocol connection, or another connection. The eNodeB may perform inter-cell coordination via the cloud communication server, when other cells are in communication with the cloud coordination server. The eNodeB may communicate with the cloud coordination server to determine whether the UE has the ability to support a handover to Wi-Fi, e.g., in a heterogeneous network. Although the methods above are described as separate embodiments, one of skill in the art would understand that it would be possible and desirable to combine several of the above methods into a single embodiment, or to combine disparate methods into a single embodiment. For example, all of the above methods could be combined. In the scenarios where multiple embodiments are described, the methods could be combined in sequential order, in various orders as necessary. Although the above systems and methods for providing interference mitigation are described in reference to the Long Term Evolution (LTE) standard, one of skill in the art would understand that these systems and methods could be adapted for use with other wireless standards or versions thereof. For example, while certain methods are understood to utilize FAPI, other methods and aspects do not require the LTE Small Cell Forum FAPI or any 3GPP Release. In some embodiments, the software needed for implementing the methods and procedures described herein may be implemented in a high level procedural or an object-oriented language such as C, C++, C#, Python, or Java. The software may also be implemented in assembly language if desired. Packet processing implemented in a network device can include any processing determined by the context. For example, packet processing may involve high-level data link control (HDLC) framing, header compression, and/or encryption. In some embodiments, software that, when executed, causes a device to perform the methods described herein may be stored on a computer-readable medium such as read-only memory (ROM), programmable-read-only memory (PROM), electrically erasable programmable-read-only memory (EEPROM), flash memory, or a magnetic disk that is readable by a general or special purpose-processing unit to perform the processes described in this document. The processors can include any microprocessor (single or multiple core), system on chip (SoC), microcontroller, digital signal processor (DSP), graphics processing unit (GPU), or any other integrated circuit capable of processing instructions such as an x86 microprocessor. Although the present disclosure has been described and illustrated in the foregoing example embodiments, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the disclosure may be made without departing from the spirit and scope of the disclosure, which is limited only by the claims which follow. Various components in the devices described herein may be added, removed, or substituted with those having the same or similar functionality. Various steps as described in the figures and specification may be added or removed from the processes described herein, and the steps described may be performed in an alternative order, consistent with the spirit of the invention. Features of one embodiment may be used in another embodiment. Other embodiments are within the following claims. | 32,734 |
11943051 | DETAILED DESCRIPTION The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. While aspects and implementations are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, implementations and/or uses may come about via integrated chip implementations and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, artificial intelligence (AI)-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also include additional components and features for implementation and practice of claimed and described aspect. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor(s), interleaver, adders/summers, etc.). It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc. of varying sizes, shapes, and constitution. FIG.1is a diagram illustrating an example of a wireless communications system and an access network100. The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations102, UEs104, an Evolved Packet Core (EPC)160, and another core network190(e.g., a 5G Core (5GC)). The base stations102may include macrocells (high power cellular base station) and/or small cells (low power cellular base station). The macrocells include base stations. The small cells include femtocells, picocells, and microcells. The base stations102configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC160through first backhaul links132(e.g., S1 interface). The base stations102configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network190through second backhaul links184. In addition to other functions, the base stations102may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations102may communicate directly or indirectly (e.g., through the EPC160or core network190) with each other over third backhaul links134(e.g., X2 interface). The first backhaul links132, the second backhaul links184, and the third backhaul links134may be wired or wireless. The base stations102may wirelessly communicate with the UEs104. Each of the base stations102may provide communication coverage for a respective geographic coverage area110. There may be overlapping geographic coverage areas110. For example, the small cell102′ may have a coverage area110′ that overlaps the coverage area110of one or more macro base stations102. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links120between the base stations102and the UEs104may include uplink (UL) (also referred to as reverse link) transmissions from a UE104to a base station102and/or downlink (DL) (also referred to as forward link) transmissions from a base station102to a UE104. The communication links120may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations102/UEs104may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). Certain UEs104may communicate with each other using device-to-device (D2D) communication link158. The D2D communication link158may use the DL/UL WWAN spectrum. The D2D communication link158may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR. The wireless communications system may further include a Wi-Fi access point (AP)150in communication with Wi-Fi stations (STAs)152via communication links154, e.g., in a 5 GHz unlicensed frequency spectrum or the like. When communicating in an unlicensed frequency spectrum, the STAs152/AP150may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. The small cell102′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell102′ may employ NR and use the same unlicensed frequency spectrum (e.g., 5 GHz, or the like) as used by the Wi-Fi AP150. The small cell102′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz). Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz), and FR5 (114.25 GHz-300 GHz). Each of these higher frequency bands falls within the EHF band. With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a or FR4-1, and/or FR5, or may be within the EHF band. A base station102, whether a small cell102′ or a large cell (e.g., macro base station), may include and/or be referred to as an eNB, gNodeB (gNB), or another type of base station. Some base stations, such as gNB180may operate in a traditional sub 6 GHz spectrum, in millimeter wave frequencies, and/or near millimeter wave frequencies in communication with the UE104. When the gNB180operates in millimeter wave or near millimeter wave frequencies, the gNB180may be referred to as a millimeter wave base station. The millimeter wave base station180may utilize beamforming182with the UE104to compensate for the path loss and short range. The base station180and the UE104may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming. The base station180may transmit a beamformed signal to the UE104in one or more transmit directions182′. The UE104may receive the beamformed signal from the base station180in one or more receive directions182″. The UE104may also transmit a beamformed signal to the base station180in one or more transmit directions. The base station180may receive the beamformed signal from the UE104in one or more receive directions. The base station180/UE104may perform beam training to determine the best receive and transmit directions for each of the base station180/UE104. The transmit and receive directions for the base station180may or may not be the same. The transmit and receive directions for the UE104may or may not be the same. The EPC160may include a Mobility Management Entity (MME)162, other MMEs164, a Serving Gateway166, a Multimedia Broadcast Multicast Service (MBMS) Gateway168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway172. The MME162may be in communication with a Home Subscriber Server (HSS)174. The MME162is the control node that processes the signaling between the UEs104and the EPC160. Generally, the MME162provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway166, which itself is connected to the PDN Gateway172. The PDN Gateway172provides UE IP address allocation as well as other functions. The PDN Gateway172and the BM-SC170are connected to the IP Services176. The IP Services176may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BM-SC170may provide functions for MBMS user service provisioning and delivery. The BM-SC170may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway168may be used to distribute MBMS traffic to the base stations102belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. The core network190may include an Access and Mobility Management Function (AMF)192, other AMFs193, a Session Management Function (SMF)194, and a User Plane Function (UPF)195. The AMF192may be in communication with a Unified Data Management (UDM)196. The AMF192is the control node that processes the signaling between the UEs104and the core network190. Generally, the AMF192provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF195. The UPF195provides UE IP address allocation as well as other functions. The UPF195is connected to the IP Services197. The IP Services197may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switch (PS) Streaming (PSS) Service, and/or other IP services. The base station may include and/or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. The base station102provides an access point to the EPC160or core network190for a UE104. Examples of UEs104include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs104may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE104may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. In some scenarios, the term UE may also apply to one or more companion devices such as in a device constellation arrangement. One or more of these devices may collectively access the network and/or individually access the network. Referring again toFIG.1, in certain aspects, the UE104may include a transmission component198configured to encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits. Transmission component198may also be configured to configure at least one channel interleaver for the plurality of bits associated with the QAM. Transmission component198may also be configured to enable or disable the at least one channel interleaver based on the at least one RV. Transmission component198may also be configured to store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer. Transmission component198may also be configured to transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer. Transmission component198may also be configured to map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols. Transmission component198may also be configured to transmit, to a base station, the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols. Referring again toFIG.1, in certain aspects, the base station180may include a transmission component199configured to encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits. Transmission component199may also be configured to configure at least one channel interleaver for the plurality of bits associated with the QAM. Transmission component199may also be configured to enable or disable the at least one channel interleaver based on the at least one RV. Transmission component199may also be configured to store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer. Transmission component199may also be configured to transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer. Transmission component199may also be configured to map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols. Transmission component199may also be configured to transmit, to a user equipment (UE), the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols. Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies. FIG.2Ais a diagram200illustrating an example of a first subframe within a 5G NR frame structure.FIG.2Bis a diagram230illustrating an example of DL channels within a 5G NR subframe.FIG.2Cis a diagram250illustrating an example of a second subframe within a 5G NR frame structure.FIG.2Dis a diagram280illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided byFIGS.2A,2C, the 5G NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL), where D is DL, U is UL, and F is flexible for use between DL/UL, and subframe 3 being configured with slot format 1 (with all UL). While subframes 3, 4 are shown with slot formats 1, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI), or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI). Note that the description infra applies also to a 5G NR frame structure that is TDD. FIGS.2A-2Dillustrate a frame structure, and the aspects of the present disclosure may be applicable to other wireless communication technologies, which may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For normal CP, each slot may include 14 symbols, and for extended CP, each slot may include 12 symbols. The symbols on DL may be CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission). The number of slots within a subframe is based on the CP and the numerology. The numerology defines the subcarrier spacing (SCS) and, effectively, the symbol length/duration, which is equal to 1/SCS. SCSμΔf = 2μ· 15[kHz]Cyclic prefix015Normal130Normal260Normal, Extended3120Normal4240Normal For normal CP (14 symbols/slot), different numerologies μ 0 to 4 allow for 1, 2, 4, 8, and 16 slots, respectively, per subframe. For extended CP, the numerology 2 allows for 4 slots per subframe. Accordingly, for normal CP and numerology μ, there are 14 symbols/slot and 2μslots/subframe. The subcarrier spacing may be equal to 2μ*15 kHz, where μ is the numerology 0 to 4. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=4 has a subcarrier spacing of 240 kHz. The symbol length/duration is inversely related to the subcarrier spacing.FIGS.2A-2Dprovide an example of normal CP with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (seeFIG.2B) that are frequency division multiplexed. Each BWP may have a particular numerology and CP (normal or extended). A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme. As illustrated inFIG.2A, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulation RS (DM-RS) (indicated as R for one particular configuration, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and phase tracking RS (PT-RS). FIG.2Billustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within one BWP may be referred to as a control resource set (CORESET). A UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., common search space, UE-specific search space) during PDCCH monitoring occasions on the CORESET, where the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE104to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the DM-RS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block (also referred to as SS block (SSB)). The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages. As illustrated inFIG.2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS). The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL. FIG.2Dillustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgment (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACK and/or negative ACK (NACK)). The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI. FIG.3is a block diagram of a base station310in communication with a UE350in an access network. In the DL, IP packets from the EPC160may be provided to a controller/processor375. The controller/processor375implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor375provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. The transmit (TX) processor316and the receive (RX) processor370implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor316handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator374may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE350. Each spatial stream may then be provided to a different antenna320via a separate transmitter318TX. Each transmitter318TX may modulate a radio frequency (RF) carrier with a respective spatial stream for transmission. At the UE350, each receiver354RX receives a signal through its respective antenna352. Each receiver354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor356. The TX processor368and the RX processor356implement layer 1 functionality associated with various signal processing functions. The RX processor356may perform spatial processing on the information to recover any spatial streams destined for the UE350. If multiple spatial streams are destined for the UE350, they may be combined by the RX processor356into a single OFDM symbol stream. The RX processor356then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station310. These soft decisions may be based on channel estimates computed by the channel estimator358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station310on the physical channel. The data and control signals are then provided to the controller/processor359, which implements layer 3 and layer 2 functionality. The controller/processor359can be associated with a memory360that stores program codes and data. The memory360may be referred to as a computer-readable medium. In the UL, the controller/processor359provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC160. The controller/processor359is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. Similar to the functionality described in connection with the DL transmission by the base station310, the controller/processor359provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. Channel estimates derived by a channel estimator358from a reference signal or feedback transmitted by the base station310may be used by the TX processor368to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor368may be provided to different antenna352via separate transmitters354TX. Each transmitter354TX may modulate an RF carrier with a respective spatial stream for transmission. The UL transmission is processed at the base station310in a manner similar to that described in connection with the receiver function at the UE350. Each receiver318RX receives a signal through its respective antenna320. Each receiver318RX recovers information modulated onto an RF carrier and provides the information to a RX processor370. The controller/processor375can be associated with a memory376that stores program codes and data. The memory376may be referred to as a computer-readable medium. In the UL, the controller/processor375provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE350. IP packets from the controller/processor375may be provided to the EPC160. The controller/processor375is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. At least one of the TX processor368, the RX processor356, and the controller/processor359may be configured to perform aspects in connection with198ofFIG.1. At least one of the TX processor316, the RX processor370, and the controller/processor375may be configured to perform aspects in connection with199ofFIG.1. Some aspects of wireless communication may utilize quadrature amplitude modulation (QAM), i.e., a type of modulation method that is used to transmit information. QAM is a form of modulation that combines phase modulation and amplitude modulation. Further, QAM may include digital modulation methods or analog modulation methods. For instance, QAM may convey multiple analog signals or digital bit streams by changing (i.e., modulating) the amplitudes of two carrier waves. This modulation process may be performed using an amplitude-shift keying (ASK) digital modulation scheme or an amplitude modulation (AM) analog modulation scheme. A transmitted signal may be created by adding the two carrier waves together. In some instances, the QAM scheme may represent bits as points in a quadrant grid, i.e., a constellation map, which may be referred to as QAM constellation. For example, a constellation map may be a graph of the phase and amplitude modulation points in a given modulation scheme. Some instances of QAM constellations or constellation maps may utilize each value with equal probability. Also, information theory states that an optimum constellation map includes a two-dimensional (2D) Gaussian distribution. Non-uniform spacing within a QAM constellation is one way to approximate a 2D Gaussian distribution. However, non-uniform spacing may result in increased demodulation complexity. Probabilistic shaping of the constellation map is another alternative which controls the probability of each modulation value to approximate a 2D Gaussian distribution, such as by using a uniformly spaced constellation. In some instances, a uniformly spaced constellation may utilize a shaping encoder at a transmitter prior to modulation and a shaping decoder at a receiver after demodulation. Currently, shaping encoders may include variable rate encoders based on a type of coding, e.g., Huffman coding. For example, a fixed-sized block of pre-shaped bits may be converted into a variable-sized block of post-shaped bits. In order to deal with the variable rate code, methods may be needed to compensate for the variable rate code. Some examples of probabilistic shaping may include an outer source encoder to change the distribution of amplitude mapping bits, e.g., pulse-amplitude modulation (PAM) amplitude mapping bits. In some aspects, probabilistic shaping may include different types of encoding, e.g., arithmetic encoding and prefix encoding, where prefix encoding may be more suitable in some instances due to complexity. Aspects of probabilistic shaping may also include different types of encoding flows, such as a shaping-low density parity check (LDPC) encoding flow. In shaping-LDPC encoding flows, different types of bits may be distributed or mapped, such as parity bits and systematic bits. For instance, parity bits may be evenly distributed and used for in-phase and quadrature (I/Q) sign bits. Also, systematic bits may be mapped to a QAM amplitude and may need to be pre-encoded. FIG.4illustrates a diagram400of one example of an encoding process. More specifically, diagram400inFIG.4displays an encoding process for probabilistic shaping. As shown inFIG.4, diagram400includes scrambler410, shaping encoder420, LDPC encoder430, and QAM modulator440.FIG.4illustrates that certain data units, e.g., physical layer convergence protocol (PLCP) service data units (PSDUs) or aggregated MAC protocol data units (A-MPDUs), may be input to the scrambler410. The scrambler410may output the scrambled PSDUs to the shaping encoder420, e.g., a variable-rate shaping encoder. Next, the shaping encoder420may output the type of bits, e.g., systematic bits and parity bits. As depicted inFIG.4, the LDPC encoder430may be between the shaping encoder420and the QAM modulator440, where the LDPC encoder430outputs the parity bits. The systematic bits and the parity bits may be input to the QAM modulator440as amplitude bits and sign bits, respectively. Finally, the QAM modulator440may output QAM symbols. Additionally, some types of shaping encoders may map or assign a variable number of input bits to a fixed number of output bits. In some instances, the number of output bits may be selected to accommodate size limitations of an LDPC encoder input. Further, there may be methods to ensure an appropriate number of input bits is selected for the desired number of output bits. Also, the shaped bits may be grouped into uniform sized clusters, as depicted inFIG.5Abelow. FIG.5Aillustrates a diagram500of one example of a prefix encoding process. More specifically,FIG.5Adisplays an example prefix encoding process for 256-QAM. As shown inFIG.5A, diagram500includes input bits, output bits, an I/Q level of the bits, and probability (p) of each outcome.FIG.5Adiscloses that the shaped output bits are grouped into uniformly sized clusters. For example, in the case of 256-QAM with the prefix coding inFIG.5A, shaped bit stream ‘100101111100101xx . . . ’ has the following inherent grouping: ‘100,101,111,110,010,1xx, . . . ’ In order to keep the integrity of the shaped bits inFIG.5A, i.e., achieve the desired constellation shaping, the grouped bit clusters may be preserved. In general, each cluster consists of a certain number of bits, e.g., (M−2) bits, where M is the order of modulation, e.g., M=8 for 256-QAM. When mapping to a modulation symbol, it may be necessary to use the original clusters of the shaped bit stream. For example, if the sequence of the example above is shifted by a certain amount, e.g., shifted by a single bit as shown inFIG.5B, the constellation shaping may no longer be achieved. FIG.5Billustrates a diagram550of one example of a shifted bit sequence. More specifically,FIG.5Bdisplays an example bit shifting process that shifts a bit sequence by one (1) bit. As shown inFIG.5B, diagram550shifts the bit sequence inFIG.5Aby a single bit. For example, the bit sequence ‘xxx,100,101,111,110,010,1xx, . . . ’ inFIG.5Ais shifted by one (1) bit to produce ‘xx1,001,011,111,100,101,xx, . . . ’ inFIG.5B. As indicated above, the constellation shaping inFIG.5Ais no longer achieved due to the 1-bit shifting inFIG.5B. Some aspects of wireless communication may utilize channel interleaving, i.e., allocating contiguous portions of data across interleaved channels. Channel interleaving may increase a potential read bandwidth as requests for data may be made to each interleaved channel in an overlapped manner. In some instances, the systematic bits at the output of the channel encoder (e.g., an LDPC encoder) may have a desired distribution defined by the shaping code. Existing channel interleaver designs may apply to certain mapping principles, e.g., systematic bit-priority mapping based principles. Additionally, the row-to-column interleaving may break or interrupt the order of the shaped systematic bits. Thus, the channel interleaver output may break or interrupt the original integrity of the shaped bits in the bit stream. FIG.6illustrates a diagram600of one example of a channel interleaving process. More specifically, diagram600inFIG.6displays a channel interleaving process for systematic bits at the output of a low density parity check (LDPC) encoder. As shown inFIG.6, diagram600depicts a number of bits including a length of an input sequence (Er) and a modulation order (Qm).FIG.6also shows that the bits are written corresponding to the ratio of input sequence/modulation order (Er/Qm) and read corresponding to the modulation order (Qm). In some instances, systematic bits may be shaped, i.e., the order of the bits are arranged with a shaping encoder, and the parity bits may not be shaped. When a redundancy version (RV) of a circular buffer includes both types of bits, the bits-to-modulation-symbol mapping process may need to ensure that the clusters of the shaped systematic bits are maintained. Also, there may be multiple types of circular buffers with corresponding RVs. Two types of circular buffers and associated RVs are shown inFIGS.7A and7B. FIGS.7A and7Billustrate diagrams700and750, respectively, of example circular buffers. More specifically,FIGS.7A and7Bdisplay circular buffers with corresponding redundancy versions (RVs) including systematic bits and parity bits. As shown inFIG.7A, diagram700is a circular buffer with four types of corresponding RVs, e.g., first RV (RV0), second RV (RV1), third RV (RV2), and fourth RV (RV2). Both systematic bits and parity bits are stored in the circular buffer in diagram500. As shown inFIG.7B, diagram750is also a circular buffer with four types of corresponding RVs, e.g., first RV (RV0), second RV (RV1), third RV (RV2), and fourth RV (RV2). Further, both systematic bits and parity bits are stored in the circular buffer in diagram550. InFIGS.7A and7B, the RVs are shifted differently and there is a different amount of systematic bits compared to parity bits. For instance, there are more systematic bits stored in the circular buffer inFIG.7Acompared to the systematic bits stored in the circular buffer inFIG.7B. As indicated inFIGS.7A and7B, even without channel interleaving, the bits in a circular buffer may be sequentially read out and mapped to modulation symbols according to a modulation and coding scheme (MCS) configuration. This process may be easily achieved by a first RV (RV0), which begins with systematic bits. For other RVs, this may be more difficult, as there may be no way to preserve the integrity of the shaped bits. For example, when a second RV (RV1) is configured, although it starts from a systematic bit in the circular buffer, the systematic bit may not be the first bit of a cluster or group of shaped bits. Additionally, when a fourth RV (RV3) is configured, it may begin with parity bits in the circular buffer. As indicated above, when the systematic bits are read, there may be no way to ensure that clusters of certain bits, e.g., systematic bits, are mapped to the desired modulation symbols. Accordingly, the mapping from channel-coded bits to modulation symbols may not preserve the shaped constellation. As such, it may be beneficial to ensure that clusters of bits are mapped to desired modulation symbols. Further, it may be beneficial to preserve a shaped constellation based on mapping from channel-coded bits to modulation symbols. Aspects of the present disclosure may ensure that clusters of bits are mapped to desired modulation symbols. For instance, aspects of the present disclosure may preserve a shaped constellation based on mapping from channel-coded bits to modulation symbols. In order to preserve shaped constellations, aspects of the present disclosure may utilize probabilistic shaping. For example, aspects of the present disclosure may utilize rate matching and channel interleaving to preserve shaped constellations. In some instances, aspects of the present disclosure may apply probabilistic shaping to high signal-to-interference plus noise (SINR) scenarios, where the effective coding rate is high. For instance, there may be no need to consider probabilistic shaping for scenarios with an effective low coding rate. Aspects of the present disclosure may disable channel interleavers for probabilistic shaping. For instance, aspects of the present disclosure may include a static solution, such that when probabilistic shaping is enabled, the channel interleaving step is bypassed. Further, probabilistic shaping may be applied to high signal-to-noise ratio (SNR) additive white Gaussian noise (AWGN) channel scenarios, where the benefit of applying channel interleaving is negligible. Aspects of the present disclosure may also include more dynamic solutions, such as to enable or disable channel interleaving depending on the configured RV. For example, if RV1 or RV2 is utilized, channel interleaving may be enabled, and if RV0 or RV3 are utilized, channel interleaving may be disabled. This may be indicated by DCI that contains the scheduling information for the transmission or retransmission. Additionally, aspects of the present disclosure may include separate interleavers for different types of bits, e.g., systematic bits and parity bits. For instance, a row-to-column interleaver may be applied at the output of the shaping encoder and another row-to-column interleaver may be applied at the LDPC output on the systematic bits. By doing so, LDPC may work on the interleaved bits to generate parity bits without changing the shaping. Also, another interleaver may be applied to parity bits generated from the LDPC encoder. Aspects of the present disclosure may also define a procedure for RV-to-modulation symbol mapping. With probabilistic shaping, bits in an RV may be split into two categories: amplitude bits (i.e., bits representing the amplitude corresponding to modulation symbols) and sign bits (i.e., bits representing the sign corresponding to modulation symbols). Both the shaped bits (i.e., systematic bits) and the unshaped bits (i.e., parity bits) may be either amplitude bits or sign bits. Aspects of the present disclosure may establish two separate buffers that store amplitude bits and sign bits, respectively, i.e., an amplitude bit buffer and a sign bit buffer. For example, the bits may be read from the circular buffer according to RV configuration and then written into the amplitude bit buffers and sign bit buffers. FIGS.8A and8Billustrate diagrams800and850, respectively, of example buffers according to aspects of the present disclosure. More specifically,FIGS.8A and8Bdisplay an amplitude bit buffer and a sign bit buffer, respectively. As shown inFIG.8A, diagram800includes an amplitude bit buffer that stores a plurality of amplitude bits, e.g., I/Q amplitude bits. For example, the amplitude bit buffer inFIG.8Acorresponds to 1024-QAM, i.e., M=10.FIG.8Bdisplays diagram850including a sign bit buffer that stores a plurality of sign bits, e.g., I/Q sign bits. For example, the sign bit buffer inFIG.8Bcorresponds to 1024-QAM, i.e., M=10. Aspects of the present disclosure may include procedures to establish an amplitude bit buffer and a sign bit buffer. For instance, aspects of the present disclosure may read RV bits from a circular buffer and write into an amplitude bit buffer and a sign bit buffer. In order to establish an amplitude bit buffer and a sign bit buffer, aspects of the present disclosure may define a number of variables, such as: a modulation order (M), a number of modulation symbols (Nmod), a number of systematic bits in the RV (nsys), a number of parity bits in the RV (npar), a starting index of the systematic bits (isys) (e.g., isys=0 for RV0), a number of amplitude bits (namp) (e.g., namp=(M−2)Nmod), a number of sign bits (nsgn) (e.g., nsgn=2Nmod), and an offset applied to a starting index of the systematic bits (isys_off). In some instances, aspects of the present disclosure may determine nsys, where nsysis a function of RV configuration, Nmod, and M. If nsys=0, aspects of the present disclosure may fill the amplitude bit buffer and the sign bit buffer with parity bits sequentially, where the amplitude bit buffer is filled first. If nsys≤(M−2)Nmod, if mod(isys,(M−2))=0, isys_off=0; else isys_off=(M−2)−mod(isys,(M−2)), where ‘mod’ is a modulo operation that returns the remainder or signed remainder of a division operation, i.e., after one number is divided by another number. Also, if nsys≤(M−2)Nmod, aspects of the present disclosure may read from index (isys+isys_off) of the systematic bits in the circular buffer and write into the amplitude bit buffer. This process may fill the amplitude bit buffer with nsys−isys_offbits. After that, aspects of the present disclosure may write the isys_offnumber of systematic bits that are bypassed into the amplitude buffer. Aspects of the present disclosure may also fill the remaining portion of the amplitude buffer, followed by the sign bit buffer, with nparparity bits sequentially. Additionally, if mod(isys,(M−2))=0, isys_off=0; else isys_off=(M−2)−mod(isys,(M−2)). Also, aspects of the present disclosure may read from index (isys+isys_off) of the systematic bits in the circular buffer and write into the amplitude bit buffer until it is filled. Aspects of the present disclosure may also write the isys_offnumber of systematic bits that are bypassed into the sign bit buffer, followed by the remaining systematic bits and the parity bits. In some instances, the value of isys_offmay be transferred to the UE, such as via piggyback DCI. Aspects of the present disclosure may include many alternative ways to map the RV bits to modulation symbols while preserving the integrity of the shaped constellation. For instance, the order of how bits are written into the sign bit buffer may not be important and alternative procedures may be utilized. For example, when RV1 and RV2 are used, the original RV-to-modulation symbol mapping method may be used, as there are little to no shaped bits in these RVs. Moreover, this mapping may be semi-statically or dynamically configured via radio resource control (RRC) signaling, a medium access control (MAC) control element (MAC-CE), or downlink control information (DCI). FIG.9is a diagram900illustrating example communication between a UE902and a base station904. At912, UE902may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits. The plurality of bits may further include a plurality of parity bits. The plurality of bits may be encoded based on prefix encoding or a low density parity check (LDPC) encoder. If the plurality of bits is encoded based on the LDPC encoder, an output of the LDPC encoder may correspond to the plurality of bits including a plurality of parity bits. Also, the plurality of systematic bits may be associated with probabilistic shaping. At914, base station904may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits. At922, UE902may configure at least one channel interleaver for the plurality of bits associated with the QAM. The at least one channel interleaver may include a first channel interleaver for a plurality of parity bits and a second channel interleaver for the plurality of systematic bits. Also, the at least one channel interleaver may include a first row-to-column interleaver and a second row-to-column interleaver. The first row-to-column interleaver may be associated with an output of a shaping encoder and the second row-to-column interleaver may be associated with a low density parity check (LDPC) output of the plurality of systematic bits. At924, base station904may configure at least one channel interleaver for the plurality of bits associated with the QAM. At932, UE902may enable or disable the at least one channel interleaver based on the at least one RV. At934, base station904may enable or disable the at least one channel interleaver based on the at least one RV. At942, UE902may store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer. At944, base station904may store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer. At952, UE902may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer. The plurality of bits may be transferred to the first buffer and the second buffer based on pseudocode. In some aspects, the UE902may read the plurality of bits from the circular buffer and write the plurality of bits to the first buffer and the second buffer. For instance, transferring the plurality of bits may include reading the plurality of bits from the circular buffer and writing the plurality of bits to the first buffer and the second buffer. At954, base station904may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer. In some aspects, the first buffer may be an amplitude bit buffer and the second buffer may be a sign bit buffer. If a number of the plurality of systematic bits in the at least one RV (nsys) is equal to zero, the amplitude bit buffer and the sign bit buffer may be filled sequentially with a plurality of parity bits of the plurality of bits, where the amplitude bit buffer may be filled prior to the sign bit buffer. If nsys≤(M−2)Nmod, and if mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where nsysis a number of the plurality of systematic bits in the at least one RV, M is a modulation order, Nmodis a number of modulation symbols, isysis a starting index of the plurality of systematic bits, and isys_offis an offset applied to the starting index of the plurality of systematic bits. If mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where isysis a starting index of the plurality of systematic bits, M is a modulation order, and isys_offis an offset applied to the starting index of the plurality of systematic bits. At962, UE902may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols. At964, base station904may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols. At972, UE902may transmit, to a base station (e.g., base station904), the plurality of modulation symbols (e.g., modulation symbols980), where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols. At974, base station904may transmit, to a UE (e.g., UE902), the plurality of modulation symbols (e.g., modulation symbols980), where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols. FIG.10is a flowchart1000of a method of wireless communication. The method may be performed by a UE or a component of a UE (e.g., the UE104,350,902; the apparatus1402). The methods described herein may provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings. At1002, the UE may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, as described in connection with the examples inFIGS.4-9. For example, UE902may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, as described in connection with912inFIG.9. Further,1002may be performed by determination component1440inFIG.14. The plurality of bits may further include a plurality of parity bits. The plurality of bits may be encoded based on prefix encoding or a low density parity check (LDPC) encoder. If the plurality of bits is encoded based on the LDPC encoder, an output of the LDPC encoder may correspond to the plurality of bits including a plurality of parity bits. Also, the plurality of systematic bits may be associated with probabilistic shaping. At1010, the UE may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, as described in connection with the examples inFIGS.4-9. For example, UE902may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, as described in connection with952inFIG.9. Further,1010may be performed by determination component1440inFIG.14. The plurality of bits may be transferred to the first buffer and the second buffer based on pseudocode. In some aspects, the UE902may read the plurality of bits from the circular buffer and write the plurality of bits to the first buffer and the second buffer. For instance, transferring the plurality of bits may include reading the plurality of bits from the circular buffer and writing the plurality of bits to the first buffer and the second buffer. In some aspects, the first buffer may be an amplitude bit buffer and the second buffer may be a sign bit buffer. If a number of the plurality of systematic bits in the at least one RV (nsys) is equal to zero, the amplitude bit buffer and the sign bit buffer may be filled sequentially with a plurality of parity bits of the plurality of bits, where the amplitude bit buffer may be filled prior to the sign bit buffer. If nsys≤(M−2)Nmod, and if mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where nsysis a number of the plurality of systematic bits in the at least one RV, M is a modulation order, Nmodis a number of modulation symbols, isysis a starting index of the plurality of systematic bits, and isys_offis an offset applied to the starting index of the plurality of systematic bits. If mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where isysis a starting index of the plurality of systematic bits, M is a modulation order, and isys_offis an offset applied to the starting index of the plurality of systematic bits. At1012, the UE may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, as described in connection with the examples inFIGS.4-9. For example, UE902may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, as described in connection with962inFIG.9. Further,1012may be performed by determination component1440inFIG.14. FIG.11is a flowchart1100of a method of wireless communication. The method may be performed by a UE or a component of a UE (e.g., the UE104,350,902; the apparatus1402). The methods described herein may provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings. At1102, the UE may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, as described in connection with the examples inFIGS.4-9. For example, UE902may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, as described in connection with912inFIG.9. Further,1102may be performed by determination component1440inFIG.14. The plurality of bits may further include a plurality of parity bits. The plurality of bits may be encoded based on prefix encoding or a low density parity check (LDPC) encoder. If the plurality of bits is encoded based on the LDPC encoder, an output of the LDPC encoder may correspond to the plurality of bits including a plurality of parity bits. Also, the plurality of systematic bits may be associated with probabilistic shaping. At1104, the UE may configure at least one channel interleaver for the plurality of bits associated with the QAM, as described in connection with the examples inFIGS.4-9. For example, UE902may configure at least one channel interleaver for the plurality of bits associated with the QAM, as described in connection with922inFIG.9. Further,1104may be performed by determination component1440inFIG.14. The at least one channel interleaver may include a first channel interleaver for a plurality of parity bits and a second channel interleaver for the plurality of systematic bits. Also, the at least one channel interleaver may include a first row-to-column interleaver and a second row-to-column interleaver. The first row-to-column interleaver may be associated with an output of a shaping encoder and the second row-to-column interleaver may be associated with a low density parity check (LDPC) output of the plurality of systematic bits. At1106, the UE may enable or disable the at least one channel interleaver based on the at least one RV, as described in connection with the examples inFIGS.4-9. For example, UE902may enable or disable the at least one channel interleaver based on the at least one RV, as described in connection with932inFIG.9. Further,1106may be performed by determination component1440inFIG.14. At1108, the UE may store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer, as described in connection with the examples inFIGS.4-9. For example, UE902may store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer, as described in connection with942inFIG.9. Further,1108may be performed by determination component1440inFIG.14. At1110, the UE may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, as described in connection with the examples inFIGS.4-9. For example, UE902may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, as described in connection with952inFIG.9. Further,1110may be performed by determination component1440inFIG.14. The plurality of bits may be transferred to the first buffer and the second buffer based on pseudocode. In some aspects, the UE902may read the plurality of bits from the circular buffer and write the plurality of bits to the first buffer and the second buffer. For instance, transferring the plurality of bits may include reading the plurality of bits from the circular buffer and writing the plurality of bits to the first buffer and the second buffer. In some aspects, the first buffer may be an amplitude bit buffer and the second buffer may be a sign bit buffer. If a number of the plurality of systematic bits in the at least one RV (nsys) is equal to zero, the amplitude bit buffer and the sign bit buffer may be filled sequentially with a plurality of parity bits of the plurality of bits, where the amplitude bit buffer may be filled prior to the sign bit buffer. If nsys≤(M−2)Nmod, and if mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where nsysis a number of the plurality of systematic bits in the at least one RV, M is a modulation order, Nmodis a number of modulation symbols, isysis a starting index of the plurality of systematic bits, and isys_offis an offset applied to the starting index of the plurality of systematic bits. If mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where isysis a starting index of the plurality of systematic bits, M is a modulation order, and isys_offis an offset applied to the starting index of the plurality of systematic bits. At1112, the UE may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, as described in connection with the examples inFIGS.4-9. For example, UE902may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, as described in connection with962inFIG.9. Further,1112may be performed by determination component1440inFIG.14. At1114, the UE may transmit, to a base station, the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols, as described in connection with the examples inFIGS.4-9. For example, UE902may transmit, to a base station, the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols, as described in connection with972inFIG.9. Further,1114may be performed by determination component1440inFIG.14. FIG.12is a flowchart1200of a method of wireless communication. The method may be performed by a base station or a component of a base station (e.g., the base station102,180,310,904; the apparatus1502). The methods described herein may provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings. At1202, the base station may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, as described in connection with the examples inFIGS.4-9. For example, base station904may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, as described in connection with914inFIG.9. Further,1202may be performed by determination component1540inFIG.15. The plurality of bits may further include a plurality of parity bits. The plurality of bits may be encoded based on prefix encoding or a low density parity check (LDPC) encoder. If the plurality of bits is encoded based on the LDPC encoder, an output of the LDPC encoder may correspond to the plurality of bits including a plurality of parity bits. Also, the plurality of systematic bits may be associated with probabilistic shaping. At1210, the base station may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, as described in connection with the examples inFIGS.4-9. For example, base station904may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, as described in connection with954inFIG.9. Further,1210may be performed by determination component1540inFIG.15. The plurality of bits may be transferred to the first buffer and the second buffer based on pseudocode. In some aspects, the UE902may read the plurality of bits from the circular buffer and write the plurality of bits to the first buffer and the second buffer. For instance, transferring the plurality of bits may include reading the plurality of bits from the circular buffer and writing the plurality of bits to the first buffer and the second buffer. In some aspects, the first buffer may be an amplitude bit buffer and the second buffer may be a sign bit buffer. If a number of the plurality of systematic bits in the at least one RV (nsys) is equal to zero, the amplitude bit buffer and the sign bit buffer may be filled sequentially with a plurality of parity bits of the plurality of bits, where the amplitude bit buffer may be filled prior to the sign bit buffer. If nsys≤(M−2)Nmod, and if mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where nsysis a number of the plurality of systematic bits in the at least one RV, M is a modulation order, Nmodis a number of modulation symbols, isysis a starting index of the plurality of systematic bits, and isys_offis an offset applied to the starting index of the plurality of systematic bits. If mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where isysis a starting index of the plurality of systematic bits, M is a modulation order, and isys_offis an offset applied to the starting index of the plurality of systematic bits. At1212, the base station may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, as described in connection with the examples inFIGS.4-9. For example, base station904may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, as described in connection with964inFIG.9. Further,1212may be performed by determination component1540inFIG.15. FIG.13is a flowchart1300of a method of wireless communication. The method may be performed by a base station or a component of a base station (e.g., the base station102,180,310,904; the apparatus1502). The methods described herein may provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings. At1302, the base station may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, as described in connection with the examples inFIGS.4-9. For example, base station904may encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, as described in connection with914inFIG.9. Further,1302may be performed by determination component1540inFIG.15. The plurality of bits may further include a plurality of parity bits. The plurality of bits may be encoded based on prefix encoding or a low density parity check (LDPC) encoder. If the plurality of bits is encoded based on the LDPC encoder, an output of the LDPC encoder may correspond to the plurality of bits including a plurality of parity bits. Also, the plurality of systematic bits may be associated with probabilistic shaping. At1304, the base station may configure at least one channel interleaver for the plurality of bits associated with the QAM, as described in connection with the examples inFIGS.4-9. For example, base station904may configure at least one channel interleaver for the plurality of bits associated with the QAM, as described in connection with924inFIG.9. Further,1304may be performed by determination component1540inFIG.15. The at least one channel interleaver may include a first channel interleaver for a plurality of parity bits and a second channel interleaver for the plurality of systematic bits. Also, the at least one channel interleaver may include a first row-to-column interleaver and a second row-to-column interleaver. The first row-to-column interleaver may be associated with an output of a shaping encoder and the second row-to-column interleaver may be associated with a low density parity check (LDPC) output of the plurality of systematic bits. At1306, the base station may enable or disable the at least one channel interleaver based on the at least one RV, as described in connection with the examples inFIGS.4-9. For example, base station904may enable or disable the at least one channel interleaver based on the at least one RV, as described in connection with934inFIG.9. Further,1306may be performed by determination component1540inFIG.15. At1308, the base station may store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer, as described in connection with the examples inFIGS.4-9. For example, base station904may store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer, as described in connection with944inFIG.9. Further,1308may be performed by determination component1540inFIG.15. At1310, the base station may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, as described in connection with the examples inFIGS.4-9. For example, base station904may transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, as described in connection with954inFIG.9. Further,1310may be performed by determination component1540inFIG.15. The plurality of bits may be transferred to the first buffer and the second buffer based on pseudocode. In some aspects, the UE902may read the plurality of bits from the circular buffer and write the plurality of bits to the first buffer and the second buffer. For instance, transferring the plurality of bits may include reading the plurality of bits from the circular buffer and writing the plurality of bits to the first buffer and the second buffer. In some aspects, the first buffer may be an amplitude bit buffer and the second buffer may be a sign bit buffer. If a number of the plurality of systematic bits in the at least one RV (nsys) is equal to zero, the amplitude bit buffer and the sign bit buffer may be filled sequentially with a plurality of parity bits of the plurality of bits, where the amplitude bit buffer may be filled prior to the sign bit buffer. If nsys≤(M−2)Nmod, and if mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where nsysis a number of the plurality of systematic bits in the at least one RV, M is a modulation order, Nmodis a number of modulation symbols, isysis a starting index of the plurality of systematic bits, and isys_offis an offset applied to the starting index of the plurality of systematic bits. If mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where isysis a starting index of the plurality of systematic bits, M is a modulation order, and isys_offis an offset applied to the starting index of the plurality of systematic bits. At1312, the base station may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, as described in connection with the examples inFIGS.4-9. For example, base station904may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, as described in connection with964inFIG.9. Further,1312may be performed by determination component1540inFIG.15. At1314, the base station may transmit, to a UE, the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols, as described in connection with the examples inFIGS.4-9. For example, base station904may transmit, to a UE, the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols, as described in connection with974inFIG.9. Further,1314may be performed by determination component1540inFIG.15. FIG.14is a diagram1400illustrating an example of a hardware implementation for an apparatus1402. The apparatus1402may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the apparatus1402may include a cellular baseband processor1404(also referred to as a modem) coupled to a cellular RF transceiver1422. In some aspects, the apparatus1402may further include one or more subscriber identity modules (SIM) cards1420, an application processor1406coupled to a secure digital (SD) card1408and a screen1410, a Bluetooth module1412, a wireless local area network (WLAN) module1414, a Global Positioning System (GPS) module1416, or a power supply1418. The cellular baseband processor1404communicates through the cellular RF transceiver1422with the UE104and/or BS102/180. The cellular baseband processor1404may include a computer-readable medium/memory. The computer-readable medium/memory may be non-transitory. The cellular baseband processor1404is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the cellular baseband processor1404, causes the cellular baseband processor1404to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the cellular baseband processor1404when executing software. The cellular baseband processor1404further includes a reception component1430, a communication manager1432, and a transmission component1434. The communication manager1432includes the one or more illustrated components. The components within the communication manager1432may be stored in the computer-readable medium/memory and/or configured as hardware within the cellular baseband processor1404. The cellular baseband processor1404may be a component of the UE350and may include the memory360and/or at least one of the TX processor368, the RX processor356, and the controller/processor359. In one configuration, the apparatus1402may be a modem chip and include just the baseband processor1404, and in another configuration, the apparatus1402may be the entire UE (e.g., see350ofFIG.3) and include the additional modules of the apparatus1402. The communication manager1432includes a determination component1440that is configured to encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, e.g., as described in connection with step1102above. Determination component1440may also be configured to configure at least one channel interleaver for the plurality of bits associated with the QAM, e.g., as described in connection with step1104above. Determination component1440may also be configured to enable or disable the at least one channel interleaver based on the at least one RV, e.g., as described in connection with step1106above. Determination component1440may also be configured to store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer, e.g., as described in connection with step1108above. Determination component1440may also be configured to transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, e.g., as described in connection with step1110above. Determination component1440may also be configured to map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, e.g., as described in connection with step1112above. Determination component1440may also be configured to transmit, to a base station, the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols, e.g., as described in connection with step1114above. The apparatus may include additional components that perform each of the blocks of the algorithm in the flowcharts ofFIGS.9-11. As such, each block in the flowcharts ofFIGS.9-11may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. As shown, the apparatus1402may include a variety of components configured for various functions. In one configuration, the apparatus1402, and in particular the cellular baseband processor1404, includes means for encoding a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits; means for configuring at least one channel interleaver for the plurality of bits associated with the QAM; means for enabling or means for disabling the at least one channel interleaver based on the at least one RV; means for storing the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer; means for transferring the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer; means for mapping the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols; and means for transmitting, to a base station, the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols. The means may be one or more of the components of the apparatus1402configured to perform the functions recited by the means. As described supra, the apparatus1402may include the TX Processor368, the RX Processor356, and the controller/processor359. As such, in one configuration, the means may be the TX Processor368, the RX Processor356, and the controller/processor359configured to perform the functions recited by the means. FIG.15is a diagram1500illustrating an example of a hardware implementation for an apparatus1502. The apparatus1502may be a base station, a component of a base station, or may implement base station functionality. In some aspects, the apparatus1502may include a baseband unit1504. The baseband unit1504may communicate through a cellular RF transceiver1522with the UE104. The baseband unit1504may include a computer-readable medium/memory. The baseband unit1504is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the baseband unit1504, causes the baseband unit1504to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the baseband unit1504when executing software. The baseband unit1504further includes a reception component1530, a communication manager1532, and a transmission component1534. The communication manager1532includes the one or more illustrated components. The components within the communication manager1532may be stored in the computer-readable medium/memory and/or configured as hardware within the baseband unit1504. The baseband unit1504may be a component of the base station310and may include the memory376and/or at least one of the TX processor316, the RX processor370, and the controller/processor375. The communication manager1532includes a determination component1540that is configured to encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits, e.g., as described in connection with step1302above. Determination component1540may also be configured to configure at least one channel interleaver for the plurality of bits associated with the QAM, e.g., as described in connection with step1304above. Determination component1540may also be configured to enable or disable the at least one channel interleaver based on the at least one RV, e.g., as described in connection with step1306above. Determination component1540may also be configured to store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer, e.g., as described in connection with step1308above. Determination component1540may also be configured to transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer, e.g., as described in connection with step1310above. Determination component1540may also be configured to map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols, e.g., as described in connection with step1312above. Determination component1540may also be configured to transmit, to a user equipment (UE), the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols, e.g., as described in connection with step1314above. The apparatus may include additional components that perform each of the blocks of the algorithm in the flowcharts ofFIGS.9,12, and13. As such, each block in the flowcharts ofFIGS.9,12, and13may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. As shown, the apparatus1502may include a variety of components configured for various functions. In one configuration, the apparatus1502, and in particular the baseband unit1504, includes means for encoding a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits; means for configuring at least one channel interleaver for the plurality of bits associated with the QAM; means for enabling or means for disabling the at least one channel interleaver based on the at least one RV; means for storing the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer; means for transferring the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer; means for mapping the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols; and means for transmitting, to a user equipment (UE), the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols. The means may be one or more of the components of the apparatus1502configured to perform the functions recited by the means. As described supra, the apparatus1502may include the TX Processor316, the RX Processor370, and the controller/processor375. As such, in one configuration, the means may be the TX Processor316, the RX Processor370, and the controller/processor375configured to perform the functions recited by the means. It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented. The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Terms such as “if,” “when,” and “while” should be interpreted to mean “under the condition that” rather than imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when,” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module,” “mechanism,” “element,” “device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.” The following aspects are illustrative only and may be combined with other aspects or teachings described herein, without limitation. Aspect 1 is an apparatus for wireless communication at a UE including at least one processor coupled to a memory and configured to: encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits; transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer; and map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols. Aspect 2 is the apparatus of aspect 1, where the at least one processor is further configured to: transmit, to a base station, the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols. Aspect 3 is the apparatus of any of aspects 1 and 2, where the at least one processor is further configured to: configure at least one channel interleaver for the plurality of bits associated with the QAM. Aspect 4 is the apparatus of any of aspects 1 to 3, where the at least one channel interleaver includes a first channel interleaver for a plurality of parity bits and a second channel interleaver for the plurality of systematic bits. Aspect 5 is the apparatus of any of aspects 1 to 4, where the at least one channel interleaver includes a first row-to-column interleaver and a second row-to-column interleaver. Aspect 6 is the apparatus of any of aspects 1 to 5, where the first row-to-column interleaver is associated with an output of a shaping encoder and the second row-to-column interleaver is associated with a low density parity check (LDPC) output of the plurality of systematic bits. Aspect 7 is the apparatus of any of aspects 1 to 6, where the at least one processor is further configured to: enable or disable the at least one channel interleaver based on the at least one RV. Aspect 8 is the apparatus of any of aspects 1 to 7, where transferring the plurality of bits includes: reading the plurality of bits from the circular buffer and writing the plurality of bits to the first buffer and the second buffer. Aspect 9 is the apparatus of any of aspects 1 to 8, where the plurality of bits further includes a plurality of parity bits. Aspect 10 is the apparatus of any of aspects 1 to 9, where the first buffer is an amplitude bit buffer and the second buffer is a sign bit buffer. Aspect 11 is the apparatus of any of aspects 1 to 10, where if a number of the plurality of systematic bits in the at least one RV (nsys) is equal to zero, the amplitude bit buffer and the sign bit buffer are filled sequentially with a plurality of parity bits of the plurality of bits, where the amplitude bit buffer is filled prior to the sign bit buffer. Aspect 12 is the apparatus of any of aspects 1 to 11, where if nsys≤(M−2)Nmod, and if mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where nsysis a number of the plurality of systematic bits in the at least one RV, M is a modulation order, Nmodis a number of modulation symbols, isysis a starting index of the plurality of systematic bits, and isys_offis an offset applied to the starting index of the plurality of systematic bits. Aspect 13 is the apparatus of any of aspects 1 to 12, where if mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where isysis a starting index of the plurality of systematic bits, M is a modulation order, and isys_offis an offset applied to the starting index of the plurality of systematic bit. Aspect 14 is the apparatus of any of aspects 1 to 13, the at least one processor is further configured to: store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer. Aspect 15 is the apparatus of any of aspects 1 to 14, where the plurality of bits is transferred to the first buffer and the second buffer based on pseudocode. Aspect 16 is the apparatus of any of aspects 1 to 15, where the plurality of bits is encoded based on prefix encoding or a low density parity check (LDPC) encoder. Aspect 17 is the apparatus of any of aspects 1 to 16, where if the plurality of bits is encoded based on the LDPC encoder, an output of the LDPC encoder corresponds to the plurality of bits including a plurality of parity bits. Aspect 18 is the apparatus of any of aspects 1 to 17, where the plurality of systematic bits is associated with probabilistic shaping. Aspect 19 is the apparatus of any of aspects 1 to 18, further including a transceiver or an antenna coupled to the at least one processor. Aspect 20 is a method of wireless communication for implementing any of aspects 1 to 19. Aspect 21 is an apparatus for wireless communication including means for implementing any of aspects 1 to 19. Aspect 22 is a computer-readable medium storing computer executable code, where the code when executed by a processor causes the processor to implement any of aspects 1 to 19. Aspect 23 is an apparatus for wireless communication at a base station including at least one processor coupled to a memory and configured to: encode a plurality of bits associated with quadrature amplitude modulation (QAM), the plurality of bits corresponding to a circular buffer associated with at least one redundancy version (RV), the plurality of bits including a plurality of systematic bits; transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer; and map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols. Aspect 24 is the apparatus of aspect 23, where the at least one processor is further configured to: transmit, to a user equipment (UE), the plurality of modulation symbols, where the plurality of modulation symbols is transmitted after the plurality of bits is mapped from the first buffer and the second buffer to the plurality of modulation symbols. Aspect 25 is the apparatus of any of aspects 23 and 24, where the at least one processor is further configured to: configure at least one channel interleaver for the plurality of bits associated with the QAM. Aspect 26 is the apparatus of any of aspects 23 to 25, where the at least one channel interleaver includes a first channel interleaver for a plurality of parity bits and a second channel interleaver for the plurality of systematic bits. Aspect 27 is the apparatus of any of aspects 23 to 26, where the at least one channel interleaver includes a first row-to-column interleaver and a second row-to-column interleaver. Aspect 28 is the apparatus of any of aspects 23 to 27, where the first row-to-column interleaver is associated with an output of a shaping encoder and the second row-to-column interleaver is associated with a low density parity check (LDPC) output of the plurality of systematic bits. Aspect 29 is the apparatus of any of aspects 23 to 28, where the at least one processor is further configured to: enable or disable the at least one channel interleaver based on the at least one RV. Aspect 30 is the apparatus of any of aspects 23 to 29, where transferring the plurality of bits includes: reading the plurality of bits from the circular buffer and writing the plurality of bits to the first buffer and the second buffer. Aspect 31 is the apparatus of any of aspects 23 to 30, where the plurality of bits further includes a plurality of parity bits. Aspect 32 is the apparatus of any of aspects 23 to 31, where the first buffer is an amplitude bit buffer and the second buffer is a sign bit buffer. Aspect 33 is the apparatus of any of aspects 23 to 32, where if a number of the plurality of systematic bits in the at least one RV is equal to zero, the amplitude bit buffer and the sign bit buffer are filled sequentially with a plurality of parity bits of the plurality of bits, where the amplitude bit buffer is filled prior to the sign bit buffer. Aspect 34 is the apparatus of any of aspects 23 to 33, where if nsys≤(M−2)Nmod, and if mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where nsysis a number of the plurality of systematic bits in the at least one RV, M is a modulation order, Nmodis a number of modulation symbols, isysis a starting index of the plurality of systematic bits, and isys_offis an offset applied to the starting index of the plurality of systematic bits. Aspect 35 is the apparatus of any of aspects 23 to 34, where if mod(isys, (M−2))=0, then isys_off=0; else isys_off=(M−2)−mod(isys, (M−2)), where isysis a starting index of the plurality of systematic bits, M is a modulation order, and isys_offis an offset applied to the starting index of the plurality of systematic bits. Aspect 36 is the apparatus of any of aspects 23 to 35, where the at least one processor is further configured to: store the plurality of bits in the circular buffer prior to transferring the plurality of bits to the first buffer and the second buffer. Aspect 37 is the apparatus of any of aspects 23 to 36, where the plurality of bits is transferred to the first buffer and the second buffer based on pseudocode. Aspect 38 is the apparatus of any of aspects 23 to 37, where the plurality of bits is encoded based on prefix encoding or a low density parity check (LDPC) encoder. Aspect 39 is the apparatus of any of aspects 23 to 38, where if the plurality of bits is encoded based on the LDPC encoder, an output of the LDPC encoder corresponds to the plurality of bits including a plurality of parity bits. Aspect 40 is the apparatus of any of aspects 23 to 39, where the plurality of systematic bits is associated with probabilistic shaping. Aspect 41 is the apparatus of any of aspects 23 to 40, further including a transceiver or an antenna coupled to the at least one processor. Aspect 42 is a method of wireless communication for implementing any of aspects 23 to 41. Aspect 43 is an apparatus for wireless communication including means for implementing any of aspects 23 to 41. Aspect 44 is a computer-readable medium storing computer executable code, where the code when executed by a processor causes the processor to implement any of aspects 23 to 41. | 106,376 |
11943052 | DESCRIPTION OF EMBODIMENTS A key problem that needs to be resolved in modern wireless communication is how to further improve spectrum utilization and transmission reliability of a system. As a multi-carrier technology, in orthogonal frequency division multiplexing (orthogonal frequency division multiplexing, OFDM), a channel is divided into several orthogonal sub-channels, a high-speed data signal is converted into parallel low-speed sub-data streams, and the parallel low-speed sub-data streams are modulated to each sub-channel for transmission. Carriers in OFDM are mutually orthogonal, each carrier has an integer number of subcarrier periods in one symbol time, and a zero point of a spectrum of each carrier overlaps a zero point of a neighboring carrier. In this way, inter-carrier interference is reduced. Because carriers partially overlap, frequency band utilization is improved compared with a conventional frequency division multiplexing technology, and performance of avoiding selective fading of frequency that is better than that in a conventional single-carrier system is provided. Based on the foregoing advantages, an OFDM technology is widely used in an existing wireless local area network (wireless local area network, WLAN) standard (such as 802.11a/n/ac). To further improve transmission reliability of the system on a fading channel, a system framework based on bit-interleaved coded modulation (bit-interleaved coded modulation, BICM) is used in many wireless communication standards (such as HSPA/LTE, IEEE 802.11a/g/n/ac, or DVB-T2/S2/C2). To be specific, one channel encoder (encoder), one interleaver (interleaver), and one memoryless constellation mapper (constellation mapper) are cascaded in series. On the fading channel, in a BICM system, cascaded interleavers are used to increase a channel coding gain, so that transmission reliability of the system is effectively improved. In an existing WLAN standard, the OFDM technology and a BICM technology are combined to perform an interleaving operation on a coded bit sequence of the channel before OFDM modulation, to obtain a frequency domain coding diversity gain on a radio fading channel. FIG.1is a block diagram of a partial architecture of a BICM system when binary convolutional code (binary convolution code, BCC) coding is used in a WLAN standard. The partial architecture includes a forward error control (forward error control, FCC) encoder, a stream parser (stream parser), an interleaver, a constellation mapper, and a cyclic shift diversity (cyclic shift diversity, CSD) device that are sequentially cascaded in series. The interleaver usually includes three parts (or three specific interleavers, where an interleaver 1, an interleaver 2, and an interleaver 3 are used below) that are cascaded in series. The interleaver 1 maps adjacent coded bits to non-adjacent OFDM subcarriers. FIG.2is a diagram of an interleaving principle of a conventional row/column interleaver. The conventional row/column interleaver inputs data in a row form and reads the data in a column form. Parameters of the conventional row/column interleaver are NCOLand NROW. NROWis a number of rows, and NCOLis a number of columns. Bits before and after interleaving are respectively xkand wi. In this case, an interleaving formula of the interleaver 1 is: i=NROW×(kmodNCOL)+⌊kNCOL⌋(1) ⌊kNCOL⌋ represents rounding down kNCOL, k mod NCOLrepresents a remainder obtained after dividing k by NCOL, k is an identifier of a location of an uninterleaved bit in a bitstream, and i is an identifier of a location of an interleaved bit in the bitstream. k=0, 1, . . . , NCBPSS(iSS)−1, where iSSis a sequence number of a current spatial data stream, and NCBPSSis a total number of bits of a bitstream that is currently input into the interleaver (or a total number of bits of a bitstream that is currently processed by the interleaver). The interleaver 2 alternately maps adjacent coded bits to a least significant bit (least significant bit, LSB) and a most significant bit (most significant bit, MSB) in a constellation diagram, to avoid a case in which coded bits are continuously mapped to the least significant bit. m=log2M is a constellation modulation order (M is a quadrature amplitude modulation (quadrature amplitude modulation, QAM) scheme, for example, when a modulation scheme is 64 QAM, m=log264=6), and bits before and after interleaving are respectively yjand wk. In this case, an interleaving formula of the interleaver 2 is: j=s·⌊ks⌋+(k+NCBPSS-⌊NCOL·kNCBPSS⌋)mods(2) s=max {1, m/2}, NCBPSSis a number of coded bits of each symbol in each spatial data stream, k is an identifier of a location of an uninterleaved bit in a bitstream, and j is an identifier of a location of an interleaved bit in the bitstream. As shown inFIG.3, before the interleaver 2 performs interleaving, coded bits in a first column are mapped to most significant bits, coded bits in a second column are mapped to intermediate significant bits, and coded bits in a third column are mapped to least significant bits; and therefore, adjacent coded bits are continuously mapped to relatively low and relatively high significant bits in the constellation diagram. After the interleaver 2 performs interleaving, adjacent coded bits in each column are alternately mapped to the relatively low and relatively high significant bits in the constellation diagram, to avoid long-time running of a low-reliability (LSB) bit. It should be understood that input of the interleaver 2 is actually output of the interleaver 1. Therefore, uninterleaved bits in the interleaver 2 herein correspond to interleaved bits of the interleaver 1; in other words, k in the interleaver 2 is not equivalent to k in the interleaver 1, and k in the interleaver 2 actually needs to be equivalent to i in the interleaver 1. Interleaver 3: If there is more than one spatial data stream, there is the interleaver 3. The interleaver performs a frequency domain rotation operation on an additional spatial data stream. A parameter of the interleaver 3 is NROTand indicates frequency rotation of a current spatial data stream. Bits before and after interleaving are respectively Zrand yk. In this case, an interleaving formula of the interleaver 3 is: r=(k+(((iSS-1)·2)mod3+3·⌊iss-13⌋)·NROT·m)modNCBPSS(3) iSSrepresents a sequence number of the current spatial data stream, and r is an identifier of a location of an interleaved bit in a bitstream. It should be understood that input of the interleaver 3 is actually output of the interleaver 2. Therefore, uninterleaved bits in the interleaver 3 herein correspond to interleaved bits of the interleaver 2; in other words, k in the interleaver 3 is not equivalent to k in the interleaver 2 or the interleaver 1, and k in the interleaver 3 actually needs to be equivalent to j in the interleaver 2. To further improve transmission efficiency of a multi-user system, an orthogonal frequency division multiple access (orthogonal frequency division multiple access, OFDMA) technology is introduced in an 802.11ax standard. In OFDMA, a transmission bandwidth is divided into a series of orthogonal and non-overlapping subcarrier sets, and different subcarrier sets are allocated to different users to implement multiple access. Compared with the OFDM technology, in an OFDMA system, an available bandwidth resource can be dynamically allocated to a user with a requirement, so that it is easy to optimize use of system resources. Different subcarrier sets in each OFDM symbol are allocated to different users. A 26-tone resource unit (26-tone resource unit, 26-tone RU), a 52-tone RU, a 106-tone RU, a 242-tone RU, a 484-tone RU, a 996-tone RU, and a 2×996-tone RU are defined in 802.11ax. In addition, each user is required to receive or send data in only one RU. In addition, the interleaver performs an operation in one RU; in other words, for bits in different RUs, different interleavers need to be used for interleaving. In this way, for each user, procedures of the interleaver 1, the interleaver 2, and the interleaver 3 may still be used. FIG.4,FIG.5, andFIG.6are diagrams of resource unit division of a 20 MHz bandwidth, a 40 MHz bandwidth, and an 80 MHz bandwidth that are defined in 802.11ax. Refer toFIG.4. When a bandwidth is 20 MHz, the entire bandwidth may include an entire 242-tone RU, or may include various combinations of a 26-tone RU, a 52-tone RU, and a 106-tone RU. In addition to an RU used to transmit data, some guard (guard) subcarriers, null subcarriers, direct current (direct current, DC) subcarriers, and the like are included. Refer toFIG.5. When a bandwidth is 40 MHz, the entire bandwidth is approximately equivalent to replication of distribution of a 20 MHz subcarrier, and the entire bandwidth may include an entire 484-tone RU, or may include various combinations of a 26-tone RU, a 52-tone RU, a 106-tone RU, and a 242-tone RU. Refer toFIG.6. When a bandwidth is 80 MHz, the entire bandwidth includes four resource units in units of 242-tone RUs. Specifically, in the middle of the entire bandwidth, there is another intermediate 26-tone RU including two 13-tone subunits. The entire bandwidth may include an entire 996-tone RU, or may include various combinations of a 26-tone RU, a 52-tone RU, a 106-tone RU, a 242-tone RU, and a 484-tone RU. When the bandwidth is 160 MHz or 80+80 MHz, the entire bandwidth may be considered as replication of distribution of two 80 MHz subcarriers. The entire bandwidth may include an entire 2×996-tone RU, or may include various combinations of a 26-tone RU, a 52-tone RU, a 106-tone RU, a 242-tone RU, a 484-tone RU, and a 996-tone RU. No diagram examples are provided one by one herein. In a next-generation WLAN standard 802.11be, a case in which a plurality of RUs are allocated to one user may be supported for an OFDMA system. However, there is no specific solution in a conventional technology to how to design an interleaver or an LDPC tone mapper for a user to whom a plurality of RUs are allocated. Therefore, a data processing method is provided in an embodiment of this application. As shown inFIG.7, if n RUs are allocated to a same user, where n is greater than 1, an interleaving module may be divided into two levels of processing units. A first level of processing unit alternately allocates data bits to different RUs of a single user by using a sequential bit allocator, and a second level of processing unit interleave bits in each RU by using a conventional interleaver (generally including an interleaver 1 and an interleaver 2 in a conventional WLAN standard). In this solution, the second level of processing unit only needs to design an interleaver for a size of an RU block, and therefore implementation is relatively simple. However, the user needs to support a plurality of RU interleavers in parallel; in other words, a corresponding interleaver needs to be separately designed for each RU. Consequently, hardware costs are increased. The foregoing interleaver mainly interleaves bits of BCC coding. However, for another coding technology in an 802.11 system: low-density parity check code (low density parity code, LDPC) coding, as shown inFIG.8, another data processing method is provided in an embodiment of this application. After constellation mapping is performed, bits are scrambled by using an LDPC tone mapper, and an interleaving effect equivalent to that of a row/column interleaver in BCC can be achieved (in other words, bits are reordered). In an LDPC coding manner, if a plurality of RUs are allocated to a user, the user also needs to support a plurality of LDPC tone mappers in parallel; in other words, a corresponding LDPC tone mapper needs to be separately designed for each RU, but a problem of high hardware costs still exists. Therefore, a data processing method is further provided in an embodiment of this application, to scramble, with low costs, a bit sequence of a bitstream of a user to whom a plurality of RUs are allocated. Specifically, when a plurality of RUs are allocated to a same user (for example, a first user) or a large RU (or a new RU) including a plurality of RUs is allocated to a same user, a unified interleaver with new parameters (unified interleaver with new parameters) is designed to uniformly interleave all bits in the plurality of RUs of the user, or a unified LDPC tone mapper with new parameters (Unified LDPC tone mapper with new parameters) is designed to uniformly scramble all bits in the plurality of RUs of the user. In this way, for bit data of the user, it may not be required to design a large number of RU interleavers or LDPC tone mappers in parallel, so that hardware costs can be effectively reduced. Technical solutions in embodiments of this application may be applied to various communication systems, for example, a global system for mobile communications (global system for mobile communication, GSM) system, a code division multiple access (code division multiple access, CDMA) system, a wideband code division multiple access (wideband code division multiple access, WCDMA) system, a general packet radio service (general packet radio service, GPRS), a long term evolution (long term evolution, LTE) system, an LTE frequency division duplex (frequency division duplex, FDD) system, an LTE time division duplex (time division duplex, TDD) system, a universal mobile telecommunication system (universal mobile telecommunication system, UMTS), a worldwide interoperability for microwave access (worldwide interoperability for microwave access, WiMAX) communication system, a 5th generation (5th generation, 5G) system such as NR, and a future communication system such as a 6G system. Certainly, the technical solutions in embodiments of this application may also be applied to another communication system, provided that data is received and/or sent in the communication system. The technical solutions in embodiments of this application may be further applicable to a wireless local area network (wireless local area network, WLAN) scenario, may be applicable to an IEEE 802.11 system standard (such as an IEEE 802.11a/n/ac standard), a next-generation WLAN standard (such as 802.11be), or a further next-generation standard, and may be applicable to a wireless local area network system including but not limited to an internet of things (internet of things, IoT) network or a vehicle-to-everything (Vehicle to X, V2X) network. For example,FIG.9is a schematic diagram of a network architecture of a WLAN to which an embodiment of this application is applicable. Devices in this communication system include an access point (access point, AP) and a station (station, STA). A type of communication in the communication system includes data communication between one or more wireless access points (access point, AP) and one or more stations (station, STA), data communication between one or more APs and one or more APs, data communication between one or more STAs and one or more STAs, and the like. In the communication system, any AP may schedule a radio resource for a STA associated with and/or not associated with the any AP, and transmit data to the STA on the scheduled radio resource. A data transmission type includes uplink transmission and/or downlink transmission. For example, an AP1inFIG.9may schedule radio resources for a STA 1 and a STA 2. For ease of description, only two APs and three STAs are shown inFIG.9. However, it should be understood that the WLAN system may further include more or fewer APs and more or fewer STAs. In addition, the APs may communicate with each other by using a distributed system (distributed system, DS). Further, the STAs may also communicate with each other. This is not specifically limited in this embodiment of this application. The STA involved in this application may be any user terminal, user apparatus, access apparatus, subscriber station, subscriber unit, mobile station, user agent, user equipment, or another name that has a wireless communication function. The user terminal may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem that have a wireless communication function, and various forms of user equipment (user equipment, UE), mobile stations (mobile station, MS), terminals (terminal), terminal equipment (terminal equipment), portable communication devices, handheld devices, portable computing devices, entertainment devices, game devices or systems, global positioning system devices, or any other suitable devices configured to perform network communication by using a wireless medium. Herein, for ease of description, the devices mentioned above are collectively referred to as a station or a STA. The AP involved in this application is an apparatus deployed in a wireless communication network to provide a wireless communication function for a STA associated with the AP. The AP may be used as a hub of the communication system, and may be a communication device such as a base station, a router, a gateway, a relay, a communication server, a switch, or a bridge. The base station may include various forms of macro base stations, micro base stations, and relay stations. Herein, for ease of description, the devices mentioned above are collectively referred to as an access point or an AP. To make the objectives, technical solutions, and advantages of this application clearer, embodiments of this application are specifically described below with reference to the accompanying drawings of this specification. It should be noted that terms used in embodiments of this application are only used to explain specific embodiments of this application, but are not intended to limit this application. It should be understood that, in the following descriptions, “and/or” describes an association relationship of associated objects, and represents that there may be three relationships. For example, A and/or B may represent three cases: only A exists, both A and B exist, and only B exists. The character “I” generally indicates an “or” relationship between the associated objects. “At least one” involved in this application means one or more, and “a plurality of” means two or more. Words such as “first” and “second” are merely used for distinguishing purposes, and cannot be understood as an indication or implication of relative importance, and cannot be understood as an indication or implication of a sequence. In this application, an explanation of a symbol, a parameter, a label, a term, or the like may be applied to an entire application document. FIG.10is a flowchart of a data processing method according to an embodiment of this application. The method may be applied to the WLAN system shown inFIG.9. S1001: A transmit end allocates a coded bitstream of a first user to M RUs or a first RU including M RUs, where the M RUs or the first RU is an RU allocated to the first user, and M is a positive integer greater than 1. The transmit end may be a STA in a WLAN system, or may be an AP. This is not limited herein. The RU herein includes but is not limited to the 26-tone RU, the 52-tone RU, the 106-tone RU, the 242-tone RU, the 484-tone RU, the 996-tone RU, the 2×996-tone RU, and the like in the foregoing descriptions. In this embodiment of this application, there may be the following two understandings for the RU allocated to the first user. In a first understanding, the M RUs are allocated to the first user, and M is a positive integer greater than 1. It should be noted that the M RUs may be continuous or discontinuous in a spectrum bandwidth. This is not limited herein. In addition, types of the M RUs (or sizes of the RUs) may be the same or different. This is not limited herein. For example, the M RUs may be one 26-tone RU and one 52-tone RU, one 26-tone RU and one 106-tone RU, two 242-tone RUs, twelve 242-tone RUs, or the like. In a second understanding, the RU allocated to the first user is the first RU (or a large RU or a new RU) including (or combining) M RUs, and M is a positive integer greater than 1. For example, the first RU may be a 78-tone RU including one 26-tone RU and one 52-tone RU, a 132-tone RU including one 26-tone RU and one 106-tone RU, a 484-tone RU including two 242-tone RUs, or a 2904-tone RU including twelve 242-tone RUs. It should be noted that the M RUs and the first RU in the foregoing two understandings essentially represent resources (or resources of a same size) in a same location in the spectrum bandwidth. In other words, in this embodiment of this application, “M RUs” and “first RU” may be replaced with each other. S1002: The transmit end reorders all bits in the coded bitstream by using a first interleaver or a first tone mapper. For different coding manners, different solutions for reordering bits may be used. For example, if a coding manner of the bitstream is BCC, the transmit end reorders all the bits in the coded bitstream by using the first interleaver. It should be understood that the first interleaver herein is an interleaver with new parameters that is designed for the M RUs. If a coding manner of the bitstream is LDPC, the transmit end reorders all the bits in the coded bitstream by using the first tone mapper. It should be understood that the first tone mapper herein is a tone mapper with new parameters that is designed for the M RUs. In a possible implementation, in specific implementation of step S1001, a specific manner in which the transmit end allocates the coded bitstream of the first user to the M RUs may be as follows: Manner 1: The transmit end sequentially and alternately allocates, to the M RUs in a bit sequence, bits that are output by a stream parser. For example, it is assumed that the M RUs are one 26-tone RU (including 24 data subcarriers, and assuming that data of 24 bits can be carried) and one 52-tone RU (including 48 data subcarriers, and assuming that data of 48 bits can be carried), and the coded bitstream has a total of 72 bits. In this case, the transmit end may first allocate a first bit to a 24th bit in the bitstream (data of a total of 72 bits) to the 26-tone RU in the bit sequence, and then allocate a 25thbit to a 72ndbit in the bitstream to the 52-tone RU. It should be noted that in actual application, a total number of bits of the bitstream may alternatively be less than or greater than a number of bits that can be carried by the M RUs. If the total number of bits of the bitstream is less than the number of bits that can be carried by the M RUs, for example, is 70 bits, the bitstream needs to be padded; in other words, the bitstream is interleaved after being supplemented to 72 bits. If the total number of bits of the bitstream is greater than the number of bits that can be carried by the M RUs, interleaving is performed in units of symbols. For example, if the total number of bits of the bitstream is 144 bits, an interleaving operation needs to be performed on the bitstream twice, and 72 bits are interleaved each time. The first interleaver is used as an example. As shown inFIG.11A, after performing channel coding on the bits by using an encoder, the transmit end performs, by using the stream parser, stream parsing on a coded bitstream that is output by the encoder (in other words, allocates the bitstream to different spatial streams), and then sequentially and alternately allocates, to the M RUs in a bit sequence by using a sequential bit allocator (sequential bit allocator), bits that are output by the stream parser, and finally uniformly inputs the bits allocated to the M RUs into a unified interleaver (that is, the first interleaver) with new parameters and reorders the bit sequence. The first tone mapper is used as an example. As shown inFIG.11B, after performing channel coding on the bits by using an encoder, the transmit end performs, by using the stream parser, stream parsing on a coded bitstream that is output by the encoder, and then sequentially and alternately allocates, to the M RUs in a bit sequence by using a sequential bit allocator (sequential bit allocator), bits that are output by the stream parser, and then uniformly inputs the bits allocated to the M RUs into a unified tone mapper (that is, the first tone mapper) with new parameters and reorders the bit sequence, and then performs operations such as constellation mapping, spatial/time block coding, and CSD. It should be understood that in this allocation manner, because all bits in the coded bitstream sequentially enter a same interleaver or tone mapper in sequence, it may also be considered that the transmit end does not have a process of allocating the coded bitstream to the M RUs, but directly inputs the coded bitstream into the first interleaver or the first tone mapper in sequence. Therefore, a dashed-line part inFIG.11Amay not be drawn, as shown inFIG.11C. Similarly, a dashed-line part inFIG.11Bmay not be drawn, as shown inFIG.11D. Therefore, in this allocation manner, step S1001may alternatively be replaced with the following: inputting all bits in a coded bitstream of a first user into a first interleaver or a first tone mapper, where M RUs or a first RU including M RUs is allocated to the first user, and M is a positive integer greater than 1. In another possible implementation, in specific implementation of step S1001, a specific manner in which the transmit end allocates the coded bitstream of the first user to the M RUs may be as follows: Manner 2: The transmit end alternately allocates, to each of the M RUs based on a preset rule by using a sequential bit allocator (Sequential Bit Allocator), bits that are output by the stream parser, and then uniformly interleaves all the allocated bits by using the first interleaver. For example, assuming that the bitstream has a total of 72 bits, and the M RUs are one 26-tone RU (including 24 data subcarriers, and assuming that data of 24 bits can be carried) and one 52-tone RU (including 48 data subcarriers, and assuming that data of 48 bits can be carried), the transmit end may allocate the bits in the bitstream to the 26-tone RU and the 52-tone RU based on a preset rule by using a bit allocator. For example, the bits in the bitstream are sequentially and alternately allocated to the 26-tone RU and the 52-tone RU in a bit sequence: A first bit is allocated to the 26-tone RU, a second bit is allocated to the 52-tone RU, a third bit is allocated to the 26-tone RU, a fourth bit is allocated to the 52-tone RU, a fifth bit is allocated to the 26-tone RU, a sixth bit is allocated to the 52-tone RU, . . . , and so on. For another example, the bits are alternately allocated to the 26-tone RU and the 52-tone RU based on a size ratio of the RUs: A first bit is allocated to the 26-tone RU, a second bit and a third bit are allocated to the 52-tone RU, a fourth bit is allocated to the 26-tone RU, a fifth bit and a sixth bit are allocated to the 52-tone RU, . . . , and so on. It should be understood that the manner 1 may also be understood as a special example of the manner 2. The first interleaver is used as an example. As shown inFIG.11E, after performing channel coding on the bits by using an encoder, the transmit end performs, by using the stream parser, stream parsing on a coded bitstream that is output by the encoder (in other words, allocates the bitstream to different spatial streams), and then allocates, to the M RUs based on a preset rule by using a sequential bit allocator, bits that are output by the stream parser, and finally uniformly inputs the bits allocated to the M RUs into a unified interleaver (that is, the first interleaver) with new parameters and reorders the bit sequence. The first tone mapper is used as an example. As shown inFIG.11F, after performing channel coding on the bits by using an encoder, the transmit end performs, by using the stream parser, stream parsing on a coded bitstream that is output by the encoder, and then allocates, to the M RUs based on a preset rule by using a sequential bit allocator, bits that are output by the stream parser, and then uniformly inputs the bits allocated to the M RUs into a unified tone mapper (that is, the first tone mapper) with new parameters and reorders the bit sequence, and then performs operations such as constellation mapping, spatial/time block coding, and CSD. In this embodiment of this application, when a plurality of RUs (or a first RU including a plurality of RUs) are allocated to the first user, all bits in the plurality of RUs (or the first RU) of the user are reordered by using an interleaver with new parameters or an LDPC tone mapper with new parameters (Unified LDPC tone mapper with new parameters), and coded bits of the user with the plurality of RUs can be reordered without a need to support a plurality of RU interleavers or a plurality of LDPC tone mappers in parallel. In this way, hardware costs can be effectively reduced. Methods for designing parameters of the first interleaver and the first tone mapper are described in detail below by using several specific embodiments. Embodiment 1 Design of a parameter of the first interleaver is mainly described in Embodiment 1. For an interleaving process of the first interleaver, procedures of the interleaver 1, the interleaver 2, and the interleaver 3 mentioned above may be reused. However, because a total size of the M RUs (or a size of the first RU) is different from that of an existing RU, corresponding parameters need to be redesigned based on the M RUs (or the first RU). (1) Determine a number NSDof data subcarriers of the first interleaver (that is, a number NSDof data subcarriers of the first RU). Specifically, one RU includes a data subcarrier and a pilot subcarrier. The pilot subcarrier is used for phase tracking, to reduce impact exerted by a phase difference and a frequency difference on receive performance. The data subcarrier is used to carry data, and a part that needs to be interleaved is also a data subcarrier. Therefore, design of a data subcarrier of the first interleaver depends on a number of data subcarriers in the M RUs. For example, an RU26(an abbreviation of a 26-tone-RU) includes 24 data subcarriers (NSD=24) and two pilot subcarriers, and an RU52(an abbreviation of a 52-tone-RU) includes 48 data subcarriers and four pilot subcarriers. Therefore, an RU78(an abbreviation of a 78-tone-RU) obtained after combining the RU26and the RU52includes 72 data subcarriers and six pilot subcarriers. For example, an RU26includes 24 data subcarriers and two pilot subcarriers, and an RU106(an abbreviation of a 106-tone-RU) includes 102 data subcarriers and four pilot subcarriers. Therefore, an RU132(an abbreviation of a 132-tone-RU) obtained after combining the RU26and the RU106includes 126 data subcarriers and six pilot subcarriers. In some possible designs, to further improve data transmission efficiency, for a new RU obtained after combination, an original pilot subcarrier may also be used as a data subcarrier. For example, for a case in which RU132=RU106+RU26, all subcarriers in the RU26may be used as data subcarriers. Therefore, the RU132obtained after combining the RU106and the RU26includes 128 data subcarriers and four pilot subcarriers. Therefore, in this embodiment of this application, a value of NSDof the first interleaver may be summarized as any positive integer in [NSD_min, NSD_max], where NSD_minis a sum of numbers of data subcarriers included in all the M RUs, and NSD_maxis a sum of numbers of subcarriers included in all the M RUs. It should be understood that [NSD_min, NSD_max] in this application represents a closed interval; in other words, a minimum value of NSDof the first interleaver may be NSD_min, and a maximum value may be NSD_max. A value of the data subcarrier of the first interleaver in a case in which dual-carrier modulation (DCM) is not used is described above. If DCM is used, it indicates that a same data bit is to be mapped to two subcarriers, and this is equivalent to half of data subcarriers that can be carried by the first RU. For example, NSDof an RU78changes to 36. Therefore, in this embodiment of this application, if whether to use DCM is further considered, NSDof the first interleaver may be summarized as any positive integer in [NSD_min/Q, NSD_max/Q], where NSD_minis a sum of numbers of data subcarriers included in all the M RUs, NSD_maxis a sum of numbers of subcarriers included in all the M RUs, and Q is a number of data subcarriers to which one data bit is mapped. A value of Q may also be understood as a modulation mode of a carrier. For example, when a dual-carrier modulation mode is used, one data bit is to be mapped to two data subcarriers, and Q=2. When the dual-carrier modulation mode is not used, one data bit is to be mapped to one data subcarrier, and Q=1. It should be noted that, based on a current WLAN standard, when the dual-carrier modulation mode is not used, it is considered by default that one data bit is to be mapped to one data subcarrier; in other words, Q=1. However, if one data bit is to be mapped to more data subcarriers in a future WLAN standard such as a next-generation WLAN standard or a further next-generation standard, the value of Q also changes accordingly. For example, if one data bit is to be mapped to four data subcarriers (or a four-carrier modulation mode is used), Q=4. For ease of description, in the following description, an example in which one data bit is to be mapped to one data subcarrier (that is, Q=1) by default when the dual-carrier modulation mode is not used is mainly used for description. (2) Determine a number NCOLof columns and a number NROWof rows of the first interleaver. Specifically, the number NCOLof columns and the number NROWof rows meet the following relationship: (NCOL×NROW)/NBPSCS=NSD(4) NBPSCSrepresents a number of coded bits carried on each subcarrier of each spatial data stream (number of coded bits per subcarrier per spatial stream). RU78=RU26+RU52is used as an example, and a total number of data subcarriers corresponding to the RU78is 72. It is assumed that NBPSCSis 1, and a number NCOLof columns and a number NROWof rows of a first interleaver corresponding to the RU78may be a combination such as 24×3, 18×4, 12×6, or 9×8. In some possible designs, for a number NCOLof columns and a number NROWof rows corresponding to the first RU, values close to a number NCOLof columns and a number NROWof rows corresponding to a surrounding RU of the first RU. The surrounding RU herein is an RU for which a number of included data subcarriers is close to NSDof the first RU. Generally, the first RU may have a maximum of two surrounding RUs, that is, an RU (which may be referred to as a left RU of the first RU) for which a number of included data subcarriers is less than NSDof the first RU and is the closest to NSDof the first RU and an RU (which may be referred to as a right RU of the first RU) for which a number of included data subcarriers is greater than NSDof the first RU and is the closest to NSDof the first RU. For example, the RU78may be 18×4 with reference to column and row values (that is, 16×3) of the RU52and column and row values (that is, 17×6) of the RU106. For example, an RU132may be 18×7 or 16×8 with reference to column and row values (17×6) of the RU106. In this way, performance of the first interleaver or the first tone mapper (for example, the RU78) corresponding to the first RU may be similar to performance of an interleaver or a tone mapper corresponding to an already verified existing RU (that is, the RU52and the RU106), so that performance of a first interleaver or a first tone mapper corresponding to a newly designed RU is ensured, and a number of tested and compared parameter groups can be reduced. Similar to (1), if DCM is used, an operation of dividing Ncol, or NROWby2is further required for NCOLand NROW. For example, for the RU78, if column and row values are 18×4 when dual-carrier modulation is not used, column and row values are 9×4 when dual-carrier modulation is used. For example, for the RU132, if column and row values are 18×7 or 16×8 when dual-carrier modulation is not used, column and row values are 9×7 or 16×4 when dual-carrier modulation is used. (3) If a plurality of spatial data streams are included, a frequency rotation parameter NROTof the first interleaver further needs to be determined. Specifically, the frequency rotation parameter may be determined by using the following two rules. Rule 1: NROTis determined based on a formula NROT=floor(NSD/4), where floor means rounding down. This formula is an empirical formula obtained with reference to values of NROTof a 40 MHz bandwidth and an 80 MHz in a standard 802.11ac. For example, for a value of NROTof an RU78, when DCM is not used, NROT−1=floor(72/4)=18; and when DCM is used, NROT−2=floor(36/4)=9. Rule 2: A positive integer that enables a packet error rate (packet error rate, PER) of a receive end to be minimum or a positive integer that enables a signal-to-noise ratio (signal-to-noise ratio, SNR) required when a PER of a receive end is a preset value to be minimum is selected from [NROT_min, NROT_max] as NROT, where NROT_minis a frequency rotation parameter of a second interleaver corresponding to an RU in which a number of included data subcarriers is less than NSDand is the closest to NSD, and NROT_maxis a frequency rotation parameter of a third interleaver corresponding to an RU in which a number of included data subcarriers is greater than NSDand is the closest to NSD. For example, for a value of NROTof an RU78, refer to values of NROTof an RU52and an RU106through simulation. When DCM is not used, a parameter that enables an SNR required when the PER of the receive end is 10% to be minimum is selected from [11, 12, 13, 14, . . . , 29]. When DCM is not used, the value of NROTof the RU52is 11, and the value of NROTof the RU106is 29. When DCM is used, a value that enables the SNR required when the PER of the receive end is 10% to be minimum is selected from [2, 3, 4, 5, . . . , 11]. When DCM is used, the value of NROTof the RU52is 2, and the value of NROTof the RU106is 11. Table 1 provides a possible solution for designing a parameter of an RU78obtained by combining an RU26and an RU52and two possible solutions for designing a parameter of an RU132obtained by combining an RU106and an RU26. TABLE 1132132(Solution(SolutionType2652781061)2)242NoNSD244872102126128234DCMNCOL8161817181626NROW3 × Nbpscs3 × Nbpscs4 × Nbpscs6 × Nbpscs7 × Nbpscs8 × Nbpscs9 × NbpscsNROW211NROT-129NROT-3NROT-558DCMNSD122436516364117NCOL4891791613NROW3 × Nbpscs3 × Nbpscs4 × Nbpscs3 × Nbpscs7 × Nbpscs4 × Nbpscs9 × NbpscsNROT22NROT-211NROT-4NROT-629 For the 78-tone RU, values of parameters are as follows: If the dual-carrier modulation mode is not used, NSD=72, NCOL=18, NROW=4×NBPSCSand NROT−1=18; and if the dual-carrier modulation mode is used, NSD=36, NCOL=9, NROW=4×NBPSCSand NROT−2=9. Certainly, values of parameters in Table 1 are only a possible example. In specific implementation, there may be another value manner. For example, when the dual-carrier modulation mode is used, the values of the parameters may alternatively be: NSD=36, NCOL=18, NROW=2×NBPSCS, and NROT=2=9. For the 132-tone RU, the RU106includes 102 data subcarriers and four pilot subcarriers. If direct splicing is performed, 126 data subcarriers and six pilot subcarriers are included. An idea similar to the RU78is used, and a value of a parameter of an interleaver of the RU132is shown in the solution 1 of the RU132in Table 1. If the dual-carrier modulation mode is not used, NSDis 126, NCOL=18, and NROW=7×NBPSCSIf the dual-carrier modulation mode is used, NSDis 63, NCOL=9, and NROW=7×NBPSCS. To further improve transmission efficiency, for the 132-tone RU, two data subcarriers may be added, and two pilot subcarriers may be reduced. For example, if all subcarriers in the RU26are used as data subcarriers, 128 data subcarriers and four pilot subcarriers are included, and a value of a parameter of an interleaver is shown in the solution 2 of the RU132in the table. If the dual-carrier modulation mode is not used, NSDis 128, NCOL=16, and NROW=8×NBPIf the dual-carrier modulation mode is used, NSDis 64, NCOL=16, and NROW=4×NBPSCS. Values of NROT−3, NROT−4, NROT−5, and NROT−6 may be determined based on the foregoing rule 1 and rule 2. The values may be specifically the following values. TABLE 2NROTRule 1Rule 2NROT-331From 29 to 58 (including 29 and 58), NROT-3obtained when an SNR corresponding to a PERof 10% is minimumNROT-415From 11 to 29, NROT-4 obtained when an SNRcorresponding to a PER of 10% is minimumNROT-532From 29 to 58 (including 29 and 58), NROT-5obtained when an SNR corresponding to a PERof 10% is minimumNROT-616From 11 to 29, NROT-6 obtained when an SNRcorresponding to a PER of 10% is minimum A simulation example of NROT−1 is provided below. There are four antennas at the transmit end and three antennas at the receive end, there are three spatial streams, and BCC coding is used. A modulation and coding scheme MCS5, that is, 64 QAM, and a bit rate 2/3 are used. For a 78-tone RU, NCOLand NROWare shown in Table 1, and different NROT−1 is selected to obtain different PER curves, and a signal-to-noise ratio SNR corresponding to a PER of 10% is selected for comparison, to obtain optimal NROT−1 through calculation. When NROT−1=11, a PER curve is shown inFIG.12A, and an SNR corresponding to the PER of 10% is 26.35. When NROT−1=29, a PER curve is shown inFIG.12B, and an SNR corresponding to the PER of 10% is 26.25. Similarly, for other different values of NROT−1, a value of an SNR corresponding to a PER of 10% is as follows: TABLE 3NROT-11113151718192129SNR26.3526.2826.3826.2526.3126.2426.2726.25 It can be learned from a simulation result shown in Table 3 that in the foregoing simulation configuration case, optimal NROT−1 is 19. Certainly, another value of NROT−1 whose SNR has a difference less than 0.1 dB from an SNR corresponding to 19 may also be a candidate value. Certainly, for different numbers of spatial streams and different modulation and coding schemes MCS, an optimal value of NROT−1 may differ. After comprehensive consideration, values of NROTwith a largest number of optimal and sub-optimal cases in a plurality of different cases may be selected. Principles of NROT−2, NROT−3, and NROT−4 are similar to this, and details are not described herein again. It should be noted that, when the transmit end performs a specific interleaving operation by using the first interleaver, a process of determining the parameter of the first interleaver may be merely a table lookup process (for example, searching for a parameter in Table 1 or Table 2) or a mapping lookup process. Method steps in (1), (2), and (3) are merely to describe a principle/process of designing the parameter of the first interleaver in this embodiment of this application, and are not necessarily equivalent to the process of determining the parameter of the first interleaver. A simple interleaving method for combination of several specific RUs (the RU26, the RU52, the RU106, or the like) in BCC coding is provided in this embodiment, and a specific method for designing a number of data subcarriers, a number of pilot subcarriers, and an interleaver parameter (for example, NCOL, NROW, and NROT) is provided for a unified interleaver (that is, the first interleaver) corresponding to an RU obtained after combination. In this way, flexibility of this solution is improved, and hardware costs of the interleaver can be effectively reduced. Embodiment 2 Design of a parameter of the first tone mapper is mainly described in Embodiment 2. An idea of Embodiment 2 is similar to that of Embodiment 1, and a plurality of small RUs may be considered as a combined large RU. A difference lies in that a parameter is designed as a parameter of a tone mapper for LDPC coding. The parameter of the first tone mapper includes a number NSDof data subcarriers. For a specific determining method, refer to the method for determining the number of data subcarriers of the first interleaver in Embodiment 1. Details are not described herein again. The parameter of the first tone mapper further includes a tone mapping distance parameter that may be understood as a degree to which continuous bits are scrambled, as shown in Table 4. TABLE 4132132Type265278106Solution 1Solution 22424849962*996No DCM,DTM13DTM-16DTM-3DTM-59122020DCMDTM11DTM-23DTM-4DTM-6991414 A necessary requirement that DTMmeets is: DTMis a common divisor of NSD. A method for designing DTMincludes but is not limited to the following three rules: Rule 1: A positive integer is selected from [DTM_min, DTM_max] as DTM, where DTM_minis a tone mapping distance parameter corresponding to a second tone mapper corresponding to an RU in which a number of included data subcarriers is less than NSDand is the closest to NSD, and DTM_maxis a tone mapping distance parameter corresponding to a third tone mapper corresponding to an RU in which a number of included data subcarriers is greater than NSDand is the closest to NSD. For example, for DTM−1 of an RU78, refer to values of a surrounding RU52and RU106. A positive integer is selected from [3, 6]. Because DTM−1 needs to be a common divisor of NSD=72 when there is no DCM, DTM−1 may be 4 or 6. Rule 2: A ratio NSD/NCOLof NSDto NCOLof a first interleaver with a same RU size as the first tone mapper is used as DTM. For example, for an RU78, when there is no DCM, for a first interleaver corresponding to the RU78, NSD=72, and NCOL=18. If this rule is used, DTM−1=4. When there is DCM, DTM−2 may be 2 or 3. Rule 3: Through simulation, a positive integer that enables a PER of a receive end to be minimum or a positive integer that enables an SNR required when a PER of a receive end is a preset value (for example, 10%) to be minimum is selected from [DTM_min, DTM_max] as DTM. Similarly, DTM−3 may be 7 or 9 when the rule 1 is used, and may be 7 when the rule 2 is used. Similarly, DTM−4 may be 7 or 9 when the rule 1 is used, and may be 7 when the rule 2 is used. Similarly, DTM−5 may be 8 when the rule 1 is used, and may be 8 when the rule 2 is used. Similarly, DTM−6 may be 4 or 8 when the rule 1 is used, and may be 8 when the rule 2 is used. It should be noted that, when the transmit end performs a specific tone mapping operation by using the first tone mapper, a process of determining the parameter of the first tone mapper may be merely a table lookup process (for example, searching for a parameter in Table 4) or a mapping lookup process. The foregoing method steps are merely to describe a principle/process of designing the parameter of the first tone mapper in this embodiment of this application, and are not necessarily equivalent to the process of determining the parameter of the first tone mapper. A simple tone mapping method for combination of several specific RUs (an RU26, an RU52, an RU106, or the like) in LDPC coding is provided in this embodiment, and a specific method for designing a number of data subcarriers, a number of pilot subcarriers, and a tone mapper parameter (for example, DTM) is provided for a unified tone mapper (that is, the first tone mapper) corresponding to an RU obtained after combination. In this way, hardware costs of the tone mapper can be effectively reduced. Embodiment 3 Design of a parameter in LDPC coding for a combined large RU including M 242-tone RUs is mainly described in Embodiment 3. For combination of two 242-tone RUs and combination of four 242-tone RUs, parameters of a 484-tone RU and a 996-tone RU may be reused, as shown in Table 5 below. TABLE 5Type242484 or 242 × 2242 × 3996 or 242 × 42 × 996 or 242 × 8No DCM,NSD234234 × 2234 × 3980 or 234 × 4980 × 2 or 234 × 8DTM912DTM-12020DCMNSD117234117 × 3490 or 234 × 2980 or 234 × 4(Dual-carrier modulation)DTM99DTM-21414 For a 242×3-tone RU, similar to a principle in Embodiment 2, refer to values of DTMof RUs (that is, a 484-tone RU and a 996-tone RU) that already exist on the left and the right of the 242×3-tone RU. In addition, in consideration of a fact that DTM−1 needs to be a common divisor of NSD, a value of DTM−1 may be 13 or 18. Similarly, DTM−2 is 9 or 13. Because it is specified in an 802.11ax standard that BCC coding is not used for an RU whose number of subcarriers is greater than 242 tones, a value of DTMcannot be obtained by using a parameter of BCC herein. Certainly, optimal DTM−1 and optimal DTM−2 may alternatively be obtained through simulation. A simple tone mapping method for combination of a plurality of RUs242in LDPC coding is provided in this embodiment, and a specific method for designing a number of data subcarriers, a number of pilot subcarriers, and a tone mapper parameter (for example, DTM) is provided for a unified tone mapper (that is, the first tone mapper) corresponding to an RU obtained after combination. In this way, flexibility of this solution is improved, and hardware costs of the tone mapper can be effectively reduced. Embodiment 4 The following is mainly described in Embodiment 4: When a total bandwidth of M RUs is greater than a preset value (for example, 80 MHz), the total bandwidth of the M RUs may be first segmented, and then the method procedure shown inFIG.10is separately performed for an RU in each segment. FIG.13shows another data processing method according to an embodiment of this application. The method includes the following steps: S1301: A transmit end divides a total bandwidth of a first user into N sub-bandwidths, where at least one of the N sub-bandwidths includes a plurality of RUs. S1302: The transmit end allocates a coded bitstream of the first user to the N sub-bandwidths. S1303: The transmit end allocates a coded bitstream on a first sub-bandwidth to M RUs or a first RU including M RUs, where the first sub-bandwidth is any one of the at least one sub-bandwidth. S1304: The transmit end reorders all bits in all coded bitstreams on the first sub-bandwidth by using a first tone mapper. It should be understood that, if two sub-bandwidths in the N sub-bandwidths are different, parameter design of tone mappers separately corresponding to the two sub-bandwidths may be different. For example, if the first sub-bandwidth and a second sub-bandwidth in the N sub-bandwidths are different in size, a parameter of a first tone mapper corresponding to the first sub-bandwidth is different from a parameter of a second tone mapper corresponding to the second sub-bandwidth. Design of a parameter in LDPC coding for a combined large RU including M 242-tone RUs is used as an example below, and M is greater than 5. That M is greater than 5 indicates that a total bandwidth of the M 242-tone RUs is at least greater than 80 MHz. A maximum bandwidth in 802.11ax is 160 MHz. In this case, the entire bandwidth may be divided into two parts in units of 80 MHz. Each 80 MHz is referred to as a segment (segment). Therefore, when M is greater than 5, there are at least two segments, and certainly, there may be three segments (a total bandwidth is 240 MHz) or four segments (a total bandwidth is 320 MHz). The total bandwidth is determined because some channels of the entire bandwidth are punctured, and an RU obtained when subcarriers on remaining channels are equivalently combined is a 242×n-tone RU. Herein, n may be different values, for example, n=1, . . . , M. For example, refer toFIG.14. Each trapezoid inFIG.14represents one 242-tone RU, and there are a total of twelve 242-tone RUs; in other words, M=12. Based on a segmentation case inFIG.14, there are a total of four segments. When there are a plurality of segments, segment parsing is first performed in units of segments. Then, in each segment, a plurality of existing RUs are equivalently combined, and an RU obtained after combination is performed in each segment may be a 242-tone RU, a 484-tone RU, a 242×3-tone RU, or a 242×4-tone RU. FIG.15shows a procedure of an LDPC tone mapper for segmenting a total bandwidth of M RUs. As shown inFIG.15, a transmit end first sequentially performs pre-FEC physical layer padding, FEC (LDPC) coding, a post-FEC physical layer padding operation, and data stream parsing on data bits; then performs segment parsing on a coded data stream that is output after stream parsing, and separately performs the following operations for each segment: constellation mapping, a tone mapping operation, space time block code (space time block code, STBC) coding, CSD per stream, space-frequency mapping, inverse discrete Fourier transform (inverse discrete fourier transform, IDFT), guard interval and windowing (guard interval&windowing, GI&W), and analog and radio frequency (analog&radio frequency, A&RF); and finally sends the data stream by using an antenna. A unified tone mapping operation is performed on bits in each segment by using an LDPC tone mapper. In some special cases, for example, when there is a 242×2-tone RU in a first segment and there is a 242×1-tone RU in a second segment, although n=3, a procedure in which segmentation is performed first and then LDPC tone mapping is performed in each segment may still be used. A method in which segmentation is performed first and then unified tone mapping is separately performed for RUs in each segment is provided in Embodiment 4. In this way, flexibility of this solution is improved, and a problem that hardware costs of the LDPC tone mapper are high when the total bandwidth is relatively large is resolved. A method procedure performed by the transmit end is described in the foregoing embodiments. For a method procedure performed by a receive end, an inverse process of the transmit end is performed. FIG.16shows another data processing method according to an embodiment of this application. The method may be applied to the WLAN system shown inFIG.9. The method includes the following steps: S1601: A receive end obtains a reordered bitstream of a first user from M RUs or a first RU including M RUs, where the M RUs or the first RU is an RU allocated to the first user, and M is a positive integer greater than 1. S1602: The receive end restores a sequence of all bits in the reordered bitstream by using a first deinterleaver or a first tone demapper. A type of the receive end may be a STA, or may be an AP, and this is not limited herein. The M RUs or the first RU allocated to the first user is the same as that in the foregoing embodiment shown inFIG.10. Details are not described herein again. Specifically, an entire process of the first deinterleaver is an inverse process of the first interleaver. As shown inFIG.17, after sequentially performing CSD and constellation mapping on received signals, the receive end performs unified deinterleaving by using a first deinterleaver with new parameters, and then extracts, in sequence, a bitstream from a large RU (that is, the first RU) obtained after combining the M RUs, performs inverse stream parsing, and finally performs BCC decoding. Parameters (NSD, NROW, . . . , and NCOL) of the first deinterleaver entirely correspond to the parameters (NSD, NROW, and NCOL) of the first interleaver, and details are not described herein again. Similarly, an entire process of the first tone demapper is an inverse process of the first tone mapper. As shown inFIG.18, after separately performing CSD on received signals, the receive end performs unified demapping by using a first tone demapper with new parameters, and then performs a constellation demapping operation, extracts, in sequence, a bitstream from a large RU (that is, the first RU) obtained after combining the M RUs, and performs inverse stream parsing, and finally performs BCC decoding. Parameters (NSDand DTM) of the first tone demapper entirely correspond to the parameters (NSDand DTM) of the first tone mapper, and details are not described herein again. The foregoing embodiments may be combined to implement different technical effects. The data processing method in embodiments of this application is described above, and a data processing apparatus in embodiments of this application is described below. FIG.19shows a first type of processing apparatus1900at a transmit end according to an embodiment of this application. The processing apparatus1900includes:a sequential bit allocator1901, configured to allocate a coded bitstream of a first user to M RUs or a first RU including M RUs, where the M RUs or the first RU is an RU allocated to the first user, and M is a positive integer greater than 1; anda first interleaver or a first tone mapper1902, configured to reorder all bits in the coded bitstream. The data processing apparatus1900in this embodiment of this application has any function of the transmit end in the foregoing methods, and details are not described herein again. FIG.20shows a second type of data processing apparatus2000at a transmit end according to an embodiment of this application. The data processing apparatus2000includes: a processor2001, configured to input all bits in a coded bitstream of a first user into a first interleaver or a first tone mapper, where M RUs or a first RU including M RUs is allocated to the first user, and M is a positive integer greater than 1; and the first interleaver or the first tone mapper2002, configured to reorder all bits in the coded bitstream. The data processing apparatus2000in this embodiment of this application has any function of the transmit end in the foregoing methods, and details are not described herein again. FIG.21shows a third type of data processing apparatus2100at a transmit end according to an embodiment of this application. The data processing apparatus2100includes:a processor2101, configured to divide a total bandwidth of a first user into N sub-bandwidths, where at least one of the N sub-bandwidths includes a plurality of RUs;a sequential bit allocator2102, configured to: allocate a coded bitstream of the first user to the N sub-bandwidths, and allocate a coded bitstream on a first sub-bandwidth to M RUs or a first RU including M RUs, where the first sub-bandwidth is any one of the at least one sub-bandwidth; anda first interleaver or a first tone mapper2103, configured to reorder all bits in all coded bitstreams on the first sub-bandwidth. The data processing apparatus2100in this embodiment of this application has any function of the transmit end in the foregoing methods, and details are not described herein again. The data processing apparatus at the transmit end in embodiments of this application is described above, and a possible product form of the data processing apparatus at the transmit end is described below. It should be understood that any product of any form that has a function of the processing apparatus shown inFIG.19toFIG.21falls within the protection scope of embodiments of this application. It should also be understood that the following descriptions are merely examples, and a product form of the data processing apparatus in embodiments of this application is not limited thereto. In a possible product form, the data processing apparatus in embodiments of this application may be implemented by a general bus architecture. The sequential bit allocator and the first interleaver may be implemented by a processor, or the sequential bit allocator and the first tone mapper may be implemented by a processor. Optionally, the data processing apparatus may further include a memory, and the memory is configured to store instructions executed by the processor. In a possible product form, the data processing apparatus in embodiments of this application may be implemented by a sequential bit allocation circuit and an interleaving circuit, or may be implemented by a sequential bit allocation circuit and a tone mapping circuit. Optionally, the data processing apparatus may further include a storage medium, and the storage medium is configured to store instructions executed by the sequential bit allocation circuit and the interleaving circuit, or is configured to store instructions executed by the sequential bit allocation circuit and the tone mapping circuit. In a possible product form, the data transmission apparatus in embodiments of this application may be alternatively implemented by using the following: one or more FPGAs (field programmable gate array), a PLD (programmable logic device), a controller, a state machine, gate logic, a discrete hardware component, any other suitable circuit, or any combination of circuits that can execute various functions described in this application. It should be understood that the foregoing data processing apparatuses in various product forms have any function of a data processing apparatus located at the transmit end in the foregoing method embodiments, and details are not described herein again. FIG.22shows a data processing apparatus2200at a receive end according to an embodiment of this application. The data processing apparatus2200includes:a processor2201, configured to obtain a reordered bitstream of a first user from M RUs or a first RU including M RUs, where the M RUs or the first RU is an RU allocated to the first user, and M is a positive integer greater than 1; anda first deinterleaver or a first tone demapper2202, configured to restore a sequence of all bits in the reordered bitstream. The data processing apparatus2200in this embodiment of this application has any function of the receive end in the foregoing methods, and details are not described herein again. The data processing apparatus at the receive end in embodiments of this application is described above, and a possible product form of the data processing apparatus at the receive end is described below. It should be understood that any product of any form that has a function of the data apparatus shown inFIG.22falls within the protection scope of embodiments of this application. It should also be understood that the following descriptions are merely examples, and a product form of the data processing apparatus in embodiments of this application is not limited thereto. In a possible product form, the data processing apparatus in embodiments of this application may be implemented by a general bus architecture. The processor and the first deinterleaver may be implemented by a processor, or the processor and the first tone demapper may be implemented by a processor. Optionally, the data processing apparatus may further include a memory, and the memory is configured to store instructions executed by the processor. In a possible product form, the data processing apparatus in embodiments of this application may be implemented by a processing circuit and a deinterleaving circuit, or may be implemented by a processing circuit and a tone demapping circuit. Optionally, the data processing apparatus may further include a storage medium, and the storage medium is configured to store instructions executed by the processing circuit and the deinterleaving circuit, or is configured to store instructions executed by the processing circuit and the tone demapping circuit. In a possible product form, the data transmission apparatus in embodiments of this application may be alternatively implemented by using the following: one or more FPGAs (field programmable gate array), a PLD (programmable logic device), a controller, a state machine, gate logic, a discrete hardware component, any other suitable circuit, or any combination of circuits that can execute various functions described in this application. It should be understood that the foregoing data processing apparatuses in various product forms have any function of a data processing apparatus located at the receive end in the foregoing method embodiments, and details are not described herein again. In embodiments of this application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logical block diagrams disclosed in embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor or the like. The steps of the method disclosed with reference to embodiments of this application may be directly performed by a hardware processor, or may be performed by using a combination of hardware in the processor and a software module. The memory involved in embodiments of this application may be a non-volatile memory such as a hard disk drive (hard disk drive, HDD) or a solid-state drive (solid-state drive, SSD), or may be a volatile memory (volatile memory) such as a random access memory (random-access memory, RAM). The memory is any other medium that can carry or store expected program code in a form of an instruction or a data structure and that can be accessed by a computer, but is not limited thereto. The memory in embodiments of this application may alternatively be a circuit or any other apparatus that can implement a storage function, and is configured to store the program instructions and/or the data. A person of ordinary skill in the art may be aware that, in combination with the examples described in embodiments disclosed in this specification, method steps and units may be implemented by electronic hardware, computer software, or a combination thereof. To clearly describe the interchangeability between the hardware and the software, the foregoing has generally described steps and compositions of each embodiment according to functions. Whether the functions are performed by hardware or software depends on particular applications and design constraint conditions of the technical solutions. A person of ordinary skill in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of this application. It may be clearly understood by a person skilled in the art that, for the purpose of convenient and brief description, for a detailed working process of the foregoing system, apparatus, and unit, refer to a corresponding process in the foregoing method embodiments, and details are not described herein again. In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiment is merely an example. For example, division into the units is merely logical function division and may be other division in actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces, indirect couplings or communication connections between the apparatuses or units, or electrical connections, mechanical connections, or connections in other forms. The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual requirements to achieve the objectives of the solutions of embodiments in this application. In addition, functional units in embodiments of this application may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units are integrated into one unit. The integrated unit may be implemented in a form of hardware, or may be implemented in a form of a software functional unit. When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, the integrated unit may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of embodiments of this application essentially, or the part contributing to the conventional technology, or all or some of the technical solutions may be implemented in the form of a software product. The software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) or a processor to perform all or some of the steps of the methods described in embodiments of this application. The foregoing storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (read-only memory, ROM), a random access memory (random access memory, RAM), a magnetic disk, or an optical disc. The foregoing descriptions are merely specific embodiments of this application, but are not intended to limit the protection scope of this application. Any modification or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims. | 69,747 |
11943053 | DETAILED DESCRIPTION The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure. At least some of the following abbreviations and terms may be used in this disclosure.2D Two Dimensional3GPP Third Generation Partnership Project5G Fifth GenerationAAS Antenna Array SystemAoA Angle of ArrivalAoD Angle of DepartureASIC Application Specific Integrated CircuitBF BeamformingBLER Block Error RateBW BeamwidthCPU Central Processing UnitCSI Channel State InformationdB DecibelDCI Downlink Control InformationDFT Discrete Fourier TransformDSP Digital Signal ProcessoreNB Enhanced or Evolved Node BFIR Finite Impulse ResponseFPGA Field Programmable Gate ArraygNB New Radio Base StationICC Information Carrying CapacityIIR Infinite Impulse ResponseLTE Long Term EvolutionMIMO Multiple Input Multiple OutputMME Mobility Management EntityMMSE Minimum Mean Square ErrorMTC Machine Type CommunicationNR New RadioOTT Over-the-TopPBCH Physical Broadcast ChannelPDCCH Physical Downlink Control ChannelPDSCH Physical Downlink Shared ChannelP-GW Packet Data Network GatewayRAM Random Access MemoryROM Read Only MemoryRRC Radio Resource ControlRRH Remote Radio HeadSCEF Service Capability Exposure FunctionSINR Signal to Interference plus Noise RatioTBS Transmission Block SizeUE User EquipmentULA Uniform Linear ArrayURA Uniform Rectangular Array Radio Node: As used herein, a “radio node” is either a radio access node or a wireless device. Radio Access Node: As used herein, a “radio access node” or “radio network node” is any node in a radio access network of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), and a relay node. Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), or the like. Wireless Device: As used herein, a “wireless device” is any type of device that has access to (i.e., is served by) a cellular communications network by wirelessly transmitting (and/or receiving) signals to (and/or from) a radio access node. Some examples of a wireless device include, but are not limited to, a User Equipment device (UE) in a 3GPP network and a Machine Type Communication (MTC) device. Network Node: As used herein, a “network node” is any node that is either part of the radio access network or the core network of a cellular communications network/system. Cell: As used herein, a “cell” is a combination of radio resources (such as, for example, antenna port allocation, time and frequency) that a wireless device may use to exchange radio signals with a radio access node, which may be referred to as a host node or a serving node of the cell. However, it is important to note that beams may be used instead of cells, particularly with respect to 5G NR. As such, it should be appreciated that the techniques described herein are equally applicable to both cells and beams. Note that references in this disclosure to various standards (such as 3GPP TS 38.211 V15.1.0 (2018-09) and 3GPP TS 38.214 V15.1.0 (2018-09), for example) should be understood as referring to the most recent version of such standards at the time the present application was filed, and may also refer to any applicable successors of such standards. Note that the description herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system. FIG.2illustrates one example of a cellular communications network200in which embodiments of the present disclosure may be implemented. In the embodiments described herein, the cellular communications network200is a Public Land Mobility Network (PLMN) conforming to one or more of the LTE, 3G, 4G and 5G NR standards, or their successors. In the illustrated example, the cellular communications network200includes a (Radio) Access Network (RAN)202comprising base stations204-1and204-2controlling radio communications with wireless devices206-1,206-2,206-3,206-4,206-5within corresponding macro cells208-1and208-2. Each macro cell208may be defined by any suitable combination of geography, frequency, Radio Access Technology (RAT) and modulation scheme. Base stations204can be any type of network access device capable of establishing radio connection(s) with one or more wireless devices206within a respective coverage area of the base station204or low power node212, and further configured to forward subscriber traffic between the core network214and the one or more wireless devices206. An important feature of a base station204is that it is configured with both a radio interface configured to send and receive radio signals to and from a wireless device206, and a network interface configured to exchange electronic and/or optical signals with the core network214. Examples of base stations204and low power nodes212include: Evolved Node B (eNB) systems (known, for example, in the 3GPP standards): WiFi access points (known, for example from IEEE 802.11 standards) or the like. In some contexts, a base station2104may be referred to as an access point (AP) regardless of the Radio Access Technology (RAT) that it supports. The illustrated RAN202also includes small cells210-1through210-4, within which radio communication can be controlled by corresponding low power nodes212-1through212-4. As with the macro cells208, each small cell may be defined by any suitable combination of geography, frequency, Radio Access Technology (RAT) and modulation scheme. As with the base stations204, a low power node212can be any type of network access device capable of establishing radio connection(s) with one or more wireless devices206within a respective coverage area of the low power node212, and further configured to forward subscriber traffic between the core network214and the one or more wireless devices206. An important feature of a low power node212is that it is configured with both a radio interface configured to send and receive radio signals to and from a wireless device106, and a network interface configured to exchange electronic and/or optical signals with the core network214. In some embodiments, a low power node212may be connected to the core network214by a direct connection, such as an optical cable. In other embodiments, a low power node112may be connected to the core network214by an indirect connection, such as via a radio or optical fiber link to a base station204. Examples of low power nodes212include: Remote Radio Heads (RRHs) connected to a base station or a network router (not shown): WiFi access points or the like. In some contexts, a low power node212may be referred to as an access point (AP) regardless of the specific Radio Access Technology (RAT) that it supports. Notably, while not illustrated, a particular small cell210may alternatively be controlled by a base station204, for example using a beam-forming technique. In such cases, the particular small cell210will not be associated with a respective low power node212per se. Rather, the particular small cell210will be associated with a respective set of parameters implemented in the base station204. In this disclosure, the term “cell” is used to refer to a defined combination of parameters (such as geography, frequency, Radio Access Technology, RAT, modulation scheme, identifiers and the like) that can be used by a wireless device106to access communication services of the network200. The term “cell” does not imply any particular parameter values, or any particular physical configuration of devices needed to enable a wireless device206to access those communication services. Wireless devices206can be any type of device capable of sending and receiving radio signals to and from a base station204and/or low power node212. Examples of wireless device206include cellular phones, Personal Data Assistants (PDAs), mobile computers, Internet of Things (IoT) devices, autonomous vehicle controllers, and the like. In some contexts, a wireless device206may be referred to as a User Equipment (UE) or a mobile device. In some embodiments, the macro cells208-1and208-2may overlap each other, and may also overlap one or more small cells210. For example, a particular macro cell108-1may be one macro cell208among a plurality of macro cells covering a common geographical region and having a common RAT and modulation scheme, but using respective different frequencies and/or AP identifiers. In such cases, a wireless device206located within a region covered by two or more overlapping cells208,212may send and receive radio signals to and from each of the corresponding base stations204and/or low power nodes212. In the illustrated example, the RAN202is connected to a Core Network (CN)214, which may also be referred to as Evolved Core Network (ECN) or Evolved Packet Core (EPC). The CN214includes (or, equivalently, is connected to) one or more servers216configured to provide networking services such as, for example, Network Functions (NFs) described in 3GPP TS 23.501 V15.2.0 (2018-06) “System Architecture for the 5G System” and its successors. The CN214also includes one or more gateway (GW) nodes118configured to connect the CN214to a packet data network (DN)220such as, for example, the internet. A gateway node218may be referred to as a packet gateway (PGW) and/or a serving gateway (SGW). The DN220may provide communications services to support end-to-end communications between wireless devices206and one or more application servers (ASs)222configured to exchange data packet flows with the wireless devices206via the CN214and RAN202. In some contexts, an application server (AS)222may also be referred to as a host server. In some contexts, an end-to-end signal path between an AS222and one or more wireless devices206may be referred to as an Over-The-Top (OTT) connection. Similarly, a communication service that employs signal transmission between an AS222and one or more wireless devices206may be referred to as an OTT service. It should be appreciated that the separation between the CN214and the DN220can be purely logical, in order to simplify understanding of their respective roles. In particular, the CN214is primarily focused on providing wireless device access services and supporting wireless device mobility. On the other hand, the DN220is primarily focused on providing end-to-end communications, particularly across network domains. However, it will be appreciated that both the CN214and the DN220can be implemented on common physical network infrastructure, if desired. FIGS.3A and3Bis a block diagram schematically illustrating a communications system300including a computing device302usable in embodiments of the present invention. In various embodiments, any or all of the base stations104or112, wireless devices106, core network servers116or gateways118and data network servers122may be implemented using systems and principles in accordance with the computing device302. It may also be appreciated that any or all of the elements of the network100may be virtualized using techniques known in the art or developed in the future, in which case the functions of any or all the base stations104or112, core network servers116or gateways118, and/or any or all of the network functions206-226may be implemented by suitable software executing within a computing device302or within a data center (non shown) composed of multiple computing devices302. In the example ofFIG.3A, the communications system300generally includes computing device302connected to one or more networks310and one or more radio units312. The computing device302includes one or more processors304, a memory306, one or more network interfaces308. The processors304may be provided as any suitable combination of Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), or the like. Similarly, the memory306may be provided as any suitable combination of Random Access Memory (RAM), Read Only Memory (ROM) and mass storage technologies such as magnetic or optical disc storage or the like. The network interfaces308enable signaling between the computing device300and the networks310, such as the Core Network114, the data network120, or a private domain network such as a data center (not shown). Each radio unit312typically includes at least one transmitter (Tx)314and at least one receiver (Rx)316coupled to one or more antennas318. In the example ofFIG.3A, the radio unit(s)312is(are) shown as being external to the computing device302and connected to the computing device302via a suitable physical connection (such as a copper cable or an optical cable). In the example ofFIG.3B, the radio unit(s)312is(are) shown as being connected to computing device302via a network310and a network interface308. In still other embodiments, the radio unit(s)312and optionally also the antenna(s)318may be integrated together with the computing device302. The one or more processors304operate to provide functions of the computing device302. Typically, these function(s) are implemented as software applications (APPs)320or modules that are stored in the memory306, for example, and executed by the one or more processors304. In some embodiments, one or more software applications or modules320may execute within a secure run-time environment (RTE)322maintained by an operating system (not shown) of the computing device302. It may be appreciated that specific embodiments may exclude one or more of the elements illustrated inFIGS.3A and3B. For example, a computing device302configured to implement a wireless device106may incorporate one or more processors304, a memory306, and one or more radio units312, but may exclude a network interface308. Conversely, a computing device302configured to implement a server116or122may include one or more processors304, a memory306, and one or more network interfaces308, but may exclude radio units312. A computing device302configured to implement a base station104or112, on the other hand, will normally include one or more processors304, a memory306, and both radio units312and network interfaces308. FIG.4is a block diagram schematically illustrating an example architecture for network element virtualization usable in embodiments of the present invention. It is contemplated that the network elements may be physically implemented using one or more computers, data storage devices and routers (any or all of which may be constructed in accordance with the system300described above with reference toFIG.3) interconnected together and executing suitable software to perform its intended functions. Those of ordinary skill will recognize that there are many suitable combinations of hardware and software that may be used for this purpose, which are either known in the art or may be developed in the future. For this reason, a figure showing physical hardware components and connections is not included herein. As maybe seen inFIG.4, the illustrated architecture400generally comprises hosting infrastructure402, a virtualization layer404and an Application Platform Services layer406. The hosting infrastructure402comprises physical hardware resources provided by the infrastructure on which the architecture400is being implemented. These physical hardware resources may include any or all of the processors304, memory306, network interfaces308and radio units312described above with reference toFIG.3, and may also include traffic forwarding and routing hardware408. The virtualization layer404presents an abstraction of the hardware resources402to the Application Platform Services layer406. The specific details of this abstraction will depend on the requirements of the applications320being hosted by the Application Platform Services layer406. Thus, for example, an APP320that provides traffic forwarding functions (for example as part of a User Plane Function, UPF) may be presented with an abstraction of the hardware resources406(e.g. processor(s)304, memory306and traffic forwarding hardware408) that simplifies the implementation of traffic forwarding policies. Similarly, an application that provides data storage functions (for example implementing a Unified Data Management, UDM, and/or a Unified Data Repository, UDR) may be presented with an abstraction of the hardware resources406(e.g. processor(s)304and memory306) that facilitates the storage and retrieval of data (for example using Lightweight Directory Access Protocol—LDAP). The application platform406provides the capabilities for hosting applications. In some embodiments, the application platform406supports a flexible and efficient multi-tenancy run-time and hosting environment for applications320by providing Infrastructure as a Service (IaaS) facilities. In operation, the application platform406may provide a security and resource “sandbox” for each application320being hosted by the platform406. Each “sandbox” may be implemented as a Virtual Machine (VM) image410that may include an appropriate operating system and controlled access to (virtualized) hardware resources402. The application platform406may also provide a set of middleware application services and infrastructure services to the applications320hosted on the application platform406, as will be described in greater detail below. Applications320from vendors, service providers, and third-parties may be deployed and executed within a respective Virtual Machine410. For example, a Policy Control Function (PCF) may be implemented by means of one or more applications320hosted on the application platform406as described above. Communication between applications320and services of the application platform406may conveniently be designed according to the principles of Service-Oriented Architecture (SOA) known in the art. Communication services412may allow applications320to communicate with the application platform406(through pre-defined Application Programming Interfaces (APIs) for example) and with each other (for example through a service-specific API). A Service registry414may provide visibility of the services available on the server200. In addition, the service registry220may present service availability (e.g. status of the service) together with the related interfaces and versions. This may be used by applications214to discover and locate the end-points for the services they require, and to publish their own service end-point for other applications to use. Network Information Services (NIS)416may provide applications320with low-level network information pertaining to a network service instance or one or more PDU sessions, for example. For example, the information provided by NIS416may be used by an application320to calculate and present relevant data (such as: cell-ID, location of the subscriber, cell load and throughput guidance) to a Service Management Function (SMF), an Access and Mobility Function (AMF) and the PCF, any or all of which may themselves to implemented by applications320executing in respective VMs410. A Traffic Off-Load Function (TOF) service418may prioritize traffic, and route selected, policy-based, data streams to and from applications320. FIG.5shows an example of a MAC PDU structure in 5G. As may be seen inFIG.5, the MAC PDU500may be formed by prepending a MAC Header502to an RLC PDU504. In such a case, the MAC header normally includes an indication of the length of the RLC PDU504. Alternatively, a MAC PDU500may be constructed using any other suitable payload (in place of the RLC PDU504). For example, the MAC PDU500may be a MAC Control Element (MCE) packet. In any such embodiments, MAC Header502will normally include an indication of the packet length, which enables a receiver to separate MAC PDUs recovered from an incoming stream of CBs or CBGs. In the embodiment illustrated inFIG.5, the RLC PDU504includes an RLC header506, a Packet Data Convergence Protocol (PDCP) header508, a Service Data Adaptation Protocol (SDAP) header510, and an Internet Protocol (IP) packet512. One problem with current ARQ techniques is that when a CBG is missing or incorrectly decoded, all subsequent CBGs have to be buffered even if they are all correctly decoded, until the missing CBG is successfully received. This not only introduces a large delay in delivering decoded PDUs to the higher layer(s), but also increases the required size of the ARQ buffers. FIG.6Illustrates this problem in greater detail. As may be seen inFIG.6, a sequence600of successively transmitted CBGs106is shown. Each CBG106may include one or more CBs104(not shown), and may contain encoded data of part of a MAC PDU500or of multiple MAC PDUs500. The alignment between each MAC header502and the boundaries of any given CBG106is arbitrary, and changes depending on the variable lengths of the MAC PDUs500. Consequently, it is not possible to use the boundaries of a CBG106to locate the start of a MAC PDU500. Rather, the PDU length indication within the MAC header502is used to locate the start of the next MAC PDU (which may be located in the same CBG or in a later CBG in the sequence600). However, if a CBG106is missing or fails to decode, any MAC header(s)502contained within that CBG106will also be missing, so that it is not possible to identify the start of the next MAC PDU500encoded in the CBG sequence600. FIG.6illustrates and example in which CBG(1)106-1is missing, e.g. due to a failure to correctly decode. In this example, CBG(1)106-1contains the trailing part of PDU(0)500-0, and the leading portion (including the MAC header502-1) of PDU(1)500-1. Since the MAC header502-1of PDU(1) is missing, there is no means of locating the starting point of PDU(2)500-2in CBG(2)106-2, even if CBG(2) is properly decoded. As a result, the entire content of CBG(2) (and any subsequently received CBGs) must be buffered until CBG(1) has been successfully received. Systems and methods are disclosed herein that reduce the time delay of delivering decoded PDUs to higher layers as well as to reduce the ARQ data buffer size. Referring toFIG.7, in accordance with embodiments of the present disclosure, this is accomplished by providing a respective CBG header700in each CBG106. The CBG header700may be located at any desired position within the CBG. In the illustrated embodiments, the CBG header700is located at the beginning of the CBG106. For example, the CBG header700may occupy the first one or more bytes of the CBG106. However, other locations within the CBG106may be used, if desired. The CBG header700includes an indication of the starting location of the first PDU within that CBG106. In some embodiments, the indication of the starting location may include a pointer to the starting location. In the example ofFIG.7, the starting location of a PDU within a CBG is the location of a set of bytes702corresponding to the MAC header502of the MAC PDU500encoded within the CBG106. For clarity of understanding the present disclosure, the “first PDU within the CBG” should be understood to refer to the PDU having a starting location nearest to the leading boundary of the CBG. For example, inFIG.7, CBG(1) contains the trailing portion of PDU(n−1), the entirety of PDU(n) and a leading portion of PDU(n+1). In this case, the PDU having a starting location nearest to the leading boundary of CBG(1) corresponds to PDU(n), and so the CBG header700-1of CBG(1) would include an indication of the starting location of PDU(n) within CBG(1). As noted above, this starting location may be taken as the location of encoded bytes702corresponding with the MAC header502of PDU(n). In some embodiments, the starting location of each PDU is indicated by a known header, such as, for example, a MAC header502. Other headers may also be used either in addition to or instead of the MAC header502. For example, any of the RLC header506, PDCP header508, or the SDAP header510may be used (alone or in combination) to identify the start of a PDU. Other techniques for marking the starting location may also be used, if desired. For example, a predetermined binary symbol sequence could be used, although this approach may undesirably increase overhead. For simplicity of description, example embodiments are illustrated in which the PDUs encoded within the stream of CBGs are MAC PDUs500. However, it will be appreciated that the present technique is not restricted to MAC PDUs. For example, the PDUs encoded within the stream of CBGs may be MAC PDUs, RLC PDUs (i.e. without a MAC header502), MAC Control Element, MCEs, or any other suitable protocol data units. For simplicity of description example embodiments are illustrated in which the PDUs encoded within a stream of code block groups (CBGs). A code block group may encompass one or more code blocks (CBs). For the reduced case in which each CBG includes only one CB, the CBG header700becomes a code block header (CBH), which indicates the starting location of the first PDU within that CB. If desired per-CB code block headers may be used in CBGs including more than one CB. This solution enables detection of the starting location of the first PDU with a finer granularity than a whole CBG, but at a cost of greater overhead. An advantage of this arrangement is that, as long as a CBG is correctly decoded, any decoded PDUs that start within that CBG can be immediately delivered to higher layers even if one or more previous CBGs have been missed.FIG.7illustrates and example in which (as inFIG.6described above) CBG(1)106-1is missing, e.g. due to a failure to correctly decode. In this example, CBG(1)106-1contains the trailing part of PDU(0)500-0, and the leading portion (including the MAC header502-1) of PDU(1)500-1. However, unlike in the example ofFIG.6, the CBG header700-2of CBG(2)106-2contains an indication of the starting point of the first PDU in that code block group, which in this example is PDU(2). Accordingly, upon successful decoding of CBG(2), the starting location of PDU(2)502-2can be located so the PDU(2) and following PDUs can be forwarded, even before CBG(1) has been successfully received. This means that the ARQ buffer(s) only need to store data directly affected by the failure of CBG(1), which in the example ofFIG.7relates to PDU(0) and PDU(1). Because the content of CBG(2) and any subsequently received CBGs do not need to be buffered until CBG(1) has been successfully received, the required size of the ARQ buffer is reduced as compared to conventional ARQ techniques. The methods disclosed herein can be applied to any suitable communications technology, including LTE and 5G NR. FIG.9is a flowchart illustrating a method900that may be implemented in a sending node in accordance with embodiments of the present invention. The method ofFIG.9includes: Encoding902a transport block, TB, including data of at least one protocol data unit (PDU) to generate a code block group, CBG, comprising one or more code blocks, CBs; Defining904a CBG header of the CBG, the CBG header being indicative of a starting location of a first PDU within the CBG; and Transmitting906the CBG to a receiving node of the communications network. FIG.10is a flowchart illustrating a method1000that may be implemented in a receiving node in accordance with embodiments of the present invention. The method ofFIG.10includes: Receiving (at1002) one or more code block groups (CBGs) from a sending node of the communications network, each CBG comprising one or more code blocks (CBs) and a CBG header indicative of a start location of a respective first protocol data unit (PDU) within the CBG; Attempting to decode (at1004) each received CBG; Responsive to failing to decode a first CBG (at1006), attempting to decode (at1008) a second CBG, and responsive to successfully decoding (at1010) the second CBG: Identifying (at1012) the start location of the respective first PDU in the second CBG, using the CBG header; Buffering (at1014) data of the second CBG prior to the identified start location; and Forwarding (at1016) data of PDUs following the identified start location. For simplicity, the flowchart ofFIG.10illustrates the decoding and processing of received CBGs in sequence. However, it will be appreciated that the techniques of the present disclosure may equally be applied to embodiments in which two or more received CBGs are decoded and processed in parallel. While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is representative (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.). Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein. | 30,013 |
11943054 | DETAILED DESCRIPTION The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology can be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, the subject technology is not limited to the specific details set forth herein and can be practiced using one or more other implementations. In one or more implementations, structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. Wireless communication technologies may utilize block acknowledgements to reduce overhead and increase effective throughput. For example, a block acknowledgment frame may be used to acknowledge several previously transmitted frames, instead of an acknowledgment frame that acknowledges only one previously transmitted frame. Similarly multicast transmissions may be used to transmit a given frame to multiple different recipients. One example of a multicast transmission may be a groupcast with retries (GCR) transmission, where retransmissions are group addressed. Although multicast transmissions may be intended for multiple different recipients, multicast transmissions may also utilize block acknowledgments, such as to improve effective network throughput. Wireless communication technologies may also improve effective throughput by aggregating frames from multiple streams, such as packets classified by different traffic identifiers (TIDs), e.g., from the same or different quality of service (QoS) access categories. In one or more implementations, a traffic identifier may be considered an identifier that can be used to classify a packet. For example, a packet classified as audio (and/or video) may be given higher priority than, for example, a packet classified as a data frame. The ability to aggregate frames across different QoS traffic classes (e.g., different streams/TIDs) may allow transmissions to be aggregated more efficiently and thereby reduce overhead. In one or more implementations, each TID may represent a different source of data information, each potentially having a distinct priority. The efficiencies achieved through multicast transmissions, and those achieved through transmitting multiple concurrent streams may be enhanced by combining multicast transmissions with transmissions of multiple concurrent streams (e.g., multiple TID transmissions), such as a multiple TID GCR transmission. Furthermore, the efficiencies achieved through the use of block acknowledgments and those achieved through the use of multicast transmissions that include multiple concurrent streams may be enhanced by utilizing block acknowledgments in conjunction with multicast transmissions that include multiple concurrent streams. The subject system provides for block acknowledgment requests and block acknowledgment frames that can be used in conjunction with multicast transmissions that include multiple concurrent streams, e.g. a multiple TID GCR transmission and/or session. Thus, the subject system reduces the overhead associated with multicast transmissions that include multiple concurrent streams, thereby increasing the effective throughput of such transmissions and overall network efficiency. FIG.1illustrates an example network environment in which block acknowledgments for a multicast transmission with multiple concurrent streams may be utilized for in accordance with one or more implementations. Not all of the depicted components may be used in all implementations, however, and one or more implementations may include additional or different components than those shown in the figure. Variations in the arrangement and type of the components may be made without departing from the spirit or scope of the claims as set forth herein. Additional components, different components, or fewer components may be provided. The network environment100includes one or more electronic devices102A-C, a wireless access point104, and a base station106. One or more of the electronic devices102A-C may include, may be a component of, and/or may be referred to as, a User Equipment (UE), station (STA), or terminal device. One or more of the electronic devices102A-C may include suitable logic, circuitry, interfaces, memory, and/or code that enables communications, e.g., with one or more of the wireless access point104or the base station106, via wireless interfaces and utilizing one or more radio transceivers, such as WiFi and/or cellular transceivers. One or more of the electronic devices102A-C may also be operable to communicate wirelessly with one or more other user devices, one or more other base stations, and/or one or more other access points not shown inFIG.1. One or more of the electronic devices102A-C may be, for example, a portable computing device such as a laptop device, a smartphone, a peripheral device (e.g., a digital camera, headphones), a smart television device, a tablet device, a wearable device such as a watch, a band, and the like, or any other appropriate device that includes, for example, one or more wireless interfaces, such as wireless local area network (WLAN) radios, Wi-Fi radios, cellular radios, Bluetooth radios, Zigbee radios, near field communication (NFC) radios, and/or other wireless radios. InFIG.1, by way of example, the electronic device102A is depicted as a tablet device, the electronic device102B is depicted as a mobile device, and the electronic device102C is depicted as a laptop device. One or more of the electronic devices102A-C may be, and/or may include all or part of, the electronic device discussed below with respect toFIG.2, and/or the electronic system discussed below with respect toFIG.7. The base station106may be a component of, and/or may be referred to as, a cell, a node B (NB), an evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) node B, an evolved nodeB (eNodeB or eNB), and the like. The base station106may include suitable logic, circuitry, interfaces, memory, and/or code that enable cellular communications, e.g., with one or more of the electronic devices102A-C and/or other base stations (not shown), via wireless interfaces and utilize one or more radio transceivers. In one or more implementations, the base station106may be a base station of a cellular-based wireless network, such as a long term evolution (LTE) communications network, global system for mobile (GSM) communications network, UMTS communications network, or generally any cellular-based communications network. The base station106may utilize an unlicensed spectrum for cellular communications, such as in a carrier aggregation procedure, e.g., in licensed assisted access (LAA) communication. Thus, the cellular communications may include communications over licensed spectrum, such as spectrum licensed by the mobile network operator associated with the base station106, and/or communications over unlicensed spectrum, such as, for example, the 5 GHz spectrum. The base station106may be, and/or may include all or part of, the electronic device discussed below with respect toFIG.2, and/or the electronic system discussed below with respect toFIG.6. The wireless access point104may include, may be a component of, and/or may be referred to as, a WLAN access point. The wireless access point104includes suitable logic, circuitry, interfaces, memory, and/or code that enable WiFi communications, e.g., with one or more of the electronic devices102A-C via wireless interfaces and utilize one or more radio transceivers. The WiFi communications may include communications over one or more of a 2.4 GHz spectrum, a 5 GHz spectrum, a 60 GHz spectrum, and/or other spectrums utilized for WiFi communications. The wireless access point104may be, and/or may include all or part of, the electronic device discussed below with respect toFIG.2, and/or the electronic system discussed below with respect toFIG.7. InFIG.1, the electronic device102B is illustrated as participating in cellular communications with the base station106. However, the electronic device102B may also participate in WiFi communications with the wireless access point104, such as concurrently with the cellular communications with the base station106. In one or more implementations, the electronic device102B may participate in a licensed assisted access procedure with the base station106in order to utilize unlicensed spectrum (e.g., spectrum that is not licensed by any mobile network operator) for cellular communications, such as via carrier aggregation. Thus, if the electronic device102B is located near one or more of the electronic devices102A,C that are utilizing the 5 GHz spectrum for WiFi communications, e.g. with the wireless access point104, the WiFi communications of the electronic devices102A,C on the 5 GHz spectrum may interfere with the cellular communications of the electronic device102B on the 5 GHz spectrum (and vice-versa). In the subject system one or more of the electronic devices102A-C, the wireless access point104, and/or the base station106may utilize block acknowledgements for a multicast transmission that includes multiple concurrent streams. An example process for utilizing block acknowledgments for a multicast transmission that includes multiple concurrent streams is discussed further below with respect toFIG.3. An example of a block acknowledgement type that may be utilized for block acknowledgments for a multicast transmission that includes multiple concurrent streams is discussed further below with respect toFIG.4. Furthermore, an example frame format for a block acknowledgment request for a multicast transmission that includes multiple concurrent streams is discussed further below with respect toFIG.5, and a corresponding block acknowledgment frame format is discussed further below with respect toFIG.6. FIG.2illustrates an example electronic device102A that may be used in accordance with one or more implementations. Not all of the depicted components may be used in all implementations, however, and one or more implementations may include additional or different components than those shown in the figure. Variations in the arrangement and type of the components may be made without departing from the spirit or scope of the claims as set forth herein. Additional components, different components, or fewer components may be provided. In one or more implementations, one or more components of the example electronic device102A may be implemented by one or more the electronic devices102B-C, the wireless access point104, and/or the base station106. The electronic device102A may include, among other components, a host processor202, a memory204, and RF circuitry206. The RF circuitry206may include channel occupancy detection circuitry208. The host processor202, which may also be referred to as an application processor or a processor, may include suitable logic, circuitry, and/or code that enables processing data and/or controlling operations of the electronic device102A. In this regard, the host processor202may be enabled to provide control signals to various other components of the electronic device102A. The host processor202may also control transfers of data between various portions of the electronic device102A. Additionally, the host processor202may enable implementation of an operating system or otherwise execute code to manage operations of the electronic device102A. The memory204may include suitable logic, circuitry, and/or code that enable storage of various types of information such as received data, generated data, code, and/or configuration information. The memory204may include, for example, random access memory (RAM), read-only memory (ROM), flash, and/or magnetic storage. The RF circuitry206may include suitable logic circuitry and/or code that may be operable to transmit and receive one or more types of wireless signals, such as WiFi signals, cellular signals, and the like. For example, the RF circuitry206may include an RF front end, a baseband processor, and/or one or more other components that facilitate wireless communications. In one or more implementations, one or more of the host processor202, the memory204, the RF circuitry206, and/or one or more portions thereof, may be implemented in software (e.g., subroutines and code), hardware (e.g., an ASIC, an FPGA, a PLD, a controller, a state machine, gated logic, discrete hardware components, or any other suitable devices) and/or a combination of both. FIG.3illustrates a flow diagram of an example process300of utilizing block acknowledgments for a multicast transmission that includes multiple concurrent streams in accordance with one or more implementations. For explanatory purposes, the process300is primarily described herein with reference to the electronic device102A ofFIG.1. However, the process300is not limited to the electronic device102A ofFIG.1, and one or more blocks (or operations) of the process300may be performed by one or more components or chips of the electronic device102A. The electronic device102A is also presented as an exemplary device and the operations described herein may be performed by any suitable device, such as one or more of the electronic devices102B-C, the wireless access point104, and/or the base station106. Further for explanatory purposes, the blocks of the process300are described herein as occurring in serial, or linearly. However, multiple blocks of the process300may occur in parallel. In addition, the blocks of the process300need not be performed in the order shown and/or one or more blocks of the process300need not be performed and/or can be replaced by other operations. The process300may be initiated when the electronic device102A transmits a block acknowledgment request for a multicast transmission that includes multiple concurrent streams (102), such as the block acknowledgment request discussed further below with respect toFIG.5. For example, one or more other electronic devices may have registered for a multicast transmission from the electronic device102A, such as by registering for a particular multicast address and/or GCR address. The electronic device102A may use the multicast registrations to populate a data structure, such as a table or any other data structure, that is used to track which of the registered electronic devices have acknowledged which multicast frames. For example, the electronic device102A may identify multicast frames to be transmitted that include multiple different streams (or traffic identifiers), and may then send the block acknowledgment request in advance of the corresponding multicast transmission. The block acknowledgment request may identify a respective set (or range) of frames (e.g., a starting sequence number and an ending sequence number) to be transmitted for each respective stream of the corresponding multicast transmission. The transmitted block acknowledgment request may be received by one or more of the electronic devices that registered for the multicast transmission. In one or more implementations, multiple block acknowledgment requests may be transmitted for a given multicast transmission. The electronic device102A then transmits the multicast transmission that includes multiple concurrent streams (304). For example, the electronic device102A may transmit multiple multicast frames using the corresponding multicast address, such as by setting the destination address of the frames to the multicast address. One or more of the multicast frames may be associated with one or more different streams, such as streams having a different traffic identifier (or a different class of traffic). One or more of the registered electronic devices may receive one or more of the multicast frames and may transmit a corresponding block acknowledgment, such as the block acknowledgment discussed further below with respect toFIG.6. The electronic device102A may receive one or more block acknowledgments from the one or more registered electronic devices and may update the corresponding data structure accordingly (306). If one or more of the registered electronic devices did not receive a particular multicast frame for a particular traffic identifier, the electronic device102A may, for example, retransmit the multicast frame for the particular traffic identifier, such as via a unicast transmission and/or via a multicast transmission. In one or more implementations, a block acknowledgment from a registered device may indicate, for each stream, which frames were received by the device and/or which frames were not received by the device. For example, the frames may include sequence numbers from which the electronic device can determine whether one or more frames were not received. Thus, conversely, an electronic device registered for a multicast transmission may receive, from a transmitting electronic device, a block acknowledgement request frame for the multicast transmission that indicates the different streams to be included in at least a portion of the multicast transmission, as well as a set of frames to be transmitted for each stream. The electronic device may then receive one or more (or none) of the set of frames for each stream, and may subsequently generate and transmit a block acknowledgment for the multicast transmission which indicates whether one or more frames of each stream was received by the electronic device. The transmitting electronic device may receive the block acknowledgment and retransmit any frames that were not received. FIG.4illustrates an example block acknowledgment type table400in accordance with one or more implementations. As shown in the table400, a block acknowledgment request/block acknowledgment type identifier of 7 may be used to identify a block acknowledgment request/block acknowledgement for a multicast transmission that includes multiple concurrent streams. However, in one or more implementations, any of the reserved identifiers, such as 4, 5, 8, 9, or 12-15 may be used and/or any existing identifier may be repurposed. As is discussed further below with respect toFIGS.5and6, the block acknowledgement identifier may be included in block acknowledgement requests and/or block acknowledgments. FIG.5illustrates an example block acknowledgment request frame format in accordance with one or more implementations. Not all of the depicted frame components may be used in all implementations, however, and one or more implementations may include additional or different frame components than those shown in the figure. Variations in the arrangement and type of the frame components may be made without departing from the spirit or scope of the claims as set forth herein. Additional frame components, different frame components, or fewer frame components may be provided. As shown inFIG.5, a block acknowledgment request frame500may include a control section520and an information section530, and the information section530may include one or more session info sections540. The control section520may include a type field set to, for example 7 (or any pre-determined value), and a TID info field that indicates the number of traffic identifiers in the multicast session (e.g., indicated by the number of TIDs minus 1). The information section530may include the GCR (or multicast) address and the one or more session info sections540. A session info section540may include a traffic (e.g., stream) identifier, a starting sequence number, and a maximum sequence number. The sequence numbers may correspond to the packet (or frame) sequence numbers for which the block acknowledgement is being requested for that particular traffic identifier, such as the starting, or first sequence number, and the maximum, or last sequence number. Thus, the difference between the maximum sequence number and the starting sequence number may indicate the number of frames to be transmitted for the given traffic identifier. Thus, an electronic device may generate and transmit a block acknowledgment request frame for subsequent concurrent multicast transmissions across multiple different traffic identifiers, where the block acknowledgment request frame includes a respective session info section540corresponding to each respective traffic identifier of each multicast transmission. A respective session info section540for a given traffic identifier may indicate the starting sequence number and the maximum sequence number for the corresponding subsequent multicast transmission. In this manner, an electronic device receiving the block acknowledgment request frame can determine which (if any) frames for each multicast transmission were not received, such as any frames that were not received having a sequence number between the starting sequence number and the maximum sequence number indicated in the bar session info section540for the corresponding traffic identifier. FIG.6illustrates an example block acknowledgment frame format in accordance with one or more implementations. Not all of the depicted frame components may be used in all implementations, however, and one or more implementations may include additional or different frame components than those shown in the figure. Variations in the arrangement and type of the frame components may be made without departing from the spirit or scope of the claims as set forth herein. Additional frame components, different frame components, or fewer frame components may be provided. As shown inFIG.6, a block acknowledgment frame600may include a control section and an information section620, and the information section620may include one or more session info sections630. In one or more implementations, a block acknowledgment frame600generated by an electronic device may correspond to a block acknowledgment request frame500received by the electronic device. The information section620may include a GCR (e.g., multicast) address corresponding to the block acknowledgment, and one or more session info sections630. A session info section630may include a traffic (stream) identifier, a starting sequence number, and a bitmap. The starting sequence number may correspond to the sequence number of the first packet for the traffic identifier for the block acknowledgment, and the bitmap may include a bit set to, for example, 0 or 1 to indicate whether a corresponding packet was received. For example, the first bit in the bitmap may correspond to the packet with the indicated starting sequence number and each subsequent bit may correspond to each subsequent sequence numbered packet. FIG.7illustrates an electronic system700with which one or more implementations of the subject technology may be implemented. The electronic system700can be, and/or can be a part of, one or more of the electronic devices102A-C, the wireless access point104, and/or the base station106shown inFIG.1. The electronic system700may include various types of computer readable media and interfaces for various other types of computer readable media. The electronic system700includes a bus708, one or more processing unit(s)712, a system memory704(and/or buffer), a ROM710, a permanent storage device702, an input device interface714, an output device interface706, and one or more network interfaces716, or subsets and variations thereof. The bus708collectively represents all system, peripheral, and chipset buses that communicatively connect the numerous internal devices of the electronic system700. In one or more implementations, the bus708communicatively connects the one or more processing unit(s)712with the ROM710, the system memory704, and the permanent storage device702. From these various memory units, the one or more processing unit(s)712retrieves instructions to execute and data to process in order to execute the processes of the subject disclosure. The one or more processing unit(s)712can be a single processor or a multi-core processor in different implementations. The ROM710stores static data and instructions that are needed by the one or more processing unit(s)712and other modules of the electronic system700. The permanent storage device702, on the other hand, may be a read-and-write memory device. The permanent storage device702may be a non-volatile memory unit that stores instructions and data even when the electronic system700is off. In one or more implementations, a mass-storage device (such as a magnetic or optical disk and its corresponding disk drive) may be used as the permanent storage device702. In one or more implementations, a removable storage device (such as a floppy disk, flash drive, and its corresponding disk drive) may be used as the permanent storage device702. Like the permanent storage device702, the system memory704may be a read-and-write memory device. However, unlike the permanent storage device702, the system memory704may be a volatile read-and-write memory, such as random access memory. The system memory704may store any of the instructions and data that one or more processing unit(s)712may need at runtime. In one or more implementations, the processes of the subject disclosure are stored in the system memory704, the permanent storage device702, and/or the ROM710. From these various memory units, the one or more processing unit(s)712retrieves instructions to execute and data to process in order to execute the processes of one or more implementations. The bus708also connects to the input and output device interfaces714and706. The input device interface714enables a user to communicate information and select commands to the electronic system700. Input devices that may be used with the input device interface714may include, for example, alphanumeric keyboards and pointing devices (also called “cursor control devices”). The output device interface706may enable, for example, the display of images generated by electronic system700. Output devices that may be used with the output device interface706may include, for example, printers and display devices, such as a liquid crystal display (LCD), a light emitting diode (LED) display, an organic light emitting diode (OLED) display, a flexible display, a flat panel display, a solid state display, a projector, or any other device for outputting information. One or more implementations may include devices that function as both input and output devices, such as a touchscreen. In these implementations, feedback provided to the user can be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. Finally, as shown inFIG.7, the bus708also couples the electronic system700to one or more networks and/or to one or more network nodes, through the one or more network interface(s)716. In this manner, the electronic system700can be a part of a network of computers (such as a LAN, a wide area network (“WAN”), or an Intranet, or a network of networks, such as the Internet. Any or all components of the electronic system700can be used in conjunction with the subject disclosure. As described above, an aspect of the present technology may be the gathering and use of data available from specific and legitimate sources to improve the present technology. The present disclosure contemplates that in some instances, this gathered data may include personal information data that uniquely identifies or can be used to identify a specific person. Such personal information data can include demographic data, location-based data, online identifiers, telephone numbers, email addresses, home addresses, data or records relating to a user's health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, or any other personal information. The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. For instance, health and fitness data may be used, in accordance with the user's preferences to provide insights into their general wellness, or may be used as positive feedback to individuals using technology to pursue wellness goals. The present disclosure contemplates that those entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities would be expected to implement and consistently apply privacy practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. Such information regarding the use of personal data should be prominently and easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate uses only. Further, such collection/sharing should occur only after receiving the consent of the users or other legitimate basis specified in applicable law. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations which may serve to impose a higher standard. For instance, in the US, collection of or access to certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user may be notified upon downloading an app that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app. Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user's privacy. De-identification may be facilitated, when appropriate, by removing identifiers, controlling the amount or specificity of data stored (e.g., collecting location data at city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and/or other methods such as differential privacy. Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. Implementations within the scope of the present disclosure can be partially or entirely realized using a tangible computer-readable storage medium (or multiple tangible computer-readable storage media of one or more types) encoding one or more instructions. The tangible computer-readable storage medium also can be non-transitory in nature. The computer-readable storage medium can be any storage medium that can be read, written, or otherwise accessed by a general purpose or special purpose computing device, including any processing electronics and/or processing circuitry capable of executing instructions. For example, without limitation, the computer-readable medium can include any volatile semiconductor memory, such as RAM, DRAM, SRAM, T-RAM, Z-RAM, and TTRAM. The computer-readable medium also can include any non-volatile semiconductor memory, such as ROM, PROM, EPROM, EEPROM, NVRAM, flash, nvSRAM, FeRAM, FeTRAM, MRAM, PRAM, CBRAM, SONOS, RRAM, NRAM, racetrack memory, FJG, and Millipede memory. Further, the computer-readable storage medium can include any non-semiconductor memory, such as optical disk storage, magnetic disk storage, magnetic tape, other magnetic storage devices, or any other medium capable of storing one or more instructions. In one or more implementations, the tangible computer-readable storage medium can be directly coupled to a computing device, while in other implementations, the tangible computer-readable storage medium can be indirectly coupled to a computing device, e.g., via one or more wired connections, one or more wireless connections, or any combination thereof. Instructions can be directly executable or can be used to develop executable instructions. For example, instructions can be realized as executable or non-executable machine code or as instructions in a high-level language that can be compiled to produce executable or non-executable machine code. Further, instructions also can be realized as or can include data. Computer-executable instructions also can be organized in any format, including routines, subroutines, programs, data structures, objects, modules, applications, applets, functions, etc. As recognized by those of skill in the art, details including, but not limited to, the number, structure, sequence, and organization of instructions can vary significantly without varying the underlying logic, function, processing, and output. While the above discussion primarily refers to microprocessor or multi-core processors that execute software, one or more implementations are performed by one or more integrated circuits, such as ASICs or FPGAs. In one or more implementations, such integrated circuits execute instructions that are stored on the circuit itself. Those of skill in the art would appreciate that the various illustrative blocks, modules, elements, components, methods, and algorithms described herein may be implemented as electronic hardware, computer software, or combinations of both. To illustrate this interchangeability of hardware and software, various illustrative blocks, modules, elements, components, methods, and algorithms have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application. Various components and blocks may be arranged differently (e.g., arranged in a different order, or partitioned in a different way) all without departing from the scope of the subject technology. It is understood that any specific order or hierarchy of blocks in the processes disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes may be rearranged, or that all illustrated blocks be performed. Any of the blocks may be performed simultaneously. In one or more implementations, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. As used in this specification and any claims of this application, the terms “base station”, “receiver”, “computer”, “server”, “processor”, and “memory” all refer to electronic or other technological devices. These terms exclude people or groups of people. For the purposes of the specification, the terms “display” or “displaying” means displaying on an electronic device. As used herein, the phrase “at least one of” preceding a series of items, with the term “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase “at least one of” does not require selection of at least one of each item listed; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C. The predicate words “configured to”, “operable to”, and “programmed to” do not imply any particular tangible or intangible modification of a subject, but, rather, are intended to be used interchangeably. In one or more implementations, a processor configured to monitor and control an operation or a component may also mean the processor being programmed to monitor and control the operation or the processor being operable to monitor and control the operation. Likewise, a processor configured to execute code can be construed as a processor programmed to execute code or operable to execute code. Phrases such as an aspect, the aspect, another aspect, some aspects, one or more aspects, an implementation, the implementation, another implementation, some implementations, one or more implementations, an embodiment, the embodiment, another embodiment, some implementations, one or more implementations, a configuration, the configuration, another configuration, some configurations, one or more configurations, the subject technology, the disclosure, the present disclosure, other variations thereof and alike are for convenience and do not imply that a disclosure relating to such phrase(s) is essential to the subject technology or that such disclosure applies to all configurations of the subject technology. A disclosure relating to such phrase(s) may apply to all configurations, or one or more configurations. A disclosure relating to such phrase(s) may provide one or more examples. A phrase such as an aspect or some aspects may refer to one or more aspects and vice versa, and this applies similarly to other foregoing phrases. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration”. Any embodiment described herein as “exemplary” or as an “example” is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, to the extent that the term “include”, “have”, or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for”. The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the subject disclosure. | 42,002 |
11943055 | MODE FOR CARRYING OUT THE INVENTION The following description will explain embodiments of the technology disclosed herein in detail with reference to the drawings. Example 1 A. System Configuration FIG.1shows a configuration example of a communication system to which the technology disclosed herein can be applied. In the figure, lines between communication devices are shown with broken lines. A communication device includes base stations (microcell base stations, small cell base stations), a control entity, a gateway device, and the like. It should be noted that a line mentioned here means a logical connection and is not necessarily directly connected physically. The communication area provided by the communication system is configured with “cells” where a plurality of base stations respectively provides services. InFIG.1, a cell is drawn as an ellipse. One base station may provide a plurality of cells. Examples of a base station include a macro cell base station that provides service in a macro cell area, and a small cell base station that provides service in a small cell area. A small cell area is basically arranged to overlap a macro cell area. However, a small cell area may exist partially or completely outside a macro cell area. A group (cluster) may be configured with a plurality of small cell base stations. Furthermore, a base station having a role of a cluster head may be provided in a cluster. A macro cell and a small cell may be characterized by a radio resource to be used. For example, a macro cell and a small cell may use the same frequency resource F1or the same time resource T1. In this way, it is possible to improve the usage efficiency of a radio resource as an entire communication system. On the other hand, a macro cell may use a frequency resource F1or a time resource T1, while a small cell may use a frequency resource F2or a time resource T2. In this way, it is possible to avoid interference between a macro cell and a small cell. Moreover, the frequency resources F1and F2or the time resources T1and T2may be used by both a macro cell and a small cell. The idea is especially equivalent to carrier aggregation (CA) when applied to a frequency resource. Base stations can communicate with each other via a backhaul, and mainly implement exchange of control information. The topology of the backhaul between base stations may be mesh type, star type, ring type, or another type. Furthermore, the backhaul may connect the base station and the core network via an external network. The backhaul may be wired or wireless. The backhaul may employ, for example, exchange of information using a protocol of an X2 interface or an S1 interface. Furthermore, the base station also has a backhaul to be connected with a core network of the communication system. As illustrated, the communication system may be connected with the core network via connection with the control entity. The control entity may also be regarded as one of the elements of the core network. Furthermore, a base station may be connected with the core network not via the control entity but via an external network. For example, a communication system is connected with an external network via a femtocell base station device or a Home eNodeB (HeNB) device that can be installed indoors or at home. B. Procedure of FEC and HARQ In the communication system according to the present example, it is assumed that forward error correction (FEC) and HARQ are combined in a physical layer (Layer 1), for example, in the process of in-cell communication. FIG.2shows a functional configuration example of a signal processing unit on the transmitting side in a communication system according to the present embodiment. Furthermore,FIG.3shows a functional configuration example of a signal processing unit on the receiving side in a communication system according to the present embodiment. In the present embodiment, a plurality of forward error correction (FEC) codes is applied to the information sequence to be transmitted/received. On the transmitting side, a first FEC coding processing unit202is inserted between a first transmission processing unit201and a second transmission processing unit203, and a second FEC coding processing unit204is inserted between the second transmission processing unit203and a third transmission processing unit205as shown inFIG.2. Furthermore, on the receiving side, a second FEC decoding processing unit302is inserted between a first receiving unit301and a second receiving unit303, and a first FEC decoding processing unit304is inserted between a second reception processing unit303and a third reception processing unit305as shown inFIG.3. The first FEC decoding processing in the first FEC decoding processing unit304is decoding processing corresponding to the first FEC coding processing in the first FEC coding unit202on the transmitting side. Furthermore, the second FEC decoding processing in the second FEC decoding processing unit302is decoding processing corresponding to the second FEC coding processing in the second FEC coding unit204on the transmitting side. The types of the first FEC are shown in Table 1 below, and the types of the second FEC are shown in Table 2 below. TABLE 1Example of first FECcodeErasure codeRateless codeFountain codeTornade codeLT codeRaptor codeRaptor Q codeLDPC codeBCH codeRS codeXOR code TABLE 2Example of second FEC codeConvolutional codeTurbo codeLDPC codePolar code It is desirable that the first FEC is an FEC method included in categories such as erasure codes, rateless codes, and fountain codes, or an FEC method of coding a plurality of bit sequences by linear synthesis or XOR synthesis. Furthermore, it is desirable that the second FEC is an FEC method included in categories such as convolutional codes, turbo codes, low density parity check (LDPC) codes, and polar codes. As described later, processing of the first FEC coding and decoding proceeds with predetermined bit blocks (which will also be hereinafter referred to as “blocks” in the present specification) as a unit in the present embodiment. Table 3 below shows the input/output correspondence between blocks on the transmitting side and the receiving side. TABLE 3Example to be citedTransmitting sideReceiving sideespeciallyInformationInformationTransport Block, PSDUsequence fromsequence to upper(Physical Layerupper layerlayerService Data Unit),PPDU (Physical LayerProtocol Data Unit)First FEC codingFirst FECInformation sequenceinputdecoding outputhaving CRC addedthereto, informationsequence havingpadding bit addedtheretoFirst FEC codingFirst FECCode Block, Codedoutputdecoding inputBlock, Unit ofSecond FECdepuncturing indecoding outputpresent embodiment(case wherepuncturing anddepuncturing arenot performed)Second FECSecond FECCode Block, Codedcoding inputdecoding outputBlockSecond FECSecond FECCodewordcoding outputdecoding input FIGS.4and5illustrate the procedures of FEC and HARQ in a communication system according to the present embodiment. The figures show a procedure in which FEC and HARQ are implemented by the base station device as the transmitting side and the terminal device connected to the cell of the base station device as the receiving side in the process of downlink communication. First, the terminal device notifies the base station device of a cell connected with the terminal device itself of information regarding the terminal capability of the terminal device itself (SEQ401). This capability information also includes information regarding the capability of the first FEC and the capability of the second FEC. The notification of information regarding the terminal capability is given during the initial access procedure or after the initial access procedure. At least any one of a random access channel (PRACH: Physical Random Access Channel), an uplink control channel (PUCCH: Physical Uplink Control Channel), or an uplink shared channel (PUSCH: Physical Uplink Shared Channel) is used as a physical channel for notification. The base station device notifies the terminal device connected with a cell managed by the base station device itself of quasi-static control information including information regarding the first FEC and the second FEC (SEQ451). This quasi-static control information may be cell-specific control information. The notification of this control information is given during the initial access procedure or after the initial access procedure. Furthermore, notification of this control information may be given as a part of the radio resource control (RRC) procedure such as RRC Signaling or RRC Configuration. Furthermore, notification of this control information may be periodically given from the base station device to the terminal device. At least any one of a broadcast channel (PBCH: Physical Broadcast Channel), a downlink control channel (PDCCH: Physical Downlink Control Channel, EPDCCH: Enhanced PDCCH), or a downlink shared channel (PDSCH: Physical Downlink Shared Channel) is used as a physical channel for notification of this control information. The terminal device implements quasi-static setting of FEC of the terminal device itself on the basis of the quasi-static control information regarding FEC, notification of which has been given from the base station device (SEQ402). Thereafter, in a case where downlink communication occurs specifically from the base station device to the terminal device (for example, a case where the terminal device requests data download (pull) or a case where push data to the terminal device occurs, etc.), notification of control information (dynamic control information) such as a radio resource used for downlink communication is given from the base station device to the terminal device (SEQ452). This dynamic control information may be terminal-specific (user equipment (UE)-specific) or terminal group-specific (UE-group-specific) control information. The terminal group mentioned here corresponds to, for example, a group of one or more terminal devices to be transmitted in a case where downlink communication is multicast or broadcast. Furthermore, the dynamic control information mentioned here includes a frequency resource (e.g., a resource block, a subcarrier, a subcarrier group, etc.) that allocates downlink communication to the target terminal device (or terminal group), a time resource (e.g., a subframe, a slot, a mini-slot, a symbol, etc.), a spatial resource (e.g., an antenna, an antenna port, a spatial layer, a spatial stream, etc.), a non-orthogonal resource (a power resource, an interleave pattern) of non-orthogonal multiple access (NOMA), multiuser superposition transmission (MUST), interleave division multiple access (IDMA), and code division multiple access (CDMA), a modulation order, information regarding the code rate of the second FEC (MCS: Modulation and Coding Set), information regarding the coding method and the code rate of the first FEC, information regarding the code rate of the second FEC, setting regarding ARQ/HARQ (new data indication (NDI)), redundancy version (RV), etc.), and the like. The terminal device makes setting to prepare for appropriate reception of downlink communication according to the dynamic control information received from the base station device (SEQ403). Thereafter, the base station device implements the first FEC coding (SEQ453), the second FEC coding (SEQ454), and modulation processing for data of downlink communication to the terminal device so as to match the control information, notification of which has been given to the terminal device. Then, the base station device transmits the coded and modulated data as a radio signal to the terminal device (SEQ455). The terminal device implements demodulation and decoding processing including the second FEC decoding (SEQ404) and the first FEC decoding (SEQ405) of a radio signal from the base station device according to the above-described setting specified in the control information. Then, the terminal device implements processing related to ARQ or HARQ depending on whether data decoding has succeeded or failed (SEQ406), and returns ACK or NACK for downlink communication to the base station (SEQ407). In the example shown inFIG.4, since an error has occurred in the received data, the terminal device returns NACK for downlink communication to the base station device. It is desirable to change the setting of ARQ/HARQ processing depending on whether data decoding has succeeded or failed on the terminal device side (or receiving side). For example, in a case where decoding has failed on the receiving side, it is desirable that the decoding result or data in the process of decoding on the receiving side (soft decision value (soft information, soft decision information), log likelihood ratio (LLR), etc.) is stored in a memory in order to implement retransmission and synthesis of the next HARQ on the transmitting side. The base station device executes the processing to be implemented next, according to the ACK/NACK received from the terminal device (SEQ456). For example, in a case where the base station device receives the NACK notification from the terminal device, the base station device implements preparation for retransmission of ARQ/HARQ. Examples of this preparation for retransmission include RV selection, MCS selection, radio resource selection, and the like. Furthermore, in a case where the base station device receives ACK notification from the terminal device, it means that the target data has been transmitted/received without any problem, and therefore the processing shifts to communication of the next new data without performing the preparation for retransmission described above. The base station device shifts to retransmission or implementation of downlink communication of new data according to the processing of ARQ/HARQ corresponding to ACK or NACK received from the terminal device. Therefore, the base station device notifies the terminal device of control information (dynamic control information) such as a radio resource used for downlink communication again (SEQ457). Then, the terminal device makes setting to prepare for appropriate reception for downlink communication according to the dynamic control information received from the base station device (SEQ408). The base station device implements the first FEC coding (SEQ458), the second FEC coding (SEQ459), and modulation processing for the data of downlink communication to the terminal device so as to match the control information, notification of which has been given to the terminal device. Then, the base station device transmits (retransmits in the example shown inFIG.5) the coded and modulated data as a radio signal to the terminal device (SEQ460). The terminal device implements demodulation and decoding processing including the second FEC decoding (SEQ409) and the first FEC decoding (SEQ410) of a radio signal from the base station device according to the above-described setting specified in the control information. Then, the terminal device implements processing related to ARQ or HARQ (SEQ411) depending on whether decoding of retransmitted data has succeeded or failed, and returns ACK or NACK for downlink communication to the base station (SEQ412). In the example shown inFIG.4, since no error has occurred in the received data at the time of retransmission, the terminal device returns ACK for downlink communication to the base station device. The base station device executes the processing to be implemented next, according to ACK/NACK received from the terminal device (SEQ461). Here, since the base station device receives the ACK notification from the terminal device, the base station device shifts to communication of the next new data. The base station device shifts to retransmission or implementation of downlink communication of new data, according to the processing of ARQ or HARQ corresponding to ACK and NACK received from the terminal device. Therefore, the base station device notifies the target terminal device of the dynamic control information again, and repeatedly executes the downlink communication according to the setting in a manner similar to that described above. C. Details of Transmission Processing and Coding Processing Then, the details of the transmission processing in a communication system according to the present embodiment will be described. FIG.6shows a detailed processing procedure of the transmission processing in the form of a flowchart. The illustrated processing procedure shall be implemented by the base station device at the time of downlink communication and implemented by the terminal device at the time of uplink communication. The transmitting side communication device first receives an information sequence to be transmitted/received from the upper layer (step S601). The process is implemented by, for example, the first transmission processing unit201. A transport block, a media access control (MAC) physical data unit (MPDU), a physical layer service data unit (PSDU), a MAC service data unit (MSDU), and the like can be applicable as the information sequence from the upper layer. Next, the transmitting side communication device implements division of an information sequence received from an upper layer as first transmission processing (step S602). The process is implemented by, for example, the first transmission processing unit201. As a procedure for dividing an information sequence, a cyclic redundancy check (CRC) bit sequence is first added to the information sequence, and the information sequence having CRC added thereto is divided into a predetermined number of blocks. Note that another error detection code sequence having an error correction capability may be added instead of a CRC bit sequence. Here, it is assumed that an information sequence is divided into L pieces, and the data size of the l-th block is Dlbit. The data sizes of the blocks obtained by division may be different or may be equal. Although the processing procedure shown inFIG.6includes a process of switching whether to implement the first FEC coding or not (step S604described later), it is desirable that the data sizes of the blocks are equal in a case where the first FEC coding is to be implemented. In a case where the data sizes of the blocks are equal, a padding bit is added to each block so that the data sizes become equal even if a fraction occurs (step S603). The process is implemented by, for example, the first transmission processing unit201. However, a method of adding padding bits to blocks may be a method of adding the padding bits to the respective blocks substantially evenly, or a method of collectively adding the padding bits to a specific block (e.g., the L-th block). In a case where the data sizes of the blocks are to be equal to D bit, (D−Dl−DCRC) bit will be added to the l-th block. In a case where the data sizes of the blocks are already equal before the padding bits are added, it is not necessary to add the padding bits. After a padding bit is added, the CRC bit sequence (data size DCRC) may be added to each block (step S605) before the first FEC coding (step S606). FIG.7shows how an information sequence (obtained after adding CRC) is divided and a padding bit and CRC are added to each block in step S603described above. As described above, the original information sequence and the CRC bit sequence are added, so that the data size becomes Dubit. Then, the information sequence having a CRC bit sequence added thereto is divided into L blocks #1 to #L. Moreover, padding bits are added to the blocks #1 to #L substantially evenly, and the data size of each block becomes DL. Thereafter, a CRC bit sequence is further added to each of the blocks #1 to #7. Furthermore, as another example of the first transmission processing, the content of the first transmission processing of a case where the first FEC is implemented and the content of the first transmission processing of a case where the first FEC is not implemented may be completely separated with other procedures. For example, whether block division is performed or not, the method of determining the data of a block to be divided, whether there is a padding bit or not, or the like may be changed in relation to whether the first FEC is implemented or not. The procedure of the transmission processing will be described continuously with reference toFIG.6again. After the first transmission processing (steps S602to S603), the first FEC coding is implemented. In the processing procedure shown inFIG.6, whether to implement the first FEC coding or not is first determined (step S604). Since overhead due to implementation of the first FEC may occur, it is not always a good idea to always implement the first FEC. Therefore, in the processing procedure shown inFIG.6, a dynamic response according to the requirement condition of quality of service is realized by switching implementation of the first FEC according to the application. FIG.8shows a detailed processing procedure for determining whether to implement the first FEC coding, which is implemented in step S604in the flowchart shown inFIG.6, or not in the form of a flowchart. This determination processing is implemented by, for example, the first transmission processing unit201or the first FEC coding unit202. When the transmitting side communication device starts determination of the condition for implementing the first FEC (step S801), whether the receiving side communication device supports the first FEC or not is first checked (step S802). In a case where the transmitting side communication device transmits data to a plurality of communication devices, whether all the receiving side communication devices support the first FEC or not is checked. In a case where any one of the receiving side communication devices does not support the first FEC (No in step S802), the transmitting side communication device determines that the first FEC is not to be implemented (step S808) and terminates this processing. In a case where all receiving side communication devices support the first FEC (Yes in step S802), the transmitting side communication device then checks whether the application of the target information sequence is broadcast or multicast or not (step S803). In a case where the application of the target information sequence is broadcast or multicast (Yes in step S803), the transmitting side communication device determines that the first FEC is to be implemented (step S804) and terminates this processing. On the other hand, in a case where the application of the target information sequence is neither broadcast nor multicast (No in step S803), the transmitting side communication device then checks whether the application (QCI: Quality of Service (QoS) Class Indicator) of the target information sequence requires real time property (or low latency) or not (step S805). In a case where the application (QCI) of the target information sequence requires real time property (low latency) (Yes in step S805), the transmitting side communication device then checks whether the data size of the target information sequence is larger than a predetermined threshold or not (step S806). Furthermore, in a case where the application (QCI) of the target information sequence does not require real time property (low latency) (No in step S805), the transmitting side communication device further checks whether the application (QCI) of the target information sequence requires high reliability (low error rate) or not (step S807). In a case where the application (QCI) of the target information sequence requires high reliability (low error rate) (Yes in step S807), the transmitting side communication device then checks whether the data size of the target information sequence is larger than a predetermined threshold or not (step S806). In a case where the data size of the target information sequence is larger than the predetermined threshold (Yes in step S806), the transmitting side communication device determines that the first FEC is to be implemented (step S804) and terminates this processing. Furthermore, in a case where the data size of the target information sequence is equal to or smaller than the predetermined threshold (No in step S806) or in a case where the application (QCI) of the target information sequence does not require high reliability (low error rate) (No in step S807), the transmitting side communication device determines that the first FEC is not to be implemented (step S808) and terminates this processing. Furthermore,FIG.9shows another example of a processing procedure for determining whether to implement the first FEC coding, which is implemented in step S604in the flowchart shown inFIG.6, or not in the form of a flowchart. This determination processing is implemented by, for example, the first transmission processing unit201or the first FEC coding unit202. When the transmitting side communication device starts determining the condition for implementing the first FEC (step S901), whether the receiving side communication device supports the first FEC or not is first checked (step S902). In a case where the transmitting side communication device transmits data to a plurality of communication devices, whether all the receiving side communication devices support the first FEC or not is checked. In a case where any one of the receiving side communication devices does not support the first FEC (No in step S902), the transmitting side communication device determines that the first FEC is not to be implemented (step S908) and terminates this processing. In a case where all receiving side communication devices support the first FEC (Yes in step S902), the transmitting side communication device then checks whether the data size of the target information sequence is larger than a predetermined threshold or not (step S903). In a case where the data size of the target information sequence is equal to or smaller than the predetermined threshold (No in step S903), the transmitting side communication device determines that the first FEC is not to be implemented (step S908) and terminates this processing. On the other hand, in a case where the data size of the target information sequence is larger than the predetermined threshold (Yes in step S903), the transmitting side communication device then checks whether the application of the target information sequence is broadcast or multicast or not (step S904). In a case where the application of the target information sequence is broadcast or multicast (Yes in step S904), the transmitting side communication device determines that the first FEC is to be implemented (step S905) and terminates this processing. Furthermore, in a case where the application of the target information sequence is neither broadcast nor multicast (No in step S904), the transmitting side communication device then further checks whether the application (QCI) of the target information sequence requires real time property (or low latency) or not (step S906). In a case where the application (QCI) of the target information sequence requires real time property (low latency) (Yes in step S906), the transmitting side communication device determines that the first FEC is to be implemented (step S905) and terminates this processing. In a case where the application (QCI) of the target information sequence does not require real time property (low latency) (No in step S906), the transmitting side communication device further checks whether the application (QCI) of the target information sequence requires high reliability (low error rate) or not (step S907). In a case where the application (QCI) of the target information sequence requires high reliability (low error rate) (Yes in step S907), the transmitting side communication device determines that the first FEC is to be implemented (step S905) and terminates this processing. In a case where the application (QCI) of the target information sequence does not require high reliability (low error rate) (No in step S907), the transmitting side communication device determines that the first FEC is not to be implemented (step S908) and terminates this processing. To summarize the processing procedures shown inFIGS.8and9, the transmitting side communication device determines whether to implement the first FEC coding or not in view of the following conditions (i) to (iii).(i) Status of receiving side communication device(ii) Application and requirement of target information sequence(iii) Status of target information sequence A condition of the status of the receiving side communication device is that the receiving side communication device supports the first FEC. In the case of broadcast or multicast, there will be a receiving side communication device that cannot decode the received information sequence if not “all” receiving side communication devices support the first FEC. Therefore, it is desirable not to implement the first FEC in a case where there is at least one receiving side communication device that does not support the first FEC. Regarding the application and requirement of the target information sequence, it is desirable to implement the first FEC in a case where the target application is broadcast or multicast, for example. In the case of broadcast or multicast, an error may occur only for the second FEC (implemented in the subsequent stage), and it is difficult to implement retransmission in that case. Accordingly, it becomes possible to improve the reliability of broadcast or multicast by increasing the error correction capability by the first FEC. Furthermore, it is also desirable to implement the first FEC in a case where the target application requires real time property (low latency) or high reliability (low error rate (bit error rate (BER), block error rate (BLER), packet error rate (PER), frame error rate (FER), etc.)). This is because the effect of reducing errors that cannot be removed by error correction of the second FEC alone or of reducing the delay due to retransmission control due to errors can be expected by implementing the first FEC. Regarding the status of the target information sequence, the first FEC shall be implemented in a case where the data size of the information sequence is larger than a predetermined size (the number of bits or bytes) (or equal to or larger than a predetermined size), for example. In a case where the size is smaller than a predetermined size, there is a concern that the effect of the first FEC, especially the erasure code, may become small, and therefore the influence of the demerits of the overhead required for the first FEC (coding time on the transmitting side, decoding time on the receiving side, notification of control information for the first FEC, etc.) becomes large, and it may be desirable to determine that the first FEC is not to be implemented. In the present embodiment, QCI can be considered as a reference and as a requirement condition for the application. The QCI is a parameter that is linked with each target information sequence, each application associated with a target information sequence, each session, or each bearer and is shown so as to achieve the quality of service (QoS) to be required in the process of transmitting and receiving the information sequence. Table 4 below shows the elements of QCI and the conditions for determining whether the first FEC is implemented or not for each element. TABLE 4Condition forimplementing firstElement of QCISpecific contentFECResource TypeGBR or Non-GBRImplementation incase where GBR isrequested (orimplement first FECalways)PriorityHigh, Medium, LowImplementation incase of High orMedium (orimplement first FECalways)ReliabilityTransport factor ofImplementation ininformationcase wheresequence (100% -reliability equalinformationto or higher thansequence error99.999% israte)requiredLatency (Real-time)Delay time forImplementation inpassing informationcase where delaysequence from layertime equal to or2 to layer 3shorter than 1Delay time ofmillisecond isEND-to-END (E2E)required In the present embodiment, it is desirable to determine whether the first FEC is implemented or not, especially for the requirements of reliability and latency (Real Time). Alternatively, in addition to reliability and latency, whether the first FEC is implemented or not may be determined for the resource type (guaranteed bit rate (GBR), non-GBR) or priority. Furthermore, in the present embodiment, the first FEC may be mapped to a bearer. For example, in a certain bearer, the same first FEC coding method, code rate, block size, and the like shall be commonly used. In this way, it becomes possible to manage or handle the quality condition collectively with a bearer as a unit. The procedure of the transmission processing will be described continuously with reference toFIG.6again. In a case where it is determined in step S604that the first FEC is to be implemented, the transmitting side communication device adds CRC to each block obtained by dividing the target information sequence (seeFIG.7) (step S605), implements the first FEC using the blocks obtained by division (step S606), and adds CRC to each coded block (step S607). The first FEC coding processing is implemented by the first FEC coding unit202. The first FEC coding generates N coded blocks from L pre-coded blocks (blocks including padding bits, CRC, etc.).FIG.10illustrates how the first FEC coding is implemented for the information sequence divided into blocks (step S606) and CRC is added to each coded block (step S607). Here, it is desirable that N=L+P and P<L≤N are satisfied. Furthermore, it is desirable that the data size of a pre-coded block and the data size of a coded block are the same size (D bit inFIG.10). The code rate r of the first FEC is as expressed in the following equation (1). This code rate r may be predetermined depending on the FEC code adopted. [Math.1]r=LN=LL+P(1) The encoder inFIG.10will be described in detail. The i-th bit bl) of the l-th pre-coded block is as expressed in the following equation (2). [Math. 2] bl(i)∈{0,1},(i=1, . . . ,D) (2) Then, a coded block is generated as expressed in the following equation (4), assuming that the n-th coded block (output of the n-th encoder #n) dnis as expressed in the following equation (3). [Math. 3] dn(i)∈{0,1},(i=1, . . . ,D) (3) [Math. 4] dn(i)=cn,1(i)bl(i)⊕cn,2(i)bl(i)⊕ . . . ⊕cn,L(i)bl(i) (4) However, cn,l(i), (i=1, . . . , D, n=1, . . . , L) in the above equation (4) is a weighting factor for the l-th pre-coded block of the n-th encoder #n (the l-th input to the n-th encoder #n). For example, the values that cn,l(i) can take are as expressed in the following equation (5). [Math. 5] cn,l(i)∈{0,1} (5) Furthermore, the operator (enclosed character of the symbol “+”) in the above equation (4) means the operation in an encoder. It is desirable that this operation is, for example, any one of XOR (addition of Mod 2), OR, or AND. Examples of XOR, OR, and AND operations are shown respectively in Tables 5, 6, and 7. TABLE 5Example of XOR operationaba ⊕ b000011101110 TABLE 6Example of OR operationaba ⊕ b000011101111 TABLE 7Example of AND operationaba ⊕ b000010100111 The procedure of the transmission processing will be described continuously with reference toFIG.6again. After first FEC is implemented in step S606and CRC is added to each coded block in step S607, puncturing of the coded block is implemented (step S608). The processes according to steps S607and S608are implemented by, for example, the second transmission processing unit203. In this embodiment, block-based puncturing is applied. Bitwise puncturing already exists. On the other hand, in the present embodiment, since a block becomes the correction unit of the first FEC in consideration of the coding method adopted to the first FEC coding, it can be said that it is desirable to implement puncturing with a block as a unit as well. By puncturing, some of coded blocks obtained after first FEC coding are used to implement second FEC coding in the subsequent stage. It is assumed that K coded blocks of N coded blocks are transmitted as a general system (that is, (N-K) blocks are excluded from the transmission target by puncturing). Here, it is desirable that the value of K is a positive integer that satisfies the following equation (6). Furthermore, it is desirable that the value of K is equal to the number of second FEC encoders (i.e., the number of code blocks) in the subsequent stage (i.e., used in the second FEC coding processing implemented in step S609). [Math.6]K≥floor(N2)orK≥ceil(N2)(6) Specifically, in the present embodiment, it is desirable to select and puncture a block by any one of the following equations (7) to (9). (a) Select and puncture j-th block, j+floor(NN-K) -th block, j+2floor(NN-K) -th block, . . . , j+(N-K-1)floor(NN-K) -th block (or select and puncture j+k·floor(NN-K) -th block. Here, k is an integer within the range of 0≤k≤N−K−1. Here, j is an integer within the range of 1≤j≤N-(N-K-1)floor(NK). The value of j may be shared by the transmitting side and the receiving side. Furthermore, cell( ) (round up) or round( ) (rounding) may be used instead of floor( ) (round down) here. (b) Select and puncture the (j+N−K−1)-th blocks aligned in series from the j-th block. Here, j is an integer within the range of 1≤j≤K+1. The value of j may be shared by the transmitting side and the receiving side. (c) Select and puncture K blocks randomly on the transmitting side. Furthermore, the specific block to be punctured may be determined on the basis of whether it is the first transmission or retransmission. For example, the value of j described above is changed depending on the number of transmissions. In this case, for example, puncturing is implemented with j=t+toffset(however, toffsetis a fixed offset value) at the time of the t-th transmission. As yet another example, a block is reselected each retransmission time in a case where a puncturing block is randomly selected. FIG.11shows an example of puncturing a coded block. In the illustrated example, the blocks to be punctured are sequentially changed according to the number of transmission times. In the present embodiment, note that the rules of the method for selecting or determining a block to be punctured described above are known in advance for the transmitting side communication device and the receiving side communication device. Sharing this setting in advance can be realized by, for example, putting information regarding the rule in quasi-static control information or dynamic control information, or by making the setting as a fixed rule (pre-configuration) in advance. Moreover, in the case of retransmission, a coded block, transmission/reception of which has succeeded in the last time transmission/reception, may be preferentially punctured (in other words, not retransmitted). Furthermore, a coded block that has been punctured in the last time transmission/reception is not preferentially punctured. In any case, retransmission is implemented by a combination of different coded sequences for each transmission time. In this way, it is possible to improve the decoding performance by using the reception results up to the last time when decoding the first FEC. In a case where such a puncturing rule is applied, it is considered that there is no coded block, transmission/reception of which has succeeded, among transmission candidates with respect to the puncturing rule described above. That is, in a case where transmission/reception of Nsuccess,tcoded blocks of Ntblocks to be transmitted in the t-th transmission succeeds, (Nt− Nsuccess,t) coded blocks excluding the successful blocks are to be punctured in the (t+1)-th transmission (that is, the number Nt+1of blocks to be the target of the (t+1)-th transmission becomes Nt+1=Nt−Nsuccess,t). The procedure of the transmission processing will be described continuously with reference toFIG.6again. After puncturing is performed by the second transmission processing unit203in step S608, for example, the coded block is subjected to the second FEC coding (step S609). Accordingly, some of a plurality of coded sequences obtained after first FEC coding will be punctured, and the other coded sequences will be used for implementing second FEC coding. The second FEC coding is implemented by the second FEC coding unit204.FIG.12shows the flow of processing related to the second FEC coding. In the present embodiment, the second coding is implemented with a coded block as a unit. Therefore, the number Q of the encoders satisfies Q≥K. In particular, it is desirable that Q=K is satisfied. Furthermore, it is desirable to have a one-to-one mapping between a coded block obtained after puncturing and a second FEC encoder. By associating the second coding in this way, it becomes possible to immediately determine which block causes an error after the second FEC decoding at the time of decoding on the receiving side. For example, it is desirable that the relationship q=k is satisfied in a case where the k-th coded block obtained after puncturing is associated to be inputted to the q-th (second FEC) encoder. Alternatively, it is desirable that the relationship of q=(k+j) mod Q is satisfied. Note that the rule for mapping the coded block (obtained after puncturing) and the (second FEC) encoder described above shall be known in advance by the transmitting side communication device and the receiving side communication device in the present embodiment. To make this setting known in advance is realized by, for example, putting information regarding the rule into quasi-static control information or dynamic control information, or making setting in advance as a fixed rule (pre-configuration). As shown inFIGS.6and12, after the second FEC coding is implemented (step S609), rate matching processing is further implemented (step S610). In the rate matching processing, the code rate of the second FEC coding is adjusted. It is desirable that the code rate value adjusted by rate matching is specified in, for example, dynamic control information from the base station device and set on the basis thereof. Furthermore, it is desirable to use a circular buffer as a rate matching method. After the rate matching processing (step S610), a plurality of coded blocks is inputted to the coupler and concatenated (step S611). As a result of the concatenation, a coded information sequence is outputted. The coded information sequence corresponds to, for example, a codeword. By the rate matching processing described above, some of the coded blocks subjected to the second FEC coding are concatenated, so that the code rate is adjusted. Then, after a predetermined signal format is formed (step S612), the signal is transmitted (step S613). The processes of steps S610to S613are implemented by, for example, the third transmission processing unit205. D. Details of Reception Processing and Decoding Processing Then, the details of the decoding processing on the receiving side in a communication system according to the present embodiment will be described. FIG.13shows a detailed processing procedure of the reception processing in the form of a flowchart. The illustrated processing procedure shall be implemented by the terminal device at the time of downlink communication and implemented by the base station device at the time of uplink communication. After the receiving side communication device receives a signal transmitted from the transmitting side communication device (step S1301), the receiving side communication device generates the likelihood information of each bit of the coded information sequence (e.g., codeword) (step S1302). The likelihood information mentioned here may be a soft decision value, a log likelihood ratio, or the like. The processes of steps S1301and S1302are implemented by the first reception processing unit301. Next, the receiving side communication device divides the likelihood information of the coded sequence into blocks corresponding to the decoding units of the second FEC decoding in the subsequent stage (step S1303). Then, the receiving side communication device implements rate de-matching corresponding to rate matching on the transmitting side (step S610inFIG.6) to readjust the code rate adjusted on the transmitting side (step S1304). The processes of steps S1303and S1304are implemented by the first reception processing unit301. Here, in a case where retransmission by HARQ is performed for a soft decision value of each block of the signal received this time or a target block, the input of rate de-matching shall be a block obtained by synthesizing or coupling the reception result (soft decision value) of a target block of a signal received up to the last time and a soft decision value of the target block received this time. That is, rate de-matching is implemented for the target block in consideration of the past retransmissions. After implementing rate de-matching, the receiving side communication device implements second FEC decoding corresponding to the second FEC coding for each block (step S1305). The second FEC decoding processing is implemented by the second FEC decoding unit302. It is desirable to output both likelihood information obtained after decoding (soft decision value) and a hard decision value obtained after decoding (hard Information, hard decision information, for example, each bit (0 or 1), (−1 or 1), etc. of an information sequence) as the output of the decoder. When the second FEC decoding is completed, the receiving side communication device determines whether an error has occurred in each block after decoding or not (step S1306). This determination is implemented using the CRC bit sequence added on the transmitting side. Then, whether there is an error in each block or not is recorded (step S1307). The processes of steps S1306and S1307are implemented by the second reception processing unit303. The receiving side communication device further records the result itself of the second FEC decoding for each block, in addition to whether there is an error or not (step S1308). It is desirable to record both a soft decision value (likelihood information) and a hard decision value (0 or 1, or −1 or 1 for each bit) for bit for the contents of each block as the content to be recorded here. This is because it is used in the first FEC decoding in the subsequent stage in the reception processing according to the present embodiment, and it is used for synthesis or coupling in the rate de-matching described above when it becomes necessary to retransmit HARQ. The process of step S1308is implemented by the second reception processing unit303. The receiving side communication device implements depuncturing of each block on a block obtained after the second FEC decoding (step S1309), and synthesizes the blocks (step S1310). The processes of steps S1309and S1310are implemented by the second reception processing unit303. Examples of a method of synthesizing blocks include chase combining or incremental redundancy.FIG.14illustrates the flow of processing leading to division of the likelihood information of the coded information sequence, rate de-matching, the second FEC decoding, and depuncturing. Furthermore,FIG.15shows an example (case of L=4 and N=8) of depuncturing with a block as a unit. The receiving side communication device has a function of performing HARQ synthesis, and synthesizes a block obtained by dividing the received information sequence received this time and a block obtained by dividing the received information sequence received last time. Furthermore, in the process of the second FEC decoding in retransmission, the second FEC decoding is implemented only for a block in which an error has occurred in the second FEC decoding last time as can be seen fromFIG.15. In the depuncturing according to the present embodiment, block replacement or the like is implemented before input to the first FEC decoding in the subsequent stage. Specifically, the following replacements (a) to (c) are implemented according to the state of the block. (a) For a block that has no error as a result of the second FEC decoding, a sequence of the hard decision value (0 or 1, −1 or 1, etc.) of the block is used. Here, a block having no error as a result of second FEC decoding includes a block, decoding of which has succeeded before the last time transmission/reception, in addition to the decoding result at that time. The hard decision value of a block, transmission/reception of which has succeeded before the last time, may be recorded as a result in a memory or the like and then read therefrom. (b) In a case where an error occurs as a result of the second FEC decoding, a sequence of a soft decision value (likelihood information) of the result of the second FEC decoding shall be replaced with either a null sequence or a dummy sequence. Here, it is desirable that a dummy sequence is any one of a sequence in which all the blocks are zero, all blocks are +1, or all blocks are −1, −1 and +1 random numbers, 0 and 1 random numbers, or predetermined −1 and +1, or a sequence in which all blocks are predetermined 0 and +1. (c) A block that is punctured on the transmitting side is replaced with either a null block or a dummy block. The reception processing procedure will be described continuously with reference toFIG.13again. After implementing depuncturing, the receiving side communication device inputs each block to the decoder of the first FEC decoding to obtain a decoded block (step S1311). Accordingly, the first FEC decoding is implemented after depuncturing is performed for a sequence obtained after the second FEC decoding. The first FEC decoding processing is implemented by the first FEC decoding unit304. In the first FEC decoding, the first FEC decoding processing is implemented using a block in which no error has occurred in the second decoding last time, in addition to the block obtained after the second FEC decoding. Then, the receiving side communication device detects whether there is an error in the result of first FEC decoding or not by using the CRC bit sequence added on the transmitting side (step S1312). The process of step S1312is implemented by the third reception processing unit305. In a case where no error is detected in the result of the first FEC decoding (No in step S1313), the receiving side communication device passes the decoded information sequence to the upper layer even if an error is detected in the second FEC decoding (step S1316), returns ACK to the transmitting side communication device (step S1317), and terminates this processing. Accordingly, it can be said that reliability enhancement can be realized by introducing a plurality of FEC codes into a communication system. Furthermore, by introducing a plurality of FEC codes, latency lowering and reliability enhancement are realized while substantially preventing increase in the amount of data to be transmitted/received in the physical layer or reducing the amount of data to be transmitted/received in the physical layer even in a status where an error occurs in single FEC. On the other hand, in a case where an error is detected in the result of the first FEC decoding (Yes in step S1313), the receiving side communication device generates information regarding a block to be retransmitted from the record of the error for each block (step S1314), returns NACK to the transmitting side communication device (step S1315), and terminates this processing. Here, the contents of NACK shall include, for example, at least one of the fact that the target information sequence is incorrect, the block number (index) before the first FEC coding in which an error has occurred, or the block number (index) after the first FEC coding in which an error has occurred, in other words, information for specifying which of blocks obtained after second FEC decoding includes the error. FIG.16shows a processing procedure for determining whether to implement puncturing and interleaving in the upper layer on the transmitting side or not in the form of a flowchart. First, whether the upper layer FEC is implemented or not is checked (step S1601). In a case where the upper layer FEC is not implemented (No in step S1601), the information sequence is passed to the next process (step S1606) without implementing either upper layer depuncturing or interleaving, and this processing is terminated. On the other hand, in a case where upper layer FEC is implemented (Yes in step S1601), whether the condition for implementing upper layer puncturing is satisfied or not is then checked (step S1602). Then, in a case where the condition for implementing the upper layer puncturing is satisfied (Yes in step S1602), puncturing is implemented for the information sequence in the transmitting side upper layer (step S1603). Then, whether the condition for implementing upper layer interleaving is satisfied or not is checked (step S1604). Then, in a case where the condition for implementing the upper layer interleaving is satisfied (Yes in step S1604), interleaving is implemented for the information sequence in the transmitting side upper layer (step S1605). Then, the information sequence (obtained after the upper layer depuncturing is implemented) is passed to the next processing (step S1606), and this processing is terminated. Puncturing and interleaving of the upper layer is based on implementation of the first FEC coding. This is because decoding cannot be performed on the receiving side when puncturing is performed without the first FEC coding. Furthermore, it can be said that the interleaving has no effect (or the effect is low) in a case where the first FEC coding is not implemented. In a case where the first FEC coding is implemented and the condition for puncturing is satisfied (Yes in step S1602), puncturing is implemented in the upper layer (step S1603). Furthermore, in a case where the first FEC coding is implemented and the condition for interleaving is satisfied (Yes in step S1604), interleaving is implemented in the upper layer (step S1605). In the processing procedure shown inFIG.16, the determination of implementation of puncturing and interleaving is performed independently. Furthermore, the order of determination and implementation of puncturing and interleaving is arbitrary, and unlikeFIG.16, the determination of implementation of interleaving may be performed first, and the determination of implementation of puncturing may be performed later. FIG.17shows another example of a processing procedure for determining whether to implement puncturing and interleaving in the upper layer on the transmitting side or not in the form of a flowchart. First, whether the upper layer FEC is implemented or not is checked (step S1701). In a case where the upper layer FEC is not implemented (No in step S1701), the information sequence is passed to the next processing (step S1706) without implementing either upper layer depuncturing or interleaving, and this processing is terminated. On the other hand, in a case where upper layer FEC is implemented (Yes in step S1701), whether the condition for implementing upper layer puncturing (or interleaving) is satisfied or not is checked (step S1702). Here, in a case where the condition for implementing upper layer puncturing (or interleaving) is satisfied (Yes in step S1702), puncturing is implemented for the information sequence in the transmitting side upper layer (step S1703), and then interleaving is implemented (step S1704). Then, the information sequence (obtained after the upper layer depuncturing is implemented) is passed to the next process (step S1705), and this processing is terminated. Furthermore, in a case where the condition for implementing upper layer puncturing (or interleaving) is not satisfied (No in step S1702), neither puncturing nor interleaving is implemented for the information sequence in the transmitting side upper layer, the information sequence (obtained after the upper layer depuncturing is implemented) is passed to the next process (step S1705), and this processing is terminated. Although the determination of implementation of upper layer puncturing and interleaving is performed independently in the processing procedure shown inFIG.16, the determination of implementation of both upper layer puncturing and interleaving is performed in one processing step in the processing procedure shown inFIG.17. FIG.18shows a processing procedure for determining whether to implement upper layer puncturing or not in the form of a flowchart. When the transmitting side communication device starts determining the condition for implementing the upper layer puncturing (step S1801), the transmitting side communication device checks whether all the receiving side communication devices support the upper layer puncturing or not (step S1802). In a case where all the receiving side communication devices support the upper layer puncturing (Yes in step S1802), the transmitting side communication device implements upper layer puncturing (step S1803) and terminates this processing. On the other hand, in a case where any one of the receiving side communication devices does not support the upper layer puncturing (No in step S1802), the transmitting side communication device does not implement the upper layer puncturing (step S1804) and terminates this processing. Similarly to the processing of determining whether to implement the first FEC coding or not (seeFIGS.8and9), it is possible to implement the upper layer puncturing in a case where all the receiving side communication devices support the upper layer puncturing, including the case of broadcast or multicast applications. On the other hand, upper layer puncturing should not be implemented in a case where some of the receiving side communication devices do not support upper layer puncturing. Note that a processing procedure for determining whether to implement upper layer interleaving or not can be employed by replacing “puncturing” inFIG.18with “interleaving”. E. Measurement of the Performance of the First FEC and the Second FEC The receiving side communication device may implement measurement of the performance of the first FEC and the second FEC. This measurement result may be fed back to, for example, the transmitting side communication device and reflected in the setting of the first FEC and the second FEC (setting or selection of coding method, code rate, puncturing rate, etc.) in the process of implementation of the subsequent communication. The receiving side communication device may feed back the measurement result to the transmitting side communication device by using ACK or NACK. There is already a technology for measuring and feeding back the error rate (or reception quality) obtained after FEC decoding in a communication system that employs single FEC. On the other hand, the present embodiment differs from the prior art in that measurement of the performance is implemented for a plurality of FECs, that is, the first FEC and the second FEC. By implementing measurement of the performance of each FEC, it becomes possible to make setting of the FEC in more detail. Table 8 below summarizes the measurement items and units of measurement related to the performance of the first FEC and the second FEC. TABLE 8Measurement itemMeasurement unitError rate after FECMeasurement at each ofdecodingpoint after first FECdecoding and point aftersecond FEC decoding.MCS or CQI that can satisfyMeasurement at each ofpredetermined receptionpoint after first FECqualitydecoding and point aftersecond FEC decoding.Value of predeterminedreception quality may bedifferent between first FECand second FEC.ThroughputCommon measurementregardless of FEC (e.g.,measurement at point afterfirst FEC decoding)DelayCommon measurementregardless of FEC (e.g.,measurement at point afterfirst FEC decoding) Examples of the measurement item can include the error rate obtained after the first FEC decoding (e.g., the error rate with a coded block as a unit) and the error rate obtained after the second FEC decoding (e.g., the error rate with a transport block as a unit). These items are measured at a stage after the first FEC decoding and after the second FEC decoding, respectively, in the signal processing on the receiving side shown inFIG.3. CRC is added to each coded block and each transport block. Accordingly, it is possible to measure the error rate by implementing error detection using CRC. Instead of a method of directly measuring the error rate after the first FEC decoding or after the second FEC decoding, the MCS or channel quality indicator (CQI) that satisfies the reception quality required by each FEC may be measured (or estimated). Examples of the reception quality mentioned here include, for example, the error rate of the coded block, the error rate of the transport block, the bit error rate (BER), the block error rate (BLER), the signal-to-noise power rate (SNR), the signal-to-interference noise power rate (SINR), the received signal strength indicator (RSSI), the reference signal received power (RSRP), and the reference signal received quality (RSRQ). For example, in the receiving side communication device, the MCS or CQI capable of achieving BLER=10−1is estimated, so that the value is fed back to the transmitting side communication device. In addition to the error rate, the receiving side communication device may measure the throughput value or the delay value and feed the same back to the transmitting side communication device. For example, the receiving side communication device may measure the throughput or delay at a stage after the first FEC decoding. F. Combination of Support of First FEC in Communication Device Table 9 below summarizes the status where the communication device supports first FEC and puncturing. TABLE 9CategoryCategorydisplaySupportSupportsupporting firstfieldof firstof punc-FECvalueFECturingNoteCommunication000NoNoCorresponding todevice category Alegacy communicationdeviceCommunication111YesYesIdeal communicationdevice category Bdevice categoryCommunication100YesNoPresent embodimentdevice category CCommunication110YesYesPresent embodimentdevice category DCommunication101YesNoPresent embodimentdevice category ECommunication011NoYesCategory that cannotdevice category Fexist (Exceptionalprocessing orprocessing ascategory)Communication010NoYesCategory that cannotdevice category Gexist (Exceptionalprocessing orprocessing ascategory)Communication001NoNoCategory that cannotdevice category Hexist (Exceptionalprocessing orprocessing ascategory) It can be said ideal that the communication device supports both FEC and puncturing. On the other hand, there may be variations in whether puncturing is supported or not. For example, there may be a communication device category that does not support bitwise puncturing and division block-unit puncturing, or supports only one thereof. Note that it can be said that a communication category that does not support the first FEC and supports puncturing is a category that should not exist (or has no meaning in existence). Here, it is desirable that the meaning of “to support first FEC” means to support both coding (transmitting side) and decoding (receiving side). Furthermore, it is also desirable that the meaning of “to support puncturing” means to support both puncturing (transmitting side) and depuncturing (receiving side). It is desirable that the information regarding the supporting status of the first FEC is shared between the transmitting side communication device and the receiving side communication device. In particular, sharing with the transmitting side communication device whether the receiving side communication device supports it or not is related to determining whether to apply the technology according to the present embodiment or not. Information regarding the supporting status is shared at the time of, for example, the connection establishment stage (Initial access) before shifting to execution of actual data communication, RRC Connection, hand-over (hand-off), or hand-shake. Example 2 Here, an additional example will be described in view of the configuration of a communication system in which the technology proposed herein is adopted. G. Case where there is a Distinction Between Roles of the Transmitting Device and the Receiving Device A communication system may be a system in which the roles of the transmitting side communication device and the receiving side communication device are substantially equal, and a system in which the roles are different. Examples of the former system in which the roles of the transmission and reception are substantially equal include, for example, the wireless LAN and Wi-Fi (registered trademark). Furthermore, examples of the latter system in which the roles of the transmission and reception are different include, for example, a cellular system, 4G, long term evolution (LTE), 5G, new radio (NR), wireless LAN after IEEE802.11ac, and Wi-Fi (registered trademark). Example of the relationship between transmission and reception with different roles include a base station device (base station (BS), eNB, gNB) and a terminal device (user equipment (UE), mobile terminal (MT), etc.), an access point device (access point (AP)) and a station device (Station (STA)), and the like. In this section, an example of a system in which the roles of transmission and reception are different will be described by unifying the examples of the base station device and the terminal device for convenience. FIG.19shows an example of a procedure for setting the first FEC in the downlink. In the downlink, the base station device functions as the transmitting side, and the terminal device connected to the cell of the base station device functions as the receiving side as shown in the figure. In this case, it is desirable that notification of application of the first FEC and specific configuration parameters is given from the base station device on the transmitting device to the terminal device on the receiving side, so that the first FEC is implemented. First, the terminal device notifies the base station device of the cell connected with the terminal device itself of information regarding the terminal capability of the terminal device itself (SEQ1901). This capability information also includes information regarding the capability of the first FEC. The notification of information regarding the terminal capability is given during the initial access procedure or after the initial access procedure. At least any one of a random access channel (PRACH), an uplink control channel (PUCCH), or an uplink shared channel (PUSCH) is used as a physical channel for notification. The base station device notifies the terminal device connected with a cell managed by the base station device itself of quasi-static control information including information regarding the first FEC (SEQ1951). This quasi-static control information may be cell-specific control information. The notification of this control information is given during the initial access procedure or after the initial access procedure. Furthermore, notification of this control information may be given as a part of the RRC procedure such as RRC signaling or RRC configuration. Furthermore, notification of this control information may be periodically given from the base station device to the terminal device. At least any one of a broadcast channel (PBCH), a downlink control channel (PDCCH, EPDCCH), or a downlink shared channel (PDSCH) is used as a physical channel for notification of this control information. The terminal device implements quasi-static setting of the FEC of the terminal device itself on the basis of the quasi-static control information regarding the first FEC, notification of which has been given from the base station device (SEQ1902). Thereafter, in a case where downlink communication occurs specifically from the base station device to the terminal device (for example, a case where the terminal device requests data download (pull) or a case where push data to the terminal device occurs, etc.), notification of control information (dynamic control information) such as a radio resource used for downlink communication is given from the base station device to the terminal device (SEQ1952). This dynamic control information may be terminal-specific (UE-specific) or terminal group-specific (UE-group-specific) control information. The terminal group mentioned here corresponds to, for example, a group of one or more terminal devices to be transmitted in a case where downlink communication is multicast or broadcast. Furthermore, the dynamic control information mentioned here includes a frequency resource (e.g., a resource block, a subcarrier, a subcarrier group, etc.) that allocates downlink communication to the target terminal device (or terminal group), a time resource (e.g., a subframe, a slot, a mini-slot, a symbol, etc.), a spatial resource (e.g., an antenna, an antenna port, a spatial layer, a spatial stream, etc.), a non-orthogonal resource (a power resource, an interleave pattern) of NOMA, MUST, IDMA, CDMA), a modulation order of a lower layer (physical layer), information regarding the FEC code rate (MCS), information regarding the coding method and the code rate of the first FEC (including upper layer puncturing, etc.), setting (NDI, RV, etc.) regarding ARQ/HARQ, and the like. The terminal device makes setting to prepare for appropriate reception of downlink communication according to the dynamic control information received from the base station device (SEQ1903). Thereafter, the base station device implements coding and modulation processing of the data of downlink communication to the terminal device in each of the upper layer and the lower layer so as to match the control information, notification of which has been given to the terminal device (SEQ1953, SEQ1954). Then, the base station device transmits the coded and modulated data as a radio signal to the terminal device (SEQ1955). The terminal device implements demodulation and decoding processing of a radio signal from the base station device in each of the lower layer and the upper layer according to the above-described setting specified in the control information from the base station device (SEQ1904, SEQ1905). Then, the terminal device implements processing related to ARQ/HARQ (SEQ1906) according to whether data decoding up to first FEC has succeeded or failed, and returns ACK or NACK for downlink communication to the base station device (SEQ1907). Here, it is desirable that the terminal device changes the setting of ARQ/HARQ processing according to whether data decoding up to first FEC has succeeded or failed. For example, in a case where decoding fails on the receiving side, it is desirable that the decoding result or data in the process of decoding on the receiving side (soft decision value, log likelihood ratio (LLR), etc.) is stored in a memory in order to implement retransmission and synthesis of the next HARQ on the transmitting side. The base station device executes the processing to be implemented next, according to ACK/NACK received from the terminal device (SEQ1956). For example, in a case where the base station device receives the NACK notification from the terminal device, the base station device implements preparation for retransmission of ARQ/HARQ. Examples of this preparation for retransmission include RV selection, MCS selection, radio resource selection, and the like. Furthermore, in a case where the base station device receives ACK notification from the terminal device, it means that the target data has been transmitted/received without any problem, and therefore the processing shifts to communication of the next new data without performing the preparation for retransmission described above. The base station device shifts to retransmission or implementation of downlink communication of new data according to the processing of ARQ/HARQ corresponding to ACK or NACK received from the terminal device. Therefore, the base station device notifies the terminal device of control information (dynamic control information) such as a radio resource used for downlink communication again (SEQ1957). Then, the terminal device makes setting to prepare for appropriate reception of downlink communication according to the dynamic control information received from the base station device (SEQ1908), and executes downlink communication according to the setting. FIG.20shows an example of a procedure for setting the first FEC in the uplink. In the uplink, the terminal device functions as the transmitting side, and the base station device of the cell connected with the terminal device functions as the receiving side as shown in the figure. In this case, it is desirable that notification of application of the first FEC and specific configuration parameters is given from the base station device on the receiving side to the terminal device on the transmitting side, so that the first FEC is implemented. First, the terminal device notifies the base station device of the cell connected with the terminal device itself of information regarding the terminal capability of the terminal device itself (SEQ2001). This capability information also includes information regarding the capability of the first FEC. The notification of information regarding the terminal capability is given during the initial access procedure or after the initial access procedure. At least any one of a random access channel (PRACH), an uplink control channel (PUCCH), or an uplink shared channel (PUSCH) is used as a physical channel for notification. The base station device notifies the terminal device connected with a cell managed by the base station device itself of quasi-static control information including information regarding the first FEC (SEQ2051). This quasi-static control information may be cell-specific control information. The notification of this control information is given during the initial access procedure or after the initial access procedure. Furthermore, notification of this control information may be given as a part of the RRC procedure such as RRC signaling or RRC configuration. Furthermore, notification of this control information may be periodically given from the base station device to the terminal device. At least any one of a broadcast channel (PBCH), a downlink control channel (PDCCH, EPDCCH), or a downlink shared channel (PDSCH) is used as a physical channel for notification of this control information. The terminal device implements quasi-static setting of the FEC of the terminal device itself on the basis of the quasi-static control information regarding the first FEC, notification of which has been given from the base station device (SEQ2002). Thereafter, in a case where uplink communication occurs specifically from the base station device to the terminal device (for example, a case where the terminal device requests data upload, a case where a data request is received from another communication device, a case where notification of periodic status information of a terminal device is given, etc.), notification of a scheduling request for uplink communication is given to the base station device (SEQ2003). As a result, the terminal device requests the base station device to allocate a radio resource and the like used for uplink communication. When the base station device receives a scheduling request from the terminal device, the base station device notifies the terminal device of control information (dynamic control information) such as a radio resource used for uplink communication (SEQ2053). This dynamic control information may be terminal-specific (UE-specific) or terminal group-specific (UE-group-specific) control information. The terminal group mentioned here corresponds to, for example, a group of one or more terminal devices having a common part in the control information for uplink communication. Furthermore, the dynamic control information mentioned here includes a frequency resource (e.g., a resource block, a subcarrier, a subcarrier group, etc.) that allocates uplink communication to the target terminal device (or terminal group), a time resource (e.g., a subframe, a slot, a mini-slot, a symbol, etc.), a spatial resource (e.g., an antenna, an antenna port, a spatial layer, a spatial stream, etc.), a non-orthogonal resource (a power resource, an interleave pattern) of NOMA, MUST, IDMA, CDMA), a modulation order of a lower layer (physical layer), information regarding the FEC code rate (MCS), information regarding the coding method and the code rate of first FEC (including upper layer puncturing, etc.), setting regarding ARQ/HARQ (NDI, RV, etc.), and the like. The terminal device makes setting to prepare for appropriate reception of uplink communication according to the dynamic control information received from the base station device (SEQ2004). Thereafter, the terminal device implements coding and modulation processing of the data of uplink communication to the terminal device in each of the upper layer and the lower layer so as to match the control information, notification of which has been given from the base station device (SEQ2005, SEQ2006). Then, the terminal device transmits the coded and modulated data as a radio signal to the base station device (SEQ2007). The base station device implements demodulation and decoding processing of a radio signal from the terminal device in each of the lower layer and the upper layer according to the above-described setting specified for the terminal device in the control information (SEQ2054, SEQ2055). Then, the base station device implements processing related to ARQ/HARQ (SEQ2057) according to whether data decoding up to first FEC has succeeded or failed, and returns ACK or NACK for uplink communication to the terminal device (SEQ2058). Here, it is desirable that the base station device changes the setting of ARQ/HARQ processing according to whether data decoding up to first FEC has succeeded or failed. For example, in a case where decoding fails on the receiving side, it is desirable that the decoding result or data in the process of decoding on the receiving side (soft decision value, log likelihood ratio (LLR), etc.) is stored in a memory in order to implement retransmission and synthesis of the next HARQ on the transmitting side. The terminal device executes the processing to be implemented next, according to ACK/NACK received from the base station device (SEQ2008). For example, in a case where the terminal device receives NACK notification from the base station device, the terminal device implements preparation for retransmission of ARQ/HARQ. Examples of this preparation for retransmission include waiting for the next dynamic control information from the base station device. Furthermore, in a case where the terminal device receives ACK notification from the base station device, it means that the target data has been transmitted and received without any problem, and therefore the terminal device shifts to communication of the next new data without performing the preparation for retransmission described above. The terminal device shifts to retransmission or implementation of uplink communication of new data according to ARQ/HARQ processing corresponding to ACK or NACK received from the base station device. Therefore, the base station device notifies the terminal device of control information (dynamic control information) such as a radio resource used for uplink communication again (SEQ2059). Then, the terminal device makes setting to prepare for appropriate reception of uplink communication according to the dynamic control information received from the base station device (SEQ2009), and executes the uplink communication according to the setting. FIGS.21and22show an example of a procedure for setting the first FEC in the sidelink between the terminal devices. In the sidelink, one terminal device A connected with the cell of the base station device functions as the transmitting side, and the other terminal device B connected with the cell of the same base station device functions as the receiving side as shown in the figure. In this case, it is desirable that notification of application of the first FEC and specific configuration parameters is given from the base station device to the terminal devices A and B, so that the first FEC is implemented. First, the terminal device B notifies the base station device of the cell connected with the terminal device B itself of information regarding the terminal capability of the terminal device B itself (SEQ2131). Similarly, the terminal device A notifies the base station device of the cell connected with the terminal device A itself of information regarding the terminal capability of the terminal device A itself (SEQ2101). The notification of information regarding the terminal capability is given during the initial access procedure or after the initial access procedure. At least any one of a random access channel (PRACH), an uplink control channel (PUCCH), or an uplink shared channel (PUSCH) is used as a physical channel for notification. The base station device notifies the terminal devices A and B connected with a cell managed by the base station device itself of quasi-static control information including information regarding a sidelink radio resource (SEQ2151, SEQ2152). Examples of quasi-static control information regarding a radio resource of the sidelink include specification of a frequency resource (e.g., a resource block, a subcarrier group, a subcarrier, etc.) and a time resource (a radio frame, a subframe, a slot, a mini-slot, a symbol, etc.) of a radio resource pool for the sidelink. A subordinate terminal device may implement sidelink communication by using a radio resource within the range of this radio resource pool. As for the radio resource pool, it is desirable to divert a part of the uplink resource of the target cell to the radio resource pool for the sidelink. Alternatively, a part of the downlink resource of the target cell may be diverted to the radio resource pool for the sidelink. Furthermore, the base station device notifies the terminal devices A and B of quasi-static control information including information regarding the first FEC (SEQ2153, SEQ2154). Notification of the quasi-static control information regarding the radio resource of the sidelink and the quasi-static control information regarding the first FEC may be given to the individual terminal devices A and B as shown in the figure, or may be given to the terminal devices A and B simultaneously. Such quasi-static control information may be cell-specific control information. Notification of the quasi-static control information is given during the initial access procedure or after the initial access procedure. Furthermore, notification of this control information may be given as a part of the RRC procedure such as RRC signaling or RRC configuration. Furthermore, notification of this control information may be periodically given from the base station device to the terminal devices A and B. At least any one of a broadcast channel (PBCH), a downlink control channel (PDCCH, EPDCCH), or a downlink shared channel (PDSCH) is used as a physical channel for giving notification of the control information. The terminal devices A and B respectively implement quasi-static setting of FEC of the terminal devices A and B themselves on the basis of the quasi-static control information regarding the first FEC, notification of which has been given from the base station device (SEQ2102, SEQ2132). Thereafter, in a case where sidelink communication occurs from the terminal device A to the terminal device B specifically (for example, a case where direct communication between terminal devices occurs, a case where the terminal device A receives a request for direct communication from the terminal device B, etc.), the terminal device A on the transmitting side notifies the terminal device B on the receiving side of control information (dynamic control information) such as a radio resource used for sidelink communication (SEQ2103). This dynamic control information may be terminal-specific (UE-specific) or terminal group-specific (UE-group-specific) control information. The terminal group mentioned here corresponds to, for example, a group of one or more terminal devices to be transmission destination of a case where sidelink communication is multicast or broadcast. Furthermore, the dynamic control information mentioned here includes a frequency resource (e.g., a resource block, a subcarrier, a subcarrier group, etc.) that allocates sidelink communication to the target terminal device (or terminal group), a time resource (e.g., a subframe, a slot, a mini-slot, a symbol, etc.), a spatial resource (e.g., an antenna, an antenna port, a spatial layer, a spatial stream, etc.), a non-orthogonal resource (a power resource, an interleave pattern) of NOMA, MUST, IDMA, CDMA), a modulation order of a lower layer (physical layer), information regarding the FEC code rate (MCS), information regarding the coding method and the code rate of the first FEC (including upper layer puncturing, etc.), setting regarding ARQ/HARQ (NDI, RV, etc.), and the like. The receiving side terminal device B makes setting to prepare for appropriate reception of sidelink communication according to the dynamic control information received from the transmitting side terminal device A (SEQ2133). Thereafter, the terminal device A implements coding and modulation processing of the data of sidelink communication to the terminal device B in each of the upper layer and the lower layer so as to match the control information, notification of which has been given to the terminal device B (SEQ2104, SEQ2105). Then, the terminal device A transmits the coded and modulated data as a radio signal to the terminal device B (SEQ2106). The terminal device B implements demodulation and decoding processing of a radio signal from the terminal device A in each of the lower layer and the upper layer according to the above-described setting specified in the control information from the terminal device A (SEQ2134, SEQ2135). Then, the terminal device B implements processing related to ARQ/HARQ (SEQ2136) according to whether data decoding up to first FEC has succeeded or failed, and returns ACK or NACK for downlink communication to the terminal device A (SEQ2137). Here, it is desirable that the terminal device B changes the setting of ARQ/HARQ processing according to whether data decoding up to first FEC has succeeded or failed. For example, in a case where decoding has failed on the receiving side, it is desirable that the decoding result or data in the process of decoding on the receiving side terminal device B (soft decision value, log likelihood ratio (LLR), etc.) is stored in a memory in order to implement retransmission and synthesis of the next HARQ on the transmitting side terminal device A. The terminal device A executes the processing to be implemented next, according to ACK/NACK received from the terminal device B (SEQ2107). For example, in a case where the terminal device A receives NACK notification from the terminal device B, the terminal device A implements preparation for retransmission of ARQ/HARQ. Examples of this preparation for retransmission include waiting for the next dynamic control information. Furthermore, in a case where the terminal device A receives ACK notification from the terminal device B, it means that the target data has been transmitted and received without any problem, and therefore the terminal device A shifts to a scheduling request for communication of the next new data without performing the preparation for retransmission described above. The terminal device A shifts to retransmission or implementation of sidelink communication of new data according to ARQ/HARQ processing corresponding to ACK or NACK received from the terminal device B. The base station device notifies terminal devices A and B of quasi-static control information including information regarding a sidelink radio resource again (SEQ2155, SEQ2156), and furthermore, quasi-static control information including information regarding the first FEC again (SEQ2157, SEQ2158). Then, the terminal devices A and B respectively implement quasi-static setting of the FEC of the terminal devices A and B themselves on the basis of the quasi-static control information regarding the first FEC, notification of which has been given from the base station device (SEQ2108, SEQ2138). Next, the terminal device A notifies the terminal device B of control information (dynamic control information) such as a radio resource used for sidelink communication again (SEQ2109). Then, the terminal device B makes setting to prepare for appropriate reception of side link communication according to the dynamic control information received from the terminal device A (SEQ2139), and executes sidelink communication according to the setting. H. Case where the Roles of the Transmitting Device and the Receiving Device are Substantially Equal Examples of a system in which the roles of the transmission and reception are substantially equal include, for example, the wireless LAN and Wi-Fi (registered trademark) (as described above). In this section, an example of a system in which the roles of transmission and reception are substantially equal will be described. FIG.23shows an example of a procedure for setting the first FEC in a communication system in which the roles of transmission and reception are substantially equal. As shown in the figure, the terminal device A functions as the transmitting side, and the terminal device B functions as the receiving side. The terminal device A notifies the terminal device B, which functions as a substantially equal communication partner, of information regarding the terminal capability of the terminal device A itself (SEQ2301). This capability information also includes information regarding the capability of the first FEC. Similarly, the terminal device B notifies the terminal device A of information regarding the terminal capability of the terminal device B itself (SEQ2311). In a case where data transmission to the terminal device B occurs in the terminal device A, the terminal device A implements coding and modulation processing of the data to be transmitted in each of the upper layer and the lower layer according to the capability of the terminal device A and the terminal device B (SEQ2302, SEQ2303). Then, the terminal device A transmits the coded and modulated data as a radio signal to the terminal device B (SEQ2304). This radio signal is configured with each part of a lower layer preamble, a lower layer header, a lower layer payload, and a lower layer CRC as a lower layer packet (or a lower layer frame). The lower layer preamble includes dynamic control information regarding lower layers of lower layer MCS, FEC coding, a frequency resource (a resource block, a subcarrier group, a subcarrier, etc.), a time resource (the lower layer frame length (the number of symbols), etc.), or a spatial resource (an antenna, an antenna port, a spatial layer, a spatial stream, etc.). It is desirable that dynamic control information of this lower layer is valid only for this lower layer packet. The lower layer payload is further configured with one or more division blocks (corresponding to the division blocks and coded blocks described above). The division block is configured with an upper layer header (including first FEC information), an upper layer payload, and upper layer CRC. When the terminal device B receives a radio signal (lower layer packet) from the terminal device A, the terminal device B decodes the lower layer header, acquires dynamic control information necessary for demodulating and decoding the lower layer payload, and sets the dynamic control information in the terminal device itself (SEQ2312). The terminal device B implements demodulation and decoding processing of the lower layer payload on the basis of the dynamic control information of a lower layer (SEQ2313). Then, the terminal device B demodulates and decodes the payload of a lower layer, and then implements decoding (including first FEC decoding and interleaving/deinterleaving) of a division block in an upper layer (SEQ2314). When decoding including first FEC is completed, the terminal device B implements processing related to ARQ/HARQ according to whether data decoding up to first FEC has succeeded or failed (SEQ2315), and implements or updates the setting related to ARQ/HARQ. Then, the terminal device B returns ACK or NACK to the terminal device A depending on whether data decoding has succeeded or failed (SEQ2316). The terminal device A executes ARQ/HARQ processing corresponding to ACK/NACK received from the terminal device B (SEQ2305). Then, the terminal device A shifts to retransmission or transmission processing of new data according to ARQ/HARQ processing. That is, the terminal device A implements coding and modulation processing of the data to be transmitted in each of the upper layer and the lower layer (SEQ2306, SEQ2307), and transmits the coded and modulated data as a radio signal to the terminal device B (SEQ2308). Finally, the effects of the technology proposed herein will be mentioned. It is possible with the technology proposed herein to realize latency lowering and reliability enhancement while substantially preventing increase in the amount of data to be transmitted/received in the physical layer or reducing the amount of data to be transmitted/received in the physical layer even in a status where an error occurs in single FEC, by introducing a plurality of FEC codes into a communication system and implementing puncturing with a coded block as a unit. INDUSTRIAL APPLICABILITY The technology disclosed herein has been described above in detail with reference to specific embodiments. However, it is obvious that a person skilled in the art can make modifications or substitutions of the embodiments without departing from the gist of the technology disclosed herein. The technology disclosed herein can be applied to, for example, any of a communication system in which the roles of the transmission and reception are substantially equal, such as the wireless LAN or Wi-Fi (registered trademark), and a communication system in which the roles of the transmission and reception are different, such as a cellular system, 4G, LTE, 5G, NR, wireless LAN after IEEE802.11ac, or Wi-Fi. In short, the technology disclosed herein has been described in the form of exemplification, and the contents described herein should not be interpreted in a limited manner. To determine the gist of the technology disclosed herein, the claims should be taken into consideration. Note that the technology disclosed herein can also have the following configurations. (1) A communication device including: a first CRC addition unit that adds a CRC sequence to an information sequence to be transmitted; a division unit that divides an information sequence having a CRC sequence added thereto into a plurality of sequences; a first FEC coding unit that implements first FEC coding by using a sequence obtained by division; a second CRC addition unit that adds a CRC sequence to a coded sequence obtained after first FEC coding; a second FEC coding unit that implements second FEC coding by using a coded sequence having a CRC sequence added thereto; a coupling unit that couples coded sequences obtained after second coding; a transmitting unit that transmits a coded information sequence obtained after coupling to another communication device; and a retransmission control unit that controls retransmission with a coded sequence obtained after first coding as a unit. (1-1) The communication device according to (1), further including a padding unit that adds a padding bit so that data sizes of sequences obtained by division become equal. (1-2) The communication device according to (1), in which first FEC is any one of an erasure code, a rateless code, a Raptor code, or a Raptor Q code. (1-3) The communication device according to (1), in which second FEC is either an LDPC code or a Polar code. (2) The communication device according to (1), further including a determination unit that determines whether to implement first FEC coding or not. (3) The communication device according to (2), in which the determination unit determines whether to implement first FEC coding or not on the basis of at least one of status of a receiving side communication device, an application of a target information sequence, or status of a target information sequence. (4) The communication device according to any one of (1) to (3), in which the second FEC coding unit implements second FEC coding by using some of a plurality of coded sequences obtained after first FEC coding. (4-1) The communication device according to (4), in which the second FEC coding unit changes a coded sequence to be subjected to second FEC coding according to the number of transmission times of an information sequence. (4-2) The communication device according to (4-1), in which the second FEC coding unit selects a coded sequence, for which second FEC coding is not performed, on the basis of transmission/reception result of previous transmission. (4-2-1) The communication device according to (4-2), in which the second FEC coding unit does not implement second FEC coding for a coded sequence, transmission/reception of which has succeeded in previous transmission. (4-2-2) The communication device according to (4-2), in which second FEC coding is implemented for at least some of coded sequences that have not been transmitted in the last time transmission. (5) The communication device according to any one of (1) to (3), in which the second FEC coding unit punctures some of a plurality of coded sequences obtained after first FEC coding, and implements second FEC coding by using the other coded sequences. (6) The communication device according to any one of (1) to (5), in which the coupling unit couples some of a plurality of coded sequences obtained after second FEC coding. (7) The communication device according to any one of (1) to (6), in which the retransmission control unit retransmits at least some of coded sequences that have not been transmitted in the last time transmission. (8) The communication device according to any one of (1) to (6), in which the retransmission control unit implements retransmission by a combination of different coded sequences for each transmission time. (9) The communication device according to any one of (1) to (6), in which the retransmission control unit selects a coded sequence to be retransmitted on the basis of transmission/reception result of previous transmission. (9-1) The communication device according to (9), in which the retransmission control unit retransmits at least some of coded sequences, transmission/reception of which has failed in the last time transmission. (10) A communication method including: a first CRC addition step of adding a CRC sequence to an information sequence to be transmitted; a division step of dividing an information sequence having a CRC sequence added thereto into a plurality of sequences; a first FEC coding step of implementing first FEC coding by using a sequence obtained by division; a second CRC addition step of adding a CRC sequence to a coded sequence obtained after first FEC coding; a second FEC coding step of implementing second FEC coding by using a coded sequence having a CRC sequence added thereto; a coupling step of coupling coded sequences obtained after second coding; a transmission step of transmitting a coded information sequence obtained after coupling to another communication device; and a retransmission step of controlling retransmission with a coded sequence obtained after first coding as a unit. (11) A communication device including: a division unit that divides a received information sequence generated from a received signal into a plurality of sequences; a second decoding unit that implements second FEC decoding by using a sequence obtained by division; a first determination unit that determines whether a sequence obtained after second FEC decoding includes an error or not; a first decoding unit that implements first FEC decoding by using a sequence obtained after second FEC decoding; a second determination unit that determines whether a sequence obtained after first decoding includes an error or not; and a control unit that controls transmission of ACK or NACK to a communication device on a transmitting side on the basis of determination result by the second determination unit. (11-1) The communication device according to (11), in which first FEC is any one of an erasure code, a rateless code, a Raptor code, or a Raptor Q code. (11-2) The communication device according to (11), in which second FEC is either an LDPC code or a Polar code. (12) The communication device according to (11), in which the control unit controls transmission of NACK including information for identifying which of sequences obtained after second FEC decoding includes an error in a case where a sequence obtained after first decoding includes an error. (12-1) The communication device according to (11) or (12), in which the control unit controls retransmission with a coded sequence obtained after first coding as a unit. (13) The communication device according to (11) or (11), further having a function of HARQ synthesis, in which the second FEC decoding unit implements second FEC decoding only for a sequence in which an error has occurred in second FEC decoding last time. (14) The communication device according to (13), in which a sequence obtained by dividing a received information sequence received this time and a sequence obtained by dividing a received information sequence received last time are synthesized. (15) The communication device according to (14), in which a sequence obtained by dividing a received information sequence is synthesized by one synthesis method of chase combining or incremental redundancy. (16) The communication device according to (14) or (15), in which the first decoding unit implements first FEC decoding processing by using a sequence in which no error has occurred in second decoding last time in addition to a sequence obtained after second FEC decoding. (17) The communication device according to any one of (12) to (16), in which the first decoding unit implements first FEC decoding processing by using a dummy information sequence in addition to a sequence obtained after second FEC decoding. (18) The communication device according to any one of (12) to (16), in which the first decoding unit implements first FEC decoding processing after depuncturing is performed for a sequence obtained after second FEC decoding. (19) The communication device according to (17), in which a dummy information sequence is an information sequence configured with a predetermined value. (20) The communication device according to any one of (11) to (19), further including a measuring unit that measures reception quality at at least one stage after decoding by the second decoding unit or after decoding by a decoding unit by the first decoding unit. (21) A communication method including: a division step of dividing a received information sequence generated from a received signal into a plurality of sequences; a second decoding step of implementing second FEC decoding by using a sequence obtained by division; a first determination step of determining whether a sequence obtained after second FEC decoding includes an error or not; a first decoding step of implementing first FEC decoding by using a sequence obtained after second FEC decoding; a second determination step of determining whether a sequence obtained after first decoding includes an error or not; and a control step of controlling transmission of ACK or NACK to a communication device on a transmitting side on the basis of determination result in the second determination step. (22) The communication device according to any one of (1) to (9) or (11) to (20), which operates as a terminal device connected with a cell of a base station device, and acquires at least one of information regarding a setting of first FEC or information regarding a setting of second FEC from the base station device. (23) The communication device according to (22), which acquires information regarding a setting of first FEC and information regarding a setting of second FEC from the same control information. (24) The communication device according to (22), which acquires information regarding a setting of first FEC and information regarding a setting of second FEC from different control information. (25) The communication device according to (22), which acquires a part of information regarding a setting of first FEC and information regarding a setting of second FEC from quasi-static control information, and acquires another part of information regarding a setting of first FEC and information regarding a setting of second FEC from dynamic control information (26) The communication device according to (22), which determines whether first FEC is implemented or not on the basis of information regarding a setting of first FEC. (27) The communication device according to any one of (1) to (9) or (11) to (20), which operates as a base station device, and notifies a terminal device connected with a cell of the communication device itself of at least one of information regarding a setting of first FEC or information regarding a setting of second FEC. (28) The communication device according to (27), which notifies the terminal device of information regarding a setting of first FEC and information regarding a setting of second FEC by using the same control information. (29) The communication device according to (27), which notifies the terminal device of information regarding a setting of first FEC and information regarding a setting of second FEC by using different control information. (30) The communication device according to (27), which notifies the terminal device of a part of information regarding a setting of first FEC and information regarding a setting of second FEC by quasi-static control information, and notifies the terminal device of another part of information regarding a setting of first FEC and information regarding a setting of second FEC by dynamic control information. (31) The communication device according to (27), which notifies the terminal device of whether first FEC is implemented or not on the basis of information regarding a setting of first FEC. REFERENCE SIGNS LIST 201First transmission processing unit202First FEC coding unit203Second transmission processing unit204Second FEC coding unit205Third transmission processing unit301First reception processing unit302Second FEC decoding unit303Second reception processing unit304First FEC decoding unit305Third reception processing unit | 107,849 |
11943056 | DETAILED DESCRIPTION Sidelink communications may include the use of a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH), each occupying at least one subchannel. A wireless device may receive sidelink control information (SCI) on the PSCCH, where the SCI may include control information on how to decode a transport block (TB). The wireless device may receive the TB on the PSSCH and may decode the TB using the control information in the received SCI. Some sidelink wireless communications systems support relatively large bandwidths (e.g., approximately 1.8 GHz available in the 5 GHz/6 GHz unlicensed band and approximately 7 GHz in the 60 GHz unlicensed band) such that wireless devices may communicate using larger TBs (e.g., jumbo TBs). In such examples, communicating devices may segment the TBs in the frequency domain into one or more code block groups (CBGs). Segmenting TBs into one or more CBGs may support more efficient communications, for example, in cases where a wireless device is requested to retransmit a TB or a portion of a TB. For example, sidelink wireless communications systems may support hybrid automatic repeat request (HARQ) such that a receiving device may transmit a HARQ response indicating successful (or unsuccessful) reception of a TB to a transmitting device. If the receiving device indicates a failed TB reception, the transmitting device may send a retransmission to the receiving device. In some cases, the receiving device may indicate a failed reception of specific CBGs, or portions of a TB. In some cases, SCI may not include information associated with CBG allocations, making it difficult for a receiving device to indicate a specific CBG, for example, in a HARQ response. Enhanced control information supporting sidelink CBG retransmissions may be desired. A wireless device may transmit control information including information supporting flexible frequency domain resource allocations (FDRAs) in a communication environment. For example, a wireless device may transmit an SCI, associated with an initial TB, to a receiving device. The SCI may include an indication of an FDRA (e.g., a number of subchannels) for the initial (or current) TB and an indication of an FDRA for a subsequent TB. In some cases, the wireless device may indicate the FDRA for the initial TB as a scaling factor (e.g., multiple) of the FDRA for the subsequent TB. In other cases, the wireless device may indicate the FDRA for the initial TB as an adjustment (e.g., addition/subtraction) of the FDRA for the subsequent TB. In some cases, the wireless device may indicate the FDRA for the initial TB in an additional FDRA codepoint (e.g., in addition to an FDRA for a subsequent TB in the control information). The additional FDRA codepoint may include an explicit indication of a number of subchannels for the initial TB or the additional FDRA codepoint may include a pointer associated with a table of defined FDRA information for the initial TB (e.g., defined before the communication link is established and stored in a memory of the wireless device). In some examples, the additional FDRA codepoint may include a pointer associated with a table of defined FDRA information for both the initial TB and the subsequent TB (e.g., defined before the communication link is established and stored in a memory of the wireless device). In some cases, the wireless device may indicate a leading subchannel of the FDRA for the subsequent TB. Further, the wireless device may transmit a second SCI, associated with the subsequent TB, including an indication of a TB size (TBS) for the subsequent TB. In some cases, the indication of the TBS for the subsequent TB may be associated with a TBS of the initial TB. For example, the wireless device may indicate that the TBS for the subsequent TB may be the same TBS as a CBG of the initial TB. In other cases, the wireless device may indicate the TBS for the subsequent TB as a scaling factor of the TBS of the initial TB or an adjustment factor of the TBS of the initial TB. In some cases, the wireless device may indicate the TBS of the subsequent TB with the additional FDRA codepoint. In some other cases, the wireless device may indicate the TBS of the subsequent TB in a new bit field of the SCI. The FDRA for the initial TB may indicate one or more CBGs for the initial TB. For example, the initial TB may be segmented into a quantity of subchannels based on the FDRA for the initial TB. In such examples, each subchannel may correspond to a respective CBG such that the initial TB may include a quantity of CBGs equal to the quantity of subchannels. Indicating the FDRA for the initial TB may support CBG retransmissions as a receiving device may be aware of the CBG division for the initial TB and may signal CBG retransmissions based on that information. Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are also described in the context of resource configurations and process flows. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to flexible FDRA for sidelink. FIG.1illustrates an example of a wireless communications system100that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The wireless communications system100may include one or more base stations105, one or more UEs115, and a core network130. In some examples, the wireless communications system100may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system100may support enhanced broadband communications, ultra-reliable communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof. The base stations105may be dispersed throughout a geographic area to form the wireless communications system100and may be devices in different forms or having different capabilities. The base stations105and the UEs115may wirelessly communicate via one or more communication links125. Each base station105may provide a coverage area110over which the UEs115and the base station105may establish one or more communication links125. The coverage area110may be an example of a geographic area over which a base station105and a UE115may support the communication of signals according to one or more radio access technologies. The UEs115may be dispersed throughout a coverage area110of the wireless communications system100, and each UE115may be stationary, or mobile, or both at different times. The UEs115may be devices in different forms or having different capabilities. Some example UEs115are illustrated inFIG.1. The UEs115described herein may be able to communicate with various types of devices, such as other UEs115, the base stations105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), as shown inFIG.1. The base stations105may communicate with the core network130, or with one another, or both. For example, the base stations105may interface with the core network130through one or more backhaul links120(e.g., via an S1, N2, N3, or other interface). The base stations105may communicate with one another over the backhaul links120(e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations105), or indirectly (e.g., via core network130), or both. In some examples, the backhaul links120may be or include one or more wireless links. One or more of the base stations105described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology. A UE115may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE115may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE115may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples. The UEs115described herein may be able to communicate with various types of devices, such as other UEs115that may sometimes act as relays as well as the base stations105and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown inFIG.1. The UEs115and the base stations105may wirelessly communicate with one another via one or more communication links125over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links125. For example, a carrier used for a communication link125may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP)) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system100may support communication with a UE115using carrier aggregation or multi-carrier operation. A UE115may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and may be positioned according to a channel raster for discovery by the UEs115. A carrier may be operated in a standalone mode where initial acquisition and connection may be conducted by the UEs115via the carrier, or the carrier may be operated in a non-standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology). The communication links125shown in the wireless communications system100may include uplink transmissions from a UE115to a base station105, or downlink transmissions from a base station105to a UE115. Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode). A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system100. For example, the carrier bandwidth may be one of a number of determined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)). Devices of the wireless communications system100(e.g., the base stations105, the UEs115, or both) may have hardware configurations that support communications over a particular carrier bandwidth or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system100may include base stations105or UEs115that support simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE115may be configured for operating over portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth. Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements that a UE115receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE115. A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams), and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE115. The time intervals for the base stations105or the UEs115may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of Ts=1/(Δfmax·Nf) seconds, where Δfmaxmay represent the maximum supported subcarrier spacing, and Nfmay represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023). Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some wireless communications systems100, a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., Nf) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation. A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system100and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system100may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)). Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs115. For example, one or more of the UEs115may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs115and UE-specific search space sets for sending control information to a specific UE115. Each base station105may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a base station105(e.g., over a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or others). In some examples, a cell may also refer to a geographic coverage area110or a portion of a geographic coverage area110(e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station105. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas110, among other examples. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs115with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station105, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs115with service subscriptions with the network provider or may provide restricted access to the UEs115having an association with the small cell (e.g., the UEs115in a closed subscriber group (CSG), the UEs115associated with users in a home or office). A base station105may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access for different types of devices. In some examples, a base station105may be movable and therefore provide communication coverage for a moving geographic coverage area110. In some examples, different geographic coverage areas110associated with different technologies may overlap, but the different geographic coverage areas110may be supported by the same base station105. In other examples, the overlapping geographic coverage areas110associated with different technologies may be supported by different base stations105. The wireless communications system100may include, for example, a heterogeneous network in which different types of the base stations105provide coverage for various geographic coverage areas110using the same or different radio access technologies. The wireless communications system100may support synchronous or asynchronous operation. For synchronous operation, the base stations105may have similar frame timings, and transmissions from different base stations105may be approximately aligned in time. For asynchronous operation, the base stations105may have different frame timings, and transmissions from different base stations105may, in some examples, not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations. Some UEs115, such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station105without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application program that makes use of the information or presents the information to humans interacting with the application program. Some UEs115may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging. The wireless communications system100may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system100may be configured to support ultra-reliable low-latency communications (URLLC). The UEs115may be designed to support ultra-reliable, low-latency, or critical functions. Ultra-reliable communications may include private communication or group communication and may be supported by one or more services such as push-to-talk, video, or data. Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, and ultra-reliable low-latency may be used interchangeably herein. In some examples, a UE115may also be able to communicate directly with other UEs115over a device-to-device (D2D) communication link135(e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs115utilizing D2D communications may be within the geographic coverage area110of a base station105. Other UEs115in such a group may be outside the geographic coverage area110of a base station105or be otherwise unable to receive transmissions from a base station105. In some examples, groups of the UEs115communicating via D2D communications may utilize a one-to-many (1:M) system in which each UE115transmits to every other UE115in the group. In some examples, a base station105facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs115without the involvement of a base station105. In some systems, the D2D communication link135may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs115). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations105) using vehicle-to-network (V2N) communications, or with both. The core network130may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network130may be an evolved packet core (EPC) or 5G core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs115served by the base stations105associated with the core network130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to IP services150for one or more network operators. The IP services150may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet-Switched Streaming Service. Some of the network devices, such as a base station105, may include subcomponents such as an access network entity140, which may be an example of an access node controller (ANC). Each access network entity140may communicate with the UEs115through one or more other access network transmission entities145, which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs). Each access network transmission entity145may include one or more antenna panels. In some configurations, various functions of each access network entity140or base station105may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station105). The wireless communications system100may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs115located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz. The wireless communications system100may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band, or in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, the wireless communications system100may support millimeter wave (mmW) communications between the UEs115and the base stations105, and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate use of antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body. The wireless communications system100may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system100may employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations105and the UEs115may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples. A base station105or a UE115may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station105or a UE115may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station105may be located in diverse geographic locations. A base station105may have an antenna array with a number of rows and columns of antenna ports that the base station105may use to support beamforming of communications with a UE115. Likewise, a UE115may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port. The base stations105or the UEs115may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices. Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station105, a UE115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation). A base station105or a UE115may use beam sweeping techniques as part of beam forming operations. For example, a base station105may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station105multiple times in different directions. For example, the base station105may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by a transmitting device, such as a base station105, or by a receiving device, such as a UE115) a beam direction for later transmission or reception by the base station105. Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station105in a single beam direction (e.g., a direction associated with the receiving device, such as a UE115). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted in one or more beam directions. For example, a UE115may receive one or more of the signals transmitted by the base station105in different directions and may report to the base station105an indication of the signal that the UE115received with a highest signal quality or an otherwise acceptable signal quality. In some examples, transmissions by a device (e.g., by a base station105or a UE115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from a base station105to a UE115). The UE115may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station105may transmit a reference signal (e.g., a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)), which may be precoded or unprecoded. The UE115may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted in one or more directions by a base station105, a UE115may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE115) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device). A receiving device (e.g., a UE115) may try multiple receive configurations (e.g., directional listening) when receiving various signals from the base station105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR), or otherwise acceptable signal quality based on listening according to multiple beam directions). The wireless communications system100may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE115and a base station105or a core network130supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels. The UEs115and the base stations105may support retransmissions of data to increase the likelihood that data is received successfully. HARQ feedback is one technique for increasing the likelihood that data is received correctly over a communication link125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions). In some examples, a device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval. In some examples, a wireless device may identify that within a control message, an additional FDRA codepoint indicates that an initial, or current TB occupies a different quantity of subchannels as compared to a subsequent, or reserved TB. In some examples, the additional FDRA codepoint may include a scaling factor, an adjustment number, may point to an FDRA table, along with other methods of indicating FDRA for the initial TB. Devices may further be configured to indicate TBS for subsequent, or reserved PSSCH. In some examples, to facilitate CBG based retransmissions, CBG transmission information (CBGTI) and CBG flushing out information (CBGFI) may be signaled in a second control message. The presence of CBGTI and CBGFI in the second control message may indicate that a wireless device may use a same TBS as indicated in a previous SCI associated with a TB, where at least a portion of the TB is to be retransmitted. For example, the second control message may include a CBGTI, a CBGFI, or both, indicating that the wireless device may receive the subsequent TB using the TBS of the portion of the initial TB (e.g., a CBG of the initial TB) as indicated in a previous control message. Additionally or alternatively, the second control message may include scaling factors, adjustment factors, specific TBS values, additional bit fields, or a combination thereof, to indicate the TBS of the subsequent TB. FIG.2illustrates an example of a wireless communications system200that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The wireless communications system200may implement or be implemented by aspects of the wireless communications system100. For example, the wireless communications system200may include a wireless device205-aand a wireless device205-b, which may be examples of base stations105, UEs115, sidelink enabled devices, or any other device as described with reference toFIG.1. The wireless device205-aand the wireless device205-bmay communicate using NR sidelink, where the wireless device205-amay transmit, and the wireless device205-bmay receive, control information210indicating an FDRA of a first TB. In some cases, the wireless device205-aand the wireless device205-bmay communicate using NR sidelink communications. For example, the wireless device205-amay be a vehicle with wireless communication capabilities, where the wireless device205-amay support V2X communications. In such an environment, the wireless device205-amay transmit relatively small, periodic messages (e.g., safety related messages) to one or more other devices, such as the wireless device205-bover a sidelink communication link (e.g., using a sub-6 GHz, licensed band). In some cases, sidelink communications may include two resource allocation (or channel access) modes. In a first resource allocation mode (e.g., mode 1), for an in-coverage deployment, a device (e.g., a transmitting device) may receive a grant for sidelink channel access. For example, the wireless device205-amay be located in coverage area corresponding to (or served) by a base station (e.g., a gNB) and, in accordance with the first resource allocation mode, the wireless device205-amay receive a grant from the base station to access a sidelink channel (e.g., managed scheduling techniques). In a second resource allocation mode (e.g., mode 2), for an autonomous deployment, a device (e.g., a transmitting device) may use sensing to perform distributed channel access. For example, the wireless device205-amay use contention-based scheduling techniques (e.g., with performing a channel sensing procedure) to access a sidelink channel. In some cases, each sidelink channel may include a PSCCH and a PSSCH, where the PSCCH and the PSSCH may each occupy at least one subchannel to transmit data in a TB. To support decoding data on the PSSCH, a device may receive SCI on the PSCCH. For example, the wireless device205-amay transmit control information210, to the wireless device205-bon the PSCCH, and may transmit a TB to the wireless device205-bon the PSSCH. The control information210may include information specifying that the wireless device205-bmay decode the TB as well as information on how to decode the TB. In some cases, devices may communicate using jumbo TBs, supporting transmitting TBs with relatively large payloads (e.g., as compared to transmitting TBs). To transmit a jumbo TB, a transmitting device may assign the jumbo TB to more than one subchannel on the PSSCH. In some cases, sidelink devices may support HARQ communications, for example, to improve the reliability of unicast and groupcast communications. For example, the wireless device205-amay be a transmitting device, where the wireless device205-amay transmit one or more TBs to the wireless device205-b. In such an example, the wireless device205-amay transmit control information210to the wireless device205-b, where the control information210may further include a request for a HARQ response from the wireless device205-b. Upon receiving the request for the HARQ response, the wireless device205-amay transmit the HARQ response, to the wireless device205-a, on the physical sidelink feedback channel (PSFCH). For example, the wireless device205-bmay transmit a one bit response, to the wireless device205-a, indicating successful (or unsuccessful) reception of the one or more TBs. In some cases, the wireless device205-amay retransmit the one or more TBs, for example, in cases where the wireless device205-afails to receive an acknowledgement (ACK) message. As such, the wireless device205-amay retransmit the one or more TBs using a same quantity of subchannels the wireless device205-aused for the original transmission of the one or more TBs. Sidelink communications may be applicable to one or more industries, enterprises, and other vertical domains. However, in some domains, access to specific frequencies and frequency ranges may be limited, for example, within the sub-6 GHz licensed band. There may be available frequency ranges in one or more unlicensed bands supporting relatively large bandwidth communications. For example, there may be approximately 1.8 GHz available in the 5 GHz/6 GHz unlicensed band and approximately 7 GHz available in the 60 GHz unlicensed band. Using such wider bandwidths may create different deployment scenarios, as compared to using limited bandwidths, for example, in the licensed spectrum. For example, eMBB-like communication traffic may be relatively dominant (e.g., frequent) where one or more vertical domains may support relatively high bandwidth communications. As such, communicating devices may use jumbo TBs more frequently, for example, when communicating using long data bursts. However, in some cases, communicating using jumbo TBs may result in relatively low spectral efficiency, for example, in HARQ based communication environments. For example, the wireless device205-amay transmit a jumbo TB to the wireless device205-busing five subcarriers. The wireless device205-bmay fail to receive a portion of the jumbo TB, so the wireless device205-bmay indicate unsuccessful reception of the jumbo TB to the wireless device205-a. As such, the wireless device205-amay retransmit the entire jumbo TB to the wireless device205-b, as compared to retransmitting the portion of the jumbo TB that the wireless device205-bfailed to receive. In some examples, sidelink communications may support CBG transmissions, where TBs may be divided into one or more CBGs. As per the previous example, the wireless device205-amay transmit a jumbo TB to the wireless device205-busing five subcarriers. In such an example, the jumbo TB may be divided into five CBGs, for example, divided per subcarrier. Transmitting TBs divided into CBGs may reduce a number of resources used for retransmissions. For example, the wireless device205-bmay indicate an unsuccessful reception of a TB in accordance with a block error rate (BLER) threshold (e.g., with 10% BLER as a rate control operating point). In such an example, the wireless device205-bmay determine that the BLER for a portion of the TB satisfies the BLER threshold. The portion of the TB may be (or may be part of) a CBG of the TB. CBG based HARQ communications may support the wireless device205-bindicating unsuccessful reception of the CBG, where the wireless device205-amay retransmit the CBG indicated by the wireless device205-binstead of retransmitting the entire TB. Some wireless communications systems may not support CBG transmissions and may thus use a same number of subchannels for both initial transmissions and retransmissions. Additionally, in such cases, resource reservation may be declared through over the air (OTA) signaling (e.g., for contention-based scheduling techniques), for example in stage-one SCI to facilitate autonomous channel access (e.g., mode 2). For example, in stage-one SCI, retransmissions may be indicated for one length for up to three PSSCH transmissions (e.g., TBs). That is, there may be one “length” indication for up to three PSSCHs, such that retransmissions use the same number of subchannels as their original transmissions. As such, flexible FDRA for retransmissions may be desired, for example, in wireless communications systems using non-CBG transmissions. For example, in a mode 2 deployment (e.g., autonomous channel access) with a relatively heavy load, as compared to the bandwidth of a communication link, three subchannels (or fewer) may be available. In this example, a first, a second, and a third subchannel may be available, where the first subchannel and the second subchannel may each have relaxed demodulation reference signal (DMRS) thresholds. In some examples, a transmitting device may perform a first transmission occupying the first subchannel and the second subchannel. If the transmitting device is to retransmit a portion of the first transmission, the transmitting device may schedule the retransmission for the third subchannel, for example, to satisfy a packet delay budget. In some examples, to perform flexible FDRA, a sidelink device may indicate an additional FDRA codepoint in a PSCCH message, where the codepoint may define one or more subchannels for PSSCH transmissions, for example, different from what may be indicated in a non-flexible FDRA environment (e.g., with a frequency resource assignment configuration). In some cases, when performing sensing procedures, a sidelink device may parse through a frequency resource assignment configuration to identify channel resource reservations. For example, the wireless device205-amay transmit the control information210on the PSCCH indicating a frequency resource assignment configuration. The wireless device205-bmay receive the control information210and may parse through the frequency resource assignment configuration to identify one or more resource reservations, for example, for subsequent transmissions. The wireless device205-bmay identify that within the control information210, the additional FDRA codepoint indicates that an initial, or current PSSCH occupies a different quantity of subchannels as compared to a subsequent, or reserved PSSCH. In some examples, the additional FDRA codepoint may include a scaling factor (e.g., s), indicating that a quantity of subchannels of the initial PSSCH is s-times a quantity of subchannels of the subsequent PSSCH. In other examples, the additional FDRA codepoint may include an adjustment number (e.g., δ) indicating that the quantity of subchannels of the initial PSSCH occupies δ more (or δ) less subchannels than the quantity of subchannels of the subsequent PSSCH. Additionally or alternatively, the additional FDRA codepoint may point to an FDRA table (e.g., in L1 bits) indicating the FDRA for the initial PSSCH. The FDRA table may include one or more scaling factors, adjustment numbers, explicit FDRA indications (e.g., explicit subchannel quantities), or any other value corresponding to FDRA assignment for the initial PSSCH. Using flexible FDRA, wireless devices205may be operable to communicate, over the sidelink channel, signaling220in response to identifying the FDRA for the initial PSSCH. Such signaling220may include data payloads, control signaling, one or more TBs, among other examples. In further support of flexible FDRA, devices may be configured to indicate TBS for subsequent, or reserved PSSCH. In some examples, to facilitate CBG based retransmissions, CBGTI and CBGFI may be signaled in second control information215(e.g., in stage-two SCI for retransmissions). The presence of CBGTI and CBGFI in the second control information215may indicate that the wireless device205-bmay use a same TBS as indicated in a previous SCI carrying the same TB. For example, the second control information215may include a CBGTI, a CBGFI, or both, indicating that the wireless device205-bmay receive the subsequent PSSCH using the same TBS as the initial PSSCH as indicated in a previous control information (e.g., the control information210). Additionally or alternatively, the second control information215may include scaling factors, adjustment factors, specific TBS values, additional bit fields, or a combination thereof, to indicate the TBS of the subsequent TB. Thus, wireless devices205may communicate, over the sidelink channel, signaling220in response to identifying the TBS for the subsequent PSSCH. Some wireless communications systems, such as NR Uu deployments, may support TBS indications using reserved modulation and coding scheme (MCS). That is, a device may indicate an MCS for a reserved transmission, in part, specifying a size of the subsequent transmission. However, devices using NR sidelink communications may use explicit MCS indications to decode stage-two SCI and may not be configured to use reserved MCS to indicate TBS. In such cases, a device receiving a TB may calculate TBS for each received PSSCH, and to avoid ambiguity, retransmissions for each received PSSCH may be arranged to be received with the same parameters (e.g., same TBS, same MCS, same DMRS pattern) as the original PSSCH transmission. Arranging PSSCH retransmissions to mirror the same parameters as their respective original PSSCH transmissions may diminish the flexibility of sidelink communications. To facilitate flexible FDRA (e.g., with CBGs) another indicator for TBS, other than CBGTI and CGBFI, such as the TBS indicator in the second control information215, may be desired. As such, configuring wireless devices205to indicate FDRA for an initial TB and a TBS for a subsequent TB according to the methods descried herein (e.g., supporting flexible FDRA) may improve the efficiency of communication resource usage. For example, providing signaling supporting the use of CBG transmissions in a sidelink communication environment may reduce an amount of resources used for TB retransmissions. FIG.3illustrates an example of a resource configuration300that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. In some examples, the resource configuration300may implement aspects of wireless communications system100or200. In this example, a transmitting device (e.g., wireless device205-aas described with reference toFIG.2) may be configured to transmit one or more TBs to a receiving device (e.g., wireless device205-bas described with reference toFIG.2) according to resource configuration300. That is, the transmitting device may transmit a first TB305on a PSSCH and a first control information310on a PSCCH to a receiving device. The first TB305may be equivalently referred to as an initial TB or a current TB. Additionally, the transmitting device may transmit a second TB315on a PSSCH and a second control information320on a PSCCH to the receiving device. The second TB315may be equivalently referred to as a reserved TB or a subsequent TB. The transmitting device may include information within the first control information310and the second control information320to support flexible FDRA as described herein. To support flexible frequency domain resource allocations for transmissions and retransmissions, the transmitting device may indicate respective FDRA for a current (or initial) PSSCH and reserved (or subsequent) PSSCH(s). For example, the first control information310may indicate an FDRA for the first TB305(e.g., FDRA1) and an FDRA for the second TB315(e.g., FDRA2). In resource configuration300, the first control information310may indicate that the first TB305may be assigned to five subchannels and the second TB315may be assigned to one subchannel. In some examples, the transmitting device may include a scaling factor (e.g., s≥1) in the first control information310, where the scaling factor may indicate that a quantity of subchannels of the current TB may be s-times a quantity of subchannels indicated in the FDRA for the second TB315(e.g., in a frequency resource assignment configuration as described with reference toFIG.2). For example, in resource configuration300, the first control information310may indicate a scaling factor of five, indicating that the first TB305may be transmitted across five times the subchannels indicated in the FDRA for the second TB315. The receiving device may receive the first control information310including the scaling factor and may obtain the quantity of subchannels for the reserved PSSCH. By multiplying the quantity of subchannels for the reserved PSSCH, the receiving device may obtain the quantity of subchannels for the current PSSCH and may reconstruct the PSSCH DMRS accordingly, for example, to proceed to decoding stage-two SCI. In cases where the first control information310includes the scaling factor to indicate the FDRA for the initial TB, there may be no impact to a reservation mechanism used by devices not configured for flexible FDRA (e.g., referencing solely the frequency resource assignment configuration). Additionally or alternatively, the transmitting device may include an adjustment factor (e.g., δ), where the adjustment factor may indicate that the quantity of subchannels of the current PSSCH occupies δ more (or δ less) subchannels than the quantity of subchannels of the subsequent PSSCH (e.g., in the frequency resource assignment configuration). For example, in resource configuration300, the first control information may include an adjustment factor equal to four, where the receiving device may determine that the quantity of subchannels for the first TB305may be equal to four more subchannels than the quantity of subchannels for the second TB315. In some examples, the transmitting device may include an additional FDRA codepoint (e.g., information element or portion of an information element) for the current PSSCH. In some cases, the additional FDRA codepoint may include an absolute quantity of subchannels of the current PSSCH. For example, in resource configuration300, the first control information310may include the additional FDRA codepoint containing an explicit indication of five subchannels for the first TB305. As such, the receiving device may receive the first control information310and may determine that the first TB305spans five subchannels. In some cases, the additional FDRA codepoint may include a pointer to a table of stored values (e.g., an L3 table), where the table of stored values may include a defined set of FDRAs (e.g., predefined FDRAs and other parameters), for example, as a set of absolute subchannel quantities, scaling factors, or adjustment numbers. The receiving device may receive the first control information310and identify the additional FDRA for the first TB305based on the codepoint pointing to an absolute subchannel quantity (e.g., five subchannels), a scaling factor (e.g., s=5), or an adjustment number (e.g., δ=4), in the table of stored values. In some examples, the additional FDRA codepoint may be logically independent from a reservation field. That is, the additional FDRA codepoint may be independent from a field indicating the FDRA for the subsequent TB, or a subsequent TB reservation field. As such, in cases where the first control information310includes the additional FDRA codepoint, there may be no impact to a reservation mechanism used by devices not configured for flexible FDRA. In some examples, the additional FDRA codepoint may indicate an FDRA for all PSSCHs (i.e., an FDRA for the initial PSSCH and an FDRA for the subsequent PSSCH). In such examples, the receiving device may receive the additional FDRA codepoint and may understand that the additional FDRA codepoint may apply to both the initial PSSCH and the subsequent PSSCH. That is, the receiving device may use the additional FDRA codepoint, rather than the indication in a subsequent TB reservation field (e.g., within the frequency resource assignment configuration), to determine the FDRA for the subsequent PSSCH. In such cases, the starting points indicated by frequency indicator values (IVs) in the subsequent TB reservation field may remain valid. In some cases, the additional FDRA codepoint may include a pointer to a table of stored values (e.g., an L3 table), where the table of stored values may include a predefined set of FDRAs, for example, as a set of absolute subchannel quantities, scaling factors, or adjustment numbers for the initial TB and the subsequent TB. In some examples, the FDRA codepoint may include an index indicating an FDRA1 and an FDRA2 corresponding to the initial TB FDRA and the subsequent TB FDRA, respectively. As an illustrative example, the table of stored values may include FDRA indications as described with Table 1. TABLE 1IndexFDRA1FDRA2041151. . .. . .. . . In the example of resource configuration300, the receiving device may receive the first control information310with the additional FDRA codepoint including an index of 1. As such, and with reference to Table 1, the receiving device may determine that the first TB305may span five subchannels and that the second TB315may span one subchannel. In some examples, the transmitting device may redefine the subsequent TB reservation field to specify a leading subchannel of respective reserved (subsequent) PSSCHs. In some cases, the subsequent TB reservation field may specify both a leading subchannel (i.e., a frequency starting point) as well as a quantity of subchannels (i.e., a length, in the frequency domain, of the TB). In such cases, the quantity of subchannels of the subsequent TB reservation field may be signaled using [log2(NsubChannelSL(NsubChannelSL+1)2)] bits when sl-MaxNumPerReserve is configured as 2 and may be signaled using [log2(NsubChannelSL(NsubChannelSL+1)(2NsubChannelSL+1)6)] bits when sl-MaxNumPerReserve is configured as 3. The transmitting device may redefine the subsequent TB reservation field to specify the leading subchannel (i.e., a frequency starting point only). In such cases, the leading subchannel may be signaled using [log2(NsubChannelSL)] bits when sl-MaxNumPerReserve is configured as 2 and may be signaled using 2[log2(NsubChannelSL)] bits when sl-MaxNumPerReserve is configured as 3. Redefining the subsequent TB reservation field to specify solely the leading subchannel may correspond to considerable gain, for example, signaling only the leading subchannel may reduce a quantity of bits used to signal FDRA. In some examples, such as within an SCI of a retransmission PSSCH, the transmitting device may indicate a determined TBS to the receiving device. In the example of resource configuration300, the transmitting device may indicate the TBS of the second TB315within the second control information320. In some examples, the transmitting device may indicate the TBS with the presence of a CBGTI, a CBGFI, or both in stage-two SCI. For example, the second control information320may include a CBGTI, a CBGFI, or both, which may indicate the TBS of the second TB315. The receiving device may thus be indicated to use a TBS from the initial TB for a CBG retransmission such as in cases where the second TB315is a retransmission of a portion (e.g., a CBG) of the first TB305. In some examples, the transmitting device may indicate the TBS with a scaling factor. For example, the second control information320may include a scaling factor and the receiving device may determine the TBS for the second TB315by multiplying the scaling factor with a TBS of the first TB305, for example, a TBS received in the first control information310. In some examples, the transmitting device may indicate the TBS with an adjustment factor. For example, the second control information320may include the adjustment factor and the receiving device may determine the TBS for the second TB315by adding (or subtracting) the adjustment factor to (or from) the TBS of the first TB305. In some other examples, the transmitting device may indicate the TBS in the additional FDRA codepoint. In some cases, the additional FDRA codepoint may indicate the TBS as an explicit size, for example, in addition to the one or more FDRA indications. In yet other examples, the transmitting device may indicate the TBS in an additional bit field within stage-two SCI. For example, the second control information320may include an additional bit field corresponding to the TBS of the second TB315. In some examples, the techniques as described herein may be applied to enhance downlink control information (DCI) signaling, for example, to support flexible FDRA in NR sidelink mode 1. For example, in an in-coverage deployment, the transmitting device may receive a grant for sidelink channel access, where the grant may be transmitted by a base station serving an area where the transmitting device is located. In such examples, the base station may transmit the grant as a DCI format 3_0, including a frequency resource assignment configuration. The techniques described herein may thus interact with the frequency resource assignment configuration within the DCI format 3_0. That is, the DCI format 3_0 may include an FDRA for the initial TB as a scaling factor of the FDRA of the subsequent TB (e.g., from the frequency resource assignment configuration), an adjustment factor of the FDRA of the subsequent TB, an explicit number of subchannels, a pointer to a table of stored values associated with FDRA. Further, the DCI format 3_0 may indicate the FDRA for the subsequent TB as a leading subchannel. In some examples, a base station may use a DCI (e.g., DCI format 3_0) to request, from the transmitting device, an uplink control information (UCI) with more than one bit to determine whether a retransmission may be requested. If retransmission is requested, the UCI may further indicate an amount of radio resources (e.g., in terms of a quantity of subchannels) that the transmitting device may use for the retransmission. For example, the transmitting device may receive a retransmission request from the receiving device and the transmitting device may transmit a UCI, to the base station, indicating the retransmission request. In some examples, the receiving device may indicate a portion of a TB for retransmission and the transmitting device may further indicate, within the UCI, an amount of resources requested for the retransmission of the portion of the TB. In some cases, the transmitting device may indicate the amount of resources based on, or otherwise referencing, an amount of resources used for the previous transmission (e.g., within a previous grant). As an illustrative example, the UCI may include a two-bit (e.g., m=2) indication of the retransmission request as described with Table 2. TABLE 2m = 2Request for retransmission resources“00”None“01”One quarter of #subchannels of previous grant“10”One half of #subchannels of previous grant“11”Same # of subchannels as previous grant In the example of resource configuration300, the transmitting device may transmit the first TB305using five subchannels. In some examples, the receiving device may fail to receive a portion of the first TB305. For example, the receiving device may fail to receive the portion of the first TB305transmitted via a first subchannel, or a first CBG of the first TB305. As such, the receiving device may request a retransmission of the portion of the first TB305. The transmitting device may transmit a UCI to a serving base station, the UCI including a request for sidelink retransmission resources that the transmitting device may use to retransmit the portion of the first TB305. In the case of resource configuration300, the transmitting device may request one fifth of the quantity of subchannels used for the initial transmission of the first TB305. As such, the serving base station may transmit a grant to the transmitting device such that the transmitting device may transmit the second TB315as a retransmission of the portion of the first TB305, the second TB315occupying a single subcarrier. In further support of flexible FDRA, the techniques as described herein may apply to CG communications in NR sidelink. That is, a sidelink CG may include an FDRA for an initial TB as a scaling factor of the FDRA of a subsequent TB, an adjustment factor of the FDRA of the subsequent TB, an explicit number of subchannels, a pointer to a table of stored values associated with FDRA, and in some cases, as a leading subchannel. Further, CG communications may support retransmission requests and subcarrier quantity specification as described with reference to the transmitting device transmitting UCI to a serving base station. Configuring devices to indicate FDRA for an initial TB and a TBS for a subsequent TB according to the methods descried herein may support a more granular allocation of resources, reducing use of extraneous communication resources, thereby increasing the efficiency of wireless communications. For example, signaling TB transmissions according to resource configuration300may reduce an amount of resources used for TB retransmissions. FIG.4illustrates an example of a process flow400that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. In some examples, the process flow400may implement aspects of wireless communications systems100or200. For example, process flow400may include wireless device205-cand wireless device205-d, which may be examples of corresponding devices as described with reference toFIG.2. Further, process flow400may implement aspects of resource configuration300as described with reference toFIG.3. For example, the wireless devices205may communicate according to resource configuration300, such that the wireless devices205may support flexible FDRA in a sidelink communications environment. In the following description of the process flow400, the operations may be performed (e.g., reported or provided) in a different order than the order shown, or the operations performed by the wireless devices205may be performed in different orders or at different times. For example, specific operations also may be left out of the process flow400, or other operations may be added to the process flow400. Further, although some operations or signaling may be shown to occur at different times for discussion purposes, these operations may actually occur at the same time. At405, wireless device205-dmay identify a first FDRA of a first TB associated with an initial transmission. For example, wireless device205-dmay identify that the first TB may occupy a first quantity of subchannels, such as five subchannels corresponding to the first TB305as described with reference toFIG.3. At410, wireless device205-dmay identify a second FDRA of a second TB associated with a subsequent transmission, where identifying the first FDRA may be based on identifying the second FDRA of the second TB. For example, wireless device205-dmay identify that the second TB may occupy a second quantity of subchannels, such as one subchannel corresponding to the second TB315as described with reference toFIG.3. At415, wireless device205-dmay transmit, and wireless device205-cmay receive, control information including a parameter associated with the first FDRA and an indication of the second FDRA. In some cases, the control information may be communicated over a PSCCH. In some examples, the wireless device205-dmay transmit the control information including a scaling factor, where the parameter associated with the first FDRA includes the scaling factor. In some examples, the wireless device205-dmay transmit the control information including an adjustment factor, where the parameter includes the adjustment factor. In some examples, the parameter may include a second indication of the first FDRA of the first TB. For example, the parameter may include an explicit, or absolute, indication of a quantity of subchannels for the first TB. In some examples, the wireless device205-dmay determine an index associated with stored values of the first FDRA of the first TB, where the parameter may include the index. In such examples, the stored values may include one or more frequency domain resources (e.g., explicit subchannel quantities), one or more scaling factors, or one or more adjustment factors associated with the first FDRA. In some examples, the wireless device205-dmay transmit the control information including a second indication including an index associated with stored values of the first FDRA of the first TB and with stored values of the second FDRA for the second TB. For example, the wireless device205-dmay transmit the control information including the second indication including an index as described in Table 1. In any case, the indication of the second FDRA of the second TB may include an indication of a leading subchannel, for example, as described with reference toFIG.3. Additionally or alternatively, the control information may be associated with a CG for sidelink communications. At420, the wireless device205-dmay transmit the first TB to the wireless device205-c. For example, the wireless device205-dmay transmit the first TB using five subcarriers, such as the five subcarriers used to transmit the first TB305as described with reference toFIG.3. The first TB may be communicated over a PSSCH. At425, the wireless device205-cmay identify the first FDRA of the first TB based on receiving the control information that includes the parameter and the indication. In some examples, the wireless device205-cmay apply the scaling factor to the second FDRA, where the parameter associated with the first FDRA of the first TB includes the scaling factor. To identify the first FDRA, the wireless device205-cmay multiply the scaling factor with the second FDRA, where the product of the multiplication may be the first FDRA. In some examples, the wireless device205-cmay combine the adjustment factor with the second FDRA, where the parameter associated with the first FDRA of the first TB includes the adjustment factor. To identify the first FDRA, the wireless device205-cmay add or subtract the adjustment factor to or from the second FDRA, where the sum or difference may be the first FDRA. In examples where the parameter includes the second indication of the first FDRA of the first TB, identifying the first FDRA may be based on the second indication included in the control information. That is, the wireless device205-cmay identify the first FDRA based on receiving an explicit, or absolute, indication of a quantity of subchannels for the first FDRA. In examples where the parameter includes an index associated with stored values of the first FDRA of the first TB, the wireless device205-cmay identify a stored value of the stored values that is associated with the index based on receiving the index, where identifying the first FDRA may be based on the stored value. In some cases, the control information may include a second indication including an index associated with stored values of the first FDRA of the first TB and with stored values of the second FDRA for the second TB. As such, the wireless device205-cmay receive the second indication and may determine both the first FDRA and the second FDRA based on the index. In some examples, the indication of the second FDRA of the second TB may include an indication of a leading subchannel (e.g., redefining a subsequent TB reservation field as described with reference toFIG.3). In some examples, the wireless device205-cmay be configured to identify a format associated with the control information, where identifying the first FDRA of the first TB may be based on the format associated with the control information. In such examples, the control information may be (or may be within) SCI. At430, the wireless device205-dmay determine a size of the second TB. That is, the wireless device205-dmay determine a TBS of the second TB, for example, in cases where the second TB may be a retransmission of at least a portion of the first TB. In some examples, the wireless device205-dmay determine the TBS of the second TB based on a TBS of the first TB. For example, the wireless device205-bmay associate the TBS of the second TB with a CBGTI, a CBGFI, or both of the first TB, a scaling factor of the TBS of the first TB, an adjustment factor of the TBS of the first TB, or the like. At435, the wireless device205-dmay transmit, and the wireless device205-cmay receive, over a second sidelink channel, second control information including a second parameter associated with the size of the second TB. In some cases, the second control information may be communicated over the PSCCH. In some examples, the wireless device205-dmay transmit, within the second control information, CBG information associated with the first TB, where the size of the second TB may be based on the CBG. For example, in cases where the second TB includes a retransmission of a portion of the first TB, the presence of CBGTI, CBGFI, or both, within the second control information, may indicate that the TBS of the second TB may be the same as the TB of the portion of the first TB. In some examples, the wireless device205-dmay transmit the second control information including a scaling factor, where the second parameter includes the scaling factor. In some examples, the wireless device205-dmay transmit the second control information including an adjustment factor, where the second parameter includes the adjustment factor. In some examples, the second parameter may include a second index associated with stored values associated with TBS. For example, the second index may be associated with stored values such as the stored values in Table 1. That is, in some examples, the Table 1 may additionally include one or more TBS values such that the second index may point to a specific value in Table 1 (e.g., in the additional FDRA codepoint). In such examples, determining the size of the second TB may further include identifying a stored value associated with the second index and corresponding to the size of the second TB. In some examples, wireless device205-dmay transmit the second control information including a bit field indicating the size of the second TB. Phrased alternatively, the wireless device205-dmay transmit the second control information including an additional bit field for indicating the size of the second TB. In some examples, at440, the wireless device205-cmay transmit, to the wireless device205-dover the sidelink channel, a request to retransmit a portion of the first TB. For example, the wireless device205-cmay fail to receive, or decode, a CBG of the first TB and the wireless device205-cmay indicate the failure to the wireless device205-d. In some examples, the request to retransmit the portion of the first TB may include an indication of an amount of frequency domain resources for the second TB. For example, the request to retransmit the portion of the first TB may include an indication that the second TB may occupy one subchannel such as the one subchannel allocated to the second TB315as described with reference toFIG.3. At445, the wireless device205-dmay transmit, and the wireless device205-cmay receive, the second TB (e.g., communicated over the PSSCH). For example, the wireless device205-dmay transmit the second TB using one subcarrier, such as the one subcarrier used to transmit the second TB315as described with reference toFIG.3. In some examples, the wireless device205-dmay transmit a UCI to a base station to request access to the sidelink channel in accordance with sidelink channel access mode 1. In such cases, the UCI may include an indication of an amount of frequency domain resources for the second TB. The base station may grant the sidelink channel access request for the amount of frequency domain resources for the second TB. In some examples, the base station may grant the request by transmitting a DCI (e.g., DCI format 3_0) to the wireless device205-d. At450, the wireless device205-cmay determine the size of the second TB based on receiving the second control information. In some examples, the wireless device205-cmay determine the size of the second TB by identifying, within the second control information, CBG information associated with the first TB, where the size of the second TB is based on the CBG information. For example, in cases where the second TB is a retransmission of a portion of the first TB (e.g., a CBG of the first TB), the presence of CBGTI, CBGFI, or both in the second control information may indicate that the size of the second TB corresponds to the size of the portion of the first TB. In some examples, the wireless device205-cmay determine the size of the second TB by applying the scaling factor to a size of the first TB, where the second parameter includes the scaling factor. That is, the wireless device205-cmay multiply the scaling factor to the size of the first TB, the product being the size of the second TB. In some examples, the wireless device205-cmay determine the size of the second TB by combining the adjustment factor to a size of the first TB, where the second parameter includes the adjustment factor. That is, the wireless device205-cmay add or subtract the adjustment factor to or from the size of the first TB, where the sum or difference may be the size of the second TB. In examples where the second parameter includes the second index associated with stored values associated with TBS, the wireless device205-cmay identify a stored value associated with the second index and corresponding to the size of the second TB. In some examples, the wireless device205-cmay identify, within the second control information, a bit field indicating the size of the second TB. That is, the wireless device205-cmay identify an additional bit field for indicating the size of the second TB, within the second control information. At455, the wireless device205-cand the wireless device205-dmay communicate, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and receiving the indication of the second FDRA of the second TB. FIG.5shows a block diagram500of a device505that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The device505may be an example of aspects of a wireless device, such as a receiving device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIGS.2through4) as described herein. In some examples, the receiving device may be a transmitting device as described herein. The device505may include a receiver510, a transmitter515, and a communications manager520. The device505may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver510may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to flexible FDRA for sidelink). Information may be passed on to other components of the device505. The receiver510may utilize a single antenna or a set of multiple antennas. The transmitter515may provide a means for transmitting signals generated by other components of the device505. For example, the transmitter515may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to flexible FDRA for sidelink). In some examples, the transmitter515may be co-located with a receiver510in a transceiver module. The transmitter515may utilize a single antenna or a set of multiple antennas. The communications manager520, the receiver510, the transmitter515, or various combinations thereof or various components thereof may be examples of means for performing various aspects of flexible FDRA for sidelink as described herein. For example, the communications manager520, the receiver510, the transmitter515, or various combinations or components thereof may support a method for performing one or more of the functions described herein. In some examples, the communications manager520, the receiver510, the transmitter515, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some examples, a processor and memory coupled with the processor may be configured to perform one or more of the functions described herein (e.g., by executing, by the processor, instructions stored in the memory). Additionally or alternatively, in some examples, the communications manager520, the receiver510, the transmitter515, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by a processor. If implemented in code executed by a processor, the functions of the communications manager520, the receiver510, the transmitter515, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting a means for performing the functions described in the present disclosure). In some examples, the communications manager520may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver510, the transmitter515, or both. For example, the communications manager520may receive information from the receiver510, send information to the transmitter515, or be integrated in combination with the receiver510, the transmitter515, or both to receive information, transmit information, or perform various other operations as described herein. The communications manager520may support wireless communications at a wireless device in accordance with examples as disclosed herein. For example, the communications manager520may be configured as or otherwise support a means for receiving, over a sidelink channel, control information including a parameter associated with a first FDRA of a first TB associated with an initial transmission and an indication of a second FDRA of a second TB associated with a subsequent transmission after the initial transmission. The communications manager520may be configured as or otherwise support a means for identifying the first FDRA of the first TB based on receiving the control information that includes the parameter and the indication. The communications manager520may be configured as or otherwise support a means for communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and receiving the indication of the second FDRA of the second TB. By including or configuring the communications manager520in accordance with examples as described herein, the device505(e.g., a processor controlling or otherwise coupled to the receiver510, the transmitter515, the communications manager520, or a combination thereof) may support techniques for receiving control information supporting flexible FDRA, resulting in more efficient utilization of communication resources, reduced power usage, and diminished extraneous signal processing. FIG.6shows a block diagram600of a device605that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The device605may be an example of aspects of a device505or a receiving device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIGS.2through4) as described herein. In some examples, the receiving device may be a transmitting device as described herein. The device605may include a receiver610, a transmitter615, and a communications manager620. The device605may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver610may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to flexible FDRA for sidelink). Information may be passed on to other components of the device605. The receiver610may utilize a single antenna or a set of multiple antennas. The transmitter615may provide a means for transmitting signals generated by other components of the device605. For example, the transmitter615may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to flexible FDRA for sidelink). In some examples, the transmitter615may be co-located with a receiver610in a transceiver module. The transmitter615may utilize a single antenna or a set of multiple antennas. The device605, or various components thereof, may be an example of means for performing various aspects of flexible FDRA for sidelink as described herein. For example, the communications manager620may include a control information receiver625, an FDRA identification component630, a signal communication component635, or any combination thereof. The communications manager620may be an example of aspects of a communications manager520as described herein. In some examples, the communications manager620, or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver610, the transmitter615, or both. For example, the communications manager620may receive information from the receiver610, send information to the transmitter615, or be integrated in combination with the receiver610, the transmitter615, or both to receive information, transmit information, or perform various other operations as described herein. The communications manager620may support wireless communications at a wireless device in accordance with examples as disclosed herein. The control information receiver625may be configured as or otherwise support a means for receiving, over a sidelink channel, control information including a parameter associated with a first FDRA of a first TB associated with an initial transmission and an indication of a second FDRA of a second TB associated with a subsequent transmission after the initial transmission. The FDRA identification component630may be configured as or otherwise support a means for identifying the first FDRA of the first TB based on receiving the control information that includes the parameter and the indication. The signal communication component635may be configured as or otherwise support a means for communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and receiving the indication of the second FDRA of the second TB. FIG.7shows a block diagram700of a communications manager720that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The communications manager720may be an example of aspects of a communications manager520, a communications manager620, or both, as described herein. The communications manager720, or various components thereof, may be an example of means for performing various aspects of flexible FDRA for sidelink as described herein. For example, the communications manager720may include a control information receiver725, an FDRA identification component730, a signal communication component735, a TBS determination component740, a format identification component745, a retransmission request transmitter750, a stored value identification component755, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses). The communications manager720may support wireless communications at a wireless device in accordance with examples as disclosed herein. The control information receiver725may be configured as or otherwise support a means for receiving, over a sidelink channel, control information including a parameter associated with a first FDRA of a first TB associated with an initial transmission and an indication of a second FDRA of a second TB associated with a subsequent transmission after the initial transmission. The FDRA identification component730may be configured as or otherwise support a means for identifying the first FDRA of the first TB based on receiving the control information that includes the parameter and the indication. The signal communication component735may be configured as or otherwise support a means for communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and receiving the indication of the second FDRA of the second TB. In some examples, to support identifying the first FDRA, the FDRA identification component730may be configured as or otherwise support a means for applying a scaling factor to the second FDRA, where the parameter associated with the first FDRA of the first TB includes the scaling factor. In some examples, to support identifying the first FDRA, the FDRA identification component730may be configured as or otherwise support a means for combining an adjustment factor with the second FDRA, where the parameter associated with the first FDRA of the first TB includes the adjustment factor. In some examples, the parameter includes a second indication of the first FDRA of the first TB. In some examples, identifying the first FDRA is based on the second indication included in the control information. In some examples, the parameter includes an index associated with stored values of the first FDRA of the first TB. In some examples, the stored value identification component755may be configured as or otherwise support a means for identifying a stored value of the stored values that is associated with the index based on receiving the index, where identifying the first FDRA is based on the stored value. In some examples, the stored values include one or more frequency domain resources, one or more scaling factors, or one or more adjustment factors associated with the first FDRA. In some examples, the control information includes a second indication including an index associated with stored values of the first FDRA of the first TB and with stored values of the second FDRA for the second TB. In some examples, the indication of the second FDRA of the second TB includes an indication of a leading subchannel. In some examples, the control information receiver725may be configured as or otherwise support a means for receiving, over a second sidelink channel, second control information including a second parameter associated with a size of the second TB. In some examples, the TBS determination component740may be configured as or otherwise support a means for determining the size of the second TB based on receiving the second control information. In some examples, to support determining the size of the second TB, the TBS determination component740may be configured as or otherwise support a means for identifying, within the second control information, CBG information associated with the first TB, where the size of the second TB is based on the CBG information. In some examples, to support determining the size of the second TB, the TBS determination component740may be configured as or otherwise support a means for applying a scaling factor to a size of the first TB, where the second parameter includes the scaling factor. In some examples, to support determining the size of the second TB, the TBS determination component740may be configured as or otherwise support a means for combining an adjustment factor with a size of the first TB, where the second parameter includes the adjustment factor. In some examples, to support determining the size of the second TB, the stored value identification component755may be configured as or otherwise support a means for identifying a stored value associated with the second index and corresponding to the size of the second TB. In some examples, to support determining the size of the second TB, the TBS determination component740may be configured as or otherwise support a means for identifying, within the second control information, a bit field indicating the size of the second TB. In some examples, the format identification component745may be configured as or otherwise support a means for identifying a format associated with the control information, where identifying the first FDRA of the first TB is based on the format associated with the control information. In some examples, the control information includes SCI. In some examples, the retransmission request transmitter750may be configured as or otherwise support a means for transmitting, to a second wireless device over the sidelink channel, a request to retransmit a portion of the first TB, where the second TB includes the portion of the first TB. In some examples, the request to retransmit the portion of the first TB includes an indication of an amount of frequency domain resources for the second TB. In some examples, the control information is associated with a CG for sidelink communications. In some examples, the control information is communicated over a physical sidelink control channel and the first TB and the second TB are communicated over a physical sidelink shared channel. FIG.8shows a diagram of a system800including a device805that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The device805may be an example of or include the components of a device505, a device605, or a receiving device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIGS.2through4) as described herein. In some examples, the receiving device may be a transmitting device as described herein. The device805may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager820, an I/O controller810, a transceiver815, an antenna825, a memory830, code835, and a processor840. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus845). The I/O controller810may manage input and output signals for the device805. The I/O controller810may also manage peripherals not integrated into the device805. In some cases, the I/O controller810may represent a physical connection or port to an external peripheral. In some cases, the I/O controller810may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. Additionally or alternatively, the I/O controller810may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller810may be implemented as part of a processor, such as the processor840. In some cases, a user may interact with the device805via the I/O controller810or via hardware components controlled by the I/O controller810. In some cases, the device805may include a single antenna825. However, in some other cases, the device805may have more than one antenna825, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver815may communicate bi-directionally, via the one or more antennas825, wired, or wireless links as described herein. For example, the transceiver815may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver815may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas825for transmission, and to demodulate packets received from the one or more antennas825. The transceiver815, or the transceiver815and one or more antennas825, may be an example of a transmitter515, a transmitter615, a receiver510, a receiver610, or any combination thereof or component thereof, as described herein. The memory830may include random access memory (RAM) and read-only memory (ROM). The memory830may store computer-readable, computer-executable code835including instructions that, when executed by the processor840, cause the device805to perform various functions described herein. The code835may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code835may not be directly executable by the processor840but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the memory830may contain, among other things, a basic input output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices. The processor840may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor840may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor840. The processor840may be configured to execute computer-readable instructions stored in a memory (e.g., the memory830) to cause the device805to perform various functions (e.g., functions or tasks supporting flexible FDRA for sidelink). For example, the device805or a component of the device805may include a processor840and memory830coupled to the processor840, the processor840and memory830configured to perform various functions described herein. The communications manager820may support wireless communications at a wireless device in accordance with examples as disclosed herein. For example, the communications manager820may be configured as or otherwise support a means for receiving, over a sidelink channel, control information including a parameter associated with a first FDRA of a first TB associated with an initial transmission and an indication of a second FDRA of a second TB associated with a subsequent transmission after the initial transmission. The communications manager820may be configured as or otherwise support a means for identifying the first FDRA of the first TB based on receiving the control information that includes the parameter and the indication. The communications manager820may be configured as or otherwise support a means for communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and receiving the indication of the second FDRA of the second TB. By including or configuring the communications manager820in accordance with examples as described herein, the device805may support techniques for receiving control information supporting flexible FDRA, resulting in reduced power consumption, more efficient utilization of communication resources, improved coordination between devices, longer battery life, and improved utilization of processing capability. In some examples, the communications manager820may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver815, the one or more antennas825, or any combination thereof. Although the communications manager820is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager820may be supported by or performed by the processor840, the memory830, the code835, or any combination thereof. For example, the code835may include instructions executable by the processor840to cause the device805to perform various aspects of flexible FDRA for sidelink as described herein, or the processor840and the memory830may be otherwise configured to perform or support such operations. FIG.9shows a block diagram900of a device905that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The device905may be an example of aspects of a wireless device, such as a transmitting device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIGS.2through4) as described herein. In some examples, the transmitting device may be a receiving device as described herein. The device905may include a receiver910, a transmitter915, and a communications manager920. The device905may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver910may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to flexible FDRA for sidelink). Information may be passed on to other components of the device905. The receiver910may utilize a single antenna or a set of multiple antennas. The transmitter915may provide a means for transmitting signals generated by other components of the device905. For example, the transmitter915may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to flexible FDRA for sidelink). In some examples, the transmitter915may be co-located with a receiver910in a transceiver module. The transmitter915may utilize a single antenna or a set of multiple antennas. The communications manager920, the receiver910, the transmitter915, or various combinations thereof or various components thereof may be examples of means for performing various aspects of flexible FDRA for sidelink as described herein. For example, the communications manager920, the receiver910, the transmitter915, or various combinations or components thereof may support a method for performing one or more of the functions described herein. In some examples, the communications manager920, the receiver910, the transmitter915, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a DSP, an ASIC, an FPGA or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some examples, a processor and memory coupled with the processor may be configured to perform one or more of the functions described herein (e.g., by executing, by the processor, instructions stored in the memory). Additionally or alternatively, in some examples, the communications manager920, the receiver910, the transmitter915, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by a processor. If implemented in code executed by a processor, the functions of the communications manager920, the receiver910, the transmitter915, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting a means for performing the functions described in the present disclosure). In some examples, the communications manager920may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver910, the transmitter915, or both. For example, the communications manager920may receive information from the receiver910, send information to the transmitter915, or be integrated in combination with the receiver910, the transmitter915, or both to receive information, transmit information, or perform various other operations as described herein. The communications manager920may support wireless communications at a wireless device in accordance with examples as disclosed herein. For example, the communications manager920may be configured as or otherwise support a means for identifying a first FDRA of a first TB associated with an initial transmission. The communications manager920may be configured as or otherwise support a means for identifying a second FDRA of a second TB associated with a subsequent transmission, where identifying the first FDRA is based on identifying the second FDRA of the second TB. The communications manager920may be configured as or otherwise support a means for transmitting, over a sidelink channel, control information including a parameter associated with the first FDRA and an indication of the second FDRA. The communications manager920may be configured as or otherwise support a means for communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and identifying the second FDRA of the second TB. By including or configuring the communications manager920in accordance with examples as described herein, the device905(e.g., a processor controlling or otherwise coupled to the receiver910, the transmitter915, the communications manager920, or a combination thereof) may support techniques for transmitting control information supporting flexible FDRA, resulting in more efficient utilization of communication resources, reduced power usage, and diminished extraneous signal processing. FIG.10shows a block diagram1000of a device1005that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The device1005may be an example of aspects of a device905or a transmitting device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIGS.2through4) as described herein. In some examples, the transmitting device may be a receiving device as described herein. The device1005may include a receiver1010, a transmitter1015, and a communications manager1020. The device1005may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). The receiver1010may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to flexible FDRA for sidelink). Information may be passed on to other components of the device1005. The receiver1010may utilize a single antenna or a set of multiple antennas. The transmitter1015may provide a means for transmitting signals generated by other components of the device1005. For example, the transmitter1015may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to flexible FDRA for sidelink). In some examples, the transmitter1015may be co-located with a receiver1010in a transceiver module. The transmitter1015may utilize a single antenna or a set of multiple antennas. The device1005, or various components thereof, may be an example of means for performing various aspects of flexible FDRA for sidelink as described herein. For example, the communications manager1020may include an FDRA identification component1025, a control information transmitter1030, a signal communication component1035, or any combination thereof. The communications manager1020may be an example of aspects of a communications manager920as described herein. In some examples, the communications manager1020, or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver1010, the transmitter1015, or both. For example, the communications manager1020may receive information from the receiver1010, send information to the transmitter1015, or be integrated in combination with the receiver1010, the transmitter1015, or both to receive information, transmit information, or perform various other operations as described herein. The communications manager1020may support wireless communications at a wireless device in accordance with examples as disclosed herein. The FDRA identification component1025may be configured as or otherwise support a means for identifying a first FDRA of a first TB associated with an initial transmission. The FDRA identification component1025may be configured as or otherwise support a means for identifying a second FDRA of a second TB associated with a subsequent transmission, where identifying the first FDRA is based on identifying the second FDRA of the second TB. The control information transmitter1030may be configured as or otherwise support a means for transmitting, over a sidelink channel, control information including a parameter associated with the first FDRA and an indication of the second FDRA. The signal communication component1035may be configured as or otherwise support a means for communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and identifying the second FDRA of the second TB. FIG.11shows a block diagram1100of a communications manager1120that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The communications manager1120may be an example of aspects of a communications manager920, a communications manager1020, or both, as described herein. The communications manager1120, or various components thereof, may be an example of means for performing various aspects of flexible FDRA for sidelink as described herein. For example, the communications manager1120may include an FDRA identification component1125, a control information transmitter1130, a signal communication component1135, an index determination component1140, a TBS determination component1145, a retransmission request receiver1150, a stored value identification component1155, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses). The communications manager1120may support wireless communications at a wireless device in accordance with examples as disclosed herein. The FDRA identification component1125may be configured as or otherwise support a means for identifying a first FDRA of a first TB associated with an initial transmission. In some examples, the FDRA identification component1125may be configured as or otherwise support a means for identifying a second FDRA of a second TB associated with a subsequent transmission, where identifying the first FDRA is based on identifying the second FDRA of the second TB. The control information transmitter1130may be configured as or otherwise support a means for transmitting, over a sidelink channel, control information including a parameter associated with the first FDRA and an indication of the second FDRA. The signal communication component1135may be configured as or otherwise support a means for communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and identifying the second FDRA of the second TB. In some examples, to support transmitting the control information, the control information transmitter1130may be configured as or otherwise support a means for transmitting the control information including a scaling factor, where the parameter includes the scaling factor. In some examples, to support transmitting the control information, the control information transmitter1130may be configured as or otherwise support a means for transmitting the control information including an adjustment factor, where the parameter includes the adjustment factor. In some examples, the parameter includes a second indication of the first FDRA of the first TB. In some examples, the index determination component1140may be configured as or otherwise support a means for determining an index associated with stored values of the first FDRA of the first TB, where the parameter includes the index. In some examples, the stored values include one or more frequency domain resources, one or more scaling factors, or one or more adjustment factors associated with the first FDRA. In some examples, to support transmitting the control information, the control information transmitter1130may be configured as or otherwise support a means for transmitting the control information including a second indication including an index associated with stored values of the first FDRA of the first TB and with stored values of the second FDRA for the second TB. In some examples, the indication of the second FDRA of the second TB includes an indication of a leading subchannel. In some examples, the TBS determination component1145may be configured as or otherwise support a means for determining a size of the second TB. In some examples, the control information transmitter1130may be configured as or otherwise support a means for transmitting, over a second sidelink channel, second control information including a second parameter associated with the size of the second TB. In some examples, to support transmitting the second control information, the control information transmitter1130may be configured as or otherwise support a means for transmitting, within the second control information, CBG information associated with the first TB, where the size of the second TB is based on the CBG information. In some examples, to support transmitting the second control information, the control information transmitter1130may be configured as or otherwise support a means for transmitting the second control information including a scaling factor, where the second parameter includes the scaling factor. In some examples, to support transmitting the second control information, the control information transmitter1130may be configured as or otherwise support a means for transmitting the second control information including an adjustment factor, where the second parameter includes the adjustment factor. In some examples, to support determining the size of the second TB, the stored value identification component1155may be configured as or otherwise support a means for identifying a stored value associated with the second index and corresponding to the size of the second TB. In some examples, to support transmitting the second control information, the control information transmitter1130may be configured as or otherwise support a means for transmitting the second control information including a bit field indicating the size of the second TB. In some examples, the control information corresponds to a format. In some examples, the first FDRA of the first TB is based on the format of the control information. In some examples, the control information includes SCI. In some examples, the retransmission request receiver1150may be configured as or otherwise support a means for receiving, from a second wireless device over the sidelink channel, a request to retransmit a portion of the first TB, where the second TB includes the portion of the first TB. In some examples, the request to retransmit the portion of the first TB includes an indication of an amount of frequency domain resources for the second TB. In some examples, the control information is associated with a CG for sidelink communications. In some examples, the control information is communicated over a physical sidelink control channel and the first TB and the second TB are communicated over a physical sidelink shared channel. FIG.12shows a diagram of a system1200including a device1205that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The device1205may be an example of or include the components of a device905, a device1005, or a transmitting device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIGS.2through4) as described herein. In some examples, the transmitting device may be a receiving device as described herein. The device1205may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager1220, a I/O controller1210, a transceiver1215, an antenna1225, a memory1230, code1235, and a processor1240. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus1245). The I/O controller1210may manage input and output signals for the device1205. The I/O controller1210may also manage peripherals not integrated into the device1205. In some cases, the I/O controller1210may represent a physical connection or port to an external peripheral. In some cases, the I/O controller1210may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. Additionally or alternatively, the I/O controller1210may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller1210may be implemented as part of a processor, such as the processor1240. In some cases, a user may interact with the device1205via the I/O controller1210or via hardware components controlled by the I/O controller1210. In some cases, the device1205may include a single antenna1225. However, in some other cases the device1205may have more than one antenna1225, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver1215may communicate bi-directionally, via the one or more antennas1225, wired, or wireless links as described herein. For example, the transceiver1215may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver1215may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas1225for transmission, and to demodulate packets received from the one or more antennas1225. The transceiver1215, or the transceiver1215and one or more antennas1225, may be an example of a transmitter915, a transmitter1015, a receiver910, a receiver1010, or any combination thereof or component thereof, as described herein. The memory1230may include RAM and ROM. The memory1230may store computer-readable, computer-executable code1235including instructions that, when executed by the processor1240, cause the device1205to perform various functions described herein. The code1235may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code1235may not be directly executable by the processor1240but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the memory1230may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. The processor1240may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor1240may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor1240. The processor1240may be configured to execute computer-readable instructions stored in a memory (e.g., the memory1230) to cause the device1205to perform various functions (e.g., functions or tasks supporting flexible FDRA for sidelink). For example, the device1205or a component of the device1205may include a processor1240and memory1230coupled to the processor1240, the processor1240and memory1230configured to perform various functions described herein. The communications manager1220may support wireless communications at a wireless device in accordance with examples as disclosed herein. For example, the communications manager1220may be configured as or otherwise support a means for identifying a first FDRA of a first TB associated with an initial transmission. The communications manager1220may be configured as or otherwise support a means for identifying a second FDRA of a second TB associated with a subsequent transmission, where identifying the first FDRA is based on identifying the second FDRA of the second TB. The communications manager1220may be configured as or otherwise support a means for transmitting, over a sidelink channel, control information including a parameter associated with the first FDRA and an indication of the second FDRA. The communications manager1220may be configured as or otherwise support a means for communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and identifying the second FDRA of the second TB. By including or configuring the communications manager1220in accordance with examples as described herein, the device1205may support techniques for transmitting control information supporting flexible FDRA, resulting in reduced power consumption, more efficient utilization of communication resources, improved coordination between devices, longer battery life, and improved utilization of processing capability. In some examples, the communications manager1220may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver1215, the one or more antennas1225, or any combination thereof. Although the communications manager1220is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager1220may be supported by or performed by the processor1240, the memory1230, the code1235, or any combination thereof. For example, the code1235may include instructions executable by the processor1240to cause the device1205to perform various aspects of flexible FDRA for sidelink as described herein, or the processor1240and the memory1230may be otherwise configured to perform or support such operations. FIG.13shows a flowchart illustrating a method1300that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The operations of the method1300may be implemented by a wireless device, such as a receiving device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIG.2through4) or its components as described herein. For example, the operations of the method1300may be performed by a receiving device as described with reference toFIGS.1through8. In some examples, the receiving device may be a transmitting device as described herein. In some examples, a receiving device may execute a set of instructions to control the functional elements of the receiving device to perform the described functions. Additionally or alternatively, the receiving device may perform aspects of the described functions using special-purpose hardware. At1305, the method may include receiving, over a sidelink channel, control information including a parameter associated with a first FDRA of a first TB associated with an initial transmission and an indication of a second FDRA of a second TB associated with a subsequent transmission after the initial transmission. The operations of1305may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1305may be performed by a control information receiver725as described with reference toFIG.7. At1310, the method may include identifying the first FDRA of the first TB based on receiving the control information that includes the parameter and the indication. The operations of1310may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1310may be performed by an FDRA identification component730as described with reference toFIG.7. At1315, the method may include communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and receiving the indication of the second FDRA of the second TB. The operations of1315may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1315may be performed by a signal communication component735as described with reference toFIG.7. FIG.14shows a flowchart illustrating a method1400that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The operations of the method1400may be implemented by a wireless device, such as a receiving device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIG.2through4) or its components as described herein. For example, the operations of the method1400may be performed by a receiving device as described with reference toFIGS.1through8. In some examples, the receiving device may be a transmitting device as described herein. In some examples, a receiving device may execute a set of instructions to control the functional elements of the receiving device to perform the described functions. Additionally or alternatively, the receiving device may perform aspects of the described functions using special-purpose hardware. At1405, the method may include receiving, over a sidelink channel, control information including a parameter associated with a first FDRA of a first TB associated with an initial transmission and an indication of a second FDRA of a second TB associated with a subsequent transmission after the initial transmission. The operations of1405may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1405may be performed by a control information receiver725as described with reference toFIG.7. At1410, the method may include identifying the first FDRA of the first TB based on receiving the control information that includes the parameter and the indication. The operations of1410may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1410may be performed by an FDRA identification component730as described with reference toFIG.7. At1415, the method may include communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and receiving the indication of the second FDRA of the second TB. The operations of1415may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1415may be performed by a signal communication component735as described with reference toFIG.7. At1420, the method may include receiving, over a second sidelink channel, second control information including a second parameter associated with a size of the second TB. The operations of1420may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1420may be performed by a control information receiver725as described with reference toFIG.7. At1425, the method may include determining the size of the second TB based on receiving the second control information. The operations of1425may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1425may be performed by a TBS determination component740as described with reference toFIG.7. FIG.15shows a flowchart illustrating a method1500that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The operations of the method1500may be implemented by a wireless device, such as a transmitting device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIG.2through4) or its components as described herein. For example, the operations of the method1500may be performed by a transmitting device as described with reference toFIGS.1through4and9through12. In some examples, the transmitting device may be a receiving device as described herein. In some examples, a transmitting device may execute a set of instructions to control the functional elements of the transmitting device to perform the described functions. Additionally or alternatively, the transmitting device may perform aspects of the described functions using special-purpose hardware. At1505, the method may include identifying a first FDRA of a first TB associated with an initial transmission. The operations of1505may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1505may be performed by an FDRA identification component1125as described with reference toFIG.11. At1510, the method may include identifying a second FDRA of a second TB associated with a subsequent transmission, where identifying the first FDRA is based on identifying the second FDRA of the second TB. The operations of1510may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1510may be performed by an FDRA identification component1125as described with reference toFIG.11. At1515, the method may include transmitting, over a sidelink channel, control information including a parameter associated with the first FDRA and an indication of the second FDRA. The operations of1515may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1515may be performed by a control information transmitter1130as described with reference toFIG.11. At1520, the method may include communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and identifying the second FDRA of the second TB. The operations of1520may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1520may be performed by a signal communication component1135as described with reference toFIG.11. FIG.16shows a flowchart illustrating a method1600that supports flexible FDRA for sidelink in accordance with aspects of the present disclosure. The operations of the method1600may be implemented by a wireless device, such as a transmitting device (e.g., a UE, a base station, a sidelink enabled device, a wireless device as described with reference toFIG.2through4) or its components as described herein. For example, the operations of the method1600may be performed by a transmitting device as described with reference toFIGS.1through4and9through12. In some examples, the receiving device may be a receiving device as described herein. In some examples, a transmitting device may execute a set of instructions to control the functional elements of the transmitting device to perform the described functions. Additionally or alternatively, the transmitting device may perform aspects of the described functions using special-purpose hardware. At1605, the method may include identifying a first FDRA of a first TB associated with an initial transmission. The operations of1605may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1605may be performed by an FDRA identification component1125as described with reference toFIG.11. At1610, the method may include identifying a second FDRA of a second TB associated with a subsequent transmission, where identifying the first FDRA is based on identifying the second FDRA of the second TB. The operations of1610may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1610may be performed by an FDRA identification component1125as described with reference toFIG.11. At1615, the method may include transmitting, over a sidelink channel, control information including a parameter associated with the first FDRA and an indication of the second FDRA. The operations of1615may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1615may be performed by a control information transmitter1130as described with reference toFIG.11. At1620, the method may include communicating, over the sidelink channel, one or more signals based on identifying the first FDRA of the first TB and identifying the second FDRA of the second TB. The operations of1620may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1620may be performed by a signal communication component1135as described with reference toFIG.11. At1625, the method may include determining a size of the second TB. The operations of1625may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1625may be performed by a TBS determination component1145as described with reference toFIG.11. At1630, the method may include transmitting, over a second sidelink channel, second control information including a second parameter associated with the size of the second TB. The operations of1630may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1630may be performed by a control information transmitter1130as described with reference toFIG.11. The following provides an overview of aspects of the present disclosure: Aspect 1: A method for wireless communications at a wireless device, comprising: receiving, over a sidelink channel, control information including a parameter associated with a first frequency domain resource allocation of a first transport block associated with an initial transmission and an indication of a second frequency domain resource allocation of a second transport block associated with a subsequent transmission after the initial transmission; identifying the first frequency domain resource allocation of the first transport block based at least in part on receiving the control information that includes the parameter and the indication; and communicating, over the sidelink channel, one or more signals based at least in part on identifying the first frequency domain resource allocation of the first transport block and receiving the indication of the second frequency domain resource allocation of the second transport block. Aspect 2: The method of aspect 1, wherein identifying the first frequency domain resource allocation further comprises: applying a scaling factor to the second frequency domain resource allocation, wherein the parameter associated with the first frequency domain resource allocation of the first transport block comprises the scaling factor. Aspect 3: The method of any of aspects 1 through 2, wherein identifying the first frequency domain resource allocation further comprises: combining an adjustment factor with the second frequency domain resource allocation, wherein the parameter associated with the first frequency domain resource allocation of the first transport block comprises the adjustment factor. Aspect 4: The method of any of aspects 1 through 3, wherein the parameter comprises a second indication of the first frequency domain resource allocation of the first transport block, identifying the first frequency domain resource allocation is based at least in part on the second indication included in the control information. Aspect 5: The method of any of aspects 1 through 4, wherein the parameter comprises an index associated with stored values of the first frequency domain resource allocation of the first transport block. Aspect 6: The method of aspect 5, further comprising: identifying a stored value of the stored values that is associated with the index based at least in part on receiving the index, wherein identifying the first frequency domain resource allocation is based at least in part on the stored value. Aspect 7: The method of aspect 6, wherein the stored values include one or more frequency domain resources, one or more scaling factors, or one or more adjustment factors associated with the first frequency domain resource allocation. Aspect 8: The method of any of aspects 1 through 7, wherein the control information includes a second indication comprising an index associated with stored values of the first frequency domain resource allocation of the first transport block and with stored values of the second frequency domain resource allocation for the second transport block. Aspect 9: The method of any of aspects 1 through 8, wherein the indication of the second frequency domain resource allocation of the second transport block comprises an indication of a leading subchannel. Aspect 10: The method of any of aspects 1 through 9, further comprising: receiving, over a second sidelink channel, second control information including a second parameter associated with a size of the second transport block; and determining the size of the second transport block based at least in part on receiving the second control information. Aspect 11: The method of aspect 10, wherein determining the size of the second transport block further comprises: identifying, within the second control information, code block group information associated with the first transport block, wherein the size of the second transport block is based at least in part on the code block group information. Aspect 12: The method of any of aspects 10 through 11, wherein determining the size of the second transport block further comprises: applying a scaling factor to a size of the first transport block, wherein the second parameter comprises the scaling factor. Aspect 13: The method of any of aspects 10 through 12, wherein determining the size of the second transport block further comprises: combining an adjustment factor with a size of the first transport block, wherein the second parameter comprises the adjustment factor. Aspect 14: The method of any of aspects 10 through 13, wherein the second parameter comprises a second index associated with stored values associated with transport block size and wherein determining the size of the second transport block further comprises: identifying a stored value associated with the second index and corresponding to the size of the second transport block. Aspect 15: The method of any of aspects 10 through 14, wherein determining the size of the second transport block further comprises: identifying, within the second control information, a bit field indicating the size of the second transport block. Aspect 16: The method of any of aspects 1 through 15, further comprising: identifying a format associated with the control information, wherein identifying the first frequency domain resource allocation of the first transport block is based at least in part on the format associated with the control information. Aspect 17: The method of aspect 16, wherein the control information comprises sidelink control information. Aspect 18: The method of any of aspects 1 through 17, further comprising: transmitting, to a second wireless device over the sidelink channel, a request to retransmit a portion of the first transport block, wherein the second transport block comprises the portion of the first transport block. Aspect 19: The method of aspect 18, wherein the request to retransmit the portion of the first transport block comprises an indication of an amount of frequency domain resources for the second transport block. Aspect 20: The method of any of aspects 1 through 19, wherein the control information is associated with a configured grant for sidelink communications. Aspect 21: The method of any of aspects 1 through 20, wherein the control information is communicated over a physical sidelink control channel and the first transport block and the second transport block are communicated over a physical sidelink shared channel. Aspect 22: A method for wireless communications at a wireless device, comprising: identifying a first frequency domain resource allocation of a first transport block associated with an initial transmission; identifying a second frequency domain resource allocation of a second transport block associated with a subsequent transmission, wherein identifying the first frequency domain resource allocation is based at least in part on identifying the second frequency domain resource allocation of the second transport block; transmitting, over a sidelink channel, control information including a parameter associated with the first frequency domain resource allocation and an indication of the second frequency domain resource allocation; and communicating, over the sidelink channel, one or more signals based at least in part on identifying the first frequency domain resource allocation of the first transport block and identifying the second frequency domain resource allocation of the second transport block. Aspect 23: The method of aspect 22, wherein transmitting the control information further comprises: transmitting the control information including a scaling factor, wherein the parameter comprises the scaling factor. Aspect 24: The method of any of aspects 22 through 23, wherein transmitting the control information further comprises: transmitting the control information including an adjustment factor, wherein the parameter comprises the adjustment factor. Aspect 25: The method of any of aspects 22 through 24, wherein the parameter comprises a second indication of the first frequency domain resource allocation of the first transport block. Aspect 26: The method of any of aspects 22 through 25, further comprising: determining an index associated with stored values of the first frequency domain resource allocation of the first transport block, wherein the parameter comprises the index. Aspect 27: The method of aspect 26, wherein the stored values include one or more frequency domain resources, one or more scaling factors, or one or more adjustment factors associated with the first frequency domain resource allocation. Aspect 28: The method of any of aspects 22 through 27, wherein transmitting the control information further comprises: transmitting the control information including a second indication comprising an index associated with stored values of the first frequency domain resource allocation of the first transport block and with stored values of the second frequency domain resource allocation for the second transport block. Aspect 29: The method of any of aspects 22 through 28, wherein the indication of the second frequency domain resource allocation of the second transport block comprises an indication of a leading subchannel. Aspect 30: The method of any of aspects 22 through 29, further comprising: determining a size of the second transport block; transmitting, over a second sidelink channel, second control information including a second parameter associated with the size of the second transport block. Aspect 31: The method of aspect 30, wherein transmitting the second control information further comprises: transmitting, within the second control information, code block group information associated with the first transport block, wherein the size of the second transport block is based at least in part on the code block group information. Aspect 32: The method of any of aspects 30 through 31, wherein transmitting the second control information further comprises: transmitting the second control information including a scaling factor, wherein the second parameter comprises the scaling factor. Aspect 33: The method of any of aspects 30 through 32, wherein transmitting the second control information further comprises: transmitting the second control information including an adjustment factor, wherein the second parameter comprises the adjustment factor. Aspect 34: The method of any of aspects 30 through 33, wherein the second parameter comprises a second index associated with stored values associated with transport block size and wherein determining the size of the second transport block further comprises: identifying a stored value associated with the second index and corresponding to the size of the second transport block. Aspect 35: The method of any of aspects 30 through 34, wherein transmitting the second control information further comprises: transmitting the second control information including a bit field indicating the size of the second transport block. Aspect 36: The method of any of aspects 22 through 35, wherein the control information corresponds to a format, the first frequency domain resource allocation of the first transport block is based at least in part on the format of the control information. Aspect 37: The method of aspect 36, wherein the control information comprises sidelink control information. Aspect 38: The method of any of aspects 22 through 37, further comprising: receiving, from a second wireless device over the sidelink channel, a request to retransmit a portion of the first transport block, wherein the second transport block comprises the portion of the first transport block. Aspect 39: The method of aspect 38, wherein the request to retransmit the portion of the first transport block comprises an indication of an amount of frequency domain resources for the second transport block. Aspect 40: The method of any of aspects 22 through 39, wherein the control information is associated with a configured grant for sidelink communications. Aspect 41: The method of any of aspects 22 through 40, wherein the control information is communicated over a physical sidelink control channel and the first transport block and the second transport block are communicated over a physical sidelink shared channel. Aspect 42: An apparatus for wireless communications at a wireless device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 1 through 21. Aspect 43: An apparatus for wireless communications at a wireless device, comprising at least one means for performing a method of any of aspects 1 through 21. Aspect 44: A non-transitory computer-readable medium storing code for wireless communications at a wireless device, the code comprising instructions executable by a processor to perform a method of any of aspects 1 through 21. Aspect 45: An apparatus for wireless communications at a wireless device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 22 through 41. Aspect 46: An apparatus for wireless communications at a wireless device, comprising at least one means for performing a method of any of aspects 22 through 41. Aspect 47: A non-transitory computer-readable medium storing code for wireless communications at a wireless device, the code comprising instructions executable by a processor to perform a method of any of aspects 22 through 41. It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined. Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.” The term “determine” or “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” can include receiving (such as receiving information), accessing (such as accessing data in a memory) and the like. Also, “determining” can include resolving, selecting, choosing, establishing and other such similar actions. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label. The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples. The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein. | 159,326 |
11943057 | DETAILED DESCRIPTION Embodiments will be described in detail herein, with the illustrations thereof represented in the drawings. When the following descriptions involve the drawings, like numerals in different drawings refer to like or similar elements unless otherwise indicated. The embodiments described in the following examples do not represent all embodiments consistent with the present disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the present disclosure. The terms used in the present disclosure are for the purpose of describing particular embodiments only, and are not intended to limit the present disclosure. Terms “a”, “the” and “said” in their singular forms in the present disclosure and the appended claims are also intended to include plurality, unless clearly indicated otherwise in the context. It should also be understood that the term “and/or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items. It is to be understood that, although the terms “first,” “second,” “third,” and the like may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one category of information from another. For example, without departing from the scope of the present disclosure, first information may be referred as second information; and similarly, the second information may also be referred as the first information. Depending on the context, the term “if” as used herein may be interpreted as “when” or “upon” or “in response to determining”. The terms “module,” “sub-module,” “circuit,” “sub-circuit,” “circuitry,” “sub-circuitry,” “unit,” or “sub-unit” may include memory (shared, dedicated, or group) that stores code or instructions that can be executed by one or more processors. A module may include one or more circuits with or without stored code or instructions. The module or circuit may include one or more components that are directly or indirectly connected. These components may or may not be physically attached to, or located adjacent to, one another. A unit or module may be implemented purely by software, purely by hardware, or by a combination of hardware and software. In a pure software implementation, for example, the unit or module may include functionally related code blocks or software components, that are directly or indirectly linked together, so as to perform a particular function. A method of indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback provided by the examples of the present disclosure is firstly described below at the base station side. In an example of the present disclosure, a method of indicating a sidelink HARQ feedback is provided. The method may be applied to a base station.FIG.1is a flowchart illustrating a method of indicating a sidelink HARQ feedback according to one or more examples of the present disclosure. The method may include the following steps. At step101, a target resource is allocated to a user equipment to perform sidelink communication. In this step, the target resource is a time resource and/or a frequency resource allocated by the base station for the user equipment to perform the sidelink communication within at least one period. At step102, a downlink control signaling is sent to the user equipment. In an example of the present disclosure, the downlink control signaling may be downlink Radio Resource Control (RRC) information or Downlink Control Information (DCI). The downlink control signaling includes the target resource configured by the base station for the user equipment. In addition, the downlink control signaling also includes first indication information, where the first indication information indicates at least one of the followings:when the user equipment uses the target resource allocated by the base station to perform sidelink unicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform sidelink multicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, a feedback manner of performing the sidelink HARQ feedback. The user equipment may, based on the first indication information, determine whether to perform the sidelink HARQ feedback when using the target resource to perform the sidelink unicast communication or the sidelink multicast communication, and the feedback manner of performing the sidelink HARQ feedback when performing the sidelink multicast communication. In the above example, for the target resource allocated by the base station to the user equipment, whether to perform the HARQ feedback when the user equipment uses the target resource to perform the sidelink unicast communication and/or the sidelink multicast communication, and the feedback manner of performing the sidelink HARQ feedback when performing the sidelink multicast communication are indicated. In an example, if the base station allocates the target resource to the user equipment to perform the sidelink unicast communication, correspondingly, the first indication information may indicate, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication, whether to perform the sidelink HARQ feedback. The user equipment may, based on the content of the first indication information, determine whether to perform the sidelink HARQ feedback when using the target resource to perform the sidelink unicast communication, and feed back ACK upon successful reception of data after determining the sidelink HARQ feedback is to be performed, or feed back NACK. In the above example, by using the above manner, for the target resource allocated by the base station to the user equipment to perform the sidelink unicast communication, whether to perform the sidelink HARQ feedback when the user equipment performs the sidelink unicast communication is determined. In an example, if the base station allocates the target resource to the user equipment to perform the sidelink multicast communication, correspondingly, the first indication information indicates at least one of the followings:when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, the feedback manner of performing the sidelink HARQ feedback. The user equipment may, based on the content of the first indication information, determine whether to perform the sidelink HARQ feedback when using the target resource allocated by the base station to perform the sidelink multicast communication and the feedback manner of performing the sidelink HARQ feedback. In the above example, for the target resource allocated by the base station to the user equipment to perform the sidelink multicast communication, whether to perform the sidelink HARQ feedback when the user equipment performs the sidelink multicast communication and the feedback manner of performing the sidelink HARQ feedback are determined. In some examples, the downlink control signaling includes second indication information. In an example of the present disclosure, the second indication information may indicate that the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication. For example, the base station may use 3 bits in the downlink control signaling, for example, in the downlink RRC information or DCI to indicate whether the user equipment may use the target resource to send sidelink unicast data, sidelink multicast data or sidelink broadcast data. If each bit is 0, it indicates that the target resource is not allowed to be used to send the corresponding sidelink data; and if each bit is 1, it indicates that the target resource is allowed to be used to send the corresponding sidelink data. In an example of the present disclosure, only when the user equipment may use the target resource in unicast and/or multicast communication, the content of the first indication information is valid and otherwise, invalid. In some examples, if the downlink control signaling, for example, the downlink RRC information or DCI, does not include the second indication information, the user equipment defaults to use the target resource in all transmission modes (sidelink unicast, sidelink multicast or sidelink broadcast). The user equipment determines to or not to perform the sidelink HARQ feedback based on the content of the first indication information only when performing the sidelink unicast communication or the sidelink multicast communication, and performs the sidelink HARQ feedback by using the feedback manner indicated by the first indication information when performing the sidelink multicast communication and required to perform the sidelink HARQ feedback. In some examples, the downlink control signaling includes third indication information. The base station may include the third indication information in the downlink control signaling, for example, in the downlink RRC information or DCI. The third indication information indicates a target address for performing the sidelink communication, and the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication. For example, when the target address indicated by the third indication information is a unicast address, the user equipment may perform the sidelink unicast communication, and the first indication information may indicate, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication, whether to perform the sidelink HARQ feedback. When the target address indicated by the third indication information is a multicast address, the user equipment may perform the sidelink multicast communication, and the first indication information may indicate, when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, whether to perform the sidelink HARQ feedback and the feedback manner of performing the sidelink HARQ feedback. When the target address indicated by the third indication information is a broadcast address, the first indication information does not include the above content or the first indication information is invalid. In the above example, the base station may include second indication information or third indication information in the downlink control signaling. The second indication information indicates that the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication, and the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication. When the second indication information or the target address indicates the sidelink unicast communication or the sidelink multicast communication, the user equipment may determine whether to perform the sidelink HARQ feedback and a corresponding sidelink HARQ feedback manner based on the content of the first indication information, thereby increasing the availability. In an example, when the downlink control signaling is the downlink RRC information, the base station may configure the target resource for sending a sidelink communication control channel and/or data channel for the user equipment based on the downlink RRC information. The base station may carry the target resource and the first indication information in the downlink RRC information and send the downlink RRC information to the user equipment. In the above example, when configuring the target resource for the user equipment by using the downlink RRC information, the base station may carry the target resource and the first indication information in the downlink RRC information and send the downlink RRC information to the user equipment. In this process, the base station may carry the first indication information by use of the downlink RRC information for allocating the target resource, thus saving signaling resource, bringing easy implementation and high availability. In an example, an information domain corresponding to the first indication information may be pre-allocated in the downlink RRC information, and the content of the first indication information may be notified to the user equipment directly by using a bit value of the information domain. In some examples of the present disclosure, the information domain corresponding to the first indication information may respectively identify whether to perform the sidelink HARQ feedback in response to the sidelink unicast communication and the sidelink multicast communication by a separate bit value. For example, the information domain has two bits. When a first bit value is 1, it indicates that the user equipment is to perform the sidelink HARQ feedback when performing the sidelink unicast communication; and when the first bit value is 0, it indicates the user equipment is not to perform the sidelink HARQ feedback when performing the sidelink unicast communication. Similarly, when a second bit value is 1, it indicates that the user equipment is to perform the sidelink HARQ feedback when performing the sidelink multicast communication; and when the second bit value is 0, it indicates that the user equipment is not to perform the sidelink HARQ feedback when performing the sidelink multicast communication. Alternatively, the information domain corresponding to the first indication information may indicate the content corresponding to the first indication information by using bit combination. For example, the information domain has two bits. When the bit value is 00, it indicates that no sidelink HARQ feedback is performed regardless of the sidelink unicast communication or the sidelink multicast communication. When the bit value of the information domain is 01, it indicates that in response to the sidelink unicast communication and the sidelink multicast communication, the sidelink HARQ feedback is performed, and the feedback manner of performing the sidelink HARQ feedback in response to the sidelink multicast communication is to feed back NACK only in response to incorrect reception of data. When the bit value of the information domain is 10, it indicates that in response to the sidelink unicast communication and the sidelink multicast communication, the sidelink HARQ feedback is performed, and the feedback manner of performing the sidelink HARQ feedback in response to the sidelink multicast communication is to feed back ACK upon correct reception and feed back NACK upon incorrect reception. When the bit value of the information domain is 11, it indicates that in response to the sidelink unicast communication and the sidelink multicast communication, the sidelink HARQ feedback is performed, and the feedback manner in response to the sidelink multicast communication is determined by the user equipment itself. If the information domain corresponding to the first indication information may indicate the content of the first indication information by using a bit combination and the information domain includes two bits, the two bits indicate, by default, whether to perform the sidelink HARQ feedback for the corresponding sidelink unicast communication and sidelink multicast communication and the feedback manner of performing the sidelink HARQ feedback in response to the sidelink multicast communication and do not indicate the circumstance corresponding to the sidelink broadcast communication. If the information domain include three or more bits, these bits may indicate whether to perform the sidelink HARQ feedback for the corresponding sidelink unicast communication, sidelink multicast communication and sidelink broadcast communication together or indicate whether to perform the sidelink HARQ feedback and a corresponding feedback manner for different sidelink communications by using different bits according to an agreement between the station and the user equipment, which is not limited herein. Alternatively, in an example of the present disclosure, the information domain corresponding to the first indication information may not be configured in the downlink RRC information, but the content corresponding to the first indication information is notified to the user equipment in an implicit manner. In some examples, the downlink RRC information indicates the content corresponding to the first indication information based on whether a Physical Uplink Control CHannel (PUCCH) resource configuration used by the user equipment to report HARQ feedback information corresponding to the sidelink communication is included. For example, if the downlink RRC information includes the PUCCH resource configuration, the user equipment may think that the content of the first indication information is to perform the sidelink HARQ feedback when performing the sidelink unicast communication or the sidelink multicast communication. If the downlink RRC information does not include the PUCCH resource configuration, no sidelink HARQ feedback is performed when performing the sidelink unicast communication or the sidelink multicast communication. In the above example, the downlink RRC information sent by the base station may directly include a pre-allocated information domain corresponding to the first indication information, and the user equipment may determine the content of the first indication information based on the bit value of the information domain. Alternatively, the downlink RRC information sent by the base station may not include the information domain, but the content to be indicated by the first indication information is indicated implicitly based on whether the PUCCH resource configuration used by the user equipment to report HARQ feedback information corresponding to the sidelink communication is included. In the above manner, the user equipment is enabled to quickly determine the content of the first indication information, leading to high availability. In an example, when the downlink control signaling is DCI, the base station may schedule the target resource for sending a sidelink communication control channel and/or data channel for the user equipment based on the DCI. The base station carries the target resource and the first indication information in the DCI and sends the DCI to the user equipment. In the above example, the base station may also carry the target resource and the first indication information by using the DCI for scheduling the target resource and send the DCI to the user equipment. In the above process, the base station may carry the target resource and the first indication information by using the DCI for allocating the target resource, thereby saving signaling resource, bringing easy implementation and high availability. In an example, when the first indication information is carried by the DCI, a preset value of a specified information domain the DCI may indicate the content corresponding to the first indication information, or a preset combination of values of the specified information domain of the DCI may indicate the content corresponding to the first indication information. For example, two separate bits of the specified information domain in the DCI are used to respectively indicate whether to perform the HARQ feedback when performing the sidelink unicast communication or the sidelink multicast communication, or a combination of two bit values in the specified information domain is used to indicate the content of the first indication information. The specific manner is the same as the manner in which the content of the first indication information is indicated by use of combination of two bit values in the downlink RRC information, which is not repeated herein. For another example, when the above second resource configuration manner is adopted, the base station may send the downlink control signaling, for example, the downlink RRC information and DCI, to the user equipment. The DCI includes an information domain indicating reporting the PUCCH resource position for transmitting the HARQ feedback information to the base station, the base station pre-configures one group of PUCCH resources (8 at most) to the user equipment by using the RRC information, and one bit is selected from the information domain (for example, the information domain includes 3 bits) in the DCI to transmit the HARQ feedback information. Less than 8 PUCCH resources may be configured by using the downlink RRC information. If 7 PUCCH resources are configured, the un-configured resource, for example, the eighth resource, indicates not performing the sidelink HARQ feedback when performing the sidelink unicast communication or the sidelink multicast communication. If one configured PUCCH resource is indicated by the DCI, it indicates performing the sidelink HARQ feedback when performing the sidelink unicast communication or the sidelink multicast communication. In the above example, the base station may indicate the content corresponding to the first indication information by using the preset value of the specified information domain in the DCI, or indicate the content corresponding to the first indication information by using the preset combination of values of the specified information domain in the DCI. In the above process, the user equipment is enabled to quickly determine the content of the first indication information, leading to high availability. In some examples, the target resource and the first indication information may use a same downlink control signaling, for example, the target resource and the first indication information are sent at the same time by using the downlink RRC information, or by using the DCI. Different downlink control signalings may be used, for example, the target resource is sent by using the downlink RRC information, and a resource usable by the user equipment in a current period in the target resource and the first indication information are sent by using the DCI, or the target resource and the first indication information are sent by using the downlink RRC information and a resource usable by the user equipment in a current period in the target resource is sent by using the DCI. In the above example, the base station send the target resource and the first indication information at the same time by using a same downlink control signaling, or send the target resource and the first indication information by using different downlink control signalings respectively, which is not limited herein. A method of indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback provided by the examples of the present disclosure will be described below at the user equipment side. The method of indicating a sidelink HARQ feedback provided by the examples of the present disclosure may be applied to a user equipment. The user equipment may be a handheld terminal of a user in a vehicle network, or another vehicle-mounted device or the like.FIG.2is a flowchart illustrating another method of indicating a sidelink HARQ feedback according to one or more examples of the present disclosure. The method may include the following steps. At step201, a downlink control signaling is received from a base station. In an example of the present disclosure, the downlink control signaling may be downlink RRC information or DCI. The downlink control signaling includes a target resource and first indication information. The target resource is time resource and frequency resource allocated by the base station to the user equipment to perform sidelink communication. The first indication information indicates at least one of the followings:when the user equipment uses the target resource allocated by the base station to perform sidelink unicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform sidelink multicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, a feedback manner of performing the sidelink HARQ feedback. At step202, according to indication of the first indication information, a sidelink HARQ feedback operation is performed and/or a sidelink HARQ feedback result is reported to the base station. The user equipment may, after receiving the first indication information from the base station, perform the sidelink HARQ feedback operation and report the sidelink HARQ feedback result to the base station based on the indication of the first indication information. In the above example, after receiving the downlink control signaling including the target resource and the first indication information from the base station, the user equipment may, based on the indication of the first indication information, perform the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station. The first indication information indicates at least one of: when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication or the sidelink multicast communication, whether to perform sidelink HARQ feedback; and when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, the feedback manner of performing the sidelink HARQ feedback. By the above process, for the target resource allocated by the base station to the user equipment, the user equipment may, based on the content of the first indication information, perform the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station when performing the sidelink unicast communication and/or the sidelink multicast communication using the target resource. In an example, performing the sidelink HARQ feedback operation based on the indication of the first indication information in step202may include the following step:at step202-1, when the user equipment is taken as a sending end device of the sidelink communication, fourth indication information is sent to a receiving end device of the sidelink communication according to the first indication information. The fourth indication information includes at least one of the followings:whether to perform the sidelink HARQ feedback;when the sidelink communication is multicast communication, the feedback manner of performing the sidelink HARQ feedback. In this step, the user equipment, as the sending end device of the sidelink communication, may send the fourth indication information to the receiving end device based on the first indication information. The receiving end device may, based on the fourth indication information, determine whether to perform the sidelink HARQ feedback and the feedback manner of performing the sidelink HARQ feedback when the sidelink communication is multicast communication. In the above example, the user equipment, as the sending end device of the sidelink communication, may send the fourth indication information to the receiving end device, such that the receiving end device may, based on the fourth indication information, determine whether to perform the sidelink HARQ feedback and the feedback manner of performing the sidelink HARQ feedback when the sidelink communication is multicast communication, thus increasing the availability. In an example, the user equipment may carry the fourth indication information in Sidelink Control Information (SCI) and send the fourth indication information to the receiving end device by using the SCI. In the above example, the user equipment, as the sending end device, can send the fourth indication information to the receiving end device by using the SCI, leading to easy implementation and high availability. In an example, performing the sidelink HARQ feedback operation based on the indication of the first indication information in step202may include the following:at step202-2, when the first indication information indicates not performing the sidelink HARQ feedback, a correct reception (ACK) result is reported to the base station. In an example of the present disclosure, if the first indication information indicates not performing the sidelink HARQ feedback in response to the sidelink unicast communication or the sidelink multicast communication, the user equipment at receiving end may always report a correct reception (ACK) result to the base station. In some examples, the downlink control signaling includes second indication information. The downlink control signaling may be the downlink RRC information or DCI. The second indication information indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication. Alternatively, the downlink control signaling includes third indication information. The third indication information indicates a target address for performing the sidelink communication and the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication. In an example of the present disclosure, if the second indication information or the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication, the first indication information indicates, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication, whether to perform the sidelink HARQ feedback. The user equipment may, based on the indication of the first indication information, perform the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station. If the second indication information or the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication, the first indication information indicates, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication, whether to perform the sidelink HARQ feedback. Similarly, the user equipment may, based on the indication of the first indication information, perform the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station. When the second indication information or the target address indicates the sidelink communication performed by the user equipment is the sidelink multicast communication, the first indication information indicates at least one of the followings: when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, whether to perform the sidelink HARQ feedback; when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, the feedback manner of performing the sidelink HARQ feedback. Similarly, the user equipment may, based on the indication of the first indication information, perform the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station. In an example, the base station indicates the target resource and the first indication information at the same time by using the downlink RRC information, the user equipment may continue performing step202to, based on the indication of the first indication information, perform the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station. In an example, the downlink RRC information includes a pre-allocated information domain corresponding to the first indication information, and thus the user equipment may determine the content of the first indication information based directly on a bit value of the information domain corresponding to the first indication information. For example, the information domain has two bits. When a first bit value is 1, it indicates that the user equipment is to perform the sidelink HARQ feedback when performing the sidelink unicast communication; and when the first bit value is 0, it indicates the user equipment is not to perform the sidelink HARQ feedback when performing the sidelink unicast communication. Similarly, when a second bit value is 1, it indicates that the user equipment is to perform the sidelink HARQ feedback when performing the sidelink multicast communication; and when the second bit value is 0, it indicates that the user equipment is not to perform the sidelink HARQ feedback when performing the sidelink multicast communication. Alternatively, the information domain has two bits. When the bit value is 00, it indicates that no sidelink HARQ feedback is performed regardless of the sidelink unicast communication or the sidelink multicast communication. When the bit value is 01, it indicates that in response to the sidelink unicast communication and the sidelink multicast communication, the sidelink HARQ feedback is performed, and the feedback manner of performing the sidelink HARQ feedback in response to the sidelink multicast communication is to feed back NACK only in response to incorrect reception of data. When the bit value is 10, it indicates that in response to the sidelink unicast communication and the sidelink multicast communication, the sidelink HARQ feedback is performed, and the feedback manner of performing the sidelink HARQ feedback in response to the sidelink multicast communication is to feed back ACK upon correct reception and feed back NACK upon incorrect reception. When the bit value is 11, it indicates that in response to the sidelink unicast communication and the sidelink multicast communication, the sidelink HARQ feedback is performed, and the feedback manner in response to the sidelink multicast communication is determined by the user equipment itself. If the information domain corresponding to the first indication information may indicate the content corresponding to the first indication information by using a bit combination and the information domain includes two bits, the two bits indicate, by default, whether to perform the sidelink HARQ feedback for the corresponding sidelink unicast communication and sidelink multicast communication and the feedback manner of performing the sidelink HARQ feedback in response to the sidelink multicast communication and do not indicate the circumstance corresponding to the sidelink broadcast communication. If the information domain include three or more bits, these bits may indicate whether to perform the sidelink HARQ feedback for the corresponding sidelink unicast communication, sidelink multicast communication and sidelink broadcast communication together or indicate whether to perform the sidelink HARQ feedback and a corresponding feedback manner for different sidelink communications by using different bits according to an agreement between the station and the user equipment, which is not limited herein. In some examples of the present disclosure, the downlink RRC information indicates the content corresponding to the first indication information based on whether a Physical Uplink Control CHannel (PUCCH) resource configuration used by the user equipment to report HARQ feedback information corresponding to the sidelink communication is included.when the downlink RRC information includes the PUCCH resource configuration, the user equipment may determine that the content corresponding to the first indication information is that, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication or the sidelink multicast communication, the sidelink HARQ feedback is performed. When the downlink RRC information does not include the PUCCH resource configuration, the user equipment may determine that the content corresponding to the first indication information is that, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication or the sidelink multicast communication, the sidelink HARQ feedback is not performed. In the above manner, the content of the first indication information may be indicated implicitly in the downlink RRC information, leading to high availability. In an example, the downlink control signaling may also be the DCI. The target resource and the first indication information are carried in the DCI. The base station may send the target resource and the first indication information to the user equipment by using the DCI. After receiving them, the user equipment may perform the step202. In an example, the DCI indicates the content corresponding to the first indication information by using a preset value of a specified information domain; orthe DCI indicates the content corresponding to the first indication information by using a preset combination of values of the specified information domain. For example, two separate bits of the specified information domain in the DCI are used to respectively indicate whether to perform the HARQ feedback when performing the sidelink unicast communication or the sidelink multicast communication, or a combination of two bit values in the specified information domain is used to indicate the content of the first indication information. The specific manner is the same as the manner in which the content of the first indication information is indicated by use of combination of two bit values in the downlink RRC information, which is not repeated herein. For another example, when the above second resource configuration manner is adopted, the base station may send the downlink control signaling, for example, the downlink RRC information and DCI, to the user equipment. The DCI includes an information domain indicating reporting the PUCCH resource position for transmitting the HARQ feedback information to the base station, the base station pre-configures one group of PUCCH resources (8 at most) to the user equipment by using the RRC information, and one bit is selected from the information domain (for example, the information domain includes 3 bits) in the DCI to transmit the HARQ feedback information. Less than 8 PUCCH resources may be configured by using the downlink RRC information. If 7 PUCCH resources are configured, the un-configured resource, for example, the eighth resource, indicates not performing the sidelink HARQ feedback when performing the sidelink unicast communication or the sidelink multicast communication. If one configured PUCCH resource is indicated by the DCI, it indicates performing the sidelink HARQ feedback when performing the sidelink unicast communication or the sidelink multicast communication. In some examples, the target resource and the first indication information may use a same downlink control signaling, for example, the target resource and the first indication information are sent at the same time by using the downlink RRC information, or by using the DCI. Different downlink control signalings may be used, for example, the target resource is sent by using the downlink RRC information, and a resource usable by the user equipment in a current period in the target resource and the first indication information are sent by using the DCI, or the target resource and the first indication information are sent by using the downlink RRC information and a resource usable by the user equipment in a current period in the target resource is sent by using the DCI. According to the indication of the first indication information in the received downlink RRC information or DCI, the user equipment performs the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station. The method of indicating a sidelink HARQ feedback provided above will be further described below with examples. For the first allocation solution in the model resource allocation manner of the sidelink communication, the downlink control signaling is the downlink RRC information, that is, the target resource is configured for the user equipment by using the semi-static downlink RRC information, and the base station may carry the target resource and the first indication information in the downlink RRC information. In an example of the present disclosure, the downlink RRC information may include a pre-allocated information domain corresponding to the first indication information. In some examples, the first indication information may respectively indicate, by using separate bit values, whether to perform the sidelink HARQ feedback when performing the sidelink unicast communication or the sidelink multicast communication, or indicate the corresponding content by using combination of two bits. Alternatively, the downlink RRC information indicates the content corresponding to the first indication information based on whether a Physical Uplink Control CHannel (PUCCH) resource configuration used by the user equipment to report HARQ feedback information corresponding to the sidelink communication is included. In an example of the present disclosure, the downlink RRC information may further include second indication information or third indication information. The second indication information indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication, the third indication information indicates a target address for performing the sidelink communication, and the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication. When the second indication information or the target address indicates performing the sidelink unicast communication or the sidelink multicast communication, the user equipment performs the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station based on the indication of the first indication information. Performing, by the user equipment, the sidelink HARQ feedback operation based on the indication of the first indication information means that the user equipment, as a sending end device, may send fourth indication information to a receiving end device by using the SCI based on the first indication information. information Reporting, by the user equipment, the sidelink HARQ feedback result to the base station based on the indication of the first indication information means that when the first indication information indicates not performing the sidelink HARQ feedback, a correct reception (ACK) result is reported to the base station. For the third allocation solution in the model resource allocation manner of the sidelink communication, the downlink control signaling is the DCI, that is, the base station configures the target resource for the user equipment based on the DCI, and the base station may carry the target resource and the first indication information in the DCI. In an example of the present disclosure, the base station may indicate the content corresponding to the first indication information by using a preset value of a specified information domain in the DCI; or indicate the content corresponding to the first indication information by using a preset combination of values of the specified information domain in the DCI. The specific manner is the same as that in the above examples and will not be repeated herein. In some examples, the specified information domain may be an information domain irrelevant to sidelink resource scheduling in the DCI, for example, a Modulation and Coding Scheme (MSC) information domain. Similarly, the user equipment may perform the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station based on the indication of the first indication information. For the second allocation solution in the model resource allocation manner of the sidelink communication, the base station firstly allocates the target resource to the user equipment by using the downlink RRC information and indicates the specific usable resource by using the DCI each time. Correspondingly, the first indication information may be carried in the downlink RRC information or the DCI, and the user equipment may, based on the indication of the first indication information, perform the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station. In the above example, for the target resource allocated by the base station to the user equipment, whether to perform the HARQ feedback when the user equipment uses the target resource to the user equipment to perform the sidelink unicast communication and/or the sidelink multicast communication, and the feedback manner of performing the sidelink HARQ feedback in response to performing the sidelink multicast communication are indicated. Corresponding to the above examples with the application functions implementing the methods, apparatus examples with application functions implementing apparatuses are further provided in the present disclosure. FIG.3is a block diagram illustrating an apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback according to one or more examples of the present disclosure. The apparatus is applied to a base station and includes:a resource allocating module310, configured to allocate a target resource to a user equipment to perform sidelink communication;a sending module320, configured to send a downlink control signaling to the user equipment, where the downlink control signaling includes the target resource and first indication information; the first indication information indicates at least one of the followings:when the user equipment uses the target resource allocated by the base station to perform sidelink unicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform sidelink multicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, a feedback manner of performing the sidelink HARQ feedback. FIG.4is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback according to one or more examples of the present disclosure. The resource allocating module310includes:a first allocating sub-module311, configured to allocate the target resource to the user equipment to perform the sidelink unicast communication;where the first indication information indicates, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication, whether to perform the sidelink HARQ feedback. FIG.5is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback based on the example ofFIG.3. The resource allocating module310includes:a second allocating sub-module312, configured to allocate the target resource to the user equipment to perform the sidelink multicast communication;where the first indication information indicates at least one of the followings: when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, the feedback manner of performing the sidelink HARQ feedback. In some examples, the downlink control signaling includes second indication information; where the second indication information indicates that the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication; orthe downlink control signaling includes third indication information; where the third indication information indicates a target address for performing the sidelink communication, and the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication. FIG.6is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback based on the example ofFIG.3. The sending module320includes:a first sending sub-module321, configured to, when downlink radio resource control (RRC) information is used to configure the target resource for sending a sidelink communication control channel and/or data channel for the user equipment, carry the target resource and the first indication information in the downlink RRC information and send the downlink RRC information to the user equipment. In some examples, the downlink RRC information includes a pre-allocated information domain corresponding to the first indication information; orthe downlink RRC information indicates a content corresponding to the first indication information based on whether a Physical Uplink Control CHannel (PUCCH) resource configuration used by the user equipment to report HARQ feedback information corresponding to the sidelink communication is included. FIG.7is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback based on the example ofFIG.3. The sending module320includes:a second sending sub-module322, configured to, when downlink control information (DCI) is used to schedule the target resource for sending the sidelink communication control channel and/or data channel for the user equipment, carry the target resource and the first indication information in the DCI and send the DCI to the user equipment. In some examples, a preset value of a specified information domain in the DCI is used to indicate the content corresponding to the first indication information; ora preset combination of values of the specified information domain in the DCI is used to indicate the content corresponding to the first indication information. FIG.8is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback according to one or more examples of the present disclosure. The apparatus is applied to a user equipment and includes:a receiving module410, configured to receive a downlink control signaling from a base station, where the downlink control signaling includes a target resource allocated by the base station to the user equipment to perform sidelink communication and first indication information;an performing module420, configured to, according to indication of the first indication information, perform a sidelink HARQ feedback operation and/or report a sidelink HARQ feedback result to the base station;where the first indication information indicates at least one of the followings:when the user equipment uses the target resource allocated by the base station to perform sidelink unicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform sidelink multicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, a feedback manner of performing the sidelink HARQ feedback. FIG.9is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback base on the example ofFIG.8. The performing module420includes:a third sending sub-module421, configured to, when the user equipment is taken as a sending end device of the sidelink communication, send fourth indication information to a receiving end device of the sidelink communication based on the first indication information;where the fourth indication information includes at least one of the followings:whether to perform the sidelink HARQ feedback;when the sidelink communication is multicast communication, the feedback manner of performing the sidelink HARQ feedback. FIG.10is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback base on the example ofFIG.9. The third sending sub-module421includes:a sending unit4211, configured to carry the fourth indication information in sidelink control information (SCI) and send the SCI to the receiving end device. FIG.11is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback base on the example ofFIG.8. The performing module420includes:a reporting sub-module422, configured to, when the first indication information indicates not performing the sidelink HARQ feedback, report a correct reception (ACK) result to the base station. In some examples, the downlink control signaling includes second indication information; where the second indication information indicates that the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication; orthe downlink control signaling includes third indication information; where the third indication information indicates a target address for performing the sidelink communication, and the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication;when the second indication information or the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication, the first indication information indicates, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication, whether to perform the sidelink HARQ feedback;when the second indication information or the target address indicates the sidelink communication performed by the user equipment is the sidelink multicast communication, the first indication information indicates at least one of the followings:when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, the feedback manner of performing the sidelink HARQ feedback. FIG.12is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback base on the example ofFIG.8. The receiving module410includes:a first receiving sub-module411, configured to receive downlink radio resource control (RRC) information used by the base station to configure the target resource for the user equipment, where the downlink RRC information carries the target resource and the first indication information. In some examples, the downlink RRC information includes a pre-allocated information domain corresponding to the first indication information; orthe downlink RRC information indicates the content corresponding to the first indication information based on whether a Physical Uplink Control CHannel (PUCCH) resource configuration used by the user equipment to report HARQ feedback information corresponding to the sidelink communication is included;when the downlink RRC information includes the PUCCH resource configuration, it is determined that the content corresponding to the first indication information is that, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication or the sidelink multicast communication, the sidelink HARQ feedback is performed;when the downlink RRC information does not include the PUCCH resource configuration, it is determined that the content corresponding to the first indication information is that, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication or the sidelink multicast communication, the sidelink HARQ feedback is not performed. FIG.13is a block diagram illustrating another apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback base on the example ofFIG.8. The receiving module410includes:a second receiving sub-module412, configured to receive downlink control information (DCI) used by the base station to schedule the target resource for the user equipment, where the target resource and the first indication information are carried in the DCI. In some examples, the DCI indicates the content corresponding to the first indication information by using a preset value of a specified information domain; orthe DCI indicates the content corresponding to the first indication information by using a preset combination of values of the specified information domain. Since the apparatus examples are basically similar to the method examples, reference may be made to the descriptions of the method examples for relevant parts. The apparatus examples described above are merely illustrative, where the units described as separate members may be or not be physically separated, and the members displayed as units may be or not be physical units, i.e., may be located in one place, or may be distributed to a plurality of network units. Part or all of the modules may be selected according to actual requirements to implement the objectives of the solutions in the examples. Those of ordinary skill in the art may understand and carry out them without creative work. Correspondingly, a computer readable storage medium with computer programs stored thereon is further provided in the present disclosure, where the computer programs are executed to implement the method of indicating a sidelink HARQ feedback according to any one of the above items at base station side. Correspondingly, a computer readable storage medium with computer programs stored thereon is further provided in the present disclosure, where the computer programs are executed to implement the method of indicating a sidelink HARQ feedback according to any one of the above items at user equipment side. Correspondingly, an apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback is further provided in the present disclosure. The apparatus is applied to a base station and includes:a processor;a memory configured to store instructions executable by the processor;where, the processor is configured to:allocate a target resource to a user equipment to perform sidelink communication;send a downlink control signaling to the user equipment, where the downlink control signaling includes the target resource and first indication information; the first indication information indicates at least one of the followings:when the user equipment uses the target resource allocated by the base station to perform sidelink unicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform sidelink multicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, a feedback manner of performing the sidelink HARQ feedback. FIG.14is a structural schematic diagram illustrating an apparatus1400for indicating a sidelink HARQ feedback according to one or more examples of the present disclosure. The apparatus1400may be provided as a base station. As shown inFIG.14, the apparatus1400includes a process component1422, a wireless transmission/reception component1424, an antenna component1426, and a signal processing part specific to wireless interface, where the processing component1422may further include one or more processors. One processor of the processing component1422may be configured to implement any method of indicating a sidelink HARQ feedback as above. Correspondingly, an apparatus for indicating a sidelink Hybrid Automatic Repeat reQuest (HARQ) feedback is further provided in the present disclosure. The apparatus is applied to a user equipment and includes:a processor;a memory configured to store instructions executable by the processor;where, the processor is configured to:receive a downlink control signaling from a base station, where the downlink control signaling includes a target resource allocated by the base station to the user equipment to perform sidelink communication and first indication information;according to indication of the first indication information, perform a sidelink HARQ feedback operation and/or reporting a sidelink HARQ feedback result to the base station;where the first indication information indicates at least one of the followings:when the user equipment uses the target resource allocated by the base station to perform sidelink unicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform sidelink multicast communication, whether to perform the sidelink HARQ feedback;when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, a feedback manner of performing the sidelink HARQ feedback. FIG.15is a block diagram illustrating an apparatus1500for indicating a sidelink HARQ feedback according to one or more examples of the present disclosure. For example, the apparatus1500may be a user equipment such as smart phone, tablet computer, electronic book reader, multimedia play device, wearable device, vehicle-mounted device and the like. As shown inFIG.15, the apparatus1500may include one or more of the following components: a processing component1502, a memory1504, a power supply component1506, a multimedia component1508, an audio component1510, an input/output (I/O) interface1512, a sensor component1516and a communication component1518. The processing component1502generally controls overall operations of the apparatus1500, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component1502may include one or more processors1520to execute instructions to complete all or part of the steps of the above methods. In addition, the processing component1502may include one or more modules which facilitate the interaction between the processing component1502and other components. For example, the processing component1502may include a multimedia module to facilitate the interaction between the multimedia component1508and the processing component1502. For another example, the processing component1502may read instructions from the memory to perform the steps of the method of indicating a sidelink HARQ feedback according to the above examples. The memory1504is configured to store various types of data to support the operation of the apparatus1500. Examples of such data include instructions for any application or method operated on the apparatus1500, contact data, phonebook data, messages, pictures, videos, and so on. The memory1504may be implemented by any type of volatile or non-volatile storage devices or a combination thereof, such as a Static Random Access Memory (SRAM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), an Erasable Programmable Read-Only Memory (EPROM), a Programmable Read-Only Memory (PROM), a Read-Only Memory (ROM), a magnetic memory, a flash memory, a magnetic or compact disk. The power supply component1506supplies power for different components of the apparatus1500. The power supply component1506may include a power supply management system, one or more power supplies, and other components associated with generating, managing and distributing power for the apparatus1500. The multimedia component1508includes a screen that provides an output interface between the apparatus1500and a user. In some examples, the multimedia component1508includes a front camera and/or a rear camera. When the apparatus1500is in an operation mode, such as a shooting mode or a video mode, the front camera and/or the rear camera may receive external multimedia data. Each of the front and rear cameras may be a fixed optical lens system or have a focal length and an optical zoom capability. The audio component1510is configured to output and/or input audio signals. For example, the audio component1510includes a microphone (MIC) configured to receive an external audio signal when the apparatus1500is in an operation mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signal may be further stored in the memory1504or transmitted via the communication component1518. In some examples, the audio component1510also includes a loudspeaker for outputting an audio signal. The I/O interface1512provides an interface between the processing component1502and a peripheral interface module which may be a keyboard, a click wheel, a button, or the like. These buttons may include, but are not limited to a home button, a volume button, a start button, and a lock button. The sensor component1516includes one or more sensors for providing a status assessment in various aspects to the apparatus1500. For example, the sensor component1516may detect an open/closed state of the apparatus1500, and the relative positioning of components, for example, the component is a display and a keypad of the apparatus1500. The sensor component1516may also detect a change in position of the apparatus1500or a component of the apparatus1500, the presence or absence of a user in contact with the apparatus1500, the orientation or acceleration/deceleration of the apparatus1500and a change in temperature of the apparatus1500. The sensor component1516may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. The sensor component1516may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some examples, the sensor component1516may also include an acceleration sensor, a gyro sensor, a magnetic sensor, a pressure sensor, or a temperature sensor. The communication component1518is configured to facilitate wired or wireless communication between the apparatus1500and other devices. The apparatus1500may access a wireless network based on a communication standard, such as WiFi, 2G or 3G, 4G or 5G a combination thereof. In an example, the communication component1518receives broadcast signals or broadcast associated information from an external broadcast management system via a broadcast channel. In an example, the communication component1518also includes a near field communication (NFC) module to facilitate short range communication. For example, the NFC module may be implemented based on a radio frequency identification (RFID) technology, an infrared data association (IrDA) technology, an ultrawideband (UWB) technology, a Bluetooth (BT) technology, and other technologies. In an example, the apparatus1500may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor or other electronic elements for performing the above methods. In an example, there is further provided a non-transitory machine readable storage medium including instructions, for example, the memory1504including instructions. The above instructions may be executed by the processor1502of the apparatus1500to implement the above methods. For example, the non-transitory machine readable storage medium may be Read Only Memory (ROM), Random Access Memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device and the like. Other implementations of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the present disclosure herein. The present disclosure is intended to cover any variations, uses, modification or adaptations of the present disclosure that follow the general principles thereof and include common knowledge or conventional technical means that are not disclosed in the present disclosure. The specification and examples are considered as exemplary only. In the examples of the present disclosure, a base station may allocate a target resource to a user equipment to perform sidelink communication and send a downlink control signaling including the target resource and first indication information to the user equipment. The base station may indicate, by the first indication information, at least one of: when the user equipment uses the target resource to perform sidelink unicast communication, whether to perform sidelink HARQ feedback; when the user equipment uses the target resource to perform sidelink multicast communication, whether to perform the sidelink HARQ feedback, and when the user equipment uses the target resource to perform the sidelink multicast communication, the feedback manner of performing the sidelink HARQ feedback. By the above process, for the target resource allocated by the base station to the user equipment, whether to perform the HARQ feedback when the user equipment uses the target resource allocated by the base station to the user equipment to perform the sidelink unicast communication and/or the sidelink multicast communication, and the feedback manner of performing the sidelink HARQ feedback in response to the sidelink multicast communication are indicated. In the examples of the present disclosure, when the base station allocates the target resource to the user equipment to perform the sidelink unicast communication, correspondingly, the first indication information may indicate, when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication, whether to perform the sidelink HARQ feedback. In response to sidelink unicast communication, the user equipment has only one feedback manner of performing the sidelink HARQ feedback. Therefore, in the above manner, for the target resource allocated by the base station to the user equipment to perform the sidelink unicast communication, whether to perform the sidelink HARQ feedback when the user equipment performs the sidelink unicast communication is determined. In the examples of the present disclosure, if the base station allocates the target resource to the user equipment to perform the sidelink multicast communication, the first indication information may indicate: when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, whether to perform the sidelink HARQ feedback, and/or when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, the feedback manner of performing the sidelink HARQ feedback. In this manner, for the target resource allocated by the base station to the user equipment to perform the sidelink multicast communication, whether to perform the sidelink HARQ feedback when the user equipment performs the sidelink multicast communication and the feedback manner of performing the sidelink HARQ feedback are determined. In the examples of the present disclosure, a downlink control signaling may further include second indication information or third indication information. The second indication information indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication and the target address indicates the sidelink communication performed by the user equipment is the sidelink unicast communication or the sidelink multicast communication. When the second indication information or the target address indicates the sidelink unicast communication or the sidelink multicast communication, the user equipment may determine whether to perform the sidelink HARQ feedback and a corresponding sidelink HARQ feedback manner based on the content of the first indication information, thereby increasing the availability. In the examples of the present disclosure, when the base station uses downlink RRC information to configure the target resource for the user equipment, the downlink RRC information may carry the target resource and the first indication information and then be sent to the user equipment. In the above process, the base station may carry the target resource and the first indication information by the downlink RRC information, saving signaling resource, bringing easy implementation and high availability. In the examples of the present disclosure, the downlink RRC information sent by the base station may directly include a pre-allocated information domain corresponding to the first indication information, and the user equipment may, based on a bit value of the information domain, determine the content of the first indication information. Alternatively, the downlink RRC information sent by the base station may not include the information domain but implicitly indicate the content to be indicated by the first indication information based on whether a Physical Uplink Control CHannel (PUCCH) resource configuration used by the user equipment to report HARQ feedback information corresponding to the sidelink communication is included. In the above manner, the user equipment is enabled to quickly determine the content of the first indication information, leading to high availability. In the examples of the present disclosure, the base station may also use downlink control information (DCI) for scheduling the target resource to carry the target resource and the first indication information and send the DCI to the user equipment. In the above process, the base station may carry the target resource and the first indication information by the DCI, thus saving signaling resource, bringing easy implementation and high availability. In the examples of the present disclosure, the base station may indicate the content corresponding to the first indication information by use of a preset value of a specified information domain in the DCI, or indicate the content corresponding to the first indication information by use of a preset combination of values of the specified information domain in the DCI. In the above process, the user equipment is enabled to quickly determine the content of the first indication information, leading to high availability. In the examples of the present disclosure, after receiving the downlink control signaling sent by the base station, the user equipment may, based on indication of the first indication information included in the downlink control signaling, perform a sidelink HARQ feedback operation and/or report a sidelink HARQ feedback result to the base station. The first indication information indicates at least one of: when the user equipment uses the target resource allocated by the base station to perform the sidelink unicast communication or the sidelink multicast communication, whether to perform the sidelink HARQ feedback; and when the user equipment uses the target resource allocated by the base station to perform the sidelink multicast communication, a feedback manner of performing the sidelink HARQ feedback. In the above process, for the target resource allocated by the base station to the user equipment, the user equipment may, based on the indication of the first indication information, perform the sidelink HARQ feedback operation and/or report the sidelink HARQ feedback result to the base station in response to using the target resource to perform the sidelink unicast communication and/or the sidelink multicast communication. It is to be understood that the present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and that various modifications and changes may be made without departing from the scope thereof. | 77,352 |
11943058 | DETAILED DESCRIPTION The present disclosure presents techniques for uplink data transmission and scheduling whereby a timer with a corresponding maximum retransmission time is configured for a wireless device such that when the timer expires, the wireless device can reuse the used HARQ process for transmission of new UL data or for retransmission of all or part of an original transmission. These techniques are based on the reality that there are two possible assumptions if the UE has not received any feedback. First, the wireless device could assume that the original transmission was correctly received (i.e., assumes an ACK) for the TB. Under this first possible assumption, the wireless device could generate and transmit a new TB for the given HARQ process at the next transmission occasion. This scenario would be applicable, for example, where the reliability requirements for receiving the transmission at the network node are not particularly high (e.g., in an enhanced Mobile Broadband (eMBB) use-case). The other alternative is to assume that the data was not properly received and that a negative acknowledgement (NACK) should have been sent. In this case, the wireless device would generate and transmit the data of the original TB at the next transmission occasion of the HARQ process. This scenario would be applicable, for example, where the reliability requirements for receiving the data transmission at the network node are relatively high (e.g., in an ultra-reliable low latency communications (URLLC) use-case). In either of these example scenarios, and following either assumption above, in an aspect of the example embodiments presented herein, transmissions and retransmissions can be governed according to a HARQ policy that defines a timer counting a pre-configured maximum feedback time period (T) and/or a default operation (e.g., according to one of the above-recited scenarios and assumptions). This default operation, which can include whether to transmit new data using a particular HARQ ID or to retransmit data that was previously transmitted using the HARQ ID, can be triggered after the timer expires without the transmitting device receiving HARQ feedback from a receiving device. In some examples, the timer could begin counting down the associated time period T when it transmits the original TB data, while in other examples the countdown could start when the wireless device receives the UL resource grant for the original TB data transmission. In addition, as indicated above, the default operation will be triggered in some embodiments where feedback has not been received by the time the timer has expired. This feedback associated with the timer could include an ACK, a NACK, a new data indicator (e.g., new data exists in a transmission queue), or a new resource grant for one or more uplink transmissions. In a further aspect of some example embodiments, the maximum feedback time period T205can be selected or adapted (e.g., by the network node106or by another network-side device controlled by a network operator, for examples) based on the number of HARQ processes to be utilized for wireless communication between the wireless device102and the network node106(or at least for uplink transmissions105,107). In some examples, when the number of HARQ processes is relatively small (e.g., based on a threshold number, for instance) the value of the time period for the timer can be set to a relatively low value to allow for reuse of individual HARQ process numbers. Alternatively, where the number of HARQ processes is relatively large, the wireless device102can wait longer for a feedback before it must reuse the corresponding HARQ process number for new data, and therefore the time period can be set to a relatively higher value. Furthermore, as multiple HARQ processes are available for use concurrently (i.e. as in LTE, where eight HARQ processes are available as discussed above), any available HARQ process can be used to transmit new data while waiting for maximum feedback time period T205of a particular HARQ ID. Thus, in a further aspect of the present disclosure, each HARQ process can operate its own timer, optionally with a same maximum feedback time period or with different time periods in other examples. Aspects of these and other possible implementations will now be described in reference to the accompanying figures.FIG.1illustrates a wireless communication system10that includes a network node106and a wireless device102in wireless communication over one or more communication channels. As shown, the wireless device102is configured to transmit uplink messages to the network node. In an aspect, these uplink transmissions can include an original (e.g., first or earlier in time) TB transmission105comprising data and having a HARQ process ID. In addition, the uplink transmissions can include a subsequent TB transmission107, which, depending on the HARQ policy113stored at the wireless device102and the network node106, can include either new data or all or part of the original data for retransmission using the HARQ process ID of the original TB transmission105. In addition, as shown inFIG.1, the network node106is configured to transmit downlink messages to the wireless device102. These downlink messages can include one or more uplink scheduling grants109, which in some instances can implement SPS techniques (i.e., one uplink scheduling grant109being transmitted for every n transmission occasions where n>1). In addition, the downlink transmissions can include configuration information111, which can include information related to the HARQ processes, such as information needed at the wireless device102to carry out the HARQ policy113. For instance, the configuration information may include a value for the time period T205associated with the timer. Additionally, in some examples, the configuration information can include control or characteristic data gathered by the network node106to aid the wireless device102in determining the HARQ policy113and/or the time period associated with the timer. Such information may include a number of HARQ processes to be utilized by the wireless device102in its transmissions to the network node106, a periodicity of periodic transmission occasions (i.e., how frequently uplink transmission occasions or opportunities are available), a delay tolerance of a service corresponding to data that may be carried by a TB transmitted by the wireless device102, network load information, a processing time required for the network node to process received uplink transmissions from the wireless device102, among other factors that may be needed to ensure proper transmission timing and/or HARQ policy selection by the wireless device102. In an aspect, the selection of the HARQ policy (by wireless device102, for instance) includes determining whether the wireless device102is to retransmit all or part of the TB data transmitted in the original transmission105or is to use the HARQ process ID of that original transmission105to transmit new data in a TB at a next transmission occasion for that HARQ process if the timer expires without the wireless device102having received HARQ feedback for the original TB transmission105. FIG.2illustrates an example of uplink transmission timing in the wireless communication system10ofFIG.1, which allows for functional retransmission operations without using explicit HARQ feedback. In the simplified use-case illustrated in the figure, there is only a single HARQ process used in semi-persistent scheduling. As shown, the wireless device102can initially send an original TB transmission105at a periodic transmission occasion201defined by the corresponding uplink grant (e.g., in an earlier SPS message from the network node106). In the example shown, the timer115is started by the wireless device102contemporaneous with the original TB transmission105(though in other examples, the timer115could be started when the uplink grant for periodic transmission occasion201is received by the wireless device102). After transmitting the original TB and stating the timer115, the wireless device102then waits for a time period T205This time period T205may be selected by the wireless device102, preconfigured by a network operator, or assigned by the network node106. If the wireless device102determines that no HARQ feedback has been received for the original TB transmission105, the wireless device102is configured to, at the next periodic transmission occasion203following expiration of the timer, either (a) reuse the HARQ process ID of the original TB transmission105to transmit new data in a new TB or (b) retransmit all or part of the original TB transmission105using the same HARQ process ID. In an aspect of the present disclosure, this determination regarding whether to transmit new data or retransmit the original data is governed by the HARQ policy113. Therefore, upon determining that the timer has expired and no HARQ feedback was received, the wireless device102takes the action mandated by the HARQ policy113in effect at the time. Thus, in some instances, depending on the HARQ policy113, the TB sent by the wireless device102at a next transmission occasion for the relevant HARQ process ID (i.e., the first occasion available for the HARQ process after the timer expires) could be either a retransmission of the original data or a new TB containing new data. Furthermore, in example embodiments of the present disclosure, the HARQ policy113can be determined by the wireless device102(and optionally relayed to the network node106). In some examples, the HARQ policy113can be set by the wireless device102based on network-side factors such as observed or estimated latency, network load, Quality of Service (QoS) requirements of the service to which the transmitted data pertains or to which the data is to likely pertain, reliability requirements of the underlying service (e.g., eMBB vs. URLCC), and the like. Moving on,FIG.3shows another example implementation where the number of HARQ processes is four. In this example, the timer time period T305is relatively long compared to the time period T205ofFIG.2, and as a result, multiple transmission occasions for other HARQ process IDs occur during the time period T305—namely, TB transmissions300B,300C, and300D at periodic transmission occasions301B,301C, and301D, respectively. For purposes of the present disclosure, although the timer is described as having an associated time period T, the terms meant to be read as interchangeable such that when a timer is referred to, so is a time period T, and vice versa. Returning to the operation of the present solutions, again, as inFIG.2, upon expiration of the timer after time period T305elapses inFIG.3, the wireless device102either retransmits all or part of the data transmitted in the TB of300A or transmits new data in a TB at the next periodic transmission occasion by reusing the HARQ process ID of the original TB transmission300A. As a comparison ofFIG.2andFIG.3shows, the timer can be set (for instance, by the network node106or another network-side device) to have an associated time period T205,305that differs based on one or more parameters. For instance, the time period T205,305of the timer can be set based on one or more of the number of HARQ processes to be used by the wireless device102, a periodicity of the SPS transmission, or a degree of delay-tolerance associated with the service or application corresponding to the data contained in one or more of the uplink TB transmissions300A-D and307. The timer could further be configured based on a processing time required by the network node106to decode and process received data of a given TB and perform a reliability check on the received data (e.g., cyclic redundancy check (CRC) or the like). In some instances, the time period T205,305of the timer may additionally or alternatively be set based on the load in the network or network node106and/or throughput or QoS metrics mandated by an underlying service. For instance, in an example aspect, If the load is higher in the cell or cells operating on the same network node106, the network node106can configure (or reconfigure) the time period T205,305based on a present (or time-averaged) processing load present at the network node106, and may further set the time period T such that the network node106is able to respond to the wireless device102with HARQ feedback within the configured time period T at a rate that is greater than or equal to a threshold value (or is projected to meet the threshold value through extrapolation or similar predictive methods). Turning toFIG.4, the figure depicts an example method400for managing TB transmissions by the wireless device102to a network node106at periodic transmission occasions, which can be performed by a wireless device102(e.g., a UE) according to some implementations. The method400can include, for instance, starting a timer for a HARQ process associated with a transport block transmission by the wireless device102to the network node106(i.e., original TB data transmissions105and300A ofFIGS.2and3, respectively) at block402. In addition, the example method400can include, at block404, identifying a HARQ policy for the HARQ process, where the HARQ policy governs whether the wireless device102is to retransmit the TB or the original transmission105or transmit a new TB where no HARQ feedback responsive to the original TB transmission is received from the network node106before the timer expires. In addition, the method400can include, at block406, retransmitting the TB or transmitting the new TB according to the HARQ policy at a next periodic transmission occasion for the HARQ process after the timer expires. Furthermore, although not explicitly shown inFIG.4, additional or alternative aspects of the present disclosure could be included in method400in some embodiments. For instance, as shown inFIG.3, in some examples of method400, at least one additional HARQ process (see e.g., items300B,300C,300D) is executed after starting the timer and before the timer expires. In an additional optional aspect of method400, the time period T associated with the timer can be set (e.g., by the network node106) according to one or more of: a number of HARQ processes utilized by the wireless device102, a periodicity of periodic transmission occasions, a delay tolerance of a service corresponding to data carried by the TB and/or the new TB, a processing time of the network node106, and a network load. In addition, as mentioned above, the timer for a relevant HARQ process can be started upon transmission of the original TB or upon the wireless device102receiving an uplink grant from the network node106for transmission of the TB. Also, as introduced above, the method400can include the wireless device102generating the HARQ policy. FIG.5illustrates an example method500performed by a network node for managing TB transmissions by a wireless device102to the network node106at periodic transmission occasions. In an aspect, method500may include, at block502, configuring a timer for a HARQ process associated with a TB transmission by the wireless device to the network node. In addition, method500may include, at block504, identifying a HARQ policy for the HARQ process, where the HARQ policy governs whether the wireless device102is to retransmit the TB or transmit a new TB to the network node106in scenarios where the wireless device102receives no HARQ feedback from the network node106responsive to the TB transmission before the timer expires. Furthermore, at block506, method500may include receiving a retransmitted TB or a new TB according to the HARQ policy at a next periodic transmission occasion for the HARQ process after the timer expires. Furthermore, although not explicitly shown inFIG.5, additional or alternative aspects of the present disclosure could be included in method500in some embodiments. For instance, in some examples, identifying the HARQ policy at block504may also include obtaining the HARQ policy from the wireless device102, for instance, via control signaling in a stand-alone uplink transmission or via a signal transmitted by the wireless device102of any other sort (e.g., higher-level signaling, trailing bits of control or data transmissions by the wireless device, etc.) where the HARQ policy can optionally be indicated in one or more piggybacked bits. In an additional aspect of some embodiments, identifying the HARQ policy can include setting the HARQ policy at the network node106, which can be based on one or more of the following non-limiting list of factors: a number of HARQ processes utilized by the wireless device102, a periodicity of periodic transmission occasions, a delay tolerance and/or a reliability requirement of a service corresponding to data carried by the TB and/or the new TB, a processing time of the network node106, and a network load. In addition, in some examples, the time period T of the timer can be set by the network node106based on one or more of these factors. The method500can also include the network node106determining that the network load has reached a threshold value and, based on this determination, increasing the time period of the timer. In a further aspect of the method500, and the functionality of the network node106generally, the network node106may be configured to perform error detection on one or more TBs received from the wireless device102. This can involve, for instance, performing CRC operations or otherwise processing received data using other error detection mechanisms known in the art. Based on the results of these error detection operations, the network node106can optionally transmit HARQ feedback to the wireless device assuming the configured HARQ policy allows for such transmissions to the wireless device102. Leveraging the unique features of the techniques presented herein, the network node106can then determine a TB and/or HARQ process that is to be transmitted or retransmitted during a next periodic transmission occasion based on a result of the error detection, the configured HARQ policy, and/or a time at which the HARQ feedback is transmitted to the wireless device102or is to be received by the wireless device102. Moreover, though not explicitly shown in methods400or500ofFIG.4orFIG.5, respectively, these methods may exhibit further optional aspects in some embodiments. For instance, in method400or method500, the periodic transmission occasions (e.g.201,203ofFIG.2,300A-300D,307ofFIG.3) are defined according to an SPS scheme, which may also be referred to as “UL transmission without dynamic scheduling”, “configured grant scheduling,” or “configured scheduling.” In a further optional aspect, although the HARQ policy can be selected by the wireless device102, in some instances, it can alternatively be preconfigured, for instance, by a manufacturer, network operator, a particular radio access technology utilized by the wireless device102and the network node106, or the like. In the same vein, in some instances the HARQ policy may be static, where in other instances it may be dynamic in that it can change over time based on one or more factors, including those discussed above. In addition, for purposes of the present disclosure, the wireless device102can be considered to be a user equipment, though, again, this is not a limiting aspect. Furthermore, in any of the example embodiments of the present disclosure, though not limiting, the network node106can be a gNB, eNB, Base Station, 802.11 Access Point, or any other radio access network device in communication with one or more wireless devices102. In other words, the network node106, as that term is used herein, is a general term and can correspond to any type of radio network node or any network node which communicates with a wireless device and/or with another network node. Examples of network nodes include, but are not limited to NodeB, base station (BS), multi-standard radio (MSR) radio node such as MSR BS, evolved node B (eNodeB), new generation (5G) node B (gNodeB), macro evolved Node B (MeNB), small evolved Node B (SeNB), network controller, radio network controller (RNC), base station controller (BSC), relay, donor node controlling relay, base transceiver station (BTS), access point (AP), transmission points, transmission nodes, remote radio unit (RRU), remote radio head (RRH), nodes in distributed antenna system (DAS), core network node (e.g., mobile switching center (MSC), MME, etc.), operations & maintenance (O&M), open storage service (OSS), self-organizing network (SON), positioning node (e.g., evolved serving location center (E-SMLC)), minimizing of driving test (MDT), etc. With these devices in mind, let us turn toFIGS.6A,6B,7A, and7B, which present example aspects of a wireless device102and network node106that are configured to carry out the techniques and methods presented above.FIG.6Aillustrates additional details of an example wireless device102of a wireless communication system10according to one or more embodiments. The wireless device102is configured, e.g., via functional means or units (also may be referred to as modules or components herein), to implement processing to perform certain aspects described above in reference to at least the aspects ofFIGS.2and3the related methods presented inFIGS.4and5. As shown inFIG.6B, the wireless device102in some embodiments for example includes means, modules, components, or units630,640, and650(among other possible means, modules, components, or units not shown explicitly inFIG.6B) for performing aspects of these methods. In some examples, these means, modules, components, or units can be realized in processing circuitry600. Specifically, the functional means or units of the wireless device102may include a timing unit/module630configured to start and manage a timer for one or more HARQ processes, such as in block402ofFIG.4. In addition, the wireless device102can include a HARQ policy unit/module640to identify a HARQ policy for one or more HARQ processes governing whether the wireless device102is to retransmit a TB or portion thereof, or transmit a new TB where no HARQ feedback responsive to the TB transmission is received from the network node before the timer expires, for example, as performed in block404ofFIG.4, above. In addition, wireless device102may include a transmitting/retransmitting unit/module for retransmitting a TB or a portion thereof, or transmitting a new TB according to the HARQ policy at a next periodic transmission occasion for the HARQ process after the timer expires, for instance, as performed at block406inFIG.4. In at least some embodiments, the wireless device102comprises one or more processing circuitry/circuits600configured to implement processing of the methods presented inFIGS.4and5and certain associated processing of the features described in relation to other figures, such as by implementing functional means or units above. In one embodiment, for example, the processing circuit(s)600implements functional means or units as respective circuits. The circuits in this regard may comprise circuits dedicated to performing certain functional processing and/or one or more microprocessors in conjunction with memory620. In embodiments that employ memory620, which may comprise one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc., the memory620stores program code that, when executed by the one or more for carrying out one or more microprocessors, carries out the techniques described herein. In one or more embodiments, the wireless device102also comprises communication circuitry610. The communication circuitry610includes various components (e.g., antennas) for sending and receiving data and control signals. More particularly, the circuitry610includes a transmitter that is configured to use known signal processing techniques, typically according to one or more standards, and is configured to condition a signal for transmission (e.g., over the air via one or more antennas). Similarly, the communication circuitry includes a receiver that is configured to convert signals received (e.g., via the antenna(s)) into digital samples for processing by the one or more processing circuits. FIG.7Aillustrates additional details of an example network node106of a wireless communication system10according to one or more embodiments. The network node106is configured, e.g., via functional means or units (also may be referred to as modules or components herein), to implement processing to perform certain aspects described above in reference to at least the aspects ofFIGS.2and3the related methods presented inFIGS.4and5. As shown inFIG.7B, the network node106in some embodiments for example includes means, modules, components, or units730,740, and750(among other possible means, modules, components, or units not shown explicitly inFIG.7B) for performing aspects of these methods. In some examples, these means, modules, components, or units can be realized in processing circuitry700. Specifically, the functional means or units of the network node106may include a timing unit/module730configured to configure a timer and/or a time period associated with the timer for a HARQ process associated with a TB transmission by a wireless device102to the network node106, such as in block502ofFIG.5. In addition, the network node106can include a HARQ policy unit/module740to identify a HARQ policy for one or more HARQ processes governing whether the network node106is to retransmit a TB or portion thereof, or transmit a new TB where no HARQ feedback responsive to the TB transmission is received from the network node before the timer expires, for example, as performed in block504ofFIG.5, above. In addition, network node106may include a receiving unit/module for receiving a retransmitted TB or a portion thereof, or receiving a new TB according to the HARQ policy at a next periodic transmission occasion for the HARQ process after the timer expires, for instance, as performed at block506inFIG.5. In at least some embodiments, the network node106comprises one or more processing circuitry/circuits700configured to implement processing of the methods presented inFIGS.4and5and certain associated processing of the features described in relation to other figures, such as by implementing functional means or units above. In one embodiment, for example, the processing circuit(s)700implements functional means or units as respective circuits. The circuits in this regard may comprise circuits dedicated to performing certain functional processing and/or one or more microprocessors in conjunction with memory720. In embodiments that employ memory720, which may comprise one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc., the memory720stores program code that, when executed by the one or more for carrying out one or more microprocessors, carries out the techniques described herein. In one or more embodiments, the network node106also comprises communication circuitry710. The communication circuitry710includes various components (e.g., antennas) for sending and receiving data and control signals. More particularly, the circuitry710includes a transmitter that is configured to use known signal processing techniques, typically according to one or more standards, and is configured to condition a signal for transmission (e.g., over the air via one or more antennas). Similarly, the communication circuitry includes a receiver that is configured to convert signals received (e.g., via the antenna(s)) into digital samples for processing by the one or more processing circuits. Those skilled in the art will also appreciate that embodiments herein further include corresponding computer programs. A computer program comprises instructions which, when executed on at least one processor of the network node106or wireless device102, cause these devices to carry out any of the respective processing described above. Furthermore, the processing or functionality of network node106or wireless device102may be considered as being performed by a single instance or device or may be divided across a plurality of instances of network node106or wireless device102that may be present in a given system such that together the device instances perform all disclosed functionality. In an aspect, the wireless device102may correspond to any mobile (or even stationary) device that is configured to receive/consume user data from a network-side infrastructure, including laptops, phones, tablets, IoT devices, etc. As recited above, the network node106may be any network device, such as a base station, eNB, gNB, access point, or any other similar device. Embodiments further include a carrier containing such a computer program. This carrier may comprise one of an electronic signal, optical signal, radio signal, or computer readable storage medium. A computer program in this regard may comprise one or more code modules corresponding to the means or units described above. The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. | 29,696 |
11943059 | DETAILED DESCRIPTION In the present disclosure, various embodiments are presented as examples of how the disclosed techniques may be implemented and/or how the disclosed techniques may be practiced in environments and scenarios. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope. In fact, after reading the description, it will be apparent to one skilled in the relevant art how to implement alternative embodiments. The present embodiments should not be limited by any of the described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. Limitations, features, and/or elements from the disclosed example embodiments may be combined to create further embodiments within the scope of the disclosure. Any figures which highlight the functionality and advantages, are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than that shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments. Embodiments may be configured to operate as needed. The disclosed mechanism may be performed when certain criteria are met, for example, in a wireless device, a base station, a radio environment, a network, a combination of the above, and/or the like. Example criteria may be based, at least in part, on for example, wireless device or network node configurations, traffic load, initial system set up, packet sizes, traffic characteristics, a combination of the above, and/or the like. When the one or more criteria are met, various example embodiments may be applied. Therefore, it may be possible to implement example embodiments that selectively implement disclosed protocols. A base station may communicate with a mix of wireless devices. Wireless devices and/or base stations may support multiple technologies, and/or multiple releases of the same technology. Wireless devices may have some specific capability(ies) depending on wireless device category and/or capability(ies). When this disclosure refers to a base station communicating with a plurality of wireless devices, this disclosure may refer to a subset of the total wireless devices in a coverage area. This disclosure may refer to, for example, a plurality of wireless devices of a given LTE or 5G release with a given capability and in a given sector of the base station. The plurality of wireless devices in this disclosure may refer to a selected plurality of wireless devices, and/or a subset of total wireless devices in a coverage area which perform according to disclosed methods, and/or the like. There may be a plurality of base stations or a plurality of wireless devices in a coverage area that may not comply with the disclosed methods, for example, those wireless devices or base stations may perform based on older releases of LTE or 5G technology. In this disclosure, “a” and “an” and similar phrases are to be interpreted as “at least one” and “one or more.” Similarly, any term that ends with the suffix “(s)” is to be interpreted as “at least one” and “one or more.” In this disclosure, the term “may” is to be interpreted as “may, for example.” In other words, the term “may” is indicative that the phrase following the term “may” is an example of one of a multitude of suitable possibilities that may, or may not, be employed by one or more of the various embodiments. The terms “comprises” and “consists of”, as used herein, enumerate one or more components of the element being described. The term “comprises” is interchangeable with “includes” and does not exclude unenumerated components from being included in the element being described. By contrast, “consists of” provides a complete enumeration of the one or more components of the element being described. The term “based on”, as used herein, should be interpreted as “based at least in part on” rather than, for example, “based solely on”. The term “and/or” as used herein represents any possible combination of enumerated elements. For example, “A, B, and/or C” may represent A; B; C; A and B; A and C; B and C; or A, B, and C. If A and B are sets and every element of A is an element of B, A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B={cell1, cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on” (or equally “based at least on”) is indicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employing/using” (or equally “employing/using at least”) is indicative that the phrase following the phrase “employing/using” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The term configured may relate to the capacity of a device whether the device is in an operational or non-operational state. Configured may refer to specific settings in a device that effect the operational characteristics of the device whether the device is in an operational or non-operational state. In other words, the hardware, software, firmware, registers, memory values, and/or the like may be “configured” within a device, whether the device is in an operational or nonoperational state, to provide the device with specific characteristics. Terms such as “a control message to cause in a device” may mean that a control message has parameters that may be used to configure specific characteristics or may be used to implement certain actions in the device, whether the device is in an operational or non-operational state. In this disclosure, parameters (or equally called, fields, or Information elements: IEs) may comprise one or more information objects, and an information object may comprise one or more other objects. For example, if parameter (IE) N comprises parameter (IE) M, and parameter (IE) M comprises parameter (IE) K, and parameter (IE) K comprises parameter (information element) J. Then, for example, N comprises K, and N comprises J. In an example embodiment, when one or more messages comprise a plurality of parameters, it implies that a parameter in the plurality of parameters is in at least one of the one or more messages, but does not have to be in each of the one or more messages. Many features presented are described as being optional through the use of “may” or the use of parentheses. For the sake of brevity and legibility, the present disclosure does not explicitly recite each and every permutation that may be obtained by choosing from the set of optional features. The present disclosure is to be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features may be embodied in seven ways, namely with just one of the three possible features, with any two of the three possible features or with three of the three possible features. Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with a biological element) or a combination thereof, which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab or the like) or a modeling/simulation program such as Simulink, Stateflow, GNU Octave, or Lab VIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and/or quantum hardware. Examples of programmable hardware comprise: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers and microprocessors are programmed using languages such as assembly, C, C++ or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The mentioned technologies are often used in combination to achieve the result of a functional module. FIG.1Aillustrates an example of a mobile communication network100in which embodiments of the present disclosure may be implemented. The mobile communication network100may be, for example, a public land mobile network (PLMN) run by a network operator. As illustrated inFIG.1A, the mobile communication network100includes a core network (CN)102, a radio access network (RAN)104, and a wireless device106. The CN102may provide the wireless device106with an interface to one or more data networks (DNs), such as public DNs (e.g., the Internet), private DNs, and/or intra-operator DNs. As part of the interface functionality, the CN102may set up end-to-end connections between the wireless device106and the one or more DNs, authenticate the wireless device106, and provide charging functionality. The RAN104may connect the CN102to the wireless device106through radio communications over an air interface. As part of the radio communications, the RAN104may provide scheduling, radio resource management, and retransmission protocols. The communication direction from the RAN104to the wireless device106over the air interface is known as the downlink and the communication direction from the wireless device106to the RAN104over the air interface is known as the uplink. Downlink transmissions may be separated from uplink transmissions using frequency division duplexing (FDD), time-division duplexing (TDD), and/or some combination of the two duplexing techniques. The term wireless device may be used throughout this disclosure to refer to and encompass any mobile device or fixed (non-mobile) device for which wireless communication is needed or usable. For example, a wireless device may be a telephone, smart phone, tablet, computer, laptop, sensor, meter, wearable device, Internet of Things (IoT) device, vehicle road side unit (RSU), relay node, automobile, and/or any combination thereof. The term wireless device encompasses other terminology, including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit and receive unit (WTRU), and/or wireless communication device. The RAN104may include one or more base stations (not shown). The term base station may be used throughout this disclosure to refer to and encompass a Node B (associated with UMTS and/or 3G standards), an Evolved Node B (eNB, associated with E-UTRA and/or 4G standards), a remote radio head (RRH), a baseband processing unit coupled to one or more RRHs, a repeater node or relay node used to extend the coverage area of a donor node, a Next Generation Evolved Node B (ng-eNB), a Generation Node B (gNB, associated with NR and/or 5G standards), an access point (AP, associated with, for example, Wi-Fi or any other suitable wireless communication standard), and/or any combination thereof. A base station may comprise at least one gNB Central Unit (gNB-CU) and at least one a gNB Distributed Unit (gNB-DU). A base station included in the RAN104may include one or more sets of antennas for communicating with the wireless device106over the air interface. For example, one or more of the base stations may include three sets of antennas to respectively control three cells (or sectors). The size of a cell may be determined by a range at which a receiver (e.g., a base station receiver) can successfully receive the transmissions from a transmitter (e.g., a wireless device transmitter) operating in the cell. Together, the cells of the base stations may provide radio coverage to the wireless device106over a wide geographic area to support wireless device mobility. In addition to three-sector sites, other implementations of base stations are possible. For example, one or more of the base stations in the RAN104may be implemented as a sectored site with more or less than three sectors. One or more of the base stations in the RAN104may be implemented as an access point, as a baseband processing unit coupled to several remote radio heads (RRHs), and/or as a repeater or relay node used to extend the coverage area of a donor node. A baseband processing unit coupled to RRHs may be part of a centralized or cloud RAN architecture, where the baseband processing unit may be either centralized in a pool of baseband processing units or virtualized. A repeater node may amplify and rebroadcast a radio signal received from a donor node. A relay node may perform the same/similar functions as a repeater node but may decode the radio signal received from the donor node to remove noise before amplifying and rebroadcasting the radio signal. The RAN104may be deployed as a homogenous network of macrocell base stations that have similar antenna patterns and similar high-level transmit powers. The RAN104may be deployed as a heterogeneous network. In heterogeneous networks, small cell base stations may be used to provide small coverage areas, for example, coverage areas that overlap with the comparatively larger coverage areas provided by macrocell base stations. The small coverage areas may be provided in areas with high data traffic (or so-called “hotspots”) or in areas with weak macrocell coverage. Examples of small cell base stations include, in order of decreasing coverage area, microcell base stations, picocell base stations, and femtocell base stations or home base stations. The Third-Generation Partnership Project (3GPP) was formed in 1998 to provide global standardization of specifications for mobile communication networks similar to the mobile communication network100inFIG.1A. To date, 3GPP has produced specifications for three generations of mobile networks: a third generation (3G) network known as Universal Mobile Telecommunications System (UMTS), a fourth generation (4G) network known as Long-Term Evolution (LTE), and a fifth generation (5G) network known as 5G System (5GS). Embodiments of the present disclosure are described with reference to the RAN of a 3GPP 5G network, referred to as next-generation RAN (NG-RAN). Embodiments may be applicable to RANs of other mobile communication networks, such as the RAN104inFIG.1A, the RANs of earlier 3G and 4G networks, and those of future networks yet to be specified (e.g., a 3GPP 6G network). NG-RAN implements 5G radio access technology known as New Radio (NR) and may be provisioned to implement 4G radio access technology or other radio access technologies, including non-3GPP radio access technologies. FIG.1Billustrates another example mobile communication network150in which embodiments of the present disclosure may be implemented. Mobile communication network150may be, for example, a PLMN run by a network operator. As illustrated inFIG.1B, mobile communication network150includes a 5G core network (5G-CN)152, an NG-RAN154, and UEs156A and156B (collectively UEs156). These components may be implemented and operate in the same or similar manner as corresponding components described with respect toFIG.1A. The 5G-CN152provides the UEs156with an interface to one or more DNs, such as public DNs (e.g., the Internet), private DNs, and/or intra-operator DNs. As part of the interface functionality, the 5G-CN152may set up end-to-end connections between the UEs156and the one or more DNs, authenticate the UEs156, and provide charging functionality. Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN152may be a service-based architecture. This means that the architecture of the nodes making up the 5G-CN152may be defined as network functions that offer services via interfaces to other network functions. The network functions of the 5G-CN152may be implemented in several ways, including as network elements on dedicated or shared hardware, as software instances running on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform). As illustrated inFIG.1B, the 5G-CN152includes an Access and Mobility Management Function (AMF)158A and a User Plane Function (UPF)158B, which are shown as one component AMF/UPF158inFIG.1Bfor ease of illustration. The UPF158B may serve as a gateway between the NG-RAN154and the one or more DNs. The UPF158B may perform functions such as packet routing and forwarding, packet inspection and user plane policy rule enforcement, traffic usage reporting, uplink classification to support routing of traffic flows to the one or more DNs, quality of service (QoS) handling for the user plane (e.g., packet filtering, gating, uplink/downlink rate enforcement, and uplink traffic verification), downlink packet buffering, and downlink data notification triggering. The UPF158B may serve as an anchor point for intra-/inter-Radio Access Technology (RAT) mobility, an external protocol (or packet) data unit (PDU) session point of interconnect to the one or more DNs, and/or a branching point to support a multi-homed PDU session. The UEs156may be configured to receive services through a PDU session, which is a logical connection between a UE and a DN. The AMF158A may perform functions such as Non-Access Stratum (NAS) signaling termination, NAS signaling security, Access Stratum (AS) security control, inter-CN node signaling for mobility between 3GPP access networks, idle mode UE reachability (e.g., control and execution of paging retransmission), registration area management, intra-system and inter-system mobility support, access authentication, access authorization including checking of roaming rights, mobility management control (subscription and policies), network slicing support, and/or session management function (SMF) selection. NAS may refer to the functionality operating between a CN and a UE, and AS may refer to the functionality operating between the UE and a RAN. The 5G-CN152may include one or more additional network functions that are not shown inFIG.1Bfor the sake of clarity. For example, the 5G-CN152may include one or more of a Session Management Function (SMF), an NR Repository Function (NRF), a Policy Control Function (PCF), a Network Exposure Function (NEF), a Unified Data Management (UDM), an Application Function (AF), and/or an Authentication Server Function (AUSF). The NG-RAN154may connect the 5G-CN152to the UEs156through radio communications over the air interface. The NG-RAN154may include one or more gNB s, illustrated as gNB160A and gNB160B (collectively gNBs160) and/or one or more ng-eNB s, illustrated as ng-eNB162A and ng-eNB162B (collectively ng-eNBs162). The gNBs160and ng-eNBs162may be more generically referred to as base stations. The gNBs160and ng-eNBs162may include one or more sets of antennas for communicating with the UEs156over an air interface. For example, one or more of the gNBs160and/or one or more of the ng-eNBs162may include three sets of antennas to respectively control three cells (or sectors). Together, the cells of the gNBs160and the ng-eNBs162may provide radio coverage to the UEs156over a wide geographic area to support UE mobility. As shown inFIG.1B, the gNBs160and/or the ng-eNBs162may be connected to the 5G-CN152by means of an NG interface and to other base stations by an Xn interface. The NG and Xn interfaces may be established using direct physical connections and/or indirect connections over an underlying transport network, such as an internet protocol (IP) transport network. The gNBs160and/or the ng-eNBs162may be connected to the UEs156by means of a Uu interface. For example, as illustrated inFIG.1B, gNB160A may be connected to the UE156A by means of a Uu interface. The NG, Xn, and Uu interfaces are associated with a protocol stack. The protocol stacks associated with the interfaces may be used by the network elements inFIG.1Bto exchange data and signaling messages and may include two planes: a user plane and a control plane. The user plane may handle data of interest to a user. The control plane may handle signaling messages of interest to the network elements. The gNBs160and/or the ng-eNBs162may be connected to one or more AMF/UPF functions of the 5G-CN152, such as the AMF/UPF158, by means of one or more NG interfaces. For example, the gNB160A may be connected to the UPF158B of the AMF/UPF158by means of an NG-User plane (NG-U) interface. The NG-U interface may provide delivery (e.g., non-guaranteed delivery) of user plane PDUs between the gNB160A and the UPF158B. The gNB160A may be connected to the AMF158A by means of an NG-Control plane (NG-C) interface. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, transport of NAS messages, paging, PDU session management, and configuration transfer and/or warning message transmission. The gNBs160may provide NR user plane and control plane protocol terminations towards the UEs156over the Uu interface. For example, the gNB160A may provide NR user plane and control plane protocol terminations toward the UE156A over a Uu interface associated with a first protocol stack. The ng-eNBs162may provide Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol terminations towards the UEs156over a Uu interface, where E-UTRA refers to the 3GPP 4G radio-access technology. For example, the ng-eNB162B may provide E-UTRA user plane and control plane protocol terminations towards the UE156B over a Uu interface associated with a second protocol stack. The 5G-CN152was described as being configured to handle NR and 4G radio accesses. It will be appreciated by one of ordinary skill in the art that it may be possible for NR to connect to a 4G core network in a mode known as “non-standalone operation.” In non-standalone operation, a 4G core network is used to provide (or at least support) control-plane functionality (e.g., initial access, mobility, and paging). Although only one AMF/UPF158is shown inFIG.1B, one gNB or ng-eNB may be connected to multiple AMF/UPF nodes to provide redundancy and/or to load share across the multiple AMF/UPF nodes. As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between the network elements inFIG.1Bmay be associated with a protocol stack that the network elements use to exchange data and signaling messages. A protocol stack may include two planes: a user plane and a control plane. The user plane may handle data of interest to a user, and the control plane may handle signaling messages of interest to the network elements. FIG.2AandFIG.2Brespectively illustrate examples of NR user plane and NR control plane protocol stacks for the Uu interface that lies between a UE210and a gNB220. The protocol stacks illustrated inFIG.2AandFIG.2Bmay be the same or similar to those used for the Uu interface between, for example, the UE156A and the gNB160A shown inFIG.1B. FIG.2Aillustrates a NR user plane protocol stack comprising five layers implemented in the UE210and the gNB220. At the bottom of the protocol stack, physical layers (PHYs)211and221may provide transport services to the higher layers of the protocol stack and may correspond to layer 1 of the Open Systems Interconnection (OSI) model. The next four protocols above PHYs211and221comprise media access control layers (MACs)212and222, radio link control layers (RLCs)213and223, packet data convergence protocol layers (PDCPs)214and224, and service data application protocol layers (SDAPs)215and225. Together, these four protocols may make up layer 2, or the data link layer, of the OSI model. FIG.3illustrates an example of services provided between protocol layers of the NR user plane protocol stack. Starting from the top ofFIG.2AandFIG.3, the SDAPs215and225may perform QoS flow handling. The UE210may receive services through a PDU session, which may be a logical connection between the UE210and a DN. The PDU session may have one or more QoS flows. A UPF of a CN (e.g., the UPF158B) may map IP packets to the one or more QoS flows of the PDU session based on QoS requirements (e.g., in terms of delay, data rate, and/or error rate). The SDAPs215and225may perform mapping/de-mapping between the one or more QoS flows and one or more data radio bearers. The mapping/de-mapping between the QoS flows and the data radio bearers may be determined by the SDAP225at the gNB220. The SDAP215at the UE210may be informed of the mapping between the QoS flows and the data radio bearers through reflective mapping or control signaling received from the gNB220. For reflective mapping, the SDAP225at the gNB220may mark the downlink packets with a QoS flow indicator (QFI), which may be observed by the SDAP215at the UE210to determine the mapping/de-mapping between the QoS flows and the data radio bearers. The PDCPs214and224may perform header compression/decompression to reduce the amount of data that needs to be transmitted over the air interface, ciphering/deciphering to prevent unauthorized decoding of data transmitted over the air interface, and integrity protection (to ensure control messages originate from intended sources. The PDCPs214and224may perform retransmissions of undelivered packets, in-sequence delivery and reordering of packets, and removal of packets received in duplicate due to, for example, an intra-gNB handover. The PDCPs214and224may perform packet duplication to improve the likelihood of the packet being received and, at the receiver, remove any duplicate packets. Packet duplication may be useful for services that require high reliability. Although not shown inFIG.3, PDCPs214and224may perform mapping/de-mapping between a split radio bearer and RLC channels in a dual connectivity scenario. Dual connectivity is a technique that allows a UE to connect to two cells or, more generally, two cell groups: a master cell group (MCG) and a secondary cell group (SCG). A split bearer is when a single radio bearer, such as one of the radio bearers provided by the PDCPs214and224as a service to the SDAPs215and225, is handled by cell groups in dual connectivity. The PDCPs214and224may map/de-map the split radio bearer between RLC channels belonging to cell groups. The RLCs213and223may perform segmentation, retransmission through Automatic Repeat Request (ARQ), and removal of duplicate data units received from MACs212and222, respectively. The RLCs213and223may support three transmission modes: transparent mode (TM); unacknowledged mode (UM); and acknowledged mode (AM). Based on the transmission mode an RLC is operating, the RLC may perform one or more of the noted functions. The RLC configuration may be per logical channel with no dependency on numerologies and/or Transmission Time Interval (TTI) durations. As shown inFIG.3, the RLCs213and223may provide RLC channels as a service to PDCPs214and224, respectively. The MACs212and222may perform multiplexing/demultiplexing of logical channels and/or mapping between logical channels and transport channels. The multiplexing/demultiplexing may include multiplexing/demultiplexing of data units, belonging to the one or more logical channels, into/from Transport Blocks (TBs) delivered to/from the PHYs211and221. The MAC222may be configured to perform scheduling, scheduling information reporting, and priority handling between UEs by means of dynamic scheduling. Scheduling may be performed in the gNB220(at the MAC222) for downlink and uplink. The MACs212and222may be configured to perform error correction through Hybrid Automatic Repeat Request (HARQ) (e.g., one HARQ entity per carrier in case of Carrier Aggregation (CA)), priority handling between logical channels of the UE210by means of logical channel prioritization, and/or padding. The MACs212and222may support one or more numerologies and/or transmission timings. In an example, mapping restrictions in a logical channel prioritization may control which numerology and/or transmission timing a logical channel may use. As shown inFIG.3, the MACs212and222may provide logical channels as a service to the RLCs213and223. The PHYs211and221may perform mapping of transport channels to physical channels and digital and analog signal processing functions for sending and receiving information over the air interface. These digital and analog signal processing functions may include, for example, coding/decoding and modulation/demodulation. The PHYs211and221may perform multi-antenna mapping. As shown inFIG.3, the PHYs211and221may provide one or more transport channels as a service to the MACs212and222. FIG.4Aillustrates an example downlink data flow through the NR user plane protocol stack.FIG.4Aillustrates a downlink data flow of three IP packets (n, n+1, and m) through the NR user plane protocol stack to generate two TB s at the gNB220. An uplink data flow through the NR user plane protocol stack may be similar to the downlink data flow depicted inFIG.4A. The downlink data flow ofFIG.4Abegins when SDAP225receives the three IP packets from one or more QoS flows and maps the three packets to radio bearers. InFIG.4A, the SDAP225maps IP packets n and n+1 to a first radio bearer402and maps IP packet m to a second radio bearer404. An SDAP header (labeled with an “H” inFIG.4A) is added to an IP packet. The data unit from/to a higher protocol layer is referred to as a service data unit (SDU) of the lower protocol layer and the data unit to/from a lower protocol layer is referred to as a protocol data unit (PDU) of the higher protocol layer. As shown inFIG.4A, the data unit from the SDAP225is an SDU of lower protocol layer PDCP224and is a PDU of the SDAP225. The remaining protocol layers inFIG.4Amay perform their associated functionality (e.g., with respect toFIG.3), add corresponding headers, and forward their respective outputs to the next lower layer. For example, the PDCP224may perform IP-header compression and ciphering and forward its output to the RLC223. The RLC223may optionally perform segmentation (e.g., as shown for IP packet m inFIG.4A) and forward its output to the MAC222. The MAC222may multiplex a number of RLC PDUs and may attach a MAC subheader to an RLC PDU to form a transport block. In NR, the MAC subheaders may be distributed across the MAC PDU, as illustrated inFIG.4A. In LTE, the MAC subheaders may be entirely located at the beginning of the MAC PDU. The NR MAC PDU structure may reduce processing time and associated latency because the MAC PDU subheaders may be computed before the full MAC PDU is assembled. FIG.4Billustrates an example format of a MAC subheader in a MAC PDU. The MAC subheader includes: an SDU length field for indicating the length (e.g., in bytes) of the MAC SDU to which the MAC subheader corresponds; a logical channel identifier (LCID) field for identifying the logical channel from which the MAC SDU originated to aid in the demultiplexing process; a flag (F) for indicating the size of the SDU length field; and a reserved bit (R) field for future use. FIG.4Bfurther illustrates MAC control elements (CEs) inserted into the MAC PDU by a MAC, such as MAC223or MAC222. For example,FIG.4Billustrates two MAC CEs inserted into the MAC PDU. MAC CEs may be inserted at the beginning of a MAC PDU for downlink transmissions (as shown inFIG.4B) and at the end of a MAC PDU for uplink transmissions. MAC CEs may be used for in-band control signaling. Example MAC CEs include: scheduling-related MAC CEs, such as buffer status reports and power headroom reports; activation/deactivation MAC CEs, such as those for activation/deactivation of PDCP duplication detection, channel state information (CSI) reporting, sounding reference signal (SRS) transmission, and prior configured components; discontinuous reception (DRX) related MAC CEs; timing advance MAC CEs; and random access related MAC CEs. A MAC CE may be preceded by a MAC subheader with a similar format as described for MAC SDUs and may be identified with a reserved value in the LCID field that indicates the type of control information included in the MAC CE. Before describing the NR control plane protocol stack, logical channels, transport channels, and physical channels are first described as well as a mapping between the channel types. One or more of the channels may be used to carry out functions associated with the NR control plane protocol stack described later below. FIG.5AandFIG.5Billustrate, for downlink and uplink respectively, a mapping between logical channels, transport channels, and physical channels. Information is passed through channels between the RLC, the MAC, and the PHY of the NR protocol stack. A logical channel may be used between the RLC and the MAC and may be classified as a control channel that carries control and configuration information in the NR control plane or as a traffic channel that carries data in the NR user plane. A logical channel may be classified as a dedicated logical channel that is dedicated to a specific UE or as a common logical channel that may be used by more than one UE. A logical channel may also be defined by the type of information it carries. The set of logical channels defined by NR include, for example:a paging control channel (PCCH) for carrying paging messages used to page a UE whose location is not known to the network on a cell level;a broadcast control channel (BCCH) for carrying system information messages in the form of a master information block (MIB) and several system information blocks (SIBs), wherein the system information messages may be used by the UEs to obtain information about how a cell is configured and how to operate within the cell;a common control channel (CCCH) for carrying control messages together with random access;a dedicated control channel (DCCH) for carrying control messages to/from a specific the UE to configure the UE; anda dedicated traffic channel (DTCH) for carrying user data to/from a specific the UE. Transport channels are used between the MAC and PHY layers and may be defined by how the information they carry is transmitted over the air interface. The set of transport channels defined by NR include, for example:a paging channel (PCH) for carrying paging messages that originated from the PCCH;a broadcast channel (BCH) for carrying the MIB from the BCCH;a downlink shared channel (DL-SCH) for carrying downlink data and signaling messages, including the SIBs from the BCCH;an uplink shared channel (UL-SCH) for carrying uplink data and signaling messages; anda random access channel (RACH) for allowing a UE to contact the network without any prior scheduling. The PHY may use physical channels to pass information between processing levels of the PHY. A physical channel may have an associated set of time-frequency resources for carrying the information of one or more transport channels. The PHY may generate control information to support the low-level operation of the PHY and provide the control information to the lower levels of the PHY via physical control channels, known as L1/L2 control channels. The set of physical channels and physical control channels defined by NR include, for example:a physical broadcast channel (PBCH) for carrying the MIB from the BCH;a physical downlink shared channel (PDSCH) for carrying downlink data and signaling messages from the DL-SCH, as well as paging messages from the PCH;a physical downlink control channel (PDCCH) for carrying downlink control information (DCI), which may include downlink scheduling commands, uplink scheduling grants, and uplink power control commands;a physical uplink shared channel (PUSCH) for carrying uplink data and signaling messages from the UL-SCH and in some instances uplink control information (UCI) as described below;a physical uplink control channel (PUCCH) for carrying UCI, which may include HARQ acknowledgments, channel quality indicators (CQI), pre-coding matrix indicators (PMI), rank indicators (RI), and scheduling requests (SR); anda physical random access channel (PRACH) for random access. Similar to the physical control channels, the physical layer generates physical signals to support the low-level operation of the physical layer. As shown inFIG.5AandFIG.5B, the physical layer signals defined by NR include: primary synchronization signals (PSS), secondary synchronization signals (SSS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), sounding reference signals (SRS), and phase-tracking reference signals (PT-RS). These physical layer signals will be described in greater detail below. FIG.2Billustrates an example NR control plane protocol stack. As shown inFIG.2B, the NR control plane protocol stack may use the same/similar first four protocol layers as the example NR user plane protocol stack. These four protocol layers include the PHYs211and221, the MACs212and222, the RLCs213and223, and the PDCPs214and224. Instead of having the SDAPs215and225at the top of the stack as in the NR user plane protocol stack, the NR control plane stack has radio resource controls (RRCs)216and226and NAS protocols217and237at the top of the NR control plane protocol stack. The NAS protocols217and237may provide control plane functionality between the UE210and the AMF230(e.g., the AMF158A) or, more generally, between the UE210and the CN. The NAS protocols217and237may provide control plane functionality between the UE210and the AMF230via signaling messages, referred to as NAS messages. There is no direct path between the UE210and the AMF230through which the NAS messages can be transported. The NAS messages may be transported using the AS of the Uu and NG interfaces. NAS protocols217and237may provide control plane functionality such as authentication, security, connection setup, mobility management, and session management. The RRCs216and226may provide control plane functionality between the UE210and the gNB220or, more generally, between the UE210and the RAN. The RRCs216and226may provide control plane functionality between the UE210and the gNB220via signaling messages, referred to as RRC messages. RRC messages may be transmitted between the UE210and the RAN using signaling radio bearers and the same/similar PDCP, RLC, MAC, and PHY protocol layers. The MAC may multiplex control-plane and user-plane data into the same transport block (TB). The RRCs216and226may provide control plane functionality such as: broadcast of system information related to AS and NAS; paging initiated by the CN or the RAN; establishment, maintenance and release of an RRC connection between the UE210and the RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers and data radio bearers; mobility functions; QoS management functions; the UE measurement reporting and control of the reporting; detection of and recovery from radio link failure (RLF); and/or NAS message transfer. As part of establishing an RRC connection, RRCs216and226may establish an RRC context, which may involve configuring parameters for communication between the UE210and the RAN. FIG.6is an example diagram showing RRC state transitions of a UE. The UE may be the same or similar to the wireless device106depicted inFIG.1A, the UE210depicted inFIG.2AandFIG.2B, or any other wireless device described in the present disclosure. As illustrated inFIG.6, a UE may be in at least one of three RRC states: RRC connected602(e.g., RRC_CONNECTED), RRC idle604(e.g., RRC_IDLE), and RRC inactive606(e.g., RRC_INACTIVE). In RRC connected602, the UE has an established RRC context and may have at least one RRC connection with a base station. The base station may be similar to one of the one or more base stations included in the RAN104depicted inFIG.1A, one of the gNBs160or ng-eNBs162depicted inFIG.1B, the gNB220depicted inFIG.2AandFIG.2B, or any other base station described in the present disclosure. The base station with which the UE is connected may have the RRC context for the UE. The RRC context, referred to as the UE context, may comprise parameters for communication between the UE and the base station. These parameters may include, for example: one or more AS contexts; one or more radio link configuration parameters; bearer configuration information (e.g., relating to a data radio bearer, signaling radio bearer, logical channel, QoS flow, and/or PDU session); security information; and/or PHY, MAC, RLC, PDCP, and/or SDAP layer configuration information. While in RRC connected602, mobility of the UE may be managed by the RAN (e.g., the RAN104or the NG-RAN154). The UE may measure the signal levels (e.g., reference signal levels) from a serving cell and neighboring cells and report these measurements to the base station currently serving the UE. The UE's serving base station may request a handover to a cell of one of the neighboring base stations based on the reported measurements. The RRC state may transition from RRC connected602to RRC idle604through a connection release procedure608or to RRC inactive606through a connection inactivation procedure610. In RRC idle604, an RRC context may not be established for the UE. In RRC idle604, the UE may not have an RRC connection with the base station. While in RRC idle604, the UE may be in a sleep state for the majority of the time (e.g., to conserve battery power). The UE may wake up periodically (e.g., once in every discontinuous reception cycle) to monitor for paging messages from the RAN. Mobility of the UE may be managed by the UE through a procedure known as cell reselection. The RRC state may transition from RRC idle604to RRC connected602through a connection establishment procedure612, which may involve a random access procedure as discussed in greater detail below. In RRC inactive606, the RRC context previously established is maintained in the UE and the base station. This allows for a fast transition to RRC connected602with reduced signaling overhead as compared to the transition from RRC idle604to RRC connected602. While in RRC inactive606, the UE may be in a sleep state and mobility of the UE may be managed by the UE through cell reselection. The RRC state may transition from RRC inactive606to RRC connected602through a connection resume procedure614or to RRC idle604though a connection release procedure616that may be the same as or similar to connection release procedure608. An RRC state may be associated with a mobility management mechanism. In RRC idle604and RRC inactive606, mobility is managed by the UE through cell reselection. The purpose of mobility management in RRC idle604and RRC inactive606is to allow the network to be able to notify the UE of an event via a paging message without having to broadcast the paging message over the entire mobile communications network. The mobility management mechanism used in RRC idle604and RRC inactive606may allow the network to track the UE on a cell-group level so that the paging message may be broadcast over the cells of the cell group that the UE currently resides within instead of the entire mobile communication network. The mobility management mechanisms for RRC idle604and RRC inactive606track the UE on a cell-group level. They may do so using different granularities of grouping. For example, there may be three levels of cell-grouping granularity: individual cells; cells within a RAN area identified by a RAN area identifier (RAI); and cells within a group of RAN areas, referred to as a tracking area and identified by a tracking area identifier (TAI). Tracking areas may be used to track the UE at the CN level. The CN (e.g., the CN102or the 5G-CN152) may provide the UE with a list of TAIs associated with a UE registration area. If the UE moves, through cell reselection, to a cell associated with a TAI not included in the list of TAIs associated with the UE registration area, the UE may perform a registration update with the CN to allow the CN to update the UE's location and provide the UE with a new the UE registration area. RAN areas may be used to track the UE at the RAN level. For a UE in RRC inactive606state, the UE may be assigned a RAN notification area. A RAN notification area may comprise one or more cell identities, a list of RAIs, or a list of TAIs. In an example, a base station may belong to one or more RAN notification areas. In an example, a cell may belong to one or more RAN notification areas. If the UE moves, through cell reselection, to a cell not included in the RAN notification area assigned to the UE, the UE may perform a notification area update with the RAN to update the UE's RAN notification area. A base station storing an RRC context for a UE or a last serving base station of the UE may be referred to as an anchor base station. An anchor base station may maintain an RRC context for the UE at least during a period of time that the UE stays in a RAN notification area of the anchor base station and/or during a period of time that the UE stays in RRC inactive606. A gNB, such as gNBs160inFIG.1B, may be split in two parts: a central unit (gNB-CU), and one or more distributed units (gNB-DU). A gNB-CU may be coupled to one or more gNB-DUs using an F1 interface. The gNB-CU may comprise the RRC, the PDCP, and the SDAP. A gNB-DU may comprise the RLC, the MAC, and the PHY. In NR, the physical signals and physical channels (discussed with respect toFIG.5AandFIG.5B) may be mapped onto orthogonal frequency divisional multiplexing (OFDM) symbols. OFDM is a multicarrier communication scheme that transmits data over F orthogonal subcarriers (or tones). Before transmission, the data may be mapped to a series of complex symbols (e.g., M-quadrature amplitude modulation (M-QAM) or M-phase shift keying (M-PSK) symbols), referred to as source symbols, and divided into F parallel symbol streams. The F parallel symbol streams may be treated as though they are in the frequency domain and used as inputs to an Inverse Fast Fourier Transform (IFFT) block that transforms them into the time domain. The IFFT block may take in F source symbols at a time, one from each of the F parallel symbol streams, and use each source symbol to modulate the amplitude and phase of one of F sinusoidal basis functions that correspond to the F orthogonal subcarriers. The output of the IFFT block may be F time-domain samples that represent the summation of the F orthogonal subcarriers. The F time-domain samples may form a single OFDM symbol. After some processing (e.g., addition of a cyclic prefix) and up-conversion, an OFDM symbol provided by the IFFT block may be transmitted over the air interface on a carrier frequency. The F parallel symbol streams may be mixed using an FFT block before being processed by the IFFT block. This operation produces Discrete Fourier Transform (DFT)-precoded OFDM symbols and may be used by UEs in the uplink to reduce the peak to average power ratio (PAPR). Inverse processing may be performed on the OFDM symbol at a receiver using an FFT block to recover the data mapped to the source symbols. FIG.7illustrates an example configuration of an NR frame into which OFDM symbols are grouped. An NR frame may be identified by a system frame number (SFN). The SFN may repeat with a period of 1024 frames. As illustrated, one NR frame may be 10 milliseconds (ms) in duration and may include 10 subframes that are 1 ms in duration. A subframe may be divided into slots that include, for example, 14 OFDM symbols per slot. The duration of a slot may depend on the numerology used for the OFDM symbols of the slot. In NR, a flexible numerology is supported to accommodate different cell deployments (e.g., cells with carrier frequencies below 1 GHz up to cells with carrier frequencies in the mm-wave range). A numerology may be defined in terms of subcarrier spacing and cyclic prefix duration. For a numerology in NR, subcarrier spacings may be scaled up by powers of two from a baseline subcarrier spacing of 15 kHz, and cyclic prefix durations may be scaled down by powers of two from a baseline cyclic prefix duration of 4.7 μs. For example, NR defines numerologies with the following subcarrier spacing/cyclic prefix duration combinations: 15 kHz/4.7 μs; 30 kHz/2.3 μs; 60 kHz/1.2 μs; 120 kHz/0.59 μs; and 240 kHz/0.29 μs. A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols). A numerology with a higher subcarrier spacing has a shorter slot duration and, correspondingly, more slots per subframe.FIG.7illustrates this numerology-dependent slot duration and slots-per-subframe transmission structure (the numerology with a subcarrier spacing of 240 kHz is not shown inFIG.7for ease of illustration). A subframe in NR may be used as a numerology-independent time reference, while a slot may be used as the unit upon which uplink and downlink transmissions are scheduled. To support low latency, scheduling in NR may be decoupled from the slot duration and start at any OFDM symbol and last for as many symbols as needed for a transmission. These partial slot transmissions may be referred to as mini-slot or subslot transmissions. FIG.8illustrates an example configuration of a slot in the time and frequency domain for an NR carrier. The slot includes resource elements (REs) and resource blocks (RBs). An RE is the smallest physical resource in NR. An RE spans one OFDM symbol in the time domain by one subcarrier in the frequency domain as shown inFIG.8. An RB spans twelve consecutive REs in the frequency domain as shown inFIG.8. An NR carrier may be limited to a width of 275 RBs or 275×12=3300 subcarriers. Such a limitation, if used, may limit the NR carrier to 50, 100, 200, and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz, respectively, where the 400 MHz bandwidth may be set based on a 400 MHz per carrier bandwidth limit. FIG.8illustrates a single numerology being used across the entire bandwidth of the NR carrier. In other example configurations, multiple numerologies may be supported on the same carrier. NR may support wide carrier bandwidths (e.g., up to 400 MHz for a subcarrier spacing of 120 kHz). Not all UEs may be able to receive the full carrier bandwidth (e.g., due to hardware limitations). Also, receiving the full carrier bandwidth may be prohibitive in terms of UE power consumption. In an example, to reduce power consumption and/or for other purposes, a UE may adapt the size of the UE's receive bandwidth based on the amount of traffic the UE is scheduled to receive. This is referred to as bandwidth adaptation. NR defines bandwidth parts (BWPs) to support UEs not capable of receiving the full carrier bandwidth and to support bandwidth adaptation. In an example, a BWP may be defined by a subset of contiguous RBs on a carrier. A UE may be configured (e.g., via RRC layer) with one or more downlink BWPs and one or more uplink BWPs per serving cell (e.g., up to four downlink BWPs and up to four uplink BWPs per serving cell). At a given time, one or more of the configured BWPs for a serving cell may be active. These one or more BWPs may be referred to as active BWPs of the serving cell. When a serving cell is configured with a secondary uplink carrier, the serving cell may have one or more first active BWPs in the uplink carrier and one or more second active BWPs in the secondary uplink carrier. For unpaired spectra, a downlink BWP from a set of configured downlink BWPs may be linked with an uplink BWP from a set of configured uplink BWPs if a downlink BWP index of the downlink BWP and an uplink BWP index of the uplink BWP are the same. For unpaired spectra, a UE may expect that a center frequency for a downlink BWP is the same as a center frequency for an uplink BWP. For a downlink BWP in a set of configured downlink BWPs on a primary cell (PCell), a base station may configure a UE with one or more control resource sets (CORESETs) for at least one search space. A search space is a set of locations in the time and frequency domains where the UE may find control information. The search space may be a UE-specific search space or a common search space (potentially usable by a plurality of UEs). For example, a base station may configure a UE with a common search space, on a PCell or on a primary secondary cell (PSCell), in an active downlink BWP. For an uplink BWP in a set of configured uplink BWPs, a BS may configure a UE with one or more resource sets for one or more PUCCH transmissions. A UE may receive downlink receptions (e.g., PDCCH or PDSCH) in a downlink BWP according to a configured numerology (e.g., subcarrier spacing and cyclic prefix duration) for the downlink BWP. The UE may transmit uplink transmissions (e.g., PUCCH or PUSCH) in an uplink BWP according to a configured numerology (e.g., subcarrier spacing and cyclic prefix length for the uplink BWP). One or more BWP indicator fields may be provided in Downlink Control Information (DCI). A value of a BWP indicator field may indicate which BWP in a set of configured BWPs is an active downlink BWP for one or more downlink receptions. The value of the one or more BWP indicator fields may indicate an active uplink BWP for one or more uplink transmissions. A base station may semi-statically configure a UE with a default downlink BWP within a set of configured downlink BWPs associated with a PCell. If the base station does not provide the default downlink BWP to the UE, the default downlink BWP may be an initial active downlink BWP. The UE may determine which BWP is the initial active downlink BWP based on a CORESET configuration obtained using the PBCH. A base station may configure a UE with a BWP inactivity timer value for a PCell. The UE may start or restart a BWP inactivity timer at any appropriate time. For example, the UE may start or restart the BWP inactivity timer (a) when the UE detects a DCI indicating an active downlink BWP other than a default downlink BWP for a paired spectra operation; or (b) when a UE detects a DCI indicating an active downlink BWP or active uplink BWP other than a default downlink BWP or uplink BWP for an unpaired spectra operation. If the UE does not detect DCI during an interval of time (e.g., 1 ms or 0.5 ms), the UE may run the BWP inactivity timer toward expiration (for example, increment from zero to the BWP inactivity timer value, or decrement from the BWP inactivity timer value to zero). When the BWP inactivity timer expires, the UE may switch from the active downlink BWP to the default downlink BWP. In an example, a base station may semi-statically configure a UE with one or more BWPs. A UE may switch an active BWP from a first BWP to a second BWP in response to receiving a DCI indicating the second BWP as an active BWP and/or in response to an expiry of the BWP inactivity timer (e.g., if the second BWP is the default BWP). Downlink and uplink BWP switching (where BWP switching refers to switching from a currently active BWP to a not currently active BWP) may be performed independently in paired spectra. In unpaired spectra, downlink and uplink BWP switching may be performed simultaneously. Switching between configured BWPs may occur based on RRC signaling, DCI, expiration of a BWP inactivity timer, and/or an initiation of random access. FIG.9illustrates an example of bandwidth adaptation using three configured BWPs for an NR carrier. A UE configured with the three BWPs may switch from one BWP to another BWP at a switching point. In the example illustrated inFIG.9, the BWPs include: a BWP902with a bandwidth of 40 MHz and a subcarrier spacing of 15 kHz; a BWP904with a bandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and a BWP906with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. The BWP902may be an initial active BWP, and the BWP904may be a default BWP. The UE may switch between BWPs at switching points. In the example ofFIG.9, the UE may switch from the BWP902to the BWP904at a switching point908. The switching at the switching point908may occur for any suitable reason, for example, in response to an expiry of a BWP inactivity timer (indicating switching to the default BWP) and/or in response to receiving a DCI indicating BWP904as the active BWP. The UE may switch at a switching point910from active BWP904to BWP906in response receiving a DCI indicating BWP906as the active BWP. The UE may switch at a switching point912from active BWP906to BWP904in response to an expiry of a BWP inactivity timer and/or in response receiving a DCI indicating BWP904as the active BWP. The UE may switch at a switching point914from active BWP904to BWP902in response receiving a DCI indicating BWP902as the active BWP. If a UE is configured for a secondary cell with a default downlink BWP in a set of configured downlink BWPs and a timer value, UE procedures for switching BWPs on a secondary cell may be the same/similar as those on a primary cell. For example, the UE may use the timer value and the default downlink BWP for the secondary cell in the same/similar manner as the UE would use these values for a primary cell. To provide for greater data rates, two or more carriers can be aggregated and simultaneously transmitted to/from the same UE using carrier aggregation (CA). The aggregated carriers in CA may be referred to as component carriers (CCs). When CA is used, there are a number of serving cells for the UE, one for a CC. The CCs may have three configurations in the frequency domain. FIG.10Aillustrates the three CA configurations with two CCs. In the intraband, contiguous configuration1002, the two CCs are aggregated in the same frequency band (frequency band A) and are located directly adjacent to each other within the frequency band. In the intraband, non-contiguous configuration1004, the two CCs are aggregated in the same frequency band (frequency band A) and are separated in the frequency band by a gap. In the interband configuration1006, the two CCs are located in frequency bands (frequency band A and frequency band B). In an example, up to 32 CCs may be aggregated. The aggregated CCs may have the same or different bandwidths, subcarrier spacing, and/or duplexing schemes (TDD or FDD). A serving cell for a UE using CA may have a downlink CC. For FDD, one or more uplink CCs may be optionally configured for a serving cell. The ability to aggregate more downlink carriers than uplink carriers may be useful, for example, when the UE has more data traffic in the downlink than in the uplink. When CA is used, one of the aggregated cells for a UE may be referred to as a primary cell (PCell). The PCell may be the serving cell that the UE initially connects to at RRC connection establishment, reestablishment, and/or handover. The PCell may provide the UE with NAS mobility information and the security input. UEs may have different PCells. In the downlink, the carrier corresponding to the PCell may be referred to as the downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell may be referred to as the uplink primary CC (UL PCC). The other aggregated cells for the UE may be referred to as secondary cells (SCells). In an example, the SCells may be configured after the PCell is configured for the UE. For example, an SCell may be configured through an RRC Connection Reconfiguration procedure. In the downlink, the carrier corresponding to an SCell may be referred to as a downlink secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell may be referred to as the uplink secondary CC (UL SCC). Configured SCells for a UE may be activated and deactivated based on, for example, traffic and channel conditions. Deactivation of an SCell may mean that PDCCH and PDSCH reception on the SCell is stopped and PUSCH, SRS, and CQI transmissions on the SCell are stopped. Configured SCells may be activated and deactivated using a MAC CE with respect toFIG.4B. For example, a MAC CE may use a bitmap (e.g., one bit per SCell) to indicate which SCells (e.g., in a subset of configured SCells) for the UE are activated or deactivated. Configured SCells may be deactivated in response to an expiration of an SCell deactivation timer (e.g., one SCell deactivation timer per SCell). Downlink control information, such as scheduling assignments and scheduling grants, for a cell may be transmitted on the cell corresponding to the assignments and grants, which is known as self-scheduling. The DCI for the cell may be transmitted on another cell, which is known as cross-carrier scheduling. Uplink control information (e.g., HARQ acknowledgments and channel state feedback, such as CQI, PMI, and/or RI) for aggregated cells may be transmitted on the PUCCH of the PCell. For a larger number of aggregated downlink CCs, the PUCCH of the PCell may become overloaded. Cells may be divided into multiple PUCCH groups. FIG.10Billustrates an example of how aggregated cells may be configured into one or more PUCCH groups. A PUCCH group1010and a PUCCH group1050may include one or more downlink CCs, respectively. In the example ofFIG.10B, the PUCCH group1010includes three downlink CCs: a PCell1011, an SCell1012, and an SCell1013. The PUCCH group1050includes three downlink CCs in the present example: a PCell1051, an SCell1052, and an SCell1053. One or more uplink CCs may be configured as a PCell1021, an SCell1022, and an SCell1023. One or more other uplink CCs may be configured as a primary Scell (PSCell)1061, an SCell1062, and an SCell1063. Uplink control information (UCI) related to the downlink CCs of the PUCCH group1010, shown as UCI1031, UCI1032, and UCI1033, may be transmitted in the uplink of the PCell1021. Uplink control information (UCI) related to the downlink CCs of the PUCCH group1050, shown as UCI1071, UCI1072, and UCI1073, may be transmitted in the uplink of the PSCell1061. In an example, if the aggregated cells depicted inFIG.10Bwere not divided into the PUCCH group1010and the PUCCH group1050, a single uplink PCell to transmit UCI relating to the downlink CCs, and the PCell may become overloaded. By dividing transmissions of UCI between the PCell1021and the PSCell1061, overloading may be prevented. A cell, comprising a downlink carrier and optionally an uplink carrier, may be assigned with a physical cell ID and a cell index. The physical cell ID or the cell index may identify a downlink carrier and/or an uplink carrier of the cell, for example, depending on the context in which the physical cell ID is used. A physical cell ID may be determined using a synchronization signal transmitted on a downlink component carrier. A cell index may be determined using RRC messages. In the disclosure, a physical cell ID may be referred to as a carrier ID, and a cell index may be referred to as a carrier index. For example, when the disclosure refers to a first physical cell ID for a first downlink carrier, the disclosure may mean the first physical cell ID is for a cell comprising the first downlink carrier. The same/similar concept may apply to, for example, a carrier activation. When the disclosure indicates that a first carrier is activated, the specification may mean that a cell comprising the first carrier is activated. In CA, a multi-carrier nature of a PHY may be exposed to a MAC. In an example, a HARQ entity may operate on a serving cell. A transport block may be generated per assignment/grant per serving cell. A transport block and potential HARQ retransmissions of the transport block may be mapped to a serving cell. In the downlink, a base station may transmit (e.g., unicast, multicast, and/or broadcast) one or more Reference Signals (RSs) to a UE (e.g., PSS, SSS, CSI-RS, DMRS, and/or PT-RS, as shown inFIG.5A). In the uplink, the UE may transmit one or more RSs to the base station (e.g., DMRS, PT-RS, and/or SRS, as shown inFIG.5B). The PSS and the SSS may be transmitted by the base station and used by the UE to synchronize the UE to the base station. The PSS and the SSS may be provided in a synchronization signal (SS)/physical broadcast channel (PBCH) block that includes the PSS, the SSS, and the PBCH. The base station may periodically transmit a burst of SS/PBCH blocks. FIG.11Aillustrates an example of an SS/PBCH block's structure and location. A burst of SS/PBCH blocks may include one or more SS/PBCH blocks (e.g.,4SS/PBCH blocks, as shown inFIG.11A). Bursts may be transmitted periodically (e.g., every 2 frames or 20 ms). A burst may be restricted to a half-frame (e.g., a first half-frame having a duration of 5 ms). It will be understood thatFIG.11Ais an example, and that these parameters (number of SS/PBCH blocks per burst, periodicity of bursts, position of burst within the frame) may be configured based on, for example: a carrier frequency of a cell in which the SS/PBCH block is transmitted; a numerology or subcarrier spacing of the cell; a configuration by the network (e.g., using RRC signaling); or any other suitable factor. In an example, the UE may assume a subcarrier spacing for the SS/PBCH block based on the carrier frequency being monitored, unless the radio network configured the UE to assume a different subcarrier spacing. The SS/PBCH block may span one or more OFDM symbols in the time domain (e.g., 4 OFDM symbols, as shown in the example ofFIG.11A) and may span one or more subcarriers in the frequency domain (e.g., 240 contiguous subcarriers). The PSS, the SSS, and the PBCH may have a common center frequency. The PSS may be transmitted first and may span, for example, 1 OFDM symbol and 127 subcarriers. The SSS may be transmitted after the PSS (e.g., two symbols later) and may span 1 OFDM symbol and 127 subcarriers. The PBCH may be transmitted after the PSS (e.g., across the next 3 OFDM symbols) and may span 240 subcarriers. The location of the SS/PBCH block in the time and frequency domains may not be known to the UE (e.g., if the UE is searching for the cell). To find and select the cell, the UE may monitor a carrier for the PSS. For example, the UE may monitor a frequency location within the carrier. If the PSS is not found after a certain duration (e.g., 20 ms), the UE may search for the PSS at a different frequency location within the carrier, as indicated by a synchronization raster. If the PSS is found at a location in the time and frequency domains, the UE may determine, based on a known structure of the SS/PBCH block, the locations of the SSS and the PBCH, respectively. The SS/PBCH block may be a cell-defining SS block (CD-SSB). In an example, a primary cell may be associated with a CD-SSB. The CD-SSB may be located on a synchronization raster. In an example, a cell selection/search and/or reselection may be based on the CD-SSB. The SS/PBCH block may be used by the UE to determine one or more parameters of the cell. For example, the UE may determine a physical cell identifier (PCI) of the cell based on the sequences of the PSS and the SSS, respectively. The UE may determine a location of a frame boundary of the cell based on the location of the SS/PBCH block. For example, the SS/PBCH block may indicate that it has been transmitted in accordance with a transmission pattern, wherein a SS/PBCH block in the transmission pattern is a known distance from the frame boundary. The PBCH may use a QPSK modulation and may use forward error correction (FEC). The FEC may use polar coding. One or more symbols spanned by the PBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCH may include an indication of a current system frame number (SFN) of the cell and/or a SS/PBCH block timing index. These parameters may facilitate time synchronization of the UE to the base station. The PBCH may include a master information block (MIB) used to provide the UE with one or more parameters. The MIB may be used by the UE to locate remaining minimum system information (RMSI) associated with the cell. The RMSI may include a System Information Block Type 1 (SIB1). The SIB1 may contain information needed by the UE to access the cell. The UE may use one or more parameters of the MIB to monitor PDCCH, which may be used to schedule PDSCH. The PDSCH may include the SIB1. The SIB1 may be decoded using parameters provided in the MIB. The PBCH may indicate an absence of SIB1. Based on the PBCH indicating the absence of SIB1, the UE may be pointed to a frequency. The UE may search for an SS/PBCH block at the frequency to which the UE is pointed. The UE may assume that one or more SS/PBCH blocks transmitted with a same SS/PBCH block index are quasi co-located (QCLed) (e.g., having the same/similar Doppler spread, Doppler shift, average gain, average delay, and/or spatial Rx parameters). The UE may not assume QCL for SS/PBCH block transmissions having different SS/PBCH block indices. SS/PBCH blocks (e.g., those within a half-frame) may be transmitted in spatial directions (e.g., using different beams that span a coverage area of the cell). In an example, a first SS/PBCH block may be transmitted in a first spatial direction using a first beam, and a second SS/PBCH block may be transmitted in a second spatial direction using a second beam. In an example, within a frequency span of a carrier, a base station may transmit a plurality of SS/PBCH blocks. In an example, a first PCI of a first SS/PBCH block of the plurality of SS/PBCH blocks may be different from a second PCI of a second SS/PBCH block of the plurality of SS/PBCH blocks. The PCIs of SS/PBCH blocks transmitted in different frequency locations may be different or the same. The CSI-RS may be transmitted by the base station and used by the UE to acquire channel state information (CSI). The base station may configure the UE with one or more CSI-RSs for channel estimation or any other suitable purpose. The base station may configure a UE with one or more of the same/similar CSI-RSs. The UE may measure the one or more CSI-RSs. The UE may estimate a downlink channel state and/or generate a CSI report based on the measuring of the one or more downlink CSI-RSs. The UE may provide the CSI report to the base station. The base station may use feedback provided by the UE (e.g., the estimated downlink channel state) to perform link adaptation. The base station may semi-statically configure the UE with one or more CSI-RS resource sets. A CSI-RS resource may be associated with a location in the time and frequency domains and a periodicity. The base station may selectively activate and/or deactivate a CSI-RS resource. The base station may indicate to the UE that a CSI-RS resource in the CSI-RS resource set is activated and/or deactivated. The base station may configure the UE to report CSI measurements. The base station may configure the UE to provide CSI reports periodically, aperiodically, or semi-persistently. For periodic CSI reporting, the UE may be configured with a timing and/or periodicity of a plurality of CSI reports. For aperiodic CSI reporting, the base station may request a CSI report. For example, the base station may command the UE to measure a configured CSI-RS resource and provide a CSI report relating to the measurements. For semi-persistent CSI reporting, the base station may configure the UE to transmit periodically, and selectively activate or deactivate the periodic reporting. The base station may configure the UE with a CSI-RS resource set and CSI reports using RRC signaling. The CSI-RS configuration may comprise one or more parameters indicating, for example, up to 32 antenna ports. The UE may be configured to employ the same OFDM symbols for a downlink CSI-RS and a control resource set (CORESET) when the downlink CSI-RS and CORESET are spatially QCLed and resource elements associated with the downlink CSI-RS are outside of the physical resource blocks (PRBs) configured for the CORESET. The UE may be configured to employ the same OFDM symbols for downlink CSI-RS and SS/PBCH blocks when the downlink CSI-RS and SS/PBCH blocks are spatially QCLed and resource elements associated with the downlink CSI-RS are outside of PRBs configured for the SS/PBCH blocks. Downlink DMRSs may be transmitted by a base station and used by a UE for channel estimation. For example, the downlink DMRS may be used for coherent demodulation of one or more downlink physical channels (e.g., PDSCH). An NR network may support one or more variable and/or configurable DMRS patterns for data demodulation. At least one downlink DMRS configuration may support a front-loaded DMRS pattern. A front-loaded DMRS may be mapped over one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). A base station may semi-statically configure the UE with a number (e.g., a maximum number) of front-loaded DMRS symbols for PDSCH. A DMRS configuration may support one or more DMRS ports. For example, for single user-MIMO, a DMRS configuration may support up to eight orthogonal downlink DMRS ports per UE. For multiuser-MIMO, a DMRS configuration may support up to 4 orthogonal downlink DMRS ports per UE. A radio network may support (e.g., at least for CP-OFDM) a common DMRS structure for downlink and uplink, wherein a DMRS location, a DMRS pattern, and/or a scrambling sequence may be the same or different. The base station may transmit a downlink DMRS and a corresponding PDSCH using the same precoding matrix. The UE may use the one or more downlink DMRSs for coherent demodulation/channel estimation of the PDSCH. In an example, a transmitter (e.g., a base station) may use a precoder matrices for a part of a transmission bandwidth. For example, the transmitter may use a first precoder matrix for a first bandwidth and a second precoder matrix for a second bandwidth. The first precoder matrix and the second precoder matrix may be different based on the first bandwidth being different from the second bandwidth. The UE may assume that a same precoding matrix is used across a set of PRBs. The set of PRBs may be denoted as a precoding resource block group (PRG). A PDSCH may comprise one or more layers. The UE may assume that at least one symbol with DMRS is present on a layer of the one or more layers of the PDSCH. A higher layer may configure up to 3 DMRSs for the PDSCH. Downlink PT-RS may be transmitted by a base station and used by a UE for phase-noise compensation. Whether a downlink PT-RS is present or not may depend on an RRC configuration. The presence and/or pattern of the downlink PT-RS may be configured on a UE-specific basis using a combination of RRC signaling and/or an association with one or more parameters employed for other purposes (e.g., modulation and coding scheme (MCS)), which may be indicated by DCI. When configured, a dynamic presence of a downlink PT-RS may be associated with one or more DCI parameters comprising at least MCS. An NR network may support a plurality of PT-RS densities defined in the time and/or frequency domains. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. The UE may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be fewer than a number of DMRS ports in a scheduled resource. Downlink PT-RS may be confined in the scheduled time/frequency duration for the UE. Downlink PT-RS may be transmitted on symbols to facilitate phase tracking at the receiver. The UE may transmit an uplink DMRS to a base station for channel estimation. For example, the base station may use the uplink DMRS for coherent demodulation of one or more uplink physical channels. For example, the UE may transmit an uplink DMRS with a PUSCH and/or a PUCCH. The uplink DM-RS may span a range of frequencies that is similar to a range of frequencies associated with the corresponding physical channel. The base station may configure the UE with one or more uplink DMRS configurations. At least one DMRS configuration may support a front-loaded DMRS pattern. The front-loaded DMRS may be mapped over one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). One or more uplink DMRSs may be configured to transmit at one or more symbols of a PUSCH and/or a PUCCH. The base station may semi-statically configure the UE with a number (e.g., maximum number) of front-loaded DMRS symbols for the PUSCH and/or the PUCCH, which the UE may use to schedule a single-symbol DMRS and/or a double-symbol DMRS. An NR network may support (e.g., for cyclic prefix orthogonal frequency division multiplexing (CP-OFDM)) a common DMRS structure for downlink and uplink, wherein a DMRS location, a DMRS pattern, and/or a scrambling sequence for the DMRS may be the same or different. A PUSCH may comprise one or more layers, and the UE may transmit at least one symbol with DMRS present on a layer of the one or more layers of the PUSCH. In an example, a higher layer may configure up to three DMRSs for the PUSCH. Uplink PT-RS (which may be used by a base station for phase tracking and/or phase-noise compensation) may or may not be present depending on an RRC configuration of the UE. The presence and/or pattern of uplink PT-RS may be configured on a UE-specific basis by a combination of RRC signaling and/or one or more parameters employed for other purposes (e.g., Modulation and Coding Scheme (MCS)), which may be indicated by DCI. When configured, a dynamic presence of uplink PT-RS may be associated with one or more DCI parameters comprising at least MCS. A radio network may support a plurality of uplink PT-RS densities defined in time/frequency domain. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. The UE may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be fewer than a number of DMRS ports in a scheduled resource. For example, uplink PT-RS may be confined in the scheduled time/frequency duration for the UE. SRS may be transmitted by a UE to a base station for channel state estimation to support uplink channel dependent scheduling and/or link adaptation. SRS transmitted by the UE may allow a base station to estimate an uplink channel state at one or more frequencies. A scheduler at the base station may employ the estimated uplink channel state to assign one or more resource blocks for an uplink PUSCH transmission from the UE. The base station may semi-statically configure the UE with one or more SRS resource sets. For an SRS resource set, the base station may configure the UE with one or more SRS resources. An SRS resource set applicability may be configured by a higher layer (e.g., RRC) parameter. For example, when a higher layer parameter indicates beam management, an SRS resource in a SRS resource set of the one or more SRS resource sets (e.g., with the same/similar time domain behavior, periodic, aperiodic, and/or the like) may be transmitted at a time instant (e.g., simultaneously). The UE may transmit one or more SRS resources in SRS resource sets. An NR network may support aperiodic, periodic and/or semi-persistent SRS transmissions. The UE may transmit SRS resources based on one or more trigger types, wherein the one or more trigger types may comprise higher layer signaling (e.g., RRC) and/or one or more DCI formats. In an example, at least one DCI format may be employed for the UE to select at least one of one or more configured SRS resource sets. An SRS trigger type 0 may refer to an SRS triggered based on a higher layer signaling. An SRS trigger type 1 may refer to an SRS triggered based on one or more DCI formats. In an example, when PUSCH and SRS are transmitted in a same slot, the UE may be configured to transmit SRS after a transmission of a PUSCH and a corresponding uplink DMRS. The base station may semi-statically configure the UE with one or more SRS configuration parameters indicating at least one of following: a SRS resource configuration identifier; a number of SRS ports; time domain behavior of an SRS resource configuration (e.g., an indication of periodic, semi-persistent, or aperiodic SRS); slot, mini-slot, and/or subframe level periodicity; offset for a periodic and/or an aperiodic SRS resource; a number of OFDM symbols in an SRS resource; a starting OFDM symbol of an SRS resource; an SRS bandwidth; a frequency hopping bandwidth; a cyclic shift; and/or an SRS sequence ID. An antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed. If a first symbol and a second symbol are transmitted on the same antenna port, the receiver may infer the channel (e.g., fading gain, multipath delay, and/or the like) for conveying the second symbol on the antenna port, from the channel for conveying the first symbol on the antenna port. A first antenna port and a second antenna port may be referred to as quasi co-located (QCLed) if one or more large-scale properties of the channel over which a first symbol on the first antenna port is conveyed may be inferred from the channel over which a second symbol on a second antenna port is conveyed. The one or more large-scale properties may comprise at least one of: a delay spread; a Doppler spread; a Doppler shift; an average gain; an average delay; and/or spatial Receiving (Rx) parameters. Channels that use beamforming require beam management. Beam management may comprise beam measurement, beam selection, and beam indication. A beam may be associated with one or more reference signals. For example, a beam may be identified by one or more beamformed reference signals. The UE may perform downlink beam measurement based on downlink reference signals (e.g., a channel state information reference signal (CSI-RS)) and generate a beam measurement report. The UE may perform the downlink beam measurement procedure after an RRC connection is set up with a base station. FIG.11Billustrates an example of channel state information reference signals (CSI-RS s) that are mapped in the time and frequency domains. A square shown inFIG.11Bmay span a resource block (RB) within a bandwidth of a cell. A base station may transmit one or more RRC messages comprising CSI-RS resource configuration parameters indicating one or more CSI-RSs. One or more of the following parameters may be configured by higher layer signaling (e.g., RRC and/or MAC signaling) for a CSI-RS resource configuration: a CSI-RS resource configuration identity, a number of CSI-RS ports, a CSI-RS configuration (e.g., symbol and resource element (RE) locations in a subframe), a CSI-RS subframe configuration (e.g., subframe location, offset, and periodicity in a radio frame), a CSI-RS power parameter, a CSI-RS sequence parameter, a code division multiplexing (CDM) type parameter, a frequency density, a transmission comb, quasi co-location (QCL) parameters (e.g., QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist, csi-rs-configZPid, qcl-csi-rs-configNZPid), and/or other radio resource parameters. The three beams illustrated inFIG.11Bmay be configured for a UE in a UE-specific configuration. Three beams are illustrated inFIG.11B(beam #1, beam #2, and beam #3), more or fewer beams may be configured. Beam #1 may be allocated with CSI-RS1101that may be transmitted in one or more subcarriers in an RB of a first symbol. Beam #2 may be allocated with CSI-RS1102that may be transmitted in one or more subcarriers in an RB of a second symbol. Beam #3 may be allocated with CSI-RS1103that may be transmitted in one or more subcarriers in an RB of a third symbol. By using frequency division multiplexing (FDM), a base station may use other subcarriers in a same RB (for example, those that are not used to transmit CSI-RS1101) to transmit another CSI-RS associated with a beam for another UE. By using time domain multiplexing (TDM), beams used for the UE may be configured such that beams for the UE use symbols from beams of other UEs. CSI-RSs such as those illustrated inFIG.11B(e.g., CSI-RS1101,1102,1103) may be transmitted by the base station and used by the UE for one or more measurements. For example, the UE may measure a reference signal received power (RSRP) of configured CSI-RS resources. The base station may configure the UE with a reporting configuration and the UE may report the RSRP measurements to a network (for example, via one or more base stations) based on the reporting configuration. In an example, the base station may determine, based on the reported measurement results, one or more transmission configuration indication (TCI) states comprising a number of reference signals. In an example, the base station may indicate one or more TCI states to the UE (e.g., via RRC signaling, a MAC CE, and/or a DCI). The UE may receive a downlink transmission with a receive (Rx) beam determined based on the one or more TCI states. In an example, the UE may or may not have a capability of beam correspondence. If the UE has the capability of beam correspondence, the UE may determine a spatial domain filter of a transmit (Tx) beam based on a spatial domain filter of the corresponding Rx beam. If the UE does not have the capability of beam correspondence, the UE may perform an uplink beam selection procedure to determine the spatial domain filter of the Tx beam. The UE may perform the uplink beam selection procedure based on one or more sounding reference signal (SRS) resources configured to the UE by the base station. The base station may select and indicate uplink beams for the UE based on measurements of the one or more SRS resources transmitted by the UE. In a beam management procedure, a UE may assess (e.g., measure) a channel quality of one or more beam pair links, a beam pair link comprising a transmitting beam transmitted by a base station and a receiving beam received by the UE. Based on the assessment, the UE may transmit a beam measurement report indicating one or more beam pair quality parameters comprising, e.g., one or more beam identifications (e.g., a beam index, a reference signal index, or the like), RSRP, a precoding matrix indicator (PMI), a channel quality indicator (CQI), and/or a rank indicator (RI). FIG.12Aillustrates examples of three downlink beam management procedures: P1, P2, and P3. Procedure P1 may enable a UE measurement on transmit (Tx) beams of a transmission reception point (TRP) (or multiple TRPs), e.g., to support a selection of one or more base station Tx beams and/or UE Rx beams (shown as ovals in the top row and bottom row, respectively, of P1). Beamforming at a TRP may comprise a Tx beam sweep for a set of beams (shown, in the top rows of P1 and P2, as ovals rotated in a counter-clockwise direction indicated by the dashed arrow). Beamforming at a UE may comprise an Rx beam sweep for a set of beams (shown, in the bottom rows of P1 and P3, as ovals rotated in a clockwise direction indicated by the dashed arrow). Procedure P2 may be used to enable a UE measurement on Tx beams of a TRP (shown, in the top row of P2, as ovals rotated in a counter-clockwise direction indicated by the dashed arrow). The UE and/or the base station may perform procedure P2 using a smaller set of beams than is used in procedure P1, or using narrower beams than the beams used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure P3 for Rx beam determination by using the same Tx beam at the base station and sweeping an Rx beam at the UE. FIG.12Billustrates examples of three uplink beam management procedures: U1, U2, and U3. Procedure U1 may be used to enable a base station to perform a measurement on Tx beams of a UE, e.g., to support a selection of one or more UE Tx beams and/or base station Rx beams (shown as ovals in the top row and bottom row, respectively, of U1). Beamforming at the UE may include, e.g., a Tx beam sweep from a set of beams (shown in the bottom rows of U1 and U3 as ovals rotated in a clockwise direction indicated by the dashed arrow). Beamforming at the base station may include, e.g., an Rx beam sweep from a set of beams (shown, in the top rows of U1 and U2, as ovals rotated in a counter-clockwise direction indicated by the dashed arrow). Procedure U2 may be used to enable the base station to adjust its Rx beam when the UE uses a fixed Tx beam. The UE and/or the base station may perform procedure U2 using a smaller set of beams than is used in procedure P1, or using narrower beams than the beams used in procedure P1. This may be referred to as beam refinement The UE may perform procedure U3 to adjust its Tx beam when the base station uses a fixed Rx beam. A UE may initiate a beam failure recovery (BFR) procedure based on detecting a beam failure. The UE may transmit a BFR request (e.g., a preamble, a UCI, an SR, a MAC CE, and/or the like) based on the initiating of the BFR procedure. The UE may detect the beam failure based on a determination that a quality of beam pair link(s) of an associated control channel is unsatisfactory (e.g., having an error rate higher than an error rate threshold, a received signal power lower than a received signal power threshold, an expiration of a timer, and/or the like). The UE may measure a quality of a beam pair link using one or more reference signals (RSs) comprising one or more SS/PBCH blocks, one or more CSI-RS resources, and/or one or more demodulation reference signals (DMRSs). A quality of the beam pair link may be based on one or more of a block error rate (BLER), an RSRP value, a signal to interference plus noise ratio (SINR) value, a reference signal received quality (RSRQ) value, and/or a CSI value measured on RS resources. The base station may indicate that an RS resource is quasi co-located (QCLed) with one or more DM-RSs of a channel (e.g., a control channel, a shared data channel, and/or the like). The RS resource and the one or more DMRSs of the channel may be QCLed when the channel characteristics (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameter, fading, and/or the like) from a transmission via the RS resource to the UE are similar or the same as the channel characteristics from a transmission via the channel to the UE. A network (e.g., a gNB and/or an ng-eNB of a network) and/or the UE may initiate a random access procedure. A UE in an RRC_IDLE state and/or an RRC_INACTIVE state may initiate the random access procedure to request a connection setup to a network. The UE may initiate the random access procedure from an RRC_CONNECTED state. The UE may initiate the random access procedure to request uplink resources (e.g., for uplink transmission of an SR when there is no PUCCH resource available) and/or acquire uplink timing (e.g., when uplink synchronization status is non-synchronized). The UE may initiate the random access procedure to request one or more system information blocks (SIBs) (e.g., other system information such as SIB2, SIB3, and/or the like). The UE may initiate the random access procedure for a beam failure recovery request. A network may initiate a random access procedure for a handover and/or for establishing time alignment for an SCell addition. FIG.13Aillustrates a four-step contention-based random access procedure. Prior to initiation of the procedure, a base station may transmit a configuration message1310to the UE. The procedure illustrated inFIG.13Acomprises transmission of four messages: a Msg 11311, a Msg 21312, a Msg 31313, and a Msg 41314. The Msg 11311may include and/or be referred to as a preamble (or a random access preamble). The Msg 21312may include and/or be referred to as a random access response (RAR). The configuration message1310may be transmitted, for example, using one or more RRC messages. The one or more RRC messages may indicate one or more random access channel (RACH) parameters to the UE. The one or more RACH parameters may comprise at least one of following: general parameters for one or more random access procedures (e.g., RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon); and/or dedicated parameters (e.g., RACH-configDedicated). The base station may broadcast or multicast the one or more RRC messages to one or more UEs. The one or more RRC messages may be UE-specific (e.g., dedicated RRC messages transmitted to a UE in an RRC_CONNECTED state and/or in an RRC_INACTIVE state). The UE may determine, based on the one or more RACH parameters, a time-frequency resource and/or an uplink transmit power for transmission of the Msg 11311and/or the Msg 31313. Based on the one or more RACH parameters, the UE may determine a reception timing and a downlink channel for receiving the Msg 21312and the Msg 41314. The one or more RACH parameters provided in the configuration message1310may indicate one or more Physical RACH (PRACH) occasions available for transmission of the Msg 11311. The one or more PRACH occasions may be predefined. The one or more RACH parameters may indicate one or more available sets of one or more PRACH occasions (e.g., prach-ConfigIndex). The one or more RACH parameters may indicate an association between (a) one or more PRACH occasions and (b) one or more reference signals. The one or more RACH parameters may indicate an association between (a) one or more preambles and (b) one or more reference signals. The one or more reference signals may be SS/PBCH blocks and/or CSI-RSs. For example, the one or more RACH parameters may indicate a number of SS/PBCH blocks mapped to a PRACH occasion and/or a number of preambles mapped to a SS/PBCH blocks. The one or more RACH parameters provided in the configuration message1310may be used to determine an uplink transmit power of Msg 11311and/or Msg 31313. For example, the one or more RACH parameters may indicate a reference power for a preamble transmission (e.g., a received target power and/or an initial power of the preamble transmission). There may be one or more power offsets indicated by the one or more RACH parameters. For example, the one or more RACH parameters may indicate: a power ramping step; a power offset between SSB and CSI-RS; a power offset between transmissions of the Msg 11311and the Msg 31313; and/or a power offset value between preamble groups. The one or more RACH parameters may indicate one or more thresholds based on which the UE may determine at least one reference signal (e.g., an SSB and/or CSI-RS) and/or an uplink carrier (e.g., a normal uplink (NUL) carrier and/or a supplemental uplink (SUL) carrier). The Msg 11311may include one or more preamble transmissions (e.g., a preamble transmission and one or more preamble retransmissions). An RRC message may be used to configure one or more preamble groups (e.g., group A and/or group B). A preamble group may comprise one or more preambles. The UE may determine the preamble group based on a pathloss measurement and/or a size of the Msg 31313. The UE may measure an RSRP of one or more reference signals (e.g., SSBs and/or CSI-RSs) and determine at least one reference signal having an RSRP above an RSRP threshold (e.g., rsrp-ThresholdSSB and/or rsrp-ThresholdCSI-RS). The UE may select at least one preamble associated with the one or more reference signals and/or a selected preamble group, for example, if the association between the one or more preambles and the at least one reference signal is configured by an RRC message. The UE may determine the preamble based on the one or more RACH parameters provided in the configuration message1310. For example, the UE may determine the preamble based on a pathloss measurement, an RSRP measurement, and/or a size of the Msg 31313. As another example, the one or more RACH parameters may indicate: a preamble format; a maximum number of preamble transmissions; and/or one or more thresholds for determining one or more preamble groups (e.g., group A and group B). A base station may use the one or more RACH parameters to configure the UE with an association between one or more preambles and one or more reference signals (e.g., SSBs and/or CSI-RSs). If the association is configured, the UE may determine the preamble to include in Msg 11311based on the association. The Msg 11311may be transmitted to the base station via one or more PRACH occasions. The UE may use one or more reference signals (e.g., SSBs and/or CSI-RSs) for selection of the preamble and for determining of the PRACH occasion. One or more RACH parameters (e.g., ra-ssb-OccasionMskIndex and/or ra-OccasionList) may indicate an association between the PRACH occasions and the one or more reference signals. The UE may perform a preamble retransmission if no response is received following a preamble transmission. The UE may increase an uplink transmit power for the preamble retransmission. The UE may select an initial preamble transmit power based on a pathloss measurement and/or a target received preamble power configured by the network. The UE may determine to retransmit a preamble and may ramp up the uplink transmit power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preamble retransmission. The ramping step may be an amount of incremental increase in uplink transmit power for a retransmission. The UE may ramp up the uplink transmit power if the UE determines a reference signal (e.g., SSB and/or CSI-RS) that is the same as a previous preamble transmission. The UE may count a number of preamble transmissions and/or retransmissions (e.g., PREAMBLE TRANSMISSION COUNTER). The UE may determine that a random access procedure completed unsuccessfully, for example, if the number of preamble transmissions exceeds a threshold configured by the one or more RACH parameters (e.g., preambleTransMax). The Msg 21312received by the UE may include an RAR. In some scenarios, the Msg 21312may include multiple RARs corresponding to multiple UEs. The Msg 21312may be received after or in response to the transmitting of the Msg 11311. The Msg 21312may be scheduled on the DL-SCH and indicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 21312may indicate that the Msg 11311was received by the base station. The Msg 21312may include a time-alignment command that may be used by the UE to adjust the UE's transmission timing, a scheduling grant for transmission of the Msg 31313, and/or a Temporary Cell RNTI (TC-RNTI). After transmitting a preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor a PDCCH for the Msg 21312. The UE may determine when to start the time window based on a PRACH occasion that the UE uses to transmit the preamble. For example, the UE may start the time window one or more symbols after a last symbol of the preamble (e.g., at a first PDCCH occasion from an end of a preamble transmission). The one or more symbols may be determined based on a numerology. The PDCCH may be in a common search space (e.g., a Type1-PDCCH common search space) configured by an RRC message. The UE may identify the RAR based on a Radio Network Temporary Identifier (RNTI). RNTIs may be used depending on one or more events initiating the random access procedure. The UE may use random access RNTI (RA-RNTI). The RA-RNTI may be associated with PRACH occasions in which the UE transmits a preamble. For example, the UE may determine the RA-RNTI based on: an OFDM symbol index; a slot index; a frequency domain index; and/or a UL carrier indicator of the PRACH occasions. An example of RA-RNTI may be as follows: RA-RNTI=1+s_id+14×t_id+14×80×_f_id+14×80×8×ul_carrier_id where s_id may be an index of a first OFDM symbol of the PRACH occasion (e.g., 0≤s_id<14), t_id may be an index of a first slot of the PRACH occasion in a system frame (e.g., 0≤t_id<80), f_id may be an index of the PRACH occasion in the frequency domain (e.g., 0≤f_id<8), and ul_carrier_id may be a UL carrier used for a preamble transmission (e.g., 0 for an NUL carrier, and 1 for an SUL carrier). The UE may transmit the Msg 31313in response to a successful reception of the Msg 21312(e.g., using resources identified in the Msg 21312). The Msg 31313may be used for contention resolution in, for example, the contention-based random access procedure illustrated inFIG.13A. In some scenarios, a plurality of UEs may transmit a same preamble to a base station and the base station may provide an RAR that corresponds to a UE. Collisions may occur if the plurality of UEs interpret the RAR as corresponding to themselves. Contention resolution (e.g., using the Msg 31313and the Msg 41314) may be used to increase the likelihood that the UE does not incorrectly use an identity of another the UE. To perform contention resolution, the UE may include a device identifier in the Msg 31313(e.g., a C-RNTI if assigned, a TC-RNTI included in the Msg 21312, and/or any other suitable identifier). The Msg 41314may be received after or in response to the transmitting of the Msg 31313. If a C-RNTI was included in the Msg 31313, the base station will address the UE on the PDCCH using the C-RNTI. If the UE's unique C-RNTI is detected on the PDCCH, the random access procedure is determined to be successfully completed. If a TC-RNTI is included in the Msg 31313(e.g., if the UE is in an RRC_IDLE state or not otherwise connected to the base station), Msg 41314will be received using a DL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decoded and a MAC PDU comprises the UE contention resolution identity MAC CE that matches or otherwise corresponds with the CCCH SDU sent (e.g., transmitted) in Msg 31313, the UE may determine that the contention resolution is successful and/or the UE may determine that the random access procedure is successfully completed. The UE may be configured with a supplementary uplink (SUL) carrier and a normal uplink (NUL) carrier. An initial access (e.g., random access procedure) may be supported in an uplink carrier. For example, a base station may configure the UE with two separate RACH configurations: one for an SUL carrier and the other for an NUL carrier. For random access in a cell configured with an SUL carrier, the network may indicate which carrier to use (NUL or SUL). The UE may determine the SUL carrier, for example, if a measured quality of one or more reference signals is lower than a broadcast threshold. Uplink transmissions of the random access procedure (e.g., the Msg 11311and/or the Msg 31313) may remain on the selected carrier. The UE may switch an uplink carrier during the random access procedure (e.g., between the Msg 11311and the Msg 31313) in one or more cases. For example, the UE may determine and/or switch an uplink carrier for the Msg 11311and/or the Msg 31313based on a channel clear assessment (e.g., a listen-before-talk). FIG.13Billustrates a two-step contention-free random access procedure. Similar to the four-step contention-based random access procedure illustrated inFIG.13A, a base station may, prior to initiation of the procedure, transmit a configuration message1320to the UE. The configuration message1320may be analogous in some respects to the configuration message1310. The procedure illustrated inFIG.13Bcomprises transmission of two messages: a Msg 11321and a Msg 21322. The Msg 11321and the Msg 21322may be analogous in some respects to the Msg 11311and a Msg 21312illustrated inFIG.13A, respectively. As will be understood fromFIGS.13A and13B, the contention-free random access procedure may not include messages analogous to the Msg 31313and/or the Msg 41314. The contention-free random access procedure illustrated inFIG.13Bmay be initiated for a beam failure recovery, other SI request, SCell addition, and/or handover. For example, a base station may indicate or assign to the UE the preamble to be used for the Msg 11321. The UE may receive, from the base station via PDCCH and/or RRC, an indication of a preamble (e.g., ra-PreambleIndex). After transmitting a preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of a beam failure recovery request, the base station may configure the UE with a separate time window and/or a separate PDCCH in a search space indicated by an RRC message (e.g., recoverySearchSpaceId). The UE may monitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) on the search space. In the contention-free random access procedure illustrated inFIG.13B, the UE may determine that a random access procedure successfully completes after or in response to transmission of Msg 11321and reception of a corresponding Msg 21322. The UE may determine that a random access procedure successfully completes, for example, if a PDCCH transmission is addressed to a C-RNTI. The UE may determine that a random access procedure successfully completes, for example, if the UE receives an RAR comprising a preamble identifier corresponding to a preamble transmitted by the UE and/or the RAR comprises a MAC sub-PDU with the preamble identifier. The UE may determine the response as an indication of an acknowledgement for an SI request. FIG.13Cillustrates another two-step random access procedure. Similar to the random access procedures illustrated inFIGS.13A and13B, a base station may, prior to initiation of the procedure, transmit a configuration message1330to the UE. The configuration message1330may be analogous in some respects to the configuration message1310and/or the configuration message1320. The procedure illustrated inFIG.13Ccomprises transmission of two messages: a Msg A1331and a Msg B1332. Msg A1331may be transmitted in an uplink transmission by the UE. Msg A1331may comprise one or more transmissions of a preamble1341and/or one or more transmissions of a transport block1342. The transport block1342may comprise contents that are similar and/or equivalent to the contents of the Msg 31313illustrated inFIG.13A. The transport block1342may comprise UCI (e.g., an SR, a HARQ ACK/NACK, and/or the like). The UE may receive the Msg B1332after or in response to transmitting the Msg A1331. The Msg B1332may comprise contents that are similar and/or equivalent to the contents of the Msg 21312(e.g., an RAR) illustrated inFIGS.13A and13Band/or the Msg 41314illustrated inFIG.13A. The UE may initiate the two-step random access procedure inFIG.13Cfor licensed spectrum and/or unlicensed spectrum. The UE may determine, based on one or more factors, whether to initiate the two-step random access procedure. The one or more factors may be: a radio access technology in use (e.g., LTE, NR, and/or the like); whether the UE has valid TA or not; a cell size; the UE's RRC state; a type of spectrum (e.g., licensed vs. unlicensed); and/or any other suitable factors. The UE may determine, based on two-step RACH parameters included in the configuration message1330, a radio resource and/or an uplink transmit power for the preamble1341and/or the transport block1342included in the Msg A1331. The RACH parameters may indicate a modulation and coding schemes (MCS), a time-frequency resource, and/or a power control for the preamble1341and/or the transport block1342. A time-frequency resource for transmission of the preamble1341(e.g., a PRACH) and a time-frequency resource for transmission of the transport block1342(e.g., a PUSCH) may be multiplexed using FDM, TDM, and/or CDM. The RACH parameters may enable the UE to determine a reception timing and a downlink channel for monitoring for and/or receiving Msg B1332. The transport block1342may comprise data (e.g., delay-sensitive data), an identifier of the UE, security information, and/or device information (e.g., an International Mobile Subscriber Identity (IMSI)). The base station may transmit the Msg B1332as a response to the Msg A1331. The Msg B1332may comprise at least one of following: a preamble identifier; a timing advance command; a power control command; an uplink grant (e.g., a radio resource assignment and/or an MCS); a UE identifier for contention resolution; and/or an RNTI (e.g., a C-RNTI or a TC-RNTI). The UE may determine that the two-step random access procedure is successfully completed if: a preamble identifier in the Msg B1332is matched to a preamble transmitted by the UE; and/or the identifier of the UE in Msg B1332is matched to the identifier of the UE in the Msg A1331(e.g., the transport block1342). A UE and a base station may exchange control signaling. The control signaling may be referred to as L1/L2 control signaling and may originate from the PHY layer (e.g., layer 1) and/or the MAC layer (e.g., layer 2). The control signaling may comprise downlink control signaling transmitted from the base station to the UE and/or uplink control signaling transmitted from the UE to the base station. The downlink control signaling may comprise: a downlink scheduling assignment; an uplink scheduling grant indicating uplink radio resources and/or a transport format; a slot format information; a preemption indication; a power control command; and/or any other suitable signaling. The UE may receive the downlink control signaling in a payload transmitted by the base station on a physical downlink control channel (PDCCH). The payload transmitted on the PDCCH may be referred to as downlink control information (DCI). In some scenarios, the PDCCH may be a group common PDCCH (GC-PDCCH) that is common to a group of UEs. A base station may attach one or more cyclic redundancy check (CRC) parity bits to a DCI in order to facilitate detection of transmission errors. When the DCI is intended for a UE (or a group of the UEs), the base station may scramble the CRC parity bits with an identifier of the UE (or an identifier of the group of the UEs). Scrambling the CRC parity bits with the identifier may comprise Modulo-2 addition (or an exclusive OR operation) of the identifier value and the CRC parity bits. The identifier may comprise a 16-bit value of a radio network temporary identifier (RNTI). DCIs may be used for different purposes. A purpose may be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI having CRC parity bits scrambled with a paging RNTI (P-RNTI) may indicate paging information and/or a system information change notification. The P-RNTI may be predefined as “FFFE” in hexadecimal. A DCI having CRC parity bits scrambled with a system information RNTI (SI-RNTI) may indicate a broadcast transmission of the system information. The SI-RNTI may be predefined as “FFFF” in hexadecimal. A DCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI) may indicate a random access response (RAR). A DCI having CRC parity bits scrambled with a cell RNTI (C-RNTI) may indicate a dynamically scheduled unicast transmission and/or a triggering of PDCCH-ordered random access. A DCI having CRC parity bits scrambled with a temporary cell RNTI (TC-RNTI) may indicate a contention resolution (e.g., a Msg 3 analogous to the Msg 31313illustrated inFIG.13A). Other RNTIs configured to the UE by a base station may comprise a Configured Scheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI (TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI), a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), an Interruption RNTI (INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-Persistent CSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI (MCS-C-RNTI), and/or the like. Depending on the purpose and/or content of a DCI, the base station may transmit the DCIs with one or more DCI formats. For example, DCI format 0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may be a fallback DCI format (e.g., with compact DCI payloads). DCI format 0_1 may be used for scheduling of PUSCH in a cell (e.g., with more DCI payloads than DCI format 0_0). DCI format 1_0 may be used for scheduling of PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g., with compact DCI payloads). DCI format 1_1 may be used for scheduling of PDSCH in a cell (e.g., with more DCI payloads than DCI format 1_0). DCI format 2_0 may be used for providing a slot format indication to a group of UEs. DCI format 2_1 may be used for notifying a group of UEs of a physical resource block and/or OFDM symbol where the UE may assume no transmission is intended to the UE. DCI format 2_2 may be used for transmission of a transmit power control (TPC) command for PUCCH or PUSCH. DCI format 2_3 may be used for transmission of a group of TPC commands for SRS transmissions by one or more UEs. DCI format(s) for new functions may be defined in future releases. DCI formats may have different DCI sizes, or may share the same DCI size. After scrambling a DCI with a RNTI, the base station may process the DCI with channel coding (e.g., polar coding), rate matching, scrambling and/or QPSK modulation. A base station may map the coded and modulated DCI on resource elements used and/or configured for a PDCCH. Based on a payload size of the DCI and/or a coverage of the base station, the base station may transmit the DCI via a PDCCH occupying a number of contiguous control channel elements (CCEs). The number of the contiguous CCEs (referred to as aggregation level) may be 1, 2, 4, 8, 16, and/or any other suitable number. A CCE may comprise a number (e.g., 6) of resource-element groups (REGs). A REG may comprise a resource block in an OFDM symbol. The mapping of the coded and modulated DCI on the resource elements may be based on mapping of CCEs and REGs (e.g., CCE-to-REG mapping). FIG.14Aillustrates an example of CORESET configurations for a bandwidth part. The base station may transmit a DCI via a PDCCH on one or more control resource sets (CORESETs). A CORESET may comprise a time-frequency resource in which the UE tries to decode a DCI using one or more search spaces. The base station may configure a CORESET in the time-frequency domain. In the example ofFIG.14A, a first CORESET1401and a second CORESET1402occur at the first symbol in a slot. The first CORESET1401overlaps with the second CORESET1402in the frequency domain. A third CORESET1403occurs at a third symbol in the slot. A fourth CORESET1404occurs at the seventh symbol in the slot. CORESETs may have a different number of resource blocks in frequency domain. FIG.14Billustrates an example of a CCE-to-REG mapping for DCI transmission on a CORESET and PDCCH processing. The CCE-to-REG mapping may be an interleaved mapping (e.g., for the purpose of providing frequency diversity) or a non-interleaved mapping (e.g., for the purposes of facilitating interference coordination and/or frequency-selective transmission of control channels). The base station may perform different or same CCE-to-REG mapping on different CORESETs. A CORESET may be associated with a CCE-to-REG mapping by RRC configuration. A CORESET may be configured with an antenna port quasi co-location (QCL) parameter. The antenna port QCL parameter may indicate QCL information of a demodulation reference signal (DMRS) for PDCCH reception in the CORESET. The base station may transmit, to the UE, RRC messages comprising configuration parameters of one or more CORESETs and one or more search space sets. The configuration parameters may indicate an association between a search space set and a CORESET. A search space set may comprise a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters may indicate: a number of PDCCH candidates to be monitored per aggregation level; a PDCCH monitoring periodicity and a PDCCH monitoring pattern; one or more DCI formats to be monitored by the UE; and/or whether a search space set is a common search space set or a UE-specific search space set. A set of CCEs in the common search space set may be predefined and known to the UE. A set of CCEs in the UE-specific search space set may be configured based on the UE's identity (e.g., C-RNTI). As shown inFIG.14B, the UE may determine a time-frequency resource for a CORESET based on RRC messages. The UE may determine a CCE-to-REG mapping (e.g., interleaved or non-interleaved, and/or mapping parameters) for the CORESET based on configuration parameters of the CORESET. The UE may determine a number (e.g., at most 10) of search space sets configured on the CORESET based on the RRC messages. The UE may monitor a set of PDCCH candidates according to configuration parameters of a search space set. The UE may monitor a set of PDCCH candidates in one or more CORESETs for detecting one or more DCIs. Monitoring may comprise decoding one or more PDCCH candidates of the set of the PDCCH candidates according to the monitored DCI formats. Monitoring may comprise decoding a DCI content of one or more PDCCH candidates with possible (or configured) PDCCH locations, possible (or configured) PDCCH formats (e.g., number of CCEs, number of PDCCH candidates in common search spaces, and/or number of PDCCH candidates in the UE-specific search spaces) and possible (or configured) DCI formats. The decoding may be referred to as blind decoding. The UE may determine a DCI as valid for the UE, in response to CRC checking (e.g., scrambled bits for CRC parity bits of the DCI matching a RNTI value). The UE may process information contained in the DCI (e.g., a scheduling assignment, an uplink grant, power control, a slot format indication, a downlink preemption, and/or the like). The UE may transmit uplink control signaling (e.g., uplink control information (UCI)) to a base station. The uplink control signaling may comprise hybrid automatic repeat request (HARQ) acknowledgements for received DL-SCH transport blocks. The UE may transmit the HARQ acknowledgements after receiving a DL-SCH transport block. Uplink control signaling may comprise channel state information (CSI) indicating channel quality of a physical downlink channel. The UE may transmit the CSI to the base station. The base station, based on the received CSI, may determine transmission format parameters (e.g., comprising multi-antenna and beamforming schemes) for a downlink transmission. Uplink control signaling may comprise scheduling requests (SR). The UE may transmit an SR indicating that uplink data is available for transmission to the base station. The UE may transmit a UCI (e.g., HARQ acknowledgements (HARQ-ACK), CSI report, SR, and the like) via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). The UE may transmit the uplink control signaling via a PUCCH using one of several PUCCH formats. There may be five PUCCH formats and the UE may determine a PUCCH format based on a size of the UCI (e.g., a number of uplink symbols of UCI transmission and a number of UCI bits). PUCCH format 0 may have a length of one or two OFDM symbols and may include two or fewer bits. The UE may transmit UCI in a PUCCH resource using PUCCH format 0 if the transmission is over one or two symbols and the number of HARQ-ACK information bits with positive or negative SR (HARQ-ACK/SR bits) is one or two. PUCCH format 1 may occupy a number between four and fourteen OFDM symbols and may include two or fewer bits. The UE may use PUCCH format 1 if the transmission is four or more symbols and the number of HARQ-ACK/SR bits is one or two. PUCCH format 2 may occupy one or two OFDM symbols and may include more than two bits. The UE may use PUCCH format 2 if the transmission is over one or two symbols and the number of UCI bits is two or more. PUCCH format 3 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 3 if the transmission is four or more symbols, the number of UCI bits is two or more and PUCCH resource does not include an orthogonal cover code. PUCCH format 4 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 4 if the transmission is four or more symbols, the number of UCI bits is two or more and the PUCCH resource includes an orthogonal cover code. The base station may transmit configuration parameters to the UE for a plurality of PUCCH resource sets using, for example, an RRC message. The plurality of PUCCH resource sets (e.g., up to four sets) may be configured on an uplink BWP of a cell. A PUCCH resource set may be configured with a PUCCH resource set index, a plurality of PUCCH resources with a PUCCH resource being identified by a PUCCH resource identifier (e.g., pucch-Resourceid), and/or a number (e.g., a maximum number) of UCI information bits the UE may transmit using one of the plurality of PUCCH resources in the PUCCH resource set. When configured with a plurality of PUCCH resource sets, the UE may select one of the plurality of PUCCH resource sets based on a total bit length of the UCI information bits (e.g., HARQ-ACK, SR, and/or CSI). If the total bit length of UCI information bits is two or fewer, the UE may select a first PUCCH resource set having a PUCCH resource set index equal to “0”. If the total bit length of UCI information bits is greater than two and less than or equal to a first configured value, the UE may select a second PUCCH resource set having a PUCCH resource set index equal to “1”. If the total bit length of UCI information bits is greater than the first configured value and less than or equal to a second configured value, the UE may select a third PUCCH resource set having a PUCCH resource set index equal to “2”. If the total bit length of UCI information bits is greater than the second configured value and less than or equal to a third value (e.g., 1406), the UE may select a fourth PUCCH resource set having a PUCCH resource set index equal to “3”. After determining a PUCCH resource set from a plurality of PUCCH resource sets, the UE may determine a PUCCH resource from the PUCCH resource set for UCI (HARQ-ACK, CSI, and/or SR) transmission. The UE may determine the PUCCH resource based on a PUCCH resource indicator in a DCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. A three-bit PUCCH resource indicator in the DCI may indicate one of eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE may transmit the UCI (HARQ-ACK, CSI and/or SR) using a PUCCH resource indicated by the PUCCH resource indicator in the DCI. FIG.15illustrates an example of a wireless device1502in communication with a base station1504in accordance with embodiments of the present disclosure. The wireless device1502and base station1504may be part of a mobile communication network, such as the mobile communication network100illustrated inFIG.1A, the mobile communication network150illustrated inFIG.1B, or any other communication network. Only one wireless device1502and one base station1504are illustrated inFIG.15, but it will be understood that a mobile communication network may include more than one UE and/or more than one base station, with the same or similar configuration as those shown inFIG.15. The base station1504may connect the wireless device1502to a core network (not shown) through radio communications over the air interface (or radio interface)1506. The communication direction from the base station1504to the wireless device1502over the air interface1506is known as the downlink, and the communication direction from the wireless device1502to the base station1504over the air interface is known as the uplink. Downlink transmissions may be separated from uplink transmissions using FDD, TDD, and/or some combination of the two duplexing techniques. In the downlink, data to be sent to the wireless device1502from the base station1504may be provided to the processing system1508of the base station1504. The data may be provided to the processing system1508by, for example, a core network. In the uplink, data to be sent to the base station1504from the wireless device1502may be provided to the processing system1518of the wireless device1502. The processing system1508and the processing system1518may implement layer 3 and layer 2 OSI functionality to process the data for transmission. Layer 2 may include an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer, for example, with respect toFIG.2A,FIG.2B,FIG.3, andFIG.4A. Layer 3 may include an RRC layer as with respect toFIG.2B. After being processed by processing system1508, the data to be sent to the wireless device1502may be provided to a transmission processing system1510of base station1504. Similarly, after being processed by the processing system1518, the data to be sent to base station1504may be provided to a transmission processing system1520of the wireless device1502. The transmission processing system1510and the transmission processing system1520may implement layer 1 OSI functionality. Layer 1 may include a PHY layer with respect toFIG.2A,FIG.2B,FIG.3, andFIG.4A. For transmit processing, the PHY layer may perform, for example, forward error correction coding of transport channels, interleaving, rate matching, mapping of transport channels to physical channels, modulation of physical channel, multiple-input multiple-output (MIMO) or multi-antenna processing, and/or the like. At the base station1504, a reception processing system1512may receive the uplink transmission from the wireless device1502. At the wireless device1502, a reception processing system1522may receive the downlink transmission from base station1504. The reception processing system1512and the reception processing system1522may implement layer 1 OSI functionality. Layer 1 may include a PHY layer with respect toFIG.2A,FIG.2B,FIG.3, andFIG.4A. For receive processing, the PHY layer may perform, for example, error detection, forward error correction decoding, deinterleaving, demapping of transport channels to physical channels, demodulation of physical channels, MIMO or multi-antenna processing, and/or the like. As shown inFIG.15, a wireless device1502and the base station1504may include multiple antennas. The multiple antennas may be used to perform one or more MIMO or multi-antenna techniques, such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit/receive diversity, and/or beamforming. In other examples, the wireless device1502and/or the base station1504may have a single antenna. The processing system1508and the processing system1518may be associated with a memory1514and a memory1524, respectively. Memory1514and memory1524(e.g., one or more non-transitory computer readable mediums) may store computer program instructions or code that may be executed by the processing system1508and/or the processing system1518to carry out one or more of the functionalities discussed in the present application. Although not shown inFIG.15, the transmission processing system1510, the transmission processing system1520, the reception processing system1512, and/or the reception processing system1522may be coupled to a memory (e.g., one or more non-transitory computer readable mediums) storing computer program instructions or code that may be executed to carry out one or more of their respective functionalities. The processing system1508and/or the processing system1518may comprise one or more controllers and/or one or more processors. The one or more controllers and/or one or more processors may comprise, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and/or other programmable logic device, discrete gate and/or transistor logic, discrete hardware components, an on-board unit, or any combination thereof. The processing system1508and/or the processing system1518may perform at least one of signal coding/processing, data processing, power control, input/output processing, and/or any other functionality that may enable the wireless device1502and the base station1504to operate in a wireless environment. The processing system1508and/or the processing system1518may be connected to one or more peripherals1516and one or more peripherals1526, respectively. The one or more peripherals1516and the one or more peripherals1526may include software and/or hardware that provide features and/or functionalities, for example, a speaker, a microphone, a keypad, a display, a touchpad, a power source, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulated (FM) radio unit, a media player, an Internet browser, an electronic control unit (e.g., for a motor vehicle), and/or one or more sensors (e.g., an accelerometer, a gyroscope, a temperature sensor, a radar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, a camera, and/or the like). The processing system1508and/or the processing system1518may receive user input data from and/or provide user output data to the one or more peripherals1516and/or the one or more peripherals1526. The processing system1518in the wireless device1502may receive power from a power source and/or may be configured to distribute the power to the other components in the wireless device1502. The power source may comprise one or more sources of power, for example, a battery, a solar cell, a fuel cell, or any combination thereof. The processing system1508and/or the processing system1518may be connected to a GPS chipset1517and a GPS chipset1527, respectively. The GPS chipset1517and the GPS chipset1527may be configured to provide geographic location information of the wireless device1502and the base station1504, respectively. FIG.16Aillustrates an example structure for uplink transmission. A baseband signal representing a physical uplink shared channel may perform one or more functions. The one or more functions may comprise at least one of: scrambling; modulation of scrambled bits to generate complex-valued symbols; mapping of the complex-valued modulation symbols onto one or several transmission layers; transform precoding to generate complex-valued symbols; precoding of the complex-valued symbols; mapping of precoded complex-valued symbols to resource elements; generation of complex-valued time-domain Single Carrier-Frequency Division Multiple Access (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like. In an example, when transform precoding is enabled, a SC-FDMA signal for uplink transmission may be generated. In an example, when transform precoding is not enabled, an CP-OFDM signal for uplink transmission may be generated byFIG.16A. These functions are illustrated as examples and it is anticipated that other mechanisms may be implemented in various embodiments. FIG.16Billustrates an example structure for modulation and up-conversion of a baseband signal to a carrier frequency. The baseband signal may be a complex-valued SC-FDMA or CP-OFDM baseband signal for an antenna port and/or a complex-valued Physical Random Access Channel (PRACH) baseband signal. Filtering may be employed prior to transmission. FIG.16Cillustrates an example structure for downlink transmissions. A baseband signal representing a physical downlink channel may perform one or more functions. The one or more functions may comprise: scrambling of coded bits in a codeword to be transmitted on a physical channel; modulation of scrambled bits to generate complex-valued modulation symbols; mapping of the complex-valued modulation symbols onto one or several transmission layers; precoding of the complex-valued modulation symbols on a layer for transmission on the antenna ports; mapping of complex-valued modulation symbols for an antenna port to resource elements; generation of complex-valued time-domain OFDM signal for an antenna port; and/or the like. These functions are illustrated as examples and it is anticipated that other mechanisms may be implemented in various embodiments. FIG.16Dillustrates another example structure for modulation and up-conversion of a baseband signal to a carrier frequency. The baseband signal may be a complex-valued OFDM baseband signal for an antenna port. Filtering may be employed prior to transmission. A wireless device may receive from a base station one or more messages (e.g., RRC messages) comprising configuration parameters of a plurality of cells (e.g., primary cell, secondary cell). The wireless device may communicate with at least one base station (e.g., two or more base stations in dual-connectivity) via the plurality of cells. The one or more messages (e.g., as a part of the configuration parameters) may comprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers for configuring the wireless device. For example, the configuration parameters may comprise parameters for configuring physical and MAC layer channels, bearers, etc. For example, the configuration parameters may comprise parameters indicating values of timers for physical, MAC, RLC, PCDP, SDAP, RRC layers, and/or communication channels. A timer may begin running once it is started and continue running until it is stopped or until it expires. A timer may be started if it is not running or restarted if it is running. A timer may be associated with a value (e.g., the timer may be started or restarted from a value or may be started from zero and expire once it reaches the value). The duration of a timer may not be updated until the timer is stopped or expires (e.g., due to BWP switching). A timer may be used to measure a time period/window for a process. When the specification refers to an implementation and procedure related to one or more timers, it will be understood that there are multiple ways to implement the one or more timers. For example, it will be understood that one or more of the multiple ways to implement a timer may be used to measure a time period/window for the procedure. For example, a random access response window timer may be used for measuring a window of time for receiving a random access response. In an example, instead of starting and expiry of a random access response window timer, the time difference between two time stamps may be used. When a timer is restarted, a process for measurement of time window may be restarted. Other example implementations may be provided to restart a measurement of a time window. A base station and a wireless device may use a plurality of downlink control information (DCI) formats to communicate control information. The control information may be used to schedule downlink data and/or uplink data or for other purposes. For example, a DCI format 0_0 may be used to schedule an uplink resource for a PUSCH over a cell. A DCI format 0_1 may be used to schedule one or more PUSCHs in one cell or may be used to indicate downlink feedback information for configured grant PUSCH (CG-DFI). A DCI format 0_2 may be used to schedule a resource for a PUSCH in one cell. Similarly, for downlink scheduling, a DCI format 1_0 may schedule a resource for a PDSCH in one cell. A DCI format 1_1 may be used to schedule a PDSCH in one cell or trigger one shot HARQ-ACK feedback. A DCI format 1_2 may be used to schedule a resource for a PDSCH in one cell. There are one or more DCI formats that are used to communicate non-scheduling information. For example, a DCI format 2_0 may be used to indicate slot formation information for one or more slots of one or more cells. A DCI format 2_2 may be used to indicate one or more transmit power control commands for PUCCH and PUSCH. A DCI format 2_3 may be used to indicate one or more transmit power control for SRS. A DCI format 2_4 may be used to indicate an uplink cancellation information. A DCI format 2_5 may be used to indicate preemption information. A DCI format 2_6 may be used to indicate a power saving state outside of DRX active time. A DCI format 3_0 or 3_1 may be used to schedule NR sidelink resource or LTE sidelink resource in one cell. In an example, a DCI format 0_0 and a DCI format 1_0 may be referred to as fallback DCI formats for scheduling uplink and downlink, respectively. In an example, a DCI format 0_1 and a DCI format 1_1 may be referred to as a non-fallback DCI format scheduling uplink and downlink, respectively. In an example, a DCI format 0_2 and a DCI format 1_2 may be referred as a compact DCI format for scheduling uplink and downlink, respectively. A base station may configure one or more DCI formats for scheduling downlink and/or uplink resources. FIG.17illustrates a table of example DCI formats and usages.FIG.17illustrates that a DCI format 0_0, 0_1, and 0_2 may be used to schedule uplink resource(s) for one or more PUSCHs. A DCI format 1_0, 1_1, and 1_2 may be used to schedule downlink resource(s) for one or more PDSCHs. A DCI format 2_0, 2_1, 2_2, 2_3, 2_4, 2_5, and 2_6 may be used for a group-common DCI transmission. For example, a DCI format 2_4 may be used to indicate uplink resources for a group of wireless devices. In response to receiving a DCI based on the DCI format 2_4, a wireless device may cancel any uplink resource, scheduled prior to receiving the DCI format 2_4, that is overlapped with uplink resources indicated by the DCI format 2_4. A DCI format may comprise one or more DCI fields. A DCI field may have a DCI size. A wireless device may determine one or more sizes (e.g., in terms of bits) of one or more DCI fields of the DCI format based on one or more radio resource control (RRC) configuration parameters received from a base station. For example, the one or more RRC configuration parameters may be transmitted via a master information block (MIB). For example, the one or more RRC configuration parameters may be transmitted via one or more system information blocks (SIBs). For example, the one or more RRC configuration parameters may be transmitted via one or more wireless device specific messages. For example, the wireless device may determine one or more DCI sizes of one or more DCI fields of a DCI format 0_0 based on the one or more RRC configuration parameters transmitted via the MIB and/or the SIB s. The wireless device may be able to determine the one or more DCI sizes of the DCI format 0_0 without receiving any wireless device specific message. Similarly, the wireless device may determine one or more DCI sizes of one or more second DCI fields of a DCI format 1_0 based on the one or more RRC configuration parameters transmitted via the MIB and/or the SIB s. For example, the wireless device may determine one or more first DCI sizes of one or more first DCI fields of a DCI format 0_2 based on one or more RRC configuration parameters transmitted via the MIB and/or the SIB s and/or the wireless device specific RRC message(s). The wireless device may determine one or more bitfield sizes of the one or more first DCI fields based on the one or more RRC configuration parameters.FIG.18illustrates an example of the one or more first DCI fields of the DCI format 0_2. InFIG.18, there are one or more second DCI fields that may present in the DCI format 0_2 regardless of the wireless device specific RRC message(s). For example, the one or more second DCI fields may comprise at least one of DL/UL indicator, frequency domain resource allocation, MCS, NDI, and TPC fields. For example, the one or more first DCI fields may comprise the one or more second DCI fields and one or more third DCI fields. A DCI field of the one or more third DCI fields may be present or may not be present based on one or more configuration parameters transmitted by the base station. For example, the one or more third DCI fields may comprise at least one of a BWP index, RV, HARQ process #, PMI, antenna ports, and/or beta offset. For example, the DCI format 0_2 may comprise a 1-bit DL/UL indicator where the bit is configured with zero (‘0’) to indicate an uplink grant for the DCI format 0_2. DCI field(s) shown in dotted boxes inFIG.18may not be present or a size of the DCI field(s) may be configured as zero. For example, a carrier indicator may be present when the DCI format 0_2 is used to schedule a cell based on cross-carrier scheduling. The carrier indicator may indicate a cell index of a scheduled cell by the cross-carrier scheduling. For example, UL/SUL indicator (labeled UL/SUL inFIG.18) may indicate whether a DCI based the DCI format 0_2 schedules a resource for an uplink carrier or a supplemental uplink. The UL/SUL indicator field may be present when the wireless device is configured with a supplemental uplink for a scheduled cell of the DCI. Otherwise, the UL/SUL indicator field is not present. A field of BWP index may indicate a bandwidth part indicator. The base station may transmit configuration parameters indicating one or more uplink BWPs for the scheduled cell. The wireless device may determine a bit size of the field of BWP index based on a number of the one or more uplink BWPs. For example, 1 bit may be used. The number of the one or more uplink BWPs (excluding an initial UL BWP) is two. The field of BWP index may be used to indicate an uplink BWP switching. The wireless device may switch to a first BWP in response to receiving the DCI indicating an index of the first BWP. The first BWP is different from an active uplink BWP (active before receiving the DCI). A DCI field of frequency domain resource allocation (labeled frequency domain RA inFIG.18) may indicate uplink resource(s) of the scheduled cell. For example, the base station may transmit configuration parameters indicating a resource allocation type 0. With the resource allocation type 0, a bitmap over one or more resource block groups (RBGs) may schedule the uplink resource(s). With a resource allocation type 1, a starting PRB index and a length of the scheduled uplink resource(s) may be indicated. In an example, a length may be a multiple of K1 resource blocks. For example, the configuration parameters may comprise a resource allocation type1 granularity for the DCI format 0_2 (e.g., K1). A default value of the K1 may be one (‘1’). The base station may transmit configuration parameters indicating a dynamic change between the resource allocation type 0 and the resource allocation type 1 (e.g., ‘dynamicswitch’). The wireless device may determine a field size of the frequency domain RA field based on the configured resource allocation type and a bandwidth of an active UL BWP of the scheduled cell. The wireless device may further determine the field size of the frequency domain RA field based on the K1 value, when the resource allocation type 1 may be used/configured. For example, when the resource allocation type 0 is configured, the bitmap may indicate each of the one or more RBGs covering the bandwidth of the active UL BWP. A size of the bitmap may be determined based on a number of the one or more RBGs of the active UL BWP. For example, the wireless device may determine the size of the frequency domain RA field based on the resource allocation type 1 based on the bandwidth of the active uplink BWP (e.g., ceil (log 2(BW/K1(BW/K1+1)/2) and the resource allocation type1 granularity. E.g., the BW is the bandwidth of the active uplink BWP. E.g., the K1 is the resource allocation type1 granularity). The wireless device may determine a resource allocation indicator value (RIV) table, where an entry of the table may comprise a starting PRB index and a length value. The wireless device may determine the RIV table based on the resource allocation type1 granularity. For example, when the dynamic change between the resource allocation type 0 and the resource allocation type 1 is used, a larger size between a first size based on the resource allocation type 0 (e.g., the bitmap size) and a second size based on the resource allocation type 1 (e.g., the RIV table size) with additional 1 bit indication to indicate either the resource allocation type 0 or the resource allocation type 1. For example, the frequency domain RA field may indicate a frequency hopping offset. The base station may use K (e.g., 1 bit for two offset values, 2 bits for up to four offset values) bit(s) to indicate the frequency hopping offset from one or more configured offset values, based on the resource allocation type 1. The base station may use ceil(log 2(BW/K1(BW/K1+1)/2)−K bits to indicate the uplink resource(s) based on the resource allocation type 1, when frequency hopping is enabled. Otherwise, the base station/wireless device may use ceil(log 2(BW/K1(BW/K1+1)/2) bits to indicate the uplink resource(s) based on the resource allocation type 1. In an example, a base station may transmit one or more messages comprising configuration parameters of a BWP of a cell. The configuration parameters may comprise a resource allocation type for one or more PUSCHs scheduled by one or more DCIs, based on a first RNTI. The resource allocation type may be a resource allocation type 0 or a resource allocation type 1 or a dynamic switching between the resource allocation type 0 and the resource allocation type 1. For example, the first RNTI is a C-RNTI. The configuration parameters may comprise a configured grant configuration or a SPS configuration. The configuration parameters may indicate a resource allocation type for the configured grant configuration or the SPS configuration. The resource allocation type may be a resource allocation type 0 or a resource allocation type 1 or a dynamic switching between the resource allocation type 0 and the resource allocation type 1. A DCI field of time domain resource allocation (labeled time domain RA inFIG.18) may indicate time domain resource of one or more slots of the scheduled cell. The base station may transmit configuration parameters indicating one or more time domain resource allocation lists of a time domain resource allocation table for an uplink BWP of the scheduled cell. The wireless device may determine a bit size of the time domain RA field based on a number of the one or more time domain resource allocation lists of the time domain resource allocation table. The base station may indicate a frequency hopping flag by a FH flag (labeled FH inFIG.18). For example, the FH flag may present when the base station may enable a frequency hopping of the scheduled cell or the active UL BWP of the scheduled cell. A DCI field of modulation and coding scheme (MCS) (labeled MCS inFIG.18) may indicate a coding rate and a modulation scheme for the scheduled uplink data. In an example, a bit size of the MCS field may be predetermined as a constant (e.g., 5 bits). A new data indicator (NDI) field may indicate whether the DCI schedules the uplink resource(s) for a new/initial transmission or a retransmission. A bit size of the NDI may be fixed as a constant value (e.g., 1 bit). A redundancy version (RV) field may indicate one or more RV values (e.g., a RV value may be 0, 2, 3, or 1) for one or more PUSCHs scheduled over the one or more slots of the scheduled cells. For example, the DCI may schedule a single PUSCH via one slot, a RV value is indicated. For example, the DCI may schedule two PUSCHs via two slots, two RV values may be indicated. A number of PUSCHs scheduled by a DCI may be indicated in a time domain resource allocation list of the one or more time domain resource allocation lists. The configuration parameters may comprise a bit size of the RV field. For example, the bit size may be 0, 1 or 2 bits for a single PUSCH. When the bit size is configured as zero (‘0’), the wireless device may apply a RV=0 for any uplink resource scheduled by a DCI based on the DCI format 0_2. A DCI field of hybrid automatic repeat request (HARQ) process number (HARQ process # inFIG.18) may indicate an index of a HARQ process used for the one or more PUSCHs. The wireless device may determine one or more HARQ processes for the one or more PUSCHs based on the index of the HARQ process. The wireless device may determine the index for a first HARQ process of a first PUSCH of the one or more PUSCHs and select a next index as a second HARQ process of a second PUSCH of the one or more PUSCHs and so on. The configuration parameters may comprise a bit size for the HARQ process # field. For example, the bit size may be 0, 1, 2, 3 or 4 bits for a single PUSCH. The wireless device may assume that a HARQ process index=0 in case the bit size is configured as zero. The wireless device may assume that a HARQ process index in a range of [0, 1] when the bit size is configured as one. The wireless device may assume that a HARQ process index in a range of [0, . . . , 3] when the bit size is configured as two. The wireless device may assume that a HARQ process index in a range of [0, . . . , 7] when the bit size is configured as three. For the 4 bits of bit size, the wireless device may use a HARQ process in a range of [0, . . . , 15]. The DCI format 0_2 may have a first downlink assignment index (1stDAI) and/or a second DAI (2ndDAI). The configuration parameters may comprise a parameter to indicate whether to use DAI for the DCI format 0_2 (e.g., Downlinkassignmentindex-ForDCIFormat0_2). The first DAI may be used to indicate a first size of bits of first HARQ-ACK codebook group. The second DAI may be present when the base station may transmit configuration parameters indicating a plurality of HARQ-ACK codebook groups. When there is no HARQ-ACK codebook group configured, the wireless device may assume the first HARQ-ACK codebook group only. The second DAI may indicate a second size of bits of second HARQ-ACK codebook group. The first DAI may be 1 bit when a semi-static HARQ-ACK codebook generation mechanism is used. The first DAI may be 2 bits or 4 bits when a dynamic HARQ-ACK codebook generation mechanism is used. A field of transmission power control (labeled TPC inFIG.18) may indicate a power offset value to adjust transmission power of the one or more scheduled PUSCHs. A field of sounding reference signal (SRS) resource indicator (SRI) may indicate an index of one or more configured SRS resources of an SRS resource set. A field of precoding information and number of layers (labeled PMI inFIG.18) may indicate a precoding and a MIMO layer information for the one or more scheduled PUSCHs. A field of antenna ports may indicate DMRS pattern(s) for the one or more scheduled PUSCHs. A field of SRS request may indicate to trigger a SRS transmission of a SRS resource or skip SRS transmission. A field of CSI request may indicate to trigger a CSI feedback based on a CSI-RS configuration or skip CSI feedback. A field of phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association (labeled PTRS inFIG.18) may indicate an association between one or more ports of PTRS and one or more ports of DM-RS. The one or more ports may be indicated in the field of antenna ports. A field of beta offset indicator (beta offset inFIG.18) may indicate a code rate for transmission of uplink control information (UCI) via a PUSCH of the one or more scheduled PUSCHs. A field of DM-RS sequence initialization (labeled DMRS inFIG.18) may present based on a configuration of transform precoding. A field of UL-SCH indicator (UL-SCH) may indicate whether a UCI may be transmitted via a PUSCH of the one or more scheduled PUSCHs or not. A field of open loop power control parameter set indication (open loop power inFIG.18) may indicate a set of power control configuration parameters. The wireless device is configured with one or more sets of power control configuration parameters. A field of priority indicator (priority) may indicate a priority value of the one or more scheduled PUSCHs. A field of invalid symbol pattern indicator (invalid OS) may indicate one or more unavailable/not-available OFDM symbols to be used for the one or more scheduled PUSCHs. It should be noted that additional DCI field(s), not shown inFIG.18, may be present for the DCI format 0_2. For example, a downlink feedback information (DFI) field indicating for one or more configured grant resources may present for an unlicensed/shared spectrum cell. For example, the unlicensed/shared spectrum cell is a scheduled cell. When the DCI format 0_2 is used for indicating downlink feedback information for the one or more configured grant resources, other DCI fields may be used to indicate a HARQ-ACK bitmap for the one or more configured grant resources and TPC commands for a scheduled PUSCH. Remaining bits may be reserved and filled with zeros (‘0’s). FIG.19shows an example of a DCI format 1_2. For example, the DCI format 1_2 may schedule a downlink resource for a scheduled downlink cell. The DCI format 1_2 may comprise one or more DCI fields such as an identifier for DCI formats (DL/UL), a carrier indicator, bandwidth part indicator (BWP index), a frequency domain resource assignment (frequency domain RA), a time domain resource assignment (time domain RA), a virtual resource block to physical resource block mapping (VRB-PRB), Physical resource block (PRB) bundling size indicator (PRB bundle), rate matching indicator (rate matching), zero power CSI-RS (ZP-CSI), a MCS, a NDI, a RV, a HARQ process number, a downlink assignment index (DAI), a TPC command for a PUCCH, a PUCCH resource indicator (PUCCH-RI), a PDSCH-to-HARQ_feedback timing indicator (PDSCH-to-HARQ inFIG.19), an antenna ports, a transmission configuration indication (TCI), a SRS request, DMRS sequence initialization (DMRS), and a priority indicator (priority). The base station may transmit one or more messages indicating configuration parameters for the DCI format 1_2. Similar to the DCI format 0_2 ofFIG.18, one or more DCI fields shown in dotted lined boxes may be present or may not be present based on the configuration parameters. The configuration parameters may comprise one or more DCI bit sizes and/or related configuration parameters/values for the one or more DCI fields. For example, the VRB-PRB field may indicate whether a mapping is based on a virtual RB or a physical RB. For example, the PRB bundle may indicate a size of PRB bundle when a dynamic PRB bundling is enabled. For example, the rate matching may indicate one or more rate matching resources where the scheduled data may be mapped around based on the rate matching. For example, the ZP-CSI field may indicate a number of aperiodic ZP CSI-RS resource sets configured by the base station. For example, the DCI format 1_2 may also include MCS, NDI and RV for a second transport block, in response to a max number of codewords scheduled by DCI may be configured as two. The DCI format 1_2 may not include MCS, NDI and RV field for the second transport block. For example, the DAI field may indicate a size of bits of HARQ-ACK codebook. The TPC field may indicate a power offset for the scheduled PUCCH. The wireless device may transmit the scheduled PUCCH comprising HARQ-ACK bit(s) of the scheduled downlink data by the DCI. The PUCCH-RI may indicate a PUCCH resource of one or more PUCCH resources configured by the base station. The PDSCH-to-HARQ field may indicate a timing offset between an end of a scheduled PDSCH by the DCI and a starting of the scheduled PUCCH. The field of antenna ports may indicate DMRS patterns for the scheduled PDSCH. The TCI field may indicate a TCI code point of one or more active TCI code points/active TCI states. The base station may transmit configuration parameters indicating one or more TCI states for the scheduled cell. The base station may active one or more second TCI states of the one or more TCI states via one or more MAC CEs/DCIs. The wireless device may map an active TCI code point of the one or more active TCI code points to an active TCI of the one or more second TCI states. In an example, a wireless device may receive a DCI indicating an activation, a release, or a retransmission for one or more configured grant configurations or one or more semi-persistent scheduling configurations. The DCI may be cyclic redundancy check (CRC) scrambled with a first radio network temporary identifier (RNTI). The wireless device may receive a second DCI indicating one or more resources for scheduling downlink and/or uplink data. The second DCI may be CRC scrambled with a second RNTI. For example, the second RNTI may be a cell RNTI (C-RNTI) and/or MCS-C-RNTI. For example, the first RNTI may be configured scheduling RNTI (CS-RNTI) for an uplink configured grant configuration. The first RNTI may be semi-persistent scheduling RNTI (SPS-RNTI). The DCI and the second DCI may be based on a DCI format. For example, the DCI and the second DCI may be based on a DCI format 0_2 for uplink (e.g., uplink grant and/or configured grant (CG)). For example, the DCI and the second DCI may be based on a DCI format 1_2 for downlink (e.g., downlink scheduling and/or semi-persistent scheduling (SPS)). For example, the wireless device may determine whether the DCI indicates the activation, the release or the retransmission for the one or more CG configurations or for the one or more SPS configurations based on determining one or more values of one or more DCI fields of the DCI format used for the DCI. For example, the wireless device may determine the DCI indicates the activation in response to receiving the DCI with a HARQ process # (HARQ process number) field of the DCI format indicating zero(s) (e.g., ‘0, . . . , 0’) and a RV (redundancy version) field of the DCI indicating zero(s). The wireless device may first determine whether a NDI field of the DCI indicates a new data or not. In response to receiving the DCI with the NDI field of the new data, the wireless device may further determine the HARQ process number field and the redundancy version field of the DCI. In response to determining the HARQ process number field being set to a predetermined value (e.g., zero(s)) and the redundancy version field being set to a predetermined value (e.g., zero(s)), the wireless device may determine the DCI indicates the activation or the release of at least one CG configuration or at least one SPS configuration. For example, the wireless device may further check/determine a MCS (modulation and coding scheme) field of the DCI and/or a FDRA (frequency domain resource assignment) field of the DCI to differentiate between the activation and the release. In response to the MCS field being set to a second predetermined value (e.g., one(s), ‘1, . . . , 1’) and the FDRA field being set to a third predetermined value (e.g., zero(s) for resource allocation type 0 or a resource allocation type 2 with mu=1, one(s) for resource allocation type 1 or the resource allocation type 2 with mu=0), the wireless device may determine the DCI indicates the release for the at least one CG configuration or the at least one SPS configuration. In response to the MCS field being set to different value from the second predetermined value and/or the FDRA field being set to the third predetermined value, the wireless device may determine the DCI indicates the activation for the at least one CG configuration or the at least one SPS configuration. For example, a DCI format 0_0/0_1/0_2, CRC scrambled with the first RNTI, may be used to indicate an activation, a release and/or retransmission for a configured grant (CG) based on setting one or more DCI fields with one or more predetermined values. For example, a DCI format 1_0/1_2, CRC scrambled with a third RNTI (e.g., SPS-RNTI), may be used to indicate an activation, a release and/or retransmission for a semi-persistent scheduling (SPS) on setting the one or more DCI fields with one or more predetermined values. In existing technologies, a wireless device may determine whether a DCI indicates an activation, a release, or a retransmission for a configured grant (CG) resource or a semi-persistent scheduling (SPS) resource based on one or more DCI fields of a DCI format. For example, the one or more DCI fields may comprise an NDI field, a HARQ process number (HARQ process #) field, and a redundancy version (RV) field. When the DCI is scrambled with a first RNTI, corresponding to an RNTI used for indicating the CG or SPS resource, the wireless device may determine whether the NDI field indicates activation or release of the CG or SPS resource based on the NDI field being set to a predetermined value (e.g., ‘0’). After determining the DCI is for activation or release, the wireless device may then determine which of activation or release the DCI is for based on values of the HARQ process number and RV field being set to some predetermined values (e.g., all zeros). In response to the determining, the wireless device may determine the DCI is for activation or release of the SPS resource or the CG resource. In existing technologies, a DCI based on a DCI format 0_2 or a DCI format 1_2 may not comprise a HARQ process number field and/or a RV field. For example, a base station may transmit messages(s) comprising configuration parameters for the DCI format 0_2 and/or the DCI format 1_2. The configuration parameters may indicate zero bits for the HARQ process number field and/or zero bits for the RV field of the DCI format 0_2 and/or the DCI format 1_2. When either or both of the HARQ process number field and the RV field are not present in the DCI, the wireless device may not be able to determine whether the DCI indicates an activation or a release when an NDI field of the first DCI indicates activation or release based on the NDI field being set to some predetermined value (e.g., ‘0’). Based on lack of one or more DCI fields, required for validating the activation or release, the wireless device may not be able to validate the DCI for the activation or release of a CG resource or a SPS resource. Supporting validation of a CG resource or a SPS resource based on a DCI format 0_2 or a DCI format 1_2 may require enhancements in cases where one or more DCI fields, needed for validation of a DCI for the CG resource or the SPS resource based on existing technologies, may not be present in the DCI. In example embodiments of the present disclosure, a wireless device may receive a CG configuration and/or a SPS configuration for a serving cell. The wireless device may receive one or more radio resource control (RRC) messages comprising one or more configuration parameters. The configuration parameters may indicate/comprise a first bit size of a HARQ process number field of a DCI format and a second bit size of a RV field of the DCI format. For example, the first bit size and the second bit size may be zero bits. The wireless device may validate/determine the DCI, which is CRC scrambled with a first RNTI (e.g., CS-RNTI), indicates an activation of the CG configuration or the SPS configuration based on the first bit size being zero, the second bit size being zero, an NDI field of the DCI indicating a predetermined value, and the CS configuration or the SPS configuration being in an inactive state (e.g., has not been activated). The wireless device may determine/validate that the DCI activates the CG configuration or the SPS configuration based on the NDI field of the DCI and a state of the CG configuration or the SPS configuration. For example, the wireless device may determine that the DCI indicates the activation of the CG configuration or the SPS configuration in response to the state of the CG configuration or the SPS configuration being inactive, or in response to the CG configuration or the SPS configuration has not been activated yet. The wireless device may further validate/determine/check one or more DCI fields of the DCI being different from one or more predetermined values. For example, the wireless device may determine that a frequency domain resource allocation (FDRA) field of the DCI has a value that is different than a first predetermined value. The first predetermined value may be used to indicate a release of the CG configuration or the SPS configuration. The wireless device may further determine that a modulation and coding scheme (MCS) field has a value that is different than a second predetermined value. The second predetermined value may be used to indicate a release of the CG configuration or the SPS configuration Based on determining that the FDRA and MCS fields have values different than the first and second predetermined values, respectively, the wireless device may validate that the DCI activates the CG configuration or the SPS configuration, in response to the CG configuration or the SPS configuration being in inactive state. Embodiments of the present disclosure may allow a DCI based on a DCI format 0_2 or a DCI format 1_2 to be used for activating or releasing a CG configuration or a SPS configuration. A wireless device may validate/determine a DCI schedules/indicates a release or an activation of a DL SPS configuration or a UL CG configuration based on one or more conditions being satisfied. For example, the DCI may be called as a DL SPS scheduling DCI for the DL SPS configuration. For example, the DCI may be called as a UL CG resource UL grant for the UL CG configuration. For example, a cyclic redundancy check (CRC) of a DCI (may be scrambled with a first RNTI (e.g., CS-RNTI, cs-RNTI). For example, an NDI field of the first DCI or the second DCI may indicate ‘0’ or indicate a new data transmission. For example, a DFI flag field, if present, of the first DCI or the second DCI may be set to ‘0’. For example, a base station may transmit one or more RRC messages comprising configuration parameters. The configuration parameters may indicate/comprise a CG resource configuration or a SPS resource configuration for a first cell. For example, the first cell is a serving cell of the wireless device. For example, the first cell is a primary cell or a secondary cell. In an example the configuration parameters comprise a single CG configuration or a single SPS configuration for the first cell. For example, the wireless device may validate/determine a first DCI (e.g., a uplink grant for the single CG configuration) or a second DCI (e.g., a downlink scheduling DCI for the single SPS configuration) indicate an activation or a release based on a HARQ process number field and a RV field. For example, the HARQ process number field and/or the RV field are present in the first DCI or the second DCI. A first bit size of the HARQ process number field and/or a second bit size of the RV field may not be zero. For example, the first DCI or the second DCI may be scrambled with the CS-RNTI. For example, the first DCI or the second DCI may have an NDI field with a value of ‘0’. For example, when the configuration parameters comprise a plurality of CG configurations or a plurality of SPS configurations, the wireless device may use the HARQ process number field to determine an index of a CG configuration of the plurality of CG configurations or an index of a SPS configuration of the plurality of SPS configurations. The wireless device may determine the first DCI or the second DCI activates the CG configuration with a same index or the SPS configuration with the same index to a value of the HARQ process number field. The wireless device may determine the first DCI or the second DCI may release one or more CG configurations or one or more SPS configurations based on one or more parameters (e.g., Type2Confugredgrantconfig-ReleaseStateList, or SPS-ReleaseStateList). For example, the wireless device may determine/validate the first DCI or the second DCI when one or more DCI fields of the first DCI or the second DCI are set to one or more predetermined values. For example, the first DCI may be based on a first DCI format (e.g., DCI format 0_2). For example, the second DCI may be based on a second DCI format (e.g., DCI format 1_2). The configuration parameters may indicate/comprise a first bit size of a HARQ process number field of the first DCI format and a second bit size of a RV field of the first DCI format. For example, the first bit size and the second bit size may be zero. The configuration parameters may indicate/comprise a third bit size of a HARQ process number field of the second DCI format and a fourth bit size of a RV field of the second DCI format. For example, the third bit size and the fourth bit size may be zero. For example, the wireless device may determine that the HARQ process number field is set to a predetermined value in response to the first bit size being zero. For example, the predetermined value may be all zeros (e.g., ‘0, . . . , 0’, or 0). For example, the wireless device may determine that the RV field may set to a predetermined value in response to the second bit size being zero. For example, the predetermined value may be all zeros or zero (e.g., ‘0, . . . , 0’, or 0). The wireless device may determine/validate the first DCI or the second DCI based on one or more of following conditions may be satisfied. For example, the wireless device may determine/validate the first DCI or the second DCI indicating an activation of a CG configuration or a SPS configuration based on satisfying the following conditions. For example, the wireless device may determine/validate the first DCI or the second DCI indicating an activation of a CG configuration or a SPS configuration based on satisfying condition (1), (2), (3) and (6). For example, the wireless device may determine/validate the first DCI or the second DCI indicating an activation of a CG configuration or a SPS configuration based on satisfying condition (1), (2), (3) (4) and (5). For example, the wireless device may determine/validate the first DCI or the second DCI indicating an activation of a CG configuration or a SPS configuration based on satisfying condition (1), (2), (3) (4), (5) and (6). For example, the wireless device may determine/validate the first DCI or the second DCI indicating an activation of a CG configuration or a SPS configuration based on satisfying condition (1), (2), (7) and (8). One or more combinations or one or more selections from the following conditions may be considered. The first (1) of the eight conditions mentioned above may comprise that an NDI field of the first DCI based on the first DCI format or a NDI field of the second DCI based on the second DCI format may be set to ‘0’. The second (2) of the eight conditions may comprise that the first DCI or the second DCI may be CRC scrambled with a CS-RNTI. The third (3) of the eight conditions may comprise that the wireless device may be configured with a single CG configuration for a first cell and/or a single SPS configuration for the first cell. The wireless device may have received the first DCI or the second DCI for the first cell. The wireless device may receive the first DCI or the second DCI via the first cell, based on self-carrier scheduling. The wireless device may receive the first DCI or the second DCI via a second cell, based on cross-carrier scheduling. For example, the second cell may be configured as a scheduling cell for the first cell based on the cross-carrier scheduling. The fourth (4) of the eight conditions may comprise that a MCS field of the first DCI based on the first DCI format or a MCS field of the second DCI based on the second DCI format may be different from a first predetermined value. For example, the first predetermined value may be ‘11111’ or all ones. The fifth (5) of the eight conditions may comprise that a frequency domain resource allocation (FDRA) field of the first DCI based on the first DCI format or a FDRA field of the second DCI based on the second DCI format may be different from a second predetermined value. For example, the second predetermined value may be ‘0, . . . , 0’ (or all zeros) in response to a resource allocation type 0 may be used for the single CG configuration or the single SPS configuration. For example, the second predetermined value may be ‘1, . . . , 1’ (or all ones) in response to a resource allocation type 1 may be used for the single CG configuration or the single SPS configuration. The sixth (6) of the eight conditions may comprise that the single CG configuration or the single SPS configuration has not been activated. The single CG configuration or the SPS may be in inactive/deactivated/deactive/not-activated/suspended state. The seventh (7) of the eight conditions may comprise that the MCS field of the first DCI based on the first DCI format or a MCS field of the second DCI based on the second DCI format may be same to a third predetermined value. For example, the third predetermined value may be ‘11110’ or ‘01111’ or 0 in most significant bit with all ones in remaining bits or 1 in least significant bit with all ones in remaining bits or some predetermined value. Finally, the eighth (8) of the eight conditions may comprise that a frequency domain resource allocation (FDRA) field of the first DCI based on the first DCI format or a FDRA field of the second DCI based on the second DCI format may be same to a fourth predetermined value. For example, the fourth predetermined value may be ‘0, . . . , 1’ or ‘1, 0, . . . , 0’ (or all zeros except a least significant bit with zero, or all zeros except a most significant bit with one or a predetermined value) in response to a resource allocation type 0 may be used for the single CG configuration or the single SPS configuration. For example, the second predetermined value may be ‘1, . . . , 0’ or ‘0, 1, . . . , 1’ (or all ones except a least significant bit with zero or all ones except a most significant bit with zero, or a predetermined value) in response to a resource allocation type 1 may be used for the single CG configuration or the single SPS configuration. The wireless device may determine/validate, a first DCI or a second DCI may indicate a release of a CG configuration of a first cell or a SPS configuration of the first cell, based on one or more of following conditions may be satisfied. For example, the wireless device may determine/validate the first DCI or the second DCI indicating a release of a CG configuration or a SPS configuration based on satisfying the following conditions. For example, the wireless device may determine/validate the first DCI or the second DCI indicating a release of a CG configuration or a SPS configuration based on satisfying condition (1), (2), (3) and (6). For example, the wireless device may determine/validate the first DCI or the second DCI indicating a release of a CG configuration or a SPS configuration based on satisfying condition (1), (2), (3) (4) and (5). For example, the wireless device may determine/validate the first DCI or the second DCI indicating a release of a CG configuration or a SPS configuration based on satisfying condition (1), (2), (3) (4), (5) and (6). One or more combinations or one or more selections from the following conditions may be considered. The first (1) of the six conditions mentioned above may comprise a NDI field of the first DCI based on the first DCI format or a NDI field of the second DCI based on the second DCI format may be set to ‘0’. The second (2) of the six conditions mentioned above may comprise the first DCI or the second DCI may be CRC scrambled with a CS-RNTI. The third (3) of the six conditions mentioned above may comprise the wireless device may be configured with a single CG configuration for a first cell and/or a single SPS configuration for the first cell. The wireless device may have received the first DCI or the second DCI for the first cell. The wireless device may receive the first DCI or the second DCI via the first cell, based on self-carrier scheduling. The wireless device may receive the first DCI or the second DCI via a second cell, based on cross-carrier scheduling. The fifth (5) of the six conditions mentioned above may comprise a MCS field of the first DCI based on the first DCI format or a MCS field of the second DCI based on the second DCI format may be same to a first predetermined value. For example, the first predetermined value may be ‘11111’ or all ones. The sixth (6) of the six conditions mentioned above may comprise a frequency domain resource allocation (FDRA) field of the first DCI based on the first DCI format or a FDRA field of the second DCI based on the second DCI format may be same to a second predetermined value. For example, the second predetermined value may be ‘0, . . . , 0’ (or all zeros) in response to a resource allocation type 0 may be used for the single CG configuration or the single SPS configuration. For example, the second predetermined value may be ‘1, . . . , 1’ (or all ones) in response to a resource allocation type 1 may be used for the single CG configuration or the single SPS configuration. (6) the single CG configuration or the single SPS configuration has been activated. The single CG configuration or the SPS may be in active/activated/non-suspended state. FIG.21illustrates an example diagram of embodiments of a procedure for activating/releasing one or more periodic resources between a base station and a wireless device in accordance with embodiments of the present disclosure. The base station may transmit one or more RRC messages comprising configuration parameters. The configuration parameters may comprise parameters for a DCI format 0_2 and/or a DCI format 1_2. The parameters may indicate a first bit size of a HARQ process number field for the DCI format 0_2 and/or the DCI format 1_2. The parameters may indicate a second bit size of a RV field for the DCI format 0_2 and/or the DCI format 1_2. The parameters may be configured for a BWP of a first cell. The configuration parameters may indicate a CG configuration or a SPS configuration for the BWP of the first cell. The configuration parameters may indicate a CS-RNTI, used for a DCI to activate/release or schedule a retransmission for the CG configuration or the SPS configuration. The base station may transmit a DCI, CRC scrambled with the CS-RNTI, to indicate an activation or a release or scheduling of retransmission for the CG configuration or the SPS configuration. In response to receiving the DCI, CRC scrambled with the CS-RNTI, the wireless device may determine whether the DCI be for the activation or the release for the CG configuration or the SPS configuration. The wireless device may perform the determining based on an NDI field of the DCI. For example, when the NDI field may indicate a value ‘0’. The wireless device may determine/validate the activation or the release based on one or more DCI fields of the DCI format 0_2 or the DCI format 1_2 for the CG configuration or the SPS configuration. In an example, a base station may indicate a first bit size, of a HARQ process number field of a DCI format 0_2, being greater than zero in response to the base station configuring one or more configured grant configurations for a first cell. For example, the one or more CG configurations may be activated or released based on a DCI (e.g., type 2 CG configuration). The base station may configure a second bit size, of a RV field of the DCI format 0_2, being greater than zero in response to the base station configuring the one or more CG configurations for the first cell. The base station may configure the first bit size and the second bit size to be greater than zero in response to the one or more CG configurations for the first cell. The base station may transmit one or more messages indicating configuration parameters. The configuration parameters may comprise the first bit size and the second bit size for the DCI format 0_2. Similarly, for a DCI format 1_2, the base station may configure a third bit size for a HARQ process number field and/or a fourth bit size for a RV field of the DCI format 1_2. In response to configuring/indicating at least one SPS configuration for the first cell, the base station may indicate the third bit size and/or the fourth bit size as being greater than zero. In an example, a base station may transmit one or more messages comprising configuration parameters. For example, the configuration parameters may indicate a first bit size for a HARQ process number field of a DCI format and a second bit size for a RV field of the DCI format. For example, the DCI format may be a DCI format 0_2. For example, the DCI format may be a DCI format 1_2. For example, the first bit size may be zero. For example, the second bit size may be zero. In an example, a wireless device may receive a DCI based on the DCI format, with the DCI CRC-scrambled with a first RNTI (e.g., CS-RNTI) for a CG configuration or a SPS configuration. In response to being configured with zero size for the first bit size and/or the second bit size, the wireless device may determine the DCI as a retransmission scheduling DCI for the CG configuration or the SPS configuration regardless of a NDI field of the DCI. The wireless device may not validate/determine whether the DCI activates or releases the CG configuration or the SPS configuration for the first cell. The wireless device may determine the DCI schedules resources for retransmission of the CG configuration or the SPS configuration. The wireless device may activate the CG configuration or the SPS configuration in response to receiving one or more RRC messages indicating the CG configuration or the SPS configuration (e.g., type 1 CG configuration, automatic activated SPS configuration). The wireless device may release the CG configuration or the SPS configuration in response to receiving one or more RRC messages indicating removing/releasing/updating/changing the CG configuration or the SPS configuration. Configuration parameters of the specification may comprise one or more parameters for a DCI format of a BWP of a cell. In an example, a base station may transmit one or more messages indicating configuration parameters. The configuration parameters may indicate a first bit size for a HARQ process number for a DCI format for a BWP of a cell. For example, the first bit size may be zero. The wireless device may determine a HARQ process index used for a transport block scheduled via one or more DCIs and/or via one or more resources of a CG configuration or a SPS configuration. In an example, the wireless device may determine the HARQ process index as zero (e.g., HARQ process index=0) in response to the first bit size being zero. In an example, a base station may transmit one or more RRC messages indicating a first RNTI and a second RNTI for a CG configuration or a SPS configuration. A wireless device may receive a first DCI, CRC scrambled with the first RNTI. Based on the first DCI being scrambled with the first RNTI, the wireless device may determine that the first DCI may indicate an activation or a release of one or more CG configurations or one or more SPS configurations. The wireless device may receive a second DCI, CRC scrambled with a second RNTI. Based on the second RNTI scrambled, the wireless device may determine that the second DCI may schedule resource(s) for retransmission for the one or more CG configurations or the one or more SPS configurations. In an example, the wireless device may determine the second RNTI based on the first RNTI. For example, the first RNTI may be a CS-RNTI, a RNTI used for a CG configuration or a SPS configuration. For example, the wireless device may determine the second RNTI by incrementing (e.g., by K) the first RNTI (e.g., the second RNTI=the first RNTI+K, K=1). For example, the wireless device may receive the first RNTI via one or more RRC signaling. The wireless device may determine a first CRC based on the first RNTI. The first CRC may be used for the first DCI to indicate the activation or the release for the one or more CG configurations or the one or more SPS configurations. The wireless device may determine a second CRC based on the first RNTI. The second CRC may be used for the second DCI to indicate the retransmission for the one or more CG configurations or the one or more SPS configurations. For example, the wireless device may determine the second CRC based on the first CRC, by adding K (e.g., the second CRC=the first CRC+K, e.g., K=1). In an example, a base station may transmit RRC messages indicating configuration parameters. The configuration parameters may comprise a first control resource set (coreset) of a BWP of a cell to a wireless device. The base station may configure a second coreset of the BWP of the cell to the wireless device. The base station may transmit a first DCI via the first coreset. The base station may transmit a second DCI via the second coreset. A wireless device may determine that the first DCI may indicate an activation or a release of one or more CG configurations or one or more SPS configurations based on receiving the first DCI via the first coreset. The wireless device may determine that the second DCI may indicate a retransmission scheduling information for the one or more CG configurations or the one or more SPS configurations based on receiving the first DCI via the second coreset. In an example, the configuration parameters may comprise ‘ActivationRelease’ for the first coreset. The ‘ActiveRelease’ may indicate that the first coreset may be used for the first DCI. In response to not receiving the ‘ActiveRelease’ for the second coreset, the wireless device may not expect to receive the first DCI via the second coreset. In an example, a base station may transmit RRC messages indicating configuration parameters. The configuration parameters may comprise a first search space (SS) of a BWP of a cell to a wireless device. The base station may configure a second SS of the BWP of the cell to the wireless device. The base station may transmit a first DCI via the first SS. The base station may transmit a second DCI via the second SS. A wireless device may determine that the first DCI may indicate an activation or a release of one or more CG configurations or one or more SPS configurations based on receiving the first DCI via the first coreset. The wireless device may determine that the second DCI may indicate a retransmission scheduling information for the one or more CG configurations or the one or more SPS configurations based on receiving the first DCI via the second coreset. In an example, the configuration parameters may comprise ‘ActivationRelease’ for the first SS. The ‘ActiveRelease’ may indicate that the first SS may be used for the first DCI. In response to not receiving the ‘ActiveRelease’ for the second SS, the wireless device may not expect to receive the first DCI via the second SS. FIG.22illustrates an example of activation/releasing for one or more periodic resources via a plurality of coresets between a wireless device and a base station. The wireless device may receive one or more messages comprising configuration parameters for a BWP of a cell. For example, the configuration parameters may comprise parameters for a first coreset and a second coreset. The configuration parameters may comprise one or more CG configurations and/or one or more SPS configurations for the BWP of the cell. The wireless device may receive a first RRC config for the first coreset and the second coreset. The wireless device may receive a second RRC config for a CG configuration. The wireless device may receive a first DCI via the first coreset, CRC scrambled with a first RNTI (e.g., CS-RNTI), for the CG configuration. The wireless device may determine/validate the DCI for activating/releasing for the CG configuration, in response to receiving the first DCI via the first coreset. The wireless device may receive a second DCI via the second coreset, CRC scrambled with the first RNTI (e.g., CS-RNTI), for the CG configuration. The wireless device may determine/validate the DCI for scheduling a retransmission for the CG configuration, in response to receiving the second DCI via the second coreset. In an example, when a first candidate of the first SS may transmit the first DCI and a second candidate of the second SS may transmit the second DCI, the wireless device may determine a priority between the first DCI and the second DCI based on one or more rules. For example, the wireless device may prioritize the second DCI in response to having transmitted/receive data via a resource of the one or more CG configurations or the one or more SPS configurations. The wireless device may expect to receive a rescheduling DCI for the transmitted/received data. For example, the wireless device may prioritize the first DCI than the second DCI. The wireless device may assume that the first DCI may have been transmitted when the first candidate and the second candidate may be same. For example, the wireless device may prioritize the second DCI than the first DCI. The wireless device may assume that the second DCI may have been transmitted when the first candidate and the second candidate may be same. In an example, a base station may transmit RRC messages indicating configuration parameters. The configuration parameters may comprise a first search space (SS) of a BWP of a cell to a wireless device. The configuration parameters may comprise an interval and/or an offset for the first SS. The wireless device may determine one or more SS occasions of the first SS based on the interval and/or the offset. The wireless device may expect to receive a first DCI via the one or more SS occasions of the first SS. For example, the interval may be implicitly indicated. The interval may be same as an interval parameter of a CG configuration or a SPS configuration. For example, the CG configuration and the SPS configuration may be configured for the BWP of the cell. For example, the offset may indicate a location (e.g., a slot index) to monitor one or more candidates via a SS occasion of the one or more SS occasions. The wireless device may determine the first DCI, when the wireless device may receive a DCI via the one or more SS occasions. The wireless device may determine a second DCI, when the wireless device may receive a DCI via other SS occasions. The other SS occasions may not compromise the one or more SS occasions. For example, the first DCI may indicate an activation or a release for the CG configuration and the SPS configuration. For example, the second DCI may indicate a rescheduling for the CG configuration and the SPS configuration. In an example, a wireless device may receive a first DCI, scrambled with a first RNTI, for a semi-persistent CSI feedback. For example, the first RNTI may be a sp-CSI-RNTI or SP-CSI-RNTI. In response to receiving the first RNTI, scrambled with the first RNTI, the wireless device may determine/validate the DCI that may indicate an activation or a release of one or more SP-CSI configurations based on one or more DCI fields of a DCI format used for the DCI. For example, the DCI format may be a DCI format 0_1 or a DCI format 0_2. For example, the one or more DCI fields may comprise a HARQ process number field and RV field. For example, the wireless device may determine that a first value of the HARQ process number field of the DCI based on the DCI format being same (or different) to a first predetermined value (e.g., the first predetermined value may be all zeros, ‘0, . . . , 0’). The wireless device may determine that a second value of the RV field of the DCI based on the DCI format being same to a second predetermined value (e.g., the second predetermined value may be all zeros, ‘0, . . . , 0’). The one or more DCI fields may further comprise a MCS field. The one or more DCI fields may further comprise a frequency resource allocation assignment (FDRA). The wireless device may determine that a third value of the MCS field being same to a third predetermined value (e.g., the third predetermined value may be all ones, ‘1, . . . , 1’). The wireless device may determine that a fourth value of the FDRA field being same to a forth predetermined value (e.g., the fourth predetermined value may be all zeros when a resource allocation type 0 may be used, the fourth predetermined value may be all ones when a resource allocation type 1 may be used, the fourth predetermined value may be set such that a most significant bit may be configured as ‘0’ and all remaining bits may be set to all ones when a resource allocation may be dynamically switched between the resource allocation type 0 and the resource allocation type 1, e.g., ‘0, 1, . . . , 1’). A base station may transmit one or more messages indicating configuration parameters. The configuration parameters may comprise a first bit size for a HARQ process number field of a DCI format. The configuration parameters may comprise a second bit size for a RV field of the DCI format. For example, the first bit size may be zero. The second bit size may be zero. For example, the wireless device may determine that the HARQ process number field may be set to a predetermined in response to the first bit size being zero. For example, the predetermined value may be all zeros (e.g., ‘0, . . . , 0’, or 0). For example, the wireless device may determine that the RV field may set to a predetermined value in response to the second bit size being zero. For example, the predetermined value may be all zeros or zero (e.g., ‘0, . . . , 0’, or 0). In an example, in response to the first bit size and/or the second bit size being zero, the wireless device may not be able to determine/validate a DCI based on the DCI format for an activation or a release for one or more SP-CSI configuration. The wireless device may determine/validate the DCI activates the one or more SP-CSI configuration based on one or more of following conditions. For example, a first condition (1) of the conditions may comprise that the DCI is CRC scrambled with a sp-CSI-RNTI. A second condition (2) of the conditions may comprise that a MCS field of the DCI based on the DCI format may be set to a different value from a first predetermined value. For example, the first predetermined value may be ‘11111’ or all ones. A third condition (3) of the conditions may comprise that a frequency domain resource allocation (FDRA) field of the DCI based on the DCI format may be set to a different value from a second predetermined value. For example, the second predetermined value may be ‘0, . . . , 0’ (or all zeros) in response to a resource allocation type 0 may be used for uplink data transmission via a dynamic control information (e.g., in a PUSCH-Config). For example, the second predetermined value may be ‘1, . . . , 1’ (or all ones) in response to a resource allocation type 1 may be used for the uplink data transmission. A fourth condition (4) of the conditions may comprise that a SP-CSI configuration of the one or more SP-CSI configurations, indicated by a CSI request field of the DCI, may have not been activated or may not be in active state or may be inactive state or may be deactivated. A fifth condition (5) of the conditions may comprise that the MCS field of the DCI based on the DCI format may be same to a third predetermined value. For example, the third predetermined value may be ‘11110’ or ‘01111’ or 0 in most significant bit with all ones in remaining bits or 1 in least significant bit with all ones in remaining bits or some predetermined value. A sixth condition (6) of the conditions may comprise that a frequency domain resource allocation (FDRA) field of the DCI based on the DCI format may be same to a fourth predetermined value. For example, the fourth predetermined value may be ‘0, . . . , 1’ or ‘1, 0, . . . , 0’ (or all zeros except a least significant bit with zero, or all zeros except a most significant bit with one or a predetermined value) in response to a resource allocation type 0 may be used for the single CG configuration or the single SPS configuration. For example, the second predetermined value may be ‘1, . . . , 0’ or ‘0, 1, . . . , 1’ (or all ones except a least significant bit with zero or all ones except a most significant bit with zero, or a predetermined value) in response to a resource allocation type 1 may be used for the single CG configuration or the single SPS configuration. When dynamic switching between the resource allocation type 0 and the resource allocation type 1 is used, the fourth predetermined value may be ‘0, 0, 1, . . . , 1’ or ‘0, 1, . . . , 1, 0’ (e.g., two MSB bits are zero with rest with ones, or a MSB bit is zero and LSB bit is zero and rest with ones). For example, the wireless device may determine/validate the DCI indicating an activation of at least one SP-CSI configuration based on satisfying condition (1), (2), (3) and (4). For example, the wireless device may determine/validate the DCI indicating an activation of at least one SP-CSI configuration based on satisfying condition (1), (2), (3), (5) and (6). For example, the wireless device may determine/validate the DCI indicating an activation of at least one SP-CSI configuration based on satisfying condition (1), (2), (3), (4), (5) and (6). For example, the wireless device may determine/validate the DCI indicating an activation of at least one SP-CSI configuration based on satisfying condition (1), (5), and (6) (and/or (1), (2), (5) and (6)). One or more combinations or one or more selections from the following conditions may be considered. Similarly, the wireless device may determine the DCI indicates a release of the one ore SP-CSI configurations based on one or more of following conditions. For example, the wireless device may determine/validate the DCI indicating an release of at least one SP-CSI configuration based on satisfying one or more of following conditions. For example, a first condition (1) of the conditions may comprise that the DCI may be CRC scrambled with a sp-CSI-RNTI. A second condition (2) of the conditions may comprise that a MCS field of the DCI based on the DCI format may be set to a first predetermined value. For example, the first predetermined value may be ‘11111’ or all ones. A third condition (3) of the conditions may comprise that a frequency domain resource allocation (FDRA) field of the DCI based on the DCI format may be set to a second predetermined value. For example, the second predetermined value may be ‘0, . . . , 0’ (or all zeros) in response to a resource allocation type 0 may be used for uplink data transmission via a dynamic control information (e.g., in a PUSCH-Config). For example, the second predetermined value may be ‘1, . . . , 1’ (or all ones) in response to a resource allocation type 1 may be used for the uplink data transmission. A fourth condition (4) of the conditions may comprise that a SP-CSI configuration of the one or more SP-CSI configurations, indicated by a CSI request field of the DCI, may have been activated or may be in active state or may not be suspended or may be activated. For example, the wireless device may determine/validate the DCI indicating an release of at least one SP-CSI configuration based on satisfying condition (1), (2), and (3). For example, the wireless device may determine/validate the DCI indicating an release of at least one SP-CSI configuration based on satisfying condition (1) and (4). One or more combinations or one or more selections from the following conditions may be considered. FIG.23illustrates a flow diagram of an example embodiment of an activation/release procedure for one or more periodic resources. In an example, a base station may transmit one or more RRC messages comprising configuration parameters. The configuration parameters may comprise a first bit size of a HARQ process number (HARQ ID) field of a DCI format. For example, the DCI format may be a DCI format 0_2 or a DCI format 1_2. The configuration parameters may comprise a second size of a RV (redundancy version) field of the DCI format. The configuration parameters may be for a BWP of a cell. The configuration parameter may be configured for a search space of the BWP of the cell. The configuration parameter may be configured for a coreset of the BWP of the cell. A wireless device may receive a DCI based on the DCI format. The wireless device may determine a CRC scrambling of the DCI. For example, when the CRC scrambling of the DCI may be a first RNTI (e.g., the first RNTI may be a CS-RNTI or a sp-CSI-RNTI), the wireless device may determine that the DCI may be scheduled for one or more periodic resources/configurations. For example, the one or more periodic resources/configuration may be one or more CG configurations. For example, the one or more periodic resources/configurations may be one or more SPS configurations. For example, the one or more periodic resources/configurations may be one or more SP-CSI configurations. The wireless device may determine whether a NDI field of the DCI indicates a value of zero (‘0’) or a predetermined value or may indicate a new data transmission. The wireless device may determine the DCI comprises one or more resources for scheduling downlink or uplink data in response to the NDI field indicating non-zero or non-predetermined value or may indicate a retransmission. The wireless device may determine the DCI for a retransmission for the one or more periodic resources/configurations. In response to the NDI field indicating a predetermined value (e.g., zero) or the predetermined value or indicating the new data transmission, the wireless device may perform a validation of the DCI based on the HARQ process number field and/or the RV field. The wireless device may check/determine the first bit size and the second bit size. In response to determining that the first bit size may be zero and/or the second bit size may be zero, the wireless device may determine/validate the DCI for an activation or a release of the one or more periodic resources/configurations based on a state of the one or more periodic resources/configurations. For example, when the one or more periodic resources/configuration (e.g., CG configuration) is in active state or has been activated, the wireless device may determine/validate that the DCI activates the one or more periodic resources/configurations. Otherwise, the wireless device may further check/determine a first value of an MCS field and/or a second value of a FDRA field. In response to the first value being same to a first predetermined value and a second value being same to a second predetermined value, the wireless device may determine/validate that the DCI releases the one or more periodic resources/configurations. In an example, the DCI may activate a single periodic resource/configuration. In an example, the DCI may release a single periodic resource/configuration. In an example, the DCI may activate a single periodic resource/configuration of the one or more periodic resources/configurations. In an example, a DCI field may indicate an index of the single periodic resource/configuration. For example, the DCI field may be a CSI request field for one or more SP-CSI configurations. For example, the DCI field may be an SRS request field for one or more SP-SRS configurations. For example, SP-SRS configurations may comprise semi-persistent (periodic) resources for one or more SRS transmissions. In an example, the DCI may release a plurality of periodic resources/configurations. In response to the determining, the wireless device may validate the DCI releases the one or more periodic resources/configurations. Otherwise, the wireless device may determine/validate the DCI activates the one or more periodic resources/configurations. FIG.24illustrates a flow diagram of an example embodiment.FIG.24may illustrate a similar procedure toFIG.23. For determining/validating the DCI for an activation of the one or more periodic resources/configurations, the wireless device may check a first value of the MCS field and a second value of a FDRA field. For example, the checking may be further performed in response to a state of the one or more periodic resources/configurations being active. For example, the checking may be performed regardless of the state of the one or more periodic resources/configurations. In response to the first value is same to a third predetermined value and the second value is same to a fourth predetermined value, the wireless device may determine that the DCI activates the one or more configured resources/configurations. In response to the first value is same to the first predetermined value and the second value is same to the second predetermined value, the wireless device may determine that the DCI activates the one or more configured resources/configurations. For example, the third predetermined value may be different from the first predetermined value. The fourth predetermined value may be different from the second predetermined value. In an example, a wireless device may receive configuration parameters for a cell. The configuration parameters may comprise a first bit size of a hybrid automatic repeat request (HARQ) process identifier field of a DCI format; a second bit size of a redundancy version (RV) field of the DCI format; and a periodic resource configuration of the cell. The wireless device may receive a DCI. The wireless device may validate/determine the DCI indicates an activation of the periodic resource configuration based on the first bit size being zero; the second bit size being zero; a new data indicator of the DCI indicating a predetermined value; and the periodic resource configuration being inactive state. For example, the predetermined value may be zero. In response to the determining, the wireless device may activate the periodic resource configuration. According to an example embodiment, the first RNTI may be a CS-RNTI or a sp-CSI-RNTI. For example, the determining may be further based on a first value of a modulation and coding scheme (MCS) field of the DCI being different from a first predetermined value and a second value of a frequency domain resource assignment field of the DCI being different from a second predetermined value. For example, the first predetermined value may be all ones. For example, the second predetermined value may be determined based on a resource allocation type. According to an example embodiment, the determining may be further based on a first value of a modulation and coding scheme (MCS) field of the DCI being different from a first predetermined value and being same to a third predetermined value; and a second value of a frequency domain resource assignment field of the DCI being different from a second predetermined value and being same to a fourth predetermined value. For example, the third predetermined value may be incremented by K from the first predetermined value or decremented by K from the first predetermined value. For example, K=1. For example, the fourth predetermined value may be incremented by K from the second predetermined value or decremented by K from the second predetermined value. In an example, a wireless device may receive configuration parameters for a cell. The configuration parameters may comprise a first bit size of a hybrid automatic repeat request (HARQ) process identifier field of a DCI format; a second bit size of a redundancy version (RV) field of the DCI format; and a periodic resource configuration of the cell. The wireless device may receive a DCI. The wireless device may validate/determine the DCI indicates an activation of the periodic resource configuration based on the first bit size being zero; the second bit size being zero; a new data indicator of the DCI indicating a predetermined value; a first value of a modulation and coding scheme (MCS) field of the DCI being same as a third predetermined value, wherein the third predetermined value is different form a first predetermined value; and a second value of a frequency domain resource assignment field of the DCI being same as a fourth predetermined value, wherein the fourth predetermined value is different from a second predetermined value. For example, the predetermined value may be zero. In response to the determining, the wireless device may activate the periodic resource configuration. In an example, a wireless device may receive configuration parameters for a cell. The configuration parameters may comprise a first bit size of a hybrid automatic repeat request (HARQ) process identifier field of a DCI format; a second bit size of a redundancy version (RV) field of the DCI format; and a periodic resource configuration of the cell. The wireless device may receive a DCI. The wireless device may validate/determine the DCI indicates an activation of the periodic resource configuration based on the first bit size being zero; the second bit size being zero; a new data indicator of the DCI indicating a predetermined value; the periodic resource configuration being inactive state; a first value of a modulation and coding scheme (MCS) field of the DCI being same as a third predetermined value, wherein the third predetermined value is different form a first predetermined value; and a second value of a frequency domain resource assignment field of the DCI being same as a fourth predetermined value, wherein the fourth predetermined value is different from a second predetermined value. For example, the predetermined value may be zero. In response to the determining, the wireless device may activate the periodic resource configuration. For example, the wireless device may determine that the HARQ process number field may be set to a predetermined in response to the first bit size being zero. For example, the predetermined value may be all zeros (e.g., ‘0, . . . , 0’, or 0). For example, the wireless device may determine that the RV field may set to a predetermined value in response to the second bit size being zero. For example, the predetermined value may be all zeros or zero (e.g., ‘0, . . . , 0’, or 0). | 210,926 |
11943060 | DETAILED DESCRIPTION The ensuing description provides preferred exemplary embodiments(s) only, and is not intended to limit the scope, applicability or configuration of the invention. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims. Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function. Embodiments, or portions thereof, may be embodied in program instructions operable upon a processing nun for performing functions and operations as described herein. The program instructions making up the various embodiments may be stored in a non-transitory storage medium. The program instructions making up the various embodiments may be stored in a storage medium. Moreover, as disclosed herein, the term “non-transitory storage medium” may represent one or more devices for storing data, including read only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), random access memory (RAM), magnetic RAM, core memory, floppy disk, flexible disk, hard disk, magnetic tape, CD-ROM, flash memory devices, a memory card and/or other machine readable mediums for storing information. The term “machine-readable medium” includes, but is not limited to portable or fixed storage devices, optical storage mediums, magnetic mediums, memory chips or cartridges, wireless channels and various other mediums capable of storing, containing or carrying instruction(s) and/or data. A machine-readable medium can be realized by virtualization, and can be a virtual machine readable medium including a virtual machine readable medium in a cloud-based instance. The term computer-readable medium, main memory, or secondary storage, as used herein refers to any medium that participates in providing instructions to a processing unit for execution. The computer-readable medium is just one example of a machine-readable medium, which may carry instructions for implementing any of the methods and/or techniques described herein. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, optical or magnetic disks. Volatile media includes dynamic memory. Transmission media includes coaxial cables, copper wire and fiber optics. Transmission media can also take the form of acoustic or light waves, such as those generated dining radio-wave and infra-red data communications. A volatile storage may be used for storing temporary variables or other intermediate information during execution of instructions by a processing unit. A non-volatile storage or static storage may be used for storing static information and instructions for processor, as well as various system configuration parameters. The storage medium may include a number of software modules that may be implemented as software code to be executed by the processing unit using any suitable computer instruction type. The software code may be stored as a series of instructions or commands, or as a program in the storage medium. Various forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to the processor for execution. For example, the instructions may initially be carried on a magnetic disk from a remote computer. Alternatively, a remote computer can load the instructions into its dynamic memory and send the instructions to the system that runs the one or more sequences of one or more instructions. A processing unit may be a microprocessor, a microcontroller, a digital signal processor (DSP), any combination of those devices, or any other circuitry configured to process information. A processing unit executes program instructions or code segments for implementing embodiments of the present invention. Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program instructions to perform the necessary tasks may be stored in a computer readable storage medium. A processing unit(s) can be realized by virtualization, and can be a virtual processing unit(s) including a virtual processing unit in a cloud-based instance. Embodiments of the present invention are related to the use of a computer system for implementing the techniques described herein. In an embodiment, the inventive processing units may reside on a machine such as a computer platform. According to one embodiment of the invention, the techniques described herein are performed by computer system in response to the processing unit executing one or more sequences of one or more instructions contained in the volatile memory. Such instructions may be read into the volatile memory from another computer-readable medium. Execution of the sequences of instructions contained in the volatile memory causes the processing unit to perform the process steps described herein. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement the invention. Thus, embodiments of the invention are not limited to any specific combination of hardware circuitry and software. A code segment, such as program instructions, may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc. Alternatively, hardwired circuitry may be used in place of, or in combination with, software instructions to implement processes consistent with the principles of the invention. Thus, implementations consistent with principles of the invention are not limited to any specific combination of hardware circuitry and software. A network interface that may be provided by a node is an Ethernet interface, a frame relay interface, a fibre optic interface, a cable interface, a DSL interface, a token ring interface, a serial bus interface, a universal serial bus (USB) interface, Firewire interface, Peripheral Component Interconnect (PCI) interface, etc. A network interface may be implemented by a standalone electronic component or may be integrated with other electronic components. A network interface may have no network connection or at least one network connection depending on the configuration. A network interface may be an Ethernet interface, a frame relay interface, a fibre optic interface, a cable interface, a Digital Subscriber Line (DSL) interface, a token ring interface, a serial bus interface, a universal serial bus (USB) interface, Firewire interface, Peripheral Component Interconnect (PCI) interface, cellular network interface, etc. A network interface may connect to a wired or wireless access network. An access network may carry one or more network protocol data. A wired access network may be implemented using Ethernet, fiber optic, cable, DSL, frame relay, token ring, serial bus, USB, Firewire, PCI, or any material that can pass information. An wireless access network may be implemented using infra-red, High-Speed Packet Access (HSPA), HSPA+, Long Term Evolution (LTE), WiMax, General, packet radio service (GPRS), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), Code division multiple access (CDMA), WiFi, CDMA2000, Wideband CDMA (WCDMA), Time Division CDMA (TD-SCDMA), BLUETOOTH, WiBRO, Evolution-Data Optimized (EV-DO); Digital Enhanced. Cordless Telecommunications (DECT); Digital AMPS (IS-136/TDMA); Integrated Digital Enhanced (iDEN) or any other wireless technologies. For example, a network interface may be used as a local area network (LAN) interface or a wide area network (WAN) interface. Embodiments, or portions thereof, may be embodied in a computer data signal, which may be in any suitable form for communication over a transmission medium such that it is readable for execution by a functional device (e.g., processing unit) for performing the operations described herein. The computer data signal may include any binary digital electronic signal that can propagate over a transmission medium such as electronic network channels, optical fibers, air, electromagnetic media, radio frequency (RF) links, and the like, and thus the data signal may be in the form of an electrical signal, optical signal, radio frequency or other wireless communication signal, etc. The code segments may, in certain embodiments, be downloaded via computer networks such as the Internet, an intranet, LAN, metropolitan area network (MAN), wide area network (WAN), the public switched telephone network (PSTN), a satellite communication system, a cable transmission system, and/or the like. FIG.1Aillustrates system100adapted according to embodiments configured to optimize the throughput of bonded multiple variable bandwidth connections by adjusting a tunnel bandwidth weighting schema during a data transfer session. System100includes multiple sites102and104, which each comprise at least one network node. A network node may be referred to as a communications router. However the scope of the invention is not limited to communications routers, such that the invention can be carried out at gateways, routers, servers, or any other types of network nodes. For simplicity,FIG.1Aillustrates that sites102and104comprise communications router106and108respectively. Communication routers106and108may be embodied as multi WAN routers which support aggregating the bandwidth of multiple Internet connections. Communications routers106and108are connected over network110. Network110may comprise a LAN, MAN, WAN, wireless network, the PSTN, the Internet, an intranet, an extranet, etc. Site102and router106may comprise M connections112, and site104and router108may comprise N connections114. Connections112and114are data connections for communicating information within network110between sites102and104. In the illustrated embodiment, M is equal to 3 and N is equal to 2; however, these values may vary according to desired routers and configurations. Connections112and114may have similar or differing bandwidth capabilities. Further, connections112and114may comprise different types of WAN connections, such as a WiFi, cable, DSL, T1, 3G, 4G, satellite connections, and the like. It is also noted that site102and site104may be thought of as both a sender or receiver, and discussions regarding the functionality of either site may be implemented on the other site. In other words, system100may be implemented as a symmetrical network. FIG.1Billustrates a network environment according to one of the embodiments of the present invention. Tunnels103A,103B and103C are established between communications router106and communications router108. Tunnels103A,103B and103C may be bonded to form an aggregated connection. Communications routers106and108may have a plurality of network interfaces according to one of the embodiments. Communications router106establishes tunnels103A,103B, and103C via one or more of its plurality of network interfaces with one or more network interfaces of communications router108. Communication device106and108may work as a gateway, a router, a switch, an access point, a hub, a bridge, etc. FIG.1Cillustrates system100adapted according to embodiments configured to optimize the throughput of bonded multiple variable bandwidth connections. System100is similar to system101, with the exception of M×N virtual tunnels116. When establishing a bonded connection between sites102and104, such as by implementing a bonded site-to-site VPN connection, M.times.N tunnels116may be created. Tunnels116correspond to a unique permutation of the network connections of site102and the network connections of site104. An aggregated connection may be formed between communications routers106and108. Tunnels116may be virtual tunnels. A plurality of established tunnels116may be aggregated, combined or bonded together to form one aggregated connection. Those skilled in the arts would appreciate that there are myriad ways to aggregate, combine, or bond a plurality of established tunnels to forum one aggregate tunnel. An aggregated connection is perceived as one tunnel by sessions or applications that are using it. An aggregated connection may be an end-to-end connection, a virtual private network connection or connectionless oriented connection. For example, an aggregated connection may be a TCP connection or UDP connection. In another example, aggregated connection is an aggregation of a plurality of tunnels, and each tunnel is linked between communications router106and communications router108. In another example, an aggregated connection may be a VPN tunnel, comprising a plurality of established tunnels, and each established tunnel is linked between communications router106and communications router108. FIG.2Ashows a high level flow diagram of operation of system100depicting a method200for increasing throughput of a bonded connection. It should be appreciated that the particular functionality, the order of the functionality, etc. provided inFIG.2is intended to be exemplary of operation in accordance with the concepts of the present invention. Accordingly, the concepts herein may be implemented in various ways differing from that of the illustrated embodiment. At block201of the illustrated embodiment when establishing a bonded connection between routers102and104, such as by implementing a bonded site-to-site VPN connection, M.times.N virtual tunnels116may be created, as illustrated inFIG.1C. Virtual tunnels116correspond to a unique permutation of the network connections of site102and the network connections of site104. At block202of the illustrated embodiment, default weights for the tunnels are determined and/or assigned. To determine default weights embodiments exchange uplink and downlink bandwidth data of connections112and114between sites102and104. Using this bandwidth data, a default weight may be calculated according to the following: suppose site102's downlink bandwidths of connections 1 to m are d1 d2, . . . dm, and site104's uplink bandwidths of connections 1 to n are ur, U2, . . . Un; the default weight for the tunnel between site102's connection X and site104's connection V may be defined as DW(x,y), where DW(x,y)=dx,dy. Using the above method to calculate default weight, if connections112-1through1123are WAN connections of a multi WAN router with respective uplink/downlink bandwidths of 10M/6M, 8M/4M, and 6M /6M, and connections114-1through114-2are WAN connections of a multi WAN router with respective uplink dot bandwidths of 7M/5M and 9M/3M, the respective default weights for each tunnel will be as follows: TABLE 0001For site 102For site 104DW(1, 1) = 6 * 7 = 42DW(1, 1) = 5 * 10 = 50DW(1, 2) = 6 * 9 = 54DW(1, 2) = 5 * 8 = 40DW(2, 1) = 4 * 7 = 28DW(1, 3) = 5 * 6 = 30DW(2, 2) = 4 * 9 = 36DW(2, 1) = 3 * 10 = 30DW(3, 1) = 6 * 7 = 42DW(2, 2) = 3 * 8 = 24DW(3, 2) = 6 * 9 = 54DW(2, 3) = 3 * 6 = 18 It is noted that other ways to calculate default weight are contemplated, and the above is simply an example of the implementation of an embodiment of the present invention. It is noted that many different weighting schema may be used to define the initial bandwidth of a tunnel. For example, one may desire to only weight a tunnel in one direction using the downlink capacity of a receiving site and the uplink capacity of the sending site. Any weighting scheme used to characterize capacity of the tunnels at the establishment of the bonded connection may be used for the purposes of the present invention. When packets are being routed from site102to site104according to embodiments, the packets will be distributed to the tunnels in a ratio according to an effective weight EW(x,y). Initially the effective weight of embodiments is set to be equal to the default weight, EW(x,y)=DW(x,y), and if the bandwidth of tunnels116remains unchanged from the initial setting, the effective weight is optimal for packet distribution. However, if a user is downloading a file over a bonded network connection in a TCP session with one or more tunnels having packet drops, the overall throughput of the session will drop dramatically. This is in part because the packet drops will keep causing TCP retransmissions and TCP's flow control will maintain a lower throughput even though tunnels without packet drops are not fully occupied. One effective was to increase throughput would be to avoid such packet drops. To do so, embodiments of the present invention discern when tunnels are experiencing an increase or decrease in packet drop rates at block203of the illustrated embodiment. Embodiments further function to modify the effective weight of tunnels which are experiencing or have experienced changes in packet drop rates at block204. The packet drop rate information may be monitored continuously or be monitored based on specific time periods. Once it is determined that a tunnel is experiencing an unacceptable rate of packet drops (block204-1), the illustrated embodiment decreases the effective weight of the tunnel at block204-2. In some embodiments, unacceptable may mean that the packet drop rate is a non-zero quantity, while other embodiments may determine that an unacceptable rate is any rate beyond a predefined threshold. Embodiments implement these decreases in stepwise fashion, in a continuous manner, in a reduction at one time in proportion to the increase in the packet drop rate, etc. When reductions are done in a gradual manner, embodiments, may continue to monitor the tunnel in order to optimize the amount of reduction which is implemented. Tunnels116may be established or monitored by sending heartbeat packets through each tunnel from either router106or router108. In some embodiments when the receive end fails to receive heartbeat packets from a tunnel for a period of time, it will treat that tunnel as down and the tunnel will not be used for routing traffic. If heartbeat packets again start being received, the tunnel may be re-established and be, weighted along with the other tunnels. As such, in the event that all packets are being dropped in a tunnel and the effective weight of that tunnel is reduced to zero, embodiments may utilize heartbeat packets to monitor and reestablish a connection. Moreover, when tunnels recover all or part of their respective bandwidths, e.g. it is determined that the packet drop rate decreases (block204-3), the illustrated embodiment functions to increase the effective weight of such tunnels (block204-4) in order to fully, or more fully, utilize the bandwidth. Some embodiments increase the effective weight for a tunnel using predetermined step sizes until an accurate effective weight is regained. Other embodiments increase the effective weight proportionate to a newly measured bandwidth which may correspond to a newly measured packet drop rate. Moreover, embodiments may increase the effective weight for a tunnel based on a predetermined linear or exponential scale. After the effective weight of the tunnels are adjusted, or it is determined that no adjustment is needed, the weighting scheme of the system is updated at block205of the illustrated embodiment. This update may comprise storing any processed, information, using such information in further processing, causing the system to take no action, etc. For example, processing performed with respect to block205may operate to average weighting schemes over a period of time, such as to mitigate error associated with highly transient anomalies. Further, the updated, information may be used on system100to modify the packet distribution of the data transfer session, as discussed with respect toFIG.2B, System100may continue to implement steps203-205continuously or periodically throughout a data transfer session. FIG.2Billustrates an embodiment where, after weighting method200is implemented, the packets are distributed based, at least in part, on the modified weight of the tunnels. Specifically, block206of the illustrated embodiment operates to distribute packets across the tunnels in accordance with the weighting scheme determined by operation of method200. In some embodiments, this distribution will change throughout a data transfer session, and therefore the steps ofFIG.2Bare shown as repeating. Some embodiments change the packet distribution each time the system is updated at block205. Moreover, block205may cause changes to be implemented periodically, in response to certain drop rate change thresholds, etc. It should be appreciated that the determination of weighting, by operation of method200and the application of determined weighting to packet distribution at block206may have different periodicity. For example, method200may operate to provide updates of weighting scheme information using a relatively short iterative cycle while the distribution of packets is altered based upon such weighting scheme information using a longer iterative cycle. To monitor the bandwidth of the various tunnels116, some embodiments of the present invention encapsulate each transmitted IP packet with various information.FIG.3illustrates an example embodiment showing the type of information300which may be encapsulated in a transmitted IP packet. Version field302may contain information about the protocol version being utilized and protocol type field303may contain the protocol type of the payload packet. In general, the value of this field will correspond to the Ethernet protocol type for the packet. However, additional values may be defined in other documents. Tunnel ID field304may be a 32-bit field and may contain an identifier to identify the current tunnel of the IP packet. Advanced Encryption Standard (AES) initialization sector field306may be a 32-bit field and may contain an initialization vector for AES encryption. Global sequence number field308may be a 32-bit field and may contain a sequence number which is utilized to re-sequence each of the packets for various sessions into the proper order when they have emerged from their respective tunnels. Per tunnel sequence number field310may be a 32-bit field which may represent a sequence number that is assigned to each packet routed to a particular tunnel. AES encrypted payload field312may be utilized to convey the payload of the IP packet. AES encryption, may be applied for higher security of the payload in order to prevent attacks from third parties. The per tunnel sequence number discussed above may be used to monitor dropped packets in a tunnel. In one embodiment the router on the receiving end calculates the packet drop rate of each tunnel, DR(x,y), every f seconds by monitoring the per tunnel sequence number of the received packets. DR(x,y) may be characterized as the sequence numbers missed divided by a sequence number increase for a period f. The length of period f may vary, and in one embodiment f is equal to 5 seconds. Other methods may also be used to monitor dropped packets, e.g.: the sender may periodically inform the receive end how many packets it has sent, the sender sends a heartbeat packet to the receive end every constant period of time and the receive end can estimate the overall drop rate by monitoring the heartbeat packets' drop rate, by acquiring drop rate figures from physical interface/device/layer, etc. The receive end may feedback a particular tunnel's drop rate, effective weight, or other bandwidth indicators, to the sending router. When the sender receives information regarding packet drops, some embodiments lower the effective weight EW(x,y) of a tunnel by EW(x,y)DR(x,y). Other metrics may be used to modify the effective weight of a tunnel. In some embodiments, the sender may receive feedback and the effective weight may be reduced by number that is greater than or less than the packet drop rate. Such variances may be configured according to the particular needs of a communication system. The above example represents a metric that attempts to lower the effective weight of the tunnel to a weight which prevents further packet drops while maximizing the amount of usable bandwidth of the tunnel. Any metric which finds this balance may be preferred. FIG.4Aillustrates an example embodiment of the type of information400which may be encapsulated in a feedback packet which is sent to the transmitting router in order to report packet drop rates or other bandwidth related data received at the receiving end router. Type field402may include data regarding the type of data that will be included in data 1 field404and data 2 field406. Data 1 field404and data 2 field406may contain any information which may be used to assist the router in determining tunnel information with regard to the number of tunnels, bandwidth of tunnels, number of dropped packets in a tunnel, and the like. An example of possible values of the type field402in the data fields404and406is shown in the chart ofFIG.4B. The information which is encapsulated in transmitted IP packets, such as shown inFIG.3andFIG.4may also be used for packet buffering and re-sequencing. Because each tunnel's latency can be different, when two consecutive packets of the same TCP session are sent to a VPN peer over a bonded VPN tunnel, they may not arrive in sequence because they are routed via two different tunnels. If the TCP session receives the out-of-sequence packets from the VPN, the TCP session will slow down due to TCP retransmissions. Accordingly, the receive end should buffer the packets that come too early until either the slower packets arrive or until an expiration time has passed. With such buffering, late packets that come prior to an expiration time will be forwarded to the destination device in sequence. This buffering assists in the optimization of end-to-end throughput. It is noted that embodiments described herein are, at times, discussed in the context of a VPN connection. These discussions are presented in order to show an example embodiment of a bonded connection. The inventive concepts described in claimed herein are not limited to such connections. In fact, any connection where sufficient data may be obtained and exchanged in order to dynamically monitor the bandwidth of a plurality of communication paths which are being used in a data transfer session may be implemented with the embodiments of the present invention. As discussed above, each packet may be assigned two different sequence numbers, a global sequence number (GSN) and a per tunnel sequence number (PTSN). These numbers may be used to assist in packet buffering and re-sequencing operations. After a packet is passed to an upper layer, the receive end may update a next expected per-tunnel sequence number (NE-PTSN) and a next expected global sequence number (NE-GSN). The following will describe one method of how a packet may be buffered or forwarded to destination device after it is received and decrypted.1. If the packet's GSN equals to zero, forward it to destination device immediately.2. Check if the packet's PTSN equals to the NE-PTSN. If not, dequeue (forward to destination device) in sequence all packets that have a smaller GSN than the packet's. Keep the packet unprocessed.3. Update the NE-PTSN (i.e., set NE-PTSN to PTSN+1).4. If the GSN is less than the NE-GSN, forward to destination device.5. If the packet's GSN is equal to the NE-GSN, update the NE-GSN (i.e., set NEGSN to GSN+1) and forward to destination device. Repeat updating the NE-GSN and dequeuing the buffer head from the butler if the head's GSN equals to the new NE-GSN.6. Otherwise (GSN is larger than the NE-GSN), enqueue the packet in the order of the GSN.7. If a packet has been in the queue longer than a fixed amount of time, set the NEGSN to the packet's GSN+1 and dequeue in sequence the packet and all packets that have a smaller GSN than the packet's. Therefore, the encapsulated packet information discussed inFIG.2andFIG.3may include information that optimizes overall throughput of the data transmission system, such as100, both by assisting in the optimization of tunnel bandwidth in response to monitoring packet drop rates, and by assisting in the efficient re-sequencing of received packets in a data transfer session. FIG.5illustrates an exemplary processor-based system500which may be employed to implement the systems, devices, and methods according to certain embodiments. Processor-based system500may represent the architecture of communications router106and108. Central processing unit (CPU)501is coupled to system bus502. CPU501may be any general purpose CPU, or may be a special purpose CPU designed to implement the above teachings. The present disclosure is not restricted by the architecture of CPU501(or other components of exemplary system500) as long as CPU501(and other components of system500) supports the inventive operations as described herein. CPU501may execute the various logical instructions described herein. For example, CPU501may execute machine-level instructions according to the exemplary operational flow described above in conjunction withFIG.2. When executing instructions representative of the operational steps illustrated inFIG.2, CPU501becomes a special-purpose processor of a special purpose computing platform configured specifically to operate according to the various embodiments of the teachings described herein. System500also includes random access memory (RAM)503, which may be SRAM, DRAM, SDRAM, or the like. RAM503may be a secondary storage which stores program instructions executable by CPU501. System500includes read-only memory (ROM)504which may be PROM, EPROM, EEPROM, or the like. RAM503and ROM504hold user and system data and programs, as are well known in the art. System500also includes input/output (I/O) adapter505, communications adapter511, user interface adapter508, and display adapter509. I/O adapter505, user interface adapter508, and/or communications adapter511may, in certain embodiments, enable a user to interact with system500in, order to input information. I/O adapter505connects storage device(s)506, such as one or more of hard drive, compact disc (CD) drive, floppy disk drive, tape drive, etc., to system500. The storage devices are utilized in addition to RAM503for the memory requirements associated performing the operations discussed in the above embodiments. Communications adapter511is adapted to couple system500to network512, which may enable information to be input to and/or output from system500via such network512(e.g., the Internet or other wide-area network, a local-area network, a public or private switched telephony network, a wireless network, any combination of the foregoing). Communications adapter511may be regarded as a network interface, and system500may comprise a plurality of communications adapters511. User interface adapter508couples user input devices, such as keyboard513, pointing device507, and microphone514and/or output devices, such as speakers)515to system500. Display adapter509is driven by CPU501to control the display on display device510. Display adapter509transmits instructions for transforming or manipulating the state of the various numbers of pixels used by display device510to visually present the desired information to a user. Such instructions include instructions for changing state from on to off setting a particular color, intensity, duration, or the like. Each such instruction makes up the rendering instructions that control how and what is displayed on display device510. FIG.6illustrates a network environment based on the network environment illustrated inFIG.1A. One of the LAN interface of communications router106is connected to host103and one of the LAN interface of communications router108is connected to host105. Hosts103and105are in sites102and104respectively. A plurality of tunnels may be established between communications routers106and108through network110. Communications router106may establish tunnels with communications router108through one or more WAN interfaces of communications router106and one or more WAN interfaces of communications router108. For illustration purpose only, communications router108connects to the Internet110through two connections while communications router106connects to the network110through two connections. Network110may be an interconnected network, such as the internet. FIG.7is a sequence diagram illustrating how data is transferred between host105and host103according, to one of the embodiments of the present invention. In flow701, data-1 is transmitted from host103to communications router106. Data-1 is originated at host103, and is intended to be transmitted to host105. Data-1 can be comprised in one or more data packets, one or more frames, or any other data unit. Whether data-1 is comprised in one data packet or more data packets depends on the size of data-1. If size of data-1 is such that data-1 can be encapsulated in one data packet, then data-1 is comprised in one data packet. If size of data-1 is too big to be encapsulated in one data packet, data-1 may be fragmented into a plurality of parts and the plurality of parts are encapsulated in a plurality of data packets respectively. Communications router106then sends data-1 to communications router108in flow702through interconnected networks110. Communications router108forwards data-1 to host105. When host105receives data-1, it creates an acknowledgement packet, Ack-1, which is destined to host103. Ack-1 is received at communications router108at flow704, and forwarded to communications router106at flow705. Communications router106then sends Ack-1 to host103in flow706. Therefore host103now knows that data-1 reached host105successfully. Host103then transmits data-2 to host105through communications routers106and108. Data-2 is transmitted from host103to communications router106in707. Communications router106forwards data-2 to communications router108in flow708. Communications router108does not receive data-2 on time, as data-2 may be dropped or may be delayed when being transmitted to communications router108. Communications router108then creates and sends a delay inquiry message in flow709to inform communications router106that data-2 has not been received yet and to check why there is a delay. When communications router106receives the delay inquiry message, it determines that data-2 had been lost, and therefore it activates an error correction mode. Under the error correction mode, communications router106sends data-2-1 and data-2-EC in flows710and711respectively. Data-2-1 may be the same as data-2, whereas data-2-EC comprises error correction data corresponding to data-2. Using data-2-1 and/or data-2-EC, communications router108can create data-2 and send data-2 to host105in flow712. When host105receives data-2, it creates an acknowledgement packet, Ack-2, which is destined to host103. Ack-2 is received at communications router108at flow713and forwarded to communications router106at flow714. Communications router106then sends Ack-2 to host103in flow715. Host103sends data-3 to host105through communications routers106and108. Data-3 is transmitted to communications router106in flow716. Since the error correction mode is activated in communications muter106, communications router106sends both data-3 and data-3-1, and also and data-3-EC to communications router108in flows717,718and722respectively. Communications router108successfully receives data-3-1 and forwards data-3 to host105in flow719. Host105then creates and sends an acknowledgement packet, Ack-3, which is destined to host103. Ack-3 is received at communications router108at flow720, and forwarded to communications router106at flow721. Communications router106then sends Ack-3 to host103in flow723. As communications router108receives both data-3-1 and data-3-EC, it determines that data is no longer being lost, and therefore sends a back-to-normal message to communications router106in flow724. When communications muter106receives the back-to-normal message, it can deactivate the error correction mode. When the error correction mode is deactivated, communications router106no longer sends error correction packets such as data-2-EC and data-3-EC. In some communication protocols, such as TCP, when a data transfer session ends, an end message may be sent from the sender to the receiver in order to indicate that the data transfer session has ended, i.e., no more data packets belonging to the data transfer session will be sent. Communications router108may determine that data, such as data-2, is delayed or lost, as it may not have received any end message after receiving data-1. Therefore, it sends the delay inquiry message in flow709in order to request communications router106to resend data-2. When data is received at communications router106from host103, communications router106may save the data in a local storage medium, such as a cache, such that it may send copies of the data when necessary without requiring host103to resend the data. In case the data is lost when being transmitted to communications router108, communications router106can quickly resend the data. There is no need to wait for host103to resend the data or inform host103about the lost. Those who are skilled in the art would appreciate that in some communication protocols, when host103is aware the host that data is lost, host103may slow down the data transmission. Since the waiting time is reduced, communications router108is able to receive a retransmission of the data from communication router106, instead of making a retransmission request to host103. In flow721, communications router106sends out data-3-EC. For illustration purpose, coincidentally data-3-EC is sent before Ack-3 is received at communications router106. In one variant, if Ack-3 had been received earlier at communications router106, communications router106would not have transmitted data-3-EC. Contents of data-2-1 may be the same as contents of data-2, as communications router106resends data-2 by sending data-2-1. Data-2-EC is encapsulated in error correction packets. In one variant, the data packet encapsulating data-2-1 is identical to the data packet encapsulating data-2 as the content of data-2-1 is the same as the content of data-2, source addresses of the data packets are the same and destination addresses of the data packets are the same. Error correction packets may be packets that are transmitted by communications router106to correct or detect any errors in data packets that are transmitted from communications router106to communications router108. Error correction packets include Forward error correction (FEC) packets or Automatic repeat request (ARQ) packets, Parity packets, or the like. In one variant, error correction packets may also be combinations of two or more packets. For example, if a first packet comprises data-2 and a second packet comprises data-2-EC, a third packet may comprise data content based on an exclusive OR (XOR) operation applied to the contents of first and second packets. Using data-2-EC, communications router108may be able to retrieve data-2, and sends data-2 to host105. In one variant, data-2 may be fragmented into two parts. A first part of data-2 is encapsulated in a first data packet and a second part of data-2 is encapsulated in a second data packet. For illustration purpose, when communications router106sends data-2 to communications router108in flow708, communications router108receives the first data packet, but the second data packet is dropped or lost. Communications router108then sends the delay inquiry message in flow709. Data-2-EC may comprise an error correction packet whose data content is based on an XOR operation applied to the contents of the first data packet and the second data packet, i.e., the XOR operation is applied to the first part of data-2 and the second part of data-2. When communications router106sends data-2-EC, communications router108can retrieve the second part of data-2 by using the first part of data-2 and data-2-EC. It would be known to those skilled in the art how the second part of data-2 can be retrieved using the first part of data-2 and data-2-EC, as data-2-EC is based on the first and second part of data-2. In one variant, when communications router106receives the delay inquiry message and error correction mode is activated, communications router106may only send error correction packets, such as data-2-EC, and does not send data-2-1. In another variant, when communications router106receives the delay inquiry message, communications router106may only send data-2-1 and not send data-2-EC. The benefit of sending either only one of data-2-1 and data-2-EC is that fewer number of packets are transmitted, and hence lower bandwidth is consumed. This may help reduce traffic congestion. However, in some scenarios, data-2-EC alone may not help in retrieving data-2 if data-2-1 is not received. For example, when data-2-EC only contains a checksum or parity packets, it can only be used for error detection. In another example, when data-2-EC is created by applying XOR operation on two packets of data-2, data-2 can only be retrieved from data-2-EC if at least one of the two packets of data-2 had been received. Thus, sending data-2-1 may be helpful, such that data-2 may be retrieved using data-2-1 and data-2-EC. In one variant, as there may be some errors in data-2-1 received at communications router108, data-2-EC may be used to correct the errors. FIG.11illustrates the structure of a delay inquiry message according to one of the embodiments of the present invention. Delay inquiry message1100may be sent when any data packet is dropped or lost, i.e., there is a missing data packet. Delay inquiry message1100may be an IP packet comprising IP header1101, other information field1104and payload1105. IP header1101comprises a source address field1102and destination address field1101. For example, referring toFIG.7, the delay inquiry message sent in flow709is the source address is IP address of communications router108and the destination address is the IP address of communications router106. Other information field1104may include various information such as the nature of the IP packet, i.e. information that the TP packet is a delay inquiry message. This indicates to communications router106that the IP packet is not a data packet, and just a management message. Communications router106may process data packets and management messages differently. For example, communications router106may store data packets received from communications router108in a cache, but communications router106may not store management messages such as the delay inquiry message in the cache. Other information field1102may further include session information in order to indicate which session the missing packet belongs to. Payload1105may contain GSN of the missing packet. For example, in flow709, payload1105of delay inquiry message1100sent by communications router108to communications router106may contain GSN of one or more data packets corresponding to data-2as data-2 had not reached communications router108successfully. When communications router106receives delay inquiry message1100from communications router108, and payload1105contains GSN of one or more data packets corresponding to data-2, communications router106may determine that communications router108has not received data-2. Therefore communications router106then sends data-2-1 and data-2-EC to communications router108. The scope of the invention is not limited to the delay inquiry message being an IP packet. The delay inquiry message may be a short messaging service (SMS) message, a multimedia messaging service (MMS) message, or any other type of message that can be sent by communications router108to communications router106for giving information of any missing data packets. FIG.8is a sequence diagram illustrating how data is transferred between host105and host103according to one of the embodiments of the present invention. Host103sends data-1 to host105through communications routers106and108. Data-1 is transmitted from host103to communications router106in flow801. Communications router106then transmits data-1 to communications router108in flow802and communications router108forwards data-1 to host105in flow803. Communications router106is initially in error correction mode, and hence, after a waiting time period, it sends data-1-1 and data-1-EC in flows806and807respectively. The benefit of transmitting data-1-1 and data-1-EC is that in case data-1 was lost, host103would not have to retransmit data-1. Data-1-1 and data-1-EC may help communications router108to create and send data-1 to host105in case data-1 was lost in flow802. When host105receives data-1, it creates an acknowledgement packet, Ack-1, which is destined to host103. Ack-1 is transmitted to communications router108in flow804and is transmitted by communications router108to communications router106in flow805. As communications router108receives both data-1 and data-1-1 from communications router106, it sends a back-to-normal message to communications router106in flow808. After receiving the back-to-normal message to communications router106deactivates the error correction mode as packets are no longer being lost. Host103transmits data-2 which is destined to host105. When data-2 is received at communications router106in flow810, communications router106forwards data-2 to communications router108in flow811. Communications router108then forwards data-2 to host105in flow812. As the error correction mode has been deactivated, communications router106does not send any error correction packets for data-2. When host105receives data-2. it creates an acknowledgement packet, Ack-2, which is destined to host103. Ack-2 is sent to communications router108in flow813, and is forwarded to communications router106in flow814. Communications muter106then sends Ack-2 to host103in flow815. The waiting time period between communications router106sending data-1 and sending data-1-1 may be adjusted or adapted to different networking need. The purpose of transmitting data-1-1 is to reduce the probability of host103retransmitting data-1. Host103may retransmit data-1 for one or both of the following reasons: (i) when host103determines that data-1 is lost because an acknowledgement has not been received, and (ii) when host105sends a request to host103to resend data-1. Therefore, in one variant, the waiting time period is preferably smaller than both (i) a first time period between host103sending data-1 and host103deciding to retransmit data-1, and (ii) a second time period between host103transmitting data-1 and host105deciding to send a request to host103to resend data-1. The first time period and the second time period may be defined in the transmission protocol, such as TCP protocol. As a certain delay is caused for data to travel from communications router106to communications router108, a third time period required for a data packet to be transmitted from communications router106to communications router108may also be taken into consideration for setting the waiting time period. The third time period may vary according to network conditions. The waiting time period may then be smaller than the first time period minus the third time period, and may also be smaller than the second time period minus the third time period. The benefit of reducing the probability of host103retransmitting data-1 is that host103does not slow down the data transmission because of the packet drop. In another variant the waiting time period is larger than a fourth time period, which is the time required, in general, for Ack-1 to be transmitted from communications router108to communications router106. This may cause communications router108to wait for receiving Ack-1 for the time required, and if Ack-1 is not received within the fourth time period, data-1-1 and data-1-EC are transmitted. The benefit of the waiting time period being larger than the fourth time period is that less bandwidth may be consumed, as data-1-1 and data-1-EC is not transmitted if Ack-1 is received. However, the fourth time period may vary according to network conditions. The disadvantage of the waiting time period being larger than the fourth time period is that when the fourth time period has passed, host103may retransmit data-1, and may also slow down the data transmission. Therefore it is preferred to take into consideration the first, second, and third time periods as discussed above, and ignore the fourth time period. This ensures that data is transmitted successfully and data transmission is not slowed down, even though bandwidth consumption may be higher. In another variant, the waiting time period is adjustable by the administrator of communication routers106and108. The difference between the sequence diagrams inFIG.7andFIG.8is that inFIG.7, the error correction mode is activated at communications router106when a delay inquiry message is received at communications router106. Alternatively, inFIG.8, the error correction mode may be activated by default, or may be activated by a user or administrator of communications router106. If the error correction mode is activated by default, there may be traffic congestion caused by error correction packets and resending of data packets. This may slow down the data transmission and consume significantly high bandwidth. Therefore, it may be beneficial to activate the error correction mode only when a delay inquiry message is received in order to save bandwidth and reduce traffic congestion. However, having the error correction mode activated by default may make the process of resending data packets and error correction packets faster, as communications router106does not need to wait for communications router108to send the delay inquiry message. This can be beneficial when communications router106already knows that the packet drop rate or the packet loss rate of a tunnel is high. When packet drop rate or packet loss rate is high, communications router106resends data packets and sends error correction packets. In an example, when host103is transmitting data to host105through communications router106and108using TCP, and many packets are being dropped or lost, host103may reduce transmission rate in order to reduce packet loss and packet drop. This may make the overall transmission much slower, even if the increase in packet drop is temporary. Additionally, when host103determines that a packet has been dropped or lost, it will resend the packet. The overall transmission may be faster when communications router106resends packets, compared to when host103resends packets. In order to avoid host103reducing transmission rate and resending packets, communications router106sends more than one copy of the same packet, for example data-2 and data-2-1, and may also send error correction packets, for example data-2-EC. When communications router106sends more than one copy of the same packet, redundancy is higher and it is more likely that the packet will be received at host105. Therefore, acknowledgement packets may be sent from host105and received at host103on time, and host103would not need to reduce the transmission rate or resend packets. In a preferred embodiment, copies of the same packet are transmitted through different tunnels of an aggregated connection, if possible. For example, referring toFIG.7, if data-2 is transmitted in flow708through tunnel103A, data-2-1 is transmitted in flow710through tunnel103B and data-2-EC is transmitted in flow711through tunnel103C. This may allow data-2, data-2-1 and data-2-EC to be transmitted substantially at the same time. Furthermore, if tunnels103A,103B and103C are established using networks provided by different service providers, the chance of at least one of data-2, data-2-1 and data-2-EC reaching communications router108successfully is higher. This is because the network quality of the tunnels may differ. If the network quality of tunnel103A is not satisfactory or tunnel103A is broken or tunnel103A is experiencing lots of packets drop, data-2 may not reach communications router108successfully. If data-2 is sent through tunnel103A, data-2-1 may experience the same network problem as data-2 has just experienced. Therefore, it is preferred to send data-2-1 through a different tunnel, such as tunnel103B, which may experience better network performance as the path, route or connection used by tunnel103B may be different from the path, route or connection used by tunnel103A. The use of different tunnels is more like to increase the probability of data-2-1 to reach communications router108successfully. FIG.9is a flowchart illustrating a process carried out at communications router106according to one of the embodiments of the present invention. Communications router106receives data from host103in step901, where the data is destined to host105. Communications router106determines, in step902, whether the error correction mode is activated. If the error correction mode is activated, communications router106sends both the original data and error correction data for the original data in step903. The original data is same as data received originally from host103. Alternatively, if the error correction mode is not activated, communications router only sends the original data in step904. The process ends in step905. FIG.10is a flowchart illustrating a process carried out at communications router108according to one of the embodiments of the present invention. Communications router108receives data from communications router106in step1001. Communications router108then determines in step1002whether all data is received on time. When error correction mode is activated in communications router106, all data comprises original data sent by host103, and error correction data originated at communications router106. If all data, is received on time, communications router108sends a back-to-normal message to communications router106in step1003. Communications router108may forward the original data to host105. Alternatively, if all data is not received on time, communications router108sends a request to communications router106in step1001, where the request is to resend the data. The process ends in step1005. In one variant, if the error correction mode is already deactivated,1003is omitted. Communications router108determines whether the error correction mode is activated or not. It is preferred that communications router108sends the request to reseed data in step1001before host103determines that the data has not been transmitted successfully. When communications router100receives the request to resend data, it resends a copy of the data to communications router108. Communications router106may also send error correction data to communications router108. Communications routers106and108preferably have a large cache memory. According to the present invention, communications router106has to create and send error correction packets and copies of packets based on packets sent by host103and saved in the cache memory of communications router106. Therefore communications router106may need to save many packets in its cache memory. Additionally, a plurality of management messages, such as back-to-normal message and delay inquiry message may need to be exchanged between communications routers106and108. These management messages may also need to be saved in the cache memory of communications router106and108. It should be appreciated that communications router108is capable of performing the same processes as communications router106and vice versa. In the above description, communications router106has been described as the data sender and communications router108has been described as the data receiver for readability. It should be noted that the scope of the invention is not limited to only host103sending data to host105, such that data transmission can also take place from host105to host103. The data transmission can also be bidirectional, such that both host103and host105may send data to each other. As communication routers need to store data for resending, storage medium is used for storing the data. The amount of storage required should be able to hold at least a few seconds of data being transmitted. Tt is preferred to store about twenty seconds of data transmission. For example, for an access connection that is capable of sending 100 Mbit per seconds, the amount of storage should be about twenty seconds times 100 Mbit per seconds and-results in about 250 MBytes of storage. Those who are skilled in the art would appreciate that the larger the storage is, the more data can be retransmitted. | 58,865 |
11943061 | DESCRIPTION OF EMBODIMENTS A user equipment (UE) is described. The UE includes a higher layer processor configured to configure physical uplink control channel (PUCCH) resources for HARQ-ACK feedback of ultra-reliable low-latency communication (URLLC) physical downlink shared channel (PDSCH) transmissions. The higher layer processor is also configured to determine if there is a collision between a PUCCH for HARQ-ACK feedback of URLLC PDSCH transmissions and other uplink (UL) channels. The higher layer processor is further configured to determine if simultaneous UL transmissions is supported for URLLC transmissions and other UL channels. The UE also includes transmitting circuitry configured to transmit HARQ-ACK feedback for URLLC PDSCH transmission and other UL channels. If there is a collision between a PUCCH for HARQ-ACK feedback of URLLC PDSCH transmissions and other UL channels, and if simultaneous UL transmissions is not supported for URLLC transmissions and other UL channels, the UE may transmit the PUCCH for HARQ-ACK feedback of URLLC PDSCH transmission and may drop the overlapping symbols on other UL channels. If there is a collision between a PUCCH for HARQ-ACK feedback of URLLC PDSCH transmissions and other UL channels, and if simultaneous UL transmissions is supported for URLLC transmissions and other UL channels, the UE may transmit the PUCCH for HARQ-ACK feedback of URLLC PDSCH transmissions, and one of the other UL channels with highest priority. Another UE is described. The UE includes a higher layer processor configured to configure PUCCH resources for HARQ-ACK feedback of URLLC PDSCH transmission. The higher layer processor is also configured to determine if ACK feedback is on or off for HARQ-ACK feedback of the URLLC PDSCH transmission. The UE also includes transmitting circuitry configured to transmit HARQ-ACK feedback for URLLC DL data based on the configured PUCCH resource and HARQ-ACK status. The ACK feedback for a URLLC PDSCH transmission may be turned off. If the ACK feedback is turned off, and if the HARQ-ACK is corresponding to NACK, the UE may report a NACK using the configured PUCCH resource. If the ACK feedback is turned off, and if the HARQ-ACK is corresponding to ACK, the UE may not transmit a PUCCH corresponding to the PDSCH. The ACK feedback for a URLLC PDSCH transmission may be turned on or off by higher layer signaling (e.g., RRC signaling). The ACK feedback for a URLLC PDSCH transmission may be turned on or off by indication of the fields in the scheduling DCI formats. The ACK feedback for a URLLC PDSCH transmission may be turned on or off by the MCS setting or the scrambling RNTI of the scheduling DCI. The 3rd Generation Partnership Project, also referred to as “3GPP,” is a collaboration agreement that aims to define globally applicable technical specifications and technical reports for third and fourth generation wireless communication systems. The 3GPP may define specifications for next generation mobile networks, systems and devices. 3GPP Long Term Evolution (LTE) is the name given to a project to improve the Universal Mobile Telecommunications System (UMTS) mobile phone or device standard to cope with future requirements. In one aspect, UMTS has been modified to provide support and specification for the Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN). At least some aspects of the systems and methods disclosed herein may be described in relation to the 3GPP LTE, LTE-Advanced (LTE-A) and other standards (e.g., 3GPP Releases 8, 9, 10, 11 and/or 12). However, the scope of the present disclosure should not be limited in this regard. At least some aspects of the systems and methods disclosed herein may be utilized in other types of wireless communication systems. A wireless communication device may be an electronic device used to communicate voice and/or data to a base station, which in turn may communicate with a network of devices (e.g., public switched telephone network (PSTN), the Internet, etc.). In describing systems and methods herein, a wireless communication device may alternatively be referred to as a mobile station, a UE, an access terminal, a subscriber station, a mobile terminal, a remote station, a user terminal, a terminal, a subscriber unit, a mobile device, etc. Examples of wireless communication devices include cellular phones, smart phones, personal digital assistants (PDAs), laptop computers, netbooks, e-readers, wireless modems, etc. In 3GPP specifications, a wireless communication device is typically referred to as a UE. However, as the scope of the present disclosure should not be limited to the 3GPP standards, the terms “UE” and “wireless communication device” may be used interchangeably herein to mean the more general term “wireless communication device.” A UE may also be more generally referred to as a terminal device. In 3GPP specifications, a base station is typically referred to as a Node B, an evolved Node B (eNB), a home enhanced or evolved Node B (HeNB) or some other similar terminology. As the scope of the disclosure should not be limited to 3GPP standards, the terms “base station,” “Node B,” “eNB,” “gNB” and/or “HeNB” may be used interchangeably herein to mean the more general term “base station.” Furthermore, the term “base station” may be used to denote an access point. An access point may be an electronic device that provides access to a network (e.g., Local Area Network (LAN), the Internet, etc.) for wireless communication devices. The term “communication device” may be used to denote both a wireless communication device and/or a base station. An eNB may also be more generally referred to as a base station device. It should be noted that as used herein, a “cell” may be any communication channel that is specified by standardization or regulatory bodies to be used for International Mobile Telecommunications-Advanced (IMT-Advanced) and all of it or a subset of it may be adopted by 3GPP as licensed bands (e.g., frequency bands) to be used for communication between an eNB and a UE. It should also be noted that in E-UTRA and E-UTRAN overall description, as used herein, a “cell” may be defined as “combination of downlink and optionally uplink resources.” The linking between the carrier frequency of the downlink resources and the carrier frequency of the uplink resources may be indicated in the system information transmitted on the downlink resources. “Configured cells” are those cells of which the UE is aware and is allowed by an eNB to transmit or receive information. “Configured cell(s)” may be serving cell(s). The UE may receive system information and perform the required measurements on all configured cells. “Configured cell(s)” for a radio connection may include a primary cell and/or no, one, or more secondary cell(s). “Activated cells” are those configured cells on which the UE is transmitting and receiving. That is, activated cells are those cells for which the UE monitors the physical downlink control channel (PDCCH) and in the case of a downlink transmission, those cells for which the UE decodes a physical downlink shared channel (PDSCH). “Deactivated cells” are those configured cells that the UE is not monitoring the transmission PDCCH. It should be noted that a “cell” may be described in terms of differing dimensions. For example, a “cell” may have temporal, spatial (e.g., geographical) and frequency characteristics. Fifth generation (5G) cellular communications (also referred to as “New Radio,” “New Radio Access Technology” or “NR” by 3GPP) envisions the use of time/frequency/space resources to allow for enhanced mobile broadband (eMBB) communication and ultra-reliable low-latency communication (URLLC) services, as well as massive machine type communication (MMTC) like services. A new radio (NR) base station may be referred to as a gNB. A gNB may also be more generally referred to as a base station device. In 5G NR, different services can be supported with different quality of service (QoS) requirements (e.g., reliability and delay tolerance). For example, eMBB may be targeted for high data rate, and URLLC is for ultra-reliability and low latency. To provide ultra-reliability for URLLC traffic, the PUCCH for UCI feedback may be enhanced to the same reliability level as the data for URLLC. Due to the ultra-low latency requirements, the PUCCH format 0 (i.e., short PUCCH with up to 2 bits of UCI) is more suitable for URLLC data HARQ-ACK feedback. For HARQ-ACK feedback, different bit error rate (BER) requirements are applied for ACK to NACK error, and NACK to ACK error. Some differentiation methods may be introduced to provide better protection of NACK feedback than ACK feedback. Furthermore, the PUCCH carrying HARQ-ACK for a URLLC PDSCH may have higher priority than other channels. Thus, a PUCCH carrying HARQ-ACK for a URLLC PDSCH transmission may puncture any other UL channels if collision occurs. If the ACK is always reported, excessive dropping of other UL channels may happen since the URLLC data has very low error probability of 10−5. Therefore, methods to avoid unnecessary UL channel dropping while providing the desirable reliability may be beneficial. Various examples of the systems and methods disclosed herein are now described with reference to the Figures, where like reference numbers may indicate functionally similar elements. The systems and methods as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different implementations. Thus, the following more detailed description of several implementations, as represented in the Figures, is not intended to limit scope, as claimed, but is merely representative of the systems and methods. FIG.1is a block diagram illustrating one implementation of one or more base stations (gNBs)160and one or more user equipments (UEs)102in which channel collision handling with ultra-reliable low-latency communication (URLLC), and acknowledgment (ACK) feedback ON/OFF for HARQ-ACK of URLLC physical downlink shared channel (PDSCH) transmissions may be implemented. The one or more UEs102communicate with one or more gNBs160using one or more antennas122a-n. For example, a UE102transmits electromagnetic signals to the gNB160and receives electromagnetic signals from the gNB160using the one or more antennas122a-n. The gNB160communicates with the UE102using one or more antennas180a-n. The UE102and the gNB160may use one or more channels119,121to communicate with each other. For example, a UE102may transmit information or data to the gNB160using one or more uplink channels121. Examples of uplink channels121include a PUCCH (Physical Uplink Control Channel) and a PUSCH (Physical Uplink Shared Channel), PRACH (Physical Random Access Channel), etc. For example, uplink channels121(e.g., PUSCH) may be used for transmitting UL data (i.e., Transport Block(s), MAC PDU, and/or UL-SCH (Uplink-Shared Channel)). Here, UL data may include URLLC data. The URLLC data may be UL-SCH data. Here, URLLC-PUSCH (i.e., a different Physical Uplink Shared Channel from PUSCH) may be defined for transmitting the URLLC data. For the sake of simple description, the term “PUSCH” may mean any of (1) only PUSCH (e.g., regular PUSCH, non-URLLC-PUSCH, etc.), (2) PUSCH or URLLC-PUSCH, (3) PUSCH and URLLC-PUSCH, or (4) only URLLC-PUSCH (e.g., not regular PUSCH). Also, for example, uplink channels121may be used for transmitting Hybrid Automatic Repeat Request-ACK (HARQ-ACK), Channel State Information (CSI), and/or Scheduling Request (SR). The HARQ-ACK may include information indicating a positive acknowledgment (ACK) or a negative acknowledgment (NACK) for DL data (i.e., Transport Block(s), Medium Access Control Protocol Data Unit (MAC PDU), and/or DL-SCH (Downlink-Shared Channel)). The CSI may include information indicating a channel quality of downlink. The SR may be used for requesting UL-SCH (Uplink-Shared Channel) resources for new transmission and/or retransmission. Namely, the SR may be used for requesting UL resources for transmitting UL data. The one or more gNBs160may also transmit information or data to the one or more UEs102using one or more downlink channels119, for instance. Examples of downlink channels119include a PDCCH, a PDSCH, etc. Other kinds of channels may be used. The PDCCH may be used for transmitting Downlink Control Information (DCI). Each of the one or more UEs102may include one or more transceivers118, one or more demodulators114, one or more decoders108, one or more encoders150, one or more modulators154, a data buffer104and a UE operations module124. For example, one or more reception and/or transmission paths may be implemented in the UE102. For convenience, only a single transceiver118, decoder108, demodulator114, encoder150and modulator154are illustrated in the UE102, though multiple parallel elements (e.g., transceivers118, decoders108, demodulators114, encoders150and modulators154) may be implemented. The transceiver118may include one or more receivers120and one or more transmitters158. The one or more receivers120may receive signals from the gNB160using one or more antennas122a-n. For example, the receiver120may receive and downconvert signals to produce one or more received signals116. The one or more received signals116may be provided to a demodulator114. The one or more transmitters158may transmit signals to the gNB160using one or more antennas122a-n. For example, the one or more transmitters158may upconvert and transmit one or more modulated signals156. The demodulator114may demodulate the one or more received signals116to produce one or more demodulated signals112. The one or more demodulated signals112may be provided to the decoder108. The UE102may use the decoder108to decode signals. The decoder108may produce decoded signals110, which may include a UE-decoded signal106(also referred to as a first UE-decoded signal106). For example, the first UE-decoded signal106may comprise received payload data, which may be stored in a data buffer104. Another signal included in the decoded signals110(also referred to as a second UE-decoded signal110) may comprise overhead data and/or control data. For example, the second UE-decoded signal110may provide data that may be used by the UE operations module124to perform one or more operations. In general, the UE operations module124may enable the UE102to communicate with the one or more gNBs160. The UE operations module124may include a UE scheduling module126. The UE scheduling module126may perform collision handling with URLLC, and ACK feedback ON/OFF for HARQ-ACK of URLLC PDSCH transmissions. For URLLC PDSCH transmissions, the HARQ-ACK feedback of a URLLC downlink (DL) data may have the same reliability requirements as the URLLC data transmission itself. The current NR PUCCH design is targeted for an acknowledgment (ACK) miss-detection probability of 1% and negative-acknowledgment (NACK) to ACK error probability of 0.1%. Therefore, some enhancements may be specified to increase the PUCCH reliability for HARQ-ACK feedback of URLLC traffic. In NR, PUCCH format 0 is a short PUCCH with 1 or 2 symbols, and is designed for feedback of up to 2 UCI bits. To reduce the error probability of PUCCH format 0, several methods can be considered (e.g., configuring more than one physical resource block (PRB); time domain repetition; transmit diversity; different transmit power settings). These methods can be configured independently or jointly. A new PUCCH format may be defined to capture these enhancements. Due to low latency requirements, two or more PUCCH resources may need to be configured in a single slot. The current time domain allocation for short PUCCH by configuring a single starting symbol in a slot will not be sufficient. Therefore, the PUCCH resource sets for URLLC traffic may be configured independently and separately from eMBB PUCCH resource sets. The PUCCH resource for URLLC may be configured with different parameters and/or with some different fields from that of eMBB resources. For URLLC, a PDSCH transmission with a single codeword or TB is the most common case because only one codeword is supported for MIMO transmission with up to 4 layers. The error probability of a PUCCH carrying HARQ-ACK of a URLLC PDSCH should be targeted to at least the same error probability as the URLLC data (e.g., 10−5), or an order of magnitude lower (e.g., 10−6). Furthermore, the NACK to ACK error probability should be even lower than the ACK to NACK error probability. Thus, the NACK to ACK error probability may be 10−6, or even lower at 10−7. To provide enough protection to NACK feedback, in one method, the PUCCH for both ACK and NACK feedback should be enhanced to achieve the lower error probability defined by NACK (e.g. 10−6or 10−7). But this may result in excessive resource allocation for PUCCH. In another method, if different BER requirements are applied between ACK to NACK error and NACK to ACK error, some differentiation method may be introduced to provide better protection of NACK feedback than ACK feedback. For example, differentiation methods may include different PUCCH resources for ACK and NACK feedback, more PRB or time domain repetition for NACK feedback than ACK feedback, and/or higher transmit power for NACK feedback than ACK feedback. Furthermore, the PUCCH carrying HARQ-ACK for a URLLC PDSCH may have higher priority than other channels. Thus, a PUCCH carrying HARQ-ACK for a URLLC PDSCH transmission may puncture any other UL channels if collision occurs. If the FACK is always reported, excessive dropping of other UL channels may happen since the URLLC data has very low error probability of 10−5. To avoid excessive dropping of other channels, the ACK feedback can be turned on/off. If the ACK feedback is turned off, only NACK is reported for URLLC DL data. Aspects of PUCCH formats in NR are described herein. PUCCH may be used to report important uplink control information (UCI), which includes HARQ-ACK, SR, channel state information (CSI), etc. While NR release-15 is designed mainly for enhanced mobile broadband (eMBB), several physical uplink control channel (PUCCH) formats are specified for different number of bits, as given below.The physical uplink control channel supports multiple formats as shown in Table 1. In case frequency hopping is configured for PUCCH format 1, 3, or 4, the number of symbols in the first hop is given by ⌊NsymbPUCCH/2⌋ where NsymbPUCCHis the length of the PUCCH transmission in OFDM symbols. TABLE 1Length in OFDM symbolsNumberPUCCH formatNsymbPUCCHof bits01-2≤214-14≤221-2>234-14>244-14>2 In 5G NR, different services can be supported with different quality of service (QoS) requirements (e.g., reliability and delay tolerance). For example, eMBB may be targeted for high data rate, and URLLC is for ultra-reliability and low latency. The URLLC traffic may use the same numerology as eMBB service. The URLLC downlink transmission may also use a different SCS than eMBB DL transmission. For example, the URLLC traffic may use a higher numerology than eMBB service (i.e., the subcarrier spacing (SCS) of a URLLC transmission may be larger than that of an eMBB transmission). A larger SCS configuration for URLLC reduces the length of an OFDM symbol, and thus the latency of a transmission and its HARQ-ACK feedback. In some approaches, the URLLC DL transmission and UL transmission may be configured with the same numerology. In other approaches, the URLLC DL transmission and UL transmission may be configured with the different numerologies. For HARQ-ACK feedback for of DL URLLC transmission, a URLLC short PUCCH may use a different numerology than other short PUCCH. For example, the URLLC PUCCH may have shorter symbol lengths than other short PUCCH or PUSCH transmissions. In this disclosure, URLLC DL data transmission and the corresponding HARQ-ACK feedback on PUCCH is described. To provide ultra-reliability for URLLC traffic, a different CQI and MCS table maybe configured for URLLC with 10−5error probability. At the same time, the PUCCH for HARQ-ACK feedback of URLLC data may be enhanced at least to the same reliability level as the data for URLLC. For URLLC traffic, several aspects may be considered for PUCCH design and PUCCH transmissions. URLLC traffic requires ultra-reliability and low latency. The HARQ-ACK for URLLC packet may be supported to provide the required reliability. Furthermore, the HARQ-ACK feedback may be reported immediately after a URLLC transmission. Moreover, the HARQ-ACK feedback may have the same reliability as the URLLC data transmission (i.e., the current PUCCH channel BER requirements of 1% or 0.1% may not satisfy the URLLC requirements). The HARQ-ACK BER requirement may be the same or better than the URLLC data channel (i.e., at least 10−5or 10−6). The URLLC traffic may share the HARQ-ACK processes with eMBB. However, the number of HARQ-ACK processes for URLLC can be limited (e.g., only 1 or 2 HARQ-ACK processes for URLLC traffic). Thus, the PUCCH format for URLLC DL transmission may also provide ultra-reliability and low latency after a URLLC DL transmission. Only short PUCCH may be used for URLLC HARQ-ACK feedback. The position of short PUCCH can be determined dynamically based on URLLC DL data transmission (e.g., immediately after a URLLC DL transmission with a gap satisfying the processing time requirements). Due to the ultra-low latency requirements, the PUCCH format 0 (i.e., the short PUCCH with up to 2 bits of UCI) is more suitable for URLLC data HARQ-ACK feedback. The NR PUCCH format 0 occupies a single physical resource block (PRB) and uses sequences to indicate up to 2 bits of payload. To reduce the error probability of PUCCH format 0, several methods may be considered (e.g., configuring more than one PRBs, time domain repetition, transmit diversity, different transmit power settings). These methods may be configured independently or jointly. A new PUCCH format may be defined to capture these enhancements. The new PUCCH format may be named as PUCCH format 5, PUCCH format 0_1, advanced PUCCH format 0 (PUCCH format 0a), enhanced PUCCH format 0 (PUCCH Format 0e), ultra-reliable PUCCH format 0 (PUCCH format 0_r, or format 0_u), etc. URLLC PUCCH resource allocation and configuration is described herein. In NR, multiple PUCCH resource sets may be configured for different payload sizes. In each PUCCH resource set, up to 16 PUCCH resources can be configured. If the number of resources is more than 4, subsets are formed. In NR, for a PUCCH reporting, the PUCCH resource set may first be determined based on the UCI payload size. The ARI field may indicate the PUCCH resource subset in a PUCCH resource set. If there are more than 1 PUCCH resources in each subset, the PUCCH resource for UCI reporting may be determined implicitly based on CCE index of the scheduling DCI. For URLLC, the short PUCCH may be useful because of the low latency requirements. At least one PUCCH resource set for up to 2 bits of UCI may be configured. Since URLLC has different reliability and delay requirements from eMBB. The HARQ-ACK feedback PUCCH resources for URLLC may be configured separately from eMBB. The PUCCH resources for URLLC may be configured with different parameters than normal PUCCH resources for eMBB. To provide desired reliability for DL URLLC transmission, PUCCH resources may be allocated to allow PDSCH retransmissions. Due to high reliability and low latency requirements, to support re-transmission of URLLC PDSCH, one or more HARQ-ACK feedback may be reported within a subframe, and more than 2 PUCCH resources may be configured in a subframe or a slot, as shown inFIG.2. The current time domain allocation for a short PUCCH by configuring a starting symbol and a duration may not be sufficient. Some enhancements for time domain PUCCH resource allocation and configuration for enhanced short PUCCH may be implemented (e.g., a PUCCH resource subset includes multiple PUCCH resources with different starting symbols in a slot; a single PUCCH resource may be configured with multiple starting symbol positions in a slot; a PUCCH resource may be configured with a PUCCH format and a periodicity, etc.). URLLC ACK and NACK feedback differentiation is described herein. The BER requirement of HARQ-ACK feedback on PUCCH for a URLLC PDSCH transmission should be the same as or better than the URLLC data channel (e.g., at least 10−5or 10−6). Moreover, the NACK to ACK error probability should be much lower than the ACK to NACK error probability. If an ACK is detected as a NACK, the PDSCH will be re-transmitted and cause unnecessary waste of resource. On the other hand, if a NACK is detected as an ACK, the gNB160may assume it is correctly received, and the packet data will be dropped. This may cause much more overhead of re-transmission. If a segment is dropped by mistake, all segments may have to be re-transmitted by higher layer packet dropping and re-transmission. Thus, if the ACK to NACK error probability is 10−5, the NACK to ACK error probability should be 10−6; if the ACK to NACK error probability is 10−6, the NACK to ACK error probability should be 10−7. To provide enough protection to NACK feedback, in one method, the PUCCH for both ACK and NACK feedback should be enhanced to achieve the lower error probability required for NACK (e.g., 10−6or 10−7). But this may result in excessive resource allocation for PUCCH. In another method, if different BER requirements are applied between ACK to NACK error and NACK to ACK error, some differentiation methods may be introduced to provide better protection on NACK feedback than ACK feedback. Several methods are described herein.FIG.3illustrates two ACK and NACK feedback differentiation methods described herein. In a first method (Method 1), a PUCCH resource may be configured to report HARQ-ACK (either ACK or NACK) for URLLC PDSCH transmission, but different actual transmission modes and configurations may be used for reporting of ACK and NACK. A PUCCH resource for URLLC may be configured with multiple PRBs, time domain repetition, transmit diversity and/or enhanced power control. The PUCCH resource may be configured based on the higher reliability requirement between ACK and NACK (e.g., based on NACK feedback BER requirements). If the feedback is a NACK, the configured parameters may be used. If the feedback is an ACK, different PUCCH parameters may be used to reduce the PUCCH resource overhead. Namely, based on a detection of the PDSCH transmission, if the UE102feedbacks HARQ-ACK (either ACK or NACK), the UE102may use the PUCCH resource based on the configured parameters to feedback the HARQ-ACK. And, if the HARQ-ACK is corresponding to NACK, the UE102may use a whole of the PUCCH resource configured by the parameters. Also, if the HARQ-ACK is corresponding to ACK, the UE102may use a part of the PUCCH resource configured by the parameters. In an example, if multiple PRBs are configured, the NACK should be reported using all configured PRBs, and ACK may be reported with fewer PRBs. In another example, if time domain repetition is configured, the NACK may be reported using the configured number of time domain repetitions (e.g., the number of slot(s) and/or symbol(s)), and the ACK may be reported with fewer numbers of time domain repetitions. As a special case, if a two-symbol PUCCH is configured, the NACK should be reported using two-symbol PUCCH and the ACK may be reported with a one-symbol PUCCH by using only the first symbol of the two-symbol PUCCH resource. In another example, if TxD is configured, NACK should be transmitted with two antenna ports using two PUCCH resources, ACK may be reported with a single antenna port on a single PUCCH resource. In yet another example, different transmit power may be applied for the PUCCH transmission for ACK and NACK. The transmit power for a NACK feedback should be higher than the transmission of an ACK feedback. The difference between the transmit power or the delta value may be pre-defined or RRC configured to a UE102. It should be noted that the different parameters may be configured independently or jointly for the PUCCH resources of ACK and NACK feedback. For example, the gNB160may transmit, by using a higher layer signal(s) (e.g., an RRC message), the parameter(s) used for configuring the PUCCH resource(s) of ACK and NACK. Also, the gNB160may transmit, by using DCI included in the DCI format(s) used for scheduling of the PDSCH transmission, the parameter(s) used for indicating the PUCCH resource(s) of ACK and NACK. Also, the PDCCH scheduling the PDSCH transmission (e.g., a control channel element(s) of the PDCCH) may be used for indicating the PUCCH resource(s) of ACK and NACK. Here, as described above, the gNB160may configure the parameter(s) only for the short PUCCH format(s) (e.g., the PUCCH format 0 and/or the PUCCH format 1). Here, as described above, the parameter(s) may include, at least, a parameter(s) used for configuring a starting PRB index(es) and/or the number of PRB(s) (i.e., a frequency domain configuration). Also, the parameter(s) may include, at least, a parameter(s) used for configuring the number of repetition(s) (i.e., a time domain configuration). Also, the parameter(s) may include, at least, a parameter(s) used for configuring the number of antenna port(s) (i.e., a spatial domain configuration, whether two antenna ports are used or not). Also, the parameter(s) may include, at least, a parameter(s) used for configuring transmit power. Also, as described below, the parameter(s) may include, at least, a parameter(s) used for configuring a value of cyclic shift. As described above, the UE102may use the PUCCH resource (i.e., one PUCCH resource(s)) based on the parameter(s) to transmit HARQ-ACK (either ACK or NACK). And, the UE102may determine, based on whether the HARQ-ACK is corresponding to ACK or NACK, the amount of resources (e.g., the number of resource elements (RE(s)) in frequency and/or time domain) used for HARQ-ACK feedback. For example, for ACK feedback, the UE102may use less amounts of resources than that of resources used for NACK feedback. Here, how to determine the amount of resources (e.g., the amount of resources for ACK feedback) may be determined, in advance, by the specification, etc., (e.g., by using an equation). Also, the gNB160may configure, by using the higher layer signal(s), a parameter(s) (e.g., an offset value(s)) used for configuring the amount of resources (e.g., the amount of resource for ACK feedback). The UE102may determine, based on the parameter(s) (e.g., the offset value(s)), the amount of resources used for HARQ-ACK feedback (e.g., the amount of resources for ACK feedback) on the PUCCH resource. In a second method (Method 2), separate PUCCH resources may be configured for ACK feedback and NACK feedback. For example, the gNB160may configure PUCCH resources only used for ACK feedback, and may configure PUCCH resources only used for NACK feedback. And, based on a detection of PDSCH transmission, if HARQ-ACK is corresponding to ACK, the UE102may use the PUCCH resource only used for ACK feedback. Also, based on a detection of PDSCH transmission, if HARQ-ACK is corresponding to NACK, the UE102may use the PUCCH resource only used for NACK feedback. In this method, different PUCCH resources and different parameters are configured for ACK feedback and NACK feedback. The PUCCH resource for a NACK feedback may be configured with parameters that provide better BER performance than that of the PUCCH resource for an ACK feedback. In an example, the PUCCH resources for ACK and NACK feedback may have different starting PRB indexes and a different number of PRBs. The number of PRBs (e.g., supported number of PRBs) configured for NACK feedback may be higher than that of ACK feedback. In another example, the PUCCH resources for ACK and NACK feedback may have a different number of symbols (e.g., supported number of symbols) or number of time domain repetitions (e.g., supported number of time domain repetitions). For example, 1 symbol PUCCH for ACK feedback and 2-symbol PUCCH for NACK feedback. In another example, the PUCCH for NACK feedback may be configured with TxD, and the PUCCH for ACK may not be configured with TxD. Namely, only for NACK feedback, two antenna ports transmission may be supported. For example, if the UE102is configured with two antenna ports transmission for PUCCH format 0, for HARQ-ACK transmission using PUCCH format 0, the UE102may use two antenna ports (with two PUCCH resources) only for NACK feedback, and use single antenna port (with single PUCCH resource) for ACK feedback. In yet another example, the transmit power for a NACK feedback may be configured with a higher value than that of a PUCCH for ACK feedback. The difference between the transmit power or the delta value may be pre-defined or RRC configured to a UE102. It should be noted that the different parameters may be configured independently or jointly for PUCCH resources of ACK and NACK feedback. Here, as with the method 1, the gNB160may configure the different parameters for PUCCH resources. Also, the different parameter(s) may include, at least, the parameter(s) described in the method 1. In this second method, besides the PUCCH transmission and detection, another level of ACK/NACK feedback may be provided by on/off keying of different PUCCH resources. NACK may be reported only on a configured NACK resource (e.g., the PUCCH resource only used for NACK feedback) and ACK may be reported only on a configured ACK resource (e.g., the PUCCH resource only used for ACK feedback). With PUCCH Format 0, a resource is defined by a sequence and a cyclic shift in each configured RB. Thus, if one PUCCH resource is configured for a single bit of ACK or NACK feedback (e.g., similar with the method 1), two cyclic shifts with distance of 6 are reserved, and the resource is configured based on the lowest BER requirements between ACK and NACK. If two different PUCCH resources are configured for ACK and NACK feedback (e.g., similar with the method 2), each PUCCH resource only reserves one cyclic shift of the sequence. Thus, the PUCCH resource overhead is not increased. In fact, since a PUCCH resource for an ACK feedback has less redundancy or overhead than a PUCCH resource for a NACK feedback, the overall resource overhead for separate PUCCH resources for ACK and NACK feedback in method 2 is lower than that of a single PUCCH resource for both ACK and NACK feedback in method 1. Moreover, due to ultra-low error probability, the ACK feedback may be turned off, as described in detail below. In this case, the UE102may be configured with only PUCCH resources for NACK feedback. URLLC PUCCH transmission and collision handling with other UL channels is also described herein. URLLC traffic requires ultra-reliability and low latency. An URLLC UL data transmission may collide with a PUCCH or a PUSCH transmission of the same UE102(e.g., on the same symbol). An example of a collision of URLLC PUCCH for HARQ-ACK with other UL channels is illustrated inFIG.4. As a general rule, the URLLC traffic should have higher priority than any other UL transmissions. Furthermore, the HARQ-ACK feedback of a DL URLLC PDSCH transmission should have higher priority than an UL URLLC data. Thus, the PUCCH feedback for a URLLC PDSCH transmission should have the highest priority among all channels or UL transmissions. In NR release-15, simultaneous UL channel transmission on the same BWP or CC is not supported. In case of full overlapping or partial overlapping between PUCCHs and/or PUSCHs, some UCI multiplexing rules may be defined with some processing time restrictions. At least for PUCCH carrying HARQ-ACK feedback of URLLC PDSCH transmission, UCI multiplexing with other PUCCH for normal PDSCH transmission is difficult for several reasons. Multiplex HARQ-ACK of URLLC traffic on a normal PUCCH cannot satisfy the ultra-low BER requirement. And, there are not enough resources for the PUCCH to increase the reliability to the desired level. Multiplex on a HARQ-ACK PUCCH for URLLC will increase the payload, and reduces the BER performance of HARQ-ACK feedback for URLLC traffic. The starting position and duration of the normal PUCCH may be very different from a PUCCH for URLLC feedback. Additionally, the normal PUCCH and URLLC PUCCH may not be aligned. At least for PUCCH carrying HARQ-ACK feedback of URLLC PDSCH transmission, HARQ-ACK multiplexing on a normal PUSCH transmission may also be difficult. The RE mapping for URLLC HARQ-ACK should be different from normal HARQ-ACK. A much higher beta offset value may be used. The UE102may not have enough processing time to handle the PUSCH data puncturing or rate matching. The HARQ-ACK of a URLLC may come at any symbol, if the HARQ-ACK is multiplexed after a DMRS symbol, the timing requirement may be violated for URLLC traffic. Therefore, the PUCCH carrying HARQ-ACK for URLLC PDSCH may always be transmitted, and the other UL channels may be de-prioritized or dropped. In a first method (Method 1), PUCCH carrying HARQ-ACK of URLLC PDSCH may be transmitted and any other UL channel(s) in the overlapping symbol is dropped. An example where URLLC PUCCH for HARQ-ACK punctures all other channels in the overlapping symbols is illustrated inFIG.5. This is a simple solution and can be applicable in all cases regardless of the type of overlapping channels. In case the URLLC traffic is configured with a higher SCS than the eMBB traffic, the whole symbol in the overlapping channel should be dropped even if the PUCCH for URLLC occupies part of the symbol duration of the overlapping channel. For example, a first SCS may be configured for a first PDCCH and/or a first PDSCH. The first PDCCH may be used for scheduling of the PDSCH. Also, a second SCS may be configured for a second PDCCH and/or a second PDSCH. The second PDCCH may be used for scheduling of the second PDSCH. Here, the first SCS and the second SCS may be configured for the same BWP (e.g., the same DL BWP) and/or the same timing (e.g., the same slot(s) and/or symbol(s)). In a case that the first SCS (e.g., 60 kHz SCS) is configured with a higher SCS than the second SCS (e.g., 15 kHz), if the UE102detects the first PDCCH and/or the first PDSCH, the UE102may perform on the PUCCH, HARQ-ACK transmission corresponding to the first PDSCH (e.g., even if the PUCCH symbol(s) for the first PDSCH and the PUCCH symbols(s) for the second PDSCH are overlapped). In this case, the UE102may drop HARQ-ACK transmission for the second PDSCH (e.g., drop the whole symbol of the PUCCH for HARQ-ACK transmission for the second PDSCH). In a second method (Method 2), simultaneous transmission of PUCCH carrying HARQ-ACK for URLLC PDSCH and other PUCCH or PUSCH transmission may occur, with power scaling on other channels in a power limited case. An example of simultaneous URLLC PUCCH for HARQ-ACK and other UL channels is illustrated inFIG.6. To support URLLC traffic without dropping too many UL channels, simultaneous UL channel transmission may be supported in Release-16 and later. If supported, the PUCCH for URLLC traffic may be transmitted simultaneously with another PUCCH or PUSCH channel. If simultaneous transmission of PUCCH for URLLC and another UL channel (PUCCH or PUSCH) is supported on the same symbol, and if there are overlapping REs between the PUCCH for URLLC PDSCH feedback and the other UL channel, the overlapping REs of the other UL channel is punctured by the PUCCH for URLLC PDSCH feedback. Furthermore, UL transmit power should be allocated to the PUCCH for URLLC traffic first. The remaining power can be allocated to the remaining REs of the other UL channel in the same UL symbol. In a power limited case, power scaling should be performed on the remaining REs of the other UL channel in the same UL symbol to satisfy the Pcmax limit on the given BWP or serving cell. Simultaneous UL channel transmission may be limited to URLLC transmissions (e.g., simultaneous UL transmission may be supported only if one of the UL channel is for URLLC or sub-slot transmission). In this case, the simultaneous UL channel transmission support may be defined as a UE feature under URLLC, and may be configured to a UE102from a gNB160by RRC signaling. If configured, the following simultaneous transmission may be supported: A PUCCH for HARQ-ACK of URLLC PDSCH can be transmitted simultaneously with other UL channels; a URLLC PUSCH (e.g., a sub-slot PUSCH with new MCS table of 10−5target BLER) can be simultaneously transmitted with other UL channels; and/or a PUCCH for HARQ-ACK of URLLC PDSCH may be simultaneously transmitted with a URLLC PUSCH transmission by either grant-based or grant-free scheduling. Simultaneous UL channel transmission may be extended to all traffic types (e.g., both PUCCH and PUSCH are for eMBB transmissions). In this case, the simultaneous UL channel transmission support may be defined as a separate UE feature, and may be configured to a UE102from a gNB160by RRC signaling. To simplify the process, simultaneous UL transmission may be limited to 2 UL channels. An order of priority may be defined for UL channels from the highest priority to lowest priority (e.g., PUCCH for HARQ-ACK of URLLC PDSCH transmission>PUCCH for SR of URLLC>PUSCH for URLLC>PUCCH for URLLC CSI reporting>PUCCH for HARQ-ACK feedback of eMBB PDSCH>PUCCH for SR of eMBB>PUCCH for CSI feedback of eMBB PDSCH>PUSCH for eMBB). URLLC PUCCH ON/OFF for ACK feedback is also described herein. Due to ultra-reliability of URLLC data transmission, the probability than a NACK is reported is very low at 10−5. In another words, 99.999% of HARQ-ACK feedback for URLLC PDSCH will be ACK. If the PUCCH for HARQ-ACK feedback is always reported for a URLLC PDSCH transmission, 99.999% of time ACK is reported. Whenever there is a collision between the PUCCH for URLLC traffic and another UL channel, the other UL channel is dropped if method 1 (e.g., URLLC PUCCH punctures any other UL channel) above is applied; or the performance is degraded if method 2 (e.g., simultaneous transmission of PUCCH for URLLC and other channel) above is applied. To avoid excessive dropping of other UL channels, the ACK feedback can be turned on or off. If the ACK feedback is turned off, only NACK is reported on the PUCCH (e.g., the PUCCH for URLLC DL data). This significantly reduces the number of PUCCH transmissions because the NACK probability is only 10−5. Therefore, the other UL channel transmissions are not impacted in most cases. There is one potential issue for the DL miss-detection. For normal PDSCH transmission, the PDCCH miss-detection probability is 1%, the block error rate (BLER) target for a PDSCH decoding is 10%, and the HARQ-ACK feedback error probability is 1% to 0.1%. In a normal HARQ-ACK procedure, for a single PDSCH transmission, if a UE102does not detect a scheduling DCI correctly for the given PDSCH transmission, no HARQ-ACK is reported and no PUCCH is transmitted. The gNB160treats the missing of a corresponding PUCCH feedback as a DTX, and the gNB160then re-transmits the PDSCH. If the ACK feedback is turned off (e.g., for URLLC PDSCH transmission), the gNB160cannot differentiate a DTX from an ACK. In case of a DTX occurs, the gNB160may think the PDSCH is correctly received because no NACK is reported. However, if the PDCCH miss-detection probability is lower than the data error probability, the PDCCH miss-detection error is acceptable because it already satisfies the data performance criteria. For example, if the expected URLLC data error probability is 10−5, and the PDCCH error probability is 10−5or 10−6, the DTX error is acceptable even if the ACK feedback is turned off. It should be noted that the error probability for a PDSCH already considers necessary PDSCH re-transmissions, and the initial PDSCH transmission probability may be much higher than the expected URLLC data error probability. For example, the initial PDSCH transmission error probability may be 10−3, after a retransmission, the PDSCH error probability may be reduced to 10−5or 10−6. In conclusion, if the PDCCH for URLLC scheduling is enhanced to have the same or much lower error probability than the target URLLC data error probability, the ACK feedback (e.g., for URLLC PDSCH transmission) may be turned off to avoid excessive dropping of other UL channels. The ACK feedback on/off can be regarded as a special handling of ACK and NACK differentiation. In this extreme case, the ACK does not need to be reported, and only NACK is reported. If the ACK feedback is turned off, the UE102can be configured with PUCCH resource for only NACK reporting (e.g., for sequence base format 0 feedback) and only one cyclic shift of a sequence needs to be reserved for the HARQ-ACK feedback. No PUCCH reporting will be treated as an ACK, and the detection of the PUCCH transmission is a NACK. Basically, the NACK feedback is confirmed with ON/OFF keying of PUCCH transmission. The combination of on/off keying and NACK detection on PUCCH will provide higher reliability for the HARQ-ACK feedback. Several methods are described for signaling of ACK feedback on/off. In one method, the on/off of ACK feedback (e.g., for URLLC DL transmission) may be configured by higher layer signaling. If the ACK feedback (e.g., for URLLC DL transmission) is turned off, the PUCCH resources for HARQ-ACK feedback are configured for only NACK feedback. Namely, the gNB160may transmit, by using the higher layer signal(s), a parameter(s) used for indicating whether ACK feedback is performed or not (i.e., ACK feedback is turned on or off). For example, the gNB160may configure, per PUCCH format, the parameter(s) used for indicating whether ACK feedback is performed or not. Also, the gNB160may configure, per BWP (e.g., UL BWP), the parameter(s) used for indicating whether ACK feedback is performed or not. Also, the gNB160may configure, per serving cell, the parameter(s) used for indicating whether ACK feedback is performed or not. Also, the gNB160may configure, per PUCCH sell group (e.g., a primary PUCCH group and a secondary PUCCH group), the parameter(s) used for indicating whether ACK feedback is performed or not. And, the UE102may determine, based on the parameter(s), whether ACK feedback is performed or not. For example, in a case that ACK feedback is configured with “turned on” by the higher layer signal(s), for eMBB PDSCH transmission (i.e., PDSCH transmission), the UE102may perform HARQ-ACK (i.e., either ACK or NACK) feedback. The gNB160may configure first PUCCH resources used for HARQ-ACK (i.e., either ACK or NACK) feedback. In a case that ACK feedback is configured with “turned on” by the higher layer signal(s), for URLLC PDSCH transmission (i.e., PDSCH transmission), the UE102may perform HARQ-ACK (i.e., either ACK or NACK) feedback. The gNB160may configure first PUCCH resources used for HARQ-ACK (i.e., either ACK or NACK) feedback. In a case that ACK feedback is configured with “turned off” by the higher layer signal(s), for eMBB PDSCH transmission, the UE102may perform HARQ-ACK (i.e., either ACK or NACK) feedback. The gNB160may configure first PUCCH resources used for HARQ-ACK (i.e., either ACK or NACK) feedback. In a case that ACK feedback is configured with “turned off” by the higher layer signal(s), for URLLC PDSCH transmission, the UE102may perform only NACK feedback. The gNB160may configure second PUCCH resources used only for NACK feedback. Namely, the UE102may apply for the on/off of ACK feedback only for URLLC PDSCH transmission. Alternatively, in a case that ACK feedback is configured with “turned off” by the higher layer signal(s), for eMBB and URLLC PDSCH transmission (i.e., PDSCH transmission), the UE102may perform only NACK feedback. The gNB160may configure second PUCCH resources used only for NACK feedback. Namely, the UE102may apply for the on/off of ACK feedback or eMBB and URLLC PDSCH transmission. Here, the first PUCCH resources may correspond to the PUCCH resource described in the method 1 and/or 2. In another method, the on/off of ACK feedback for URLLC DL transmission may be signaled in a DCI format. Namely, information used for indicating whether ACK feedback is perform or not (i.e., ACK feedback is turned on or off) may be included in the DCI format (e.g., the DCI format used for scheduling of the PDSCH (i.e., the PDSCH transmission)). For example, in a case that “turned on” of ACK feedback is indicated by DCI (e.g., the DCI format), the UE102may perform HARQ-ACK (i.e., either ACK or NACK) feedback. The gNB160may configure first PUCCH resources used for HARQ-ACK (i.e., either ACK or NACK) feedback. In a case that “turned off” of ACK feedback is indicated by DCI (e.g., the DCI format), the UE102may perform only NACK feedback. The gNB160may configure second PUCCH resources used only for NACK feedback. In one case, the URLLC PDSCH HARQ-ACK feedback timing may be indicated in DCI by the PDSCH-to-HARQ-timing indicator field. If ACK on/off is supported, the entries for the PDSCH-to-HARQ-timing indicator field maybe divided into 2 groups, one group indicates the timing with ACK feedback ON, another group indicates timing with ACK feedback OFF. Therefore, only 4 different timings can be indicated by the 8 entries of the PDSCH-to-HARQ-timing indicator field. In a similar approach, the current 3-bit PDSCH-to-HARQ-timing indicator field may be divided into two parts. Two bits are used to indicate the HARQ-ACK timing by an index of a RRC configured timing table with 4 entries only. The other bit is used to explicitly indicate whether ACK should be reported or not. If the bit is “0”, no ACK is reported and only NACK is reported; if the bit is “1”, both ACK and NACK should be reported. In yet another approach, a new field with length of one bit may be added to the DCI to explicit indicate whether ACK should be reported or not. If the bit is “0”, no ACK is reported and only NACK is reported; if the bit is “1”, both ACK and NACK should be reported. In another case, the URLLC PDSCH HARQ-ACK feedback timing may be determined based on a pre-defined or configured processing time table, and the PDSCH-to-HARQ-timing-indicator field may be ignored or removed from the PDSCH scheduling DCI format for URLLC data. In this case, a new field with length of one bit may be added to the DCI to explicit indicate whether ACK should be reported or not. If the bit is “0”, no ACK is reported and only NACK is reported; if the bit is “1”, both ACK and NACK should be reported. In yet another method, different DCI formats may be used to implicitly determine whether ACK feedback should be reported or not (i.e., turned on or off). For example, a compact DCI without HARQ-ACK timing information implies ACK feedback is turned OFF. Note in this case, a default HARQ-ACK timing is applied for a NACK feedback of the scheduled URLLC PDSCH transmission. A regular DCI or a long DCI with timing indication implies feedback for both ACK and NACK is required. For example, in a case that the regular DCI or the long DCI (e.g., a first DCI format) used for scheduling of the PDSCH is detected, the UE102may perform HARQ-ACK (i.e., either ACK or NACK) feedback. The gNB160may configure first PUCCH resources used for HARQ-ACK (i.e., either ACK or NACK) feedback. In a case that the compact DCI (e.g., a second DCI format) used for scheduling of the PDSCH is detected, the UE102may perform only NACK feedback. The gNB160may configure second PUCCH resources used only for NACK feedback. In another method, the ACK feedback ON/OFF may be determined based on the MCS setting of a PDSCH transmission. For PDSCH and PUSCH with CP-OFDM, a new MCS table is introduced for URLLC, as given in Table 2 below. The new MCS table has a BLER target of 10−5. The normal MCS table has a BLER target of 10%. TABLE 2MCS IndexModulationCode rateSpectralIMCSOrder QmR × 1024efficiency02300.058612400.078122500.097732640.125042780.152352990.1934621200.2344721570.3066821930.3770922510.49021023080.60161123790.74021224490.87701325261.02731426021.17581543401.32811643781.47661744341.69531844901.91411945532.16022046162.40632164382.56642264662.73052365173.02932465673.32232566163.60942666663.90232767194.21292867724.5234292Reserved304316 For a PDSCH scheduling, the MCS information field in DCI is 5-bit. If the DCI CRC is scrambled with the new RNTI, the new MCS table is used with a target BLER of 10−5, the ACK feedback may be turned off; otherwise, the legacy MCS tables are used with a target BLER of 10%, and the ACK feedback is ON. For DL SPS, RRC indicates if the new 64QAM table is configured. The indication for the new MCS table for DL SPS is separate from the one for grant-based DL scheduling. Therefore, if the new MCS table is configured for a DL SPS transmission, the ACK feedback may be turned off; otherwise, the ACK feedback is on. Namely, for example, in a case that the PDSCH transmission is corresponding to old MCS table (e.g., a first MCS table), the UE102may perform HARQ-ACK (i.e., either ACK or NACK) feedback. The gNB160may configure first PUCCH resources used for HARQ-ACK (i.e., either ACK or NACK) feedback. In a case that the PDSCH transmission is corresponding to new MCS table (e.g., a second MCS table), the UE102may perform only NACK feedback. The gNB160may configure second PUCCH resources used only for NACK feedback. Also, for example, in a case that the PDSCH transmission is indicated by the DCI format with CRC scrambled by old RNTI (e.g., C-RNTI), the UE102may perform HARQ-ACK (i.e., either ACK or NACK) feedback. The gNB160may configure first PUCCH resources used for HARQ-ACK (i.e., either ACK or NACK) feedback. In a case that the PDSCH transmission is indicated by the DCI format with CRC scrambled by new RNTI (e.g., a first RNTI different from the C-RNTI), the UE102may perform only NACK feedback. The gNB160may configure second PUCCH resources used only for NACK feedback. Here, the new RNTI (i.e., the DCI format with CRC scrambled by the new RNTI) may be used for identifying the new MCS table. Namely, the UE102may determine the MCS table (e.g., select one MCS table from more than one MCS table) based on the detected RNTI (e.g., the C-RNTI or the new RNTI). Also, the MCS table (i.e., the first MCS table and the second MCS table) may be used to determine the target MCS and/or code rate. As described above, even in the case that ACK feedback is configured with “turned off”, for eMBB PDSCH transmission, the UE102may perform HARQ-ACK (either ACK or NACK) feedback. Namely, the UE102may apply for the on/off of ACK feedback only for URLLC PDSCH transmission. The following descriptions are examples for the UE behavior in the case that ACK feedback is configured with “turned off”. For example, the eMBB PDSCH transmission and the URLLC PDSCH transmission may be identified by information included in the DCI format (e.g., the DCI format used for scheduling of the PDSCH). For example, similar with the description above, the eMBB PDSCH transmission and the URLLC PDSCH transmission may be identified by a value(s) set to the PDSCH-to-HARQ-timing indicator field (or 1-bit information). Also, the eMBB PDSCH transmission and the URLLC PDSCH transmission may be identified by the DCI formats (e.g., the long DCI, the compact DCI). For example, the UE102may identify eMBB PDSCH transmission based on a detection of the long DCI format (i.e., the first DCI format). For example, based on the detection of the long DCI format, the UE102may perform HARQ-ACK (either ACK or NACK) feedback for eMBB PDSCH transmission. Also, the UE102may identify URLLC PDSCH transmission based on a detection of the compact DCI format (i.e., the second DCI format). For example, based on the detection of the compact DCI format, the UE102may perform only NACK feedback for a URLLC PDSCH transmission. Also, the eMBB PDSCH transmission and the URLLC PDSCH transmission may be identified by the MCS table. For example, the UE102may identify eMBB PDSCH transmission based on the MCS table corresponding to the PDSCH transmission. For example, in a case that the PDSCH transmission is corresponding to the old MCS table (i.e., the first MCS table), the UE102may perform HARQ-ACK (either ACK or NACK) feedback for eMBB PDSCH transmission. Also, the UE102may identify URLLC PDSCH transmission based on the MCS table corresponding to the PDSCH transmission. For example, in a case that the PDSCH transmission is corresponding to the new MCS table (i.e., the second MCS table), the UE102may perform only NACK feedback for URLLC PDSCH transmission. Also, the eMBB PDSCH transmission and the URLLC PDSCH transmission may be identified by RNTI used for scrambling of CRC to be attached to the DCI format. For example, the UE102may identify eMBB PDSCH transmission based on a detection of the DCI format with CRC scrambled by the old RNTI (e.g., the C-RNTI). For example, in a case that the PDSCH transmission is indicated by the DCI format with CRC scrambled by the old RNTI (e.g., the C-RNTI), the UE102may perform HARQ-ACK (either ACK or NACK) feedback for eMBB PDSCH transmission. Also, the UE102may identify URLLC PDSCH transmission based on a detection of the DCI format with CRC scrambled by the new RNTI (e.g., the first RNTI). For example, in a case that the PDSCH transmission is indicated by the DCI format with CRC scrambled by the new RNTI (e.g., the first RNTI), the UE102may perform only NACK feedback for URLLC PDSCH transmission. The UE operations module124may provide information148to the one or more receivers120. For example, the UE operations module124may inform the receiver(s)120when to receive retransmissions. The UE operations module124may provide information138to the demodulator114. For example, the UE operations module124may inform the demodulator114of a modulation pattern anticipated for transmissions from the gNB160. The UE operations module124may provide information136to the decoder108. For example, the UE operations module124may inform the decoder108of an anticipated encoding for transmissions from the gNB160. The UE operations module124may provide information142to the encoder150. The information142may include data to be encoded and/or instructions for encoding. For example, the UE operations module124may instruct the encoder150to encode transmission data146and/or other information142. The other information142may include PDSCH HARQ-ACK information. The encoder150may encode transmission data146and/or other information142provided by the UE operations module124. For example, encoding the data146and/or other information142may involve error detection and/or correction coding, mapping data to space, time and/or frequency resources for transmission, multiplexing, etc. The encoder150may provide encoded data152to the modulator154. The UE operations module124may provide information144to the modulator154. For example, the UE operations module124may inform the modulator154of a modulation type (e.g., constellation mapping) to be used for transmissions to the gNB160. The modulator154may modulate the encoded data152to provide one or more modulated signals156to the one or more transmitters158. The UE operations module124may provide information140to the one or more transmitters158. This information140may include instructions for the one or more transmitters158. For example, the UE operations module124may instruct the one or more transmitters158when to transmit a signal to the gNB160. For instance, the one or more transmitters158may transmit during a UL subframe. The one or more transmitters158may upconvert and transmit the modulated signal(s)156to one or more gNBs160. Each of the one or more gNBs160may include one or more transceivers176, one or more demodulators172, one or more decoders166, one or more encoders109, one or more modulators113, a data buffer162and a gNB operations module182. For example, one or more reception and/or transmission paths may be implemented in a gNB160. For convenience, only a single transceiver176, decoder166, demodulator172, encoder109and modulator113are illustrated in the gNB160, though multiple parallel elements (e.g., transceivers176, decoders166, demodulators172, encoders109and modulators113) may be implemented. The transceiver176may include one or more receivers178and one or more transmitters117. The one or more receivers178may receive signals from the UE102using one or more antennas180a-n. For example, the receiver178may receive and downconvert signals to produce one or more received signals174. The one or more received signals174may be provided to a demodulator172. The one or more transmitters117may transmit signals to the UE102using one or more antennas180a-n. For example, the one or more transmitters117may upconvert and transmit one or more modulated signals115. The demodulator172may demodulate the one or more received signals174to produce one or more demodulated signals170. The one or more demodulated signals170may be provided to the decoder166. The gNB160may use the decoder166to decode signals. The decoder166may produce one or more decoded signals164,168. For example, a first eNB-decoded signal164may comprise received payload data, which may be stored in a data buffer162. A second eNB-decoded signal168may comprise overhead data and/or control data. For example, the second eNB-decoded signal168may provide data (e.g., PDSCH HARQ-ACK information) that may be used by the gNB operations module182to perform one or more operations. In general, the gNB operations module182may enable the gNB160to communicate with the one or more UEs102. The gNB operations module182may include a gNB scheduling module194. The gNB scheduling module194may perform operations for channel collision handling with URLLC, and ACK feedback ON/OFF for HARQ-ACK of URLLC PDSCH transmissions as described herein. The gNB operations module182may provide information188to the demodulator172. For example, the gNB operations module182may inform the demodulator172of a modulation pattern anticipated for transmissions from the UE(s)102. The gNB operations module182may provide information186to the decoder166. For example, the gNB operations module182may inform the decoder166of an anticipated encoding for transmissions from the UE(s)102. The gNB operations module182may provide information101to the encoder109. The information101may include data to be encoded and/or instructions for encoding. For example, the gNB operations module182may instruct the encoder109to encode information101, including transmission data105. The encoder109may encode transmission data105and/or other information included in the information101provided by the gNB operations module182. For example, encoding the data105and/or other information included in the information101may involve error detection and/or correction coding, mapping data to space, time and/or frequency resources for transmission, multiplexing, etc. The encoder109may provide encoded data111to the modulator113. The transmission data105may include network data to be relayed to the UE102. The gNB operations module182may provide information103to the modulator113. This information103may include instructions for the modulator113. For example, the gNB operations module182may inform the modulator113of a modulation type (e.g., constellation mapping) to be used for transmissions to the UE(s)102. The modulator113may modulate the encoded data111to provide one or more modulated signals115to the one or more transmitters117. The gNB operations module182may provide information192to the one or more transmitters117. This information192may include instructions for the one or more transmitters117. For example, the gNB operations module182may instruct the one or more transmitters117when to (or when not to) transmit a signal to the UE(s)102. The one or more transmitters117may upconvert and transmit the modulated signal(s)115to one or more UEs102. It should be noted that a DL subframe may be transmitted from the gNB160to one or more UEs102and that a UL subframe may be transmitted from one or more UEs102to the gNB160. Furthermore, both the gNB160and the one or more UEs102may transmit data in a standard special subframe. It should also be noted that one or more of the elements or parts thereof included in the eNB(s)160and UE(s)102may be implemented in hardware. For example, one or more of these elements or parts thereof may be implemented as a chip, circuitry or hardware components, etc. It should also be noted that one or more of the functions or methods described herein may be implemented in and/or performed using hardware. For example, one or more of the methods described herein may be implemented in and/or realized using a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc. URLLC may coexist with other services (e.g., eMBB). Due to the latency requirement, URLLC may have a highest priority in some approaches. Some examples of URLLC coexistence with other services are given herein (e.g., in one or more of the following Figure descriptions). FIG.2is an example illustrating sub-slot URLLC PDSCH and HARQ-ACK feedback within 1 subframe. FIG.3illustrates ACK and NACK feedback differentiation methods. In a first method (Method 1), a HARQ-ACK PUCCH resource is configured, but NACK and ACK are transmitted with different parameters (e.g., number of PRBs, TxD, transmit power, etc.). In a second method (Method 2), different PUCCH resources are configured for NACK and ACK feedback with different parameters. FIG.4illustrates an example of a collision of URLLC PUCCH for HARQ-ACK with other UL channels. FIG.5illustrates an example where URLLC PUCCH for HARQ-ACK punctures all other channels in the overlapping symbols. FIG.6illustrates an example of simultaneous URLLC PUCCH for HARQ-ACK and other UL channels. FIG.7is a diagram illustrating one example of a resource grid for the downlink. The resource grid illustrated inFIG.7may be utilized in some implementations of the systems and methods disclosed herein. More detail regarding the resource grid is given in connection withFIG.1. InFIG.7, one downlink subframe769may include two downlink slots783. NDLRBis downlink bandwidth configuration of the serving cell, expressed in multiples of NRBsc, where NRBscis a resource block789size in the frequency domain expressed as a number of subcarriers, and NDLsymbis the number of OFDM symbols787in a downlink slot783. A resource block789may include a number of resource elements (RE)791.For a PCell, NDLRBis broadcast as a part of system information. For an SCell (including an Licensed Assisted Access (LAA) SCell), NDLRBis configured by a RRC message dedicated to a UE102. For PDSCH mapping, the available RE791may be the RE791whose index 1 fulfils 1≥1data,startand/or 1data,end≥1 in a subframe. In the downlink, the OFDM access scheme with cyclic prefix (CP) may be employed, which may be also referred to as CP-OFDM. In the downlink, PDCCH, enhanced PDCCH (EPDCCH), PDSCH and the like may be transmitted. A downlink radio frame may include multiple pairs of downlink resource blocks (RBs) which is also referred to as physical resource blocks (PRBs). The downlink RB pair is a unit for assigning downlink radio resources, defined by a predetermined bandwidth (RB bandwidth) and a time slot. The downlink RB pair includes two downlink RBs that are continuous in the time domain. The downlink RB includes twelve sub-carriers in frequency domain and seven (for normal CP) or six (for extended CP) OFDM symbols in time domain. A region defined by one sub-carrier in frequency domain and one OFDM symbol in time domain is referred to as a resource element (RE) and is uniquely identified by the index pair (k,l) in a slot, where k and1are indices in the frequency and time domains, respectively. While downlink subframes in one component carrier (CC) are discussed herein, downlink subframes are defined for each CC and downlink subframes are substantially in synchronization with each other among CCs. FIG.8is a diagram illustrating one example of a resource grid for the uplink. The resource grid illustrated inFIG.8may be utilized in some implementations of the systems and methods disclosed herein. More detail regarding the resource grid is given in connection withFIG.1. InFIG.8, one uplink subframe869may include two uplink slots883. NULRBis uplink bandwidth configuration of the serving cell, expressed in multiples of NRBsc, where NRBscis a resource block889size in the frequency domain expressed as a number of subcarriers, and NULsymbis the number of SC-FDMA symbols893in an uplink slot883. A resource block889may include a number of resource elements (RE)891. For a PCell, NULRBis broadcast as a part of system information. For an SCell (including an LAA SCell), NULRBis configured by a RRC message dedicated to a UE102. In the uplink, in addition to CP-OFDM, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) access scheme may be employed, which is also referred to as Discrete Fourier Transform-Spreading OFDM (DFT-S-OFDM). In the uplink, PUCCH, PUSCH, PRACH and the like may be transmitted. An uplink radio frame may include multiple pairs of uplink resource blocks. The uplink RB pair is a unit for assigning uplink radio resources, defined by a predetermined bandwidth (RB bandwidth) and a time slot. The uplink RB pair includes two uplink RBs that are continuous in the time domain. The uplink RB may include twelve sub-carriers in frequency domain and seven (for normal CP) or six (for extended CP) OFDM/DFT-S-OFDM symbols in time domain. A region defined by one sub-carrier in the frequency domain and one OFDM/DFT-S-OFDM symbol in the time domain is referred to as a RE and is uniquely identified by the index pair (k,l) in a slot, where k and l are indices in the frequency and time domains respectively. While uplink subframes in one component carrier (CC) are discussed herein, uplink subframes are defined for each CC. FIG.9shows examples of several numerologies901. The numerology #1901amay be a basic numerology (e.g., a reference numerology). For example, a RE995aof the basic numerology901amay be defined with subcarrier spacing905aof 15 kHz in frequency domain and 2048 Ts+CP length (e.g., 160 Ts or 144 Ts) in time domain (i.e., symbol length #1903a), where Ts denotes a baseband sampling time unit defined as 1/(15000*2048) seconds. For the i-th numerology, the subcarrier spacing905may be equal to 15*2iand the effective OFDM symbol length 2048*2−i*Ts. It may cause the symbol length is 2048*2−i*Ts+CP length (e.g., 160*2−i*Ts or 144*2−i*Ts). In other words, the subcarrier spacing of the i+1-th numerology is a double of the one for the i-th numerology, and the symbol length of the i+1-th numerology is a half of the one for the i-th numerology.FIG.9shows four numerologies, but the system may support another number of numerologies. Furthermore, the system does not have to support all of the 0-th to the I-th numerologies, i=0, 1, . . . , I. For example, the first UL transmission on the first SPS resource as above mentioned may be performed only on the numerology #1 (e.g., a subcarrier spacing of 15 kHz). Here, the UE102may acquire (detect) the numerology #1 based on a synchronization signal. Also, the UE102may receive a dedicated RRC signal including information (e.g., a handover command) configuring the numerology #1. The dedicated RRC signal may be a UE-specific signal. Here, the first UL transmission on the first SPS resource may be performed on the numerology #1, the numerology #2 (a subcarrier spacing of 30 kHz), and/or the numerology #3 (a subcarrier spacing of 60 kHz). Also, the second UL transmission on the second SPS resource as above mentioned may be performed only on the numerology #3. Here, for example, the UE102may receive System Information (e.g., Master Information Block (MIB) and/or System Information Block (SIB)) including information configuring the numerology #2 and/or the numerology #3. Also, the UE102may receive the dedicated RRC signal including information (e.g., the handover command) configuring the numerology #2 and/or the numerology #3. The System Information (e.g., MIB) may be transmitted on BCH (Broadcast Channel) and/or the dedicated RRC signal. The System Information (e.g., SIB) may contain information relevant when evaluating if a UE102is allowed to access a cell and/or defines the scheduling of other system information. The System Information (SIB) may contain radio resource configuration information that is common for multiple UEs102. Namely, the dedicated RRC signal may include each of multiple numerology configurations (the first numerology, the second numerology, and/or the third numerology) for each of UL transmissions (e.g., each of UL-SCH transmissions, each of PUSCH transmissions). Also, the dedicated RRC signal may include each of multiple numerology configurations (the first numerology, the second numerology, and/or the third numerology) for each of DL transmissions (each of PDCCH transmissions). FIG.10shows examples of subframe structures for the numerologies1001that are shown inFIG.9. Given that a slot1083includes NDLsymb(or NULsymb)=7 symbols, the slot length of the i+1-th numerology1001is a half of the one for the i-th numerology1001, and eventually the number of slots1083in a subframe (i.e., 1 ms) becomes double. It may be noted that a radio frame may include 10 subframes, and the radio frame length may be equal to 10 ms. FIG.11shows examples of slots1183and sub-slots1107. If a sub-slot1107is not configured by higher layer, the UE102and the eNB/gNB160may only use a slot1183as a scheduling unit. More specifically, a given transport block may be allocated to a slot1183. If the sub-slot1107is configured by higher layer, the UE102and the eNB/gNB160may use the sub-slot1107as well as the slot1183. The sub-slot1107may include one or more OFDM symbols. The maximum number of OFDM symbols that constitute the sub-slot1107may be NDLsymb−1 (or NULsymb−1). The sub-slot length may be configured by higher layer signaling. Alternatively, the sub-slot length may be indicated by a physical layer control channel (e.g., by DCI format). The sub-slot1107may start at any symbol within a slot1183unless it collides with a control channel. There could be restrictions of mini-slot length based on restrictions on starting position. For example, the sub-slot1107with the length of NDLsymb−1 (or NULsymb−1) may start at the second symbol in a slot1183. The starting position of a sub-slot1107may be indicated by a physical layer control channel (e.g., by DCI format). Alternatively, the starting position of a sub-slot1107may be derived from information (e.g., search space index, blind decoding candidate index, frequency and/or time resource indices, PRB index, a control channel element index, control channel element aggregation level, an antenna port index, etc.) of the physical layer control channel which schedules the data in the concerned sub-slot1107. In cases when the sub-slot1107is configured, a given transport block may be allocated to either a slot1183, a sub-slot1107, aggregated sub-slots1107or aggregated sub-slot(s)1107and slot1183. This unit may also be a unit for HARQ-ACK bit generation. FIG.12shows examples of scheduling timelines1209. For a normal DL scheduling timeline1209a, DL control channels are mapped the initial part of a slot1283a. The DL control channels1211schedule DL shared channels1213ain the same slot1283a. HARQ-ACKs for the DL shared channels1213a(i.e., HARQ-ACKs each of which indicates whether or not transport block in each DL shared channel1213ais detected successfully) are reported via UL control channels1215ain a later slot1283b. In this instance, a given slot1283may contain either one of DL transmission and UL transmission. For a normal UL scheduling timeline1209b, DL control channels1211bare mapped the initial part of a slot1283c. The DL control channels1211bschedule UL shared channels1217ain a later slot1283d. For these cases, the association timing (time shift) between the DL slot1283cand the UL slot1283dmay be fixed or configured by higher layer signaling. Alternatively, it may be indicated by a physical layer control channel (e.g., the DL assignment DCI format, the UL grant DCI format, or another DCI format such as UE-common signaling DCI format which may be monitored in common search space). For a self-contained base DL scheduling timeline1209c, DL control channels1211care mapped to the initial part of a slot1283e. The DL control channels1211cschedule DL shared channels1213bin the same slot1283e. HARQ-ACKs for the DL shared channels1213bare reported in UL control channels1215b, which are mapped at the ending part of the slot1283e. For a self-contained base UL scheduling timeline1209d, DL control channels1211dare mapped to the initial part of a slot1283f. The DL control channels1211dschedule UL shared channels1217bin the same slot1283f. For these cases, the slot1283fmay contain DL and UL portions, and there may be a guard period between the DL and UL transmissions. The use of a self-contained slot may be upon a configuration of self-contained slot. Alternatively, the use of a self-contained slot may be upon a configuration of the sub-slot. Yet alternatively, the use of a self-contained slot may be upon a configuration of shortened physical channel (e.g., PDSCH, PUSCH, PUCCH, etc.). FIG.13shows examples of DL control channel monitoring regions. One or more sets of PRB(s) may be configured for DL control channel monitoring. In other words, a control resource set is, in the frequency domain, a set of PRBs within which the UE102attempts to blindly decode downlink control information, where the PRBs may or may not be frequency contiguous, a UE102may have one or more control resource sets, and one DCI message may be located within one control resource set. In the frequency-domain, a PRB is the resource unit size (which may or may not include Demodulation reference signals (DM-RS)) for a control channel. A DL shared channel may start at a later OFDM symbol than the one(s) which carries the detected DL control channel. Alternatively, the DL shared channel may start at (or earlier than) an OFDM symbol than the last OFDM symbol which carries the detected DL control channel. In other words, dynamic reuse of at least part of resources in the control resource sets for data for the same or a different UE102, at least in the frequency domain may be supported. FIG.14shows examples of DL control channel which includes more than one control channel elements. When the control resource set spans multiple OFDM symbols, a control channel candidate may be mapped to multiple OFDM symbols or may be mapped to a single OFDM symbol. One DL control channel element may be mapped on REs defined by a single PRB and a single OFDM symbol. If more than one DL control channel elements are used for a single DL control channel transmission, DL control channel element aggregation may be performed. The number of aggregated DL control channel elements is referred to as DL control channel element aggregation level. The DL control channel element aggregation level may be 1 or 2 to the power of an integer. The gNB160may inform a UE102of which control channel candidates are mapped to each subset of OFDM symbols in the control resource set. If one DL control channel is mapped to a single OFDM symbol and does not span multiple OFDM symbols, the DL control channel element aggregation is performed within an OFDM symbol, namely multiple DL control channel elements within an OFDM symbol are aggregated. Otherwise, DL control channel elements in different OFDM symbols can be aggregated. FIG.15shows examples of UL control channel structures. UL control channel may be mapped on REs which are defined a PRB and a slot in frequency and time domains, respectively. This UL control channel may be referred to as a long format (or just the 1st format). UL control channels may be mapped on REs on a limited OFDM symbols in time domain. This may be referred to as a short format (or just the 2nd format). The UL control channels with a short format may be mapped on REs within a single PRB. Alternatively, the UL control channels with a short format may be mapped on REs within multiple PRB s. For example, interlaced mapping may be applied, namely the UL control channel may be mapped to every N PRBs (e.g. 5 or 10) within a system bandwidth. FIG.16is a block diagram illustrating one implementation of a gNB1660. The gNB1660may include a higher layer processor1623, a DL transmitter1625, a UL receiver1633, and one or more antenna1631. The DL transmitter1625may include a PDCCH transmitter1627and a PDSCH transmitter1629. The UL receiver1633may include a PUCCH receiver1635and a PUSCH receiver1637. The higher layer processor1623may manage physical layer's behaviors (the DL transmitter's and the UL receiver's behaviors) and provide higher layer parameters to the physical layer. The higher layer processor1623may obtain transport blocks from the physical layer. The higher layer processor1623may send/acquire higher layer messages such as an RRC message and MAC message to/from a UE's higher layer. The higher layer processor1623may provide the PDSCH transmitter transport blocks and provide the PDCCH transmitter transmission parameters related to the transport blocks. The DL transmitter1625may multiplex downlink physical channels and downlink physical signals (including reservation signal) and transmit them via transmission antennas1631. The UL receiver1633may receive multiplexed uplink physical channels and uplink physical signals via receiving antennas1631and de-multiplex them. The PUCCH receiver1635may provide the higher layer processor1623UCI. The PUSCH receiver1637may provide the higher layer processor1623received transport blocks. FIG.17is a block diagram illustrating one implementation of a UE1702. The UE1702may include a higher layer processor1723, a UL transmitter1751, a DL receiver1743, and one or more antenna1731. The UL transmitter1751may include a PUCCH transmitter1753and a PUSCH transmitter1755. The DL receiver1743may include a PDCCH receiver1745and a PDSCH receiver1747. The higher layer processor1723may manage physical layer's behaviors (the UL transmitter's and the DL receiver's behaviors) and provide higher layer parameters to the physical layer. The higher layer processor1723may obtain transport blocks from the physical layer. The higher layer processor1723may send/acquire higher layer messages such as an RRC message and MAC message to/from a UE's higher layer. The higher layer processor1723may provide the PUSCH transmitter transport blocks and provide the PUCCH transmitter1753UCI. The DL receiver1743may receive multiplexed downlink physical channels and downlink physical signals via receiving antennas1731and de-multiplex them. The PDCCH receiver1745may provide the higher layer processor1723DCI. The PDSCH receiver1747may provide the higher layer processor1723received transport blocks. It should be noted that names of physical channels described herein are examples. The other names such as “NRPDCCH, NRPDSCH, NRPUCCH and NRPUSCH”, “new Generation-(G)PDCCH, GPDSCH, GPUCCH and GPUSCH” or the like can be used. FIG.18illustrates various components that may be utilized in a UE1802. The UE1802described in connection withFIG.18may be implemented in accordance with the UE102described in connection withFIG.1. The UE1802includes a processor1803that controls operation of the UE1802. The processor1803may also be referred to as a central processing unit (CPU). Memory1805, which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions1807aand data1809ato the processor1803. A portion of the memory1805may also include non-volatile random-access memory (NVRAM). Instructions1807band data1809bmay also reside in the processor1803. Instructions1807band/or data1809bloaded into the processor1803may also include instructions1807aand/or data1809afrom memory1805that were loaded for execution or processing by the processor1803. The instructions1807bmay be executed by the processor1803to implement the methods described above. The UE1802may also include a housing that contains one or more transmitters1858and one or more receivers1820to allow transmission and reception of data. The transmitter(s)1858and receiver(s)1820may be combined into one or more transceivers1818. One or more antennas1822a-nare attached to the housing and electrically coupled to the transceiver1818. The various components of the UE1802are coupled together by a bus system1811, which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various buses are illustrated inFIG.18as the bus system1811. The UE1802may also include a digital signal processor (DSP)1813for use in processing signals. The UE1802may also include a communications interface1815that provides user access to the functions of the UE1802. The UE1802illustrated inFIG.18is a functional block diagram rather than a listing of specific components. FIG.19illustrates various components that may be utilized in a gNB1960. The gNB1960described in connection withFIG.19may be implemented in accordance with the gNB160described in connection withFIG.1. The gNB1960includes a processor1903that controls operation of the gNB1960. The processor1903may also be referred to as a central processing unit (CPU). Memory1905, which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions1907aand data1909ato the processor1903. A portion of the memory1905may also include non-volatile random-access memory (NVRAM). Instructions1907band data1909bmay also reside in the processor1903. Instructions1907band/or data1909bloaded into the processor1903may also include instructions1907aand/or data1909afrom memory1905that were loaded for execution or processing by the processor1903. The instructions1907bmay be executed by the processor1903to implement the methods described above. The gNB1960may also include a housing that contains one or more transmitters1917and one or more receivers1978to allow transmission and reception of data. The transmitter(s)1917and receiver(s)1978may be combined into one or more transceivers1976. One or more antennas1980a-nare attached to the housing and electrically coupled to the transceiver1976. The various components of the gNB1960are coupled together by a bus system1911, which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various buses are illustrated inFIG.19as the bus system1911. The gNB1960may also include a digital signal processor (DSP)1913for use in processing signals. The gNB1960may also include a communications interface1915that provides user access to the functions of the gNB1960. The gNB1960illustrated inFIG.19is a functional block diagram rather than a listing of specific components. FIG.20is a block diagram illustrating one implementation of a UE2002in which channel collision handling with URLLC, and ACK feedback ON/OFF for HARQ-ACK of URLLC PDSCH transmissions may be implemented. The UE2002includes transmit means2058, receive means2020and control means2024. The transmit means2058, receive means2020and control means2024may be configured to perform one or more of the functions described in connection withFIG.1above.FIG.18above illustrates one example of a concrete apparatus structure ofFIG.20. Other various structures may be implemented to realize one or more of the functions ofFIG.1. For example, a DSP may be realized by software. FIG.21is a block diagram illustrating one implementation of a gNB2160in which channel collision handling with URLLC, and ACK feedback ON/OFF for HARQ-ACK of URLLC PDSCH transmissions may be implemented. The gNB2160includes transmit means2123, receive means2178and control means2182. The transmit means2123, receive means2178and control means2182may be configured to perform one or more of the functions described in connection withFIG.1above.FIG.19above illustrates one example of a concrete apparatus structure ofFIG.21. Other various structures may be implemented to realize one or more of the functions ofFIG.1. For example, a DSP may be realized by software.The term “computer-readable medium” refers to any available medium that can be accessed by a computer or a processor. The term “computer-readable medium,” as used herein, may denote a computer- and/or processor-readable medium that is non-transitory and tangible. By way of example, and not limitation, a computer-readable or processor-readable medium may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer or processor. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. It should be noted that one or more of the methods described herein may be implemented in and/or performed using hardware. For example, one or more of the methods described herein may be implemented in and/or realized using a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc. Each of the methods disclosed herein comprises one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another and/or combined into a single step without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims. It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the systems, methods, and apparatus described herein without departing from the scope of the claims. A program running on the gNB160or the UE102according to the described systems and methods is a program (a program for causing a computer to operate) that controls a CPU and the like in such a manner as to realize the function according to the described systems and methods. Then, the information that is handled in these apparatuses is temporarily stored in a RAM while being processed. Thereafter, the information is stored in various ROMs or HDDs, and whenever necessary, is read by the CPU to be modified or written. As a recording medium on which the program is stored, among a semiconductor (for example, a ROM, a nonvolatile memory card, and the like), an optical storage medium (for example, a DVD, a MO, a MD, a CD, a BD, and the like), a magnetic storage medium (for example, a magnetic tape, a flexible disk, and the like), and the like, any one may be possible. Furthermore, in some cases, the function according to the described systems and methods described above is realized by running the loaded program, and in addition, the function according to the described systems and methods is realized in conjunction with an operating system or other application programs, based on an instruction from the program. Furthermore, in a case where the programs are available on the market, the program stored on a portable recording medium can be distributed or the program can be transmitted to a server computer that connects through a network such as the Internet. In this case, a storage device in the server computer also is included. Furthermore, some or all of the gNB160and the UE102according to the systems and methods described above may be realized as an LSI that is a typical integrated circuit. Each functional block of the gNB160and the UE102may be individually built into a chip, and some or all functional blocks may be integrated into a chip. Furthermore, a technique of the integrated circuit is not limited to the LSI, and an integrated circuit for the functional block may be realized with a dedicated circuit or a general-purpose processor. Furthermore, if with advances in a semiconductor technology, a technology of an integrated circuit that substitutes for the LSI appears, it is also possible to use an integrated circuit to which the technology applies. Moreover, each functional block or various features of the base station device and the terminal device used in each of the aforementioned implementations may be implemented or executed by a circuitry, which is typically an integrated circuit or a plurality of integrated circuits. The circuitry designed to execute the functions described in the present specification may comprise a general-purpose processor, a digital signal processor (DSP), an application specific or general application integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic, or a discrete hardware component, or a combination thereof. The general-purpose processor may be a microprocessor, or alternatively, the processor may be a conventional processor, a controller, a microcontroller or a state machine. The general-purpose processor or each circuit described above may be configured by a digital circuit or may be configured by an analogue circuit. Further, when a technology of making into an integrated circuit superseding integrated circuits at the present time appears due to advancement of a semiconductor technology, the integrated circuit by this technology is also able to be used. As used herein, the term “and/or” should be interpreted to mean one or more items. For example, the phrase “A, B and/or C” should be interpreted to mean any of: only A, only B, only C, A and B (but not C), B and C (but not A), A and C (but not B), or all of A, B, and C. As used herein, the phrase “at least one of” should be interpreted to mean one or more items. For example, the phrase “at least one of A, B and C” or the phrase “at least one of A, B or C” should be interpreted to mean any of: only A, only B, only C, A and B (but not C), B and C (but not A), A and C (but not B), or all of A, B, and C. As used herein, the phrase “one or more of” should be interpreted to mean one or more items. For example, the phrase “one or more of A, B and C” or the phrase “one or more of A, B or C” should be interpreted to mean any of: only A, only B, only C, A and B (but not C), B and C (but not A), A and C (but not B), or all of A, B, and C. CROSS REFERENCE This Nonprovisional application claims priority under 35 U.S.C. § 119 on provisional Application No. 62/716,836 on Aug. 9, 2018, the entire contents of which are hereby incorporated by reference. | 95,807 |
11943062 | DETAILED DESCRIPTION FIGS.1through30, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system. Exemplary embodiments of the present disclosure are described with reference to the accompanying drawings in detail. Detailed description of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. Further, the following terms are defined in consideration of the functionality in the present disclosure, and may vary according to the intention of a user or an operator, usage, etc. Therefore, the definition should be made on the basis of the overall content of the present specification. Advantages and features of the present disclosure and methods of accomplishing the same may be understood more readily by reference to the following detailed description of exemplary embodiments and the accompanying drawings. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the disclosure to those skilled in the art, and the present disclosure will only be defined by the appended claims. Like reference numerals refer to like elements throughout the specification. It will be understood that each block of the flowcharts and/or block diagrams, and combinations of blocks in the flowcharts and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing apparatus, such that the instructions which are executed via the processor of the computer or other programmable data processing apparatus create means for implementing the functions/acts specified in the flowcharts and/or block diagrams. These computer program instructions may also be stored in a non-transitory computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the non-transitory computer-readable memory produce manufacture articles embedding instruction means which implement the function/act specified in the flowcharts and/or block diagrams. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which are executed on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowcharts and/or block diagrams. Furthermore, the respective block diagrams may illustrate parts of modules, segments, or codes including at least one or more executable instructions for performing specific logic function(s). Moreover, it should be noted that the functions of the blocks may be performed in a different order in several modifications. For example, two successive blocks may be performed substantially at the same time, or may be performed in reverse order according to their functions. According to various embodiments of the present disclosure, the term “module”, means, but is not limited to, a software or hardware component, such as a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks. A module may advantageously be configured to reside on the addressable storage medium and configured to be executed on one or more processors. Thus, a module may include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided for in the components and modules may be combined into fewer components and modules or further separated into additional components and modules. In addition, the components and modules may be implemented such that they execute one or more CPUs in a device or a secure multimedia card. First Embodiment The first embodiment of the present disclosure proposes a method for supporting a light connected mode as a new terminal operation mode in addition to the legacy idle and connected modes for improving operation efficiency of terminals and base station in a mobile communication system. FIG.1is a diagram illustrating architecture of an LTE system to which the first embodiment of the present disclosure is applied. In reference toFIG.1, the Radio Access Network of the LTE system includes next generation base stations (evolved Node Bs (eNBs))1-05,1-10,1-15, and1-20; a Mobility Management Entity (MME)1-25; and a Serving Gateway (S-GW)1-30. A user terminal (User Equipment (UE))1-35connects to an external network via the eNBs1-05,1-10,1-15, and1-20and the S-GW1-30. InFIG.1, the eNBs1-05,1-10,1-15, and1-20are equivalent to a legacy node B of the universal mobile telecommunications system (UMTS). The UE1-35connects to one of the eNBs1-05,1-10,1-15, and1-20via a radio channel, and the eNBs1-05,1-10,1-15, and1-20are more complex in functionality than the legacy node B. In the LTE system where all user traffic including real time services such as Voice over IP (VoIP) is served through share channels, it is beneficial to schedule UEs based on scheduling information such as buffer status, power headroom status, and channel status collected from the UEs, an eNB serving the UEs takes charge of this function. Typically, one eNB hosts a plurality of cells. For example, the LTE system adopts Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology to secure a data rate of up to 100 Mbps in a bandwidth of 20 MHz. The LTE system also adopts Adaptive Modulation and Coding (AMC) to determine the modulation scheme and channel coding rate in adaptation to the channel condition of the UE. The S-GW1-30as an entity handling bearers establishes and releases data bearers under the control of the MME1-25. The MME1-25takes charge of various control functions and maintains connections with a plurality of eNBs. FIG.2is a diagram illustrating a protocol stack of an interface between UE and an eNB in an LTE system to which the first embodiment of the present disclosure is applied. In reference toFIG.2, the protocol stack of the interface between the UE and the eNB includes a plurality of protocol layers stacked from the bottom to the top: physical layer denoted by reference numbers2-20and2-25, medium access control (MAC) layer denoted by reference numbers2-15and2-30, radio link control (RLC) layer denoted by reference numbers2-10and2-35, and packet data convergence protocol (PDCP) layer denoted by reference numbers2-05and2-40. The PDCP layer denoted by reference numbers2-05and2-40takes charge of compressing/decompressing an IP header, and the RLC layer denoted by reference numbers2-10and2-15takes charge of segmenting a PDCP Packet Data Unit (PDU) into segments of appropriate size. The MAC layer denoted by reference number2-15and2-30allows for connection of multiple RLC entities and takes charge of multiplexing RLC PDUs from the RLC layer into a MAC PDU and demultiplexing a MAC PDU into RLC PDUs. The PHY layer denoted by reference numbers2-20and2-25takes charge of channel-coding and modulation on higher layer data to generate and transmit OFDM symbols over a radio channel, and demodulating and channel-decoding on OFDM symbols received over the radio channel to deliver the decoded data to the higher layers. FIG.3is a diagram illustrating a configuration of a Paging Area (PA) for explaining the concept of light connection. The light connection technique is introduced to define a new UE operation mode in addition to the legacy idle and connected modes to reduce signaling overhead caused by legacy handover and paging operations. The terminal3-03in the light connected mode is characterized by the S1 connections kept between the MME3-01and the eNBs3-02and3-04and in that one of the MME3-01and the eNBs3-02and3-04triggers paging. The MME3-01assumes that the UE in the light connected mode is operating in the connected mode and thus, if there is any data to transmit to the UE, the MME3-01transmits the data to the eNB without triggering a paging procedure. If the data are received, the eNB transmits a paging message to all eNBs within the PA3-05such that the eNBs broadcast the paging message. The present disclosure proposes UE and network operations in a Mobile Termination (MT) or Mobile Originating (MO) transfer or PA change situation in consideration of the above-described characteristics of light connection. FIG.4is a signal flow diagram illustrating a procedure of transmitting MT data to a UE according to the first embodiment of the present disclosure. The UE4-01in the connected state (or mode) to the Anchor eNB4-02receives a light connection command from the anchor eNB4-02at step4-05. The light connection command may be used to instruct the UE4-01to transition to the light connected mode and include at least one of a resume ID and PA information. The resume ID may be used as an identifier for identifying a UE in the light connected mode. The resume ID may also be associated with the eNB transmitting the light connection command. The resume ID is unique in a predetermined area, i.e., PA. An example of the PA information is a list of eNBs forming a PA. The PA information is described later in more detail. The anchor eNB4-02may store the UE context of the UE4-01at step4-07. The UE4-01may move to a new eNB4-03within the same PA at step4-06. If the MME4-04has any MT data (or downlink data) to transmit to the UE4-01, it transmits the data to the anchor eNB4-02at step4-08. The MME4-04transmits to the anchor eNB4-02the MT data rather than a paging request because it regards the UE4-01in the light connected mode as a UE in the connected mode. If the MT data is received, the anchor eNB4-02triggers a paging procedure to broadcast a paging message within its service area (RAN paging) at step4-10. The anchor eNB4-02also transmits the paging message to neighboring eNBs located within the same PA at step4-09. Upon receipt of the paging message, the neighboring eNBs broadcast the paging message at step4-11. One of the important characteristics of the light connection technique is that the paging procedure is triggered by an eNB rather than the MME4-04. The paging message includes a resume ID for identifying the UE in the light connected mode. The UE4-01may determine whether the paging message is destined for the UE4-01based on the resume ID. In order to distinguish the eNB-triggered paging from the legacy paging, it may be possible to define a separate Radio Network Temporary Identifier called RP-RNTI. The UE4-01may receive the paging message from a new eNB4-03located within the same PA as that in which the anchor eNB4-02is located. The UE4-01transmits a light connection update message to the new eNB4-03at step4-12. The light connection update message may include at least one of a resume ID, a Message Authentication Code for Integrity (MAC-I), and an establishment cause. Upon receipt of the light connection update message, the new eNB4-03may identify the anchor eNB4-02using the resume ID at step4-13. Accordingly, the new eNB4-03may request to the anchor eNB4-02for the UE context of the UE4-01at steps4-14and4-15. At this time, it may be possible to use UE CONTEXT REQUEST and UE CONTEXT RESPONSE messages. The new eNB4-30may transmit the UE CONTEXT REQUEST message to the anchor eNB4-02to retrieve the UE context of the UE4-01from the anchor eNB4-02. The anchor eNB4-02may transmit the UE CONTEXT RESPONSE message including the UE context of the UE4-01to the new eNB4-03in response to the UE CONTEXT REQUEST message. The new eNB4-03transmits a RESUME CONNECTION message to the UE4-01at step4-16. Upon receipt of the RESUME CONNECTION message, the UE4-01reactivates the DRB at step4-17to receive MT data. After transmitting the RESUME CONNECTION message, the new eNB4-03transmits a HANDOVER REQUEST ACK message to the anchor eNB4-02at step4-18; if the anchor eNB4-02has data to forward, it forwards the data to the new eNB4-03at step4-19. The new eNB4-03may use the HANDOVER REQUEST ACK message to notify the anchor eNB4-02that the UE4-01has connected to the new eNB4-03for data communication. Afterward, the new eNB4-03which has received a paging response is regarded as a new anchor eNB because the UE4-01is out of the service area of the anchor eNB4-02. The new eNB4-03requests to the MME4-04for path switch at steps4-21and4-22and to the anchor eNB4-02for context release at step4-23. FIG.5is a signal flow diagram illustrating a procedure for transmitting MO data to a UE according to the first embodiment of the present disclosure. The UE5-01in the connected state to the Anchor eNB5-02receives a light connection command from the anchor eNB5-02at step5-05. Upon receipt of the light connection command, the UE5-01transitions to the light connected mode. The anchor eNB5-02stores the UE context of the UE5-01at step5-07. The UE5-01may move to a new eNB5-03within the same PA at step5-06. If MO data is generated at the UE5-01at step5-08, the UE5-01may move and transmit a light connection update message to the new eNB5-03rather than the anchor eNB5-02at step5-09. The light connection update message may include at least one of a resume ID, a MAC-I, and an establishment cause. Upon receipt of the light connection update message, the new eNB5-03may identify the anchor eNB5-02based on the resume ID at step5-10. The new eNB5-03may request to the anchor eNB5-02for UE context of the UE5-01at steps5-11and5-12. The new eNB5-03may transmit a UE CONTEXT REQUEST message to the anchor eNB5-02for retrieving the UE context of the UE5-01from the anchor eNB5-02. The anchor eNB5-02may transmit a UE CONTEXT RESPONSE message including the UE context of the UE5-01in response to the UE CONTEXT REQUEST message. The new eNB5-03transmits a RESUME CONNECTION message to the UE5-01at step5-13. Upon receipt of the RESUME CONNECTION message, the UE5-01reactivates the DRB to transmit MO data. After transmitting the RESUME CONNECTION message, the new eNB5-03transmits a HANDOVER REQUEST ACK message to the anchor eNB5-02at step5-15; if the anchor eNB5-02has data to forward, it forwards the data to the new eNB5-03at step5-16. Next, the new eNB5-03which has transmitted the RESUME CONNECTION message may be regarded as a new anchor eNB because the UE5-01is out of the service area of the anchor eNB5-02. The new eNB5-03requests to the MME/S-GW5-04at steps5-17and5-18and to the anchor eNB5-02for context release at step5-19. Afterward, the UE5-01transmit uplink data to the MME/S-GW5-04via the new eNB5-03at step5-20. FIG.6is a signal flow diagram illustrating a PA change procedure according to the first embodiment of the present disclosure. The UE6-01in the connected state to the anchor eNB6-02receives a light connection command from the anchor eNB6-02at step6-05. Upon receipt of the light connection command, the UE6-01transitions to the light connected mode. The anchor eNB6-02stores the UE context of the UE6-01at step6-07. The UE6-01may move to a new eNB6-03located in another PA at step6-06. The new eNB6-03transmits its PA information to the UE6-01using a System Information Block (SIBx) at step6-08. Upon receipt of the PA information, the UE6-01may determine whether the eNB6-03on which it has camped and the anchor eNB6-02which has transmitted the light connection command are located in the same PA. If the eNB6-03on which the UE6-01has camped and the anchor eNB6-02which has transmitted the light connection command are located in different PAs, the UE6-01transmits, at step6-09, a light connection update message to the eNB6-03on which it has camped. The light connection update message may include at least one of a resume ID, a MAC-I, and an establishment cause. Upon receipt of the light connection update message, the new eNB6-03may identify the anchor eNB6-02based on the resume ID at step6-10. Accordingly, the new eNB6-03may request to the anchor eNB6-02for the UE context of the UE6-01at steps6-11and6-12. Next, the new eNB6-03transmits a light connection command message to the UE6-01at step6-13. The light connection command message includes a new resume ID and PA information. After transmitting the light connection command message, the eNB6-03transmits a HANDOVER REQUEST ACK message to the anchor eNB6-02at step6-14; if the anchor eNB6-02has data to forward, it forwards the data to the new eNB6-03. Next, the new eNB6-03which has transmitted the light connection command message may be regarded as a new anchor eNB because the UE6-01is out of the service area of the anchor eNB6-02. Accordingly, the new eNB6-03requests to the MME6-04for path switch at step6-15and6-16and to the anchor eNB6-02for context release at step6-17. FIG.7is a signal flow diagram illustrating another PA change procedure according to the first embodiment of the present disclosure. The UE7-01in the connected state to the anchor eNB7-02receives a light connection command from the anchor eNB7-02at step7-05. Upon receipt of the light connection command, the UE7-01transitions to the light connected mode. The anchor eNB7-02stores the UE context of the UE7-01at step7-07. The UE7-01may move to a new eNB7-03located in a PA different from that in which the anchor eNB7-02is located at step7-06. The new eNB7-03transmits its PA information to the UE7-01using a SIB (SIBx) at step7-08. Upon receipt of the PA information, the UE7-01may determine whether new eNB7-03on which the UE7-01has camped and the anchor eNB7-02which has transmitted the light connection command are located in the same PA. If the new eNB7-03on which the UE7-01has camped and the anchor eNB7-02which has transmitted the light connection command are located in different PAs, the UE7-01transmits, at step7-09, a light connection update message to the new eNB7-03on which it has camped. The light connection update message may include at least one of a resume ID, a MAC-I, and an establishment cause. Upon receipt of the light connection update message, the new eNB7-03may identify the anchor eNB7-02based on the resume ID at step7-10. When the UE7-01moves from one PA to another PA, it is useful to transfer the UE context of the UE7-01from the anchor eNB7-02located in one PA to the new eNB7-03located in another PA. It may also be useful to switch the path to the MME/S-GW7-04from the anchor eNB7-02to the new eNB7-03. Such a procedure entails signaling overhead and thus frequent PA change significantly increases signaling overhead. The signaling overhead also increases as the number of UEs to serve increases. One of the solutions to mitigate the signaling overhead problem is not to transmit the UE context of the UE7-01to the new eNB7-03even when the UE7-01changes the PA. Instead, the new eNB7-03may provide the anchor eNB7-02with a list of the eNB IDs of eNBs (including the new eNB7-03) located within a new PA at step7-12. The new eNB7-03provides the UE7-01with a new resume ID and new PA information using the light connection command at step7-11. If there is MT data to transmit to the UE7-01, the anchor eNB7-02triggers a paging procedure and transmits a paging message to the new eNB7-03. The new eNB7-03may transmit the paging message to the eNBs located in the same PA as that in which the anchor eNB7-02is located. The new eNB7-03may also transmit the paging message to the eNBs located in the same PA as that in which the new eNB7-03is located. Upon receipt of the paging message, the eNBs broadcast the paging message. Table 1 lists available PA ID (PAI) management methods according to the first embodiment of the present disclosure. In the legacy LTE, the paging message is broadcast by the Tracking Area (TA). The UE has a TA Update (TAU) list transmitted by the MME and, if it enters a TA which is not included in the TAU list, performs TAU. TABLE 1NWUECurrentA single TAI is broadcastedUE stores TAI list received from TAU acceptin the SIB 1UE initiates TAU upon entering TA not in the listof TAI listOption 1A single PAI is broadcastedUE stores the PAI of the cell when LC startedin the SIB xUE initiates PAU upon entering different PAOption 1aSame as option 1ENB provides PAI list when LC startsUE initiates PAU upon entering cell where none of PAIin the list matches with PAI of the cellOption 2Multiple PAIsUE stores the PAIs of the cell when LC startedare broadcastedUE inititated PAU upon entering cell where nonein the SIB xof PAI matchOption 2aSame as option 2ENB indicates a single PAI when LC startedUE initiates PAU upon entering cell wherenone of PAIs of the current cellmatches with the stored PAIOption 3ECGI (cellIdentity)ENB provides n bit mask when LCis broadcastedstarted n can be 19, 20 or 21in the SIB 1 as nowbit UE initiate PAU upon entering cell where n MSBof cellIdentity does not match with maskOption 4ECGI (cellIdentity)ENB provides ECGIs stated when LC startedis broadcastedUE initiates PAU upon entering cell whose cell idin the SIB 1 as nowdoes not match In the present disclosure, the PA is similar to the legacy TA with the exception that the PA is managed by the eNB. That is, it is not necessary for the MME to manage the PA or to have the information on the PA. In option 1 in table 1, each cell broadcasts the ID of the PA to which it belongs (single PAI) using a SIBx. The UE stores the PAI (e.g., when the light connected mode starts) and initiates Paging Area Update (PAU) upon entering a different PA. Option 1a is similar to option 1 with the exception that the eNB provides multiple PAIS in the form of a PAI list when the light connected mode starts. The UE initiates PAU upon entering a cell where none of the PAIS matches the PAI broadcast by the cell. In option 2 of table 1, each cell broadcasts the IDs of multiple PAs to which it belongs (multiple PAIS) using a SIBx. The UE stores the PAIS (e.g., when the light connected mode starts) and initiates PAU upon entering a cell of which PAI match none of the stored PAIS. Option 2a is similar to option 2 with the exception that the eNB indicates a signal PAI when the light connected mode starts. The UE initiates PAU upon entering the cell where none of the PAIS of the current cell matches with the stored PAIS. In option 3 of table 1, the eNB provides an n-bit mask information when the light connected mode starts. The UE initiates PAU upon entering a cell where n-MSB of a cellldentity (E-UTRAN Cell Global Identifier (ECGI)) of the current cell does not match the mask. In option 4 of table 1, the eNB provides ECGIs when the light connected mode starts. The UE initiates PAU upon entering a cell whose cell ID does not match any of the ECGIs. FIG.8is a flowchart illustrating operations of a UE according to the first embodiment of the present disclosure. The UE receives a Light Connection Command message from an eNB at step8-01. The UE stores the resume ID and PA information included in the Light Connection Command message at step8-02. The UE transitions to the light connected mode at step8-03. The UE receives a paging message and determines at step8-04whether the received paging message is a RAN-triggered paging message. The RAN-triggered paging message is distinguished the legacy paging message in terms of being transmitted with a newly defined RNTI, i.e., RP-RNTI. If it is determined at step8-04that the received paging message is a RAN-triggered paging message, the UE generates a Light Connection Update message at step8-05, the Light Connection Update message including the resume ID, MAC-I, and establishment cause value stored previously. The UE transmits the Light Connection Update message to the eNB at step8-06. The UE receives a Resume Connection message from the eNB at step8-07. The UE resumes the DRB at step8-08. If it is determined at step8-04that the received paging message is not a RAN-triggered paging message, the UE determines at step8-09whether PA change occurs. If it is determined at step8-09that PA change occurs, the UE transmits to the eNB a Light Connection Update message including the previously stored resume ID, MAC-I, and establishment cause value at step8-10. The establishment cause value is a newly introduced value indicating PA change. The UE receives a new Light Connection Command at step8-11. The UE stores a resume ID and PA information different from the previous ones at step8-12. FIG.9is a flowchart illustrating operations of an anchor eNB according to the first embodiment of the present disclosure. An eNB determines to transition a UE to the Light Connected mode at step9-01. The eNB becomes the anchor eNB of the UE. The eNB transmits to the UE a Light Connection Command message including a resume ID and PA information at step9-02. The eNB receives a signal and determines at step9-03whether the signal carries data transmitted from an S-GW to the UE or a UE CONTEXT REQUEST message from another eNB. If it is determined at step9-03that the received signal carries the data from the S-GW, the anchor eNB broadcasts a paging message to locate the UE and transmits the paging message to neighboring eNBs within the same PA as that of the anchor eNB at step9-04. The eNB receives a Light Connection Update message from the UE at step9-05. The eNB determines whether the resume ID included in the Light Connection Update message matches the resume ID used in the paging message and, if the resume IDs match, assumes that UE has successfully received the paging message. The eNB transmits a Resume Connection message at step9-06. If it is determined at step9-03that the received signal caries the UE CONTEXT REQUEST message transmitted by another eNB, the anchor eNB transmits a UE CONTEXT RESPONSE message to the corresponding eNB at step9-07. The UE CONTEXT RESPONSE message includes the UE context of the corresponding UE. The anchor eNB receives a HANDOVER REQUEST ACK message from the corresponding eNB at step9-08and, if it has data to transmit, forwards the data to the corresponding eNB at step9-09. The anchor eNB receives a CONTEXT RELEASE message from the corresponding eNB at step9-10and deletes the UE context of the UE from its storage. FIG.10is a diagram illustrating a configuration of a UE according to the first embodiment of the present disclosure. In reference toFIG.10, the UE includes a transceiver10-00, a multiplexer/demultiplexer10-05, a higher layer entity10-10, a control message processor10-15, and a controller10-20. In reference toFIG.10, the UE communicates data by means of the higher layer entity10-10and communicate control messages by means of the control message processor10-15. In the case of transmitting control signals and/or data to the eNB, the UE multiplexes the controls signals and/or data by means of the multiplexer/demultiplexer10-05and transmits the multiplexed signal by means of the transceiver10-00under the control of the controller10-20. In the case of receiving signals, the UE receives a physical layer signal by means of the transceiver10-00, demultiplexes the received signal by means of the multiplexer/demultiplexer10-05, and delivers the demultiplexed information to the higher layer entity10-10and/or control message processor10-15, under the control of the controller10-20. FIG.11is a block diagram illustrating a configuration of an eNB according to the first embodiment of the present disclosure. In reference toFIG.11, the eNB includes a transceiver11-05, a controller11-10, a multiplexer/demultiplexer11-20, a control message processor11-35, higher layer entities11-25and11-30, and a scheduler11-15. The transceiver11-05transmits data and predetermined control signals on a downlink carrier and receives data and predetermined controls signals on an uplink carrier. In the case that multiple carriers are configured, the transceiver11-05transmits and receives data and control signals on the multiple carriers. The multiplexer/demultiplexer11-20multiplexes data generated from the higher layer entities11-25and11-30and/or the control message processor11-35and demultiplexes the data received by the transceiver11-05, the multiplexed data or demultiplexed data being delivered to the higher layer entities11-25and11-30, the control message processor11-35, and/or the controller11-10. The controller11-10determines whether to apply a band-specific measurement gap to a certain UE and whether to include the configuration information to an RRCConnectionReconfiguration message. The control message processor11-35generates the RRCConnectionReconfiguration message to a higher layer under the control of the control message processor11-35, the RRCConnectionReconfiguration message being transmitted to the UE. The higher layer entities11-25and11-30may be established per UE or per service to process data generated by a user service such as File Transfer Protocol (FTP) and Voice over IP (VoIP) services, the processed data being transferred to the multiplexer/demultiplexer11-20, or to process data from the multiplexer/demultiplexer11-20, the processed data being delivered to a higher layer service application. The scheduler11-15allocates transmission resources at a suitable timing to a UE in consideration of UE's buffer status, channel status, and Active Time and controls the transceiver11-05to process the signal transmitted by the UE or to be transmitted to the UE. Second Embodiment The second embodiment relates to a method for performing random access in a wireless communication system, e.g., 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) system, operating in an uplink asynchronous Hybrid Repeat Request (HARQ) mode. In the following description, the terms indicating various access nodes, network entities, messages, interfaces between network entities, and information items are used for convenience of explanation of the present disclosure. Accordingly, the terms used in the following description are not limited to specific meanings but may be replaced by other terms that are equivalent in technical meanings. In the following description, the terms and definitions given in the 3rd Generation Partnership Project Long Term Evolution (3PP LTE) standard are used for convenience of explanation. However, the present disclosure is not limited by the terms and definitions but can be applied to other standard communication systems in the same manner. FIG.12is a diagram illustrating architecture of an LTE system to which the second embodiment of the present disclosure is applied. In reference toFIG.12, the LTE system includes eNBs12-05,12-10,12-15, and12-20; a Mobility Management Entity (MME)12-25; and a Serving Gateway (S-GW)12-30. A user terminal (User Equipment (UE))12-35connects to an external network via the eNBs12-05,12-10,12-15, and12-20and the S-GW12-30. The eNBs12-05,12-10,12-15, and12-20access nodes of a cellular network to provide network access service to UEs camped thereon. That is, the eNBs12-05,12-10,12-15, and12-20schedules the UEs based on buffer status, power headroom status, and channel status collected from the UEs to connect the UEs to the Core Network (CN). The MME12-25is an entity taking charge of UE mobility management and other control functions and maintains connections with a plurality of eNBs, and the S-GW12-30is an entity for handling bearers. The MME12-25and the S-GW12-30may perform authentication on the UEs connected to the network, manage bearers, and process the packets from the eNBs12-05,12-10,12-15, and12-20or to be transmitted to the eNBs12-05,12-10,12-15, and12-20. FIG.13is a diagram illustrating a protocol stack of an interface between UE and an eNB in an LTE system to which the second embodiment of the present disclosure is applied. In reference toFIG.13, the protocol stack of the interface between the UE and the eNB includes a plurality of protocol layers stacked from the bottom to the top: physical layer denoted by reference numbers13-20and13-25, medium access control (MAC) layer denoted by reference numbers13-15and13-30, radio link control (RLC) layer denoted by reference numbers13-10and13-35, and packet data convergence control (PDCP) layer denoted by reference numbers13-05and13-40. The PDCP layer denoted by reference numbers13-05and13-40takes charge of compressing/decompressing an IP header, and the RLC layer denoted by reference numbers13-10and13-35takes charge of segmenting a PDCP Packet Data Unit (PDU) into segments of appropriate size. The MAC layer denoted by reference number13-15and13-30allows for connection of multiple RLC entities and takes charge of multiplexing RLC PDUs from the RLC layer into a MAC PDU and demultiplexing a MAC PDU into RLC PDUs. The PHY layer denoted by reference numbers13-20and13-25takes charge of channel-coding and modulation on higher layer data to generate and transmit OFDM symbols over a radio channel, and demodulating and channel-decoding on OFDM symbols received over the radio channel to deliver the decoded data to the higher layers. The PHY layer uses Hybrid ARQ (HARQ) for additional error correction by transmitting 1-bit information indicative of positive or negative acknowledgement from the receiver to the transmitter. This is referred to as HARQ ACK/NACK information. The downlink HARQ ACK/NACK corresponding to the uplink transmission is carried by Physical Hybrid-ARQ Indicator Channel (PHICH), and the uplink HARQ ACK/NACK corresponding to downlink transmission is carried by Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH). The HARQ is categorized into one of asynchronous HARQ and synchronous HARQ. The asynchronous HARQ is characterized by a variable retransmission timing for transmission whereas the synchronous HARQ is characterized by a fixed retransmission timing (e.g., 8 ms). Also, it may be possible to configure multiple HARQ processes running in parallel in downlink and uplink for one UE, the HARQ processes being identified by HARQ process identifiers (IDs). In the asynchronous HARQ, it is important for the eNB to provide the UE with the information on the HARQ process to which the current transmission belongs and whether the current transmission is an initial transmission or retransmission through a Physical Downlink Control Channel (PDCCH). In detail, the HARQ process to which the current transmission belongs is indicated by a HARQ Process ID field of the PDCCH, and whether the current transmission is the initial transmission or retransmission is indicated by a New Data Indicator (NDI) bit in the PDCCH (the NDI bit is not toggled to indicate retransmission but is toggled to indicate initial transmission). Accordingly, the UE acquires the detailed information on the corresponding transmission based on the resource allocation information included in the PDCCH transmitted by the eNB to receive downlink data through a Physical Downlink Shared Channel (PDSCH) or to transmit uplink data through a Physical Uplink Shared Channel (PUSCH). Although not shown in the drawing, a Radio Resource Control (RRC) layer resides above the PDCP layer at both the UE and the eNB, and the UE and the eNB may exchange connection and measurement configuration control messaged for radio resource management through RRC layer signaling. FIG.14is a signal flow diagram illustrating a random access procedure in an uplink synchronous HARQ mode. The UE14-01initiates a random access procedure as follows in a situation requiring random access such as initial access or re-access to an eNB and handover as follows. First, the UE14-01transmits a Random Access Preamble to the eNB14-03through a Physical Random Access Channel (PRACH) at step14-11. The preamble may be randomly selected or preconfigured by the eNB14-03. The eNB14-03transmits a Random Access Response (RAR) message to the UE14-01in response to the Random Access Preamble at step14-13. The RAR message includes a preamble identity information used at step14-11, uplink transmission timing information, and uplink resource allocation information and Temporarily UE identifier to be used at a subsequent step (i.e., step14-15). The uplink resource allocation information does not include the aforementioned HARQ Process ID and NDI because it is assumed that the synchronous HARQ is used in uplink. For example, it is possible to analogize the HARQ Process ID from the subframe index of the subframe in which uplink resources are allocated and ignore the NDI value for the corresponding resource allocation. If the RAR message is received, the UE14-01transmits to the eNB14-03, at step14-15, a message which is determined according to one of the aforementioned purposes using the resources allocated by means of the RAR message. For example, the message may be a Radio Resource Control (RRC) Connection Request message (RRCConnectionRequest) for the purpose of initial access, an RRC Connection Reestablishment Request message (RRCConnectionReestablishmentRequest) for the purpose of re-access, or a RRC Connection Reconfiguration Complete message (RRCConnectionReconfigurationComplete) for the purpose of handover. The message may be a Buffer Status Report (BSR) message for the purpose of resource request. Whether the message transmission made at step14-15has succeeded is determined through a Physical HARQ Indicator Channel (PHICH) at step14-17and, if it is determined that the transmission has failed, the UE performs retransmission at step14-19and14-25. If no PDCCH is received after transmission, the retransmission is performed using the resources allocated by means of the RAR message according to a predetermined scheme at step14-19; if a PDCCH is received in response to the corresponding retransmission at step14-23, the retransmission is performed according to the information included in the PDCCH at step14-25. The PDCCH transmitted at step14-23includes a HARQ Process ID and an NDI which is ignorable as aforementioned. For every (re)transmission, the UE14-01determines whether the (re)transmission has succeed based on the PHICH at steps14-17,14-21, and14-27. In a contention-based random access procedure (i.e., if the UE transmits a randomly selected preamble), the eNB14-03transmits a contention resolution message to the UE14-01at step14-31; however, the eNB14-03does not transmit the corresponding message in a non-contention-based random access procedure (i.e., if the eNB has command the UE to use a specific preamble). FIG.15is a signal flow diagram illustrating a random access procedure in an uplink asynchronous HARQ mode. The UE15-01initiates a random access procedure as follows in a situation requiring random access such as initial (re)access or re-access to an eNB and handover. The UE15-01transmits a Random Access Preamble to the eNB14-03through a Physical Random Access Channel (PRACH) at step15-11. The preamble may be randomly selected or preconfigured by the eNB15-03. The eNB15-03transmits a Random Access Response (RAR) message to the UE15-01in response to the Random Access Preamble at step15-13. The RAR message includes a preamble identity information used at step15-11, uplink transmission timing information, and uplink resource allocation information and Temporarily UE identifier to be used at a subsequent step (i.e., step15-15). Although the uplink resource allocation information does not include the HARQ Process ID and NDI as inFIG.14, these parameters are used for asynchronous HARQ, and the present disclosure proposes a method for determining a HARQ Process ID according to a predetermined rule or using a predetermined value. For example, the HARQ Process ID may be calculated through a modulo operation on the subframe index by 4 or fixed to a specific value (e.g., 0). In the asynchronous HARQ process in which every retransmission requires PDCCH transmission, the UE may determine whether the current transmission with the corresponding HARQ process ID is an initial transmission or a retransmission based on the NDI value included in every PDCCH being received afterward under the assumption that the NDI is set to a value included in the initially transmitted PDCCH (e.g., PDCCH transmitted at step15-14or, if step15-14is skipped, PDCCH transmitted at15-17) or a fixed value (e.g., 0 or 1). If the RAR message is received, the UE15-01transmits to the eNB15-03, at step15-15, a message which is determined according to one of the aforementioned purposes using the resources allocated by means of the RAR message. For example, the message may be a Radio Resource Control (RRC) Connection Request message (RRCConnectionRequest) for the purpose of initial access, an RRC Connection Reestablishment Request message (RRCConnectionReestablishmentRequest) for the purpose of re-access, or a RRC Connection Reconfiguration Complete message (RRCConnectionReconfigurationComplete) for the purpose of handover. The message may be a Buffer Status Report (BSR) message for the purpose of resource request. Meanwhile, whether the message transmission made at step15-15has succeeded is determined based on the HARQ Process ID and NDI value included in every PDCCH at steps15-14,15-17, and15-23in the asynchronous HARQ unlike the synchronous HARQ using PHICH. For example, if the NDI set to a value in the initial PDCCH or a fixed value (e.g., 0 or 1) which is received along with the same HARQ ID is not toggled, the UE15-01determines that the current transmission is a retransmission; otherwise if the NDI is toggled, the UE15-01determines that the current transmission is an initial transmission. Whether the current transmission is a retransmission or an initial transmission is determined in this way and, the eNB15-03performs transmission at step15-15or retransmission at steps15-19and15-25according to the information included in every PDCCH. That is, the UE15-01determines whether the (re)transmission has succeed based on the PDCCH received at step15-14,15-17, and15-23. In a contention-based random access procedure (i.e., if the UE transmits randomly selected preamble), the eNB15-03transmits a contention resolution message to the UE15-01at step15-31; however, the eNB15-03does not transmit the corresponding message in a non-contention-based random access procedure (i.e., if the eNB has command the UE to use a specific preamble). FIG.16is a flowchart illustrating a random access procedure of a UE according to an embodiment of the present disclosure. In the random access procedure, the UE selects one of random access schemes 1 and 2 in consideration of the PRACH transmission resource position and type (e.g., resource positon for enhanced Machine Type Communication (eMTC)) and purpose of random access (e.g., transmission of eMTC traffic) at step16-03. For example, if the UE is an MTC UE restricted in bandwidth (Bandwidth reduced Low complexity (BL) UE or Coverage Enhancement (CE) UE), it uses random access scheme 2. The UE also uses random access scheme 2 for transmission in a cell operating in an unlicensed band. Random access scheme 1 is designed for use in the uplink synchronous HARQ mode described with reference toFIG.14, and random access scheme 2 is designed for use in the uplink asynchronous HARQ mode described with reference toFIG.15. The UE determines whether the selected random access scheme is random access scheme 1 or 2 at step16-05. If it is determined to use random access scheme 1, the procedure goes to step16-07. At step16-07, if uplink resources are allocated by means of a RAR message received in response to a random access preamble, the UE determines a HARQ process ID based on the RAR message reception time point or the uplink resource use time point. Afterward, the UE may determine whether to perform retransmission on the data transmitted using the allocated uplink resources based on the HARQ feedback (i.e., ACK/NACK received through PHICH). If a PDCCH is additionally received for allocating uplink resources, the UE determines whether to perform the retransmission regardless of the value of the NDI included in the corresponding PDCCH and uses the NDI value to determine whether the subsequent transmission made in the same HARQ process is an initial transmission or retransmission. If it is determined to use random access scheme 2, the procedure goes to step16-09. At step16-09, if uplink resources are allocated by means of a RAR message received in response to a random access preamble, the UE determines a HARQ process ID according to a predetermined rule or sets the HARQ process ID to a predetermined value. For example, the HARQ process ID may be calculated through a modulo operation on the subframe index by 4, fixed to a specific value (e.g., 0), or determined based on the last PDCCH reception time point. For example, if the last PDCCH reception time points for HARQ process 0, HARQ process 1, and HARQ process 2 are t0, t1, and t2, respectively, the oldest HARQ process 1 (if t0>t1>t2) may be determined for message 3 transmission. Unlike random access scheme 1, the UE determines whether to perform a retransmission based on the PDCCH rather than PHICH. If the RAR is received, the UE registers an NDI value (e.g., 0 or 1) and determines whether a subsequent transmission is an initial transmission or a retransmission based on the HARQ process ID and the NDI value included in the PDCCH being received afterward, i.e., retransmission with the untoggled NDI value or initial transmission with the toggled NDI value. FIG.17is a block diagram illustrating UE in a wireless communication system according to an embodiment of the present disclosure. In reference toFIG.17, the UE includes a Radio Frequency (RF) unit17-10, a baseband processor17-20, a storage unit17-30, and a controller17-40. The RF unit17-10performs signal band conversion and amplification for transmitting/receiving signals over a radio channel. That is, the RF unit17-10up-converts a baseband signal output from the baseband processor17-20to an RF signal to be transmitted through an antenna and down-converts an RF signal received by the antenna to a baseband signal. For example, the RF unit17-10may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a Digital to Analog Converter (DAC), and an analog to Digital Converter (ADC). Although one antenna is depicted inFIG.17, the UE may include a plurality of antennas. The RF unit17-10may include a plurality of RF chains. Furthermore, the RF unit17-10may be configured to perform beamforming. For beamforming operation, the RF unit17-10may adjust phases and sizes of the signals transmitted/received through the plural antennas or antenna elements. The baseband processor17-20is responsible for conversion between baseband signals and bit strings according to a physical layer standard of the system. For example, the baseband processor17-20performs encoding and modulation on a transmission bit string to generate complex symbols in a data transmission mode. The baseband processor17-20also performs demodulation and decoding on the baseband signal output from the RF unit17-10to recover the original bit string in a data reception mode. In an exemplary case of using Orthogonal Frequency Division Multiplexing (OFDM), the baseband processor17-20performs encoding and modulation on the transmission bit string to generate complex symbols, maps the complex symbols to subcarriers, performs Inverse Fast Fourier Transform (IFFT) operation on the subcarrier-mapped complex symbols, and inserts Cyclic Prefix to generate OFDM symbols in the data transmission mode. The baseband processor17-20also segments a baseband signal from the RF unit17-10into OFDM symbols, performs Fast Fourier Transform (FFT) operation on the OFDM symbols to recover subcarrier-mapped signals, and performs demodulation and decoding on the subcarrier-mapped signals to recover the original bit string in the data reception mode. The baseband processor17-20and the RF unit17-10perform signal processing as described above to transmit and receive the signals. Accordingly, the baseband processor17-20and the RF unit17-10may be integrally referred to as transmitter, receiver, transceiver, or communication unit. Also, at least one of the baseband processor17-20and the RF unit17-10may include a plurality of communication modules to support different radio access technologies. Also, at least one of the baseband processor17-20and the RF unit17-10may include multiple communication modules designed for processing signals in different frequency bands. For example, the radio access technologies may include a Wireless Local Area Network (WLAN) (e.g., IEEE 802.11) and cellular network (e.g., LTE). The different frequency bands may include a Super High Frequency (SHF) band (e.g., 2.5 GHz and 5 GHz bands) and a millimeter wave (mmWave) band (e.g., 60 GHz band). The storage unit17-30stores basic programs for operation of the UE, application programs, and data including configuration information. Particularly, the storage unit17-30may store the information related to a WLAN node performing radio communication with a WLAN access technology. The storage unit17-30also provides data stored therein on request from the controller17-40. The controller17-40controls overall operations of the UE. For example, the controller17-40controls the baseband processor17-20and the RF unit17-10to transmit and receive signals. The controller17-40also writes and reads data to and from the storage unit17-30. For this purpose, the controller17-40may include at least one processor. For example, the controller17-40may include a Communication Processor (CP) for controlling communication and an Application Processor (AP) for controlling higher layer applications. According to the second embodiment of the present disclosure, the controller17-40includes a multi-connectivity processor17-42for supporting multi-connectivity mode. For example, the controller17-40may control the UE to perform the UE operations depicted inFIG.16. According to the second embodiment of the present disclosure, the controller17-40determines whether to use random access mode 1 or 2 and performs random access to the eNB according to the determined random access mode. The methods disclosed in the claims and embodiments specified in the specification may be implemented in hardware, software, or a combination thereof. In the case of being implemented in software, it may be possible to store at least one program (software module) in a computer-readable storage medium. The at least one program stored in the computer-readable storage medium may be configured for execution by at least one processor embedded in an electronic device. The at least one program includes instructions executable by the electronic device to perform the methods disclosed in the claims and specifications of the present disclosure. Such a program (software module or software program) may be stored in a non-volatile memory such as random access memory (RAM) and flash memory, Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), a magnetic disc storage device, a Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs) or other type of optical storage device, and a magnetic cassette. It may also be possible to store the program in a memory device implemented in combination of part or whole of the aforementioned media. The storage unit may include a plurality of memories. The program may be stored in an attachable storage device accessible through a communication network implemented as a combination of Internet, intranet, Local Area Network (LAN), Wireless LAN (WLAN), and Storage Area Network (SAN). The storage device may be attached to the device performing the methods according to embodiments of the present disclosure by means of an external port. It may also be possible for a separate storage device installed on a communication network to attach to the device performing the methods according to embodiments of the present disclosure. Third Embodiment FIG.18is s a diagram illustrating architecture of an LTE system to which the third embodiment of the present disclosure is applied. In reference toFIG.18, the LTE system includes eNBs18-05,18-10,18-15, and18-20; a Mobility Management Entity (MME)18-25; and a Serving Gateway (S-GW)18-30. A user terminal (User Equipment (UE))18-35connects to an external network via the eNBs18-05,18-10,18-15, and18-20and the S-GW18-30. The eNBs18-05,18-10,18-15, and18-20access nodes of a cellular network to provide network access service to UEs camped thereon. That is, the eNBs18-05,18-10,18-15, and18-20schedules the UEs based on buffer status, power headroom status, and channel status collected from the UEs to connect the UEs to the Core Network (CN). The MME18-25is an entity taking charge of UE mobility management and other control functions and maintains connections with a plurality of eNBs, and the S-GW18-30is an entity for handling bearers. The MME18-25and the S-GW18-30may perform authentication on the UEs connected to the network, manage bearers, and process the packets from the eNBs18-05,18-10,18-15, and18-20or to be transmitted to the eNBs18-05,18-10,18-15, and18-20. FIG.19is a diagram illustrating a protocol stack of an interface between UE and an eNB in an LTE system to which the third embodiment of the present disclosure is applied. In reference toFIG.19, the protocol stack of the interface between the UE and the eNB includes a plurality of protocol layers stacked from the bottom to the top: physical layer denoted by reference numbers19-20and19-25, medium access control (MAC) layer denoted by reference numbers19-15and19-30, radio link control (RLC) layer denoted by reference numbers19-10and19-35, and packet data convergence control (PDCP) layer denoted by reference numbers19-05and19-40. The PDCP layer denoted by reference numbers19-05and19-40takes charge of compressing/decompressing an IP header, and the RLC layer denoted by reference numbers19-10and19-35takes charge of segmenting a PDCP Packet Data Unit (PDU) into segments of appropriate size. The MAC layer denoted by reference number19-15and19-30allows for connection of multiple RLC entities and takes charge of multiplexing RLC PDUs from the RLC layer into a MAC PDU and demultiplexing a MAC PDU into RLC PDUs. The PHY layer denoted by reference numbers19-20and19-25takes charge of channel-coding and modulation on higher layer data to generate and transmit OFDM symbols over a radio channel, and demodulating and channel-decoding on OFDM symbols received over the radio channel to deliver the decoded data to the higher layers. The PHY layer uses Hybrid ARQ (HARQ) for additional error correction by transmitting 1-bit information indicative of positive or negative acknowledgement from the receiver to the transmitter. This is referred to as HARQ ACK/NACK information. The downlink HARQ ACK/NACK corresponding to the uplink transmission is carried by Physical Hybrid-ARQ Indicator Channel (PHICH), and the uplink HARQ ACK/NACK corresponding to downlink transmission is carried by Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH). Although not shown in the drawing, a Radio Resource Control (RRC) layer resides above the PDCP layer at both the UE and the eNB, and the UE and the eNB may exchange connection and measurement configuration control messages for radio resource management through RRC layer signaling. In the LTE system, a UE to which no connection is configured (idle UE) performs a random access procedure to connect to a network. FIG.20is a signal flow diagram illustrating a random access procedure. At step20-20, RACH procedure-related system information is broadcast. The system information includes information on the preamble ID range of RACH preamble group A, the preamble ID range of RACH preamble group B, UE transmission message size threshold (THRES), and channel status offset. For more details on the above parameters, refer to the 3PP standard TS36.331. If a preamble group and a preamble are selected, the UE20-05transmits the preamble (hereinafter, interchangeably referred to as message 1 or Msg1) to the eNB20-10, using PRACH resource, at step20-25. If the preamble is received, the eNB20-10transmits to the UE20-05a Random Access Response (RAR) message (hereinafter, interchangeably referred to as message 2 or Msg2), as an RACH response message, including a Random Access Preamble ID (RAPID) for identifying the received preamble, Timing Advance (TA) information for adjusting uplink timing, an uplink (UL) resource allocation information for transmitting the message at step20-35(UL grant), and a Temporary UE identity information (Temporary C-RNTI) at step20-30. The RAR message may also include the information on various types of preambles as described above. That is, the RAR message may include a plurality of RAPIDs, TAs, UL grants, Temporary C-RNTIs. The UE20-05may identify the signal carrying information for it with the RAPID. If multiple UEs transmit the same preamble at step20-25, collision may occur and, in this case, the eNB20-10transmits to the UE20-05a collision resolution message at step20-40, the collision resolution message including UE-specific IDs (S-TMSIs) or random number information of the UEs which have transmitted the preamble in the collision situation, the information being received at step20-35. Each of the UEs which have used the same preamble at step20-25determines whether any of the UE-specific IDs or random number information included in the message received at step20-40matches the UE-specific ID or random number information it has transmitted at step20-35and, if so, performs an RRC connection establishment procedure and otherwise, if not, the RACH procedure again. In the RRC connection establishment procedure, the UE20-05achieves uplink synchronization with the eNB20-10through the random access procedure and transmits the RRCConnectionRequest message (hereinafter, interchangeably referred to as message 3 or Msg3) at step20-35. The RRCConnectionRequest message includes the identifier of the UE20-05and a connection establishment cause. The eNB20-10transmits an RRCConnectionSetup message (hereinafter, interchangeably referred to as message 4 or Msg4) for establishing an RRC connection along with the collision resolution message at step20-40. The RRCConnectionSetup message includes RRC connection setup information. The RRC connection is also referred to as Signaling Radio Bearer (SRB) and used for exchanging RRC messages as control messages between the UE20-05and the eNB20-10. After the RRC connection setup has been completed, the UE20-05transmits an RRCConnectionSetupComplete message (hereinafter, interchangeably referred to as message 5 or Msg5) to the eNB20-10at step20-45. The RRCConnectionSetupComplete message includes a control message called SERVICE REQUEST in order of the UE20-05to request to the MME for bearer establishment for a predetermined service. The eNB20-10transmits to the MME the SERVICE REQUEST message included in the RRCConnectionSetupComplete message at step20-50, and the MME determines whether to provide the service requested by the UE20-05. If it is determined to provide the service requested by the UE20-05, the MME transmits an INITIAL CONTEXT SETUP REQUEST message to the eNB20-10at step20-55. The INITIAL CONTEXT SETUP REQUEST message includes Quality of Service (QoS) and security information (e.g., Security Key and Security Algorithm) for use in establishing a Data Radio Bearer (DRB). The eNB20-10transmits a SecurityModeCommand message to the UE20-05at step20-60, and the UE20-05transmits a SecurityModeComplete message to the eNB20-10in response to the SecurityModeCommand message at step20-65, resulting in security setup. If the security setup has been completed, the eNB20-10transmits an RRCConnectionReconfiguration message to the UE20-05at step20-70. The RRCConnectionReconfiguration message includes DRB configuration information for use in processing user data and thus the UE20-05configure a DRB based on the DRB configuration information and then transmits an RRCConnectionReconfigurationComplete message to the eNB20-10at step20-75. After configuring the DRB to the UE20-05, the eNB20-10transmits an INITIAL CONTEXT SETUP COMPLETE message to the MME at step20-80and, upon receipt of this message, the MME transmits an S1 BEARER SETUP message to the S-GW at step20-85and receives an S1 BEARER SETUP RESPONSE message from the S-GW to configure an S1 bearer. The S1 bearer is a dedicated data connection being established between the S-GW and the eNB20-1and corresponds to the DRB one by one. If the above operations have been completed, the UE20-05and the eNB20-10perform data communication via the S-GW at steps20-95and20-100. As described above, the data transmission procedure is typically divided into three phases: RRC connection setup, security configuration, and DRB configuration. If there is no data to transmit during a predetermined period or if connection failure occurs because of a network condition, the eNB in the RRC connected state transitions back to the idle state in which, in order to attempt to connect the network again, it has to perform the above-described procedure. If a large number of UEs perform the procedure represented by steps20-20to20-90simultaneously, this may cause significant battery consumption problem as well as significant signaling overhead. Furthermore, if the number of UEs operating in an extended coverage mode (such as NB-IoT UEs, BL UEs, UEs in CE, and eMTC UEs) increased in addition to the ordinary UEs in the network, the signaling overhead problem may become worse. There are two solutions to solve the above problems. The first solution is a Control Plane-based (CP-based) solution for transmitting the data in Non Access Stratum (NAS) messages over control plane SRB to efficiently process the packets of the extended coverage mode UEs, the packets being small in size and occurring sporadically. That is, the UE20-05may transmit packets to the eNB20-10using a dedicatedNASInfo field of the RRCConnectionSetupComplete message at step20-45ofFIG.20. Here, the NAS messages are control messages exchanged between the UE20-05and the MME. The second solution is a User Plane-based (UP-based) solution in which the UE20-05and the network store the UE information (UE context) for reuse in the next connection. An embodiment of the present disclosure proposes the elements used for implementing the second solution along with detailed description thereof. If a UE in the RRC-connected state has no data to transmit/receive during a predetermined period, the eNB releases the connection with the UE and thus the UE enters the idle state and, in this case, the eNB and the UE delete the UE context. In order for the UE in the idle state to connect to the network again, it has to perform the procedure represented by steps20-20to20-90ofFIG.20. In order to reduce such signaling overhead, it may be considered that the eNB and the UE maintain the UE context, even when the UE enters the idle state, for reuse in the next network connection attempt. However, this operation requires a new request message (hereinafter, referred to as Resume Request message or RRCConnectionResumeRequest). It may be possible to use a message defined for Common Control Channel (CCCH) (e.g., RRCConnectionRequest) as the Resume Request message or to newly define the Resume Request message. The Resume Request message may include a Resume ID, a Short MAC-I, and an Establishment cause. The Resume ID included in the Resume Request message is used by the eNB which has received the Resume Request message from the UE for identifying the corresponding UE. The Resume ID may have a size of 40 bits or 25 bits and, for convenience of explanation, the 40-bit Resume ID is referred to as Full ID (FID) while the 25-bit Resume ID is referred to as Truncated ID (TID). If the eNB releases the connection of the UE in the RRC-connected state, it allocates a 40-bit Resume ID. If it becomes beneficial to connect to the network afterward, the UE transmits the Msg3 including the Resume ID to a new eNB or the old eNB to which it has connected (when the UE mobility is low). In order to use the 40-bit Resume ID, however, it is useful to extend the size of the current Msg3. The Transport Block Size (TBS) of the legacy Msg3 (i.e., legacy RRCConnectionRequest) is 56 bits which is not enough to carry the 4-bit FID. In the present disclosure, it is proposed to use the legacy 56-bit TBS for TID and a 72-bit TBS for FID. The eNB notifies the UE of the type of the Resume ID (i.e., FID or TID) to use, and the UE determines whether to perform a Resume procedure or the legacy RRC Connection Setup (or establishment) procedure based on the type of the Resume ID and channel condition. In the present disclosure, the UE determines the type of Msg3 (or type of Resume ID or CCCH message) according to its operation mode. The operation mode is categorized into one of and enhanced coverage mode for machine type communication and a normal mode for ordinary communication. In the enhanced coverage mode, the UE perform all uplink transmission and downlink reception repeatedly a number of times as instructed by the eNB. Meanwhile, in the normal mode, the UE does not repeat receiving downlink signals (downlink reception in the random access procedure) and, unless otherwise instructed by the eNB using a dedicated RRC message, transmitting uplink signals. The UE may determine its operation mode in the cell selection/reselection procedure and, if a normal mode operation-capable cell and an enhanced coverage mode-only cell coexist, selects the normal mode operation-capable cell with priority. The radio resources designated for the enhanced coverage mode and normal mode are mutually exclusive. For example, the UE can use only dedicated-coverage mode frequency/time resources in the enhanced coverage mode and only dedicated-normal mode frequency/time resources in the normal mode. In the present disclosure, the eNB broadcasts a UP solution (or UEL context retrieval solution) supportability and type of required Resume ID using its system information, and the UE determine the types of the CCH message and Resume ID in consideration of its operation mode, the broadcast information, the channel condition. If the UE operating in the enhanced coverage mode performs the Resume operation, it determines the type of CCCH message based on whether the serving cell supports the UP solution. If the serving cell supports the UP solution, the UE transmits a Resume Request message including the FID; if the serving cell does not support the UP solution, the UE transmits a RRC Connection Request message. The reason why the TID is not used in the enhanced coverage mode is that it is possible to transmit a large CCCH message through repetitive transmission even when the channel condition is bad. For the UE operating in the normal mode, it is required for the serving cell to support the UP solution and for the UE to use the FID and, if the channel condition is better than a predetermined threshold, the UE transmits the Resume Request message including the FID. If the UP solution is supported and the use of TID15required, the UE transmits the Resume Request message including the TID without consideration of the channel condition. If the channel condition is worse than a predetermined threshold although the UP solution is supported and the use of FID is required, the UE initiates the legacy RRC Connection Setup procedure rather than the Resume procedure. That is, the UE transmits an RRC Connection Request message. FIG.21is a diagram illustrating a message format of Msg3 including a CCCH SDU for use in LTE uplink. As shown inFIG.21, the legacy LTE Msg3 is 56 bits and includes a MAC header and a CCCH SDU. The extended Msg3 (e.g., 72-bit extended Msg3) may include a Resume ID (40 bits), an Establishment cause (3 bits), a Short MAC-I (16 bits), a MAC/RRC overhead (12 bits), and a Spare (1 bit). In the case of using a new Resume Request message, it may be useful to define the new Resume Request message with 1 extra bit to be distinguished from the legacy LTE Msg3. In the Resume Request message21-05, an available payload size is 44 bits including 16 bits for the short MAC-I and 3 bits for the Establishment cause. Accordingly, the Resume ID may be allocated the remaining 25 bits (or 24 bits if one bit is reserved for future use). However, when the eNB serving the UE in the RRC-connected state releases the connection with the corresponding UE, it allocates a 40-bit Resume ID. Accordingly, in order for a normal UE to use the legacy LTE Msg3 (56 bits), it is useful to divide the 40-bit Resume ID into several parts and combine a few of the parts into a Truncated resume ID (e.g., 25-bit Truncated resume ID). FIG.22is a diagram illustrating truncating option 1 for generating a Truncated resume ID (e.g., 25-bit TID) by dividing a 40-bit Resume ID into several parts and combining a few of the parts according to an embodiment of the present disclosure. The eNB has a real Resume ID (RID)22-10to be allocated to the UE to which the connection the eNB intends to release, the real RID consisting of a 20-bit UE ID and a 20-bit eNB ID22-05. The eNB divides the RID into several parts and rearranges the parts to generate a full resume ID (FID)22-15. In the process, the eNB divides the 20-bit UE ID into a UE ID Most Significant Bits (MSB) part of 15 bits and a UE ID Least Significant Bits (LSB) part of 5 bits and the 20-bit eNB ID into an eNB ID MSB part of 10 bits and an eNB ID LSB part of 10 bits and then rearranges the UE ID MSB and LSB parts and the eNB ID MSB and LSB parts to generate the FID. Here, the combination of the UE ID MSB part and the eNB ID MSB part is used as the Truncated resume ID (TID). If the FID is received, the UE may use the 40-bit resumed FID22-15in need of FID transmission and the 25-bit TID22-20in need of TDI transmission. FIG.23is a diagram illustrating truncating option 2 for generating a Truncated resume ID (e.g., 25-bit TID) by dividing a 40-bit Resume ID into several parts and rearranging the parts according to an embodiment of the present disclosure. The eNB has a Real Resume ID (RID)23-10to be allocated to the UE to which the connection the eNB intends to release, the real RID consisting of a 20-bit UE ID and a 20-bit eNB ID23-05. The eNB has an RID and allocates the RID as an FID23-15to the UE without modification. The UE processes the FID to generate a TID23-20. In this process, the UE divides the 20-bit UE ID into a UE ID Most Significant Bits (MSB) part of 15 bits and a UE ID Least Significant Bits (LSB) part of 5 bits and the 20-bit eNB ID into an eNB ID MSB part of 10 bits and an eNB ID LSB part of 10 bits and then combines the UE ID MSB and the eNB ID MSB to generate the 25-bit TID. The UE may use the FID23-15identical with the RID23-10in need of FID transmission and the 25-bit TID23-20in need of TID transmission. As described above, the UE operating in an extended coverage mode (NB-IOT UE, BL UE, UE in CE, or eMTC UE) uses the legacy LTE Msg3 of 56 bits or the extended Msg3 of 72 bits according to the system information broadcast by the eNB, and a normal UE determines the type of Msg3 to use according to the system information and uplink channel condition. However, the eNB cannot be aware of the type of Msg3 selected by the UE (legacy LTE Msg3 or extended Msg3). This means that the eNB cannot allocate resources suitable for the size of the Msg3 to be transmitted by the UE in the RAR Msg2 for allocating uplink resources to the UE (uplink grant) at step20-30ofFIG.20. Such an operation causes resource waste. In order to protect against such resource waste, the third embodiment of the present disclosure proposes a method for sorting random access preamble resources into preamble groups and determining one of the preamble group for the UE to inform the eNB of the type of Msg3 to be used using the Msg1 along with the eNB operation in association with Msg2 and UE operation in association with Msg3, the method being escribed in detail with reference toFIG.24and tables 2 and 3. FIG.24is a diagram illustrating PRACH resource structures for an eNB to support normal UEs and UEs operating in the extended coverage modes (or normal mode and enhanced mode). As denoted by reference number24-05, 64 preamble resources are sorted for use by the normal UE and UEs operating in the extended coverage UEs. A normal UE selects one of group A and group B in consideration of channel condition and transmits the Msg120-25ofFIG.20(random access procedure) with a preamble selected in the corresponding group. Whether the channel is good or bad is may be determined based on path-loss. If the path-loss is greater than a predetermined threshold, the UE may determine that the channel is bad and, as a consequence, select the preamble group A; if the path-loss is less than a predetermined threshold, the UE may determine that the channel is good and, as a consequence, select the preamble group B. The UE operating in the extended coverage mode has a Coverage Extension (CE) function to overcome a low transmit power because it is likely to be installed in an area with bad communication conditions. For the CE function, the UEs operating in the extended coverage mode may be categorized into CE levels 0 to 3 based on the cell level (CE level 0 indicates a normal coverage, and the coverage increases in the ascending order of the CE levels). In the case of a UE operating in the extended coverage mode, the UE may sort the preamble resources into groups by the CE level as denoted by reference number24-05ofFIG.24. An eNB supporting the UEs operating in the extended coverage mode may sort the preamble resources into preamble groups by the CE level as denoted by reference number24-10ofFIG.24. TABLE 2Supported resume ID in the current cellPreamble Group/TruncatedFullResume ID typeresume IDresume IDSelection(TID)(FID)PRACHOnly GroupAlways GroupInvalid ConfigurationpartitioningAA & TIDin the currentBoth GroupAlways GroupIf path loss < threshold,cellA and BA & TIDGroup B & FID otherwise,Group A (fall back). Table 2 shows the types of resume ID available for Msg3 and preamble groups from which a preamble is selected for Msg1 for use by a normal UE according to an embodiment of the present disclosure. A UE operating in the extended coverage mode uses a resume ID supported by the cell in consideration of the system information. The normal UE may receive the information on the resume ID supported by the corresponding cell, preamble groups, and path loss through the system information. If the corresponding cell supports TID, the UE transmits the Msg1 with a preamble belonging to Group A. If the corresponding cell supports FID, the UE transmits the Msg1 with a preamble belonging to Group B for the case where the path loss is less than a predetermined threshold (channel condition is good) or with a preamble belonging to Group A for the case where the path loss is greater than a predetermined threshold (channel condition is bad) and then returns to the RRC Connection Request procedure without Resume Request Procedure. That is, the UE determines that the 72-bit extended message longer than the legacy 56-bit LTE message is supported when the channel condition is good. TABLE 3Supported resume ID in the current cellExceptedTruncated resumeFull resumebehaviorID (TID)ID (FID)eNB56 bits grant in RAR (Msg2)72 bits grant in RAR (Msg2)UEResume with TID (Msg3)Resume with FID (Msg3) Table 3 summarizes an eNB operation in association with Msg2 transmission and a normal UE operation in association with Msg3 transmission when the normal UE selects a preamble group and transmits the Msg1 with a preamble from the corresponding preamble group. If it is determined that the preamble received from the UE belongs to preamble group A, the eNB allocates 56-bit uplink resource to the UE using the Msg2. If the Msg2 is received, the UE transmits the Msg3 including a TID to the eNB. If it is determined that the preamble received from the UE belongs to preamble group B, the eNB allocates 72-bit uplink resources to the UE using the Msg2. If the Msg2 is received, the UE transmits the Msg3 including an FID to the eNB. FIG.25is a flowchart illustrating a procedure for a UE to resume the RRC connection according to the third embodiment of the present disclosure. The UE of which connection to the network is suspended may resume the connection at step25-05. The UE camps on a cell through an initial procedure for RRC connection setup and receives system information of the corresponding cell. The system information may include type of resume ID supported in the corresponding cell, CP-based scheme or UP-based scheme supportability, preamble group information, and path-loss information. The UE determines step25-10whether the corresponding cell support the UP-based scheme based on the system information. If it is determined that the cell does not support the UP-based scheme, the UE performs the connection setup procedure using the RRCConnectionRequest message of the legacy LTE system at step25-15. If it is determined at step25-10that the cell supports the UP-based scheme, the procedure goes to step25-20. At step25-20, if the UE is a NB-IoT UE, a BL UE, a UE in CE, or an eMTC UE, it attempts connection setup using the newly defined RRCConnectionResumeRequest message at step25-30. Otherwise, if it is determined at step25-20that the UE is neither a NB-IoT UE, a BL UE, a UE in CE, nor an eMTC UE, the procedure goes to step25-25. At step25-25, the UE determines whether the cell on which the UE camps uses FID and path-loss in the cell is greater than a predetermined value and, if so, performs the connection setup procedure using the RCCConnectionRequest message of the legacy LTE system at step25-15 The type of resumed ID for use in determining whether the UE uses FID may be included in the system information, particularly, SIB2. The predetermined value may be calculated by Pcmax,c—preambleInitialReceiveTargetPower—deltaPreambleMsg3—messagePowerOffsetGroupB. The above parameters are defined in TS36.331, and the predetermined value may be calculated using other parameters. If it is determined at step25-25that the cell on which the UE camps neither uses FID nor path-loss in the cell is greater than the predetermined value, the UE attempts connections setup using the newly defined RRCConnectionResumeRequest message at step25-30. FIG.26is a flowchart illustrating a procedure for a normal UE to determine the type of preamble for use in Msg1 and the type of resume ID for use in Msg3 in the random access procedure based on the system information and channel condition according to an embodiment of the present disclosure. The eNB releases the connection of a normal UE in the RRC-connected state thereto without data transmission during a predetermined period and allocates a 40-bit resume ID to the UE. The 40-bit resume ID may have a structure of FID as shown inFIGS.22and23. The normal UE of which connection is released (hereinafter, referred to as suspended UE) may trigger a connection resume procedure at step26-05. The normal UE camps on a cell through an RRC Connection setup procedure and receives system information of the corresponding cell. The system information may include type of resume ID supported in the corresponding cell, CP-based scheme or UP-based scheme supportability, preamble group information, and path-loss information. The UE determines at step26-10whether the corresponding cell supports the UP-based scheme based on the system information. If it is determined that the cell does not support the UP-based scheme, the UE transmits a preamble selected from preamble group A using Msg1 for the random access procedure at step26-15and performs the RRC Connection Establishment procedure at step26-20. If it is determined at step26-10that the cell supports the UP-based scheme, the UE checks for preamble group information, type of resume ID supported by the corresponding cell, and channel condition at step26-25. If the type of resume ID supported by the corresponding cell is TID, the UE transmits a preamble selected from preamble group A using the Msg1 of the random access procedure at step26-30and generates the Msg3 with the TID as the resume ID at step26-35. If the type of the resume ID supported by the corresponding cell is FID, the UE determines whether the path-loss is less than a predetermined threshold (channel is good), and if so, transmits a preamble selected from preamble group B using the Msg1 of the random access procedure at step26-40and generates the Msg3 with the FID as the resume ID at step26-45. If it is determined at step26-25that the resume ID supported by the corresponding cell is FID and the path-loss is greater than a predetermined threshold (channel is bad), the UE transmits a preamble selected from preamble group A using the Msg1 of the random access procedure at step26-15and performs the RRC connection establishment procedure at step26-20. FIG.27is a signal flow diagram illustrating signal flows among a UE, a source eNB, a target eNB, and an MME in a Resume request procedure according to the third embodiment of the present disclosure. The resume request procedure is performed efficiently by reuse of the UE context between a UE and an eNB to reuse the UE context, resulting reduction of battery power waste and signaling overhead. InFIG.27, the UE in the RRC-connected state is communicating data with the source eNB. If the data communication is stopped, the source eNB starts a timer and, if data transmission is not resumed before the expiry of the timer at step27-05, considers releasing the RRC connection of the UE. The source eNB releases the RRC connection of the UE according to a predetermined rule, stores the UE context, and transmits a control message indicating the UE to release the RRC connection with a 40-bit resume ID. The UE is aware of the necessity of storing the UE context based on the allocation of the resume ID or a separate context preservation indicator transmitted by the source eNB at step27-10. The control message may include a context preservation period of the eNB or a list of cells in which the UE is capable of performing the RRC connection reconfiguration procedure with the stored context during a validity period. The resume ID may be allocated according to the methods proposed inFIGS.4E and4F. After releasing the RRC connection of the UE, the source eNB maintains the UE context and S1 bearer at step27-15. The S1 bearer denotes the S1-control bearer for use in exchanging control messages between the eNB and the MME and the S1-user plane bearer for use in transmitting user data between the eNB and the S-GW. By maintaining the S1 bearer, it is possible to skip an S1 bearer configuration procedure when the UE establish an RRC connection to the same cell or same eNB. Upon expiry of the validity period, the source eNB may delete the UE context and release the S1 bearer. The source eNB transmits a control message requesting to the MME for connection suspension at step27-20. If the control message is received, the MME instructs the S-GW to request, when downlink data for the UE is received, to the MME for triggering a paging procedure rather than to forward the downlink data to the source eNB, and the S-GW operates according to the instruction at step27-40. If the network entities do not operate as above, i.e., if the S-GW forwards the downlink data to the source eNB, the source eNB has to receive and store the downlink data destined for the UE of which RRC connection has been released and perform a paging procedure. If the UE has moved to the service area of another target eNB (target eNB inFIG.27), it may be useful to laboriously request to the MME to trigger a paging procedure. In order to avoid this laboriousness, the source eNB transmits to the MME the connection suspension control message for the UE of which the RRC connection has been released but the UE context has been stored. If the RRC connection release message including context preservation indicator information and the 40-bit resume ID is received at step27-10, the UE releases the RRC connection, starts a timer for monitoring the validity period, writes an available cell list in the memory, and maintain the current UE context at step27-25. The UE context information includes various types of information related to the RRC configuration of the UE such as SRB configuration information, DRB configuration information, and security information. Afterward, the UE may establish an RRC connection for a certain reason at step27-30. A UE which is neither allocated a resume ID nor instructed to maintain the UE context in the previous RRC connection release procedure initiates the legacy RRC connection setup procedure, but a UE which is allocated the resume ID in the previous RRC connection release procedure attempts the RRC connection setup procedure with the stored UE context (UP-based scheme). The UE receives the system information of the cell on which it has camped on at step27-35. The system information may include type of resume ID, CP-scheme or UP-scheme supportability, preamble group, and path-loss. The UE selects a preamble to be transmitted as the Msg1 and a resume ID to be transmitted with the Msg3 in the random access procedure using tables 2 and 3 according to the procedure ofFIG.26at step27-50. The UE transmits the selected preamble, i.e., Msg1 at step27-55. The eNB which has received the Msg1 (preamble) determines the preamble group to which the preamble belongs and allocates uplink resources to the UE using the Msg2 according to the determined preamble group using table 2 at step27-60. The UE transmits a Resume request message including the selected resume ID using the allocated uplink resources at step27-65. The Resume request message may be generated by modifying the RRC Connection Request message or newly defined (e.g., RRC Connection Resume Request message). If the UE of which the connection to the source eNB is released and moves, in the idle state, and camps on a cell of another eNB (target eNB inFIG.27), the target eNB receives checks the resume request message for the resource ID of the UE and identify the source eNB which has served the UE. If the target eNB identifies the source eNB successfully with the resume ID, it triggers a context retrieve procedure at step27-70. The target eNB may bring the UE context from the source eNB through the S1 or X2 interface (if the target eNB fails identifying the source eNB although it has received the resume ID, it may transmit an RRC Connection Setup message to the UE to return to the legacy RRC connection establishment procedure). The target eNB determines the RRC connection configuration for the UE based on the retrieved UE context and transmits to the UE a modified RRC connection setup message including the configuration information at step27-75. The modified RRC connection setup message may be generated by including a REUSE INDICATOR indicating ‘RRC context reuse’ in the legacy RRC connection setup message. The modified RRC connection setup message may include information related to the RRC connection configuration of the UE like the legacy RRC connection setup message. If the UE receives the legacy RRC connection setup message it configures the RRC connection based on the configuration information included in the RRC connection setup message; if the UE receives the modified RRC connection setup message, it configures the RRC connections in consideration of both the previously store configuration information and the configuration information included in the control message (Delta configuration). The UE determines the received configuration information as the delta information corresponding to the stored configuration information and updates the configuration information the UE context with the data information at step27-80. For example, if the modified RRC connection setup message includes SRB configuration information, the UE configures an SRB based on the SRB configuration information; if the modified RRC connection setup message does not include any SRB configuration information, the UE configures an SRB based on the SRB configuration information contained in the UE context. The UE configures the RRC connection based on the update UE context and configuration information and transmits a modified RRC connection setup complete message to the target eNB at step27-85. The modified RRC connection setup complete message may be generated by including message authentication information (MAC-I) in the legacy RRC connection setup complete message. The MAC-I is a message authentication code generated by the UE in such a way of applying the security information of the retrieved UE context, i.e., security key and security counter, for use in the control message. If the modified RRC connection setup complete message is received, the target eNB checks the message for integrity using the MAC-I of the modified RRC connection setup complete message and the security key and security counter contained in the UE context at step27-90. If the integrity test succeeds, the target eNB transmits to the MME a control message requesting for release of the connection suspension and reconfiguration of the S1 bearer to the target eNB at step27-95. If this control message is received, the MME instructs the S-GW to reconfigure the S1 bearer to the target eNB and to process data destined for the UE normally. If the above described procedure has been completed, the UE resumes data communication in the cell. If the UE lost the connection to the source eNB moves little in the idle state and thus camps on the cell of the source eNB again, the source eNB retrieves the UE context of the UE based on the resume ID received in the Msg3 and reconfigures the connection in a similar way as described above based on the retrieved UE context in the above procedure. FIG.28is a block diagram illustrating a configuration of a UE according to the third embodiment of the present disclosure. As shown inFIG.28, the UE according to the third embodiment of the present disclosure includes a transceiver28-05, a controller28-10, a multiplexer/demultiplexer28-15, a control message processor28-30, higher layer entities28-20and28-25, an EPS bearer manager28-35, and a NAS layer entity28-40. The transceiver28-05receives data and predetermined control signals through a downlink channel and transmits data and predetermined control signals through an uplink channel in a serving cell. In the case that multiple serving cells are configured, the transceiver28-05may perform data communication through the multiple serving cells. The multiplexer/demultiplexer28-15multiplexes data generated from the higher layer entities28-20and28-25and the control message processor28-30and demultiplexes the data received by the transceiver28-05, the demultiplexed data being delivered to the higher layer entities28-20and28-25and/or the control message processor28-30. The control message processor28-30is an RRC layer entity for processing the control message received from the eNB. For example, if the RRC CONNECTION SETUP message is received, the control message processor28-30configures an SRB and a temporary DRB. The higher layer entities28-20and28-25(each higher layer entity being established by EPS bearer) are DRB entities (each DRB entity being configured by the service). The higher layer entities28-20and28-25process the data generated in association with a user service such as File Transfer Protocol (FTP) and Voice over Internet Protocol (VoIP) services and transfer the processed data to the multiplexer/demultiplexer28-15or process the data output from the multiplexer/demultiplexer28-15and transfer the processed data to higher layer service applications. One service may be mapped to one EPS bearer and one higher layer entity one by one. The controller28-10checks for the scheduling command, e.g., uplink grant, received by the transceiver28-05and control the transceiver28-05and the multiplexer/demultiplexer28-15to perform uplink transmission using appropriate transmission resources at appropriate timings. FIG.29is a block diagram illustrating a configuration of an eNB, MME, and S-GW according to the third embodiment of the present disclosure. As shown inFIG.29, the eNB according to the third embodiment of the present disclosure includes a transceiver29-05, a controller29-10, a multiplexer/demultiplexer29-20, a control message processor29-35, higher layer entities29-25and29-30, a scheduler29-15, EPS bearer entities29-40and29-45, and a NAS layer entity29-50. The EPS bearer entity is located in an S-GW, and the NAS layer entity is located in an MME. The transceiver29-05transmits data and predetermined control signals over a downlink carrier and receives data and predetermined control signals over an uplink carrier. If multiple carriers are configured, the transceiver29-05transmits and receives the data and control signals over the multiple carriers. The multiplexer/demultiplexer29-20multiplexes data generated by the higher layer entities29-25and29-30and the control message processor29-35and demultiplex the data from the transceiver29-05, the demodulated data being delivered to the higher layer entities29-25and29-30, the control message processor29-35, and or the controller29-10. The control message processor29-35processes the control message received from the UE and takes an action according to the processing result or generates a control message to be transmitted to the UE, the control message being transferred to a higher layer. The higher layer entities29-25and29-30(each higher layer entity being established by EPS bearer) process the data from the EPS bearer entities29-40and29-45into RLC PDUs, the RLC PDUs being transferred to the multiplexer/demultiplexer29-20, or to process the RLC PDUs from the multiplexer/demultiplexer29-20into PDCP SDUs, the PDCP SDUs being delivered to the EPS bearer entities29-40and29-45. The scheduler allocates transmission resources to a UE at an appropriate timing in consideration of the buffer status and channel condition of the UE and controls the transceiver29-05to process the signals transmitted by the UE and to be transmitted to the UE. The EPS bearer entities29-40and29-45configure EPS bearers and process the data from the higher layer entities29-25and29-30, the processed data being transmitted to a next network node. The higher layer entities29-25and29-30and the EPS bearer entities29-40and29-45are connected through S1-U bearers. The higher layer entity corresponding to a common DRB connects to an EPS bearer entity established for the common DRB through a common S1-U bearer. The NAS layer entity29-50processes an IP packet contained in a NAS message and transmits the processed IP packet to the S-GW. Fourth Embodiment The fourth embodiment proposes a contention resolution method of a UE supporting the resume procedure and the RRC Connection Establishment procedure. A random access procedure consists of a preamble transmission phase, a random access response message reception phase, a Msg3 transmission phase, and a contention resolution message reception phase. The contention resolution can be achieved in such way that the eNB which has received the Msg3 indicting successful random access procedure sends the Msg3 back to the UE in a situation where more than one UE transmit same preamble. The Msg3 includes identity information capable of identifying the UE and thus the UE can determine whether it has succeeded the random access procedure based on whether the received contention resolution message is identical with the Msg3 it has transmitted. As described in embodiment 3, a RESUME request message is carried in the Msg3 of the random access procedure and has the size of 64 bits for FID or 48 bits for TID. The contention resolution message includes a 48-bit contention resolution MAC Control Element (CE) or a 64-bit contention resolution MAC CE, and the UE determines the type of the contention resolution MAC CE to be applied for contention resolution based on the size of the CCCH message it has transmitted. The contention resolution MAC CE is carried in a MAC PDU and includes a Logical Channel ID for use in identifying the 48-bit contention resolution MAC CE and 64-bit contention resolution MAC CE in order to minimize the size of the MAC header by negating the necessity of header information indicating the size of the contention resolution MAC CE. The LCID may be set to a first value (e.g., 11100) for the 48-bit MAC CE or a second value (e.g., 10111) for the 64-bit MAC CE, the first and second values being different from each other. Hereinafter, the contention resolution MAC CE identified by the LCID set to the first value is referred to as the first contention resolution MAC CE and the contention resolution MAC CE identified by the LCD set to the second value is referred to as the second contention resolution MAC CE. The first contention resolution MAC CE has a first size (e.g., 6 bytes), and the second contention resolution MAC CE has a second size (e.g., 8 bytes). FIG.30is a flowchart illustrating operations of a UE according to the fourth embodiment of the present disclosure. The UE selects one of available preambles and transmits the selected preamble at step30-05, and receives a random access response message addressed with a Radio Network Temporary Identifier in response to the preamble at step30-10. If the random access response message includes the preamble identifier indicating the preamble the UE has transmitted, the UE transmits a message 3 (Msg3) based on the information included in the random access response message at step30-15. The random access response message includes the information on the radio resources for Msg3 transmission, transmission timing for Msg3 transmission, and RNTI for use in receiving a contention resolution message. The Msg3 consists of a MAC header and a CCCH SDU as depicted inFIG.21. The MAC header is 8 bits, and the CCCH SDU is 48 bits or 64 bits. After transmitting the Msg3, the UE starts a timer, i.e., mac-ContentionResolutionTimer at step30-20. This timer is used for determining whether the contention resolution fails. If no contention resolution is received before expiry of the timer, this means contention resolution failure. The timer value is broadcast in the system information. The UE attempts to receive a MAC PDU with the RNTI carried in the Msg3 which the time is running. If a MAC PDU addressed by the RNIT is received before the expiry of the timer at step30-25, the UE stops the mac-ContentionResolutionTimer and determines whether the MAC PDU includes a valid contention resolution MAC CE at step30-30. The procedure progresses from step30-25or30-40according to the type and size of the CCCH SDU of the Msg3 the UE has transmitted. If the CCCH SDU contains an RRC Connection Request message, RRC Connection Reestablishment Request message, or 48-bit (or TID-containing) RESUME request message, the procedure goes to step30-35; if the CCCH SDU contains the 64-bit (of FID-containing) RESUME request message, the procedure goes to step30-40. At step30-35, the UE determines whether the MAC PDU includes the first contention resolution MAC CE and, if so, if the first contention resolution MAC CE is identical with the CCCH SDU carried in the Msg3. If both the two conditions are fulfilled, the procedure goes to step30-45; if at least one of the two conditions is not fulfilled, the procedure goes to step30-50. At step30-40, the UE determines whether the MAC PDU includes the second contention resolution MAC CE and, if so, if the second contention resolution MAC CE is identical with the CCCH SDU. If both the two conditions are fulfilled, the procedure goes to step30-45; if at least one of the two condition is not fulfilled, the procedure goes to step30-50. That is, if the UE transmits the Msg3 including the 64-bit CCCH SDU (or Resume request message containing an FID), if the MAC PDU received by the UE includes the second contention resolution MAC CE, and if the second contention resolution MAC CE is identical with the CCCH SDU, the procedure goes to step30-45. If the UE transmits the Msg3 including the 48-bit CCCH SDU (or Resume request, RRC Connection Request, or RRC Connection Reestablishment message including a TID, if the MAC PDU received by the UE includes the first contention resolution MAC CE, and if the first contention resolution MAC CE is identical with the CCCH SDU transmitted by the UE, the procedure goes to step30-45. At step30-45, the UE determines that the contention resolution has succeeded and thus performs demodulation on the MAC SDU (e.g., RRC message) contained in the received MAC PDU to deliver the demodulated data to the higher layer entity and end the random access procedure. At step30-50, the UE determines that the contention resolution has failed, discards the received MAC PDU, increases a preamble transmission counter by 1, and performs a predetermined subsequent operation. For example, if the preamble transmission counter has not reached its maximum value, the UE returns to the preamble transmission step to repeat the random access procedure; if the preamble transmission counter has reached its maximum value, the UE determines that the random access procedure has failed and reports the random access failure to the higher layer. As described above, the present disclosure is advantageous in terms of facilitating light connection in a mobile communication system. Also, the present disclosure is advantageous in that a base station is capable of determining presence/absence of traffic offloaded to a WLAN in association with a terminal and acquiring more detailed information from the terminal to determine whether to the offloaded traffic on the WLAN or transfer to an LTE network. Also, the present disclosure is advantageous in that a terminal is capable of using uplink resources allocated in a random access procedure for uplink asynchronous HARQ. Also, the present disclosure is advantageous in terms of providing a procedure and method for allowing an ordinary terminal and a terminal operating in an extended coverage mode (NB-IOT UE, BL UE, UE in CE, or eMTC UE) to select a resume ID which is used for fast reconnection of the terminal disconnected from a network. Also, the present disclosure is advantageous in terms of reducing signaling overhead of RRC connection setup, security configuration, and Data Radio Bearer (DRB) configuration saving battery power of the terminal. Furthermore, the multiple semi-persistent scheduling-based resource allocation method and apparatus for V2V communication according to the present disclosure is advantageous in terms of supporting the semi-persistent scheduling for V2V messages varying in size and amount and, as a consequence, reducing waste of radio resources between a terminal requesting for V2V communication and a base station allocating resources for V2V communication to the terminal. In the embodiments of the present disclosures, the components are described in singular or plural forms depending on the embodiment. However, the singular and plural forms are selected appropriately for the proposed situation just for explanation convenience without intension of limiting the present disclosure thereto and thus singular form include the plural forms as well, unless the context clearly indicates otherwise. Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. | 105,089 |
11943063 | DETAILED DESCRIPTION Hereinafter, embodiments according to the present disclosure will be described in detail by referring to accompanying drawings. Detailed description to be disclosed with accompanying drawings is to describe exemplary embodiments of the present disclosure and is not to represent the only embodiment that the present disclosure may be implemented. The following detailed description includes specific details to provide complete understanding of the present disclosure. However, those skilled in the pertinent art knows that the present disclosure may be implemented without such specific details. In some cases, known structures and devices may be omitted or may be shown in a form of a block diagram based on a core function of each structure and device in order to prevent a concept of the present disclosure from being ambiguous. In the present disclosure, when an element is referred to as being “connected”, “combined” or “linked” to another element, it may include an indirect connection relation that yet another element presents therebetween as well as a direct connection relation. In addition, in the present disclosure, a term, “include” or “have”, specifies the presence of a mentioned feature, step, operation, component and/or element, but it does not exclude the presence or addition of one or more other features, stages, operations, components, elements and/or their groups. In the present disclosure, a term such as “first”, “second”, etc. is used only to distinguish one element from other element and is not used to limit elements, and unless otherwise specified, it does not limit an order or importance, etc. between elements. Accordingly, within a scope of the present disclosure, a first element in an embodiment may be referred to as a second element in another embodiment and likewise, a second element in an embodiment may be referred to as a first element in another embodiment. A term used in the present disclosure is to describe a specific embodiment, and is not to limit a claim. As used in a described and attached claim of an embodiment, a singular form is intended to include a plural form, unless the context clearly indicates otherwise. A term used in the present disclosure, “and/or”, may refer to one of related enumerated items or it means that it refers to and includes any and all possible combinations of two or more of them. In addition, “/” between words in the present disclosure has the same meaning as “and/or”, unless otherwise described. The present disclosure describes a wireless communication network or a wireless communication system, and an operation performed in a wireless communication network may be performed in a process in which a device (e.g., a base station) controlling a corresponding wireless communication network controls a network and transmits or receives a signal, or may be performed in a process in which a terminal associated to a corresponding wireless network transmits or receives a signal with a network or between terminals. In the present disclosure, transmitting or receiving a channel includes a meaning of transmitting or receiving information or a signal through a corresponding channel. For example, transmitting a control channel means that control information or a control signal is transmitted through a control channel. Similarly, transmitting a data channel means that data information or a data signal is transmitted through a data channel. Hereinafter, a downlink (DL) means a communication from a base station to a terminal and an uplink (UL) means a communication from a terminal to a base station. In a downlink, a transmitter may be part of a base station and a receiver may be part of a terminal. In an uplink, a transmitter may be part of a terminal and a receiver may be part of a base station. A base station may be expressed as a first communication device and a terminal may be expressed as a second communication device. A base station (BS) may be substituted with a term such as a fixed station, a Node B, an eNB (evolved-NodeB), a gNB (Next Generation NodeB), a BTS (base transceiver system), an Access Point (AP), a Network (5G network), an AI (Artificial Intelligence) system/module, an RSU (road side unit), a robot, a drone (UAV: Unmanned Aerial Vehicle), an AR (Augmented Reality) device, a VR (Virtual Reality) device, etc. In addition, a terminal may be fixed or mobile, and may be substituted with a term such as a UE (User Equipment), an MS (Mobile Station), a UT (user terminal), an MSS (Mobile Subscriber Station), an SS (Subscriber Station), an AMS (Advanced Mobile Station), a WT (Wireless terminal), an MTC (Machine-Type Communication) device, an M2M (Machine-to-Machine) device, a D2D (Device-to-Device) device, a vehicle, an RSU (road side unit), a robot, an AI (Artificial Intelligence) module, a drone (UAV: Unmanned Aerial Vehicle), an AR (Augmented Reality) device, a VR (Virtual Reality) device, etc. The following description may be used for a variety of radio access systems such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may be implemented by a wireless technology such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA may be implemented by a radio technology such as GSM (Global System for Mobile communications)/GPRS (General Packet Radio Service)/EDGE (Enhanced Data Rates for GSM Evolution). OFDMA may be implemented by a radio technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (Evolved UTRA), etc. UTRA is a part of a UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is a part of an E-UMTS (Evolved UMTS) using E-UTRA and LTE-A (Advanced)/LTE-A pro is an advanced version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an advanced version of 3GPP LTE/LTE-A/LTE-A pro. To clarify description, it is described based on a 3GPP communication system (e.g., LTE-A, NR), but a technical idea of the present disclosure is not limited thereto. LTE means a technology after 3GPP TS (Technical Specification) 36.xxx Release 8. In detail, an LTE technology in or after 3GPP TS 36.xxx Release 10 is referred to as LTE-A and an LTE technology in or after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro. 3GPP NR means a technology in or after TS 38.xxx Release 15. LTE/NR may be referred to as a 3GPP system. “xxx” means a detailed number for a standard document. LTE/NR may be commonly referred to as a 3GPP system. For a background art, a term, an abbreviation, etc. used to describe the present disclosure, matters described in a standard document disclosed before the present disclosure may be referred to. For example, the following document may be referred to. For 3GPP LTE, TS 36.211 (physical channels and modulation), TS 36.212 (multiplexing and channel coding), TS 36.213 (physical layer procedures), TS 36.300 (overall description), TS 36.331 (radio resource control) may be referred to. For 3GPP NR, TS 38.211 (physical channels and modulation), TS 38.212 (multiplexing and channel coding), TS 38.213 (physical layer procedures for control), TS 38.214 (physical layer procedures for data), TS 38.300 (NR and NG-RAN(New Generation-Radio Access Network) overall description), TS 38.331 (radio resource control protocol specification) may be referred to. Abbreviations of terms which may be used in the present disclosure is defined as follows.BM: beam managementCQI: Channel Quality IndicatorCRI: channel state information—reference signal resource indicatorCSI: channel state informationCSI-IM: channel state information—interference measurementCSI-RS: channel state information reference signalDMRS: demodulation reference signalFDM: frequency division multiplexingFFT: fast Fourier transformIFDMA: interleaved frequency division multiple accessIFFT: inverse fast Fourier transformL1-RSRP: Layer 1 reference signal received powerL1-RSRQ: Layer 1 reference signal received qualityMAC: medium access controlNZP: non-zero powerOFDM: orthogonal frequency division multiplexingPDCCH: physical downlink control channelPDSCH: physical downlink shared channelPMI: precoding matrix indicatorRE: resource elementRI: Rank indicatorRRC: radio resource controlRSSI: received signal strength indicatorRx: ReceptionQCL: quasi co-locationSINR: signal to interference and noise ratioSSB (or SS/PBCH block): Synchronization signal block (including PSS (primary synchronization signal), SSS (secondary synchronization signal) and PBCH (physical broadcast channel))TDM: time division multiplexingTRP: transmission and reception pointTRS: tracking reference signalTx: transmissionUE: user equipmentZP: zero power Overall System As more communication devices have required a higher capacity, a need for an improved mobile broadband communication compared to the existing radio access technology (RAT) has emerged. In addition, massive MTC (Machine Type Communications) providing a variety of services anytime and anywhere by connecting a plurality of devices and things is also one of main issues which will be considered in a next-generation communication. Furthermore, a communication system design considering a service/a terminal sensitive to reliability and latency is also discussed. As such, introduction of a next-generation RAT considering eMBB (enhanced mobile broadband communication), mMTC (massive MTC), URLLC (Ultra-Reliable and Low Latency Communication), etc. is discussed and, for convenience, a corresponding technology is referred to as NR in the present disclosure. NR is an expression which represents an example of a 5G RAT. A new RAT system including NR uses an OFDM transmission method or a transmission method similar to it. A new RAT system may follow OFDM parameters different from OFDM parameters of LTE. Alternatively, a new RAT system follows a numerology of the existing LTE/LTE-A as it is, but may support a wider system bandwidth (e.g., 100 MHz). Alternatively, one cell may support a plurality of numerologies. In other words, terminals which operate in accordance with different numerologies may coexist in one cell. A numerology corresponds to one subcarrier spacing in a frequency domain. As a reference subcarrier spacing is scaled by an integer N, a different numerology may be defined. FIG.1illustrates a structure of a wireless communication system to which the present disclosure may be applied. In reference toFIG.1, NG-RAN is configured with gNBs which provide a control plane (RRC) protocol end for a NG-RA (NG-Radio Access) user plane (i.e., a new AS (access stratum) sublayer/PDCP (Packet Data Convergence Protocol)/RLC (Radio Link Control)/MAC/PHY) and UE. The gNBs are interconnected through a Xn interface. The gNB, in addition, is connected to an NGC (New Generation Core) through an NG interface. In more detail, the gNB is connected to an AMF (Access and Mobility Management Function) through an N2 interface, and is connected to a UPF (User Plane Function) through an N3 interface. FIG.2illustrates a frame structure in a wireless communication system to which the present disclosure may be applied. A NR system may support a plurality of numerologies. Here, a numerology may be defined by a subcarrier spacing and a cyclic prefix (CP) overhead. Here, a plurality of subcarrier spacings may be derived by scaling a basic (reference) subcarrier spacing by an integer N (or, μ). In addition, although it is assumed that a very low subcarrier spacing is not used in a very high carrier frequency, a used numerology may be selected independently from a frequency band. In addition, a variety of frame structures according to a plurality of numerologies may be supported in a NR system. Hereinafter, an OFDM numerology and frame structure which may be considered in a NR system will be described. A plurality of OFDM numerologies supported in a NR system may be defined as in the following Table 1. TABLE 1μΔf = 2μ· 15 [kHz]CP015Normal130Normal260Normal,Extended3120Normal4240Normal NR supports a plurality of numerologies (or subcarrier spacings (SCS)) for supporting a variety of 5G services. For example, when a SCS is 15 kHz, a wide area in traditional cellular bands is supported, and when a SCS is 30 kHz/60 kHz, dense-urban, lower latency and a wider carrier bandwidth are supported, and when a SCS is 60 kHz or higher, a bandwidth wider than 24.25 GHz is supported to overcome a phase noise. An NR frequency band is defined as a frequency range in two types (FR1, FR2). FR1, FR2 may be configured as in the following Table 2. In addition, FR2 may mean a millimeter wave (mmW). TABLE 2FrequencyCorrespondingRangefrequencySubcarrierdesignationrangeSpacingFR1410 MHZ-7125 MHZ15, 30, 60kHzFR224250 MHZ-52600 MHZ60, 120, 240kHz Regarding a frame structure in an NR system, a size of a variety of fields in a time domain is expresses as a multiple of a time unit of Tc=1/(Δfmax·Nf). Here, Δfmaxis 480·103Hz and N f is 4096. Downlink and uplink transmission is configured (organized) with a radio frame having a duration of Tf=1/(ΔfmaxNf/100)·Tc=10 ms. Here, a radio frame is configured with 10 subframes having a duration of Tsf=(ΔfmaxNf/1000)·Tc=1 ms, respectively. In this case, there may be one set of frames for an uplink and one set of frames for a downlink. In addition, transmission in an uplink frame No. i from a terminal should start earlier by TTA=(NTA+NTA,offset)Tcthan a corresponding downlink frame in a corresponding terminal starts. For a subcarrier spacing configuration μ, slots are numbered in an increasing order of nsμ∈{0, . . . , Nslotsubframe,μ−1} in a subframe and are numbered in an increasing order of ns,fΞ∈{0, . . . , Nslotframe,μ−1} in a radio frame. One slot is configured with Nsymbslotconsecutive OFDM symbols and Nsymbslotis determined according to CP. A start of a slot nsμin a subframe is temporally arranged with a start of an OFDM symbol nsμNsymbslotin the same subframe. All terminals may not perform transmission and reception at the same time, which means that all OFDM symbols of a downlink slot or an uplink slot may not be used. Table 3 represents the number of OFDM symbols per slot (Nsymbslot) the number of slots per radio frame (Nslotframe,μ) and the number of slots per subframe (Nslotsubframe,μ) in a normal CP and Table 4 represents the number of OFDM symbols per slot, the number of slots per radio frame and the number of slots per subframe in an extended CP. TABLE 3μNsymbslotNslotframe, μNslotsubframe, μ01410111420221440431480841416016 TABLE 4μNsymbslotNslotframe, μNslotsubframe, μ212404 FIG.2is an example on μ=2 (SCS is 60 kHz), 1 subframe may include 4 slots referring to Table 3. 1 subframe={1, 2, 4} slot shown inFIG.2is an example, the number of slots which may be included in 1 subframe is defined as in Table 3 or Table 4. In addition, a mini-slot may include 2, 4 or 7 symbols or more or less symbols. Regarding a physical resource in a NR system, an antenna port, a resource grid, a resource element, a resource block, a carrier part, etc. may be considered. Hereinafter, the physical resources which may be considered in an NR system will be described in detail. First, in relation to an antenna port, an antenna port is defined so that a channel where a symbol in an antenna port is carried can be inferred from a channel where other symbol in the same antenna port is carried. When a large-scale property of a channel where a symbol in one antenna port is carried may be inferred from a channel where a symbol in other antenna port is carried, it may be said that 2 antenna ports are in a QC/QCL (quasi co-located or quasi co-location) relationship. In this case, the large-scale property includes at least one of delay spread, doppler spread, frequency shift, average received power, received timing.FIG.3illustrates a resource grid in a wireless communication system to which the present disclosure may be applied. In reference toFIG.3, it is illustratively described that a resource grid is configured with NRBμNscRBsubcarriers in a frequency domain and one subframe is configured with 14.2μOFDM symbols, but it is not limited thereto. In an NR system, a transmitted signal is described by OFDM symbols of 2μNsymb(μ)and one or more resource grids configured with NRBμNscRBsubcarriers. Here, NRBμ≤NRBmax,μ. The NRBmax,μrepresents a maximum transmission bandwidth, which may be different between an uplink and a downlink as well as between numerologies. In this case, one resource grid may be configured per μ and antenna port p. Each element of a resource grid for μ and an antenna port p is referred to as a resource element and is uniquely identified by an index pair (k,l′). Here, k=0, . . . , NRBμNscRB−1 is an index in a frequency domain and l′=0, . . . , 2μNsymb(μ)−1 refers to a position of a symbol in a subframe. When referring to a resource element in a slot, an index pair (k,l) is used. Here, l=0, . . . , Nsymbμ−1. A resource element (k,l′) for p and an antenna port p corresponds to a complex value, ak,l′(p,μ). When there is no risk of confusion or when a specific antenna port or numerology is not specified, indexes p and μ may be dropped, whereupon a complex value may be ak,l′(p)or ak,l′. In addition, a resource block (RB) is defined as NscRB=12 consecutive subcarriers in a frequency domain. Point A plays a role as a common reference point of a resource block grid and is obtained as follows. offsetToPointA for a primary cell (PCell) downlink represents a frequency offset between point A and the lowest subcarrier of the lowest resource block overlapped with a SS/PBCH block which is used by a terminal for an initial cell selection. It is expressed in resource block units assuming a 15 kHz subcarrier spacing for FR1 and a 60 kHz subcarrier spacing for FR2. absoluteFrequencyPointA represents a frequency-position of point A expressed as in ARFCN (absolute radio-frequency channel number). Common resource blocks are numbered from 0 to the top in a frequency domain for a subcarrier spacing configuration μ. The center of subcarrier 0 of common resource block 0 for a subcarrier spacing configuration p is identical to ‘point A’. A relationship between a common resource block number nCRBμand a resource element (k,l) for a subcarrier spacing configuration μ in a frequency domain is given as in the following Equation 1. nCRBμ=⌊kNscRB⌋[Equation1] In Equation 1, k is defined relatively to point A so that k=0 corresponds to a subcarrier centering in point A. Physical resource blocks are numbered from 0 to NBWP,isize,μ−1 in a bandwidth part (BWP) and i is a number of a BWP. A relationship between a physical resource block npas and a common resource block nCRBin BWP i is given by the following Equation 2. nCRBμ=nPRBμ+NBWP,istart,μ[Equation 2] NBWP,istart,μis a common resource block that a BWP starts relatively to common resource block 0. FIG.4illustrates a physical resource block in a wireless communication system to which the present disclosure may be applied. And,FIG.5illustrates a slot structure in a wireless communication system to which the present disclosure may be applied. In reference toFIG.4andFIG.5, a slot includes a plurality of symbols in a time domain. For example, for a normal CP, one slot includes 7 symbols, but for an extended CP, one slot includes 6 symbols. A carrier includes a plurality of subcarriers in a frequency domain. An RB (Resource Block) is defined as a plurality of (e.g., 12) consecutive subcarriers in a frequency domain. A BWP (Bandwidth Part) is defined as a plurality of consecutive (physical) resource blocks in a frequency domain and may correspond to one numerology (e.g., an SCS, a CP length, etc.). A carrier may include a maximum N (e.g., 5) BWPs. A data communication may be performed through an activated BWP and only one BWP may be activated for one terminal. In a resource grid, each element is referred to as a resource element (RE) and one complex symbol may be mapped. In an NR system, up to 400 MHz may be supported per component carrier (CC). If a terminal operating in such a wideband CC always operates turning on a radio frequency (FR) chip for the whole CC, terminal battery consumption may increase. Alternatively, when several application cases operating in one wideband CC (e.g., eMBB, URLLC, Mmtc, V2X, etc.) are considered, a different numerology (e.g., a subcarrier spacing, etc.) may be supported per frequency band in a corresponding CC. Alternatively, each terminal may have a different capability for the maximum bandwidth. By considering it, a base station may indicate a terminal to operate only in a partial bandwidth, not in a full bandwidth of a wideband CC, and a corresponding partial bandwidth is defined as a bandwidth part (BWP) for convenience. A BWP may be configured with consecutive RBs on a frequency axis and may correspond to one numerology (e.g., a subcarrier spacing, a CP length, a slot/a mini-slot duration). Meanwhile, a base station may configure a plurality of BWPs even in one CC configured to a terminal. For example, a BWP occupying a relatively small frequency domain may be configured in a PDCCH monitoring slot, and a PDSCH indicated by a PDCCH may be scheduled in a greater BWP. Alternatively, when UEs are congested in a specific BWP, some terminals may be configured with other BWP for load balancing. Alternatively, considering frequency domain inter-cell interference cancellation between neighboring cells, etc., some middle spectrums of a full bandwidth may be excluded and BWPs on both edges may be configured in the same slot. In other words, a base station may configure at least one DL/UL BWP to a terminal associated with a wideband CC. A base station may activate at least one DL/UL BWP of configured DL/UL BWP(s) at a specific time (by L1 signaling or MAC CE (Control Element) or RRC signaling, etc.). In addition, a base station may indicate switching to other configured DL/UL BWP (by L1 signaling or MAC CE or RRC signaling, etc.). Alternatively, based on a timer, when a timer value is expired, it may be switched to a determined DL/UL BWP. Here, an activated DL/UL BWP is defined as an active DL/UL BWP. But, a configuration on a DL/UL BWP may not be received when a terminal performs an initial access procedure or before a RRC connection is set up, so a DL/UL BWP which is assumed by a terminal under these situations is defined as an initial active DL/UL BWP. FIG.6illustrates physical channels used in a wireless communication system to which the present disclosure may be applied and a general signal transmission and reception method using them. In a wireless communication system, a terminal receives information through a downlink from a base station and transmits information through an uplink to a base station. Information transmitted and received by a base station and a terminal includes data and a variety of control information and a variety of physical channels exist according to a type/a usage of information transmitted and received by them. When a terminal is turned on or newly enters a cell, it performs an initial cell search including synchronization with a base station or the like (S601). For the initial cell search, a terminal may synchronize with a base station by receiving a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from a base station and obtain information such as a cell identifier (ID), etc. After that, a terminal may obtain broadcasting information in a cell by receiving a physical broadcast channel (PBCH) from a base station. Meanwhile, a terminal may check out a downlink channel state by receiving a downlink reference signal (DL RS) at an initial cell search stage. A terminal which completed an initial cell search may obtain more detailed system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information carried in the PDCCH (S602). Meanwhile, when a terminal accesses to a base station for the first time or does not have a radio resource for signal transmission, it may perform a random access (RACH) procedure to a base station (S603to S606). For the random access procedure, a terminal may transmit a specific sequence as a preamble through a physical random access channel (PRACH) (S603and S605) and may receive a response message for a preamble through a PDCCH and a corresponding PDSCH (S604and S606). A contention based RACH may additionally perform a contention resolution procedure. A terminal which performed the above-described procedure subsequently may perform PDCCH/PDSCH reception (S607) and PUSCH (Physical Uplink Shared Channel)/PUCCH (physical uplink control channel) transmission (S608) as a general uplink/downlink signal transmission procedure. In particular, a terminal receives downlink control information (DCI) through a PDCCH. Here, DCI includes control information such as resource allocation information for a terminal and a format varies depending on its purpose of use. Meanwhile, control information which is transmitted by a terminal to a base station through an uplink or is received by a terminal from a base station includes a downlink/uplink ACK/NACK (Acknowledgement/Non-Acknowledgement) signal, a CQI (Channel Quality Indicator), a PMI (Precoding Matrix Indicator), a RI (Rank Indicator), etc. For a 3GPP LTE system, a terminal may transmit control information of the above-described CQI/PMI/RI, etc. through a PUSCH and/or a PUCCH. Table 5 represents an example of a DCI format in an NR system. TABLE 5DCIFormatUse0_0Scheduling of a PUSCH in one cell0_1Scheduling of one or multiple PUSCHsin one cell, or indication of cell groupdownlink feedback information to a UE0_2Scheduling of a PUSCH in one cell1_0Scheduling of a PDSCH in one DLcell1_1Scheduling of a PDSCH in one cell1_2Scheduling of a PDSCH in one cell In reference to Table 5, DCI formats 0_0, 0_1 and 0_2 may include resource information (e.g., UL/SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), information related to a transport block (TB) (e.g., MCS (Modulation Coding and Scheme), a NDI (New Data Indicator), a RV (Redundancy Version), etc.), information related to a HARQ (Hybrid—Automatic Repeat and request) (e.g., a process number, a DAI (Downlink Assignment Index), PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., DMRS sequence initialization information, an antenna port, a CSI request, etc.), power control information (e.g., PUSCH power control, etc.) related to scheduling of a PUSCH and control information included in each DCI format may be pre-defined. DCI format 0_0 is used for scheduling of a PUSCH in one cell. Information included in DCI format 0_0 is CRC (cyclic redundancy check) scrambled by a C-RNTI (Cell Radio Network Temporary Identifier) or a CS-RNTI (Configured Scheduling RNTI) or a MCS-C-RNTI (Modulation Coding Scheme Cell RNTI) and transmitted. DCI format 0_1 is used to indicate scheduling of one or more PUSCHs or configure grant (CG) downlink feedback information to a terminal in one cell. Information included in DCI format 0_1 is CRC scrambled by a C-RNTI or a CS-RNTI or a SP-CSI-RNTI (Semi-Persistent CSI RNTI) or a MCS-C-RNTI and transmitted. DCI format 0_2 is used for scheduling of a PUSCH in one cell. Information included in DCI format 0_2 is CRC scrambled by a C-RNTI or a CS-RNTI or a SP-CSI-RNTI or a MCS-C-RNTI and transmitted. Next, DCI formats 1_0, 1_1 and 1_2 may include resource information (e.g., frequency resource allocation, time resource allocation, VRB (virtual resource block)-PRB (physical resource block) mapping, etc.), information related to a transport block (TB) (e.g., MCS, NDI, RV, etc.), information related to a HARQ (e.g., a process number, DAI, PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., an antenna port, a TCI (transmission configuration indicator), a SRS (sounding reference signal) request, etc.), information related to a PUCCH (e.g., PUCCH power control, a PUCCH resource indicator, etc.) related to scheduling of a PDSCH and control information included in each DCI format may be pre-defined. DCI format 1_0 is used for scheduling of a PDSCH in one DL cell. Information included in DCI format 1_0 is CRC scrambled by a C-RNTI or a CS-RNTI or a MCS-C-RNTI and transmitted. DCI format 1_1 is used for scheduling of a PDSCH in one cell. Information included in DCI format 1_1 is CRC scrambled by a C-RNTI or a CS-RNTI or a MCS-C-RNTI and transmitted. DCI format 1_2 is used for scheduling of a PDSCH in one cell. Information included in DCI format 1_2 is CRC scrambled by a C-RNTI or a CS-RNTI or a MCS-C-RNTI and transmitted. MBMS (Multimedia Broadcast/Multicast Service) Scheme Hereinafter, the MBMS scheme of 3GPP LTE will be described. MBMS may include a single frequency network (SFN) scheme in which a plurality of base stations or a plurality of cells are synchronized to transmit the same data to a terminal, and a single cell point to multipoint (SC-PTM) scheme for broadcasting within the corresponding cell coverage through the PDCCH/PDSCH channel. Here, SFN scheme may be used to provide a broadcast service to a wide area (e.g., MBMS area) through resources allocated semi-statically in advance, and SC-PTM scheme may be mainly used to provide a broadcast service only within a cell coverage through dynamic resources. SC-PTM provides one logical channel, SC-MCCH (Single Cell Multicast Control Channel) and one or more logical channels SC-MTCH (Single Cell Multicast Traffic Channel). These logical channels (i.e., SC-MCCH and SC-MTCH) are mapped to the transport channel, DL-SCH, and the transport channel DL-SCH is mapped to the physical channel PDSCH. A PDSCH transmitting SC-MCCH or SC-MTCH data may be scheduled through a PDCCH indicated by a Group Radio Network Temporary Identifier (G-RNTI). In this case, a temporary mobile group identify (TMGI) corresponding to the service ID may be mapped one-to-one with a specific G (group)-RNTI value. Accordingly, when the base station provides a plurality of services, a plurality of G-RNTI values may be allocated for SC-PTM transmission. One or a plurality of terminals may perform PDCCH monitoring by using a specific G-RNTI to receive a specific service. And, for a specific service/specific G-RNTI, SC-PTM dedicated DRX on-duration section may be configured, and in this case, the UEs may wake up only for a specific on-duration period and perform PDCCH monitoring for the G-RNTI. MBS (Multicast Broadcast Service) Based Transmission/Reception Operation In a basic wireless communication system, the base station sets terminal-specific SPS (semi-persistent scheduling) configuration information to a specific terminal, so that a downlink (DL) SPS transmission resource that is repeated according to a configured period may be allocated to a specific terminal. In this case, the DCI transmitted through the terminal-dedicated PDCCH indicates activation of a specific SPS configuration index (SPS activation), thereby instructing the corresponding terminal to repeatedly receive the SPS transmission resource according to a configured period. This initial SPS transmission resource may be used for initial HARQ transmission, and the base station may allocate a retransmission resource of a specific SPS configuration index through DCI transmitted through a terminal-dedicated PDCCH. For example, when the terminal reports a HARQ negative acknowledgment (NACK) for the SPS transmission resource, the base station may allocate the retransmission resource to DCI so that the terminal may receive the DL retransmission. And, the DCI transmitted through the terminal-dedicated PDCCH may indicate deactivation (SPS release or SPS deactivation) of a specific SPS configuration index, and in this case, the corresponding terminal may not receive the indicated SPS transmission resource. Here, the CRC of the DCI for the activation/retransmission/deactivation may be scrambled with a CS-RNTI (Configured Scheduling RNTI). In a wireless communication system (e.g., NR), a DL broadcast or DL multicast transmission scheme for supporting an MBS similar to the above-described MBMS may be applied. The base station may provide a point-to-multipoint (PTM) transmission scheme and a point-to-point (PTP) transmission scheme for DL broadcast or DL multicast transmission. In the PTM transmission method for MBS, the base station may transmit a group common PDCCH and a group common PDSCH to a plurality of terminals, and a plurality of terminals may simultaneously receive the same group common PDCCH and group common PDSCH transmission and decode the same MBS data. In addition, in the PTP transmission method for MBS, the base station may transmit the terminal-dedicated PDCCH and the terminal-dedicated PDSCH to a specific terminal, and only the corresponding terminal may receive the terminal-dedicated PDCCH and the terminal-dedicated PDSCH. Here, when there are a plurality of terminals receiving the same MBS service, the base station may separately transmit the same MBS data to individual terminals through different terminal-dedicated PDCCHs and terminal-dedicated PDSCHs. For application of MBS, group common SPS transmission may be supported. Accordingly, the terminal may receive group common SPS transmission (i.e., static scheduling transmission) and group common dynamic scheduling transmission (dynamically scheduled transmission). In addition, the terminal may receive a group common SPS transmission and a static/dynamic scheduling transmission dedicated to the terminal. In this case, the UE may transmit the HARQ-ACK for the transmissions in the same slot or sub-slot. For example, PUCCH resource(s) for group common/terminal dedicated SPS and PUCCH resource(s) for group common/terminal dedicated dynamic scheduling transmission may be allocated to the same slot or the same sub-slot. In this case, HARQ-ACK transmissions for two or more transmissions may be multiplexed and transmitted on one PUCCH. At this time, it is not clearly defined how to configure the HARQ-ACK codebook, and accordingly, a problem that the base station cannot correctly interpret HARQ-ACK information may occur. HARQ-ACK Transmission Method for a Plurality of Group Common Transmission and/or Terminal-Dedicated Transmission In order to solve the above-mentioned problems, the present disclosure will describe a method of configuring the HARQ-ACK codebook by multiplexing the HARQ-ACKs, when HARQ-ACKs for a plurality of group common transmissions or a plurality of group common/terminal-dedicated transmissions are transmitted in the same slot/sub-slot. FIG.7is a diagram for describing a method for a terminal to perform uplink transmission according to an embodiment of the present disclosure. In describing the present disclosure, unicast SPS transmission may include at least a unicast physical downlink shared channel, and multicast SPS transmission may include at least multicast PDSCH. The UE may receive configuration information including N1 first information related to unicast semi-persistent scheduling transmission and N2 second information related to multicast SPS transmission from the base station (S710). Here, each of N1 and N2 may be an integer of 0 or more. And, the sum of N1 and N2 may be an integer less than or equal to N, and N may be predefined or configured by the base station (by higher layer signaling, etc.). That is, N may mean the maximum number of SPS configurations (per BWP). In addition, each index (e.g., ‘SPS-ConfigIndex’) of N1 first information related to unicast SPS transmission and N2 second information related to multicast SPS transmission may be configured to one of integers from 0 to N−1. For example, when N is 8, the index of each of the N1 first information and the N2 second information may be configured to one of an integer from 0 to 7. Indices of each of the N1 first information and the N2 second information may be configured to different values. And, at least one of the integers from 0 to N−1 may not be configured as an index of information related to SPS transmission, but is not limited thereto. An index of information related to SPS transmission may be configured to all integers from 0 to N−1. The terminal may transmit first HARQ-ACK information related to N1 unicast SPS transmission and second HARQ-ACK information related to N2 multicast SPS transmission multiplexed on the first physical uplink control channel to the base station (S720). Here, the first HARQ-ACK information may include HARQ-ACK for each of the N1 unicast SPS transmissions based on the N1 first information. And, the second HARQ-ACK information may include HARQ-ACK for each of N2 multicast SPS transmissions based on the N2 second information. In addition, the first HARQ-ACK information and the second HARQ-ACK information may be multiplexed on the first PUCCH based on the ascending order of each index of the N1 first information and N2 second information. That is, the terminal may multiplex HARQ-ACKs for SPS transmission based on each of the first information and the second information into one codebook based on the ascending order of each index of the first information and the second information. And, the terminal may transmit the codebook to the base station through the first PUCCH (or PUCCH resource). That is, the HARQ-ACK codebook may be configured based on the index of the SPS configuration (information). For example, the terminal may multiplex in order from HARQ-ACK for SPS transmission based on information having the smallest index among N1 first information and N2 second information on PUCCH to HARQ-ACK for SPS transmission based on information having the largest index among N1 first information and N2 second information on PUCCH. In addition, the first PUCCH may be based on a PUCCH resource for HARQ-ACK information associated with SPS transmission. For example, the first PUCCH may be based on at least one of PUCCH resources for HARQ-ACK information associated with unicast SPS transmission. As another example of the present disclosure, third HARQ-ACK information for unicast downlink control information (DCI) and fourth HARQ-ACK information for multicast DCI may be concatenated on the second PUCCH and transmitted to the base station. FIG.8is a diagram for describing a method of performing uplink reception of a base station according to an embodiment of the present disclosure. The base station may transmit configuration information including N1 first information related to unicast SPS transmission and N2 second information related to multicast SPS transmission to the user equipment (UE) (S810). The base station may receive first HARQ-ACK information associated with N1 unicast SPS transmission and second HARQ-ACK information associated with N2 multicast SPS transmission multiplexed on the first PUCCH from the UE (S820). The first HARQ-ACK information and the second HARQ-ACK information may be multiplexed on the first PUCCH based on an ascending order of each index of N1 first information and N2 second information. Regarding the first information, the second information, the HARQ-ACK information, and the uplink transmission/reception method based thereon, the details described with reference to steps S710to S730ofFIG.7and specific examples to be described later may be applied to S810to S830. Accordingly, overlapping descriptions will be omitted. Hereinafter, a method of configuring the HARQ-ACK codebook by multiplexing the HARQ-ACKs when HARQ-ACKs for a plurality of group common transmissions or a plurality of group common/terminal dedicated transmissions are transmitted in the same slot/sub-slot will be described in detail. Embodiment 1 For multiplexing HARQ-ACKs in a (sub-)slot for SPS PDSCH for multicast, SPS PDSCH for unicast, dynamically scheduled multicast PDSCH, and/or dynamically scheduled unicast PDSCH, the UE constructs codebook based on one or more of the following options. For each option described below, the dynamically scheduled unicast PDSCH may be scheduled by UE-specific DCI (e.g., DCI scrambled by C-RNTI or CS-RNTI), and the dynamically scheduled multicast PDSCH may be scheduled by a group common DCI (e.g., DCI scrambled by G-RNTI or G (group)-CS-RNTI). SPS PDSCH for unicast is specific to a UE and scheduled by RRC. SPS PDSCH for multicast (i.e., group common SPS PDSCH) is common to UEs in a group and scheduled by RRC. In addition, multicast reception may correspond to reception of dynamically scheduled multicast PDSCH and/or reception of SPS PDSCH for multicast. Alternatively, multicast reception may not include the case that HARQ feedback is disabled for reception of dynamically scheduled multicast PDSCH and/or reception of SPS PDSCH for multicast. As Option 1, if both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) are scheduled, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs for a slot. For example, within unicast HARQ-ACKs, HARQ-ACKs to dynamically scheduled unicast PDSCHs may be followed by HARQ-ACKs to SPS PDSCHs for unicast, if both dynamically scheduled unicast PDSCHs and SPS PDSCHs for unicast are scheduled. As another example, within multicast HARQ-ACKs, HARQ-ACKs to dynamically scheduled multicast PDSCHs may be followed by HARQ-ACKs to SPS PDSCHs for multicast, if both dynamically scheduled multicast PDSCHs and SPS PDSCHs for multicast are scheduled. As an option 1-1, for each TRP for each cell, unicast HARQ-ACKs are followed by multicast HARQ-ACKs. Here, for the slot, the UE may configure a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each TRP regardless of whether multicast is received. As an option 1-2, only for a TRP with multicast reception for each cell, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs. Here, for a slot, UE may construct a full codebook including both unicast HARQ-ACKs and multicast HARQ-ACKs for each TRP only with multicast reception. As an option 1-3, for each cell, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs. Here, for the slot, the UE may construct a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each cell regardless of whether multicast is received. As option 1-4, only for cells with multicast reception, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs. In this case, the UE may configure a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each cell only by multicast reception for the slot. As an option 1-5, unicast HARQ-ACKs for all cells may be followed by multicast HARQ-ACKs for all cells. Multicast HARQ-ACKs for all cells may include all serving cells regardless of which cell UE performs multicast reception for. In addition, for a slot, the UE may configure a full codebook including both unicast HARQ-ACK(s) for all cells and multicast HARQ-ACK(s) for all cells or cells with only multicast reception. As an option 1-6, for multiplexing HARQ-ACKs for each slot, UE may use one of the above sub-options of Option 1. For an example, the UE may use different options for different slots. That is, different options may be applied to the multicast reception-only slot, the unicast reception-only slot, and the unicast and multicast reception-only slot. As an option 2, when both the dynamically scheduled PDSCH(s) and the SPS PDSCH(s) are scheduled, dynamic HARQ-ACKs may be followed by SPS HARQ-ACKs for a slot. For example, within dynamic HARQ-ACKs, HARQ-ACKs to dynamically scheduled unicast PDSCHs may be followed by HARQ-ACKs to dynamically scheduled multicast PDSCHs, if both dynamically scheduled unicast PDSCHs and dynamically scheduled multicast PDSCHs are scheduled. As an another example, if both SPS PDSCH(s) for unicast and SPS PDSCH(s) for multicast are scheduled, HARQ-ACKs to SPS PDSCHs for unicast may be followed by HARQ-ACKs to SPS PDSCHs for multicast. As an option 2-1, for each TRP for each cell, dynamic HARQ-ACKs are followed by SPS HARQ-ACKs. Here, for a slot, the UE may construct a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each TRP regardless of whether multicast is received for the slot. As an option 2-2, for each cell, dynamic HARQ-ACKs may be followed by SPS HARQ-ACKs. The UE may construct a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each cell regardless of whether multicast is received for the slot. As an option 2-3, dynamic HARQ-ACKs for all cells may be followed by SPS HARQ-ACKs for all cells. Multicast HARQ-ACKs within dynamic HARQ-ACKs and/or SPS HARQ-ACKs may include all serving cells regardless of the cell in which the UE performs multicast reception. In the above option, for a slot, the UE may construct full codebook including both unicast HARQ-ACKs for all cells and multicast HARQ-ACKs for either all cells or cells only with multicast reception. As an option 2-4, for multiplexing HARQ-ACKs for each slot, the UE may use one of the sub-options (options 2-1 to 2-4) of option 2 above. For example, the UE may use a different option for each slot. That is, different options may be applied to the multicast reception-only slot, the unicast reception-only slot, and the unicast and multicast reception-only slot. As an option 3, in order to multiplex HARQ-ACK for each slot, the UE may use one of the sub-options of option 1 (i.e., Option 1-1 to Option 1-6) and one of the sub-options of option 2 (i.e., Option 2-1 to Option 2-4). For example, the UE may use a different option for each slot. That is, different options may be applied to a multicast reception-only slot, a unicast reception-only slot, and a unicast and multicast reception-only slot. Embodiment 2 For group common SPS, UE specific confirmation to group common SPS (de-)activation may be supported by PUCCH A/N. For example, UE-specific PUCCH resources may be allocated by DCI indicating SPS (non) activation. A single A/N bit of the PUCCH may be used to indicate activation or deactivation of the SPS. As another example, when a UE-specific PUCCH resource is configured for confirmation, the UE may indicate an ACK for the PUCCH resource for SPS activation confirmation, and may indicate a NACK for the PUCCH resource for SPS deactivation confirmation. Alternatively, the UE may indicate a NACK for the PUCCH resource to confirm SPS deactivation, and may indicate an ACK for the PUCCH resource to confirm the SPS activation. For a UE that not confirming the SPS activation, the base station may schedule the PTP initial transmission of the missed TB(s). After group common SPS activation, all UEs may autonomously release the group common SPS right after a pre-determined slot unless an activation DCI indicating the SPS is received up to the pre-determined slot. The activation DCI may re-activate the group common SPS right after the pre-determined time. The pre-determined time may be determined by RRC and/or DCI. For group common SPS, group common PUCCH resources used for NACK only based HARQ-ACK may be semi-statically configured per SPS configuration for SPS PDSCH transmissions. UE specific ACK/NACK based HARQ-ACK may be also configured per SPS configuration for SPS PDSCH transmissions. For group common SPS retransmission, PUCCH resources may be allocated by DCI in which CRC is scrambled by G (group)-CS-RNTI. Either NACK-based HARQ-ACK or UE-specific ACK/NACK-based HARQ-ACK may be used for SPS PDSCH retransmission. Embodiment 3 In the case of the group common SPS PDSCH (not scheduled by DCI, scheduled by RRC), a group common PUCCH resource used for NACK-only based HARQ-ACK may be semi-statically configured for one or more group common SPS configurations. Alternatively, UE-specific PUCCH resources for ACK/NACK-based HARQ-ACK may be configured for one or more group common SPS configurations. Alternatively, the group common PUCCH resource for ACK and the group common PUCCH resource for NACK may be configured separately for one or more group common configurations. Here, different SPS settings may be configured to the same PUCCH resource or different PUCCH resources. For example, when the same PUCCH resource is allocated to different SPS PDSCHs of different SPS configurations, one HARQ-ACK bit may indicate ACK or NACK for all SPS PDSCHs, or different HARQ-ACK bits may indicate ACK or NACK for different SPS PDSCHs, respectively. For example, when one HARQ-ACK bit indicates ACK or NACK for all SPS PDSCHs, when all SPS PDSCHs are successfully received, the UE may indicate ACK. And, if one or more of the SPS PDSCH is not successfully received, the UE may indicate NACK. As another example, when different PUCCH resources are allocated to different SPS PDSCHs of different SPS configurations, different HARQ-ACK resources may indicate ACK or NACK for different SPS PDSCHs, respectively. In addition, if the PUCCH resource is not explicitly configured for ‘SPS configuration index=N’, the UE may determine that the PUCCH resource for ‘SPS configuration index=N−k (or N+k)’ may be used as a PUCCH resource for ‘SPS configuration index=N’. Here, k may be 1 or another integer. Alternatively, if no PUCCH resource is explicitly configured for SPS configuration index=N, the UE may determine that HARQ-ACK is disabled for SPS PDSCH of the SPS configuration index=N. If ‘PUCCH-config’ for multicast is configured, although the UE may determine the PUCCH resource for the group common SPS configuration index (s) based on ‘PUCCH-config’ for multicast, the PUCCH resource for the UE-specific SPS configuration index(s) may be determined based on ‘PUCCH-config’ for unicast. If ‘PUCCH-config’ for multicast is not configured, the UE may determine that the PUCCH resource for the group common SPS configuration index(s) is determined based on ‘PUCCH-config’ for unicast. As another example, for group common SPS retransmission, PUCCH resources may be allocated by DCI in which CRC is scrambled by G-CS-RNTI. When determining the PUCCH resource, the UE may consider the group common SPS retransmission as a group common PDSCH scheduled by DCI. Here, when ‘PUCCH-config’ for multicast is configured, the UE may determine that the PUCCH resource for group common SPS retransmission is determined based on ‘PUCCH-config’ for multicast. If ‘PUCCH-config’ for multicast is not configured, the UE may determine that the PUCCH resource for group common SPS retransmission is determined based on ‘PUCCH-config’ for unicast. In addition, when determining the PUCCH resource, the UE may consider the SPS retransmission as a unicast PDSCH (or group common PDSCH). As another example, for the UE-specific SPS retransmission of the TB initially transmitted by the group common SPS PDSCH, the PUCCH resource may be allocated by DCI in which CRC is scrambled by CS-RNTI. When determining the PUCCH resource, the UE may consider the UE-specific SPS retransmission as a unicast PDSCH. Alternatively, when determining the PUCCH resource, the UE may consider the UE-specific SPS retransmission as a group common PDSCH scheduled by DCI. Here, when ‘PUCCH-config’ for multicast is configured, the UE may determine that the PUCCH resource for group common SPS retransmission is determined based on ‘PUCCH-config’ for multicast. Alternatively, the UE may determine to determine a PUCCH resource for group common SPS retransmission based on ‘PUCCH-config’ for unicast even if ‘PUCCH-config’ for multicast is configured. If ‘PUCCH-config’ for multicast is not configured, the UE may determine that the PUCCH resource for group common SPS retransmission is determined based on ‘PUCCH-config’ for unicast. As another example, one of NACK-based HARQ-ACK or UE-specific ACK/NACK-based HARQ-ACK may be used for SPS PDSCH retransmission. In the present disclosure, the priority of the SPS configuration or the priority of the HARQ-ACK for the SPS PDSCH may be determined based on the ‘harq-CodebookID’ of the SPS configuration configured in the ‘SPS-config’ by the RRC message. In the case of PUCCH transmission including HARQ-ACK information corresponding to SPS PDSCH reception or SPS PDSCH release, the UE may determine a priority index from ‘harq-CodebookID’ (if provided). Here, ‘harq-CodebookID’ may indicate high priority (HP) or low priority (LP) for SPS configuration. Hereinafter, a method in which a base station configures a group common SPS configuration to one or more terminals, and a base station and a terminal perform group common SPS transmission and reception will be described in detail. FIG.9is a diagram for illustrating a signaling procedure of the network side and the terminal according to an embodiment of the present disclosure. FIG.9shows an example of signaling between a network side and a terminal (UE) in an M-TRP environment (or S-TRP environment) to which embodiments (e.g., embodiment 1, embodiment 2, embodiment 3, or a combination of one or more of the detailed embodiments thereof) of the present disclosure described above may be applied. Here, the UE/network side is exemplary, and may be replaced with various devices to be described with reference toFIG.10.FIG.9is for convenience of description, and does not limit the scope of the present disclosure. Also, some step(s) shown inFIG.9may be omitted depending on circumstances and/or settings. In addition, in the operation of the network side/UE ofFIG.9, the above-described uplink transmission/reception operation and the like may be referred to or used. In the following description, the network side may be one base station including a plurality of TRPs, or may be one cell including a plurality of TRPs. Alternatively, the network side may include a plurality of remote radio heads (RRHs)/remote radio units (RRUs). As an example, an ideal/non-ideal backhaul may be configured between TRP 1 and TRP 2 included in the network side. In addition, although the following description is based on a plurality of TRPs, such description may be equivalently extended and applied to transmission through a plurality of panels/cells, and may also be extended and applied to transmission through a plurality of RRHs/RRUs. In addition, although described with reference to “TRP” in the following description, “TRP” may be replaced with and applied to a panel, an antenna array, a cell (e.g., a macro cell/small cell/pico cell, etc.), TP (transmission point), base station (base station, gNB, etc.) as described above. As described above, the TRP may be distinguished according to information (e.g., CORESET index, ID) on the CORESET group (or CORESET pool). As an example, when one UE is configured to perform transmission and reception with a plurality of TRPs (or cells), this may mean that a plurality of CORESET groups (or CORESET pools) are configured for the one UE. The configuration of such CORESET group (or CORESET pool) may be performed through higher layer signaling (e.g., RRC signaling, etc.). In addition, the base station may mean a generic term for an object that transmits/receives data to and from the UE. For example, the base station may be a concept including one or more TPs (Transmission Points), one or more TRPs (Transmission and Reception Points), or the like. In addition, the TP and/or TRP may include a panel, a transmission and reception unit, and the like of the base station. The UE may enter the RRC CONNECTED mode, and may report a message indicating one or more interested MBS services to the network side. Here, the message may be reported to the network side through at least one of Uplink Control Information (UCI), Control Element (MAC CE), and RRC messages. The MBS service of interest on the message may indicate either TMGI or G-RNTI (Group Radio Network Temporary Identifier) listed in a DL message received from the network side. G-RNTI indicates the terminal group identifier for receiving the MBS. For example, the DL message may be a service availability message listing TMGI #1, TMGI #3, TMGI #5, and TMGI #10. When the UE is interested in TMGI #5, the UE may indicate the order of TMGI #5 in the message. That is, the terminal may report ‘3’ to the network side. As an additional example, the DL message may be a service availability message listing G-RNTI #1, G-RNTI #3, G-RNTI #5, and G-RNTI #10. When the UE is interested in G-RNTI #10, the UE may indicate the order of G-RNTI #10 in the message. That is, the UE may report ‘4’ to the network side. The network side receiving the message may provide a common frequency resource (CFR) configuration, one or more group common SPS configuration including a TCI state, a search space configuration including a TCI state, and a GC (group common)-CS-RNTI value to the UE (e.g., UE 1 and UE 2) through the RRC message (S910). Upon receiving the RRC message, the UE may configure one or more group common SPS configurations according to the RRC message. Here, the RRC message may be a group common message transmitted through a PTM MCCH (Multicast Control Channel) or a UE-dedicated message transmitted through a UE-specific DCCH (Dedicated Control Channel). In addition, The UE may be configured with at least a G-RNTI value for each MBS CFR or each serving cell. GC-CS-RNTI may be configured/used for activation, retransmission or release of one or more group common SPS configurations. For example, when the UE is not configured with GC-CS-RNTI for CFR or serving cell, and CS-RNTI is configured for CFR or serving cell, the UE may use CS-RNTI for activating, retransmitting, or releasing of one or more group common SPS configurations. As another example, the network side may associate one GC-CS-RNTI value with a TMGI list or a G-RNTI list. In this case, the network side may provide a TMGI list or a G-RNTI list associated with the GC-CS-RNTI value. Each group common SPS configuration (i.e., SPS-config) may be set as the following information element as shown in Table 6 below. TABLE 8SPS-Config ::= SEQUENCE {periodicity ENUMERATED {ms10, ms20, ms32, ms40, ms64, ms80,ms128, ms160, ms320, ms640,spare6, spare5, spare4, spare3, spare2, spare1},nrofHARQ-Processes INTEGER (1..8),n1PUCCH-AN PUCCH-ResourceId OPTIONAL, -- Need Mmcs-Table ENUMERATED {qam64LowSE} OPTIONAL, -- Need Ssps-ConfigIndex-r16 SPS-ConfigIndex-r16 OPTIONAL, -- CondSPS-Listharq-ProcID-Offset-r16 INTEGER (0..15) OPTIONAL, -- Need RperiodicityExt-r16 INTEGER (1..5120) OPTIONAL, -- Need Rharq-CodebookID-r16 INTEGER (1..2) OPTIONAL, -- Need Rpdsch-AggregationFactor-r16 ENUMERATED {n1, n2, n4, n8 }OPTIONAL -- Need Stci-StatesToAddModList SEQUENCE (SIZE (1..maxNrofTCI-States) ) OF TCI-State OPTIONAL, -- Need N tci-StatesToReleaseList SEQUENCE (SIZE (1..maxNrofTCI-States) ) OFTCI-StateId OPTIONAL, -- Need NGC-CS-RNTI RNTI-Value OPTIONAL, -- Need R} Here, ‘harq-CodebookID’ may indicate the corresponding HARQ-ACK codebook for the SPS PDSCH and the HARQ-ACK codebook index for the ACK for the SPS PDSCH release. ‘harq-ProcID-offset’ may indicate an offset used to derive the HARQ process ID. ‘mcs-table’ may indicate an MCS table to be used by the UE for DL SPS. If the ‘mcs-table’ field is present, the UE must use the MCS table of the low-SE 64QAM table. If the corresponding field does not exist, the field ‘mcs-table’ of the ‘PDSCH-Config’ is configured to ‘qam256’, and the format of the active DCI is 1_1, the UE may apply the 256QAM table. Otherwise, the UE may apply a non-low-SE 64QAM table. ‘n1PUCCH-AN’ may mean a HARQ resource for PUCCH for DL SPS. The network side may configure the resource in format 0 or format 1. The actual PUCCH-resource is set in ‘PUCCH-Config’ and may be referred to as an ID. ‘nrofHARQ-process’ may indicate the number of HARQ processes configured for SPS DL. ‘pdsch-AggregationFactor’ may indicate the number of repetitions of the SPS PDSCH. If there is no corresponding field, the UE may apply a PDSCH aggregation factor of ‘PDSCH-Config’. ‘periodicity’ may indicate the period of the DL SPS. ‘periodicityExt’ may be used to calculate the periodicity of the DL SPS. If the corresponding field exists, the ‘periodicity’ field may be ignored. The following cycle may be supported according to the configured SCS[ms]. 15 kHz: ‘periodicityExt’, where ‘periodityExt’ may have a value between 1 and 640. 30 kHz: 0.5בperiodicityExt’, where ‘periodicityExt’ may have a value between 1 and 1280. 60 kHz in normal CP: 0.25בperiodityExt’, where ‘periodityExt’ may have a value between 1 and 2560. 60 kHz (including ECP): 0.25בperiodityExt’, where ‘periodityExt’ may have a value between 1 and 2560. 120 kHz: 0.125בperiodityExt’, where ‘periodityExt’ may have a value between 1 and 5120. ‘sps-ConfigIndex’ may indicate one index among multiple SPS configurations. ‘tci-StatesToAddModList’ may indicate a TCI state list indicating a transmission configuration including a QCL relationship between a DL RS and a PDSCH DMRS port in one RS set. ‘GC-CS-RNTI’ may indicate a GC-CS-RNTI value associated with ‘sps-ConfigIndex’. If the corresponding field does not exist and another GC-CS-RNTI value is configured for the CFR or serving cell related to ‘sps-ConfigIndex’, the UE may use a different GC-CS-RNTI value for ‘sps-ConfigIndex’. If the corresponding field does not exist and no other GC-CS-RNTI value is configured for the serving cell or CFR related to ‘sps-ConfigIndex’, the UE may use the CS-RNTI value for ‘sps-ConfigIndex’. For example, one or more SPS configurations may be configured and associated with a TCI state list (e.g., ‘tci-StatesToAddModList’ in ‘SPS-config’ for CFR). For one or more CFRs, different SPS configurations may be configured and associated with other ‘tci-StatesToAddModList’ in ‘SPS-config’. If the group common SPS configuration is not configured to ‘tci-StatesToAddModList’ in ‘SPS-config’, the SPS configuration may be associated with ‘tci-StatesToAddModList’ in ‘PDSCH-config’ of the CFR or the serving cell of the UE. Here, when ‘tci-StatesToAddModList’ is not configured as the SPS configuration index in ‘SPS-config’, the SPS configuration index may be a UE-specific SPS configuration rather than a group common SPS configuration used for MBS. That is, if ‘tci-StatesToAddModList’ is not configuration as the SPS configuration index in ‘SPS-config’, the UE may consider that the SPS configuration is a UE-specific SPS configuration rather than a group common SPS configuration. If ‘tci-StatesToAddModList’ is configuration as an SPS configuration index in ‘SPS-config’, the UE may consider that the SPS configuration is a group common SPS configuration. As another example, one or more TMGIs may be configured and associated with ‘tci-StatesToAddModList’. If the SPS PDSCH transmission of the SPS configuration is mapped to the TMGI associated with ‘tci-StatesToAddModList’, the SPS PDSCH transmission of the SPS configuration may be associated with the ‘tci-StatesToAddModList’. As another example, one or more G-RNTIs may be configured and associated with ‘tci-StatesToAddModList’. When SPS PDSCH transmission of SPS configuration is mapped to MBS service of G-RNTI associated with ‘tci-StatesToAddModList’, SPS PDSCH transmission of SPS configuration may be associated with ‘tci-StatesToAddModList’. As another example, a value of GC-CS-RNTI or CS-RNTI may be configured and associated with ‘tci-StatesToAddModList’. When the SPS configuration is mapped to a value of GC-CS-RNTI or CS-RNTI associated with ‘tci-StatesToAddModList’, the SPS configuration may be associated with ‘tci-StatesToAddModList’. As another example, one SPS configuration may configured one or more HARQ process IDs up to ‘nrofHARQ-Processes’ (up to ‘nrofHARQ-Processes’). The HARQ process ID may be associated with a slot from which DL SPS PDSCH transmission starts and is derived from one of Equations 3 and 4 below. HARQ process ID=[floor(CURRENT_slot×10/(numberOfSlotsPerFrame×periodicity))]modulo nrofHARQ-Processes [Equation 3] HARQ process ID=[floor(CURRENT_slot×10/(numberOfSlotsPerFrame×periodicity))]modulo nrofHARQ-Processes+harq-ProcID-Offset [Equation 4] As another example, the UE may be configured separately with one or more UE-specific SPS configuations. As option 2-1, both the UE-specific SPS configuration and the group common SPS configuration may share the ‘sps-ConfigIndex’ value. For example, ‘sps-ConfigIndex’ may be configured from 0 to 4 for five UE-specific SPS configurations, but ‘sps-ConfigIndex’ may be configured from 7 to 8 for two group common SPS configurations. In this case, ‘sps-ConfigIndex’ values 5 and 6 may not be used for the UE. In the above option, upon receiving the DCI for the SPS configuration, the UE may determine whether the SPS configuration is group common or UE specific by checking the ‘sps-ConfigIndex’ value included in the DCI. In DCI, the value of ‘sps-ConfigIndex’ may be indicated by a HARQ process number field or a configuration index field of DCI. As option 2-2, the UE-specific SPS configuration and the group common SPS configuration may have a separate space for the ‘sps-ConfigIndex’ value. For example, ‘sps-ConfigIndex’ may be configured from 0 to 4 for five UE-specific SPS configurations, but ‘sps-ConfigIndex’ may be configured from 0 to 1 for two group common SPS configurations. In the above option, upon receiving the DCI for the SPS configuration, the UE may check one of the following 1) to 4) without checking the ‘sps-ConfigIndex’ value to determine whether the SPS configuration is group common or UE specific. 1) RNTI Value Used for CRC Scrambling of DCI For example, when the RNTI value corresponds to a specific value such as the GC-CS-RNTI value, the SPS configuration may be group common. DCI Format of DCI For example, when the MBS-specific DCI format is used for DCI, the SPS configuration may be group common. 3) One or More DCI Fields May Indicate all ‘0’ or all ‘1’. For example, when one or more of ‘MCS’, ‘ZP CSI-RS trigger’, and ‘SRS request’ of DCI all indicate ‘0’, validation of DCI format for activation of group common SPS configuration may be achieved. 4) HARQ Process Number For example, one SPS configuration may configure multiple HARQ process numbers up to ‘nrofHARQ-Processes’. The first set of HARQ process numbers (e.g., 0, 2, 4) may be used for UE-specific SPS transmission, and the second set of HARQ process numbers (e.g., 1, 3, 5) may be used for group common SPS transmission. The UE may consider that the DL SPS resource of the slot associated with the first set is used for UE-specific SPS transmission, while the DL SPS resource of the slot associated with the second set is used for group common SPS transmission. Alternatively, one SPS configuration may configure several HARQ process numbers up to ‘nrofHARQ-Processes’. The first set of HARQ process numbers (e.g. 0, 2, 4) may be used in the first set of TMGI(s) or G-RNTI(s), but the second set of HARQ process numbers (e.g., 1, 3, 5) may be used in the second set of TMGI(s) or G-RNTI(s). The UE may consider that the DL SPS resource in the slot associated with the HARQ process number of the first set is used for SPS transmission for the TMGI or G-RNTI of the first set, but the DL SPS resource in the slot associated with the HARQ process number of the second set may be used for SPS transmission for the TMGI or G-RNTI of the second set. If the SPS configuration is configured for the configured CFR, the UE may monitor the PDCCH in the search space (SS) configured in the configured CFR to receive the DCI in which the CRC is scrambled with the GC-CS-RNTI for activation, retransmission, or release of the SPS configuration (S920). In step S930, for activation, retransmission, or deactivation (release) of one of the SPS configurations, the network side may transmit DCI to the UE through the PDCCH. In this case, the UE may transmit a HARQ NACK on the PUCCH to the network side for non-confirmation of the SPS configuration, and the network side may transmit a DCI back to the UE. Then, the UE may activate the SPS configuration (e.g., SPS configuration #1) (S940). Then, the UE may transmit a HARQ-ACK for confirmation of the SPS configuration (e.g., SPS configuration #1) to the network side on the PUCCH (S950). Specifically, the CRC of DCI may be scrambled by GC-CS-RNTI or CS-RNTI. The PDCCH may include at least one of a group common PDCCH or a UE specific PDCCH. HARQ feedback activation/deactivation for group common SPS configuration may be indicated by (re)activation, retransmission or release DCI of SPS configuration, group common MAC CE, or UE-specific MAC CE. MAC CE may be composed of one or more of the following information (information 1) to 4) below. 1) HARQ Feedback Enabling/Disabling Indicator for One or More G-RNTI/TMGI. According to the indicator, the UE may enable/disable HARQ feedback for the group common PDSCH of the group common SPS configuration corresponding to G-RNTI(s)/TMGI(s). 2) HARQ Feedback Enable/Disable Indicator for One or More SPS Configuration Indexes. According to the indicator, the UE may enable/disable the HARQ feedback for the group common PDSCH of the group common SPS configuration(s). 3) HARQ Feedback Enabling/Disabling Indicator for One or More G-CS-RNTI/CS-RNTI. According to the indicator, the UE may enable/disable HARQ feedback for the group common PDSCH scheduled by DCI in which CRC is scrambled by G-CS-RNTI(s)/CS-RNTI(s). 4) HARQ Feedback Enabling/Disabling Indicator for One or More PRI (PUCCH Resource Indicator) or One or More PUCCH Resource IDs. According to the indicator, the UE may enable/disable HARQ feedback for the group common PDSCH scheduled by DCI indicating PRI(s). Or/and, according to the indicator, the UE may enable/disable HARQ feedback for PUCCH resource ID(s). Here, when DCI including PRI is received, the UE may determine that one PUCCH resource ID among one or more PUCCH resource IDs included in ‘PUCCH-config’ configured by the base station in the RRC message is mapped to the PRI. The MAC CE may be group common or terminal specific. For example, when receiving a group common MAC CE for enabling/disabling HARQ feedback for the group common SPS PDSCH, the UE may enable/disable the HARQ feedback for the group common PUCCH resource for the group common SPS PDSCH according to information included in the MAC CE, and/or the UE may enable/disable HARQ feedback for any PUCCH resource for the group common SPS PDSCH according to information included in the MAC CE. As another example, when receiving a UE-specific MAC CE for enabling/disabling HARQ feedback for the group common SPS PDSCH, the UE may enable/disable the HARQ feedback for the UE-specific PUCCH resource for the group common SPS PDSCH according to the information included in the MAC CE, and/or the UE may enable/disable HARQ feedback for any PUCCH resource for the group common SPS PDSCH according to information included in the MAC CE. As another example, when receiving a MAC CE for enabling/disabling HARQ feedback for the group common SPS PDSCH, the UE may enable/disable HARQ feedback 1) immediately after processing the MAC CE or sending an ACK to the MAC CE, or/and 2) in the Kth slot (K is an integer determined by the network side or UE capability) after receiving the MAC CE or sending an ACK to the MAC CE, or/and 3) in the next SPS PDSCH after receiving the MAC CE or sending an ACK to the MAC CE, 4) in the next SPS retransmission after receiving the MAC CE or sending an ACK to the MAC CE. When both NACK-only-based HARQ-ACK and ACK/NACK-based HARQ-ACK are configured for group common SPS configuration, RRC signaling, DCI, or MAC CE may enable/disable only one of NACK-only-based HARQ-ACK and ACK/NACK-based HARQ-ACK for group common SPS configuration. When both NACK-only-based HARQ-ACK and ACK/NACK-based HARQ-ACK are configured for a group common PDSCH dynamically scheduled by DCI that is CRC scrambled by one of C-RNTI, CS-RNTI, G-RNTI, and G-CS-RNTI, RRC signaling or DCI (or MAC CE) may enable/disable only one of NACK-only-based HARQ-ACK and ACK/NACK-based HARQ-ACK for the group common PDSCH (e.g., for one of C-RNTI, CS-RNTI, G-RNTI and G-CS-RNTI). When HARQ-ACK feedback is enabled or disabled by DCI for activating or releasing SPS configuration, DCI may allocate retransmission resources for SPS configuration, group common MAC CE, or UE-specific MAC CE. When the enabling/disabling indicator is present in DCI, upon receiving activation/release DCI enabling HARQ-ACK feedback, the UE may transmit a (non)-confirmation to the activation/deactivation DCI. That is, the network side may expect confirmation/non-confirmation transmitted by the UE. If an enabling/disabling indicator is present in DCI, upon receiving the activation/release DCI disabling HARQ-ACK feedback, the UE may not transmit a non-acknowledgment to the activation/release DCI. That is, the network side may expect that no confirmation/non-confirmation is transmitted by the UE. When ACK/NACK-based HARQ-ACK feedback is configured, when receiving DCI for activating or releasing SPS configuration, UE-specific confirmation for activation/release of SPS configuration may be transmitted by ACK/NACK of UCI. Activation/deactivation of SPS configuration DCI and PUCCH resources indicated by ‘SPS-config’ may be used to transmit confirmation of activation/deactivation of SPS configuration. The same or different PUCCH resources may be used for different SPS configurations for activation/release confirmation. i. When the same PUCCH resource is used to check the activation/deactivation of other SPS configurations, a HARQ-ACK (sub) codebook may be configured based on the SPS configuration. Other bits of the HARQ-ACK (sub) codebook may indicate confirmation or non-acknowledgment of other SPS configurations. When different SPS configurations belong to the same SPS group, 1 bit of the HARQ-ACK (sub) codebook may indicate confirmation or non-confirmation of different SPS configurations within the same SPS group. ii. When different PUCCH resources are used to check activation/release of different SPS configurations, separate PUCCH resources may be used to check activation/release of each SPS configuration. When different SPS configurations belong to the same SPS group, one PUCCH resource may indicate confirmation or non-confirmation of different SPS configurations within the same SPS group. When PUCCH-based acknowledgment for activation/deactivation is multiplexed with multicast or unicast-specific HARQ-ACK feedback, activation/release confirmation for one or more SPS configurations may be multiplexed with general multicast-specific HARQ-ACK in the first bit(s) or last bit(s) of the multicast-specific HARQ-ACK (lower) codebook. In response to the group common SPS (de)activation DCI, HARQ ACK for UCI may be interpreted as confirmation for activation, and HARQ NACK for UCI may be interpreted as confirmation for deactivation. In case of group common SPS, when NACK-only HARQ-ACK feedback is configured, when receiving a DCI for activating or releasing the SPS configuration, a group common or UE-specific acknowledgment for the activation/release of the SPS configuration may be transmitted by the ACK/NACK of the UCI. Activation/deactivation of SPS configuration DCI and PUCCH resources indicated by ‘SPS-config’ may be used to transmit confirmation of activation/deactivation of SPS configuration. As option 4-1, if activation/deactivation DCI is confirmed, the UE may transmit NACK for a PUCCH resource dedicated to NACK. If activation/release DCI is not confirmed, the UE may not transmit NACK for a PUCCH resource dedicated to NACK. As option 4-2, if activation/deactivation DCI is confirmed, the UE may transmit the first sequence through PUCCH. If activation/release DCI is not confirmed, the UE may not transmit PUCCH. Alternatively, the UE may transmit the second sequence on the PUCCH. The first sequence may be associated with SPS configuration or activation/deactivation of SPS configuration. Different first sequences may be associated with different SPS configurations. The second sequence may be associated with SPS configuration. Different second sequences may be associated with different SPS configurations. As option 4-3, the UE may change from NACK-based HARQ-ACK feedback to ACK/NACK-based HARQ-ACK feedback (when activation/release DCI is confirmed). In addition, the UE may transmit an acknowledgment when the ACK/NACK-based HARQ-ACK feedback is configured. The network side may repeatedly transmit DCI indicating the same ‘sps-ConfigIndex’ using the same GC-CS-RNTI for activation, retransmission, or deactivation of the SPS configuration. DCI may be repeatedly transmitted in multiple CORESETs with the same or different TCI state. The network side may transmit the same DCI N times in the M-TCI state for activation, retransmission, or deactivation. N and M may be configured by the network side. For example, the first/second repetition of DCI is transmitted in CORESET with TCI state1, the third/fourth repetition of DCI is transmitted on CORESET with TCI state2, and (N−1) of DCI The th/Nth repetition may be transmitted through CORESET with TCI state M. The UE may select one or two TCI states and selectively receive corresponding repetitions of DCI in the CORESET associated with the selected TCI state(s). When DCI repetitions are transmitted in the same TCI state, the UE may transmit PUCCH based on the last repeated DCI to confirm SPS activation/deactivation. When DCI repetitions are transmitted in different TCI states, the UE may selectively receive DCI repetition(s) and transmit PUCCH based on the last repeated DCI of the selected TCI state for confirmation of SPS activation/deactivation. The DCI may include the fields for activation, retransmission or deactivation (i.e., release) of the SPS configuration: Identifier for DCI Formats The identifier field for the DCI format may indicate either an MBS-specific DCI format or an existing DCI format for MBS. Carrier Indicator The carrier indicator field may indicate a (serving or MBS specific) cell of the CFR or a serving cell of the active BWP of the UE associated with the CFR. Here, the group common PDCCH/PDSCH may be transmitted or the configured DL allocation of the SPS PDSCH may be allocated to the SPS configuration indicated by the DCI. BWP Indicator The carrier indicator field may indicate the BWP ID assigned to the CFR or the BWP ID of the active BWP of the terminal associated with the CFR. Here, a group common PDCCH/PDSCH may be transmitted or a configured DL allocation of the SPS PDSCH may be allocated to the SPS configuration indicated by the DCI.frequency domain resource assignmenttime domain resource assignmentVRB-PRB mappingPRB bundling size indicatorrate matching indicatorZP CSI-RS triggermodulation and coding schemenew data indicator (NDI) The NDI may be configured to 1 for retransmission for the SPS configuration indicated by the DCI. In addition, the NDI may be configured to 0 for activation or release (i.e., deactivation) for the SPS configuration indicated by the DCI.redundancy versionHARQ process numberdownlink assignment indexTPC command for scheduled PUCCHPUCCH resource indicatorPDSCH-to-HARQ feedback timing indicatorantenna port(s)transmission configuration indicatorSRS requestDMRS sequence initializationpriority indicator The DCI (i.e., activation DCI) may indicate activation of a particular SPS configuration by using of the following options: As option 4-1, for activation of the SPS configuration, the value of the HARQ process number field of the DCI format is the same value as provided by ‘sps-ConfigIndex’ of the SPS configuration, and may indicate activation of the SPS PDSCH configuration. When all RV fields for the DCI format are configured to ‘0’, validation of the DCI format may be performed. If validity is confirmed after receiving the DCI, the UE may consider the information in the DCI format as valid activation of the DL SPS configuration. If validation is not performed, the UE may discard all information in the DCI format. In option 4-1 above, the SPS configuration may support both a group common SPS by only GC-CS-RNTI, a UE-specific SPS by only CS-RNTI, or a group common SPS and UE-specific SPS with different HARQ process IDs or additional indications for ‘group common’ or ‘UE-specific’. In option 4-2, for activation of the SPS configuration, a DCI format configuration index field is added, and the configuration index field has the same value as provided by ‘sps-ConfigIndex’ of the SPS configuration and may indicate activation of the SPS PDSCH configuration. When the NDI fields for the DCI format are all configured to ‘0’ (or all ‘1’) and the RV fields for the DCI format are all configured to ‘0’, validation of the DCI format may be achieved. In the above option 4-2, the SPS configuration may support the group common SPS only when there is a configuration index field or support the UE-specific SPS only when there is no configuration index field. When validation is achieved, the UE may consider the information in the DCI format as valid activation or valid release of DL SPS or configured UL grant type 2. If validation is not achieved, the UE may discard all information in DCI format. For group common SPS, the network side, by group common or UE specific RRC message or by group common or UE specific MAC CE, may provide the UE with one or more of a service-resource mapping for an MBS service identified by TMGI or G-RNTI or GC-CS-RNTI. The data of the MBS service may be carried through the multicast traffic logical channel, that is, the MBS radio bearer (MRB) of the MTCH associated with the MBS service. The RRC message may be a group common message transmitted through a PTM multicast control channel (MCCH) or a UE-only message transmitted through a UE-specific dedicated control channel (DCCH). If the group common DCI for the activation of the SPS configuration is not confirmed by the UE, that is, the network side cannot detect the PUCCH TX for confirmation for the active DCI or receives a non-confirmation from the UE, the network side may perform an operation according to options (options 5-1 to 5-3) to be described later. As option 5-1, the network side may retransmit the group common DCI indicating activation of the SPS configuration until the active DCI is confirmed by the UE. As option 5-1A, another UE that has already activated the SPS configuration may ignore the retransmitted activated DCI. That is, confirmation of the retransmitted active DCI may not be transmitted from another UE to the network side. As option 5-1B, another UE that has already activated the SPS confirmation may re-transmit the confirmation of the retransmitted active DCI to the network side while receiving the SPS PDCCH/PDSCH transmission for the activated SPS configuration without re-activating the SPS configuration. As option 5-1C, the other UE that has already activated the SPS confirmation may re-activate the SPS configuration (i.e., release and activate the SPS configuration) and re-transmit the confirmation to the retransmitted active DCI to the network side. As option 5-2, the network side may provide the UE with a UE-specific DCI for activating the SPS configuration. DCI in which CRC is scrambled by UE-specific CS-RNTI or C-RNTI may indicate ‘sps-ConfigIndex’ of group common SPS configuration. As option 5-3, the network side may (re)transmit the TB to the C-RNTI (i.e., PTP transmission) through the UE-specific PDSCH scheduled by DCI. Here, the network side may retransmit a group common activated DCI (option 1) or a UE specific activated DCI (option 2). In this case, the network side may (re)transmit the TB(s) by PTP transmission until the retransmitted active DCI is confirmed by the UE. When receiving the activation DCI indicating activation of the SPS configuration in the configured search space, the UE may activate the SPS configuration specified by ‘sps-ConfigIndex’. In addition, upon receiving the DCI, the UE may determine the MBS service(s) associated with one or more of a short ID, an MTCH ID, an MRB ID, a G-RNTI value, and a TMGI value for each SPS PDSCH occasion of the configured DL assignment, based on mapping between MBS services and the SPS configuration indicated in the DCI, mapping between MBS services and HPNs (HARQ Process Numbers) for the SPS configuration indicated in the DCI, and/or mapping between MBS services and, if available, short ID(s) indicated in the DCI. Then, if UE is interested in the determined MBS service(s), UE may activate the SPS configuration based on the DCI indicating activation of the SPS configuration. If UE is not interested in the determined MBS service(s), UE may not activate the SPS configuration based on the DCI. If the SPS configuration indicated by the activation DCI belongs to one SPS group which include other SPS configuration(s), upon the DCI indicating activation of the SPS configuration, UE may activate the other SPS configuration(s) belong to the same SPS group. Alternatively, if the SPS configuration indicated by the activation DCI belongs to one SPS group which include other SPS configuration(s), upon the DCI indicating activation of the SPS configuration, UE may release the other SPS configuration that has been activated. After activation of the SPS configuration, as shown in Equation 5 below, the UE may sequentially consider that the N-th DL allocation of the SPS PDSCH for the SPS configuration occurs in the slot. (numberOfSlotsPerFrame×SFN+slot number in the frame)=[(numberOfSlotsPerFrame×SFNstart time+slotstart time)+N×periodicity×numberOfSlotsPerFrame/10]modulo(1024×numberOfSlotsPerFrame) [Equation 5] Here, the ‘SFNstart’ time and the ‘slotstart’ time may be the SFN and slot of the first transmission of the PDSCH in which the DL assignment configured for the SPS configuration was (re)initialized, respectively. The configured DL allocation may be configured as a set of periodic SPS PDSCH occasions for SPS configuration. In the case of an SFN that is not aligned across the carriers of the cell group, the SFN of the serving cell of the active BWP of the UE related to the CFR may be used to calculate the occurrence of the configured DL assignment. The DCI may also indicate one or more of a short ID, a MTCH ID, a MRB ID, a G-RNTI value and a TMGI value for activation of the SPS configuration. If a data unit is available on a MTCH of a MRB for a MBS service, the base station may construct and transmit a TB including the data unit for a SPS PDSCH occasion associated to the MTCH of the MRB for the MBS service, or associated to TMGI of the MBS service, or associated to a short ID of the MBS service, or associated to G-RNTI mapped to the MBS service, according to the service-to-resource mapping. If the SPS configuration has been activated by UE based on the interested MBS service, UE may periodically receive SPS PDSCH transmission occasions on the configured downlink assignment for the SPS configuration according to the above equation (S960). UE may consider the NDI to have been toggled for reception of each of the SPS PDSCH occasions. For reception of a specific SPS PDSCH transmission occasion on the configured downlink assignment for the SPS configuration, UE may consider that the SPS PDCH transmission occasion is associated to MTCH, MRB, TMGI, G-RNTI and/or short ID of the MBS service based on mapping between MBS services and the SPS configuration, mapping between MBS services and HPNs (HARQ Process Numbers) for the SPS configuration, and/or mapping between MBS services and, if available, short ID(s), as indicated in the activation DCI or the retransmission DCI and/or configured by the RRC message. If decoding the TB on the SPS PDSCH transmission occasion is unsuccessful, the UE may transmit HARQ NACK to the base station on a PUCCH resource in the configured UL CFR according to PUCCH configuration of the SPS configuration received by the RRC message, and PUCCH resource indicator and PDSCH-to-HARQ_feedback timing indicator received by the DCI activating the SPS configuration. By using the same PUCCH resource, the UE also may transmit HARQ-ACK to other PDSCH transmissions such as unicast SPS PDSCH, dynamic unicast PDSCH, PTP retransmission and/or dynamic group common PDSCH (S970). In this case, for multiplexing HARQ-ACKs on PUCCH in a (sub-)slot for SPS PDSCH for multicast, SPS PDSCH for unicast, dynamically scheduled multicast PDSCH, and/or dynamically scheduled unicast PDSCH, the UE may construct codebook based on one or more of the following options. In the following options, the dynamically scheduled unicast PDSCH may be scheduled by a UE-specific DCI (e.g., CRC scrambled DCI by C-RNTI or CS-RNTI). Alternatively, the dynamically scheduled unicast PDSCH may exclude PTP retransmissions scheduled by UE-specific DCI (e.g., DCI scrambled CRC by C-RNTI) for TBs initially scheduled by group common DCI. Alternatively, the dynamically scheduled unicast PDSCH may exclude PTP retransmissions scheduled by UE-specific DCI (e.g., DCI scrambled CRC by CS-RNTI) for TBs initially transmitted by group common SPS PDSCH without DCI. The dynamically scheduled multicast PDSCH may be scheduled by a group common DCI (e.g., DCI scrambled CRC by G-RNTI or G-CS-RNTI). Alternatively, the dynamically scheduled multicast PDSCH may also include a PTP retransmission scheduled by a UE-specific DCI (e.g., CRC scrambled by C-RNTI) for a TB initially scheduled by the group common DCI. Alternatively, the dynamically scheduled multicast PDSCH may also include PTP retransmissions scheduled by UE specific DCI (e.g., DCI scrambled CRC by CS-RNTI) for TBs initially transmitted by group common SPS PDSCH without DCI. The SPS PDSCH for unicast may be specific to the UE and may be scheduled by RRC. The SPS PDSCH for multicast (i.e., group common SPS PDSCH) may be common to UEs in the group and may be scheduled by RRC. Multicast reception may correspond to reception of a dynamically scheduled multicast PDSCH and/or reception of an SPS PDSCH for multicast. Alternatively, multicast reception may not include a case in which HARQ feedback is deactivated for reception of a dynamically scheduled multicast PDSCH and/or reception of an SPS PDSCH for multicast. As option 1, if both unicast HARQ-ACK and multicast HARQ-ACK are scheduled, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs for a slot. Within unicast HARQ-ACKs, HARQ-ACKs to dynamically scheduled unicast PDSCHs may be followed by HARQ-ACKs to SPS PDSCHs for unicast, if both dynamically scheduled unicast PDSCHs and SPS PDSCHs for unicast are scheduled. As option 1A-1, a separate sub-codebook may be configured for HARQ-ACK for dynamically scheduled unicast PDSCH and SPS PDSCH for unicast. For one PUCCH in the same slot, the UE may concatenate a separate lower codebook to the PUCCH (e.g., based on the Type-2 HARQ-ACK codebook). For two PUCCHs in the same slot, the UE may use separate sub-codebooks for different PUCCHs, respectively. As option 1A-2, a single codebook may be configured for HARQ-ACK for dynamically scheduled unicast PDSCH and HARQ-ACK for SPS PDSCH for unicast. For example, the UE may configure the Type-1 HARQ-ACK codebook based on a combination of a dynamically scheduled unicast PDSCH and a unicast SPS PDSCH. If the HARQ-ACK codebook is configured based on HPN, the UE may concatenate HARQ-ACK to unicast PDSCH dynamically scheduled in ascending order of dynamic HPN and concatenate HARQ-ACK(s) to unicast SPS PDSCH in ascending order of SPS HPN. Alternatively, the UE may configure HARQ-ACK for the dynamically scheduled unicast PDSCH and unicast SPS PDSCH in ascending order of HPN. Within the multicast HARQ-ACK, the HARQ-ACK for the dynamically scheduled multicast PDSCH may be followed by the HARQ-ACK(s) for the SPS PDSCH for the multicast. As option 1A-1, a separate sub-codebook may be configured for the HARQ-ACK for the dynamically scheduled multicast PDSCH and the SPS PDSCH for multicast. For one PUCCH in the same slot, the UE may concatenate a separate lower codebook to the PUCCH (based on the Type-2 HARQ-ACK codebook). For two PUCCHs in the same slot, the UE may use separate sub-codebooks for different PUCCHs, respectively. As option 1A-2, a single codebook may be configured for HARQ-ACK(s) for dynamically scheduled multicast PDSCH and HARQ-ACK(s) for SPS PDSCH for multicast. For example, the UE may configure the Type-1 HARQ-ACK codebook based on a combination of the dynamically scheduled multicast PDSCH and multicast SPS PDSCH. If the HARQ-ACK codebook is configured based on HPN, the UE may concatenate the HARQ-ACK(s) to the dynamically scheduled multicast PDSCH in the ascending order of the dynamic HPN and concatenate the HARQ-ACK(s) to the multicast SPS PDSCH in the ascending order of the SPS HPN. Alternatively, the UE may configure HARQ-ACK in increasing order of HPNs for the dynamically scheduled multicast PDSCH and multicast SPS PDSCH. In option 1, a single HARQ-ACK codebook may consist of unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for HARQ-ACK. Alternatively, a separate sub codebook may consist of unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for HARQ-ACK. For one PUCCH in the same slot, the UE may concatenate a separate lower codebook on the PUCCH. For two PUCCHs in the same slot, the UE may use separate sub-codebooks for different PUCCHs, respectively. As option 1-1, for each TRP for each cell, unicast HARQ-ACKs are followed by multicast HARQ-ACKs. For example, if two TRPs of a serving cell are configured for a UE, UE may construct HARQ-ACK codebook for a slot as follows. HARQ-ACKs for TRP #1 may be followed by HARQ-ACKs for TRP #2 for the slot for the cell. As option A, if multiple cells are configured for the UE, HARQ-ACKs for TRP #1 may be followed by HARQ-ACKs for TRP #2 for a slot for each cell. As option B, if multiple cells are configured for the UE, HARQ-ACKs for TRP #1 for all cells are followed by HARQ-ACKs for TRP #2 for all cells for the slot. For HARQ-ACKs for the slot for TRP #1, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs. If there is no multicast reception from TRP #1, multicast HARQ-ACKs may indicate all ACKs (or all NACKs). If there is multicast reception from TRP #1 for which HARQ feedback is disabled for the slot, multicast HARQ-ACKs may indicate all ACKs (or all NACKs). For HARQ-ACKs for the slot for TRP #2, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs. In the above option, the UE may configure a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each TRP regardless of whether multicast is received for the slot. As option 1-2, only for a TRP with multicast reception for each cell, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs. For example, if two TRPs of a serving cell are configured for a UE, UE may construct HARQ-ACK codebook for a slot as follows. In the HARQ-ACK codebook, for a slot for a cell, HARQ-ACK(s) for TRP #1 may be followed by HARQ-ACK(s) for TRP #2. As option A, if multiple cells are configured for the UE, HARQ-ACKs for TRP #1 may be followed by HARQ-ACKs for TRP #2 for the slot for each cell. As option B, if multiple cells are configured for the UE, HARQ-ACKs for TRP #1 for all cells may be followed by HARQ-ACKs for TRP #2 for all cells for the slot. For HARQ-ACKs for the slot for TRP #1 with multicast reception, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs. If there is multicast reception from TRP #1 in which HARQ feedback is deactivated for one slot, the multicast HARQ-ACK may not be included in the HARQ-ACK codebook for TRP #1. Alternatively, if there is multicast reception in which HARQ feedback is disabled from TRP #1, multicast HARQ-ACK may indicate all ACKs (or all NACKs). In the case of HARQ-ACK for a slot for TRP #2 without multicast reception, only unicast HARQ-ACK may be included in the HARQ-ACK codebook. And, there may be no multicast HARQ-ACK(s) in the HARQ-ACK codebook. In the above option, the UE may configure a full codebook including both unicast HARQ-ACK and multicast HARQ-ACK for each TRP only by multicast reception for the slot. For each TRP with multicast reception, in the case of a unicast reception-only TRP slot, the UE may configure a HARQ-ACK codebook for unicast reception only. For each TRP with multicast reception, in the case of a slot for multicast reception-only TRP, the UE may configure a multicast reception-only HARQ-ACK codebook. For each TRP with multicast reception, in the case of a slot for TRP in which both unicast and multicast reception are possible, the UE may configure a full HARQ-ACK codebook for both unicast and multicast reception. In option 1-3, for each cell, unicast HARQ-ACKs are followed by multicast HARQ-ACKs. For example, when two serving cells are configured for the UE, the UE may configure the HARQ-ACK codebook for the slot as follows. For example, HARQ-ACK(s) for cell #1 may be followed by HARQ-ACK(s) for cell #2 for slot. As another example, for HARQ-ACK for the slot for cell #1, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs. If there is no multicast reception from cell #1, multicast HARQ-ACKs may indicate all ACKs or all NACKs. As another example, if there is multicast reception from cell #1 in which HARQ feedback is disabled for the corresponding slot, multicast HARQ-ACK(s) may indicate all ACKs (or all NACKs). As another example, for HARQ-ACKs for the slot for cell #2, unicast HARQ-ACKs may be followed by multicast HARQ-ACKs. In the above option, the UE may configure a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each cell regardless of whether multicast is received for the slot. As option 1-4, unicast HARQ-ACK(s) may be followed by multicast HARQ-ACK(s) only for cells with multicast reception. For example, when two serving cells are configured for the UE, the UE may configure the HARQ-ACK codebook for the slot as follows. For example, HARQ-ACK(s) for cell #1 may be followed by HARQ-ACK(s) for cell #2 for slot. As another example, in the case of HARQ-ACK(s) for a slot for cell #1 with multicast reception, a unicast HARQ-ACK(s) may be followed by a multicast HARQ-ACK(s). As another example, if there is multicast reception from cell #1 in which HARQ feedback is disabled for the corresponding slot, multicast HARQ-ACK(s) may not be included in the HARQ-ACK codebook for cell #1. As another example, if there is multicast reception from cell #1 in which HARQ feedback is disabled, multicast HARQ-ACK(s) may indicate all ACKs (or all NACKs). In the case of HARQ-ACK(s) for a slot for cell #2 without multicast reception, only unicast HARQ-ACK(s) may be included in the HARQ-ACK codebook. There may be no multicast HARQ-ACK in the HARQ-ACK codebook. In the above option, the UE may configure a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each cell only by multicast reception for the slot. For each cell with multicast reception, in the case of a unicast reception-only cell, the UE may configure a HARQ-ACK codebook for unicast reception only. For each cell with multicast reception, in the case of a slot for a multicast reception-only cell, the UE may configure a multicast reception-only HARQ-ACK codebook. For each cell with multicast reception, in the case of a slot for a cell capable of both unicast and multicast reception, the UE may configure a full HARQ-ACK codebook for both unicast and multicast reception. As options 1-5, unicast HARQ-ACK(s) for all cells may be followed by multicast HARQ-ACK for all cells. Multicast HARQ-ACK(s) for all cells may include all serving cells regardless of the cell in which the UE performs multicast reception. Alternatively, multicast HARQ-ACK(s) for all cells may exclude all serving cells without multicast reception. That is, the multicast HARQ-ACK(s) for all cells may include all serving cell(s) with multicast reception. Alternatively, multicast HARQ-ACK(s) for all cells may exclude all serving cells with multicast reception in which HARQ feedback is disabled. That is, the multicast HARQ-ACK(s) for all cells may include all serving cell(s) having multicast reception for which HARQ feedback is enabled. For example, when two serving cells are configured for the UE, the UE may configure the HARQ-ACK codebook for the slot as follows. For unicast HARQ-ACK for all cells, unicast HARQ-ACK(s) for cell #1 may be followed by unicast HARQ-ACK for cell #2 for slot. For multicast HARQ-ACK(s) for all cells, multicast HARQ-ACK(s) for cell #1 may be followed by multicast HARQ-ACK(s) for cell #2 for slot. If there is multicast reception from cell #1 without multicast reception for one slot, multicast HARQ-ACK(s) for cell #1 may not be included in the HARQ-ACK codebook. Alternatively, when there is no multicast reception from cell #1, multicast HARQ-ACK(s) may indicate all ACKs (or all NACKs). If there is multicast reception from cell #1 with multicast reception in which HARQ feedback is disabled for the corresponding slot, multicast HARQ-ACK(s) for cell #1 may not be included in the HARQ-ACK codebook. Alternatively, when there is multicast reception from cell #1 in which HARQ feedback is disabled, multicast HARQ-ACK(s) may indicate all ACKs (or all NACKs). Alternatively, in the case of HARQ-ACK(s) for a slot for cell #2 without multicast reception, only HARQ-ACK(s) for cell #1 may be included in the HARQ-ACK codebook. In the above option, the UE may configure a full codebook including both unicast HARQ-ACK for all cells and multicast HARQ-ACK for all cells or cells with only multicast reception for a slot. For all cells, in the case of slots for all cells in which only unicast reception is possible, the UE may configure a HARQ-ACK codebook for unicast reception only. For all cells, in the case of slots for all cells dedicated to multicast reception, the UE may configure a HARQ-ACK codebook dedicated to multicast reception. In the case of slots for all cells including one or more cells capable of both unicast and multicast reception for all cells, the UE may configure a full HARQ-ACK codebook for both unicast and multicast reception. As options 1-6, in order to multiplex HARQ-ACK for each slot, the UE may use one of the sub-options of option 1 above. The UE may use a different option for each slot. That is, different options may be applied to a multicast reception-only slot, a unicast reception-only slot, and a unicast and multicast reception-only slot. For example, options 1-4 may be used for slots with only multicast HARQ-ACK(s) or slots with only unicast HARQ-ACK(s), and option 1-5 may be used for slots with both unicast HARQ-ACK(s) and multicast HARQ-ACK(s). As another example, option 1-2 may be used for slots with only multicast HARQ-ACK(s), option 1-1 may be used for slots with only unicast HARQ-ACK(s), and options 1-5 may be used for slots with both unicast HARQ-ACK and multicast HARQ-ACK. As option 2, when both the dynamically scheduled PDSCH and the SPS PDSCH are scheduled, the dynamic HARQ-ACK(s) may be followed by the SPS HARQ-ACK(s) for the slot. In the dynamic HARQ-ACK(s), when both the dynamically scheduled unicast PDSCH and the dynamically scheduled multicast PDSCH are scheduled, the HARQ-ACK(S) for the dynamically scheduled unicast PDSCH may be followed by the HARQ-ACK(s) for the dynamically scheduled multicast PDSCH. As option 2A-1, separate sub-codebooks may be configured for HARQ-ACK(s) for dynamically scheduled unicast PDSCH and HARQ-ACK(s) for dynamically scheduled multicast PDSCH. For one PUCCH on the same slot, the UE may concatenate a separate lower codebook to the PUCCH based on the Type-2 HARQ-ACK codebook. For two PUCCHs in the same slot, the UE may use separate sub-codebooks for different PUCCHs, respectively. As option 2A-2, a single codebook may be configured for HARQ-ACK(s) for dynamically scheduled unicast PDSCH and HARQ-ACK(s) for dynamically scheduled multicast PDSCH. For example, the UE may configure the Type-1 HARQ-ACK codebook based on a combination of a dynamically scheduled unicast PDSCH and a dynamically scheduled multicast PDSCH. If the HARQ-ACK codebook is configured based on HPN, the UE may concatenate the HARQ-ACK(s) to the dynamically scheduled unicast PDSCH in ascending order of the unicast HPN, and HARQ-ACK(s) may be attached to the dynamically scheduled unicast PDSCH in ascending order of the multicast HPN. Alternatively, when unicast and multicast share HPN, the UE may configure HARQ-ACK(s) in ascending order of HPN for dynamically scheduled unicast/multicast PDSCH. In the SPS HARQ-ACK, when both the unicast SPS PDSCH and the multicast SPS PDSCH are scheduled, HARQ-ACK for SPS PDSCH for unicast may be followed by HARQ-ACK for SPS PDSCH for multicast. As option 2B-1, separate sub-codebooks may be configured for HARQ-ACK(s) for unicast SPS PDSCH and HARQ-ACK(s) for multicast SPS PDSCH. For one PUCCH in the same slot, the UE may concatenate a separate lower codebook to the PUCCH based on the Type-2 HARQ-ACK codebook. For two PUCCHs in the same slot, the UE may use separate sub-codebooks for different PUCCHs, respectively. As option 2B-2, a single codebook may be configured for HARQ-ACK(s) for unicast SPS PDSCH and HARQ-ACK(s) for multicast SPS PDSCH. If the HARQ-ACK codebook is configured based on HPN, the UE may concatenate HARQ-ACK(s) to unicast SPS PDSCH in ascending order of unicast HPN, and concatenate HARQ-ACK(s) to multicast SPS PDSCH in ascending order of multicast HPN. Alternatively, when unicast and multicast share HPN, the UE may configure HARQ-ACK(s) for unicast/multicast SPS PDSCH in ascending order of HPN. When configuring the HARQ-ACK codebook based on the SPS configuration index, the UE may concatenate HARQ-ACK(s) to the unicast SPS PDSCH in the ascending order of the unicast SPS configuration index, and concatenate the HARQ-ACK(s) to the multicast SPS PDSCH in the ascending order of the multicast SPS configuration index. Alternatively, when unicast and multicast share the SPS configuration index, the UE may configure HARQ-ACK(s) for the unicast/multicast SPS PDSCH in an ascending order of the SPS configuration index. As option 2, for HARQ-ACK for dynamic HARQ-ACK(s) and SPS HARQ-ACK(s), a single HARQ-ACK codebook may be configured. Alternatively, a separate sub-codebook may be configured for HARQ-ACK(s) for dynamic HARQ-ACK(s) and SPS HARQ-ACK(s). For one PUCCH in the same slot, the UE may concatenate a separate lower codebook to the PUCCH. For two PUCCHs in the same slot, the UE may use a separate sub-codebook for each of the different PUCCHs. As option 2-1, for each TRP for each cell, dynamic HARQ-ACK(s) may be followed by SPS HARQ-ACK(s). For example, if two TRPs of the serving cell are configured for the UE, the UE may configure the HARQ-ACK codebook for the slot as follows. For the slot for the cell, HARQ-ACK(s) for TRP #1 may be followed by HARQ-ACK(s) for TRP #2. As option A, if multiple cells are configured for the UE, HARQ-ACKs for TRP #1 may be followed by HARQ-ACKs for TRP #2 for the slot for each cell. As option B, if multiple cells are configured for the UE, HARQ-ACKs for TRP #1 for all cells may be followed by HARQ-ACKs for TRP #2 for all cells for the slot. Alternatively, in the case of HARQ-ACK(s) for the slot for TRP #1, the dynamic HARQ-ACK(s) may be followed by SPS HARQ-ACK(s). When there is no multicast reception from TRP #1, multicast HARQ-ACK(s) in dynamic HARQ-ACK(s) and/or SPS HARQ-ACK(s) may indicate all ACKs (or all NACKs). If there is multicast reception with HARQ feedback disabled for that slot in TRP #1, multicast HARQ-ACK(s) in dynamic HARQ-ACK(s) and/or SPS HARQ-ACK(s) may indicate all ACKs (or all NACKs). In the case of HARQ-ACK(s) for the slot for TRP #2, the dynamic HARQ-ACK(s) may be followed by SPS HARQ-ACK(s). In the above option, the UE may construct a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each TRP regardless of whether multicast is received for the slot. Alternatively, for the slot, the UE may construct a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) only for each TRP with multicast reception. Alternatively, the UE may construct a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) only for each TRP with multicast reception with HARQ feedback enabled for the slot. For each TRP with multicast reception, in the case of a unicast reception-only TRP slot, the UE may construct a HARQ-ACK codebook for unicast reception only. For each TRP with multicast reception, in the case of a slot for multicast reception-only TRP, the UE may construct a multicast reception-only HARQ-ACK codebook. For each TRP with multicast reception, in the case of a slot for TRP in which both unicast and multicast reception are possible, the UE may construct a full HARQ-ACK codebook for both unicast and multicast reception. As option 2-2, dynamic HARQ-ACK(s) may be followed by SPS HARQ-ACK(s) for each cell. For example, when two serving cells are configured for the UE, the UE may construct the HARQ-ACK codebook for the slot as follows. For the slot, HARQ-ACK(s) for cell #1 may be followed by HARQ-ACK(s) for cell #2. In the case of HARQ-ACK for the slot for cell #1, dynamic HARQ-ACK(s) may be followed by SPS HARQ-ACK(s). If there is no multicast reception from cell #1, multicast HARQ-ACK(s) in dynamic HARQ-ACK(s) and/or SPS HARQ-ACK(s) may indicate all ACKs (or all NACKs). If there is multicast reception with HARQ feedback disabled for the slot from cell #1, multicast HARQ-ACK(s) in dynamic HARQ-ACK(s) and/or SPS HARQ-ACK(s) may indicate all ACKs (or all NACKs). For HARQ-ACK(s) for the slot for cell #2, the dynamic HARQ-ACK(s) may be followed by SPS HARQ-ACK(s). In the above option, the UE may construct a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) for each cell regardless of whether multicast is received for the slot. Alternatively, the UE may construct a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) only for each cell with multicast reception for a slot. Alternatively, for the slot, the UE may construct a full codebook including both unicast HARQ-ACK(s) and multicast HARQ-ACK(s) only for each cell with multicast reception in which HARQ feedback is enabled. For each cell with multicast reception, in the case of a unicast reception-only cell, the UE may construct a HARQ-ACK codebook for unicast reception only. For each cell with multicast reception, in the case of a slot for a multicast reception-only cell, the UE may construct a multicast reception-only HARQ-ACK codebook. For each cell with multicast reception, in the case of a slot for a cell capable of both unicast and multicast reception, the UE may construct a full HARQ-ACK codebook for both unicast and multicast reception. As option 2-3, dynamic HARQ-ACK(s) for all cells may be followed by SPS HARQ-ACK(s) for all cells. Multicast HARQ-ACK(s) in dynamic HARQ-ACK(s) and/or SPS HARQ-ACK(s) may include all serving cells regardless of the cell in which the UE performs multicast reception. Alternatively, multicast HARQ-ACK(s) for all cells may exclude all serving cells without multicast reception. That is, the multicast HARQ-ACK(s) for all cells may include all serving cell(s) with multicast reception. Alternatively, multicast HARQ-ACK(s) for all cells may exclude all serving cells with multicast reception in which HARQ feedback is disabled. That is, the multicast HARQ-ACK(s) for all cells may include all serving cell(s) having multicast reception for which HARQ feedback is enabled. For example, if two serving cells are configured, the UE may construct the HARQ-ACK codebook for the slot as follows. For example, in the case of dynamic HARQ-ACK(s) for all cells, the dynamic HARQ-ACK(s) for cell #1 may be followed by dynamic HARQ-ACK(s) for cell #2 for the slot. For SPS HARQ-ACK(s) for all cells, SPS HARQ-ACK(s) for cell #1 may be followed by SPS HARQ-ACK(s) for cell #2 for a slot. If there is multicast reception from cell #1 without multicast reception for one slot, multicast HARQ-ACK(s) for cell #1 may not be included in the HARQ-ACK codebook. Alternatively, if there is no multicast reception from cell #1, multicast HARQ-ACK(s) may indicate all ACKs (or all NACKs). If there is multicast reception from cell #1 with multicast reception in which HARQ feedback is disabled for the corresponding slot, multicast HARQ-ACK(s) for cell #1 may not be included in the HARQ-ACK codebook. Alternatively, if there is multicast reception from cell #1 in which HARQ feedback is disabled, multicast HARQ-ACK(s) may indicate all ACKs (or all NACKs). In case of HARQ-ACK(s) for a slot for cell #2 without multicast reception, only HARQ-ACK(s) for cell #1 may be included in the HARQ-ACK codebook. In the above option, for a slot, the UE may construct a full codebook including both unicast HARQ-ACK(s) for all cells and multicast HARQ-ACK(s) for all cells or cells with only multicast reception. For all cells, in the case of slots for all cells in which only unicast reception is possible, the UE may construct a HARQ-ACK codebook for unicast reception only. For all cells, in the case of slots for all cells dedicated to multicast reception, the UE may construct a HARQ-ACK codebook dedicated to multicast reception. For all cells, in the case of slots for all cells including one or more cells capable of both unicast and multicast reception, the UE may construct a full HARQ-ACK codebook for both unicast and multicast reception. As option 2-4, in order to multiplex HARQ-ACK for each slot, one of the sub-options of option 2 may be used by the UE. The UE may use different options for each slot. That is, different options may be used for the multicast reception-only slot, the unicast reception-only slot, and the unicast and multicast reception-only slot. For example, option 2-1 may be used for slots with only multicast HARQ-ACK(s) or slots with only unicast HARQ-ACK(s), and option 2-3 may be used for slots with unicast HARQ-ACK(s) and only unicast HARQ-ACK(s). Multicast HARQ-ACK(s) may be used in all slots. For example, option 2-1 may be used for slots with only multicast HARQ-ACK(s) or option 2-2 may be used for slots with only unicast HARQ-ACK(s). Option 2-3 may be used for slots with both unicast HARQ-ACK(s) and multicast HARQ-ACK(s). As option 3, in order to multiplex HARQ-ACK(s) for each slot, the UE may use one of the sub-options of option 1 and one of the sub-options of option 2. The UE may use different options for each slot. That is, different options may be applied to a multicast reception-only slot, a unicast reception-only slot, and a unicast and multicast reception-only slot. For example, option 2-2 may be used for slots with only multicast HARQ-ACK(s) or slots with only unicast HARQ-ACK(s), and options 1-3 or 1-4 may be used for slots with both unicast HARQ-ACK(s) and multicast HARQ-ACK(s). For example, option 2-2 may be used for slots with only multicast HARQ-ACK(s), option 2-1 may be used for slots with only unicast HARQ-ACK(s), options 1-3 or 1-4 may be used for slots with both unicast HARQ-ACK and multicast HARQ-ACK. Upon receiving the HARQ-ACK(s) having the TCI state, the network side may transmit the PDCCH and the PDSCH together with the TCI state in the DL CFR configured for retransmission of the TB. The UE may monitor the group common and/or UE-specific PDCCH with the TCI state for the search space configured in the DL CFR in order to receive the retransmission of the TB. The PDCCH for allocating retransmission resources for SPS configuration may be a group common PDCCH or a UE-specific PDCCH regardless of whether the SPS configuration is activated by a group common PDCCH or a UE-specific PDCCH. For example, after activating the SPS configuration for a group of UEs, the network side may retransmit the TB of the SPS configuration by only one of the UEs of the group by the UE-specific PDCCH, but other UEs may not receive the retransmission of the TB for the SPS (because the TB was successfully received). For retransmission of the activated SPS configuration, the network side may transmit DCI to the UE through the PDCCH. The CRC of DCI may be scrambled to one of GC-CS-RNTI, CS-RNTI, G-RNTI and C-RNTI. In order to decode the TB on the SPS PDSCH transmission occasion, the UE may consider that the TB is associated with the short ID of the MTCH, MRB, TMGI, G-RNTI and/or MBS service, based on the mapping between the MBS service and the SPS configuration, the mapping between the MBS service and the HPN (HARQ process number) for the SPS configuration, and/or the mapping between the MBS services, and the short ID(s) indicated in the DCI if available. Upon receiving the PDCCH for retransmission of the TB, the UE may receive the PDSCH scheduled by the DCI of the PDCCH. If the TB on the PDSCH is successfully decoded, if possible, the UE may consider that the short ID(s) decoded TB is associated with the MTCH, MRB, TMGI, G-RNTI and/or short ID of the MBS service, based on the mapping between the MBS service and the SPS configuration, the mapping between the MBS service and the HPN (HARQ process number) for the SPS configuration, and/or the mapping between the MBS services, as indicated in the activation DCI or retransmission DCI and/or as configured by the RRC message. If TB decoding is successful during SPS PDSCH transmission, the UE may transmit HARQ ACK(s) to the network side through the PUCCH configuration of SPS configuration received by RRC message, PUCCH resource indicator received by the retransmission DCI, and PUCCH resource of UL CFR configured according to ‘PDSCH-to-HARQ feedback’ timing indicator. By using the same PUCCH resource, the UE may transmit HARQ-ACK(s) for transmission of other PDSCHs such as unicast SPS PDSCH, dynamic unicast PDSCH, PTP retransmission and/or dynamic group common PDSCH. In this case, to multiplex HARQ-ACK(s) on PUCCH in (sub)slots for SPS PDSCH for multicast, SPS PDSCH for unicast, dynamically scheduled multicast PDSCH and/or dynamically scheduled unicast PDSCH to multiplex, the UE may construct the codebook based on one or more of the above-described options (e.g., option 1, option 2, option 3 or/and sub-options of each option). When the network side changes the mapping between the MBS service and the SPS configuration, the mapping between the MBS service and the HPN (HARQ process number) for the SPS configuration, and/or the mapping between the MBS services, short ID(s) if possible, indicated by the network side on the activation DCI or retransmission DCI and/or configured by the RRC message, the network side may re-activate the SPS configuration. For example, if the SPS configuration is activated for the first MBS service by transmitting an activation DCI indicating the first MBS service, and the network side changes the SPS configuration mapping from the first MBS service to the second MBS service, the network side may reactivate the SPS configuration by transmitting an activation DCI indicating the second MBS service. For example, the reactivation DCI may indicate a short ID associated with the second MBS service or a G-RNTI/TMGI of the second MBS service. Upon receiving the reactivation DCI, the UE may consider that the SPS configuration is remapped to the second MBS service (and not mapped to the first MBS service). For example, when the SPS configuration is activated for the first MBS service by transmitting an activation DCI indicating the first MBS service, and the network side adds the mapping of the second MBS service to the SPS configuration in addition to the first MBS service, the network side may reactivate the SPS configuration by transmitting an activation DCI indicating the second MBS service. For example, the reactivation DCI may indicate a short ID associated with the second MBS service or a G-RNTI/TMGI of the second MBS service. Upon receiving the reactivation DCI, the UE may consider that the SPS configuration is mapped not only to the first MBS service but also to the second MBS service. If the PDCCH/PDSCH of the activated SPS configuration collides with other transmission/reception, the high priority of the PDCCH/PDSCH of the activated SPS configuration may ignore other transmission/reception, and other transmission/reception may ignore the low priority of the PDCCH/PDSCH of the activated SPS configuration. If the PUCCH/PUSCH for the activated SPS configuration collides with other transmission and reception, the high priority of PUCCH/PUSCH of the activated SPS configuration may ignore other transmission/reception, and other transmission/reception may ignore the low priority of PUCCH/PUSCH of the activated SPS configuration. The priority may be determined as follows. As option 15-1, activation or retransmission or release DCI with GC-CS-RNTI or CS-RNTI may indicate high priority or low priority for SPS configuration. As option 15-2, a high priority or a low priority may be configured for each SPS configuration by the RRC. As option 15-3, for each RNTI value used to activate the SPS configuration by the RRC, a high priority or a low priority may be configured. The RNTI may be one of G-RNTI, CS-RNTI and GC-CS-RNTI. When the SPS configuration is configured on the network side, the group common SPS configuration may be implicitly released. As option 16-1, after activation of SPS configuration symbol/slot receiving DCI or symbol/slot receiving PDCCH/PDSCH transmission of SPS configuration, the SPS configuration may be released in N cycles. N may be configured by RRC or DCI activating the SPS configuration. For example, in case of SPS configuration, the activation DCI received in the last Nth period of the group common SPS may reactivate the group common SPS immediately after the end of the Nth periodicity, that is, at the start of the (N+1)th periodicity. As another example, in the case of SPS configuration, the network side may transmit DCI indicating explicit release of SPS configuration (e.g., in the middle of N periods of SPS configuration). As option 16-2, the SPS configuration may be released when the timer expires. The timer may (re)start after a symbol/slot in which the activation DCI of the SPS configuration is received or a symbol/slot in which the PDCCH/PDSCH transmission of the SPS configuration is received. The timer value may be (re)configured by RRC or DCI that activates the SPS configuration. As option 16-3, when UCI transmits Nth HARQ NACK for SPS configuration, the UE may release SPS configuration and notify the network side of SPS configuration release by UCI or MAC CE. As option 16-4, after activation of the group common SPS, all UEs may autonomously release the group common SPS immediately after the predetermined slot as long as the activation DCI indicating the SPS is not received until the predetermined slot. Here, the activation DCI or the retransmission DCI may reactivate the group common SPS immediately after a predetermined time. The predetermined time may be determined by RRC and/or DCI. For deactivation of the SPS configuration, the network side may transmit DCI to the UE through the PDCCH. CRC of DCI may be scrambled by GC-CS-RNTI or CS-RNTI. The PDCCH for DCI indicating deactivation of the SPS configuration may be a group common PDCCH or a UE specific PDCCH regardless of whether the SPS configuration is activated by a group common PDCCH or a UE specific PDCCH. For example, after activating the SPS configuration for the UE group, the network side may deactivate the SPS configuration for only one of the UEs of the group by the UE-specific PDCCH, and the other UE may still activate the SPS configuration. Deactivation/Release DCI may indicate deactivation/release of SPS configurations using the following options. As option 17-1, when ‘sps-ConfigDeactivationStateList’ is provided to the UE, the HARQ process number field value of the DCI format may indicate a corresponding entry for de-scheduling of one or more SPS PDSCH configurations. As option 17-2, if ‘sps-ConfigDeactivationStateList’ is not provided to the UE, the value of the HARQ process number field of the DCI format may indicate the configuration of the SPS PDSCH having the same value provided by each of ‘ConfiguredGrantConfigIndex’ or ‘sps-ConfigIndex’ or release of the corresponding UL grant type 2 PUSCH. If the group common DCI for the release of the SPS configuration is not confirmed by the UE, that is, the network side cannot detect the PUCCH TX for confirmation for the release DCI or receives a non-confirmation, it may operate like option 17A or option 17B, which will be described later. As option 17A, the network side may retransmit the group common DCI indicating the release of the SPS configuration until the release DCI is confirmed by the UE. As option 17A-1, another UE that has already released the SPS configuration may ignore the retransmitted release DCI. That is, the confirmation for the retransmitted release DCI may not be transmitted. As option 17A-2, the other UE that has already released the SPS confirmation may re-transmit the confirmation for the retransmitted release DCI to the network side while the SPS configuration is released, without releasing the SPS configuration again. As option 17B, the network side may provide the UE with a UE-specific DCI for releasing the SPS configuration. DCI in which CRC is scrambled by UE-specific CS-RNTI or C-RNTI may indicate ‘sps-ConfigIndex’ of group common SPS configuration. In step S980, The network side may transmit deactivation/release DCI for the activated SPS configuration (e.g., SPS configuration #1) to the UE, and the UE may transmit a HARQ-ACK (or HARQ-NACK) for non-confirmation (or confirmation) of the SPS configuration (e.g., SPS configuration #1) on the PUCCH to the network side. And, in step S990, when the UE transmits the HARQ-ACK for non-confirmation of the SPS configuration (e.g., SPS configuration #1) on the PUCCH to the network side, the network side may again transmit the deactivation/release DCI for the SPS configuration (e.g., SPS configuration #1) to the UE, and the UE may transmit a HARQ-NACK for confirmation of the SPS configuration (e.g., SPS configuration #1) to the network side on the PUCCH having the TCI state1. Specifically, upon receiving the deactivation/release DCI for the activated SPS configuration, the UE may deactivate/release the SPS configuration and all configurations related to the SPS configuration. If the SPS configuration indicated by the release DCI belongs to one SPS group including other SPS configuration(s), according to the DCI instructing release of the SPS configuration, the UE may release other SPS configuration(s) belonging to the same SPS group. Alternatively, if the SPS configuration indicated by the release DCI belongs to one SPS group including other SPS configuration(s), upon receiving the DCI indicating release of the SPS configuration, the UE may activate another activated SPS configuration. General Device to which the Present Disclosure May be Applied FIG.10illustrates a block diagram of a wireless communication device according to an embodiment of the present disclosure. In reference toFIG.10, a first wireless device100and a second wireless device200may transmit and receive a wireless signal through a variety of radio access technologies (e.g., LTE, NR). A first wireless device100may include one or more processors102and one or more memories104and may additionally include one or more transceivers106and/or one or more antennas108. A processor102may control a memory104and/or a transceiver106and may be configured to implement description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. For example, a processor102may transmit a wireless signal including first information/signal through a transceiver106after generating first information/signal by processing information in a memory104. In addition, a processor102may receive a wireless signal including second information/signal through a transceiver106and then store information obtained by signal processing of second information/signal in a memory104. A memory104may be connected to a processor102and may store a variety of information related to an operation of a processor102. For example, a memory104may store a software code including commands for performing all or part of processes controlled by a processor102or for performing description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. Here, a processor102and a memory104may be part of a communication modem/circuit/chip designed to implement a wireless communication technology (e.g., LTE, NR). A transceiver106may be connected to a processor102and may transmit and/or receive a wireless signal through one or more antennas108. A transceiver106may include a transmitter and/or a receiver. A transceiver106may be used together with a RF (Radio Frequency) unit. In the present disclosure, a wireless device may mean a communication modem/circuit/chip. A second wireless device200may include one or more processors202and one or more memories204and may additionally include one or more transceivers206and/or one or more antennas208. A processor202may control a memory204and/or a transceiver206and may be configured to implement description, functions, procedures, proposals, methods and/or operation flows charts disclosed in the present disclosure. For example, a processor202may generate third information/signal by processing information in a memory204, and then transmit a wireless signal including third information/signal through a transceiver206. In addition, a processor202may receive a wireless signal including fourth information/signal through a transceiver206, and then store information obtained by signal processing of fourth information/signal in a memory204. A memory204may be connected to a processor202and may store a variety of information related to an operation of a processor202. For example, a memory204may store a software code including commands for performing all or part of processes controlled by a processor202or for performing description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. Here, a processor202and a memory204may be part of a communication modem/circuit/chip designed to implement a wireless communication technology (e.g., LTE, NR). A transceiver206may be connected to a processor202and may transmit and/or receive a wireless signal through one or more antennas208. A transceiver206may include a transmitter and/or a receiver. A transceiver206may be used together with a RF unit. In the present disclosure, a wireless device may mean a communication modem/circuit/chip. Hereinafter, a hardware element of a wireless device100,200will be described in more detail. It is not limited thereto, but one or more protocol layers may be implemented by one or more processors102,202. For example, one or more processors102,202may implement one or more layers (e.g., a functional layer such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors102,202may generate one or more PDUs (Protocol Data Unit) and/or one or more SDUs (Service Data Unit) according to description, functions, procedures, proposals, methods and/or operation flow charts included in the present disclosure. One or more processors102,202may generate a message, control information, data or information according to description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. One or more processors102,202may generate a signal (e.g., a baseband signal) including a PDU, a SDU, a message, control information, data or information according to functions, procedures, proposals and/or methods disclosed in the present disclosure to provide it to one or more transceivers106,206. One or more processors102,202may receive a signal (e.g., a baseband signal) from one or more transceivers106,206and obtain a PDU, a SDU, a message, control information, data or information according to description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. One or more processors102,202may be referred to as a controller, a micro controller, a micro processor or a micro computer. One or more processors102,202may be implemented by a hardware, a firmware, a software, or their combination. In an example, one or more ASICs (Application Specific Integrated Circuit), one or more DSPs (Digital Signal Processor), one or more DSPDs (Digital Signal Processing Device), one or more PLDs (Programmable Logic Device) or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors102,202. Description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure may be implemented by using a firmware or a software and a firmware or a software may be implemented to include a module, a procedure, a function, etc. A firmware or a software configured to perform description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure may be included in one or more processors102,202or may be stored in one or more memories104,204and driven by one or more processors102,202. Description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure may be implemented by using a firmware or a software in a form of a code, a command and/or a set of commands. One or more memories104,204may be connected to one or more processors102,202and may store data, a signal, a message, information, a program, a code, an instruction and/or a command in various forms. One or more memories104,204may be configured with ROM, RAM, EPROM, a flash memory, a hard drive, a register, a cash memory, a computer readable storage medium and/or their combination. One or more memories104,204may be positioned inside and/or outside one or more processors102,202. In addition, one or more memories104,204may be connected to one or more processors102,202through a variety of technologies such as a wire or wireless connection. One or more transceivers106,206may transmit user data, control information, a wireless signal/channel, etc. mentioned in methods and/or operation flow charts, etc. of the present disclosure to one or more other devices. One or more transceivers106,206may receiver user data, control information, a wireless signal/channel, etc. mentioned in description, functions, procedures, proposals, methods and/or operation flow charts, etc. disclosed in the present disclosure from one or more other devices. For example, one or more transceivers106,206may be connected to one or more processors102,202and may transmit and receive a wireless signal. For example, one or more processors102,202may control one or more transceivers106,206to transmit user data, control information or a wireless signal to one or more other devices. In addition, one or more processors102,202may control one or more transceivers106,206to receive user data, control information or a wireless signal from one or more other devices. In addition, one or more transceivers106,206may be connected to one or more antennas108,208and one or more transceivers106,206may be configured to transmit and receive user data, control information, a wireless signal/channel, etc. mentioned in description, functions, procedures, proposals, methods and/or operation flow charts, etc. disclosed in the present disclosure through one or more antennas108,208. In the present disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., an antenna port). One or more transceivers106,206may convert a received wireless signal/channel, etc. into a baseband signal from a RF band signal to process received user data, control information, wireless signal/channel, etc. by using one or more processors102,202. One or more transceivers106,206may convert user data, control information, a wireless signal/channel, etc. which are processed by using one or more processors102,202from a baseband signal to a RF band signal. Therefore, one or more transceivers106,206may include an (analogue) oscillator and/or a filter. Embodiments described above are that elements and features of the present disclosure are combined in a predetermined form. Each element or feature should be considered to be optional unless otherwise explicitly mentioned. Each element or feature may be implemented in a form that it is not combined with other element or feature. In addition, an embodiment of the present disclosure may include combining a part of elements and/or features. An order of operations described in embodiments of the present disclosure may be changed. Some elements or features of one embodiment may be included in other embodiment or may be substituted with a corresponding element or a feature of other embodiment. It is clear that an embodiment may include combining claims without an explicit dependency relationship in claims or may be included as a new claim by amendment after application. It is clear to a person skilled in the pertinent art that the present disclosure may be implemented in other specific form in a scope not going beyond an essential feature of the present disclosure. Accordingly, the above-described detailed description should not be restrictively construed in every aspect and should be considered to be illustrative. A scope of the present disclosure should be determined by reasonable construction of an attached claim and all changes within an equivalent scope of the present disclosure are included in a scope of the present disclosure. A scope of the present disclosure includes software or machine-executable commands (e.g., an operating system, an application, a firmware, a program, etc.) which execute an operation according to a method of various embodiments in a device or a computer and a non-transitory computer-readable medium that such a software or a command, etc. are stored and are executable in a device or a computer. A command which may be used to program a processing system performing a feature described in the present disclosure may be stored in a storage medium or a computer-readable storage medium and a feature described in the present disclosure may be implemented by using a computer program product including such a storage medium. A storage medium may include a high-speed random-access memory such as DRAM, SRAM, DDR RAM or other random-access solid state memory device, but it is not limited thereto, and it may include a nonvolatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices or other nonvolatile solid state storage devices. A memory optionally includes one or more storage devices positioned remotely from processor(s). A memory or alternatively, nonvolatile memory device(s) in a memory include a non-transitory computer-readable storage medium. A feature described in the present disclosure may be stored in any one of machine-readable mediums to control a hardware of a processing system and may be integrated into a software and/or a firmware which allows a processing system to interact with other mechanism utilizing a result from an embodiment of the present disclosure. Such a software or a firmware may include an application code, a device driver, an operating system and an execution environment/container, but it is not limited thereto. Here, a wireless communication technology implemented in a wireless device100,200of the present disclosure may include Narrowband Internet of Things for a low-power communication as well as LTE, NR and 6G. Here, for example, an NB-IoT technology may be an example of a LPWAN (Low Power Wide Area Network) technology, may be implemented in a standard of LTE Cat NB1 and/or LTE Cat NB2, etc. and is not limited to the above-described name. Additionally or alternatively, a wireless communication technology implemented in a wireless device100,200of the present disclosure may perform a communication based on a LTE-M technology. Here, in an example, a LTE-M technology may be an example of a LPWAN technology and may be referred to a variety of names such as an eMTC (enhanced Machine Type Communication), etc. For example, an LTE-M technology may be implemented in at least any one of various standards including 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M and so on and it is not limited to the above-described name. Additionally or alternatively, a wireless communication technology implemented in a wireless device100,200of the present disclosure may include at least any one of a ZigBee, a Bluetooth and a low power wide area network (LPWAN) considering a low-power communication and it is not limited to the above-described name. In an example, a ZigBee technology may generate PAN (personal area networks) related to a small/low-power digital communication based on a variety of standards such as IEEE 802.15.4, etc. and may be referred to as a variety of names. A method proposed by the present disclosure is mainly described based on an example applied to 3GPP LTE/LTE-A, 5G system, but may be applied to various wireless communication systems other than the 3GPP LTE/LTE-A, 5G system. | 142,213 |
11943064 | DETAILED DESCRIPTION Technical solutions of implementations will be described in connection with the accompanying drawings. Implementations herein are applicable to any terminal-to-terminal communication framework, for example, V2V communication, vehicle to everything (V2X) communication, device to device (D2D) communication, etc. A terminal device of implementations may be any device or apparatus equipped with a physical layer and a media access control (MAC) layer. The terminal device may also be referred to an access terminal, for example, a user equipment (UE), a subscriber unit, a subscriber station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. The access terminal may be a cellular radio telephone, a cordless telephone, a session initiation protocol (SIP) telephone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication functions, a computing device, other processing devices coupled with a wireless modem, an in-vehicle device, a wearable device, or the like. In implementations herein, a vehicle user equipment (VUE) is taken as an example for description, but the disclosure is not limited in this regard. Implementations herein are adapted to transmission mode 3 and transmission mode 4 defined in 3rd generation partnership project (3GPP) Rel-14. FIG.1is a schematic diagram of mode 3 according to implementations.FIG.2is a schematic diagram of mode 4 according to implementations. In transmission mode 3 illustrated inFIG.1, transmission resources of a VUE (namely VUE121and VUE122) are allocated by a base station110. The VUE can transmit data on an SL by using a resource allocated by the base station110. The resource allocated by the base station110to a terminal device may be a resource used for a single transmission or a resource used for semi-static transmission. In transmission mode 4 illustrated inFIG.2, the VUE (namely VUE131and VUE132) can adopt a “sensing+reservation” transmission mode. The VUE can autonomously select, from SL resources, a transmission resource to transmit data. The following will take the VUE131as an example for description. The VUE131can acquire, through sensing, an available transmission resource set from a resource pool, and then randomly select a resource from the transmission resource set to transmit data. Since a service in an IoV system is periodic, the VUE131can also adopt a semi-static transmission mode, that is, the VUE131can select a transmission resource and continuously use the selected transmission resource in multiple transmission periods, which can reduce probability of resource reselection and probability of resource collision. In addition, the VUE131can carry, in control information of the current transmission, information indicative of a resource reserved for a next transmission, such that other terminal devices (such as the VUE132) can determine, by detecting the control information, whether the resource has been reserved or used, thereby reducing probability of resource collision. According to implementations, a first terminal device can transmit data directly to a second terminal device without routing through a network device. However, in a D2D scenario, how to ensure reliability of data transmission has become a problem to be solved. FIG.3is a schematic flowchart of a method for transmission of feedback information according to implementations, which is conducive to reliability of data transmission. The method illustrated inFIG.3can be performed by a terminal device. A first terminal device illustrated inFIG.3may be the VUE121illustrated inFIG.1, and a second terminal device illustrated inFIG.3may be the VUE122illustrated inFIG.1. Similarly, the first terminal device illustrated inFIG.3may be the VUE131illustrated inFIG.2, and the second terminal device illustrated inFIG.3may be the VUE132illustrated inFIG.2. The method illustrated inFIG.3includes some or all of the following operations. At block310, the first terminal device obtains a feedback resource, where the feedback resource is used for carrying feedback information responsive to the second terminal device. The feedback information may be fed back by the first terminal device responsive to a first message sent by the second terminal device. In some implementations, the first message may be data information sent by the second terminal device to the first terminal device, or may be a reference signal or control information sent by the second terminal device to the first terminal device. The reference signal may be, for example, a channel state information reference signal (CSI-RS). When the feedback information is responsive to data sent by the second terminal device, the data may be initially-transmitted data or retransmitted data. At block320, the first terminal device sends the feedback information to the second terminal device on the feedback resource. “The first terminal device sends the feedback information to the second terminal device” means that the first terminal device sends the feedback information directly to the second terminal device without routing through a network device. “The first terminal device sends the feedback information directly to the second terminal device” may be that the first terminal device sends the feedback information to the second terminal device through D2D communication. In some situations, “D2D communication” can also mean that the first terminal device sends the feedback information to the second terminal device through V2V communication, or the first terminal device sends the feedback information to the second terminal device on an SL. By means of the technical solutions of implementations, when the first terminal device communicates with the second terminal device through D2D communication, the first terminal device can feed back to the second terminal device according to the first message sent by the second terminal device, which is beneficial for the second terminal device to make a proper communication decision according to the feedback information, thereby improving reliability of communication. FIG.4is a schematic flowchart of a method for transmission of feedback information according to other implementations. The method illustrated inFIG.4includes some or all of the following operations. At block410, a second terminal device sends a first message to a first terminal device. “The second terminal device sends the first message to the first terminal device” can be that the second terminal device sends the first message to the first terminal device through D2D communication. In some situations, “D2D communication” may also be comprehended as V2V communication or SL communication. At block420, the second terminal device sends first indication information to the first terminal device, where the first indication information is indicative of a feedback resource. The feedback resource is used for carrying feedback information of the first terminal device responsive to the second terminal device. The feedback resource may be a resource used for sending, by the first terminal device, to the second terminal device feedback information responsive to the first message through D2D communication. FIG.5is a schematic flowchart of a method for transmission of feedback information according to other implementations. The method illustrated inFIG.5includes some or all of the following operations. At block510, a network device sends first indication information to a first terminal device, where the first indication information is indicative of a feedback resource, and the feedback resource is used for carrying feedback information, which is responsive to a second terminal device and is sent by the first terminal device to the second terminal device through D2D communication. The feedback information, which is sent by the first terminal device to the second terminal device, may be responsive to a first message sent by the second terminal device. In some situations, “D2D communication” may also be comprehended as V2V communication or SL communication. The following will describe in detail the methods illustrated inFIG.3,FIG.4, andFIG.5. In some implementations, the feedback information may be, for example, at least one of: acknowledgement (ACK) information, negative acknowledgment (NACK) information, channel quality information, power control information, and a multiple antenna scheme. The ACK information/NACK information may be feedback responsive to the data information sent by the second terminal device. The first terminal device can send the feedback information to the second terminal device according to reception of data. The channel quality information, the power control information, or the multiple antenna scheme may be feedback information which is sent by the first terminal device to the second terminal device according to reception of the first message sent by the second terminal device. The channel quality information may be sent by the first terminal device to the second terminal device according to reception quality of the first message. The power control information may be fed back by the first terminal device to the second terminal device according to a reception power of the first message. The second terminal device can adjust a transmission power of a signal according to the power control information. The multiple antenna scheme may be sent by the first terminal device to the second terminal device according to reception of the first message. The multiple antenna scheme may include, for example, whether a precoding matrix is required for encoding, the manner of precoding, whether transmit diversity is adopted and/or whether space multiplexing is adopted, etc. The manner of precoding may be various, for example, codebook-based precoding and non-codebook based precoding. The manner of transmit diversity may be various, for example, space frequency block code (SFBC), frequency switched transmit diversity (FSTD), time switched transmit diversity (TSTD), or the like. The manner in which first terminal device obtains the feedback resource is not limited herein. For example, the first terminal device can obtain the feedback resource through autonomous resource selection. For another example, the first terminal device can obtain the feedback resource according to indication information. In case of autonomous resource selection, the first terminal device obtains the feedback resource based on resource contention. The first terminal device, after success in resource contention, can use the feedback resource, which is successfully contended, to send the feedback information. The manner of resource contention may be various. For example, a listen before talk (LBT) mode may be adopted for resource contention. When the first terminal device senses that a transmission resource is in an idle state, the first terminal device can use the transmission resource to send the feedback information. When the first terminal device senses that the transmission resource is occupied, the first terminal device cannot use the transmission resource to send the feedback information. For another example, resource contention can be carried out in the manner of obtaining resources in IoV mode 4 of Rel-14 and Rel-15. When the first terminal device senses that a transmission resource is available, the first terminal device can use the transmission resource to send the feedback information. When the first terminal device senses that the transmission resource is occupied, the first terminal device cannot use the transmission resource to send the feedback information. “The first terminal device obtains the feedback resource” may be that the first terminal device obtains the feedback resource according to the first indication information. In some implementations, the first indication information can be indicative of the feedback resource. The first terminal device can send the feedback information on the feedback resource. In other implementations, the first indication information can be indicative of a feedback resource set. The first terminal device can select the feedback resource from the feedback resource set to send the feedback information. In some implementations, the first indication information may be indicative of time information and/or frequency information of the feedback resource. The following will describe in detail the manner in which the first terminal device obtains the feedback resource according to the first indication information. In some implementations, the first terminal device can receive the first indication information sent by the second terminal device. The first indication information is indicative of an available feedback resource. The first terminal device can determine the feedback resource according to the first indication information. In other implementations, before the second terminal device sends the first indication information to the first terminal device, the second terminal device can receive second indication information sent by the network device, where the second indication information is indicative of an available feedback resource, and the second terminal device can generate the first indication information according to the second indication information. Then the second terminal device can send the first indication information to the first terminal device. It can be understood that, the first indication information and the second indication information can both be indicative of a feedback resource set. Alternatively, the second indication information is indicative of an available feedback resource set, and the first indication information is indicative of a feedback resource in the available feedback resource set. In this scenario, the second terminal device can select a feedback resource from the feedback resource set indicated by the second indication information, to generate the first indication information. As an example, the network device can send the second indication information to the second terminal device while sending third indication information to the second terminal device, where the third indication information is indicative of a resource used for sending, by the second terminal device, the first message to the first terminal device. In other words, the feedback resource indicated by network device to the second terminal device may be indicated by the network device in control information which is indicative of a resource used for sending the first message by the second terminal device. In other implementations, the first terminal device can pre-configure the first indication information. For example, the first terminal device can pre-configure frequency resource locations and/or time resource locations of feedback resources or of the feedback resource set. The first terminal device can select a feedback resource from the pre-configured feedback resources or the feedback resource set. For another example, the first terminal device may pre-configure the feedback resource. The first terminal device can send the feedback information on the pre-configured feedback resource. In other implementations, the first terminal device can receive the first indication information sent by the network device. The first terminal device can obtain the feedback resource according to the first indication information. The first indication information may be sent by the network device directly to the first terminal device. Alternatively, the first indication information may be sent by the network device to the first terminal device after the first terminal device sends a resource request message to the network device. For example, the first terminal device, upon receiving data sent by the second terminal device, can send the resource request message to the network device. In response to the resource request message, the network device sends the first indication information to the first terminal device. The resource request message may be used for requesting the feedback resource. The network device, upon receiving the resource request message, can send to the first terminal device the first indication information indicative of the feedback resource. In some implementations, the resource request message includes time information and/or frequency information of a resource requested by the first terminal device. In this case, the first indication information sent by the network device may be an ACK message/NACK message, where the ACK message indicates that the resource requested by the first terminal device can be used for sending the feedback information, and the NACK message indicates that the resource requested by the first terminal device cannot be used for sending the feedback information. The first terminal device, upon receiving the NACK message, can resend the resource request message to the network device, or the network device can directly indicate an available feedback resource to the first terminal device. In some implementations, the resource request message is carried in a physical uplink control channel (PUCCH) (such as uplink control information (UCI) signaling in the PUCCH), a MAC control element (MAC CE), or radio resource control (RRC) signaling. The first indication information and the second indication information can both be indicative of the time information and/or frequency information of the feedback resource. When the first indication information indicates the time information of the feedback resource, the frequency information of the feedback resource may be a default frequency. The default frequency may be, for example, a frequency specified in a protocol, or a frequency agreed between the first terminal device and the second terminal device, or a frequency at which the first terminal device receives the first message. The first terminal device can send the feedback information at a time indicated by the first indication information and at the default frequency. When the first indication information indicates the frequency information of the feedback resource, the time information of the feedback resource may be a default time. The default time may be, for example, a Kthsubframe subsequent to receiving, by the first terminal device, the first message sent by the second terminal device. The first terminal device can send the feedback information at a frequency indicated by the first indication information and at the default time. K is a positive integer. The value of K may be an value agreed between the first terminal device and the second terminal device, or may be a value indicated by the second terminal device to the first terminal device. For example, if the first terminal device receives the first message in an Nthsubframe, the first terminal device can send the feedback information responsive to the first message in an (N+K)thsubframe, where N is a positive integer, and the value of K may be, for example, 4. The first indication information may implicitly indicate the feedback resource. For example, the first terminal device can determine, according to time and frequency at which the first message is received, time information and frequency information for sending the feedback information. For example, the first terminal device can send the feedback information in an (N+4)thsubframe at a frequency at which the first message is received. The first indication information can be indicative of a starting position of a time-domain resource and the length of the time-domain resource. The first terminal device can send the feedback information on the time-domain resource indicated by the first indication information. Alternatively, the first indication information can be indicative of a starting position of a frequency-domain resource and the length of the frequency-domain resource. The first terminal device can send the feedback information on the frequency-domain resource indicated by the first indication information. In some implementations, the feedback resource indicated by the first indication information takes time and/or frequency of the second terminal device as a synchronization reference. In other implementations, the feedback resource indicated by the first indication information takes time and/or frequency of the network device as a synchronization reference. In other implementations, the feedback resource indicated by the first indication information takes time and/or frequency of a global navigation satellite system (GNSS) as a synchronization reference. For example, the starting position of the time-domain resource may take the time of the second terminal device as a time reference. Alternatively, the starting position of the time-domain resource may take the time of the network device as a time reference. Alternatively, the starting position of the time-domain resource may take the time of the GNSS as a time reference. For another example, the starting position of the frequency-domain resource may take the frequency of the second terminal device as a reference. Alternatively, the starting position of the frequency-domain resource may take the frequency of the network device as a reference. Alternatively, the starting position of the frequency-domain resource may take the frequency of the GNSS as a reference. In some implementations, before the first terminal device sends the feedback information to the second terminal device on the feedback resource, the first terminal device can obtain the feedback resource through autonomous resource selection. The manner of autonomous resource selection may be, for example, resource contention. The first terminal device can use the feedback resource to send the feedback information only when resource contention succeeds. In other words, the first terminal device, after obtaining the feedback resource according to the first indication information, needs to contend for the feedback resource, and the first terminal device can use the feedback resource to send the feedback information only when contention succeeds. The manner of resource contention may be various. For example, an LBT mode may be adopted for resource contention. When the first terminal device senses that a feedback resource is in an idle state, the first terminal device can use the feedback resource to send the feedback information. When the first terminal device senses that the feedback resource is occupied, the first terminal device cannot use the feedback resource to send the feedback information. For another example, resource contention can be carried out in the manner of obtaining resources in IoV mode 4 of Rel-14 and Rel-15. When the first terminal device senses that a transmission resource is available, the first terminal device can use the transmission resource to send the feedback information. When the first terminal device senses that the transmission resource is occupied, the first terminal device cannot use the transmission resource to send the feedback information. “The second terminal device receives the feedback information sent by the first terminal device” may be that the second terminal device senses, on each of multiple feedback resources, whether the first terminal device sends the feedback resource to the second terminal device. The multiple feedback resources may refer to a feedback resource set which can be used for sending the feedback information. “The first terminal device sends the feedback information to the second terminal device” can be comprehended as follows. The first terminal device may send the feedback information only after receiving the first message from the second terminal device, or may send the feedback information to the second terminal device periodically. FIG.6is a schematic flowchart of a method for data retransmission according to implementations. The method illustrated inFIG.6can be performed by a terminal device. A first terminal device illustrated inFIG.6may be the VUE121illustrated inFIG.1, and a second terminal device illustrated inFIG.6may be the VUE122illustrated inFIG.1. Similarly, the first terminal device illustrated inFIG.6may be the VUE131illustrated inFIG.2, and the second terminal device illustrated inFIG.6may be the VUE132illustrated inFIG.2. The method illustrated inFIG.6includes some or all of the following operations. At block610, the second terminal device sends first data to the first terminal device. “The second terminal device sends the first data to the first terminal device” means that the second terminal device sends the first data directly to the first terminal device without routing through a network device. “The second terminal device sends the first data directly to the first terminal device” may be that the second terminal device sends the first data to the first terminal device through D2D communication. In some situations, “D2D communication” can also be comprehended as V2V communication or SL communication. The first data may be initially-transmitted data or retransmitted data. At block620, the second terminal device obtains a retransmission resource. Information of the retransmission resource may include time information and/or frequency information of the retransmission resource. At block630, the second terminal device retransmits the first data to the first terminal device on the retransmission resource, according to feedback information of the first terminal device responsive to the first data. “The second terminal device retransmits the first data to the first terminal device” means that the second terminal device retransmits the first data to the first terminal device through D2D communication. In some situations, “D2D communication” can also be comprehended as V2V communication or SL communication. By means of the technical solutions of implementations, when the first terminal device communicates with the second terminal device through D2D communication, data retransmission by the second terminal device to first terminal device is performed according to feedback of the first terminal device responsive to the first data, instead of adopting a fixed number of retransmissions. As such, it is beneficial for the second terminal device to determine a proper retransmission scheme, to ensure that the first terminal device can correctly receive the first data, which can improve reliability of data transmission. FIG.7is a schematic flowchart of a method for data retransmission according to other implementations. The method illustrated inFIG.7includes some or all of the following operations. At block710, a first terminal device receives, through D2D communication, first data sent by a second terminal device. At block720, the first terminal device sends to the second terminal device feedback information responsive to the first data through D2D communication. At block730, the first terminal device receives, through D2D communication, the first data retransmitted by the second terminal device. FIG.8is a schematic flowchart of a method for data retransmission according to other implementations. The method illustrated inFIG.8includes some or all of the following operations. At block810, a network device sends indication information to a second terminal device, where the indication information is indicative of a retransmission resource, and the retransmission resource is used for carrying first data, which is retransmitted by the second terminal device to a first terminal device through D2D communication according to feedback information of the first terminal device responsive to the first data sent by the second terminal device. In some implementations, the feedback information includes at least one of: an ACK message, a NACK message, and discontinuous transmission (DTX). The following will describe in detail the methods illustrated inFIG.6,FIG.7, andFIG.8. The second terminal device can determine, according to the feedback information of the first terminal device responsive to the first data, whether to retransmit the first data to the first terminal device. If the first terminal device feeds back ACK information, it indicates that the first terminal device has received the first data successfully. The second terminal device does not have to retransmit the first data to the first terminal device, which is possible to reduce waste of resources. If the first terminal device feeds back NACK information or the DTX, it indicates that the first terminal device has not received the first data. The second terminal device can retransmit the first data to the first terminal device, which is conducive to reliability of communication. As an example, before the second terminal device retransmits the first data to the first terminal device on the retransmission resource, the second terminal device may receive NACK feedback information sent by the first terminal device, or the second terminal device may fail to receive, within a preset time period, the feedback information sent by the first terminal device. When the feedback information received by the second terminal device is ACK, it indicates that the first terminal device has received the first data successfully. In this case, the second terminal device does not have to retransmit the first data, and the first terminal device does not have to obtain the retransmission resource. When the feedback information received by the second terminal device is NACK or the DTX, it indicates that the first terminal device has not received the first data. In this case, the second terminal device needs to retransmit the first data to the first terminal device. Before retransmitting the first data, the second terminal device needs to obtain the retransmission resource. When the second terminal device has not received, within the preset time period, the feedback information sent by the first terminal device, the second terminal device can consider that first terminal device has not received the first data. The second terminal device can retransmit the first data to the first terminal device on the retransmission resource. The manner in which the second terminal device obtains the retransmission resource can be various. For example, the second terminal device can obtain the retransmission resource according to indication of the network device. For another example, the second terminal device can obtain the retransmission resource through autonomous resource selection. “The second terminal device obtains the retransmission resource according to the indication of the network device” may be that the second terminal device receives indication information sent by the network device and obtains the retransmission resource according to the indication information. “The network device indicates the retransmission resource” means that the network device directly indicates the retransmission resource, or means that the network device indicates the retransmission resource to the second terminal device after the second terminal device sends a resource request message to the network device. As an example, the second terminal device can determine, according to the feedback information received from the first terminal device, whether to send the resource request message to the network device. For example, when the feedback information sent by the first terminal device is ACK, the second terminal device does not have to send the resource request message to the network device to request the retransmission resource. When the feedback information sent by the first terminal device is NACK, the second terminal device can send the resource request message to the network device to request the retransmission resource. When the second terminal device has not received the feedback information sent by the first terminal device, the second terminal device can also send the resource request message to the network device to request the retransmission resource. In some implementations, the resource request message may include the feedback information sent by the first terminal device to the second terminal device. In other words, the second terminal device can report to the network device the feedback information sent by the first terminal device. In response to the resource request message, the network device can indicate the retransmission resource to the second terminal device. In other implementations, the resource request message may include time information and/or frequency information of a resource requested by the second terminal device. In this case, the indication information sent by the network device may be an ACK message/NACK message, where ACK message indicates that the resource requested by the second terminal device can be used for retransmission, and the NACK message indicates that the resource requested by the second terminal device cannot be used for retransmission. The second terminal device, upon receiving the NACK message, can resend the resource request message to the network device, or the network device can directly indicate an available retransmission resource to the second terminal device. In some implementations, a resource used for sending the resource request message is a resource indicated by the network device. For example, the network device can indicate to the second terminal device the resource used for sending the resource request message while indicating to the second terminal device a resource used for sending the first data. In some implementations, a retransmission resource indicated by the network device is indicated by the network device in control information which is indicative of the resource used for sending the first data by the second terminal device. In some implementations, the resource used for sending the resource request message by the second terminal device is a PUCCH or a physical uplink shared channel (PUSCH). In some implementations, the resource request message is carried in a scheduling request (SR) message in the PUCCH, an ACK message/NACK message in the PUCCH, a MAC CE, or RRC signaling. The manner in which the second terminal device obtains the retransmission resource through resource contention may be various. For example, an LBT mode may be adopted for resource contention. When the first terminal device senses that a feedback resource is in an idle state, the first terminal device can use the feedback resource to send the feedback information. When the first terminal device senses that the feedback resource is occupied, the first terminal device cannot use the feedback resource to send the feedback information. For another example, resource contention can be carried out in the manner of obtaining resources in IoV mode 4 of Rel-14 and Rel-15. When the first terminal device senses that a transmission resource is available, the first terminal device can use the transmission resource to send the feedback information. When the first terminal device senses that the transmission resource is occupied, the first terminal device cannot use the transmission resource to send the feedback information. According to implementations, after the second terminal device obtains the retransmission resource according to the indication of the network device, the second terminal device can determine, through resource contention, whether the retransmission resource can be used. If resource contention succeeds, the second terminal device uses the retransmission resource for retransmission. If resource contention fails, the second terminal device cannot use the retransmission resource to retransmit data. According to implementations, before the first terminal device sends the feedback information to the second terminal device, for the manner in which the first terminal device obtains the feedback resource, reference can be made to the foregoing description, which will not be repeated herein to avoid repetition. FIG.9is a schematic block diagram of a first terminal device according to implementations. As illustrated inFIG.9, the first terminal device900includes a processing unit910and a communicating unit920. The processing unit910is configured to obtain a feedback resource according to first indication information, where the feedback resource is used for carrying feedback information of the first terminal device responsive to a first message sent by a second terminal device. The communicating unit920is configured to send feedback information to the second terminal device on the feedback resource through D2D communication. In some implementations, the communicating unit920is further configured to receive the first indication information sent by the second terminal device. In some implementations, the processing unit910is further configured to pre-configure the first indication information. In other implementations, the communicating unit920is further configured to receive the first indication information sent by a network device. In some implementations, the first indication information is indicative of time information and/or frequency information of the feedback resource. In other implementations, the first indication information is indicative of an available feedback resource set. The processing unit910is configured to select the feedback resource from the feedback resource set. In some implementations, the communicating unit920is further configured to send a resource request message to the network device. In some implementations, the resource request message includes time information and/or frequency information of a feedback resource requested by the first terminal device. In some implementations, the resource request message is carried in a PUCCH, a MAC CE, or RRC signaling. In some implementations, the processing unit910is further configured to obtain the feedback resource through autonomous resource selection. In some implementations, the feedback resource takes time and/or frequency of the second terminal device as a synchronization reference. In other implementations, the feedback resource takes time and/or frequency of the network device as a synchronization reference. In other implementations, the feedback resource takes time and/or frequency of a GNSS as a synchronization reference. In some implementations, the feedback information includes at least one of: ACK information, NACK information, channel quality information, power control information, and a multiple antenna scheme. In some implementations, the first message includes data information, control information, or a reference signal sent by the second terminal device to the first terminal device. FIG.10is a schematic block diagram of a second terminal device according to implementations. As illustrated inFIG.10, the second terminal device1000includes a communicating unit1010. The communicating unit1010is configured to send a first message to a first terminal device through D2D communication, and send first indication information to the first terminal device, where the first indication information is indicative of a feedback resource, and the feedback resource is a resource used for sending, by the first terminal device, to the second terminal device feedback information responsive to the first message through D2D communication. In some implementations, the communicating unit1010is further configured to receive second indication information sent by a network device, where the second indication information is indicative of the feedback resource. The second terminal device further includes a processing unit. The processing unit is configured to generate the first indication information according to the second indication information. In some implementations, the first indication information is indicative of time information and/or frequency information of the feedback resource. In some implementations, the feedback resource takes time and/or frequency of the second terminal device as a synchronization reference. In other implementations, the feedback resource takes time and/or frequency of the network device as a synchronization reference. In other implementations, the feedback resource takes time and/or frequency of a GNSS as a synchronization reference. In some implementations, the feedback information includes at least one of: ACK information, NACK information, channel quality information, power control information, and a multiple antenna scheme. In some implementations, the first message includes data information, control information, or a reference signal sent by the second terminal device to the first terminal device. FIG.11is a schematic block diagram of a network device according to implementations. As illustrated inFIG.11, the network device1100includes a communicating unit1110. The communicating unit1110is configured to send first indication information to a first terminal device, where the first indication information is indicative of a feedback resource, and the feedback resource is used for carrying feedback information, which is responsive to a first message sent by a second terminal device and is sent by the first terminal device to the second terminal device through D2D communication. In some implementations, the communicating unit1110is further configured to receive a resource request message sent by the first terminal device. In some implementations, the resource request message includes time information and/or frequency information of a feedback resource requested by the first terminal device. In some implementations, the resource request message is carried in a PUCCH, a MAC CE, or RRC signaling. In some implementations, the feedback resource takes time and/or frequency of the second terminal device as a synchronization reference. In other implementations, the feedback resource takes time and/or frequency of the network device as a synchronization reference. In other implementations, the feedback resource takes time and/or frequency of a GNSS as a synchronization reference. In some implementations, the feedback information includes at least one of: ACK information, NACK information, channel quality information, power control information, and a multiple antenna scheme. In some implementations, the first message includes data information, control information, or a reference signal sent by the second terminal device to the first terminal device. FIG.12is a schematic block diagram of a second terminal device according to other implementations. As illustrated inFIG.12, the second terminal device1200includes a communicating unit1210and a processing unit1220. The communicating unit1210is configured to send first data to a first terminal device through D2D communication. The processing unit1220is configured to obtain a retransmission resource. The communicating unit1210is further configured to retransmit the first data to the first terminal device on the retransmission resource through D2D communication, according to feedback information of the first terminal device responsive to the first data. In some implementations, the processing unit1220is configured to obtain the retransmission resource according to indication information sent by a network device. In some implementations, the communicating unit1210is further configured to send a resource request message to the network device. In some implementations, the communicating unit1210is configured to send the resource request message to the network device, according to the feedback information of the first terminal device responsive to the first data. In some implementations, the resource request message includes the feedback information of the first terminal device responsive to the first data. In some implementations, the resource request message includes time information and/or frequency information of a retransmission resource requested by the second terminal device. In some implementations, the feedback information includes at least one of: an ACK message, a NACK message, and DTX. In some implementations, a resource used for sending the resource request message is a resource indicated by the network device. In some implementations, the resource indicated by the network device is indicated by the network device in control information which is indicative of a resource used for sending the first data by the second terminal device. In some implementations, the resource used for sending the resource request message is a PUCCH or a PUSCH. In some implementations, the resource request message is carried in an SR message in the PUCCH, an ACK message/NACK message in the PUCCH, a MAC CE, or RRC signaling. In some implementations, the resource request message is carried in a BSR. In some implementations, the communicating unit1210is further configured to obtain the retransmission resource through autonomous resource selection. FIG.13is a schematic block diagram of a first terminal device according to other implementations. As illustrated inFIG.13, the first terminal device1300includes a communicating unit1310. The communicating unit1310is configured to operate as follows. The communicating unit1310is configured to receive, through D2D communication, first data sent by a second terminal device. The communicating unit1310is configured to send to the second terminal device feedback information responsive to the first data through D2D communication. The communicating unit1310is configured to receive, through D2D communication, the first data retransmitted by the second terminal device. In some implementations, the feedback information includes at least one of: an ACK message, a NACK message, and DTX. FIG.14is a schematic block diagram of a network device according to other implementations. As illustrated inFIG.14, the network device1400includes a communicating unit1410. The communicating unit1410is configured to send indication information to a second terminal device, where the indication information is indicative of a retransmission resource, and the retransmission resource is used for carrying first data, which is retransmitted by the second terminal device to a first terminal device through D2D communication according to feedback information of the first terminal device responsive to the first data sent by the second terminal device. In some implementations, the communicating unit1410is further configured to receive a resource request message sent by the second terminal device. In some implementations, the resource request message includes the feedback information of the first terminal device responsive to the first data. In some implementations, the resource request message includes time information and/or frequency information of a retransmission resource requested by the second terminal device. In some implementations, the feedback information includes at least one of: an ACK message, a NACK message, and DTX. In some implementations, the communicating unit1410is further configured to send to the second terminal device indication information indicative of a resource used for sending the resource request message. In some implementations, the resource used for sending the resource request message indicated by the network device is indicated by the network device in control information which is indicative of a resource used for sending the first data by the second terminal device. In some implementations, the resource used for sending the resource request message is a PUCCH or a PUSCH. In some implementations, the resource request message is carried in an SR message in the PUCCH, an ACK message/NACK message in the PUCCH, a MAC CE, and RRC signaling. In some implementations, the resource request message is carried in a BSR. FIG.15is a schematic block diagram of a communication device1500according to implementations. As illustrated inFIG.15, the communication device1500includes a processor1510. The processor1510can invoke and execute computer programs stored in a memory to perform the method provided in implementations. As illustrated inFIG.15, the communication device1500can further include the memory1520. The processor1510can invoke and execute the computer programs stored in the memory1520to perform the method provided in implementations. The memory1520may be a separate device independent of the processor1510, or may be integrated into the processor1510. As illustrated inFIG.15, the communication device1500can further include a transceiver1530. The processor1510can control the transceiver1530to communicate with other devices, for example, to send information or data to other devices, or to receive information or data from other devices. The transceiver1530may include a transmitter and a receiver. The transceiver1530may further include an antenna, where one or more antenna can be provided. The communication device1500may be the terminal device of implementations, and the communication device1500can implement the operations performed by the terminal device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. Alternatively, the communication device1500may be the network device of implementations, and the communication device1500can implement the operations performed by the network device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. FIG.16is a schematic structural diagram of a chip according to implementations. As illustrated inFIG.16, the chip1600includes a processor1610. The processor1610is configured to invoke and execute computer programs stored in a memory to perform the method provided in implementations. As illustrated inFIG.16, the chip1600further includes the memory1620. The processor1610can invoke and execute the computer programs stored in the memory1620to perform the method provided in implementations. The memory1620may be a separate device independent of the processor1610, or may be integrated into the processor1610. The chip1600may further include an input interface1630. The processor1610can control the input interface1630to communicate with other devices or chips, for example, to acquire information or data sent by other devices or chips. The chip1600may further include an output interface1640. The processor1610can control the output interface1640to communicate with other devices or chips, for example, to output information or data to other devices or chips. The chip is applicable to the terminal device of implementations, and the chip can implement the operations performed by the terminal device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. Alternatively, the chip is applicable to the network device of implementations, and the chip can implement the operations performed by the network device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. It should be understood that, the chip herein may also be referred to as a system-on-chip (SOC). It should be understood that, the processor referred to herein may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the foregoing method may be completed by an integrated logic circuit in the form of hardware or an instruction in the form of software in the processor. The processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic devices, or discrete hardware components, which can implement or execute the methods, steps, and logic blocks disclosed in implementations. The general purpose processor may be a microprocessor, or the processor may be any conventional processor or the like. The steps of the method disclosed in implementations may be implemented through a hardware decoding processor, or may be performed by hardware and software modules in the decoding processor. The software module can be located in a storage medium such as a random access memory (RAM), a flash memory, a read only memory (ROM), a programmable ROM (PROM), or an electrically erasable programmable memory, registers, and the like. The storage medium is located in the memory. The processor reads the information in the memory, and completes the steps of the method described above with the hardware of the processor. It can be understood that, the memory according to implementations may be a volatile memory or a non-volatile memory, or may include both the volatile memory and the non-volatile memory. The non-volatile memory may be a ROM, a PROM, an erasable programmable read only memory (erasable PROM, EPROM), an electrically erasable programmable read only memory (electrically EPROM, EEPROM), or flash memory. The volatile memory can be a RAM that acts as an external cache. By way of example but not limitation, many forms of RAM are available, such as a static random access memory (static RAM, SRAM), a dynamic random access memory (dynamic RAM, DRAM), a synchronous dynamic random access memory (synchronous DRAM, SDRAM), a double data rate SDRAM (DDR SDRAM), an enhanced SDRAM (ESDRAM), a synchronous link dynamic random access memory (synch-link DRAM, SLDRAM), and a direct rambus random access memory (direct rambus RAM, DRRAIVI). The memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory. It should be understood that, the above description of the memory is intended for illustration rather than limitation. For example, the memory of implementations may also be an SRAM, a DRAM, an SDRAM, a DDR SDRAM, an ESDRAM, an SLDRAM, a DR RAM, etc. In other words, the memory of implementations is intended to include, but is not limited to, these and any other suitable types of memory. FIG.17is a schematic block diagram of a communication system1700according to implementations. As illustrated inFIG.17, the communication system1700includes a terminal device1710and a network device1720. The terminal device1710can implement functions of the terminal device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. The network device1720can implement functions of the network device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. Implementations further provide a computer readable storage medium. The computer readable storage medium is configured to store computer programs. The computer readable storage medium is applicable to the network device. The computer programs, when executed, are operable with a computer to implement the operations performed by the network device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. Alternatively, the computer readable storage medium is applicable to the terminal device of implementations. The computer programs, when executed, are operable with a computer to implement the operations performed by the terminal device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. Implementations further provide a computer program product. The computer program product includes computer program instructions. The computer program product is applicable to the network device of implementations. The computer program instructions, when executed, are operable with a computer to implement the operations performed by the network device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. Alternatively, the computer program product is applicable to the terminal device of implementations. The computer program instructions, when executed, are operable with a computer to implement the operations performed by the terminal device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. Implementations further provide a computer program. The computer program is applicable to the network device of implementations. The computer program, when executed by a computer, is operable with the computer to implement the operations performed by the network device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. Alternatively, the computer program is applicable to the terminal device of implementations. The computer program, when executed by a computer, is operable with the computer to implement the operations performed by the terminal device described in the foregoing method implementations, which will not be repeated herein for the sake of simplicity. It should be understood that, the terms “system” and “network” herein are usually used interchangeably throughout this disclosure. The term “and/or” herein only describes an association relationship between associated objects, which means that there can be three relationships. For example, A and/or B can mean A alone, both A and B exist, and B alone. In addition, the character “/” herein, unless otherwise specified, generally indicates that the associated objects are in an “or” relationship. In addition, according to implementations, “B corresponding to (which corresponds to) A” means that B is associated with A, and B can be determined according to A. However, “B can be determined according to A” does not mean that B can be determined only according to A, and instead, B can also be determined according to A and/or other information. Those of ordinary skill in the art will appreciate that units and algorithmic operations of various examples described in connection with implementations herein can be implemented by electronic hardware or by a combination of computer software and electronic hardware. Whether these functions are performed by means of hardware or software depends on the application and the design constraints of the associated technical solution. Those skilled in the art may use different methods with regard to each particular application to implement the described functionality, but such methods should not be regarded as lying beyond the scope of the disclosure. It will be evident to those skilled in the art that, for the sake of convenience and simplicity, in terms of the working processes of the foregoing systems, apparatuses, and units, reference can be made to the corresponding processes of the above method implementations, which will not be repeated herein. It will be appreciated that the systems, apparatuses, and methods disclosed in implementations herein may also be implemented in various other manners. For example, the above apparatus implementations are merely illustrative, e.g., the division of units is only a division of logical functions, and there may exist other manners of division in practice, e.g., multiple units or assemblies may be combined or may be integrated into another system, or some features may be ignored or skipped. In other respects, the coupling or direct coupling or communication connection as illustrated or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be electrical, mechanical, or otherwise. Separated units as illustrated may or may not be physically separated. Components displayed as units may or may not be physical units, and may reside at one location or may be distributed to multiple networked units. Some or all of the units may be selectively adopted according to practical needs to achieve desired objectives of the disclosure. Various functional units described in implementations herein may be integrated into one processing unit or may be present as a number of physically separated units, and two or more units may be integrated into one. If the integrated units are implemented as software functional units and sold or used as standalone products, they may be stored in a computer readable storage medium. Based on such an understanding, the essential technical solution, or the portion that contributes to the prior art, or part of the technical solution of the disclosure may be embodied as software products. The computer software products can be stored in a storage medium and may include multiple instructions that, when executed, can cause a computing device, e.g., a personal computer, a server, a network device, etc., to execute some or all operations of the methods described in various implementations. The above storage medium may include various kinds of media that can store program codes, such as a universal serial bus (USB) flash disk, a mobile hard drive, a ROM, a RAM, a magnetic disk, or an optical disk. While the disclosure has been described in connection with certain embodiments, it is to be understood that the disclosure is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. | 61,687 |
11943065 | DETAILED DESCRIPTION Section headings are used in the present document only to improve readability and do not limit scope of the disclosed embodiments and techniques in each section to only that section. With the development of wireless communication technologies, the performance including transmission rate, delay, throughput, and reliability has been improved through various technologies. However, to achieve high-performance wireless transmission, user equipment (also referred to as a terminal or UE) must perform more complex processing to meet the performance requirements. For example, a UE that detects a larger control channel bandwidth is subject to more complex control information including data encoding, decoding processing, and the like. A UE that operate at high frequencies may use a large bandwidth to achieve a high data rate or high-capacity transmission. This may use more computational resources which may result in high power consumption. In Release-15, the NR (new radio), the multi-transmission reception points (TRP) joint transmission does not support data transmission by the same user by multiple TRPs. For the ultra-reliable low-latency communication (URLLC) service, techniques are disclosed herein for using multi-TRP transmission for improved reliability. In one configuration, multiple TRPs, or base stations such a next generation node B (gNB) base stations send different transport blocks (TBs) to a user equipment (UE) at the same time or at different times. In another configuration, multiple base stations may send the same data at the same time to a UE. When the same data is being sent by multiple base stations to a UE, the UE must be notified by some mechanism. Disclosed herein are multiple mechanism for notifying the UE that multiple base stations will be transmitting the same data at the same time. NR release15does not specify a multi-TRP transmission scheme. As shown inFIG.1, TRP0110and TRP1120may transmit data to the same UE130, which can be on the same time unit or on different time units. When there is a backhaul140between TRP0110and TRP1120, TRP0110and TRP1120can choose to send the same data stream to increase the reliability of the transmission when, for example, the UE receives at a low signal-to-noise ratio (SNR). In the case of high SNR, TRP0110and TRP1120can choose to send different data streams to increase the transmission capacity. Referring toFIG.2, when doing multi-TRP transmission, TRP0110A may send one physical downlink control channel (PDCCH) with downlink control information (DCI)0205A, and TRP1120A may send one PDCCH with DCI1207A. DCI0205A schedules one physical downlink shared channel (PDSCH)0, and DCI1207A schedules another PDSCH1. At a low SNR, the two base stations110A and120A (eNBs or gNBs) can choose to schedule the same transmission block (TB). In this case, PDSCH0scheduled by DCI0205A and PDSCH1scheduled by DCI1207A correspond to the same TB, TB0210A. Even if the channel conditions of the UE130A are not so good, the UE130A can jointly demodulate two identical TBs (TB0210A), which will increase the probability of correct demodulation. In the case of a high SNR, the two base stations110B and120B can choose to schedule different TBs, that is, PDSCH0scheduled by DCI0205B and PDSCH1scheduled by DCI1207B correspond to different TBs, TB0210B and TB1220B. At this time, if the channel conditions of the UE are good and each TB can be demodulated correctly, the system capacity will be increased. For uRLLC services, the reliability of transmission must be very high because these services are essential such as providing emergency services. If TRP0and TRP1can transmit the same or related data, the probability that the UE receives the correct data is increased, thereby increasing the transmission reliability and reducing the transmission delay which could be caused by retransmissions when the SNR is low. However, even for uRLLC services, multi-TRP transmission may not possible at every time, and it is not necessary for each TRP to transmit the same or related data at every time. For example, in the case of high channel quality, TRP0and TRP1can transmit different data streams or transmission blocks to increase transmission capacity. In the case of low channel quality, TRP0and TRP1can transmit the same or related data to increase reliability. The most flexible solution is to support dynamic switching between multi-TRP transmission and single TRP transmission, and to support dynamic switching between repeated TBs and non-repeated TBs transmitted by the multiple TRPs during multi-TRP transmission. The disclosed solutions can be broken into three categories. In a first category, one field in a DCI indicates to the UE whether the PDSCH scheduled by this DCI is associated with one PDSCH scheduled by another DCI. In a second category, dedicated bits in the DCI field can be used to indicate whether the PDSCH scheduled by the DCI is associated with a PDSCH scheduled by another DCI. In a third category, if the scheduling information carried by DCIx and DCIy are associated, PDSCHx and PDSCHy are associated. These categories are described below. “x” and “y” are used herein to indicate two DCIs and two PDSCHs. First Category In some example embodiments, one field is introduced in a DCI to indicate to the UE whether the PDSCH scheduled by the DCI is associated with a PDSCH scheduled by another DCI. Two associated PDSCHs means transmission data from two PDSCHs are not independent. The UE can perform combining and detection for the two PDSCHs. For the two associated PDSCHs, the UE can feedback one combined acknowledgement message (ACK/NACK or A/N). For example, when TB0and TB1are from PDSCH0and PDSCH1respectively and PDSCH0and PDSCH1are associated, the UE may feedback one bit A/N for these two PDSCH. In another example, TB0, TB1may be from PDSCH0, and TB2and TB3are from PDSCH1. When PDSCH0and PDSCH1are associated, TB0and TB2are associated, and TB1and TB3are associated. Then, the UE only need feedback one bit A/N for TB0and TB2, and 1 bit A/N for TB1and TB3. Two associated PDSCHs means the TBs included in the two PDSCH are the same. The field can include one bit in DCIx. The one bit may be used to indicate the relationship between PDSCHx scheduled by DCIx and PDSCHy scheduled by another DCIy. The base station can use higher layer signaling to set up the relationship between DCIx and DCIy, e.g. the gNB higher layer configures one group_index in each CORESET or search space, or search space set. If the two CORESETs/search spacse/search space sets for DCIx and DCIy are configured with the same group_index, PDSCHx scheduled by DCIx and PDSCHy scheduled by DCIy may or may not have the association. In this case, if the value of the new field is set to 1 for DCIy, PDSCHy and the most recent PDSCHx are associated. And if the value of the new field is set to 0 for DCIy, PDSCHy and the most recent PDSCHx are not associated. However, if the two CORESET/search space/search space set for DCIx and DCIy are configured with different group_index, PDSCHx scheduled by DCIx and PDSCH y scheduled by DCIy are not associated. DCIx and DCIy can be in the same bandwidth part (BWP) or carrier components (CC). Alternatively, DCIx and DCIy can be in different BWP or CC. Similarly, PDSCHx and PDSCHy can be the same or different CC/BWP. If PDSCHx and PDSCHy are limited within one CC or BWP, setting up the possible relationship by higher layer signaling is unnecessary. One bit field is used to indicate the relationship between PDSCHx and PDSCHy which is in the same CC or BWP. This field can also include more than 1 bit. In this case, gNB can use higher layer signaling to set up the relationship between several DCIs. For one PDSCH transmission scheduled by DCIx, this field may indicate whether PDSCHx is associated with another PDSCHi, and indicate a value for i. For instance, DCIx, DCIy, DCIz, DCIm have potential relationships which are configured by radio resource control (RRC) signaling or medium access control (MAC) control element (CE) or MAC-CE. A two-bit field may be included in DCIx, where 00 means no association between PDSCHx and PDSCH scheduled by another DCI, 01 means PDSCHx is associated with PDSCHy, 02 means PDSCHx is associated with PDSCHz scheduled by DCIz, 03 means PDSCHx is associated with PDSCHm scheduled by DCIm. Since scheduling can happen in every slot, the associated PDSCHy, z, and m can be restricted as the same slot with PDSCHx. The above technique uses DCI bits to indicate whether multiple PDSCH scheduled by multiple DCI are associated or not. Different DCI can be from different TRP or serving cell or CC. If multiple PDSCH are associated, it is enough for UE to correctly detect any one of these associated PDSCH. In order to save feedback overhead, one combined A/N feedback is enough (1 bit in the case of one TB per PDSCH, 2 bits in the case of two TBs per PDSCH). The A/N feedback slot can be the same for these associated PDSCH. As shown inFIG.3, the slot of A/N feedback for PDSCH0can be the same as the slot of A/N feedback for PDSCH1if the PDSCH0and PDSCH1are associated. As shown inFIG.3, two TRPs transmit two independent PDCCHs. The PUCCH resource for A/N feedback for PDSCH0can be the same as that for PDSCH1which results in feedback overhead that is reduced. In this case, a TPC indication by DCI may also be the same in DCI0and DCI1since PDSCH0and1carry the same TBs. Two associated PDSCH can be restricted within one slot in order to reduce the transmission latency for URLLC traffic. In this case, the UE can do the soft combining of PDSCH0and PDSCH1at the same slot with improved data reliability. As noted above, if the PDSCH0and PDSCH1are associated, data transmission is successful when the UE can detect one of the two PDSCHa. Therefore, the downlink assignment indicator (DAI) counter and/or DAI total in DCI0and DCI1can be the same if DCI0and DCI1are in the same slot, BWP and scrambled by the same radio network temporary identifier (RNTI). As shown inFIG.4A, the DAI counter is the same for DCI0and DCII.FIG.4Adepicts two TRPs transmitting two independent PDCCH with the same DAI. Repetition in two PDSCHs may be used for uRLLC traffic, so the two PDCCH may be scrambled by the same RNTI, e.g. MCS-C-RNTI, or C-RNTI. Further restriction can be done for hybrid automatic repeat request (HARQ) process ID for the two associated PDSCH, e.g. the same HARQ process ID. Based on above description, one technique is to use explicit DCI bits to indicate whether multiple PDSCHs scheduled by multiple DCIs are associated. If the multiple PDSCH scheduled by the DCIs are associated, the contents of the multiple DCI are not independent. Some parameter values of the DCI are associated. The parameters that may be used to indicate association include one or more: DAI, HARQ process number, TPC command for scheduled PUCCH, PUCCH resource indicator, PDSCH-to-HARQ_feedback timing indicator, Time domain resource assignment, RNTI, carrier indicator, and/or bandwidth part indicator. When the scheduling information carried by two DCI is associated, then the scheduling information carried by the two DCI satisfies some predefined conditions. If some parameter values of two DCI are associated, the parameter values do not need to be the same, but they do have some relationship. For example, DCI0and DCI1are associated, then the time-domain resource assignment for PDSCH0and PDSCH1does not need to be the same, but the values should ensure PDSCH0and PDSCH1are transmitted in the same slot. A carrier indicator and bandwidth part indicator can ensure the two PDSCHs are transmitted in the same BWP. Two PDSCHs carrying associated TB(s) requires TBS(s) carried by the associated PDSCHs are the same or similar. For instance, the TBS for both PDSCH0and PDSCH1are the same. Second Category Above in category 1, DCI bits are used to indicate whether two PDSCHs are associated. There is some association between two DCIs when two PDSCHs are associated. Another technique is described below. gNB uses explicit DCI bits and the association between two DCIs to inform a UE whether PDSCHs scheduled by the two DCIs are associated. In other words, when both explicit DCI field values and the association between the two DCIs is satisfied, then the two PDSCHs are associated. If the value of the new field in DCIX is 1, and some parameter values of DCIx and DCIy are associated, then PDSCHx and PDSCHy are associated. The parameters include one or more of: DAI, HARQ process number, TPC command for scheduled PUCCH, PUCCH resource indicator, PDSCH-to-HARQ_feedback timing indicator, time domain resource assignment, RNTI, carrier indicator, bandwidth part indicator. Otherwise, PDSCHx and PDSHy may not be associated. For instance, when the 1 bit field in DCIx is 1, and the following conditions are the same in DCIx and DCIy: the same HARQ process number, the same RNTI, the same TPC command, PDSCH-to-HARQ_feedback timing indicators of the two DCI should ensure the two A/N feedback in the same slot. Another condition may be added such as the TBS(s) for the two PDSCH are the same. In this case, the TB(s) from the two TRP are the same, and the UE can do soft combining at the receiver. Third Category The above techniques can support dynamic selection between TRPs sending the same TB and TRPs sending different TBs. These techniques use some DCI overhead. Another technique is to use an implicit way to indicate the two PDSCHs scheduled by two DCIs are associated. As described in the above two categories, if the scheduling information carried by DCIx and DCIy are associated, PDSCHx and PDSCHy are associated. If two PDSCH are associated, the UE can perform combined detection of the two PDSCHs because the TBs carried by two PDSCHs are the same. If the scheduling information carried by two DCI is associated, the scheduling information carried by the two DCI satisfy some conditions. The scheduling information at least derived from one or more of following parameters: DAI, HARQ process number, TPC command for scheduled PUCCH, PUCCH resource indicator, PDSCH-to-HARQ_feedback timing indicator, time-domain resource assignment, RNTI, carrier indicator, bandwidth part indicator, and/or new data indicator (NDI). In addition, TBS(s) of PDSCHx and PDSCHy may be the same or the difference of TB(s) of PDSCHx and PDSCHy is smaller than a threshold. Since two DCIs and corresponding PDSCHs may be transmitted from different TRPs, some higher layer configurations may be independent. For example, TCI configuration by RRC signaling or MAC-CE to PDSCHx and PDSCHy may be independent because two TRPs' locations are different, so QCL (Quasi co-location) information from the two TRPs to the UE may be different. So, TCI State configurations by RRC signaling or MAC CE for PDSCHx and PDSCHy may be independent. Similarly, some other configurations for PDSCHx and PDSCHy may be independent, or some other configurations for PDCCHx and PDCCHy may be independent. Although PDSCHx and PDSCHy, or PDCCHx and PDCCHy are in the same CC or BWP, they may be from different TRPs, like different cells, the higher layer configurations may be independent. Those mentioned configurations may be configured by RRC signaling or MAC-CE. For example: PDCCH-config are independent for PDCCHx and PDCCHy; control resource set or search space are independent for PDCCHx and PDCCHy; and/or PDSCH-config are independent for PDSCHx and PDSCHy. In example condition 1, at least one of carrier indicator, bandwidth part indicator in DCIX and DCIy are the same. In another example, the condition can be that CC (component carrier) and BWP in DCIx and DCIy have a predefined relationship. For example, base station use higher layer signaling to set up the relationship between two CCs or BWPs which carry DCIX and DCIy respectively. These two CCs or BWPs can be from different CC groups or BWP groups. These two CCs/BWPs may overlap in frequency range. In example condition 2, HARQ process number carried by DCIx and DCIy are the same. The HARQ process number by DCIx and DCIy may satisfy one predefined condition, e.g. HARQ process number for PDSCHx+ HARQ process number for PDSCHy=8. The predefined condition means some rules are known at both transmit side and receive side in advance. In example condition 2a based on condition 2: HARQ process number carried by DCIx and DCIy are the same, PDSCHy transmission is before A/N feedback of PDSCHx, PDSCHy transmission is not before PDSCHx transmission. In the current standard, the procedure inFIG.4Bis not supported when PDSCHx and PDSCHy carry the same TB and they use the same HARQ process number. In other words, PDSCHy should be transmitted after A/N for PDSCHx. If NACK is reported by the UE, then PDSCHx was not detected correctly at the UE. Then the same TB can be transmitted but will increase the transmission latency. In order to reduce the latency, TRP0can transmit PDSCHx first, and TRP1can transmit PDSCHy before A/N feedback for PDSCHx. Then the UE can perform joint detection of PDSCHx and PDSCHy. Since PDSCHx and PDSCHy are associated, the probability of correct detection will be increased. One combined A/N can be fed back. Some higher layer configurations may be independent for PDSCHx and PDSCHy or for PDCCHx and PDCCHy. After A/N feedback of PDSCHx, PDSCHy carries the same TB(s) with PDSCHx can still be transmitted. This is re-transmission which is same as the traditional procedure, wherein MCS value may be one of 28, 29, 30, 31 if the maximum modulation order is 8, or may be one of 29,30,31 if the maximum modulation order is 6. In example condition 2b, some higher layer configurations may be independent for PDSCHx and PDSCHy or for PDCCHx and PDCCHy. PDSCHy transmission is before than S symbols of A/N feedback of PDSCHx. S is an integer value for conditions 1 and 2, 2a, and 2b above. A further condition 3 may be included in condition 1 and 2: TBS(s) of PDSCHx and PDSCHy are the same. It is noted that TBS is derived by scheduling information including some indicated by DCI, e.g. MCS, time-domain resource assignment, frequency domain resource assignment, ZP CSI-RS trigger and rate matching indicator and some configured by higher layer parameters. Alternatively, for condition 3 the difference between the TBS(s) of PDSCHx and PDSCHy may be smaller than a threshold. If PDSCHx is an initial transmission, the MCS value in DCIx may be ranged from 0-28 if the maximum modulation order is 6 (64 QAM) or ranged from 0-27 if the maximum modulation order is 8 (256QAM), then PDSCHy may also be an initial transmission and the MCS value in DCIy should not be ranged from 28, 29, 30, 31 if the maximum modulation order is 8, or should not be one of 29,30,31 if the maximum modulation order is 6. In other words, one more condition 3a can be: If PDSCHx are traditional re-transmission transmissions, the MCS value in DCIX is ranged from 29-31 and if maximum modulation order is 6 (64 QAM) or ranged from 28-31 if maximum modulation order is 8 (256QAM), then PDSCHy may also be a re-transmission, the MCS value in DCIy may not be ranged from 0-27 if the maximum modulation order is 8, or may not be ranged from 0-28 if the maximum modulation order is 6. Then, successful detection of one of pair (DCIx, PDSCHx) and (DCIy, PDSCHy) is enough since both DCIX and DCIy contain the complete scheduling MCS information. If the traditional procedure is used, PDSCHy is as a re-transmission of PDSCHx, MCS value of PDSCHy is in a range of 29-31 or 28-31, PDSCHy and DCIy are unusable if DCIx is not detected correctly. Condition 3a may be: if a MCS value in DCIx is ranged 0-A, MCS value in DCIy may also be in range 0-(A-1). A can be 29. Alternatively, A can be 28. If the MCS value in DCIx is ranged A-31, MCS value in DCIy may also be in range A-31. Based on the condition 1 or 2, two TRPs can transmit the same TBs in the same slot or very adjacent slot. The UE can perform soft combing for joint detection resulting in improved data reliability. In this case, condition 3b can be: NDI value carried by DCIx and DCIy may be the same since they schedule the same TB(s). In example condition 4, PDSCHx and PDSCHy may be transmitted in the same slot or same symbol. This will further reduce the transmission latency. Example condition 4a can be included in condition 4 where a DAI total or counter carried by DCIx and DCIy satisfy a special condition or are the same. Example condition 5 can be included in conditions 1,2 where A/N feedback for the PDSCHx and PDSCHy may be transmitted at the same slot or same symbol. This will further reduce the transmission latency. Further condition 6 can be included in condition 5: PUCCH resource of A/N feedback for the PDSCHx and PDSCHy may be the same. This will reduce the uplink feedback overhead but may impact the reliability of A/N transmissions. Further condition 6a can be included in condition 6: TPC command for scheduled PUCCH carried by DCIx and DCIy should be the same. Further condition 7 can be included in condition 1,2,3: RNTI of DCIx and DCIy should be the same. Any conditions mentioned above can be combined as a new condition. For example, a final condition may include condition 1+2a+2b+3a. If time domain resources and frequency domain resources are not exactly same for PDSCHx and PDSCHy, it is hard to ensure the TBSs are the same. gNB can use DCI signaling to adjust TBS for PDSCHx or PDSCHy. An offset value can be indicated by the DCI. Alternatively, RRC or MAC signaling can be used to further adjust TBS. FIG.5depict a process, in accordance with some example embodiments. The process includes a method of wireless communication. At502, the method includes receiving a first downlink control information (DCI) message to schedule a first shared resource (e.g., a first PDSCH) and a second DCI message to schedule a second shared resource (e.g., a second PDSCH). At504, method includes determining a relationship between first scheduling information indicated by the first DCI message and second scheduling information indicated by the second DCI message. At506, the method includes determining whether a first transport block (TB) communicated by the first shared resource is associated with a second TB communicated by the second shared resource. The determining the first TB is associated with the second TB may depend on a relationship between the first scheduling information and the second scheduling information satisfying one or more predefined conditions. Although above examples may be used for downlink transmission, the same solutions can also be used for uplink transmissions. For uplink transmissions, DCIx and DCIy schedule PUSCHx and PUSCHy respectively. In the above conditions, PDSCH is replaced by PUSCH, TCI is replaced by SRI (SRS resource indicator), or spatial related information. FIG.6depicts another process, in accordance with some example embodiments. The process includes a method of wireless communication. At602, the method includes sending a first downlink control information (DCI) message to schedule a first shared resource, the first shared resource may be a physical downlink shared channel (PDSCH). At604, the method includes sending a second DCI message to schedule a second shared resource, the second shared resource may be a PDSCH. At606, the method includes determining a relationship between first scheduling information indicated by the first DCI message and second scheduling information indicated by the second DCI message. At608, the method includes sending a first transport block (TB) communicated by the first shared resource associated with a second TB communicated in the second shared resource. The determining the first TB is associated with the second TB may depend on a relationship between the first scheduling information and the second scheduling information satisfying one or more predefined conditions. FIG.7depicts a block diagram700representing of a portion of a radio station. A radio station700such as a base station or a wireless device (or UE) can include one or more processors710such as a microprocessor that implements one or more of the wireless techniques presented in this document. The radio station700can include transmitter electronics715to send and receiver electronics720to receive wireless signals over one or more communication interfaces such as an antenna. The radio station700can include other communication interfaces for transmitting and receiving data. Radio station700can include one or more memories705configured to store information such as data and/or instructions. In some implementations, the processor electronics710can include at least a portion of the transceiver electronics720/715. In some embodiments, at least some of the disclosed techniques, modules or functions are implemented using the radio station700. From the foregoing, it will be appreciated that specific embodiments of the presently disclosed technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the scope of the invention. Accordingly, the presently disclosed technology is not limited except as by the appended claims. The disclosed and other embodiments, modules and the functional operations described in this document can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, or in combinations of one or more of them. The disclosed and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more them. The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus. A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network. The processes and logic flows described in this document can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit). Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random-access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry. While this patent document contains many specifics, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this patent document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments. Only a few implementations and examples are described, and other implementations, enhancements and variations can be made based on what is described and illustrated in this patent document. | 31,102 |
11943066 | DETAILED DESCRIPTION The accompanying drawings and descriptions provide examples. It is to be understood that the examples shown in the drawings and/or described are non-exclusive and that there are other examples of how features shown and described may be practiced. Examples are provided for operation of wireless communication systems which may be used in the technical field of multicarrier communication systems. More particularly, the technology described herein may, for example, relate to wireless communication systems in multicarrier communication systems. The following acronyms are used throughout the drawings and/or descriptions, and are provided below for convenience although other acronyms may be introduced in the detailed description:3GPP 3rd Generation Partnership Project5GC 5G Core NetworkACK AcknowledgementAMF Access and Mobility Management FunctionARQ Automatic Repeat RequestAS Access StratumASIC Application-Specific Integrated CircuitBA Bandwidth AdaptationBCCH Broadcast Control ChannelBCH Broadcast ChannelBPSK Binary Phase Shift KeyingBWP Bandwidth PartCA Carrier AggregationCC Component CarrierCCCH Common Control CHannelCDMA Code Division Multiple AccessCN Core NetworkCP Cyclic PrefixCP-OFDM Cyclic Prefix-Orthogonal Frequency Division MultiplexC-RNTI Cell-Radio Network Temporary IdentifierCS Configured SchedulingCSI Channel State InformationCSI-RS Channel State Information-Reference SignalCQI Channel Quality IndicatorCSS Common Search SpaceCU Central UnitDC Dual ConnectivityDCCH Dedicated Control ChannelDCI Downlink Control InformationDL DownlinkDL-SCH Downlink Shared CHannelDM-RS DeModulation Reference SignalDRB Data Radio BearerDRX Discontinuous ReceptionDTCH Dedicated Traffic ChannelDU Distributed UnitEPC Evolved Packet CoreE-UTRA Evolved UMTS Terrestrial Radio AccessE-UTRAN Evolved-Universal Terrestrial Radio Access NetworkFDD Frequency Division DuplexFPGA Field Programmable Gate ArraysF1-C F1-Control planeF1-U F1-User planegNB next generation Node BHARQ Hybrid Automatic Repeat reQuestHDL Hardware Description LanguagesIE Information ElementIP Internet ProtocolLCID Logical Channel IdentifierLTE Long Term EvolutionMAC Media Access ControlMCG Master Cell GroupMCS Modulation and Coding SchemeMeNB Master evolved Node BMIB Master Information BlockMME Mobility Management EntityMN Master NodeNACK Negative AcknowledgementNAS Non-Access StratumNG CP Next Generation Control PlaneNGC Next Generation CoreNG-C NG-Control planeng-eNB next generation evolved Node BNG-U NG-User planeNR New RadioNR MAC New Radio MACNR PDCP New Radio PDCPNR PHY New Radio PHYsicalNR RLC New Radio RLCNR RRC New Radio RRCNSSAI Network Slice Selection Assistance InformationO&M Operation and MaintenanceOFDM Orthogonal Frequency Division MultiplexingPBCH Physical Broadcast CHannelPCC Primary Component CarrierPCCH Paging Control CHannelPCell Primary CellPCH Paging CHannelPDCCH Physical Downlink Control CHannelPDCP Packet Data Convergence ProtocolPDSCH Physical Downlink Shared CHannelPDU Protocol Data UnitPHICH Physical HARQ Indicator CHannelPHY PHYsicalPLMN Public Land Mobile NetworkPMI Precoding Matrix IndicatorPRACH Physical Random Access CHannelPRB Physical Resource BlockPSCell Primary Secondary CellPSS Primary Synchronization SignalpTAG primary Timing Advance GroupPT-RS Phase Tracking Reference SignalPUCCH Physical Uplink Control CHannelPUSCH Physical Uplink Shared CHannelQAM Quadrature Amplitude ModulationQFI Quality of Service IndicatorQoS Quality of ServiceQPSK Quadrature Phase Shift KeyingRA Random AccessRACH Random Access CHannelRAN Radio Access NetworkRAT Radio Access TechnologyRA-RNTI Random Access-Radio Network Temporary IdentifierRB Resource BlocksRBG Resource Block GroupsRI Rank indicatorRLC Radio Link ControlRRC Radio Resource ControlRS Reference SignalRSRP Reference Signal Received PowerSCC Secondary Component CarrierSCell Secondary CellSCG Secondary Cell GroupSC-FDMA Single Carrier-Frequency Division Multiple AccessSDAP Service Data Adaptation ProtocolSDU Service Data UnitSeNB Secondary evolved Node BSFN System Frame NumberS-GW Serving GateWaySI System InformationSIB System Information BlockSMF Session Management FunctionSN Secondary NodeSpCell Special CellSRB Signaling Radio BearerSRS Sounding Reference SignalSS Synchronization SignalSSS Secondary Synchronization SignalsTAG secondary Timing Advance GroupTA Timing AdvanceTAG Timing Advance GroupTAI Tracking Area IdentifierTAT Time Alignment TimerTB Transport BlockTC-RNTI Temporary Cell-Radio Network Temporary IdentifierTDD Time Division DuplexTDMA Time Division Multiple AccessTTI Transmission Time IntervalUCI Uplink Control InformationUE User EquipmentUL UplinkUL-SCH Uplink Shared CHannelUPF User Plane FunctionUPGW User Plane GatewayVHDL VHSIC Hardware Description LanguageXn-C Xn-Control planeXn-U Xn-User plane Examples described herein may be implemented using various physical layer modulation and transmission mechanisms. Example transmission mechanisms may include, but are not limited to: Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Time Division Multiple Access (TDMA), Wavelet technologies, and/or the like. Hybrid transmission mechanisms such as TDMA/CDMA, and/or OFDM/CDMA may be used. Various modulation schemes may be used for signal transmission in the physical layer. Examples of modulation schemes include, but are not limited to: phase, amplitude, code, a combination of these, and/or the like. An example radio transmission method may implement Quadrature Amplitude Modulation (QAM) using Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), 16-QAM, 64-QAM, 256-QAM, and/or the like. Physical radio transmission may be enhanced by dynamically or semi-dynamically changing the modulation and coding scheme, for example, depending on transmission requirements and/or radio conditions. FIG.1shows an example Radio Access Network (RAN) architecture. A RAN node may comprise a next generation Node B (gNB) (e.g.,120A,120B) providing New Radio (NR) user plane and control plane protocol terminations towards a first wireless device (e.g.,110A). A RAN node may comprise a base station such as a next generation evolved Node B (ng-eNB) (e.g.,120C,120D), providing Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol terminations towards a second wireless device (e.g.,110B). A first wireless device110A may communicate with a base station, such as a gNB120A, over a Uu interface. A second wireless device110B may communicate with a base station, such as an ng-eNB120D, over a Uu interface. The wireless devices110A and/or110B may be structurally similar to wireless devices shown in and/or described in connection with other drawing figures. The Node B120A, the Node B120B, the Node B120C, and/or the Node B120D may be structurally similar to Nodes B and/or base stations shown in and/or described in connection with other drawing figures. A base station, such as a gNB (e.g.,120A,120B, etc.) and/or an ng-eNB (e.g.,120C,120D, etc.) may host functions such as radio resource management and scheduling, IP header compression, encryption and integrity protection of data, selection of Access and Mobility Management Function (AMF) at wireless device (e.g., User Equipment (UE)) attachment, routing of user plane and control plane data, connection setup and release, scheduling and transmission of paging messages (e.g., originated from the AMF), scheduling and transmission of system broadcast information (e.g., originated from the AMF or Operation and Maintenance (O&M)), measurement and measurement reporting configuration, transport level packet marking in the uplink, session management, support of network slicing, Quality of Service (QoS) flow management and mapping to data radio bearers, support of wireless devices in an inactive state (e.g., RRC_INACTIVE state), distribution function for Non-Access Stratum (NAS) messages, RAN sharing, dual connectivity, and/or tight interworking between NR and E-UTRA. One or more first base stations (e.g., gNBs120A and120B) and/or one or more second base stations (e.g., ng-eNBs120C and120D) may be interconnected with each other via Xn interface. A first base station (e.g., gNB120A,120B, etc.) or a second base station (e.g., ng-eNB120C,120D, etc.) may be connected via NG interfaces to a network, such as a 5G Core Network (5GC). A 5GC may comprise one or more AMF/User Plan Function (UPF) functions (e.g.,130A and/or130B). A base station (e.g., a gNB and/or an ng-eNB) may be connected to a UPF via an NG-User plane (NG-U) interface. The NG-U interface may provide delivery (e.g., non-guaranteed delivery) of user plane Protocol Data Units (PDUs) between a RAN node and the UPF. A base station (e.g., a gNB and/or an ng-eNB) may be connected to an AMF via an NG-Control plane (NG-C) interface. The NG-C interface may provide functions such as NG interface management, wireless device (e.g., UE) context management, wireless device (e.g., UE) mobility management, transport of NAS messages, paging, PDU session management, configuration transfer, and/or warning message transmission. A UPF may host functions such as anchor point for intra-/inter-Radio Access Technology (RAT) mobility (e.g., if applicable), external PDU session point of interconnect to data network, packet routing and forwarding, packet inspection and user plane part of policy rule enforcement, traffic usage reporting, uplink classifier to support routing traffic flows to a data network, branching point to support multi-homed PDU session, quality of service (QoS) handling for user plane, packet filtering, gating, Uplink (UL)/Downlink (DL) rate enforcement, uplink traffic verification (e.g., Service Data Flow (SDF) to QoS flow mapping), downlink packet buffering, and/or downlink data notification triggering. An AMF may host functions such as NAS signaling termination, NAS signaling security, Access Stratum (AS) security control, inter Core Network (CN) node signaling (e.g., for mobility between 3rd Generation Partnership Project (3GPP) access networks), idle mode wireless device reachability (e.g., control and execution of paging retransmission), registration area management, support of intra-system and inter-system mobility, access authentication, access authorization including check of roaming rights, mobility management control (e.g., subscription and/or policies), support of network slicing, and/or Session Management Function (SMF) selection. FIG.2Ashows an example user plane protocol stack. A Service Data Adaptation Protocol (SDAP) (e.g.,211and221), Packet Data Convergence Protocol (PDCP) (e.g.,212and222), Radio Link Control (RLC) (e.g.,213and223), and Media Access Control (MAC) (e.g.,214and224) sublayers, and a Physical (PHY) (e.g.,215and225) layer, may be terminated in a wireless device (e.g.,110) and in a base station (e.g.,120) on a network side. A PHY layer may provide transport services to higher layers (e.g., MAC, RRC, etc.). Services and/or functions of a MAC sublayer may comprise mapping between logical channels and transport channels, multiplexing and/or demultiplexing of MAC Service Data Units (SDUs) belonging to the same or different logical channels into and/or from Transport Blocks (TBs) delivered to and/or from the PHY layer, scheduling information reporting, error correction through Hybrid Automatic Repeat request (HARQ) (e.g., one HARQ entity per carrier for Carrier Aggregation (CA)), priority handling between wireless devices such as by using dynamic scheduling, priority handling between logical channels of a wireless device such as by using logical channel prioritization, and/or padding. A MAC entity may support one or multiple numerologies and/or transmission timings. Mapping restrictions in a logical channel prioritization may control which numerology and/or transmission timing a logical channel may use. An RLC sublayer may support transparent mode (TM), unacknowledged mode (UM), and/or acknowledged mode (AM) transmission modes. The RLC configuration may be per logical channel with no dependency on numerologies and/or Transmission Time Interval (TTI) durations. Automatic Repeat Request (ARQ) may operate on any of the numerologies and/or TTI durations with which the logical channel is configured. Services and functions of the PDCP layer for the user plane may comprise, for example, sequence numbering, header compression and decompression, transfer of user data, reordering and duplicate detection, PDCP PDU routing (e.g., such as for split bearers), retransmission of PDCP SDUs, ciphering, deciphering and integrity protection, PDCP SDU discard, PDCP re-establishment and data recovery for RLC AM, and/or duplication of PDCP PDUs. Services and/or functions of SDAP may comprise, for example, mapping between a QoS flow and a data radio bearer. Services and/or functions of SDAP may comprise mapping a Quality of Service Indicator (QFI) in DL and UL packets. A protocol entity of SDAP may be configured for an individual PDU session. FIG.2Bshows an example control plane protocol stack. A PDCP (e.g.,233and242), RLC (e.g.,234and243), and MAC (e.g.,235and244) sublayers, and a PHY (e.g.,236and245) layer, may be terminated in a wireless device (e.g.,110), and in a base station (e.g.,120) on a network side, and perform service and/or functions described above. RRC (e.g.,232and241) may be terminated in a wireless device and a base station on a network side. Services and/or functions of RRC may comprise broadcast of system information related to AS and/or NAS; paging (e.g., initiated by a 5GC or a RAN); establishment, maintenance, and/or release of an RRC connection between the wireless device and RAN; security functions such as key management, establishment, configuration, maintenance, and/or release of Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs); mobility functions; QoS management functions; wireless device measurement reporting and control of the reporting; detection of and recovery from radio link failure; and/or NAS message transfer to/from NAS from/to a wireless device. NAS control protocol (e.g.,231and251) may be terminated in the wireless device and AMF (e.g.,130) on a network side. NAS control protocol may perform functions such as authentication, mobility management between a wireless device and an AMF (e.g., for 3GPP access and non-3GPP access), and/or session management between a wireless device and an SMF (e.g., for 3GPP access and non-3GPP access). A base station may configure a plurality of logical channels for a wireless device. A logical channel of the plurality of logical channels may correspond to a radio bearer. The radio bearer may be associated with a QoS requirement. A base station may configure a logical channel to be mapped to one or more TTIs and/or numerologies in a plurality of TTIs and/or numerologies. The wireless device may receive Downlink Control Information (DCI) via a Physical Downlink Control CHannel (PDCCH) indicating an uplink grant. The uplink grant may be for a first TTI and/or a first numerology and may indicate uplink resources for transmission of a transport block. The base station may configure each logical channel in the plurality of logical channels with one or more parameters to be used by a logical channel prioritization procedure at the MAC layer of the wireless device. The one or more parameters may comprise, for example, priority, prioritized bit rate, etc. A logical channel in the plurality of logical channels may correspond to one or more buffers comprising data associated with the logical channel. The logical channel prioritization procedure may allocate the uplink resources to one or more first logical channels in the plurality of logical channels and/or to one or more MAC Control Elements (CEs). The one or more first logical channels may be mapped to the first TTI and/or the first numerology. The MAC layer at the wireless device may multiplex one or more MAC CEs and/or one or more MAC SDUs (e.g., logical channel) in a MAC PDU (e.g., transport block). The MAC PDU may comprise a MAC header comprising a plurality of MAC sub-headers. A MAC sub-header in the plurality of MAC sub-headers may correspond to a MAC CE or a MAC SUD (e.g., logical channel) in the one or more MAC CEs and/or in the one or more MAC SDUs. A MAC CE and/or a logical channel may be configured with a Logical Channel IDentifier (LCID). An LCID for a logical channel and/or a MAC CE may be fixed and/or pre-configured. An LCID for a logical channel and/or MAC CE may be configured for the wireless device by the base station. The MAC sub-header corresponding to a MAC CE and/or a MAC SDU may comprise an LCID associated with the MAC CE and/or the MAC SDU. A base station may activate, deactivate, and/or impact one or more processes (e.g., set values of one or more parameters of the one or more processes or start and/or stop one or more timers of the one or more processes) at the wireless device, for example, by using one or more MAC commands. The one or more MAC commands may comprise one or more MAC control elements. The one or more processes may comprise activation and/or deactivation of PDCP packet duplication for one or more radio bearers. The base station may send (e.g., transmit) a MAC CE comprising one or more fields. The values of the fields may indicate activation and/or deactivation of PDCP duplication for the one or more radio bearers. The one or more processes may comprise Channel State Information (CSI) transmission for one or more cells. The base station may send (e.g., transmit) one or more MAC CEs indicating activation and/or deactivation of the CSI transmission on the one or more cells. The one or more processes may comprise activation and/or deactivation of one or more secondary cells. The base station may send (e.g., transmit) a MA CE indicating activation and/or deactivation of one or more secondary cells. The base station may send (e.g., transmit) one or more MAC CEs indicating starting and/or stopping of one or more Discontinuous Reception (DRX) timers at the wireless device. The base station may send (e.g., transmit) one or more MAC CEs indicating one or more timing advance values for one or more Timing Advance Groups (TAGs). FIG.3shows an example of base stations (base station 1,120A, and base station 2,120B) and a wireless device110. The wireless device110may comprise a UE or any other wireless device. The base station (e.g.,120A,120B) may comprise a Node B, eNB, gNB, ng-eNB, or any other base station. A wireless device and/or a base station may perform one or more functions of a relay node. The base station 1,120A, may comprise at least one communication interface320A (e.g., a wireless modem, an antenna, a wired modem, and/or the like), at least one processor321A, and at least one set of program code instructions323A that may be stored in non-transitory memory322A and executable by the at least one processor321A. The base station 2,120B, may comprise at least one communication interface320B, at least one processor321B, and at least one set of program code instructions323B that may be stored in non-transitory memory322B and executable by the at least one processor321B. A base station may comprise any number of sectors, for example: 1, 2, 3, 4, or 6 sectors. A base station may comprise any number of cells, for example, ranging from 1 to 50 cells or more. A cell may be categorized, for example, as a primary cell or secondary cell. At Radio Resource Control (RRC) connection establishment, re-establishment, handover, etc., a serving cell may provide NAS (non-access stratum) mobility information (e.g., Tracking Area Identifier (TAI)). At RRC connection re-establishment and/or handover, a serving cell may provide security input. This serving cell may be referred to as the Primary Cell (PCell). In the downlink, a carrier corresponding to the PCell may be a DL Primary Component Carrier (PCC). In the uplink, a carrier may be an UL PCC. Secondary Cells (SCells) may be configured to form together with a PCell a set of serving cells, for example, depending on wireless device capabilities. In a downlink, a carrier corresponding to an SCell may be a downlink secondary component carrier (DL SCC). In an uplink, a carrier may be an uplink secondary component carrier (UL SCC). An SCell may or may not have an uplink carrier. A cell, comprising a downlink carrier and optionally an uplink carrier, may be assigned a physical cell ID and/or a cell index. A carrier (downlink and/or uplink) may belong to one cell. The cell ID and/or cell index may identify the downlink carrier and/or uplink carrier of the cell (e.g., depending on the context it is used). A cell ID may be equally referred to as a carrier ID, and a cell index may be referred to as a carrier index. A physical cell ID and/or a cell index may be assigned to a cell. A cell ID may be determined using a synchronization signal transmitted via a downlink carrier. A cell index may be determined using RRC messages. A first physical cell ID for a first downlink carrier may indicate that the first physical cell ID is for a cell comprising the first downlink carrier. The same concept may be used, for example, with carrier activation and/or deactivation (e.g., secondary cell activation and/or deactivation). A first carrier that is activated may indicate that a cell comprising the first carrier is activated. A base station may send (e.g., transmit) to a wireless device one or more messages (e.g., RRC messages) comprising a plurality of configuration parameters for one or more cells. One or more cells may comprise at least one primary cell and at least one secondary cell. An RRC message may be broadcasted and/or unicasted to the wireless device. Configuration parameters may comprise common parameters and dedicated parameters. Services and/or functions of an RRC sublayer may comprise at least one of: broadcast of system information related to AS and/or NAS; paging initiated by a 5GC and/or an NG-RAN; establishment, maintenance, and/or release of an RRC connection between a wireless device and an NG-RAN, which may comprise at least one of addition, modification, and/or release of carrier aggregation; and/or addition, modification, and/or release of dual connectivity in NR or between E-UTRA and NR. Services and/or functions of an RRC sublayer may comprise at least one of security functions comprising key management; establishment, configuration, maintenance, and/or release of Signaling Radio Bearers (SRBs) and/or Data Radio Bearers (DRBs); mobility functions which may comprise at least one of a handover (e.g., intra NR mobility or inter-RAT mobility) and/or a context transfer; and/or a wireless device cell selection and/or reselection and/or control of cell selection and reselection. Services and/or functions of an RRC sublayer may comprise at least one of QoS management functions; a wireless device measurement configuration/reporting; detection of and/or recovery from radio link failure; and/or NAS message transfer to and/or from a core network entity (e.g., AMF, Mobility Management Entity (MME)) from and/or to the wireless device. An RRC sublayer may support an RRC_Idle state, an RRC_Inactive state, and/or an RRC_Connected state for a wireless device. In an RRC_Idle state, a wireless device may perform at least one of: Public Land Mobile Network (PLMN) selection; receiving broadcasted system information; cell selection and/or re-selection; monitoring and/or receiving a paging for mobile terminated data initiated by 5GC; paging for mobile terminated data area managed by 5GC; and/or DRX for CN paging configured via NAS. In an RRC_Inactive state, a wireless device may perform at least one of: receiving broadcasted system information; cell selection and/or re-selection; monitoring and/or receiving a RAN and/or CN paging initiated by an NG-RAN and/or a 5GC; RAN-based notification area (RNA) managed by an NG-RAN; and/or DRX for a RAN and/or CN paging configured by NG-RAN/NAS. In an RRC_Idle state of a wireless device, a base station (e.g., NG-RAN) may keep a 5GC-NG-RAN connection (e.g., both C/U-planes) for the wireless device; and/or store a wireless device AS context for the wireless device. In an RRC_Connected state of a wireless device, a base station (e.g., NG-RAN) may perform at least one of: establishment of 5GC-NG-RAN connection (both C/U-planes) for the wireless device; storing a UE AS context for the wireless device; send (e.g., transmit) and/or receive of unicast data to and/or from the wireless device; and/or network-controlled mobility based on measurement results received from the wireless device. In an RRC_Connected state of a wireless device, an NG-RAN may know a cell to which the wireless device belongs. System information (SI) may be divided into minimum SI and other SI. The minimum SI may be periodically broadcast. The minimum SI may comprise basic information required for initial access and/or information for acquiring any other SI broadcast periodically and/or provisioned on-demand (e.g., scheduling information). The other SI may either be broadcast, and/or be provisioned in a dedicated manner, such as either triggered by a network and/or upon request from a wireless device. A minimum SI may be transmitted via two different downlink channels using different messages (e.g., MasterInformationBlock and SystemInformationBlockType1). Another SI may be transmitted via SystemInformationBlockType2. For a wireless device in an RRC_Connected state, dedicated RRC signaling may be used for the request and delivery of the other SI. For the wireless device in the RRC_Idle state and/or in the RRC_Inactive state, the request may trigger a random-access procedure. A wireless device may report its radio access capability information, which may be static. A base station may request one or more indications of capabilities for a wireless device to report based on band information. A temporary capability restriction request may be sent by the wireless device (e.g., if allowed by a network) to signal the limited availability of some capabilities (e.g., due to hardware sharing, interference, and/or overheating) to the base station. The base station may confirm or reject the request. The temporary capability restriction may be transparent to 5GC (e.g., static capabilities may be stored in 5GC). A wireless device may have an RRC connection with a network, for example, if CA is configured. At RRC connection establishment, re-establishment, and/or handover procedures, a serving cell may provide NAS mobility information. At RRC connection re-establishment and/or handover, a serving cell may provide a security input. This serving cell may be referred to as the PCell. SCells may be configured to form together with the PCell a set of serving cells, for example, depending on the capabilities of the wireless device. The configured set of serving cells for the wireless device may comprise a PCell and one or more SCells. The reconfiguration, addition, and/or removal of SCells may be performed by RRC messaging. At intra-NR handover, RRC may add, remove, and/or reconfigure SCells for usage with the target PCell. Dedicated RRC signaling may be used (e.g., if adding a new SCell) to send all required system information of the SCell (e.g., if in connected mode, wireless devices may not acquire broadcasted system information directly from the SCells). The purpose of an RRC connection reconfiguration procedure may be to modify an RRC connection, (e.g., to establish, modify, and/or release RBs; to perform handover; to setup, modify, and/or release measurements, for example, to add, modify, and/or release SCells and cell groups). NAS dedicated information may be transferred from the network to the wireless device, for example, as part of the RRC connection reconfiguration procedure. The RRCConnectionReconfiguration message may be a command to modify an RRC connection. One or more RRC messages may convey information for measurement configuration, mobility control, and/or radio resource configuration (e.g., RBs, MAC main configuration, and/or physical channel configuration), which may comprise any associated dedicated NAS information and/or security configuration. The wireless device may perform an SCell release, for example, if the received RRC Connection Reconfiguration message includes the sCellToReleaseList. The wireless device may perform SCell additions or modification, for example, if the received RRC Connection Reconfiguration message includes the sCellToAddModList. An RRC connection establishment, reestablishment, and/or resume procedure may be to establish, reestablish, and/or resume an RRC connection, respectively. An RRC connection establishment procedure may comprise SRB1 establishment. The RRC connection establishment procedure may be used to transfer the initial NAS dedicated information and/or message from a wireless device to an E-UTRAN. The RRCConnectionReestablishment message may be used to re-establish SRB1. A measurement report procedure may be used to transfer measurement results from a wireless device to an NG-RAN. The wireless device may initiate a measurement report procedure, for example, after successful security activation. A measurement report message may be used to send (e.g., transmit) measurement results. The wireless device110may comprise at least one communication interface310(e.g., a wireless modem, an antenna, and/or the like), at least one processor314, and at least one set of program code instructions316that may be stored in non-transitory memory315and executable by the at least one processor314. The wireless device110may further comprise at least one of at least one speaker and/or microphone311, at least one keypad312, at least one display and/or touchpad313, at least one power source317, at least one global positioning system (GPS) chipset318, and/or other peripherals319. The processor314of the wireless device110, the processor321A of the base station 1120A, and/or the processor321B of the base station 2120B may comprise at least one of a general-purpose processor, a digital signal processor (DSP), a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and/or other programmable logic device, discrete gate and/or transistor logic, discrete hardware components, and/or the like. The processor314of the wireless device110, the processor321A in base station 1120A, and/or the processor321B in base station 2120B may perform at least one of signal coding and/or processing, data processing, power control, input/output processing, and/or any other functionality that may enable the wireless device110, the base station 1120A and/or the base station 2120B to operate in a wireless environment. The processor314of the wireless device110may be connected to and/or in communication with the speaker and/or microphone311, the keypad312, and/or the display and/or touchpad313. The processor314may receive user input data from and/or provide user output data to the speaker and/or microphone311, the keypad312, and/or the display and/or touchpad313. The processor314in the wireless device110may receive power from the power source317and/or may be configured to distribute the power to the other components in the wireless device110. The power source317may comprise at least one of one or more dry cell batteries, solar cells, fuel cells, and/or the like. The processor314may be connected to the GPS chipset318. The GPS chipset318may be configured to provide geographic location information of the wireless device110. The processor314of the wireless device110may further be connected to and/or in communication with other peripherals319, which may comprise one or more software and/or hardware modules that may provide additional features and/or functionalities. For example, the peripherals319may comprise at least one of an accelerometer, a satellite transceiver, a digital camera, a universal serial bus (USB) port, a hands-free headset, a frequency modulated (FM) radio unit, a media player, an Internet browser, and/or the like. The communication interface320A of the base station 1,120A, and/or the communication interface320B of the base station 2,120B, may be configured to communicate with the communication interface310of the wireless device110, for example, via a wireless link330A and/or via a wireless link330B, respectively. The communication interface320A of the base station 1,120A, may communicate with the communication interface320B of the base station 2 and/or other RAN and/or core network nodes. The wireless link330A and/or the wireless link330B may comprise at least one of a bi-directional link and/or a directional link. The communication interface310of the wireless device110may be configured to communicate with the communication interface320A of the base station 1120A and/or with the communication interface320B of the base station 2120B. The base station 1120A and the wireless device110, and/or the base station 2120B and the wireless device110, may be configured to send and receive transport blocks, for example, via the wireless link330A and/or via the wireless link330B, respectively. The wireless link330A and/or the wireless link330B may use at least one frequency carrier. Transceiver(s) may be used. A transceiver may be a device that comprises both a transmitter and a receiver. Transceivers may be used in devices such as wireless devices, base stations, relay nodes, computing devices, and/or the like. Radio technology may be implemented in the communication interface310,320A, and/or320B, and the wireless link330A and/or330B. The radio technology may comprise one or more elements shown inFIG.4A,FIG.4B,FIG.4C,FIG.4D,FIG.6,FIG.7A,FIG.7B,FIG.8, and associated text, described below. Other nodes in a wireless network (e.g., AMF, UPF, SMF, etc.) may comprise one or more communication interfaces, one or more processors, and memory storing instructions. A node (e.g., wireless device, base station, AMF, SMF, UPF, servers, switches, antennas, and/or the like) may comprise one or more processors, and memory storing instructions that when executed by the one or more processors causes the node to perform certain processes and/or functions. Single-carrier and/or multi-carrier communication operation may be performed. A non-transitory tangible computer readable media may comprise instructions executable by one or more processors to cause operation of single-carrier and/or multi-carrier communications. An article of manufacture may comprise a non-transitory tangible computer readable machine-accessible medium having instructions encoded thereon for enabling programmable hardware to cause a node to enable operation of single-carrier and/or multi-carrier communications. The node may include processors, memory, interfaces, and/or the like. An interface may comprise at least one of a hardware interface, a firmware interface, a software interface, and/or a combination thereof. The hardware interface may comprise connectors, wires, and/or electronic devices such as drivers, amplifiers, and/or the like. The software interface may comprise code stored in a memory device to implement protocol(s), protocol layers, communication drivers, device drivers, combinations thereof, and/or the like. The firmware interface may comprise a combination of embedded hardware and/or code stored in (and/or in communication with) a memory device to implement connections, electronic device operations, protocol(s), protocol layers, communication drivers, device drivers, hardware operations, combinations thereof, and/or the like. A communication network may comprise the wireless device110, the base station 1,120A, the base station 2,120B, and/or any other device. The communication network may comprise any number and/or type of devices, such as, for example, computing devices, wireless devices, mobile devices, handsets, tablets, laptops, internet of things (IoT) devices, hotspots, cellular repeaters, computing devices, and/or, more generally, user equipment (e.g., UE). Although one or more of the above types of devices may be referenced herein (e.g., UE, wireless device, computing device, etc.), it should be understood that any device herein may comprise any one or more of the above types of devices or similar devices. The communication network, and any other network referenced herein, may comprise an LTE network, a 5G network, or any other network for wireless communications. Apparatuses, systems, and/or methods described herein may generally be described as implemented on one or more devices (e.g., wireless device, base station, eNB, gNB, computing device, etc.), in one or more networks, but it will be understood that one or more features and steps may be implemented on any device and/or in any network. As used throughout, the term “base station” may comprise one or more of: a base station, a node, a Node B, a gNB, an eNB, an ng-eNB, a relay node (e.g., an integrated access and backhaul (IAB) node), a donor node (e.g., a donor eNB, a donor gNB, etc.), an access point (e.g., a WiFi access point), a computing device, a device capable of wirelessly communicating, or any other device capable of sending and/or receiving signals. As used throughout, the term “wireless device” may comprise one or more of: a UE, a handset, a mobile device, a computing device, a node, a device capable of wirelessly communicating, or any other device capable of sending and/or receiving signals. Any reference to one or more of these terms/devices also considers use of any other term/device mentioned above. FIG.4A,FIG.4B,FIG.4CandFIG.4Dshow examples of uplink and downlink signal transmission.FIG.4Ashows an example uplink transmitter for at least one physical channel. A baseband signal representing a physical uplink shared channel may perform one or more functions. The one or more functions may comprise at least one of: scrambling (e.g., by Scrambling); modulation of scrambled bits to generate complex-valued symbols (e.g., by a Modulation mapper); mapping of the complex-valued modulation symbols onto one or several transmission layers (e.g., by a Layer mapper); transform precoding to generate complex-valued symbols (e.g., by a Transform precoder); precoding of the complex-valued symbols (e.g., by a Precoder); mapping of precoded complex-valued symbols to resource elements (e.g., by a Resource element mapper); generation of complex-valued time-domain Single Carrier-Frequency Division Multiple Access (SC-FDMA) or CP-OFDM signal for an antenna port (e.g., by a signal gen.); and/or the like. A SC-FDMA signal for uplink transmission may be generated, for example, if transform precoding is enabled. A CP-OFDM signal for uplink transmission may be generated byFIG.4A, for example, if transform precoding is not enabled. These functions are shown as examples and other mechanisms may be implemented. FIG.4Bshows an example of modulation and up-conversion to the carrier frequency of a complex-valued SC-FDMA or CP-OFDM baseband signal for an antenna port and/or for the complex-valued Physical Random Access CHannel (PRACH) baseband signal. Filtering may be performed prior to transmission. FIG.4Cshows an example of downlink transmissions. The baseband signal representing a downlink physical channel may perform one or more functions. The one or more functions may comprise: scrambling of coded bits in a codeword to be transmitted on a physical channel (e.g., by Scrambling); modulation of scrambled bits to generate complex-valued modulation symbols (e.g., by a Modulation mapper); mapping of the complex-valued modulation symbols onto one or several transmission layers (e.g., by a Layer mapper); precoding of the complex-valued modulation symbols on a layer for transmission on the antenna ports (e.g., by Precoding); mapping of complex-valued modulation symbols for an antenna port to resource elements (e.g., by a Resource element mapper); generation of complex-valued time-domain OFDM signal for an antenna port (e.g., by an OFDM signal gen.); and/or the like. These functions are shown as examples and other mechanisms may be implemented. A base station may send (e.g., transmit) a first symbol and a second symbol on an antenna port, to a wireless device. The wireless device may infer the channel (e.g., fading gain, multipath delay, etc.) for conveying the second symbol on the antenna port, from the channel for conveying the first symbol on the antenna port. A first antenna port and a second antenna port may be quasi co-located, for example, if one or more large-scale properties of the channel over which a first symbol on the first antenna port is conveyed may be inferred from the channel over which a second symbol on a second antenna port is conveyed. The one or more large-scale properties may comprise at least one of: delay spread; Doppler spread; Doppler shift; average gain; average delay; and/or spatial receiving (Rx) parameters. FIG.4Dshows an example modulation and up-conversion to the carrier frequency of the complex-valued OFDM baseband signal for an antenna port. Filtering may be performed prior to transmission. FIG.5Ashows example uplink channel mapping and example uplink physical signals. A physical layer may provide one or more information transfer services to a MAC and/or one or more higher layers. The physical layer may provide the one or more information transfer services to the MAC via one or more transport channels. An information transfer service may indicate how and/or with what characteristics data is transferred over the radio interface. Uplink transport channels may comprise an Uplink-Shared CHannel (UL-SCH)501and/or a Random Access CHannel (RACH)502. A wireless device may send (e.g., transmit) one or more uplink DM-RSs506to a base station for channel estimation, for example, for coherent demodulation of one or more uplink physical channels (e.g., PUSCH503and/or PUCCH504). The wireless device may send (e.g., transmit) to a base station at least one uplink DM-RS506with PUSCH503and/or PUCCH504, wherein the at least one uplink DM-RS506may be spanning a same frequency range as a corresponding physical channel. The base station may configure the wireless device with one or more uplink DM-RS configurations. At least one DM-RS configuration may support a front-loaded DM-RS pattern. A front-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1 or 2 adjacent OFDM symbols). One or more additional uplink DM-RS may be configured to send (e.g., transmit) at one or more symbols of a PUSCH and/or PUCCH. The base station may semi-statically configure the wireless device with a maximum number of front-loaded DM-RS symbols for PUSCH and/or PUCCH. The wireless device may schedule a single-symbol DM-RS and/or double symbol DM-RS based on a maximum number of front-loaded DM-RS symbols, wherein the base station may configure the wireless device with one or more additional uplink DM-RS for PUSCH and/or PUCCH. A new radio network may support, for example, at least for CP-OFDM, a common DM-RS structure for DL and UL, wherein a DM-RS location, DM-RS pattern, and/or scrambling sequence may be same or different. Whether or not an uplink PT-RS507is present may depend on an RRC configuration. A presence of the uplink PT-RS may be wireless device-specifically configured. A presence and/or a pattern of the uplink PT-RS507in a scheduled resource may be wireless device-specifically configured by a combination of RRC signaling and/or association with one or more parameters used for other purposes (e.g., Modulation and Coding Scheme (MCS)) which may be indicated by DCI. If configured, a dynamic presence of uplink PT-RS507may be associated with one or more DCI parameters comprising at least a MCS. A radio network may support a plurality of uplink PT-RS densities defined in time/frequency domain. If present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. A wireless device may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be less than a number of DM-RS ports in a scheduled resource. The uplink PT-RS507may be confined in the scheduled time/frequency duration for a wireless device. A wireless device may send (e.g., transmit) an SRS508to a base station for channel state estimation, for example, to support uplink channel dependent scheduling and/or link adaptation. The SRS508sent (e.g., transmitted) by the wireless device may allow for the base station to estimate an uplink channel state at one or more different frequencies. A base station scheduler may use an uplink channel state to assign one or more resource blocks of a certain quality (e.g., above a quality threshold) for an uplink PUSCH transmission from the wireless device. The base station may semi-statically configure the wireless device with one or more SRS resource sets. For an SRS resource set, the base station may configure the wireless device with one or more SRS resources. An SRS resource set applicability may be configured by a higher layer (e.g., RRC) parameter. An SRS resource in each of one or more SRS resource sets may be sent (e.g., transmitted) at a time instant, for example, if a higher layer parameter indicates beam management. The wireless device may send (e.g., transmit) one or more SRS resources in different SRS resource sets simultaneously. A new radio network may support aperiodic, periodic, and/or semi-persistent SRS transmissions. The wireless device may send (e.g., transmit) SRS resources, for example, based on one or more trigger types. The one or more trigger types may comprise higher layer signaling (e.g., RRC) and/or one or more DCI formats (e.g., at least one DCI format may be used for a wireless device to select at least one of one or more configured SRS resource sets). An SRS trigger type 0 may refer to an SRS triggered based on a higher layer signaling. An SRS trigger type 1 may refer to an SRS triggered based on one or more DCI formats. The wireless device may be configured to send (e.g., transmit) the SRS508after a transmission of PUSCH503and corresponding uplink DM-RS506, for example, if PUSCH503and the SRS508are transmitted in a same slot. A base station may semi-statically configure a wireless device with one or more SRS configuration parameters indicating at least one of following: an SRS resource configuration identifier, a number of SRS ports, time domain behavior of SRS resource configuration (e.g., an indication of periodic, semi-persistent, or aperiodic SRS), slot (mini-slot, and/or subframe) level periodicity and/or offset for a periodic and/or aperiodic SRS resource, a number of OFDM symbols in a SRS resource, starting OFDM symbol of a SRS resource, an SRS bandwidth, a frequency hopping bandwidth, a cyclic shift, and/or an SRS sequence ID. FIG.5Bshows an example downlink channel mapping and downlink physical signals. Downlink transport channels may comprise a Downlink-Shared CHannel (DL-SCH)511, a Paging CHannel (PCH)512, and/or a Broadcast CHannel (BCH)513. A transport channel may be mapped to one or more corresponding physical channels. A UL-SCH501may be mapped to a Physical Uplink Shared CHannel (PUSCH)503. A RACH502may be mapped to a PRACH505. A DL-SCH511and a PCH512may be mapped to a Physical Downlink Shared CHannel (PDSCH)514. A BCH513may be mapped to a Physical Broadcast CHannel (PBCH)516. A radio network may comprise one or more downlink and/or uplink transport channels. The radio network may comprise one or more physical channels without a corresponding transport channel. The one or more physical channels may be used for an Uplink Control Information (UCI)509and/or a Downlink Control Information (DCI)517. A Physical Uplink Control CHannel (PUCCH)504may carry UCI509from a wireless device to a base station. A Physical Downlink Control CHannel (PDCCH)515may carry the DCI517from a base station to a wireless device. The radio network (e.g., NR) may support the UCI509multiplexing in the PUSCH503, for example, if the UCI509and the PUSCH503transmissions may coincide in a slot (e.g., at least in part). The UCI509may comprise at least one of a CSI, an Acknowledgement (ACK)/Negative Acknowledgement (NACK), and/or a scheduling request. The DCI517via the PDCCH515may indicate at least one of following: one or more downlink assignments and/or one or more uplink scheduling grants. In uplink, a wireless device may send (e.g., transmit) one or more Reference Signals (RSs) to a base station. The one or more RSs may comprise at least one of a Demodulation-RS (DM-RS) 506, a Phase Tracking-RS (PT-RS)507, and/or a Sounding RS (SRS)508. In downlink, a base station may send (e.g., transmit, unicast, multicast, and/or broadcast) one or more RSs to a wireless device. The one or more RSs may comprise at least one of a Primary Synchronization Signal (PSS)/Secondary Synchronization Signal (SSS)521, a CSI-RS522, a DM-RS523, and/or a PT-RS524. In a time domain, an SS/PBCH block may comprise one or more OFDM symbols (e.g., 4 OFDM symbols numbered in increasing order from 0 to 3) within the SS/PBCH block. An SS/PBCH block may comprise the PSS/SSS521and/or the PBCH516. In the frequency domain, an SS/PBCH block may comprise one or more contiguous subcarriers (e.g., 240 contiguous subcarriers with the subcarriers numbered in increasing order from 0 to 239) within the SS/PBCH block. The PSS/SSS521may occupy, for example, 1 OFDM symbol and 127 subcarriers. The PBCH516may span across, for example, 3 OFDM symbols and 240 subcarriers. A wireless device may assume that one or more SS/PBCH blocks transmitted with a same block index may be quasi co-located, for example, with respect to Doppler spread, Doppler shift, average gain, average delay, and/or spatial Rx parameters. A wireless device may not assume quasi co-location for other SS/PBCH block transmissions. A periodicity of an SS/PBCH block may be configured by a radio network (e.g., by an RRC signaling). One or more time locations in which the SS/PBCH block may be sent may be determined by sub-carrier spacing. A wireless device may assume a band-specific sub-carrier spacing for an SS/PBCH block, for example, unless a radio network has configured the wireless device to assume a different sub-carrier spacing. The downlink CSI-RS522may be used for a wireless device to acquire channel state information. A radio network may support periodic, aperiodic, and/or semi-persistent transmission of the downlink CSI-RS522. A base station may semi-statically configure and/or reconfigure a wireless device with periodic transmission of the downlink CSI-RS522. A configured CSI-RS resources may be activated and/or deactivated. For semi-persistent transmission, an activation and/or deactivation of a CSI-RS resource may be triggered dynamically. A CSI-RS configuration may comprise one or more parameters indicating at least a number of antenna ports. A base station may configure a wireless device with 32 ports, or any other number of ports. A base station may semi-statically configure a wireless device with one or more CSI-RS resource sets. One or more CSI-RS resources may be allocated from one or more CSI-RS resource sets to one or more wireless devices. A base station may semi-statically configure one or more parameters indicating CSI RS resource mapping, for example, time-domain location of one or more CSI-RS resources, a bandwidth of a CSI-RS resource, and/or a periodicity. A wireless device may be configured to use the same OFDM symbols for the downlink CSI-RS522and the Control Resource Set (CORESET), for example, if the downlink CSI-RS522and the CORESET are spatially quasi co-located and resource elements associated with the downlink CSI-RS522are the outside of PRBs configured for the CORESET. A wireless device may be configured to use the same OFDM symbols for downlink CSI-RS522and SSB/PBCH, for example, if the downlink CSI-RS522and SSB/PBCH are spatially quasi co-located and resource elements associated with the downlink CSI-RS522are outside of the PRBs configured for the SSB/PBCH. A wireless device may send (e.g., transmit) one or more downlink DM-RSs523to a base station for channel estimation, for example, for coherent demodulation of one or more downlink physical channels (e.g., PDSCH514). A radio network may support one or more variable and/or configurable DM-RS patterns for data demodulation. At least one downlink DM-RS configuration may support a front-loaded DM-RS pattern. A front-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1 or 2 adjacent OFDM symbols). A base station may semi-statically configure a wireless device with a maximum number of front-loaded DM-RS symbols for PDSCH514. A DM-RS configuration may support one or more DM-RS ports. A DM-RS configuration may support at least 8 orthogonal downlink DM-RS ports, for example, for single user-MIMO. ADM-RS configuration may support 12 orthogonal downlink DM-RS ports, for example, for multiuser-MIMO. A radio network may support, for example, at least for CP-OFDM, a common DM-RS structure for DL and UL, wherein a DM-RS location, DM-RS pattern, and/or scrambling sequence may be the same or different. Whether or not the downlink PT-RS524is present may depend on an RRC configuration. A presence of the downlink PT-RS524may be wireless device-specifically configured. A presence and/or a pattern of the downlink PT-RS524in a scheduled resource may be wireless device-specifically configured, for example, by a combination of RRC signaling and/or an association with one or more parameters used for other purposes (e.g., MCS) which may be indicated by the DCI. If configured, a dynamic presence of the downlink PT-RS524may be associated with one or more DCI parameters comprising at least MCS. A radio network may support a plurality of PT-RS densities in a time/frequency domain. If present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. A wireless device may assume the same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be less than a number of DM-RS ports in a scheduled resource. The downlink PT-RS524may be confined in the scheduled time/frequency duration for a wireless device. FIG.6shows an example transmission time and reception time, as well as an example frame structure, for a carrier. A multicarrier OFDM communication system may include one or more carriers, for example, ranging from 1 to 32 carriers (such as for carrier aggregation) or ranging from 1 to 64 carriers (such as for dual connectivity). Different radio frame structures may be supported (e.g., for FDD and/or for TDD duplex mechanisms).FIG.6shows an example frame timing. Downlink and uplink transmissions may be organized into radio frames601. Radio frame duration may be 10 milliseconds (ms). A 10 ms radio frame601may be divided into ten equally sized subframes602, each with a 1 ms duration. Subframe(s) may comprise one or more slots (e.g., slots603and605) depending on subcarrier spacing and/or CP length. For example, a subframe with 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz and 480 kHz subcarrier spacing may comprise one, two, four, eight, sixteen and thirty-two slots, respectively. InFIG.6, a subframe may be divided into two equally sized slots603with 0.5 ms duration. For example, 10 subframes may be available for downlink transmission and 10 subframes may be available for uplink transmissions in a 10 ms interval. Other subframe durations such as, for example, 0.5 ms, 1 ms, 2 ms, and 5 ms may be supported. Uplink and downlink transmissions may be separated in the frequency domain. Slot(s) may include a plurality of OFDM symbols604. The number of OFDM symbols604in a slot605may depend on the cyclic prefix length. A slot may be 14 OFDM symbols for the same subcarrier spacing of up to 480 kHz with normal CP. A slot may be 12 OFDM symbols for the same subcarrier spacing of 60 kHz with extended CP. A slot may comprise downlink, uplink, and/or a downlink part and an uplink part, and/or alike. FIG.7Ashows example sets of OFDM subcarriers. A base station may communicate with a wireless device using a carrier having an example channel bandwidth700. Arrow(s) in the example may depict a subcarrier in a multicarrier OFDM system. The OFDM system may use technology such as OFDM technology, SC-FDMA technology, and/or the like. An arrow701shows a subcarrier transmitting information symbols. A subcarrier spacing702, between two contiguous subcarriers in a carrier, may be any one of 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, or any other frequency. Different subcarrier spacing may correspond to different transmission numerologies. A transmission numerology may comprise at least: a numerology index; a value of subcarrier spacing; and/or a type of cyclic prefix (CP). A base station may send (e.g., transmit) to and/or receive from a wireless device via a number of subcarriers703in a carrier. A bandwidth occupied by a number of subcarriers703(e.g., transmission bandwidth) may be smaller than the channel bandwidth700of a carrier, for example, due to guard bands704and705. Guard bands704and705may be used to reduce interference to and from one or more neighbor carriers. A number of subcarriers (e.g., transmission bandwidth) in a carrier may depend on the channel bandwidth of the carrier and/or the subcarrier spacing. A transmission bandwidth, for a carrier with a 20 MHz channel bandwidth and a 15 kHz subcarrier spacing, may be in number of 1024 subcarriers. A base station and a wireless device may communicate with multiple component carriers (CCs), for example, if configured with CA. Different component carriers may have different bandwidth and/or different subcarrier spacing, for example, if CA is supported. A base station may send (e.g., transmit) a first type of service to a wireless device via a first component carrier. The base station may send (e.g., transmit) a second type of service to the wireless device via a second component carrier. Different types of services may have different service requirements (e.g., data rate, latency, reliability), which may be suitable for transmission via different component carriers having different subcarrier spacing and/or different bandwidth. FIG.7Bshows examples of component carriers. A first component carrier may comprise a first number of subcarriers706having a first subcarrier spacing709. A second component carrier may comprise a second number of subcarriers707having a second subcarrier spacing710. A third component carrier may comprise a third number of subcarriers708having a third subcarrier spacing711. Carriers in a multicarrier OFDM communication system may be contiguous carriers, non-contiguous carriers, or a combination of both contiguous and non-contiguous carriers. FIG.8shows an example of OFDM radio resources. A carrier may have a transmission bandwidth801. A resource grid may be in a structure of frequency domain802and time domain803. A resource grid may comprise a first number of OFDM symbols in a subframe and a second number of resource blocks, starting from a common resource block indicated by higher-layer signaling (e.g., RRC signaling), for a transmission numerology and a carrier. In a resource grid, a resource element805may comprise a resource unit that may be identified by a subcarrier index and a symbol index. A subframe may comprise a first number of OFDM symbols807that may depend on a numerology associated with a carrier. A subframe may have 14 OFDM symbols for a carrier, for example, if a subcarrier spacing of a numerology of a carrier is 15 kHz. A subframe may have 28 OFDM symbols, for example, if a subcarrier spacing of a numerology is 30 kHz. A subframe may have 56 OFDM symbols, for example, if a subcarrier spacing of a numerology is 60 kHz. A subcarrier spacing of a numerology may comprise any other frequency. A second number of resource blocks comprised in a resource grid of a carrier may depend on a bandwidth and a numerology of the carrier. A resource block806may comprise 12 subcarriers. Multiple resource blocks may be grouped into a Resource Block Group (RBG)804. A size of a RBG may depend on at least one of: a RRC message indicating a RBG size configuration; a size of a carrier bandwidth; and/or a size of a bandwidth part of a carrier. A carrier may comprise multiple bandwidth parts. A first bandwidth part of a carrier may have a different frequency location and/or a different bandwidth from a second bandwidth part of the carrier. A base station may send (e.g., transmit), to a wireless device, a downlink control information comprising a downlink or uplink resource block assignment. A base station may send (e.g., transmit) to and/or receive from, a wireless device, data packets (e.g., transport blocks). The data packets may be scheduled on and transmitted via one or more resource blocks and one or more slots indicated by parameters in downlink control information and/or RRC message(s). A starting symbol relative to a first slot of the one or more slots may be indicated to the wireless device. A base station may send (e.g., transmit) to and/or receive from, a wireless device, data packets. The data packets may be scheduled for transmission on one or more RBGs and in one or more slots. A base station may send (e.g., transmit), to a wireless device, downlink control information comprising a downlink assignment. The base station may send (e.g., transmit) the DCI via one or more PDCCHs. The downlink assignment may comprise parameters indicating at least one of a modulation and coding format; resource allocation; and/or HARQ information related to the DL-SCH. The resource allocation may comprise parameters of resource block allocation; and/or slot allocation. A base station may allocate (e.g., dynamically) resources to a wireless device, for example, via a Cell-Radio Network Temporary Identifier (C-RNTI) on one or more PDCCHs. The wireless device may monitor the one or more PDCCHs, for example, in order to find possible allocation if its downlink reception is enabled. The wireless device may receive one or more downlink data packets on one or more PDSCH scheduled by the one or more PDCCHs, for example, if the wireless device successfully detects the one or more PDCCHs. A base station may allocate Configured Scheduling (CS) resources for down link transmission to a wireless device. The base station may send (e.g., transmit) one or more RRC messages indicating a periodicity of the CS grant. The base station may send (e.g., transmit) DCI via a PDCCH addressed to a Configured Scheduling-RNTI (CS-RNTI) activating the CS resources. The DCI may comprise parameters indicating that the downlink grant is a CS grant. The CS grant may be implicitly reused according to the periodicity defined by the one or more RRC messages. The CS grant may be implicitly reused, for example, until deactivated. A base station may send (e.g., transmit), to a wireless device via one or more PDCCHs, downlink control information comprising an uplink grant. The uplink grant may comprise parameters indicating at least one of a modulation and coding format; a resource allocation; and/or HARQ information related to the UL-SCH. The resource allocation may comprise parameters of resource block allocation; and/or slot allocation. The base station may dynamically allocate resources to the wireless device via a C-RNTI on one or more PDCCHs. The wireless device may monitor the one or more PDCCHs, for example, in order to find possible resource allocation. The wireless device may send (e.g., transmit) one or more uplink data packets via one or more PUSCH scheduled by the one or more PDCCHs, for example, if the wireless device successfully detects the one or more PDCCHs. The base station may allocate CS resources for uplink data transmission to a wireless device. The base station may transmit one or more RRC messages indicating a periodicity of the CS grant. The base station may send (e.g., transmit) DCI via a PDCCH addressed to a CS-RNTI to activate the CS resources. The DCI may comprise parameters indicating that the uplink grant is a CS grant. The CS grant may be implicitly reused according to the periodicity defined by the one or more RRC message, The CS grant may be implicitly reused, for example, until deactivated. A base station may send (e.g., transmit) DCI and/or control signaling via a PDCCH. The DCI may comprise a format of a plurality of formats. The DCI may comprise downlink and/or uplink scheduling information (e.g., resource allocation information, HARQ related parameters, MCS), request(s) for CSI (e.g., aperiodic CQI reports), request(s) for an SRS, uplink power control commands for one or more cells, one or more timing information (e.g., TB transmission/reception timing, HARQ feedback timing, etc.), and/or the like. The DCI may indicate an uplink grant comprising transmission parameters for one or more transport blocks. The DCI may indicate a downlink assignment indicating parameters for receiving one or more transport blocks. The DCI may be used by the base station to initiate a contention-free random access at the wireless device. The base station may send (e.g., transmit) DCI comprising a slot format indicator (SFI) indicating a slot format. The base station may send (e.g., transmit) DCI comprising a preemption indication indicating the PRB(s) and/or OFDM symbol(s) in which a wireless device may assume no transmission is intended for the wireless device. The base station may send (e.g., transmit) DCI for group power control of the PUCCH, the PUSCH, and/or an SRS. DCI may correspond to an RNTI. The wireless device may obtain an RNTI after or in response to completing the initial access (e.g., C-RNTI). The base station may configure an RNTI for the wireless (e.g., CS-RNTI, TPC-CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, TPC-SRS-RNTI, etc.). The wireless device may determine (e.g., compute) an RNTI (e.g., the wireless device may determine the RA-RNTI based on resources used for transmission of a preamble). An RNTI may have a pre-configured value (e.g., P-RNTI or SI-RNTI). The wireless device may monitor a group common search space which may be used by the base station for sending (e.g., transmitting) DCIs that are intended for a group of wireless devices. A group common DCI may correspond to an RNTI which is commonly configured for a group of wireless devices. The wireless device may monitor a wireless device-specific search space. A wireless device specific DCI may correspond to an RNTI configured for the wireless device. A communications system (e.g., an NR system) may support a single beam operation and/or a multi-beam operation. In a multi-beam operation, a base station may perform a downlink beam sweeping to provide coverage for common control channels and/or downlink SS blocks, which may comprise at least a PSS, a SSS, and/or PBCH. A wireless device may measure quality of a beam pair link using one or more RSs. One or more SS blocks, or one or more CSI-RS resources (e.g., which may be associated with a CSI-RS resource index (CRI)), and/or one or more DM-RSs of a PBCH, may be used as an RS for measuring a quality of a beam pair link. The quality of a beam pair link may be based on a reference signal received power (RSRP) value, a reference signal received quality (RSRQ) value, and/or a CSI value measured on RS resources. The base station may indicate whether an RS resource, used for measuring a beam pair link quality, is quasi-co-located (QCLed) with DM-RSs of a control channel. An RS resource and DM-RSs of a control channel may be called QCLed, for example, if channel characteristics from a transmission on an RS to a wireless device, and that from a transmission on a control channel to a wireless device, are similar or the same under a configured criterion. In a multi-beam operation, a wireless device may perform an uplink beam sweeping to access a cell. A wireless device may be configured to monitor a PDCCH on one or more beam pair links simultaneously, for example, depending on a capability of the wireless device. This monitoring may increase robustness against beam pair link blocking. A base station may send (e.g., transmit) one or more messages to configure the wireless device to monitor the PDCCH on one or more beam pair links in different PDCCH OFDM symbols. A base station may send (e.g., transmit) higher layer signaling (e.g., RRC signaling) and/or a MAC CE comprising parameters related to the Rx beam setting of the wireless device for monitoring the PDCCH on one or more beam pair links. The base station may send (e.g., transmit) an indication of a spatial QCL assumption between an DL RS antenna port(s) (e.g., a cell-specific CSI-RS, a wireless device-specific CSI-RS, an SS block, and/or a PBCH with or without DM-RSs of the PBCH) and/or DL RS antenna port(s) for demodulation of a DL control channel. Signaling for beam indication for a PDCCH may comprise MAC CE signaling, RRC signaling, DCI signaling, and/or specification-transparent and/or implicit method, and/or any combination of signaling methods. A base station may indicate spatial QCL parameters between DL RS antenna port(s) and DM-RS antenna port(s) of a DL data channel, for example, for reception of a unicast DL data channel. The base station may send (e.g., transmit) DCI (e.g., downlink grants) comprising information indicating the RS antenna port(s). The information may indicate RS antenna port(s) that may be QCLed with the DM-RS antenna port(s). A different set of DM-RS antenna port(s) for a DL data channel may be indicated as QCL with a different set of the RS antenna port(s). FIG.9Ashows an example of beam sweeping in a DL channel. In an RRC_INACTIVE state or RRC_IDLE state, a wireless device may assume that SS blocks form an SS burst940, and an SS burst set950. The SS burst set950may have a given periodicity. A base station120may send (e.g., transmit) SS blocks in multiple beams, together forming a SS burst940, for example, in a multi-beam operation. One or more SS blocks may be sent (e.g., transmitted) on one beam. If multiple SS bursts940are transmitted with multiple beams, SS bursts together may form SS burst set950. A wireless device may use CSI-RS for estimating a beam quality of a link between a wireless device and a base station, for example, in the multi beam operation. A beam may be associated with a CSI-RS. A wireless device may (e.g., based on a RSRP measurement on CSI-RS) report a beam index, which may be indicated in a CRI for downlink beam selection and/or associated with an RSRP value of a beam. A CSI-RS may be sent (e.g., transmitted) on a CSI-RS resource, which may comprise at least one of: one or more antenna ports and/or one or more time and/or frequency radio resources. A CSI-RS resource may be configured in a cell-specific way such as by common RRC signaling, or in a wireless device-specific way such as by dedicated RRC signaling and/or L1/L2 signaling. Multiple wireless devices covered by a cell may measure a cell-specific CSI-RS resource. A dedicated subset of wireless devices covered by a cell may measure a wireless device-specific CSI-RS resource. A CSI-RS resource may be sent (e.g., transmitted) periodically, using aperiodic transmission, or using a multi-shot or semi-persistent transmission. In a periodic transmission inFIG.9A, a base station120may send (e.g., transmit) configured CSI-RS resources940periodically using a configured periodicity in a time domain. In an aperiodic transmission, a configured CSI-RS resource may be sent (e.g., transmitted) in a dedicated time slot. In a multi-shot and/or semi-persistent transmission, a configured CSI-RS resource may be sent (e.g., transmitted) within a configured period. Beams used for CSI-RS transmission may have a different beam width than beams used for SS-blocks transmission. FIG.9Bshows an example of a beam management procedure, such as in an example new radio network. The base station120and/or the wireless device110may perform a downlink L1/L2 beam management procedure. One or more of the following downlink L1/L2 beam management procedures may be performed within one or more wireless devices110and one or more base stations120. A P1 procedure910may be used to enable the wireless device110to measure one or more Transmission (Tx) beams associated with the base station120, for example, to support a selection of a first set of Tx beams associated with the base station120and a first set of Rx beam(s) associated with the wireless device110. A base station120may sweep a set of different Tx beams, for example, for beamforming at a base station120(such as shown in the top row, in a counter-clockwise direction). A wireless device110may sweep a set of different Rx beams, for example, for beamforming at a wireless device110(such as shown in the bottom row, in a clockwise direction). A P2 procedure920may be used to enable a wireless device110to measure one or more Tx beams associated with a base station120, for example, to possibly change a first set of Tx beams associated with a base station120. A P2 procedure920may be performed on a possibly smaller set of beams (e.g., for beam refinement) than in the P1 procedure910. A P2 procedure920may be a special example of a P1 procedure910. A P3 procedure930may be used to enable a wireless device110to measure at least one Tx beam associated with a base station120, for example, to change a first set of Rx beams associated with a wireless device110. A wireless device110may send (e.g., transmit) one or more beam management reports to a base station120. In one or more beam management reports, a wireless device110may indicate one or more beam pair quality parameters comprising one or more of: a beam identification; an RSRP; a Precoding Matrix Indicator (PMI), Channel Quality Indicator (CQI), and/or Rank Indicator (RI) of a subset of configured beams. Based on one or more beam management reports, the base station120may send (e.g., transmit) to a wireless device110a signal indicating that one or more beam pair links are one or more serving beams. The base station120may send (e.g., transmit) the PDCCH and the PDSCH for a wireless device110using one or more serving beams. A communications network (e.g., a new radio network) may support a Bandwidth Adaptation (BA). Receive and/or transmit bandwidths that may be configured for a wireless device using a BA may not be large. Receive and/or transmit bandwidth may not be as large as a bandwidth of a cell. Receive and/or transmit bandwidths may be adjustable. A wireless device may change receive and/or transmit bandwidths, for example, to reduce (e.g., shrink) the bandwidth(s) at (e.g., during) a period of low activity such as to save power. A wireless device may change a location of receive and/or transmit bandwidths in a frequency domain, for example, to increase scheduling flexibility. A wireless device may change a subcarrier spacing, for example, to allow different services. A Bandwidth Part (BWP) may comprise a subset of a total cell bandwidth of a cell. A base station may configure a wireless device with one or more BWPs, for example, to achieve a BA. A base station may indicate, to a wireless device, which of the one or more (configured) BWPs is an active BWP. FIG.10shows an example of BWP configurations. BWPs may be configured as follows: BWP1 (1010and1050) with a width of 40 MHz and subcarrier spacing of 15 kHz; BWP2 (1020and1040) with a width of 10 MHz and subcarrier spacing of 15 kHz; BWP31030with a width of 20 MHz and subcarrier spacing of 60 kHz. Any number of BWP configurations may comprise any other width and subcarrier spacing combination. A wireless device, configured for operation in one or more BWPs of a cell, may be configured by one or more higher layers (e.g., RRC layer). The wireless device may be configured for a cell with: a set of one or more BWPs (e.g., at most four BWPs) for reception (e.g., a DL BWP set) in a DL bandwidth by at least one parameter DL-BWP; and a set of one or more BWPs (e.g., at most four BWPs) for transmissions (e.g., UL BWP set) in an UL bandwidth by at least one parameter UL-BWP. A base station may configure a wireless device with one or more UL and DL BWP pairs, for example, to enable BA on the PCell. To enable BA on SCells (e.g., for CA), a base station may configure a wireless device at least with one or more DL BWPs (e.g., there may be none in an UL). An initial active DL BWP may comprise at least one of a location and number of contiguous PRBs, a subcarrier spacing, or a cyclic prefix, for example, for a control resource set for at least one common search space. For operation on the PCell, one or more higher layer parameters may indicate at least one initial UL BWP for a random access procedure. If a wireless device is configured with a secondary carrier on a primary cell, the wireless device may be configured with an initial BWP for random access procedure on a secondary carrier. A wireless device may expect that a center frequency for a DL BWP may be same as a center frequency for a UL BWP, for example, for unpaired spectrum operation. A base statin may semi-statically configure a wireless device for a cell with one or more parameters, for example, for a DL BWP or an UL BWP in a set of one or more DL BWPs or one or more UL BWPs, respectively. The one or more parameters may indicate one or more of following: a subcarrier spacing; a cyclic prefix; a number of contiguous PRBs; an index in the set of one or more DL BWPs and/or one or more UL BWPs; a link between a DL BWP and an UL BWP from a set of configured DL BWPs and UL BWPs; DCI detection to a PDSCH reception timing; a PDSCH reception to a HARQ-ACK transmission timing value; DCI detection to a PUSCH transmission timing value; and/or an offset of a first PRB of a DL bandwidth or an UL bandwidth, respectively, relative to a first PRB of a bandwidth. For a DL BWP in a set of one or more DL BWPs on a PCell, a base station may configure a wireless device with one or more control resource sets for at least one type of common search space and/or one wireless device-specific search space. A base station may not configure a wireless device without a common search space on a PCell, or on a PSCell, in an active DL BWP. For an UL BWP in a set of one or more UL BWPs, a base station may configure a wireless device with one or more resource sets for one or more PUCCH transmissions. DCI may comprise a BWP indicator field. The BWP indicator field value may indicate an active DL BWP, from a configured DL BWP set, for one or more DL receptions. The BWP indicator field value may indicate an active UL BWP, from a configured UL BWP set, for one or more UL transmissions. For a PCell, a base station may semi-statically configure a wireless device with a default DL BWP among configured DL BWPs. If a wireless device is not provided a default DL BWP, a default BWP may be an initial active DL BWP. A base station may configure a wireless device with a timer value for a PCell. A wireless device may start a timer (e.g., a BWP inactivity timer), for example, if a wireless device detects DCI indicating an active DL BWP, other than a default DL BWP, for a paired spectrum operation, and/or if a wireless device detects DCI indicating an active DL BWP or UL BWP, other than a default DL BWP or UL BWP, for an unpaired spectrum operation. The wireless device may increment the timer by an interval of a first value (e.g., the first value may be 1 millisecond, 0.5 milliseconds, or any other time duration), for example, if the wireless device does not detect DCI at (e.g., during) the interval for a paired spectrum operation or for an unpaired spectrum operation. The timer may expire at a time that the timer is equal to the timer value. A wireless device may switch to the default DL BWP from an active DL BWP, for example, if the timer expires. A base station may semi-statically configure a wireless device with one or more BWPs. A wireless device may switch an active BWP from a first BWP to a second BWP, for example, after or in response to receiving DCI indicating the second BWP as an active BWP, and/or after or in response to an expiry of BWP inactivity timer (e.g., the second BWP may be a default BWP).FIG.10shows an example of three BWPs configured, BWP1 (1010and1050), BWP2 (1020and1040), and BWP3 (1030). BWP2 (1020and1040) may be a default BWP. BWP1 (1010) may be an initial active BWP. A wireless device may switch an active BWP from BWP11010to BWP21020, for example, after or in response to an expiry of the BWP inactivity timer. A wireless device may switch an active BWP from BWP21020to BWP31030, for example, after or in response to receiving DCI indicating BWP31030as an active BWP. Switching an active BWP from BWP31030to BWP21040and/or from BWP21040to BWP11050may be after or in response to receiving DCI indicating an active BWP, and/or after or in response to an expiry of BWP inactivity timer. Wireless device procedures on a secondary cell may be same as on a primary cell using the timer value for the secondary cell and the default DL BWP for the secondary cell, for example, if a wireless device is configured for a secondary cell with a default DL BWP among configured DL BWPs and a timer value. A wireless device may use an indicated DL BWP and an indicated UL BWP on a secondary cell as a respective first active DL BWP and first active UL BWP on a secondary cell or carrier, for example, if a base station configures a wireless device with a first active DL BWP and a first active UL BWP on a secondary cell or carrier. FIG.11AandFIG.11Bshow packet flows using a multi connectivity (e.g., dual connectivity, multi connectivity, tight interworking, and/or the like).FIG.11Ashows an example of a protocol structure of a wireless device110(e.g., UE) with CA and/or multi connectivity.FIG.11Bshows an example of a protocol structure of multiple base stations with CA and/or multi connectivity. The multiple base stations may comprise a master node, MN1130(e.g., a master node, a master base station, a master gNB, a master eNB, and/or the like) and a secondary node, SN1150(e.g., a secondary node, a secondary base station, a secondary gNB, a secondary eNB, and/or the like). A master node1130and a secondary node1150may co-work to communicate with a wireless device110. If multi connectivity is configured for a wireless device110, the wireless device110, which may support multiple reception and/or transmission functions in an RRC connected state, may be configured to utilize radio resources provided by multiple schedulers of a multiple base stations. Multiple base stations may be inter-connected via a non-ideal or ideal backhaul (e.g., Xn interface, X2 interface, and/or the like). A base station involved in multi connectivity for a certain wireless device may perform at least one of two different roles: a base station may act as a master base station or act as a secondary base station. In multi connectivity, a wireless device may be connected to one master base station and one or more secondary base stations. A master base station (e.g., the MN1130) may provide a master cell group (MCG) comprising a primary cell and/or one or more secondary cells for a wireless device (e.g., the wireless device110). A secondary base station (e.g., the SN1150) may provide a secondary cell group (SCG) comprising a primary secondary cell (PSCell) and/or one or more secondary cells for a wireless device (e.g., the wireless device110). In multi connectivity, a radio protocol architecture that a bearer uses may depend on how a bearer is setup. Three different types of bearer setup options may be supported: an MCG bearer, an SCG bearer, and/or a split bearer. A wireless device may receive and/or send (e.g., transmit) packets of an MCG bearer via one or more cells of the MCG. A wireless device may receive and/or send (e.g., transmit) packets of an SCG bearer via one or more cells of an SCG. Multi-connectivity may indicate having at least one bearer configured to use radio resources provided by the secondary base station. Multi-connectivity may or may not be configured and/or implemented. A wireless device (e.g., wireless device110) may send (e.g., transmit) and/or receive: packets of an MCG bearer via an SDAP layer (e.g., SDAP1110), a PDCP layer (e.g., NR PDCP1111), an RLC layer (e.g., MN RLC1114), and a MAC layer (e.g., MN MAC1118); packets of a split bearer via an SDAP layer (e.g., SDAP1110), a PDCP layer (e.g., NR PDCP1112), one of a master or secondary RLC layer (e.g., MN RLC1115, SN RLC1116), and one of a master or secondary MAC layer (e.g., MN MAC1118, SN MAC1119); and/or packets of an SCG bearer via an SDAP layer (e.g., SDAP1110), a PDCP layer (e.g., NR PDCP1113), an RLC layer (e.g., SN RLC1117), and a MAC layer (e.g., MN MAC1119). A master base station (e.g., MN1130) and/or a secondary base station (e.g., SN1150) may send (e.g., transmit) and/or receive: packets of an MCG bearer via a master or secondary node SDAP layer (e.g., SDAP1120, SDAP1140), a master or secondary node PDCP layer (e.g., NR PDCP1121, NR PDCP1142), a master node RLC layer (e.g., MN RLC1124, MN RLC1125), and a master node MAC layer (e.g., MN MAC1128); packets of an SCG bearer via a master or secondary node SDAP layer (e.g., SDAP1120, SDAP1140), a master or secondary node PDCP layer (e.g., NR PDCP1122, NR PDCP1143), a secondary node RLC layer (e.g., SN RLC1146, SN RLC1147), and a secondary node MAC layer (e.g., SN MAC1148); packets of a split bearer via a master or secondary node SDAP layer (e.g., SDAP1120, SDAP1140), a master or secondary node PDCP layer (e.g., NR PDCP1123, NR PDCP1141), a master or secondary node RLC layer (e.g., MN RLC1126, SN RLC1144, SN RLC1145, MN RLC1127), and a master or secondary node MAC layer (e.g., MN MAC1128, SN MAC1148). In multi connectivity, a wireless device may configure multiple MAC entities, such as one MAC entity (e.g., MN MAC1118) for a master base station, and other MAC entities (e.g., SN MAC1119) for a secondary base station. In multi-connectivity, a configured set of serving cells for a wireless device may comprise two subsets: an MCG comprising serving cells of a master base station, and SCGs comprising serving cells of a secondary base station. For an SCG, one or more of following configurations may be used. At least one cell of an SCG may have a configured UL CC and at least one cell of a SCG, named as primary secondary cell (e.g., PSCell, PCell of SCG, PCell), and may be configured with PUCCH resources. If an SCG is configured, there may be at least one SCG bearer or one split bearer. After or upon detection of a physical layer problem or a random access problem on a PSCell, or a number of NR RLC retransmissions has been reached associated with the SCG, or after or upon detection of an access problem on a PSCell associated with (e.g., during) a SCG addition or an SCG change: an RRC connection re-establishment procedure may not be triggered, UL transmissions towards cells of an SCG may be stopped, a master base station may be informed by a wireless device of a SCG failure type, a DL data transfer over a master base station may be maintained (e.g., for a split bearer). An NR RLC acknowledged mode (AM) bearer may be configured for a split bearer. A PCell and/or a PSCell may not be de-activated. A PSCell may be changed with a SCG change procedure (e.g., with security key change and a RACH procedure). A bearer type change between a split bearer and a SCG bearer, and/or simultaneous configuration of a SCG and a split bearer, may or may not be supported. With respect to interactions between a master base station and a secondary base stations for multi-connectivity, one or more of the following may be used. A master base station and/or a secondary base station may maintain RRM measurement configurations of a wireless device. A master base station may determine (e.g., based on received measurement reports, traffic conditions, and/or bearer types) to request a secondary base station to provide additional resources (e.g., serving cells) for a wireless device. After or upon receiving a request from a master base station, a secondary base station may create and/or modify a container that may result in a configuration of additional serving cells for a wireless device (or decide that the secondary base station has no resource available to do so). For a wireless device capability coordination, a master base station may provide (e.g., all or a part of) an AS configuration and wireless device capabilities to a secondary base station. A master base station and a secondary base station may exchange information about a wireless device configuration such as by using RRC containers (e.g., inter-node messages) carried via Xn messages. A secondary base station may initiate a reconfiguration of the secondary base station existing serving cells (e.g., PUCCH towards the secondary base station). A secondary base station may decide which cell is a PSCell within a SCG. A master base station may or may not change content of RRC configurations provided by a secondary base station. A master base station may provide recent (and/or the latest) measurement results for SCG cell(s), for example, if an SCG addition and/or an SCG SCell addition occurs. A master base station and secondary base stations may receive information of SFN and/or subframe offset of each other from an OAM and/or via an Xn interface (e.g., for a purpose of DRX alignment and/or identification of a measurement gap). Dedicated RRC signaling may be used for sending required system information of a cell as for CA, for example, if adding a new SCG SCell, except for an SFN acquired from an MIB of a PSCell of a SCG. FIG.12shows an example of a random access procedure. One or more events may trigger a random access procedure. For example, one or more events may be at least one of following: initial access from RRC_IDLE, RRC connection re-establishment procedure, handover, DL or UL data arrival in (e.g., during) a state of RRC_CONNECTED (e.g., if UL synchronization status is non-synchronized), transition from RRC_Inactive, and/or request for other system information. A PDCCH order, a MAC entity, and/or a beam failure indication may initiate a random access procedure. A random access procedure may comprise or be one of at least a contention based random access procedure and/or a contention free random access procedure. A contention based random access procedure may comprise one or more Msg 11220transmissions, one or more Msg21230transmissions, one or more Msg31240transmissions, and contention resolution1250. A contention free random access procedure may comprise one or more Msg 11220transmissions and one or more Msg21230transmissions. One or more of Msg 11220, Msg 21230, Msg 31240, and/or contention resolution1250may be transmitted in the same step. A two-step random access procedure, for example, may comprise a first transmission (e.g., Msg A) and a second transmission (e.g., Msg B). The first transmission (e.g., Msg A) may comprise transmitting, by a wireless device (e.g., wireless device110) to a base station (e.g., base station120), one or more messages indicating an equivalent and/or similar contents of Msg11220and Msg31240of a four-step random access procedure. The second transmission (e.g., Msg B) may comprise transmitting, by the base station (e.g., base station120) to a wireless device (e.g., wireless device110) after or in response to the first message, one or more messages indicating an equivalent and/or similar content of Msg21230and contention resolution1250of a four-step random access procedure. A base station may send (e.g., transmit, unicast, multicast, broadcast, etc.), to a wireless device, a RACH configuration1210via one or more beams. The RACH configuration1210may comprise one or more parameters indicating at least one of following: an available set of PRACH resources for a transmission of a random access preamble, initial preamble power (e.g., random access preamble initial received target power), an RSRP threshold for a selection of a SS block and corresponding PRACH resource, a power-ramping factor (e.g., random access preamble power ramping step), a random access preamble index, a maximum number of preamble transmissions, preamble group A and group B, a threshold (e.g., message size) to determine the groups of random access preambles, a set of one or more random access preambles for a system information request and corresponding PRACH resource(s) (e.g., if any), a set of one or more random access preambles for a beam failure recovery (BFR) procedure and corresponding PRACH resource(s) (e.g., if any), a time window to monitor RA response(s), a time window to monitor response(s) on a BFR procedure, and/or a contention resolution timer. The Msg11220may comprise one or more transmissions of a random access preamble. For a contention based random access procedure, a wireless device may select an SS block with an RSRP above the RSRP threshold. If random access preambles group B exists, a wireless device may select one or more random access preambles from a group A or a group B, for example, depending on a potential Msg31240size. If a random access preambles group B does not exist, a wireless device may select the one or more random access preambles from a group A. A wireless device may select a random access preamble index randomly (e.g., with equal probability or a normal distribution) from one or more random access preambles associated with a selected group. If a base station semi-statically configures a wireless device with an association between random access preambles and SS blocks, the wireless device may select a random access preamble index randomly with equal probability from one or more random access preambles associated with a selected SS block and a selected group. A wireless device may initiate a contention free random access procedure, for example, based on a beam failure indication from a lower layer. A base station may semi-statically configure a wireless device with one or more contention free PRACH resources for a BFR procedure associated with at least one of SS blocks and/or CSI-RSs. A wireless device may select a random access preamble index corresponding to a selected SS block or a CSI-RS from a set of one or more random access preambles for a BFR procedure, for example, if at least one of the SS blocks with an RSRP above a first RSRP threshold amongst associated SS blocks is available, and/or if at least one of CSI-RSs with a RSRP above a second RSRP threshold amongst associated CSI-RSs is available. A wireless device may receive, from a base station, a random access preamble index via PDCCH or RRC for a contention free random access procedure. The wireless device may select a random access preamble index, for example, if a base station does not configure a wireless device with at least one contention free PRACH resource associated with SS blocks or CSI-RS. The wireless device may select the at least one SS block and/or select a random access preamble corresponding to the at least one SS block, for example, if a base station configures the wireless device with one or more contention free PRACH resources associated with SS blocks and/or if at least one SS block with a RSRP above a first RSRP threshold amongst associated SS blocks is available. The wireless device may select the at least one CSI-RS and/or select a random access preamble corresponding to the at least one CSI-RS, for example, if a base station configures a wireless device with one or more contention free PRACH resources associated with CSI-RSs and/or if at least one CSI-RS with a RSRP above a second RSPR threshold amongst the associated CSI-RSs is available. A wireless device may perform one or more Msg11220transmissions, for example, by sending (e.g., transmitting) the selected random access preamble. The wireless device may determine a PRACH occasion from one or more PRACH occasions corresponding to a selected SS block, for example, if the wireless device selects an SS block and is configured with an association between one or more PRACH occasions and/or one or more SS blocks. The wireless device may determine a PRACH occasion from one or more PRACH occasions corresponding to a selected CSI-RS, for example, if the wireless device selects a CSI-RS and is configured with an association between one or more PRACH occasions and one or more CSI-RSs. The wireless device may send (e.g., transmit), to a base station, a selected random access preamble via a selected PRACH occasions. The wireless device may determine a transmit power for a transmission of a selected random access preamble at least based on an initial preamble power and a power-ramping factor. The wireless device may determine an RA-RNTI associated with a selected PRACH occasion in which a selected random access preamble is sent (e.g., transmitted). The wireless device may not determine an RA-RNTI for a BFR procedure. The wireless device may determine an RA-RNTI at least based on an index of a first OFDM symbol, an index of a first slot of a selected PRACH occasions, and/or an uplink carrier index for a transmission of Msg11220. A wireless device may receive, from a base station, a random access response, Msg 21230. The wireless device may start a time window (e.g., ra-ResponseWindow) to monitor a random access response. For a BFR procedure, the base station may configure the wireless device with a different time window (e.g., bfr-ResponseWindow) to monitor response on a BFR procedure. The wireless device may start a time window (e.g., ra-ResponseWindow or bfr-ResponseWindow) at a start of a first PDCCH occasion, for example, after a fixed duration of one or more symbols from an end of a preamble transmission. If the wireless device sends (e.g., transmits) multiple preambles, the wireless device may start a time window at a start of a first PDCCH occasion after a fixed duration of one or more symbols from an end of a first preamble transmission. The wireless device may monitor a PDCCH of a cell for at least one random access response identified by a RA-RNTI, or for at least one response to a BFR procedure identified by a C-RNTI, at a time that a timer for a time window is running. A wireless device may determine that a reception of random access response is successful, for example, if at least one random access response comprises a random access preamble identifier corresponding to a random access preamble sent (e.g., transmitted) by the wireless device. The wireless device may determine that the contention free random access procedure is successfully completed, for example, if a reception of a random access response is successful. The wireless device may determine that a contention free random access procedure is successfully complete, for example, if a contention free random access procedure is triggered for a BFR procedure and if a PDCCH transmission is addressed to a C-RNTI. The wireless device may determine that the random access procedure is successfully completed, and may indicate a reception of an acknowledgement for a system information request to upper layers, for example, if at least one random access response comprises a random access preamble identifier. The wireless device may stop sending (e.g., transmitting) remaining preambles (if any) after or in response to a successful reception of a corresponding random access response, for example, if the wireless device has signaled multiple preamble transmissions. The wireless device may perform one or more Msg 31240transmissions, for example, after or in response to a successful reception of random access response (e.g., for a contention based random access procedure). The wireless device may adjust an uplink transmission timing, for example, based on a timing advanced command indicated by a random access response. The wireless device may send (e.g., transmit) one or more transport blocks, for example, based on an uplink grant indicated by a random access response. Subcarrier spacing for PUSCH transmission for Msg31240may be provided by at least one higher layer (e.g., RRC) parameter. The wireless device may send (e.g., transmit) a random access preamble via a PRACH, and Msg31240via PUSCH, on the same cell. A base station may indicate an UL BWP for a PUSCH transmission of Msg31240via system information block. The wireless device may use HARQ for a retransmission of Msg 31240. Multiple wireless devices may perform Msg 11220, for example, by sending (e.g., transmitting) the same preamble to a base station. The multiple wireless devices may receive, from the base station, the same random access response comprising an identity (e.g., TC-RNTI). Contention resolution (e.g., comprising the wireless device110receiving contention resolution1250) may be used to increase the likelihood that a wireless device does not incorrectly use an identity of another wireless device. The contention resolution1250may be based on, for example, a C-RNTI on a PDCCH, and/or a wireless device contention resolution identity on a DL-SCH. If a base station assigns a C-RNTI to a wireless device, the wireless device may perform contention resolution (e.g., comprising receiving contention resolution1250), for example, based on a reception of a PDCCH transmission that is addressed to the C-RNTI. The wireless device may determine that contention resolution is successful, and/or that a random access procedure is successfully completed, for example, after or in response to detecting a C-RNTI on a PDCCH. If a wireless device has no valid C-RNTI, a contention resolution may be addressed by using a TC-RNTI. If a MAC PDU is successfully decoded and a MAC PDU comprises a wireless device contention resolution identity MAC CE that matches or otherwise corresponds with the CCCH SDU sent (e.g., transmitted) in Msg31250, the wireless device may determine that the contention resolution (e.g., comprising contention resolution1250) is successful and/or the wireless device may determine that the random access procedure is successfully completed. FIG.13shows an example structure for MAC entities. A wireless device may be configured to operate in a multi-connectivity mode. A wireless device in RRC_CONNECTED with multiple Rx/Tx may be configured to utilize radio resources provided by multiple schedulers that may be located in a plurality of base stations. The plurality of base stations may be connected via a non-ideal or ideal backhaul over the Xn interface. A base station in a plurality of base stations may act as a master base station or as a secondary base station. A wireless device may be connected to and/or in communication with, for example, one master base station and one or more secondary base stations. A wireless device may be configured with multiple MAC entities, for example, one MAC entity for a master base station, and one or more other MAC entities for secondary base station(s). A configured set of serving cells for a wireless device may comprise two subsets: an MCG comprising serving cells of a master base station, and one or more SCGs comprising serving cells of a secondary base station(s).FIG.13shows an example structure for MAC entities in which a MCG and a SCG are configured for a wireless device. At least one cell in a SCG may have a configured UL CC. A cell of the at least one cell may comprise a PSCell or a PCell of a SCG, or a PCell. A PSCell may be configured with PUCCH resources. There may be at least one SCG bearer, or one split bearer, for a SCG that is configured. After or upon detection of a physical layer problem or a random access problem on a PSCell, after or upon reaching a number of RLC retransmissions associated with the SCG, and/or after or upon detection of an access problem on a PSCell associated with (e.g., during) a SCG addition or a SCG change: an RRC connection re-establishment procedure may not be triggered, UL transmissions towards cells of a SCG may be stopped, and/or a master base station may be informed by a wireless device of a SCG failure type and DL data transfer over a master base station may be maintained. A MAC sublayer may provide services such as data transfer and radio resource allocation to upper layers (e.g.,1310or1320). A MAC sublayer may comprise a plurality of MAC entities (e.g.,1350and1360). A MAC sublayer may provide data transfer services on logical channels. To accommodate different kinds of data transfer services, multiple types of logical channels may be defined. A logical channel may support transfer of a particular type of information. A logical channel type may be defined by what type of information (e.g., control or data) is transferred. BCCH, PCCH, CCCH and/or DCCH may be control channels, and DTCH may be a traffic channel. A first MAC entity (e.g.,1310) may provide services on PCCH, BCCH, CCCH, DCCH, DTCH, and/or MAC control elements. A second MAC entity (e.g.,1320) may provide services on BCCH, DCCH, DTCH, and/or MAC control elements. A MAC sublayer may expect from a physical layer (e.g.,1330or1340) services such as data transfer services, signaling of HARQ feedback, and/or signaling of scheduling request or measurements (e.g., CQI). In dual connectivity, two MAC entities may be configured for a wireless device: one for a MCG and one for a SCG. A MAC entity of a wireless device may handle a plurality of transport channels. A first MAC entity may handle first transport channels comprising a PCCH of a MCG, a first BCH of the MCG, one or more first DL-SCHs of the MCG, one or more first UL-SCHs of the MCG, and/or one or more first RACHs of the MCG. A second MAC entity may handle second transport channels comprising a second BCH of a SCG, one or more second DL-SCHs of the SCG, one or more second UL-SCHs of the SCG, and/or one or more second RACHs of the SCG. If a MAC entity is configured with one or more SCells, there may be multiple DL-SCHs, multiple UL-SCHs, and/or multiple RACHs per MAC entity. There may be one DL-SCH and/or one UL-SCH on an SpCell. There may be one DL-SCH, zero or one UL-SCH, and/or zero or one RACH for an SCell. A DL-SCH may support receptions using different numerologies and/or TTI duration within a MAC entity. A UL-SCH may support transmissions using different numerologies and/or TTI duration within the MAC entity. A MAC sublayer may support different functions. The MAC sublayer may control these functions with a control (e.g., Control1355and/or Control1365) element. Functions performed by a MAC entity may comprise one or more of: mapping between logical channels and transport channels (e.g., in uplink or downlink), multiplexing (e.g., (De-) Multiplexing1352and/or (De-) Multiplexing1362) of MAC SDUs from one or different logical channels onto transport blocks (TBs) to be delivered to the physical layer on transport channels (e.g., in uplink), demultiplexing (e.g., (De-) Multiplexing1352and/or (De-) Multiplexing1362) of MAC SDUs to one or different logical channels from transport blocks (TBs) delivered from the physical layer on transport channels (e.g., in downlink), scheduling information reporting (e.g., in uplink), error correction through HARQ in uplink and/or downlink (e.g.,1363), and logical channel prioritization in uplink (e.g., Logical Channel Prioritization1351and/or Logical Channel Prioritization1361). A MAC entity may handle a random access process (e.g., Random Access Control1354and/or Random Access Control1364). FIG.14shows an example of a RAN architecture comprising one or more base stations. A protocol stack (e.g., RRC, SDAP, PDCP, RLC, MAC, and/or PHY) may be supported at a node. A base station (e.g., gNB120A and/or120B) may comprise a base station central unit (CU) (e.g., gNB-CU1420A or1420B) and at least one base station distributed unit (DU) (e.g., gNB-DU1430A,1430B,1430C, and/or1430D), for example, if a functional split is configured. Upper protocol layers of a base station may be located in a base station CU, and lower layers of the base station may be located in the base station DUs. An F1 interface (e.g., CU-DU interface) connecting a base station CU and base station DUs may be an ideal or non-ideal backhaul. F1-C may provide a control plane connection over an F1 interface, and F1-U may provide a user plane connection over the F1 interface. An Xn interface may be configured between base station CUs. A base station CU may comprise an RRC function, an SDAP layer, and/or a PDCP layer. Base station DUs may comprise an RLC layer, a MAC layer, and/or a PHY layer. Various functional split options between a base station CU and base station DUs may be possible, for example, by locating different combinations of upper protocol layers (e.g., RAN functions) in a base station CU and different combinations of lower protocol layers (e.g., RAN functions) in base station DUs. A functional split may support flexibility to move protocol layers between a base station CU and base station DUs, for example, depending on service requirements and/or network environments. Functional split options may be configured per base station, per base station CU, per base station DU, per wireless device, per bearer, per slice, and/or with other granularities. In a per base station CU split, a base station CU may have a fixed split option, and base station DUs may be configured to match a split option of a base station CU. In a per base station DU split, a base station DU may be configured with a different split option, and a base station CU may provide different split options for different base station DUs. In a per wireless device split, a base station (e.g., a base station CU and at least one base station DUs) may provide different split options for different wireless devices. In a per bearer split, different split options may be utilized for different bearers. In a per slice splice, different split options may be used for different slices. FIG.15shows example RRC state transitions of a wireless device. A wireless device may be in at least one RRC state among an RRC connected state (e.g., RRC_Connected1530, RRC_Connected, etc.), an RRC idle state (e.g., RRC_Idle1510, RRC_Idle, etc.), and/or an RRC inactive state (e.g., RRC_Inactive1520, RRC_Inactive, etc.). In an RRC connected state, a wireless device may have at least one RRC connection with at least one base station (e.g., gNB and/or eNB), which may have a context of the wireless device (e.g., UE context). A wireless device context (e.g., UE context) may comprise at least one of an access stratum context, one or more radio link configuration parameters, bearer (e.g., data radio bearer (DRB), signaling radio bearer (SRB), logical channel, QoS flow, PDU session, and/or the like) configuration information, security information, PHY/MAC/RLC/PDCP/SDAP layer configuration information, and/or the like configuration information for a wireless device. In an RRC idle state, a wireless device may not have an RRC connection with a base station, and a context of the wireless device may not be stored in a base station. In an RRC inactive state, a wireless device may not have an RRC connection with a base station. A context of a wireless device may be stored in a base station, which may comprise an anchor base station (e.g., a last serving base station). A wireless device may transition an RRC state (e.g., UE RRC state) between an RRC idle state and an RRC connected state in both ways (e.g., connection release1540or connection establishment1550; and/or connection reestablishment) and/or between an RRC inactive state and an RRC connected state in both ways (e.g., connection inactivation1570or connection resume1580). A wireless device may transition its RRC state from an RRC inactive state to an RRC idle state (e.g., connection release1560). An anchor base station may be a base station that may keep a context of a wireless device (e.g., UE context) at least at (e.g., during) a time period that the wireless device stays in a RAN notification area (RNA) of an anchor base station, and/or at (e.g., during) a time period that the wireless device stays in an RRC inactive state. An anchor base station may comprise a base station that a wireless device in an RRC inactive state was most recently connected to in a latest RRC connected state, and/or a base station in which a wireless device most recently performed an RNA update procedure. An RNA may comprise one or more cells operated by one or more base stations. A base station may belong to one or more RNAs. A cell may belong to one or more RNAs. A wireless device may transition, in a base station, an RRC state (e.g., UE RRC state) from an RRC connected state to an RRC inactive state. The wireless device may receive RNA information from the base station. RNA information may comprise at least one of an RNA identifier, one or more cell identifiers of one or more cells of an RNA, a base station identifier, an IP address of the base station, an AS context identifier of the wireless device, a resume identifier, and/or the like. An anchor base station may broadcast a message (e.g., RAN paging message) to base stations of an RNA to reach to a wireless device in an RRC inactive state. The base stations receiving the message from the anchor base station may broadcast and/or multicast another message (e.g., paging message) to wireless devices in their coverage area, cell coverage area, and/or beam coverage area associated with the RNA via an air interface. A wireless device may perform an RNA update (RNAU) procedure, for example, if the wireless device is in an RRC inactive state and moves into a new RNA. The RNAU procedure may comprise a random access procedure by the wireless device and/or a context retrieve procedure (e.g., UE context retrieve). A context retrieve procedure may comprise: receiving, by a base station from a wireless device, a random access preamble; and requesting and/or receiving (e.g., fetching), by a base station, a context of the wireless device (e.g., UE context) from an old anchor base station. The requesting and/or receiving (e.g., fetching) may comprise: sending a retrieve context request message (e.g., UE context request message) comprising a resume identifier to the old anchor base station and receiving a retrieve context response message comprising the context of the wireless device from the old anchor base station. A wireless device in an RRC inactive state may select a cell to camp on based on at least a measurement result for one or more cells, a cell in which a wireless device may monitor an RNA paging message, and/or a core network paging message from a base station. A wireless device in an RRC inactive state may select a cell to perform a random access procedure to resume an RRC connection and/or to send (e.g., transmit) one or more packets to a base station (e.g., to a network). The wireless device may initiate a random access procedure to perform an RNA update procedure, for example, if a cell selected belongs to a different RNA from an RNA for the wireless device in an RRC inactive state. The wireless device may initiate a random access procedure to send (e.g., transmit) one or more packets to a base station of a cell that the wireless device selects, for example, if the wireless device is in an RRC inactive state and has one or more packets (e.g., in a buffer) to send (e.g., transmit) to a network. A random access procedure may be performed with two messages (e.g., 2-stage or 2-step random access) and/or four messages (e.g., 4-stage or 4-step random access) between the wireless device and the base station. A base station receiving one or more uplink packets from a wireless device in an RRC inactive state may request and/or receive (e.g., fetch) a context of a wireless device (e.g., UE context), for example, by sending (e.g., transmitting) a retrieve context request message for the wireless device to an anchor base station of the wireless device based on at least one of an AS context identifier, an RNA identifier, a base station identifier, a resume identifier, and/or a cell identifier received from the wireless device. A base station may send (e.g., transmit) a path switch request for a wireless device to a core network entity (e.g., AMF, MME, and/or the like), for example, after or in response to requesting and/or receiving (e.g., fetching) a context. A core network entity may update a downlink tunnel endpoint identifier for one or more bearers established for the wireless device between a user plane core network entity (e.g., UPF, S-GW, and/or the like) and a RAN node (e.g., the base station), such as by changing a downlink tunnel endpoint identifier from an address of the anchor base station to an address of the base station). A base station may communicate with a wireless device via a wireless network using one or more technologies, such as new radio technologies (e.g., NR, 5G, etc.). The one or more radio technologies may comprise at least one of: multiple technologies related to physical layer; multiple technologies related to medium access control layer; and/or multiple technologies related to radio resource control layer. Enhancing the one or more radio technologies may improve performance of a wireless network. System throughput, and/or data rate of transmission, may be increased. Battery consumption of a wireless device may be reduced. Latency of data transmission between a base station and a wireless device may be improved. Network coverage of a wireless network may be improved. Transmission efficiency of a wireless network may be improved. A base station, for example, a base station CU, may initiate PDCP duplication (e.g., PDCP packet duplication) for a bearer for a wireless device. The bearer may be an SRB and/or a DRB. A base station CU may, for example, initiate PDCP duplication for the bearer to increase a transmission reliability by creating a diversity gain of multiple packet transmission paths for packets (e.g., a first path for original packets and a second path for duplicated packets (e.g., duplicated versions of the original packets)). The bearer may, for example, be used for ultra-reliable low-latency communications (URLLC) services. If duplication is configured for a bearer via an RRC layer, an additional RLC entity and/or an additional logical channel may be configured for the radio bearer to handle duplicated PDCP PDUs. PDCP packet duplication may comprise sending the same PDCP PDUs at least twice: once by the original RLC entity and a second time by the additional RLC entity. By allowing two independent transmission paths, packet duplication may increase reliability and may reduce latency by reducing packet retransmission delays. PDCP duplication may be beneficial for a variety of services such as, for example, URLLC services. Original PDCP PDUs and corresponding duplicate PDCP PDUs may be sent (e.g., transmitted) on different carriers. Two different logical channels may belong to a same MAC entity (e.g., if CA is used) and/or to different MAC entities (e.g., if DC is used). If CA is used, logical channel mapping restrictions may be used by a MAC entity to avoid a logical channel carrying the original PDCP PDUs and a logical channel carrying the corresponding PDCP PDUs being sent on the same carrier. If PDCP packet duplication is configured and, for example, for uplink packet transmissions, packet duplication may be activated and/or de-activated per DRB (and/or SRB) by using a MAC control element (MAC CE). If CA is used, and if duplication is deactivated, logical channel mapping restrictions may be lifted. If DC is used, a wireless device (e.g., a UE) may apply MAC CE commands regardless of the origin(s) (e.g., a MCG and/or an SCG) of those MAC CEs. If one or more DRBs are configured with PDCP packet duplication, a network may, for example, activate and deactivate the PDCP packet duplication for the configured DRB(s). Uplink PDCP packet duplication for the configured DRB(s) may be activated and deactivated based on sending, to a wireless device, a duplication activation/deactivation MAC CE. A MAC entity processing the duplication activation/deactivation MAC CE may be for a DRB configured with duplication. If a duplication activation/deactivation MAC CE is received activating the PDCP duplication of the DRB, for example, the MAC entity may indicate the activation of PDCP packet duplication of the DRB to upper layers and/or may apply the allowedServingCells parameter(s) (e.g., received in one or more configuration messages) to the logical channels of the DRB. If a duplication activation/deactivation MAC CE is received deactivating PDCP packet duplication for the DRB, the MAC entity may indicate the deactivation of PDCP packet duplication of the DRB to upper layers and/or may refrain from applying the allowedServingCells parameter(s) to the logical channels of the DRB. FIG.16Ashows an example duplication activation/deactivation MAC CE. A duplication activation/deactivation MAC CE may have a fixed size. As shown inFIG.16A, a duplication activation/deactivation MAC CE may comprise a single octet containing eight D-fields. Di may indicate that the activation/deactivation status of PDCP packet duplication for DRB i, and i may be the ascending order of DRB IDs configured with packet duplication. The Di field may be set to one to indicate that PDCP packet duplication of DRB i may be activated. The Di field may be set to zero to indicate that PDCP packet duplication of DRB i may be deactivated. FIG.16Bshows example values for a Logical Channel IDentifier (LCID) field. A duplication activation/deactivation MAC CE may be part of a MAC PDU and may be indicated by a MAC PDU subheader with an LCID. The MAC subheader may comprise an LCID field identifying the logical channel instance of the corresponding MAC SDU, the type of the corresponding MAC CE, and/or padding for a DL-SCH. There may be one LCID field per MAC subheader. The LCID field size may be 6 bits. An LCID value for a subheader indicating a duplication activation/deactivation MAC CE may, for example, as shown inFIG.16B, be 111000. An L (Length) field of the subheader may indicate the length of the corresponding MAC SDU or variable-sized MAC CE in bytes. There may be one L field per MAC subheader except for subheaders corresponding to fixed-sized MAC CEs or padding. The size of the L field may be indicated by an F (Format) field indicating the size of the Length field. There may be one F field per MAC subheader except for subheaders corresponding to fixed-sized MAC CEs or padding. The size of the F field may be 1 bit. The value 0 may indicate 8 bits of the Length field. The value 1 may indicate 16 bits of the Length field. An R (Reserved bit) of the MAC subheader maybe set to zero. The MAC subheader may be octet aligned. If two UL General Packet Radio Service (GPRS) Tunneling Protocol (GTP) Tunnel Endpoint IEs are included in a UE CONTEXT SETUP REQUEST message for a DRB, a DU (e.g., a gNB-DU) may include two DL GTP Tunnel Endpoint IEs in a UE CONTEXT SETUP RESPONSE message. A CU (e.g., a gNB-CU) and/or a DU (e.g., gNB-DU) may use the UL GTP Tunnel Endpoint IEs and DL GTP Tunnel Endpoint IEs to support packet duplication for intra-DU (e.g., intra-gNB-DU) CA. A base station may, for example, if PDCP packet duplication is configured for a bearer of a wireless device, activate or deactivate PDCP packet duplication. The base station may, for example, activate packet duplication for the bearer based on: one or more radio conditions, status of one or more resources, and/or one or more configuration policies. If a radio quality for a wireless device decreases (e.g., below a predetermined level and/or based on one or more measurements), a base station may activate PDCP packet duplication (e.g., for uplink and/or downlink PDCP packets) of a bearer. PDCP packet duplication may be used, for example, for high reliability and/or low latency services. A base station may deactivate PDCP packet duplication for a bearer if, for example, resources of a network (e.g., of the base station and/or of the wireless device) are determined insufficient to support PDCP packet duplication. Functions of a base station may be separately performed by different network nodes. Functions of a base station may station may, for example, be performed by a base station CU and at least one base station DU. Functions of a base station CU may be further divided, for example, between a central unit user plane (CU-UP) node and central unit control plane (CU-CP) node. A CU-CP node may, for example, perform an RRC function. A CU-UP node may, for example, control upper layer user plane functions (e.g., one or more PDCP layer functions, and/or one or more SDAP layer functions). A DU may control lower layer functions (e.g., one or more physical layer functions, one or more MAC layer functions, and/or one or more RLC layer functions). A CU-UP node controlling a PDCP layer may perform duplication of at least downlink PDCP packets if PDCP packet duplication is activated for a bearer and/or for a wireless device. A CU-UP node may activate PDCP packet duplication without status information for other network nodes (e.g., for a DU, a CU-CP node, and/or a wireless device) that control operations that may be affected by, and/or that may have an effect on, PDCP packet duplication. Without such status information, a CU-UP node may activate and/or maintain PDCP packet duplication during periods when packet duplication is undesirable. If a DU is in a high traffic load state, for example, there may be insufficient resources to support packet duplication. Use of packet duplication under such circumstances may lead to call dropping and/or other losses of service. If radio link quality is sufficiently good, packet duplication may provide little or no advantage (e.g., there may be little or no packet loss on a single bearer), and using resources for unnecessary packet duplication may reduce resources available for allocation to communications to or from other devices. A CU-UP node without status information from other nodes may also or alternatively deactivate PDCP packet duplication during periods (e.g., if a DU is not in a high traffic load state and/or if radio link quality is not good) packet duplication may be desirable. Communication reliability and/or resource utilization efficiency may be adversely affected if status information is unavailable for determining packet duplication activation and/or deactivation. Without such information and/or signaling mechanisms facilitating coordination of operations (e.g., packet duplication activation/deactivation) among split base station nodes (e.g., a CU-CP node, a CU-UP node, and/or a DU) decreased reliability and inefficient resource utilization may increase call dropping rate, may increase packet transmission delay, and/or may otherwise impact services requiring high reliability and/or low latency. One or more of these problems may be avoided and/or reduced by improved PDCP packet duplication signaling. A CU-CP node may, for example, determine activation and/or deactivation of PDCP packet duplication based on radio channel quality and/or based on traffic load status of a DU and/or of a wireless device. Based on such a determination, the CU-CP node may send, to a CU-UP node, an activation/deactivation indication for PDCP packet duplication. The CU-UP node may activate and/or deactivate PDCP packet duplication based on the activation/deactivation indication received from CU-CP node, thereby facilitating activation and/or deactivation based on radio channel quality and/or traffic load status, and allowing increased resource utilization efficiency and/or increased packet transmission reliability. A CU-UP node may also or alternatively determine activation and/or deactivation of PDCP packet duplication. The CU-UP node may determine such activation and/or deactivation based on status information received, for example, from a CU-CP node. Determining activation and/or deactivation based on such status information may facilitate activation and/or deactivation based on radio channel quality and/or traffic load status, and may allow increased resource utilization efficiency and/or increased packet transmission reliability. A CU-UP node that determines activation and/or deactivation may also or alternatively inform the CU-CP node of such determination, thereby allowing, for example, more efficient allocation of resources. A DU may also or alternatively determine activation and/or deactivation of PDCP packet duplication. The DU may determine such activation and/or deactivation based on status information received, for example, from a CU-CP node and/or from a wireless device. Determining activation and/or deactivation based on such status information may facilitate activation and/or deactivation based on radio channel quality and/or traffic load status, and may allow increased resource utilization efficiency and/or increased packet transmission reliability. A DU that determines activation and/or deactivation may also or alternatively inform the CU-CP node of such determination, thereby allowing, for example more efficient allocation of resources. FIG.17shows example nodes (e.g., an example CU-CP node, an example CU-UP node, an example DU, and an example wireless device) that may be associated with PDCP packet duplication. InFIG.17and in various other figures WD is used as an abbreviation for wireless device (e.g., UE). A base station may comprise a CU-CP node1701, a CU-UP node1702, and/or one or more DUs1703. The DU1703may communicate with a wireless device1704(e.g., a UE). The CU-CP node1701and the CU-UP node1702may, for example, be nodes of a CU such as the gNB-CU1420A or the gNB-CU1420B ofFIG.14. The DU(s)1703may, for example, be one or more of the gNB-DUs1430A,1430B,1430C, or1430D ofFIG.14. The wireless device1704may be one of the wireless devices described in connection with other figures described herein. The CU-CP node1701may comprise upper layer control plane functions (e.g., RRC functions). The CU-UP node1702may comprise upper layer user plane functions (e.g., SDAP functions and/or PDCP functions). The DU1703may comprise lower layer functions (e.g., RLC functions, MAC functions, and/or PHY functions). PDCP packets (e.g., PDCP PDUs and/or PDCP SDUs) may be sent (e.g., transmitted) via an interface (e.g., an F1 user plane interface (and/or an interface between the CU-CP node1701and the DU1703)) between the CU-UP node1702(and/or the CU-CP node1701) and the DU1703. As shown inFIG.17with large-dash broken lines, DL PDCP duplicate packets may be generated and sent, with original PDCP packets, by the CU-UP node1702to the DU1703, which may forward those original and duplicate packets to the wireless device1704. DL original and duplicate PDCP packets may also or alternatively be generated and sent (e.g., transmitted) by the CU-CP node1701to the DU1703, which may forward such packets to the wireless device1704. The wireless device1704may also or alternatively generate original and duplicate UL PDCP packets and send those packets to the DU1703, which may forward those UL packets to the CU-UP node1702(and/or to the CU-CP node1701). The CU-CP node1701may send one or more messages to the CU-UP node1702to configure, activate, and/or deactivate PDCP packet duplication. The CU-CP node1701may, for example send one or more messages to configure PDCP packet duplication for a bearer (e.g., by indicating a bearer, a logical channel, a QoS flow, and/or a PDU session) for the wireless device1704. That bearer may comprise a packet flow to provide one or more URLLCs, one or more vehicle communications, one or more emergency services communications, one or more drone control communications, one or more remote control communications, and/or one or more other services for the wireless device1704. The bearer may comprise at least one of an SRB or a DRB. FIG.18shows an example initial context setup request message. A bearer (e.g., for which PDCP packet duplication is being configured) may comprise one or more packet flows of a PDU session for the wireless device1704. The PDU session may be configured based on a context setup request message from a core network entity (e.g., an AMF and/or a MME) for the wireless device. The context setup request message may be an initial context setup request message (e.g., as shown inFIG.18) and/or a wireless device (e.g., UE) context modification request message. The CU-UP node1702may send one or more response messages to the CU-CP node1701based on receiving one or more messages to configure, activate, and/or deactivate PDCP packet duplication. As shown inFIG.17with small-dash broken lines, and as further described below, information (e.g., status information) may be communicated by the wireless device1704to the DU1703and/or the CU-CP node1701, and/or from the DU1703to the CU-CP node1701. The wireless device1704may, for example, send one or more CSI reports and/or SRSs to the DU1703and/or send (e.g., via the DU1703) RRC UE status information to the CU-CP1701. The DU1703may, for example, send DU and/or lower layer wireless device (e.g., UE) status information to the CU-CP node1701. FIG.19shows an example method, for PDCP packet duplication configuration, activation, and/or deactivation, that may be performed by one or more of the CU-CP node1701, the CU-UP node1702, the DU1703, and/or the wireless devices1704, and/or by one or more other nodes. The CU-CP node1701may send (e.g., transmit), to the CU-UP node1702, one or more messages1901indicating a bearer configuration request for the wireless device1704. The bearer configuration request of the message(s)1901may be associated with at least a first bearer for which PDCP packet duplication is being configured. The first bearer may comprise a bearer configured for E-UTRAN and/or NG-RAN. The message(s)1901may comprise a bearer context setup request message (e.g., as shown inFIG.20), a bearer context modification request message, a bearer context modification confirm message, and/or other type(s) of message(s). The message(s)1901may comprise a PDCP configuration parameter indicating that PDCP packet duplication is configured for the first bearer. A PDCP-Config (e.g., an RRC information element (IE)) of the message(s)1901may, for example, comprise the PDCP configuration parameter. A pdcp-Duplication IE of a PDCP-Config IE (see, e.g., “>>>>PDCP Configuration” inFIG.20) may, for example, indicate ENUMERATED {true}, indicating that PDCP packet duplication is configured for the first bearer. The message(s)1901may, for example, comprise an information element explicitly indicating activation or deactivation of uplink and/or downlink PDCP packet duplication of the first bearer (e.g., the bearer for which PDCP packet duplication is being configured). Also or alternatively, uplink and/or downlink PDCP packet duplication may be implicitly activated or deactivated via the message(s)1901. Implicit activation may occur, for example, if the CU-UP node1702is configured to determine, based on receiving one or more messages1901indicating that PDCP packet duplication is configured, that PDCP packet duplication is initially activated for uplink and/or downlink based on that initial configuration. Implicit deactivation may occur, for example, if the CU-UP node1702is configured to determine, based on receiving the message(s)1901indicating that PDCP packet duplication is configured, that PDCP packet duplication is initially deactivated for uplink and/or downlink based on that configuration. The message(s)1901may, for example, comprise at least one of: a wireless device identifier (e.g., a gNB-CU-CP UE E1AP ID, a gNB-CU-UP UE E1AP ID, an IMEI, and/or a TMSI) of the wireless device1704, a bearer identifier of the first bearer (e.g., the bearer for which PDCP packet duplication is being configured), one or more bearer identifiers of one or more other bearers requested to be setup, modified, and/or removed, one or more identifiers of one or more PDU sessions, and/or one or more identifiers of one or more QoS flows requested to setup, modified, and/or removed. The message(s)1901may also or alternatively comprise, for example, one or more PDCP configuration information elements of the first bearer, QoS information (e.g., QCI, ARP, 5QI, session AMBR, and/or other information) of the first bearer and/or of other bearer(s), PDU session(s), and/or QoS flow(s) requested to be setup and/or modified, S1/NG uplink user plane transport layer information (e.g., a tunnel endpoint identifier, an IP address of an S-GW, and/or a UPF), and/or data forwarding information. The message(s)1901may also or alternatively comprise, for example, cell group information (e.g., an MCG and/or an SCG), a PDU session identifier of a PDU session associated with the first bearer, and/or one or more network slice identifiers (e.g., an NSSAI and/or a single-NSSAI (S-NSSAI)) of one or more network slices associated with the first bearer and/or with other bearer(s), with one or more PDU sessions, and/or with one or more QoS flows. The message(s)1901may also or alternatively comprise, for example, flow mapping information and/or other information. The message(s)1901may, for example, comprise a first logical channel identifier of a first logical channel for PDCP packets of the first bearer (e.g., the bearer for which PDCP packet duplication is being configured) and/or a second logical channel identifier of a second logical channel for duplicated PDCP packets of the first bearer. The message(s)1901may, for example, comprise a DL tunnel endpoint identifier (TEID) of a first tunnel for PDCP packets of the first bearer and/or a second DL TEID of a second tunnel for duplicated PDCP packets of the first bearer. The first DL TEID and/or the second DL TEID may comprise addresses (e.g., IP addresses) of a DU (e.g., of the DU1703). The CU-UP node1702may send (e.g., transmit) PDCP packets (e.g., original PDCP packets) of the first bearer to the first DL TEID, and/or may (e.g., if PDCP packet duplication is activated) send (e.g., transmit) duplicated PDCP packets (e.g., duplicated versions of the original packets) of the first bearer to the second DL TEID. The CU-CP node1701may receive the first DL TEID and/or the second DL TEID from the DU (e.g., the DU1703). The first DL TEID and/or the second DL TEID may also or alternatively be sent (e.g., transmitted), from the CU-CP node1701to the CU-UP node1702, via another message different from the message(s)1901. The first DL TEID and/or the second DL TEID may, for example, be sent via one or more messages1907(described below), one or more messages2103(FIG.21), one or more messages2107(FIG.21), one or more messages2205(FIG.22), and/or one or more messages2209(FIG.22). The CU-UP node1702may, for example, based on receiving the message(s)1901, configure a first packet flow (e.g., a tunnel, a logical channel, a bearer, a QoS flow, and/or a PDU session) for PDCP packets of the first bearer (e.g., the bearer for which PDCP packet duplication is being configured) and/or may configure a second packet flow (e.g., a tunnel, a logical channel, a bearer, a QoS flow, and/or a PDU session) for duplicated PDCP packets of the first bearer. The CU-UP node1702may, for example, based on receiving the message(s)1901, configure a first UL TEID of a first tunnel for PDCP packets (e.g., packets, PDCP PDUs and/or PDCP SDUs) of the first bearer and/or a second UL TEID of a second tunnel for duplicated PDCP packets (e.g., duplicated packets, PDCP PDUs, and/or PDCP SDUs) of the first bearer. The CU-UP node1702may, for example, based on the message(s)1901and/or on configuration performed based on the message(s)1901, send (e.g., transmit), to the CU-CP node1701, one or more messages1902indicating that the PDCP packet duplication of the first bearer has been set up (e.g., configured) by the CU-UP node1702. The message(s)1902may, for example, further indicate that a bearer configuration request (e.g., of the message(s)1901) for the wireless device1704is accepted (e.g., allowed and/or configured at the CU-UP node1702). The message(s)1902may comprise at least one of a bearer context setup response message, a bearer context modification response message, a bearer context modification required message, and/or other type of message. The message(s)1902may, for example, further comprise the first UL TEID of the first tunnel for PDCP packets of the first bearer and/or the second UL TEID of the second tunnel for duplicated PDCP packets of the first bearer for the wireless device. The DU1703may send (e.g., transmit) PDCP packets (e.g., original PDCP packets) of the first bearer to the first UL TEID, and/or may (e.g., if PDCP packet duplication is activated) send (e.g., transmit) duplicated PDCP packets of the first bearer to the second UL TEID. The DU1703may receive the first UL TEID and/or the second UL TEID from the CU-CP node1701. The first UL TEID and/or the second UL TEID may comprise addresses (e.g., IP addresses) of the CU-UP node1702. The first UL TEID and/or the second UL TEID, if present in the message(s)1902, may indicate that PDCP packet duplication for the first bearer is setup (e.g., configured) at the CU-UP node1702. The message(s)1902may, for example, comprise at least one of: the wireless device identifier (e.g., a gNB-CU-CP UE E1AP ID, a gNB-CU-UP UE E1AP ID, a IMEI, and/or a TMSI) of the wireless device1704, the first bearer identifier of the first bearer (e.g., the bearer for which PDCP packet duplication is being configured), one or more bearer identifiers of one or more bearers for which setup or modification failed or succeeded, one or more identifiers of one or more PDU sessions and/or one or more QoS flows for which setup or modification failed or succeeded, and/or one or more failure causes for bearer(s), PDU session(s), and/or QoS flows for which setup or modification failed. The message(s)1902may also or alternatively comprise, for example, PDCP configuration result information of the first bearer and/or QoS information (e.g., QCI, ARP, 5QI, session AMBR, and/or other information) of one or more bearers, one or more PDU sessions, and/or one or more QoS flows to be setup and/or modified. The message(s)1902may also or alternatively comprise, for example, S1/NG downlink user plane transport layer information (e.g., a tunnel endpoint identifier and/or an IP address of the CU-UP node1702), uplink user plane transport parameters comprising user plane transport layer information and/or cell group identifiers, data forwarding information, cell group information (e.g., MCG and/or SCG), the PDU session identifier of the PDU session associated with the first bearer, the network slice identifier (e.g., an NSSAI and/or an S-NSSAI) of the network slice associated with the first bearer, one or more network slice identifiers of one or more network slices associated with the one or more other bearers, flow mapping information, and/or other information. The CU-UP node1702may, for example, based on the CU-UP node1702status, determine to setup, modify, and/or fail one or more bearers, one or more PDU sessions, one or more QoS flows, and/or the PDCP duplication configuration of the first bearer requested by the CU-CP node1701. The status of the CP-UP node1702may, for example, comprise a network resource status, a processing resource status (e.g., CPU, RAM, bus, and/or other system capacity), an interface congestion status of NG, F1, and/or S1 interfaces, bearer priority information (e.g., a bearer QoS level and/or a network slice priority of the bearer), and/or other information. If, for example, the network resources of the CU-UP node1702are not sufficient to serve all requested elements (e.g., all bearers, PDU sessions, QoS flows, and/or PDCP duplication), the CU-UP node1702may determine to fail one or more of the requested elements and may indicate the determined failure to the CU-CP node1701via the message(s)1902. The CU-CP node1701may, for example, send (e.g., transmit) one or more messages1903indicating a bearer configuration request for the first bearer (e.g., the bearer for which PDCP packet duplication is being configured) of the wireless device. The CU-CP node1701may send (e.g., transmit) the message(s)1903to the DU1703based on receiving the message(s)1902from the CU-UP node1702. Alternatively, the CU-CP node1701may send (e.g., transmit) message(s), similar to the message(s)1903, to the DU1703before receiving messages, similar to the message(s)1902, from the CU-UP node1702. Also or alternatively, the CU-CP node1701may send (e.g., transmit) messages, similar to the message(s)1902, to the DU1703before sending (e.g., transmitting) messages, similar to the message(s)1901, to the CU-UP node1702. The messages1903, and/or other bearer configuration requests sent from the CU-CP node1701to the DU1703, may indicate that PDCP packet duplication is configured for the first bearer of the wireless device. The message(s)1903may comprise the first UL TEID of the first tunnel for PDCP packets of the first bearer and/or the second UL TEID of the second tunnel for duplicated PDCP packets of the first bearer for the wireless device. The first UL TEID and/or the second UL TEID may be received, by the CU-CP node1701, via the message(s)1902and/or via other message(s) from the CU-UP node1702. The DU1703may, for example, based on the first UL TEID and/or the second UL TEID for the first bearer, recognize that PDCP duplication is configured for the first bearer. The DU1703may, for example, based on the message(s)1903, send (e.g., transmit) PDCP packets (e.g., original PDCP packets) of the first bearer to the first UL TEID, and/or may (e.g., if packet duplication is activated) send (e.g., transmit) duplicated PDCP packets of the first bearer to the second UL TEID. The message(s)1903may, for example, comprise at least one of a wireless device (e.g., UE) context setup request message, a wireless device (e.g., UE) context modification request message, a wireless device (e.g., UE) context modification confirm message, and/or another type of message. Also or alternatively, the message(s)1903may comprise at least one of: a wireless device identifier (e.g., a gNB-CU-UE FLAP ID, a gNB-DU UE F1AP ID, an IMEI, and/or a TMSI) of the wireless device1704, an SpCell identifier, one or more candidate SpCell identifiers of one or more candidate SpCells, CU-to-DU RRC information, DRX cycle information, a resource coordination transfer container, and/or one or more SCell (secondary cell) identifiers of one or more SCells to be setup. Also or alternatively, the message(s)1903may comprise one or more bearer identifiers of one or more bearers (e.g., DRB, SRB) to be setup, modified, and/or removed, may comprise one or more identifiers of one or more PDU sessions and/or one or more QoS flows requested to be setup, modified, and/or removed, may comprise one or more QoS information of the one or more bearers to be setup and/or modified, and/or may comprise one or more tunnel information associated with the one or more bearers to be setup and/or modified. Also or alternatively, the message(s)1903may comprise one or more network slice identifiers (e.g., an NSSAI, and/or an S-NSSAI) of one or more network slices associated with the first bearer, with one or more other bearers (e.g., other bearers indicated in the message(s)1903for setup, modification, and/or removal), with one or more PDU sessions (e.g., other PDU sessions indicated in the fourth message(s)1903for setup, modification, and/or removal), and/or with one or more QoS flows (e.g., QoS flows indicated in the message(s)1903for setup, modification, and/or removal), may comprise RLC mode information of one or more bearers, may comprise uplink configuration information of one or more bearers, and/or may comprise other information. The DU1703may, for example, based on receiving the message(s)1903, configure a first packet flow (e.g., a tunnel, a logical channel, a bearer, a QoS flow, and/or a PDU session) for PDCP packets of the first bearer and/or may configure a second packet flow (e.g., a tunnel, a logical channel, a bearer, a QoS flow, and/or a PDU session) for duplicated PDCP packets of the first bearer. The DU1703may, for example, based on receiving the message(s)1903, configure a first DL TEID of a first tunnel for PDCP packets (e.g., packets, PDCP PDUs, and/or PDCP SDUs) of the first bearer and/or a second DL TEID of a second tunnel for duplicated PDCP packets (e.g., duplicated packets, PDCP PDUs, and/or PDCP SDUs) of the first bearer. The first DL TEID and/or the first UL TEID may, for example, be associated with the first tunnel for PDCP packets of the first bearer. The second DL TEID and/or the second UL TEID may, for example, be associated with the second tunnel for duplicated PDCP packets of the first bearer. The DU1703may, for example, based on the message(s)1903, send (e.g., transmit), to the CU-CP node1701, one or more message(s)1904indicating that the PDCP packet duplication of the first bearer (e.g., the bearer for which PDCP packet duplication is being configured) is set up (e.g., configured). The message(s)1904may, for example, further indicate that one or more requests of the message(s)1903(or other bearer configuration request for the wireless device) are accepted (e.g., allowed and/or configured at the DU1703). The message(s)1904may, for example, comprise at least one of a wireless device (e.g., UE) context setup response message, a wireless device (e.g., UE) context modification response message, a wireless device (e.g., UE) context modification required message, and/or another type of message. The message(s)1904may, for example, indicate that PDCP packet duplication for the first bearer is setup (e.g., configured) at the DU1703. The message(s)1904may, for example, comprise the first DL TEID of the first tunnel for PDCP packets of the first bearer and/or the second DL TEID of the second tunnel for duplicated PDCP packets of the first bearer for the wireless device. The CU-UP node1702may, for example, send (e.g., transmit) downlink PDCP packets (e.g., original PDCP packets) of the first bearer to the first DL TEID, and/or may (e.g., if PDCP packet duplication is activated) send (e.g., transmit) duplicated downlink PDCP packets of the first bearer to the second DL TEID. The first DL TEID and/or the second DL TEID may comprise addresses (e.g., IP addresses) of the DU1703. The first DL TEID and/or the second DL TEID may, for example, be sent (e.g., transmitted) from the DU1703to the CU-CP node1701via one or more other messages different from the message(s)1904. The first DL TEID and/or the second DL TEID being present in the message(s) may, for example, indicate that PDCP packet duplication for the first bearer is setup (e.g., configured) at the DU1703. Also or alternatively, the message(s)1904may comprise at least one of: the wireless device identifier (e.g., a gNB-CU UE F1AP ID, a gNB-DU UE F1AP ID, an IMEI, and/or a TMSI) of the wireless device1704, DU-to-CU RRC information, a resource coordination transfer container, and/or the bearer identifier of the first bearer (e.g., the bearer for which PDCP packet duplication is being configured). Also or alternatively, the message(s)1904may comprise one or more bearer identifiers of one or more other bearers (e.g., SRBs, DRBs) for which setup or modification failed or succeeded, one or more identifiers of one or more PDU sessions and/or of one or more QoS flows for which set or modification failed or succeeded, and/or one or more failure causes for one or more bearers, one or more PDU sessions, and/or the one or more QoS flows for which setup or modification failed. Also or alternatively, the message(s)1904may comprise QoS information (e.g., QCI, ARP, 5QI, session AMBR, and/or other information) of one or more bearers, or one or more PDU sessions, and/or of one or more QoS flows to be setup and/or modified, and/or may comprise downlink tunnel endpoint identifiers (e.g., IP addresses of the DU1703) of one or more tunnels associated with one or more bearers, one or more PDU sessions, and/or of one or more QoS flows to setup and/or modify. Also or alternatively, the message(s)1904may comprise cell group information (e.g., MCG and/or SCG), the PDU session identifier of the PDU session associated with the first bearer, the network slice identifier(s) (e.g., an NSSAI and/or an S-NSSAI) of the network slice associated with the first bearer and/or of one or more network slices associated with one or more other bearers, and/or flow mapping information. The DU1703may, for example, based on the DU1703status, determine to setup, modify, and/or fail one or more bearers, one or more PDU sessions, one or more QoS flows, and/or the PDCP duplication configuration of the first bearer requested by the CU-CP node1701. The status of the DU1703may, for example, comprise a network resource status, a radio resource status, a processing resource status (e.g., CPU, RAM, bus, and/or other system capacity), an interface congestion status of F1 and/or Uu interfaces, bearer priority information (e.g., a bearer QoS level and/or a network slice priority of the bearer), and/or other information. If, for example, the network resources of the DU1703are not sufficient to serve all requested elements (e.g., all bearers, PDU sessions, QoS flows, and/or PDCP duplication), the DU1703may determine to fail one or more of the requested elements and may indicate the determined failure to the CU-CP node1701via the message(s)1904. The CU-CP node1701may, for example, based on receiving the message(s)1902and/or the message(s)1904, send (e.g., transmit), to the wireless device1704, one or more messages1905. The message(s)1905may comprise an RRC message (e.g., an RRC connection reconfiguration message) comprising a PDCP configuration parameter indicating that PDCP packet duplication is configured for the first bearer. The CU-CP node1701may send (e.g., transmit) the message(s)1905to the DU1703via an F1 interface message (e.g., a DL RRC message transfer message and/or a wireless device (e.g., UE) context modification request message), and the DU1703may forward the message(s)1905to the wireless device1704. A PDCP-Config (e.g., an RRC IE) of the message(s)1905may comprise the PDCP configuration parameter. A pdcp-Duplication IE of the PDCP-Config IE may indicate ENUMERATED {true}, indicating that PDCP packet duplication is configured for the first bearer. The message(s)1905may further comprise a bearer identifier of the first bearer, a first logical channel identifier of a first logical channel for duplicated PDCP packets of the first bearer, a second logical channel identifier of a second logical channel for (original) PDCP packets of the first bearer, one or more first cell identifiers of one or more first cells for duplicated PDCP packets of the first bearer, one or more second cell identifiers of one or more second cells for (original) PDCP packets of the first bearer, and/or other information. The wireless device1704may, for example, based on the message(s)1905, send one or more messages1906. The message(s)1906may comprise an RRC message (e.g., an RRC connection reconfiguration complete message) indicating that the wireless device1704set up one or more configurations of the message(s)1905(e.g., the PDCP configuration parameter and/or PDCP duplication related configurations for the first bearer). The CU-CP node1701may receive the message(s)1906via the DU1703(e.g., via an F1 interface message, a UL RRC message transfer message, and/or a wireless device (e.g., UE) context modification required message). The DU1703may forward the message(s)1906from the wireless device1704to the CU-CP node1701. The CU-CP node1701may, for example, based on receiving the message(s)1906, send (e.g., transmit), to the DU1703, an RRC configuration confirmation message (e.g., wireless device (e.g., UE) context modification request message) indicating that RRC configurations for the wireless device1704(e.g., PDCP packet duplication configuration for the first bearer) are completed. The DU1703may (e.g., based on the RRC configuration confirmation message) send (e.g., transmit), to the wireless device1704, a MAC CE indicating activation and/or deactivation of (uplink) PDCP packet duplication for the first bearer. The CU-UP node1702may receive the first DL TEID and/or the second DL TEID from the CU-CP node1701via one or more messages such as, for example, the message(s)1901, the message(s)1907, the message(s)2103(FIG.21), the message(s)2107(FIG.21), the message(s)2205(FIG.22), and/or the message(s)2209(FIG.22). The CU-CP node1701may send (e.g., transmit) such one or more messages to the CU-UP node1702based on receiving information (e.g., via the message(s)1904and/or other message(s)) from the DU1703. The CU-CP may send (e.g., transmit) such one or more messages to the CU-UP1702before receiving information (e.g., via the message(s)1904and/or other message(s)) from the DU1703. Such one or more messages may comprise at least one of a bearer context setup request message, a bearer context modification request message, a bearer context modification confirm message, and/or another type of message. The CU-CP node1701may send one or more messages1907to the CU-UP node1702. The message(s)1907may activate PDCP packet duplication (e.g., if PDCP packet duplication was not explicitly or implicitly activated in connection with the message(s)1901and/or other message(s)) or may deactivate PDCP packet duplication (e.g., if PDCP packet duplication was explicitly or implicitly activated in connection with the message(s)1901and/or other message(s)). Also or alternatively, the CU-CP node1701may send one or more messages1908to the DU1703. The message(s)1908may similarly activate PDCP packet duplication (e.g., if PDCP packet duplication was not activated in connection with the message(s)1904and/or other message(s)) or may deactivate PDCP packet duplication (e.g., if PDCP packet duplication was activated in connection with the message(s)1904and/or other message(s)). The CU-UP node1702may send one or more messages1909to the CU-CP node1701. The message(s)1909may indicate that the CU-UP node1702has determined to activate PDCP packet duplication (e.g., if PDCP packet duplication was not explicitly or implicitly activated in connection with the message(s)1901and/or other message(s)) or may indicate that the CU-UP node1702has determined to deactivate PDCP packet duplication (e.g., if PDCP packet duplication was explicitly or implicitly activated in connection with the message(s)1901and/or other message(s)). The DU1703may send one or more messages1910to the CU-CP node1701and/or may send one or more messages1911to the wireless device1704. The message(s)1910and/or the message(s)1911may indicate that the DU1703has determined to activate PDCP packet duplication (e.g., if PDCP packet duplication was not explicitly or implicitly activated in connection with the message(s)1903and/or other message(s)) or may indicate that the DU1703has determined to deactivate PDCP packet duplication (e.g., if PDCP packet duplication was explicitly or implicitly activated in connection with the message(s)1903and/or other message(s)). FIG.21shows an example method, for PDCP packet duplication configuration, activation, and/or deactivation, that may be performed by one or more of the CU-CP node1701, the CU-UP node1702, the DU1703, and/or the wireless devices1704, and/or by one or more other nodes. The CU-CP node1701may send (e.g., transmit) one or more messages2101, to the DU1703, comprising a request for PDCP packet duplication configuration of a first bearer. The one or more messages2101may be similar to the message(s)1903ofFIG.19, and/or one or more actions performed based on the message(s)2101may be similar to one or more actions performed based on the message(s)1903. The DU1703may send, to the CU-CP node1701, one or more messages2102comprising the first DL TEID and the second DL TEID for PDCP packet duplication of the first bearer. The one or more messages2102may be similar to the message(s)1904ofFIG.19, and/or one or more actions performed based on the message(s)2102may be similar to one or more actions performed based on the message(s)1904. The CU-CP node1701may, for example, based on receiving the message(s)2102, send, to the CU-UP node1702, one or more messages2103(e.g., comprising the first DL TEID and the second DL TEID) indicating a request for PDCP packet duplication configuration for the first bearer. The one or more messages2103may be similar to the message(s)1901ofFIG.19, and/or one or more actions performed based on the message(s)2103may be similar to one or more actions performed based on the message(s)1901. The CU-UP node1702may, for example, based on the message(s)2103, send, to the CU-CP node1701, one or more messages2104comprising the first UL TEID and the second UP TEID for PDCP packet duplication of the first bearer. The one or more messages2104may be similar to the message(s)1902ofFIG.19, and/or one or more actions performed based on the message(s)2104may be similar to one or more actions performed based on the message(s)1902. The CU-CP node1701may, for example, based on the message(s)2104, send (e.g., transmit), to the DU1703, a message comprising the first UL TEID and the second UP TEID for PDCP packet duplication of the first bearer. The one or more messages2105may be similar to the message(s)1905ofFIG.19, and/or one or more actions performed based on the message(s)2105may be similar to one or more actions performed based on the message(s)1905. The one or more messages2106may be similar to the message(s)1906ofFIG.19, and/or one or more actions performed based on the message(s)2106may be similar to one or more actions performed based on the message(s)1906. The one or more messages2107may be similar to the message(s)1907ofFIG.19, and/or one or more actions performed based on the message(s)2107may be similar to one or more actions performed based on the message(s)1907. The one or more messages2108may be similar to the message(s)1908ofFIG.19, and/or one or more actions performed based on the message(s)2108may be similar to one or more actions performed based on the message(s)1908. The one or more messages2109may be similar to the message(s)1909ofFIG.19, and/or one or more actions performed based on the message(s)2109may be similar to one or more actions performed based on the message(s)1909. The one or more messages2110may be similar to the message(s)1910ofFIG.19, and/or one or more actions performed based on the message(s)2110may be similar to one or more actions performed based on the message(s)1910. The one or more messages2111may be similar to the message(s)1911ofFIG.19, and/or one or more actions performed based on the message(s)2111may be similar to one or more actions performed based on the message(s)1911. FIG.22shows an example method, for PDCP packet duplication configuration, activation, and/or deactivation, that may be performed by one or more of the CU-CP node1701, the CU-UP node1702, the DU1703, and/or the wireless devices1704, and/or by one or more other nodes. The one or more messages2201may be similar to the message(s)1901ofFIG.19, and/or one or more actions performed based on the message(s)2201may be similar to one or more actions performed based on the message(s)1901. The one or more messages2202may be similar to the message(s)1902ofFIG.19, and/or one or more actions performed based on the message(s)2202may be similar to one or more actions performed based on the message(s)1902. The one or more messages2203may be similar to the message(s)1903ofFIG.19, and/or one or more actions performed based on the message(s)2203may be similar to one or more actions performed based on the message(s)1903. The one or more messages2204may be similar to the message(s)1904ofFIG.19, and/or one or more actions performed based on the message(s)2204may be similar to one or more actions performed based on the message(s)1904. The one or more messages2207may be similar to the message(s)1905ofFIG.19, and/or one or more actions performed based on the message(s)2207may be similar to one or more actions performed based on the message(s)1905. The one or more messages2208may be similar to the message(s)1906ofFIG.19, and/or one or more actions performed based on the message(s)2208may be similar to one or more actions performed based on the message(s)1906. The one or more messages2209may be similar to the message(s)1907ofFIG.19, and/or one or more actions performed based on the message(s)2209may be similar to one or more actions performed based on the message(s)1907. The one or more messages2210may be similar to the message(s)1908ofFIG.19, and/or one or more actions performed based on the message(s)2210may be similar to one or more actions performed based on the message(s)1908. The one or more messages2211may be similar to the message(s)1909ofFIG.19, and/or one or more actions performed based on the message(s)2211may be similar to one or more actions performed based on the message(s)1909. The one or more messages2212may be similar to the message(s)1910ofFIG.19, and/or one or more actions performed based on the message(s)2212may be similar to one or more actions performed based on the message(s)1910. The one or more messages2213may be similar to the message(s)1911ofFIG.19, and/or one or more actions performed based on the message(s)2213may be similar to one or more actions performed based on the message(s)1911. The CU-CP node1701may, for example, based on receiving the message(s)2204, send one or more messages2205to the CU-UP node1702. The message(s)2204may, for example, indicate DL TEIDs for original packets and/or duplicate packets. Also or alternatively, the message(s)2204may indicate acceptance and/or rejection for bearer configurations (e.g., for PDCP packet duplication). The message(s)2205may, for example, indicate a bearer context modification request. The message(s)2205may, for example, comprise a bearer context modification request message, a bearer context modification confirm message, and/or other type(s) of message(s). The CU-CP node1701may forward, to the CU-UP node1702via the message(s)2205, one or more DL TEIDs received via the message(s)2204. The CU-CP node1701may, for example, depending on acceptance and/or rejection from the DU1703, update configurations (e.g., for PDCP packet duplication) via the message(s)2205. The CU-UP node1702may, for example, based on receiving the message(s)2205, apply and/or otherwise use DL TEIDs for downlink packet transmission for the bearer (e.g., for original and/or duplicate packets). The CU-UP node1702may update configurations based on the messages(s)2205. If, for example, the DU1703rejects PDCP duplication configuration or setup of the bearer, the CU-UP node1702may remove/delete/reset configurations request via the message(s)2201(e.g., PDCP duplication configuration or bearer setup of the bearer). The CU-UP node1702may, for example, based on receiving the message(s)2205, send one or more messages2206to the CU-CP node1701. The message(s)2206may, for example, indicate a bearer context modification request. The message(s)2206may, for example, comprise a bearer context modification request message, a bearer context modification confirm message, and/or other type(s) of message(s). The message(s)2206may indicate that the CU-UP node1702modified bearer configurations based on the message(s)2205. The message(s)2206may indicate acceptance or rejection of one or more (e.g., each of) configuration modifications communicated via the message(s)2205. The CU-CP node1701may, for example, based on receiving the message(s)2206, confirm that some or all network nodes (e.g., the CU-UP node1702and/or the DU1703) are configured to serve the wireless device1704. The CU-CP node1701may send one or more RRC connection reconfiguration messages2207, to the wireless device1704via the DU1703, to configure the wireless device1704based on network node configurations. The wireless device1704may, based on the message(s)2207, send one or more RRC connection reconfiguration complete messages2208to the CU-CP node1701via the DU1703. If modification of the CU-UP node1702occurs after RRC (re)configuration (e.g., via the message(s)1907inFIG.19), the CU-CP node1701may complete the bearer modification procedure (e.g., based on the RRC (re)configuration). FIG.23shows examples of communications (e.g., requests and/or reports of PDCP packet duplication activation and/or deactivation, status information) among the CU-CP node1701, the CU-UP node1702, the DU1703, and/or the wireless device1704.FIGS.24,25, and26show examples of PDCP packet activation and/or deactivation and/or of related communications. One or more communications shown inFIGS.23through26may be the same or similar as one or more communications shown in, and/or described in connection with, preceding figures, and/or may comprise, in whole or in part, one or more communications separate from communications shown in, and/or described in connection with, other figures. One or more communications shown in, and/or described in connection with, one or more ofFIG.17or21through26(and/or other figures) may be the same or similar as (and/or may be combined with and/or otherwise used in combination with) one or more other communications shown in, and/or described in connection with, one or more ofFIG.17or21through26(and/or other figures). As shown inFIG.23(e.g., message(s)2303) and inFIG.24(e.g., as message(s) causing activation2403, deactivation2402, and/or activation2401), the CU-CP node1701may send (e.g., transmit), to the CU-UP node1702, one or more messages indicating an activation and/or a deactivation of PDCP packet duplication of a bearer of the wireless device1704. The activation and/or the deactivation may be based on the PDCP packet duplication configuration of the CU-UP node1702(e.g., indicated one or more messages causing activation2401). The activation and/or the deactivation may be based on PDCP packet duplication configuration of the CU-CP node1701(indicated, e.g., via one or more messages causing activation2401) and/or of the DU1703(e.g., indicated via one or more messages2405). As shown inFIG.23,FIG.25, and/orFIG.26, the CU-UP node1702may determine to activate and/or deactivate PDCP packet duplication (e.g., UL PDCP packet duplication via UL tunnel endpoints1and2and/or DL PDCP packet duplication via DL tunnel endpoints1and2) for a bearer of the wireless device1704. The CU-UP node1702may make that determination, for example, based on status information (e.g., information2313) for the CU-UP node1702obtained by monitoring systems of the CU-UP node1702. Also or alternatively, the CU-UP node1702may determine to activate and/or deactivate PDCP packet duplication based on status information for the CU-CP node1701received from the CU-CP node1701(e.g., via one or more messages2301). Also or alternatively, the CU-UP node1702may determine to activate and/or deactivate PDCP packet duplication based on status information for the DU1703received from the CU-CP node1701(e.g., via message(s)2301). Status information for the DU1703in message(s)2301may comprise information from, and/or be otherwise based on, one or more messages2309received by the CU-CP node1701from the DU1703. Also or alternatively, the CU-UP node1702may determine to activate and/or deactivate PDCP packet duplication based on RRC wireless device (e.g., UE) status information received from the CU-CP node1701(e.g., via message(s)2301). RRC wireless device (e.g., UE) status information in message(s)2301may comprise information from, and/or be otherwise based on, one or more messages2308received by the CU-CP node1701from the wireless device1704via the DU1703. Also or alternatively, the CU-UP node1702may determine to activate and/or deactivate PDCP packet duplication based on lower layer wireless device (e.g., UE) status information received from the CU-CP node1701(e.g., via message(s)2301). Lower layer wireless device (e.g., UE) status information in message(s)2301may comprise information from, and/or be otherwise based on, one or more messages2310received by the CU-CP node1701from the wireless device1704via the DU1703. Also or alternatively, the CU-UP node1702may determine to activate and/or deactivate PDCP packet duplication based on other information. The CU-CP node1701may send, via the DU1703, one or more messages2606to the wireless device1704. The message(s)2606may be sent, for example, prior to or concurrently with activation and/or deactivation of PDCP packet duplication. The message(s)2606may be sent after activation and/or deactivation of PDCP packet duplication (e.g., by the CU-UP1702). The message(s)2606may comprise RRC reconfiguration message(s) indicating that PDCP packet duplication has been configured and/or may comprise one or more PDCP packet duplication configuration parameters. The CU-UP node1702may determine to activate uplink and/or downlink PDCP packet duplication for a bearer, if, for example, status information and/or other information indicates that corresponding resources are available to support PDCP packet duplication (e.g., if a resource utilization ratio is lower than a threshold value), and/or that radio signaling quality is sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication (e.g., if a radio quality is lower than a threshold value). The CU-UP node1702may determine to deactivate uplink and/or downlink PDCP packet duplication for a bearer, if, for example, status information and/or other information indicates that corresponding resources to support the PDCP duplication are or may be insufficient (e.g., if resource utilization ratio is higher than a threshold value), and/or that radio signaling quality is sufficiently good and/or reliable so as to indicate that benefit(s) from PDCP packet duplication may be minimal (e.g., if radio quality is higher than a threshold value). Status information may, for example, comprise one or more of: the status information for the CU-UP node1702, the status information for the CU-CP node1701, the status information for the DU1703, the RRC wireless device (e.g., UE) status information, and/or the lower layer wireless device (e.g., UE) status information. The CU-UP node1702may send (e.g., transmit), to the CU-CP node1701, one or more CU-UP configuration update messages (e.g., one or more messages2304and/or one more messages2601) indicating activation (e.g., activation2602and/or activation2604) of UL and/or DL PDCP packet duplication of a bearer. For example, the CU-UP node1702may send such one or more CU-UP configuration update messages based on and/or after determining activation of uplink and/or downlink PDCP packet duplication of a bearer. The CU-UP configuration update message may comprise at least one of a bearer context modification required message, a bearer context modification response message, a bearer context modification failure message, a bearer context setup response message, a bearer context setup failure message, a bearer context release complete message, a bearer context release request message, and/or another type of message. The CU-CP node1701may send (e.g., transmit), to the DU1703, one or more messages (e.g., one or more messages2305and/or one more messages2605) indicating the activation of UL and/or DL PDCP packet duplication of a bearer. The CU-CP node1701may send such one or more messages indicating the activation of UL and/or DL PDCP packet duplication based on, for example, in response to, receiving the CU-UP configuration update message(s). The one or more messages indicating the activation of UL and/or DL PDCP packet duplication (e.g., the message(s)2305and/or the message(s)2605) may comprise a wireless device (e.g., UE) context setup request message, a wireless device (e.g., UE) context modification request message, a wireless device (e.g., UE) context modification confirm message, and/or another type of message. For the activation of the UL PDCP packet duplication, the DU1703may send (e.g., transmit), to the wireless device1704, a MAC CE indicating activation of the UL PDCP packet duplication of the first bearer. The DU1703may send that MAC CE in one or more messages2311. The wireless device1704may send (e.g., transmit) UL duplicated PDCP packets (e.g., via a second logical channel) and original PDCP packets (e.g., via a first logical channel) to the CU-UP node1702via the DU1703. The wireless device1704may send UL duplicated PDCP packets and original PDCP packets to the CU-UP node1702based on, for example, in response to, receiving the MAC CE indicating activation of UL PDCP packet duplication. The UL original PDCP packets may be sent to a first UL TEID (e.g., the uplink tunnel endpoint1inFIG.25) and the UL duplicated PDCP packets may be sent to a second UL TEID (e.g., the uplink tunnel endpoint2inFIG.25). The wireless device1704may send (e.g., transmit) UL original PDCP packets via a group of cells and may send (e.g., transmit) the UL duplicated PDCP packets via a separate group of cells. If DL PDCP packet duplication is activated, the DU1703may forward DL duplicated PDCP packets (e.g., via the second logical channel) and original PDCP packets (e.g., via the first logical channel) from the CU-UP node1702to the wireless device1704. The DU1703may use a group of cells to send (e.g., transmit) DL original PDCP packets to the wireless device and a separate group of cells to send (e.g., transmit) DL duplicated PDCP packets to the wireless device. The CU-UP node1702may discard duplicated UL PDCP packets of the bearer received from the DU1703and/or the wireless device1704via the DU1703. The CU-UP node1702may discard duplicated UL PDCP packets of the bearer (e.g., received from the DU1703and/or the wireless device1704) based on, for example, in response to, determining activation of UL PDCP packet duplication of a bearer. That discarding may begin after indicating activation of PDCP packet duplication to the CU-CP node1701and/or after determining activation. The CU-UP node1702may send (e.g., transmit) original DL PDCP packets and duplicated DL PDCP packets of the bearer to the DU1703and/or to the wireless device1704via the DU1703. The CU-UP node1702may send original DL PDCP packets and duplicated DL PDCP packets of the bearer (e.g., to the DU1703and/or to the wireless device1704via the DU1703) based on, for example, in response to (and/or after) determining activation of DL PDCP packet duplication of a bearer. The CU-UP node1702may, for example, send original PDCP packets to a first DL TEID (e.g., the downlink tunnel endpoint1inFIG.25) and duplicated PDCP packets to a second DL TEID (e.g., the downlink tunnel endpoint2inFIG.25). The CU-UP node1702may send (e.g., transmit), to the CU-CP node1701, a CU-UP configuration update message (e.g., one or more of the messages2303and/or one or more of the messages2601) indicating the deactivation of UL and/or DL PDCP packet duplication of the bearer. The CU-UP node1702may send such a CU-UP configuration update message after determining deactivation of UL and/or DL PDCP packet duplication of a bearer (e.g., the deactivation2603). That CU-UP configuration update message indicating deactivation may be based on (e.g., in response to) determining deactivation UL and/or DL PDCP packet duplication and may comprise at least one of a bearer context modification required message, a bearer context modification response message, a bearer context modification failure message, a bearer context setup response message, a bearer context setup failure message, a bearer context release complete message, a bearer context release request message, and/or another type of message. The CU-CP node1701may send (e.g., transmit), to the DU1703, one or more messages2305(e.g., one or more wireless device (e.g., UE) context setup request messages, one or more wireless device (e.g., UE) context modification request messages, one or more wireless device (e.g., UE) context modification confirm messages, one or more wireless device (e.g., UE) context release command messages, and/or one or more other type messages) indicating the deactivation of the UL and/or DL PDCP packet duplication of the bearer. The CU-CP node1701may send message(s)2305based on, for example, in response to, receiving a CU-UP configuration update message indicating deactivation. For deactivation of UL PDCP packet duplication, the DU1703may send (e.g., transmit), to the wireless device1704, a MAC CE indicating deactivation of the UL PDCP packet duplication of the bearer. The wireless device1704may (e.g., based on, for example, in response to, receiving that MAC CE indicating deactivation of UL PDCP packet duplication) stop sending (e.g., transmitting) UL duplicated PDCP packets (e.g., via the second logical channel) or may stop sending (e.g., transmitting) original UL PDCP packets (e.g., via the first logical channel) to the DU1703(e.g., to the CU-UP node1702via the DU1703). UL original PDCP packets may be sent (e.g., transmitted) via one or more of serving cells of the wireless device1704. If DL PDCP packet duplication is deactivated, the DU1703may forward one of duplicated DL PDCP packets (e.g., via the second logical channel) or original DL PDCP packets (e.g., via the first logical channel) from the CU-UP node1702to the wireless device1704. The DU1703may use one or more of serving cells of the wireless device1704to send (e.g., transmit) original DL PDCP packets to the wireless device1704. The CU-UP node1702may process UL PDCP packets of the first bearer received from the DU1703and/or from the wireless device1704via the DU1703. That processing may occur after determining deactivation of UL PDCP packet duplication of the first bearer and/or after indicating deactivation to the CU-CP node1701. That processing may occur based on (for example, in response to) determining deactivation of UL PDCP packet duplication. If, for example, the CU-UP node1702is receiving duplicated PDCP packets, the CU-UP node1702may discard the duplicated PDCP packets. The CU-UP node1702may stop sending (e.g., transmitting) duplicated DL PDCP packets of the first bearer to the DU1703and/or to the wireless device1704via the DU1703. The CU-UP node1702may stop sending those duplicated DL PDCP packets after determining deactivation of DL PDCP packet duplication of the first bearer. The CU-UP node1702may stop sending those duplicated DL PDCP packets based on, for example, in response to, determining deactivation of DL PDCP packet duplication. The DL original PDCP packets may be sent (e.g., transmitted) via one of the first logical channel (e.g., via the first tunnel and the first TEID) or the second logical channel (e.g., via the second tunnel and the second TEID). As shown, for example, inFIG.23,FIG.24, andFIG.25, the CU-CP node1701may determine activation or deactivation of PDCP packet duplication for a bearer of the wireless device1704. The CU-CP node1701may determine such activation or deactivation based on at least one of status information2302for the CU-UP node1702received from the CU-UP node1702, status information2312for the CU-CP node1701obtained by monitoring systems of the CU-CP node1701, status information2309of the DU1703received from the DU1703, RRC wireless device (e.g., UE) status information2308received from the wireless device1704via one or more RRC messages (e.g., from the wireless device1704via the DU1703), lower layer wireless device (e.g., UE) status information2309received from the DU1703(e.g., from the wireless device1704via the DU1703), and/or other information. The lower layer wireless device (e.g., UE) status information2309may comprise and/or be based on the wireless device (e.g., UE) status information2310sent from the wireless device1704to the DU1703. The CU-CP node1701may determine to activate UL and/or DL PDCP packet duplication for a bearer, if, for example, status information and/or other information indicates that corresponding resources to support PDCP packet duplication are available (e.g., if a resource utilization ratio is lower than a threshold value) and/or that radio signaling quality is sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication (e.g., if a radio quality is lower than a threshold value). The CU-CP node1701may determine to deactivate UL and/or DL PDCP packet duplication for a bearer, if, for example, status information and/or other information indicates that corresponding resources to support PDCP packet duplication are or may be insufficient (e.g., if a resource utilization ratio is higher than a threshold value) and/or that radio signaling quality is sufficiently good and/or reliable so as to indicate that benefit(s) from PDCP packet duplication may be minimal (e.g., if radio quality is higher than a threshold value). Status information may comprise one or more of: the CU-UP status information2302, the CU-CP status information2312, the DU status information2309, the RRC wireless device (e.g., UE) status information2308, and/or the lower layer wireless device (e.g., UE) status information2309. The CU-CP node1701may send (e.g., transmit), to the CU-UP node1702, a CU-CP configuration update message indicating the activation of UL and/or DL PDCP packet duplication of the bearer. The CU-CP node1701may send that configuration update message after determining activation of UL and/or DL PDCP packet duplication of a bearer. The CU-CP node1701may send that configuration update message based on (e.g., in response to) determining activation of PDCP packet duplication of the bearer. The CU-CP configuration update message (e.g., one or more of the messages causing the activation2403or one or more of the messages causing the activation2401) may comprise at least one of a bearer context modification request message, a bearer context modification confirm message, a bearer context setup request message, a bearer context release command message, and/or another type of message. The CU-CP node1701may send one or more messages2404configuring the bearer for PDCP packet duplication. The CU-UP node1702may discard duplicated UL PDCP packets of the first bearer received from the DU1703and/or from the wireless device1704(e.g., via the DU1703). The CU-UP node1702may discard those duplicated UL PDCP packets after receiving the CU-CP configuration update message indicating the activation of the UL PDCP packet duplication of the bearer. The CU-UP node1702may discard those duplicated UL PDCP packets based on (e.g., in response to) receiving the CU-CP configuration update message indicating the activation of the UL PDCP packet duplication of the bearer. The duplicated UL PDCP packets may be sent (e.g., by the wireless device1704, and/or by the wireless device1704via the DU1703) to a second UL TEID (e.g., the uplink tunnel endpoint2) and original UL PDCP packets may be sent to a first UL TEID (e.g., the uplink tunnel endpoint1). The CU-UP node may send (e.g., transmit) original DL PDCP packets and duplicated DL PDCP packets of the bearer to the DU1703. The CU-UP node1702may send original DL PDCP packets and duplicated DL PDCP packets after receiving the CU-CP configuration update message indicating the activation of the DL PDCP packet duplication of the bearer. The CU-UP node1702may send original DL PDCP packets and duplicated DL PDCP packets based on (e.g., in response to) receiving the CU-CP configuration update message indicating the activation of the DL PDCP packet duplication. The CU-UP node may send the original DL PDCP packets to a first DL TEID (e.g., the downlink tunnel endpoint1) and duplicated PDCP packets to a second DL TEID (e.g., the downlink tunnel endpoint1), and/or to the wireless device1703via the DU1703. The CU-CP node1701may send (e.g., transmit), to the DU1703, a one or more CU-CP configuration update messages (e.g., one or more of the messages2305and or one or more of the messages2405). The one or more CU-CP configuration update messages sent to the DU1703may be sent after determining activation of UL and/or DL PDCP packet duplication of the bearer. The one or more CU-CP configuration update messages sent to the DU1703may be sent based on (e.g., in response to) determining UL and/or DL PDCP packet duplication, may comprise a wireless device (e.g., UE) context setup request message, a wireless device (e.g., UE) context modification request message, a wireless device (e.g., UE) context modification confirm message, and/or other type of message, and/or may indicate the activation of the UL and/or DL PDCP packet duplication of the bearer. For the activation of UL PDCP packet duplication, the DU1703may send (e.g., transmit), to the wireless device1704, a MAC CE indicating activation of UL PDCP packet duplication of the bearer. The wireless device1704may send (e.g., transmit) UL duplicated PDCP packets (e.g., via a second logical channel) and UL PDCP packets (e.g., via a first logical channel) to the DU1703and/or to the CU-UP node1702via the DU1703. The wireless device1704may send such UL duplicated PDCP packets and UL PDCP packets based on, for example, in response to, receiving the MAC CE indicating activation of UL PDCP packet duplication. The UL PDCP packets may be sent via a group of cells and the UL duplicated PDCP packets may be sent via a separate group of cells. If DL PDCP packet duplication is activated, the DU1703may forward DL duplicated PDCP packets (e.g., via the second logical channel) and DL original PDCP packets (e.g., via the first logical channel) from the CU-UP node1702to the wireless device1704. The DU1703may use a group of cells to send (e.g., transmit) DL original PDCP packets to the wireless device1704and a separate group of cells to send (e.g., transmit) DL duplicated PDCP packets to the wireless device1704. The CU-CP node1701may send (e.g., transmit), to the CU-UP node1702, a CU-CP configuration update message indicating the deactivation of UL and/or DL PDCP packet duplication of the bearer. The CU-CP node1701may send that configuration update message after determining deactivation of UL and/or DL PDCP packet duplication of a bearer. The CU-CP node1701may send that configuration update message based on (e.g., in response to) determining deactivation of PDCP packet duplication of the bearer. The CU-CP configuration update message (e.g., one or more of the messages causing the deactivation2402) may comprise at least one of a bearer context modification request message, a bearer context modification confirm message, a bearer context setup request message, a bearer context release command message, and/or another type of message. The CU-UP node1702may process UL PDCP packets of the bearer received from the DU1703and/or from the wireless device1704via the DU1703. The CU-UP node1702may process those UL PDCP packets after receiving a CU-CP configuration update message indicating the deactivation of UL PDCP packet duplication of the bearer. The CU-UP node1702may process those UL PDCP packets based on (e.g., in response to) receiving the CU-CP configuration update message indicating the deactivation of UL PDCP packet duplication. The CU-UP may, for example, if receiving duplicated PDCP packets, discard the duplicated PDCP packets. The CU-UP node1702may stop sending (e.g., transmitting) duplicated DL PDCP packets of the bearer to the DU1703and/or to the wireless device1704via the DU1703. The CU-UP node1702may stop sending the duplicated DL PDCP packets after receiving the CU-CP configuration update message indicating the deactivation of the DL PDCP packet duplication of the first bearer. The CU-UP node1702may stop sending the duplicated DL PDCP packets based on, for example, in response to receiving the CU-CP configuration update message indicating the deactivation of the DL PDCP packet duplication. The DL original PDCP packets may be transmitted via one of a first logical channel (e.g., via a first tunnel and/or a first TEID) or a second logical channel (e.g., via a second tunnel and/or a second TEID). The CU-CP node1701may send (e.g., transmit), to the DU1703, one or more CU-CP configuration update messages. Those one or more CU-CP configuration update messages (e.g., one or more of the message(s)2305and/or2405) may be sent after determining deactivation of UL and/or DL PDCP packet duplication of a bearer. Those one or more CU-CP configuration update messages (e.g., one or more of the message(s)2305and/or2405) may be sent based on (e.g., in response to) determining deactivation of PDCP packet duplication, comprise a wireless device (e.g., UE) context setup request message, a wireless device (e.g., UE) context modification request message, a wireless device (e.g., UE) context modification confirm message, a wireless device (e.g., UE) context release command message, and/or another type of message, and may indicate the deactivation of the UL and/or DL PDCP packet duplication of the bearer. For the deactivation of UL PDCP packet duplication, the DU1703may send (e.g., transmit), to the wireless device1704, a MAC CE indicating deactivation of the UL PDCP packet duplication of the bearer. The wireless device1704may stop sending (e.g., transmitting) UL duplicated PDCP packets (e.g., via the second logical channel or the first logical channel) to the DU1703and/or to the CU-UP node1702via the DU1703. The wireless device1704may stop sending UL duplicated PDCP packets based on (e.g., in response to) receiving the MAC CE indicating the deactivation of the UL PDCP packet duplication. Alternatively, the wireless device1704may stop sending the original UL PDCP packets to the DU1703and/or to the CU-UP node1702via the DU1703. The UL PDCP packets may be transmitted via one or more of serving cells of the wireless device1704. If DL PDCP packet duplication is deactivated, the DU1703may, for example, may forward one of duplicated DL PDCP packets (e.g., via the second logical channel) or original DL PDCP packets (e.g., via the first logical channel) from the CU-UP node1702to the wireless device1704. The DU1703may use one or more of serving cells of the wireless device1704to send (e.g., transmit) the original DL PDCP packets to the wireless device1704. The CU-CP node1701may send, via the DU1703, one or more messages2406to the wireless device1704. The message(s)2406may be sent, for example, prior to or concurrently with activation and/or deactivation of PDCP packet duplication. The message(s)2406may be sent after activation and/or deactivation of PDCP packet duplication (e.g., by the CU-CP1701). The message(s)2406may comprise RRC reconfiguration message(s) indicating that PDCP packet duplication has been configured and/or may comprise one or more PDCP packet duplication configuration parameters. As shown, for example, inFIG.23, the DU1703may determine activation and/or deactivation of PDCP packet duplication for a bearer of the wireless device1704. The DU1703may determine such activation and/or deactivation based on at least one of CU-UP status information2307received from the CU-CP node1701(which information may, e.g., comprise and/or be based on CU-UP status information2302sent by the CU-UP node1702to the CU-CP node1701), CU-CP status information2307received from the CU-CP node1701, DU status information2314obtained by monitoring systems of the DU1703, RRC wireless device (e.g., UE) status information received from the CU-CP node1701(e.g., from the wireless device1704via the DU1703and/or via one or more RRC messages), lower layer wireless device (e.g., UE) status information2310received from the wireless device, and/or other information. If, for example the CU-UP status information and/or the CU-CP status information2307, the DU status information2314, the RRC wireless device (e.g., UE) status information, the lower layer wireless device (e.g., UE) status information2310, and/or other information indicates that corresponding resources to support PDCP packet duplication are available (e.g., if a resource utilization ratio is lower than a threshold value) and/or that radio signaling quality is sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication (e.g., if radio quality is lower than a threshold value), the DU1703may determine to activate UL and/or DL PDCP packet duplication for a bearer. If, for example, at least one of the CU-UP status information and/or the CU-CP status information2307, the DU status information2314, the RRC wireless device (e.g., UE) status information, the lower layer wireless device (e.g., UE) status information2310, and/or other information indicates that corresponding resources to support PDCP packet duplication are or may be insufficient (e.g., if a resource utilization ratio is higher than a threshold value) and/or that radio signaling quality is sufficiently good and/or reliable so as to indicate that benefit(s) from PDCP duplication may be minimal (e.g., if radio quality is higher than a threshold value), the DU1703may determine to deactivate UL and/or DL PDCP packet duplication for the bearer. The DU1703may send (e.g., transmit), to the CU-CP node1701, one or more DU configuration update messages2306indicating activation of UL and/or DL PDCP packet duplication of the bearer. The DU1703may send the message(s)2306after determining activation of UL and/or DL PDCP packet duplication of the bearer. The DU1703may send the message(s)2306based on, for example, in response to, the determination to activate PDCP packet duplication. The DU configuration update message(s)2306may comprise at least one of a wireless device (e.g., UE) context setup response message, a wireless device (e.g., UE) context setup failure message, a wireless device (e.g., UE) context modification required message, a wireless device (e.g., UE) context modification response message, a wireless device (e.g., UE) context modification failure message, a wireless device (e.g., UE) context release request message, a wireless device (e.g., UE) context release complete message, and/or another type of message. The CU-CP node1701may send (e.g., transmit), to the CU-UP node11702, one or more messages (e.g., a bearer context modification request message, a bearer context modification confirm message, a bearer context setup request message, a bearer context release command message, and/or another type of message) indicating the activation of UL and/or DL PDCP packet duplication of the bearer. The CU-CP node1701may send one or more messages indicating the activation of UL and/or DL PDCP packet duplication of the bearer based on, for example, in response to, receiving the DU configuration update message(s)2306indicating the activation of UL and/or DL PDCP packet duplication of the bearer. The CU-UP node1702may discard duplicated UL PDCP packets of the bearer received from the DU1703and/or from the wireless device1704via the DU1703. The CU-UP node1702may discard those duplicated packets after receiving the message indicating the activation of UL PDCP packet duplication of the bearer. The CU-UP node1702may discard those duplicated packets based on, for example, in response to, receiving the message indicating the activation of UL PDCP packet duplication. The CU-UP node1702may send (e.g., transmit) original DL PDCP packets and duplicated DL PDCP packets of the bearer to the DU1703(e.g., send PDCP packets to a first DL TEID (e.g., the downlink tunnel endpoint1) and duplicated PDCP packets to a second DL TEID (e.g., the downlink tunnel endpoint2)) and/or to the wireless device1704via the DU1703. The CU-UP node1702may send original DL PDCP packets and duplicated DL PDCP packets after receiving the message indicating the activation of DL PDCP packet duplication of the bearer. The CU-UP node1702may send original DL PDCP packets and duplicated DL PDCP packets based on, for example, in response to, receiving the message indicating the activation of DL PDCP packet duplication. The DU1703may send (e.g., transmit), to the wireless device, a MAC CE (e.g., as shown at2311inFIG.23) indicating the activation of UL and/or DL PDCP packet duplication of the bearer. The DU1703may send that MAC CE after determining activation of UL and/or DL PDCP packet duplication of the bearer. The DU1703may send that MAC CE based on, for example, in response to, determining activation of UL and/or DL PDCP packet duplication. For activation of UL PDCP packet duplication, the DU1703may send (e.g., transmit), to the wireless device1704, a MAC CE indicating activation of UL PDCP packet duplication of the bearer. The wireless device1704may send (e.g., transmit) UL duplicated PDCP packets (e.g., via a second logical channel) and UL original PDCP packets (e.g., via a first logical channel) to the DU1703and/or to the CU-UP node1702via the DU1703. The wireless device1704may send such UL duplicated PDCP packets and UL original PDCP packets based on, for example, in response to, receiving the MAC CE indicating the activation of UL PDCP packet duplication. The UL original PDCP packets and the UL duplicated PDCP packets may respectively be sent (e.g., transmitted) via separate groups of cells. If DL PDCP packet duplication is activated, the DU1703may, for example, forward DL duplicated PDCP packets (e.g., via the second logical channel) and DL original PDCP packets (e.g., via the first logical channel) from the CU-UP node1702to the wireless device1704. The DU1703may use separate groups of cells to send DL original PDCP packets and DL duplicated PDCP packets to the wireless device1704. The DU1703may send (e.g., transmit), to the CU-CP node1701, a DU configuration update message2306indicating the deactivation of UL and/or DL PDCP packet duplication of the bearer. The DU1703may send that DU configuration update message2306indicating the deactivation after determining deactivation of UL and/or DL PDCP packet duplication of a bearer. The DU1703may send that DU configuration update message2306indicating the deactivation based on, for example, in response to, determining the deactivation of UL and/or DL PDCP packet duplication. The DU configuration update message2306indicating the deactivation may comprise at least one of: a wireless device (e.g., UE) context setup response message, a wireless device (e.g., UE) context setup failure message, a wireless device (e.g., UE) context modification required message, a wireless device (e.g., UE) context modification response message, a wireless device (e.g., UE) context modification failure message, a wireless device (e.g., UE) context release request message, a wireless device (e.g., UE) context release complete message, and/or another type of message. The CU-CP node1701may send (e.g., transmit), to the CU-UP node1702, one or more messages (e.g., a bearer context modification request message, a bearer context modification confirm message, a bearer context setup request message, a bearer context release command message, and/or another type of message) indicating the deactivation of the UL and/or DL PDCP packet duplication of the bearer. The CU-CP node1701may send such one or more messages indicating the deactivation of the UL and/or DL PDCP packet duplication of the bearer based on, for example, in response to, receiving the DU configuration update message indicating the deactivation of UL and/or DL PDCP packet duplication of the bearer. The CU-UP node1702may process UL PDCP packets of the bearer received from the DU1703and/or from the wireless device1704via the DU1703. The CU-UP node1702may process those UL PDCP packets after receiving the message indicating the deactivation of the UL PDCP packet duplication of the bearer. The CU-UP node1702may process those UL PDCP packets based on, for example, in response to, receiving the message indicating the deactivation of the UL PDCP packet duplication. If receiving duplicated PDCP packets, the CU-UP node1702may, for example, discard the duplicated PDCP packets. The CU-UP node1702may stop sending (e.g., transmitting) duplicated DL PDCP packets of the bearer to the DU1703and/or to the wireless device1704via the DU1703. The CU-UP node1702may stop sending those duplicated DL PDCP packets after receiving the message indicating the deactivation of DL PDCP packet duplication of the bearer. The CU-UP node1702may stop sending those duplicated DL PDCP packets based on, for example, in response to, receiving the message indicating the deactivation of DL PDCP packet duplication. The CU-UP node1702may send (e.g., transmit) DL original PDCP packets via one of the first logical channel (e.g., via a first tunnel and/or a first TEID) or the second logical channel (e.g., via a second tunnel and/or a second TEID). The DU1703may send (e.g., transmit), to the wireless device1704, a MAC CE (e.g., as shown at2311inFIG.23) indicating the deactivation of UL and/or DL PDCP packet duplication of the bearer. The DU1703may send that MAC CE after determining deactivation of UL and/or DL PDCP packet duplication of a bearer. The DU1703may send that MAC CE based on, for example, in response to, determining deactivation of UL and/or DL PDCP packet duplication. For deactivation of UL PDCP packet duplication, the DU1703may send (e.g., transmit), to the wireless device1704, a MAC CE indicating deactivation of UL PDCP packet duplication of the bearer. The wireless device1704may stop sending (e.g., transmitting) UL duplicated PDCP packets (e.g., via the second logical channel or the first logical channel) to the DU1703and/or to the CU-UP node1702via the DU1703. The wireless device1704may stop sending such UL duplicated PDCP packets based on, for example, in response to, receiving the MAC CE indicating the deactivation of UL PDCP packet duplication. Alternatively, the wireless device1704may stop sending the original UL PDCP packets to the DU1703and/or to the CU-UP node1702via the DU1703. The UL original PDCP packets may be sent (e.g., transmitted) via one or more of serving cells of the wireless device1704. If DL PDCP packet duplication is deactivated, the DU1703may, for example, forward one of duplicated DL PDCP packets (e.g., via the second logical channel) or original DL PDCP packets (e.g., via the first logical channel) from the CU-UP node1702to the wireless device1704. The DU1703may use one or more of serving cells of the wireless device1704to send (e.g., transmit) original DL PDCP packets to the wireless device1704. CU-UP status information (e.g., the status information2302and/or the status information2313obtained by monitoring the CU-UP node1702) may, for example, comprise at least one of: a hardware load indicator, an NG interface load indicator (e.g., a load indicator for an interface between the CU-UP node1702and a core network entity), an F1 interface load indicator (e.g., load information for an interface between the CU-UP node1702and the DU1703), a composite available capacity group, and/or a network slice overload indicator of the CU-UP node1702. CU-CP status information (e.g., the status information2312) may, for example, comprise at least one of: a hardware load indicator, an NG interface load indicator (e.g., a load indicator for an interface between the CU-CP node1701and a core network entity), an F1 interface load indicator (e.g., load information for an interface between the CU-CP node1701and the DU1703), a composite available capacity group, and/or a network slice overload indicator of the CU-CP node1701. DU status information (e.g., the status information2314) may, for example, comprise at least one of: a hardware load indicator, an F1 interface load indicator (e.g., load information for an interface between the CU-CP node1701or the CU-UP node1702and the DU1703), a radio resource status, a composite available capacity group, and/or a network slice overload indicator of the DU1703. DU status information may also or alternatively comprise UL radio signaling quality information of the wireless device1704(e.g., based on SRS, RSRQ, and/or RSRP). RRC wireless device (e.g., UE) status information may, for example, comprise at least one of: measurement results (e.g., RSRP and/or RSRQ of one or more serving cells), battery status information, a number of RLC retransmissions for UL transmission, UL transport block transmission failure rate, random access failure rate, configured resource (e.g., Type 1, grant free resource) access failure rate, UL PDCP delay information, and/or other information. Lower layer wireless device (e.g., UE) status information may, for example, comprise at least one of: a CQI report, information of RSRQ or RSRP of CSI-RS or SS, hybrid ARQ retransmission number information, buffer status report of one or more logical channels (e.g., associated with a bearer for which PDCP packet duplication is configured and/or activated), and/or other information. A hardware load indicator may, for example, indicate hardware load information (e.g., load or other status of a CPU, memory, and/or a bus, and/or information) of corresponding node and/or one or more associated cells. A hardware load indicator may comprise hardware load information for each network slice of the one or more slices served via the corresponding node and/or a cell. Hardware load information may, for example, indicate a hardware load level status. Hardware load information may, for example, indicate a low load status, a medium load status, a high load status, and/or an overload status. Hardware load information may, for example, comprise one or more network slice identifiers of one or more overloaded network slices. Hardware load information may, for example, indicate a hardware load share status of one or more associated cells and/or each network slice of one or more network slices. Hardware load information may, for example, indicate a hardware resource usage amount ratio (e.g., a hardware load share amount ratio) of one or more associated cells compared to a hardware resource usage amount of other cells and/or compared to a total hardware resource amount of a corresponding node. Hardware load information may, for example, indicate a hardware resource usage amount ratio (e.g., a hardware load share amount ratio) of each network slice of one or more network slices compared to a hardware resource usage amount of other network slices in a corresponding node and/or one or more associated cells. Hardware load information may, for example, indicate a hardware resource usage amount ratio (e.g., a hardware load share amount ratio) of each network slice of one or more network slices compared to a total hardware resource amount of a corresponding node and/or one or more associated cells. An NG interface load indicator may, for example, indicate a load of an interface between a corresponding node (e.g., the CU-CP node1701and/or the CU-UP node1702) and a core network entity. An NG interface load indicator may comprise an NG interface load information for each network slice of one or more network slices. NG interface load information may, for example, indicate an NG interface load level status of a corresponding node and/or of each network slice of one or more network slices. NG interface load information may, for example, indicate a low load status, a medium load status, a high load status, and/or an overload status. NG interface load information may, for example, comprise one or more network slice identifiers of one or more overloaded network slices of a corresponding node. NG interface load information may, for example, indicate an NG interface load share status of a corresponding node and/or each network slice of one or more network slices. NG interface load information may, for example, indicate an NG interface resource usage amount ratio (e.g., an NG interface load share amount ratio) of each network slice of one or more network slices compared to an NG interface resource usage amount of other network slices. NG interface load information may, for example, indicate an NG interface resource usage amount ratio (e.g., an NG interface load share amount ratio) of each network slice of one or more network slices compared to a total NG interface resource amount of a corresponding node. An F1 interface load indicator may, for example, indicate load information of an interface between a corresponding node (e.g., the CU-CP node1701and/or the CU-UP node1702) and the DU1703. An F1 interface load indicator may indicate F1 interface load information for one or more serving cells. An F1 interface load indicator may indicate F1 interface load information for each network slice of one or more network slices. F1 interface load information may, for example, indicate an F1 interface load level status of a corresponding node, and/or each network slice of one or more network slices. F1 interface load information may, for example, indicate a low load status, a medium load status, a high load status, and/or an overload status of a corresponding node, and/or each network slice of one or more network slices. F1 interface load information may, for example, comprise one or more network slice identifiers of one or more overloaded network slices. F1 interface load information may, for example, comprise one or more cell identifiers of one or more overloaded cells of the DU1703. F1 interface load information may, for example, indicate an F1 interface load share status of each network slice of one or more network slices. F1 interface load information may, for example, indicate an F1 interface resource usage amount ratio (e.g., an F1 interface load share amount ratio) of each network slice of one or more network slices compared to an F1 interface resource usage amount of other network slices. F1 interface load information may, for example, indicate an F1 interface resource usage amount ratio (e.g., an F1 interface load share amount ratio) of each network slice of one or more first network slices compared to a total F1 interface resource amount of a corresponding node and/or one or more serving cells. Radio resource status may, for example, comprise a physical layer resource block usage information for a downlink GBR, a downlink non-GBR, an uplink GBR, an uplink non-GBR, a total downlink, and/or a total uplink transmission associated with one or more serving cells and/or each network slice of one or more network slices. Radio resource status may, for example, comprise a physical layer resource block usage information for each network slice of one or more network slices. Physical layer resource block usage information may, for example, indicate a physical layer resource block usage level of one or more serving cells and/or each network slice of one or more network slices. Physical layer resource block usage information may, for example, indicate a low usage status, a medium usage status, a high usage status, and/or a full usage status of one or more serving cells and/or each network slice of one or more network slices. Physical layer resource block usage information may, for example, comprise one or more network slice identifiers of one or more overloaded network slices. Physical layer resource block usage information may, for example, indicate a physical layer resource block usage status of one or more serving cells and/or each network slice of one or more network slices. Physical layer resource block usage status may, for example, be associated with a downlink GBR, a downlink non-GBR, an uplink GBR, an uplink non-GBR, a total downlink, and/or a total uplink transmission of one or more serving cells and/or each network slice of one or more network slices. Physical layer resource block usage information may, for example, indicate a physical layer resource block usage amount ratio of each network slice of one or more network slices compared to a physical layer resource block usage amount of other network slices. Physical layer resource block usage information may, for example, indicate a physical layer resource block usage amount ratio of each network slice of one or more network slices compared to a total physical layer resource block amount. Physical layer resource block usage information may, for example, indicate a physical layer resource block usage amount ratio of each network slice of one or more network slices compared to a physical layer resource block amount allowed for each network slice. A composite available capacity group may, for example, comprise a cell capacity class value and/or a capacity value for a DL and/or an UL associated with a corresponding node, one or more service cells, and/or each network slice of one or more network slices. A cell capacity class value may, for example, indicate a value classifying a cell capacity of one or more serving cells with regards to other cells. A cell capacity class value may, for example, indicate a value classifying a capacity for each network slice of one or more network slices with regards to other cells and/or other network slices. The capacity value may indicate an amount of resources, for one or more serving cells and/or each network slice of one or more network slices, that are available relative to a total resource for corresponding node, one or more serving cells, and/or each network slice of one or more network slices. A network slice overload indicator may, for example, indicate whether each network slice of one or more network slices is overloaded. A network slice overload indicator may, for example, indicate a low load status, a medium load status, a high load status, and/or an overload status of each network slice of one or more network slices. FIG.27shows an example method that may, for example, be performed by a CU-CP node (e.g., the CU-CP node1701). Status information may be received in step2701. The status information may, for example, comprise status information from self-monitoring (e.g., the status information2312), status information (e.g., the status information2302) for a CU-UP node (e.g., the CU-UP node1702), status information (e.g., the status information2309) for a DU (e.g., the DU1703), RRC wireless device (e.g., UE) status information (e.g., the status information2309) received from a wireless device (e.g., the wireless device1704) via the DU, lower layer status information (e.g., the status information2309) received from the DU and/or from the wireless device (e.g., the status information2310), and/or other information. In step2702, a determination, regarding the availability of resources to support packet duplication, may be made. The determination may be based on one or more parts of the status information received in step2701and may comprise, for example, determining whether a resource utilization ratio satisfies (e.g., is lower than) a first threshold value. The first threshold value may be predetermined. The first threshold value for the method ofFIG.27may be the same as, or different from, the first threshold value for the method ofFIG.28, and/or may be the same as, or different from, the first threshold value for the method ofFIG.29. If it is determined in step2702that resources to support packet duplication are not available (e.g., if the utilization ratio does not satisfy (e.g., is not lower than) the first threshold value), step2706(described below) may be performed. If it is determined in step2702that resources to support packet duplication are available (e.g., if the utilization ratio satisfies (e.g., is lower than) the first threshold value), step2703may be performed. In step2703, a determination, of whether radio signaling quality is sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication, may be made. The determination may be based on one or more parts of the status information received in step2701and may comprise, for example, determining if a radio quality satisfies (e.g., is lower than) a second threshold value. The second threshold value may be predetermined. The second threshold value for the method ofFIG.27may be the same as, or different from, the second threshold value for the method ofFIG.28, and/or may be the same as, or different from, the second threshold value for the method ofFIG.29. If it is determined in step2703that radio signaling quality is not sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication (e.g., if the radio quality does not satisfy (e.g., is not lower than) the second threshold value), step2705may be performed. If it is determined in step2703that radio signaling quality is sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication (e.g., if the radio quality does satisfy (e.g., is lower than) the second threshold value), step2704may be performed. In step2704, a determination, of whether PDCP packet duplication is activated, may be made. If PDCP packet duplication is activated, step2701may be repeated. If PDCP packet duplication is not activated, step2705may be performed. In step2705, activation of UL PDCP packet duplication and/or of DL PADCP packet duplication may be caused. An indication of UL and/or DL PDCP packet duplication activation may, as part of step2705, be sent to the CU-UP node and/or to the DU. The method may end. Alternatively, and as shown with a broken line, the method may begin again by repeating step2701. If it is determined in step2703that radio signaling quality is not sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication, step2706may be performed. In step2706, a determination, of whether PDCP packet duplication is activated, may be made. If PDCP packet duplication is not activated, step2701may be repeated. If PDCP packet duplication is activated, step2707may be performed. In step2707, deactivation of UL and/or DL PDCP packet duplication for a bearer may be caused. An indication of UL and/or DL PDCP packet duplication deactivation may, as part of step2707, be sent to the CU-UP node and/or to the DU. The method may end. Alternatively, and as shown with a broken line, the method may begin again by repeating step2701. FIG.28shows an example method that may, for example, be performed by a CU-UP node (e.g., the CU-UP node1702). Status information may be received in step2801. The status information may, for example, comprise status information from self-monitoring (e.g., the status information2313) and/or status information (e.g., the status information2301) for a CU-CP node (e.g., the CU-CP node1701), status information for a DU (e.g., the DU1703), RRC wireless device (e.g., UE) status information, lower layer wireless device (e.g., UE) status information, and/or other information. In step2802, a determination, regarding the availability of resources to support packet duplication, may be made. The determination may be based on one or more parts of the status information received in step2801and may comprise, for example, determining whether a resource utilization ratio satisfies (e.g., is lower than) a first threshold value. The first threshold value may be predetermined. The first threshold value for the method ofFIG.28may be the same as, or different from, the first threshold value for the method ofFIG.27, and/or may be the same as, or different from, the first threshold value for the method ofFIG.29. If it is determined in step2802that resources to support packet duplication are not available (e.g., if the utilization ratio does not satisfy (e.g., is not lower than) the first threshold value), step2807(described below) may be performed. If it is determined in step2802that resources to support packet duplication are available (e.g., if the utilization ratio satisfies (e.g., is lower than) the first threshold value), step2803may be performed. In step2803, a determination, of whether radio signaling quality is sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication, may be made. The determination may be based on one or more parts of the status information received in step2801and may comprise, for example, determining if a radio quality satisfies (e.g., is lower than) a second threshold value. The second threshold value may be predetermined. The second threshold value for the method ofFIG.28may be the same as, or different from, the second threshold value for the method ofFIG.27, and/or may be the same as, or different from, the second threshold value for the method ofFIG.29. If it is determined in step2803that radio signaling quality is not sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication (e.g., if the radio quality does not satisfy (e.g., is not lower than) the second threshold value), step2807may be performed. If it is determined in step2803that radio signaling quality is sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication (e.g., if the radio quality does satisfy (e.g., is lower than) the second threshold value), step2804may be performed. In step2804, a determination, of whether PDCP packet duplication is activated, may be made. If PDCP packet duplication is activated, step2801may be repeated. If PDCP packet duplication is not activated, step2805may be performed. In step2805, activation of UL PDCP packet duplication and/or of DL PDCP packet duplication may be caused. An indication of UL and/or DL PDCP packet duplication activation may, as part of step2805, be sent to the CU-CP node and/or to the DU. In step2806, the start of sending of duplicated DL PDCP packets, and/or the start of discarding duplicated UL PDCP packets, may be caused. The method may end. Alternatively, and as shown with a broken line, the method may begin again by repeating step2801. If it is determined in step2803that radio signaling quality is not sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication, step2807may be performed. In step2807, a determination, of whether PDCP packet duplication is activated, may be made. If PDCP packet duplication is not activated, step2801may be repeated. If PDCP packet duplication is activated, step2808may be performed. In step2808, deactivation of UL and/or DL PDCP packet duplication for a bearer may be caused. An indication of UL and/or DL PDCP packet duplication deactivation may, as part of step2808, be sent to the CU-CP node and/or to the DU. In step2809, the cessation of sending duplicated DL PDCP packets may be caused. The method may end. Alternatively, and as shown with a broken line, the method may begin again by repeating step2801. FIG.29shows an example method that may, for example, be performed by a DU (e.g., the DU1703). Status information may be received in step2901. The status information may, for example, comprise status information from self-monitoring (e.g., the status information2314), status information (e.g., the status information2307) for a CU-CP node (e.g., the CU-CP node1701) and/or a CU-UP node (e.g., the CU-UP node1702), RRC wireless device (e.g., UE) status information, lower layer wireless device (e.g., UE) status information, and/or other information. In step2902, a determination, regarding the availability of resources to support packet duplication, may be made. The determination may be based on one or more parts of the status information received in step2901and may comprise, for example, determining whether a resource utilization ratio satisfies (e.g., is lower than) a first threshold value. The first threshold value may be predetermined. The first threshold value for the method ofFIG.29may be the same as, or different from, the first threshold value for the method ofFIG.27, and/or may be the same as, or different from, the first threshold value for the method ofFIG.28. If it is determined in step2902that resources to support packet duplication are not available (e.g., if the utilization ratio does not satisfy (e.g., is not lower than) the first threshold value), step2906(described below) may be performed. If it is determined in step2902that resources to support packet duplication are available (e.g., if the utilization ratio satisfies (e.g., is lower than) the first threshold value), step2903may be performed. In step2903, a determination, of whether radio signaling quality is sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication, may be made. The determination may be based on one or more parts of the status information received in step2901and may comprise, for example, determining if a radio quality satisfies (e.g., is lower than) a second threshold value. The second threshold value may be predetermined. The second threshold value for the method ofFIG.29may be the same as, or different from, the second threshold value for the method ofFIG.27, and/or may be the same as, or different from, the second threshold value for the method ofFIG.28. If it is determined in step2903that radio signaling quality is not sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication (e.g., if the radio quality does not satisfy (e.g., is not lower than) the second threshold value), step2906may be performed. If it is determined in step2903that radio signaling quality is sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication (e.g., if the radio quality does satisfy (e.g., is lower than) the second threshold value), step2904may be performed. In step2904, a determination, of whether PDCP packet duplication is activated, may be made. If PDCP packet duplication is activated, step2901may be repeated. If PDCP packet duplication is not activated, step2905may be performed. In step2905, activation of UL PDCP packet duplication and/or of DL PADCP packet duplication may be caused. An indication of UL and/or DL PDCP packet duplication activation may, as part of step2905, be sent to the CU-CP node and/or to a wireless device (e.g., to the wireless device1704). The method may end. Alternatively, and as shown with a broken line, the method may begin again by repeating step2901. If it is determined in step2903that radio signaling quality is not sufficiently poor and/or unstable so as to indicate a benefit from PDCP packet duplication, step2906may be performed. In step2906, a determination, of whether PDCP packet duplication is activated, may be made. If PDCP packet duplication is not activated, step2901may be repeated. If PDCP packet duplication is activated, step2907may be performed. In step2907, deactivation of UL and/or DL PDCP packet duplication for a bearer may be caused. An indication of UL and/or DL PDCP packet duplication deactivation may, as part of step2907, be sent to the CU-CP node and/or to the wireless device. The method may end. Alternatively, and as shown with a broken line, the method may begin again by repeating step2901. FIG.30shows an example method that may, for example, be performed by a wireless device (e.g., the wireless device1704). In step3001, a MAC CE indicating activation or deactivation of UL PDCP packet duplication may be received. The MAC CE may be received, for example, from a DU (e.g., the DU1703). In step3002, a determination, or whether the MAC CE indicates activation of PDCP packet duplication or deactivation of PDCP packet duplication, may be made. If the MAC CE indicates activation of PDCP packet duplication, and as shown in step3003, the start of sending duplicated PDCP packets may be caused. If the MAC CE indicates deactivation of PDCP packet duplication, and as shown in step3004, cessation of sending duplicated PDCP packets may be caused. PDCP packet duplication may be activated (e.g., caused to be activated) by one of the CU-CP1701, the CU-UP1702, or the DU1703, and may subsequently be deactivated (e.g., caused to be deactivated) by a different one of the CU-CP1701, the CU-UP1702, or the DU1703. PDCP packet duplication may be activated (e.g., caused to be activated) by one of the CU-CP1701, the CU-UP1702, or the DU1703, and at a different time may be activated (e.g., caused to be activated) by a different one of the CU-CP1701, the CU-UP1702, or the DU1703. PDCP packet duplication may be deactivated (e.g., caused to be deactivated) by one of the CU-CP1701, the CU-UP1702, or the DU1703, and at a different time may be deactivated (e.g., caused to be deactivated) by a different one of the CU-CP1701, the CU-UP1702, or the DU1703. A CU-CP (e.g., a CU-CP node) may transmit, to a CU-UP (e.g., a CU-UP node), a first message indicating a first bearer configuration request for a wireless device. The first message may comprise a first bearer identifier of a first bearer and/or a PDCP configuration parameter indicating that PDCP packet duplication is configured for the first bearer. The CU-CP may receive, from the CU-UP, a second message indicating that the PDCP packet duplication of the first bearer is set up (e.g., configured). The CU-UP may send (e.g., transmit), to the CU-UP, a third message indicating a first activation or a first deactivation of the PDCP packet duplication of the first bearer. The second message may comprise UL tunnel information of the first bearer. The UL tunnel information may comprise a first UL TEID and/or a second UL TEID. The CU-CP may send (e.g., transmit), to a DU and based on (e.g., in response to) receiving the second message, a fourth message indicating a second bearer configuration request for the first bearer of the wireless device. The fourth message may comprise the UL tunnel information of the first bearer. The CU-CP may receive, from the DU and based on (e.g., in response to) the fourth message, a fifth message comprising DL tunnel information of the first bearer. The DL tunnel information may comprise a first DL TEID and/or a second DL TEID. The CU-CP may send (e.g., transmit), to the CU-UP, a sixth message comprising the DL tunnel information for the first bearer. A first base station may comprise the CU-CP, the CU-UP, and/or the DU. The DU may, for example, send (e.g., transmit), to the wireless device, a MAC CE indicating a second activation or a second deactivation of the PDCP packet duplication. The second activation and the second deactivation may be associated with an UL PDCP packet duplication. The DU may receive, from the wireless device, duplicated PDCP packets of the first bearer if the MAC CE indicates the second activation. Based on (e.g., in response to) the third message: if the third message indicates the first activation, the CU-CP may transmit duplicated PDCP packets of the first bearer; and/or if the third message indicates the first deactivation, the CU-CP may stop transmitting duplicated PDCP packets of the first bearer. The CU-UP may, for example, discard duplicated PDCP packets of the first bearer received from the wireless device if the third message indicates the first activation. The first activation and/or the first deactivation may, for example, be associated with at least one of an UL PDCP packet duplication and/or a DL PDCP packet duplication. The first message may, for example, further indicate and/or comprise an IE indicating a third activation or a third deactivation of the PDCP packet duplication. The third activation and the third deactivation may be associated with at least one of an UL PDCP packet duplication and/or a DL PDCP packet duplication. The CU-CP may, for example send (e.g., transmit), to the wireless device, an RRC message indicating that the PDCP packet duplication for the first bearer is configured. The wireless device may, for example, discard duplicated PDCP packets of the first bearer received from the CU-UP (and/or the DU) if the third message indicates the first activation. The first activation or the first deactivation may, for example, be based on at least one of: first status information received from a DU, the first status information comprising DU status information and/or lower layer wireless device status information; and/or second status information received from the wireless device, the second status information comprising RRC wireless device status information. A CU-CP may, for example, send (e.g., transmit), to a CU-UP, a first message indicating a first bearer configuration request for a wireless device. The first message may comprise a first bearer identifier of a first bearer and/or a PDCP configuration parameter indicating that PDCP packet duplication is configured for the first bearer. The CU-CP may receive, from the CU-UP, a second message indicating that the PDCP packet duplication of the first bearer is set up (e.g., configured). The CU-CP may receive, from the CU-UP, a third message indicating a fourth activation or a fourth deactivation of the PDCP packet duplication of the first bearer. The CU-UP may initiate the fourth activation and the fourth deactivation. The fourth activation and the fourth deactivation may, for example, be associated with at least one of an UL PDCP packet duplication and/or a DL PDCP packet duplication. Based on, for example, in response to, the third message: if the third message indicates the fourth activation, the CU-UP may transmit duplicated PDCP packets of the first bearer; and/or if the third message indicates the fourth deactivation, the CU-UP may stop transmitting duplicated PDCP packets of the first bearer. The CU-UP may, for example, discard duplicated PDCP packets of the first bearer received from the wireless device if the third message indicates the fourth activation. The wireless device may, for example, discard duplicated PDCP packets of the first bearer received from the CU-UP (and/or the DU) if the third message indicates the fourth activation. The fourth activation or the fourth deactivation may be based on first status information received from a CU-CP. The first status information may comprise at least one of CU-CP status information, DU status information, RRC wireless device status information, and/or lower layer wireless device status information. A method may comprise receiving, by a central unit user plane (CU-UP) node from a central unit control plane (CU-CP) node, one or more messages. The one or more messages may indicate: configuration of packet duplication for a bearer, and activation of the packet duplication. The method may comprise sending, by the CU-UP node and based on the one or more messages, packets for the bearer and duplicated versions of the packets. The one or more messages may comprise a configuration message indicating a bearer configuration request for a wireless device. The sending may comprise sending the packets and the duplicated versions of the packets, via a distributed unit of a base station, to a wireless device. The one or more messages may comprise logical channel information, for the bearer, comprising: a first logical channel identifier of a first logical channel for the packets, and a second logical channel identifier of a second logical channel for the duplicated versions of the packets. The method may comprise after receiving the one or more messages, sending, by the CU-UP node to the CU-CP node, one or more second messages comprising uplink tunnel information, for the bearer, comprising: a first uplink tunnel endpoint identifier for a first tunnel for uplink packets of the bearer, and a second uplink tunnel endpoint identifier for a second tunnel for duplicated uplink packets. The method may comprise after sending the one or more second messages, receiving, from the CU-CP node, a configuration update message indicating downlink tunnel information for the bearer. The method may comprise receiving, by the CU-UP node from the CU-CP node, one or more messages indicating deactivation of the packet duplication; and based on the one or more messages indicating the deactivation, discontinuing the sending of the duplicated versions of the packets. The method may comprise based on status information associated with the CU-CP node, deactivating, by the CU-UP node, the packet duplication. The method may comprise based on status information associated with a distributed unit of a base station, deactivating, by the CU-UP node, the packet duplication. The method may comprise based on status information received by the CU-UP node, deactivating the packet duplication, wherein the status information may comprise indications of one or more of: a hardware load, a load of an N2 interface between the CU-UP node and a core network entity, a load of an F1 interface between the CU-UP node and a distributed unit of a base station, a composite available capacity group, or a network slice overload. The method may comprise deactivating, by the CU-UP node, the packet duplication; and sending, by the CU-UP node to the CU-CP node, one or more messages indicating the deactivation of the packet duplication. The method may comprise activating, by the CU-UP node and based on status information received by the CU-UP node, packet duplication, wherein the status information may comprise one or more of: status information associated with the CU-CP node, or status information associated with a distributed unit of a base station; and sending by the CU-UP node to the CU-CP node, one or more messages indicating the activation by the CU-UP node. The packet duplication may comprise packet data convergence protocol (PDCP) packet duplication. A method may comprise receiving, by a central unit user plane (CU-UP) node from a central unit control plane (CU-CP) node, one or more messages indicating activation of packet duplication for a bearer. The method may comprise sending, by the CU-UP node and based on the one or more messages, packets for the bearer and duplicated versions of the packets. The method may comprise receiving, by the CU-UP node from the CU-CP node, one or more messages indicating deactivation of the packet duplication. The method may comprise based on the one or more messages indicating the deactivation, discontinuing the sending of the duplicated versions of the packets. The method may comprise determining, by the CU-UP node and based on status information received by the CU-UP node after a second activation of the packet duplication, to perform a second deactivation of the packet duplication, wherein the status information may comprise status information associated with one or more of the CU-CP node or a distributed unit (DU) of a base station. The method may comprise activating, by the CU-UP node, the packet duplication; and sending by the CU-UP node to the CU-CP node, one or more messages indicating the activation by the CU-UP node. The method may comprise based on additional status information received by the CU-UP node, activating, by the CU-UP node, packet duplication, wherein the additional status information may comprise one or more of: additional status information associated with the CU-CP node, or additional status information associated with a distributed unit (DU) of a base station. A method may comprise based on status information received by a central unit user plane (CU-UP) node, activating, by the CU-UP node, packet duplication. The status information may comprise one or more of: status information associated with a central unit control plane (CU-CP) node, or status information associated with a distributed unit (DU). The method may comprise sending, by the CU-UP node to the CU-CP node, one or more messages indicating the activation. The method may comprise based on the activation, sending, via the DU and to a wireless device, packets and duplicated versions of the packets. The status information may comprise indications of one or more of: a hardware load, a load of an N2 interface between the CU-UP node and a core network entity, a load of an F1 interface between the CU-UP node and the DU, a composite available capacity group, or a network slice overload. The method may comprise deactivating, by the CU-UP node, the packet duplication; and sending, by the CU-UP node to the CU-CP node, one or more messages indicating the deactivation of the packet duplication. A method may comprise receiving, by a central unit user plane from a central unit control plane, a configuration message indicating a bearer configuration request for a wireless device. The configuration message may comprise: a bearer identifier of a bearer; a packet data convergence protocol (PDCP) duplication parameter indicating that PDCP packet duplication is configured for the bearer; and a duplication activation parameter indicating that the PDCP packet duplication is activated. The method may comprise transmitting, by the central unit user plane to the central unit control plane, a response message for the configuration message. The method may comprise transmitting, by the central unit user plane to the wireless device and based on the duplication activation parameter, packets for the bearer and duplicated packets of the packets. The configuration message may comprise logical channel information of the bearer, and the logical channel information may comprise: a first logical channel identifier of a first logical channel for packets of the bearer; and a second logical channel identifier of a second logical channel for duplication of the packets. The response message may comprise uplink tunnel information of the bearer, and the uplink tunnel information may comprise: a first uplink tunnel endpoint identifier for a first tunnel for uplink packets of the bearer; and a second uplink tunnel endpoint identifier for a second tunnel for duplication of the uplink packets. The method may comprise transmitting, by the central unit control plane to a distributed unit and in response to receiving the response message, a second configuration message indicating a second bearer configuration request for the bearer of the wireless device, the second configuration message comprising the uplink tunnel information of the bearer. The method may comprise receiving, by the central unit control plane from the distributed unit and in response to the message, a second response message comprising downlink tunnel information of the bearer, and the downlink tunnel information may comprise: a first downlink tunnel endpoint identifier for the first tunnel; and a second downlink tunnel endpoint identifier for the second tunnel. The method may comprise transmitting, by the central unit control plane to the central unit user plane, a configuration update message comprising the downlink tunnel information for the bearer. A base station may comprise: the central unit control plane; the central unit user plane; and the distributed unit. The method may comprise transmitting, by the distributed unit to the wireless device, a medium access control control element indicating a second activation or a second deactivation of the PDCP packet duplication, wherein the second activation and the second deactivation are for an uplink PDCP packet duplication. The method may comprise receiving, by the distributed unit from the wireless device, duplicated PDCP packets of the bearer if the medium access control control element indicates the second activation. The method may comprise receiving, by the central unit user plane from the central unit control plane, a third configuration message comprising a duplication deactivation parameter indicating that the PDCP packet duplication is deactivated. The method may comprise stopping, by the central unit user plane, transmitting duplicated packets of packets for the bearer. The method may comprise receiving, by the central unit user plane from the central unit control plane, a fourth configuration message comprising a second duplication activation parameter indicating that the PDCP packet duplication is deactivated. The method may comprise transmitting, by the central unit user plane to the wireless device and based on the second duplication activation parameter, second packets for the bearer and second duplicated packets of the second packets. The method may comprise receiving, by the central unit user plane from the wireless device, uplink packets for the bearer and uplink duplicated packets of the uplink packets. The method may comprise discarding, by the central unit user plane, at least one of the uplink packets or the uplink duplicated packets. The method may comprise discarding, by the wireless device, at least one of the packets for the bearer or the duplicated packets of the packets. The method may comprise transmitting, by the central unit control plan to the wireless device, a radio resource control message indicating that the PDCP packet duplication for the bearer is configured. The central unit control plane may determine the activation of the PDCP packet duplication based on at least one of: first status information received from a distributed unit (and the first status information may comprise at least one of: distributed unit status information; or lower layer wireless device status information of the wireless device); or second status information received from the wireless device (the second status information may comprise radio resource control wireless device status information). The distributed unit status information may comprise at least one of: a hardware load indicator; a F1 interface load indicator indicating load information of an interface between the central unit user plane and the distributed unit; a radio resource status information; a composite available capacity group; or a network slice overload indicator of the distributed unit. The lower layer wireless device status information may comprise at least one of: uplink radio signaling quality information; or downlink radio signaling quality information. The uplink radio signaling quality information may comprise at least one of: one or more sounding reference signals received from the wireless device; hybrid automatic repeat request (HARD) retransmission number information; or buffer status information of one or more logical channels. The downlink radio signaling quality information may comprise a channel status information report received from the wireless device. The channel status information may comprise at least one of: a reference signal received power; or a reference signal received quality. The radio resource control wireless device status information comprises at least one of: a reference signal received power; a reference signal received quality; battery status information; a number of radio link control (RLC) retransmissions; a transport block transmission failure rate; a random access failure rate; a configured resource access failure rate; or PDCP delay information. The method may comprise determining, by the central unit user plane, deactivation of the PDCP packet duplication. The method may comprise stopping, by the central unit user plane and in response to determining the deactivation, transmitting duplicated packets of packets for the bearer. The determining the deactivation may be based on status information of the central unit control plane, the status information comprising at least one of: a hardware load; an N2 interface load of an N2 interface between the central unit user plane and a core network entity; an F1 interface load of an F1 interface between the central unit user plane and a distributed unit; a composite available capacity group; or a network slice overload. The method may comprise transmitting, by the central unit user plane to central unit control plane, a configuration update request message indicating the deactivation of the PDCP packet duplication. A method may comprise sending, by a central unit control plane to a central unit user plane, a configuration message indicating a first bearer configuration request for a wireless device, and the configuration message may comprise: a bearer identifier of a bearer; and a packet data convergence protocol (PDCP) configuration parameter indicating that PDCP packet duplication is configured for the bearer. The method may comprise receiving, by the central unit control plane from a base station distributed unit, distributed unit status information. The method may comprise determining, by the central unit control plane, to activate the PDCP packet duplication based on the distributed unit status information. The method may comprise sending, by the central unit control plane to the central unit user plane, a configuration update message indicating activation of the PDCP packet duplication of the bearer. A method may comprise determining, by a central unit control plane, to activate a packet data convergence protocol (PDCP) packet duplication for a bearer of a wireless device. The method may comprise sending, by a central unit control plane to a central unit user plane, a configuration message indicating a bearer configuration request for the wireless device. The configuration message may comprise: a bearer identifier of a bearer; a PDCP duplication parameter indicating that PDCP packet duplication is configured for the bearer; and a duplication activation parameter indicating that the PDCP packet duplication is activated. The method may comprise receiving, by the central unit control plane from a base station distributed unit, a response message for the configuration message. A method may comprise receiving, by a central unit control plane from a core network node, a context setup message requesting configuration of a session for a wireless device. The method may comprise determining, by the central unit control plane: to configure packet data convergence protocol (PDCP) packet duplication for a bearer of the session; and to activate the PDCP duplication based on distributed unit status information. The method may comprise sending, by a central unit control plane to a central unit user plane, a configuration message indicating a bearer configuration request for the wireless device. The configuration message may comprise: a bearer identifier of the bearer; and PDCP configuration parameters. The PDCP configuration parameters may indicate that: the PDCP packet duplication is configured for the bearer; and the PDCP packet duplication is activated for the bearer. The method may comprise receiving, by the central unit control plane from a base station distributed unit, a response message for the configuration message. The response message may indicate that the PDCP configuration parameters are configured. A method may comprise transmitting, by a central unit control plane to a central unit user plane, a first message indicating a bearer configuration request for a wireless device. The first message may comprise: a bearer identifier of a bearer; and a packet data convergence protocol (PDCP) configuration parameter indicating that PDCP packet duplication is configured for the bearer. The method may comprise receiving, by the central unit control plane from the central unit user plane, a second message indicating that the PDCP packet duplication of the bearer is set up. The method may comprise receiving, by the central unit control plane from the central unit user plane, a third message indicating an activation or a deactivation of the PDCP packet duplication of the bearer. The activation and the deactivation may be initiated by the central unit user plane. The activation and the deactivation may be associated with at least one of: an uplink PDCP packet duplication; or a downlink PDCP packet duplication. The method may comprise, in response to the third message: if the third message indicates the activation, transmitting, by the central unit user plane, duplicated PDCP packets of the bearer; and if the third message indicates the deactivation, stopping, by the central unit user plane, transmitting duplicated PDCP packets of the bearer. The method may comprise discarding, by the central unit user plane, duplicated PDCP packets of the bearer received from the wireless device if the third message indicates the activation. The method may comprise discarding, by the wireless device, at least one of PDCP packets of the bearer or duplicated PDCP packets of the PDCP packets received from the central unit user plane. The activation or the deactivation may be based on at least one of status information received from a central unit control plane. The status information may comprise at least one of: central unit control plane status information; distributed unit status information; radio resource control wireless device status information; or lower layer wireless device status information. FIG.31shows example elements of a computing device that may be used to implement any of the various devices described herein, including, e.g., the base station120A and/or120B, the wireless device110(e.g.,110A and/or110B), or any other base station, wireless device, or computing device described herein. The computing device3100may include one or more processors3101, which may execute instructions stored in the random access memory (RAM)3103, the removable media3104(such as a Universal Serial Bus (USB) drive, compact disk (CD) or digital versatile disk (DVD), or floppy disk drive), or any other desired storage medium. Instructions may also be stored in an attached (or internal) hard drive3105. The computing device3100may also include a security processor (not shown), which may execute instructions of one or more computer programs to monitor the processes executing on the processor3101and any process that requests access to any hardware and/or software components of the computing device3100(e.g., ROM3102, RAM3103, the removable media3104, the hard drive3105, the device controller3107, a network interface3109, a GPS3111, a Bluetooth interface3112, a WiFi interface3113, etc.). The computing device3100may include one or more output devices, such as the display3106(e.g., a screen, a display device, a monitor, a television, etc.), and may include one or more output device controllers3107, such as a video processor. There may also be one or more user input devices3108, such as a remote control, keyboard, mouse, touch screen, microphone, etc. The computing device3100may also include one or more network interfaces, such as a network interface3109, which may be a wired interface, a wireless interface, or a combination of the two. The network interface3109may provide an interface for the computing device3100to communicate with a network3110(e.g., a RAN, or any other network). The network interface3109may include a modem (e.g., a cable modem), and the external network3110may include communication links, an external network, an in-home network, a provider's wireless, coaxial, fiber, or hybrid fiber/coaxial distribution system (e.g., a DOCSIS network), or any other desired network. Additionally, the computing device3100may include a location-detecting device, such as a global positioning system (GPS) microprocessor3111, which may be configured to receive and process global positioning signals and determine, with possible assistance from an external server and antenna, a geographic position of the computing device3100. The example inFIG.31may be a hardware configuration, although the components shown may be implemented as software as well. Modifications may be made to add, remove, combine, divide, etc. components of the computing device3100as desired. Additionally, the components may be implemented using basic computing devices and components, and the same components (e.g., processor3101, ROM storage3102, display3106, etc.) may be used to implement any of the other computing devices and components described herein. For example, the various components described herein may be implemented using computing devices having components such as a processor executing computer-executable instructions stored on a computer-readable medium, as shown inFIG.31. Some or all of the entities described herein may be software based, and may co-exist in a common physical platform (e.g., a requesting entity may be a separate software process and program from a dependent entity, both of which may be executed as software on a common computing device). The disclosed mechanisms herein may be performed if certain criteria are met, for example, in a wireless device, a base station, a radio environment, a network, a combination of the above, and/or the like. Example criteria may be based on, for example, wireless device and/or network node configurations, traffic load, initial system set up, packet sizes, traffic characteristics, a combination of the above, and/or the like. If the one or more criteria are met, various examples may be used. It may be possible to implement examples that selectively implement disclosed protocols. A base station may communicate with a mix of wireless devices. Wireless devices and/or base stations may support multiple technologies, and/or multiple releases of the same technology. Wireless devices may have some specific capability(ies) depending on wireless device category and/or capability(ies). A base station may comprise multiple sectors. A base station communicating with a plurality of wireless devices may refer to base station communicating with a subset of the total wireless devices in a coverage area. Wireless devices referred to herein may correspond to a plurality of wireless devices of a particular LTE or 5G release with a given capability and in a given sector of a base station. A plurality of wireless devices may refer to a selected plurality of wireless devices, and/or a subset of total wireless devices in a coverage area. Such devices may operate, function, and/or perform based on or according to drawings and/or descriptions herein, and/or the like. There may be a plurality of base stations or a plurality of wireless devices in a coverage area that may not comply with the disclosed methods, for example, because those wireless devices and/or base stations perform based on older releases of LTE or 5G technology. One or more features described herein may be implemented in a computer-usable data and/or computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other data processing device. The computer executable instructions may be stored on one or more computer readable media such as a hard disk, optical disk, removable storage media, solid state memory, RAM, etc. The functionality of the program modules may be combined or distributed as desired. The functionality may be implemented in whole or in part in firmware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA), and the like. Particular data structures may be used to more effectively implement one or more features described herein, and such data structures are contemplated within the scope of computer executable instructions and computer-usable data described herein. Many of the elements in examples may be implemented as modules. A module may be an isolatable element that performs a defined function and has a defined interface to other elements. The modules may be implemented in hardware, software in combination with hardware, firmware, wetware (i.e., hardware with a biological element) or a combination thereof, all of which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab or the like) or a modeling/simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. Additionally or alternatively, it may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and/or quantum hardware. Examples of programmable hardware may comprise: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors may be programmed using languages such as assembly, C, C++ or the like. FPGAs, ASICs, and CPLDs may be programmed using hardware description languages (HDL), such as VHSIC hardware description language (VHDL) or Verilog, which may configure connections between internal hardware modules with lesser functionality on a programmable device. The above-mentioned technologies may be used in combination to achieve the result of a functional module. A non-transitory tangible computer readable media may comprise instructions executable by one or more processors configured to cause operations of multi-carrier communications described herein. An article of manufacture may comprise a non-transitory tangible computer readable machine-accessible medium having instructions encoded thereon for enabling programmable hardware to cause a device (e.g., a wireless device, wireless communicator, a wireless device, a base station, and the like) to allow operation of multi-carrier communications described herein. The device, or one or more devices such as in a system, may include one or more processors, memory, interfaces, and/or the like. Other examples may comprise communication networks comprising devices such as base stations, wireless devices or user equipment (wireless device), servers, switches, antennas, and/or the like. A network may comprise any wireless technology, including but not limited to, cellular, wireless, WiFi, 4G, 5G, any generation of 3GPP or other cellular standard or recommendation, wireless local area networks, wireless personal area networks, wireless ad hoc networks, wireless metropolitan area networks, wireless wide area networks, global area networks, space networks, and any other network using wireless communications. Any device (e.g., a wireless device, a base station, or any other device) or combination of devices may be used to perform any combination of one or more of steps described herein, including, for example, any complementary step or steps of one or more of the above steps. Although examples are described above, features and/or steps of those examples may be combined, divided, omitted, rearranged, revised, and/or augmented in any desired manner. Various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this description, though not expressly stated herein, and are intended to be within the spirit and scope of the descriptions herein. Accordingly, the foregoing description is by way of example only, and is not limiting. | 267,815 |
11943067 | Similar reference numerals may have been used in different figures to denote similar components. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS For illustrative purposes, specific example embodiments will now be explained in greater detail below in conjunction with the figures. The embodiments set forth herein represent information sufficient to practice the claimed subject matter and illustrate ways of practicing such subject matter. Upon reading the following description in light of the accompanying figures, those of skill in the art will understand the concepts of the claimed subject matter and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims. Moreover, it will be appreciated that any module, component, or device disclosed herein that executes instructions may include or otherwise have access to a non-transitory computer/processor readable storage medium or media for storage of information, such as computer/processor readable instructions, data structures, program modules, and/or other data. A non-exhaustive list of examples of non-transitory computer/processor readable storage media includes magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, optical disks such as compact disc read-only memory (CD-ROM), digital video discs or digital versatile discs (i.e. DVDs), Blu-ray Disc™, or other optical storage, volatile and non-volatile, removable and non-removable media implemented in any method or technology, random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology. Any such non-transitory computer/processor storage media may be part of a device or accessible or connectable thereto. Computer/processor readable/executable instructions to implement an application or module described herein may be stored or otherwise held by such non-transitory computer/processor readable storage media. Example embodiments described herein may be applied to, among other things, NR V2X SL communications. In some V2X scenarios, such as NR V2X mode 2, SL resource allocation is based on sensing and resource selection procedures. In NR V2X mode 2 transmission, a UE may autonomously select SL resources for SL transmission within configured or preconfigured resource pools (RPs) or within pre-configured resources within RPs. However, because NR requires high reliability and may include multiple repetitions, potential SL transmission collisions between the transmissions of multiple UEs may arise when a UE selects SL transmission resources that may be reserved by the other UEs, which may cause lower reliability and higher latency. Accordingly, the present disclosure relates to methods, devices or apparatus for sensing and indicating information for selection and reservation of communication resources for SL communication, and selecting and reserving communication resources based on at least in part such indications. It has been recognized that resource selection for reservation may be made at least in part based on the type of the reservation to be made for transmitting a transport block (TB). It can be appreciated, and will be explained in more detail below, that depending on the reservation type, the probability that the reserved resources will be actually used to transmit a later TB can vary. Reservations of resources with a higher probability of utilization in a future transmission should be given a higher priority to be excluded from the available resource set or resource pool for a further selection. In one implementation, the threshold for excluding these types of reservations from further selection should be low. Therefore, it would facilitate efficient selection and reservation of resources to determine reservation priorities or exclusion thresholds for different the resources and resource reservations, and select and reserve a particular resource based at least in part on the associated reservation priority or exclusion threshold. In this regard, it has been further recognized that it would be convenient if the reservation type information is readily accessible and available during SL communication. For example, the reservation type information may be indicated in a reservation signal, particularly, an indication signal, transmitted from a first UE to other UEs for reservation of SL communication resources, such as time-frequency resources in SL communication between different UEs. The indication signal may be a sidelink control indicator, also commonly referred to as sidelink control information (SCI), which is usually transmitted through a SL control channel (SCC), for example, the physical sidelink control channel (PSCCH). The first UE may be a transmitting UE that is transmitting the TB to the second UE or another UE. The second UE may be a sensing UE that is sensing the transmitted signal and TB. The second UE, or a sensing UE, may also be a receiving UE or target UE, which is the desired final recipient of transmitted TB. A sensing UE may perform sensing by decoding indication signals including SCI transmitted by the first UE even if the data associated with the SCI is not intended to be received by the sensing UE. The sensing UE may need to select and reserve communication resources for receiving and transmitting relevant data based on the sensed information. Therefore, even though it may not be necessary for the sensing UE to decode the transmitted data packet or TB entirely, the sensing UE may still need to obtain certain information for processing the received data. For NR V2X SL communication, it has been agreed that the SCI is a 2-stage indication signal. In one embodiment, the reservation type information is indicated in the first stage SCI, because it is then sufficient for a sensing UE to decode only the first stage SCI to obtain the needed information for selection and reservation of the time-frequency resources. Accordingly, in a particular embodiment, a process for sensing and indicating information for selection and reservation of resources includes generating, at a first UE, a first stage SCI which includes an indicator that indicates the reservation type of the reservation of time-frequency resources for communicating a transport block (TB) between UEs through SL communication; and transmitting an indication signal including the first stage SCI to a second UE. In a further embodiment, a process performed at the second UE includes receiving from the first UE the indication signal, and selecting and reserving time-frequency resources based on at least in part the reservation type indicated by the indication signal. Depending on the nature of the particular TB to be transmitted and the reservation types, the indication signal including the SCI may contain other indicators or information. For example, for transmission of different TBs, the first stage SCI may include information indicating the reservation period (RSVP), and information indicating a reservation type. The reservation type may be indicated explicitly or implicitly. For example, the reservation type may be implicitly indicated by information specifying or indicating a functionality of a specific type of reservation. The reservation type may also be implicitly indicated by information specifying or indicating specific actions to be performed by the UE in association with the specific type of reservation. The reservation type may be selected from at least the following reservation types:Long-term reservation similar to LTE V2X reservationNo resource reservation for a different TBReservation of a fixed number of resources for different TBs. For transmission (including retransmission) of the same TB, the first stage SCI may include the following information:Whether the reserved retransmission is a blind retransmission or a HARQ feedback based retransmission.The number of retransmission resources reserved (including the current transmission)Time and frequency resources for all transmission/retransmission resources reserved (including the current transmission), or time-frequency resource pattern (TFRP) index among the pool of (pre)configured TFRPs.Optionally, retransmission index j, where j=[0, 1, . . . , K−1] refers to the index of the number of transmissions of the TB starting with index 0. In different embodiments, the sensing UE may use the information in SCI to allocate, select and reserve resources. In some embodiments, there may be two stage SCI. In the case of two stage SCI, the first stage SCI is usually for the purpose of indicating sensing information and scheduling the resource for the second stage SCI. By this design, the sensing UEs that are not the target receivers of the data only need to decode the first stage SCI for sensing and resource selection purposes. For the receiver UE that is the intend recipient of the data, the receiving UE can further decode the second stage SCI using information obtained from first stage SCI. The second stage SCI may contain any further information that is required for decoding the data that may not be present in the first stage SCI. Therefore, the receiving UE can further decode the data after decoding the second stage SCI. By this design, the first stage SCI can be made in smaller size. The first stage SCI is usually transmitted in the PSCCH. For this reason, the sensing and reservation information described in this disclosure is usually included in the first stage SCI if the two stage SCI design is used. For example, for reservation of retransmission resources/TFRPs with possible different number of retransmissions, the following options are available. Details of how to indicate reservation of retransmission resources are further discussed below. In a first option, the first stage SCI may indicate the number of retransmissions reserved and a TFRP index for a given number of retransmissions. In a second option, the TFRP pool already includes TFRPs with different number of retransmissions, in which case the first stage SCI may indicate only a TFRP index. In a third option, the first stage SCI indicates the number of retransmission(s) reserved, a time domain slot pattern indication, and a frequency domain subchannel based hopping offset. In a fourth option, the first stage SCI indicates the TFRP for 2 transmissions. The 2 transmission patterns may be either repeated or concatenated by a number of times to achieve multiples of 2-transmission patterns, such as 4 transmissions. In an example embodiment of the disclosure, the indication signal associated with reservation of time-frequency resources for a given TB indicates a reservation type selected from three possible types, which are supported by the particular network used for the SL communication. The three types of reservation includes: (a) reservation of a sidelink resource for transmission of a TB via signaling associated with a prior transmission of a different TB; (b) reservation of a sidelink resource for blind retransmission of a TB via signaling associated with a prior transmission of the same TB; (c) reservation of a sidelink resource for hybrid automatic repeat request (HARQ)-feedback based retransmission of a TB via signaling associated with a prior transmission of the same TB. An example of sensing using reservation Type (a) is similar to LTE long term sensing. Reservation Types (b) and (c) are supported in NR. In a selection process according to an embodiment herein, a sensing UE determines a resource selection window, and then selects the resources within the resource selection window. The selection is made with an aim to avoid conflict between resources reserved under Type (a) reservation or transmission/retransmission resources indicated by other UEs under Type (b) or (c) reservations. Type (a) reservation may further include the following sub-types: Sub-type (a1)—long-term reservation, similar to LTE V2X; Sub-type (a2)—reservation of a fixed number of periodic resources (e.g., for later transmission of different TBs); and Sub-type (a3)—no reservation of periodic resources. The HARQ mechanism is a link adaptation technique that can reduce the error rate of data packets in wireless communication networks. The HARQ feedback includes a HARQ acknowledgement (ACK, or HARQ-ACK), or negative ACK (NACK). Typically, when a receiving UE successfully decodes a received data packet, the receiving UE may transmit a HARQ ACK to the transmitting UE or the source of the packet. If a packet is not successfully received and decoded within a certain time period or a certain number of transmission attempts, the receiving UE may transmit a NACK to the transmitting UE. To indicate the reservation information of different reservation types for the sensing UE to perform resource selection, at least the following signaling should be indicated in the SCI, particularly in the first stage SCI if two stage SCI is used:the priority of the data packets, or quality of service (QoS) priority, that will be used for resource selection,time frequency resources of the reserved transmission/retransmission,reservation periodicity (RSVP), or TFRP periodicity, and number of periodic resources, m, explicitly reserved based on RSVP. In some embodiment, RSVP may be predefined or (pre)configured and does not need to be explicitly indicated in SCI. For example, RSVP can be (pre)configured in a resource pool configuration. In some embodiments, m=0 may indicate no reservation for periodic resource, m=infinite or unknown may indicate long term reservation similar to LTE V2X (or reservation of an unknown number of periodic resources), m=other positive integer among possible choices indicates reservation of a specific number of periodic resources for different TBs. In some other embodiments, there may be a separate bit to indicate whether there is a periodic reservation. In this case, the option of m=0 is not needed for this purpose and can be reserved or used for a different indication. The time frequency resources may include slots and sub-channels of the initial transmission and retransmission resources for a TB. This field is used for reservation of the transmission/retransmission of the same TB as the current SL data transmission associated with the SCI. This field may be further used for decoding the data by the receiver UE. In networks supporting or requiring 2-stage SCI, the above signaling or indication information can be indicated in the first stage SCI. A convenient benefit of indicating the above information including the reservation type in the first stage SCI is that a sensing UE other than the target UE or receiving US does not need to decode the second stage SCI for sensing purpose. In LTE V2X, no field is provided in the SCI to indicate the number of resources explicitly reserved based on the RSVP or whether the periodic reservation is enabled or not. The reason is that LTE V2X is mainly targeting periodic traffic, and every UE performs semi-persistent periodic transmission, for which the reservation can be considered as a long-term reservation or reserving an infinite or an a priori unknown number of resources because the transmitting UE (Tx UE) will use the periodic resource until a resource reselection is triggered. It is expected that in NR-V2X, data transmission may be aperiodic and involve data traffic with significant fluctuation and bursts of peak traffic periods. In some situations, the transmitting UE intends to perform a one-time transmission of a TB using a particular resource and does not intend to reserve the resource for any periodic transmission. In this situation, it may be beneficial for the transmitting UE to indicate the intention so that a sensing UE will not exclude the particular resource derived from current resource and reservation period from the set of available resources in a later time period. If the transmitting UE has a large data packet to transmit, the UE can predict that the UE requires more than one resource for transmitting the packet. In this case, the UE can explicitly reserve a fixed number of periodic resources. Therefore, the SCI field indicating the number of explicitly reserved periodic resources can indicate either no periodic reservation, long-term reservation (or reservation of infinite or unknown amount of periodic resources) similar to LTE-V, or a specific number of explicitly reserved periodic resources. Alternatively, the SCI could contain one field indicating whether or not the resource reservation is for a periodic resource, and a separate field indicating the number of periods for which the resource is reserved. In another embodiment, the RSVP field may have a special value/choice that corresponds to no periodic reservation and no separate field is needed to indicate whether there is reservation of periodic resource (for a different TB than current transmission). Note that here reservation of resources for a different TB or future TB is used to distinguish reservation of resource for retransmission, which is the same TB of the current transmission. In a further example, a one-time transmission is illustrated. In this example, the number (m) of periodic resources reserved is zero (0) or the bit to indicate whether a periodic resource is reserved is false. The process includes a one-time transmission of a small data packet. The transmitting UE may indicate that m=0, such that a sensing UE can determine the transmission is a one-time transmission and will not exclude the resource derived from this transmission and reservation period from further resource selection procedure. As another example, in performing a sidelink transmission, when the transmitting UE receives a NACK after a maximum number of reserved retransmissions of a data packet, the transmitting UE can further reserve a retransmission resource for retransmitting the same data packet one more time, but does not need to reserve this resource for transmitting other and future TBs. In this case, the transmitting UE may indicate that there is no reservation for a future transmission of the same TB or a different TB. In a typical resource selection procedure, when a resource selection or re-selection triggers, the UE collects all the sensing information during a sensing window and selects a resource among all candidate resources within a resource selection window based on the sensing results for its own transmission. The sensing window usually is defined a certain time window before the resource (re)selection triggers. Collecting sensing information includes decoding SCI (or other type of the reservation signal) of other UEs' transmissions and obtaining reservation information. If a UE decodes a SCI within the sensing window and a corresponding power/energy measurement of the transmission associated with the SCI is above a threshold, the corresponding reserved resource, if falls within the resource selection window, may be excluded from the candidate resources for resource selection to avoid collision. One typical example of such measurement is sidelink reference signal received power (SL-RSRP), which is usually measured based on PSSCH or PSCCH DMRS associated with the SCI that indicates the reservation. An exclusion threshold Th may be used by a UE to exclude resources for selection from a resource pool (RP). Depending on the situation, the UE may increase or decrease the threshold such that less or more resources will be excluded during selection. For example, in an embodiment, when UE decodes a reservation signal in SCI within the sensing window and the SCI indicates a reserved resource, which is a potential candidate resource within the resource selection window. If the power/energy measurement associated with the reservation signal (e.g. SCI), such as the side link reference signal received power (SL-RSRP), exceeds the determined exclusion threshold, such as when SL-RSRP>Th and the number of other UEs sensed using that candidate resource is larger than a threshold number L, where L can be 0, 1, 2 . . . , the potential candidate resource can be excluded from the candidate resource set/pool for selecting a resource for its own transmission by the sensing UE. In some embodiments, the number of L may not need to be taken into account for resource exclusion, and only the RSRP value and the threshold (Th) are taken into account. It can be understood that the lower the exclusion threshold (Th), the more likely a potential candidate resource will be excluded from the candidate resource set. Thus, a reservation of resources with a higher priority from the perspective of the sensing UE should be associated with a lower threshold, so that the resource will be more likely excluded from selection of resources for other transmissions. The threshold can be determined at least based on the packet or QoS priority in the decoded SCI for reservation and the packet or QoS priority of its own transmission, through a mapping table or other rules. See Tables 1 and 2 and associated discussions below. In a further embodiment, the reservation type is used to set or adjust an exclusion threshold (Th). For example, the SL reference signal received power (SL-RSRP) threshold is a function of at least the priority of the SL transmission indicated in the received SCI and the priority of the transmission for which resources are being selected by the UE. The threshold may be further adjusted based on the different reservation types/sub-types described in this disclosure. Alternatively, the priority value used to find the threshold for resource selection may be adjusted based on the reservation type. For determining the reserved resource for different types of reservations, the reservation information included in an SCI may specify that a particular time-frequency resource, e.g. (t0, fi), within a RP is to be reserved. In another embodiment, the reserved resource may be determined based on periodic reservations. For example, with regard to determining the time frequency location of reserved resource by reservation type a1, a2 and a3, the following example of determining the location of reserved resource can be used: For long term reservation or type a1 reservation, if the time frequency location for the current transmission associated with the SCI is (t0, f0), then periodic resources (t0+n×RSVP,f0) (n is any positive integer) are considered to be reserved resources. For reservation type a2 which reserves a fixed number (m) of periodic resources, the resource at time frequency location (t0+n×RSVP,f0), where (1<=n<=m) are considered to be reserved resources; for type a3 reservation where no periodic resource is reserved, (t0+n×RSVP,f0) is not considered a reserved resource. When different types of reservations are possible, the priority or threshold may be set or adjusted in view of the reservation type. Different reservation types may have different impacts on the resource selection and reservation. For example, for Sub-type (a1) reservation, the UE that reserves periodic resources based on long term reservation may not actually use a reserved resource during the resource selection window of the sensing UE simply because the UE may not have a packet to transmit or the UE has performed a resource (re)selection before using the reserved resource. For Sub-type (a3), there is no reservation of resources. Therefore, the reserved resource based on RSVP is still treated as being available for use. For type (b) reservation, the UE that reserves a resource for blind retransmission is highly likely to use the reserved retransmission resource. Similarly, when the UE reserves a fixed number of resources for different TBs under Sub-type (a2), the UE is very likely to use those resources. For Type (c) reservation, the UE which makes the reservation for HARQ-feedback based retransmission may release the retransmission resource due to receiving an ACK before the retransmission. Therefore, in general, Type (b) and Sub-type (a2) reservations should be assigned or associated with or adjust to a higher priority or choose a lower RSRP threshold as compared to Type (a) and Type (c) reservations for the same packet priority. The adjustment of the priority can be implemented by applying a reservation type specific coefficient to the packet priority before using the priority value to determine the RSRP threshold. Some embodiments disclosed herein relate to example methods for selecting resources based on different priority levels that are dependent on the types of resource reservations. Different priorities or priority adjustment value (e.g. priority coefficient that is described in more detail later) are assigned to resource reservations based on the types of transmissions that the reservation is being made in respect of. For example, priority levels may be respectively assigned to the following types of resource reservations: (a1) long term resource reservation for future transmission of different transport blocks (TBs); (a2) resource reservation for future transmission of an explicitly specified number of TBs; (b) resource reservation for blind retransmission; (c) resource reservation for feedback-based retransmission; and (d) resource reservation for an initial transmission of a TB using a standalone advance control signal preceding initial transmission of the TB. In example embodiments, the respective priority levels associated with each type of resource reservation are configured or preconfigured or predefined. A UE requesting a resource reservation can transmit a priority indicator that identifies the priority value of the resource reservation that the UE is requesting. Other UEs can sense the priorities and make resource selections for their own transmissions based on the sensed priorities. At least for unicast, a HARQ feedback can be supported for SL transmissions. In the case of HARQ feedback based SL retransmission, the receiving UE (Rx UE) can adjust its behavior on whether or not to expect a retransmission based on the HARQ feedback. For the sensing UE (other UE), its resource selection scheme should lower the priority of a reservation if the reserved resource can be released. This can be achieved by adjusting the priority level by multiplying it with a coefficient less than one if there is a chance the reserved resource may be released based on HARQ feedback. In some example embodiments disclosed herein, different priorities are associated with different reservation types which reflect different reservation mechanisms. In some example embodiments disclosed here, a sensing UE adjusts the priority associated with a reservation of HARQ-feedback based retransmission to be lower than the reservation of blind retransmission for the purpose of resource selection or reselection. In some example embodiments disclosed here, for the purpose of resource selection or reselection, a sensing UE adjusts the priority associated with a long-term reservation, or Type (a1) reservation, for an a priori unknown number of different TBs to be lower than that for the reservation of resources for a fixed number of resources for different TBs, or a type (a2) reservation. The indication of the reservation type in the SCI allows the sensing UE to conveniently identify the reservation type. By adjusting the priority and mapping the priority or reservation type to a different threshold, e.g., a RSRP threshold, for resource selection, the sensing UE can exclude resources more accurately for resource selection, and the overall resource utilization efficiency and system performance can be improved. In some embodiments, various options may be provided for indicating retransmission resources to be reserved where the number of retransmissions K can have different possible values. Note the number of retransmissions K may be defined to include the current transmission or it can be defined as the number of retransmissions excluding the current transmission. The definition results in a difference of 1 for the value of K and is otherwise equivalent. For notational simplicity and without loss of generality, we assume the number of retransmissions or repetitions K includes the initial transmission, but the same method would apply for indicating K that does not include the initial transmission. In one embodiment, the SCI (or first stage SCI for a two stage SCI design) optionally includes an indicator indicating the number of retransmissions for which resources are to be reserved, and an indicator indicating the TFRP index for the given number of retransmissions. In another embodiment, if the available TFRP pool of the sensing UE already includes TFRPs associated with different number of retransmissions, the SCI or first stage SCI may optionally include only the TFRP index. In this case, the TFRP index would be sufficient for the sensing UE to select the appropriate TFRPs. In a further embodiment, the first stage SCI may include indication information for indicating the TFRP for two (2) retransmissions. When four (4) retransmissions are required, the resource pattern for a 4-retransmission may be formed by repeatedly applying the indicated TFRP for 2-retransmission to each subsequent pair of retransmissions. To illustrate with reference toFIG.1AandFIG.3supposing the indicated TFRP for the 2-retransmission is pattern UE1, which corresponds to (T0, F0) and (T1, F2) for the first 2 transmissions of the TB, then slot (T0+period, F0) and (T1+period, F2), or the same UE1 pattern of the next TFRP window is used for the last two transmissions of the TB among the 4 transmissions. Here period=5 slots for a TFRP pool indicated byFIG.1. Alternatively, two different 2-retransmission TFRPs may be concatenated to form the resource pattern for a 4-retransmission. In this case two different indexes may be used to indicate the first 2 transmissions and last 2 transmissions. Supposing the first 2-retransmission TFRP is indicated as pattern UE1, which corresponds to (T0, F0) and (T1, F2) for the first 2 transmissions of the TB, and second 2 transmission TFRP is indicated as UE6, which corresponds to (T1+period, F1) and (T3+period, F3), the resource pattern for the 4-retransmission may be formed by combining UE1 pattern in the first TFRP window and UE6 pattern in the second TFRP window. The resource patterns for other multiples of 2 retransmissions may be formed similarly by repetition or concatenation. Similarly, if no explicit TFRP pool is defined, the resource indicated for the first 2 transmissions of a TB may be repeated or concatenated to form the resources of 4 transmissions of a TB. In yet another embodiment, the SCI may indicate the number of retransmissions, and further include a time domain slot pattern indication and a frequency domain hopping information (such as subchannel based hopping offset). For example, in cases where the available resources include a (pre)configured TFRP pool, the SCI may indicate the TFRP index for resource selection and reservation. The various embodiments are further illustrated with the following detailed embodiments with reference to the drawings. FIG.1Aillustrates a resource grid showing an example of two-dimensional resource configurations available for SL transmissions for different UEs, 10 UEs as depicted inFIG.1A. The resource grid may be applied in NR V2X communications. In an example embodiment, the resource grid ofFIG.1Arepresents transmission resources available in a physical sidelink shared channel (PSSCH). In this regard, the time-frequency resource grid ofFIG.1Arepresents a resource pool (RP)100that includes frequency-domain resources F0, F1, F2 and F3; and time-domain resources T0, T1, T2, T3 and T4. Each combination of frequency-domain resource and time-domain resource forms a transmission resource for an SL transmission. The RP100shown inFIG.1Aillustrates a pool of transmission resources that are potentially available for SL transmissions by different UEs within transmission pattern window. Each transmission resource represents a potential data transmission of a transport block (TB). In example embodiments, a UE may use multiple transmission resources based on a selection of one or more configured or preconfigured transmission patterns (e.g. time-frequency resource patterns (TFRPs) or time frequency repetition patterns) or based on a combination of multiple selected resource without explicitly defining a pool of TFRPs. In the case of UE1, the illustrated transmission pattern represented inFIG.1Aincludes two time-frequency transmission resources (for example, T0/F0 and T1/F2, as indicated in crosshatch) that can be used by UE1 to transmit a TB. A redundancy version (RV) for each transmission resource is also shown (for example, RV0 or RV3). InFIG.1A, the transmission pattern for UE 1 provides UE1 with communication resources to transmit a TB twice over the length of the transmission pattern window duration (for example a first retransmission of a TB followed by a second retransmission of the TB). Thus, the repetition number, K, for the transmission pattern for UE1 is 2. The grid ofFIG.1Aillustrates ten respective transmission patterns, each of which includes two respective communication resources. Thus, RP100includes a pool of 10 transmission patterns, each of which includes 2 transmission resources. In some examples, K can be 1, or can be greater than 2. As presented inFIG.1A, the RP100has a frequency-domain length of 4 and a time-domain length of 5. In the time-domain, time durations T0 to T4 could be slots, mini-slots, symbols, or any other quantization or unit of time. As can be appreciated,FIG.1Aillustrates a TFRP pool for two transmissions. “K” is used herein to denote the number of transmissions. For two (2) transmissions, K=2. Another example grid is shown inFIG.1B, illustrating a TFRP pool for K=4. Unlike inFIG.1A, the TFRP pool as depicted inFIG.1Bprovides resources for only 5 UEs or 5 non-overlapping patterns, due to the increased number of possible retransmissions. The optional redundancy version (RV) is not indicated inFIG.1B. As discussed above, for a K=4 transmission, it is also possible to indicate the time frequency resources for the first two transmissions, and the indicated time frequency resources may be used again in a later period of the TFRP pattern for the last two transmissions as discussed earlier. Alternatively, the time frequency resources for the first two transmissions and the last two transmissions may be indicated separately using 2-transmission resource patterns as discussed earlier. In the frequency-domain, frequency durations F0 to F3 could be frequency sub-channels, combinations of sub-channels, resource blocks (RBs), resource block groups (RBGs), bandwidth parts (BWPs), subcarriers, groups of subcarriers, or any other quantization or unit of frequency. Furthermore, different frequency domain sub-channels are just an example. Sub-channels can instead be associated with different layers of non-orthogonal multiple access (NoMA), different pilot resources, and/or other resources. As described above, a transmission resource refers to at least time and frequency resources (e.g. a time duration and frequency bandwidth) to transmit a TB. In some other examples, the transmission resources could also or instead include code-domain resources (such as sparse code multiple access), space-domain resources, and/or different demodulation reference signals (DMRS). Moreover, the transmission resources are not limited to two-dimensions, and therefore could include a number of dimensions greater or less than two. In example embodiments, each UE in a group of UEs may be configured with multiple transmission parameter sets or multiple configurations that form a candidate set of transmission parameter sets that the UE can select from for SL V2X transmissions. Each transmission parameter set may define: transmission resources (e.g. time/frequency location), periodicity, frequency sub-channel definition, DMRS/preamble, transmission pattern (e.g. TRFP), SCI location, modulation and coding scheme (MCS), repetition number K, hybrid automatic repeat request (HARQ) process related parameters, and feedback channel indicator, among other things. In some example embodiments, each transmission parameter set is associated with a DMRS that can be used to determine the other properties of the transmission parameter set, for example transmission resources. Accordingly, each UE can be configured or preconfigured with a pool of candidate transmission patterns. In example embodiments, a SL communication may be established by performing a series of procedures that are configured for the UE to select communication resources that are not reserved by other UEs to transmit data, thereby mitigating against collisions. The series of procedures may include one or more of: a configuration procedure, a resource indication procedure, a sensing procedure, a resource selection procedure, and a transmission procedure, which will be described respectively in greater detail below. Configuration Procedure: Regarding the configuration procedure, each UE (e.g., a single UE or each UE in a UE group520as described in greater detail below with reference toFIG.5) may have a default initial transmission parameter set (e.g., defining initial transmission resources/patterns) or may otherwise be configured prior to transmitting a TB with an initial transmission parameter set to use for that TB. In some examples, each UE may be configured or preconfigured with an RP, such as an RP100. The RP may be any resource pool with an explicit definition of preconfigured resource/repetition pattern pool. In an embodiment, the RP may include the transmission pattern pool shown inFIG.1A. In the case of a TFRP pool, the initial transmission parameter set may include periodicity, length of a selection window, number of the repetition, size (e.g., time-domain length and frequency-domain length) of each resource for data transmission in the RP, etc. In some embodiments, the RP may be any pool of time frequency resources that is configured and can be used by a UE to perform SL transmissions. In some scenarios, there may be no explicit TFRP pool configured for a UE. The UE may select resources among a (pre)-configured RP for sidelink transmission. As noted above, in example embodiments different priority levels are associated with different types of resource reservations. In example embodiments, the UEs are configured or preconfigured with information that defines the relative priority levels for different types of resource reservations. In some examples, during the configuration procedure, a UE is configured with a TFRP pool and possibly an initial/default TFRP. The TFRP pool configuration should include at least a periodicity and offset (starting slot). The TFRP pool can repeat itself in a non-overlapping way. An example of TFRP configuration can be a non-overlapping TFRP pool defined inFIG.1A, which repeats itself every 5 slots (periodicity=5 slots) and offset is the starting slot number of the TFRP window/period, or a partially overlapping TFRP pool. In some examples, the partially overlapping TFRP pool may have a periodicity of 10 slots, as shown inFIG.8. Because the TFRPs in this case are non-overlapped (orthogonal), then in case flexible TFRP starting location is supported, only 1 bit of information carried by DM RS is needed to indicate whether the detected PSSCH corresponds to an initial transmission or a retransmission. In the case where TFRP pool is a partial overlapping TFRP pool, only 3 options (<2 bits) would need to be indicated by DMRS for sensing purposes because the location of PSSCH associated with the DMRS is already known. This can be done by setting a mapping relationship between the DMRS ports/sequences and the index of TFRPs that are partially overlapping. Considering 8 DMRS ports are available based on NR Uu design which corresponds to 3 information bits, then 2 bits of DM RS port information can be used to indicate the TFRP pattern. If flexible starting location of repetition is supported, the remaining bit can be used to indicate whether the current transmission is an initial transmission or a retransmission. In summary, a typical signaling for mode 2 TFRP operation may include the following: (1) indication from (pre-)configuration as part of RP (pre)-configuration including Periodicity, Offset (starting slot), Number of repetitions, and Time Frequency allocation or TFRP pool. In some examples, the TFRP pool can also be derived based on pre-configured parameters in the RP, such as periodicity, offset, etc., according to some rules which are not part of the RP configuration. Information carried by DMRS port/sequence may include up to 2 bits for TFRP pattern indication (zero bits are needed in case of orthogonal TFRPs), 1 bit for retransmission or initial transmission (zero bits are needed in case of a fixed TFRP starting position), 2 bits for MCS indication, 3 bits for quality of service (QoS) if QoS is indicated in the physical layer and not carried by SCI. In case of no explicit TFRP pool configuration, the RP may at least indicate the division of subchannels in frequency domain (such as the starting location of 1stsubchannel, the number of available subchannels and the size of subchannel in terms of number of resource blocks per subchannel), and RP may also indicate the available time domain resources (e.g. which slots) that can be used by the UE that is configured with this RP. With respect to the initialization procedure, each UE, e.g. UEs in the group520shown inFIG.5, may use a default or configured initial transmission parameter set or use the configured initial transmission parameter set in the configuration procedure to select resources for an initial transmission. In some examples, if some UEs have not been configured with an initial transmission parameter set, those UEs may just select resources among the RP, such as a specific transmission pattern, from the RP. Resource Indication/Reservation Procedure: Regarding the resource indication/reservation, each UE may use the default or preconfigured initial transmission parameter set in the initialization procedure to transmit an indication signal in a SL channel, such as a physical sidelink control channel (PSCCH), or a physical sidelink shared channel (PSSCH), to indicate reserved transmission resources to other UEs. The common way to carry the reservation information is SCI, as described earlier. In example embodiments, each reserved transmission resource is associated with a priority indicator that indicates a priority value of the reservation. The priority value may be a value indicating the priority associated with a data packet or data. The priority may be determined based on quality of service (QoS) of the data or data packet. For example, the priority can be ProSe Per-Packet Priority (PPPP) based on the per-packet QoS model. As noted elsewhere in this disclosure, the priority value may be assigned or adjusted depending on the type of transmission that the reservation is being made or to be made (The adjustment of the priority may be used to find the RSRP threshold for resource selection purposes. In this regard, in example embodiments the indication signal sent by a UE includes a resource indication that identifies the transmission resources the UE is reserving, as well as a priority indicator for the resource reservation (e.g., the priority of the packet to be transmitted) and/or reservation type information for resource selection and reservation. The priority indicator may indicate a priority of the data packet or a QoS priority of the data that is been transmitted in the current transmission or to be transmitted on the reserved resource by the reservation UE. The reservation type information may explicitly or implicitly indicate the resource reservation type as discussed earlier. UEs that detect and receive the indication signal can determine, based on the information included in the reservation indication, the resource reservation type, and priority identifier, what transmission resources to exclude from a pool of candidate resources in order to mitigate against collisions. In some examples, the indication signal may additionally indicate current resource in use, general time-frequency resource for transmission, one or more of periodicity numbers. In some examples, the reserved transmission resources may include transmission resources for future transmissions and/or retransmission. Prior to describing the sensing procedure, resource selection procedure, and transmission procedures, a description of the types of resource reservation and the assignment of priority levels to those resource reservation types will now be provided in greater details according to example embodiments. As noted above, examples of different resource reservation types include:(a) reservation for future transmission of different TBs, including subtypes of(a1) long term reservation of SL resource,(a2) reservation of SL resource for transmission of a selected or explicitly indicated number of resources for different TBs, and(a3) no reservation of SL resources for different TBs; and(b) resource reservation for blind retransmission of the same TB; and(c) resource reservation for feedback-based retransmission of the same TB; and(d) resource reservation for an initial transmission of a TB using a standalone advance control signal preceding initial transmission of the TB. In example embodiments, the resource reservation type is indicated in the SL control information (SCI) transmitted through a physical SL control channel (PSCCH), such as in SCI, or in the first stage of a two-stage SCI. In one embodiment, the SCI optionally includes an indicator indicating the number of retransmissions for which resources are to be reserved, and an indicator indicating the TFRP index for the given number of retransmissions. The number of retransmissions may include the current transmission or exclude the current transmission. In another embodiment, if the available TFRP pool of the sensing UE already includes TFRPs associated with different number of retransmissions, the first stage SCI may optionally include only the TFRP index. In this case, the TFRP index would be sufficient for the sensing UE to select the appropriate TFRPs. Resource Reservation Type (a) Reservation Type (a1)—Long Term Resource Reservation for Future Transmission of a Different TB: Type (a1) reservation is a reservation of a sidelink resource for a transmission of a TB via signaling associated with a prior transmission of a different TB. Resource reservation for future transmission of a different TB refers to a reservation that is specified in the indication signal sent in association with a first data transmission (e.g. a first TB) to reserve transmission resources for a future, different data transmission (e.g., a second TB that is not a repetition of the first TB). Thus, resources reservation of a future TB means that each UE may use the indication signal sent in association with a first TB to reserve resources for transmission of a future, second TB that is different than the first TB. For example, the indication signal transmitted in an SCI associated with a first TB, e.g. TB1, can include a resource reservation for a transmission of a second TB, e.g., TB2. In different examples, the resource reservation for TB2 may be included only in an indication signal associated with the initial transmission of TB1. In some examples, the resource reservation for the future TB2 may be included in the indication signal associated with both an initial transmission of TB1 and any retransmissions of TB1. In various examples, the resource reservation for TB2 could include reservations for transmission resources for: (i) only the initial transmission of TB2; (ii) the initial transmission and all or a specified number of retransmissions of TB2; or (iii) only a specified number of retransmissions of TB2. In example embodiments, some or all of the above examples may be available as configurable options. Long term here refers to reservation of future transmission resources in a periodic way, without specifying a fixed number of TBs to be reserved. The periodicity or resource reservation period (RSVP) can be indicated in the reservation signal or is a predefined value or configured/preconfigured values in the RP configuration (e.g. the reservation period is the same period of TFRP pool described byFIG.1AandFIG.3). The expression “long term” is used here to differentiate Type (a1) from Type (a2) to be described below, which reserves a specific number of resources for future TBs. For example, when a transmitting UE transmits a TB through sidelink transmission using a specific resource located at T0, the associated indication signal may explicitly or implicitly indicate that the transmitting UE will use the resources at t0+n×RSVP (n>=1 and n is an integer) at the same frequency location to transmit future TBs. In some other scenarios, the frequency location of the reserved resource for a future TB may be the same as the frequency location for the current transmission. The frequency location for a future TB may be determined based on frequency hopping or other factors other than the frequency location of the current transmission. With a long term reservation, the UE may change the resource used in the future if a resource reselection is triggered, or might not use the reserved resource at a given time if the UE does not have any data packet to transmit at that time. Reservation Type (a2)—Resource Reservation for Future Transmission of an Explicitly Specified Number of Resources for Future TBs: In reservation Type (a2), a transmitting UE may explicitly reserve resources for a selected or defined number of future TBs to be transmitted using the same periodic resources. For example, the reservation indicator included in an SCI associated with an initial data transmission (e.g. initial TB1 transmission) may specify that a particular time/frequency resource at time frequency location, e.g. (t0,fi), within a RP is to be reserved for the TB1 transmission. The reservation indicator may also indicate that the same resource will be required for a resource reservation period (RSVP) for each of a specified fixed number (m) of TBs. Thus, the transmitting UE will use the resource at time location t0+n×RSVP (1<=n<=m) and same frequency location to transmit m number of future TBs. When the transmitting UE knows the number (m) of future TBs to be transmitted, the UE can reserve resources, with the initial TB request, for the future (m) TBs without the need to perform any resource reselection until after transmission of the m TBs has been completed. In some embodiments, if the transmission pattern pool or TFRP pool is defined periodically with a periodicity, then the RSVP may be equal to the periodicity. Reservation Type (a3)—No Resource Reservation: When no periodic resource is to be selected or reserved, the SCI may simply indicate no reservation with an indicator. In some embodiments, the SCI may indicate the number (m) of resources reserved for future transmission where one of the possible choices is m=0. When m=0, it is indicated that there is no reservation of resources for future TBs. Another possible value of m is infinity or unknown, indicating a long term reservation. When m is a finite positive integer, it indicates m number of resources are to be reserved for transmission of future TBs. Reservation Type (b)—Resource Reservation for Blind Retransmission: Type (b) reservation is a reservation of a sidelink resource for transmission of a TB via signaling associated with a prior transmission of a different TB. A blind retransmission, also referred to as repetition, is a retransmission of a TB that is not triggered or terminated by HARQ feedback or scheduling grant. After an initial transmission, a TB is retransmitted without waiting for a feedback of the initial transmission and without receiving a new scheduling grant for a retransmission. In some examples, reservation of resources for one or more blind retransmissions can be indicated in the indication signal sent as SCI associated with the initial TB transmission. In some other examples, reservation of transmission resources for the blind retransmission may be an indication implied in a DMRS sent with the initial TB transmission. The indication may be implicit. For example, the DMRS information (e.g. DMRS port or DM RS sequence) may have a mapping relationship with TFRP or the location of time frequency resource of the retransmission, in which case detecting the DMRS gives the information which TFRP or which time frequency resource for retransmission is used by the transmit UE. The reservation indication for a resource reservation for a blind retransmission typically includes an indication of the time-frequency resources, e.g. indication of a TFRP, that will be used for the blind retransmission. If the number of retransmissions of a TB is greater than 1, two options for reserving retransmission resources include: option 1, for each transmission, for example including an initial transmission and each retransmission, of a TB, reserve the resources for all of the following transmissions/retransmissions of the TB; and option 2, for each transmission, e.g., initial transmission or retransmission, of a TB, only reserve the resources required for the next/subsequent retransmission of the TB. Option 1 provides earlier notification of subsequent resource requirements but may require more network overhead to indicate the reserved resources. In some example embodiments, a UE may be configured to only perform option 1, and in some example embodiments a UE may be configured to only perform option 2. In some examples, a UE may be configured to select between option 1 or 2 based on one or more criteria. For example, a UE could be configured to determine if the number of TB retransmissions is greater than a threshold, and if so, use option 2, otherwise use option 1. In some examples, option selection could be based on sensed channel information. In some examples, the number of blind retransmissions that will be performed may be configured or preconfigured for the UE, and in some examples the UE may be configured or preconfigured to select the number of blind retransmissions up to a predefined or (pre-)configured number. The selection can be based on criteria such as sensed channel conditions or transmission backlog at the UE. Reservation Type (c)—Resource Reservation for Feedback-Based Retransmission: Reservation Type (c) relates to reservation of feedback-based retransmission, which is similar to reservation for blind retransmission but allows the UE to take account of feedback information about the success of earlier data transmissions. Example feedback information includes, for example, Hybrid automatic repeat request (HARQ) feedback. In an embodiment, in a reservation Type (c) transmission, the indication signal sent by the transmitting UE associated with an initial data transmission, e.g. transmission of TB1, or one of the retransmissions of the TB, may include a reservation indication for K potential retransmissions including the initial transmission. However, upon receiving feedback indicating that a prior transmission or retransmission was successful, e.g. upon receiving an ACK indicating successful decoding of the transmitted TB1, the UE may release the previously reserved resources for future transmission and will not perform the retransmission using that reserved transmission resource. The UE may or may not send out a further indication/notification to release these reserved retransmission resources. Reservation Type (d)—Resource Reservation for an Initial Transmission of a TB Using a Standalone Advance Control Signal Preceding Initial Transmission of the TB: Reservation Type (d) reserves resources for initial transmission of a TB using a standalone SCI. When a transmitting UE reserves an initial transmission of a TB, the reservation signal can be sent in advance without an associated data or PSSCH transmission. The reservation signal can be sent in an SCI or a dedicated reservation signal. The reservation of the initial transmission of the TB may be indicated and sent in a separate indication signal, e.g., SCI, in a control channel in advance. Additional Example Indication Options In a further embodiment, to indicate the resources to be reserved for the current transmission and for retransmission of the same TB, and/or for detection purpose, the SCI may include indication information for indicating the TFRP for two (2) retransmissions. When four (4) retransmissions are required, the indication for the 2-retransmission TFRP may be repeated in the indication signal, or two indications for two different 2-retransmission TFRPs may be concatenated to form the indication for the 4 retransmissions. Indication for other multiples of 2 retransmissions may be formed similarly by repetition or concatenation. In yet another embodiment, the SCI may indicate the number of retransmissions, and further include a time domain slot pattern indication and a frequency domain subchannel based hopping offset. For example, in cases where the available resources include a (pre)configured TFRP pool, the SCI may indicate the TFRP index for resource selection and reservation. As an example for illustrative purposes, if the number of retransmissions is denoted as “K” and the maximum number of retransmissions is denoted as “K max,” which includes the current transmission, and the K max is limited to 4, then the possible choice of the K are [1, 2, 3, 4]. In some scenario, the choice of K is further limited, e.g., K can be [1, 2 or 4], but cannot be 3 in order to reduce signaling overhead. A TFRP pool may be defined for each particular number of retransmissions, and the TFRP pool is associated with a TFRP index. During operation, the indication signal may simply indicate the TFRP index in order to indicate the particular TFRP pool associated with the particular TFRP index. Examples of TFRP are shown inFIGS.1A and1B. It is noted that as shown in the below examples the TFRP pool for 4 transmissions may need 5 TFRPs in the pool. If it is desired to use the same pool size, or the same number of TFRPs in the pool, for different numbers of transmissions, a possible option is to repeat the same TFRP pool for 4 transmissions over the next 5 slots. Another possible option is to create an N=4 TFRP pool by repeating an N=2 TFRP pool. In another example, two TFRP pools for N=2 and N=4 may be combined to form one TFRP pool with 15 resource patterns, and the resulting TFRP is associated with a separate TFRP index. In this case, the indication signal only needs to indicate the TFRP index of the combined TFRP pool to indicate that the combined TFRP pool is to be reserved. In a further example, the TFRP index of the TFRP for a first 2-transmission reservation is indicated in a first indication signal. To reserve the resources for K=4 retransmission, the TFRP for the 2-transmission may be repeatedly used, or a second indication signal may indicate a different TFRP index for a different TFRP for two (2) of the four (4) transmissions. Regardless of whether a TFRP pool has been configured or pre-configured, the indication signal may directly indicate the actual time-frequency resource to be reserved, without explicitly indicating any (pre)configured TFRP pool. Therefore, in various embodiments, indication of a TFRP index in a TFRP pool can be replaced with direct indication of the time frequency resources of the TFRP. It is possible to indicate time frequency resources based on a given TFRP pool with all possible combinations of the TFRPs in the pool under certain constraints. For example, a possible constraint may be that all transmissions of a TB must fit within a predetermined or preconfigured maximum number of slots. In various embodiments, when the time frequency resources of the current transmission and the reserved retransmission are indicated in the indication signal, the time resources and frequency resources may be indicated separately and independently. In the time domain, the time resources may be indicated using a bit map, or an index of all time slot combination options within a delay constraint. For example, the delay constraint may be that the maximum time gap between the first transmission and the last transmission is a given number of slots, such as M slots. For time resource indication, a bit map may be used to indicate whether each particular time slot has been used or not. As an example, assume the maximum time gap between the first and last transmission is 7 slots. If a total of K=4 transmissions for a TB is indicated, with the time gap between adjacent transmission as 2 slots, 1 slot and 2 slots, then the bit map can be indicated as [0 1 1 0 1 0 0], with respect to the current slot (denoted as slot 0) that is used to perform the first transmission, so that slots 2, 3 and 5 are used for retransmissions, and slots 1, 4, 6 and 7 do not have any transmissions. For time resource indication, a time resource index may be used to indicate a time domain pattern among a predefined pool of time domain patterns. The time domain pattern and index may be assigned based on predefined table mapping, or based on certain rules. As an example, if the maximum time gap (T) between the first and last transmissions is T=7 and the number of retransmission resources reserved is 3, the total number of reserved transmission and retransmission resources including the current transmission is 4. It is not necessary to indicate the time location, e.g. the time slot number, of the current transmission if this time location is in the same time slot as the SCI. The total number of available choices of possible combination of 3 retransmission resources among 7 slots is 35 (=7 choose 3=7*6*5/3*2*1). This number of choices will require 6 bits to indicate in this example. In the above example, it is assumed that the number of reserved retransmission resources is known or has been indicated separately. In some embodiments, all combinations of possible numbers of reserved retransmission resources and possible time domain resource patterns may be indicated using a single time domain resource pattern index. For example, if the only possible repetition numbers are 1, 2, or 4, the number of possible resource combinations is 35, as illustrated above. Similarly, it can be shown that the number of possible resource combinations is 7 for up to two (2) retransmissions, and 1 for one retransmission. The total number of possible resource combinations is thus 43=35+7+1=43. An index for indicating all the 43 possible combinations may be defined using a time domain resource index. The mapping of the index to all 43 possibilities may be defined in a table or described in a predefined rule. The number of reserved retransmission resources can be derived from the time domain resource index or a resource pattern index. Thus, it may not be necessary to separately indicate the number of reserved retransmission resources. Another possible option for indicating the time resource is to indicate the time gap between each transmission and its next transmission. For example, for a total of 4 reserved transmission/retransmission resources including the current transmission, it is possible to indicate the time gap between the current transmission and the next (2nd) transmission, the gap between the 2ndand 3rdtransmissions, the gap between the 3rdand 4thtransmission. For a total of N transmissions, the indicated time gap may be up to the gap between the (N−1)th and Nth transmissions. For example, if the maximum gap between two adjacent transmissions is 4 slots, for 4 transmissions, a total of 2*3=6 bits are needed to indicate the time gaps. If the maximum gap is 2 slots, then only 3 bits are needed to indicate the time gaps. In some embodiments, the time gaps between all adjacent transmissions may be the same, in which case only one time gap value needs to be indicated. In the frequency domain, a hopping offset in terms of the number of subchannels hopped between two repetitions can be indicated. The indication signal may indicate the frequency resources to be reserved by indicating the following information. The indication signal may indicate the size of the frequency resources in terms of the number of subchannels, the starting subchannel index of the initial transmission, and possible further optional information for retransmission as discussed next. One possible option is to use the same subchannel or subchannels used for the initial transmission for all subsequent retransmissions, in which case no further information, and 0 bit, is needed to indicate the frequency resources for retransmission. Another option is to indicate the starting subchannel index for current transmissions and retransmissions separately. The number of subchannels used for each transmission may be the same, in which case only the number of subchannels used for the current transmission need to be indicated. A further option is to indicate the frequency resource for the initial transmission or the first transmission and a Frequency offset (F0), in terms of the number of subchannels, for frequency resources to be used in retransmission. The frequency resource for initial transmission may include size of the frequency resources in terms of the number of subchannels, and the starting subchannel index of the initial transmission. In this case, the FO can be assigned or specified in various suitable manners. For example, the FO can be an offset between odd frequency slots and even frequency slots based on an absolute slot index. The FO can be an offset between any adjacent pair of slots. The FO can be an offset between adjacent odd and even numbered repetitions. The FO can be between any adjacent repetitions. As an example of subchannel based frequency offset indication, assuming j=[0, 1, . . . , K−1] refers to the retransmission/repetition index, i.e., the index of the number of transmissions starting from 0. If in the SCI, the starting frequency subchannel indicated as f_0, then the starting frequency subchannel of all transmissions with retransmission index j is given by f_(j+1)=(f_j+F0) mod (total number of available frequency subchannels M_sub); j=[0, . . . , K−2] and f_j=f_0 at j=0; mod is the modular function, and the modular function is optional, and the purpose of modular function is to ensure the frequency subchannel after offset still located within the range of available frequency subchannels. If the frequency offset is defined for only between odd and even adjacent repetitions, then we may have f_j=(f_0+F0) mod M_sub, if j=odd number, and f_j=f_0 if j=even number. In the case, the 2ndrepetition has an offset FO with respect to the 1st transmission, but 3rd repetition has the same frequency location as the 1sttransmission, and 4threpetition has an offset of FO with respect to the 3rdrepetition. Similarly, if the frequency offset is defined with respect to the slot index, we have for a repetition located in slot index j, f_(j+1)=(f_j+F0) mod M_sub, where j=[0, 1, . . . , M_slot−1], where j is the slot index in a frame and M_slot is the number of slots in a frame and f_0 is indicated. Again, if frequency offset is defined between even and odd slots, we have for a repetition located in slot index j, f_j=(f_0+F0) mod M_slot, if j is an odd number, and f_j=f_0 if j is an even number. To accommodate the added indication information related to reservation type and identification of reservation resources, the SCI may have different data sizes, e.g. bit sizes, and different formats. For example, in some embodiments, depending on the number of retransmissions, the SCI may have a different format for each different number of retransmissions, in this case, the number of retransmissions may be implicitly indicated by the SCI format and does not need a specific field within the SCI to explicitly indicate it. In another embodiment, only 1 SCI format used for all possible numbers of retransmissions. The SCI may be formatted to consider all possible numbers of retransmission reservations together, and use one index to indicate the time frequency resource index, or only the time domain resource index. In an example embodiment, a unique priority indicator or priority coefficient or priority adjustment value for adjusting the priority of a data packet, or a resource exclusion threshold for excluding resources from selection, may be set/preconfigured to correspond to the associated reservation type. In example embodiments, a priority indicator for a resource reservation may be included in an indication signal that is sent in respect of the resource reservation. In various example embodiments, the indication signal may be incorporated into one or more of SCI sent in the PSCCH, or a DM RS or preamble sent in the PSSCH. In some examples, the indication signal may be an advanced indication signal that precedes a data transmission. As now can be appreciated, in an embodiment, the sensing UE needs to know the reservation type of a data transmission reservation from the reservation UE in order to adjust the data packet priority for resource selection. Conveniently, the reservation type can be explicitly indicated in the reservation signal, such as a first stage CSI. In some embodiments, the reservation type may be Implicitly obtained from a property of the reservation, or from a combination of multiple reservation properties and the reservation signal. For example, for reservation of retransmissions of the same TB as the current transmission associated with the SCI, if the retransmission resources are indicated, it implies such retransmission resources are also reserved. Other ways of indicating retransmission resource have been described above. If a retransmission resource is indicated, it may by default indicate that the corresponding retransmission resource is reserved, and there is no need to have an extra bit to indicate whether there is a reservation for retransmission of the same TB. However, in order to know whether the reservation is for blind retransmission or feedback based retransmission for the same TB, there may be a bit (A) to indicate which one of the two types is for the reservation of retransmission resource. In some scenarios, there may be also a bit (B) within SCI to indicate whether the receiver UE should send HARQ feedback for the current data transmission associated with the SCI. In some scenarios, the bit B to indicate whether there is HARQ feedback associated with the current transmission and the bit A to indicate whether the reservation type is blind retransmission (Type b) or feedback based retransmission (Type c) may be the same. In this case, the UE may use bit B to implicitly derive whether the reservation of retransmission resources is for blind retransmission or feedback based retransmission. In some other scenarios, the bit B and bit A may be separate bits in SCI, and they can be different. As an example of different bits, if reservation of 4 transmissions of a TB is indicated in SCI, in the SCI fields for bit B of the 4 SCIs associated with the 4 transmissions may be [0, 1, 0, 1], respectively, indicating to the receiver to send HARQ feedback for the 2ndand the 4thtransmissions, but no feedback for the 1st and 3rdtransmissions. However, in the SCI of the 1st transmission reserving all 4 transmissions, bit A may be 1, indicating that this is a feedback based retransmission for the sensing UE, because the 3rdand 4thtransmission may be terminated and resource may not be used, so the sensing UE should treat the priority adjustment and RSRP threshold adjustment for resource selection according to Type c, i.e., reservation for feedback based retransmission. For reservation of periodic resources for a different TB, the UE may determine whether the reservation is for sub-type a1) a2) or a3) from one or more of the relative information indicated in SCI, e.g., RSVP, number of reserved period resources and/or bit indicating whether reservation of periodic resource is enabled or not. The details have been described earlier. In another embodiment, whether reservation of resources for a different TB is supported can be enable/disabled by (pre)configuration. For example, in the RP configuration, there may be one bit indicating whether reservation of resources for a different TB is enabled or disabled. If reservation of resources for a different TB is disabled, then sensing UE may always assume no periodic reservation (Type a3), and in the SCI format, the respective reservation field, such as RSVP, number of reserved period resources and/or bit indicating whether reservation of periodic resource is enabled or not are not needed to be in the SCI. On the other hand, if reservation of resources for a different TB is enabled, the UE may have the option to choose sub-type a1, a2 or a3 and indicate the type through the respective field in SCI (RSVP, number of reserved period resource and/or bit indicating whether reservation of periodic resource is enabled or not). In this case, there may be two different SCI formats corresponding to the two case whether reservation of resources for a different TB is enabled or disabled. In another embodiment, the method to assign different priorities to different reservation types may be achieved by directly incorporating the different priority levels associated with different reservation types in the reservation signal. In this case, when a transmitting/reservation UE obtains the packet priority Pdfrom the priority information associated with the data transmission, the transmitting/reservation UE may directly apply different predefined or preconfigured or configured coefficients (e.g., aior ci) to obtain or calculate P(a1), P(a2), P(b), P(c), and P(d) respectively, and indicate the final priority level P(i) instead of Pd. In this case, the sensing UE does not need to take into account the reservation type when processing the priority information from the reservation signal to be used for resource selection. For example, for reservation Type (a1), a transmitting UE indicates P(a1)=aa1*Pd in the priority indication of the reservation signal, whereas for reservation Type (b), a transmitting UE may indicate P(b)=ab×Pd, where aa1and abare the priority coefficients associated with Type (a1) and Type (b) reservations respectively. In an example, abis between 0 and 1, and aa1=1. In this case, the sensing UE obtains the priority information that has already taken into account the reservation type, and the sensing UE does not need to differentiate the reservation type to use the priority value for resource selection. In some examples, the priority levels may be dynamically determined based on sensed information, including sensed reservation type, by each sensing UE when the sensing UE performs the sensing procedure, which will be described in more detail in the sensing procedure section below. In some examples, different reservation types may have different impacts on the resource selection procedure. For example, as discussed earlier, for reservation Type (a1), the reservation UE might not actually use the same resource during the resource selection window of the sensing UE because it may not have a data packet to transmit or a (re)selection has occurred. For reservation Type (b), the reservation UE reserves the resources for blind retransmission and is more likely to use the reserved resource for retransmission thus having an impact on the sensing UE. For reservation Type (c), the reservation UE may release the reserved resource for retransmission based on a HARQ-feedback indicating receipt of an ACK before the retransmission. Therefore, reservation Type (b) may be given a higher priority over reservation Type (a1) and Type (c). That is, P(b)>P(a1), and P(b)>P(c). One way to realize the different priority of different type is through adjusting the priority (e.g. by applying a reservation type specific coefficient) to the packet priority before using it to determine the RSRP threshold, as further described later. In another embodiment, with respect to reservation Type (c) resource reservation for feedback-based retransmission, for unicast, a receiving UE (Rx UE) can adjust its behavior on whether or not to expect a retransmission based on the HARQ feedback. For a sensing UE (other UE), their resource selection scheme should lower the priority of a reservation if the reserved resource can be released. This can be achieved by adjusting the priority level by multiplying it with a coefficient less than one if there is a chance the reserved resource may be released based on the HARQ feedback. In such case, a sensing UE should adjust the priority associated with reservation of HARQ-feedback based retransmission to be lower than the reservation of blind retransmission for the purpose of resource (re)selection. In this case, P(b)>P(c). Similarly, reservation using a standalone SCI cannot be terminated by any HARQ feedback, i.e., type (d), may have higher priority than type b), e.g. P(d)>P(c) and may be P(d)=P(c); The sensing procedure, resource selection procedure, and transmission procedure will be described in greater detail next. The sensing procedure, resource selection procedure, and transmission procedure may be performed by a UE autonomously. As a result of these procedures, the available candidate resources to a UE may be reduced, which decreases the risk of collision. The probability that multiple UEs will select a common resource for transmission at the same may be reduced according to these procedures. Before the resource selection procedure, such as TFRP selection, a sensing UE may perform sensing based on decoding of the SCI. The sensed information may include all potential reservation types indicated earlier. During the sensing procedure, each UE listens to a communication channel, such as PSCCH or PSSCH, to detect signals, including for example SCI sent on PSCCH and DM RS sent on PSSCH, from other UEs within the sensing window. The sensed information or signal may be utilized to reduce the size of a set or pool of candidate resources available for selection by the UE for transmission. During the selection process, the UE selects radio resources from the reduced set or pool of candidate resources. During the transmission process, the UE uses the selected physical resources to transmit data and control information. In example embodiments, the reservation/selection and transmission processes are performed by the UE autonomously. Sensing Procedure: In the sensing procedure, during a sensing window, a UE such as a sensing UE monitors indication signals and other signals from another UE in one or more SL communication channels, such as SCI in PSCCH or DMRS in PSSCH, to determine what channel resources are being used and being reserved by other UEs. As noted above, in example embodiments the indication signals include a reservation indication indicating what resources are being reserved, including the reservation type, and possibly priority indications (e.g. packet priority) for respective resource reservations. In the case where an indication signal is incorporated into SCI, a sensing UE receives and decodes the SCI to obtain information including resource indications and resource reservation type indications, and possibly priority indications. In some examples, DMRS can be used as implicit indication signals. In some examples, DMRS reception can be blindly performed by a sensing UE, and in some examples a sensing UE may be configured or preconfigured with information about DM RS configurations. In the case where a sensing UE has detected a DMRS blindly in PSSCH, the sensing UE may measure SL reference signal received power (RSRP) of the DMRS. In some examples, each UE is configured or preconfigured with a transmission pattern pool, such as a TFRP pool, a DMRS pool, or a priority pool, along with mapping information that maps each DM RS from the DMRS pool to a transmission pattern from the transmission pattern pool and a respective priority level from the priority pool. In some examples, multiple different DMRS may map to the same transmission pattern or priority level. In this regard, the DM RS can function as an indication signal that includes a reservation indicator and a priority indicator, with each DM RS mapping to a transmission pattern and mapping to a priority level. In some examples, the association/mapping configuration may be updated at UEs through signaling, such as through radio resource control (RRC) signaling. Using these mapping relationships, the sensing UE can derive or determine, based on detected DMRS, which resources or patterns other UEs are using and which resources or patterns other UEs have reserved, and the priority levels associated with these resource reservations. The mapping of DMRS to specific patterns/priority levels may be based on one or a combination of DMRS sequence, different roots/initialization for the DMRS sequence, different cyclic shift values, DMRS time and frequency locations such as different symbols, different orthogonal cover code used, different antenna ports, different code division multiplexing (CDM) groups, different DMRS patterns, or some other aspects of the DMRS. Resource Selection Procedure: The sensing UE selects resources for a subsequent transmission or a retransmission based at least in part on reservation type, the packet priority indicated by other UEs and the packet priority level of the data that is being transmitted by the sensing UE. The sensing UE then adjust the packet priority value of the reservation based on the reservation type and find the RSRP threshold according to the adjust priority value and determines whether to exclude resources reserved by the sensed reservation type. The priority (P) or threshold (Th) associated with a reservation may be determined or adjusted based on the reservation type. Example reservation types and their corresponding priorities or thresholds are described in greater detail below. Priority P(a1) for Reservation Type (a1) For illustrative purposes, the priority indicator P(a1) is used herein to represent a priority value or a priority level that is associated with or dependent on the reservation Type (a1) resource reservation for future transmission of a different TB. However, in some example embodiments different priority values may be assigned to a given reservation type described herein including Type (a1). Similarly, priority indicators P(a2), P(b), P(c), and P(d) are used herein to respectively represent a priority value or a priority level that is associated with the respective reservation Type (a2), Type (b), Type (c), or Type (d), or that is dependent on the respective reservation type. Each of these priority indicators may also depend on the priority of the data packet. In at least some examples, different priority levels may be associated with each one of the different reservation types. In some examples, a priority indicator, such as one or more of priority indicators P(a1), P(a2), P(b), P(c), and P(d), may be obtained through an equation, a value, a mapping table, or any other types of parameters to define the priority value or the priority level. In some examples, NR V2X supports an initial transmission of a TB without reservation, depending on the sensing and resource selection procedure. In some examples, a priority indicator corresponds to NR V2X specified functionality that supports reservation of a SL resource for an initial transmission of a TB at least by an SCI associated with a different TB, depending on the sensing and resource selection procedure. This functionality can be enabled/disabled by configuration or pre-configuration. Priority P(a2) for Reservation Type (a2) A difference between Type (a2) and Type (a1) is that a UE is more likely to use the resources it has reserved in Type (a2) than in Type (a1), because in Type (a2) the UE has information on the number of the data packets or TBs to be transmitted and does not need to perform reselection of resources before the expected m TBs have been transmitted. For illustrative purposes, the priority indicator P(a2) is used herein to represent a priority value or a priority level that is associated with, or dependent on, the reservation Type (a2) resource reservation for future transmission of an explicitly specified number of TBs. No priority indicator for reservation Type (a3). When no resource is to be selected or reserved, there is no need to specify any priority or threshold. Priority P(b) for Reservation Type (b) For illustrative purposes, the priority indicator “P(b)” is used herein to represent a priority value or a priority level that is associated with the reservation Type (b), or dependent on the reservation Type (b). Priority P(c) for Reservation Type (c) For illustrative purposes, the priority indicator P(c) is used herein to represent a priority value or a priority level associated with or dependent on the reservation Type (c) for feedback-based retransmission. Priority P(d) for Reservation Type (d) For illustrative purposes, the priority indicator P(d) is used herein to represent a priority value or a priority level that is associated with, or dependent on, the reservation Type (d) resource reservation for an initial transmission of a TB using a standalone advance control signal preceding initial transmission of the TB. Sensing UE's resource selection behavior with respect to the different reservation type can be summarized as the following steps:1) The sensing UE obtains the packet priority of the reservation from decoding the SCI of other UE that performs the reservation, and obtains the corresponding packet priority field in the SCI2) The UE determines the reservation type or sub-type explicitly or implicitly based on corresponding information in the SCI as described earlier3) The UE adjusts the packet priority of the reservation based on the reservation typea) The adjustment can be done by multiplying the packet priority value with a reservation type specific coefficientb) The priority coefficient for reservation of HARQ-feedback based retransmission<Priority associated with the reservation of blind retransmissionsc) The priority coefficient for long-term reservation<Priority associated reservation of resources for a fixed number of TBs4) The UE uses the adjusted packet priority, along with the packet priority of its own data to be transmitted, to find the corresponding RSRP threshold (e.g. through a mapping table)5) If the RSRP measurement associated with the reservation SCI is above the determined RSRP threshold, the corresponding reserved resource should be excluded in the candidate resource in the resource selection procedure As illustrated earlier, in some examples, the priority values associated with different reservation types that are used for resource selection by a sensing UE may be derived or determined based on the packet priority for the reservation as well as the reservation type. For example, an adjusted priority P(i) may be calculated using one of Equations (1), (2) or (3), P(i)=ai×Pd, (1) P(i)=ai×ΔPd, (2) P(i)=Pd+ci, (3) where i may represent a1, a2, b, c, or d, corresponding to Type (a1) to Type (d) respectively; aiis a priority coefficient associated with reservation Type (i); ΔPd=Pd−Pself; and ciis a constant associated with Type (i). Pdis an indicator indicating a relative priority of the current or future data transmission of the UE that performs the reservation, which is the priority of the data packet being transmitted using the TB. Pselfis the priority value of the data to be transmitted by the UE that is performing the sensing and resource selection. The UE that performs the reservation may be referred to as the “reservation UE” herein and the UE that performs sensing and resource selection may be referred to as the “sensing UE” herein. A sensing UE may be a reservation UE depending on the context. The priority coefficient, ai, can be predefined, configured or pre-configured during operation, or derived or determined based on known parameters/factors. In some examples, the priority coefficient aimay be determined by a sensing UE based on the reservation type indicated in a sensed indication signal. For example, when the sensed reservation type is Type (b), a1may be used to calculate P(b). The value of abmay be determined in view of Type (b) reservation. Similarly, aa1, aa2, ac, or admay be used for Types (a1), (a2), (c), (d) respectively in a similar manner. The following inequality among the coefficients may be set according to reasons described in this disclosure: aa1<aa2; ab>ac; ad>ac; An example is aa2=ad=ab=1, while 0<aa1<1 and 0<ac<1, which means only type c and type a1 reservation need to adjust the priority value. Note that this inequality assumes a higher value of priority level means higher priority. If higher value of priority level means lower priority, then the inequality is reversed. Priority indicator Pdindicates a priority value or level that is associated with the priority of the data packet/traffic the reservation UE is currently transmitting, or with the priority of some data packet/traffic to be transmitted in the reserved resource for future transmission. In some embodiments, the priority level Pdis associated with a priority related property in the logical channel of the transmitted data. The priority indicator Pdcan be explicitly or implicitly indicated in the indication signal (e.g. SCI) or any signal that is associated with the data transmission. For example, a priority level of the data (Pd) can be indicated in the sidelink control channel for transmitting SCI that is associated with the SL data transmission in the PSSCH, or priority level Pdcan be implicitly indicated using DM RS information, such as DMRS port/sequence information, and its mapping relationship to the priority level. Thus, in such examples, the priority value applied by a UE to a reservation can be based on both the reservation type, with an associated priority coefficient aibeing used to assign different priority levels to different reservation types, and a priority level Pdof the data to be transmitted for which the resource reservation is being made. In some embodiments, the priority value after adjustment P(a) to P(d) may be determined based on their associated reservation type as follows. Priority level P(b) may be assigned or set to have a value greater than the value of P(a1), i.e., P(b)>P(a1), for the following reasons. Correspondingly, the priority coefficient may be set to be ab>a_a1. For Type (b) reservation, the transmitting UE reserves the resources for blind retransmission and there is a high probability that the reserved resources will be actually used for retransmission, and the reservation will have an impact on the resources available to the sensing UE. By comparison, reservation Type (a1) is used for long term reservation, and the transmitting UE that reserves the resources or TFRP may not need to actually use the same resources during the resource selection window of the sensing UE, because the transmitting UE may not have a data packet to transmit or a further resource (re)selection has occurred. Therefore, data transmission with Type (b) reservation may be given a higher priority over Type (a1) reservation. In these examples, a higher value of P(i) indicates a higher priority. In some examples, P(b) and P(a1) may be determined using Equation (1) with the coefficients aa1and abbeing configured to have the relationship of ab>aa1. For example, in a specific embodiment, it may be configured so that, ab=1, and 0<aa1<1. In one example, aa1=0.5. In another example, aa1=0.6. The coefficients ab, aa1may be respectively indicated by two different indication signals, or may be indicated in one indication signal. In some examples, P(b) and P(a1) may be determined using Equation (2). In these examples, a sensing UE can take account of the priority of the data the sensing UE will be transmitting and the priority of the data for which a reservation UE has reserved a resource. In another example, P(b) and P(a1) may be determined using Equation (3), where cb<ca1. In a specific example, cb=0, and ca1=1. The determination of other priority indicators P(i) may be similarly made depending on the relevant reservation types in view of the disclosure herein. As a further example, P(a2) may be greater than P(a1), i.e. P(a2)>P(a1). For instance, P(a1) and P(a2) may be configured to have the following relationships: P(a2)=Pd, and P(a1)=aa1×P(a2); or P(a2)=aa2×Pd, and P(a1)=aa1×Pd. That is, P(a1) and P(a2) are determined using Equation (1), where aa1has a value between 0 and 1, and aa2=1. The values of aa1and aa2may otherwise satisfy the relationship aa1<aa2. For example, aa1may be 0.5, and aa2may be 0.9. The reason for the above relationship is that there is a high probability that the reservation UE that reserved resources for a specific number of TBs under Type (a2) reservation will actually use the reserved resources for transmission of a future TB, but under Type (a1) reservation, the reservation UE is less likely to actually use the reserved resources because reselection may occur or there may be no data to transmit as discussed earlier. In some examples, P(a2) may be equal to P(c), because in both Type (c) and Type (a2) reservation cases, the reservation UE has a relatively high probability to actually use the reserved resources. In some examples, P(b), P(a1) and P(d) may have the relationship of P(d)=P(b)>P(a1). The reason is, like in the case of Type (b), in the case of reservation Type (d) there is a relatively higher probability that the reservation UE will actually use the reserved resources than in the case of Type (a1) reservation. In some examples, P(d)=P(a2). In some examples, P(d)=P(a2)>P(a1). For example, if a sensing UE detects that a received indication signal indicating a reservation Type (b), the sensing UE may calculate a priority value P(b) corresponding to the reservation Type (b), which may be represented by Equation (1) discussed above, in order to prioritize avoiding a collision with resources that have been reserved in respect of Type (b) reservations. Thus, the sensing UE may determine, when selecting resources, whether resources reserved by the reservation Type (b) should be considered to for exclusion based on the value of P(b). If the sensing UE decides to take the resource reservation Type (b) into consideration for exclusion, when the sensing UE selects resources, the sensing UE may first exclude reserved resources of Type (b) for selection, and then select other available resources from the RP100, such as a TFRP pool. In some examples, the resource (re)selection procedure may assign different priorities to different reservation types. Determination of priorities will now be further discussed according to example embodiments in the example context of three priority levels, for example, in the context of reservation Types (a), (b) and (c). For Type (c) reservation, there are two possible mechanisms to deal with reserved HARQ-feedback based retransmission. In one embodiment, the UE is able to determine whether the transmitting UE will release the reserved retransmission resources based on the HARQ feedback information that is sent by the transmitting UE to the receiving UE. This embodiment may be applicable to unicast where HARQ feedback is supported and there is only one (1) receiver UE. However, other scenarios, such as groupcast, are not precluded from this disclosure. For each sensing UE, if the UE can decode signals on physical sidelink feedback channel (PSFCH) and obtain information of the signals, the UE can determine whether reserved resources for feedback-based retransmission are being used for the current sensing procedure based on the obtained information on PSFCH. If the sensing UE determines that resources reserved for retransmission have been released by the transmitting UE, such as the sensing UE receives an ACK for unicast transmission, the sensing UE does not need to avoid using the particular resources for its own transmissions. In another embodiment, the sensing UE may ignore the reservation information because the sensing UE can expect the transmitting UE to release the reserved resource based on the reservation type. In some examples, if the sensing UE determines that resources reserved for retransmission have not been released, such as the sensing UE detects a NACK or does not detect any signal or feedback on PSFCH, the sensing UE may set the priority level/value of Type (c) to equal to the priority level/value of the Type (b), that is, P(c)=P(b). In that case, when the sensing UE selects resources, the sensing UE excludes both the resources of Type (b) corresponding to P(b) and the resources of Type (c) corresponding to P(c), and then selects other available resources from the RP100(e.g., TFRP pool). In another method involving Type (c) reservation, a sensing UE may not be able to detect other UEs' feedback or may be unable to determine whether a transmitting UE can or will release the retransmission resource. In this case, the sensing UE can lower the priority level of the reservation Type (c) for resource selection purpose. Thus, P(c) may be set, predefined, determined, or calculated to be at a lowest level, or to be lower than the priority level of P(b), i.e. P(c)<P(b). In the case where P(c)<P(b), P(c) and P(b) may be defined using Equation (1) with P(b)=Pd, P(c)=ac×P(b), where 0<ac<1; or P(b)=ab×Pd, P(c)=ac×Pd, and ab>ac. P(b) and P(c) may be calculated by the sensing UE, at least in part based on the sensed reservation type, and used for resource selection. The coefficient acmay be predefined or (pre)-configured or derived based on potential packet loss probability and/or probability of releasing the reserved resources of the feedback-retransmission. Thus, when the receiving/sensing UE selects resources, if the receiving/sensing UE detects that an indication signal indicates a reservation Type (c), the sensing UE may determine that when selecting resources, whether resources reserved by the reservation Type (c) will be considered to be exclude by the sensing UE based on the calculated value of P(c). If Type (c) reservation is to be excluded for selection, the sensing UE may exclude reserved resources of Type (c) from selection and select other available resources from the RP100such as the TFRP pool, in order to avoid conflict with resources reserved for Type (c). In some examples, if the value of P(c) is lower than a predefined threshold, the sensing UE may decide not to exclude Type (c) resources from selection, in which case the sensing UE may select available resources from the RP100that includes Type (c) resources. Thus, in these examples the sensing UE determines the priority values or priority levels based on received/sensed information and recognized reservation type used and indicated by other UEs. In some other examples, the priorities, such as priority values or priority levels, may be indicated in an SCI or a DMRS and obtained by the sensing UE once the SCI or DMRS is decoded. In some other examples, only the reservation type may be indicated in an SCI or a DMRS and obtained by the sensing UE once the SCI or DMRS is decoded, and then the sensing UE may determine or calculate a priority value or an exclusion threshold associated with the sensed reservation type. In some examples, the priority value or the priority level of the data packet, Pd, may be determined according to a per-packet QoS model based on both ProSe Per-Packet Priority (PPPP) and ProSe Per-Packet Reliability (PPPR). The value of PPPP can be the priority value/level used to address a number of QoS-related physical layer issues, such as resource reservation and packet conflict. The value of Pdmay be obtained from a higher layer parameter configured to the UE. In some examples, in the resource selection procedure, the sensing UE may select both resources for initial transmission and resources for later retransmissions. For example, the sensing UE may select a TFRP to carry out both the initial transmission and blind retransmissions of a TB. In some examples, the reservation Type (a1) may include a type of reservation for future TBs that is similar to a long-term sensing and semi-persistent transmission scheme in LTE V2X, which is employed for resource reservation. Under Type (a1) reservation, when a transmission is performed at time t0, frequency location f0, the sensing UE may expect that the transmitting UE will continue to use the reserved resource at t0+n×RSVP, n=1, 2, . . . , at the same frequency location f0. Thus, the sensing UE can try to avoid the resources that fall into the selection window. When the reservation Type (a1) is indicated, after a selection of the resources, the sensing UE may keep using the same resources periodically until a re-selection is triggered. This type of transmission scheme may be referred to as a semi-persistent transmission scheme. When the re-selection is triggered, the UE may re-perform the resource selection procedure and select a different resource set. There are different kinds of events that may trigger a reselection, which may include an instance in which a delay requirement of data packets cannot be satisfied. The RSVP may be indicated in the SCI associated with data transmission. The reservation period may also be (pre)-configured or predefined without indicating transmissions. When a semi-persistent transmission scheme is applied, the reservation resources might not be used during the reservation period. For example, if a transmitting UE does not have any packet to transmit in the future, or a reselection has been triggered and the transmitting UE selects different resources for a subsequent transmission, the reserved resources may still be available, which may not be indicated by the sensed indication signal. Therefore, the reservation for the semi-persistent transmission scheme may not be as certain as the reservation for blind retransmission. An example embodiment of SL V2X resource allocation according to the methods describes above will now be described. FIG.2illustrates an SL communication resource sensing and reservation method in the context of a frequency (y-axis) and time (x-axis) plot. Transmission resources associated with three respective UEs (UE1, UE2 and UE3) are shown as time-frequency blocks within a sliding sensing window202and a resource reservation period (e.g., resource selection period). In the example embodiment, vehicle UEs are synchronized, which enables sensing and resource reservation/selection for V2X traffic. SCI decoding, PSSCH DMRS detection and SL measurement can be used for sensing other UE transmissions. Explicit reservation in SCI or implicit indication via PSCCH/PSSCH DMRS by a transmitting (Tx) UE for a receiving (Rx) UE can indicate the next TB or TBs which can also be used by other UEs for resource selection and exclusion. In example embodiments, UE1 applies a sliding sensing window202. The sensing window is defined as a window of length T preceding a packet arrival in which the packet is ready for transmission. The length of the sensing window can be predefined or configured/preconfigured for the resource pool. In the case of a TFRP pool that is explicitly defined with a periodicity, the length of the sensing window can be a multiple of the TFRP periodicity. Within the sliding sensing window202, UE1 continuously performs one or more of the following sensing actions to collect sensing information:(i) monitor for and decode the SCIs transmitted from other UEs such as UE2 and UE3 SCIs;(ii) perform DMRS blind detection;(iii) measure PSSCH power or energy corresponding to candidate resources by measuring PSSCH RSRP corresponding to candidate resources. The PSSCH RSRP may be measured using DMRS, e.g., PSSCH RSRP may be defined as the linear average over power distribution of the resource elements that carry DMRS. In some other embodiments, PSSCH RSRP may be measured using other reference signals or data signals(iv) Optionally measure power or energy of an alternative signal. For example, sidelink received signal strength indicator (S-RSSI) can be measured, which is a measurement of PSSCH total energy S-RSSI that may be defined as the linear average of total received power per OFDM symbol observed in the configured sub channel by the UE. For the sensing process, the S-RSSI can be the linear average of samples in a sensing window based on a fixed or configured periodicity. FIG.3shows another example configuration of a TFRP pool. In one embodiment of resource pool (RP) configuration, the time frequency resources that can be used for SL transmission are defined, e.g., the RP configuration may include the boundary and division of frequency subchannels, e.g., F0, F1, F2, F3 as shown inFIG.3, and the available time slots that can be used for SL transmission. There might be no explicit definition of a transmission pattern pool or TFRP pool, which means a sensing UE may select any combination of resources that are used for initial transmission and retransmission if needed for a TB, which forms a transmission pattern or TFRP. In another embodiment, a transmission pattern pool or TFRP pool may be further defined within the resource pool, which limits a certain number of resource combinations that UE can choose for initial transmission and retransmission of a TB, i.e., the sensing UE can choose a specific TFRP among the configured TFRP pool. As shown inFIG.3, a sensing window301and a set of selection windows302(1)-(n), which are also collectively referred to as a selection window302, are applied in RP100with a periodicity that is greater than 1. As shown in the example ofFIG.3, a sensing UE can detect other UEs' transmission or performance measurements in the sensing window301. When the data packet or TB arrives, the sensing UE may perform resource selection or reselection within a resource selection window. The resource selection window may be chosen to start at a given time such as T1 after the resource selection or reselection is triggered. T1 may typically be equal to or larger than the UE's processing time so the UE has sufficient time to perform the selection and prepare for the transmission. T1 may be predefined or configured/preconfigured. The configuration may be done within resource pool configuration. If a transmission pattern pool or TFRP pool is configured/defined as shown inFIG.1AandFIG.3, a sensing UE may select a transmission pattern among a transmission pattern pool or select a TFRP among a TFRP pool. The sensing UE may need to select all the transmission resources for a TB at the same time. The sensing UE can select a TFRP within the resource selection window. There are at least two approaches for determining the resource selection window. In a first approach, the starting location of the TFRP window is considered to be fixed. In this case, the resource (re)selection window starts at the first TFRP window that is later than Ts>=0 after the resource (re)selection is triggered. In a second approach, the selection window is set to start at any time slot, i.e., the selection window can start at any time slot where Ts>=0 after the resource (re)selection is triggered. The resource selection window length can be equal to the TFRP window length, or the periodicity, or a multiple thereof. The TFRP pool can be configured in the following manner. In the RP configuration, a periodicity, offset, number of repetitions and the RV sequence corresponding to the repetitions may be configured. The size, granularity, boundaries and division of time/frequency resources may also be configured in the RP. For example, as shown inFIG.3, F0 to F3 may be configured/defined as one or multiple frequency subchannels, where size and boundary of frequency subchannels are configured for each RP. In time domain, the granularity may be defined as one or multiple slots, e.g., T0, T1, T2, T3, T4, can each represent one slot. The pattern index (UE index as shown inFIGS.1and3) and corresponding location can be predefined or derived from the configured parameters (periodicity, offset, number of repetitions, RV sequence, frequency and time resource division etc.) based on a given rule.FIG.1Ashows an example of such TFRP pool definition, in which no two patterns share the same slot number for both repetitions, and for every pair of two patterns the allocated resources do not completely overlap. In the example ofFIG.1A, the periodicity is 5 slots, spans from T0 to T4 and the pattern repeats periodically. The starting slot is the time location of T0. The pattern repeat itself periodically with the configured/predefined periodicity as shown inFIG.3. FIG.3illustrates two examples of resource selection corresponding to whether the starting slot of the selection window is flexible. If the starting location of a pattern pool is not flexible, the sensing window can start at beginning of T0 or T0+n*periodicity where n is an integer. In the example ofFIG.3, the resource selection window can be302(1). If the starting location of pattern pool is not flexible, the sensing window can start at any slot (e.g. T0, T1, T2, T3, T4. The sensing UE then starts to select resources at any start point within a selection window302. In this example, a start point of a selection window302can be varied along the time axis, such as T0, T2, or T3 based on any suitable situation. In this example, the resource selection window can be302(1),302(2), . . . ,302(n) etc. In other examples, the length of the selection window may also be varied based on any suitable configuration. In some embodiments, the length of the selection window can be restricted to be equal to the TFRP window length or periodicity or multiple thereof. In some other embodiments, the length of selection window may not have such constraint. The length of the selection window may also be determined and bounded by the delay constraint of the data packets/traffic that UE plans to transmit. In some examples, the resource selection may be a TFRP selection. The TFRP selection may be performed at least once within a periodicity of a configured grant resource. Configuring a pool of the (pre)-configured TFRPs should enable that any two distinct TFRPs do not collide in at least one time unit, in order to alleviate a half-duplex constraint, which may help to avoid detrimental impacts. Such a method to configure the selection window may help to avoid extra delays for resource selection compared with conventional approaches in which a start point of a selection window has been set at a fixed location (e.g., always fixed at T0). It is noted that, as shown inFIG.3, to support the flexible starting location of the resource selection window, a sensing UE may be allowed to perform repetition at a flexible starting location. The flexible starting location of repetition means that instead of following the time order of transmission/repetition of the same TB as defined in the transmission pattern pool or TFRP pool, the sensing UE can start transmission/repetition of a TB at any transmission resource that belongs to the transmission pattern or TFRP. The UE may still perform the same number of repetitions for each TB. For example, with respect to UE5, if the sensing UE selects a transmission pattern corresponding to UE5 when the resource selection window corresponding to302(1) as shown inFIG.3is chosen, the sensing UE starts the initial transmission at the time frequency resource corresponding to (T1, F0) for the initial transmission for the TB and (T2, F2) for the second repetition or retransmission of the TB within window302(1). If, instead, the sensing UE chooses the transmission pattern corresponding to UE5 when the resource selection window corresponding to302(2) inFIG.3is chosen, the sensing UE then starts the initial transmission for the TB at time frequency location (T2, F2) and performs retransmission/2ndrepetition of the TB at time frequency location (T1, F0) within window302(2). The (T1, F0) in window302(2) is one period later than the (T1, F0) in window302(1). If such flexible starting location of repetition/retransmission is supported, the receiver or sensing UE may need to know 1) whether the current transmission is an initial transmission or retransmission or 2) which number (index) of transmission/repetitions among all repetitions the current transmission belongs to. This information can be either indicated in the sidelink control information (SCI) or indicated using DMRS via any DMRS properties similar to those previously described to indicate the transmission pattern. In some examples, UE1 may perform sensing via DMRS blind detection before a packet arrival. The sensing window (e.g., the sensing window301) is defined as a window of length T preceding the packet arrival. The length of the sensing window can be configured or preconfigured for the resource pool, and can be a multiple of the TFRP periodicity. In some examples, based on sensing results obtained within the sensing window, a UE performs resource selection within a resource selection window. Because a UE needs to select all the transmission resources for a TB at the same time, the UE should select a TFRP within the resource selection window. There are two methods to determine the resource selection window: In the first approach, the starting location of the TFRP window is considered to be fixed. In this case, the resource (re)selection window starts at the first TFRP window that is later than T1>=0 after the resource (re)selection trigger. In the second approach, the resource selection window is defined to start at any slot, i.e., the selection window starts T1>=0 after the resource (re)selection trigger. The resource selection window length can be equal to the TFRP window length, or the periodicity, or a multiple thereof. In some examples, once the UE determines the resource selection window, it should select a TFRP within the resource selection window such that it tries to avoid TFRPs reserved through Type (b) reservation and TFRPs conflicting with retransmission resources indicated by other UEs using Type (a1) and Type (c) reservations. Wth the three reservation types (a1), (b), and (c), listen-before-talk (LBT) type of short-term sensing is not needed in NR V2X, because it may further increase the energy consumption and complexity of the sensing procedure. Before the initial transmission of a TB, the sensing UE may continue sensing based on DMRS blind detection to further check if the selected TFRP has any conflict with, e.g., Type (a1), and Type (c) retransmission reservations. If a conflict is found, the UE will reselect or select a different TFRP within a same (re)selection window. FIG.4illustrates a method400for resource selection according to example embodiments, including a sensing and resource exclusion/resource selection process based on priorities of different reservation types. Such a method may be applied in a sensing and resource selection procedure. The method400is described below: At step405: A plurality of indication signals are sensed. The indication signals may include other UEs' scheduling assignment (SA) in a sidelink control information (SCI), or a DMRS. Each sensing UE keeps decoding other UEs' SCI and/or measures corresponding PSSCH energy and/or measures PSSCH RSRP based on DM RS or measure S-RSSI as described above. The PSSCH RSRP may be measured at a corresponding PSSCH resource when an SCI or DMRS is detected. The indication signals include reservation type information and optionally other information related to selection and reservation of SL resources as discussed above. At step410: The sensed information obtained from the reservation indication signals and SL measurements (e.g. PSSCH RSRP or S-RSSI) that are within the sensing window are collected. That means, even a UE senses a large number of indication signals all the time, only information such as indication signals, sensed within the sensing window, will be collected for resource selection. The sensed indication signal may include information regarding PSSCH blind detection, PSSCH DMRS RSRP and SL RSSI measurement. The sensed indication signals also include reservation type information or other optional information as discussed earlier. At step415: Candidate resources are excluded from a candidate resource set. The exclusion of candidate resources is now discussed in greater detail. A sensing UE first determines a resource selection window and forms a set of resources within the resource selection window as a candidate resource set that the sensing UE may select from. If the pattern pool or TFRP pool is configured/defined, the TFRP pool within the resource selection window is the candidate resources set and UE may select a TFRP among the TFRP pool. After the candidate resource set is formed, the UE needs to exclude some candidate resources that may be colliding or have conflict with other UEs' potential transmissions from the candidate resource set. It is noted that not all potential collisions have the same impact on the UE's resource selection, because if a UE's data transmission has high energy when received by the sensing UE, it has much higher impact than a UE's data transmission with lower energy. Therefore, the sensing UE (blindly) may decode SCI, or DMRS or any other indication signal at potential locations within a sensing window. If an SCI is decoded or a DMRS or any other indication signal is detected to indicate there are associated data or PSSCH transmissions, the sensing UE further measures the corresponding PSSCH RSRP for that PSSCH resource. PSSCH RSRP represents how much power or energy is detected in a received reference signal. If the PSSCH RSRP is larger than a determined threshold Th, the corresponding reserved resources within the resource selection window or candidate resource set should be excluded. If the RSRP is lower than the determined threshold, the corresponding reserved resource is not excluded. In some examples, whether to exclude resources reserved for different reservation types may be determined differently. For example, for long term reservation using signaling associated with a previous TB, the resource located at the time slot t=t0+n*RSVP or t=t0+n*periodicity, and at the same frequency location as the detected PSSCH resource that falls in the resource selection window, may be excluded, where RSVP is the reservation period and the “periodicity” is the periodicity of the pattern pool or the TFRP pool if the TFRP is configured. RSVP can be fixed, predefined, configured or preconfigured in the RP or indicated in the indication/reservation signal (e.g. SCI or DMRS). When a fixed number (e.g., m) of TBs is reserved, only a number between 1 to m that falls within the resource selection window may be excluded. In the case of reservation of blind retransmission or HARQ feedback based retransmission of the same TB, only the reserved retransmission resource that falls within the resource selection window will be excluded. The resources may be excluded based on the reservation priorities or exclusion thresholds determined based on the sensed reservation type as described herein. FIG.7illustrates a process to exclude resources within a resource selection window. For illustration purposes, two different types of resource reservations are represented, one for reservation of a different TB, and one for reservation of retransmission of the same TB. As discussed earlier, in some scenarios a sensing UE may increase or decrease the threshold Th for exclusion of resources such that less or more candidate resources will be excluded from the selection RP during selection. The lower the threshold Th, the more likely a potential candidate resource will be excluded from the candidate resource set. Thus, a reservation of resources with a higher priority from the perspective of the sensing UE should be associated with a lower threshold, so that the resource will be more likely excluded from selection of resources for other transmissions. It follows that priority values or priority levels P(a1) to P(d) may be used to set the threshold Th of the RSRP. The priority level may be obtained by adjusting the packet priority of the reservation based on reservation type (e.g. multiplying it by a reservation type specific coefficient) Alternatively, the reservation types, such as Type (a) to Type (d), may be used to set or adjust the exclusion threshold Th directly. Table 1 shows an example mapping relationship between priority and threshold. The left column shows different priority levels corresponding to the transmitted data of the sensing UE, which is performing sensing and resource selection. The top row of table 1 shows different priority levels corresponding to the other UE that is performing transmission/reservation. In this example, 4 different priority levels are defined. The number of different priority values defined is usually restricted to a certain number due to signaling overhead; however, this is illustrative. In some other examples, any number of different priority values may be applied. Table 1 shows depending on both a priority level of the sensing UE and a priority level of the reservation UE (e.g., a transmitting UE), thresholds Th1 to Th16 can be used. The threshold values Th1 to Th16 can be predefined or configured. The higher the priority level of the reservation UE, the lower the corresponding threshold may be used. In this example, assuming that level 4 has a priority higher than level 3 and level 3 has a priority high than level 2. We may have Th1>Th2>Th3>Th4 for the same level 1 data priority of sensing UE, similarly, Th5>Th6>Th7>Th8, etc. TABLE 1PRIORITY OF OTHER UE OR RESERVATIONUE (DECODED IN SCI OR INDICATED BYDMRS, TAKING INTO ACCOUNT DIFFERENTRESERVATION TYPES)LEVEL 1LEVEL 2LEVEL 3LEVEL 4PRIORITYLEVEL 1TH1TH2TH3TH4LEVEL OFLEVEL 2TH5TH6TH7TH8SENSINGLEVEL 3TH9TH10TH11TH12UELEVEL 4TH13TH14TH15TH16 Table 2 shows an example mapping relationship between the reservation type and the exclusion threshold. The left column list different priorities of the sensing UE, similar to those shown in Table 1. The top row of Table 2 lists different reservation types. In this example, 4 different priority levels are listed, and 5 different reservation types are possible, resulting in 20 possible thresholds, Th1 to Th20. Table 2 shows that, depending on both a priority level of the sensing UE and a reservation type of the resource reservation from the reservation UE or transmitting UE, different exclusion thresholds can be selected and used. Note that there may be a table including the mapping of the reservation type, the packet priority level of the other UE making the reservation, the packet priority of the sensing UE, to the RSRP threshold, i.e. the RSRP threshold depends on all 3 factors. TABLE 2RESERVATION TYPETYPE (A1)TYPE (A2)TYPE (B)TYPE (C)TYPE (D)PRIORITYLEVEL 1Th1Th2Th3Th4Th5LEVELLEVEL 2Th6Th7Th8Th9Th10LEVEL 3Th11Th12Th13Th14Th15LEVEL 4Th16Th17Th18Th19Th20 The priority value of the reservation UE may be taken into account based on the different reservation types as described above. This can be implemented in various manners including the two approaches described earlier. In one approach, the reservation UE or transmitting UE indicates the priority level of the corresponding data transmission Pdin the reservation signal, such as SCI or DM RS, without considering the reservation type, and the sensing UE adjusts the priority value in view of the reservation type indicated in the indication signal. For example, for reservation Type (a1), the sensing UE may obtain P(a1)=a2*Pd, where a2may be between 0 and 1, e.g. 0.5, and use P(a1) as the priority level of the reservation UE to find the corresponding threshold using Table 1. In another approach, it is possible for the reservation UE to indicate a priority level Pi that has been selected in view of the reservation type in the indication signal transmitted to the sensing UE, such as the reservation signal SCI or DMRS. The sensing UE uses the priority level obtained from the reservation signal directly to find the corresponding threshold from Table 1. For example, if the reservation type is Type (a1), the priority level associated with the data transmission for the reservation UE is Pd, the reservation UE then calculates P(a1)=a2*Pd, where a2is between 0 and 1, and indicates priority P(a1) in the reservation signal such as SCI or DMRS. Because the number of defined priority levels may be a maximum value, the P(b)-P(d) calculated above may be further quantized or mapped to the total number of priority values before indicating it in a reservation signal or used in Table 1 to find the threshold. For example, if a priority value/level is defined with level 1, 2, . . . n, instead of using P(a1)=a2*Pd, one may use P(a1)=floor(a2*Pd), P(a1)=ceiling(a2*Pd) or P(a1)=round(a2*Pd) to obtain the priority value P(a1) that takes account of the reservation type to ensure the final value of P(a1) is an integer and P(a1) provides a valid priority level. A further approach is to find the corresponding threshold value Th from Table 2 based on the sensed reservation type as indicated in the reservation or indication signal. In an embodiment, after determining an initial value of Th from a table such as Table 2 using the priority value from the sensed SCI, the value of Th may be adjusted at a later time. For example, the Th may be adjusted based on a reservation type. The Th may be adjusted by increase the Th by a certain amount (ΔTh). ΔTh may be dependent on the reservation type, and be different for different reservation types. A value of the ΔTh may be predefined or (pre)configured for a specific reservation type. Another method to use different priority values for resource exclusion includes ranking the priority values of all the reservation signals or indication signals detected within the sensing window in an ascending order. The candidate resources corresponding to the reserved resource may be excluded in the ascending order corresponding to a ranking of all the priority values of the corresponding reservation signals. At step420: a candidate resource from the candidate resources remaining in candidate resource set such as RP is selected based on the excluded candidate resources. In example embodiments, the candidate resource could be randomly selected from the remaining candidates within the RP. In another example, the remaining resource after exclusion may be ranked further based on S-RSSI measurement, and a subset of the remaining resources is selected. The subset may be a fixed percentage of total resources, e.g., 20%. After the subset of resources is selected, the UE may randomly select a resource or resources or a TFRP among the subset of selected resources. At step425: data such as a TB is transmitted on the selected resources according to traffic arrival at the transmitting UE, Tx UE. Optionally, at step430: if it is determined that resource re-selection is needed, restart to the sensing and selection process. If resource re-selection is not needed, data transmission is performed on the same selected resources. In some examples, re-selecting a resource may be performed in other situations, i.e. perform another resource selection according to the above procedure if any of the following triggers occur: transmission opportunities run out; UE consecutively misses a number of transmission opportunities; and the current resource selection cannot meet the latency requirement. In example embodiments, as an alternative approach of the sensing procedure based on SCI, PSSCH-RSRP can be measured based on the DMRS of PSSCH and used to determine a number of other UEs that have reserved the resource. The alternative approach may be used, for example, when no SCI is associated with data or when an SCI and its associated data are transmitted in the same slot. A candidate resource in the resource pool can be excluded if either one of the two following conditions are met: Condition 1: the candidate resource is (i) explicitly indicated or reserved by a decoded SCI and (ii) the PSSCH-RSRP in the associated PSSCH data resource is above a exclusion threshold that is determined based on the corresponding priority, P(b)-P(d), when the number of decoded SCIs for which the PSSCH-RSRP in the associated PSSCH data resource is above a threshold is larger than L. Condition 2: the candidate resource is implicitly indicated or reserved by a blindly detected PSSCH DMRS, when the number of such blindly detected DMRSs is larger than L. No SCI is needed in this case. In some embodiments, L=0. When L=0, as long as one UE reserved a resource for transmission, the reservation of the resource will be taken into account. After the resources are selected from the resource selection window or TFRP is selected from the TFRP pool within the resource selection window and before the initial transmission of a TB, the sensing UE will continue sensing based on sensing the reservation signal, e.g. DM RS blind detection or SCI detection, to further check if the selected resource or TFRP has any conflict with retransmission reservations, such as Types (ii) and (iii) reservations. If a conflict is detected, the sensing UE will (re)select a different resource or TFRP from a RP within the same (re)selection window. Once UE determines the resource selection window, it should select transmission and retransmission resources (or a TFRP) within the resource selection window. In order to select the transmission resources to be used (or TFRP), the UE first creates a candidate resource pool (in the case of TFRP selection, it can be a TFRP pool including all possible TFRPs within the resource selection window). A resource (or TFRP) is not considered as a candidate resource if the resource (or TFRP) is indicated in a received SCI and the associated L1 SL-RSRP measurement is above an SL-RSRP threshold. UE then selects the resources (or a TFRP) from among the remaining candidate resources (or TFRPs). If a TFRP can be partially overlapped with another TFRP (e.g., the TFRP pool inFIG.8of [6]), then the resource selection can be further optimized. Within the remaining candidate TFRPs, a TFRP should be selected based on the following order of preference:1. All resources of the TFRP are not in conflict with any reserved resources.2. Initial/first transmission resource of the TFRP does not conflict, but retransmission resources may conflict with reserved resources.3. Initial/first transmission resource of the TFRP conflicts with reserved resources, but at least one retransmission does not overlap with the reserved resources. The UE may select the combination of transmission/retransmission resources similarly: Within the remaining candidate resources, a combination of transmission and retransmission resources should be selected based on the following order of preference:1. All resources of the transmission/retransmission are not in conflict with any reserved resources.2. Initial/first transmission resource of the TB does not conflict, but retransmission resources may conflict with reserved resources.3. Initial/first transmission resource of the TB conflicts with reserved resources, but at least one retransmission does not overlap with the reserved resources. Before the initial transmission of a TB, the UE shall continue sensing based on SCI decoding to further check if the selected resources (or TFRP) have any conflict with retransmission reservations. If a conflict is found, the UE should (re)select different resources (or a different TFRP) within the same (re)selection window. If there is available resource located in the same time slot but in different frequency subchannels from previously selected resources that are not in conflict, then the sensing UE should simply adjust the frequency sub channel of the initial transmission resource without reselecting the time slot for the initial transmission. This is because if the same time slot of initial transmission is selected, UE does not need to do further sensing, avoiding unnecessary delays. One advantage of TFRP based resource selection is taking into account the combination of different transmission resources for the same TB in the resource selection. In high load scenarios, such design allows UEs to successfully decode a TB in spite of incurring some partial collisions. In comparison, selection based on individual resources may incur delays because a sensing UE may keep (re)selecting resources if it fails to find non-conflicted resources for all transmissions of a TB. Apparatus Descriptions FIG.5is a block diagram illustrating an example of a telecommunications network500according to one embodiment, for implementing any one or combination of two or more of the above described methods. The telecommunications network500includes a core network502and an access network506. The access network506serves a plurality of UEs504a,504b,504c,504d,504e,504f,504g,504h, and504i. The access network506could be an Evolved Universal Terrestrial Access (E-UTRA) network. As another example, the access network506could be a cloud access network (C-RAN). The access network506includes a plurality of BSs508a,508b, and508c. The BSs508a-ceach provides a respective wireless coverage area510a,510b, and510c. Each of the BSs508a-ccould be implemented using a radio transceiver, one or more antennas, and associated processing circuitry, such as antenna radio frequency (RF) circuitry, analog-to-digital/digital-to-analog converters, etc. Although not illustrated, the BSs508a-care each connected to the core network502, either directly or through one or more central processing hubs, such as servers. The BSs508a-ccould serve as a gateway between the wireline and wireless portion of the access network506. Each one of BSs508a-cmay instead be referred to as a base transceiver station, a radio BS, a network node, a transmit node, a transmit point, a Node B, an eNode B (eNB), a gNodeB, or a remote radio head (RRH), depending upon the implementation. In operation, the plurality of UEs504a-iaccess the telecommunications network500using the access network506by wirelessly communicating with one or more of the BSs508a-c. UEs504a-dare in close proximity to each other. The UEs504a-dcan each wirelessly communicate with the BS508a. The UEs504a-dcan also directly communicate with each other, as represented at516. Communications516may also be referred to as lateral communications. In embodiments disclosed herein, UE to UE communications use a SL channel and a SL air interface. On the other hand, a communication between an access network component, such as BS508a, and a UE, as in communication55, is called an access communication. The access communication occurs over an access channel, which can be a UL or DL channel, and the access communication uses a radio access communication interface, such as a cellular radio access air interface. Access and SL air interfaces may use different transmission formats, such as different waveforms, different multiple access schemes, and/or different radio access technologies. Some examples of radio access technologies that could be used by an access air interface and/or a SL air interface are: Long Term Evolution (LTE), LTE License Assisted Access (LTE-LAA), 5G New Radio, and WFi. By using the SL communications516, the UEs504a-dmay be able to assist with wireless communications between the UEs504a-dand the BS508a. As one example, if UE504cfails to correctly decode a packet received from the BS508a, but if UE504dis able to receive and correctly decode the packet from the BS508a, then UE504dcould directly transmit the decoded packet to UE504cusing SL communications516. As another example, if UE504cmoves out of wireless coverage area510c, such that UE504ccan no longer wirelessly communicate with the BS508a, then UE504bcould forward messages between the UE504cand the BS508a. As another example, UE504aand UE504ccould both receive a signal transmitted from the BS508athat carries a packet meant for UE504c. UE504amay then transmit to UE504c, via SL communications516, the signal as received by UE504a. UE504cmay then use the information received from UE504ato help decode the packet from the BS508a. In these examples, capacity and/or coverage may be enhanced through the assistance of UEs504a,504b, and/or504d. V2X communications as referenced herein are an example of SL communications. The UEs504a-dform a UE group520. The access network506could assign a group identifier (ID) to the UE group520. The UE group ID may allow the access network506to address the UE group520as a whole and distinguish the UE group520from other UE groups. The UE group ID may also be used to broadcast information within the UE group, i.e. address all other UEs within the UE group520. The UE group520may form a logical or virtual device mesh in which the members of the UE group520communicate amongst themselves using UE communications over an SL air interface. The UE group520as a whole can act as a single distributed virtual transceiver with respect to the access network506. The UE group ID may be a group radio network temporary identifier (G-RNTI), for example. When a particular UE in the UE group520is being assisted or is to be assisted with wireless communication between that UE and the BS508a, then that particular UE is referred to as the target UE (TUE). In the examples above, UE504cis being assisted and is therefore a TUE. The other UEs504a,504b, and504din the group520form a cooperation candidate set, which is a set of UEs that may cooperate to help the TUE504c. The subset of UEs in the cooperation candidate set that actually assist the target UE504cform a cooperation active set. The cooperation active set may be dynamically selected to assist the target UE504c. The UEs in the cooperation active set are referred to as cooperating UEs (CUEs). In UE group520, UEs504a,504b, and504dform the cooperation candidate set. If UEs504aand504bactually assist target UE504c, then UEs504aand504bform the cooperation active set and are the CUEs. As UEs504a-dmove around, some may leave the UE group520and/or other UEs may join the UE group520. Therefore, the cooperation candidate set may change over time, e.g., the cooperation candidate set may change semi-statically. The UE group520may also be terminated by the network506, e.g., if the network determines that there is no longer a need or opportunity for the UE group520to provide assistance in wireless communication between the BS908aand members of the UE group520. There may be more than one UE group. For example, UEs504eand504finFIG.5form another UE group522. FIG.6is a block diagram illustrating an example of a network652serving two UEs654aand654b, according to one embodiment. The network652may be the access network1406fromFIG.5, and the two UEs654aand654bmay be two of the four UEs1404a-dinFIG.5. However, more generally this need not be the case, which is why different reference numerals are used inFIG.6. The network652includes a BS656and a managing module658. The managing module658instructs the BS856to perform actions. The managing module858is illustrated as physically separate from the BS656and coupled to the BS656via a communication link660. For example, the managing module658may be part of a server in the network652. Alternatively, the managing module658may be part of the BS656. The managing module658includes a processor662, a memory664, and a communication module666. The communication module666is implemented by the processor662when the processor662accesses and executes a series of instructions stored in the memory664, the instructions defining the actions of the communication module666. When the instructions are executed, the communication module666causes the BS656to perform the actions described herein so that the network652can establish, coordinate, instruct, and/or control a UE group. Alternatively, the communication module666may be implemented using dedicated circuitry, such as an application specific integrated circuit (ASIC) or a programmed field programmable gate array (FPGA). The UE654aincludes a communication subsystem670a, two antennas672aand674a, a processor676a, and a memory678a. The UE654aalso includes a communication module680a. The communication module680ais implemented by the processor676awhen the processor676aaccesses and executes a series of instructions stored in the memory678a, the instructions defining the actions of the communication module680a. When the instructions are executed, the communication module680acauses the UE654ato perform the actions described herein in relation to establishing and participating in a UE group. Alternatively, the module680amay be implemented by dedicated circuitry, such as an ASIC or an FPGA. The communication subsystem670aincludes processing and transmit/receive circuitry for sending messages from and receiving messages at the UE654a. Although one communication subsystem670ais illustrated, the communication subsystem670amay be multiple communication subsystems. Antenna672atransmits wireless communication signals to, and receives wireless communications signals from, the BS656. Antenna674atransmits SL communication signals to, and receives SL communication signals from, other UEs, including UE654b. In some implementations there may not be two separate antennas672aand674a. A single antenna may be used. Alternatively, there may be several antennas, but not separated into antennas dedicated only to SL communication and antennas dedicated only to communicating with the BS656. SL communications could be over in which case the antenna674amay be a Wi-Fi antenna. Alternatively, the SL communications could be over Bluetooth™, in which case the antenna674amay be a Bluetooth™ antenna. SL communications could also or instead be over licensed or unlicensed spectrum. The UE654bincludes the same components described above with respect to the UE654a. That is, UE654bincludes communication subsystem670b, antennas672band674b, processor676b, memory678b, and communication module680b. The UE654ais designated as a target UE (TUE) and will therefore be called TUE654a. The UE654bis a cooperating UE and will therefore be called CUE254b. The CUE654bmay be able to assist with wireless communications between the BS656and TUE654aif a UE group were to be established that included TUE654aand CUE654b. Other communication scenarios are also contemplated, in a V2X application, for example. The UE654amay be specifically chosen as the target UE by the network652. Alternatively, the UE654amay itself determine that it wants to be a target UE and inform the network652by sending a message to the BS656. Example reasons why UE654amay choose or be selected by the network652to be a target UE include: low wireless channel quality between the UE654aand the BS656, many packets to be communicated between the BS656and the UE654a, and/or the presence of a cooperating UE that is a good candidate for helping with communications between the BS656and the UE654a. UE654aneed not always stay a target UE. For example, UE654amay lose its status as a target UE once there is no longer a need or desire for assistance with wireless communications between UE654aand the BS656. UE654amay assist another target UE that is a cooperating UE at a later time. In general, a particular UE may sometimes be a target UE and other times may be a cooperating UE assisting another target UE. Also, sometimes a particular UE may be both a target UE receiving assistance from one or more cooperating UEs and also a cooperating UE itself assisting another target UE. In the examples below, the UE654aacts only as a target UE, i.e., TUE654a, and the UE654bis a cooperating UE to the TUE654a, i.e., CUE654b. FIGS.5and6illustrate systems in which embodiments could be implemented. In some embodiments, a UE includes a processor, such as676a,676binFIG.6, and a non-transitory computer readable storage medium, such as678a,678binFIG.6, storing programming for execution by the processor. A non-transitory computer readable storage medium could also or instead be provided separately, as a computer program product. Further embodiments in this disclosure also relate to configuration, signaling and communication between a UE and a base station (BS), such as a 5G Node B (gNB), in uplink (UL) communication. As discussed earlier, in some embodiments of SL communication between UEs, HARQ feedback information is utilized for selection and reservation of time frequency resources. For NR V2X UL communication in Mode 1, the transmit UE may need to report the HARQ feedback it received from receiving UE to the gNB, such that the gNB may schedule a retransmission if a NACK is reported. The SL HARQ feedback to the gNB can be transmitted in a PUCCH resource. The PUCCH resource for reporting HARQ feedback to the base station, gNB, is indicated in RRC signal for configured grant (CG) type 1 and in activation DCI in CG type 2. As can be understood by those skilled in the art, in Type 1 CG, RRC may provide PUCCH resources for SL HARQ feedback reporting, periodicity, offset, time-frequency allocation, UE-specific DMRS configuration, MCS/TBS, # repetitions (K), power control, and the like. In Type 2 NR CG, RRC may provide periodicity, power control, the number of repetitions (K), and MCS/TBS (Transport Block Size); and the Activation DCI provides PUCCH resources for SL HARQ feedback reporting, time-frequency allocation, MCS/TBS, UE-specific DMRS configuration, and the like. The time domain offset of a resource refers to the offset with respect to a reference point (e.g. system frame number (SFN)=0 in the time domain). An example of the relationship among data transmission and feedback and control channels for multiple transmissions of a TB is illustrated inFIG.9. As depicted, the time slots for a first transmission of a TB (1stTx), a second transmission of the TB (2ndTx), PSFCH, and PUCCH are shown. In case of CG, an “offset” is indicated for CG resource configuration, which indicates the starting slot position for the first transmission with respect to a reference time. The time “T1” represents the time period from a data transmission to PSFCH. The time “T2” represents the time period from PSFCH to PUCCH. The total time from the offset time slot to PUCCH is indicated as “T3”. The resource for the first transmission (initial transmission) then periodically occurs based on the periodicity parameter configured for CG configuration. In an embodiment suitable for CG type 1, the RRC may configure the PUCCH resources for the CG so that the PUCCH shares the same periodicity with the CG resource, and only a slot offset relative to the periodicity for CG is configured. This means that for each periodicity of CG configuration, only one (1), or a single, PUCCH is configured. Within one periodicity, there may be multiple resources configured for multiple transmissions or repetitions of a TB as shown inFIG.9(FIG.9shows only 1 periodicity). In an embodiment, only the time gap from PSFCH to PUCCH, such as T2shown inFIG.9, is indicated. In case of K repetitions, although it may be possible to have multiple PSFCH resources corresponding to different repetitions, only one (1) PUCCH resource per period is configured, where the time gap corresponds to the PSFCH slot of the last repetition. Similarly, in the case of dynamic grant instead of configured grant, if the dynamic grant from the gNB indicates resources for K repetitions of a TB, the time gap from PSFCH to PUCCH, such as T2 shown inFIG.9, is indicated. In case of K repetitions, although it may be possible to have multiple PSFCH resources corresponding to different repetitions, only one (1) PUCCH resource per period is configured, where the time gap corresponds to the PSFCH slot of the last repetition. Note that in case of dynamic grant,FIG.9can correspond to the repetition resources indicated in the dynamic grant downlink control information (DCI), however, the location of first transmission is not determined based on the offset with regard to SFN=0, but determined based on the location of DCI and gap between DCI and 1sttransmission time. In another embodiment, the PUCCH may have a larger periodicity than the CG resource. For example, the periodicity is 3 times the periodicity of the CG resource, which means only one (1) PUCCH resource for 3 periodicity of CG resources and the UE only reports NACK to the base station, such as a gNB, after a given number of failed retransmissions. In this case, a NACK is only reported if a corresponding PUCCH exists. Example embodiments are described that apply generally to any communication system where UEs reserve resources for SL communications based on resource availability. The present disclosure provides examples in which resources is excluded based on a priority for a reservation type that is indicated in an indication signal, and resources is selected for a subsequent transmission based on determination result regarding whether resources reserved by the reservation type is exclude when selecting resources, which may enable the collision of resources used by different UEs to be reduced significantly. In some applications, the determination result may be obtained by calculating a priority value associated with the reservation type, and determine whether to exclude the resources reserved by the indicated reservation type based on the calculated priority value when performing resource selection. Moreover, because NR V2X supports resource reservations for blind retransmission of a TB, retransmission of future TBs, and feedback-based retransmissions, the method of taking the priorities of the different resources reservations into account provides flexibilities to exclude the resources that have been reserved, which may enable to resources to be selected more efficiently and more accurately. The present disclosure further illustrates that a start point of a selection window is varied at any time point in a periodic resource pool. Moreover, the length (time duration) of the selection window is also variable. Example embodiments of the disclosure also include the following numbered embodiments. 1. A method comprises:receiving from a first user equipment (UE), at a second UE, a signal comprising reservation information for selection and reservation of time-frequency resources associated with transmission of a first transport block (TB) by the first UE, the reservation information comprising reservation type information indicative of a type of the reservation selected from a plurality of predefined reservation types;selecting a time-frequency resource based on at least in part the reservation type indicated by the reservation type information;reserving the selected time-frequency resource for receiving retransmission of the first TB or transmission of a second TB by the first UE. 2. The method of embodiment 1, wherein the signal comprises an indication signal. 3. The method of embodiment 2, wherein the indication signal comprises first stage sidelink control information (SCI). 4. The method of any one of embodiments 1 to 3, wherein the plurality of predefined reservation types comprise type (a) associated with reservation of a sidelink resource for transmission of the second TB; type (b) associated with reservation of a sidelink resource for blind retransmission of the first TB; and type (c) associated with reservation of a sidelink resource for hybrid automatic repeat request (HARQ) feedback based retransmission of the first TB. 5. The method of embodiment 4, wherein reservation type (a) comprises type (a1) associated with long term reservation, type (a2) associated with reservation for transmission of a selected number of different TBs, and type (a3) associated with no reservation for the second TB. 6. The method of any one of embodiments 1 to 5, wherein the reservation information further comprises information indicating (i) a priority of a data packet in the first TB, or a quality of service (QoS) priority; (ii) an identifier of the time frequency resource to be reserved; (iii) a reservation periodicity (RSVP), or a time frequency repetition pattern (TFRP) periodicity; and (iv) a number of periodic resources to be reserved based on the RSVP or the TFRP periodicity. 7. The method of embodiment 6, wherein the identifier of the time and frequency resource to be reserved is a TFRP index. 8. The method of any one of embodiments 1 to 7, further comprising determining a reservation priority or threshold associated with the reservation based on, at least in part, the reservation type indicated in the reservation information; and selecting and reserving the time-frequency resource based on the reservation priority or threshold. 9. The method of embodiment 8 as dependent from embodiment 4, wherein the reservation priority associated with reservation type (b) is higher than the reservation priority associated with reservation type (c). 10. The method of embodiment 8 as dependent from embodiment 5, wherein the reservation priority associated with reservation type (a1) is lower than the reservation priority associated with reservation type (a2). 11. A method comprises:transmitting, from a first user equipment (UE) to a second UE, a signal comprising reservation information for selection and reservation of time-frequency resources associated with transmission of a first transport block (TB) by the first UE, the reservation information comprising reservation type information indicative of a type of the reservation selected from a plurality of predefined reservation types, to allow the second UE to select and reserve a time-frequency resource based on at least in part the reservation type indicated in the reservation information, for receiving the first TB, and for receiving retransmission of the first TB or transmission of a second TB by the first UE. 12. The method of embodiment 11, wherein the signal comprises an indication signal. 13. The method of embodiment 12, wherein the indication signal comprises first stage sidelink control information (SCI). 14. The method of any one of embodiments 11 to 13, wherein the plurality of predefined reservation types comprise a type (a) associated with reservation of a sidelink resource for transmission of the second TB; a type (b) associated with reservation of a sidelink resource for blind retransmission of the first TB; and a type (c) associated with reservation of a sidelink resource for hybrid automatic repeat request (HARQ) feedback based retransmission of the first TB. 15. The method of embodiment 14, wherein reservation type (a) comprises type (a1) associated with long term reservation, type (a2) associated with reservation for transmission of a selected number of different TBs, and type (a3) associated with no reservation for the second TB. 16. The method of any one of embodiments 11 to 15, wherein the reservation information further comprises information indicating (i) a priority of a data packet in the first TB, or a quality of service (QoS) priority; (ii) an identifier of a time frequency resource to be reserved; (iii) a reservation periodicity (RSVP), or a time frequency repetition pattern (TFRP) periodicity; and (iv) a number of periodic resources to be reserved based on the RSVP or the TFRP periodicity. 17. The method of embodiment 16, wherein the identifier of the time and frequency resource to be reserved is a TFRP index. 18. A user equipment (UE) comprises a transceiver and a processor, the UE being configured to perform the method of any one of embodiments 1 to 17. 19. A device comprises:a first transceiver configured to communicate with a second transceiver through a sidelink communication channel;wherein the device is configured to encode and transmit, or to receive and decode, a signal comprising reservation information for selection and reservation of time-frequency resources associated with transmission of a first transport block (TB) by a first user equipment (UE);wherein the reservation information comprises reservation type information indicative of a type of the reservation selected from a plurality of predefined reservation types, to allow a second UE to select and reserve a time-frequency resource based on at least in part the reservation type indicated in the reservation information, for receiving retransmission of the first TB or transmission of a second TB by the first UE. 20. The device of embodiment 19, wherein the signal comprises an indication signal. 21. The device of embodiment 19 or embodiment 20, wherein the indication signal comprises first stage sidelink control information (SCI). 22. The device of any one of embodiments 19 to 21, wherein the plurality of reservation types comprise type (a) associated with reservation of a sidelink resource for transmission of the second TB; type (b) associated with reservation of a sidelink resource for blind retransmission of the first TB; and type (c) associated with reservation of a sidelink resource for hybrid automatic repeat request (HARQ) feedback based retransmission of the first TB. 23. The device of embodiment 22, wherein reservation type (a) comprises type (a1) associated with long term reservation, type (a2) associated with reservation for transmission of a selected number of different TBs, and type (a3) associated with no reservation for the second TB. 24. The device of any one of embodiments 19 to 23, wherein the device is further configured to determine a priority or threshold associated with the reservation based on, at least in part, the reservation type indicated in the reservation signal; and to select and reserve the time-frequency resource based on the priority or threshold. 25. The device of any one of embodiments 19 to 24, wherein the device is associated with or mounted on a vehicle. 26. An apparatus comprises:an antenna;a processor; anda non-transitory computer readable storage medium storing processor executable instructions for execution by the processor, the processor executable instructions including instructions causing the apparatus to perform a method according to any one of embodiments 1 to 17. 27. A method comprises:receiving, at a first user equipment (UE), signaling indicating whether, when transmitting a transport block (TB), reservation of time-frequency resources for a different TB is enabled or disabled;transmitting, from the first UE to a second UE in a sidelink control channel (SCC), sidelink control information (SCI) signaling comprising indication of a first time-frequency resource for transmitting a first TB, the SCI further indicating (i) a reservation period (RSVP) and a sidelink resource to be reserved based on the RSVP when reservation of time-frequency resources for a different TB is enabled, or (ii) no reservation of a different TB without indicating the RSVP when reservation of time-frequency resources for a different TB is disabled;transmitting the first TB from the first UE to the second UE using the sidelink resource indicated in the SCI signaling. 28. The method of embodiment 27, which comprises, when reservation of time-frequency resources for a different TB is enabled, transmitting, within the reservation period, a second TB from the first UE to the second UE using the sidelink resource indicated in the SCI signaling, wherein the second TB is different from the first TB. 29. The method of embodiment 27, wherein the SCC is a physical sidelink control channel (PSCCH). 30. The method of embodiment 27, wherein the SCI signaling is a first stage SCI signaling. 31. A method comprises:receiving, from a first user equipment (UE), at a second UE, in a sidelink control channel (SCC), sidelink control information (SCI) signaling comprising indication of a first time-frequency resource for transmitting a first transport block (TB), the SCI further indicating (i) a reservation period (RSVP) and a sidelink resource to be reserved based on the RSVP when reservation of time-frequency resources for a different TB is enabled, or (ii) no reservation of a different TB without indicating the RSVP when reservation of time-frequency resources for a different TB is disabled;receiving the first TB from the first UE at the second UE using the sidelink resource indicated in the SCI signaling. 32. The method of embodiment 31, which comprises, when reservation of time-frequency resources for a different TB is enabled, receiving, within the reservation period, at the second UE from the first UE, a second TB using the sidelink resource indicated in the SCI signaling, wherein the second TB is different from the first TB. 33. The method of embodiment 31, wherein the SCC is a physical sidelink control channel (PSCCH). 34. The method of embodiment 31, wherein the SCI signaling is a first stage SCI signaling. 35. A user equipment comprising a transceiver and a processor, being configured to perform the method of embodiment 27 or 31. 36. An apparatus comprising an antenna; a processor; and a non-transitory computer readable storage medium storing processor executable instructions for execution by the processor, the processor executable instructions including instructions causing the apparatus to perform a method according to embodiment 27 or 31. 37. A method comprises:transmitting, from a first user equipment (UE), to second UE, in a sidelink control channel (SCC), sidelink control information (SCI) signaling for transmitting a transport block (TB), the SCI signaling comprising indication of a plurality of time-frequency resources, wherein time resources and frequency resources within the time-frequency resources are indicated separately and the time resources are indicated with a single time resource pattern index;transmitting the TB from the first UE to the second UE using a sidelink resource from the time-frequency resources indicated in the SCI signaling. 38. The method of embodiment 37, wherein the time resource pattern index indicates a time resource pattern for a number of retransmissions, wherein the combination of the number of retransmissions and the time resource pattern is a possible combination within a maximum time gap between a first transmission and a last transmission of the TB, and the time resource pattern index is capable of indicating any possible combination of any possible time resource pattern and any possible number of retransmission under a maximum number of retransmissions within the maximum time gap. 39. The method of embodiment 37, wherein the time resource pattern index indicates a total number of repetitions. 40. A method comprises:receiving, from a first user equipment (UE), at a second UE, in a sidelink control channel (SCC), sidelink control information (SCI) signaling for transmitting a transport block (TB), the SCI signaling comprising indication of a plurality of time-frequency resources, wherein time resources and frequency resources within the time-frequency resources are indicated separately and the time resources are indicated with a single time resource pattern index;receiving, at the second UE, the TB from the first UE, using a sidelink resource selected and reserved based on the SCI signaling. 41. The method of embodiment 40, wherein the time resource pattern index indicates a time resource pattern for a number of retransmissions, wherein the combination of the number of retransmissions and the time resource pattern is a possible combination within a maximum time gap between a first transmission and a last transmission of the TB, and the time resource pattern index is capable of indicating any possible combination of any possible time resource pattern and any possible number of retransmission under a maximum number of retransmissions within the maximum time gap. 42. The method of embodiment 40, wherein the time resource pattern index indicates a total number of repetitions. 43. A user equipment comprises a transceiver and a processor, and is configured to perform the method of embodiment 37 or embodiment 40. 44. An apparatus comprises an antenna; a processor; and a non-transitory computer readable storage medium storing processor executable instructions for execution by the processor, the processor executable instructions including instructions causing the apparatus to perform a method according to embodiment 37 or 40. Although the present disclosure describes methods and processes with action in a certain order, one or more actions of the methods and processes may be omitted or altered as appropriate. One or more actions may take place in an order other than that in which they are described, as appropriate. Although the present disclosure is described, at least in part, in terms of methods, a person of ordinary skill in the art will understand that the present disclosure is also directed to the various components for performing at least some of the aspects and features of the described methods, be it by way of hardware components, software or any combination of the two. Accordingly, the technical solution of the present disclosure may be embodied in the form of a software product. A suitable software product may be stored in a pre-recorded storage device or other similar non-volatile or non-transitory computer readable medium, including DVDs, CD-ROMs, USB flash disk, a removable hard disk, or other storage media, for example. The software product includes instructions tangibly stored thereon that enable a processing device (e.g., a personal computer, a server, or a network device) to execute examples of the methods disclosed herein. The present disclosure may be embodied in other specific forms without departing from the subject matter of the claims. The described example embodiments are to be considered in all respects as being only illustrative and not restrictive. Selected features from one or more of the above-described embodiments may be combined to create alternative embodiments not explicitly described, features suitable for such combinations being understood within the scope of this disclosure. All values and sub-ranges within disclosed ranges are also disclosed. Also, although the systems, devices and processes disclosed and shown herein may include a specific number of elements/components, the systems, devices and assemblies could be modified to include additional or fewer of such elements/components. For example, although any of the elements/components disclosed may be referenced as being singular, the embodiments disclosed herein could be modified to include a plurality of such elements/components. The subject matter described herein intends to cover and embrace all suitable changes in technology. It should be appreciated that one or more steps of the embodiment methods provided herein may be performed by corresponding units or modules. For example, a packet may be transmitted by a transmitting unit or a transmitting module. A packet may be received by a receiving unit or a receiving module. A packet may be processed by a processing unit or a processing module. The respective units/modules may be hardware, software, or a combination thereof. For instance, one or more of the units/modules may be an integrated circuit, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs). It will be appreciated that where the modules are software, they may be retrieved by a processor, in whole or part as needed, individually or together for processing, in single or multiple instances as required, and that the modules themselves may include instructions for further deployment and instantiation. Although a combination of features is shown in the illustrated embodiments, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system or method designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments. This disclosure has been described with reference to illustrative embodiments, but this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the disclosure, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the appended claims encompass any such modifications or embodiments. | 169,953 |
11943068 | In the figures, identical or functionally identical elements are provided with the same reference numeral unless otherwise indicated. DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS FIG.1shows as an example a serial bus system1, which may be designed as an arbitrary serial bus system, in which an error signaling for received messages takes place. Bus system1is, in particular, a CAN bus system, a CAN FD bus system, a FlexRay bus system, a bus system for Ethernet, a Gigabit-Ethernet, etc. Bus system1is usable in a motor vehicle, in an aircraft, etc., or in a hospital, etc. Bus system1inFIG.1has, in particular, a parallel bus line3designed as a two-wire line, to which a plurality of user stations10,20,30are connected. Messages4,5in the form of signals are transmittable serially via bus line3between individual user stations10,20,30. User stations10,20,30are arbitrary devices intended to exchange data serially with one another such as, for example, control units, sensors, display devices, etc., of a motor vehicle. Alternatively, user stations10,20,30are, for example, computers of a computer network or components of an automation network for an industrial facility. User stations10,20,30are, however, not limited to the aforementioned specific examples. The present invention is described below by way of example based on the CAN bus system and CAN FD bus system. However, the present invention is not limited thereto, rather, the present invention may be applied to an arbitrary serial bus system. As shown inFIG.1, user station10has a communication control unit11and a transceiver device12. In contrast, user station20has a communication control unit21and a transceiver device22. User station30has a communication control unit31and a transceiver device32. Transceiver devices12,22,32of user stations10,20,30are each directly connected to bus line3, even though this is not illustrated inFIG.1. Communication control unit11,21,31each serve to control a communication of respective user station10,20,30via bus line3with a different user station of user stations10,20,30, which are connected to bus line3. Communication control unit11, for the example of the CAN bus system, may be designed as a conventional CAN controller except for the differences described in greater detail below. In this case, communication control unit11creates and reads first messages4, for example, modified classic CAN messages4. Classic CAN messages4are structured according to the classic basic format except for the modifications described below, in which a number of up to 8 data bytes may be encompassed in message4as shown in the upper part ofFIG.2. Communication control unit21inFIG.1may, for the example of the CAN bus system, be designed as a conventional CAN FD controller except for the differences described in greater detail below. In this case, communication control unit21creates and reads second messages5, which are modified CAN FD messages5, for example. In this case, the modified CAN FD messages5are structured on the basis of a CAN FD format except for the modifications described below, in which a number of up to, for example, 64 data bytes may be encompassed in message5, as shown in the lower part ofFIG.2. Communication control unit31may, for the example of the CAN bus system, be designed in order, as needed, to provide to or to receive from transceiver device32a modified classic CAN message4or a modified classic CAN FD message5. Thus, communication control unit21creates and reads a first message4or second message5, first and second message4,5differing in terms of their data transmission standard, namely, in this case modified CAN or modified CAN FD. Transceiver device12may thus be designed as a conventional CAN transceiver except for the differences described in greater detail below. Transceiver device22may be designed as a conventional CAN FD transceiver except for the differences described in greater detail below. Transceiver device32may be designed in order, as needed, to provide for or to receive from communication control unit31messages4according to the modified CAN base format or messages5according to the modified CAN FD format. A formation and then transmission of messages5with the modified CAN FD or also with data rates higher than CAN FD are implementable with the two user stations20,30. The upper part ofFIG.2shows for message4a CAN frame45as it is transmitted by transceiver device12or transceiver device13, and in its lower part for message5a CAN FD frame450as it may be transmitted by transceiver device22or32. CAN frame45and CAN FD frame450are subdivided basically into two different phases or areas for the CAN communication on bus40, namely arbitration phases451,453and a data area452, which is also referred to as data field in classic or classic CAN or also as data phase452in CAN FD. The payload data of the CAN FD frame or of message5are contained in data phase452. According toFIG.2, the bit rate for following data phase452is increased, for example, to 2, 4, 8 Mbps at the end of arbitration phase451in CAN FD as compared to the classic CAN. This means that in CAN FD, the bit rate in arbitration phases451,453is lower than the bit rate in data phase452. In CAN FD, data phase452of CAN FD frame450is temporally significantly reduced compared to data phase452of CAN frame45. In a serial bus system without arbitration451,453such as, for example, Ethernet, FlexRay, etc., two data phases452follow in direct succession. FIG.3illustrates the end of a data phase452as an example of a message5based on a differential voltage VDIFF over time t. For a message4, the following embodiments are equally applicable. Message5is generated with differential symmetrical bus levels via a two-wire bus line as bus line3. The recessive bus level, which is referred to as logic ‘1’ inFIG.3, is not driven by bus user stations10,20,30, but is determined by a terminal resistance of bus line3. The dominant bus level is depicted inFIG.3as logic ‘0’. According toFIG.3, an ACK time window46for an ACK signal461and a NACK time window47for a NACK signal471follow after data phase452. Thereafter follows a sequence of recessive levels REZ, which indicates the end of the transmission of a frame of message5and is identified inFIG.3by reference numeral48. As an example, an error in data phase452is depicted inFIG.3which, in this example, is seen by at least one but not by all receivers, as a black jagged block arrow. Thus, in the example inFIG.3, both an ACK signal461as well as a NACK signal is transmitted, namely ACK signal461by the receivers, which have seen no error, and NACK signal471by those which have seen an error. In the time period between the two data phases452inFIG.3, the sender of message5does not drive the bus or the voltage level on bus line3at all. If the bus is also not driven in this time period by any other of user stations10,20,30in bus system1, a level REZ, which is between the levels for logic ‘1’ and logic ‘0’ inFIG.3arises on bus line3between the end of data phase452and the beginning of ACK time window46, as shown inFIG.3. Since the method described herein is not tied to a particular message format for the serial transmission, a case is depicted inFIG.3in which two data phases452follow in succession. Unlike the representation inFIG.3, next message5may alternatively begin with an arbitration as described above with respect to the CAN protocol. In the CAN protocol, one of the two driven bus levels is replaced by a recessive level and differential voltage VDIFF results for differential signals CAN_H and CAN_L over time t. As exemplified by the CAN protocol, ACK time window46would be the ACK slot or the ACK field after the CRC field. Regardless of selected serial bus system1, it is the case that ACK time window46and transmitted ACK signal461have defined lengths, transmitted ACK signal461not being longer than ACK time window46, as is represented inFIG.3. By superposing ACK signals461of multiple user stations10,20,30, it is possible to lengthen resulting ACK signal461on the bus. The lengths of ACK time window46and ACK signal461, as well as the permitted tolerances for identifying a valid ACK signal461by the sender are selected appropriate to the bit rate in such a way that potential phase shifts between user stations10,20,30do not distort ACK signal461. As a result, it is not necessary for the receivers of message5to check ACK signal461. A duration T1, in which the bus is not driven by any of user stations10,20,30, is situated between ACK time window46and NACK time window47. As a result, level REZ arises between time windows46,47on bus line3. NACK time window47and transmitted NACK signal471also have defined lengths, transmitted NACK signal471not being longer than NACK time window47, as represented inFIG.3. By superposing NACK signals471of multiple user stations10,20,30, it is possible to lengthen resulting NACK signal471on the bus. The lengths of NACK time window47and NACK signal471as well as the permitted tolerances for identifying a valid NACK signal471by the sender are selected appropriate to the bit rate in such a way that potential phase shifts between user stations10,20,30do not distort NACK signal471. As a result, it is not necessary for the receivers of message5to check ACK signal471. As mentioned above, a sender of message5, for example, user station20, does not drive the bus or the voltage on bus line3during ACK time window46at all. This bus level, which is not driven by a bus user station10,30,30present in the bus, is referred to here as recessive, because it is able to be overwritten by one of the driven bus levels. The same applies to NACK time window47. The receivers that have seen an error-free message5of user station20as the sender of message5, i.e., in this case, for example, user station30, drive an established bus level, for example, a ‘0’, as ACK signal461in ACK time window46, as shown inFIG.3. The receivers, which have identified an error in message5, i.e., in this case, for example, user station10, do not drive the bus or the level on bus line3in ACK time window46at all. The receivers that have seen an error in message5drive an established bus level, for example, a ‘0’ as NACK signal471in NACK time window47, as shown inFIG.3. The receivers that have identified no error in message5do not drive the bus or the level on bus line3in NACK time window47at all. If the sender of the message sees an ACK signal461and no NACK signal471, message5is successfully conveyed to all active bus users of user stations10,20,30. If the sender sees a NACK signal471and no ACK signal461, none of the active bus users has received message5. If the sender sees or receives both signals461,471, at least one of the active bus users has received message5, but at least one other of the active bus users has rejected this message5due to local errors. If the sender sees neither an ACK signal461nor a NACK signal471, it is the only active user station10,20,30in bus system1. According to one modification of the first exemplary embodiment, NACK time window47is used in order to identify user stations10,20,30that have seen an error in message5. For this purpose, each user station10,20,30of bus system1is assigned a clearly identifiable NACK symbol. With up to 31 user stations10,20,30in bus system1, it is possible to issue, for example, a five-digit bit sequence as a NACK symbol. The bits of the bit sequence may be coded similarly to the CAN arbitration, in particular, the logic ‘1’ as a recessive bus level and the logic ‘0’ as the driven bus level. In order to be able to identify the error messages of individual user stations10,20,30, the method may be applied in multiple stages as described below with respect to operating mode C). In such a modification of the first exemplary embodiment, it is possible to switch the method during the ongoing operation between at least two of the subsequently mentioned operating modes. This means, at least two of the operating modes subsequently mentioned may optionally be implemented in user stations10,20,30of bus system1. Operating mode A): all NACK senders transmit only one simple NACK signal471, which allows for no possibility of identifying the individual NACK senders. Operating mode B): the NACK senders transmit their identifiable NACK symbols. If more than one user station10,20,30transmits a NACK symbol, the NACK symbols of user stations10,20,30overlap and are no longer clearly identifiable. The sender of message5recognizes only that at least one user station10,20,30of bus system1has seen an error, as in the case of operating mode A). Operating mode B) may, however, be used for analyzing sporadic individual errors if, in general, only one user station10,20,30of bus system1sees an error in message5. Operating mode C): the NACK symbol senders arbitrate among each other according to the rules of CAN arbitration. The losers of the arbitration terminate their NACK symbol in this NACK time window47. After the first NACK time window47, in which a NACK symbol has been transmitted, a second NACK time window47is started. Here, the losers of the arbitration of the first NACK time window47restart their NACK symbols. This is repeated until an established upper limit of NACK time windows47is reached, or until a NACK time window47has remained empty. Thus, a user station10,20,30of bus system1per NACK time window47is identified, which has seen an error in message5. Operating mode C) is primarily helpful for an error search and/or an error analysis, if a search is to be made for the cause of sporadic errors. In this case, a NACK symbol may be used in order to simply ascertain also in a CAN network user station10,20,30, that has transmitted an error identifier (error flag). The established upper limit of NACK time windows47results from the fact that in a NACK time window47only one NACK system is decoded and thus when a NACK symbol has been seen, an additional NACK time window47is always appended. This demands considerable bus bandwidth, so that the upper limit establishes how much bandwidth may be provided for the error search. An alternation between at least two of the three operating modes A), B), C) may take place depending on the requirements of bus system1. The alternation of operating modes A) or B) or C) may either be centrally controlled, for example, by one of user stations10,20,30or may be controlled by an algorithm and in this way take place, in particular, as a function of the error frequency. In the example methods, the end of the transmission is identified by a sufficiently long recessive level as sequence48which, in the case of CAN, for example, is called, “end of frame”. The threshold value for the end-of-frame length or length of sequence48is a function of the bit rate and of the lengths of ACK and NACK time windows46,47. In the example described herein, the non-driven recessive bus level is overwritten with the driven level for logic ‘0’. According to one modification, the driven level may instead be used for logic ‘1’. According to one further modification of the present invention, it is possible for ACK signals461and the associated ACK symbol to use a bus level other than that used for NACK signals471and the associated NACK symbol. According to one further modification of the above-described exemplary embodiments, it is possible to use the method described for operating mode C) for identifiable NACK symbols in addition or alternatively for identifiable ACK symbols. According to still one further modification of the above-described exemplary embodiments of the present invention, it is possible to limit the transmitting of ACK symbols to the user stations of bus system1, for which the instantaneous message5,50,500is intended. According to still one further modification of the above-described exemplary embodiments of the present invention, it is possible to forego NACK symbols when identifiable ACK symbols are used. FIG.4shows with respect to a second exemplary embodiment of the present invention, the area at the end of data phase452for a message50. Here too, differential voltage VDIFF is again shown over time t with differential symmetrical bus levels via a two-wire bus line as bus line3, as already described above with reference toFIG.3. In contrast toFIG.3, NACK time window47comes before ACK time window46in the second exemplary embodiment according toFIG.4. Otherwise, the same applies as above-described in conjunction withFIG.3. FIG.5shows with respect to a third exemplary embodiment of the present invention, the area at the end of data phase452for a message500. Here too, differential voltage VDIFF is again shown over time t with differential symmetrical bus levels via a two-wire bus line as bus line3, as already described above with reference toFIG.3. In contrast toFIG.3andFIG.4, only one of time windows46,47is present in the third exemplary embodiment of the present invention. This is shown as an example inFIG.5, only ACK time window46being present. Alternatively, it is also possible, however, that only NACK time window47is present. Otherwise, the same applies as described above in conjunction withFIG.3. On the whole, it is possible with the above-described exemplary embodiments including all their embodiment variants or modifications to achieve an improved error signaling for received messages5,50500for the sender in bus system1. All of the above-described embodiments of bus system1, of user stations10,20,30and of the method carried out by the latter may be used individually or in all possible combinations. All features of the above-described exemplary embodiments and/or their embodiment variants and/or their modifications may, in particular, be arbitrarily combined. In addition or alternatively, the following modifications, in particular, are possible. The above-described bus system1according to the exemplary embodiments is described with reference to a bus system based on the CAN protocol. Bus system1according to the exemplary embodiments may, however, also be another type of serial communication network. It is advantageous, but not a necessary precondition, that in bus system1an exclusive collision-free access of a user station10,20,30to a shared channel is ensured for particular time spans. The number and configuration of user stations10,20,30in bus system1of the exemplary embodiments is arbitrary. User station10, in particular, may be omitted in bus system1. It is possible that one or multiple of user stations10or20or30are present in bus system1. | 18,613 |
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